Modification and Testing of Existing Self Propelled Multipurpose Power Unit for Sowing Operation

Transcription

1 Modification and Testing of Existing Self Propelled Multipurpose Power Unit for Sowing Operation THESIS Submitted to the Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur In partial fulfillment of the requirements for the Degree of MASTER OF TECHNOLOGY In AGRICULTURAL ENGINEERING (Farm Machinery and Power Engineering) By POONAM KHURASIA Department of Farm Machinery and Power Engineering College of Agricultural Engineering Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (M.P.) 2013

2 CERTIFICATE - I This is to certify that the thesis entitled MODIFICATION AND TESTING OF EXISTING SELF PROPELLED MULTIPURPOSE POWER UNIT FOR SOWING OPERATION submitted in partial fulfilment of the requirement for the degree of MASTER OF TECHNOLOGY IN AGRICULTURAL ENGINEERING (Farm Machinery and Power Engineering) of Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur is a record of the bonafide research work carried out by Miss. POONAM KHURASIA under my guidance and supervision. The subject of the thesis has been approved by the Student s Advisory Committee and the Director of Instruction. No part of the thesis has been submitted for any other degree or diploma (Certificate awarded etc.) or has been published/published part has been fully acknowledged. All the assistance and help received during the course of the investigation has been acknowledged by him. Place : Jabalpur Date : (Prof. N.K. Khandelwal) Chairman of the Advisory Committee THESIS APPROVED BY THE STUDENT S ADVISORY COMMITTEE Chairman : Prof. N.K. Khandelwal Member : Dr. Atul Shrivastava Member : Prof. D.K. Nilatkar Member : Prof. K.B. Tiwari.....

3 CERTIFICATE II This is to certify that the thesis entitled MODIFICATION AND TESTING OF EXISTING SELF PROPELLED MULTIPURPOSE POWER UNIT FOR SOWING OPERATION submitted by Miss. POONAM KHURASIA to the Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur in partial fulfillment of the requirements for the degree of MASTER OF TECHNOLOGY IN AGRICULTURAL ENGINEERING in the Department of Farm Machinery and Power Engineering has been, after evaluation, approved by the External Examiner and by the Student s Advisory Committee after an oral examination on the same. Place : Jabalpur Date : (Prof. N.K. Khandelwal) Chairman Advisory Committee MEMBERS OF THE ADVISORY COMMITTEE Member Member Member Dr. Atul Shrivastava Prof. D.K. Nilatkar Prof. K.B. Tiwari Head of Department Dr. Atul Shrivastava. Director of Instruction Dr. P.K Mishra...

4 ACKNOWLEDGEMENT I Poonam Khurasia, praise the Omniscient and Almighty God and express my deepest adorations for giving me this great opportunity to do M.Tech (Agril. Engg.) Farm Machinery and Power Engineering. Words fail when I express my deep sense of reverence and gratitude to Prof. N.K. Khandelwal, Associate Professor, Dept. of Farm Machinery and Power Engineering, College of Agricultural Engineering, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur, Chairman of my Advisory Committee, my venerable guide, the most efficient, eminent and sagacious personality. I am thankful to him for his most valuable and inspirational guidance, close supervision, keen interest, constant encouragement and constructive criticism which kept my moral high throughout the irksome course of my study, especially the thesis period. I am also thankful to the venerable member of my Advisory Committee Dr. Atul Shrivastava Head of the Dept. of Farm Machinery and Power Engineering College of Agril. Engg. for his expert opinion and valuable suggestions.i also would like to thank the venerable members of my Advisory Committee Prof. D.K. Nilatkar and Prof. K.B. Tiwari Dept. of Farm Machinery and Power Engineering College of Agril. Engg., for their constant guide, regular suggestions and steady encouragement. I express sincere gratitude to Dr. T.K. Bhattacharya, Dean Faculty of Agricultural Engineering, JNKVV, Jabalpur, (M.P.), for providing necessary facilities to carry out the study. With special pleasure I also acknowledge sincere advice and help received from my teachers Prof. D.K. Khare and Prof R.K. Dubey department of Farm Machinery and Power Engineering. It gives me immense pleasure in expressing my humble gratitude to Mr. Suraj Patel, Libraryrian and staff of library of College of Agricultural Engineering, J.N.K.V.V., Jabalpur for providing necessary book facilities accordingly.

5 I am good to express my thanks to all my seniors Er. Raghvendra Singh Yadav, Er. Bharat Patel and Er. Rajnish Patel who shared their worthless experience during the project work and my friends Er. Prateek Shrivastava, Er.Tarun Raut, Er. Bhagwan Singh Narwariya and Er. Anjali Bajpai for getting all sorts of help from them. My sincere thanks to Mr. G.R. Mandloi and Mr. Gaya Prasad for their valuable help and kind cooperation from time to time throughout the period of this research. I am very thankful to God and also I owe a great deal to my respected father Shri D.R. Khurasia and mother Smt. Sunita Khurasia who encouraged and helped me to build my educational career at this stage and their contribution is beyond my acknowledgements. I also thank all those who could not find a separate name but have helped directly or indirectly. Place : Jabalpur Date: (Poonam Khurasia)

6 CONTENTS S.No. CHAPTER PAGE NO. I INTRODUCTION 1-4 II REVIEW OF LITERATURE Design, development of seed drill/ planter Evaluation of existing seed drill/planter Development and evaluation of various self propelled unit 11 III DESIGN CONSIDERATION Design Step General Design Consideration Functional Requirement Agronomical Requirements Selection of Materials Design theory of different parts of seed drill Design of frame Design of hopper Design of power transmission from prime mower to wheel Length of open belt Design of power transmission from ground wheel to 28 metering device Design of chain Design of seed metering device Design of furrow opener Seed delivery tubes Pegged ground wheel 35 IV MATERIALS AND METHODS Fabrication of self propelled seed drill Fabrication of seed drill Fabrication of depth cum direction control wheel Fabrication and installation of power drive system Fabrication of hitch system for attachment of various implements Vibration isolator Performance testing and evaluation of the self propelled seed drill Preparation of self propelled seed drill for test, running in and preliminary adjustment Laboratory test Procedure for field testing Test parameter Cost of operation 55

7 V RESULTS AND DISCUSSION Identification of Problems in old unit and modification corporated in new machine Testing of machine Laboratory test Field test Cost economics 67 VI SUMMARY AND CONCLUSIONS Summary of work Conclusion 72 VII SUGGESTION FOR FURTHER WORK 73 VIII BIBLIOGRAPHY IX APPENDICES X VITA

8 LIST OF TABLES S.No. Title(Table) Page No 3.1 Physical characteristic of seed Seed and machine parameters Given the specifications of the materials for different components of a Self propelled seed drill 4.2 General Specification of Self propelled Multipurpose 48 Power Unit 5.1 Calibration of seed rate Effect of filling of seed hopper on seed rate Inter row variation of seed Effect of metering mechanism on seed germination Observed seed rate during field test Uniformity of seed distribution Observed slippage and speed with shoe type furrow opener 5.8 Observed slippage and speed with shovel type furrow opener 5.9 Performance evaluation of self propelled seed drill Calculation of cost per hour and per ha by a self propelled seed drill

9 LIST OF FIGURES S.No. Title(Figure) Page No. 3.1 Arrangement of tines on the frame Schematic diagram of seed drill showing arrangement of furrow opener and seed box Cross section of seed box Power transmission from ground wheel to seed metering device Seed feed roller Details of the Furrow openers Details of the pegged ground wheel designed for seed drill 36 Isometric view of the seed drill 4.2 Details of the depth cum direction control wheel Isometric view of modified self propelled power unit Schematic diagram of power transmission Isometric view of Self propelled seed drill 45 40

10 LIST OF PHOTOGRAPHS S.No. Title (Photos) Page no. 1.1 Previously developed self propelled Multipurpose power unit Hitch system for attachment of seed drill Vibration isolator between engine and chassis Vibration isolator View of Self Propelled unit with matching seed drill View of prepared seed drill Arrangement of seed drill in (A) old unit (B) new unit View of size of driven pulley in (A) old unit (B) new unit Depth cum direction control wheel in (A) old unit (B) new unit Field evaluation of self propelled seed drill

11 ABBREVIATIONS AND SYMBOLS AICRP All India Coordinated Research Project Agril.Engg. Agricultural Engineering Approx. Approximate (ly) av. Average B.D. Bulk Density BIS Bureau of Indian Standards CAE College of Agricultural Engineering CIAE Central Institute of Agricultural Engineering cm Centi-meter cm 2 Centi- meter square cm 3 Centi meter cube dia Diameter db Dry basis Engg. Engineering Eq. Equation et. al. and other etc. Etcectra Fig. Figure g Gram GI Galvanized Iron h Hour ha Hectare ha/h hectare per hour Hp horse power i.e. That is IS Indian Standard ICAR Indian Council of Agricultural Research J. Agril.Engg. Journal of Agricultural Engineering JNKVV Jawaharlal Nehru Krishi Vishwa Vidyalaya

12 kg Kilogram km Kilometer km/h Kilometer per hour l Liter l/h Liter per hour m Meters mm millimeter m/s meter per second m 2 m 3 min. mc. MI M.P. MS No. PAU meter square meter cube Minute moisture content moment of Inertia Madhya Pradesh Mild steel Number Punjab Agriculture University % Percentage & And = Equals to rpm Revolution per minute Rs. Rupees s Second SMC Soil moisture content S.No. Serial Number Wd Weight of dry soil Wt. Ww Weight Weight of water

13 Chapter-1 INTRODUCTION The main stay of national economy is agriculture land it account for livelihood of about 65% of country s population. Even though agriculture is the backbone of Indian economy, still the agriculture sector requires much more effort and development. Development of agriculture requires mechanization of farms. Mechanization helps to increase the productivity of land and labour in many ways such as timeliness of various farm operations and efficient use of inputs. It also contributes toward reduction of losses, as well as in improvement of quality and quantity of produce. It helps to reduce drudgery and ensure safety and comfort. Farm mechanization does not mean the use of big machines and tractors for farming work only. Mechanization is a need-based process, which provides sufficient time gap for self-adjustment of various inputs without causing sudden impact of changes. Due to ever increasing population there is a gradual reduction in average size of farm holding. Average size of a holding which was 2.28 ha in , came down to 2.00 hectare in , 1.84 hectare in , 1.69 ha in , 1.55 hectare in , 1.41 ha in , 1.33 ha in and 1.23 ha in (Source: Agricultural Census Division, Ministry of Agriculture) Among different size groups of holdings, the highest number of holdings (about 65 per cent) are marginal holdings (below 1 ha) followed by about 18 per cent small holdings (1-2 ha), about 11 per cent semi- medium holdings (2-4 ha.), about 5 per cent medium holdings (4-10 ha) and less than 1 per cent large holdings (10 ha and above). In India usually there are small and marginal farmers. It has been established that the productivity is directly proportional to the farm power availability. The power source available to the small 1

14 farmer is usually a pair of bullocks, however its maintenance is very difficult throughout the year even when there is no work in the field. This is the main reason of decreased use of bullocks as draft power. The availability of fodder and straw is also becoming difficult due to combine harvesting. Moreover, working rate of draft animals is very slow resulting in delayed farm operations. The tractors and the other large machineries are beyond the reach of small and medium farmers due to their high initial cost. Now a days there is facility to hire tractor but during the peak season tractors not available as and when required specially to those farmer who have small land holding as they cannot hire it for much time and cannot pay for it, also it is seen that small farmer usually practice broadcasting of seed or drilling in rows by hand.the main disadvantage associated with hand drill or broadcasting of seed is non uniformity distribution which cause uneven growth of crop at the later stage and finally resulted in poor yield. It is also time consuming which affect the timeliness of operations. The available power units are usually developed for a specific kind of work. Small and marginal farmer cannot purchase different machine for different operations. To overcome such circumstances development of small multipurpose power unit was considered as worthwhile endeavor in this context, which could perform different operations such as secondary tillage, sowing, harvesting of crop & crop residues. By using the multipurpose power unit the small and medium farmers can avoid the year round maintenance of bullocks and also the high investment in tractors. Development of small multipurpose power unit is quite affordable & useful to farmers. It can be fabricated & repair by village artisans. The structure of power unit is simple and this makes the operation, maintenance and repair easy. Usually repair is done by the operator himself on the spot. The self propelled multipurpose power unit appears to be replacing the animal power more effectively. Self propelled power unit require less 2

15 effort to carried out farm operations as compared to animal power. The bullock drawn implements require the hand and body pressure to achieve depth and alignment of the implement in use, whereas, in self propelled power unit the implements are mostly self guided. This reduces human drudgery to a great extent. The self propelled multipurpose power unit enables farmers to diversify cropping pattern and increase in yield of crops. It helped in reducing the seasonal fallows and thereby substantially increasing cropping intensity. One Multipurpose self propelled power unit was initially developed in College of Agricultural Engineering, JNKVV Jabalpur. This machine encountered some problem like improper traction, excessive vibration, high operating speed and slippage, non uniformity of seeding unit. To overcome these problems the new multipurpose power unit required to be developed with some modifications in existing machine. The present study will be carried out for modification, development and testing of self propelled multipurpose power unit with following objectives. Objective: 1. To identify operational and design problems in existing self propelled multipurpose power unit for its design improvement. 2. To develop a matching seed drill for modified power unit. 3. To test and evaluate field performance of the modified self propelled power unit with their matching seed drill and study its cost economics. 3

16 Chapter - 2 REVIEW OF LETERATURE In agriculture, timeliness in farm operations, especially the seedbed preparation and sowing for establishing good crop stand is of crucial importance. Unless adequate mobile farm power is not available on the farm, the sowing operation gets delayed resulting poor crop stand and yields. In the view of above self propelled seed drill has been developed which suit the needs of small and marginal farmer. This chapter deals with brief review of the research work done by various investigators in the country and abroad related to design, development and performance evaluation of various self propelled power unit and seed cum fertilizer drill. 2.1 Design, development of seed drill/planter Dransfield et al. (1964) reported that rake angle of a furrow opener was proportional to the force on it. They found that both the horizontal and vertical forces increased with increase in rake angles. Kharya (1986) designed and developed an animal drawn automatic potato planter at CAE, JNKVV, Jabalpur and tested in research and instructional farm of the College of Agricultural Engineering, Jabalpur. The planter was also tested in the laboratory. The machine consist of frame, seed and fertilizer hopper, agitator type metering device for fertilizer and vertical rotor type metering device for seed and ground wheel mounted on the metering shaft. During the field trail this planter could plant the potato seed at the rate of 0.72 to 0.80 ha/day with 60 cm inter row spacing. The field efficiency was found was per cent. Average draft was found to be Kg. The average power requirement to pull the planter was found to be 0.68 hp. Patel (1989) designed, fabricated and tested manually operated pregerminated paddy drill in CAE, JNKVV, Jabalpur. It was 4 rows, cell 4

17 type vertical wooden rotor drill provided with wedge type furrow openers. The actual Field capacity and field efficiency of drill were ha/h and per cent respectively. The power requirement varies from 0.07 to kw on puddle black cotton soil with and without standing water at 1.86 km/h operating speed. Jarudchai et al. (2002) designed and developed a garlic planter in Thailand. This study followed research after the 3 types of garlic planter was fabricated in 2001 which included (1) inclined metering plate garlic planter (2) vertical metering plate garlic planter and (3) spring plate garlic planter. In this study, 2 model were constructed which included; (1) the vertical metering plate with triangular grooves and (2) the bucket type garlic planter. The uniformity of metering system test for the 2 models, the bucket type garlic planter presented the most impressive results. The percentage of broken was very low, about 0.23 per cent. The new prototype garlic planter had 12 rows and was attached to 5 HP power tiller. The garlic planter was tested under actual field conditions at Maetang district, Chiengmai province. The result indicated that the optimum width of garlic planter was 0.8 meter or 8 rows. The soil condition was dry. Farmer should apply water after planting. The maximum forward speed was 2.63 km/h and wheel skid was found in higher side i.e. about per cent. The average depth and width of planting was 2.62 cm and 4.66 cm respectively. Time for turning at head land was 37 seconds. The field capacity was 0.31 ha/h and there were three operators. Hence, the capacity of planter was 0.83 ha./man/day. Kumar and Varshney (2003) developed power tiller operated matching implements such as ridger, leveler and two row seed drill along with their hitching system and field performance was also evaluated in terms of field capacity, field efficiency, draft, fuel consumption and slippage. The field capacity was varied from to ha/h for ridger and seed drill, for leveler 0.7 to 0.12 ha/h with corresponding field efficiency of to per cent, to per cent and to 5

18 88.24 per cent respectively at forward speed of power tiller from 2.0 to 3.0 km/h. The draft was found to 42.11kg and to kg for ridger and leveler respectively, wheel slippage was varied from to per cent and fuel consumption were also estimated as 1.35 to 1.5 l/h for ridger, leveler and seed drill. The use of modified light weight power tiller for hill agriculture gave satisfactory performance with matching implements. Narang (2003) designed a power tiller operated till plant machine at CIAE, Bhopal. He evaluates six different types of furrow openers. The furrow opener of 150 mm length with provision of separate delivery of seed and fertilizer were recommended and used for black cotton soil. The ground wheel drive was taken as 350 mm diameter below the main frame of the machine. Twelve spikes have been provided on the outer periphery of the wheel to developed significant grip to the rotating wheel. Power obtained from the rotation of the wheel is transmitted to the seed and fertilizer shafts with the help of two sets of chain and sprocket arrangement. NDUAT (2004) developed hp power-tiller-operated zero-till drill machine in Faizabad. It can directly drill seeds and fertilizers without seed-bed preparation. It is suitable for wheat, barley, lentil, chickpea, pea, paddy etc. Machine size is 5 cm 20 cm. Its cost is Rs 10,000, and its cost of operation is Rs 420/ha. It saves 68 per cent in time, 85 per cent in cost of operation compared to conventional practice, and increases yield by 6 per cent. Chandra et al. (2008) designed and developed double row manual cum bullock drawn seed cum fertilizer drill at Vivekananda Institute of Hill Agriculture, Almora, India. It consists of an MS body, inverted T-type furrow opener with 25º rake angle, adjustable MS beams for man and bullock power, seed box with fluted feed metering device, fertilizer box with agitator, plastic delivery tube, and MS transportation cum power wheel. 6

19 The machine had the capacity to sow to 0.04 ha/h. Energy savings in wheat and lentil sown with zero-till seed drill were 1,305.3 MJ/ha and 1,106.6 MJ/ha, respectively, as compared to the traditional method of broadcasting. Dewangan and Verma (2007) designed, developed and evaluated seed cum fertilizer drill. The study was conducted on design parameters of various seed, soil and machine components of a seed cum fertilizer drill. The replicated tests revealed that germination of paddy wheat, gram, soybean and linseed was not affected by the gravity flow orifice type metering mechanism. The average draft and field capacity of the seed drill were 54 kgf and 0.10 ha/h respectively. Dewangan and Verma (2007) studied mechanical consideration for design and development of furrow openers for seed cum fertilizer drill. The identified furrow openers such as shoe, shovel and inverted-t types were designed and fabricated in the research workshop at CIAE, Bhopal, India. Prime considerations were given to minimum soil disturbances and reduced tendency for clogging. The potential of the furrow openers were compared on the basis of draft requirement, soil disturbances and seed emergence. The inverted - T type furrow opener required the lowest draft of kgf, minimum soil disturbances (4-5 cm) and minimum clogging frequency as compared to the shovel and shoe type furrow opener. Seed emergence percentage (86.66 %) per meter of row length was found highest for the inverted-t opener as compared to the shoe (70.90 %) and shovel (62 %) type furrow opener. Jiraporn and Sakurai (2010) developed self propelled two wheeled walking type tractor having ten rows for garlic planting. This research focused on increasing the planter capacity by reducing the draft of the planter, increasing the field efficiency by increasing the number of rows.the field capacity was 0.13ha/h and plant spacing was cm. The percentage slip was Shoe type furrow opener was used, placed in 7

20 two lines with spacing of 250 mm. It gave a constant draft force of about 1.05 kgf /row. Nare (2010) developed self propelled garlic planter at College of Agricultural Engineering JNKVV, Jabalpur and tested in research and instructional farm of the CAE, Jabalpur. 12 elliptical spoon having fitted in round plate of diameter 200 mm plate was used for metering of cloves. The seed box was divided into three compartments having a capacity of 2.5 kg each. Spur gear with orifice was used for metering of fertilizer. The theoretical field capacity was calculated as ha/h, at a speed of 1.8 km/h, whereas, the actual field capacity was found to be ha/h with field efficiency having per cent. It was also calculated that the machine required hours to complete 1 hectare of land. The results indicated that the self propelled garlic clove planter requires only Rs per ha. for planting of garlic whereas, manual garlic planter and manually by hand dibbling requires Rs and Rs per ha. respectively. 2.2 Evaluation of existing seed drill/planters Nave and Paulsen (1979) compared five different models of seed metering devices from the viewpoint of accuracy of the space between planted seeds and mechanical damage to the seeds. They concluded that there was no significant difference between metering systems from the standpoint of seed breakage and seed germination. They also found that the fluted roller meter had the maximum fluctuation for seed spacing. Senapati et al. (1988) compared the performance of six grain drills for energy requirement, uniformity of seed distribution, and crop yield. They found that the implement factory seed-cum-fertilizer grain drill had the best overall performance coefficient. Senapati et al. (1992) evaluated the performance of five different models of grain drills in Orissa, India based on eleven important 8

21 parameters in grain drill performance. They assigned a weight to each parameter according to the role of each parameter in the grain drill performance and calculated the overall Performance Index (OPI) for each grain drill. Results of their research showed that the Gujarat Combined grain drill had the largest OPI and was the best grain drill for Orissa state in India. Heege (1993) evaluated four different planting methods in cereals, rapeseed, and beans based on uniformity of planting depth and seed distribution over the unit area. He found that the precision drilling method had the best uniformity of planting depth and the broadcast-sowing method had the best uniformity of seed distribution per unit area. In this study, the most prevalent grain drills in Iran were evaluated for overall performance index. Afzalinia et al. (2006) studied on the overall performance index (OPI) of the most common models of grain drills in Iran including Hassia, Nordstone, Hamadan Machine Barzegar, and Keshtgostar under irrigated conditions. To calculate the OPI, parameters such as required draft, field efficiency, effective field capacity, uniformity of the seed planting depth, uniformity of the seed distribution, plant population, possibility of planting seed and fertilizer simultaneously, number of required labour, the cost of operation, availability of furrower for irrigation, and planted crop yield were determined for each grain drill tested. A randomized complete block design was used to analyze data of this study. Results showed a significant difference between the grain drills for uniformity of the seed planting depth and draft requirement. The Machine Barzegar grain drill had the best planting depth uniformity (81.9%) and the highest draft requirement (7665N). Comparison of the grain drills for OPI showed that the Hamadan Machine Barzegar grain drill had the highest OPI (0.91). Singh and Shrivastava (2006) evaluated the field performances of manually operated garlic planter at Jabalpur. They compared the cost 9

22 economics and labour requirement of the planter with the traditional method. They observed that about 60 to 82 persons were required to sow one hectare of land to maintain row to row spacing by 15 cm and plant to plant spacing by 7.5 cm for better plant population which costs around Rs 5658/ ha. The results shows that the capacity of manual planter for sowing of garlic crop in small scale trials was found to vary from to ha/h. by involving 2 person, The large scale trials get to be demonstrated in the JNKVV and farmers field. Average yield of garlic recorded in manually planted plots during the year ( ) was 62.5 q/ha. Whereas, machine planted plots, it was found to be 45.4 q/ha. The main reason for lower yield in machine planted plots was mainly due to lower plant population (60/m 2 ) in comparison to 81/m 2 achieved in manual planting. Another reason was depth of planting. The depth of planting achieved by machine was much higher (6.3cm) in comparison to manual planting (3.5 cm). Germination percentage at higher depth has been observed to be quite low (78 % at 6.3 cm) due to lower seed rate, higher plant and row spacing, poor germination and missing of hills. These factors were taken into consideration and due care will be taken for further modification of the machine. Plant spacing was varied by varying the number of spoon on the plate, whereas, the depth of planting was controlled by providing gauge wheel. 2.3 Development and evaluation of various self propelled power unit Kushwaha (2002) designed and developed power weeder cum secondary tillage implement at College of Agricultural Engineering, JNKVV, Jabalpur. The machine was powered by 5 HP diesel engine. Vbelt drive was provided for transmission of power from the engine to the traction wheel. Average weeding efficiency was per cent and average effective field capacity was ha/h. Power weeder was capable of weeding 1.12 ha to 1.28 ha per day of 8 hours while C.I.A.E. wheel hand hoe and khurpi covers to and to 0.02 ha 10

23 respectively per day. The cost of weeding per hectare in case of power weeder was Rs for chili crop compared to the C.I.A.E. wheel hand hoe and khurpi in average Rs and respectively. Anon (2002) A light weight power tiller was developed at C.I.A.E., it was provided with petrol-start-kerosene-run engine of 3.75 kw. It was evaluated for puddling operation. Puddling operation was performed with the standing water of 60 mm depth in the field. The average bulk density of soil before and after puddling operation was 0.91 and 0.66 g/cc. The weed intensity before puddling operation was 45 g/m 2 (dry weight basis) with average height of mm. No weeds were found after two operations of power tiller. The power tiller was operated at the forward speed of 2.42 km/h. The effective field capacity was and 0.11 ha/h during first and second operations. Thus total time required to complete two puddling operations was h/ha. The puddling index was per cent and cone index in depth zone of mm of puddle bed was 0.55 MPa. The average depth of puddle land was 139 mm. The fuel consumption was 1.55 l/h (kerosene). Cost of operation of power tiller was worked out to be Rs 68.59/h and Rs 1,328/ha. P.A.U. (2002) developed a light weight power tiller, it was powered by 3.58 kw engine for use on small plots and terrace cultivation in hilly region. It can also be used for wide spaced row crops (cotton, castor, pigeon pea and sugarcane) for interculture. The machine consists of power transmission system, two MS wheels, a frame and a rotary blades. The rotary blades can be used for weeding or seedbed preparation. The working width of the light weight power tiller was 450 mm (adjustable).the rotary equipment of light weight power tiller was evaluated for weeding in cotton and sugarcane crops. The field capacity was 0.09 ha/h at forward speed of operation of 2.1 km/h. The weeding index was 91.3 per cent at 60 mm depth and 94.6 per cent at 100 mm depth of operation. Anon (2002) A self-propelled interculture equipment was developed in C.I.A.E. utilizing chassis of 1-m self-propelled, vertical-conveyor reaper 11

24 by replacing the present diesel-engine with a light weight petrol-start kerosene-run 1.1 kw engine having rated engine speed of 1,500 rpm (at the cam shaft). This is a light machine and can operate with 3 sweeps of 150 mm for weeding operation in crops sown at mm row to row spacing. If row spacing is 400 mm or more, only 2 sweeps of mm size can be operated. A set of narrow wheels of 150-mm width has also been developed to facilitate operations of machine during weeding. Its feasibility trials have been conducted in groundnut and soybean. Fashola et al. (2007) studied performance and evaluation of a 10 kw two wheel tractor (power tiller) and determined the cost of using power tiller in sawah rice production technology in Nigeria. The study was carried out in Bida area, Niger state, where the sawah rice production was disseminated by Watershed Initiative in Nigeria (WIN 2001). Some of the parameters assessed during the field test included average speed of operation, average wheel slip/travel reduction, average draught of implement and fuel consumption. Field efficiencies determined were 93 and 92 per cent at Eject and Shaba-Maliki respectively. Assessment of soil parameters before and after the operation showed that the power tiller with the attached tillage tool had improved the soil structure. The cost of operation over five years of usage was determined and it was therefore concluded that the power tiller is a better alternative to animal drawn equipment for small-scale farmers. Ademiluyi et al. (2008) evaluated the field performances of 9 kw two -wheel tractor on a loamy sand soil of ilorin under the Guinea Savannah ecology of Nigeria. Field operations carried out include: disc ploughing, mould board ploughing, cultivation, cultivation cum planting and harvesting; following the types of accompanying implements available. The parameters measured and determined for each case included area of land covered, average time of operation, fuel consumption, width of action, average depth of cut, wheel slippage, speed of operation, field capacity and field efficiency. Field efficiencies determined were per cent for disc ploughing, per cent for mould board ploughing, per cent 12

25 for cultivation and 81.26% for cultivation cum planting and per cent for harvesting with a reaper. It was therefore concluded that power-tillers as they are commonly called are better alternatives when compared to animal drawn equipment for several field operations like tillage, planting, harvesting and transportation. Anantachar et al. (2011) evaluated the performance of multipurpose tool carrier for power tiller. The tool carrier was operated at an average working speed of 2.0 km per hour for tilling operation with the average depth of operation of 5.15 cm. The average draft of the unit was found to be 70.0 kg. The theoretical and actual field capacity of the tool carrier was found to be 0.30 ha/h and 0.20 ha/h respectively. The field efficiency and average fuel consumption were observed to be per cent and 1.05 litres per hour for tilling operation. 13

26 Chapter - 3 DESIGN CONSIDERATIONS This chapter deals with the theoretical considerations, design calculation for modification of existing self propelled multipurpose power unit for sowing operation. 3.1 Design steps Following steps were taken in modification of self propelled power unit. a) Performance evaluation of existing unit for sowing operations to identify problems of existing machine. b) Finalize the design considerations for seed box, seed drill frame, furrow opener, seed metering device, pegged ground wheel, steering wheel, handle and attachment by using principles of machine design and strength of materials. c) Finalize the design by considering the practical problems in actual field operations and fabrications. d) List of components which are to be purchased or items to be fabricated were prepared. Information about the suppliers, specification details and cost of parts were collected. e) Using principles of machine design and strength of materials, the engineering drawings of machine was drawn and it was labeled. f) Estimated the cost of machine using available information about the cost of finished, semi finished, fabricated items, labour cost, overheads etc. g) Fabricated the prototype, according to the design specifications. h) Tested the newly developed and fabricated machine. 14

27 3.2 General design consideration The design of seed drill consists of several steps and would require basic information about the following: a) Crops and their characteristics. b) Soils and climatic conditions during sowing seasons. c) Sources of power available. d) Functional requirement of machine and its interrelationship of various components. e) Labour requirements for seeding. f) Strength requirement of its various components. g) Size of holding. h) Material substitution and selection based on analysis of forces, market availability of raw materials. i) Ease of operation, adjustment of machine and maintenance. j) Safety and operator s comfort. k) Reduction of losses and free flow of seeds, placement of seed in proper distance and depth. l) Cost of machine and farmer s paying capacity. m) Cost of machine operation 3.3 Functional requirements The seed drill was designed to fulfill the following functional requirements: 1) To meter the seeds of different shape and size properly. 2) To place the seed in the soil to a specified position. 3) To cover the seed. The mechanical functional requirements of different individual units of machines are given below. 15

28 a) Seed hopper 1. It should hold sufficient quantity of seeds. 2. The shape of the hopper should be such as it allows free flow of seeds into the seed metering device without bridging. 3. It should be easily accessible and visible to the operator. 4. The shape of the hopper should be along the length of the frame by which the load could be distributed uniformly. b)seed metering device 1. It should be able to receive the seed from hopper and push them in the seed tube attached to furrow openers. 2. It should be able to meter the seed based on seed rate recommended in terms of weight per unit area 3. There should not be any internal or external damage to the seeds. 4. There should be continuous flow of seeds. c) Seed dropping device 1. It should place the seeds uniformly on the furrow bed at a specified row to row distance. 2. It should not cause any injury to the seeds. 3. Height of fall of the seeds should be minimum. d)furrow Opener 1. It should maintain the required depth of sowing. 2. There should not be any choking on furrow opener. 3.4 Agronomical requirements The flow of seeds is determined by its physical characteristics such as size and shape, angle of repose, coefficient of friction between seed and hopper, the hopper shape, size of orifice, moisture content etc. The slope of walls of hopper should be more than the angle of repose so that grain can easily go towards the metering mechanism. The size and shape of common seeds are presented in Table

29 Table 3.1: Physical characteristic of various seeds Name Axial dimension, mm Sphericity of % Unit Moisture weight of content, Bulk density seed, g % wb kg/m Seed Length Breath Thickness Wheat Gram Soybean Linseed Source: A.K. Verma (2007) Recommended seed rates, row spacing, and other important seed machine parameters for design of seed drill are given in Table 3.2. Table 3.2: Seed and machine parameters Funneling kg/ha Row to row spacing, cm sowing, cm Wheat Gram Soybean Linseed Crop Seed rate, Depth of angle of repose Source: A.K. Verma (2007) 3.5 Selection of materials Selection of proper materials for manufacturing various components of seed drill is very important. The farm machinery has to work under severe hazardous and heterogeneous environmental conditions. It should be adequately strong, stiff, and wear resistant and serves the purpose and operating requirements of the machine elements. It should be readily shaped, welded and easily machineable. 17

30 The materials for construction of different components should be easily and locally available. Use of standard sizes of steel section, fasteners and chains would help in easy inter-changeability and replacement. It can be fabricated & repair by village artisans. The structure of power unit should be simple and this makes the operation, maintenance and repair easy. 3.6 Design of different parts of seed drill Design of frame The components of seed drill are mounted on the main frame which is supported by two ground wheels. The frame is subjected to torsion and bending moment due to soil cutting tines attached on it. The design should be based on the stress produced on the frame. Let, the furrow width is 10cm wide and 8cm deep and shape of furrow is triangular. Cross section of furrow (A) = 1 2 (w x h) = 1 (10 x 8) =40 cm (3.1) The value of the actual average soil resistance is obtained by the formula. Fx = A x PK (3.2) Where, A = Cross section of furrow Pk = Specific soil resistance for the Heavy soil Specific soil resistance P k when sowing to a depth of 15 cm under different soils are: (Varshney et al., (2004)) Light soil : 0.12 kg/cm 2 Medium soil : 0.15 kg/cm 2 Heavy soil : 0.20 kg/cm 2 Therefore, F x = 0.20 x 40 = 8 kg 18

31 The soil resistance is assumed to be 3 to 5 times higher than actual average soil resistance (F x). Draft at the tip of tine (D t ) = F x x (3 to 5 times) kg (3.3) = 8 x 3 = 24 kgf Total torque on the front of frame (T) = 3 x 24 x 32 (Clearance from ground) = 2304 kgf-cm In addition to the torque, bending will also produced on frame. The frame can be taken as simply supported beam in between the two ground wheel. The reaction at each end of two supports will be R x = (24 x 3) 2 = 36 kgf W = weight of seed box, with full of seed = 30 kg (max) and assumed to be act at the centre of the tool bar. Fig 3.1: Arrangement of tines on the frame 19

32 Formatted: Line spacing: Multiple 1.4 li Hence, Maximum bending moment on the centre M = (36 x 35) + (30 x 36) (24 x 26) = 1716 kgf-cm So, Equivalent torque (T e ) = (3.4) Formatted: Line spacing: Multiple 1.4 li, Tab stops: Not at 0.08" " Formatted: Font: 8 pt Formatted: Character scale: 103%, Expanded by 0.3 pt = Formatted: Line spacing: Multiple 1.4 li = kg-cm The maximum shear stress developed at the centre of the tool bar can be obtained by the relationship. Formatted: Centered, Line spacing: Multiple 1.4 li (3.5) Formatted: Line spacing: Multiple 1.4 li Where, Formatted: Line spacing: Multiple 1.4 li, Tab stops: Not at 0.08" " S S = Shear stress at any section; T e = Total torque developed; kg-cm I = Moment of inertia of frame (bd 3 /12 for rectangle section and for square section b=d) Formatted: Line spacing: Multiple 1.4 li y = Distance of the section from natural axis; Now, assuming maximum working stress of 500 kg/cm 2 at the center of toolbar. S s=500 kg/cm 2 Moment of inertia I= bd3 12 = d4 12 Formatted: Font: 1 pt Formatted: Font: 4 pt Formatted: Line spacing: Multiple 1.4 li 20

33 Formatted: Right, None, Line spacing: Multiple 1.4 li Formatted: Character scale: 103%, Expanded by 0.3 pt Moment of inertia = (3.6) Formatted: Right, Line spacing: Multiple 1.4 li Therefore Section modulus (Z) = I / y = (d 4 /12)/ d/2 = d 3 /6 Or d3 = 6 T e/ S s = 6 x /500 =34.47 cm 3 Formatted: None, Line spacing: Multiple 1.4 li, Tab stops: Not at 0.08" " Formatted: Line spacing: Multiple 1.4 li d=3.25 cm Thus on the basis of calculation toolbar is to be made of angle Formatted: Line spacing: Multiple 1.4 li, Tab stops: Not at 0.08" " section each side measuring 3.25cm. Therefore, the material taken for the frame was of size 4 cm x 4 cm square section with having thickness of material of 0.5 cm Seed hopper a) Shapes Hopper was designed to cover full width of the machine and located above the main frame. The cross section of the seed box may be Formatted: Adjust space between Latin and Asian text, Adjust space between Asian text and numbers, Tab stops: Not at 0.08" " trapezoidal, rectangular, triangular or cylindrical. The bottom was kept usually flat and rounded at the corners. Small machines have continuous boxes whereas bigger units have partitions at regular intervals. The boxes should be not buckle when fully filled with seed and fertilizer. Formatted: Tab stops: Not at 0.08" " The heights of hopper in seeds drill vary from 40 to 90 cm above the ground level. The appropriate height helps in preventing the excessive bending of seed delivery tubes. Inclination of delivery tubes and ease of filling the hopper are the considerations while deciding the height. The capacity of box was determined by keeping the balance between the weight of material filled (as it affects draft) and the field efficiency of the machine. Application rates and field capacity values must be taken into consideration. The inclination of front and rear walls of hopper must be greater than maximum angle of repose of seed to be handled by the 21 Formatted: Adjust space between Latin and Asian text, Adjust space between Asian text and numbers, Tab stops: Not at 0.08" "

34 machine. The thickness of mild steel and galvanized steel sheet for boxes should be not less than 1.0 mm and 0.63 mm respectively. According to design consideration, hopper are placed close to the ground level to reduce the time of travel from metering device to the furrow and to deposit seeds at low terminal velocity. b) Design of hopper The seed box made up of GI sheet; the length of box is given by Lb = Lm - 2b (3.7) Formatted: Tab stops: Not at 0.08" " Formatted: Line spacing: single Formatted: Line spacing: Multiple 1.4 li Where, L b =Length of box, cm Lm = Working width of seed drill =70cm b=distance between the side box and ground wheel (let b= 12cm) Formatted: Line spacing: single Formatted: None, Line spacing: single, Pattern: Clear Formatted: Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt, Border: : (Single solid line, Auto, 0.5 pt Line width) Formatted: Line spacing: single Fig 3.2: Schematic Diagram of Seed Drill Showing Arrangement of Furrow Opener and Seed Box Formatted: None, Line spacing: single, Pattern: Clear Length of box = 70-2 (12) =46 cm 22

35 Formatted: Font: 11 pt Formatted: Font: Not Bold Fig 3.2: Schematic diagram of seed drill showing arrangement of Formatted: Tab stops: Not at 0.08" " furrow opener and seed box Among the seed used for sowing by the seed drill, wheat has the maximum seed rate = 125 kg. Therefore, the seed drill may be designed for the seed application rate of 125kg/ha. Now, Actual field capacity of drill = Speed (km/ h)x Working width of drill (m) X field efficiency 10 Formatted: Line spacing: single Formatted: Right = ---- Formatted: Character scale: 103%, Expanded by 0.3 pt (3.8) Let speed = 2 km/h and field efficiency be 80%. Working width of machine = No. of tynes x row spacing = 2 x 20 = 60 cm = 0.6 m Formatted: Character scale: 103%, Expanded by 0.3 pt Actual field capacity of drill= =0.12 ha/h 23

36 Let us design the seed box for such a capacity, that it requires refilling of seed after one hour. Therefore, Weight of seed to be used in 1 h =Seed rate (kg/h) x Area covered (ha/h) x Time (h) Formatted: Left = 125 x 0.12 x 1 = 15 kg Formatted: Centered, Space Before: 0 pt, After: 0 pt, Line spacing: single Weight of seed (kg) Volume of seed box (Vs) Bulk density (kg/m 3 ) 15 = = 0.02m Formatted: Character scale: 103%, Expanded by 0.3 pt Volume of seed box (Vs) = = (3.9) = 0.02m3 Consider 10% free board. Therefore, the total volume of seed box 3 (Vs) of seed drill is 0.022m or cm Formatted: Tab stops: Not at 0.08" " 3 V = A Lb (3.10) Where Lb is length of seed drill = 46 cm A=Area of seed box So A = V (3.11) = (46) = cm2 24 Lb Formatted: Tab stops: Not at 0.08" "

37 The cross section of box was divided in to three sections viz. X, Y and Z. Section X and Z are rectangular and section Y is trapezoidal Formatted: Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt, Border: : (Single solid line, Auto, 0.5 pt Line width) Fig. 3.3 Cross section of seed box Formatted: Centered Cross sectional area of section X = a x b Formatted: Tab stops: Not at 0.08" " Assume a = 6 cm and b = 30 cm So, area of X =6 x 30 = 180 cm 2 Cross sectional area of section Z = B x h Assume h = 3 cm and B = 20 cm 25

38 So, area of Z =3 x 20 = 60 cm 2 Formatted: None, Tab stops: Not at 0.08" " Formatted: Tab stops: Not at 0.08" " Cross sectional area of section Y Y=H (B - H cot ) (3.12) (3.12) Formatted: Tab stops: Not at 0.08" " Where, Formatted: Tab stops: Not at 0.08" " H = Height of trapezoidal section, cm; B = Base width of trapezoidal section, cm; and Formatted: Tab stops: Not at 0.08" " = Angle of slope, degree. Y = (180+60) = cm2 Formatted: Tab stops: Not at 0.08" " Base width of the box = 20 cm and angle of repose for wheat 30 4, therefore is taken as 70 o So, = H (20 + H cot 70) H = 11cm So, the dimensions of trapezoidal section were taken for base, top Formatted: Tab stops: Not at 0.08" " width and height was 20, 30 and 11 cm respectively Design of power transmission from prime mower to wheel A 5 HP engine with 1200 rpm has been taken. The required rpm of Formatted: Pattern: Clear, Tab stops: Not at 0.08" " feed shaft should be 18 rpm (assumed). Formatted: Tab stops: Not at 0.08" " 26

39 Therefore to decrease the rpm, driven pulley is replaced with larger Formatted: Pattern: Clear, Tab stops: Not at 0.08" " diameter pulley and decrease the diameter of traction wheel. The size of driven pulley and traction wheel is decided by calculation as given below. Ne x De = Np x Dp (3.13) Formatted: Line spacing: Multiple 1.4 li Where, Ne = Number of revolution per minute of pulley of engine; Formatted: Line spacing: Multiple 1.4 li, Tab stops: Not at 0.08" " Np = Number of revolution per minute of pulley of transmission system De = Diameter of pulley of engine, cm Formatted: Line spacing: Multiple 1.4 li Dp = Diameter of pulley of transmission system, cm x 10=Np x 30 Np=400 rpm Formatted: Line spacing: Multiple 1.4 li, Tab stops: Not at 0.08" " " Since Gear ratio speed ratio = 20 1 Formatted: Line spacing: Multiple 1.4 li Number of revolution of traction wheel (N) = 20 rpm The forward speed of power unit was calculated as: Formatted: Character scale: 103%, Expanded by 0.3 pt Forward speed S= (3.14) Where, S = Speed of power unit, km/h Formatted: Line spacing: single, Tab stops: Not at 0.08" " d = Diameter of traction wheel, m Diameter of traction wheel = 640mm Formatted: Font: 2 pt Formatted: Font: 2 pt 27

40 Formatted: Character scale: 103%, Expanded by 0.3 pt = = 2.4 km/h Formatted: Line spacing: single Consider 10% slip, and then speed will be 2.16 km/h. Formatted: Line spacing: Multiple 1.4 li Length of open belt Length of open belt is calculated as (Khurmi) (3.15) Where, C= Distance between center of two pulley =36cm =137.5 cm = 140cm Thus a V belt of B 140 is selected for transmission of power Design of power transmission from Ground wheel to metering Formatted: Indent: Left: 0", Hanging: 0.47" device The power is transmitted through the ground wheel to the seed metering device with the help of set of chain and sprocket mechanism for the accurate power transmission. Speed of power unit = 2.16 km/h Diameter of pegged ground wheel (Dg) = Now for 2.16 km/h speed of power unit, the rpm of axle of pegged ground wheel is given by (3.16) 2160 Ng= =24.13rpm 3.14X0.475X60 Ng= 28 = rpm Formatted: Tab stops: Not at 0.08" "

41 The speed ratio of axle of pegged ground wheel and feed shaft was calculated as: Ng Tf = Nf Tg Formatted: Right = ---(3.17) Where, Ng =RPM of ground wheel Nf =Rpm of feed shaft Tg = Number of teeth on sprocket of axle of ground wheel Tf =Number of teeth on sprocket of feed shaft Assume speed of feed shaft is 18rpm. Speed ratio Ng = Nf = = Formatted: Right Formatted: Font: Not Bold Speed ratio= = = (3.18) Assume number of teeth on sprocket of ground wheel axle Tg= 12 Number of teeth on sprocket of feed shaft Tf= Tg x 1.4 = 12 x 1.4 = Thus the speed ratio was 1.4 for the whole metering assembly. The number of revolution per minute of the ground wheel was 1.4 times that of number of revolution per minute in the seed metering unit Design of chain 29 Formatted: Font: Not Bold Formatted: Font: Not Bold Formatted: Font: Not Bold Formatted: Font: Not Bold Formatted: Font: Not Bold Formatted: Font: Not Bold Formatted: Font: Not Bold Formatted: Font: Not Bold Formatted: Tab stops: Not at 0.08" "

42 The chains are mostly used to transmit motion and power from one Formatted: Tab stops: Not at 0.08" " shaft to another, when the centre distance between the shafts is short. In order to obtain a constant velocity ratio, chain drive is mostly preferred. The length of chain (L) attached from ground wheel axle to feed shaft was calculated as: Formatted: Font: Not Bold Formatted: Right Formatted: Character scale: 103%, Expanded by 0.3 pt (3.19) Where, p = Pitch length i. e. 1.3 cm Formatted: Tab stops: Not at 0.08" " n1 = Number of teeth on bigger sprocket i.e. 17 n2 =Number of teeth on smaller sprocket i. e. 12 C =Distance between centre of two sprockets i.e. 36 cm m = C/p = 36/1.3 = Length of the chain Formatted: Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt = Formatted: Tab stops: Not at 0.08" " =1.3 x

43 = 91.9 cm 92 cm Formatted: Font: Bold, Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt, Border: : (Single solid line, Auto, 0.5 pt Line width) Formatted: Tab stops: Not at 0.08" " Fig 3.4: Power transmission from ground wheel to seed metering Formatted: Indent: Left: -0.03", Hanging: 0.79", Tab stops: Not at 0.08" " device Design of seed metering device A seed metering device draws seed from box and delivers it at the Formatted: Level 1, Tab stops: Not at 0.08" " desired rates in the seed tubes for sowing uniformly. The device should not cause mechanical damage to seeds. Size and shape of seeds affect machine performance because of large variations in recommended rate for crops. Formatted: Tab stops: Not at 0.08" " Seed metering mechanism may be of several type: (a) Fluted feed type (b) Internal double run type (c) Cup feed type (d) Cell feed mechanism (e) Brush feed mechanism (f) Auger feed mechanism (g) Picker wheel mechanism (h) Star wheel mechanism. 31 Formatted: Level 1, Tab stops: Not at 0.08" "

44 Fluted roller type seed metering device is selected for the drill because this is the most suitable type, seed rates can easily be changed, very popular among the farmers, least damage and easily available in the local market. Formatted: Font: Bold, Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt, Border: : (Single solid line, Auto, 0.5 pt Line width) Formatted: Centered Fig 3.5: Seed feed roller The speed ratio between roller and ground wheel is 1.4 (From eq. 3.18) Area covered by seed drill in one revolution = x Dg x W =3.14 x x 0.6 = 0.89 m2 Formatted: Font: 1 pt So, Number of revolution for 1 hectare= So, revolutions of metering roller per ha = = rev. Formatted: Character scale: 103%, Expanded by 0.3 pt Formatted: Character scale: 103%, Expanded by 0.3 pt = =7981 rev Seed rate= 125 kg/h Formatted: Character scale: 103%, Expanded by 0.3 pt For dropping of 1 kg of seed = = 63 rev And seed dropped in one revolution= 32 Formatted: Font: 4 pt

45 Formatted: Character scale: 103%, Expanded by 0.3 pt = 22.5 gm Volume of 22.5 gm seed by taking bulk density as 750 kg/m 3 = 30cm3 = Formatted: Superscript Formatted: Centered 30 3 Volume for one fluted roller= Formatted: Font: 1 pt =10 cm 3 Formatted: Centered Volume for one fluted roller= Formatted: Character scale: 103%, Expanded by 0.3 pt =30 cm 3 = =10 cm 3 [ Divided by 3 as there were 3 tynes and 3 roller ] Now selecting the size of the groove according to type of grain. Let the shape of groove is parabolic. Width of groove =1.2 cm, Depth of groove = 0.5cm Let length of roller is 3.5 cm (to change the seed rate) Volume of one groove = area x length= 2/3 x 0.5 x 1.2 x 3.5 = 1.3cm 3 Formatted: Font: 10 pt Volume of one fluted roller Number of grooves = Volume of one flute Number of grooves = Number of grooves= 10/1.3 = 7.69 Formatted: Character scale: 103%, Expanded by 0.3 pt 8 Let the clearance between two grooves is 1.8 cm Periphery of roller = D f = No. of flutes x pitch (3.20) Where D f = Diameter of fluted roller D F = 8 x 1.8 Formatted: Tab stops: Not at 0.08" " 33

46 D f = 4.58cm Thus on the basis of calculation, fluted roller of diameter 4.6 cm and number of flutes in each roller should be Design of furrow opener Furrow openers of a sowing device are the final modifier of soil Formatted: Tab stops: Not at 0.08" " environment in a seedbed. Hence, they are one of the most important components of a seed drill. On the basis of working of soil engaging parts of openers they can be classified into two major groups. The furrow openers may be sliding type or rolling type. The sliding type furrow openers can be divided into two categories viz. with acute angle: shovel type, pointed shoe type, hoe type etc. and with obtuse angle: runner type. The rolling type furrow openers include single concave disc and double plane disc. Furrow opener having shoe and shovel shape were taken in the design of seed drill. The main aim is to open the furrow having 6 cm depth and 10 cm width. The shoe type furrow opener is fitted at one end of the shank and the other end of the shank is attached with frame by nuts and bolts. The Formatted: Adjust space between Latin and Asian text, Adjust space between Asian text and numbers, Tab stops: Not at 0.08" " thickness, width and length of the shank were decided on the basis of design given below. Formatted: Tab stops: Not at 0.08" " During the operation, an effective draft force D acts at the tip of the tool that generate a bending stress (fb) at the bent causing bending of the shank. Draft required per tine (D t ) = 24 kgf (already calculated) 34 Formatted: Adjust space between Latin and Asian text, Adjust space between Asian text and numbers, Tab stops: Not at 0.08" "

47 Design draft in kgf which should be kept 3 to 5 times of actual draft for safety point of view. The total draft exerted on the opener will be 72 kgf. The tine can be taken as a cantilever, so the maximum bending moment for a cantilever length of 28 cm length is Bending moment (Mb) = Draft (kgf) x Length of shank (cm) (3.21) Mb = 72 x 28 = 2016 kgf-cm. The section modulus of the shank can be computed from the Formatted: Tab stops: Not at 0.08" " classical flexure formula as given below. fb = MbY/I ---- (3.22) Where, fb = Bending stress, kgf /cm 2 Formatted: Indent: Left: 0.17", Hanging: 0.35", Tab stops: Not at 0.08" " Mb = Bending moment, kgf-cm Y = Distance from the neutral surface to the fiber where the stress is determined in cm I = Moment of inertia for rectangular cross-section about the neutral axis in cm Formatted: Tab stops: Not at 0.08" " 35

48 From equation number (3.21) Section modulus = I/Y = Mb/fb = bd2 / (3.23) fb for mild steel rectangular cross section= 1000 kgf/cm 2 It is assumed that the ratio between thickness to width b: d = 1:4 or can be taken. d =4b From equation 3.22 b3 = b = 0.91 cm, Therefore d = 4b = 4 x 0.91 = 3.64 cm Therefore Standard MS flat of size mm was used for Formatted: Tab stops: Not at 0.08" " fabricating the shank of shoe type of furrow opener. Another shovel type furrow opener made up of MS rectangle section for the increasing the strength. The dimension of rectangle section is 50mm x 20 mm x 6 mm. Fig 3.6: Details of the furrow openers 36 Formatted: Centered

49 3.6.9 Seed delivery tubes Seeds fall freely from the feed cup through the tube into the furrow. Formatted: Tab stops: Not at 0.08" " Uniform seed to seed spacing was achieved when all seeds are released by the metering device from the same height with the same velocity. The inclination of seed tubes from the vertical is kept smaller than 20 to avoid clogging. In present design transparent plastic tube of 25 mm diameter and 2 mm thick were used to convey seed from orifice to furrow opener by Formatted: Don't adjust space between Latin and Asian text, Don't adjust space between Asian text and numbers, Tab stops: Not at 0.08" " gravity. The angle of tube from vertical was 8. Formatted: Tab stops: Not at 0.08" " Formatted: Don't adjust space between Latin and Asian text, Don't adjust space between Asian text and numbers, Tab stops: Not at 0.08" " Pegged type wheel Pegged wheel was suitable for use under wet or sticky soils, where plain, lugged or even pneumatic wheels fail to work. Ground drive wheel of 400 mm diameter, having width 25 mm and was provided below the main frame of the machine. Eight spikes (50 mm x 25 mm) were provided on the outer periphery of the wheel to develop sufficient grip to the rotating wheel. Eight spokes of 8 mm diameter are fitted at the axle of ground wheel. Power developed due to the rotation of the wheel was transmitted to the seed shafts with the help of two sets of chain and sprocket arrangement. The fig 3.7 shows the pegged ground wheel for seed drill. 37

50 As the drive wheel enters in the soil it is to be considered that the half of the peg inserted in to the soil for better gripping and to reduce slippage of drive wheel, therefore, diameter of the drive wheel measured from the tip of peg to the half of base of the peg of opposite side. Formatted: Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt, Border: : (Single solid line, Auto, 0.5 pt Line width) Formatted: Font: 5 pt Fig 3.7: Details of the pegged ground wheel designed for seed drill 38

51 CHAPTER- 4 MATERIALS AND METHODS The present self propelled power unit was initially developed as Formatted: Tab stops: Not at 0.08" " power weeder for intercultural operation and later on it was further developed as multipurpose power unit to perform secondary tillage and sowing operations in the Department of Farm Machinery and Power Engineering (Kushwaha 2002). The machine is sequentially modified to full fill the need of small and medium farmers for multipurpose field operations. A new design would be initiated to overcome problems of existing machines. The self propelled seed drill was fabricated as per design in the workshop of department of Farm Machinery and Power Engineering, College of Agricultural Engineering, JNKVV, Jabalpur. Before starting the construction of self propelled seed drills following factors were considered for appropriate selection of materials. Selection of metal must be such that it can be formed into desired shape. It is based on ductility characteristics of the metal. The forming of metal is usually done by cold working that means forming is done at room temperature. The materials for fabrication of various components were selected considering their function and strength requirements as given in Table 4.1. The economics consideration of materials was also taken into account. The ease availability of material was also taken in to account for the same. 39 Formatted: Tab stops: Not at 0.08" "

52 After the design and selection of different components subsequent work Formatted: Tab stops: Not at 0.08" " was carried out in the following stages. 1. Fabrication of self propelled seed drill. 2. Performance testing and evaluation of the self propelled seed drill. Formatted: Indent: Left: 0", Hanging: 0.91", Tab stops: Not at 0.08" " Table-4.1 Specification of the materials for different components of a self propelled seed drill S. No. Parts Material Used Specifications 1. Seed box Galvanized sheet 18 Gauge 2. Fluted roller type metering devices Aluminum 46mm diameter, 8 number of flutes 3. Seed tubes Plastic 25 mm diameter, 2 mm thick, transparent 4. Tines MS Flat Iron MS Rectangle section mm size 50 x 20 x 6mm 5. Furrow openers Mild carbon steel Carbon content 0.5% 6. Boots Cold rolled MS sheet 30mm diameter, 3 mm thick 7. Shaft for seed metering Mild steel rod 16mm diameter, 600mm length 8. Ground wheel MS flat 2mm width 9. Main frame and hitches MS square section 40 x 40 x 5 mm 50 x 50 x 6mm 10. V-pulley Cast Iron Engine shaft pulley outer dia 10mm, Input gear shaft pulley outer dia 40 Formatted: Centered, Line spacing: single Formatted: Line spacing: single Formatted: Line spacing: single Formatted: Line spacing: single Formatted: Line spacing: single Formatted: Line spacing: single Formatted: Line spacing: single Formatted: Line spacing: single Formatted: Line spacing: single Formatted: Line spacing: single Formatted: Line spacing: single

53 300mm 10 V-belt 11. Accelerator wire 12. Standard finished items 4.1 Rubber fabric B (Single), length140cm 2m Roller chains, sprockets (Sheet punched), split pins, bolts and nuts plain and spring washers etc. be as per standard, used in light engineering industry. Formatted: Line spacing: single Formatted: Line spacing: single Formatted: Line spacing: single Fabrication of self propelled seed drill Fabrication of the seed drill The frame of the 3-tyne seed drill was made of MS angle of 40 x 40 Formatted: Tab stops: Not at 0.08" " x 5 mm with a square cross section. The size of frame was 600 mm. In the front arm, circular holes (10 mm) at a regular intervals (2 cm) have been made for adjusting the spacing between furrow openers to suit the spacing requirement of Formatted: Don't adjust space between Latin and Asian text, Don't adjust space between Asian text and numbers, Tab stops: Not at 0.08" " different crops. The seed box was fabricated from galvanized iron sheet of 18-Gauge. All the sides were marked and cut, then joined by riveting. Rectangle holes of 95 x 25 mm were provided at the bottom of hopper to accommodate the seed metering roller. The cross section of the box was trapezoidal. The bottom of seed box was flat. The location of the seed box was 610 mm above the ground. This height of box helps to reduce the angle of inclination of seed delivery tubes. Formatted: Tab stops: Not at 0.08" " The fluted rollers were made of aluminum die cast with 8 teeth. Dia of fluted roller is 46 mm. The feed shaft and axle of pegged ground wheels having 16 mm diameter cold rolled round section steel shafts were prepared on the lathe from a shaft of 24mm diameter. Metering rollers are fixed at three equal places on the feed shaft by split pins. The seed rate 41 Formatted: Don't adjust space between Latin and Asian text, Don't adjust space between Asian text and numbers, Tab stops: Not at 0.08" "

54 adjusting lever was made of mild steel and attached to one end of shaft of fluted roller for seed rate control. Two sprockets, one having 12 teeth and other having 17 teeth were used to transmit the power from ground wheel to the seed metering device. Small sprocket was mounted on feed shaft where as sprocket of 17 teeth was mounted on axle of ground wheel. Suitable bushes were prepared on the lathe machine to mount the sprocket with the help of bolt on feed shaft and ground wheel axle. The sprockets were directly connected by standard pitch roller chain which could be fixed at any position. The ground wheel was made up of (24 x 2mm) MS flat having length 130 cm by banding in circular shape and 8 rectangle pegs (50 x 20mm) were welded at the outer periphery of the wheel at 45 spacing with 90 lug angle for better griping with soil. It consists of 8 spokes made from MS rod of 7 mm dia. and 180mm long. These spokes were welded with the inner periphery of the rim and at the outer periphery of the hub. The hub was made of MS tube of 60mm length and with 22mm outer and 18mm inner dia. Nut and bolt type locking arrangement was provided on wheel hub for its mounting on the shaft. The isometric view of seed drill is given in Fig

55 Formatted: Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt, Border: : (Single solid line, Auto, 0.5 pt Line width) 43

56 Fig 4.1: Isometric view of the seed drill Formatted: Centered Fabrication of depth cum-direction control wheel The depth cum direction control wheel was made up of solid rubber wheel of diameter 300mm and 40mm wide. The wheel is attached with seed drill frame towards operator side. This was used for easy turning of machine. During the transportation, the ground wheel and furrow opener can be raised with the help of shaft having diameter 25 mm, which is attached to the wheel by the U clamp. Shaft can move freely in the hollow sleeve of 280mm attached to the frame. The holes were made in sleeve and shaft at regular interval for adjustment of depth of operation. 44 Formatted: Font: 1 pt Formatted: Tab stops: Not at 0.08" "

57 Formatted: Font: 1 pt, Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt, Border: : (Single solid line, Auto, 0.5 pt Line width) Formatted: Font: 1 pt Fig 4.2: Details of the depth cum direction control wheel Formatted: Centered Fabrication and Installation of Power Drive System The self propelled seed drill comprises a 5hp diesel engine, speed reduction unit (gear box), V-belt pulley arrangement, so located as to keep the machine balanced. The worm type gear reduction unit was located at the axle having gear reduction ratio of 20:1. The speed reduction was done in 2 stages. First stage gave reduction of engine speed from 1200 to 600 rpm with the help of V belt pulley. The bigger pulley fitted at the end of gear box input shaft and smaller pulley fitted on output shaft of the engine. The dia. of corresponding pulleys was 45 Formatted: Tab stops: Not at 0.08" "

58 30cm and 10 cm. These pulleys were connected to a V-belt of size B 46. Second stage reduction was in the worm gear reduction unit. The output shaft of gear was extended in both sides and used as the axle for the traction wheels. To vary the speed of operation there is an acceleration wire connected to the governor. Formatted: Tab stops: Not at 0.08" " One U clamp of flat mild steel was fabricated and arranged in such a manner so that it could move on driven clutch plate without touching its surface. It was used for engaging and disengaging the clutch. Clutch lever was supported on U clamp. The detail construction of clutch system is given in Fig 4.3. The clutch lever was connected to the clutch plate with the help of two bars which are perpendicular to each other. The horizontal bar whose one end is connected to pressure plate, consisted of flat iron of size 58 cm and 2 cm width. The vertical bar was connected to horizontal bar with the help of nuts and bolts and fixed on frame. The vertical bar was made of 8mm dia. and 65 cm length. Clutch lever was fitted along with the vertical bar with the help of spring. Under the normal condition, both plates of clutch remained in engaged position due to spring pressure ant the power from driving clutch plate was made available to the driven clutch plate and also to the output shaft of the gear reduction unit. When the clutch handle was pulled forward, the U clamp at the other end separated the driving clutch face from driven clutch face and disengaged the power supplied from the engine output shaft. 46

59 Formatted: Tab stops: Not at 0.08" " 47

60 Formatted: Font: Bold, Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt, Border: : (Single solid line, Auto, 0.5 pt Line width) 48

61 Formatted: Centered Fig 4.3: Isometric view of modified self propelled power unit 49

62 50

63 Formatted: Font: Bold, Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt, Border: : (Single solid line, Auto, 0.5 pt Line width) Fig 4.4 Schematic diagram of power transmission 51

64 Fig. 4.5: Isometric view of self propelled seed drill 52

65 Formatted: Centered, Indent: Left: 0", Hanging: 0.58", Tab stops: Not at 0.08" " Formatted Fabrication of attachment of various implement The hitching mechanism was designed taking into consideration the Formatted: Tab stops: Not at 0.08" " way it is hitched to the power unit and easy maneuverability. Various machines can be attached with the power unit by providing square box. The box was made out of hollow square bar of 40 mm sides. This square box slide forward and backward inside the hollow square section (50x50x6mm) of engine mounting frame. In the square box, circular holes (10mm) at a regular interval of 2cm have been made for adjusting overall length of machine. Provision is also made in seed drill for varying the height of hitch to obtain good performance at different operating depths. 53 Formatted: Don't adjust space between Latin and Asian text, Don't adjust space between Asian text and numbers, Tab stops: Not at 0.08" "

66 Formatted: Font: Bold, Do not check spelling or grammar, Character scale: 103%, Expanded by 0.3 pt, Border: : (Single solid line, Auto, 0.5 pt Line width) 54

67 Plate 4.1 Attachment of seed drill Vibration isolators Vibration levels depend on the terrain conditions and engine speed of the machine. It was observed that as the engine speed increases, rms acceleration also increased and it was highest on the top of the engine followed by the chassis, seat, handle, root of handle bar and gear box. The vibration at the top of the engine was the highest since the major excitation of the vibration of the machine is the unbalanced inertial force of the engine. Four vibration isolators were mounted between the engine and chassis. With this, excitation of the unbalanced inertia force of the engine gets transmitted to the chassis through the isomer only. By means of phase change and because of the high percentage of molecular diffusions in the case of rubber isomer, the mechanical energy would be consumed and dissipated as heat, and the instantaneous vibration would be attenuated rapidly. 2.5cm thick isolator was placed between two metal plates. Dimension of isolator (7.0 x 7.0 x 2.5) cm Dimension of metal plate (6.5 x 6.5 x 0.4) cm 55

68 Table 4.2 General Specification of Self propelled Multipurpose Power Unit Type Overall Walking type iron wheeled self propelled power unit Dimension Length 1880 mm (adjustable) Width 972 mm Height 840 mm Engine 5hp air Greaves Transmission V belt & pulley, chain & sprocket Drive wheel Iron wheel, lugs on periphery, dia-640mm cooled diesel engine, Lombardini width- 83mm, lugs spacing-106mm Seed box Made up of galvanized sheet (18gauge) trapezoidal shape, volume of seed box m 3, capacity 17kg, inclination of seed box wall 70 56

69 Seed metering device Fluted roller (transmission system- chain sprocket) No. of slot-8, diameter of fluted roller4.5cm Feed shaft Diameter of shaft 16mm, length 600 mm Furrow opener Shovel / shoe type, no. of furrow opener- 3, spaced 20-26cm with provision to change row spacing Pegged ground wheel MS flat, diameter of rim 400mm, width 25mm, no. of spike 8 (50 mm x 25mm) Seed tube Transparent plastic tubes, 25mm diameter 57

70 Plate 4.4 View of self propelled unit with matching seed drill Plate 4.5 View of prepared seed drill 4.2 Performance testing and evaluation of the self propelled seed drill Preparation of self propelled seed drill for test, running in and preliminary adjustment After completion of the fabrication, the machine was tested in the lab to run in and ensure trouble free movement of different moving components, evaluate the ease of operation and adjustment of different components and to observe the functional performance of different components. Lubrication of different components, where required, was done and the machine was operated for some time, clutch engaged and disengaged several times and made necessary adjustment on clutch. The machine was operated in the lab. Different parts, nuts, bolts, welding etc were checked and rectified as needed. After initial check-up the machine was 58

71 operated for about one hour continuously on the field to see its smooth and uninterrupted operation. The power system was engaged and disengaged several times with the help of clutch handle and it was found that it worked satisfactorily Laboratory test The seed drill was tested in laboratory to measure mechanical damage to seed during metering and for inter row variation and seed rate. The following tests were conducted in the laboratory. a) Metering Test- Calibration to determine the seed and fertilizer dropping rates obtained at different settings and the variation among furrow openers when machine was stationary. b) Seed Damage determination test- To determine mechanical damage occurred during the calibration. 59

72 Calibration of seed drill The seed required for unit area was calculated before field operation by given formula. Seed rate (kg/ha) can be calculated from the delivery of seed in given number of revolution of ground wheel in the laboratory using following formula (4.1) Where, Q = Seed rate (kg/ha) q = Seed delivered in given number of revolution (n) of ground wheel, kg D e= Effective diameter of ground wheel, m n = Number of revolution of ground wheel w = Nominal working width, m Seed germination The germination of seed before sowing was measured using a seed germinator. 50 seeds wrapped in tissue paper and covered with butter paper was placed in the seed germinator at 29 ± 5ºC and at relative humidity 99% for 10 days. After 10 days numbers of germinated seeds were counted and per cent of seed germination was determined by using equation (4.2) 60

73 4.2.3 Procedure for field testing The procedure followed for field testing was described below: 1. 35x10 meter plot were taken in the research farm of College of Agricultural Engineering. 2. The field preparation was done with two passes of disc harrow. 3. The soil moisture per cent and bulk density were measured. 4. Starting and ending timings of sowing operation were noted. 5. The field capacity was measured. From the actual & theoretical field capacity, the field efficiency was calculated. 6. Fuel consumption (l/h) was measured with the help of fuel measuring device developed in the college. 7. The depth and width of furrow were measured Test Parameter Seed uniformity To measure the uniformity of distribution of seed along the row, the machine was run in the test plot. The seeds were allowed to fall in the furrows and the furrow was carefully cleaned by removing the soil, so that the uniformity of seed could be measured easily and accurately. Numbers of seeds dropped in unit length of furrow were counted Seed rate The hopper was equally filled with weighed seed and then the drill was operated in the test plot. After sowing, the remaining seed in hopper was collected and weighed. 61

74 Width of cut For determining average width of cut 5 runs were taken. The measurement of composite width was taken at 5 equidistant places in direction of travel Depth of cut Vertical distance between furrow sole and ground level is referred to as depth of cut. To obtain accurate result depth was measured at 5 place along the furrow and average was taken Field capacity Theoretical field capacity was measured as per following formula. ha WS Theoretical field capacity h (4.3) Where, W = Effective width of implement, m and S = Speed of operation, km/h Actual field capacity The actual field capacity is the actual rate of coverage by the machine based upon the total field time. The machine was operated with the uniform speed for continuous field work for a fixed time and the area covered during the period was measured to determine the average output per hour. Actual field capacity (ha/h) = (4.4) Field efficiency From the actual and theoretical field capacity, the field efficiency was calculated 62

75 Field efficiency (%) = X (4.5) Where, FE= Field efficiency (%); AFC=Actual field capacity (ha/h); and TFC=Theoretical field capacity (ha/h) Fuel Consumption (l/ha) The separate fuel container with inverted scale was used, which was attached with fuel delivery and return pipe. The amount of fuel consumption was measured directly. Fuel Consumption (l/ha) = (4.6) Slippage (%) It is the difference between ideal distance a wheel should move and the distance actually moved by the wheel. Slippage (%) = X (4.7) Lo, L1 Distance covered without & with slip respectively Soil Moisture Content (SMC) It was the ratio of water to weight of dry soil in a given mass of soil (4.8) Where: Mc(db) = Moisture content dry basis (%), Ww = Weight of undried soil (g), Wd = Weight of oven dried soil (g) Bulk density It is the total mean mass of soil per unit of its total volume. It is expressed in terms of g/cm 3. 63

76 = M 4M = D2 L V (4.9) Where, ρ = Bulk density, gm/cm 3 ; M = Mass contain in soil sample of oven dry soil, gm. V = volume of cylinder sampler, cm 3 D = Diameter of cylinder sampler, cm L = Height of cylinder sample, cm. 4.3 Cost of Operation Fixed costs Depreciation This cost reflects the reduction in value of a machine with use (wear) and time (obsolescence). While actual depreciation would depend on the sale price of the machine after its use, on the basis of different computational methods depreciation can be estimated by straight-line method as given below (D) = (4.10) Where D = average depreciation cost (Rs. /year) P = purchase price of the machine (Rs.) S = residual value of the machine (Rs.) L = useful life of the machine (years) H= working hours per year 64

77 The depreciation cost per hour can be estimated by dividing D by the number of hours the machine is expected to be utilized in a year. Residual value of the machines may be taken as 10 per cent of the purchase price Interest An annual charge of interest was calculated by taking 10 per cent of purchase price of the machine. Interest was calculated by using the formula given below (4.11) Where I = Interest on capital Rs./h, P = purchase price of the machine, and S = residual value of the machine. i = interest rate in fraction H= working hours per year, hours Insurance, taxes and shelter Insurance and taxes were estimated taking as 2 per cent of average purchase price of machine Variable Cost Fuel The actual fuel consumption was observed and estimation was done accordingly Oil The cost of lubricants estimated as 10 per cent of fuel cost Repair and maintenance The cost of repair and maintenance was assumed to be 10 per cent of purchase price Wages and Labour charges The cost of labour was estimated taking the prevailing rate of Rs. 25 /h. 65

78 Chapter-5 RESULTS AND DISCUSSION This chapter deals with the study related to identifications of difficulty in existing machine and the evaluation of field performance of modified self propelled multipurpose power unit under laboratory and actual field condition. It also contains the cost economics. 5.1 Identification of problems in old unit and modification incorporated in new machine 1. In old machine the horizontal and vertical distance between seed metering device and furrow opener were 450 mm. The angle of inclination of seed tube from vertical was 45. This was not suitable for proper movement of seed, as it caused to excessive bending of seed tube. The disadvantage of this was clogging of seeds in seed tube and non uniform distribution of seeds. Plate 5.1 Arrangement of seed drill in (a) old unit (b) new unit 66

79 To eliminate this problem in seed drill furrow opener is provided directly under the seed box. The horizontal and vertical distance between the seed metering device and furrow opener are kept 40mm and 300mm respectively. This distance helped to reduce the bending of seed delivery tubes and clogging of seeds in seed tube. The angle of inclination of seed tube from vertical was 8. Due to which seed dropped uniformly in the field. The height of the seed box from the ground was 710mm in old machine. That is reduced to 610mm, this distance reduced the time of travel from metering unit to furrow and deposit seeds at a low terminal velocity, resulted into uniform falling of seeds. 2. Operating speed of existing machine was 3-4km/h, which was more for an operator to cope with machine. So operator was unable to operate it easily. To decrease the speed, driven pulley of 10cm diameter is replaced with 20cm diameter pulley and the diameter of traction wheel decreased from 750mm to 610mm. Now the theoretical speed of new machine reduced to 2.4km/h, which suit to an operator. Plate 5.2 Size and arrangement of driven pulley in (a) old unit (b) new unit 67

80 3. In old unit iron lugged wheels with 720mm diameter, 75.8mm Lugs spacing, 10 mm lug height & Lug angle 90 were provided. During sowing when machine was operated over clods caused instability of machine, due to larger diameter of wheel and small lug height, which reduced the vertical pressure per unit area during field operation. This machine was not found suitable for sowing. To eliminate this problem new traction wheel are designed and developed. Dimensions of new developed wheels were 640mm diameter and 83mm wide. The ground clearance of old unit was 280mm and due to reduction in diameter of wheels ground clearance also reduced up to 200mm. The stability of machine increased to a great extent as it is established fact that low ground clearance results in to high stability as distance between point of CG and ground reduces. 4. The field efficiency of old machine was 68 per cent that needed to be increased. This machine had high fuel consumption due to low field efficiency caused by more slippage, the average slippage value was 14 per cent at 13.6 per cent soil moisture content on dry basis. The seed metering device was driven by traction wheel that was the reason of uneven dropping of seed and seed missing. In developed machine pegged ground wheel were provided to reduce the slippage and power was transmitted to feeding shaft, this results into uniform dropping without seed missing. 5. The vibration in old unit was high that caused drudgery to the operator and required regular maintenance. In new developed machine isolator are provided in between engine and chassis to reduce the vibration shown in plate 4.2 and Depth cum direction control wheel in the old machine was made of iron that resulted in to higher vibration. In new machine iron depth and direction control iron wheel was replaced by solid rubber wheels as shown in plate

81 Plate 5.3 Depth cum direction control wheel in (a) old unit (b) new unit 7. The diameter of steering wheel was 190 mm this resulted into skidding rather than rolling while turning so steering was not easy. In developed machine diameter of depth and direction control wheel increased to 300mm that resulted into increased contact with the ground and easy rolling over the clods thus easy steering during turn. 8. In old machine the provision for attachment of various implement was limited. In newly developed machine various implement can be attached easily to the chassis with the help of rectangle box type hitching mechanism as shown in plate no Testing of machine Laboratory test Calibration of seed drill Calibration of seed drill was carried out in the laboratory to fix desired seed rate and to examine mechanical damage. The results of calibration are shown in Table 4.1. Seed rate (kg/ha) can be calculated 69

82 from obtaining total weight of seed collected in given number of revolution of ground wheel in the laboratory. Table 5.1: Seed rate at different rate setting Rate setting Observed discharge per furrow opener in 20 rev. Furrow Furrow Furrow (I) (II) (III) Total weight of seed collected in 20 rev. (gm) Seed rate (kg/ha) Fully Open /4th Half /4 th /5 th The seed rate for wheat crop varies from 80 kg/ha to 125 kg/ha. As per the calibration the semicircle indicator is provided on the feed shaft Effect of filling of seed hopper on seed rate The variation in dropping due to box filling at full, 3/4, 1/2 and 1/4 of rated capacity should not exceed 10 per cent. Table 5.2: Effect of filling of seed hopper on seed rate Desired seed Replication rate kg/ha Desired seed Level of seed in hopper discharge in 20 revolution Full 3/4 th 1/2 1/4 th (g) R R R Mean % Variation from the desired seed rate 70

83 The effect of the height of seed fill in the hopper on seed rate was studied. When the level was up to half, there was not much variation in required and observed seed rate. About 6 % variation was observed between ½ to ¼ th seed level in hopper. The reason may be the effect of static head of seed working on the seed metering device. The variation is within permissible limit as per ISI test code Uniformity of seed rate in different furrow openers Table 5.3: Inter row variation in seed rate Replication Weight of seed dropped from each furrow opener in 20 revolution (g) Total weight of seed dropped from all furrow opener (g) Furrow (i) Furrow (ii) Furrow (iii) R R R R R Mean SD CV % Table 4.3 indicates that the weight of samples collected from the three furrow openers were nearly same and there was very little deviation in seed rate among the samples i.e to 1.74 gm. On an average CV was about 0.91 %. Hence, it can be interperated that the machine metered the seed uniformly. 71

84 Mechanical damage of seed Table 5.4: Effect of metering mechanism on seed germination Sample Fresh seed germinated % Calibrated seed germination % I II III Average S.D Variety GW-273 In order to study the mechanical damage of seeds during calibration, the germination percentage of seeds was determined in the laboratory, which was found as 95.7% with 1.11 SD. The germination percentage shows that there was not much mechanical damage of seed during process of calibration of seed drill. As per the test code visible damage to the seed after drilling should not exceed 5%. In this study no visible damage was observed. Plate 5.4 View of the self propelled seed drill during field operation 72