Engineering guidelines alpine conveyors

Transcription

1 Engineering guidelines alpine conveyors What is an alpine conveyor INTRO EG-C EG-W EG-A EG-S APPL In-line or by-pass If the alpine is used as an accumulator there are two ways of using the alpine: The alpine conveyor differs from the common FlexLink conveyor in the way that the alpine is built in a compact spiral configuration. The common use of the alpine conveyor is as an accumulation/buffer zone between machines. Or, as an in-process step, e.g. cooling or drying, or simply for CONV elevation/loweration. PAL GR In-line An in-line accumulator is always included in the transport path. By-pass A by-pass accumulator which you connect to the transport path when temporary accumulation is necessary. CS C-SX In-line By-pass C-SY EM XT XC-XF FST What is an alpine conveyor 35

2 Configurations A selection of typical alpine conveyor configurations are shown below. Elevator/lowerators Elevator/lowerator (1) Entry and exit at different levels Minimum floor space In-line accumulator Suitable for end drive unit with return chain Elevator/lowerator (2) Entry and exit at different levels Minimum floor space In-line accumulator Suitable for catenary drive unit and/or horizontal bend drive unit Chain on top side only 1 Serpentines Single serpentine (3) Entry and exit at same level In-line or off-line accumulator Suitable for catenary drive unit and/or horizontal wheel bend unit Chain on top side only Compact in height 3 Double serpentine (4) 2 4 Entry and exit at same level In-line or off-line accumulator Suitable for catenary drive unit and/or horizontal wheel bend unit Chain on top side only Minimum floor space Extremely compact Benefits of using alpine conveyors A conveyor with accumulation capability will reduce the effects of machinery failures. It will accumulate the products from one machine while the next machine in the line is being repaired or adjusted. The accumulation zone is a simple yet efficient way of connecting production lines which operate at varying speeds. The accumulation zone also provides the possibility to continuously have bottleneck machines running. Many manufacturing processes require cooling times or drying times, or other in-process-steps, before further processing can take place. An alpine conveyor is a very compact way of obtaining a long cooling/drying distance. If level change is required in a conveyor with accumulation capability, the alpine conveyor will be the natural solution. At an inclination of 5 the standard plain chain will provide positive transport of most products up or down the conveyor. For inclinations over 5 FlexLink offers alternative chain types for non-accumulating applications. 36 Configurations

3 Benefits of using alpine conveyors (continued) General considerations Feature Advantage Benefit Compact components and layout Small footprint Efficient space utilization Standard components Functions of alpines Stock standard Quick and simple engineering and assembly Easily redesigned Different chain types available Suitable for many different types of products Flexibility Flexible guide rail system Can handle many different types of products Flexibility Proven design Long life Reduced maintenance High up-time Cost efficiency Short lead time Cost efficient long term solution Flexibility Smooth running Product stability during transportation High yield Experienced supplier Confidence in design, many applications as references Superior service and support Feature Advantage Benefit Buffering Ability to produce during temporary machine Cost efficient manufacturing stops Bottleneck machines can produce continuously Inline or bypass buffers Flexibility to use alpine only when necessary Optimized lead time Easy to provide time delay with alpine buffer No need for extra devices Low maintenance, cost savings Low friction accumulation No product damage Minimal maintenance High yield Cost efficiency Accumulation with FIFO Products kept in sequence Simple control Cost efficiency Open conveyor/storage structure suitable for process steps Good ventilation Operator access Short process time (cooling) Efficient manufacturing Combined elevation and accumulation Continuous process on standard conveyor High capacity Cost and space efficiency Expandable within same footprint No changes to floor layout Cost and space efficiency INTRO EG-C EG-W EG-A EG-S APPL CONV PAL GR Alpine conveyor limitations Alpine conveyors are subject to some limitations to be considered: Maximum weight In a horizontal conveyor, the maximum weight of the individual products conveyed is limited mainly by the desire to keep wear of the slide rails at an acceptable level. The total maximum weight is mainly limited by the drive unit capacity and by the tensile strength of the chain. The total product weight on the alpine conveyor should not exceed 500 kg. Maximum length and number of levels Normally alpine conveyors are built with max 10 to 12 levels and a chain length of max 120 m, depending on drive unit configuration. Product dimensions The maximum width of the goods conveyed depends on the shape of the goods and on the location of the centre of gravity. Alpines are more suitable for circular products as rectangular products may get stacked when accumulated in wheel bends. The track width (distance between guide rails) should be exceed the product diameter by at least 40%. Maximum speed The maximum conveyor speed depends on the total load and on the drive unit capacity. It s important to have in mind that higher speed, produces more wear on the chain. This requires more power and causes a higher noise level. Speed over 30 m/min is not recommended. CS C-SX Environmental factors Sometimes there are environmental factors that have to be taken into consideration when designing the conveyor. C-SY Such factors are for example: the temperature of the product, metal chips or debris from the production stage before the conveyor transport, chemical fluids or electrostatic discharge. Use another solution if the environment EM is extremely dusty. Hygienic demands XT For some applications there are hygienic demands that have to be taken into consideration when designing a conveyor system, e.g. how to clean the conveyor. XC-XF General Never use two driven sprocket wheels together. FST When a wheel bend drive unit is used, friction wheels in combination with the drive wheel minimize stick-slip because the chain is driven at more than one point. Benefits of using alpine conveyors 37

4 Components for alpine conveyors Chain See page 70. Plain chain Friction top chain Steel top chain The common chain with plain surface. Can be used up to an inclination of 5. Suitable for accumulation. The friction top chain is especially suitable for track configurations with inclines up to 30, and where a standard cleated chain is unsuitable. A friction insert moulded into the link increases the friction between goods and chain. No accumulation is possible. The steel top chain should be used if the products conveyed are causing excessive wear to the standard chain. It is intended primarily for the mechanical manufacturing industry, for transport of castings or machined items with sharp edges. Based on the standard link, the steel top chain has the same technical properties as the standard chain. Drive units for alpine conveyors The FlexLink range of drive units suitable for alpine conveyors are: End drive units. See page 79. Horizontal bend drive units with common shaft A common shaft connects the different levels in the alpine and can drive each of them, with a sprocket wheel in combination with friction wheels. The friction wheel has to run slightly faster than the driven sprocket wheel. This reduces stick-slip, since the chain is driven at more than one point. Catenary drive units for endless conveyors without a return chain. See page 83. Horizontal bend drive units for endless conveyors without a return chain. See page 84. The horizontal bend drive unit is especially suitable for endless conveyors without a return chain. There will be no free chain take-up in a conveyor with horizontal bend drive unit. The chain must be joined in a wheel bend or a connecting section X_CC 160. The chain must be stretched (remove one or several links) after some days of running, as a new chain always will have some prolongation. 38 Components for alpine conveyors

5 Components for alpine conveyors (continued) Special components The drive unit with a common shaft must be built from a standard wheel bend with the following special components added: XLEV 150F Driven wheel, friction drive Driven wheel, sprocket drive XLEX 25 LH Long drive shaft XLEN 150 Non-driven wheel XLBE 180R150 Outer bend 180 XLEY 180 Shaft support Selecting the right drive unit In alpine applications there is sometimes an advantage to use two drive units in one conveyor for the following reasons Reduced stick-slip effect due to spread out load Reduced chain tension even if total load is increased Less chain needed Less free space at the end of the conveyor needed Endless conveyors possible Longer conveyors possible Guidelines when selecting drive unit configuration The catenary drive unit is stronger than the horizontal bend drive unit and gives less problems with chain tension and prolonged chain as there is a chain slack in the INTRO unit. Small products may however, stop at the transfer plate. The next product in line will normally push them over. EG-C A catenary drive unit can sometimes be placed at a section where no products pass to avoid product getting stuck at the transfer plate. When using an end/catenary drive unit and a friction EG-W wheel bend you can allow heavy load. When using an end/catenary drive unit you can allow medium/light load on the conveyor and EG-A heavy/medium if the conveyor is only elevating or lowering. Chain tension is considerably lower in a lowering alpine compared to an elevating alpine. EG-S When using a wheel bend drive unit with one sprocket- and friction wheel you can allow medium load. APPL When using a standard wheel bend drive unit with one drive level you can only allow light loads if the conveyor is an elevating alpine. CONV The stick-slip effect often appears in applications using solvents like white spirits etc. Silicon-based lubricant (LDSS 450) sprayed on the slide rails and the chain at the start up can reduce the stick-slip effect. Carefully PAL mounted slide rails without sharp joints etc. will also help to prevent this type of problems. GR Light load Medium load High load Type 1 elevator End drive unit End drive unit End drive and wheel bend drive with common shaft and friction wheels Type 1 lowerator End drive unit End drive unit End drive unit Type 2 elevator Wheel bend drive unit with common shaft and top sprocket wheel Type 2 lowerator Standard wheel bend drive unit Type 1 etc. refer to figures on page 36. drive unit with common shaft and friction wheels Standard wheel bend drive unit Type 3 Catenary drive unit drive with common shaft and friction wheels / non driven wheels Type 4 Catenary drive unit drive with common shaft and friction wheels drive unit with common shaft and friction wheels Standard wheel bend drive unit drive with common shaft and friction wheels / non driven wheels drive with common shaft and top sprocket CS C-SX C-SY EM XT XC-XF FST Components for alpine conveyors 39

6 Components for alpine conveyors (continued) Idler units See page 87. The purpose of the idler unit is to change the direction of the chain with a minimum amount of friction. The 90 idler bend unit is used for alpines without return chain. In some alpine configurations the standard idler end is used. Wheel bends See page 88. The wheel bend used for alpines is the 180 bend. Wheel bends cannot be used when transporting wide* products in systems with accumulation of products that can block or fall off the conveyor in the bend. Cylindrical products are preferable. *Width must not exceed 2 R 40, where R is radius of wheel bend. Vertical bends 5 See page vertical bends are used to create elevation between the levels in the alpine conveyor. For one full turn four vertical bends are needed. Vertical bends increase the tension in the chain and cause higher stress on the slide rail. A straight beam section with a minimum length of 160 mm should normally be used between the vertical bend and the wheel bend. If the conveyor only uses vertical bends with a max inclination of 5, plain chain can be used. Support system components The normal way of supporting an alpine conveyor is to use one vertical support beam to support each end. The conveyor is attached to the support beam by means of beam support brackets Type C (XLCU 73/103). See page 140. If the distance between the end supports exceed 3 m it is recommended to use a centre support as well. For maximum rigidity, horizontal beams should be used to connect the vertical support beams. 40 Components for alpine conveyors