SHEAVE SOLUTIONS DCL ENGINEERING GROUP DCL ENGINEERING GROUP

Transcription

1 SHEAVE SOLUTIONS DCL ENGINEERING GROUP 1

2 Introduction Sheave s Problems. Common causes of sheave problems. Solutions. C 2

3 Sheave s Problems Wear Rifling Failure. 3

4 Sheave Wear Problems 4

5 Sheave Rifling Problems 5

6 Sheave Failure Problems 6

7 Common Causes Incorrect site installation. Lack of rope lubrication. Incorrect rope tensions. Incorrect ropes. Soft sheaves. Incorrect grooving. Bearing failures. 7

8 Incorrect site installation Includes problems caused by:- Incorrect alignments. Incorrect tensions. 8

9 A FORCE FORCE B Alignment Misalignment is caused by: 1. Incorrect vertical angularity. (twist) 2. Incorrect horizontal angularity. 3. Incorrect axial offset. 9

10 Tensions Correct groove detail. Tensioning. Re-tensioning. 10

11 Incorrect Grooving: Incorrect under cut. Incorrect pressure angle. ( deg.) Are the main causes of:- Grabbing 1.Run on. 2.Run off. Slipping 1.Run on. 2.Run off. 11

12 Groove detail 12

13 Bearings failures Due to the following: Shock pulse phase. Vibration phase. 13

14 Bearings shock pulse phase When two pieces of metal in motion contact, two interrelated yet distinct processes occur. On initial impact, a shock or pressure wave develops and quickly propagates through the metal. This shock pulse is in the ultrasonic frequency band and typically occurs around a centre frequency of 36 khz. Shock pulse amplitude is related to impact velocity. As the signal expands from its point of origin, it is dissipated by carbon and other imperfections in the metal. 14

15 Bearings vibration phase As the impact continues to develop, the metal surfaces are compressed and deflected. As the objects recoil, the metal components then rebound and continue to flex for a number of cycles until the energy is dissipated. This second collision phase is vibration, and its frequency depends on the shape, mass, stiffness and dampening of the metal. The shock pulse method filters out this collision phase since vibration magnitude is structure and material dependent. 15

16 Bearings conditions Shock pulse phase has two readings: Carpet value. Max value. Here s how each reading is derived: 16

17 Solutions Address all previous points. Thorough inspection and study of problem. Seek professional help on: Installation procedures. Grooving & re-grooving designs. Bearing Selection and lubrication. Surface hardening. TRACTkote (HVOF coating). No guessing. 17

18 TRACTkote Solution Coating System for the Elevator Industry The increasing demand for improved traction quality. Protect against the wear created from cast iron sheaves and higher MPa ropes. Surfaces coatings that minimize wear characteristics for the sheaves. TRACTkote will extend the service life of the sheave. 18

19 Demands for Higher Wear Resistance In the Elevator Industry, there are greater demands for higher wear resistance of traction in sheaves. As traditional OEM sheaves fail to meet the optimized performance, due to rapid wear and rifling in grooves. The basic factor governing wear is the types of metal to metal wear. 19

20 Conclusion :-: All these factors in this presentation accentuate the wear phenomena, and tend to lead towards replacement sheaves. DCL are pleased to supply replacement sheaves, but:- By thermal coating a sheave with TRACTkote. The sheave life will be greatly extended. The coating has also proven to enhance the traction on the sheaves. 20

21 DCL Engineering Group offer:- 30 yrs of Mechanical Lift Experience Consulting and Engineering Solutions on Mechanical problems. Designers and Manufacturers of Traction and Diverter sheaves. Most diversified workshop for break downs and repairs. 21