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1. SELECTION OF V- BELTS
- Dr. M. Satthiyaraju

2. Contents
• Selection of V- belts
• Problems

3. DESIGN OF V - BELTS

4. DESIGN OF V - BELTS

5. DESIGN OF V - BELTS

6. DESIGN OF V - BELTS

7. DESIGN OF V - BELTS

8. DESIGN OF V - BELTS

9. DESIGN OF V - BELTS

10. DESIGN OF V - BELTS

11. DESIGN OF V - BELTS

12. DESIGN OF V - BELTS

13. DESIGN OF V - BELTS

14. DESIGN OF V - BELTS

15. Example Problem
A 30 kW, 1440 rpm, motor is to drive a compressor by means of
V-belts. The diameter of pulleys are 220 mm and 750 mm; The
centre distance between the compressor and motor is 1440 mm.
Design a suitable drive.

16. DESIGN OF V - BELTS
Given data:
P = 30 x 103 Watts
Driver speed N1 = 1440 rpm;
Driver pulley dia. d = 220 mm
Driven pulley dia. D = 750 mm;
Centre distance between the compressor and motor C = 1440 mm = 1.44 m

17. DESIGN OF V - BELTS
Step 1
From PSG data book, Pg. No. 7.58.
Select Cross-section of the belt.
Select either (C), (D) or (E) Select (C) type Belt
(Since minimum pulley pitch dia = 220 mm given)
Load of drive P = 22 kW to 150 kW
Min. pulley pitch diameter = 200 mm
Nominal top width W = 22 mm
Nominal thickness t = 14 mm; Weight/meter = 0.343 kgf/m length

18. DESIGN OF V - BELTS
C.S. area of belt = ½ (W+b) T
= ½ x [22 x 11.81] x 14 = 236.67 mm2
Step 2
Nominal pitch length L

19. DESIGN OF V - BELTS
Take the nearest nominal pitch length from PSG data book.
Refer PSG data book P.No. 7.60,
Take standard nominal pitch length = 4450 mm (Nearest)
The corresponding nominal inside length = 4394 mm.
The Designation of V-belt C 4394 - 1S2494
Step 3 Calculation of Design Power P in kW
Refer PSG Data book Page No. 7.62
[S = v = velocity]

20. DESIGN OF V - BELTS
If dp - pitch dia. of smaller pulley = 220 mm
de =Equivalent pitch diameter = dp x Fb = 220 x 1.14 = 250.8 m.
D/d = 750/220 = 3.4
P = 8.4312 kW

21. DESIGN OF V - BELTS

22. DESIGN OF V - BELTS

23. DESIGN OF V - BELTS

24. DESIGN OF V - BELTS
New centre distance C = 1438.75 mm

25. DESIGN OF V - BELTS

26. DESIGN OF V - BELTS

27. DESIGN OF V - BELTS

28. DESIGN OF V - BELTS
To Find Stress fb
T = (T1+T2) = fb x area of belt
681.3274 + 94.36 = fb x 236.66
Permissible stress in the belt material;
fb = 3.28 N/mm2

29. THANK YOU