Page 155 - The Tribology Handbook

Belt drives B1

BELT DRIVE DESIGN

(c) Serpentine layout to drive more than
4al Basic &shaft drive one shaft or reverse direction
of rotation

d in rnm, n in rw/min
Belt speed S = r;rd/19100 mls

(b) Idler added to increase arc of (d/ Out-of-plane layout
contact or contro,t belt vibration

Figure 1.1 Some belt drive layouts

Belt selection, pulley size and shaft load calculation procedures for drives with two shafts

Specify rated power and pulley rev/min A typical two shaft belt arrangement is as in Figure
requirements 1.1 (a).
1

Calculate design power from rated power X service Some guides recommend selection on basis of rated
j factors power. This can result in smaller diameter pulleys and
r lighter section belts but a wider drive.

Select belt section from design power rating charts, Pulley diameter and belt section selection is a compro-
on basis of design power and rev/min of fastest mise between smaller diameter pulleys for compactness,
pulley. Choose pulley diameters greater than mini- but limited by overloading of the tension members in the
mum recommended. belts, and larger pulleys giving lower bearing ioads but
L tables ,I
requiring more space. Larger pulley diameters may always
be chosen, subject only to allowable belt speeds, and the
designer is advised to check the effect of varying diameter
Select belt width (or number of belts, for Vee belts)
by trial calculations.
capacity
belt
from
tensions and shaft loading to limit 1
[=elt Belt width and tension selection are closely related and
slip (or to ensure good meshing of synchronous depend on arc of contact as well as power and rev/min.
belts)

61.1