Page 163 - The Tribology Handbook

Belt drives B1

PULLEY DESIGN

Table 1.2 Wedge, Vee and Vee-ribbed pulley Flat belt pulley crowning requirements
groove dimensions (mm)
Both pulleys should be crowned. If one pulley is flat the
crown of the other should be increased by 50%. A similar
increase should also be applied when the shafts are vertical
or when the centre distance is short.
7.- Further information IS0 100, DIN 11 1
d
I I

lP b,," hi," e
Z 8.5 2.08 7. 1 12 8
A 11 3.3 8.7 15 12.5
B 14 4.2 10.8 19 17 d
C n9 5.7 141.3 25.5 24
D 27 8.1 19.9 37 29
SPZ 8.5 2 9 12 8
§PA 11 2.8 11 15 10
SPB 14 3.5 141- 19 12.5
SPC 19 4.8 19 25.5 17
J -0.38* 2.18 2.34 I .8
L -0.74 5.39 4.70 3.3
M -1.47 1 1.05 9.40 6.4 Avoid flanges if possible. If used, the corner must be
undercut and b 3 1.2 W.
* For Vee-ribb,ed belts the pitch line lies outside the pulley, and
the groove tips and roots are rounded.

Table 1.3 Vee and wedge groove angles a
related to pitch diameter (mm)

.?Z0 34" 36" 38" 40"
Z
s PZ <80 >80 1 .o
A <I18 >118
§PA
B <I90 >I90 E
SPB E
C >315 >315 c
SPC 0.5
D <500 >500
J >20
L >76
M >I80
Users should not attempt to manufacture their own
synchronous pulleys. 0 200 400 600
d mm
Figure 1.14 The amount of crowning required for
flat belt pulleys
Surface finish

Standard recommendations for pulley drive face surface finish vary from 1.6 to 6.3 pm R, (R: from 6.3 to 25 pm). with 1.6
to 4 pm R, being most common.
Further information
IS0 254, IS0 R468, DIN 11 1, DIN 4768
and manufacturers' catalogues
B1.9