Page 195 - The Tribology Handbook

clutches €37

Choice of lining area

The total lining area required, A, may be determined
from: A = H/&, where H is the power to be dissipated,
and K! is the duty rating of the lining material.
The power to be dissipated, H, may be determined from
the energy to be imparted to the driven component in the
time of enga~e~en~ or, if the transmitted torque is consi-
dered to be constant, from the transmitted torque and the DIA. OF CONE1 = AXIAL THRUST
mean relative speed during engagement.
When the cotal area is known, the detail dimensions of
the linings can be readily calculated for plate or drum rn-i
clutches. For cone clutches, the developed shape of the
lining is shown in Figure 7.14 and can he calculated from

= 360" sin 80

P
A = 2R sin-
2
P
B = R - (R -- 6) COS -
2

The required service life and the wear rate and allow-
able wear of the lining are also important, particularly in
lining
d~~er~~n~ng thickness.
the
Typical lining arrangements, contact pressures and
suggested duly ratings for lining materials are given in Figure 7.14 Development of liner for cone clutch
Table 7.2.
Table 7.2 Guide to design and material selection for various types of clutch

Sz&nergisation Suitable dug
Gpe %friction and sensjiiuity Angle of lining Pressure range Material Severity of the rating of lining, Coefjcient of
device aTC MN/~~ application x; b,imm? friction
Two ieading High 100" per shoe 0.14-1.0 Moulded or High 0.24 0.30
shoe drum woven
clutch Medium 0.58 0.35
Low 1.75 0.40

Band clutch Very high 270" 0.07-0.7 Rigid mouided High 0.24 0.25
operating segments,
with drum flexible Medium 0.58 0.30
rotarion moulded or
woven Low 1.15 0.35
Plate clutch None 360" 0.07-0.4 Rigid woven or High 0.12 0.30
operating moulded
under dry Medium 0.24 0.35
conditions
Low 0.58 0.40
Plate clutch None 360" 0.28-2.8 Rigid woven or High 0.15 0.06
operating moulded
under oil Medium 0.29 0.08
immersed
conditions Low 0.70 0.10
Cone clutch None 360" 0.05-0.2 Moulded or High 0.24 0.25
woven
Medium 0.35 0.30
Low 0.80 0.35

B7.5