A plate clutch has a single pair of mating friction surfaces 300 mm OD by 225 mm ID. The mean value of the coefficient of friction is 0.25, and the actuating force is 5 kN. (a) Find the maximum pressure and the torque capacity using the uniform-wear model. (b) Find the maximum pressure and the torque capacity using the uniform-pressure model. 16 – 16 16
A hydraulically operated multidisk plate clutch has an effective disk outer diameter of 6.5 in and an inner diameter of 4 in. The coefficient of friction is 0.24, and the limiting pressure is 120 psi. There are six planes of sliding present. (a) Using the uniform wear model, estimate the axial force F force F and the torque T . (b) Let the inner diameter of the friction pairs d be a variable 16 – 17 17
(c) What does the table show? 16 – 19 19
A cone clutch has D has D
=
330 mm, d
=
306 mm, a cone length of 60 mm, and a
coefficient of friction of 0.26. A torque of 200 N · m is to be transmitted. For this requirement, estimate the actuating actuati ng force and pressure by both models. 16 – 1
The figure shows an internal rim-type brake having an inside rim diameter of 12 in and
a dimension R dimension R
=
5 in. The shoes have a face width of 1½ in and are both actuated by a force
of 500 lbf. The mean coefficient of friction is 0.28. (a) Find the maximum pressure and indicate the shoe on which it occurs. (b) Estimate the braking torque effected by each shoe, and find the total braking torque. (c) Estimate the resulting hinge-pin reactions. For the brake in Prob. 16 – 1, 1, consider the pin and actuator locations to be the same. However, instead of 120°, let the friction surface of the brake shoes be 90° and centrally located. Find the maximum pressure and the total braking torque. 16 – 2
In the figure for Prob. 16 – 1, 1, the inside rim diameter is 280 mm and the dimension R is 90 mm. The shoes have a face width of 30 mm. Find the braking torque and the maximum pressure for each shoe if the actuating force is 1000 N, the drum rotation rotation is counterclockwise, 16 – 3
and f and f
=
0.30
The block-type hand brake shown in the figure has a face width of 30 mm and a mean coefficient of friction of 0.25. For an estimated actuating ac tuating force of 400 N, find the maximum pressure on the shoe and find the braking torque. 16 – 5
The brake shown in the figure has a coefficient of friction of 0.30, a face width of 2 in, and a limiting shoe lining pressure of 150 psi. Find the limiti ng actuating force F force F and the torque capacity . 16 – 13 13 The brake shown in the figure has a coefficient of friction of 0.30 and is to operate using a maximum force F force F of 400 N. If the band width is 50 mm, find the band tensions and the braking torque. 16 – 7
The figure depicts a band brake whose drum rotates counterclockwise at 200 rev/min. The drum diameter is 16 in and the band lining 3 in wide. The coefficient of friction is 0.20. The maximum lining interface pressure is 70 psi. (a) Find the brake torque, necessary force P , and steady-state power. (b) Complete the free-body diagram of the drum. Find the bearing radial load that a pair of straddle-mounted bearings would have to carry. (c) What is the lining pressure p at both ends of the contact arc? 16 – 14
