CLUTCH
1. A cone clutch has an angle of 10° and coefficient of friction of 0.42. Find the axial force required if
the capacity of the clutch is 7 kw at 500 rpm. The mean diameter of the active conical sections is 300
mm.
A. 234.45 N
B. 186.45 N
C. 368.49 N
D. 492.45 N
2. How much torque can a cone clutch transmit if the angle of the conical elements is 10 degrees the
mean diameter of the conical clutch sections 200 mm and an axial force of 550 N is applied?
Assume the coefficient of friction is 0.45.
A. 123.23 N-m
B. 34.56 N-m
C. 142.53 N-m
D. 234. 56 N-m
3. If the inertia is 90 lb-ft 2 and the speed of the driven shaft is to be increased from 0 to 2500 rpm in 5
seconds, shaft material is of SAE 4140 with yield strength of 110,000 lb/in 2, find the clutch starting
torque in ft-lb.
A. 159
B. 128
C. 146
D. 191
4. Find the frictional radius for a disc clutch. The disc clutch has an outside diameter of 10 in and an
inside diameter of 6 in.
A. 4.54 in
B. 4.08 in
C. 5.34 in
D. 8.44 in
5. In a clutch the outside diameter is 8 in and the inside diameter is 4 in. An axial force of 400 lb is
used to hold the two parts together. If the coefficient of friction of the mating materials is 0.4, how
much torque can the clutch handle?
A. 123.45 in-lb
B. 497.80 in-lb
C. 213.34 in-lb
D. 563.23 in-lb
6. A disc clutch has 6 pairs of contracting friction surfaces. The frictional radius is 2 in and the
coefficient of friction is 0.3. An axial force of 100 lbs acts on the clutch. The shaft speed is 400 rpm.
How much horsepower can the clutch transmit?
A. 2.28 hp
B. 1.23 hp
C. 3.23 hp
D. 4.23 hp
7. A cone clutch has cone elements at an angle of 10°. The clutch transmits 20 hp at a speed of 100
rpm. The mean diameter of the conical friction sections is 16 in and the coefficient of friction is 0.3.
Find the axial force needed to engage the clutch.
A. 246.37 lbs
B. 212.56 lbs
C. 234.56 lbs
D. 346.78 lbs
8. In a band clutch, the ratio of the pull on the tight side of the band to that of the slack side is 4:1. The
band contacts the drum for 250 degrees. What is the coefficient of friction?
A. 0.123
B. 0.318
C. 0.234
D. 0.462
9. A band clutch has an angle of contact of 270° on a 15 in diameter drum. The rotational speed of the
drum is 250 rpm and the clutch transmits 8 hp. The band is 1/16 in thick and has a design stress of
5000 psi. How wide should the band be? Assume a coefficient of friction of 0.40.
A. 2.123 in
B. 3.234 in
C. 1.014 in
D. 4.354 in
10. The angle of contact of a band clutch is 250 degrees. The cross section of the band is 1/16 in x 1.5
in. The design stress for the band material is 8,000 psi. If the drum is 16 inches in diameter and
rotates at 350 rpm, what is the horsepower capacity of the clutch? The coefficient of friction is 0.4.
A. 20.34 hp
B. 15.23 hp
C. 22.34 hp
D. 27.50 hp
11. Find the power capacity under uniform wear of a cone clutch with mean diameter of 250 mm if the
conical elements are inclined 8 degrees and the axial force is 450 N. The rotational speed of the
driver is 200 rpm and the coefficient of friction is 0.20.
A. 1.683 kw
B. 2.340 kw
C. 1.287 kw
D. 3.234 kw
12. Determine the power capacity of a cone clutch under uniform pressure and assuming the following
conditions: major diameter = 250 mm; minor diameter = 200 mm; length of conical elements in
contact = 125 mm; rotational speed = 870 rpm; coefficient of friction = 0.30; and allowable pressure
= 70,000 N/m2?
A. 12.34 kw
B. 19.09 kw
C. 14.56 kw
D. 23.45 kw
13. Find the power capacity under uniform wear of a cone clutch with the following specification
speed = 870 rpm; length of conical elements in contact = 125 mm; major diameter = 250 mm;
minor diameter = 200 mm; coefficient of friction = 0.30; and axial operating force = 500 N.
A. 7.69 kw
B. 5.23 kw
C. 9.34 kw
D. 3.23 kw
14. Assuming uniform wear, find the power capacity of a single disc clutch with an outside and inside
diameter of 200 mm and 100 mm respectively, rotational speed of 1160 rpm, a coefficient of
friction of 0.35 and an axial operating force of 800 Newtons.
A. 4.23 kw
B. 2.55 kw
C. 6.32 kw
D. 8.23 kw
