M7 Flashcards
Which type of key is used for mounting
shifting gears in gear boxes?
A. Splines B. Saddle
B. Square D. Flat spline
A. Splines
A solid steel machine shaft with a safe
shearing stress of 7000 psi transmits a torque of 10,500 in-lb. What is the length of the square key if it 1.5 times the diameter of the shaft?
A. 2.0 in. C. 1.75 in
B. 2.5 in D. 3.0 in
D. 3.0 in
A rectangular key was used in a pulley
connected to a line-shaft with a power of 7.46 kW at a speed of 1200 rpm. If the shearing stress of the shaft and key are 30 MPa and 240 MPa, respectively. What is the diameter of
the shaft?
A. 11.6 mm C. 21.6 mm
B. 15.6 mm D. 32.2 mm
C. 21.6 mm
A 76.2 mm (3 in) diameter shafting of
SAE 1040 grade, cold rolled, having a yield point of 50 ksi and with a 3/4″ × 3/4″ × 5″ keyway. Compute the minimum yield point in the key in order to transmit the torque of the shaft.
The factor of safety is 2 and 𝑆𝑦𝑠 = 0.5𝑆𝑦.
A. 39.12 ksi C. 47.12 ksi
B. 42.13 ksi D. 27.9ksi
C. 47.12 ksi
2005) A type of key which is chamfered at the
bottom.
A. Roll pin C. Woodruff
B. Barth key D. Gib-head taper key
B. Barth key
In the assembly of pulley, key, and shaft:
A. Key is made the strongest
B. Key is made the weakest
C. Pulley is made the weakest
D. The three are made for equal length
B. Key is made the weakest
A taper pin with a minimum diameter of
0.244 in will be applied to fix a lever to a 2-inch shaft. if the allowable design stress is 15 ksi. Calculate the maximum transmitted torque by applying a factor of safety of 2.
A. 600 C. 780
B. 700 D. 800
B. 700
A 15/16″ wide key has a depth of 5/8″.
It is 12″ long and is to be used on a 200 hp, 1160 rpm, squirrel-cage induction motor. The shaft diameter is 3-7/8″. The maximum running torque is twice the full load torque. Compute the maximum torque.
A. 17,330 ft-lb C. 37,210 ft-lb
B. 21,733 ft-lb D. 73,211 ft-lb
B. 21,733 ft-lb
From the above problem, compute the
tangential force 𝐹 𝑛 in lb.
A. 11,217 C. 27,111
B. 57,211 D. 72,211
A. 11,217
From the above problem, determine the
maximum shearing stress on the key.
A. 779 psi C. 997 psi
B. 879 psi D. 697 psi.
C. 997 psi
From the above problem, determine the
compressive stress in the key.
A. 5,990 psi C. 7,290 psi
B. 2,990 psi D. 9,990 psi
B. 2,990 psi
Drift is used by lathe operator to remove
the taper shank from the taper hole. It is also called ______.
A. Tong C. Chuck taper
B. Morse taper D. Taper key
D. Taper key
Determine the key length of a square
key for gear driven shaft to withstand a torque of 2891.4 N-m. The shaft diameter is 66 mm with design stress of 72.6 MPa in shear, the thickness and the width of key is 5/8-in.
A. 3.12 cm C. 4.22 cm
B. 3.42 cm D. 7.70 cm
D. 7.70 cm
Axially located rectangular groove in a
hub and shaft.
A. Keyseat C. Flute
B. Cotter pin set D. setscrew point
A. Keyseat
A keyed gears deliver a torque of 912.4
N-m thru its shaft of 63.5 mm outside diameter. If the key has a thickness of 15.875 mm and width of 11.125 mm, find the length of the key. Assume the permissible stress values of 61.2 MPa for shear and tension at 99.8 MPa.
A. 47.42 mm C. 42.22 mm
B. 39.72 mm D. 46.92 mm
C. 42.22 mm
