1.It is proposed to drive an industrial crushing machine, designed to crush out-of-tolerance scrap ceramic bearing liners, with an in-stock 2-hp, 1200-rpm electric motor coupled to an appropriate speed reducer. The crushing machine input shaft is to rotate at 60 rpm. A worm gear speed reducer is being considered to couple the motor to the crushing machine. A preliminary sketch of the wormset to be used in the speed reducer proposes a double-start right-hand worm with axial pitch of 0.625 inch, a normal pressure angle of 14 , and a center distance of 5.00 inches. The proposed material for the worm is steel with a minimum surface hardness of Rockwell C 58. The proposed gear material is forged bronze. Calculate or determine the following, assuming the friction coefficient between worm and gear to be 0.09, and that the motor is operating steadily at full rated power:

a. Number of teeth on the gear.

b. Lead angle of the worm.

c. Sliding velocity between worm and gear.

d. Tangential force on the worm 1 2° 700 Chapter 15 / Gears and Systems of Gears.

e. Axial force on the worm.

f. Radial force on the worm.

g. Tangential force on the gear.

h. Axial force on the gear.

i. Radial force on the gear .

j. Power delivered to the crushing machine input shaft .

k. Whether the wormset is self-locking .