1. Preliminary design calculations have suggested that design objectives may be met by a straight spur gearset using standard full-depth 2 -pitch involute gear teeth, and a 21-tooth pinion meshing with a 28-tooth gear. A 25 pressure angle has been selected for this application, and the gear teeth are to be shaved to AGMA quality number . Find the following:

a. Addendum.

b. Dedendum.

c. Clearance.

d. Circular pitch.

e. Circular tooth thickness.

f. Base pitch .

g. Length of action.

h. Profile contact ratio.

i. Module 15-27. Repeat problem 15-26, except for a 20 pressure angle.

1. For each of the design scenarios presented, suggest one or two types of gears that might make good candidates for further investigation in terms of satisfying the primary design requirements.

a. In the design of a new-concept agricultural hay-conditioner, it is necessary to transmit power from one rotating parallel shaft to another. The input shaft is to rotate at a speed of 1200 rpm and the desired output shaft speed is 350 rpm. Low cost is an important factor. What types(s) of gearing would you recommend? State your reasons.

b. In the design of a special speed reducer for a laboratory test stand, it is necessary to transmit power from one rotating shaft to another. The centerlines of the two shafts intersect. The driver shaft speed is 3600 rpm and the desired speed of the output shaft is 1200 rpm. Quiet operation is an important factor. What types(s) of gearing would you recommend? State your reasons.

c. It is desired to use a 1-hp, 1725-rpm electric motor to drive a conveyer input shaft at a speed of approximately 30 rpm. To give a compact geometry, the motor drive shaft is to be oriented at 90 degrees to the conveyor input shaft. The shaft centerline may either intersect or not, depending on designer judgment. What type(s) of gearing would you recommend? State your reasons.