West Virginia University
Department of Mechanical, Materials, and Aerospace Engineering
MAE 454 – Machine Design & Manufacturing
Homework Assignment #6 Solu4on
Semester: Fall 2025
Instructor: Dr. Shuo Xu
Due on Friday, Oct 24th, 2025. Uploading to Ecampus before the lecture.
Instructions:
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HW6.1
Show all steps clearly; partial credit may be awarded.
Clearly state assumptions.
Submit neatly written or typed solutions.
Collaboration is encouraged, but submitted work in paper must be your own.
HW6.2
A gearbox is to be designed with a compound reverted gear train that transmits 25 horsepower
with an input speed of 2500 rev/min. The output should deliver the power at a rotational speed in
the range of 280 to 300 rev/min. Spur gears with 20° pressure angle are to be used. Determine
suitable numbers of teeth for each gear, to minimize the gearbox size while providing an output
speed within the specified range. Be sure to avoid an interference problem in the teeth.
HW6.3
A compound reverted gear train is to be designed as a speed increaser to provide a total increase
of speed of exactly 45 to 1. With a 20° pressure angle, specify appropriate numbers of teeth to
minimize the gearbox size while avoiding the interference problem in the teeth. Assume all gears
will have the same diametral pitch.
HW6.4
HW6.5
HW6.6