This work offers a comprehensive solution to course questions that are common in Mechanical Engineering undergraduate course. Up to this end, the questions had remained unsatisfactorily answered.
The set of 12-questions are seemingly used by professors as the test in the Design of Machine Components course unit. They have appeared year after year, mostly in the exact form presented herein, or in a tweaked variation. This work provides a step-by-step solution, with explanations, equations, and diagrams to help the student understand the entire context of each question. All calculations have been confirmed and are presented in SI units.
That sketches are critical in such assignments, and because they are required as well, the work has included hand-drawn diagrams and/or cited-images which will help the student provide a pictorial accompaniment in each solution, as required. Students will find this solution helpful even in handling other questions in gears and gear drives.
1. With the help of the enclosed PDF, elaborate in about 15-20 lines, the ‘mechanical’ reasons for catastrophic structural failure of Aloha Flight 243.
2. You are to select a suitable drive for power transmission for an industrial equipment. As a design engineer, you select a belt-drive system over gear drive or a chain and sprocket drive. Justify your selection of a belt drive. (Parameters: Cost, Speed, Maintenance, Flexibility, Distance between driving and driven shaft, Noise and Vibration).
3. What is the RPM and rotational direction (Clockwise/Anticlockwise) of Gear D?
4. What is the RPM of Gear C?
5. Explain, with sketches, a speed reduction of 4.5:1 using (a) Simple gear train and (b) Compound gear train. Number of teeth on driving pinion in each gear train = 20 (Assume number of teeth for other gears).
6. Explain, with the help of a sketch, the Basic Law of Gearing.
7. Explain, with help of a sketch, the following gear tooth nomenclature: Addendum, Dedundum, Face width, Tooth thickness, Pitch Circle.
8. Explain, with a sketch, the working of Worm and Worm gears. In what kind of applications are worm gears preferred over traditional gear trains?
9. Why do you think a 5-speed manual Ford Mustang is geared as followed?
10. Given input rotational speed of 2000 rpm for Gear A in Clock-wise direction, find rotational speed and direction (clock-wise/anti-clock wise) for Gears B, C, D and E respectively. What is the ratio of (Power Output/ Power Input) and (Torque Output / Torque Input)?
11. Compare and contrast Spur and Helical gears with the help of sketch, based on their geometry and suitability of application.
12. Explain, with a labelled sketch, working of an automotive Serpentine Belt and its various elements.
