Internal Code: MAS3961
Engineering Assignment Help
The shaft of a DC motor is connected via a flexible coupling to the input shaft of a helical gearbox. The motor rotates in the clockwise direction as viewed from the + x axis. Bearings A and D are to take up the thrust loads.
You are required to work in a team of two to design the gearbox as shown below.

Design specification:
- Input power = 5.4 kW
- Input speed = 1,700 rpm
- Output speed = 765 rpm
- KHK stock helical pinion, right hand, transverse module 3 mm, catalogue no.
KHG3-18R
- Infinite shaft life
- Bearing requisite life greater than 8,000 hours
Requirements
1. Choose an appropriate KHK stock helical gear to mate with the given pinion.
2. Create a 3D sketch of the input shaft and the pinion, and show all the forces acting on the pinion and bearing reactions at A and B.
3. Calculate the forces acting on the pinion and bearing reactions at A and B. Show steps clearly with appropriate units.
4. Determine the output torque. State any assumption.
5. Select appropriate bearings for bearings A and B from NTN rolling bearing catalogue. Show all relevant calculations and reasoning. Attach the bearing catalogue data with your report.
6. Calculate the bearing life (L 10 ) in hours for bearings A and B.