Design Project
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.
All dimensions are in mm.
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
The module m in the KHK Helical Gears catalogue is already the transverse modulemt. No further calculation is required.
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 (L10) in hours for bearings A and B.