Mechanical Engineering Assignment Task -
Solve the given problem.
Task 1 - A spring with a one-turn loop of 40mm mean radius is formed from a round section of wire having 5 mm diameter. The straight tangential legs of the spring has lengths indicated in the diagram below. It is fixed with full moment support on the right end and the left end is loaded with a downward force P = 20 N as shown in the figure.
a) Determine the bending stress distribution for this spring using Excel spreadsheet as well as SolidWorks.
b) Also compare these induced bending stresses with those for a spring made up of a wire with 7 mm diameter and the same material.
c) If a recommended factor of safety for this design is 2.5, suggest required yield strength of the wire material and suggest suitable material based on this.
Task 2 - An electric motor shaft with a pinion transmits 350kW power at 1500rpm to a gear in a reduction gearbox with following specifications: The Gear ratio = 8:1; Distance between centres = 750 mm approximately; Involute teeth of standard proportions (addendum = 1.2 m) with pressure angle of 20.5o; Permissible normal pressure between teeth = 320 N per mm of width. Find:
1. The nearest standard module if no interference is to occur.
2. The number of teeth on each wheel.
3. The necessary width of the pinion.
4. Normal and Tangential load on the tooth of the pinion due to power transmitted.