Machine Design - II (ME 308 Lab)

Shaft Design - Project # 1

Term 991

Steps # 1 & 2

1. Using the following equation, calculate input torque:
2.  N.m. where:P is power in kW n is shaft speed in rpm

3. Draw the torque diagrams for both shafts based upon these value of T
4.

5. Calculate transmitted load between the gears:
6.  where:P is power (kW) n t is pitch line velocity = 3.37 m/sec.

7. Calculate the normal force between the gears:
8.  where:Wt is the transmitted load (N.) f is the pressure angle of the gears = 20°

9. Perform a complete force analysis on the shafts in the y and z directions to determine the resultant reactions at all 4 bearing locations:
10. Resultant reaction is given by

N.

11. Using equation (11-9) from the text book, calculate the rated force for each bearing:
12.

Use Eqn. (11-9)

Where:

FR is the Catalog Load Rating

LD is the Design Life in Hours = 20000 Hrs.

nD is the Design Speed (given in rpm)

LRnR is the Rated Life = 106 rev.

R is the Reliability = 95%

a for Ball Bearings = 3

* for the values of FD, use the values of the resultant reactions calculated for all 4 locations in step 5 of the lab-sheet

13. To calculate C, use the following equation:
14. C=A.F. ´ FR

Where:

A.F. is the Load-Application Factor - use table (11-6)

15. Select Deep Groove Ball Bearings for all 4 bearing locations on the shaft using table (11-3). Use the value of C, calculated above to select the bearing and note down all bearing data

NOTE:

• Convert LDnD to rev. before solving the equation

1. Draw the shear force and bending moment diagrams in the y and z directions and the resultant bending moment diagram with a free hand sketch of each shaft