Steps # 1 & 2

1. Using the following equation, calculate input torque:

N.m.

where: P is power in kW n is shaft speed in rpm

 

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

 

3. Calculate transmitted load between the gears:

where: P is power (kW) n t is pitch line velocity = 3.37 m/sec.

 

4. Calculate the normal force between the gears:

where: Wt is the transmitted load (N.) f is the pressure angle of the gears = 20°

 

5. Perform a complete force analysis on the shafts in the y and z directions to determine the resultant reactions at all 4 bearing locations:

Resultant reaction is given by

N.

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

 

Use Eqn. (11-9)

 

Where:

F_R is the Catalog Load Rating

F_D is the Design Load*

L_D is the Design Life in Hours = 20000 Hrs.

n_D is the Design Speed (given in rpm)

L_Rn_R is the Rated Life = 10⁶ rev.

R is the Reliability = 95%

a for Ball Bearings = 3

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

7. To calculate C, use the following equation:

C=A.F. ´ F_R

Where:

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

 

8. 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

• Convert L_Dn_D to rev. before solving the equation