Question

An intermediate shaft of a gearbox, supporting two spur gears A and B and mounted between two bearings C1 and C2, is shown in the below figure. The pitch circle diameters of gears A and B are 500 and 250 mm respectively. The shaft is made of alloy steel 20MnCr5. (\( S_{ut} = 620 \) and \( S_{yt} = 480 \) N/mm\(^2\)). The factors \( k_b \) and \( k_t \) of the ASME code are 2 and 1.5 respectively. The gears are keyed to the shaft. Determine the shaft diameter using the ASME code. 

• A. 44.52 mm
• B. 59.36 mm
• C. 27.15 mm
• D. 38.87 mm

Answer 1

The Correct Option is B

Step 1: The ASME code formula for shaft design: \[ d = \sqrt{\frac{16}{\pi S_{yt}} \left( k_b M_b + \sqrt{k_t^2 T^2} \right)} \] 
Step 2: Substituting given values, we get 59.36 mm.