Random exam questions

Question 1

A deep groove ball bearing i has a stationary outer ring, a rotating inner ring and a constant load direction. If the bearing is selected to be non-locating, would you allow sliding between inner ring and shaft or between outer ring and housing?

Answer 1

Since rotating motion is transferred by the shaft, I would choose to allow sliding between outer ring and housing

Question 2

What is the most specific property of spherical roller bearings?

Answer 2

They allow relatively large angular misalignments

Question 3

What are the 5 characteristics used to determine a safety factor in Pugsley’s Safety Factor Approach?

Answer 3

1. Quality of material
2. Control over applied load
3. Accuracy of stress analysis
4. Danger to personnel
5. Economic impact

Question 4

Name three ways of axially locating a bearing on a shaft

Answer 4

Retaining rings, nuts, step in shaft

Question 5

Give the main reasons for making a bearing arrengement where one bearing is designed to axially locating and one none-locating

Answer 5

Thermal expansions and tolerances can cause large internal thrust if both are locating

Question 6

Give two reasons why pre-tensioning of v-belts and flat-belts are considered a draw-back.

Answer 6

1. Higher bearing loads

2. Allow for tension adjustment

Question 7

Why is a curved spring washer preferred for desired preload, rather than having the lid press directly on the bering outer ring?

Answer 7

The curved spring washer makes the pretension insencitive to tolerance errors