Rotating shaft and ball-surface life

AI Thread Summary
The discussion focuses on estimating the wear life of two surfaces: the rotor in contact with a spherical ball and the casing also in contact with the ball. Key factors influencing wear include material composition, machining tolerances, clearance, lubrication, RPM, and loading conditions. The predominant stress to consider is Hertz contact stress, which significantly impacts wear rates. Understanding these elements is crucial for accurate life estimation, akin to bearing life calculations found in machine design literature. Proper analysis of these variables will lead to a more informed conclusion about which surface will wear faster.
chandran
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There is a rotating shaft which is in contact with a spherical ball. The ball is in contact with an outer casing.The casing is fixed to the ground.

I want to estimate the life of the surface which is in contact. There are two surfaces i want to estimate the life for.

1)surface of the rotor which is in contact with the ball

2)surface of the casing which is in contact with the ball.


Which surface will wear faster? Any proof of this.


Which subject i should concentrate on ( i think mechanics or rotational mechanics-any website for this) to understand this process.
 
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Chandran, you are way short of an answerable question. What are the various components made of? What are the machining tolerances? What sort of clearance? What sort of lubrication? What rpm with what sort of side/end loading? Are you starting to see the picture?
 
The biggest factors you are missing in your problem statement are the materials and the applied loads. The predominant stresses will be the Hertz contact stress. You will also have the other factors that Danger mentioned as well. It sounds conspicuously like you are trying to estimate the life of a bearing. If that is the case, you could find bearing life calculations in any design of machine elements book.
 
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