We all want to know the answer to this question as it tells us as a business where to invest our R&D development, steers us to consider what ke...

The complete Product News section from the March 2019 issue of Power Transmission Engineering.

Written by: Jerome Jennings, global product manager, SPX Cooling Technologies, Inc. Industries that require process heat rejection often use fie...

Written By: Steve Katz, President, Emerson Bearing Boston Good machinery can last a lifetime. But, replacement parts for older equipment may be ...

A bearing service life prediction methodology and tutorial indexed to eight probable causes for bearing failure and removal are presented - including fatigue. Bearing life is probabilistic and not deterministic. Bearing manufacturers' catalogue (L10) bearing life is based on rolling-element fatigue failure, at which time 90% of a population of bearings can be reasonably expected to survive, and 10% to fail by fatigue. However, approximately 95% of all bearings are removed for cause before reaching their L10 life. A bearing failure can be defined as when the bearing is no longer fit for its intended purpose. For a single bearing, you can only predict the probability of a failure occurring at a designated time - but not the actual time to failure.

Every bearing that has a non-zero contact angle will generate an axial load as a radial load is applied. This generated load is referred to by a fe...

Welcome to Part 2 of our duty cycle journey. In the first part, we reviewed how to take a duty cycle or one block of a duty cycle and reduce it to ...

Man, oh man — 2017 is going to be one for the record books! My wife and I recently had the 3rd and FINAL installment of the Parker clan. A healthy ...

A reader wants to know how to figure out the fatigues strength, tooth root tension and other technical values of new, high-performance gear materials.

Until now the estimation of rolling bearing life has been based on engineering models that consider an equivalent stress, originated beneath the contact surface, that is applied to the stressed volume of the rolling contact. Through the years, fatigue surface–originated failures, resulting from reduced lubrication or contamination, have been incorporated into the estimation of the bearing life by applying a penalty to the overall equivalent stress of the rolling contact. Due to this simplification, the accounting of some specific failure modes originated directly at the surface of the rolling contact can be challenging. In the present article, this issue is addressed by developing a general approach for rolling contact life in which the surfaceoriginated damage is explicitly formulated into the basic fatigue equations of the rolling contact. This is achieved by introducing a function to describe surface-originated failures and coupling it with the traditional, subsurface-originated fatigue risk of the rolling contact. The article presents the fundamental theory of the new model and its general behavior. The ability of the present general method to provide an account for the surface–subsurface competing fatigue mechanisms taking place in rolling bearings is discussed with reference to endurance testing data.