Author:

Keywords:

Science & Technology, Technology, Engineering, Industrial, Engineering, Electrical & Electronic, Engineering, Mechanical, Engineering

Abstract:

Although roller bearings that undergo oscillatory, periodic motion are common in industry, design and application engineer does not readily dispose of adequate models and design tools to deal with them. This paper develops a simplified method for calculating the EHL film in a time-varying EHL line contact. The model is a conditional superposition of Dowson's full-EHL, steady-state solution and a time-dependent squeeze-film part developed based on Grubin's assumption of the EHL (Hertzian) gap. The properties of the model are illustrated by examining the film-thickness behavior in function of a sinusoidal variation in the entrainment velocity, for a constant normal load. This behavior is characterized by the butterfly curves that the film height describes in function of the velocity. These loops are formed around the stationary curves, which act as attractors to them. A qualitative validation of the theoretical results is also carried out by plotting the electrical resistance through the lubricant in a roller bearing film against the time-varying driving velocity.