Proper film thickness key to bearing survival
Document Type
Article
Publication Date
12-14-2006
Abstract
The various factors affecting the design of oil and grease-lubricated bearings are discussed. The design of oil and grease-lubricated bearings depend on lubricant film thickness for smooth and trouble-free operation. For full-film lubrication of journal and thrust bearings, the composite surface roughness parameter, A is above the range of 3 to 10. Misalignment, thermal, and elastic distortions can increase that to about 10 to 20. For lubricating precision-finish journal bearings with a low-viscosity fluid the value of A should be greater than 3. Shaft journals in industrial electric motors typically have an initial surface finish of 32 μin. surface. For journal bearings, a minimum film thickness can be estimated for small fluid-film thickness in the range of 0.5 to 20 % of the radial internal clearance. Load in ball and roller bearings is distributed on extremely small contact areas, while contact stresses elastically deform the surfaces to accommodate formation of an oil film.
Publication Source (Journal or Book title)
Machine Design
First Page
100
Last Page
105
Recommended Citation
Khonsari, M., & Booser, E. (2006). Proper film thickness key to bearing survival. Machine Design, 78 (23), 100-105. Retrieved from https://repository.lsu.edu/mechanical_engineering_pubs/1401