Effect of contact geometry on lubricant replenishment in grease lubricated rolling contacts

authored by: Xuyang Jin, Xinming Li, Linqing Bai, Feng Guo, Junbin Gao, Gerhard Poll
Abstract: The contact geometries encountered in rolling element-outer race or inner race contacts in real bearings are not involved in conventional ball-on-flat disc configurations. However, the underlying lubricant replenishment mechanism induced by the contact conformity plays a significant role in maintaining a long-term operation of the rolling bearings. To reveal those replenishment mechanisms, the traditional flat disc is replaced by a grooved disc to reproduce the contact geometries. Additionally, a ball support structure consisting of dual arc-shaped rollers is employed to simulate the ball-inner race contact, aiming to explore the contributions of grease distributions to replenishment. The results show that the film thickness gradually diminishes to severe starvation states in the traditional contact configuration, while the lubrication states are efficiently improved as the ball-grooved or ball-arc shaped contact configuration is introduced, confirming the replenishment efficiency. The enhanced lubricant replenishment behaviors can be attributed to the high-strength shear exerted on the grease both at the inlet region and within the contacts where micro-slip occurs, as well as the surface tension and capillary force-induced lubricant replenishment. The findings of this study contribute to a comprehensive understanding of grease lubrication and replenishment in real bearings.
Organisation(s): Institute of Machine Elements and Engineering Design
External Organisation(s): Qingdao Technological University
Type: Article
Journal: Tribology international
Volume: 200
No. of pages: 12
ISSN: 0301-679X
Publication date: 12.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Mechanics of Materials, Mechanical Engineering, Surfaces and Interfaces, Surfaces, Coatings and Films
Electronic version(s): https://doi.org/10.1016/j.triboint.2024.110077 (Access: Closed)

BibTeX

@article{1e7db31c20644311b110459b2f04d125,
title = "Effect of contact geometry on lubricant replenishment in grease lubricated rolling contacts",
abstract = "The contact geometries encountered in rolling element-outer race or inner race contacts in real bearings are not involved in conventional ball-on-flat disc configurations. However, the underlying lubricant replenishment mechanism induced by the contact conformity plays a significant role in maintaining a long-term operation of the rolling bearings. To reveal those replenishment mechanisms, the traditional flat disc is replaced by a grooved disc to reproduce the contact geometries. Additionally, a ball support structure consisting of dual arc-shaped rollers is employed to simulate the ball-inner race contact, aiming to explore the contributions of grease distributions to replenishment. The results show that the film thickness gradually diminishes to severe starvation states in the traditional contact configuration, while the lubrication states are efficiently improved as the ball-grooved or ball-arc shaped contact configuration is introduced, confirming the replenishment efficiency. The enhanced lubricant replenishment behaviors can be attributed to the high-strength shear exerted on the grease both at the inlet region and within the contacts where micro-slip occurs, as well as the surface tension and capillary force-induced lubricant replenishment. The findings of this study contribute to a comprehensive understanding of grease lubrication and replenishment in real bearings.",
keywords = "Contact geometry, Film thickness, Grease lubrication, Replenishment, Rolling bearings",
author = "Xuyang Jin and Xinming Li and Linqing Bai and Feng Guo and Junbin Gao and Gerhard Poll",
note = "Publisher Copyright: {\textcopyright} 2024 Elsevier Ltd",
year = "2024",
month = dec,
doi = "10.1016/j.triboint.2024.110077",
language = "English",
volume = "200",
journal = "Tribology international",
issn = "0301-679X",
publisher = "Elsevier Inc.",
}