Tribodynamic modelling of high-speed rolling element bearings in flexible multi-body environments
This study presents a new flexible dynamic model for drive systems comprising lubricated bearings operating under conditions representative of electrified vehicle powertrains. The multi-physics approach importantly accounts for the tribological phenomena at the roller-race conjunction and models their effect on shaft-bearing system dynamics. This is achieved by embedding a non-linear lubricated bearing model within a flexible system level model; something which has not, to the authors’ knowledge, been reported on hitherto. The elastohydrodynamic (EHL) film is shown to increase contact deflection, leading to increased contact forces and total bearing stiffness as rotational speeds increase. Results show that for a 68 Nm hub motor operating up to 21 000 rpm, the input bearing EHL film reaches a thickness of 4.15 μm. The lubricant entrainment increases the roller-race contact deflection, causing the contact stiffness to increase non-linearly with speed. The contribution of the lubricant film leads to a 16.6 % greater bearing stiffness at 21 000 rpm when compared to conventional dry bearing modelling methods used in current multi-body dynamic software. This new methodology leads to more accurate dynamic response of high-speed systems necessary for the next generation of electrified vehicles.
Funding
Loughborough University
AVL List GmbH
History
School
- Mechanical, Electrical and Manufacturing Engineering
Published in
MachinesVolume
11Issue
1Publisher
MDPIVersion
- VoR (Version of Record)
Rights holder
© The authorsPublisher statement
This article is an Open Access article published by MDPI and distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Acceptance date
2023-01-06Publication date
2023-01-11Copyright date
2023eISSN
2075-1702Publisher version
Language
- en