The Friction of Radially Loaded Hybrid Spindle Bearings under High Speeds

Gärtner, Marcus; Brecher, Christian; Neus, Stephan; Eckel, Hans Martin; Bartelt, Andreas; Hoppert, Maik; Ilkhani, Mohammad Reza

Abstract

Friction losses are an important parameter for evaluating the operational behaviour of high-speed rolling bearings. Specifically, in machine tool applications, the bearings are subjected to high radial loads and high speeds, which lead to increased forces in the rolling contact and, as a result, increased bearing friction. In this high-speed application, hybrid spindle bearings, typically made of ceramic balls and steel raceways, show better frictional behaviour compared to full steel-made bearings. Therefore, precise knowledge of the friction characteristics of high-speed hybrid bearings can improve friction models and generalise them to spindle bearings with different types, geometries, and operating conditions. In this article, a new straightforward and cost-efficient method for measuring the frictional torque in spindle bearings is presented. A rigidly arranged 7008 hybrid spindle bearing pair was tested up to rotational speeds of 24,000 rpm and high radial loads of 3 kN. The effects of oil–air and grease lubrication are discussed in characteristic diagrams of the tested bearings. Then, based on the test results, a friction calculation model is presented and validated for the outer race control and minimised power dissipation regarding the influence of radial forces.

Citation

Gärtner, M., Brecher, C., Neus, S., Eckel, H. M., Bartelt, A., Hoppert, M., & Ilkhani, M. R. (2023). The Friction of Radially Loaded Hybrid Spindle Bearings under High Speeds. Machines, 11(6), Article 649. https://doi.org/10.3390/machines11060649

• Journal Article Type: Article
• Acceptance Date: Jun 10, 2023
• Online Publication Date: Jun 15, 2023
• Publication Date: 2023-06
• Deposit Date: Jun 24, 2023
• Publicly Available Date: Jun 29, 2023
• Journal: Machines
• Electronic ISSN: 2075-1702
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Issue: 6
• Article Number: 649
• DOI: https://doi.org/10.3390/machines11060649
• Keywords: Hybrid spindle bearings; radial load; generator test rig; lubrication; high-speed; machine tool; rigid arrangement; friction calculation
• Public URL: https://nottingham-repository.worktribe.com/output/22186806
• Additional Information: This is the peer reviewed version of the following article: Gärtner M, Brecher C, Neus S, Eckel H-M, Bartelt A, Hoppert M, Ilkhani MR. The Friction of Radially Loaded Hybrid Spindle Bearings under High Speeds. Machines. 2023; 11(6):649, which has been published in final form at https://doi.org/10.3390/machines11060649.