Details
| Original language | English |
|---|---|
| Article number | 111354 |
| Journal | Tribology international |
| Volume | 214 |
| Early online date | 1 Nov 2025 |
| Publication status | Published - Feb 2026 |
Abstract
Oscillating bearings find applications in various industries, including robotics and wind energy systems. Damage due to starvation can lead to system failures in highly precise positioning mechanisms due to unpredictable torque fluctuations. Moreover, wear damage can trigger secondary failure mechanisms. The occurrence of starvation is dependent on operating parameters, such as oscillation frequency, amplitude, load, and lubricant characteristics. Among these factors, amplitude has been identified as the most critical parameter affecting grease starvation and can even overshadow the effects of other variables. Therefore, investigating the impact of amplitude on lubrication performance is essential for optimizing the lubrication design of oscillating bearings. Hence, this experimental study addresses grease replenishment mechanisms under varying oscillation amplitudes for 6008 deep groove ball bearings with different cage structures. This is complemented by in-situ observations of film thickness formation using an optical elastohydrodynamic lubrication tribometer. Thereby, three distinct lubrication mechanisms are identified. At small amplitudes, lubrication of the contact area is primarily determined by the lubricant supply from the grease side bands. Under medium-amplitude conditions, interaction between the cage and the side bands on the rolling elements substantially enhances lubrication. At large amplitudes, when the rolling track on the rolling elements connects both the inner and outer rings, grease flow between the rings emerges as a dominant mechanism, effectively reducing wear. Understanding the above mechanisms provides a theoretical foundation for the selection of lubricating grease based on amplitude, and the structural optimization of bearings, including cage or raceways.
Keywords
- Deep groove ball bearing, Elastohydrodynamics, False brinelling, Film thickness, Grease lubrication, Interferometry, Oscillation
ASJC Scopus subject areas
- Engineering(all)
- Mechanics of Materials
- Engineering(all)
- Mechanical Engineering
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Materials Science(all)
- Surfaces, Coatings and Films
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In: Tribology international, Vol. 214, 111354, 02.2026.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Beyond starvation
T2 - Amplitude-dependent grease replenishment mechanisms in oscillating rolling bearings
AU - Liu, Muyuan
AU - Wandel, Sebastian
AU - Bader, Norbert
AU - Lin, Zongyu
AU - Bayer, Gernot
AU - Poll, Gerhard
AU - Marian, Max
N1 - Publisher Copyright: © 2025 The Authors.
PY - 2026/2
Y1 - 2026/2
N2 - Oscillating bearings find applications in various industries, including robotics and wind energy systems. Damage due to starvation can lead to system failures in highly precise positioning mechanisms due to unpredictable torque fluctuations. Moreover, wear damage can trigger secondary failure mechanisms. The occurrence of starvation is dependent on operating parameters, such as oscillation frequency, amplitude, load, and lubricant characteristics. Among these factors, amplitude has been identified as the most critical parameter affecting grease starvation and can even overshadow the effects of other variables. Therefore, investigating the impact of amplitude on lubrication performance is essential for optimizing the lubrication design of oscillating bearings. Hence, this experimental study addresses grease replenishment mechanisms under varying oscillation amplitudes for 6008 deep groove ball bearings with different cage structures. This is complemented by in-situ observations of film thickness formation using an optical elastohydrodynamic lubrication tribometer. Thereby, three distinct lubrication mechanisms are identified. At small amplitudes, lubrication of the contact area is primarily determined by the lubricant supply from the grease side bands. Under medium-amplitude conditions, interaction between the cage and the side bands on the rolling elements substantially enhances lubrication. At large amplitudes, when the rolling track on the rolling elements connects both the inner and outer rings, grease flow between the rings emerges as a dominant mechanism, effectively reducing wear. Understanding the above mechanisms provides a theoretical foundation for the selection of lubricating grease based on amplitude, and the structural optimization of bearings, including cage or raceways.
AB - Oscillating bearings find applications in various industries, including robotics and wind energy systems. Damage due to starvation can lead to system failures in highly precise positioning mechanisms due to unpredictable torque fluctuations. Moreover, wear damage can trigger secondary failure mechanisms. The occurrence of starvation is dependent on operating parameters, such as oscillation frequency, amplitude, load, and lubricant characteristics. Among these factors, amplitude has been identified as the most critical parameter affecting grease starvation and can even overshadow the effects of other variables. Therefore, investigating the impact of amplitude on lubrication performance is essential for optimizing the lubrication design of oscillating bearings. Hence, this experimental study addresses grease replenishment mechanisms under varying oscillation amplitudes for 6008 deep groove ball bearings with different cage structures. This is complemented by in-situ observations of film thickness formation using an optical elastohydrodynamic lubrication tribometer. Thereby, three distinct lubrication mechanisms are identified. At small amplitudes, lubrication of the contact area is primarily determined by the lubricant supply from the grease side bands. Under medium-amplitude conditions, interaction between the cage and the side bands on the rolling elements substantially enhances lubrication. At large amplitudes, when the rolling track on the rolling elements connects both the inner and outer rings, grease flow between the rings emerges as a dominant mechanism, effectively reducing wear. Understanding the above mechanisms provides a theoretical foundation for the selection of lubricating grease based on amplitude, and the structural optimization of bearings, including cage or raceways.
KW - Deep groove ball bearing
KW - Elastohydrodynamics
KW - False brinelling
KW - Film thickness
KW - Grease lubrication
KW - Interferometry
KW - Oscillation
UR - http://www.scopus.com/inward/record.url?scp=105021090112&partnerID=8YFLogxK
U2 - 10.1016/j.triboint.2025.111354
DO - 10.1016/j.triboint.2025.111354
M3 - Article
AN - SCOPUS:105021090112
VL - 214
JO - Tribology international
JF - Tribology international
SN - 0301-679X
M1 - 111354
ER -