Details
| Original language | English |
|---|---|
| Article number | 109771 |
| Number of pages | 12 |
| Journal | Tribology international |
| Volume | 197 |
| Early online date | 15 May 2024 |
| Publication status | Published - Sept 2024 |
Abstract
Grease-lubricated rolling element bearings that perform oscillating motion are often prone to False Brinelling. Previous investigations on oscillating open contacts, i.e. no presence of a sticking zone, identified the replenishment of the contact by bled oil through capillary forces as a key mechanism for wear prevention. This investigation aims to better understand how the replenished oil is acting around the contact. Optical investigations with greases previously studied in bearing experiments are conducted to observe the meniscus shape around the contact. Comparison with the bearing experiments shows a strong correlation between the onset of severe wear and the inlet length of the grease meniscus. This reveals a new role of the meniscus in boundary or mixed lubrication, besides its prominent function in EHL. The physical background of the measured inlet lengths for varying base oil viscosities and bleeding rates is discussed. Evaluation of the test data with respect to the capillary number and bleeding rate supports these considerations; a critical threshold value is identified. This paper is intended to provide more insight into the lubrication mechanisms under oscillating conditions. Additionally, the approach derived from the measurement data may help to predict the inlet dimensions in a practical manner for bearing calculations.
Keywords
- Blade bearing, False brinelling, Grease lubrication, Lubricant meniscus, Oscillating contacts, Pitch bearing, Starvation
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
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Tribology international, Vol. 197, 109771, 09.2024.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Influence of the meniscus on wear in grease-lubricated oscillating rolling contacts
AU - Bayer, Gernot
AU - Wandel, Sebastian
AU - Ayromlou, Ashkan
AU - Bader, Norbert
AU - Poll, Gerhard
N1 - Publisher Copyright: © 2024 The Author(s)
PY - 2024/9
Y1 - 2024/9
N2 - Grease-lubricated rolling element bearings that perform oscillating motion are often prone to False Brinelling. Previous investigations on oscillating open contacts, i.e. no presence of a sticking zone, identified the replenishment of the contact by bled oil through capillary forces as a key mechanism for wear prevention. This investigation aims to better understand how the replenished oil is acting around the contact. Optical investigations with greases previously studied in bearing experiments are conducted to observe the meniscus shape around the contact. Comparison with the bearing experiments shows a strong correlation between the onset of severe wear and the inlet length of the grease meniscus. This reveals a new role of the meniscus in boundary or mixed lubrication, besides its prominent function in EHL. The physical background of the measured inlet lengths for varying base oil viscosities and bleeding rates is discussed. Evaluation of the test data with respect to the capillary number and bleeding rate supports these considerations; a critical threshold value is identified. This paper is intended to provide more insight into the lubrication mechanisms under oscillating conditions. Additionally, the approach derived from the measurement data may help to predict the inlet dimensions in a practical manner for bearing calculations.
AB - Grease-lubricated rolling element bearings that perform oscillating motion are often prone to False Brinelling. Previous investigations on oscillating open contacts, i.e. no presence of a sticking zone, identified the replenishment of the contact by bled oil through capillary forces as a key mechanism for wear prevention. This investigation aims to better understand how the replenished oil is acting around the contact. Optical investigations with greases previously studied in bearing experiments are conducted to observe the meniscus shape around the contact. Comparison with the bearing experiments shows a strong correlation between the onset of severe wear and the inlet length of the grease meniscus. This reveals a new role of the meniscus in boundary or mixed lubrication, besides its prominent function in EHL. The physical background of the measured inlet lengths for varying base oil viscosities and bleeding rates is discussed. Evaluation of the test data with respect to the capillary number and bleeding rate supports these considerations; a critical threshold value is identified. This paper is intended to provide more insight into the lubrication mechanisms under oscillating conditions. Additionally, the approach derived from the measurement data may help to predict the inlet dimensions in a practical manner for bearing calculations.
KW - Blade bearing
KW - False brinelling
KW - Grease lubrication
KW - Lubricant meniscus
KW - Oscillating contacts
KW - Pitch bearing
KW - Starvation
UR - http://www.scopus.com/inward/record.url?scp=85193992288&partnerID=8YFLogxK
U2 - 10.1016/j.triboint.2024.109771
DO - 10.1016/j.triboint.2024.109771
M3 - Article
AN - SCOPUS:85193992288
VL - 197
JO - Tribology international
JF - Tribology international
SN - 0301-679X
M1 - 109771
ER -