TY - JOUR

T1 - Starvation and Re-lubrication in Oscillating Bearings: Influence of Grease Parameters

AU - Wandel, Sebastian

AU - Bader, Norbert Fritz

AU - Glodowski, Jakob

AU - Lehnhardt, Bela Jannis

AU - Leckner, Johan

AU - Schwack, Fabian

AU - Poll, Gerhard

N1 - Funding Information: The authors would like to thank Muyuan Liu , Josephine Kelley , and Volker Schneider for their professional advice, Marvin Woersdoerfer for the help with the experimental work and Peter Schönemeier for the help with the commissioning of the test rig. This document is a result of the research project HBDV ’Highly Accelerated Pitch Bearings’ (Grant number 0324303A) funded by the Federal Ministry for Economic Affairs and Climate Action (Germany).

PY - 2022

Y1 - 2022

N2 - A common application for grease-lubricated oscillating rolling element bearings is, e.g., rotor blade bearings in wind turbines. These bearings mainly operate under conditions that are prone to starvation. If the grease is unable to provide enough inlet lubricant supply for the contact between rolling element and bearing raceway, wear in the form of False Brinelling and thus premature bearing failure is possible. Bearing experiments with different lithium complex model greases, which differ mainly in their base oil viscosity and oil separation rate, were carried out to show the influence of the grease parameters on wear initiation. The results show that the ability of the grease to release a high amount of base oil with high mobility into the track of the rolling element is a crucial mechanism to prevent wear, especially at small oscillation angles. For oscillation angles larger than a critical angle, a secondary replenishment mechanism may prevent early wear initiation. The experimental results are used to validate a starvation model proposed in earlier work (Wandel et al. in Tribol Int 165:107276, 2022).

AB - A common application for grease-lubricated oscillating rolling element bearings is, e.g., rotor blade bearings in wind turbines. These bearings mainly operate under conditions that are prone to starvation. If the grease is unable to provide enough inlet lubricant supply for the contact between rolling element and bearing raceway, wear in the form of False Brinelling and thus premature bearing failure is possible. Bearing experiments with different lithium complex model greases, which differ mainly in their base oil viscosity and oil separation rate, were carried out to show the influence of the grease parameters on wear initiation. The results show that the ability of the grease to release a high amount of base oil with high mobility into the track of the rolling element is a crucial mechanism to prevent wear, especially at small oscillation angles. For oscillation angles larger than a critical angle, a secondary replenishment mechanism may prevent early wear initiation. The experimental results are used to validate a starvation model proposed in earlier work (Wandel et al. in Tribol Int 165:107276, 2022).

KW - Wälzlager

KW - Verschleiß

KW - Fettschmierung

KW - Rotorblattlager

KW - Rolling element bearings

KW - Wear

KW - Grease lubrication

KW - Wind turbine bearing

KW - False brinelling

KW - Starvation

KW - Oscillating bearings

KW - Re-lubrication

UR - http://www.scopus.com/inward/record.url?scp=85139241294&partnerID=8YFLogxK

U2 - 10.1007/s11249-022-01655-7

DO - 10.1007/s11249-022-01655-7

M3 - Article

VL - 70

JO - Tribology Letters

JF - Tribology Letters

SN - 1023-8883

IS - 4

M1 - 114

ER -