Open AccessFriction models for grease lubricated ball-race contacts
Author(s) -
G Ianuş,
D Cojocaru,
M. C. Oprişan,
Vlad Cârlescu,
Dumitru Olaru
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/997/1/012012
Subject(s) - friction torque , grease , thrust , ball (mathematics) , torque , mechanics , materials science , engineering , physics , mechanical engineering , composite material , mathematics , thermodynamics , geometry
In this paper the authors theoretically investigated the influence of the hydrodynamic rolling friction forces in greased ball-race contacts at low loads. Two IVR-EHL transitions equations for hydrodynamic rolling friction forces have been applied to the ball-race contacts in a modified thrust ball bearing by using three types of greases having base oil viscosities between 40 mm 2 /s and 1000 mm 2 /s. Based on the total friction torque analytically estimated and experimentally determined has been evidenced the influence of the hydrodynamic rolling friction force on the total friction torque as the most important parameter for both proposed transition equations. The theoretical values of the total friction torque have been experimentally validated. The experiments was realized with a modified tree ball thrust bearing, without cage in a range of speed between 60 rpm and 400 rpm and for a normal load of 1.422 N for each ball.