In order to more accurately calculate the film stiffness of angular contact ball bearing, it is necessary to establish the film stiffness calculation model that is consistent with reality. The frictional heat exists in high-speed ball bearings, and can impact on oil film thickness and stiffness. The calculation model of film stiffness of an angular contact ball bearing taking account of the eff...

STUDY DESIGN This is a retrospective study comparing polyethylene wear between ceramic ball heads and metal ball heads in total hip arthroplasty. BACKGROUND The ceramic-on-polyethylene bearing option has been introduced as an alternative to metal-on-polyethylene to minimize polyethylene wear debris and reduce subsequent osteolysis and aseptic loosening. However, the reported data were debatab...

An interesting feature of dung beetle behaviour is that once they have formed a piece of dung into a ball, they roll it along a straight path away from the dung pile. This straight-line orientation ensures that the beetles depart along the most direct route, guaranteeing that they will not return to the intense competition (from other beetles) that occurs near the dung pile. Before rolling a ne...

Abstract When the oil supply is not adequate to maintain ideal lubrication, angular contact ball bearing will enter into starved lubrication regime resulting in potential performance degradation and consequently severe failures. To study effects of on bearing, this paper first proposes a multi-degree-of-freedom (DOF) tribo-dynamic model by introducing five-DOF inner ring, six-DOF balls, cage. T...

In this paper the authors theoretically evaluated film thickness in a miniature angular contact ball bearing grease and oil lubricated conditions correlated with variation of electrical resistance experimentally determined by using tribometer CETR UMT-2. For considering base viscosity. The rotational speed inner race varied between 1 500 rpm axial load applied on 7000C was 8.1 N. IVR EHD lubric...