Papers by Author: Katsuyuki Kida

Abstract: Polyetheretherketone (PEEK) is a tough semi-crystalline thermoplastic polymer with excellent mechanical properties. While abilities of polyphenylenesulfide (PPS) are similar to PEEK, former material cost was lower than later. Polytetrafluoroethylene (PTFE) is well known because of its low friction coefficient and self lubrication ability. The objective of this study is to observe the friction coefficient of hybrid bearings, PTFE retainer sandwiched with PPS-races or PEEK-races. Rolling contact fatigue tests were performed and in situ friction forces wear measured. It is concluded that the PTFE retainer reduced friction coefficient.

Abstract: In order to establish an optimal material combination for the production of polymer thrust bearings, two types of components: retainer and PPS races - PPS retainer were tested by rolling contact fatigue (RCF). The wear properties of both bearing types were investigated and a relationship between thrust load, rotation speed and wear loss was established. It is concluded that by using a PTFE retainer, it is possible to improve the

Abstract: The behavior of surface cracks in PEEK thrust bearings under rolling contact fatigue (RCF) was investigated. Eight small holes were introduced along the bottom race surface, and RCF tests underwater using different loads were carried out. The cracks growing from the holes were observed by using a microscope. It was found that the surface cracks could not be explained by Hertzian crack theory or the ‘wedge effect’ models. This indicates that the standard theories cannot be generally applied to investigation of PEEK bearings working under RCF in water.