Crack Observation of PPS Polymer Thrust Bearings under RCF Test in Water

2016 ◽  
Vol 703 ◽  
pp. 178-182
Author(s):  
Xiao Chen Shi ◽  
Masatoshi Ando ◽  
Yuji Kashima ◽  
Katsuyuki Kida
Keyword(s):  
Crack Propagation ◽  
Cross Sections ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Low Friction ◽  
High Corrosion Resistance ◽  
Thrust Bearings ◽  
Bearing Failures ◽  
Polymer Bearing

Polymer bearings are widely used under certain environments due to the advantages on light weight, low friction coefficient, high corrosion resistance and electric insulation. The main reason for polymer bearing failures in water was formation of flakings due to crack propagation. However, the mechanism of fatigue crack propagation in polymer material under rolling contact condition has not been clearly explained yet. In the present study, detailed crack observations were made on cross sections along both radial and rolling directions after RCF (Rolling Contact Fatigue) test in water using PPS thrust bearings.

Observation of Cracks of PEEK Polymer Thrust Bearings under Rolling Contact Fatigue in Water

2016 ◽  
Vol 703 ◽  
pp. 172-177 ◽  
Author(s):  
Xiao Chen Shi ◽  
Masaya Orito ◽  
Yuji Kashima ◽  
Koshiro Mizobe ◽  
Katsuyuki Kida
Keyword(s):  
Corrosion Resistance ◽  
Friction Coefficient ◽  
Cross Sections ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Light Weight ◽  
Low Friction ◽  
High Corrosion Resistance ◽  
Thrust Bearings

Considering the advantages on light weight, low friction coefficient, high corrosion resistance and electric insulation, polymer bearings are widely used under certain environments, where the toughness like metal bearings is not necessary. In our previous study, it was concluded that the main reason for PEEK thrust bearings failure in water was flaking due to surface crack propagation. In the present study, crack observations were made on groove surfaces and cross sections along both radial and rolling directions in order to find the relation between cracks and flaking failures.

Effect of PTFE Retainer on Friction Coefficient in Polymer Thrust Bearings under Dry Contact

2013 ◽  
Vol 683 ◽  
pp. 90-93 ◽  
Author(s):  
Koshiro Mizobe ◽  
Takashi Honda ◽  
Hitonobu Koike ◽  
Edson Costa Santos ◽  
Yuji Kashima ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Low Friction ◽  
Friction Forces ◽  
Thrust Bearings ◽  
Dry Contact

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.

Subsurface Stress Distribution and Failure of PPS Thrust Bearings under Rolling Contact Fatigue in Water

2019 ◽  
Vol 814 ◽  
pp. 152-156 ◽  
Author(s):  
Xiao Chen Shi ◽  
Akihiro Adachi ◽  
Katsuyuki Kida
Keyword(s):  
Fatigue Crack ◽  
Stress Distribution ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Polymer Materials ◽  
Thrust Bearings ◽  
Subsurface Stress

In recent years, environments of bearings and polymer materials have been more and more attractive due to several advantages against ordinary metal material. However, there is still room for the further study about strength of polymer bearings. One of questions is the mechanism of fatigue crack propagation, which is the main cause of the damage of polymer bearings under rolling contact with lubricant, like water. In this study, subsurface stress distribution and failure of PPS thrust bearings under rolling contact fatigue in water are discussed to understand the detail of the crack propagation.

Internal Shear Stress Distribution and Subsurface Cracks of PPS Thrust Bearings under Rolling Contact Fatigue in Water

2020 ◽  
Vol 858 ◽  
pp. 101-105
Author(s):  
Syunsuke Mizozoe ◽  
Katsuyuki Kida
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Crack Propagation ◽  
Contact Stress ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Subsurface Crack ◽  
Thrust Bearings ◽  
Subsurface Cracks

In this study, crack propagation in PPS thrust bearings under rolling contact fatigue (RCF) in water was observed, and relation between subsurface crack and internal shear stress parallel to the surface was investigated. It was found the cause of flaking was subsurface crack. They were evaluated in terms of contact stress and friction between their faces. It was discovered that subsurface cracks distributed around shear stress peak, and flaking failure was dominated by subsurface shear stress.

Surface Observation of PPS Thrust Bearings under Rolling Contact Fatigue in Water

2014 ◽  
Vol 563 ◽  
pp. 270-274 ◽  
Author(s):  
Xiao Chen Shi ◽  
Yuji Kashima ◽  
Katsuyuki Kida
Keyword(s):  
Crack Propagation ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wear Loss ◽  
Heavy Load ◽  
Thrust Bearings ◽  
Surface Failure ◽  
Detailed Surface ◽  
The Relationship

There were two procedure about surface failure in rolling contact fatigue (RCF), wear and crack propagation. In our previous study, it was concluded that the main reason for PPS bearings failure in water was flaking due to surface crack propagation. The relationship between wear loss, rotation speed and thrust load of PPS bearings under RCF in water was investigated. In this study, the detailed surface profiles under heavy load were studied by using both LCM and two-dimensional measurement sensor to study the process of flaking failure.

Observation of Surface and Subsurface Crack Propagation in PPS Thrust Bearings under Rolling Contact Fatigue in Water

2021 ◽  
Vol 1020 ◽  
pp. 120-125
Author(s):  
Syunsuke Mizozoe ◽  
Takahiro Matsueda ◽  
Katsuyuki Kida ◽  
Yuji Kashima
Keyword(s):  
Crack Propagation ◽  
Contact Area ◽  
Rolling Contact Fatigue ◽  
Rolling Direction ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Direction Parallel ◽  
Thrust Bearings ◽  
Subsurface Cracks ◽  
Circular Cracks

In this study, crack propagation in PPS thrust bearings under rolling contact fatigue (RCF) in water was observed in order to investigate the relation between cracks and flakings. RCF tests in water under loads of 700 N and 900 N were performed. The semi-circular cracks propagated in a direction perpendicular to the rolling direction were observed under a load of 700 N. The line cracks propagated in a direction parallel to the rolling direction at periphery of contact area and the semi-circular cracks were observed under a load of 900 N. To study the subsurface cracks, full section of rolling contact area was observed. It is concluded that the flaking mechanism in PPS thrust bearing has three features as follows: Initiation and propagation of surface cracks depend on the load; When load is 700N, the semi-circular cracks growing from the surface and the cracks branching from the main subsurface cracks join to form the flaking; When load is 900N the line cracks and the semi-circular cracks growing from the surface join to form the flaking.

Effect of Groove Geometry on Rolling Contact Fatigue of PEEK Thrust Bearings in Water

2016 ◽  
Vol 878 ◽  
pp. 117-121 ◽  
Author(s):  
Masaya Orito ◽  
Katsuyuki Kida ◽  
Yuuki Hashizume ◽  
Masayuki Ishida ◽  
Koshiro Mizobe ◽  
...  
Keyword(s):  
Cross Sections ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Light Weight ◽  
Design Standards ◽  
Thrust Bearings ◽  
Manufacture Process ◽  
Ether Ether Ketone ◽  
Poly Ether Ether Ketone

Bearings have been used in various environments. Recently, small and light-weight bearings are developed in order to downsize mechanical components. Polymer bearings, such as PEEK (Poly-Ether-Ether-Ketone), PTFE (Poly-Tetra Fluoro-Ethylene) and PPS (Poly-Phenylene-Sulfide-Resin), are designed because of advantages of light weight, high corrosion resistance and self-lubricating. However, industrial design standards of these bearings have not been established yet, i.e., the relation between working conditions, shape, geometry, and lives of bearing components under RCF (Rolling Contact Fatigue) is not fully understood as well as crack propagation, wear and/or failure. In this study, we focused on the manufacture process of groove curvature decreasing contact stress, and observed cracks and flaking failures on groove surfaces and cross sections. Based on these observations, we investigated the relation between the groove geometry and lives of all-PEEK thrust bearings in water.

Effect of defect length on rolling contact fatigue crack propagation in high strength steel

2015 ◽  
Author(s):  
T. Makino ◽  
Y. Neishi ◽  
D. Shiozawa ◽  
Y. Neishi ◽  
D. Shiozawa ◽  
...  
Keyword(s):  
Crack Propagation ◽  
High Strength Steel ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
High Strength ◽  
Rolling Contact ◽  
Micro Ct ◽  
Middle Line ◽  
Micro Computed Tomography ◽  
Depth Direction

 The objective of the present paper is to clarify the effect of defect length in depth direction on rolling contact fatigue (RCF) crack propagation in high strength steel. RCF test and synchrotron radiation micro computed tomography (SR micro CT) imaging were conducted. In the case of the defect with the 15 ?m diameter, flaking life decreased with increasing defect length. In a comparison of the CT image and the SEM view, the shapes of defects and the locations of the horizontal cracks were almost the same respectively. The mechanism of RCF crack propagation was discussed by finite element (FE) analysis. Defects led to higher tensile residual stress than that without defects in the region where the defect exists. The shear stress range at 0.1 mm in depth on the middle line of the defect and the range of mode II stress intensity factor at the bottom of a vertical crack increased with increasing defect length.

A Predictive Rolling Contact Fatigue Crack Growth Model: Onset of Branching, Direction, and Growth—Role of Dry and Lubricated Conditions on Crack Patterns

2002 ◽  
Vol 124 (4) ◽  
pp. 680-688 ◽  
Author(s):  
M. C. Dubourg ◽  
V. Lamacq
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Interfacial Crack ◽  
Rolling Contact ◽  
Propagation Behavior ◽  
Branch Formation ◽  
Complex Crack ◽  
Crack Growth Model

Complex crack networks are initiated in rails under Rolling Contact Fatigue. This paper attempts to model the RCF crack propagation with a particular emphasis on the branching conditions and the parameters that play a role on them. The numerical tool proposed rests on the combination of the author’s RCF model, Hourlier and Pineau’s criterion for the branch prediction and experimental data and the corresponding models for fatigue crack extension that are derived from a Joint European project. Parametric studies on the influence of (i) residual stresses, (ii) both interfacial crack and wheel/rail contact frictional effects, (iii) neighboring crack are conducted to reach a better understanding of the RC crack propagation behavior and more particularly the branch conditions, i.e., the length of the primary crack prior to branch formation and the branch direction.

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