Effect of New Pocket Design on the Failure of Thrust UHMWPE Bearings in Dry Condition

2016 ◽  
Vol 703 ◽  
pp. 192-196 ◽  
Author(s):  
Koshiro Mizobe ◽  
Naoki Fujimura ◽  
Yuji Kashima ◽  
Katsuyuki Kida
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Thermoplastic Polymer ◽  
Ultra High Molecular Weight

We developed a retainer with a new kind of design. This retainer has pockets with angles which we think could improve wear durability. We used ultra high molecular weight polyethylene (UHMWPE) because it is a tough thermoplastic polymer with self-lubrication ability. We performed rolling contact fatigue tests and found that wear durability was improved compared with the standard bearings.

Relationship between Life, Load and Rotation Speed of UHMWPE Bearing under Dry Rolling Contact Fatigue

2013 ◽  
Vol 683 ◽  
pp. 77-81 ◽  
Author(s):  
Shintaro Hazeyama ◽  
Shunsuke Oyama ◽  
Katsuyuki Kida ◽  
Takashi Honda ◽  
Koshiro Mizobe ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Rotation Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Wear Loss ◽  
Bearing Life ◽  
Ultra High Molecular Weight

The polymer bearings have been widely used in recent years. In this study, ultra-high-molecular-weight-polyethylene (UHMWPE) is investigated. In order to investigate the relation between the lives, loads and rotation speeds, rolling contact fatigue tests were conducted. It was found that rotation speed related to the bearing life and wear loss.

Influence on Tribological Behavior of PEEK Composite Film Layer on PEEK-PTFE Bearings with Artificial Defect in Dry Condition

2021 ◽  
Vol 904 ◽  
pp. 243-249
Author(s):  
Hitonobu Koike ◽  
Koshiro Mizobe ◽  
Katsuyuki Kida
Keyword(s):  
Composite Film ◽  
Tribological Behavior ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Artificial Defect ◽  
Peek Composite ◽  
Film Layer ◽  
Number Of Cycles

In order to explore influence on tribological behavior of PEEK composite film layer in PEEK-PTFE composite radial alumina ball bearings, rolling contact fatigue tests were performed by using the PEEK bearing’s inner rings with the artificial defects in dry condition. When rotation speed and applied load were 600 rpm and 98 N, the number of cycles of the PEEK-PTFE bearings reached 1.0×107 fatigue cycles. The artificial defects with 0.02 mm depth on the raceway surface of the PEEK inner ring was covered with PEEK composite film accumulation.

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.

Experimental Investigations Upon Fatigue Life of Circular Contacts With Transversal Furrow

2005 ◽  
Author(s):  
Delia F. Cerlinca ◽  
Emanuel N. Diaconescu
Keyword(s):  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Geometric Parameters ◽  
Rolling Contact ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Contact Fatigue Life

Rolling contact fatigue depends essentially on both surface and subsurface populations of defects. First, this paper describes experimental results obtained in rolling contact fatigue tests in the presence of a furrow oriented transversally to the race-way. Then an attempt to predict theoretically the effect of geometric parameters of the furrow upon contact fatigue life is described.

Flaking Initiation Life under Rolling Contact Fatigue of Ceramic Coated Steels Quenched after Coating Process

2014 ◽  
Vol 597 ◽  
pp. 157-160
Author(s):  
Hirotaka Tanabe ◽  
Keiji Ogawa ◽  
Motoyuki Nishizawa ◽  
Yui Izumi ◽  
Tohru Takamatsu
Keyword(s):  
Ceramic Coating ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Coated Specimen ◽  
Rolling Contact ◽  
Process Time ◽  
Laser Quenching ◽  
Modification Method ◽  
The Difference

In our previous studies, a new surface modification method by combination of ceramic coating and heat treatment, named “substrate quenching after coating” was developed. The thrust type rolling contact fatigue tests were carried out for TiN coated steels and CrAlN coated steels processed by substrate quenching after coating, and the effects of the type of ceramic coating (TiN or CrAlN) and the quenching methods (by furnace quenching or by laser quenching) on the flaking initiation life were investigated. For the specimens quenched by furnace, the flaking life of CrAlN coated specimen was longer than that of TiN coated specimen. This reason could be explained by the difference of the oxidization of CrAlN and TiN in their furnace quenching process. For CrAlN coated specimens, the flaking life of the specimens quenched by laser was longer than that of the specimens quenched by furnace. This reason could be explained by the difference of the process time of the furnace quenching and the laser quenching. It is considered that laser quenching after coating could be an effective way to improve the flaking initiation life under rolling contact fatigue.

New Methodology to Evaluate the Rolling Contact Fatigue Performance of Bearing Steels With Surface Dents: Application to 32CrMoV13 (Nitrided) and M50 Steels

2005 ◽  
Vol 127 (3) ◽  
pp. 611-622 ◽  
Author(s):  
D. Nélias ◽  
C. Jacq ◽  
G. Lormand ◽  
G. Dudragne ◽  
A. Vincent
Keyword(s):  
Normal Load ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Experimental Result ◽  
Damage Initiation ◽  
Bearing Steels ◽  
Improved Performance

A new methodology is proposed to evaluate the rolling contact fatigue (RCF) performance of bearing steels in presence of surface dents. The experimental procedure consists of denting the raceway of test specimens with a hardness machine using spherical diamond tips of different radii (i.e., 200, 400, and 600μm) and with an applied normal load ranging from 5to50daN. Analysis of various dent geometries yield an analytical law with five parameters useful for fitting experimental profiles for contact simulation. Fatigue tests are conducted using a two-disk machine to study the effect of different operating conditions on RCF and to compare the performances of nitrided 32CrMoV13 steel versus M50 reference steel. A numerical investigation is conducted to analyze experimental result. Initially, the local residual stresses and plastic strains around the dent are obtained through finite element simulations of the indentation process. Second, the overrolling of the dent is simulated with a contact code. Finally, an indent-based endurance limit, called H1I, is proposed and comparisons are made with test results. Both RCF tests and numerical simulations show improved performance with nitrided 32CrMoV13 steel when compared to the M50 reference steel. The dominating role of sliding is also experimentally highlighted and two areas of damage initiation are identified. The effects of normal load and hoop stress are less marked.

Theory of Lubrication and Failure of Rolling Contacts

1961 ◽  
Vol 83 (2) ◽  
pp. 213-222 ◽  
Author(s):  
B. Sternlicht ◽  
P. Lewis ◽  
P. Flynn
Keyword(s):  
Fatigue Life ◽  
Contact Zone ◽  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Inlet Temperature ◽  
Fluid Properties ◽  
Contact Fatigue Life

The fatigue life of rolling-element bearings has been the subject of numerous investigations. Most recently the influence of the lubricant on fatigue failure has been given added emphasis. This paper presents the results of an investigation which was undertaken in order to gain a better understanding of fluid behavior in the contact zone and to determine the influence of the lubricant on rolling contact fatigue life. The investigation had three distinct facets: (a) An analysis was performed on pressure and temperature distribution within the contact zone of rolling disks. In the analysis Reynolds, energy, and elasticity equations were solved simultaneously and fluid properties, such as viscosity dependence on temperature and pressure were included. (b) Dynamic stresses in two contacting cylindrical bodies were measured by means of photoelastic techniques. These measurements were used to test the validity of the analytically predicted stress distribution. (c) High-speed ball-bearing fatigue tests were conducted with two specially blended oils which had the same viscosity at the bearing inlet temperature, but widely different pressure viscosity characteristics. The physical characteristics of the oils were the same as those considered in the analysis. The paper summarizes the work and presents a hypothesis for the failure mechanism.

An observation on subsurface defects of ultra high molecular weight polyethylene due to rolling contact

1996 ◽  
Vol 6 (6) ◽  
pp. 441-451 ◽  
Author(s):  
Minako Ohashi ◽  
Naohide Tomita ◽  
Yoshito Ikada ◽  
Ken Ikeuchi ◽  
Toshio Motoike
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Rolling Contact ◽  
Ultra High Molecular Weight ◽  
Subsurface Defects

Experimental and Fracture Mechanics Study of the Pit Formation Mechanism Under Repeated Lubricated Rolling-Sliding Contact: Effects of Reversal of Rotation and Change of the Driving Roller

1997 ◽  
Vol 119 (4) ◽  
pp. 788-796 ◽  
Author(s):  
Y. Murakami ◽  
C. Sakae ◽  
K. Ichimaru ◽  
T. Morita
Keyword(s):  
Fatigue Crack ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Surface Damage ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Sliding Contact ◽  
Hydraulic Pressure ◽  
Pit Formation ◽  
Original Crack

Five rolling contact fatigue tests, Tests {1}–{5} have been conducted. In Tests {1}–{3}, when a fatigue crack was initiated on the surface of a follower, the test was halted. Then, in Test {1} the rotating direction was reversed. In Test {2} the follower and driver were interchanged, and in Test {3} the test was continued unchanged. In Test {3} the original crack grew to a pit. In Tests {1} and {2} the original crack immediately stopped propagating. In Tests {4} and {5}, mating with a harder roller, a softer roller was used as the follower in Test {4} and as the driver in Test {5}. A typical pit occurred in Test {4}. In Test {5}, surface damage substantially different from a typical pit was generated. Based on these experimental results, a 3-D crack analysis including the effect of frictional force on the contact surface and oil hydraulic pressure on crack surfaces, was conducted to elucidate the mechanisms of pit formation and surface damage in contact fatigue.

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