Surface Profile Observation of PTFE Thrust Bearings under Rolling Contact Fatigue in Water

2013 ◽  
Vol 683 ◽  
pp. 391-395 ◽  
Author(s):  
Kiyoto Itakura ◽  
Takashi Honda ◽  
Shunsuke Oyama ◽  
Katsuyuki Kida ◽  
Shintaro Hazeyama ◽  
...  
Keyword(s):  
Rolling Contact Fatigue ◽  
Testing Machine ◽  
Contact Fatigue ◽  
Surface Profile ◽  
Rolling Contact ◽  
Wear Loss ◽  
Axial Loads ◽  
Before And After ◽  
Bearing Race ◽  
Dimensional Shape

The life of the PTFE thrust bearing under rolling contact fatigue (RCF) was investigated. The different conditions of axial loads and the rotating speeds under water were applied. The shapes of the bearing race before and after the tests were measured by a two-dimensional shape measurement sensor. The wear loss of PTFE bearing was rarely generated and the shape of the bearing changed slightly in the test. However, it was found that the lifetime of PTFE bearing depended on the temperature generated in the contact surface. In our testing machine condition, the bearing was collapsed over a load of 1600 N.

Surface Profile Observation of PTFE Radial Bearings under Rolling-Contact-Fatigue in Water

2013 ◽  
Vol 307 ◽  
pp. 337-341 ◽  
Author(s):  
Shunsuke Oyama ◽  
Katsuyuki Kida ◽  
Edson Costa Santos ◽  
Hitonobu Koike ◽  
Yuji Kashima
Keyword(s):  
Rotation Speed ◽  
Wear Behavior ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Surface Profile ◽  
Rolling Contact ◽  
Shape Measurement ◽  
Shape Effect ◽  
Dimensional Shape ◽  
Laser Confocal Microscope

Groove shape effect on wear behavior in PTFE radial bearings under rolling contact fatigue (RCF) was investigated. RCF tests in water-lubricated conditions were carried out at different loads and rotation speeds. The groove surfaces after testing were observed by using a laser confocal microscope and a two-dimensional shape measurement sensor. It was found that PTFE bearings under RCF generate wear debris, however no cracking or flaking failure could be observed. It is concluded that groove deformation depend on load rather than rotation speed. The biggest changes in groove profiles occurred when tested at loads close to 400N.

The Influence of Surface Texture on Rolling-Contact Fatigue of PEEK Bearings in Water

2010 ◽  
Vol 154-155 ◽  
pp. 1713-1716 ◽  
Author(s):  
Takashi Honda ◽  
Katsuyuki Kida ◽  
Edson Costa Santos ◽  
Yuji Kashima
Keyword(s):  
Surface Texture ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Surface Profile ◽  
Confocal Microscope ◽  
Rolling Contact ◽  
Initial Surface ◽  
Surface Conditions ◽  
Before And After ◽  
Laser Confocal Microscope

The effect of machining conditions on the rolling contact fatigue (RCF) strength of PEEK polymer bearings was investigated. RCF tests were carried out by using bearings machined by different conditions. The surface profile and roughness were observed before and after testing by laser confocal microscope. Pitting and cracking were associated with the different initial surface conditions. From the obtained results, we found that the RCF strength of machined surfaces decreases when the surface becomes rougher.

Influence of Radial Load on PEEK Plastic Bearings Life Cycle under Water Lubricated Conditions

2011 ◽  
Vol 217-218 ◽  
pp. 1260-1265 ◽  
Author(s):  
Hitonobu Koike ◽  
Takashi Honda ◽  
Katsuyuki Kida ◽  
Edson Costa Santos ◽  
Justyna Rozwadowska ◽  
...  
Keyword(s):  
Feed Rate ◽  
High Performance ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wear Loss ◽  
Ball Bearings ◽  
Before And After ◽  
Dry Conditions ◽  
Market Needs

Radial ball bearings made of metal, ceramics and plastics are commonly used as important components in industrial machinery. Usage of high performance engineering plastic polymers is increasing progressively as a replacement for metal components due to the latest markets demands. Poly-ether-ether-ketone (PEEK) is a promising material for precision-machined custom bearings, products that are expected to suit special market needs. In the present study, PEEK radial ball bearings were manufactured by lathe machining under different parameters and their rolling contact fatigue (RCF) resistance under water lubricated conditions was investigated. We observed the surface of the bearings prior and after testing by laser confocal microscope. The wear loss was measured by weighing the bearings before and after test. Cracks and/or flaking failures were identified on the bearing surface after testing. From the RCF tests results, we found that, at water lubricated conditions, crack initiation occurred later in the material that was machined at slower feed rate while at dry condition, the feed rate had little influence on the wear loss and cracking. Wear loss in the case of bearings tested under water was much less severe than that of bearings tested at dry conditions.

Failure Observation of 3D-Printed Thrust Bearing Specimens at Cross Section Observations in Dry Conditions

2018 ◽  
Vol 777 ◽  
pp. 446-450 ◽  
Author(s):  
Koshiro Mizobe ◽  
Masahiro Inagaki ◽  
Katsuyuki Kida
Keyword(s):  
3D Printing ◽  
Fracture Behavior ◽  
Thrust Bearing ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Dry Conditions ◽  
Moving Direction ◽  
Bearing Race ◽  
3D Printed

3D printing methods are developing and they have become popular recently. 3D printing can easily make complex and seamless parts, however, there are questions about their strength. In particular, the strength of the places where the lamination layer joins is important. We performed rolling contact fatigue (RCF) tests in dry conditions using 3D-printed bearing race and observed the fracture behavior and cracks. We found that the main crack is related to the stress moving direction.

Rolling Contact Fatigue of Titanium Alloys Coated by Gas Nitriding Using a Q-Sw Laser

2011 ◽  
Vol 83 ◽  
pp. 191-196
Author(s):  
Justyna Rozwadowska ◽  
Katsuyuki Kida ◽  
Edson Costa Santos ◽  
Takashi Honda ◽  
Hitonobu Koike ◽  
...  
Keyword(s):  
Titanium Alloys ◽  
Rolling Contact Fatigue ◽  
Pure Titanium ◽  
Contact Fatigue ◽  
Weight Ratio ◽  
High Strength ◽  
Rolling Contact ◽  
Wear Loss ◽  
Beam Diameter ◽  
Gas Nitriding

The influence of gas nitriding of commercial pure titanium and Ti-6Al-4V (Ti64) alloy by using a Q-sw laser on the wear loss during rolling contact fatigue is investigated. Despite very good biocompatibility, high strength to weight ratio and corrosion resistance, the tribological properties of titanium alloys are inferior to those of other metal alloys, such as steel. Fretting and wear related aspects become important issues when titanium alloys are used in rolling contact applications. Titanium bearings are employed in applications requiring high strength, light weight, and minimum maintenance (for example, aerospace and defense industries). In this work, a Q-sw laser was used to coat pure commercial titanium and Ti-6Al-4V bearings with TiN in a closed chamber in nitrogen atmosphere. The samples were tested under water by using a thrust-type rolling contact fatigue machine. The microstructure, morphology and crystallographic texture of the layers were observed by laser confocal microscope, scanning electron microscope and electron backscatter diffraction (EBSD). By optimizing the laser processing parameters, such as laser scanning speed, power and beam diameter, thin TiN coats of 1 to 3 mm were produced. The wear loss of the coated samples was at least ten times lower than that of the uncoated bearings.

Observation of Crack Initiation Direction around Inclusions in SUJ2 under Single-Ball Rolling Contact Fatigue

2013 ◽  
Vol 307 ◽  
pp. 342-346 ◽  
Author(s):  
Shintaro Hazeyama ◽  
Justyna Rozwadowska ◽  
Katsuyuki Kida ◽  
Edson Costa Santos ◽  
Takashi Honda ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Empirical Data ◽  
Rolling Contact Fatigue ◽  
Testing Machine ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Ball Rolling

A newly developed single-ball RCF testing machine was used in order to investigate crack initiation direction within SUJ2. From empirical data, it was found that the distribution of crack initiation direction at N = 1.0x106 cycles is very close to that at N = 1.0x107. This means that the cracks that do not cause failure stop growing by 1.0x106 cycles. Some cracks however continue to grow towards the surface, at an angle of 135 degrees.

scholarly journals Dry Rolling/Sliding Wear of Bainitic Rail Steels under Different Contact Stresses and Slip Ratios

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4678
Author(s):  
Jiapeng Liu ◽  
Yingqi Li ◽  
Yinhua Zhang ◽  
Yue Hu ◽  
Lubing Shi ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Abrasive Wear ◽  
Contact Stress ◽  
Wear Mechanism ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wear Loss ◽  
Fatigue Wear ◽  
Slip Ratio

This study aims to deeply understand the effect of contact stress and slip ratio on wear performances of bainitic rail steels. The results showed that the wear loss increased as the contact stress and slip ratio increased. Based on the surface damage morphology and microstructural analyses, it revealed that the rolling contact fatigue wear mechanism played a significant role under the low slip ratio, but the dominant wear mechanism transferred to the abrasive wear at the high slip ratio. Meanwhile, the bainitic steel specifically presented worse wear resistance under the abrasive wear mode. Compared with the influence of a slip ratio, the increase in contact stress led to severer plastic flows and contributed to the propagation of cracks. In addition, the contact stress and slip ratio had the opposite effect on the friction coefficient, that is, the friction coefficient of bainitic steels behaved the inverse proportion with the contact stress, but positive proportion with the slip ratio. At last, the increase in slip ratio had more significant effect on the reduction of retained austenite (RA) than the enlargement of contact stress due to the fact that the RA would probably be removed before the martensitic transformation occurred under the abrasive wear mechanism.

Investigation of Crack Initiation and Propagation during Rolling Contact Fatigue of SUJ2 Steel Bearings Using a Newly Developed One-Point Testing Machine

2011 ◽  
Vol 418-420 ◽  
pp. 1613-1617 ◽  
Author(s):  
Justyna Rozwadowska ◽  
Katsuyuki Kida ◽  
Edson Costa Santos ◽  
Takashi Honda ◽  
Hitonobu Koike ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Rolling Contact Fatigue ◽  
Testing Machine ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
X Ray Diffraction ◽  
Crack Initiation And Propagation ◽  
New Device ◽  
Initiation And Propagation ◽  
Laser Confocal Microscope

An innovative type of one-point rolling contact fatigue (RCF) machine was developed in order to investigate crack initiation and propagation in metals. The microstructural changes and propagation of subsurface cracks during rolling contact in specimens tested by using the new device were studied by laser confocal microscope and X-ray diffraction. It was shown that this new method presents several important advantages compared to the conventional thrust type RCF machines.

Observation of Wear in PEEK Race - PTFE Retainer Hybrid Polymer Bearings under Dry Contact

2012 ◽  
Vol 457-458 ◽  
pp. 557-562 ◽  
Author(s):  
Koshiro Mizobe ◽  
Edson Costa Santos ◽  
Takashi Honda ◽  
Hitonobu Koike ◽  
Katsuyuki Kida ◽  
...  
Keyword(s):  
Wear Track ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wear Loss ◽  
Hybrid Polymer ◽  
Wear Properties ◽  
Thrust Bearings ◽  
Dry Contact ◽  
Materials Used

In order to establish an optimal combination of materials used for polymer thrust bearings, two types of components (polyetheretherketone (PEEK) races - polytetrafluoroethylene (PTFE) retainer and PEEK races – PEEK retainer) were tested by rolling contact fatigue. Their wear properties were investigated and it was concluded that using a PTFE retainer, the wear loss was improved due to PTFE wear debris attaching to the wear track and acting as a lubricant.

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