A Study on Rolling Element Skew Measurement in a Tapered Roller Bearing With a Specialized Capacitance Probe

1999 ◽  
Vol 122 (3) ◽  
pp. 534-538 ◽  
Author(s):  
Yeyuan Yang ◽  
Steven Danyluk ◽  
Michael Hoeprich
Keyword(s):  
Rotational Speed ◽  
Chemical Potential ◽  
Contact Potential Difference ◽  
Roller Bearing ◽  
Potential Difference ◽  
Chemical Potential Difference ◽  
Contact Potential ◽  
Tapered Roller Bearing ◽  
Capacitance Probe ◽  
Tapered Roller

This paper reports on roller skew in tapered roller bearings. The roller skewing of a tapered roller bearing is experimentally measured with a specialized capacitance probe (Kelvin contact potential difference, CPD, probe). The probe measures the electro-chemical potential difference between the probe and roller surfaces. Two probes are inserted through holes in the housing and bearing outer race. The electrical signals from both ends of a roller are used to determine the skewing. The technique, as well as the effect of lubrication and rotational speed on the roller skewing, is presented. It is shown that the skewing increases with an increase in rotational speed, and the lubrication of the large end of the roller. A theoretical analysis has been developed to account for the experimental results. [S0742-4787(00)01803-8]

scholarly journals Coupled Investigation of Contact Potential and Microstructure Evolution of Ultra-Thin AlOx for Crystalline Si Passivation

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1803
Author(s):  
Zhen Zheng ◽  
Junyang An ◽  
Ruiling Gong ◽  
Yuheng Zeng ◽  
Jichun Ye ◽  
...  
Keyword(s):  
Structural Changes ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Contact Potential Difference ◽  
Potential Difference ◽  
Kelvin Probe ◽  
Contact Potential ◽  
Carrier Lifetimes ◽  
Transmission Electron ◽  
Effective Carrier

In this work, we report the same trends for the contact potential difference measured by Kelvin probe force microscopy and the effective carrier lifetime on crystalline silicon (c-Si) wafers passivated by AlOx layers of different thicknesses and submitted to annealing under various conditions. The changes in contact potential difference values and in the effective carrier lifetimes of the wafers are discussed in view of structural changes of the c-Si/SiO2/AlOx interface thanks to high resolution transmission electron microscopy. Indeed, we observed the presence of a crystalline silicon oxide interfacial layer in as-deposited (200 °C) AlOx, and a phase transformation from crystalline to amorphous silicon oxide when they were annealed in vacuum at 300 °C.

Thermal Analysis of Railroad Bearings: Effect of Wheel Heating

2009 ◽  
Author(s):  
Constantine M. Tarawneh ◽  
Arturo A. Fuentes ◽  
Brent M. Wilson ◽  
Kevin D. Cole ◽  
Lariza Navarro
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Roller Bearing ◽  
Railroad Wheel ◽  
Fe Model ◽  
Wheel Pair ◽  
Tapered Roller Bearing ◽  
Excessive Heat ◽  
Tapered Roller ◽  
Railroad Bearings

Catastrophic bearing failure is a major concern for the railroad industry because it can lead to costly train stoppages and even derailments. Excessive heat buildup within the bearing is one of the main factors that can warn of impending failure. A question is often raised regarding the transfer of heat from a wheel during braking and whether this can lead to false setouts. Therefore, this work was motivated by the need to understand and quantify the heat transfer paths to the tapered roller bearing within the railroad wheel assembly when wheel heating occurs. A series of experiments and finite element (FE) analyses were conducted in order to identify the different heat transfer mechanisms, with emphasis on radiation. The experimental setup consisted of a train axle with two wheels and bearings pressed onto their respective journals. One of the wheels was heated using an electric tape placed around the outside of the rim. A total of 32 thermocouples scattered throughout the heated wheel, the axle, and the bearing circumference measured the temperature distribution within the assembly. In order to quantify the heat radiated to the bearing, a second set of experiments was developed; these included, in addition to the axle and the wheel pair, a parabolic reflector that blocked body-to-body radiation to the bearing. The appropriate boundary conditions including ambient temperature, emissivity, and convection coefficient estimates were measured or calculated from the aforementioned experiments. The FE thermal analysis of the wheel assembly was performed using the ALGOR™ software. Experimental temperature data along the radius of the heated wheel, the bearing circumference, and at selected locations on the axle were compared to the results of the FE model to verify its accuracy. The results indicate that the effect of thermal radiation from a hot wheel on the cup temperature of the adjacent bearing is minimal when the wheel tread temperature is at 135°C (275°F), and does not exceed 17°C (31°F) when the wheel tread is at 315°C (600°F).

Effect of tribological parameters on sliding wear and friction coefficient which relates to preload loss in tapered roller bearing

2019 ◽  
Vol 71 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Ayush Jain ◽  
Abhishek Singh ◽  
Arendra Pal Singh
Keyword(s):  
Sliding Wear ◽  
Roller Bearing ◽  
Wear Test ◽  
Thickness Effect ◽  
Surface Parameters ◽  
Content Type ◽  
Tapered Roller Bearing ◽  
Tapered Roller ◽  
Tribological Parameters ◽  
Ball On Disc

Purpose This paper aims to study the sliding wear and coefficient of friction (COF) using “ball on disc” tribometer. Discs of bearing steel were subjected to different tribological parameters such as heat treatment (through hardening and case hardening), sliding speed, sliding distance and micro-geometry of the functional ball and disc point contact. Results obtained from tribometer were correlated with the preload loss in tapered roller bearing. Preload loss is subjected to wear rate pattern with respect to the internal geometry and micro-geometry of functional surfaces of the tapered roller bearing, caused by internal resistance between roller large ends sliding against cone supporting face. This confirms the optimum geometry and physical/mechanical property of the tapered roller bearing, which makes the use of these bearings under the demanding application in the automotive industry such as differential gears and installation of pinions of differential gears in power transmissions or wheels. Design/methodology/approach The paper opted for an exploratory study using the design of experiments with full factorial method. The approach was to do ball on disc sliding wear test and correlate that sliding wear with preload loss in tapered roller bearing. Findings The paper provides the limit of preload loss in tapered roller bearing. Research limitations/implications Because of the chosen research approach, the research lacks the effect of environmental conditions such as temperature and relative humidity and lube film thickness effect on wear test. It also lacks the validation part with actual preload loss on tapered roller bearings. Above work is included in future scope of work. Practical implications This paper includes the recommendation for surface parameters which can increase the bearing life by reducing the preload loss in tapered roller bearing. Social implications This paper includes the recommendation for surface parameters for bearing manufacturing industries. Originality/value This paper provides the relation between sliding wear and preload loss in tapered roller bearing.

Determination of the local contact potential difference of PTCDA on NaCl: a comparison of techniques

2009 ◽  
Vol 20 (26) ◽  
pp. 264012 ◽  
Author(s):  
S A Burke ◽  
J M LeDue ◽  
Y Miyahara ◽  
J M Topple ◽  
S Fostner ◽  
...  
Keyword(s):  
Contact Potential Difference ◽  
Potential Difference ◽  
Contact Potential ◽  
Local Contact ◽  
Comparison Of Techniques
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