Ultrasonic Measurement of Cylindrical Roller Bearing Lubrication Using High Pulse Repletion Rates

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Meng Li ◽  
Heng Liu ◽  
Cong Xu ◽  
Minqing Jing ◽  
Wenhui Xin
Keyword(s):  
Film Thickness ◽  
Thickness Distribution ◽  
Roller Bearing ◽  
Lubricant Film Thickness ◽  
Rotor Vibration ◽  
Oil Film ◽  
High Pulse ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller ◽  
Focal Zone

This paper describes a measurement of lubricant-film thickness in a roller bearing using a new ultrasonic pulser-receiver, which has a maximum pulse repetition rate (PRR) of 100 kHz. The experimental results show that a higher PRR can help to get more measurement points and more details of the oil-film thickness distribution. Furthermore, the influence of rotor vibration response for the oil-film thickness is discussed, which is in keeping with the simulation result. Finally, the limits of the PRR are discussed in detail and the effect of the transducer focal zone size is also observed.

Profiling a Cylindrical Roller Bearing Oil-Film Thickness Distribution With Ultrasound

2015 ◽  
Author(s):  
Meng Li ◽  
Li Chen ◽  
Minqing Jing ◽  
Heng Liu ◽  
Yi Liu ◽  
...  
Keyword(s):  
Film Thickness ◽  
Thickness Distribution ◽  
Roller Bearing ◽  
Thickness Measurement ◽  
Ultrasonic Pulse ◽  
Lubricant Film ◽  
Maximum Speed ◽  
Oil Film ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

The rollers and raceways in cylindrical roller bearings are separated by an extremely thin lubricant film over a narrow region, which is critical to performance. The ultrasound method has been applied successfully to a range of bearings including journal and ball bearings. But the actual maximum speed that can be measured is limited by the repetition frequency of the ultrasonic pulse. Otherwise, a single measurement point cannot image the thickness distribution of the cylindrical roller bearing. This paper describes the measurement of lubricant-film thickness distribution in a roller bearing by moving the ultrasound transducer. A new ultrasonic pulser-receiver is used to get enough effective measurement points. For a range of loads and speeds, the oil-film thicknesses of four positions along the roller are measured. The influences of the rotating speed and radial load on the film thickness measurement are consistent with the theoretical predictions. The limits of the PRR used in measurements are discussed and the averaging effect of the transducer focal zone size is observed.

Measurement of Oil Film Thickness in Cylindrical Roller Bearing by Ultrasound

2014 ◽  
Author(s):  
Kai Zhang ◽  
Qingfeng Meng ◽  
Wei Zhao
Keyword(s):  
Reflection Coefficient ◽  
Film Thickness ◽  
Roller Bearing ◽  
Piezoelectric Element ◽  
Elastohydrodynamic Lubrication ◽  
Spring Model ◽  
Oil Film ◽  
Rolling Element ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

This paper describes the measurement of oil film thickness between rolling element and inner raceway in cylindrical roller bearing. A fine piezoelectric element is bonded on the inner surface of the inner ring to measure the reflection coefficient of oil between rolling element and inner raceway. The quasi-static spring model is used to calculate oil film thickness from the corrected reflection coefficient data. Experiments are described on a simplified cylindrical roller bearing configured by one cylindrical roller, 11ø, and an inner ring from a NU209EM bearing. Reasonable agreement is shown over several loads and speeds with predictions from elastohydrodynamic lubrication (EHL) theory.

Analysis on Dynamic Characteristics of High Speed Cylindrical Roller Bearing

2011 ◽  
Vol 480-481 ◽  
pp. 980-985
Author(s):  
Yan Shuang Wang ◽  
Ning Ning Jin ◽  
Hai Feng Zhu
Keyword(s):  
Film Thickness ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Rotational Velocity ◽  
Dynamic Performance ◽  
Roller Bearing ◽  
Engineering Application ◽  
Oil Film ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

A nonlinear dynamics analysis mathematical model for the high-speed cylindrical roller bearing was built up. Dynamic performance parameters were got by Newton - Raphson method . The rotational velocity regularities of rollers were analyzed at different radial loads. The distribution of minimum oil-film thickness and contact load between rollers and bearing ring raceway were obtained. The results showed that number of loaded rollers increased with the increase of radial loads at a certain speed. Rollers slip seriously at lower radial loads. The rotation speed was low. The minimum oil-film thickness between loaded rollers and inner raceways was less than that of outer raceways. The results were compared with the results of SHARBERTH and comparison was made with testing results. It showed that the dynamic characteristics analysis method of high speed cylindrical roller bearing was accurate, reliable,simple and convenient for practical engineering application.

A Study of the Lubrication and Dynamics of Geometrically Perfect, Lightly Loaded, Cylindrical Roller Bearings with Particular Reference to Shaft Loci

1976 ◽  
Vol 18 (6) ◽  
pp. 263-270
Author(s):  
P. H. Markho ◽  
D. Dowson
Keyword(s):  
Roller Bearing ◽  
Lubricant Film Thickness ◽  
Roller Bearings ◽  
Rolling Element ◽  
Cyclic Movement ◽  
Bearing Loads ◽  
Initial Clearance ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller ◽  
Steady Load

The principal objective of this paper is to ascertain and quantify the cyclic movement of the centre of a shaft in a geometrically perfect, lubricated, cylindrical roller bearing exhibiting initial clearance and subjected to a light and steady load. The movement may be important in relation to the accuracy of location of shafts in roller bearings, and it is shown that a detailed consideration of the rolling element assembly predicts some interesting effects. The study also covers more conventional features of bearing performance such as lubricant film thickness and coefficient of friction, and shows the effect of squeeze to be negligible under steady bearing loads.

Simulation of hydrodynamic lubrication between cage pockets and rollers in cylindrical roller bearings

2014 ◽  
Vol 229 (14) ◽  
pp. 2551-2560 ◽  
Author(s):  
Fangbo Ma ◽  
Fengyuan Jiang ◽  
Qi An
Keyword(s):  
Rotation Speed ◽  
Hydrodynamic Lubrication ◽  
Roller Bearing ◽  
Angular Acceleration ◽  
Oil Film ◽  
Ring Rotation ◽  
Roller Profile ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller ◽  
Oil Film Pressure

A calculating model for roller-pocket rotation and mechanics analysis is established to investigate the hydrodynamic lubrication between rollers and straight-sided cage pockets in a cylindrical roller bearing. An algorithm for calculating roller-pocket oil film pressure and film thickness is developed. Hydrodynamic lubrication simulation of the roller-pocket clearances is carried out. Effects of inner ring rotation speed, cage angular acceleration, roller profile and cage geometry on roller-pocket oil film performance are numerically studied. Some regular curves and conclusions are obtained and analyzed.

An Optical Study of the Lubrication of a 65 mm Cylindrical Roller Bearing

1979 ◽  
Vol 101 (3) ◽  
pp. 327-337 ◽  
Author(s):  
J. C. Pemberton ◽  
A. Cameron
Keyword(s):  
Film Thickness ◽  
Roller Bearing ◽  
Oxide Coating ◽  
Video Tape ◽  
Convex Shape ◽  
Secondary Sources ◽  
Boundary Length ◽  
Cylindrical Roller Bearing ◽  
Inlet Zone ◽  
Cylindrical Roller

All measurements of EHD film thicknesses have been carried out in simulated test machines. This study uses an actual bearing. A test rig using a 65 mm bore radial cylindrical roller bearing has been constructed with a specially designed sapphire window in the outer track. Full loads, and speeds to 3000 rpm were applied. With specially polished rollers and chromic oxide coating on the window excellent interferometric film thickness measurements were found possible. A Xenon flash lamp was used and a Xenon laser of 0–50 pps, pulse half width of 150 ns and peak power of 100 watts was developed for this research. A microscope and 35 mm camera as well as video tape were used for recording results. Arrangements were made to study any chosen roller and the side of the bearing was also open to view. First the film measurements, when corrected for inlet zone viscous heating, agreed admirably with theoretical predictions for mid and exit film thickness. The effect of inlet boundary length on the film was then investigated in some depth. Studying the effect of the multiple roller system, a number of techniques were used to demonstrate that the inlet boundary length, which controls the lubricant film thickness, was itself controlled by the film thickness between the rollers and track in the unloaded zone. The ribs of oil, formed at either edge of the roller, are only secondary sources of oil for replenishment of the inlet film. It is in fact usual (as shown by the convex shape of the inlet zone) for oil to feed out of the inlet zone into the ribs. Oil globules were sometimes observed riding on an air cushion at the entry to the roller-track conjunction, though completely inoperative as providers of oil.

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