The Influence of Kapitsa’s Viscosity on the Hydrodynamic Lubrication of a Cylindrical Roller Bearing as Affecting Contact Pressure and Oil-Film Thickness

1958 ◽  
Vol 25 (4) ◽  
pp. 620-622
Author(s):  
F. W. v. Hackewitz
Keyword(s):  
Film Thickness ◽  
Contact Pressure ◽  
Hydrodynamic Lubrication ◽  
Roller Bearing ◽  
Oil Film ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

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.

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.

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.

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.

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.

Skidding research of a high-speed cylindrical roller bearing with beveled cage pockets

2020 ◽  
Vol 72 (7) ◽  
pp. 969-976
Author(s):  
Yanbin Liu ◽  
Zhanli Zhang
Keyword(s):  
Peer Review ◽  
Tilt Angle ◽  
High Speed ◽  
Hydrodynamic Lubrication ◽  
Roller Bearing ◽  
Front Wall ◽  
Dynamics Model ◽  
Content Type ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

Purpose This study aims to uncover the influencing mechanism of the tilt angles of the cage pocket walls of the high-speed cylindrical roller bearing on the bearing skidding. Design/methodology/approach A novel cylindrical roller bearing with the beveled cage pockets was proposed. Using the Hertz contact theory and the elastohydrodynamic and hydrodynamic lubrication formulas, the contact models of the bearing were built. Using the multibody kinematics and the Newton–Euler dynamics theory, a dynamics model of the bearing was established. Using the Runge–Kutta integration method, the dynamics simulations and analysis of the bearing were performed. Findings The simulation results show that the effects of the tilt angles of the front and rear walls of the pocket on the bearing skidding are remarkable. Under a 5° tilt angle of the front wall of the pocket and a 10° tilt angle of the rear wall, the bearing skidding can be effectively decreased in the rotational speed range of 10,000-70,000 r/min. Originality/value In this paper, a novel cylindrical roller bearing with the beveled cage pockets was proposed; a dynamics model of the bearing was established; the influence mechanism of the tilt angles of the front and rear walls of the pocket on the bearing skidding was investigated, which can provide fundamental theory basis for optimizing the pocket. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0035/

A Performance Prediction of Microgrooved Bearings Under Mixed Lubrication

2008 ◽  
Author(s):  
Katsuhiro Ashihara ◽  
Hiromu Hashimoto
Keyword(s):  
Film Thickness ◽  
Contact Pressure ◽  
Hydrodynamic Lubrication ◽  
Calculation Model ◽  
Mixed Lubrication ◽  
Severe Condition ◽  
Oil Film ◽  
Precise Prediction ◽  
Lubrication Condition ◽  
Bearing Alloy

In the designs and analysis of engine bearings for automobiles, the precise prediction of the lubrication condition in severe condition is important. In the mixed-elasto-hydrodynamic lubrication analysis, the contact between the projections of surface roughness distributed stochastically is usually considered. This paper describes a theoretical model under the mixed lubrication in the microgrooved bearing. In this modeling, it is assumed that the section shape of microgrooved bearing alloy takes the circular arc form. In the part where contact is caused, the contact pressure is calculated by the Hertzian equation. The elastic deformation of the bearing by the mixed pressure with which oil film pressure and contact pressure are mixed by each allotment ratio is considered. Moreover, the balance requirement between the sum total of mixed pressure on bearing surface and the journal load is met. Under such an assumption, the numerical calculation model is newly obtained to predict the bearing performance in the mixed lubrication of microgrooved bearing. The numeric solutions of EHL based on the mixed lubrication are compared with EHL based on the fluid lubrication. The predicted oil film thickness at the center of bearing by the mixed lubrication model is remarkably thin compared with that by the fluid lubrication model. This shows that the load ability of the oil film thickness decreases by generating contact.

scholarly journals Numerical study of the effect of roller profile and ring skew on roller raceways contact pressure in cylindrical roller bearing

2019 ◽  
Author(s):  
J.M. Klebanov ◽  
V.R. Petrov ◽  
I.E. Adeyanov
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Numerical Study ◽  
Roller Bearing ◽  
Contact Pressure Distribution ◽  
Normal Contact ◽  
Modified Method ◽  
Normal Contact Pressure ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

Occurring during operation inhomogeneity of the contact pressure distribution between the rollers and the bearing rings due to skew affects the durability and dynamics of the bearing parts. The article describes a modified method of normal contact pressure determination according to the theory, based on the Bousinessque equation. The efficiency of the method is estimated and results of numerical simulation of normal contact pressure distribution in the contact of the roller with the raceway of the inner ring of the cylindrical roller bearing for different roller profiles, loads, and skew angles are presented. It is shown that the logarithmic profile creates the lowest pressure concentration at the ends of the roller.

Cage Instabilities in High-Speed Cylindrical Roller Bearings

2010 ◽  
Author(s):  
Zhenhuan Ye ◽  
Liqin Wang ◽  
Le Gu ◽  
Dezhi Zheng
Keyword(s):  
Angular Velocity ◽  
Direct Contact ◽  
High Speed ◽  
Hydrodynamic Lubrication ◽  
Normal Load ◽  
Roller Bearing ◽  
Clearance Ratio ◽  
Starting Time ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

A dynamic model of the cage in an oil-lubricated cylindrical roller bearing was developed and the cage whirl has been researched by this model. In model, the forces between elements, especially the effect of EHL (Elastic Hydrodynamic Lubrication) between cage pockets and rollers were fully considered according to the geometry relationship between elements. The effects of variation in clearance ratio, load and bearing operating velocity on cage whirl have been investigated. The results of the effect of cage clearance on cage instability basically accord with the Gupta’s results, but the starting time of the direct contact between cage and guiding race is delayed while the EHL was considered. The effect of normal load is more important than bearing angular velocity on cage whirl.

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.

Sign in / Sign up

Export Citation Format

Share Document