Experimental Measurement of Oil Film Thickness Distribution in Titling-Pad Thrust Bearings by Ultrasonic Piezoelectric Elements

2021 ◽  
Author(s):  
Jie Zhu ◽  
Kai Zhang ◽  
Kai Feng
Keyword(s):  
Film Thickness ◽  
Experimental Measurement ◽  
Thickness Distribution ◽  
Oil Film ◽  
Thrust Bearings ◽  
Piezoelectric Elements

An Accurate Solution of the Gas Lubricated, Flat Sector Thrust Bearing

1977 ◽  
Vol 99 (1) ◽  
pp. 82-88 ◽  
Author(s):  
I. Etsion ◽  
D. P. Fleming
Keyword(s):  
Film Thickness ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Thickness Distribution ◽  
Maximum Load ◽  
Accurate Solution ◽  
Operating Conditions ◽  
Thrust Bearings ◽  
Practical Design ◽  
Minimum Film Thickness

A flat sector shaped pad geometry for gas lubricated thrust bearings is analyzed considering both pitch and roll angles of the pad and the true film thickness distribution. Maximum load capacity is achieved when the pad is tilted so as to create a uniform minimum film thickness along the pad trailing edge. Performance characteristics for various geometries and operating conditions of gas thrust bearings are presented in the form of design curves. A comparison is made with the rectangular slider approximation. It is found that this approximation is unsafe for practical design, since it always overestimates load capacity.

Measurement and calculation of oil film thickness in a ball bearing

2018 ◽  
Vol 70 (8) ◽  
pp. 1500-1508 ◽  
Author(s):  
Baogang Wen ◽  
Hongjun Ren ◽  
Pengfei Dang ◽  
Xu Hao ◽  
Qingkai Han
Keyword(s):  
Film Thickness ◽  
Ball Bearing ◽  
Performance Indicator ◽  
Thickness Distribution ◽  
Content Type ◽  
Oil Film ◽  
Capacitance Method ◽  
Lubrication Condition ◽  
Series Of Experiments ◽  
External Loads

PurposeThe oil film thickness provides a key performance indicator of a ball bearing lubrication condition. This paper aims to propose an approach to calculate and measure the oil film thickness of the bearing.Design/methodology/approachOn a specially designed test rig, measurement of the capacitance is used to monitor the oil film thickness of ball bearing. A corrected film thickness formula taking account of the influences of non-Newtonian shear thinning and thermal is introduced to predict the oil film thickness of ball bearing. And then the film thickness distribution and the corresponding capacitances are calculated.FindingsMeasurement and calculation of oil film thickness in a ball bearing are carried out under various rotating speeds and external loads. By comparing the calculated capacitances with measured results, it can be concluded that the calculated results obtained by the amended film thickness formula are much closer to the test findings than the classical computed values according to Hamrock–Dowson.Originality/valueA new corrected film thickness formula is introduced in predicting oil film thickness of ball bearing and verified by the series of experiments according to capacitance method.

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.

3133 Effect of EHL Oil Film Thickness Distribution on Running-in of Contact Surface under Mixed Lubrication

2008 ◽  
Vol 2008.4 (0) ◽  
pp. 63-64
Author(s):  
Susumu MATSUMOTO ◽  
Yoshiaki KIDO ◽  
Koji NISHIWAKI ◽  
Takeshi YOSHIMI
Keyword(s):  
Film Thickness ◽  
Contact Surface ◽  
Thickness Distribution ◽  
Mixed Lubrication ◽  
Oil Film

The Influence of Injection Pockets on the Performance of Tilting-Pad Thrust Bearings—Part II: Comparison Between Theory and Experiment

2007 ◽  
Vol 129 (4) ◽  
pp. 904-912 ◽  
Author(s):  
Niels Heinrichson ◽  
Axel Fuerst ◽  
Ilmar Ferreira Santos
Keyword(s):  
High Pressure ◽  
Film Thickness ◽  
Pressure Distribution ◽  
The Other ◽  
Oil Film ◽  
Thrust Bearings ◽  
Pressure Injection ◽  
Tilting Pad ◽  
Oil Injection ◽  
High Pressure Injection

This is Part II of a two-part series of papers describing the effects of high-pressure injection pockets on the operating conditions of tilting-pad thrust bearings. The paper has two main objectives. One is an experimental investigation of the influence of an oil injection pocket on the pressure distribution and oil film thickness. Two situations are analyzed: (i) when the high-pressure oil injection is turned off and (ii) when the high-pressure injection is turned on. The other objective is to validate a numerical model with respect to its ability to predict the influence of such a pocket (with and without oil injection) on the pressure distribution and oil film thickness. Measurements of the distribution of pressure and oil film thickness are presented for tilting-pad thrust bearing pads of ∼100cm2 surface area. Two pads are measured in a laboratory test rig at loads of ∼1.5MPa and ∼4.0MPa and velocities of up to 33m∕s. One pad has a plain surface. The other pad has a conical injection pocket at the pivot point and a leading-edge taper. The measurements are compared to theoretical values obtained using a three-dimensional thermoelastohydrodynamic (TEHD) numerical model. At the low load, the theoretical pressure distribution corresponds well with the measured values for both pads, although the influence of the pocket is slightly underestimated. At the high load, large discrepancies exist for the pad with an injection pocket. It is argued that the discrepancies are due mainly to geometric inaccuracies of the collar surface, although they may to some extent be due to the simplifications employed in a Reynolds equation description of the pocket flow. The measured and theoretical values of oil film thickness compare well at low loads and velocities. At high loads and velocities, discrepancies grow to up to 25%. This is due to the accuracy of the measurements. When using hydrostatic jacking the model predicts the start-up behavior well.

The Influence of Injection Pockets on the Performance of Tilting-Pad Thrust Bearings: Part II — Comparison Between Theory and Experiment

2006 ◽  
Author(s):  
Niels Heinrichson ◽  
Axel Fuerst ◽  
Ilmar Ferreira Santos
Keyword(s):  
Film Thickness ◽  
Thrust Bearing ◽  
Three Dimensional ◽  
Leading Edge ◽  
Operating Conditions ◽  
Oil Film ◽  
Thrust Bearings ◽  
Tilting Pad ◽  
High Pressure Injection ◽  
Theoretical Pressure

This is Part II of a two-part series of papers describing the effects of high pressure injection pockets on the operating conditions of tilting-pad thrust bearings. Measurements of the distribution of pressure and oil film thickness are presented for tilting-pad thrust bearing pads of approximately 100 cm2 surface area. Two pads are measured in a laboratory test-rig at loads of approximately 0.5, 1.5 and 4.0 MPa and velocities of up to 33 m/s. One pad has a plain surface. The other pad has a conical injection pocket at the pivot point and a leading edge taper. The measurements are compared to theoretical values obtained using a three dimensional thermoelasto-hydrodynamic (TEHD) numerical model. At low and intermediate loads the theoretical pressure distribution corresponds well to the measured values for both pads although the influence of the pocket is slightly underestimated. At high loads large discrepancies exist for the pad with an injection pocket. It is argued that this is likely to be due to the unevenness of the collar surface. The measured and theoretical values of oil film thickness compare well at low loads. At high loads discrepancies grow to up to 25 %. It is argued that this is due to the accuracy of the measurements.

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