Design And Experimental Research On The Test Rig For Hydrodynamic Oil Film Thickness Of Sliding Bearing

Hydrodynamic sliding bearing uses the hydrodynamic oil film to separate the two contact surfaces of the shaft and the bearing bush.In order to ensure that the hydrodynamic bearing works completely under the state of liquid friction,the minimum oil film thickness when the bearing is working must be greater than the sum of the roughness of the two contact surfaces.Therefore,the study of the minimum oil film thickness through theoretical and experimental analysis is of great significance to the study of sliding bearings.In this thesis,the measurement methods of oil film thickness are studied and analyzed.The measurement principles,advantages and disadvantages of such methods as resistance method,capacitance method,eddy current method,optical fiber displacement sensor method and optical interference method,ultrasonic method and X-ray method are discussed.The indirect measurement method of eddy current sensor is chosen as the measurement method in this thesis.The difference between the indirect measurement method of the multi-channel optical fiber displacement sensor and the indirect measurement method of eddy current sensor is analyzed,and the calculation method of minimum oil film thickness based on the indirect measurement method of eddy current sensor is determined.The scheme of the experimental rig was developed and the type of sensor was selected.The data acquisition system software is written with Lab VIEW.The minimum oil film thickness measurement experimental rig was set up and the experiment was carried out.The experimental results show that,under certain experimental conditions,the minimum oil film thickness of sliding bearing increases with the increase of rotating speed and decreases with the increase of the load.This conclusion is consistent with the existing theory.The minimum oil film angle increases with the increase of rotational speed and decreases with the increase of the load.The stability of the minimum oil film thickness increases first,then decreases and finally increases with the increase of rotating speed.The stability of the minimum oil film angle decreases first,then increases and finally decreases with the increase of rotating speed.Under certain conditions,the increase of speed and load is beneficial to improve the stability of the oil film.At the same time,when the speed is relatively low,the increase of the load can improve the stability of the oil film.At low rotational speed,the stability of oil film is weak,and it is easy to appear oil film vortex,which decreases with the increase of rotational speed.The experimental results can be used as a reference for selecting the appropriate load and speed to meet the stability requirements of oil film and the minimum thickness of oil film.The experimental rig established in this thesis can be used as an experimental platform to study the relationship between oil film stability,load and speed.