Journal bearing in high-speed working conditions will generate a lot of heat, which affects its working performance. Based on hydrodynamic lubrication theory, a model of the thermal hydrodynamic lubrication was built, and the distributions of temperatures and pressures of the oil film were obtained from the simultaneous solution of generalized Reynolds, energy and viscosity-temperature equations. The results show that the temperature will increase and the pressure decrease of the lubrication oil film with the rising of the rotating speed, which will make the the bearing capacity decrease. Compared with the traditional isothermal model, the thermal hydrodynamic lubrication model is more consistent with the engineering practice.

In order to truly reflect dynamic performance, the test machine for high speed precision micro bearing is obtained in this paper which includes gas generator part, measuring device body part, power controlling part and display part and so on, based on the technology of aerostatic bearing. Meanwhile, dynamic characteristic test and principle are elaborated at length. The result shows the test method and principle of the test machine are very effective.