A Simulation And Experimental Study On Loading Property Of Small Hybrid Bearing

Bearing is a key component in the spindle of machine tool. It influences the working performance and useful life span of spindle directly. Hybrid bearing combines the effect of hydrodynamics and the static pressure to develop a new type of bearing. The new bearing has higher speed, smaller starting torque, higher rotary precision, etc. This bearing will play an important role for the improvement of the machine tool in China.Recently, most size of hybrid bearings which are researched in China are larger than diameter60mm and the size which are smaller than diameter25mm are few. In this paper, some computer simulation and experimental study to research working property of hybrid bearing with small size of diameter25mm have been carried out. The main research works and achievements are as follows:(1) Researching on the principle of working for small size hybrid bearing, studying of the relationships between working loads and the actual force on bearing with stress analysis.(2) Constructing3-D modeling for small size hybrid bearing and making computer simulation to research the relationships between oil pressure, eccentricity, bearing speed and loading capacity.(3) Developing an experimental system which used for measuring load force and the displacement of spindle.(4) Measuring of the radial displacement of spindle in various working parameters such as eccentricity of spindle, oil pressure and working speed, analyzing of influence of those working parameters on the radial displacement and loading capacity of spindle with computer simulation. The study results showed that the oil supply pressure and eccentricity of spindle impact on loading capacity of bearing remarkably. The influence of spindle speed on the loading capacity of bearing are observable with some lower oil pressure, but if the oil pressure is higher, the spindle speed influence on loading capacity of spindle become indistinctively. When the eccentricity of spindle is larger than a critical value, the rigidity of spindle increases quickly and the critical value is between0.7and0.8in this experiment.In this paper, the small hybrid bearing are simulated in computer and perform experiment about the bearing property of small hybrid bearing. The result of this study is helpful for engineering application and study of small hybrid bearing.