The Theoretical And Experimental Research On Preload And Supporting Stiffness Of A Wire Race Ball Bearing

As a nonstandard ball bearing, the wire race ball bearing which possesses higher rotary precision, much less inertia, stronger load ability and more flexibility size design has been extensively used in many fields during recent years. The wire race ball bearing which is researched in this thesis is used in a certain type of aircraft simulating rotary table. It requests higher positioning accuracy, lower friction torque and higher supporting stiffness. Hence, the preload of the wire race ball bearing and the supporting stiffness were investigated by the analytical method and experiments.In view of controlling the preload magnitude by measuring the friction starting torque way, the mathematical model of the relationship between the friction starting torque and the preload magnitude was built, based on bearing friction torque generated mechanism, elastic hysteresis theory, micro slippery narrow-band theory, Jones race control theory and principle of superposition; the mathematical model of the relationship between the rolling resistance starting torque and the preload magnitude was built, based on the analysis of the spatial force system, the Coulomb's law of rolling resistance and the theorem of equivalent spatial couple. Through a numerical method developed in MATLAB?, two mathematical model theoretical curves were obtained by employing an example of a wire race ball bearing used in a certain type of aircraft simulating rotary table. Experimental program has been designed. Experiment measurement system has been set up. The two mathematical model of the relationship between the starting torque and the preload magnitude has been proved right. By measuring the friction starting torque way to control the preload magnitude has been achieved. Preload control of WRBB has been solved effectively.WRBB which is applied in three-axes simulation test turntable is a major bearing load components and the vibration character and the structure stability character of axial has the extremely close relationship with the shafting supporting stiffness. Hence, according to the non-conforming Hertz contact theory, the principle of virtual displacement, the cosine law, L'Hospital's rule and flexibility and load distribution, the mathematical models of the axial supporting stiffness, the radial supporting stiffness and the overturning supporting stiffness were developed. By designing the experiment measurement program of supporting stiffness, designing the axial, radial and overturning loading mechanisms, setting up the experiment measurement system, the mathematical model of the supporting stiffness has been proved right and provides parametric support for engineering application of the wire race ball bearing.