Study On Static And Vibration Characteristics Of High Precision Externally Pressurized Bearing

With the development of modern industry and high science and technology, the peopleattach importance to the technology of gas lubrication. Because of the merit of high rotary speed and precision externally pressurized bearing is applied in super precision lathe and measuring instrument. The principle axis generates vibration under outer driving. When the rotary speed come to the intrinsic frequency of system, the journal and the bearing contact thus affect the safety and reliability of equipment, lead to the harm of work personnel and the inefficiency of machine.In order to raise the safety and reliability and life span, the chief works are as follows: On the foundation of development and present research situation of internal and outer externally pressurized bearings, this paper summarized the principle of externally pressurized bearing.Using the finite element method proceeded numerical calculation and simulation on externally pressurized bearing, analyzed the influence on static characteristic of bearing parameter, defined the optimum parameter of bearing. The outcome indicated the numerical calculation based on finite element had high precision and was prone to satisfy boundary condition, and suited to complicated geometry bearing structure.Considering the situation that the gas viscosity is very poor equivalented the axis of externally pressurized bearing to spring-quality structure and built the corresponding vibration equation of two degrees without hindrance. Using the coordinate transformation made the motion equations became to mutual independence two steps differential equation. On the basis of this analyzed the motion and vibration characteristic of externally pressurized bearing in the revolving course at a high speed, and gained the intrinsic frequency and frequency response curve and vibration characteristic curve of system.Theory analysis and computer simulation result indicated the mathematical model and method used are correct, and provided reliable theory basis for design and application of externally pressurized bearing.