Property Research And Design On Fluid Pivot Tilting Pad Journal Bearing System

With the modernization of industry, the speed and power of a large number of machineries are increasing, working condition is getting more and more complicated, and bearing is a key component of mechanical equipment, the various aspects of performance requirement of bearing gets higher and higher. The structure of bearing is a key factor of bearing performance. The conventional flood-lubricated tilting pad journal bearing has several disadvantages:relatively high power loss and oil flow requirements, mechanical complexity with attendant costs, pivot fretting, cross-coupled stiffness and damping due to end seals, and, in some applications, insufficient damping capacity. In this paper, the fluid pivot journal bearing is designed, and the conventional tilting pad journal bearing’s mechanical pivot is change to be flexible pivot. It uses fluid to support bearing pad and increases the DOF of bearing pad. So it can further reduce the vibration of the bearing pad.In this paper, the principle of the hydrodynamic lubrication and the hydrodynamic lubrication journal bearing’s status of development which is both in domestic and foreign countries are analysed. The principle and structure of the fluid pivot journal bearing are designed, and the bearing’s working parameters are also designed. Then the flow which includes the design of the bearing and the parameter checking calculation is summarized. Establishing its finite element model, calculating the stress distribution which is on the bearing pad’s back through static analysis of Ansys.Using hydrodynamic lubrication theory to set up the fluid pivot journal bearing’s Reynolds equation, and the process of Reynolds equation’s solution is deduced. Using FDM to calculate the bearing’s pressure distribution of inner oil film, then the bearing static performances which include the load capacity of oil film, the flux of lubricating oil, the consumption of oil film, the temperature rise of oil film are calculated through the integral. Four stiffness coefficients and four damping coefficients of the inner oil film are calculated with the method of perturbation pressure.