Mechanism Research Of Single Ball Rolling Thrust Bearing Lubrication And Friction Abrasion

Single ball rolling thrust bearing is a simple structure and easy processing thrust bearing mounted on the displacement pressure oil pump. Displacement pressure oil pump shaft during operation, iprone to axial displacement, thereby forming an axial movement of the pump shaft, the phenomenon has a great influence on the smooth run of the pump as a whole. In order to eliminate the phenomenon of the shaft running smoothly,single ball rolling thrust bearing is designed and is applied on the pump. The bearing use the lessons medium that is from of pump as a lubricating fluid. Through ball knee opened some spiral grooves, it forms a stepped dynamic pressure effect, so that produces carrying capacity to overcome the axial force.Single ball rolling thrust bearing installed on a specific model displacement pump is the research object, the presence form of the thrust bearing lubrication and friction abrasion, deduced thrust bearing lubricated Reynolds equation form, the friction torque and bearing capacity theory and thickness of the equation; using genetic algorithm to optimize the structure parameters of thrust bearing; then, using fluid analysis software FLUENT for structural parameters of spiral groove of thrust bearing to carry on simulation analysis, considering cavitation on the thrust bearing oil film bearing capacity performance.In the process of using genetic algorithms to optimize thrust bearing structural parameters, select a minimum of friction torque and the minimum film thickness maximum as objective function, a two-axis gap, ball corners, oil viscosity and ball curvature coefficient as a constraint conditions, using MATLAB genetic algorithm toolbox to optimize design. First single objective function is optimized, respectively optimal values of design variables and objective function value, and then optimize multi-objective function to obtain a most optimal value of the objective function and design variable values. By optimizing design parameters, the basis is provides for later to use fluid analysis software modeling simulation analysis.FLUENT software is used to design and study a ball screw groove structure parameters groove depth, width, height helix angle and spiral by simulation. Results is:(1) the greater the value of the groove depth, step spiral groove’s dynamic pressure effect is more obvious, the greater the positive of pressure area, the smaller the area of low pressure region; 40μm deep circumferential groove pressure distribution is different from the other groove depth circumferential pressure distribution, and other changes in the circumferential groove depth to pressure section is not very obvious; capacity and traffic is then decreased, both in the groove depth of 160μm maximum.(2) width 0.6mm, 0.7mm of pressure distribution is basically the same, when the width changes from 0.7mm to 0.8mm, pressure contours positive pressure area is mutated, dramatically smaller, when the groove width is larger than 0.8mm, positive pressure area is slowly getting bigger; trends circumferential pressure is a positive pressure zone width increases as the pressure decreases, negative pressure zone width increases as the pressure increases; the bearing capacity in width 0.7 mm~0.8mm mutation decreases, the bearing capacity of other regions increases as the width, the flow rate increases with increasing width.(3) The film pressure distribution of the positive pressure area with the spiral angle increases, the negative pressure area with the spiral angle decreases; circumferential pressure distribution in the positive pressure area increases as the spiral angle Great, pressure decreases and then increases and finally decreases in negative zone, with the spiral angle increases, the pressure increases and then decreases to finally increase; capacity and traffic is increasing along with the spiral angle increases.(4) When the value of a smaller spiral height, this should be spaced helical grooves negative pressure zone, is now in the connected state; the general trend of the oil film pressure distribution is increased with increasing the area of the spiral highly pressurized area large, negative pressure area is reduced; when the spiral height at 1.8mm~1.9mm between the bearing capacity unchanged, when the spiral height is greater than 1.9mm, screw carrying capacity with increasing height increases; with the spiral height is increased, the flow consumption unchanged.