Research On Drag Reduction Method Of High Speed Water-lubricated Spiral Groove Bearing

The water-lubricated dynamic pressure spiral groove bearing has the advantages of high stiffness,good stability,large bearing capacity,good viscosity and temperature characteristics and no pollution.It has a broad application prospect in the fields of hydraulic machinery and machine tool spindle.With the high speed of the water lubricated dynamic pressure spiral groove bearing,its friction power loss is obviously increased.Therefore,it is necessary to research the method of reducing the resistance of the high speed water-lubricated spiral groove bearing.The specific content is as follows:(1)The surface texture technology is used as the drag reduction method for the high speed water-lubricated dynamic pressure spiral groove bearing,and the influence of the surface texture parameters on the friction torque and bearing capacity of the bearing is researched,and the design of the texture parameters of the drag reduction surface of the high speed water-lubricated dynamic pressure spiral groove bearing is completed.(2)The lubrication model of high speed water-lubricated spiral groove bearing is established.With the aid of fluid simulation software Fluent,the friction torque and bearing capacity of the bearing under turbulent state are solved.(3)A single pit micro element lubrication model is established,and the drag reduction characteristics of single pits are calculated and analyzed,and the drag reduction mechanism of concave type texture is revealed.(4)Establish a surface textured dynamic pressure spiral groove bearing lubrication model,systematically study the drag reduction and bearing characteristics of the surface texture parameters,study the drag reduction performance of the surface texture parameters under different bearing speeds and water film thickness,and analyze the influence of the working condition parameters on the optimal texture parameters.(5)The drag reduction performance and drag reduction mechanism of variable depth textures are preliminarily researched.The research results are: determined that the formation of counter flow to the vortices in the pit is the main reason for the drag reduction of the pits.The surface texture radius,depth and area ratio are all important factors affecting the drag reduction effect.The texture depth and area ratio of the best drag reduction effect can be obtained under any texture radius.The optimal texture parameters are different under different axle speeds and water film thickness.The variable depth texture has better drag reduction performance compared with the equal depth texture.For a high speed water lubricated spiral groove thrust bearing with a radius of 20 mm,the optimum depth of drag reduction is 100 m and the ratio of the optimum drag reduction area is about 25% at the speed of 30000 rpm and the thickness of the film is 20 u m.The bearing drag reduction rate is 18.87% and the bearing capacity is raised by 7.49%.