Design Of The Testing Device For The Dynamic Characteristics Of High Speed Water-lubricated Hydrodynamic Bearing

Water-lubricated bearing has been widely used in the fields of high speed machine tool spindle,ship and generator because of its low friction,low power consumption,high rotation precision and no pollution.Dynamic characteristics are important performance parameters of high speed water lubricated bearings.Therefore,it is of great engineering value to develop a testing device for dynamic characteristics of high speed water-lubricated bearings.This paper focuses on the design of the testing device for the dynamic characteristics of high speed water-lubricated bearing.The main research work is as follows:(1)In view of the static and dynamic method,it is completed that the design of the testing device for the dynamic characteristics of high speed water-lubricated bearing,including the structural layout,the shaft system structure and the bearing lubrication design.(2)Based on the theory of material mechanics and the theory of fluid lubrication,the theoretical model of the deflection of the spindle under the action of disturbance power is established,and the influence of the displacement measurement results on the experimental results is analyzed by neglecting the influence of the cross stiffness.The effect of the displacement measurement results to the experimental results is analyzed by the numerical method and the finite element method.(3)The CAD and CAE models of the spindle system structure of the testing device are established by using Solidworks and ANSYS Workbench software.The dynamic model of the spindle system structure is established and the modal of the spindle system structure and its sensitivity analysis are carried out.The results of the study show that:(1)The influence of spindle deflection on the experimental results is related to the structure of spindle system and the dynamic characteristics of experimental bearing.For the designed spindle system structure,the influence of the deflection of the spindle on the relative displacement can be ignored when the stiffness of the water film is less than 7.3×10~7N/m.Otherwise,the measured displacement should be corrected.(2)For the designed spindle system structure,the modal frequency of the pitching motion of the bearing housing is close to the working frequency,so that the spindle system structure needs to be improved or constraint conditions need to be changed.The modal frequency of the bearing housing can be increased to more than the working frequency by using lighter material(aluminium alloy)for bearing housing with no effect to the work of the testing device.