Test Research On Dynamic Parameters Of High-speed Water-lubricated Hydrodynamic Spiral Groove Bearings

The test of stiffness coefficient and damping coefficient is one of the important links in the research of journal bearings.The water-lubricated hydrodynamic bearings,especially high-speed hydrodynamic spiral groove bearings,have attracted wide attention at home and abroad for their advantages of high-speed performance,low cost,pollution-free,and no need to expensive auxiliary equipment.It is of great engineering value to carry out the research on dynamic parameters test of high-speed water-lubricated hydrodynamic bearing.High-speed hydrodynamic bearing dynamic parameters is facing many technical problems,such as high rotational speed of the tested bearing,high heat generation of the auxiliary support of the rotor,small bearing clearance and small displacement of the bearing.In this paper,a set of high-speed(24000rpm)hydrodynamic bearing dynamic parameters test device is developed.Based on the static-dynamic method,the dynamic parameters of high-speed water-lubricated hydrodynamic spiral groove bearing are tested and.The main work is as follows:(1)Development of dynamic parameters test bench for high-speed water-lubricated hydrodynamic bearing: The shafting of inverted structure test bench(including oil-air cooling and lubrication system for high-speed rotor and rolling bearing)and its high-speed drive system design,excitation load system design,vibration signal test system design and circulating water supply system design of tested bearing are completed.(2)Static and dynamic performance analysis of high-speed shafting of test-bed:Based on material mechanics theory,the calculation of shafting deflection error is completed,and the deflection error of shafting under load is calibrated by experiment;based on rotor dynamics theory,the critical speed analysis of high-speed rotor support system is completed,and the modal characteristics analysis of shafting and support components is completed based on finite element software.(3)Research on data processing methods of bearing dynamic parameters testing:oriented to static-dynamic method,a data processing method of jounal bearing dynamic parameters testing is developed;a data processing program is compiled by MATLAB,and a static-dynamic method testing software is developed.(4)Dynamic parameters test of high-speed water-lubricated hydrodynamic spiral groove bearing: Based on the static-dynamic method,the dynamic parameters test bench of high-speed water-lubricated hydrodynamic bearing was used to compare thehydrodynamic spiral grooved bearing with the non-grooved cylindrical bearing.The results show that:(1)The design of the shafting and its high-speed drive system is reasonable,the first critical speed is 76219 rpm,and the highest speed is 24000 rpm in the test,which solves the problem of high-speed drive;the oil-gas lubrication system solves the problem of large heat generated by the auxiliary support;and the developed test-bed can be used to test the dynamic parameters of high-speed hydrodynamic bearing.(2)The deflection error of shafting system is large,which can be eliminated by experiment,and the accuracy of test results can be improved.(3)Compared with non-grooved cylindrical bearings,spiral grooved bearings have larger load-carrying capacity and higher stiffness coefficient under small eccentricity,smaller damping,weaker shock resistance and vibration reduction performance.In conclusion,the paper solves the technical problems in the test of high-speed water-lubricated hydrodynamic bearings.The developed test bench provides test conditions for the dynamic performance test of high-speed water-lubricated hydrodynamic bearings.