Design And Experimental Study Of Planetary Wheel Sliding Bearing For Wind Turbine Gearbox

Traditional energy cannot meet the demand of sustainable development due to problems with high cost,limited amounts and environmental pollution.Wind energy is an important development direction of clean energy in China.It has the characteristics of green environmental protection,abundant reserves,unlimited regeneration and short cycle,and has attracted the attention of the power industry.With the development of wind power technology,the demand for single-machine capacity of wind power is growing rapidly,and the largest single-machine capacity in the world has reached 20 MW.As one of the key parts of the fan,the power and size of the gear box increase with the increase of the capacity of the single machine.In high-power gearboxes,the failure rate and processing cost of conventional rolling bearings have significantly improved with the increase in the size of the bearing,which has become a bottleneck problem that restricts the development of large wind turbines.Sliding bearings have the characteristics of high stability,good tolerance to material defects and external impurities,and low processing cost,etc.It is expected to overcome the disadvantages of the failure rate and processing cost of rolling bearings in traditional wind turbines,which increase significantly with the increase of bearing size,and has become the development trend of bearings in large wind turbines.The working conditions of wind turbine sliding bearings are harsh,so high requirements are put forward for material selection,design calculation and test verification of sliding bearings.Aiming at the development of planetary gear sliding bearings for wind power gearboxes,the main research contents of this paper are as follows:(1)According to the mechanical structure of the gear box sizes and operating conditions determine the input parameters of wind power gear planetary wheel sliding bearing,the static and dynamic performance of the bearing is theoretically analyzed and through the special software for wind turbine sliding bearings to calculate the oil film pressure,oil film thickness,the bearing capacity,bearing friction,oil film stiffness and damping parameters.The influence of the selection of clearance ratio,the parameters of bearing inner hole modification and the addition of ring grooves on bearing performance is mainly analyzed,and the bearing structure that meets the design requirements is determined.(2)Design a wind power gearbox sliding bearing test bench,and determine the overall structural scheme of the test bench based on the technical indicators of the test bench.And focus on the design and analysis of the mechanical structure system of the test bench and build a special test platform for wind power sliding bearings that meets the requirements of wind power operating conditions.(3)The rationality of the structural design of the test bench is analyzed through ANSYS,and the shear strength and tensile strength of the connecting bolts are calculated to check the strength of the bolts.Through the experimental analysis of the effect of adding ring grooves on the performance of the wind turbine gearbox planetary sliding bearing,it is determined that the sliding bearing finally adopts a ring grooveless structure.The performance test and start-stop test of the wind turbine gearbox planetary sliding bearing are carried out to test the bearing performance.The performance test results show that: under different radial loads,the bearing temperature and oil film pressure increase with the increase of radial load,bearings can operate properly under extreme loads based on torque changes and rotor wear.Under different bending moment loads,as the bending moment load increases,the bearing temperature rises,the oil film pressure fluctuates all the time,and the fluctuation range remains unchanged.The maximum bending moment load that the bearing can bear is 80 k N.The start-stop test shows that with the increase of the number of start and stop,the bearing temperature increases,the torque remains unchanged,and the average wear of the rotor is less than 0.01 mm.It is determined that the bearing material selection meets the bearing design requirements.