Analysis Of Dynamic Characteristics Of Planetary Gear System Considering Tooth Surface Wear

The wind power generation system is mostly framed at wind outlets such as mountains and deserts,which has been normally used in the harsh working environment,and there are many factors such as high-altitude construct and maintenance difficulties.Therefore,the design,manufacture,service life and reliability need to meet with more special requirements.The planetary gear is regarded as a key component of wind power generation gearboxes,and its stability and dynamics characteristics play an important role in the operation of wind turbines.In this paper,the planetary gear system is taken as the research object.In consideration of the factors such as backlash and time-varying meshing stiffness of tooth surface wear,the effects of the wear,internal excitation and external excitation on the system response are studied.The main research contents of this paper are as follows:(1)The lumped mass model of the 5-DOF planetary gear system and the tooth surface wear model with fractal contact pressure are established.The dynamic characteristics of the system in consideration of the wear clearance are analyzed and studied by taking the system parameters.The study shows that the system is very sensitive to the change of backlash in consideration of the tooth surface wear,and the change of backlash can show the change of system response caused by tooth surface wear in detail.(2)The influence of tooth surface friction on the response of the planetary gear system is studied.By changing the value of the friction coefficient,the tooth surface friction is changed,and the bifurcation diagram of the system response is obtained.The study shows that the tooth surface friction plays a hysteretic role in the low-speed region,but accelerates the energy dissipation in the high-speed region.(3)The influence of damping ratio on the response of the planetary gear system is studied.By changing the value of the damping ratio,the bifurcation diagram of the system response is obtained.The study shows that the increase of damping ratio is beneficial to the stability of the system.(4)The influence of meshing stiffness on the response of the planetary gear system is studied.By changing the average meshing stiffness,the bifurcation diagram of the system response is obtained.By changing the value of the fractal dimension D,the time-varying meshing stiffness with tooth surface wear under different fractal dimensions are calculated,and the bifurcation diagram of the system response is obtained.The increase of the average meshing stiffness is beneficial to the stability of the system,and the wear of the tooth surface leads to the reduction of the meshing stiffness,which is not conducive to the stability of the system.(5)The influence of the transmission error on the response of the planetary gear system is studied.By changing the magnitude of the transmission error and adding random components which obeys normal distribution,the bifurcation diagram of the system response is obtained.The study shows that the increase of the transmission error is not conducive to the stability of the system,and random components make the displacement of the system and the maximum meshing force fluctuate.(6)The influence of the external load on the response of the planetary gear system is studied.By changing the value of the constant load and the amplitude of the external load and adding random wind speed,the bifurcation diagram of the system response is obtained.The study shows that the increase of the constant external load makes the system more stable,and the cyclic external load and the random wind load make the system tend to unstable chaotic motion.(7)The centralized mass model and dynamic wear model of the planetary gear-spur gear system for the wind power gearbox are established.The influence of the external load on the tooth surface wear and the influence of spur gear system parameters on the system are studied.By applying different types of external loads to the system,the multi-period meshing force diagram and the wear figure of the tooth surface are obtained,and the influence of the load on the wear of the tooth surface is analyzed.By changing the transmission error,the damping ratio and the average meshing stiffness of the spur gear system,the bifurcation diagram of the system response is obtained.The study shows that the dynamic wear model reflects the interaction and influence between wear and system more accurately,and the meshing of spur gears has a significant impact on the planetary gear system.