Study On Dynamics Characteristics Of The Thring-Ring Gear Reducer With Thermoelastic Coupling

Three-ring gear reducer is the less-tooth differential planet transmission device invented by expertise in China. The principle of the device is novel, which has many advantages, such as large transmission ratio, strong bearing, small volume and simple structure, etc. But it exist big shortcoming as serious fever, vibration noise, the effect of thermal dynamics of three-ring gear reducer is consideredThe input shaft bearing stiffness was calculated after affected by heat in the paper. Then, heated stiffness is regard as the stiffness parameters of three ring gear reducer input shaft dynamics model of planetary bearings.Dynamic model of three ring gear reducer is established. The model includes input shaft subsystem, support shaft subsystem, output shaft subsystem and internal gear board subsystem. Considering the elastic deformation between input shaft and supporting shaft and elastic deformation of gear pair. Oscillatory differential equation of three-ring gear reducer is established, regarding heated stiffness as input parameter. MATLAB programming is used to figure out meshing force and load of each bearing, which provides load for thermal field of three-ring gear reducer.Three-dimensional model of three-ring gear reducer is established. ANSYS finite element analysis software is used. Base plate of reducer is restrained and natural mode and frequency of vibration are obtained using ANSYS to analyze relation between input rotate speed and frequency of vibration. According to the load of three-ring gear reducer, calorific value of each bearing of three-ring gear reducer is calculated. And ANSYS is used to simulate the temperature field of the machine. Then internal forces such as time-varying stiffness incentive, internal error incentive and meshing shock are figured out in consideration of the influence of thermal field to the whole machine. Finally, dynamic response of three-ring gear reducer is obtained. The results shows that:Bearing stiffness decreased when affected by temperature. Planetary bearing load is larger in the dynamic simulation, which causes fragileness. Meshing frequency and rotational frequency of gear system are both deviated from natural frequency, therefore, the system does not produce resonance phenomenon. In the simulation of thermal field, the temperature of the input shaft is the highest, the impact on the transmission is the heaviest. The thermal field of the body of the box is considered during the frequency analysis, which shows that gear meshing frequency has larger influence on vibration of the box.