Nonlinear Dynamic Modeling and Dynamic Load Study of Integrated Transmission Spindle-Bearing System

This paper For the integrated transmission spindle-bearing system, a bearing nonlinear dynamics model considering nonlinear Herz contact force is established, on the basis of which a 25-degree-of-freedom spindle-bearing system bending and torsion coupling nonlinear dynamics model is established by considering the eccentricity, and the effects of the gearing on the bending and torsion dynamic loads of both sides of the main shaft under the rated working condition are comparatively analyzed by taking a certain integrated transmission spindle-bearing system as an example, and the time-frequency characteristic of the dynamic loads on both sides of the main shaft are further investigated. The effects of gear position on the bending and torsional dynamic loads on both sides of the spindle at the rated operating conditions are compared and analyzed, and the time-frequency characteristics of the dynamic loads on both sides of the spindle are also investigated. With the increase of the gear position, the bending vibration load of the transmission spindle shows an increasing trend, while the torsional dynamic load shows a decreasing trend; due to the asymmetric structure of the transmission spindle, the bending and torsional dynamic load of the right side of the transmission spindle is larger than that of the left side; with the increase of the torsional stiffness ratio, the right side of the torsional dynamic load of the spindle is decreasing firstly and then increasing, while the left side of the torsional dynamic load is decreasing; when the ratio of torsional stiffness is equal to 1, the torsional stiffness ratio and eccentricity on the dynamic load of both sides are not affected by the torsional load. When the torsional stiffness ratio of both ends is equal to 1, the torsional dynamic loads of both sides are equal, and the maximum torsional dynamic load in 2nd gear is reduced by 32.5% compared with the initial design, and the maximum torsional dynamic load in 6th gear is reduced by 26.5% compared with the initial design; with the increase of eccentricity, the bending dynamic load in different gears shows the trend of incremental increase, and the higher the gear and the higher the rotational speed, then the bending dynamic load is more sensitive with the change of the eccentricity.