Multi-body Dynamics Research Of Ball Bearings-spiral Bevel Gears System

As a typical mechanical transmission device,Ball bearings-spiral bevel gear system has been used widely in the automotive, aerospace, Marine, defense and other fields,for its powerful carrying capacity,large transmission ratio,transmission stability, Ball bearing-spiral bevel gear system has a sophisticate internal structure, with a variable incentive sources from the internal or the external system, any parts performance or working condition changes will greatly affect the system as a whole. With modern industrial production towards high speed, overload, precision and high reliability development, set up the dynamics analysis model of ball bearings-spiral bevel gears multi-body system in accordance with the engineering practice as much as possible,has become increasingly urgent and important. This article from the national natural science fund project "high-performance rolling bearing flexible multi-body contact-spiral bevel gear system dynamics research" (11462008). Combined with MBD (multy body dynamics) and FEA (finite element analysis) method, the ball bearing of spiral bevel gears-spiral bevel gear system dynamics analysis model is established considering the flexible deformation of the gear, and the corresponding dynamics analysis has been done, the paper’s main research work is as follows:(1) Combining the theory of Hertz contact theory and elastic hydrodynamic lubrication (EHL), considering the bearing dynamic lubrication, to calculate the angular contact ball bearing steel ball and ring raceway, the equivalent contact stiffness between the cage. Angular contact ball bearing multi-rigid-body dynamics analysis model is established, the contrast analysis of the dry contact and lubrication condition internal contact ball bearing load distribution. Consider lubricating oil film stiffness parameters, this paper analyses the structure parameters and working conditions affect the performance of ball bearing cage dynamics, calculate that maintains stability and reduce with the increase of rotational speed and load, but maintains a skid rate increases with the rotating speed, and decreases with the load.(2) According to the principle of spiral bevel gear machining, deduced the mathematical equation of spherical involute and spiral guide line, implements the bevel gear parametric design, completed the 3 d entity modeling of spiral bevel gears. 5 was established by applying the finite element simulation analysis method, the meshing of spiral teeth hexahedral grid model, according to the load of gear tooth contact method, further calculation to obtain the single tooth meshing contact stiffness, for considering the spiral tooth meshing tooth surfaces more dynamic contact relation of gear system dynamics research laid the foundation. Meshing contact condition based on the gear assembly relation of the modal analysis of spiral bevel gears, the gear on the corresponding vibration frequency and vibration mode.(3) Based on C-B modal coupling method, combined with finite element method, established the model of flexible body of spiral bevel gears. Considering internal multibody dynamic contact relationships and ball bearing screw tooth tooth dynamic contact relationship, the more established the ball bearing spiral bevel gear system model of the coupled multi-body dynamics analysis, contrast analysis condition and operation mode under the condition of the ball bearings-dynamics characteristic of spiral bevel gears, the gear vibration displacement, vibration acceleration, gear is obtained internal contact force and contact force, the ball bearing cage of centroid trajectory, etc. The calculation results, the results show that the mass center of gear vibration displacement is affected by cage speed frequency. Steel ball and raceway contact force is mainly affected by rotation speed, and has little effect on the load.