According to the rigid body multi-body dynamic motion analysis theory and modeling ideas, the single-stage gearbox can be dissected and analyzed according to the motion relationship of each component. The kinematics topology after analysis is shown in figure (a). Among them, taking the earth as the system’s fixed reference coordinate system, the box adopts the fixed connection (odof) relative to the fixed reference system, that is, to simulate the rigid connection effect between the box and the frame or the earth through bolts; the transmission shafts 1 and 2 have six degrees of freedom relative to the space fixed reference system; at the same time, the bearing between the transmission shaft and the box is simulated by the bearing force element; the gear and the transmission shaft have six degrees of freedom relative to the space fixed reference system The assembly relationship between the shafts is also simulated by the fixed connection (odof); at the same time, the gear pair is simulated by the special gear connection force element, and the specific simulation bearing force element and gear force element are introduced in detail in the next section.
Through the above explanation of the kinematic topological diagram of the gear system, according to the modeling idea of a rigid body dynamics analysis software, the rigid body based multi-body dynamics model is established in strict accordance with the kinematic topological diagram shown in figure (a), as shown in figure (b). The gear unit, transmission shaft unit and bearing unit in the figure respectively establish the simulation analysis model of single-stage gearbox according to the position relationship and motion relationship between system components (Figure (a)).