Quasi-Static Contact Characteristics of Double Gearboxes with Coupling Misalignment

Due to its vibration reduction and error compensation capabilities, diaphragm couplings are widely used in marine multi-gearbox systems. However, due to the existence of factors such as installation error, system load deformation and asymmetric elastic support, the coupling will inevitably produce misalignment and affect the operation of the gear system. This paper proposesed a calculation method for the quasi-static contact characteristics of the gear pair considering the diaphragm coupling misalignment. By combining the coupling misalignment model, the meshing misalignment model, the system static equilibrium equation and the tooth surface load contact analysis model (LTCA) to construct an iterative calculation process, the contact characteristics analysis of the gear pair under the non-ideal meshing condition caused by the coupling misalignment was realized. Taking the double-gearbox transmission system in the multi-gearbox transmission system of ships as the research object, the influence of coupling misalignment and load torque on the meshing characteristics of the double-helical gear pair was studied. The research results show that the misalignment of the coupling on the double-helical gear near the coupling has a greater impact so that the tooth surface load is asymmetrically distributed, the tooth surface appears disengaged area, away from the coupling gear is not affected by it. As the amount of misalignment increases, the amount of meshing misalignment increases, the gear pair disengagement area increases, the actual contact line length becomes smaller, and the gear pair meshing stiffness decreases. At light loads, the gear pair contact state is more sensitive to coupling misalignment. The tooth surface will produce a large disengagement area and the mesh stiffness curve changes significantly. With the increase of torque, the tooth surface reaches the complete contact state. With the increase of torque, the tooth surface reaches a complete contact state, and there is no disengagement area on the tooth surface. However, due to the misalignment force of the coupling, the meshing misalignment between the left and right tooth surfaces of the double-helical gear pair is asymmetric, so the tooth surface presents the phenomenon of partial load.