Analysis of a misalignment-insensitive spur gear transmission using a Rzeppa joint

The design of a novel gear system based on a Rzeppa joint internal interface is presented and analysed. The joint allows the transmission of torque loads while allowing real-time re-alignment of the gear to eliminate non-torque loads arising from misalignment. This gear, when part of a misaligned pair, is shown by means of quasi-static FE simulations to remain essentially under the same stress conditions, even when under considerable misalignment, and to outperform crowned gears. The trade-off is increased contact stress at the ball elements of the joint interface. In addition, the mesh stiffness for the conventional and the novel design are estimated, showing that the proposed design produces a lower but nearly constant stiffness throughout the mesh cycle.