Theoretical investigation and experimental validation of wear in conjugate rolling friction pairs of two-dimensional piston pumps

The two-dimensional piston pump stands as an optimal power component within pump-controlled hydraulic systems due to its utilization of a rolling friction pair. However, the sustained efficiency of the two-dimensional piston pump over prolonged operational periods remains unverified, primarily owing to the insufficient exploration of the wear mechanism inherent to its unique conjugate rolling friction pair. This study combines theoretical investigation and experimental verification to determine that the primary wear trajectory of the conjugate rolling friction pair is concentrated in the region where the roller moves from the low point to the high point of the cam. The wear is most severe at the mid-point of the cam, with a depth of up to 14 μm, which is consistent with the theoretical analysis. Furthermore, experimental observations unveil inconsistencies in the two-point support of the conjugate rolling friction pair, alongside an observed impact of preload force on the wear phenomenon. These findings furnish crucial theoretical underpinnings for the prospective optimization of design strategies in future endeavors.