Lubrication Characteristics of Spherical Contact between Cylinder Block and Valve Plate via CFD Analysis

Abstract

Hydraulic systems, which are widely used in the construction of heavy equipment as well as the industrial machinery, defense, and aerospace fields, require controllability and stability. Moreover, hydraulic systems utilize systems such as hydraulic pumps and motors as energy-conversion devices. In this study, lubrication characteristics were attributed to the variation in the gaps at the spherical contact areas between the cylinder block and valve plate. Compared with the lubrication conditions of hydraulic devices with planar contact areas during the suction and discharge processes, spherical contact areas exhibit relatively high performance, high efficiency, and low noise characteristics. However, the lubrication conditions formed in the small clearances of the spherical contact areas of the valve plate, which are fixed to the high-speed rotating cylinder and valve blocks, are directly related to the performance and lifespan of hydraulic devices. Several studies have attempted to improve these characteristics.