Calculation of Specific Pressure on the Contact Surface of the Friction Pair of Rotary Joint

In the spherical friction pair of a rotary joint, the moving ring is a steel spherical body manufactured via heat treatment, while the stationary ring (floating ring) is made of graphite-based wear-resistant material and serves as the compensating element. The graphite material has a compressive strength of no less than 1400 kgf/cm² and a flexural strength of no less than 400 kgf/cm². The average normal specific pressure on the friction pair is far below these strength values, confirming that the design meets the strength requirements from the perspective of specific pressure.

Furthermore, calculations indicate that the fluid load force on the rotary joint increases proportionally with the operating medium pressure-the higher the medium pressure, the greater the load force acting on the friction pair. This is precisely why this rotary joint configuration exhibits superior sealing performance under higher fluid pressures.