Friction characteristics between seal ring and cylinder in pneumatic balancer have great significance to the optimization and upgrading of the working state. The variation law of lubricating grease film thickness and contact stress in space is solved by MATLAB. The results show that the dynamic load of pneumatic balancer has little effect on the friction characteristics of cylinders in the main contact area, and the relative motion speed can be increased. The method of rheological index can increase the thickness of lubricating grease film. In order to further study the lubrication performance of sealing rings, a two-dimensional finite element model of O-ring was established, and its transient contact strength characteristics were studied according to different pre-compression rates. The results show that the pre-compression ratio of 15% to 20% can maintain good sealing performance and ensure the working life of seal rings.
