The influence of the rod wiper on the leakage from a hydraulic cylinder gland

Abstract

This paper reports the results of testing a number of different rod wiper profiles with one standard rod seal type. Tests have been carried out at different rod speeds, pressures and temperatures on a reciprocating seal test rig. A summary of the leakage results is presented. The results show that the wiper design is an important factor in the control of leakage from a hydraulic cylinder gland. Single lip wipers can produce a much greater leakage than those with a double lip. The disadvantage of the typical double lip wiper is that it can induce a pressure trap between itself and the main rod seal, which can cause either the wiper or rod seal to be ejected from its groove. A new wiper design is described, which was also tested as part of this programme. This profile overcomes the pressure trapping problems of conventional double lip wipers, and is also shown to minimize leakage from the gland and dirt ingress into it.