COMPACT ACTUATOR WITH HYDRAULIC SEAL

摘要

An actuator (36) for use in an active mount system includes a piston (72) disposed in a casing (66), and a piston rod assembly (70) that is connected to one of a vibrating component or its support structure. A seal assembly (74), disposed either in a groove in the piston or in a groove in the casing, provides a seal betwen the piston and casing. The seal assembly includes an annular seal member (94) comprising polytetrafluoroethylene resin, backing rings (96, 98), and an annular compression spring. The spring exerts force axially to compress the seal member, impelling the seal member to increase in dimension radially and maintain the seal between the piston and casing, and allows for volume expansion of the seal member with temperature. The piston may be barrel-shaped for use in a casing with a cylindrical interior surface, or the inner surface of the casing may define an hourglass-shape for use with a cylindrical piston.