Patent ID: 7644647
Filing Date: 2010-01-12
Classification: F15B,F16H,F16J,Y10T

Abstract:
1. A hydraulic actuating device for actuating a shift rod of a gearbox for motor vehicles, comprising a cylinder chamber, provided at a location comprising one of in and on a gear housing, for accommodating a shift piston which is actively connected to the shift rod and which divides the cylinder chamber into two working chambers which are selectively pressurized by a pressure medium from a reservoir for the pressure medium, said working chambers being separated from one another by means of a sealing arrangement arranged on the shift piston; wherein the cylinder chamber is bounded by a cylinder wall that serves as a running surface for the sealing arrangement; wherein the sealing arrangement has seals and is designed in a valve-like manner so that, when at least one working chamber is pressurized by pressure medium, it connects said at least one working chamber to an auxiliary chamber which is delimited by the sealing arrangement and which in turn is connectable to the reservoir for the pressure medium; said auxiliary chamber being axially situated between the seals of the sealing arrangement, and wherein the cylinder chamber is formed by an insert which is inserted in a stepped bore in the gear housing and has a cylindrical section that forms with an inner circumference thereof the cylinder wall.