Fte Automotive Gmbh

Hubert Derra

Dieter Grimmer

Egid Macht

Stefan Gebert

Jürgen Ryba

Jochen Schneier

Robert Müller

Wolfgang Schor

Andreas Mix

A hydraulic cylinder has a pressure chamber delimited on one side by a piston accommodated in a longitudinally displaceable manner in a cylinder housing, on the other side by a housing bottom of the cylinder housing, and radially outwards by a circumferential wall of the cylinder housing, wherein the pressure chamber can be acted upon by a pressure medium via a pressure connection provided at the housing bottom in order to displace the piston in the cylinder housing. An insertion part is inserted in the pressure connection and has a channel section which communicates with the pressure connection and, in the installed position of the hydraulic cylinder, extends essentially in the vertical direction and opens into the pressure chamber in the vicinity of the circumferential wall of the cylinder housing. As a result, a hydraulic cylinder is provided which is compact and is designed in a simple manner, and which can be deaerated in a simpler manner compared to the prior art.

Hydraulic cylinder, in particular slave cylinder for a hydraulic clutch actuation system for motor vehicles

A hydraulic cylinder comprises a piston assembly with a piston and a piston rod, a cylinder housing with a housing bottom, a pressure chamber in the cylinder housing delimited by the piston and housing bottom, a spring element which prestresses the piston assembly away from the housing bottom, and a fixing element which fixes the piston assembly in a predefined stroke position relative to the cylinder housing prior to first actuation of the hydraulic cylinder and is designed to release the piston assembly relative to the cylinder housing upon first actuation of the hydraulic cylinder. The spring element is arranged on the side of the piston which is remote from the pressure chamber, whereas the fixing element is provided in the pressure chamber at the housing bottom and co-operates with a mating element on the piston to releasably fix the piston assembly relative to the cylinder housing.

A hydraulic cylinder () is disclosed comprising a cylinder housing () with a housing bore (), a piston () held longitudinally displaceably in the housing bore, a piston rod () allocated to the piston and a fixing element () which before a first cylinder operation is detachably connected with the piston rod and fixes this in a predetermined stroke position in relation to the cylinder housing and is designed to release the piston rod in relation to the cylinder housing on the first cylinder operation. According to the invention, before the first cylinder operation the fixing element in a first position is detachably connected with a center area () of the piston rod and on cylinder first operation can be moved from the first position to a second position area (), in particular stationary in relation to the piston rod, in which it can be fixed for further cylinder operations. The result is a simply designed hydraulic cylinder in which the fixing element provided for temporary tying of the piston rod in particular leaves untouched the end of the piston rod facing away from the piston and also does not hinder further the operation of the hydraulic cylinder.

Hydraulic cylinder

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Neubrunn, Germany

Hubert Derra