Rotary hydraulic cylinder

Abstract

A rotary fluid pressure actuator includes a housing having an inner actuator chamber with a cylindrical side wall extending between a pair of end walls. An integral vane rotor assembly, including a shaft and end discs, is positioned in the chamber and is rotationally reciprocated in response to the direction of flow of fluid to and from chamber segments of the housing. A fixed dam is secured between flanges in an elongated opening along the cylindrical side wall of the housing, the dam extending radially into the chamber from the opening to abut against the shaft between the end discs. The dam acts as a stop to limit the reciprocal motion of the vane and shaft in each direction.

1 . A rotary hydraulic actuator comprising: 
 (a) a housing having an inner actuator chamber including a cylindrical side wall extending between a pair of end walls;    (b) a shaft centrally positioned within the chamber with respect to the cylindrical side wall, for rotation about an axis, the shaft extending through the housing;    (c) a spaced pair of end discs extending radially from the shaft and integral therewith, the end discs adjacent the end walls of the chamber;    (d) a vane extending radially from the shaft between the spaced pair of end discs, the vane being integrally associated with the shaft and end discs, the vane having opposite faces extending outwardly from the shaft to an outer edge of the vane adjacent the side wall of the chamber;    (e) an elongated opening along the cylindrical side wall of the housing, with outwardly extending parallel flanges extending along sides of the opening;    (f) a fixed dam secured between the flanges and filling the opening along the cylindrical side wall of the housing, the dam extending radially into the chamber, from the opening, with an inner end lying adjacent the shaft between the end discs, the dam having a pair of opposed side surfaces which divide the chamber into a pair of chamber segments extending between each side surface of the dam and a corresponding face of the vane; and    (g) a pair of fluid inlet and outlet ports associated with the actuator for delivery to and removal of fluid with respect to each chamber segment,    whereby the vane and shaft are rotatably reciprocated within the housing, the vane abutting against the dam at its limit of reciprocal motion in each direction, in response to the pressure of fluid passed sequentially to and from the chamber segments during operation of the actuator.    
   
   
       2 . An actuator according to  claim 1 , wherein the fluid inlet and outlet ports extend through the chamber side wall on each side of the dam and adjacent thereto.  
   
   
       3 . An actuator according to  claim 1 , wherein the faces of the vane are flared outwardly towards the vane's outer edge, and the opposite side surfaces of the dam are contoured to conform to the corresponding faces of the vane when the vane abuts against the dam.  
   
   
       4 . An actuator according to  claim 2 , wherein the shaft has a lesser diameter between the end discs than its diameter beyond the end discs.