Hydraulic axial piston pump able to operate in both directions

Abstract

A hydraulic pump rotates in both directions of rotation, and includes a casing, a common drive shaft mounted so as to be able to rotate relative to the casing, two swashplates borne by the common drive shaft, these two swashplates being symmetric and opposite each other and each including one supply crescent, a respective hollow piston pressing against each swashplate via the intermediary of a slipper shoe and designed to slide in a respective cylinder connected to the casing, the crescent of the swashplate being in each case arranged so as to pass over the hollow piston during a suction phase of the hollow piston, each cylinder being fitted with a check valve on the discharge side, such that only one of the two swashplates provides an output when the drive shaft rotates in one direction, the other swashplate providing an output when the shaft rotates in the other direction.

1 . A hydraulic pump which rotates in both directions, and which comprises a casing, a common drive shaft mounted so as to be able to rotate relative to the casing, two swashplates borne by the common drive shaft, these two swashplates being symmetric and opposite each other and each comprising one supply crescent, a respective hollow piston pressing against each swashplate via the intermediary of a slipper shoe and designed to slide in a respective cylinder connected to the casing, the crescent of the swashplate being in each case arranged so as to pass over the hollow piston during a suction phase of the hollow piston, each cylinder being fitted with a check valve on the discharge side, such that only one of the two swashplates provides an output when the drive shaft rotates in one direction, the other swashplate providing an output when the shaft rotates in the other direction. 
     
     
         2 . The hydraulic pump as claimed in  claim 1 , comprising two discharge openings, one discharging the liquid pressurized by one of the swashplates, the other discharging the liquid pressurized by the other swashplate depending on the direction of rotation of the shaft. 
     
     
         3 . The hydraulic pump as claimed in  claim 1 , comprising at least one supply opening which opens into at least one of the chambers in which the swashplates oscillate. 
     
     
         4 . The hydraulic pump as claimed in  claim 1 , wherein the supply liquid passes through one or other of the rolling bearings carrying the shaft which carries the swashplates. 
     
     
         5 . The hydraulic pump as claimed in  claim 2 , comprising at least one supply opening which opens into at least one of the chambers in which the swashplates oscillate. 
     
     
         6 . The hydraulic pump as claimed in  claim 2 , wherein the supply liquid passes through one or other of the rolling bearings carrying the shaft which carries the swashplates.