Swashplate position sensor arrangement

Abstract

A sensor arrangement for determining an actual swashplate angle of a swashplate pivotally attached to a variable displacement hydraulic pump includes a control piston operable to control an angle of the swashplate relative to the variable displacement pump; a position marker arranged on the control piston; and a sensor arranged along the control piston to detect a movement of the position marker.

1 . A sensor arrangement for determining an actual swashplate angle of a swashplate pivotally attached to a variable displacement hydraulic pump, the arrangement comprising:
 a control piston operable to control an angle of the swashplate relative to the variable displacement pump;   a position marker arranged on the control piston; and   a sensor arranged along the control piston to detect a movement of the position marker.   
     
     
         2 . The arrangement of  claim 1 , wherein the sensor is adapted to detect the movement of the position marker in a contactless manner. 
     
     
         3 . The arrangement of  claim 1 , wherein the sensor is arranged generally parallel or coaxially to a direction of movement of the control piston. 
     
     
         4 . The arrangement of  claim 1 , wherein the sensor is a linear magnetostrictive position sensor, and
 wherein the position marker is a magnet.   
     
     
         5 . A measurement method for determining an actual swashplate angle of a swashplate pivotally attached to a variable displacement hydraulic pump, wherein a control piston is operable to control an angle of the swashplate relative to the pump, the method comprising:
 detecting a position of a position marker arranged on the control piston by a sensor arranged along the control piston; and   determining a linear translation of the control piston from a shift of the position marker relative to the sensor.   
     
     
         6 . The method of  claim 5 , wherein comprising:
 determining the actual swashplate angle of the swashplate from the linear translation of the control piston.   
     
     
         7 . The method of  claim 5 , wherein carried out using a sensor arrangement arrangement for determining an actual swashplate angle of a swashplate pivotally attached to a variable displacement hydraulic pump, the arrangement comprising:
 a control piston operable to control an angle of the swashplate relative to the variable displacement pump;   a position marker arranged on the control piston; and   a sensor arranged along the control piston to detect a movement of the position marker.   
     
     
         8 . A controller for controlling the actuation of a control piston of a variable displacement hydraulic pump, the control piston being operable to control an angle of a swashplate relative to the pump, wherein an actual swashplate angle is determined with Hall the sensor arrangement of  claim 1 . 
     
     
         9 . The controller of  claim 8 , wherein the control piston is actuated by a proportional valve. 
     
     
         10 . A variable displacement hydraulic pump comprising:
 the controller of  claim 8 ,   wherein the control piston is operable to control an angle of the swashplate relative to the pump.   
     
     
         11 . The arrangement of  claim 1 , wherein the sensor is arranged generally coaxially to a direction of movement of the control piston. 
     
     
         12 . The arrangement of  claim 1 , wherein the sensor includes a linear magnetostrictive position sensor. 
     
     
         13 . The arrangement of  claim 1 , wherein the position marker includes a magnet. 
     
     
         14 . The arrangement of  claim 1 , wherein the sensor includes a linear magnetostrictive position sensor, and
 wherein the position marker includes a magnet.