SWASHPLATE POSITION SENSOR ARRANGEMENT

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.