Actuation system for a bent axis motor

A method for controlling an inclination angle of a bent axis unit (BAU) rotary group of a variable displacement bent axis piston motor, the method comprising:

• receiving one a torque request from an operator of the variable displacement bent axis piston motor;
• setting the inclination angle of the BAU rotary group based on the torque request;
• selecting and applying a torque control strategy for controlling the inclination angle based on the torque request;
• in response to a pressure of a hydraulic fluid circulating through the BAU rotary group increasing above a threshold pressure:
• selecting a pressure control strategy for controlling the inclination angle based on a pressure reference;
• switching from the torque control strategy to the pressure control strategy;
• and
• adjusting the inclination angle in accordance with the pressure control strategy;
• and
• in response to the pressure being maintained below the threshold pressure, continuing to control the inclination angle using the torque control strategy.

A control system for a variable displacement bent axis piston motor, the control system comprising:

• a servo piston coupled to a valve plate of a bent axis unit (BAU) rotary group of the variable displacement bent axis piston motor, the valve plate configured to slide between a first position where a displacement of the BAU rotary group is maximized and a second position where the displacement is minimized, based on a position of the servo piston within a corresponding piston chamber;
• a piston position sensor that indicates a position of the servo piston within the corresponding piston chamber;
• a pressure sensor that measures an operating pressure of a hydraulic fluid circulating through the BAU rotary group;
• a speed sensor that measures a rotational speed of a drive shaft coupled to the BAU rotary group;
• a torque sensor that measures an amount of torque delivered at the drive shaft;
• an electric actuator configured to adjust the position of the servo piston within the corresponding piston chamber, the electric actuator not including hydraulic components;
• and
• a controller including a processor and instructions stored in a non-transitory memory of the controller that when executed cause the controller to:
• adjust the position of the servo piston based on one of a torque reference, a speed reference, and a pressure reference;
• and a feedback signal from one of the torque sensor, the speed sensor, and the pressure sensor.