A rotary fluid pressure device comprising: a housing assembly including an output shaft housing and a valve housing section , the output shaft housing configured to rotatably support an output shaft , and the valve housing section defining a fluid inlet and a fluid outlet ; a positive displacement device associated with the housing assembly and including a ring member and a star member , the star member eccentrically disposed within the ring member for relative orbital and rotational movement about an axis of rotation to define expanding and contracting fluid volume chambers resulting from the orbital and rotational movement; a valve mechanism including a valve spool , the valve spool rotatably disposed at the valve housing section and cooperating with the housing assembly to provide fluid communication between the fluid inlet and the expanding fluid volume chambers, and between the contracting fluid volume chambers and the fluid outlet ; a main drive shaft having a forward end and a rearward end and including a hollow at the rearward end, the main drive shaft engaging the output shaft at the forward end and engaging the star member at the rearward end to transmit torque between the output shaft and the ring member ; and a valve drive shaft having a forward end and a rearward end, the valve drive shaft engaging the valve spool at the rearward end of the valve drive shaft, to transmit torque between the main drive shaft and the valve spool and characterised in that the valve drive shaft is at least partially received within the hollow of the main drive shaft and engages the main drive shaft within the hollow at the forward end of the valve drive shaft . a housing assembly including an output shaft housing and a valve housing section , the output shaft housing configured to rotatably support an output shaft , and the valve housing section defining a fluid inlet and a fluid outlet ; a positive displacement device associated with the housing assembly and including a ring member and a star member , the star member eccentrically disposed within the ring member for relative orbital and rotational movement about an axis of rotation to define expanding and contracting fluid volume chambers resulting from the orbital and rotational movement; a valve mechanism including a valve spool , the valve spool rotatably disposed at the valve housing section and cooperating with the housing assembly to provide fluid communication between the fluid inlet and the expanding fluid volume chambers, and between the contracting fluid volume chambers and the fluid outlet ; a main drive shaft having a forward end and a rearward end and including a hollow at the rearward end, the main drive shaft engaging the output shaft at the forward end and engaging the star member at the rearward end to transmit torque between the output shaft and the ring member ; and a valve drive shaft having a forward end and a rearward end, the valve drive shaft engaging the valve spool at the rearward end of the valve drive shaft, to transmit torque between the main drive shaft and the valve spool and characterised in that the valve drive shaft is at least partially received within the hollow of the main drive shaft and engages the main drive shaft within the hollow at the forward end of the valve drive shaft . <EOS>