Torque-generating steering device

A torque generator comprising:

• a valve arrangement including a spool valve and a valve sleeve aligned along an axis of rotation, the spool valve including an input shaft, the valve sleeve being positioned over and co-axially aligned with the spool valve, wherein relative rotational movement between the valve sleeve and the spool valve about the axis of rotation allows the valve arrangement to move between a neutral state and an operating state;
• a gerotor displacement mechanism including a stator and a rotor, wherein when the valve arrangement is in the operating state, the valve arrangement is adapted to provide pressurized fluid to the gerotor displacement mechanism for driving the rotor relative to the stator;
• an output shaft coupled to the rotor;
• a torsion bar that extends axially through an interior of the spool valve along the axis of rotation;
• a first cross-shaft that rotationally fixes the torsion bar relative to the spool valve at a first axial portion of the torsion bar;
• a second cross-shaft that rotationally fixes the torsion bar relative to the valve sleeve at a second axial portion of the torsion bar, the first and second axial portions being axially spaced-apart from one another;
• the torsion bar being configured such that when the valve arrangement is moved toward the operating state by generating relative rotational movement between the spool valve and the valve sleeve, torque is applied to the torsion bar such that the torsion bar elastically twists about the axis of rotation causing a torsion load to be stored within the torsion bar between the first and second axial portions of the torsion bar, wherein the torsion load rotationally biases the valve arrangement toward the neutral state;
• and
• a torque driver that transfers torque from the rotor to the second cross-shaft for causing the valve sleeve to follow rotation of the spool valve when the valve arrangement is in the operating state,
• wherein an end of the spool valve is recessed relative to a corresponding end of the valve sleeve such that a non-overlapping region is defined at the end of the valve sleeve, wherein the second axial portion of the torsion bar is positioned at the non-overlapping region, and wherein the second cross-shaft engages the valve sleeve at the non-overlapping region, and
• wherein the torque driver includes a first end including a sleeve that receives the second axial portion of the torsion bar and a second end including splines that interface with corresponding splines of the rotor and, the sleeve defining openings for receiving the second cross-shaft, the openings being elongated in an axial direction to accommodate orbital movement of the torque driver caused by the rotor.