Camshaft adjusting device

1. A camshaft adjusting device for changing an angular relationship between a camshaft and an internal combustion engine crankshaft, comprising:

a stator and a rotor housed within and adjustable in a circumferential direction relative to the stator by a pressure medium, the rotor connectable to a camshaft and the stator connectable to the crankshaft;

a first cover plate and a second cover plate between which the stator and rotor are housed, the first cover and the second cover fixed to the stator;

a spring cover plate spaced axially apart and fixed to the first cover plate;

an outer spring retainer positioned between the spring cover plate and the first cover plate, the outer spring retainer fixed to the spring cover plate; and

a torsion spring positioned between the spring cover plate and the first cover plate, the torsion spring having an inner spring end connected to the rotor and an outer spring end engaged with the outer spring retainer thereby connecting the outer spring end to the spring cover plate, the torsion spring configured to rotate the rotor relative to the stator such that the torsion spring is rotatably fixed to the rotor; and

an inner spring retainer positioned between the spring cover plate and the first cover plate and fixed to the rotor,

wherein the inner spring end of the torsion spring engages the inner spring retainer thereby connecting the inner spring end to the rotor, and

wherein the outer spring retainer is positioned and fixed at an outwardly radial position on an inner wall of the spring cover plate; and the inner spring retainer is positioned at an inwardly radial position and fixed to the rotor by a radial shoulder that extends through the first cover and fixably engages a retaining cavity in the rotor.

2. The device of claim 1 , wherein the torsion spring is a flat spiral torsion spring.

3. The device of claim 1 , wherein the outer spring retainer is one or more radially oriented posts fixed at an outer radial position on the spring cover plate.

4. The device of claim 1 , wherein the rotor has a retaining cavity which opens towards the first cover plate; the first cover plate has an opening commensurate in radial size to the retaining cavity; and the inner spring retainer has a radial shoulder that extends through the opening in the first cover and fixably engages the retaining cavity.

5. The device of claim 1 , wherein the spring cover plate is fixed to the first cover plate, the stator and the second cover plate by fasteners that extend therethrough.

6. The device of claim 1 , wherein the spring cover plate has spacers fixed to an inside wall of the spring cover and through which fasteners extend to fix the spring cover plate to the first cover plate.

7. The device of claim 1 , wherein the axial space between the spring cover plate and the first cover plate is a spring gap.

8. The device of claim 1 , wherein an axial, central bolt connects the device to the camshaft, the axial central bolt axially press the inner spring retainer against the rotor, the second cover plate having an opening for accommodating the camshaft and allowing the axial bolt to pass through and fix the device on the camshaft and allowing the camshaft to contact the rotor, the spring cover plate having an axial central opening to allow the bolt to pass through and contact the inner spring retainer.