Patent ID: 8025035

Claim:
A device for selectively varying a relative angular position between first and second rotating shafts of an internal combustion engine, the device comprising: a first worm assembly coupled to the first and second rotating shafts and torsionally preloaded to provide a first torque tending to increase the relative angular position between the first and second rotating shafts; a second worm assembly coupled to the first and second rotating shafts and torsionally preloaded opposite to the first worm assembly to provide a second torque simultaneously tending to decrease the relative angular position between the first and second rotating shafts such that the relative angular position of the first and second rotating shafts remains substantially constant during rotation of the first and second rotating shafts; and at least one actuator selectively applying an actuating torque to respective gears of the first and second worm assemblies to rotate the first rotating shaft relative to the second rotating shaft and change the relative angular position between the first and second rotating shafts.