| 主权项 |
1. A concentric cam shaft assembly, comprising:
an electric motor; a first camshaft; a second camshaft including at least a portion disposed radially within the first camshaft; an input gear:
non-rotatably connected to the first camshaft such that relative rotation between the input gear and the first camshaft is not possible; and,arranged to rotate at a first speed, with respect to an axis of rotation for the first and second camshafts, in response to receiving rotational torque from a crankshaft of an engine; an output gear non-rotatably connected to the second camshaft; and, a harmonic drive including:
a wave generator; and,a flexible gear radially disposed about the wave generator and including a radially inner circumference in contact with the wave generator, and a radially outer circumference with a plurality of drive teeth, wherein: the input gear is arranged to rotate the first and second camshafts at the first speed; the electric motor is arranged to rotate the wave generator, with respect to the flexible gear, about an axis of rotation for the wave generator:
to change respective radial distances of a plurality of points on the outer circumference of the flexible gear with respect to an axis of rotation for the flexible gear;to urge only a respective portion of the plurality of drive teeth, and not all of the drive teeth, into contact with the one of the input or output gears; and,to circumferentially off-set, using an engagement of the respective portion of the plurality of drive teeth with the one of the input or output gears, the second camshaft with respect to the first camshaft. |
