Patent ID: 6948460
Filing Date: 2005-09-27
Classification: F02B

Abstract:
1. A drive apparatus, comprising: a piston slidably carried in a cylinder for stroking reciprocally along an axis of the cylinder; a piston rod having a first end connected to the piston and a second end; a power gear concentrically mounted to a power gear shaft; an eccentric connected between the second end of the piston rod and the power gear, the second end of the piston rod having a rod end axis offset from the power gear shaft, so that as the second end of the rod strokes, the power gear rotates; a rim gear having teeth on that mesh with teeth on the power gear, causing the power gear to orbit around an axis of the rim gear while the rim gear is stationary, the axis of the rim gear being on the axis of the cylinder, the rim gear having a pitch diameter that is a multiple of a pitch diameter of the power gear; the rim gear being rotatable an increment less than one revolution about its axis, causing the position of the eccentric relative to the rim gear to change, thereby varying the length of the stroke of the piston; and a bias member connected to the rim gear to urge the rim gear to rotate toward a position of maximum stroke of the piston.