| 摘要 |
<p>Disclosed is a crank assembly for increasing the rotation ratio, which is configured such that, with reference to the same diameter of a sprocket installed on a crankshaft, the number of rotations of a rear wheel per one rotation of a crank arm is further increased. The crank assembly for increasing the rotation ratio comprises: a crankshaft rotatably supported on a shell provided on a frame assembly; and crank arms having first ends fixed to both ends of the crankshaft, respectively, such that phases of the crank arms face in opposite directions, wherein the crank assembly comprises: a planetary gear carrier formed on the first end of one of the crank arms, the planetary gear carrier having a planetary gear arranged concentrically about the crankshaft; a sun gear having the other side portion fixed to one side of the shell and one side portion surrounding one side of the crankshaft at a distance in a tube shape, the outer peripheral surface of the sun gear meshing with the planetary gear; and a ring gear rotatably supported by the outer peripheral surface of the sun gear as a support basis, the inner peripheral surface of the ring gear meshing with the planetary gear, and at least one sprocket being provided on the outer peripheral surface of the ring gear, and the diameter of the sun gear is larger than the diameter of the planetary gear.</p> |
