Patent ID: 7758466
Filing Date: 2010-07-20
Classification: B60K,F16H

Abstract:
1. A vehicle planetary gear device comprising: an internal helical ring gear; an external helical sun gear disposed inside the ring gear so that an axis of the sun gear coincides with an axis of the ring gear; a carrier that is inserted between the ring gear and the sun gear so that an axis of the carrier coincides with the axis of the ring gear and the sun gear and that has a cylindrical portion provided with a penetration hole penetrating the cylindrical portion along a radial direction of the carrier; and an external helical pinion that is housed in the penetration hole of the carrier so as to be freely rotatable and slidable in an axis direction of the pinion and that meshes with the ring gear and the sun gear, wherein: the carrier has one inner wall surface and another inner wall surface, the one inner wall surface and the other inner wall surface facing an outer peripheral surface of the pinion; each of the one inner wall surface and the other inner wall surface is formed to have a curvature radius larger than a radius of the pinion; a curvature center of the one inner wall surface and a curvature center of the other inner wall surface are disposed on a circumference whose center is an axis center of the cylindrical portion, and which passes through a center of a width between an inner peripheral surface of the cylindrical portion and an outer peripheral surface of the cylindrical portion in the radial direction; the one inner wall surface and the other inner wall surface are disposed so that the curvature center of the one inner wall surface is apart from a center between the one inner wall surface and the other inner wall surface in a direction of the circumference, and is closer to the other inner wall surface than to the one inner wall surface, and the curvature center of the other inner wall surface is apart from the center between the one inner wall surface and the other inner wall surface in the direction of the circumference, and is closer to the one inner wall surface than to the other inner wall surface, wherein the center of the pinion is positioned at the center between the one inner wall surface and the other inner wall surface in the direction of the circumference; and the pinion is disposed with respect to the carrier so that a space is formed between each of the inner wall surfaces and the outer peripheral surface of the pinion so as to allow the pinion to slide along the radial direction of the carrier.