Patent ID: 8181734
Filing Date: 2012-05-22
Classification: B62D,F16H

Abstract:
1. A motor vehicle steering system, comprising: a transmission ratio variable mechanism capable of changing a transmission ratio of a turning angle of steered wheels relative to a steering angle of a steering member; and a steering-assist-force imparting mechanism for imparting a steering assist force, the transmission ratio variable mechanism comprising an input member and an output member capable of rotation about a first axis, a first bearing ring, having a first and a second end surfaces, for differentially rotatably coupling the input member and the output member, a second bearing ring for rotatably supporting the first bearing ring via a rolling element, and an actuator capable of rotation-driving the second bearing ring, wherein a second axis as a center line of the first bearing ring and the second bearing ring is inclined relative to the first axis, wherein the input member and the output member respectively have power transmission surfaces each opposite the first and the second end surfaces of the first bearing ring, wherein a first concave-convex engaging unit for power-transmittably engaging the first end surface of the first bearing ring and the power transmission surface of the input member corresponding to the first end surface is arranged, the first concave-convex engaging unit including a first convex portion arranged on one of the first end surface and the power transmission surface corresponding to the first end surface, and a first concave portion that is arranged on an alternate surface and that is engaged with the first convex portion, wherein a second concave-convex engaging unit for power-transmittably engaging the second end surface of the first bearing ring and the power transmission surface of the output member corresponding to the second end surface is arranged, the second concave-convex engaging unit including a second convex portion arranged on one of the second end surface and the power transmission surface corresponding to the second end surface, and a second concave portion that is arranged on an alternate surface and that is engaged with the second convex portion, and wherein output of the transmission ratio variable mechanism is transmitted to the turning mechanism via the steering-assist-force imparting mechanism.