Patent ID: 8517881
Filing Date: 2013-08-27
Classification: F16H

Abstract:
1. A micro-traction drive comprising: an inner ring that is formed in a cylindrical shape and is supported so as to be rotatable about a rotation axis; an outer ring that is formed in a cylindrical shape and has a larger diameter than the inner ring; a plurality of rolling elements that roll while being in contact with an outer circumferential surface of the inner ring and an inner circumferential surface of the outer ring; a retaining portion that keeps the plurality of rolling elements apart from one another at predetermined intervals; a pressing portion that applies a preload between the inner ring and the rolling elements and between the outer ring and the rolling elements; and an input shaft formed to have a smaller diameter than an inner circumferential surface of the inner ring, the input shaft being disposed adjacent to the inner ring and transmitting a rotational driving force to the inner circumferential surface of the inner ring, wherein one of the outer ring and the retaining portion is connected to the output shaft, and the other thereof is fixed, the input shaft is formed in a cylindrical shape having a smaller diameter than the inner circumferential surface of the inner ring, the inner circumferential surface of the inner ring is formed in a cylindrical surface shape, and the pressing portion applies a preload between the inner ring and the rolling elements and between the outer ring and the rolling elements by pressing the input shaft against the inner circumferential surface of the inner ring.