Patent ID: 8581527
Filing Date: 2013-11-12
Classification: F16H,Y10T

Abstract:
1. A mechanism for converting rotary motion into linear motion, comprising: a rod having a threaded portion constituting an outer circumferential surface thereof; a holder member disposed outside the outer circumferential surface of the rod; a plurality of rollers supported by the holder member and arranged on the rod in a manner that each of the rollers is disposed at an angle to the rod; the angle being substantially equal to a lead angle of the threaded portion; and the mechanism converting mutually between relative rotation between the rod and the holder member and relative linear motion between an axis of the rod and an axis of the holder member; wherein the roller further includes: a roller annular groove member having a plurality of annular grooves on an outer surface thereof, the plurality of annular grooves rolling on the rod while kept in mesh with the threaded portion; a roller shaft having both ends being supported by the holder member; a pair of thrust bearings that rotatably support the roller annular groove member around the roller shaft; a thrust bearing portion that is in a convex shape and is integrally formed with the roller shaft and is disposed between the pair of thrust bearings on an outer surface of an end of the roller shaft; a step surface that is formed on an inner surface of the roller annular groove member and disposed opposite to the thrust bearing portion holding a first one of the pair of thrust bearings in between; and a thrust facing member having an threaded outer surface thereof which is in mesh with an inner surface of the roller annular groove member and disposed across a second one of the pair of thrust bearings from the thrust bearing portion, the thrust facing member being spaced a distance from the step surface, the distance being alterable.