Patent ID: 9369024
Filing Date: 2016-06-14
CPC Classification: F16D,F16H,H02K,Y10T

Claim Text:
1. An electric linear motion actuator comprising: a housing; an outer ring member mounted in the housing and having a center axis; a rotary shaft extending along the center axis of the outer ring member and configured to be driven by an electric motor; a carrier supported rotatably about the rotary shaft for rotation relative to the rotary shaft; and a plurality of planetary rollers mounted between a radially outer surface of the rotary shaft and a radially inner surface of the outer ring member, the planetary rollers respectively having planetary roller axes and being rotatably supported by the carrier for rotation about the planetary roller axes, respectively, and the planetary rollers being engaged with the radially outer surface of the rotary shaft and the radially inner surface of the outer ring member, such that, upon rotation of the rotary shaft, the planetary rollers are arranged to revolve around the rotary shaft while rotating about the planetary roller axes, respectively; wherein the radially inner surface of the outer ring member is formed with at least one helical rib, the planetary rollers each having a radially outer surface formed with a plurality of circumferential grooves which are equal in pitch to the helical rib or formed with at least one helical groove equal in pitch to, and different in lead angle from, the helical rib, the helical rib being engaged in the circumferential grooves or the helical grooves of the respective planetary rollers, and wherein the outer ring member and the carrier are configured to be movable in the direction of said center axis relative to each other; and wherein the carrier is immovable in the direction of the center axis of the outer ring member, and the outer ring member is not rotatable and is fitted in a radially inner surface of the housing so as to be slidable in the direction of the center axis of the outer ring member, wherein the outer ring member acts as a linearly movable output member.