Patent ID: 6857332

Claim:
Actuator for the linear displacement of a member to be controlled, comprising a motor part ( 2 ) and an actuating device part ( 3 ) comprising a rotary member ( 9 ) provided with a threaded portion ( 10 ) complementary to a thread of a screw ( 11 ), the rotary member ( 9 ) being able to be rotated by the motor part and being supported by bearings ( 15 , 16 ; 15 ′, 16 ′; 15 ″, 16 ″) in the form of thrust ball bearings with three or four contact points arranged on either axial side of said threaded portion for axial and radial guidance of the rotary member, raceways of the balls ( 22 , 24 , 23 , 25 ; 22 ′, 23 ′) being integrated, on one hand into the rotary member ( 9 ) and on the other hand into the housing ( 14 ) or cover ( 13 ) parts of the actuator, and wherein inclined walls radially inward ( 26 , 26 ′) and radially outward ( 27 , 27 ′) of the raceways are arranged so as to satisfy the relation: A/B=C/D, where D and C are the radii of the contact points radially inward ( 28 , 28 ′) and radially outward ( 29 , 29 ″) from the axis of rotation ( 30 ) of the rotary member, while B is the diameter of the circle traveled by the contact points radially inward ( 28 , 28 ′) on a ball ( 31 ), and A is the diameter of the circle traveled by the contact points radially outward ( 29 , 29 ′) on a ball ( 31 ).