Electric Linear Actuator
AssigneeNtn Corporation
InventorsTakaaki OHNISHI, Kunimichi HATANO, Keisuke KAZUNO, Hirakazu YOSHIDA
Life of this patent
Estimating the term…
Abstract
An electric linear actuator has a housing, an electric motor, a speed reduction mechanism and a ball screw mechanism. The ball screw mechanism has a nut and screw shaft. A blind bore is formed on the housing. The blind bore contains an end of the screw shaft. An anti-rotation mechanism for the screw shaft has a sleeve and guide pin. The sleeve is press-formed from steel sheet and fit into the blind bore of the housing. The guide pin is mounted on the end of the screw shaft, via a through aperture formed in the screw shaft. The guide pin axially movably engages the sleeve.
Claims11
An electric linear actuator comprising:
- a housing;
- an electric motor mounted on the housing;
- a speed reduction mechanism for reducing rotational speed of the electric motor, via a motor shaft;
- a ball screw mechanism for converting rotational motion of the electric motor, transmitted via the speed reduction mechanism, to axial linear motion of a drive shaft, the ball screw mechanism comprising a nut and a screw shaft, the nut including a helical screw groove on its inner circumference, the nut is rotationally supported by bearings mounted on the housing but is axially immovable with respect to the housing, the screw shaft is coaxially integrated with the drive shaft, the screw shaft includes a helical screw groove on its outer circumference corresponding to the helical screw groove of the nut, the screw shaft is inserted into the nut, via a large number of balls, the screw shaft is axially movably supported on the housing but is non-rotatable with respect to the housing;
- a blind bore is formed on the housing to contain an end of the screw shaft;
- and
- an anti-rotation mechanism for the screw shaft comprises a sleeve and a guide pin, the sleeve is press-formed from steel sheet and fit in the blind bore of the housing, the guide pin is mounted on the end of the screw shaft, via an aperture formed in the screw shaft and the guide pin axially movably engages with the sleeve but is non-rotatable with respect to the sleeve.
Dependencies are inferred from the claim text.