Actuator having compact gear reduction
First Claim
1. An actuator for actuating a brake mechanism comprising a housing, which contains a motor and a screw mechanism that is engageable with the brake mechanism, said screw mechanism comprising a screw and a nut one of which is rotatably supported with respect to the housing, and a gear reduction mechanism connecting a rotor of the motor to at least one of the rotatable screw and the nut, said gear reduction mechanism comprising at least a concentric gear ring with radially inwardly directed teeth, an eccentrically positioned gear wheel having radially outwardly directed teeth wherein the outer diameter of the gear wheel is smaller than the inner diameter of the gear ring, such that the teeth of said gear wheel and gear ring engage each other along a part of their circumferences, and at an opposite part of their circumferences are out of engagement, said eccentric gear wheel being rotatably accommodated on an eccentrically shaped hub which is connected to the rotor of the motor, wherein the gear ring is integrated with the screw of the screw mechanism, said screw being rotatably supported with relation to the housing.
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Accused Products
Abstract
A screw actuator comprises a housing (1), a nut (A) and a screw (16) one of which is axially fixed with respect to the housing and the other of which is axially displaceable with respect to the housing for moving an actuating head, as well as a motor (2) which comprises a stator (6) connected to the housing, and a rotor (7). The rotor (7) of the motor is supported rotatably on a sleeve (8), said sleeve has an inwardly directed flange (21), which carries an excentric hub (23). The excentric hub (23) rotatably supports a gear wheel (24) through bearing (30), the outer teeth of which gear wheel (24) engage the inwardly directed teeth of the ring gear (25). The ring gear (25) is driving screw (16) which is rotatably supported in the housing (1). The nut (17) of the screw mechanism (4) is slidably, but not rotatably with respect to the housing. Through the screwthreads (18, 19) and balls (20), the rotary motion of the screw (16) is converted into a linear motion of the nut (17), which is contained in a cylinder space (32) in the housing (1).
27 Citations
15 Claims
- 1. An actuator for actuating a brake mechanism comprising a housing, which contains a motor and a screw mechanism that is engageable with the brake mechanism, said screw mechanism comprising a screw and a nut one of which is rotatably supported with respect to the housing, and a gear reduction mechanism connecting a rotor of the motor to at least one of the rotatable screw and the nut, said gear reduction mechanism comprising at least a concentric gear ring with radially inwardly directed teeth, an eccentrically positioned gear wheel having radially outwardly directed teeth wherein the outer diameter of the gear wheel is smaller than the inner diameter of the gear ring, such that the teeth of said gear wheel and gear ring engage each other along a part of their circumferences, and at an opposite part of their circumferences are out of engagement, said eccentric gear wheel being rotatably accommodated on an eccentrically shaped hub which is connected to the rotor of the motor, wherein the gear ring is integrated with the screw of the screw mechanism, said screw being rotatably supported with relation to the housing.
Specification