Actuator for a control unit

Abstract

An actuator for a control unit has a control motor with a motor power takeoff shaft; a control shaft that carries the control unit; and a step-up gear, disposed between the motor power takeoff shaft and the control shaft, as well as a restoring device for restoring the control unit to a basic position if the control motor fails. To make it possible to use a single-stage step-up gear with a major step-up ratio and with advantages in terms of installation space, weight, and production costs, the restoring device has two separate energy-storing means, preferably embodied as restoring springs, of which one feeds back to the motor power takeoff shaft and the other feeds back to the control shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment, taken in conjunction with the drawings, in which:

FIG. 1 is a schematic perspective side view of an actuator for a control unit; and

FIG. 2 is a schematic section taken along the line II-II in FIG. 1, with the control unit shown in fragmentary form.

Claims

1. In an actuator for a control unit, having an electric control motor that has a power takeoff shaft; having a control shaft that carries the control unit; and having both a step-up gear, disposed between the motor power takeoff shaft and the control shaft, and a restoring device for restoring the control unit to a basic position if the control motor fails, the improvement wherein the restoring device comprises two separate energy-storing means, one of which feeds back to the motor power takeoff shaft and the other of which one feeds back to the control shaft.

2. The actuator as defined by claim 1, wherein the first energy-storing means feeding back to the motor power takeoff shaft is designed for overcoming the motor locking moment, and the second energy-storing means, feeding back to the control shaft, is designed for overcoming the useful torque.

3. The actuator as defined by claim 1, wherein the step-up gear is embodied as a worm gear, with a worm disposed on the motor power takeoff shaft and a worm wheel disposed fixedly on the control shaft, the control shaft being oriented perpendicular to the motor power takeoff shaft.

4. The actuator as defined by claim 2, wherein the step-up gear is embodied as a worm gear, with a worm disposed on the motor power takeoff shaft and a worm wheel disposed fixedly on the control shaft, the control shaft being oriented perpendicular to the motor power takeoff shaft.

5. The actuator as defined by claim 1, further comprising a step-down gear disposed between the motor power takeoff shaft and the first energy-storing means the first energy-storing means being coupled to the gear output of the step-down gear.

6. The actuator as defined by claim 2, further comprising a step-down gear disposed between the motor power takeoff shaft and the first energy-storing means the first energy-storing means being coupled to the gear output of the step-down gear.

7. The actuator as defined by claim 3, further comprising a step-down gear disposed between the motor power takeoff shaft and the first energy-storing means the first energy-storing means being coupled to the gear output of the step-down gear.

8. The actuator as defined by claim 5, wherein the step-down gear comprises a spur pinion, disposed fixedly on the motor power takeoff shaft, and a contrate gear, meshing with the spur pinion, with a wheel axis oriented perpendicular to the motor power takeoff shaft; the first energy-storing means being connected to the contrate gear.

9. The actuator as defined by claim 1, wherein each energy-storing means is embodied as a restoring spring.

10. The actuator as defined by claim 2, wherein each energy-storing means is embodied as a restoring spring.

11. The actuator as defined by claim 5, wherein each energy-storing means is embodied as a restoring spring.

12. The actuator as defined by claim 9, wherein one restoring spring is a spiral spring, located in the contrate gear, one spring end of which is secured to the contrate gear and the other spring end of which is held in stationary fashion.

13. The actuator as defined by claim 10, wherein one restoring spring is a spiral spring, located in the contrate gear, one spring end of which is secured to the contrate gear and the other spring end of which is held in stationary fashion.

14. The actuator as defined by claim 11, wherein one restoring spring is a spiral spring, located in the contrate gear, one spring end of which is secured to the contrate gear and the other spring end of which is held in stationary fashion.

15. The actuator as defined by claim 9, wherein the other restoring spring is a torsion spring, concentrically surrounding the control shaft, preferably a cylindrical helical spring or a spiral spring, one spring end of which is secured to the control shaft or the control unit and the other spring end of which is held in stationary fashion.

16. The actuator as defined by claim 12, wherein the other restoring spring is a torsion spring, concentrically surrounding the control shaft, preferably a cylindrical helical spring or a spiral spring, one spring end of which is secured to the control shaft or the control unit and the other spring end of which is held in stationary fashion.

17. The actuator as defined by claim 9, wherein the step-up gear and the step-down gear are received in a actuator housing in which the wheel axis of the contrate gear is held and the control shaft is supported rotationally; and wherein the spring ends, held in stationary fashion, of the restoring springs are secured in the actuator housing.

18. The actuator as defined by claim 12, wherein the step-up gear and the step-down gear are received in a actuator housing in which the wheel axis of the contrate gear is held and the control shaft is supported rotationally; and wherein the spring ends, held in stationary fashion, of the restoring springs are secured in the actuator housing.

19. The actuator as defined by claim 15, wherein the step-up gear and the step-down gear are received in a actuator housing in which the wheel axis of the contrate gear is held and the control shaft is supported rotationally; and wherein the spring ends, held in stationary fashion, of the restoring springs are secured in the actuator housing.

20. The actuator as defined by claim 17, wherein the control motor is received in the actuator housing.