Actuator

Abstract

Actuator provided with a low voltage DC motor which is coupled via a two-stage reduction mechanism with an output gear wheel, wherein the reduction mechanism comprises a first stage with a worm carried on the motor shaft of the DC motor, which worm in a right-angle transmission cooperates with the circumference of an intermediate gear wheel, which intermediate gear wheel is carried on an intermediate shaft which carries along its axis a spiral pinion, and wherein the reduction mechanism furthermore comprises a second stage with the spiral pinion which in a parallel transmission cooperates with the circumference of the output gear wheel, which is implemented as a spiral gear wheel.

Claims

1. An adjusting instrument for an exterior vision unit for a vehicle, comprising: a base, comprising a foot and a pivoting shaft extending therefrom along a longitudinal axis, a housing which surrounds the pivoting shaft, and which is pivotable around the longitudinal axis of the pivoting shaft in an adjustment range, between at least a park position and a work position, furthermore comprising an actuator which is operative between the base and the housing to adjust the housing in the adjustment range relative to the pivoting shaft, wherein the actuator is provided with a low voltage DC motor which is coupled via a two-stage reduction mechanism with an output spiral gear wheel, wherein the reduction mechanism comprises a first stage formed by a worm and an intermediate gear wheel, wherein the worm is carried on the motor shaft of the DC motor and wherein the worm in a right-angle transmission engages the circumference of the intermediate gear wheel, wherein the intermediate gear wheel is carried on an intermediate shaft which carries along its axis a spiral pinion, and wherein the reduction mechanism further comprises a second stage formed by the spiral pinion and the output spiral gear wheel, wherein the spiral pinion in a parallel transmission engages the circumference of the output spiral gear wheel, wherein the spiral pinion directly engages with the output spiral gear wheel and a support that engagingly supports the spiral pinion.

2. The adjusting instrument according to claim 1, wherein the spiral pinion comprises a bevel toothing with a tooth angle which is greater than 15°, in particular a tooth angle which is between 15° and 35°.

3. The adjusting instrument according to claim 1, wherein the spiral pinion comprises only one or two teeth.

4. The adjusting instrument according to claim 1, wherein the axial length of the spiral pinion is chosen such that the teeth make at least a half revolution over the circumference of the spiral pinion.

5. The adjusting instrument according to claim 1, wherein the intermediate shaft near the end of the spiral pinion is provided with a bearing.

6. The adjusting instrument according to claim 1, wherein the support includes a support spiral pinion or a bearing surface.

7. The adjusting instrument according to claim 6, wherein the support is placed opposite to the side of the spiral pinion that is in engagement with the spiral gear wheel.

8. The adjusting instrument according to claim 1, wherein the spiral gear wheel is provided with an inner toothing for cooperation with a spindle.

9. The adjusting instrument according to claim 1, wherein the motor and the first stage of the actuator are carried by the housing, and wherein the spiral gear wheel is carried by the pivoting shaft.

10. The adjusting instrument according to claim 2, wherein the spiral pinion comprises only one or two teeth.

11. The adjusting instrument according to claim 2, wherein the axial length of the spiral pinion is chosen such that the teeth make at least a half revolution over the circumference of the spiral pinion.

12. The adjusting instrument according to claim 3, wherein the axial length of the spiral pinion is chosen such that the teeth make at least a half revolution over the circumference of the spiral pinion.

Description

(1) The invention will be further elucidated on the basis of exemplary embodiments that are represented in drawings. In the drawings:

(2) FIG. 1 shows a schematic side view of a first embodiment of the actuator according to the invention;

(3) FIG. 2 shows a schematic, partly sectional view of the actuator of FIG. 1;

(4) FIG. 3 shows a schematic, partly sectional view of a second embodiment of the actuator according to the invention, where a support spiral pinion has been arranged;

(5) FIG. 4 shows a schematic, partly sectional detailed view of a third embodiment of the actuator according to the invention, where a bearing surface has been arranged in a housing case, and

(6) FIG. 5 shows an exploded schematic perspective view of a fourth embodiment of the actuator according to the invention.

(7) It is noted that the figures are only schematic representations of preferred embodiments of the invention, and that these are given by way of non-limiting exemplary embodiment. In the exemplary embodiment, like or corresponding parts in the different embodiments are designated with the same reference numerals.

(8) FIG. 1 and FIG. 2 show a first embodiment of an actuator 1 according to the invention. The actuator 1 comprises a 13.5V DC electric motor 2 which is coupled via a two-stage reduction mechanism 3 with an output gear wheel 4. The reduction mechanism 3 comprises a first stage 5 with a worm 7 carried on the motor shaft 6 of the DC motor 2. The worm 7 in a right-angle transmission cooperates with the circumference of an intermediate gear wheel 8. The longitudinal axis of the motor shaft 6 which carries the worm 7 extends transversely to the longitudinal axis of the intermediate gear wheel 8. The worm 7 and the intermediate gear wheel 8 respectively form the driving element and the driven element of the first stage 5 of the reduction mechanism 3. In this exemplary embodiment, the output speed of the motor shaft 6 at nominal load is, for example, 6000 rpm at a supplied nominal moment to the motor shaft 6 of 5 Nmm. The transmission ratio of the first stage 5 in this example is 1:30, and may for instance be chosen in practice between around 1:20 and around 1:50.

(9) The intermediate gear wheel 8 is carried on an intermediate shaft 9 which carries along its axis a spiral pinion 10. The spiral pinion 10 in this example has a module of 0.7 mm, one tooth having a tooth angle of 15° and a length of 0.8 mm.

(10) Furthermore, the reduction mechanism 3 comprises a second stage 11 with the spiral pinion 10 carried on the intermediate shaft 9. The spiral pinion 10 in a parallel transmission cooperates with the circumference of an output spiral gear wheel 4. The spiral pinion 10 and the spiral gear wheel 4 respectively form the driving element and the driven element of the second stage of the reduction mechanism. The transmission ratio of the second stage 11 in this example is 1:40, and may for instance be chosen in practice between around 1:20 and around 1:60.

(11) In this parallel transmission in the second stage, the axes of the spiral pinion 10 and the spiral gear wheel 4 run substantially parallel. The intermediate gear wheel 8 is in a plane which is parallel to the spiral gear wheel 4, and can hence be implemented with a relatively large number of teeth and associated large diameter, so that a high transmission ratio can be achieved with a relatively small overall height. The intermediate gear wheel 8 and the spiral gear wheel 4 are further disposed in mutual overlap, so that also in width direction a relatively compact construction can be achieved.

(12) The intermediate shaft 9 is provided with a bearing 12 near the end of the spiral pinion 10. In this way, the spiral pinion 10 is axially retained and can be of relatively light design.

(13) Also, in the example of FIG. 2, the height H of the reduction mechanism 3 is less than the thickness D of the DC motor. Moreover, the intermediate gear wheel 8 is in a plane which extends substantially transversely to the axis of rotation of the spiral gear wheel 4. As can be seen in FIG. 4, there too, the intermediate gear wheel 8 partly overlaps the spiral gear wheel 4. In this manner, elegantly, a compact construction can be obtained.

(14) FIG. 3 shows a second embodiment of the actuator 1 according to the invention. The actuator 1 shown here shows furthermore a support 13 with which the spiral pinion 10 cooperates at its circumference. In this exemplary embodiment, the support 13 is implemented as a support spiral pinion 13a. As can be seen in FIG. 3, the support spiral pinion 13a is positioned on the side of the spiral pinion 10 opposite to that which is in engagement with the spiral gear wheel 4. Furthermore, the support spiral pinion 13a is disposed rotatably about a support shaft not shown. In this way, the support spiral pinion 13a provides for a radial bearing of the spiral pinion 10 and thereby improves the stability of the spiral pinion 10.

(15) FIG. 4 shows a third embodiment of the actuator 1 according to the invention. In this exemplary embodiment, the support 13 is implemented as a bearing surface 13b which is included in a casing of the housing of the actuator 1. The bearing surface 13b preferably extends at least over a part of the circumference of the spiral pinion 10 that is free of the part of the spiral pinion 10 that is in direct contact with the output spiral gear wheel 4. In this manner, a radial bearing of the spiral of the spiral pinion 10 is ensured in a relatively simple manner, and with a small core diameter of the spiral pinion yet a considerable force can be transmitted.

(16) The actuator can be particularly advantageously applied in a motor vehicle for adjusting a housing with an exterior vision unit, such as an exterior mirror, camera, LIDAR and/or display. The actuator can for instance be advantageously applied in an adjusting instrument for an exterior vision unit for a vehicle, in particular a motor vehicle, to observe and/or monitor the position of the vehicle with respect to the surroundings. The adjusting instrument then comprises a housing with an exterior vision unit, such as an exterior mirror, camera, LIDAR and/or display.

(17) The housing is then adjustable via the actuator relative to a base 21 of the adjusting instrument, to be mounted on the motor vehicle. The adjusting instrument is often intended to adjust the exterior vision unit between a park position, for example a fold-in position in which the housing extends substantially along the vehicle, and a work position, for example a drive position in which the housing extends substantially transversely to the vehicle.

(18) The base 21 of the adjusting instrument then comprises a foot 22 for mounting on an outer part of the body of the motor vehicle, and a pivoting shaft 23 extending from the foot 22 along a longitudinal axis of standing orientation with respect to the fixed world, for receiving the housing in a manner pivotable around it. The housing is connected to the base 21 via the actuator, so that the pivoting movement by which the carrier folds in and out can be carried out in a driven manner.

(19) In such an application, there is provided an adjusting instrument for an exterior vision unit for a vehicle, comprising: a base, comprising a foot and a pivoting shaft extending therefrom along a longitudinal axis, a housing which surrounds the pivoting shaft, and which is pivotable around the longitudinal axis of the pivoting shaft in an adjustment range, between at least a park position and a work position, and an actuator which is operative between the base and the housing to adjust the housing in the adjustment range relative to the pivoting shaft.

(20) The motor and the first stage of the actuator can then, for instance, be carried by the housing, and the spiral gear wheel may be carried by the pivoting shaft.

(21) FIG. 5 shows a fourth embodiment of the actuator 1 according to the invention. Represented in FIG. 5 is an exploded perspective view of an actuator 1 including housing 19. Included in the housing 19 is a support shaft 16 for a support spiral pinion 13a for radial bearing of the spiral pinion 10. From FIG. 5 it can be inferred from the housing 19 that the height H of the reduction mechanism 3 is less than twice the thickness D of the DC motor, and, in particular, is of the same order of magnitude as the thickness D of the DC motor. Furthermore, the output spiral gear wheel 4, along its output axis, on its inner side, is provided with a recess 14 with an inner toothing 15 which cooperates with a toothing 17 of a hollow shaft 18. The hollow shaft 18 carries the output spiral gear wheel 4 and is bearing-mounted in the housing 19. The hollow shaft 18 is provided on its inner side with screw thread 20 for cooperation with the thread of a screw spindle not shown. The spindle is suitable in particular for obtaining a linear output movement. By providing such a hollow shaft 18, this can be done cost-effectively in a special material which has been tuned for cooperation with the screw spindle, for example, a strong wear-resistant material of low friction, such as bronze or a technical plastic such as HNPE, POM, Nylon or PEPT. Such an actuator with a linear output movement can naturally also be obtained by providing the spiral gear wheel 4 with inner thread at the recess 14 for cooperation with the thread of a screw spindle not shown.

(22) Such a variant of the actuator with a rotation-translation converter on the second stage can be applied in an adjusting instrument for performing a linear adjustment on elements of motor vehicles, for example, adjustment of air guiding screens, in particular air dams. Such air guiding screens are applied for influencing air streams to, for example, a motor housing and/or disc brakes of the motor vehicle by regulation of the air supply. By regulating a position of the screens, the air supply to, for example, the motor housing and/or the disc brakes can be influenced. Also, the actuators may be used for influencing air streams around the motor vehicle by controlling, for example, screens under and/or on the rear of the motor vehicle to thereby regulate the air resistance. With such screens, for example, the consumption of the motor vehicle can be improved and/or the air resistance can be increased, for example, for a shorter brake path.

(23) In such an application, there is provided an adjusting instrument for adjusting a screen for a vehicle, comprising an actuator and a rotation-translation converter which by its input is coupled with the spiral gear wheel of the actuator, and which by its output is couplable with a spindle. During use, the output of the spiral gear wheel is then coupled with a spindle, and the spindle in its turn is coupled with a screen.

(24) It is noted furthermore that the invention is not limited to the exemplary embodiments described here. Many variants are possible. Thus, the first stage may also be implemented with multiple series-connected gear wheel pairs or with a first spiral pinion which cooperates with an intermediate spiral gear wheel. Also, the first stage may be driven by a different type of DC electric motor, such as a stepping motor or by a brushless DC motor.

(25) Such variants will be apparent to the person skilled in the art and are understood to fall within the scope of the invention as set forth in the appended claims.

LIST OF REFERENCE SIGNS

(26) 1. Actuator 2. DC motor 3. Reduction mechanism 4. Output spiral gear wheel 5. First stage 6. Motor shaft 7. Worm 8. Intermediate gear wheel 9. Intermediate shaft 10. Spiral pinion 11. Second stage 12. Bearing 13. Support 13a. Support spiral pinion 13b. Bearing surface 14. Recess 15. Inner toothing 16. Support shaft 17. Toothing 18. Hollow shaft 19. Housing 20. Screw thread 21. Base 22. Foot 23. Pivoting shaft D. Thickness of DC motor H. Height of reduction mechanism