ACTUATOR FOR AUTOMOTIVE APPLICATIONS

Abstract

An application, in particular for motor vehicle closing devices. The basic design of the motor vehicle has an electric motor and an actuating element which is acted upon by the electric motor directly or indirectly via a powertrain. The powertrain is provided with at least one Evoloid toothing. According to the invention, a drive shaft of the electric motor is equipped with an Evoloid pinion which meshes with an Evoloid output gear at the input of the powertrain, thereby directly producing the Evoloid toothing.

Claims

1. An actuator for automotive applications, the actuator comprising: an electric motor having a drive shaft with an Evoloid pinion; an actuating element; and a powertrain, wherein the actuating element is acted upon indirectly or directly by the electric motor via the powertrain at an output of the powertrain, wherein the powertrain includes an Evoloid output gear having Evoloid toothing, wherein the Evoloid pinion of the drive shaft has Evoloid toothing which meshes with the Evoloid toothing of the Evoloid output gear at an input of the powertrain.

2. The actuator according to claim 1, wherein the Evoloid pinion is formed on a spigot.

3. The actuator according to claim 2, wherein the spigot or the Evoloid pinion is fitted as a whole onto the drive shaft of the electric motor.

4. The actuator according to claim 1, wherein a transmission ratio of the Evoloid toothing is at least 5.0.

5. The actuator according to claim 1, wherein the Evoloid pinion has three teeth.

6. The actuator according to claim 1, wherein the drive shaft of the electric motor and the actuating element extend parallel to one another.

7. The actuator according to claim 1, wherein the powertrain has a supplementary transmission in addition to the Evoloid output gear having the Evoloid toothing at the input.

8. The actuator according to claim 7, wherein the supplementary transmission has one or more further Evoloid toothings.

9. The actuator according to claim 7, wherein the powertrain and/or the supplementary transmission consists at least partially of plastic gears.

10. The actuator according to claim 4, wherein the transmission ratio of the Evoloid toothing is 10.0 or more.

11. The actuator according to claim 1, wherein the Evoloid toothing of each of the Evoloid output gear is obliquely angled relative to an axis of rotation of the Evoloid output gear, and wherein the Evoloid toothing of the Evoloid pinion is obliquely angled relative to an axis of rotation of the Evoloid pinion.

12. The actuator according to claim 11, wherein the axis of rotation of the Evoloid output gear and the axis of rotation of the Evoloid pinion are parallel to each other.

13. The actuator according to claim 1, wherein the Evoloid toothing of the Evoloid output gear includes more teeth as compared with a number of teeth of the Evoloid toothing of the Evoloid pinion.

14. The actuator according to claim 13, wherein a transmission ratio of the Evoloid toothing of the Evoloid pinion relative to the Evoloid toothing of the Evoloid output gear is at least 5 to 1.

15. The actuator according to claim 1, wherein the actuating element includes a spindle that is arranged along an axis of rotation of the Evoloid output gear and is configured to provide linear movement.

16. The actuator according to claim 15, wherein the actuating element includes a threaded spindle rotatably fixed to the Evoloid output gear and a spindle nut connected to the threaded spindle at an axial end opposite an end at which the Evoloid output gear is fixed.

17. The actuator according to claim 7, wherein the supplementary transmission includes a first gear stage downstream the Evoloid pinion and the Evoloid output gear and a second gear stage downstream the first gear stage and upstream the actuating element, at least one of the first gear stage and the second gear stage including a second Evoloid pinion and a second Evoloid output gear meshingly engageable with the second Evoloid pinion.

18. The actuator according to claim 17, wherein a transmission ratio between the second Evoloid pinion and the second Evoloid output gear is less than a transmission ratio between the Evoloid pinion and the Evoloid output gear upstream the second Evoloid pinion and the second Evoloid output gear.

19. The actuator according to claim 17, wherein at least one of the first gear stage and the second gear stage includes straight-toothed gears.

Description

[0020] The invention is explained in greater detail with reference to drawings which show two exemplary embodiments. In the drawings:

[0021] FIG. 1 shows a first exemplary embodiment of the actuator according to the invention in a schematic overview,

[0022] FIG. 2 shows a perspective view of the implemented Evoloid toothing, and

[0023] FIG. 3 shows a first exemplary embodiment of the actuator according to the invention.

[0024] The drawings show an actuator for automotive applications. The automotive applications are in particular such applications in connection with and for motor vehicle closing devices, as has previously been explained in detail. For this purpose the basic design of the actuator includes an electric motor 1 and an actuating element 5.

[0025] With reference to the exemplary embodiment according to FIG. 1 it can be seen that the motor vehicle has an electric motor 1 and an actuating element 5 which is acted upon indirectly or directly via a powertrain 2, 3, 4. The exemplary embodiment according to FIG. 1 shows an actuator designed as a microdrive. In the exemplary embodiment the actuating element 5 is acted upon directly by means of the powertrain 2, 3, 4, because only one Evoloid toothing 2, 3 for transmission of the rotary movements of a drive shaft 1′ of the electric motor 1 is provided in the powertrain 2, 3, 4.

[0026] In the present case the Evoloid toothing 2, 3 is provided between an Evoloid pinion 2 and an Evoloid output gear 3. A threaded spindle 4 is connected in a rotatably fixed manner to the Evoloid output gear 3. A spindle nut which, in the context of the variant according to FIG. 1, is integrated into the actuating element 5 or constitutes a component of the actuating element 5 is accommodated on the threaded spindle 4. In this way rotations of the threaded spindle 4 lead to the actuating element 5 being capable of carrying out the linear movements indicated in FIG. 1 or translational movements in the direction of double arrow.

[0027] It will be recognized that the drive shaft 1′ at the output of the electric motor 1 is equipped with the Evoloid pinion 2. For this purpose the Evoloid pinion 2 is designed as a spigot. The spigot or the Evoloid pinion 2 is fitted as a whole onto the drive shaft 1′ of the electric motor 1 and has a hollow bore for this purpose. Moreover, the spigot 2 may be additionally secured on the drive shaft 1′ of the electric motor 1.

[0028] It will be recognized that the Evoloid toothing 2, 3 with its Evoloid pinion 2 and the Evoloid output gear 3 has in each case axes of rotation extending parallel to one another. In this way a particularly compact design is provided. The axes of rotation are oriented relative to one another with a spacing A. Moreover, as a result the design may be such that the drive shaft 1′ of the electric motor 1 and the actuating element 5 overall likewise extend parallel to one another. This is because the actuating element 5 or the spindle nut moves in its longitudinal direction along the axis of rotation of the threaded spindle 4, which coincides with the axis of rotation of the Evoloid output gear 3. Accordingly, the same spacing A can be seen between the actuating element 5 or its longitudinal axis and the drive shaft 1′ of the element 1.

[0029] Details of the Evoloid toothing 2, 3 are illustrated in FIG. 2. It will be recognized that the Evoloid pinion 2 in the exemplary embodiment is equipped with a total of four teeth. In general it is also possible to operate with fewer teeth for the Evoloid pinion 2. In the illustrated exemplary embodiment the Evoloid pinion 2 has three teeth. Moreover, the design in the exemplary case is such that the individual teeth of the Evoloid pinion 2 have a normal modulus of at least 0.4. On the other hand, the obliquely toothed Evoloid output gear 3 according to the exemplary embodiment has a total of forty teeth. The modulus or normal modulus of the Evoloid output gear 3 is likewise at least 0.4. Because of the described numbers of teeth for, on the one hand, the Evoloid pinion 2 and, on the other hand, the Evoloid output gear 3, in the exemplary embodiment a transmission ratio of the Evoloid toothing 2, 3 obtained in this way is 10.0 or 1 to 10, as indicated in FIG. 3 at this point.

[0030] In other words, one revolution of the Evoloid output gear 3 corresponds to ten revolutions of the Evoloid pinion 2. In general, other transmission ratios can be implemented at this point. The Evoloid toothing 2, 3 usually has a transmission ratio of at least 5.0 and preferably of 10.0 and more.

[0031] In the exemplary embodiment according to FIG. 1 a rotation of an output shaft of the electric motor 1 is transmitted directly to the actuating element 5 via the Evoloid output gear 3 connected in a rotatably fixed manner to the threaded spindle 4. Alternative designs can provide one or more intermediate shafts, which are also designed as Evoloid gear stages or also designed conventionally as spur gear stages, between the Evoloid output gear 3 and the threaded spindle 4.

[0032] The second exemplary embodiment according to FIG. 3 makes it clear that the powertrain 2, 3, 4 corresponding to the variant according to FIG. 1 can be equipped with a supplementary transmission 6, 7; 8, 9 in addition to the Evoloid toothing 2, 3 at its input. The transmission 6, 7; 8, 9 is made up of a first gear stage 6, 7 and a second gear stage 8, 9. FIG. 3 shows an actuator designed as a charging socket actuator which is provided in order to lock a charging socket of an electric car.

[0033] In the first gear stage 6, 7 an Evoloid pinion 6 is again used, which meshes with an obliquely toothed Evoloid output gear 7. At this point a transmission ratio of 3.6 or 1 to 3.6 is observed, as shown in FIG. 3. The Evoloid pinion 6 of the first gear stage 6, 7 is coupled in a rotatably fixed manner to the Evoloid output gear 3 of the Evoloid toothing 2, 3 at the input of the powertrain 2, 3, 4 or 2, 3.

[0034] An input gear 8 of the second gear stage 8, 9, which for its part meshes with an Evoloid output gear 9 of the second gear stage 8, 9, is connected to the Evoloid output gear 7 of the first gear stage 6, 7 in a rotatably fixed manner. The two gears 8, 9 of the second gear stage 8, 9 are designed as straight-toothed spur gears. On the other hand, the spur gears 2, 3 of the Evoloid toothing 2, 3, just like the spur gears 6, 7 of the first gear stage 6, 7, in each case have the already described Evoloid pinion 2 or 6 at the input end and the obliquely toothed Evoloid output gear 3 or 7 at the discharge end. In alternative configurations the first gear stage 6, 7 and the second gear stage 8, 9 can both be configured as Evoloid gear stages or as spur gear stages.

[0035] By means of the exemplary embodiment according to FIG. 3 it will be recognized that the Evoloid toothing 2, 3 at the input of the powertrain 2, 3, 4 or 2, 3 in conjunction with the transmission 6, 7; 8, 9 connected downstream provides overall a transmission ratio of approximately 86.4 or 1 to 86.4 (10×3.6×2.4), so that substantial transmission ratios can be implemented with a simultaneously compact design. Moreover, the possibility exists of designing the powertrain 2, 3, 4 or 2, 3, just like the transmission 6, 7; 8, 9, at least partially with plastic gears. According to the exemplary embodiment, at least the Evoloid pinion 2 and the Evoloid output gear 3 are manufactured from plastic. The further gears 6, 7; 8, 9 of the optional transmission 6, 7; 8, 9 connected downstream can also be manufactured from plastic. Overall, in the variant according to FIG. 3, the actuating element 5 indicated there is acted upon indirectly by the electric motor 1 via the powertrain 2, 3, 4, that is to say with the interposition of the transmission 6, 7; 8, 9. Moreover, in this variant the threaded spindle 4 is omitted, because in this case the actuating element 5 is acted upon by means of the Evoloid output gear 9 at the output of the second gear stage 8, 9.