Electromotive drive for motor vehicle applications
The modified planetary gear system in electric motor drives for automotive applications allows dual functional element actuation by blocking either the ring gear or planet carrier based on rotation direction, addressing complexity issues and maintaining a compact, efficient design.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- KIEKERT AG
- Filing Date
- 2025-12-11
- Publication Date
- 2026-07-23
AI Technical Summary
Existing electric motor drives for automotive applications, particularly in vehicle locks, are limited to operating on a single functional element due to the complexity of using planetary gears, making it difficult to apply them to multiple functions without increasing technological effort.
A modified planetary gear system with a locking element that selectively blocks either the ring gear or the planet carrier based on the direction of rotation, allowing independent actuation of two functional elements.
Enables the operation of two distinct functional elements using a compact and cost-effective design by switching between them based on the direction of rotation, maintaining high output torque and minimizing component count.
Smart Images
Figure DE2025101174_23072026_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] Electric motor drive for automotive applications
[0003] The invention relates to an electric motor drive for automotive applications, in particular an electric motor drive in or on a motor vehicle lock, wherein the drive is actuated by means of an electric motor via an intermediate planetary gear, and wherein the planetary gear is designed with sun gear, planet gears, planet carrier and ring gear.
[0004] Electric motor drives for automotive applications are used for a wide variety of functions in and on vehicles. For example, such electric motor drives are used in connection with power windows, mirror adjustments, seat adjustments, as well as locking mechanisms for fuel filler caps, charging port locks, flap locks, flap actuators, etc. These electric motor drives for automotive applications are operated with low-voltage direct current (DC) and therefore require an intermediate gearbox, and in this category, a planetary gear set, to move the functional elements as desired. In the example of a power window drive, the functional element could be a window pane, whereas in a mirror adjustment drive, a mirror is moved in this way. This is, of course, only an example and should not be understood as a limitation.
[0005] These types of electric motor drives are particularly favored for use in vehicle locks. A wide variety of positioning functions can be implemented here. For example, the electric motor drive in question can be used to open the vehicle lock. It can also be used to implement a closing mechanism. Furthermore, using such electric motor drives, a lifting device can be implemented in or on the vehicle lock. This device props up the door leaf, which carries the vehicle lock, relative to the vehicle body, allowing a user wishing to gain entry to open the door leaf through a gap created by the lifting device.
[0006] In this context, it is already possible to actuate both a closing device and an erecting device via a common drive unit, as described in detail in WO 2023 / 104236 A1. However, the gearbox or lever arrangement provided for in this context is complex and therefore involves increased technological effort.
[0007] In this context, when planetary gears are used in electric motor drives for automotive applications, they typically operate on only one functional element, for example, a latch inside a vehicle lock, as detailed in the prior art according to DE 10 2023 100950 A1. Such planetary gears have a compact design and enable the generation of high torques, making them ideally suited for the described applications in automotive engineering. This is because high-speed electric motors are usually available in these applications, and their rotational speed must be reduced accordingly to achieve and implement the desired actuating movement on the output side of the functional element.
[0008] However, approaches to using such electric motor drives for purposes other than, for example, closing mechanisms, as demonstrated by the prior art of DE 102023 100950 A1, are currently lacking. This is likely due to the fact that planetary gears have not yet achieved widespread use in the described sector, and their application to various functional elements has been considered technologically complex. The invention aims to remedy this situation.
[0009] The invention is based on the technical problem of further developing such an electric motor drive for automotive applications in such a way that, taking into account a still compact and simple design, it is possible to apply more than one functional element on the output side.
[0010] To solve this technical problem, the invention proposes, starting from a generic electric motor drive for automotive applications, that depending on the direction of rotation of the drive, a locking element blocks either the ring gear or the planetary gear carrier, so that a first functional element can be actuated via the ring gear and a further second functional element via the planetary gear carrier selectively and independently thereof, depending on the direction of rotation of the drive.
[0011] According to the invention, in an electric motor drive for automotive applications, the planetary gear interposed between the drive or electric motor and the functional element is modified to enable the operation of two different functional elements. The switching between the functional elements occurs depending on the direction of rotation of the drive. Typically, the direction of rotation of the drive corresponds to either a clockwise or counterclockwise rotation.
[0012] Depending on the direction of rotation of the drive, for example clockwise, the first functional element can then be actuated via the ring gear. If, on the other hand, the drive is energized in its opposite direction of rotation, in this example counterclockwise, the second functional element can be actuated via the planetary gear carrier, independently of the first. This makes it possible, in principle, as with the previously mentioned prior art according to WO 2023 / 104236 A1, to use the electric motor drive for either a pulling or a pushing motion. This depends on the input direction of the drive.
[0013] Crucial in this context is the implemented locking element. In the second scenario, this locking element blocks the ring gear when the drive is applied counterclockwise. As a result, the rotary motion transmitted from the drive, or electric motor, to the gearbox (in this example, counterclockwise) is transferred from the sun gear to the meshing planet gears. Consequently, the planet gears are set into rotation, and with them, the planet carrier, which in this example drives the second functional element.
[0014] However, if the direction of rotation of the drive is reversed, i.e., in the described example, if it rotates clockwise, the locking element blocks the planet carrier. This blockage of the planet carrier then results in the rotational motion, transmitted from the drive in the opposite direction via the sun gear to the planet gears, being transferred to the ring gear, because the planet carrier has been blocked by the locking element. Consequently, the first functional element can be driven via the ring gear. The directions of rotation assumed at the outset (clockwise or counterclockwise) are, of course, to be understood as purely illustrative, as is the notation of the functional elements as first and second functional elements, respectively.
[0015] In any case, it becomes clear that, by using a simply constructed and purely mechanical locking element, and depending on the direction of rotation of the drive, the planetary gear can be selectively switched to drive either the first or the second functional element. All this is achieved while maintaining a compact and cost-effective design, because the same planetary gear is used to drive both the first and second functional elements. This is where the key advantages lie.
[0016] To implement this in detail, the ring gear and the planet carrier are generally arranged adjacent to each other and preferably coaxially. The axis that typically shares the same axis between the ring gear and the planet carrier is usually defined by the axis of the centrally located sun gear, which may also coincide with the axis of the drive.
[0017] The locking element generally interacts with a corresponding cam on the ring gear or planetary gear carrier. This interaction results in either the ring gear or the planetary gear carrier being blocked, depending on the direction of rotation of the drive. The locking element can be a locking bolt or a locking rocker.
[0018] The cam mechanism is generally designed as a recess on the outer circumference of the ring gear or the planet carrier. Both cams on the ring gear and the planet carrier can be open to each other. This allows the locking element to move from one cam to the other, and indeed, to move because the two cams are open to each other. This movement of the locking element depends on the direction of rotation of the drive, as will be explained in more detail below with reference to the exemplary embodiment.
[0019] The cam can be a freewheel ramp, meaning a cam that provides both freewheeling and angular movement of the locking element, such that the angular movement engages the locking element and, in particular, causes it to move from one cam to the other. It is also possible to use multiple locking elements, which are engaged via the respective freewheel ramp to provide the desired selective blocking of either the ring gear or the planetary gear carrier. The cam can also incorporate the freewheel ramp itself.
[0020] As previously explained, the locking element can be a locking bolt or a locking rocker. If a locking bolt is used, it is largely radially displaceable relative to the common axis of the ring gear and planet carrier. This means that the locking bolt is largely displaced radially to move from one cam to the other. This displacement is initiated and determined by the direction of rotation of the drive.
[0021] Alternatively, the locking element can also be a locking rocker. The locking rocker is largely designed to pivot tangentially relative to the outer circumference of the ring gear and the planet carrier. For this purpose, the locking rocker generally has a rocker arm on one side and locking balls or locking pins, usually located at the ends of the rocker arm, on the other. These locking balls or locking pins engage in the gate depending on the position of the rocker arm and thus the locking rocker arm as a whole.
[0022] The invention also relates to a motor vehicle lock, and in particular a motor vehicle door lock, which is equipped with the electromechanical drive described in detail above. In this context, the electromechanical drive can act on a setting device or a closing device as respective functional elements, depending on the direction of rotation of the drive, as will be explained in more detail below.
[0023] The result is a description and presentation of an electric motor drive for automotive applications that is compact in design and requires a minimum of components. This is essentially due to the fact that, according to the invention, the planetary gear used only needs to be equipped with the two cams and the movable locking element, which practically does not change the external dimensions and can be implemented cost-effectively and reliably. This makes the electric motor drive ideal for automotive applications because it requires little installation space and simultaneously provides high output torque. These are its key advantages.
[0024] The invention will now be explained in more detail with reference to a drawing that illustrates only one embodiment; the drawing shows:
[0025] Figures 1 to 3 show an electric motor drive for automotive applications and, specifically, an indicated motor vehicle door lock with a lifting device and a closing mechanism within the framework of a first embodiment for the locking element and
[0026] Figures 4 to 6 show a further second embodiment of the electromechanical drive in conjunction with the motor vehicle door lock, taking into account a modified variant for the locking element.
[0027] The figures depict an electric motor drive 2, 3, 4, 5, 6, 7 for automotive applications. Specifically, the electric motor drive 2, 3, 4, 5, 6, 7 is arranged inside a lock housing 1 of a motor vehicle door lock, indicated only in Fig. 1. In principle, the electric motor drive 2, 3, 4, 5, 6, 7, which will be described in detail below, can also be housed outside the lock housing 1 in a separate housing for other applications. Likewise, other actuating movements besides those inside a lock housing 1 are conceivable; for these, reference is made to the introductory explanations. In any case, the electric motor drive 2, 3, 4, 5, 6, 7 is supplied with low-voltage direct current and is adapted to the specific requirements inside a motor vehicle, i.e., it is regularly enclosed in the lock housing 1 in a dust- and media-tight manner.
[0028] The electric motor drive 2, 3, 4, 5, 6, 7 initially comprises an electric motor 2 with an output worm gear on its output shaft. An output gear 3 meshes with the output worm gear on the output shaft of the electric motor 2. In this embodiment, the output gear 3 is a component of a transmission 3, 4, 5, 6, 7 downstream of the electric motor 2, which, according to this embodiment, is designed as a planetary gear 3, 4, 5, 6, 7, as additionally and purely schematically shown in the inset of Fig. 1.
[0029] It can be seen that the output gear 3 carries a sun gear 4 on its axis A in a rotationally fixed manner. This sun gear interacts with planet gears 5, which roll inside a ring gear 6. The planet gears 5 are in turn supported by a planet carrier 7. According to the exemplary embodiment, the planet carrier 7 is rotationally fixed to a gear 8, which engages with the teeth of an adjusting lever 9. Together, in this exemplary embodiment, the gear 8 and the adjusting lever 9 define an adjusting device 8, 9, which, as a second functional element 8, 9 (to be explained below), is actuated by means of the planet carrier 7.
[0030] Additionally, a closing device 11 is visible, which is connected to the ring gear 6 and performs the function of a first functional element 11, which will be explained in more detail below. For this purpose, the closing device 11 is connected to the ring gear 6 via a Bowden cable 10, which is shown schematically in Fig. 1. Depending on the direction of rotation of the ring gear 6, pulling or pushing movements are transmitted via the Bowden cable 10, which are used as a closing movement inside the vehicle lock, which is not shown in detail. In fact, a locking mechanism consisting of a rotary latch and pawl, as part of the vehicle door lock, can be closed in the housing 1 using the ring gear 6 or the closing device 11. Conversely, the opening device 8, 9 ensures that a door leaf of a vehicle door, equipped with the vehicle door lock, is opened relative to the indicated vehicle body.
[0031] The electric motor drive 2, 3, 4, 5, 6, 7 can be actuated in two different directions of rotation, which are indicated in Fig. 1 by a solid arrow and a dashed arrow. In this exemplary embodiment, the solid arrow corresponds to counterclockwise rotation and thus to the actuation of the setting device or the second functional element, 9, as will be explained in more detail below. In contrast, the dashed arrow corresponds to clockwise rotation and thus to the first direction of rotation, and to the actuation of the locking mechanism 11 or the first functional element 11, which engages the lock of the vehicle door lock.
[0032] Looking at Fig. 1 and the highlighted area showing the planetary gear set 3, 4, 5, 6, 7, it becomes clear that, in the second direction of rotation, as indicated by the solid arrow, the sun gear 4 in the center, with its rotations around axis A, causes the sun gears 5 to roll against it. The same applies to the planet carrier 7, which carries the respective axes of the sun gears 5. If, in this case, the ring gear 6 is blocked, the engagement of the sun gear 4 causes the planet carrier 7 and also the output gear 8 to rotate, as shown in Fig. 1, counterclockwise. Since the gear 8 engages with the teeth on the setting lever 9, this extends the setting lever 9, and the desired setting movement is observed in this example. The second functional element 8, 9 is then engaged. This requires - as mentioned - that the ring gear 6 is blocked.This blockage of the ring gear 6 and alternatively of the planetary gear carrier 7 is now ensured by a locking element 12, 13, 14; 15, 16, which is shown in different embodiments in Figures 1 to 3 on the one hand and Figures 4 to 6 on the other.
[0033] The locking element 12, 13, 14 in the first embodiment according to Figures 1 to 3 is a locking rocker 12, 13, 14, which is designed to pivot largely tangentially relative to the outer circumference of the ring gear 6 and the planet carrier 7. It can also be seen that the locking rocker 12, 13, 14 is equipped with an axle 13, which is arranged largely tangentially to the outer circumference of the respective ring gear 6 and the planet carrier 7, which are approximately identical in the illustrated example. Next to the axle 13, a rocker 12 is provided, each end of which is equipped with a locking ball or a locking pin 14, respectively. The locking ball or locking pin 14 at the end of the rocker 12 interacts with an associated cam 17, 18, which can be seen in Figure 3. Each of these backdrops 17, 18 is equipped with a free-running ramp 17a and 18a respectively, as will be explained in more detail below.The cam 17 is located on the outer circumference of the planet carrier 7, while the cam 18 is provided on the outer circumference of the ring gear 6.
[0034] In the embodiment shown in Figures 4 to 6, the locking element 15, 16 is a locking bolt 15, which is additionally equipped with a flange 16, for example, for its guidance. The locking element 15, 16, or the locking bolt 15, interacts—as in the embodiment shown in Figures 1 to 3—with an associated cam 19, 20. The cam 19—comparable to the cam 17—is located on the planet carrier 7, and the cam 20—similar to the cam 18—is located on the ring gear 6.
[0035] Both embodiments have in common that the ring gear 6 and the planet carrier 7 are arranged adjacent to each other. Furthermore, the ring gear 6 and the planet carrier 7 not only have approximately the same outer circumference, but are also aligned coaxially, with axis A defined by the common axis A, which is determined and specified by the sun gear 4. The associated locking element 12, 13, 14; 15, 16 interacts with the respective cam 18, 20 on the ring gear 6 and the cam 17, 19 on the planet carrier 7. It can be seen that the cam 18, 20 on the ring gear 6, as well as the cam 17, 19 on the planet carrier 7, is each formed as a recess on the outer circumference of the ring gear 6 and the planet carrier 7, respectively.
[0036] In the embodiment shown in Figures 4 to 6, the design is furthermore such that the two backdrops 19, 20 are open to each other. Moreover, the backdrops 18, 20 and 20 are...
[0037] 17, 19 each have free-running ramps or the respective cams 18, 20; 17, 19 have a corresponding free-running ramp 17a, 18a respectively 19a, 20a.
[0038] The operating principle is as follows. Considering the embodiment shown in Figures 1 to 3, as illustrated in Figure 3, applying force to the electric motor 2 in the second solid line and shown on the right causes the cam 18 in the ring gear 6 to interact with the locking ball or the locking pin 14 of the rocker arm 12, which engages the ring gear 6. For this purpose, the locking ball or locking pin 14 at the other end of the rocker arm 12 is pivoted by means of the adjacent planetary gear carrier 7 and the cam 17 located therein, so that the ring gear 6 is blocked. Since the ring gear 6 is blocked in this case, rotary movements of the sun gear 4 are transmitted via the planet gears 5 to the planet carrier 7, which as a result rotates and, via the output-side pinion 8, acts on the setting lever 9 to set up and consequently on the second function element 8,9.
[0039] Conversely, applying force to the electric motor 2 in the other first and dashed direction of rotation in the left part of Fig. 3 results in the planet carrier 7, rather than the ring gear 6, being blocked. This is achieved by using the ring gear 6 or the cam 18 on the outer circumference of the ring gear 6 or the freewheel ramp 18a to pivot the interacting locking ball or locking pin 14 so that the opposite locking ball or locking pin 14 engages in the cam 17 on the planet carrier 7 and blocks it.
[0040] Since the planet carrier 7 is blocked, a rotational movement transmitted via the sun gear 4 and the electric motor 2 causes the planet gears 5 to roll on the inside of the ring gear 6. Because the planet gears 5 maintain their position due to the stationary planet carrier 7, the ring gear 6 is set into rotation and can, via the connected closing device 11 or the first functional element 11, act as a closing mechanism on the locking mechanism of the vehicle door lock.
[0041] In the alternative variant according to the illustration in Figures 4 to 6, a rotational movement of the planet carrier 7 in the solid clockwise direction shown in Fig. 4 (first direction of rotation, shown with a dashed line in Fig. 1) leads to the planet carrier 7 being blocked in this direction of rotation and the locking element 15, 16 or the locking bolt 15 in this case securing the planet carrier 7 so that the ring gear 6 can rotate and, in the example case, thus actuates the tightening device 11 as the first functional element 11.
[0042] Conversely, a change in the direction of rotation in Fig. 4 (counterclockwise, shown here with a dashed line, represented as the second direction of rotation in Fig. 1 with a solid line) corresponds, again starting from Fig. 4, to the fact that in this case the planet carrier 7 rotates counterclockwise, so that the locking bolt 15, along the free-running ramp 19a of the cam 19 on the planet carrier 7, practically engages in the opposite and open cam 20 of the ring gear 6 and then blocks the ring gear 6. This allows the planet carrier 7 to rotate and, via the output gear 8, actuate the setting lever 9 of the setting device 8, 9 in a setting direction and consequently actuate the second functional element 8, 9.
[0043] During this process, the locking element 15, 16 moves predominantly radially with respect to axis A. To guide this movement, the flange 16 is provided on the locking bolt 15. For this purpose, the flange 16 engages in a guide pocket 22 of a stationary intermediate disk 21. As shown in Fig. 6, the intermediate disk 21 is located adjacent to and coaxially (axis A) with the ring gear 6 and thus with the sun gear 4, the planet carrier 7, and the output gear 3. Reference numeral list
[0044] 2, 3, 4, 5, 6, 7 electric motor drive 2 electric motor
[0045] 3 Output gear
[0046] 4 sun wheel
[0047] 5 planetary gears
[0048] 6. Ring gear
[0049] 7 planetary bike carriers
[0050] 8 gear, pinion
[0051] 9 setting levers
[0052] 8, 9 Mounting device
[0053] 10 Bowden cable
[0054] 11. Pull-out mechanism
[0055] 12, 13, 14; 15, 16 Locking element
[0056] 12, 13, 14 Locking rocker
[0057] 12 rocker
[0058] 13th axis
[0059] 14 Locking ball or locking pin 15, 16 Locking element
[0060] 15 locking bolts
[0061] 16 flange
[0062] 17, 18, 19, 20 Backdrop
[0063] 17a, 18a, 19a, 20a Free-running slope
[0064] 21 Intermediate disc
[0065] 22 guide bag
Claims
Patent claims 1. Electric motor drive (2, 3, 4, 5, 6, 7) for automotive applications, in particular an electric motor drive in or on a motor vehicle lock, wherein the drive (2, 3, 4, 5, 6, 7) acts on at least one functional element (8, 9; 11) by means of an electric motor (2) via an intermediate planetary gear (3, 4, 5, 6, 7), and wherein the planetary gear (3, 4, 5, 6, 7) is designed with sun gear (4), planet gears (5), planet carrier (7) and ring gear (6), characterized by the fact that Depending on the direction of rotation of the drive (2, 3, 4, 5, 6, 7), a locking element (12, 13, 14; 15, 16) either blocks the ring gear (6) or the planet carrier (7), so that a first functional element (11) can be actuated via the ring gear (6) and a further second functional element (8, 9) can be actuated via the planet carrier (7) either selectively and independently of this and depending on the direction of rotation of the drive (2, 3, 4, 5, 6, 7).
2. Electric motor drive (2, 3, 4, 5, 6, 7) according to claim 1 , characterized in that the ring gear (6) and the planet gear carrier (7) are arranged adjacent and preferably coaxially (A) to each other.
3. Electromotive drive (2, 3, 4, 5, 6, 7) according to claim 1 or 2, characterized in that the locking element (12, 13, 14; 15, 16) interacts with a respective cam (18, 20) on the ring gear (6) or a cam (17, 19) on the planet gear carrier (7).
4. Electric motor drive (2, 3, 4, 5, 6, 7) according to any one of claims 1 to 3, characterized in that the locking element (12, 13, 14; 15, 16) is designed as a locking bolt (15) or locking rocker (12, 13, 14).
5. Electric motor drive (2, 3, 4, 5, 6, 7) according to claim 4, characterized in that the locking bolt (15) is designed to be largely radially displaceable relative to the common axis (A) of the ring gear (6) and the planet carrier (7).
6. Electromotive drive (2, 3, 4, 5, 6, 7) according to claim 4, characterized in that the locking rocker (12, 13, 14) is designed to be pivotable largely tangentially relative to the outer circumference of the ring gear (6) and the planet gear carrier (7).
7. Electric motor drive (2, 3, 4, 5, 6, 7) according to one of claims 1 to 6, characterized in that the respective cam (18, 20; 17, 19) is designed as a recess on the outer circumference of the ring gear (6) or the planet gear carrier (7).
8. Electric motor drive (2, 3, 4, 5, 6, 7) according to one of claims 1 to 7, characterized in that both cams (18, 20; 17, 19) on the ring gear (6) and on the planet carrier (7) are open to each other.
9. Electric motor drive (2, 3, 4, 5, 6, 7) according to one of claims 1 to 8, characterized in that the cam (18, 20; 17, 19) is designed as a free-running ramp (18a, 20a; 17a, 19a) or includes one.
10. Motor vehicle lock, in particular motor vehicle door lock, characterized by an electromechanical drive (2, 3, 4, 5, 6, 7) according to one of claims 1 to 9.