Actuator

Abstract

Actuator (2) for an actively adjustable roll stabilizer (1) of a motor vehicle, comprising a drive train capable of rotating a stabilizer section (3b) connectable to the actuator (2) about an axis of rotation (5) for the purpose of influencing the roll behavior of the motor vehicle, wherein the drive train comprises a decoupling unit (10) with a drive part (11) rotatable about the axis of rotation (5), an output part (12) rotatable about the axis of rotation (5), and a coupling acting between them, characterized in that the coupling comprises a circumferential meander spring (13) with a plurality of alternately wound spring loops (14a, 14b), wherein the spring loops (14a, 14b) alternately enter coupling areas (15a) of the drive part (11) and in the drive part (12) for the torsionally elastic coupling of the drive part (11) and the output part (12). Opposite coupling areas (15b) of the output part (12) engage.

Description

[0001] The invention relates to an actuator according to the preamble of claim 1. The invention also relates to an adjustable roll stabilizer for a motor vehicle according to claim 12.

[0002] In chassis engineering, it is common practice to equip motor vehicles with a so-called roll stabilizer to increase vehicle stability and ride comfort. In its simplest form, this is essentially a C-shaped torsion bar spring, mounted in the middle relative to the vehicle body, with its outer, opposing ends each connected to a wheel suspension. This design ensures that when the vehicle corners, the roll stabilizer not only compresses on the outside of the curve (due to centrifugal force) but also, at least to some extent, on the inside (a copying effect to reduce body roll).

[0003] To further enhance vehicle stability and ride comfort, it is also known to design such roll stabilizers to be actively adjustable. An actively adjustable roll stabilizer for a motor vehicle comprises an actuator and is divided into two stabilizer sections that can be rotated relative to each other around a rotational axis by means of the actuator. By rotating the stabilizer sections relative to each other (around the rotational axis), a roll movement of the vehicle body is either deliberately generated or a roll movement of the vehicle body caused by external influences is deliberately counteracted.The actuator of such a roll stabilizer comprises as essential elements a drive motor, preferably in the form of an electric motor, a gearbox driven by it, preferably in the form of a multi-stage planetary gearbox, and a coupling for damping, in particular, torsional vibrations within the drive train formed from the drive motor, gearbox and thus the stabilizer section connected to the drive.

[0004] Decoupling units for general use in drive technology are known from US 1 216 227 A and DE 362 939 A.

[0005] Decoupling units for use on an actuator of an actively adjustable roll stabilizer are known from DE 10 2020 209 788 A1 and DE 10 2021 201 025 B4. Both are based on a design in which a star-shaped inner profile is formed on the drive part and a star-shaped outer profile on the output part. In a nested state, a star-shaped elastomer body acts between the drive and output parts to dampen torsional vibrations. In practice, it has been found that such elastomer bodies are expensive to manufacture due to their complex geometry. Furthermore, their material properties make them susceptible to temperature fluctuations. Specifically, this means that the decoupling behavior, including the damping effect and deformation behavior, changes depending on the temperature.This makes it more difficult, among other things, to regulate, especially with regard to the positioning (position control), an adjustable roll stabilizer equipped with it.

[0006] It is an object of the present invention to provide an actuator for an actively adjustable roll stabilizer, the decoupling unit of which is simpler to manufacture and exhibits lower temperature sensitivity. Furthermore, an adjustable roll stabilizer for a motor vehicle is to be provided, which achieves corresponding advantages.

[0007] The aforementioned problem is solved by an actuator for an actively adjustable roll stabilizer of a motor vehicle according to the features of claim 1. According to the invention, this actuator has a drive train suitable for rotating a stabilizer section connectable to the actuator about an axis of rotation for the purpose of influencing the roll behavior of the motor vehicle, wherein the drive train comprises a decoupling unit with a drive part rotatable about the axis of rotation, a driven part rotatable about the axis of rotation, and a coupling acting between them. According to the invention, the actuator is characterized in that the coupling has a circumferential meandering spring with a plurality of alternately wound spring loops, wherein the spring loops engage alternately in coupling areas of the drive part and in opposite coupling areas of the driven part for the torsionally elastic coupling of the drive part and the driven part.

[0008] According to a preferred embodiment of the actuator, its drive train comprises a drive unit that includes a drive motor and a gearbox driven by it, in particular in the form of a multi-stage planetary gearbox, which reduces a motor speed provided by the drive motor into a relatively lower gearbox output speed, with which the drive part of the decoupling unit can be driven.

[0009] The meandering spring is advantageously an elastically deformable component with a meandering path around the axis of rotation. The meandering spring forms alternately wound spring loops that engage alternately in coupling areas of the drive part and in opposing coupling areas of the driven part. The drive and driven parts are thus torsionally coupled. In this way, a decoupling unit is created that is particularly suitable for damping torsional vibrations between the drive and driven parts.

[0010] Advantageously, the decoupling unit is designed such that the coupling areas establish a mechanical coupling, in particular a positive-locking coupling, between the meander spring and the drive part, as well as between the meander spring and the driven part, in order to enable force transmission distributed around the circumference. Accordingly, force transmission takes place at a multitude of coupling areas distributed around the circumference, resulting in torque transmission between the drive part and the driven part with respect to the axis of rotation.

[0011] According to a preferred embodiment, the coupling areas are formed facing each other at the end faces of the drive part and the output part.

[0012] Advantageously, the coupling areas provided on the drive and output parts are designed to be complementary to the head sections of the meander spring, so that a head section of the associated spring loop plunges axially into them to create a positive-locking connection. The coupling areas can be designed differently; in particular, they could be formed in various pocket shapes to accommodate a head section of the associated meander spring. Other designs for the coupling areas are also conceivable to establish a connection between the meander spring and the drive or output part.

[0013] A preferred embodiment of the decoupling unit provides that the meander spring is designed as a ring, in particular as a fully closed or fully open ring. A fully closed ring design offers the advantages of simple and secure assembly as well as uniform action across the entire circumference.

[0014] Since the meander spring is preferably manufactured in one piece, it can be produced and assembled with minimal manufacturing effort. The meander spring is preferably made of a metallic material, in particular spring steel.

[0015] An advantageous design of the decoupling element provides that the spring loops of the meander spring essentially run on an imaginary cylindrical shell.

[0016] Spring loops can be designed in various ways. Easy manufacturing and assembly are achieved by having a square coil and / or a round coil at the head of each spring loop.

[0017] According to a preferred embodiment of the decoupling unit, a spring loop can be provided to have two longitudinal regions extending substantially parallel to the axis of rotation and a transverse region extending substantially in the circumferential direction.

[0018] Preferably, in an unloaded, undeformed state of the decoupling unit, the longitudinal areas of the spring loops are aligned parallel to the axis of rotation, while in a loaded, deformed state of the decoupling unit, the longitudinal areas of the spring loops are twisted relative to the axis of rotation.

[0019] The aforementioned problem is further solved by an adjustable roll stabilizer for a motor vehicle according to the features of claim 12. This comprises a first stabilizer section that can be coupled to a first wheel suspension and a second stabilizer section that can be coupled to a second wheel suspension, wherein the first stabilizer section and the second stabilizer section can be rotated relative to each other about the axis of rotation by means of an actuator of the type described above acting between them in order to influence the roll behavior of the motor vehicle.

[0020] The invention is explained in more detail below with reference to the accompanying drawing. Further advantageous effects of the invention will also become apparent from this drawing. The drawing shows: Fig. 1. An actively adjustable roll stabilizer in a simplified schematic view, Fig. 2 a decoupling unit of an actuator according to the invention in a simplified perspective view from an oblique angle above.

[0021] Fig. Figure 1 shows a schematic view of an actively adjustable roll stabilizer 1 for a motor vehicle. The adjustable roll stabilizer 1 can be mounted to the vehicle body (chassis) of a motor vehicle in the area of ​​the front axle and / or the rear axle in a manner not shown in detail here. The adjustable roll stabilizer comprises, as essential elements, a first stabilizer section 3a and a second stabilizer section 3b, which can be rotated relative to each other about a rotational axis 5 by means of an actuator 2 arranged between them. In a manner known per se, the first stabilizer section 3a is coupled at its end facing away from the actuator 2 to a simplified representation of a first wheel suspension 9a, which rotatably accommodates a first wheel 4a.Likewise, the second stabilizer section 3b is coupled at its end facing away from the actuator 2 to a second wheel suspension 9b, which rotatably accommodates a second wheel 4b.

[0022] The wheel suspensions 9a and 9b allow independent vertical movements of the wheels 4a and 4b in a vertical direction z of the vehicle, for example, to compensate for uneven road surfaces while the vehicle is in motion. However, the wheel suspensions 9a and 9b of the wheels 4a and 4b are coupled to each other via the actively adjustable roll stabilizer 1. The C-shaped arrangement formed by the first stabilizer section 3a, the actuator 2, and the second stabilizer section 3b serves, in a manner known per se, to couple the vertical movements of the wheels 4a and 4b (copying behavior). In addition, the actuator 2 can be used to actively cause a relative rotation of the stabilizer sections 3a and 3b relative to each other in order to influence the roll behavior of the vehicle.

[0023] The actuator 2, shown here in simplified form as a cylindrical body, comprises as essential elements a drive motor 7, preferably designed as an electric motor, a gearbox 8, preferably designed as a multi-stage planetary gearbox, and a decoupling unit 10. The drive motor 7, the gearbox 8 and the decoupling unit 10 are arranged coaxially with respect to the axis of rotation 5 and are located within a housing 6 of the actuator 2.

[0024] Accordingly, the actuator 2 has a drive train comprising a drive unit consisting of a drive motor 7 and the gearbox 8 driven by it, which reduces a motor speed provided by the drive motor 7 into a relatively lower gearbox output speed, with which a [further information] is driven based on the Fig. The drive element 11 of the decoupling unit 10, which is to be explained in section 2, can be driven. The drive train of the actuator 2 is suitable for rotating the stabilizer section 3b, which can be connected to the actuator 2, about the axis of rotation 5 for the purpose of influencing the roll behavior of the vehicle equipped with it. This will be explained in more detail below. Fig. In the manner to be described, the drive train of actuator 2 comprises the decoupling unit 10.

[0025] Fig. Figure 2 shows a simplified perspective view of a decoupling unit 10. This can advantageously be attached to an adjustable roll stabilizer 1 or an actuator 2 as shown by Fig. 1 explains how to use them. For orientation, see also in Fig. 2 the axis of rotation 5 is drawn, which is like the axis of rotation 5 according to Fig. 1 is aligned to thus determine their possible placement and orientation at the installation location within an actuator 2, as in Fig. 1 is shown, to indicate. Accordingly, in Fig. 2 next to the axis of rotation 5, the position of the gearbox 8 and the position of the second stabilizer section 3b on axially opposite sides of the decoupling unit 10 are also indicated by reference symbols.

[0026] According to the presentation of Fig. Figure 2 shows that the decoupling unit 10 comprises as its essential elements a drive part 11, an output part 12, and a meandering spring 13 acting between them. The illustration of the Fig. Figure 2 is schematically simplified, but the functional principle according to the invention can be explained using it.

[0027] Both the drive part 11 and the output part 12 are rotatable about the axis of rotation 5. In the installed state in an actuator 2, as shown by Fig. As shown in Figure 1, the drive element 11 is rotationally fixed to an output of the gearbox 8. Accordingly, the drive element 11 of the decoupling unit 10 – when installed in an actuator 2 – can be driven via its drive unit (formed by the drive motor 7 and the gearbox 8 driven by it). The output element 12, in turn, is installed within an actuator 2 as shown in Figure 1. Fig. 1 shown with a second stabilizer section 3b connected or connectable in a rotationally fixed manner.

[0028] The decoupling unit 10 according to Fig. The device 2 is characterized by a coupling acting between the drive part 11 and the output part 12. A key element of this coupling is a circumferential meandering spring 13, which is manufactured in one piece from an elastic material, preferably a metallic material such as spring steel. The meandering spring 13 forms a plurality of alternately wound spring loops 14a and 14b. For the torsionally elastic coupling of the drive part 11 and the output part 12, the spring loops 14a and 14b engage alternately in coupling areas 15a of the drive part 11 and in opposing coupling areas 15b of the output part 12. The coupling areas 15a and 15b provide a mechanical coupling, achieved by positive locking, between meander spring 13 and drive part 11, as well as between meander spring 13 and output part 12, in order to enable a force transmission in a comprehensively distributed manner.Accordingly, a drive torque M1 applied to the drive part 11 can be at least partially transferred to the output part 12 via the coupling formed in this way (usable output torque M2).

[0029] Advantageously, the coupling areas 15a are formed on the end face of the drive part 11, while the coupling areas 15b are formed on the end face of the output part 12.

[0030] To ensure effective power transmission, the coupling areas 15a and 15b provided on the drive part 11 and the output part 12 are preferably designed to be complementary to the head sections 16a and 16b of the meander spring 13, so that a head section 16a, 16b of the associated spring loop 14a, 14b plunges axially into it to establish a positive-locking coupling. A detailed design of the coupling areas 15a and 15b can be found in the Fig. 2 cannot be removed. Various configurations of the coupling areas are conceivable. According to a preferred design, the coupling areas 15a and 15b are, for example, pocket-shaped. Alternatively, a different structure complementary to the head sections 16a and 16b, respectively, could be formed on the drive part 11 or on the output part 12, enabling force transmission.

[0031] According to the representation in Fig. 2. The meander spring 13 is a component designed as a fully enclosed ring, in particular as a single piece. For the assembly of the decoupling unit 10, the drive part 11, the meander spring 13 and the output part 12 can be connected parallel to a joining direction 17, for example by plugging them together.

[0032] The spring loops 14a, 14b of the meander spring 13 run on an imaginary cylindrical surface. According to the illustrated embodiment, the spring loops 14a, 14b each have an angular coil at their head. Alternatively or additionally, it is conceivable that the spring loops have round coils at their head.

[0033] Each of the spring loops 14a and 14b has two longitudinal regions extending substantially parallel to the axis of rotation 5 and one transverse region extending substantially circumferentially. In a configuration such as in Fig. In the unloaded, undeformed state of the decoupling unit 10 shown in Figure 2, the longitudinal sections of the spring loops 14a and 14b are aligned parallel to the axis of rotation. Under load on the decoupling unit 10, particularly when a torque is transmitted between the drive part 11 and the output part 12, the longitudinal sections of the spring loops 14a and 14b are twisted relative to the axis of rotation 5.

[0034] The decoupling unit 10, with its coupling formed by the circumferential meandering spring 13, is advantageously easy to manufacture and assemble for the described application. Since the meandering spring 13 can be made of a metallic material, for example, spring steel, the decoupling unit 10 according to the invention can advantageously achieve a damping effect that is less sensitive to temperature compared to previously known decoupling units. These advantages also apply to the actuator according to the invention and to an adjustable roll stabilizer equipped with it. Reference sign 1 adjustable roll stabilizer 2 Actuator 3a; 3b first stabilizer section; second stabilizer section 4a; 4b first wheel; second wheel 5 Rotation axis 6 cases 7 Drive motor 8 (multi-stage planetary) gearbox 9a; 9b first wheel suspension; second wheel suspension 10 decoupling unit 11 Drive unit 12 Output part 13 Meander feather 14a; 14b Spring loop (drive side; driven side) 15a; 15b Coupling area (drive; output) 16a; 16b Head section (of the spring loop) 17 Leading direction M1 Drive torque M2 output torque x Vehicle longitudinal direction y vehicle transverse direction z Vehicle lifting direction

Claims

[1] Actuator (2) for an actively adjustable roll stabilizer (1) of a motor vehicle, comprising a drive train capable of rotating a stabilizer section (3b) connectable to the actuator (2) about an axis of rotation (5) for the purpose of influencing the roll behavior of the motor vehicle, wherein the drive train comprises a decoupling unit (10) with a drive part (11) rotatable about the axis of rotation (5), an output part (12) rotatable about the axis of rotation (5) and a coupling acting between them, characterized by , that the coupling has a circumferential meander spring (13) with a plurality of alternately wound spring loops (14a, 14b), wherein the spring loops (14a, 14b) engage alternately in coupling areas (15a) of the drive part (11) and in opposite coupling areas (15b) of the output part (12) for torsionally elastic coupling of drive part (11) and output part (12). [2] Actuator (2) according to claim 1, characterized by , that the drive train has a drive unit comprising a drive motor (7) and a gearbox (8) driven by it, in particular in the form of a multi-stage planetary gearbox, which reduces a motor speed provided by the drive motor (7) into a relatively lower gearbox output speed, with which the drive part (11) of the decoupling unit (10) can be driven. [3] Actuator according to claim 1 or 2, characterized by , that the coupling areas (15a, 15b) establish a mechanical coupling, in particular achieved by positive locking, between meander spring (13) and drive part (11), as well as between meander spring (13) and output part (12), in order to enable a force transmission distributed throughout. [4] Actuator according to any of the preceding claims, characterized by, that the coupling areas (15a, 15b) are formed facing each other on the drive part (11) and on the output part (12). [5] Actuator according to any of the preceding claims, characterized by , that the coupling areas (15a, 15b) provided on the drive part (11) and on the output part (12) are designed to be complementary to head sections (16a, 16b) of the meander spring (13), so that a head section (16a, 16b) of the associated spring loop (14a, 14b) plunges into it in the axial direction to create a positive-locking coupling. [6] Actuator according to any of the preceding claims, characterized by , that the meander spring (13) is designed as a ring, in particular as a fully closed or fully open ring. [7] Actuator according to any of the preceding claims, characterized by , that the meander spring (13) is made in one piece. [8] Actuator according to any of the preceding claims, characterized by, that the spring loops (14a, 14b) of the meander spring (13) run on an imaginary cylindrical surface. [9] Actuator according to any of the preceding claims, characterized by , that the spring loops (14a, 14b) each have an angular and / or round coil at the head end. [10] Actuator according to any of the preceding claims, characterized by , that a spring loop (14a, 14b) has two longitudinal regions extending substantially parallel to the axis of rotation (5) and a transverse region extending substantially circumferentially. [11] Actuator according to claim 10, characterized by , that in an unloaded, undeformed state of the decoupling unit (10) the longitudinal regions of the spring loops (14a, 14b) are aligned parallel to the axis of rotation (5), while in a loaded, deformed state of the decoupling unit (10) the longitudinal regions of the spring loops (14a, 14b) are twisted relative to the axis of rotation (5). [12] Adjustable roll stabilizer (1) for a motor vehicle, comprising a first stabilizer section (3a) that can be coupled to a first wheel suspension (9a) and a second stabilizer section (3b) that can be coupled to a second wheel suspension (9b), wherein the first stabilizer section (3a) and the second stabilizer section (3b) are rotatable relative to each other about the axis of rotation (5) by means of an actuator (2) acting between them according to one of the preceding claims in order to influence the roll behavior of the motor vehicle.

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