This application is a National Stage completion of PCT/EP2019/064288 filed Jun. 3, 2019, which claims priority from German patent application serial no. 10 2018 210 637.1 filed Jun. 28, 2018.

FIELD OF THE INVENTION

The invention relates to an actuator device for an adjustable roll stabilizer of a motor vehicle.

BACKGROUND OF THE INVENTION

In automotive technology, in particular chassis technology, it is known as such to equip motor vehicles with a so-termed roll stabilizer. In its simplest version, this is essentially a C-shaped torsion bar spring which is mounted in its central area so that it can rotate relative to the vehicle body and whose outer ends opposite one another are in each case coupled to a wheel suspension. By virtue of this design, the roll stabilizer ensures that while driving round a curve, not only does the body of the vehicle sinks down on the outer side of the curve (due to the centrifugal force), but also the wheel on the inside of the curve is lowered to some extent (copying behavior).

To further increase the stability of the vehicle and the driving comfort, it is known to make such roll stabilizers adjustable. In that case the roll stabilizer comprises an actuator device and is divided into stabilizer sections that, with the help of the actuator device, can be twisted relative to one another about a rotational axis. By twisting the stabilizer sections relative to one another, a rolling movement of the vehicle body is produce in a controlled manner or a rolling movement of the vehicle body brought about by external influences is counteracted in a controlled manner. Adjustable roll stabilizers are known, whose actuator device comprises an actuator in the form of an electric motor. To achieve suitable rotational speeds or torques, this is often in driving connection with a mechanical gear system, particularly configured as a preferably multi-step planetary gear system. In this connection, reference should be made, for example, to DE 10 2016 219 399 A1.

In the actuator device shown therein, the housing has an essentially rotationally-symmetrical basic shape. An electric motor, that serves as the actuator, and a multi-step planetary gear system are arranged coaxially relative to their common rotational axis. During the manufacture of the actuator device the individual components of the planetary gear system have to be introduced into the housing and secured axially after assembly. A planetary wheel carrier on the drive output side, which in the assembled condition is connected rotationally fixed to a roll stabilizer with a stabilizer section, must be mounted rotatably relative to the housing of the actuator device by means of a roller bearing. From the prior art, it is known to secure the roller bearing axially relative to the housing by means of a locking ring in the form of a circlip. The fitting of the circlip demands considerable force and skill, and adjustability of the axial securing force is hardly possible.

SUMMARY OF THE INVENTION

A purpose of the present invention is to indicate an actuator device of the type mentioned at the start, which provides a simple and reliable way to axially secure the actuator arranged inside the housing and/or components that co-operate with it, in particular components of the gear system.

This objective is achieved by an actuator device according to the independent claim(s). The device is an actuator device for an adjustable roll stabilizer of a motor vehicle, with a housing that extends in the direction of a rotational axis and has an actuator arranged inside it. The actuator device can be operated so as to twist relative to one another about the rotational axis two stabilizer sections that can be attached at opposite ends of the actuator device. According to the invention, the distinguishing feature of the actuator device is that on the housing an engagement contour is formed, which is suitable for immobilizing the housing when a torque directed about the rotational axis is applied to the housing. By means of the engagement contour, in a simple manner and in particular using a suitable tool such as a wrench, the housing of the actuator device can be held rotationally fixed. Advantageously, in that way an immobilizing torque can be produced while an assembly operation is carried out on the housing, which applies to the housing a torque directed around the rotational axis—but in the opposite direction. Such an assembly operation can be, for example, the fitting of a bearing screw connection in order to secure the drive-output-side roller bearing axially relative to the housing. The objective mentioned to begin with is thus achieved in a simply designed manner.

The engagement contour envisaged according to the invention can be designed in various ways. According to an advantageous further development of the actuator device, the housing of the actuator device is essentially rotationally symmetrical. Such a structure is in particular appropriate when an actuator and a gear system are arranged in the housing coaxially relative to the common rotational axis. A housing shape which is relatively simple to produce, which at the same time is suitable and has a high level of fitting-space that can be utilized for accommodating an electric motor and a multi-step planetary gear system, is provided by a substantially cylindrical structure of the housing.

The housing can be made in one piece. Alternatively, the housing can consist of a plurality of segments welded to one another, in particular in the sense of tube segments welded to one another circumferentially.

A preferred further development of the actuator device provides that at the end of the actuator device on the drive output side an output bearing for the rotatable mounting of a gear system component relative to the housing is arranged, which bearing is secured axially relative to the housing by a bearing screw connection, particularly one in the form of a threaded ring. Expediently, for that purpose an internal thread is formed on the housing, into which the threaded ring can be screwed once the output bearing has been fitted, in order to secure the output bearing axially. During the assembly process of screwing in the threaded ring, as the screwing-in progresses an increasing torque is exerted on the housing about the rotational axis so that without immobilizing the housing it would also co-rotate. To avoid damaging the housing, the engagement contour according to the invention can be used for immobilizing it during the fitting of the output-side bearing screw connection.

The engagement contour can be designed in various ways. Preferably, the engagement contour is formed on a housing cover section of the housing, which is arranged on an end of the actuator device opposite the output-side bearing screw connection.

For immobilizing to take place in a simple manner, the engagement contour is a two-faceted, multi-faceted, six-lobed, hexagonal, multi-toothed or similar design.

Advantageously, the engagement contour is produced by machining the housing. In addition or alternatively, the housing can be made at least in part as a forged component with the engagement contour formed on it. Thus, the engagement contour can also be produced completely by forging, in particular without any machining.

