Corner module and vehicle

Abstract

The present invention relates to a corner module for individually steering a vehicle wheel, comprising a main shaft (2) defining a steering axis of rotation of the corner module, a steering mechanism (9), and a steering motor (10). The steering motor (10) is configured to rotate the main shaft (2) about the steering axis of rotation via the steering mechanism (9). The overall height of the corner module is to be reduced. For this purpose, it is provided that the steering mechanism (9) comprises a ball screw (12) arranged perpendicular to the steering axis of rotation, wherein a longitudinal movement of a nut (13) arranged on the ball screw (12) causes a steering rotation movement of the corner module.

Description

[0001] The present invention relates to a corner module for individually steering a vehicle wheel, comprising a main shaft defining a steering axis of rotation of the corner module, a steering mechanism, and a steering motor. The steering motor is configured to rotate the main shaft about the steering axis of rotation via the steering mechanism. The invention further relates to a vehicle comprising at least one such corner module.

[0002] Such a corner module is known, for example, from GB 2582640 A. Therein, a drive assembly is disclosed comprising a vehicle-mountable connector rotatably coupled to a mounting arm to enable rotation thereof substantially perpendicular to the longitudinal and transverse axes of the vehicle. The assembly comprises an electric motor whose stator is coupled to the mounting arm, the axis of the motor rotor being substantially perpendicular to the rotational axis of the connector, and the rotor being coupled to a vehicle wheel so that the electric motor drives the vehicle wheel.

[0003] Such corner modules typically have a very high overall height, which requires a considerable amount of space within the body and thus severely limits the corner module's possible uses. Corner modules, in particular, which allow a large steering angle, require more space for the wheel pivot than conventional wheel suspensions.

[0004] The invention is therefore based on the object of providing a corner module of the type mentioned above that allows a lower construction height.

[0005] According to the invention, this object is achieved by a corner module of the type mentioned at the outset, characterized in that the steering mechanism comprises a ball screw arranged perpendicular to the steering axis of rotation, wherein a longitudinal movement of a nut arranged on the ball screw causes a steering rotation movement of the corner module.

[0006] Such a corner module allows for a compact design of the steering mechanism, meaning the corner module takes up less space on the body, especially vertically. At the same time, the steering motor can be smaller than with a direct connection of the steering motor to the main shaft.

[0007] Preferred embodiments and further developments of the invention can be found in the respective subclaims.

[0008] According to a preferred embodiment of the invention, the nut engages a rack movable parallel to the ball screw, so that the rack is displaced along the spindle axis when the nut moves. This allows the dimensions of the rack and the nut to be decoupled, and in particular, the relatively complex and cost-intensive nut of the ball screw can be made relatively short in the axial direction without limiting the length of the rack and thus the maximum steering angle.

[0009] Preferably, the corner module comprises a sensor for determining the position of the nut and / or a sensor for determining the position of the rack.

[0010] Preferably, the rack engages a pinion that is non-rotatably connected to the main shaft, so that a translational movement of the rack causes a rotational movement of the main shaft. This enables a stable connection between the steering mechanism and the main shaft without requiring the steering motor to be arranged coaxially around the main shaft.

[0011] In one embodiment, the rack is guided in a guide so that the rack can only move along a path parallel to the ball screw. This prevents twisting or tilting of the rack relative to the ball screw and the main shaft. The movement of the rack can be limited by mechanical stops.

[0012] Preferably, the guide is formed on at least two sides by housing walls of a steering mechanism housing. These are preferably two opposite housing walls, preferably an upper and a lower housing wall.

[0013] According to a further embodiment, the guide comprises rollers on at least one side of the rack, which support the translation of the rack along the guide. This design allows for the smoothest possible movement of the rack and thus also reduces friction losses in the steering mechanism.

[0014] Preferably, a drive axis of the steering motor is arranged perpendicular to the rotation axis of the corner module. This also allows for the lowest possible height of the steering mechanism and thus of the corner module. The drive axis can then be arranged parallel to the ball screw, for example.

[0015] Preferably, the steering motor is connected to the ball screw via a transmission, in particular a belt transmission or a gear transmission. This allows the steering motor and steering mechanism to be arranged around the main shaft in the most space-saving manner possible and to limit the maximum extension in one direction.

[0016] Preferably, the steering motor and the ball screw are arranged at least partially on opposite sides of the main shaft. This allows for a compact steering mechanism with a low overall height, since the steering motor and ball screw can be arranged at the same height.

[0017] In one embodiment, the nut has an anti-rotation section designed to prevent rotation of the nut relative to the rack. The nut is preferably connected to the rack in such a way that rotation of the nut is prevented, but no radial stresses are introduced into the ball screw. The anti-rotation section can be formed, for example, by a rectangular cross-section of the nut.

[0018] Preferably, the anti-rotation section engages in a recess in the rack, so that the rack is displaced in both directions when the nut moves along the spindle axis. The recess can, for example, be a notch in the rack running perpendicular to the longitudinal axis of the ball screw.

[0019] In one embodiment, the main shaft has at least one bearing relative to the steering mechanism, above and below the pinion. Thus, the main shaft is supported on both axial sides of the steering engagement. Preferably, at least one bearing comprises a ball bearing. Preferably, a bearing with a double ball bearing is arranged above the steering mechanism. Particularly preferably, at least one bearing is a radial-axial bearing.

[0020] The steering mechanism is preferably configured to allow rotation of the main shaft by at least 120°, preferably by at least 150°, and particularly preferably by at least 180°. The design with a recirculating ball screw arranged perpendicular to the steering axis of rotation, in particular with a rack, allows for wide-angle steering in a space-saving manner.

[0021] Preferably, the main shaft is connected to a main arm of the corner module, wherein on the main arm - an articulated suspension is attached, which is designed for connection to a vehicle wheel with a braking unit, preferably with a drive braking unit (e.g. an electric wheel hub motor with integrated disc brake), and / or - a suspension is attached, which is designed to cushion a connected vehicle wheel against a vehicle body. The solution according to the invention is particularly suitable for such multifunctional corner modules, since they require more installation space / wheel pivot space than a conventional wheel suspension, and thus any space savings are particularly advantageous.

[0022] In a further aspect of the invention, a vehicle is provided comprising at least one, preferably one, two, or four, individually steerable corner modules according to one of the preceding embodiments. Such a vehicle can be steered particularly flexibly and allows for a variety of body concepts. A single corner module according to the invention can be used for steering on a three-wheeled vehicle, in particular for the front wheel.

[0023] Further details of the invention emerge from the description of the illustrated embodiments and the appended claims. The drawings show: Fig. 1 an embodiment of a corner module according to the invention, Fig. 2 a view of the steering elements of the Corner module according to Fig. 1, and Fig. 3 a sectional view through the steering elements of the corner module according to Fig. 2.

[0024] In the following detailed description of preferred embodiments, like reference numerals designate substantially the same or identical parts in or on these embodiments. However, to better illustrate the invention, the preferred embodiments illustrated in the figures are not always drawn to scale.

[0025] Fig. 1 shows an embodiment of a corner module 1 according to the invention, comprising a main shaft 2 connected to a main arm 3 of the corner module 1. An articulated suspension 4 is attached to the main arm 3 and is configured for connection to a vehicle wheel 6 with a drive brake unit. A brake unit 7 (here, for example, designed as a disc brake) can be partially connected to the articulated suspension and partially to a rotor of the drive unit (not shown in detail here, for example, an electric wheel hub motor). A suspension 5 is attached to the main arm and to the articulated suspension 4 and is configured to cushion the connected vehicle wheel 6 against a vehicle body (not shown).

[0026] The corner module 1 is designed for individual steering of the vehicle wheel 6. The main shaft 2 defines a steering axis of rotation of the corner module 1. A steering mechanism housing 8 is rigidly connected to a body / chassis of the vehicle.

[0027] Preferably, power supply cables and / or signal cables and / or fluid hoses (for coolant or brake fluid) are routed through the main arm 3 and the main shaft 2 to the vehicle wheel 6 and / or to the wheel hub motor and / or to the brake unit 7.

[0028] As in Fig. 2 and Fig. 3 in more detail, the corner module 1 comprises a steering mechanism 9 which is housed in the steering mechanism housing 8 (in Fig. 2 (only the lower half of the steering mechanism housing 8 is shown) and a steering motor 10. The steering motor 10 is designed to rotate the main shaft 2 about the steering axis of rotation via the steering mechanism 9.

[0029] The steering motor 10 can be controlled via a signal received from a control unit. For example, an encoder located inside the housing of the steering motor 10 can be used (with appropriate calibration) to determine the exact rotational position of the main shaft relative to the vehicle's direction of travel.

[0030] The steering motor can be a non-self-locking electric motor, which enables self-straightening of the vehicle wheel 6, particularly when driving downhill. This saves drive energy for the steering motor 10 and reduces wear. Preferably, the corner module is configured to be installed on the vehicle with a caster angle (i.e., with a slight upper inclination of the corner module against the direction of travel), so that (together with the non-self-locking electric motor) when the steering motor 10 is switched off, the connected vehicle wheel 6 self-straightens while driving.

[0031] A rotary motion generated by the steering motor 10 is transmitted via a gear 11 to a ball screw 12 arranged perpendicular to the steering axis of rotation. Alternatively, the gear 11 can also be designed as or include a gear drive or chain.

[0032] A longitudinal movement of a nut 13 arranged on the ball screw 12 causes a steering rotation of the corner module 1. The nut 13 engages a rack 14 that can be moved parallel to the ball screw 12, so that the rack 14 is displaced along the spindle axis when the nut 13 moves. This allows the dimensions of the rack 14 and the nut 13 to be decoupled, and in particular, the relatively complex and cost-intensive nut 13 of the ball screw 12 can be made relatively short in the axial direction without limiting the length of the rack 14 and thus the maximum steering angle.

[0033] The rack 14 engages with a pinion 15 which is connected in a rotationally fixed manner to the main shaft 2, so that a translational movement of the rack 14 causes a rotational movement of the main shaft 2.

[0034] The rack 14 is guided in a guide 16, so that the rack 14 can only move along a linear displacement path parallel to the ball screw 12. This prevents twisting or tilting of the rack 14 relative to the ball screw 12 and the main shaft 2.

[0035] The guide 16 is formed on at least two sides, at least partially, by housing walls of the steering mechanism housing 8. Here, these are two opposite housing walls, an upper and a lower housing wall of the steering mechanism housing 8.

[0036] The drive axis of the steering motor 10 is arranged perpendicular to the rotational axis of the corner module 1. This achieves a low overall height of the steering mechanism 9 and thus of the corner module 1. The drive axis is also arranged parallel to the ball screw 12 and at least partially on opposite sides of the main shaft 2. This allows for a compact steering mechanism 9 with a low overall height.

[0037] The nut 13 has an anti-rotation section 17 designed to prevent rotation of the nut 13 relative to the rack 14. The anti-rotation section 17 is formed here by a rectangular cross-section of the nut 13.

[0038] The anti-rotation section 17 engages in a recess 18 of the rack 14, so that the rack 14 is displaced in both directions when the nut 13 moves along the spindle axis. The recess 18 can, for example, be a notch in the rack 14 running perpendicular to the longitudinal axis of the ball screw 12, into which a part of the anti-rotation section 17 engages.

[0039] As in Fig. As can be seen in Figure 3, the main shaft 2 has at least one bearing 19, 20, preferably a radial-axial bearing, above and below the pinion 15 relative to the steering mechanism 9. Radial-axial bearings absorb both radial and axial loads on the main shaft. Thus, the main shaft 2 is supported on both axial sides of the steering engagement. Both bearings 19, 20 comprise ball bearings. Above the steering mechanism 9, the bearing 19 comprises a double ball bearing.

[0040] The pinion 15 is formed integrally with the main shaft 2, particularly for optimal power transmission. Alternatively, however, it is also possible to provide the pinion 15 as a separate component that is secured to the main shaft 2 in a rotationally secure manner.

[0041] The corner module 1 may comprise its own control unit, e.g., on or in the steering mechanism housing 8, on or in the main arm 3, or in the vehicle wheel 6 (e.g., integrated into the wheel hub motor). Alternatively, one corner module 1 or several corner modules 1 may also be controlled by one or more control units of the vehicle.

[0042] The corner module 1 can comprise one or more sensors for determining the steering angle, for example a travel sensor for the rack 14 or an angle sensor for the main shaft 2 or for the pinion 15. List of reference symbols 1 corner module 2 main shaft 3 Main arm 4 Articulated suspension 5 Suspension 6 vehicle wheel 7 Brake unit 8 Steering mechanism housing 9 Steering mechanism 10 Steering motor 11 gearboxes 12 ball screw 13 Mother 14 Rack 15 pinions 16 Guide 17 Anti-rotation section 18 Recess 19 Storage 20 Storage QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] GB 2582640 A

[0002]

Claims

[1] Corner module (1) for the individual steering of a vehicle wheel (6), comprising a main shaft (2) defining a steering axis of rotation of the corner module (1), a steering mechanism (9) and a steering motor (10), wherein the steering motor (10) is adapted to rotate the main shaft (2) about the steering axis of rotation via the steering mechanism (9), characterized by that the steering mechanism (9) comprises a ball screw (12) arranged perpendicular to the steering axis of rotation, wherein a longitudinal movement of a nut (13) arranged on the ball screw (12) causes a steering rotation movement of the corner module (1). [2] Corner module (1) according to claim 1, characterized by that the nut (13) engages in a rack (14) which is movable parallel to the ball screw (12), so that the rack (14) is displaced along the spindle axis when the nut (13) moves. [3] Corner module (1) according to claim 2, characterized bythat the rack (14) engages in a pinion (15) which is connected in a rotationally fixed manner to the main shaft (2), so that a translational movement of the rack (14) causes a rotational movement of the main shaft (2). [4] Corner module (1) according to one of claims 1 to 3, characterized by that the rack (14) is guided in a guide (16) so that the rack (14) can only be moved along a displacement path parallel to the ball screw (12). [5] Corner module (1) according to claim 4, characterized by that the guide (16) is formed on at least two sides by housing walls of a steering mechanism housing (8). [6] Corner module (1) according to claim 4 or 5, characterized by that the guide (16) comprises rollers on at least one side of the rack (14) which support a translation of the rack (14) along the guide (16). [7] Corner module (1) according to one of the preceding claims, characterized bythat a drive axis of the steering motor (10) is arranged perpendicular to the axis of rotation of the corner module (1). [8] Corner module (1) according to one of the preceding claims, characterized by that the steering motor (10) is connected to the ball screw (12) via a gear (11), in particular a belt gear or a gear transmission. [9] Corner module (1) according to one of the preceding claims, characterized by that the steering motor (10) and the ball screw (12) are arranged at least partially on opposite sides of the main shaft (2). [10] Corner module (1) according to one of the preceding claims, characterized by that the nut (13) has an anti-rotation section (17) which is designed to prevent rotation of the nut (13) relative to the rack (14). [11] Corner module (1) according to claim 10, characterized bythat the anti-rotation section (17) engages in a recess of the rack (14) so ​​that the rack (14) is displaced in both directions when the nut (13) moves along the spindle axis (12) [12] Corner module (1) according to one of claims 3 to 11, characterized by that the main shaft (2) has at least one bearing (19, 20) above and below the pinion (15) relative to the steering mechanism (9). [13] Corner module (1) according to one of the preceding claims, characterized by that the steering mechanism (9) is designed to enable a rotation of the main shaft (2) by at least 120°, preferably by at least 150°, particularly preferably by at least 180°. [14] Corner module (1) according to one of claims 2 to 13, characterized by that the main shaft (2) is connected to a main arm (3) of the corner module (1), wherein on the main arm (3) - an articulated suspension (4) is attached, which is designed for connection to a vehicle wheel (6) with a brake unit (7), preferably with a drive brake unit, and / or - a suspension (5) is attached, which is designed to cushion a connected vehicle wheel (6) against a vehicle body. [15] Vehicle comprising at least one, preferably one, two or four, individually steerable corner modules (1) according to one of the preceding claims.

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