WHEEL DRIVE MODULE OF MODULAR CONSTRUCTION

Abstract

A wheel drive module comprises wheel (R), speed modulation gearbox (G), first electric motor (M1), and second electric motor (M2). First and second electric motors (M1, M2) jointly drive wheel (R) about wheel axis (A) by the speed modulation gearbox (G) and steer said wheel about steering axis (L). Wheel drive module comprises first motor electronics (10) for controlling first electric motor (M1) and second motor electronics (20) for controlling second electric motor (M2) and central electronics (30) connected to first and second motor electronics (10, 20), allowing a signal transfer. Wheel drive module comprises control logic for controlling first and second electric motors (M1, M2), which logic is provided by first and second motor electronics (10, 20), central electronics (30), application electronics (40) connected to the central electronics (30), allowing a signal transfer, or jointly by the central electronics (30) and the first and second motor electronics (10, 20).

Claims

1. A wheel drive module comprising a wheel (R), a speed modulation gearbox (G), as well as a first electric motor (M1) and a second electric motor (M2), wherein the first and second electric motors (M1, M2) are designed to jointly drive the wheel (R) by means of the speed modulation gearbox (G) about a wheel axis (A) and about a steering axis (L) orthogonal to the wheel axis (A), the wheel drive module further comprises a first motor electronics (10) for controlling the first electric motor (M1) and a second motor electronics (20) for controlling the second electric motor (M2) as well as a central electronics (30) which is connected to the first and second motor electronics (10, 20), allowing signal transfer, and wherein the wheel drive module comprises a control logic for controlling the first and second electric motors (M1, M2) for driving the wheel (R) about a wheel axis (A) and steering the wheel about the steering axis (L), which logic is provided by the first and second motor electronics (10, 20), the central electronics (30), application electronics (40) connected to the central electronics (30), thus allowing a signal transfer, or jointly by the central electronics (30) and the first and second motor electronics (10, 20).

2. The wheel drive module according to claim 1, wherein the first electric motor (M1) together with the first motor electronics (10) forms a first motor assembly (101) which can be replaced as a module, and the second electric motor (M2) together with the second motor electronics (20) forms a second motor assembly (102) which can be replaced as a module.

3. The wheel drive module according to claim 2, wherein the first motor assembly (101) comprises at least one first sensor for detecting motor characteristics of the first electric motor (M1), particularly for detecting a rotor position of a rotor of the first electric motor (M1) and/or for detecting a rotational speed of the first electric motor (M1).

4. The wheel drive module according to claim 2, wherein the second motor assembly (102) comprises at least one second sensor for detecting motor characteristics of the second electric motor (M2), particularly for detecting a rotor position of a rotor of the second electric motor (M2) and/or for detecting a rotational speed of the second electric motor (M2).

5. The wheel drive module according to claim 1, wherein the central electronics (30) forms a central assembly (103) which can be replaced as a module.

6. The wheel drive module according to claim 1, further comprising a third sensor for detecting wheel characteristics of the wheel (R), particularly for detecting a wheel speed of the wheel (R) about the wheel axis (A) and/or a steering angle of the wheel (R) about the steering axis (L), which sensor is connected to the central electronics (30), allowing signal transfer.

7. The wheel drive module according to claim 1, further comprising a safety brake (B) for braking a rotation of the wheel (R) about the wheel axis (A) or about the steering axis (L), which brake is connected to the central electronics (30), allowing signal transfer.

8. The wheel drive module according to claim 7, wherein the third sensor and the safety (B) form a brake assembly (104) which can be replaced as a module.

9. The wheel drive module according to claim 1, further comprising a fourth sensor (S4) for detecting motor characteristics of the first electric motor (M1), particularly for detecting a rotational speed of the first electric motor (M1).

10. The wheel drive module according to claim 1, further comprising a fifth sensor (S5) for detecting motor characteristics of the second electric motor (M2), particularly for detecting a rotational speed of the second electric motor (M2).

11. The wheel drive module according to claim 3, wherein the central electronics (30) forms a central assembly (103) and at least the first and second motor assemblies (101, 102) are connected to the central assembly (103) by a bus system and the bus system allows signal transfer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other advantageous further developments of the invention are characterized in the dependent claims or are explained in more detail below with reference to the figures and together with a preferred embodiment of the invention. Wherein:

[0036] FIG. 1 shows a wheel driven by a first and second electric motors via a speed modulation gearbox:

[0037] FIG. 2 shows a schematic view of a wheel drive module;

[0038] The figures are exemplary and schematic. Like reference numerals in the figures indicate like functional and/or structural features.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0039] FIG. 1 illustrates the wheel R, the first and second electric motors M1, M2, and the speed modulation gearbox G for driving and steering the wheel R by means of the two electric motors M1, M2. FIG. 1 only shows one possible embodiment option of the drive of the wheel R about the wheel axis A and the steering axis L by means of the first and second electric motors M1, M2. For example, the wheel R can be arranged below the drive gear rims G3, G3′, or the electric motors M1, M2 can have another transmission ratio to the drive gear rims G3, G3′ and another orientation. In the example shown, the speed modulation gearbox G comprises the pinions G1, G1′, the intermediate wheels G2, G2′, the drive gear rims G3, G3′, and the drive gearwheel G4 and output shaft G5. Furthermore, the speed modulation gearbox G can comprise other components in other embodiments.

[0040] The first and the second electric motors M1, M2 drive the first and second drive gear rims G3, G3′. The first electric motor M1 is arranged opposite the electric motor M2 in the embodiment shown, wherein the electric motors M1, M2 may each comprise a motor gear assembly of their own. The electric motors M1, M2 are each connected to a pinion G1, G1′ via a respective motor shaft.

[0041] The gearing of the first pinion G1 engages in a gearing of a first intermediate wheel G2, the gearing of which engages in a drive gearing of the first drive gear rim G3, such that the first drive gear rim G3 can be rotated about the axis of rotation or steering axis L by a rotation of the first pinion G1 driven by the first electric motor M1.

[0042] This applies analogously to the second drive gear rim G3′. The gearing of the second pinion G1′ engages in a gearing of a second intermediate wheel G2′, the gearing of which engages in a drive gearing of the second drive gear rim G3′, such that the second drive gear rim G3′ can be rotated about the axis of rotation or steering axis L by a rotation of the second pinion G1′ driven by the second electric motor M2.

[0043] An output gearwheel G4 is arranged between the first and second drive gear rims G3, G3′, the gearing of which output gearwheel engages both in a gearing of the first drive gear rim G3 facing the output gearwheel G4 and in a gearing of the second drive gear rim G3′ facing the output gearwheel G4. The rotation of the output gearwheel G4 (third rotation) is therefore determined by both the rotation of the first drive gear rim G3 (first rotation) and by the rotation of the second drive gear rim G3′ (second rotation).

[0044] A drive shaft G5 which is connected to the output gearwheel G4 in a rotationally fixed manner extends from the output gearwheel G4 along a wheel axis A towards the axis of rotation or steering axis L of the drive gear rims G3, G3′. The wheel R is connected in a rotationally fixed manner to the output shaft G5 on a side spaced apart from the output gearwheel G4 along the wheel axis A, whereby a rotation (third rotation) of the output gearwheel G4 is transmitted to the wheel R via the output shaft G5. As shown, sections of the wheel R are received between the first drive gear rim G3 and the second drive gear rim G3′, which are spaced apart along their axis of rotation L and span a wheel receiving space between each other. Both drive gear rims G3, G3′ have a rim opening extending along the axis of rotation L of the respective drive gear rim G3, G3′. The wheel R extends on at least its side facing the ground through the respective rim opening, such that the wheel R has substantially five sections. A first section, in which the wheel R is arranged between the drive gear rims, two second sections, in which the wheel R is arranged in the rim openings of the drive gear rims G3, G3′, and two third sections, in which the wheel R is located outside the gear drive rims G3, G3′ along the axis of rotation L.

[0045] Arrangement of the wheel R in the wheel receiving space has three advantageous effects. The installation space of the wheel drive module is considerably reduced, since the wheel R does not have to move around the drive gear rims G3, G3′ during a steering motion, and the potential steering angle is widened, since the wheel R can be rotated 360° in the drive gear rims G3, G3′, such that the steering motion or rotation about the axis of rotation L is limited by the intermediate wheels G2, G2′.

[0046] In addition, the wheel R is protected by the wheel drive module 1 or by the first and second drive gear rims G3, G3′, since these form a cage around the wheel R.

[0047] FIG. 2 shows a schematic view of the wheel drive module. A driving function X2 and a steering function X1 are provided at or by the wheel R by means of driving the wheel R about the steering axis L and the wheel axis A. For providing the steering and driving functions X1, X2 by means of the speed modulation gearbox G, the speed modulation gearbox is driven by the first and second electric motors M1, M2 using the first and second operative connections X31, X32.

[0048] To allow fast replacement of the electric motors M1, M2, the motors and their associated components are bundled in a respective motor assembly 101, 102. The first motor assembly 101 or the second motor assembly 102 can each be replaced fast and easily as a module. For example, one of the motor assemblies 101, 102 or both motor assemblies 101, 102 can be replaced for an alternative motor assembly which comprises an electric motor having a higher power rating as well as components adjusted to controlling the electric motor.

[0049] The first or second motor assembly 101, 102 in the embodiment shown includes a first or second motor electronics 10, 20 for directly controlling the respective electric motor M1, M2 as well as a first or second sensor S1, S2 by which motor values such as the rotor position of the respective electric motor M1, M2 are determined. In the embodiment shown, the first or second sensor S1, S2 is directly coupled to the respective motor electronics 10, 20, wherein the motor values determined by the sensors S1, S2 can be used for controlling the respective electric motor M1, M2 and the motor values can be passed on to other components as needed.

[0050] The first and second motor assemblies 101, 102 are connected to the central assembly 103, which comprises central electronics 30, by bus lines shown as solid lines. Depending on whether a control logic for controlling the electric motors M1, M2 by the first and second motor electronics 10, 20, the central logic 30, or a higher-order application electronics 40 is implemented, the central electronics can just establish a connection for the various data and bus lines and thus merely be used as an information interface, or it can have its own control logic implemented by the central electronics.

[0051] For controlling the electric motors M1, M2, another sensor S4, S5 is provided in the embodiment shown in FIG. 2 at the electric motors M1, M2 to detect the rotational speed of the electric motors. The fourth sensor S4 is assigned to the first electric motor M1 but is not a part of the motor assembly 101, and the fifth sensor S5 is assigned to the second electric motor M2 but is not a part of the second motor assembly 102. The fourth and fifth sensors S4, S5 are each connected to the central electronics 30 in the embodiment shown, wherein the sensor information or the values detected by the fourth and fifth sensors S4, S5 can be provided via the central electronics 30 to the application electronics 40 or the first or second motor electronics 10, 20.

[0052] An additional safety brake B which is combined with a third sensor S3 into a brake assembly 104 is provided to achieve a safe state in the event of a defect of the first or second electric motor M1, M2. The safety brake B can at least be used to block the driving function X2 or the rotation of the wheel R about the wheel axis A, such that wheel drive module or the wheel R can be brought to a standstill and a safe state can be achieved. The third sensor S3 directly detects status values of the wheel R, such as the rotational speed of the wheel R about the wheel axis A, wherein the detected values are available to the central electronics or the other assemblies via the connection of the brake assembly 104 to the central electronics 30.

[0053] The control logic for controlling the first and second electric motors M1, M2 can be distributed over the first and second motor electronics 10, 20, such that only a portion of the computing load must be handled by each of them. Alternatively, the control logic can also be provided by the central electronics 30, which for example provides a target motor speed to the first and second motor electronics 10, 20. Alternatively, the control logic can also be provided by the application electronics 40.

[0054] Thus an implemented control logic can be replaced fast by a deviating control logic by replacing the respective assembly. In addition, the information to be transmitted to and from the control logic and the computing load to be handled by the control logic can be reduced, since a separate control logic is provided for each wheel drive module of an application, not a central control logic for all wheel drive modules.