Wheel motor with integrated wheel control and wheel brake

Abstract

The present invention relates generally to a wheel motor with an integrated wheel brake, in particular for a motor vehicle. For this purpose, an electromechanical drive unit is proposed, comprising a drive motor with a stator and a rotor, wherein the stator is rotationally fixed to a receptacle, wherein the receptacle can be rigidly connected to a vehicle frame, the receptacle comprises a retaining plate which is annular in shape and oriented in a radial direction, wherein at least one circuit board is arranged adjacent to the retaining plate on the side of the retaining plate facing away from the vehicle frame, and wherein the electromechanical drive unit further comprises a wheel brake.

Description

[0001] The present invention generally relates to a wheel motor with a wheel-integrated control and an integrated wheel brake, in particular for a motor vehicle.

[0002] Wheel-mounted drive systems for motor vehicle wheels, also known as wheel motors or wheel hub motors, represent a current drive concept for electrically powered vehicles. The drive motor is designed for each individual wheel and located near the driven wheel, for example, near the wheel hub. The torque is transmitted via a very short drive shaft or directly to the wheel.

[0003] Wheel motors enable high efficiency thanks to a short chain of effects. They are easily configurable for two-wheel or four-wheel drive. They are also capable of supporting regenerative braking.

[0004] The electrical power supply for operating the wheel motors, i.e., applying the desired torque to the wheel, is typically provided by the vehicle's storage units or batteries. This results in a further advantage of such drive motors, which can be seen in the independent torque control. Recent developments aim to combine wheel brakes with such wheel motors.

[0005] On the other hand, alongside the advantages, there are also various challenges. For example, there can be a delay in the signal transmission between an in-vehicle or central control unit and the respective wheel-mounted drive or wheel brake.

[0006] To transmit the control signals between the central control unit and the wheel-mounted drive or wheel brake, appropriate cabling is required, which can be complex. Furthermore, a reliable power supply must be ensured. The electrical cables required for this can sometimes be exposed, for example, between the wheel and the vehicle frame, which can lead to problems, as harsh environmental conditions can prevail in such exposed locations.

[0007] If a central control unit is used for all wheel motors and wheel brakes, as may be necessary for cost-effective reasons, a delayed response may also occur. This can lead to undesirable driving characteristics, especially since an axle differential may no longer be provided.

[0008] However, arranging control units directly on or in the wheel can lead to temperature problems, as heat, such as that generated during braking or by the components of the control units themselves, cannot be dissipated easily.

[0009] Therefore, configurations of wheel motors and / or wheel brakes that do not have the above-mentioned disadvantages or at least mitigate them are desirable.

[0010] The inventors have taken on this task.

[0011] This object is achieved surprisingly simply by an electric motor drive unit, in particular for a wheel or wheel hub motor of a motor vehicle and a motor vehicle comprising such an electric motor drive unit, according to one of the independent claims.

[0012] Preferred embodiments and further developments of the invention can be found in the respective subclaims.

[0013] In a first aspect, the invention thus comprises an electric motor drive unit, in particular a wheel or wheel hub motor of a motor vehicle, comprising a wheel brake, a drive motor with a stator and a rotor, wherein the stator is arranged within the rotor and can be connected or is connected to a wheel hub in a rotationally fixed manner, and wherein the rotor comprises at least one permanent magnet arranged between the stator and the rotor, wherein the wheel hub comprises a preferably disc-shaped retaining plate which has a substantially radial orientation, and wherein at least one electronic control unit is arranged adjacent to the holding plate on the side of the holding plate facing away from the vehicle and is connected to the holding plate.

[0014] The electric motor drive unit can therefore comprise a wheel or wheel hub motor with a wheel brake for a motor vehicle. A motor vehicle can comprise at least one, preferably several, axles, wherein at least one of these axles comprises steerable wheels, and the drive of the wheels of at least one axle can be electromechanically tuned to suit each wheel.

[0015] Since a wheel or wheel hub motor is a known technology, a detailed description of its operation will be omitted here and only the elements essential to the invention will be discussed.

[0016] The drive motor can comprise a stator and a rotor. The stator can be configured in a known manner with corresponding electrical coil windings. The rotor can comprise at least one, preferably a plurality of, permanent magnets, which can be rigidly connected to the rotor. The rotor can be configured as a drum or drum-like, with the permanent magnets being arranged on the inside, preferably facing the stator. The permanent magnet and stator can be arranged relative to one another in such a way that, during operation, a corresponding drive torque can be transferred from the stator to the rotor by applying an electric field.

[0017] The drive motor can be controlled by an electronic control unit according to the amount of the accelerator pedal depressed by a driver, or by a higher-level control unit, for example in the context of driverless driving.

[0018] The stator can be arranged radially within the rotor, in particular within the permanent magnets. The stator can be connected in a rotationally fixed manner to a wheel hub, which in turn can be firmly connected to a vehicle. The rotor can be connected in a known manner to a rim, which can support the wheel.

[0019] The wheel hub can comprise a disc-shaped or, in particular, annular retaining plate, which can have a substantially radial orientation. According to a preferred embodiment of the invention, the retaining plate can virtually or largely seal the rotor from the vehicle frame, which can be advantageous for preventing dirt or the like from penetrating the rotor. Accordingly, the retaining plate can reach as far as the inner wall of the rotor without, however, touching it, allowing it to rotate freely.

[0020] According to a particularly preferred embodiment of the invention, the retaining plate can be designed to support the stator. For this purpose, the retaining plate can be provided on its end face with appropriate means and / or receptacles for secure connection to the stator.

[0021] The inventors have discovered that the potential cooling problems of the drive motor and / or power electronics, such as those associated with an electronic control unit for controlling the drive motor and / or the wheel brake, can be significantly reduced if the retaining plate is designed with at least one cooling channel. During operation, a cooling medium can be passed through the at least one cooling channel, allowing heat to be dissipated. The cooling medium can comprise a fluid, such as water or oil.

[0022] This makes it possible to arrange the electronic control unit for controlling the drive motor and / or for controlling the wheel brake or the electronic components belonging to the electronic control unit, for example a circuit board, inside the stator. According to the invention, an electronic control unit for controlling the drive motor and / or the wheel brake can thus be designed close to the wheel or integrated into the wheel, for example as a WCU (“Wheel Controlling Unit”), and arranged inside the electric motor drive unit. According to a preferred embodiment of the invention, some, preferably most, or even all of the required electronic components of the control unit can be arranged within the hollow space resulting from the arrangement of the stator. According to the invention, this hollow space can be closed off on the vehicle side with the coolable holding plate, thus enabling a good cooling effect.

[0023] Cooling of the electronic components of the wheel-integrated electronic control unit, in particular the at least one circuit board, can be achieved particularly effectively if the sensitive electronic components, such as a circuit board, are arranged close to or even directly adjacent to the mounting plate. This preferably occurs within the interior or hollow space formed by the rotor or stator, which provides better protection for the electronic components and also saves space.

[0024] A favorable embodiment of the invention provides for the at least one printed circuit board to be arranged in such a way that it is radially aligned substantially parallel to the retaining plate. This significantly improves the cooling capability of the retaining plate. The distance between the printed circuit board and the retaining plate is chosen to be as small as possible, which improves the cooling effect of the retaining plate on the printed circuit board and thus on the electronic components of the electronic control unit.

[0025] Since the electric motor drive unit may be a high-voltage system, this can lead to, for example, the drive motor becoming hot. The invention thus makes it possible to install sensitive electronic devices, such as an electronic control unit, inside the electric motor drive unit despite these unfavorable operating conditions, since these devices can be cooled directly or indirectly during operation.

[0026] According to a particularly preferred embodiment of the invention, it is provided that the at least one printed circuit board is aligned such that at least a part of a side surface of the printed circuit board is in direct contact with the holding plate or the printed circuit board rests on the latter at least in sections, which can be advantageous for heat transfer.

[0027] For this purpose, the holding plate can be equipped with corresponding, opposing recesses or receptacles in order to be able to accommodate projections or parts of the electronic components or electronic components that protrude laterally from the side surface of the circuit board, so that the contact area between the holding plate and the circuit board can be enlarged, which can further improve heat transfer.

[0028] It is also possible to arrange more than one circuit board within the stator. For example, an arrangement with two, three, or even more circuit boards is possible. A favorable arrangement involves arranging the circuit boards essentially parallel to each other and as close to each other as possible. It goes without saying that the circuit boards are electrically connected accordingly. Spacers can also be arranged between the circuit boards to ensure stability.

[0029] For the purposes of the invention, "essentially" means, with respect to a value, that a deviation of up to 10%, preferably up to 5%, and particularly preferably up to 1%, is possible between this reference value and a possible actual value. With respect to "essentially parallel," this means that the angle between the circuit board and the support plate and / or between the circuit boards can be between approximately 170° and 190° or less. A precisely parallel arrangement may offer structural or geometric advantages, but is not essential to the invention.

[0030] The cooling channel of the holding plate can, for example, comprise a single channel that is laid in windings across the surface, i.e., the circular surface of the holding plate. For particularly effective cooling, the cooling channel is provided in those areas or on the side of the holding plate that are in contact with or adjacent to the circuit board, thus enabling optimal cooling of the circuit board and high heat transfer.

[0031] In a preferred embodiment of the invention, a single continuous cooling channel is provided, which can facilitate the supply and removal of the cooling medium, since only one connection is required. The cooling channel can be designed in a meandering shape, particularly in those areas adjacent to electronic components, so that an optimal cooling effect can be achieved. Of course, it is also possible to provide multiple cooling channels.

[0032] According to a preferred embodiment of the invention, the inlet and / or outlet of the at least one cooling channel is relocated or integrated into the wheel hub. This enables reliable transmission and flow of the cooling medium, as well as simple assembly and disassembly.

[0033] According to a further preferred embodiment of the invention, it is provided that a data line for signaling connection, for example of a higher-level control unit or a vehicle bus with the electronic control unit, is laid in the wheel hub or integrated into it.

[0034] According to yet another preferred embodiment of the invention, it is provided that an electrical supply line for supplying power to the drive motor and / or the wheel brake is laid in the wheel hub or integrated into it.

[0035] The integration of all supply lines, including connections for the cooling medium, data or signal lines and / or electrical supply lines into the wheel hub thus provides a simple and combined connection concept for all lines.

[0036] In addition, the drive motor and / or the wheel brake can be controlled directly by the electronic control unit close to the wheel.

[0037] The wheel brake can, for example, comprise a disc brake or a drum brake, which can be arranged between the vehicle frame and the electric motor drive unit. A transfer plate can be provided for torque transmission, which can connect the wheel brake to the rotor in a rotationally fixed manner.

[0038] In a further aspect, the invention also includes a motor vehicle comprising at least one, preferably at least two electric motor drive units as described above.

[0039] Further details of the invention emerge from the description of the illustrated embodiments and the appended claims.

[0040] The drawings show: Fig. 1 a partial schematic sectional view of an exemplary electric motor drive unit, Fig. 2 a section of the exemplary electric motor drive unit in a sectional view from Fig. 1, Fig. 3 shows a further section of the exemplary electric motor drive unit in a sectional view from Fig. 1, and Fig. 4 the exemplary electric motor drive unit from Fig. 1 with a mounted rim in a further partial schematic representation.

[0041] In the following detailed description of preferred embodiments, for the sake of clarity, like reference numerals designate substantially similar 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.

[0042] Fig. 1 shows a partial schematic sectional view of an exemplary electric motor drive unit 100, in particular a wheel or wheel hub motor of a motor vehicle. The electric motor drive unit 100 comprises a wheel brake 102, a drive motor 101 with a stator 2 and a rotor 12, wherein the stator 2 is arranged within the rotor 12 and is rotatably connected or connected to a wheel hub 13, and wherein the rotor 12 comprises at least one permanent magnet 1 which is arranged between the stator 2 and the rotor 12, wherein the wheel hub 13 comprises a preferably disc-shaped retaining plate 4, which has a substantially radial orientation, and wherein adjacent to the holding plate 4 on the side of the holding plate 4 facing away from the vehicle, at least one electronic control unit 17 is arranged, which is connected to the holding plate 4.

[0043] The drive motor 101 is designed as a wheel or wheel hub motor. The drive motor 101 comprises a stator 2 and a rotor 12. The stator 2 is provided with corresponding electrical coil windings, which are arranged in the Fig. 1 are only shown in outline. The rotor 12 has a plurality of permanent magnets 1, although in the illustrated embodiment, only two permanent magnets 1 are visible. The permanent magnets 1 are firmly connected to the rotor.

[0044] The rotor 12 is designed as a drum or drum-like, with the permanent magnets 1 arranged on the inside of the drum facing the stator 2. The permanent magnets 1 and the stator 2 are arranged relative to one another in such a way that, during operation, a corresponding drive torque can be transferred from the stator 2 to the rotor 12 by applying an electric field. For this purpose, the air gap between the permanent magnet 1 and the stator 2 is designed to be as small as possible.

[0045] The electromagnetic drive unit 100 is controlled by an electronic control unit 17, which is responsible for both the drive control and the wheel brake control. This electronic control unit 17 is symbolized by the circuit boards 3 shown as examples. A data line 9 is provided for data transmission, which is routed through the wheel hub 13.

[0046] The stator 2 is arranged within the rotor 12, in particular within the permanent magnets 1. Furthermore, the stator 2 is connected in a rotationally fixed manner to the wheel hub 13. The rotor 2 can be connected in a known manner to a rim 104, which can support the wheel 103. Such an arrangement is shown in a partial sectional view in Fig. 4 shown.

[0047] The wheel hub 13 comprises a disc-shaped retaining plate 4, which has a substantially radial orientation. The disc-shaped design is not mandatory, but is considered expedient in order to realize sufficiently large cooling capacity in tight spaces. The orientation of the retaining plate 4 is therefore also substantially perpendicular to the wheel axis 18. The retaining plate 4 largely seals the rotor 1 from the vehicle frame, which is beneficial against the ingress of dirt. However, it does not collide with the rotor 12, allowing it to rotate freely relative to the retaining plate 4.

[0048] According to the illustrated embodiment, the holding plate 4 is designed to support the stator 2. For this purpose, the holding plate 4 is designed on the front side with corresponding means and / or receptacles for a fixed connection to the stator 2. For the fixed connection, for example, a screw connection can be provided, which for the sake of clarity is shown in Fig. 1 is not shown.

[0049] According to the invention, the holding plate 4 is provided with at least one cooling channel 11 as in Fig. 1 shown in a section. Of course, it is also possible to provide more than one cooling channel 11. The at least one cooling channel 11 can significantly reduce the potential cooling problems of the drive motor 101 and / or power electronics, such as those associated with the electronic control unit 17 for controlling the drive motor 101 and / or the wheel brake 102.

[0050] During operation of the vehicle or the electric motor drive unit 100, a cooling medium can be passed through the at least one cooling channel 11, which allows heat to be dissipated. The cooling medium can comprise a fluid, such as water or oil.

[0051] Due to the cooling, it is possible to arrange the electronic components belonging to the electronic control unit 17, for example the printed circuit boards 3, in a particularly space-saving manner inside the stator 2. In the Fig. In the embodiment of the drive unit 100 shown in Figure 1, the electronic control unit 17 for controlling the drive motor 101 and / or the wheel brake 102 is designed close to the wheel or integrated into the wheel, for example as a WCU (“Wheel Controlling Unit”), and is arranged inside the electric motor drive unit 100. According to a preferred embodiment of the invention, all required electronic components of the control unit 17, as shown in Fig. 1, arranged within the cavity defined by the stator 2.

[0052] Cooling of the electronic components or the circuit board 3 can be particularly effective if the at least one circuit board 3 is arranged directly adjacent to the holding plate 4. A favorable embodiment of the invention is shown in Fig. 1 and provides for arranging the printed circuit board 3 in such a way that it is radially aligned and thus parallel to the holding plate 4. This improves the cooling capability of the holding plate 4. The distance between the printed circuit board 3 and the holding plate 4 is chosen to be as small as possible, which significantly improves the cooling effect on the electronic components of the printed circuit board 3 and thus of the electronic control unit 17.

[0053] At the Fig. 1 shown embodiment of the invention, which in a section also in the Fig. As shown in Figure 2, the at least one printed circuit board 3 is oriented such that at least a part or a section of a side surface of the printed circuit board 3 is in direct contact with the holding plate 4. Accordingly, there is a common contact surface between the printed circuit board 3 and the holding plate 4.

[0054] The holding plate 4 can be equipped with corresponding, diametrically opposed recesses or receptacles (not shown) in order to be able to accommodate projections or parts of the electronic components protruding from the side surface of the circuit board 3 on the side facing the holding plate 4, or even electronic components themselves. In this way, the contact area between the holding plate 4 and the circuit board 3 or to the electronic components as a whole can be further enlarged. According to one embodiment of the invention, for example, particularly temperature-critical electronic components can be arranged on the side surface 19 of the circuit board 3 facing the holding plate 4 and accommodated in correspondingly shaped recesses or receptacles in the holding plate 4.

[0055] It is also possible to arrange more than one circuit board 3 within the stator 2. For example, an arrangement with two or three or even more circuit boards 3 is possible. Fig. 2 shows a section of an embodiment with three circuit boards 3. A suitable arrangement is to arrange the circuit boards 3 parallel to each other, as is the case in the Fig. 1 or Fig. 2. It is understood that the circuit boards 3 are electrically contacted with one another accordingly. Spacers 14 are arranged between the circuit boards 3, which, according to a favorable embodiment of the invention, can also provide electrical contact for the circuit boards 3. It is understood that the additional circuit boards 3 can also be arranged at a different angle to one another or have different sizes than those shown.

[0056] The cooling channel 11 of the holding plate 4 has a channel or fluid passage. This is laid out in windings across the surface, i.e., the circular surface of the holding plate. For a particularly good cooling effect, the cooling channel 11 is provided in particular in those areas of the holding plate 4 that are in contact with or adjacent to the circuit board 3, so that optimal cooling of at least the directly adjacent circuit board 3 is possible. In the example shown, the cooling channel 11 is designed in a meandering shape and extends radially across the holding plate 4.

[0057] In a preferred embodiment of the invention, as in the example of Fig. 1, a single continuous cooling channel 11 is provided, which facilitates the supply and removal of the cooling medium, since only one connection is required. Of course, it is also possible to provide multiple cooling channels 11.

[0058] According to a preferred embodiment of the invention, which is Fig. As shown in Figure 1, the inlet 15 and / or outlet 16 of the cooling channel 11 are to be relocated or integrated into the wheel hub 13. This enables reliable transmission and flow of the cooling medium, as well as simple assembly and disassembly.

[0059] According to a further preferred embodiment of the invention, which is Fig. 1, it is provided that a data line 9 for signaling connection, for example of a higher-level control unit or a vehicle bus, with the electronic control unit 17, is laid in the wheel hub 13 or integrated therein.

[0060] According to yet another preferred embodiment of the invention, which is set out in Fig. 1, it is provided that an electrical supply line 10 for supplying power to the drive motor 101 and / or the wheel brake 102 is laid into the wheel hub 13 or integrated therein.

[0061] The integration of all supply lines, including connections 15, 16 for the cooling medium, data or signal lines 9, and / or electrical supply lines 10, into the wheel hub 13 provides an easy-to-assemble and combined connection concept for all required lines. The wheel hub 13 can also include a corresponding plug or connector for easy connection, by means of which the aforementioned connections can be securely established and released.

[0062] The invention enables the drive motor 101 and / or the wheel brake 102 to be controlled close to the wheel directly by the wheel-integrated electronic control unit 17.

[0063] The wheel brake 102 can, as in Fig. 1, comprise a disc brake which is arranged between the vehicle frame (in Fig. 1 not shown) and the electric motor drive unit 100.

[0064] To connect the wheel brake to the rotor 12, a transfer plate 5 is provided, which is rotationally fixedly connected to the rotor 12 and the wheel brake 102 or a rotating portion of a wheel brake 102. This transfer plate 5 serves to transmit torque. It is coupled to the wheel hub 13 via a bearing 8.

[0065] In a further aspect, the invention also includes a motor vehicle comprising at least one, preferably at least two electric motor drive units 100 as described above. List of reference symbols: 1 permanent magnet 2 Stator 3 circuit board 4 Holding plate 5 Transfer plate 6 Friction lining 7 brake disc 8 warehouses 9 Data line 10 electrical supply line 11 Cooling channel 12 Rotor 13 Wheel hub 14 spacers 15 Entrance 16 Exit 17 Control unit 18 Wheel axle 19 Side surface 100 Electric motor drive unit 101 Drive motor 102 Wheel brake 103 bikes 104 rim

Claims

[1] Electric motor drive unit (100), in particular a wheel or wheel hub motor of a motor vehicle, comprising a wheel brake (102), a drive motor (101) with a stator (2) and a rotor (12), wherein the stator (2) is arranged within the rotor (12) and is rotatably connected or connected to a wheel hub (13), and wherein the rotor (12) comprises at least one permanent magnet (1) which is arranged between the stator (2) and the rotor (12), wherein the wheel hub (13) comprises a preferably disc-shaped retaining plate (4) which has a substantially radial orientation, and wherein at least one electronic control unit (17) is arranged adjacent to the holding plate (4) on the side of the holding plate (4) facing away from the vehicle, which control unit is connected to the holding plate (4). [2] Electric motor drive unit (100) according to the preceding claim, characterized bythat the electronic control unit (17) comprises at least one printed circuit board (3), wherein the at least one printed circuit board (3) preferably has a radial orientation or an orientation parallel to the holding plate (4). [3] Electric motor drive unit (100) according to one of the preceding claims, characterized by that the electronic control unit (17) is arranged within the cavity defined by the stator (2). [4] Electric motor drive unit (100) according to one of the preceding claims, characterized by that the electronic control unit (17) is designed to control the drive motor (101) and / or to control the wheel brake (102). [5] Electric motor drive unit (100) according to one of the preceding claims 2 to 4, characterized bythat the at least one printed circuit board (3) is aligned such that at least a portion of a side surface (14) of the printed circuit board (3) is in direct contact with the holding plate (4). [6] Electric motor drive unit (100) according to the preceding claim, characterized by that the holding plate (4) comprises opposing recesses or receptacles for receiving projections or protruding electronic components of the circuit board (3). [7] Electric motor drive unit (100) according to one of the preceding claims, characterized by that at least two or more circuit boards (3) are provided, wherein at least two circuit boards (3) are arranged parallel to one another and are electrically connected to one another. [8] Electric motor drive unit (100) according to one of the preceding claims, characterized by that the holding plate (4) reaches up to the inner wall of the rotor (12) without touching it. [9] Electric motor drive unit (100) according to one of the preceding claims, characterized by that the holding plate (4) comprises means or receptacles for fixed connection to the stator (2). [10] Electric motor drive unit (100) according to one of the preceding claims, characterized by that the holding plate (4) comprises at least one continuous cooling channel (11). [11] Electric motor drive unit (100) according to one of the preceding claims, characterized by that the at least one inlet (15) and / or at least one outlet (16) of the cooling channel (4) is guided through the wheel hub (13). [12] Electric motor drive unit (100) according to one of the preceding claims, characterized by that a data line (9) for signaling connection with the electronic control unit (17) is guided through the wheel hub (13). [13] Electric motor drive unit (100) according to one of the preceding claims, characterized bythat an electrical supply line for supplying power to the drive motor (101) and / or the wheel brake (102) is guided through the wheel hub (13). [14] Electric motor drive unit (100) according to one of the preceding claims, characterized by that the wheel brake (102) comprises a disc brake which is arranged between the vehicle frame and the drive unit (101). [15] Motor vehicle comprising at least one, preferably at least two electric motor drive units (100) according to one of the preceding claims.

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