Self-contained bearing and wireless power transmission device

Abstract

A bearing assembly includes an annular carrier body and an outer ring disposed in the carrier body. The outer ring is provided with an outer ring raceway and a transmitting coil which is spaced from the outer ring raceway in the axial direction. The transmitting coil can be electrically connected to a battery and is configured to generate an electromagnetic field when a current flows therethrough. The inner ring can be arranged around a rotating shaft of the rotor and is provided with an inner ring raceway and a receiving coil which is spaced from the inner ring raceway in the axial direction. And the receiving coil is close to the transmitting coil and is in induction connection with the transmitting coil, so that current is generated in the receiving coil when the current flows through the transmitting coil. The receiving coil is connected with an electromagnetic coil of the motor rotor, so that current flows to the electromagnetic coil from the receiving coil. A plurality of rolling bodies are disposed between the outer ring raceway and the inner ring raceway to rotatably connect the outer ring and the inner ring together.

Description

Technical Field

[0001] The present invention relates to both a bearing and a power transmission device, and in particular to a power transmission device of a motor whose rotating shaft is supported by a bearing. Background Art

[0002] Electric motors are well known and include a stator and a rotor. The stator has one or more magnets, typically electromagnets; the rotor is arranged inside the stator, mounted or connected to a shaft (hereinafter also referred to as the "rotor shaft"), and includes one or more magnets. When the rotor magnets are electromagnetic coils (hereinafter also referred to as "rotor coils"), current or power must be supplied to these coils to generate the magnetic field required to interact with the corresponding magnetic field of the stator. Typically, power is supplied to the rotor coils via one or more fixed conductors and a rotatable conductor. The fixed conductor is electrically connected to a power source (for example, a battery), and the rotatable conductor is mounted on the shaft, electrically connected to the rotor coil, and contacted by the fixed conductor.

[0003] As the rotor shaft angularly displaces about its central axis, the rotatable conductors slide against the stationary conductors, continuously delivering current from the power source to the rotor coils. This sliding action causes both the stationary and rotatable conductors to wear, which can weaken or even completely cut off the power transmission between the conductors, thereby reducing or stopping the current flow to the rotor coils. Furthermore, debris or contaminants can accumulate or become lodged at the interfaces between the conductors, reducing or stopping the current flow to the rotor. Furthermore, the sliding contact between the conductors increases the friction load on the rotor shaft.

[0004] Because of these potential issues, typical electric motors used in electric vehicles have rotors with permanent magnets, eliminating the need to supply current to the rotor. While this power supply system is relatively robust, the permanent magnets required to generate the torque needed to propel the electric vehicle are typically quite large, significantly adding weight to the vehicle. Furthermore, these large permanent magnets are often made from rare earth elements such as neodymium, terbium, and dysprosium, which can have harmful environmental impacts during mining, processing, and disposal. Summary of the Invention

[0005] In one aspect, the present invention provides a bearing assembly having a power transmission device for transmitting power from a battery to an electric motor. The electric motor includes a housing, an external stator connected to the housing, and a rotor disposed within the stator. The rotor is mounted on a shaft, rotatable about a central axis passing through the shaft, and has at least one electromagnetic coil. The bearing assembly includes an annular carrier connectable to the housing and having an inner bore, an outer ring disposed within the inner bore of the carrier. The outer ring has an outer raceway and a transmitting coil axially spaced from the outer raceway. The transmitting coil is electrically connectable to a battery and configured to generate an electromagnetic field when current flows therethrough. The inner ring is disposed about the shaft and has an inner raceway and a receiving coil axially spaced from the inner raceway. The receiving coil is positioned adjacent to the transmitting coil and inductively coupled to the transmitting coil. In this manner, when current flows through the transmitting coil, current is generated in the receiving coil. Furthermore, the receiving coil is electrically connected to at least one electromagnetic coil of the rotor, allowing current to flow from the receiving coil to the electromagnetic coil. Furthermore, a plurality of rolling elements are disposed between the outer and inner raceways, rotatably coupling the outer ring to the inner ring, thereby connecting the rotor shaft to the housing.

[0006] On the other hand, the present invention is also a drive motor assembly ( / drive motor assembly / drive motor assembly) for an electric vehicle having at least one wheel. The motor assembly includes a motor, which is configured to drive the at least one wheel in a rotatable manner. The motor has a housing, an external stator connected to the housing, and a rotor located inside the stator. The rotor is mounted on a rotating shaft, can rotate around a central axis passing through the rotating shaft, and has at least one electromagnetic coil. The motor assembly further includes a battery and the bearing assembly with a power transmission device described in the previous paragraph. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention will be better understood by reading the above summary and detailed description of preferred embodiments of the present invention in conjunction with the accompanying drawings. To illustrate the present invention, the drawings show presently preferred schematic embodiments of the present invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown. In the following drawings:

[0008] Figure 1 A schematic diagram showing an overall electric vehicle including a bearing assembly with a power transmission device according to the present invention;

[0009] Figure 2 A block diagram showing certain electronics of the vehicle's drive system, illustrating an exemplary flow of power through the vehicle;

[0010] Figure 3 An axial cross-sectional view of a drive system including the bearing assembly of the present invention is shown, wherein the bearing assembly is assembled around a rotating shaft and connected to a housing of a motor;

[0011] Figure 4 yes Figure 3 A partially enlarged cross-sectional view of ; and

[0012] Figure 5 yes Figure 3 A further enlarged partial cross-sectional view. DETAILED DESCRIPTION

[0013] In the following description, certain terms are used for convenience only and are not intended to be limiting. The terms "upper" and "lower" are used to refer to reference directions in the accompanying drawings, and "inward," "inwardly," and "outwardly" refer to directions toward and away from a designated centerline or geometric center of the described components, respectively, with their specific meanings being apparent from the context of the description. In addition, the terms "connected" and "connected" are used herein to include both a direct connection between two components (without any other components intervening) and an indirect connection between two components (with one or more other components intervening). The terms include the words specifically mentioned above, their derivatives, and words of similar meaning.

[0014] Reference is now made in detail to the drawings, wherein like numerals are used to refer to like parts throughout. Figures 1 to 5 The self-contained bearing assembly 10 is shown with an integrated wireless power transmission device 11. The power transmission device 11 preferably transmits power from a battery (preferably a battery pack) 1 to the motor 2 via an electronic power inverter connected to the motor 2. The motor 2 is preferably a drive motor of a four-wheeled electric vehicle V, such as Figure 1As shown, but it can also be any other suitable type of motor in other cases. The motor 2 has a housing 3, an external stator 4 connected to the housing 3, and a rotor 5 located inside the stator 4. The rotor 5 is mounted on a rotating shaft 6 and can rotate around a central axis A passing through the rotating shaft 6. C Rotation. The rotor 5 has at least one, and preferably multiple, electromagnetic coils 7. Generally speaking, the bearing assembly 10 with the power transmission device 11 includes a carrier 24, an outer ring 12 disposed within the carrier 24 and having a transmitter coil 14, an inner ring 16 disposed within the outer ring 12 and having a receiver coil 18, and a plurality of rolling elements 20 disposed between the inner and outer rings 16 and 12, rotatably coupling them. During the rotation of the inner ring 16, power is wirelessly transmitted from the transmitter coil 14 to the receiver coil 18, as described in detail below. Furthermore, by providing the carrier 24, the bearing assembly 10 is constructed as "self-contained," as described in detail below.

[0015] Now see Figures 3 to 5 The carrier 24 is annular and can be connected to the housing 3. Preferably, it can be positioned within the housing bore 8 of the housing 3. The carrier 24 has an inner bore 25, in which the bearing outer ring 12 is positioned. Preferably, the carrier 24 includes a cylindrical portion 26, a mounting flange portion 27A, and a retaining flange portion 27B. The cylindrical portion 26 can be positioned within the housing bore 8 of the housing 3 and has an inner circumferential surface 26a defining the carrier inner bore 25. The cylindrical portion 26 extends radially outward to form the mounting flange portion 27A, while the cylindrical portion 26 extends radially inward to form the retaining flange portion 27B. The mounting flange portion 27A can abut against the radial surface 3a of the housing 3 and is preferably connected to the housing 3 via one or more fasteners 64. Alternatively, the carrier 24 can be connected to the housing 3 via other suitable means, such as a threaded connection.

[0016] The outer ring 12 is preferably slidably disposed within the inner bore 25 of the carrier 24 to allow axial displacement of the outer ring 12 and thereby accommodate thermal expansion of the shaft 6. Specifically, the carrier 24 includes an axial retaining portion 28, preferably formed as an annular shoulder of the cylindrical portion 26, which is adapted to abut against an annular groove 35 (described below) in the outer ring 12. At least one biasing member 29 is disposed within the inner bore 25 of the carrier 24. The biasing member 29 has a first axial end 29a that abuts against the retaining flange 27B of the carrier 24 and a second axial end 29b that abuts against the first axial end 30a (described below) of the outer ring body 30. Each biasing member 29 is configured to apply an axial force to the first axial end 30a of the outer ring 12 in an axial direction toward the retaining portion 28. In this way, the bearing outer ring 12 can undergo a limited axial displacement so that a suitable preload can always be built up in the rolling elements 20 .

[0017] Furthermore, the at least one biasing member 29 is preferably a single wave spring (not shown), but in other cases may include multiple coil springs (as shown), a solid elastomeric member, etc. However, in another case, the bearing outer ring 12 may also be fixedly disposed in the inner bore 25 of the carrier 24, for example, by friction fit between the inner circumferential surface 26a of the inner bore 25 and the outer circumferential surface 34 (described below) of the bearing outer ring 12. Of course, in the latter case, the bearing assembly 10 does not include any biasing member.

[0018] Still see Figures 3 to 5 The outer ring 12 has an outer ring raceway 13. A transmitting coil 14 is connected to the outer ring 12 and is axially spaced apart from the outer ring raceway 13. The transmitting coil 14 is preferably electrically connected to the battery 1 via one or more electronic components (as described below) and is preferably configured to generate an electromagnetic field. The inner ring 16 is (can be) disposed about the rotating shaft 6 and has an inner ring raceway 17. A receiving coil 18 is connected to the inner ring 16 and is axially spaced apart from the inner ring raceway 17. The receiving coil 18 is positioned adjacent to the transmitting coil 14 and is magnetically coupled to the transmitting coil 14. The receiving coil 18 is electrically connected to at least one electromagnetic coil 7 of the rotor 5, such that current generated in the receiving coil 18 can flow to the electromagnetic coil 7 via one or more electronic components described below.

[0019] Specifically, the transmitting coil 14 receives current and generates an electromagnetic field. This electromagnetic field induces a current in the receiving coil 18, a process known as "inductive coupling" and well known in the art of electronics. Therefore, further detailed explanation of coils 14 and 18 is unnecessary for the present invention. In a preferred application for an electric vehicle V, to provide sufficient current to the rotor 5, the transmitting coil 14 is configured (i.e., constructed, dimensioned, etc.) to transmit power within a power range of 100 watts (100 W) to 3 kilowatts (3 kW). Similarly, the receiving coil 18 is configured to receive power within a power range of 100 watts (100 W) to 3 kilowatts (3 kW). However, depending on the specific application of the bearing assembly 10, both coils 14 and 18 may also be configured to have significantly less or greater power transmission capabilities.

[0020] Furthermore, a plurality of rolling elements 20 are disposed between outer ring raceway 13 and inner ring raceway 17, rotatably coupling outer ring 12 and inner ring 16 to form bearing 22. As shown, rolling elements 20 are preferably balls, but may alternatively be cylindrical rollers, tapered rollers, needle rollers, or any other suitable type of rolling element. Rolling elements 20 are conventionally made of steel, but may alternatively be formed of ceramic or other insulating materials to provide insulation between bearing raceways 13 and 17. Although not currently preferred, bearing rings 12 and 16 may alternatively be formed as components of a sliding bearing (as plain bearing rings), with the inner circumferential surface of outer ring 12 slidingly disposed about the outer circumferential surface of inner ring 16. In this case, transmitter coil 14 and receiver coil 18 are preferably disposed on plain bearing rings 12 and 16 (this structure is not shown).

[0021] Preferably, the outer ring 12 includes an annular body (hereinafter also referred to as the "outer ring body") 30. The outer ring body 30 has first and second axial ends 30a and 30b facing each other, an inner circumferential surface 32, and an outer circumferential surface 34 facing away from the inner circumferential surface 32. The outer ring raceway 13 extends radially outward from the inner circumferential surface 32 of the outer ring body 30. The transmitting coil 14 is either disposed directly on the inner circumferential surface 32 of the outer ring body 30 or, preferably, is disposed in an annular recess 36 extending radially outward from the inner circumferential surface 32 of the outer ring body 30. Furthermore, the outer circumferential surface 34 of the outer ring body 30 is slidably disposed in the inner bore 25 of the carrier 24. For reasons explained below, the outer circumferential surface 34 has an annular groove 35 extending radially inward.

[0022] Similarly, the inner ring 16 includes an annular body (hereinafter also referred to as the "inner ring body") 40. The inner ring body 40 has first and second axial ends 40a and 40b opposite to each other, an inner circumferential surface 42, and an outer circumferential surface 44 opposite to the inner circumferential surface 42. The inner ring raceway 17 extends radially inward from the outer circumferential surface 44 of the inner ring body 40. The receiving coil 18 is either disposed directly on the outer circumferential surface 44 of the inner ring body 40 or, preferably, is disposed within an annular recess 45 extending radially inward from the outer circumferential surface 44 of the inner ring body 40. In addition, the inner circumferential surface 42 of the inner ring body 40 defines an annular inner hole 46 for accommodating a portion of the rotating shaft 6. The inner ring 16 is preferably frictionally engaged with the rotating shaft 6.

[0023] Preferably, the axial length (not labeled) of the inner ring body 40 between its axial ends 40a and 40b is significantly greater than the axial length (not labeled) of the outer ring body 30 between its axial ends 30a and 30b. In this manner, an exterior mounting surface section (hereinafter referred to as "mounting surface section") 48 of the outer circumferential surface 44 of the inner ring body 40 extends between the second axial end 40b and the receiving coil 18. As described below, the mounting surface section 48 provides a mounting surface for certain electronic components connected to the receiving coil 18.

[0024] In a currently preferred embodiment, each of the transmitting coil 14 and the receiving coil 18 is annular, and the receiving coil 18 is coaxially disposed within the transmitting coil 14. Specifically, the transmitting coil 14 includes an annular body 15 having an inner circumferential surface 15a, and the receiving coil 18 includes an annular body 19 having an outer circumferential surface 19a. The outer circumferential surface 19a of the receiving coil 18 is radially spaced from the inner circumferential surface 15a of the transmitting coil 14 from the radial inside. In this manner, an annular air gap GA is defined between the two circumferential surfaces 15a and 19a, as shown in FIG. Figure 5 In a preferred embodiment, the dimensions of the transmitting coil 14 and the receiving coil 18 are set so that the radial dimension d of the annular air gap GA is R In terms of value, it does not exceed five millimeters (5 mm), and, preferably, is about one millimeter (1 mm). With such a relatively small or narrow air gap GA, the power transmission device 11 can, as described above, transmit a relatively large amount of power with a relatively high efficiency, preferably an efficiency greater than 95%.

[0025] In another embodiment, the transmitter coil 14 and receiver coil 18 may still be annular but axially spaced apart, with axial end surfaces facing each other (not shown). Alternatively, the transmitter coil 14 and receiver coil 18 may be formed with angled surfaces facing each other, spaced apart both radially and axially. Furthermore, the transmitter coil 14 and receiver coil 18, as well as their supporting electronics, may be configured or arranged to provide bidirectional transmission of signals or data. For example, data collected by sensors may be transmitted from the rotor 5 to a non-rotating component (e.g., a motor controller, a vehicle computer, etc.) to provide information about the rotor 5 (e.g., temperature) to a vehicle control system (not shown). As another example, the vehicle control system (not shown) may provide instructions for adjusting the rectifier system (not shown) by sending data or commands from the transmitter coil 14 to the receiver coil 18. In this case, the receiver coil 18 is connected to the rectifier system. The scope of the present invention includes all of these disclosed configurations of coils 14, 18, as well as any other suitable configuration that can be disposed within (or on) bearing rings 12, 16 and that can perform the functions described herein.

[0026] Now see Figure 2 、 Figure 4 and Figure 5 The battery 1 provides direct current (DC), and the electromagnetic coils 7 of the rotor 5 preferably also require DC power. However, the transmitting coil 13 requires alternating current (AC) to generate AC power within the receiving coil 18. Therefore, the power transmission device 11 further includes a direct current (DC-to-AC) power converter 50 and an alternating current (AC-to-DC) power converter 52. The DC-to-AC power converter 50 is preferably mounted on the housing 3, while the AC-to-DC power converter 52 is preferably mounted on the inner ring 16. Specifically, the DC-to-AC power converter 50 is electrically connected to the battery 1 and the transmitting coil 14, for example, via wires 54. The wires 54 can be hard-wired or removably connected (e.g., a plug-and-socket connection). The DC-to-AC power converter 50 is configured to convert the DC power from the battery 1 into AC power, which is then transmitted to the transmitting coil 14. In a preferred embodiment, the DC-AC power converter 50 is disposed on a printed circuit board (PCB) 56 that is (can be) connected to the housing 3. In a most preferred embodiment, the printed circuit board 56 is disposed on the mounting flange portion 27A of the carrier 24, preferably using the same fasteners that connect the carrier 24 to the housing 3.

[0027] Furthermore, an AC-DC power converter 52 is preferably disposed on the mounting surface 48 of the inner ring 16, electrically connected to the receiving coil 18 and also (capably) electrically connected to the at least one electromagnetic coil 7 of the rotor 5. The AC-DC power converter 52 is configured to convert the alternating current generated in the receiving coil 18 into direct current that can be transmitted to the electromagnetic coil 7. Preferably, the AC-DC power converter 52 is disposed on a printed circuit board (PCB) 58A, which is mounted on the inner ring 16, preferably on the mounting surface 48 of the inner ring 16. The PCB 58A is preferably formed as a "horseshoe-shaped" PCB with a rectifier system and is secured to the mounting surface 48 of the inner ring 16 by an annular retainer 59A. The annular retainer 59A is engaged with the mounting surface 48, for example, by friction, threads, or a keyed fit. Furthermore, the AC-DC power converter 52 is electrically connected to the electromagnetic coil 7 by any suitable means, such as two wires 54 (only one of which is shown). The wires 54 may be hardwired or removably connected (e.g., via detachable contacts). Furthermore, the bearing assembly 10 may further include a second printed circuit board 58B disposed on the mounting surface 48 of the inner ring 16. The second printed circuit board 58B is retained by a second annular retainer 59B and is used to provide additional functionality for the bearing assembly 10.

[0028] The bearing assembly 10 of the present invention offers numerous advantages over previously known motor bearings and power transmission devices for delivering current to a motor rotor. By incorporating the power transmission device 11 into the bearing assembly 10, power transmission components, such as the transmitter coil 14 and receiver coil 18, and power converters 50 and 52, are assembled simultaneously with the bearing 22 supporting the rotor shaft 6. Specifically, by arranging or connecting the components of the bearing 22 and power transmission device 11 within a carrier 24, the bearing 22 and transmission device 11 can be assembled simply by inserting the rotor shaft 6 into the bearing inner race 16 and then connecting the carrier 24 to the radial surface 3a of the housing 3.

[0029] In this manner, the separate assembly process for power components is eliminated, reducing (saving) the axial space required for these components. Furthermore, compared to power transmission using contact-type conductors, supplying power from battery 1 to rotor 5 via wireless power transmission device 11 reduces the frictional load on shaft 6, significantly improving both the reliability and power density of power transmission. Furthermore, the transmitter coil 14 and receiver coil 18 are enclosed within bearing rings 12 and 16, providing a significant degree of protection for these components 14 and 18 while also eliminating the need for a separate housing.

[0030] The above describes in detail representative non-limiting embodiments of the present invention with reference to the accompanying drawings. This detailed description is only to teach those skilled in the art to implement further details of the preferred aspects of the present invention, and is not intended to limit the scope of the present invention.

[0031] In addition, the combination of features and steps disclosed in the above detailed description may not be necessary to implement the invention in the broadest sense, but are only particularly described for the purpose of teaching (representative embodiments of the invention). In addition, various features of the above representative embodiments and the various independent and dependent claims attached hereto may also be combined in ways not specifically enumerated to provide additional useful embodiments of the invention.

[0032] All features disclosed in the specification and / or claims are disclosed separately and independently for the purposes of original written disclosure and for the purposes of limiting the claimed subject matter, regardless of the combination of features in the examples and / or claims. Furthermore, all numerical ranges or representations of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purposes of original written disclosure and for the purposes of limiting the claimed subject matter. The present invention is not limited to the embodiments described above and may be varied within the scope of the appended claims.

Claims

1. A bearing assembly having a power transmission device for transmitting power from a battery to a motor, the motor having a housing, an external stator connected to the housing, and a rotor disposed within the stator. The rotor is mounted on a rotating shaft and is rotatable about a central axis passing through the rotating shaft. The rotor has at least one electromagnetic coil. The bearing assembly includes: an annular carrier capable of being connected to the housing and having an inner hole; an outer ring disposed in the inner bore of the carrier, having an outer ring raceway and a transmitting coil axially spaced apart from the outer ring raceway, the transmitting coil being electrically connectable to a battery and configured to generate an electromagnetic field when current flows therethrough; an inner ring capable of being arranged around a rotating shaft, having an inner ring raceway and a receiving coil axially spaced apart from the inner ring raceway, such that the receiving coil is located near the transmitting coil and is inductively coupled to the transmitting coil such that when current flows through the transmitting coil, current is generated in the receiving coil, and the receiving coil is electrically connectable to the at least one electromagnetic coil of the rotor such that current flows from the receiving coil to the electromagnetic coil; and A plurality of rolling elements disposed between the outer ring raceway and the inner ring raceway rotatably couple the outer ring and the inner ring, thereby coupling the rotating shaft to the housing.

2. The bearing assembly according to claim 1, wherein: The transmitting coil is annular and has an inner circumferential surface. The receiving coil is annular and is arranged inside the transmitting coil and has an outer circumferential surface. An annular air gap is defined between the inner circumferential surface of the transmitting coil and the outer circumferential surface of the receiving coil.

3. The bearing assembly according to claim 2, wherein: The transmitting coil and the receiving coil are each dimensioned such that the annular air gap has a radial dimension not exceeding a value of 5 mm.

4. The bearing assembly according to claim 1, wherein: The transmitting coil is configured to transmit an amount of electrical power ranging from 100 watts to 3 kilowatts, and the receiving coil is configured to receive an amount of electrical power ranging from 100 watts to 3 kilowatts.

5. The bearing assembly according to claim 1, wherein: The outer ring has an inner circumferential surface, the outer ring raceway extends radially outward from the inner circumferential surface of the outer ring, and the transmitting coil is arranged on the inner circumferential surface of the outer ring, or is arranged in an annular recess extending radially outward from the inner circumferential surface of the outer ring; The inner ring has an outer circumferential surface, the inner ring raceway extends radially inward from the outer circumferential surface of the inner ring, and the receiving coil is arranged on the outer circumferential surface of the inner ring or in an annular recess extending radially inward from the outer circumferential surface of the inner ring.

6. The bearing assembly according to claim 1, wherein: The bearing assembly further includes a DC-AC power converter mounted on the carrier, which is capable of being electrically connected to a battery and also to a transmitting coil, and is configured to convert DC power from the battery into AC power and then transmit the AC power to the transmitting coil.

7. The bearing assembly according to claim 6, wherein: The DC-AC power converter is arranged on a printed circuit board connected to a carrier.

8. The bearing assembly according to claim 1, wherein: The bearing assembly further includes an AC-DC power converter mounted on the inner ring, the AC-DC power converter being electrically connected to the receiving coil and also being electrically connectable to the at least one electromagnetic coil of the motor, and being configured to convert the AC power generated in the receiving coil into DC power that can be transmitted to the electromagnetic coil.

9. The bearing assembly according to claim 8, wherein: The AC-DC power converter is provided on a printed circuit board mounted on the inner ring.

10. The bearing assembly according to claim 1, wherein: The outer ring has a first axial end and an opposite second axial end, the carrier includes an axial retaining portion that can be arranged against the second axial end of the outer ring, and the carrier is provided with at least one biasing member in its inner hole, and the biasing member is configured to apply an axial force to the first axial end of the outer ring in an axial direction toward the retaining portion.

11. The bearing assembly according to claim 10, wherein: The carrier includes a cylindrical portion having an inner circumferential surface defining an inner hole of the carrier and a mounting flange portion extending radially outward from the cylindrical portion. The cylindrical portion can be set in the housing hole of the housing, and the mounting flange portion can be connected to a radial surface of the housing.

12. A drive motor assembly for an electric vehicle having at least one wheel, the motor assembly comprising: a motor configured to rotatably drive the at least one wheel, the motor comprising a housing, an external stator connected to the housing, and a rotor disposed within the stator, the rotor being mounted on a rotating shaft and rotatable about a central axis passing through the rotating shaft, and comprising at least one electromagnetic coil; Batteries; and A bearing assembly having a power transmission device for transmitting power from a battery to a motor, comprising: an annular carrier capable of being connected to the housing and having an inner hole; an outer ring disposed in the inner hole of the carrier, having an outer ring raceway and a transmitting coil axially spaced apart from the outer ring raceway, wherein the transmitting coil is electrically connectable to a battery and is configured to generate an electromagnetic field when current flows through the transmitting coil; an inner ring disposed about the rotating shaft, having an inner ring raceway and a receiving coil axially spaced apart from the inner ring raceway, such that the receiving coil is located adjacent to the transmitting coil and is inductively coupled to the transmitting coil such that current is generated in the receiving coil when current flows through the transmitting coil, and the receiving coil is electrically connectable to the at least one electromagnetic coil of the rotor such that current flows from the receiving coil to the electromagnetic coil; and A plurality of rolling elements disposed between the outer ring raceway and the inner ring raceway rotatably couple the outer ring and the inner ring so as to rotatably couple the rotating shaft and the housing.

13. The motor assembly according to claim 12, wherein: The transmitting coil is annular and has an inner circumferential surface. The receiving coil is annular and is arranged inside the transmitting coil and has an outer circumferential surface. An annular air gap is defined between the inner circumferential surface of the transmitting coil and the outer circumferential surface of the receiving coil.

14. The motor assembly according to claim 13, wherein: The transmitting coil and the receiving coil are each dimensioned such that the annular air gap has a radial dimension not exceeding a value of 5 mm.

15. The motor assembly according to claim 12, wherein: The outer ring has an inner circumferential surface, the outer ring raceway extends radially outward from the inner circumferential surface of the outer ring, and the transmitting coil is arranged on the inner circumferential surface of the outer ring, or is arranged in an annular recess extending radially outward from the inner circumferential surface of the outer ring; The inner ring has an outer circumferential surface, the inner ring raceway extends radially inward from the outer circumferential surface of the inner ring, and the receiving coil is arranged on the outer circumferential surface of the inner ring or in an annular recess extending radially inward from the outer circumferential surface of the inner ring.

16. The motor assembly according to claim 12, wherein: The bearing assembly further includes a DC-AC power converter mounted on the carrier, which is capable of being electrically connected to a battery and also to a transmitting coil, and is configured to convert DC power from the battery into AC power and then transmit the AC power to the transmitting coil.

17. The motor assembly according to claim 16, wherein: The DC-AC power converter is arranged on a printed circuit board connected to a carrier.

18. The motor assembly according to claim 12, wherein: The bearing assembly further includes an AC-DC power converter mounted on the inner ring, the AC-DC power converter being electrically connected to the receiving coil and also being capable of being electrically connected to the at least one electromagnetic coil of the motor, and being configured to convert the AC power generated in the receiving coil into DC power that can be transmitted to the electromagnetic coil.

19. The motor assembly according to claim 18, wherein: The AC-DC power converter is provided on a printed circuit board mounted on the inner ring.

20. The motor assembly according to claim 12, wherein: The outer ring is slidably arranged in the inner hole of the carrier.

Images