Outer rotor motor for electric two-wheeled vehicle and electric two-wheeled vehicle

Abstract

The utility model belongs to the technical field of electric two-wheeled vehicles, and discloses an external rotor motor for an electric two-wheeled vehicle and an electric two-wheeled vehicle, the external rotor motor comprises a hub assembly, a stator assembly, a rotor assembly and a shaft assembly, the hub assembly defines a mounting cavity, the rotor assembly is mounted in the mounting cavity and is connected with the hub assembly, and the shaft assembly is connected with the stator assembly. The shaft assembly penetrates through the mounting cavity, the stator assembly sleeves the shaft assembly, the rotor assembly is connected with the hub assembly and sleeves the stator assembly, the rotor assembly comprises a rotor iron core, the rotor iron core is provided with a plurality of main magnetic steels and a plurality of auxiliary magnetic steels, the main magnetic steels are located on the peripheral wall, facing the hub assembly, of the rotor iron core and are connected with the hub assembly, and the auxiliary magnetic steels are located on the peripheral wall, facing the hub assembly, of the rotor iron core. The plurality of auxiliary magnetic steels are located on the inner circumferential wall, facing the stator assembly, of the rotor core. The main magnetic steel is magnetized along the radial direction of the rotor core, and the auxiliary magnetic steel is magnetized along the circumferential direction of the rotor core. The external rotor motor does not need to be controlled by a Hall sensor, and is low in maintenance frequency and high in reliability.

Description

Technical Field

[0001] This utility model relates to the field of electric two-wheeled technology, and in particular to an external rotor motor for an electric two-wheeled vehicle and the electric two-wheeled vehicle. Background Technology

[0002] As an environmentally friendly and convenient mode of transportation, the performance and reliability of the hub motor—the core power source of electric two-wheelers—directly determine the overall operating efficiency and lifespan of the vehicle. Currently, most electric two-wheelers on the market use Hall effect sensors for motor control. Specifically, the Hall effect sensor's function is to locate the rotor angle and feed back an electrical signal to the controller, thereby controlling the motor. Existing Hall effect sensors in electric two-wheelers are mostly located inside the motor, either in the stator teeth or stator slots. This makes maintenance and replacement cumbersome, and during operation, a short circuit or a broken connecting wire can cause the Hall effect sensor to malfunction, leading to motor failure and potentially endangering driver safety.

[0003] Therefore, there is an urgent need to develop an electric two-wheeler with low maintenance frequency and high reliability. Utility Model Content

[0004] The first objective of this invention is to provide an external rotor motor for electric two-wheeled vehicles, which does not require the use of Hall sensors for control, has a low maintenance frequency, and high reliability.

[0005] The second objective of this utility model is to provide an electric two-wheeled vehicle that has a low maintenance frequency and high reliability.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This utility model discloses an external rotor motor for an electric two-wheeled vehicle, including a hub assembly, a stator assembly, a rotor assembly, and a shaft assembly. The hub assembly defines a mounting cavity, the rotor assembly is mounted in the mounting cavity and connected to the hub assembly, the shaft assembly passes through the mounting cavity, the stator assembly is sleeved on the shaft assembly, and the rotor assembly is connected to the hub assembly and sleeved on the stator assembly. The rotor assembly includes a rotor core, on which multiple main magnets and multiple auxiliary magnets are mounted. The multiple main magnets are located on the outer peripheral wall of the rotor core facing the hub assembly and connected to the hub assembly, and the multiple auxiliary magnets are located on the inner peripheral wall of the rotor core facing the stator assembly. The main magnets are magnetized radially along the rotor core, and the auxiliary magnets are magnetized circumferentially along the rotor core.

[0008] In some embodiments, the outer peripheral wall of the rotor core is provided with a plurality of first mounting slots, and the inner sidewall is provided with a plurality of second mounting slots. The first mounting slots and the second mounting slots are respectively used to install the main magnet and the auxiliary magnet.

[0009] In some specific embodiments, in the circumferential direction of the rotor core, a plurality of first mounting slots and a plurality of second mounting slots are staggered.

[0010] In some specific embodiments, in the circumferential direction of the rotor core, the portion of the rotor core located between adjacent first and second mounting slots forms a magnetic isolation bridge, the width of which is 0.5mm-1mm.

[0011] In some specific embodiments, the first mounting slot includes a first slot and a second slot. Along the circumference of the rotor core, the width of the first slot is greater than that of the second slot. A portion of the main magnet is located in the first slot, and another portion is located in the second slot.

[0012] In some specific embodiments, the second mounting slot includes a third slot and a fourth slot. Along the circumference of the rotor core, the width of the third slot is greater than that of the fourth slot, and all the auxiliary magnets are located within the third slot.

[0013] In some embodiments, the salient pole ratio of the external rotor motor for the electric two-wheeler is 1.2-1.6.

[0014] In some embodiments, the main magnet is bonded to the inner wall of the hub assembly.

[0015] In some embodiments, the tooth tips on the air gap side of the rotor core are arc-shaped structures that bulge toward the air gap side.

[0016] This utility model also discloses an electric two-wheeled vehicle, including a vehicle body and the aforementioned external rotor motor for electric two-wheeled vehicles, wherein the external rotor motor for electric two-wheeled vehicles is mounted on the vehicle body.

[0017] The beneficial effects of this utility model of an external rotor motor for electric two-wheelers are as follows: Multiple main magnets are arranged on the outer peripheral wall of the rotor core, and multiple auxiliary magnets are arranged on the inner peripheral wall. The main magnets are magnetized radially along the rotor core, and the auxiliary magnets are magnetized circumferentially along the rotor core. Because the magnetic reluctance of the d-axis is different from that of the q-axis, the inductance of the q-axis is greater than that of the d-axis. In actual operation, the angle of the rotor assembly can be positioned by directly measuring the back electromotive force of the external rotor motor for electric two-wheelers, eliminating the need for Hall effect sensors for control. This results in low maintenance frequency and high reliability.

[0018] The beneficial effects of this electric two-wheeler are as follows: due to the external rotor motor for electric two-wheelers described above, the electric two-wheeler has a low maintenance frequency and high reliability.

[0019] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cooperation structure between the external rotor motor, wheel hub, and axle assembly for an electric two-wheeled vehicle according to an embodiment of the present invention.

[0021] Figure 2 This is a partial structural schematic diagram of an external rotor motor for an electric two-wheeled vehicle according to an embodiment of the present invention;

[0022] Figure 3 This is a magnetic field line and magnetic density cloud diagram of the external rotor motor for an electric two-wheeled vehicle according to an embodiment of the present invention.

[0023] Figure label:

[0024] 11. Fixed cover; 12. Wheel hub body; 13. End cover;

[0025] 20. Stator assembly; 21. Stator core; 22. Stator support;

[0026] 30. Rotor assembly; 31. Rotor core; 311. First mounting slot; 3111. First slot; 3112. Second slot; 312. Second mounting slot; 3121. Third slot; 3122. Fourth slot; 313. Magnetic bridge; 32. Main magnet; 33. Auxiliary magnet;

[0027] 40. Shaft assembly. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0029] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0031] This utility model discloses an external rotor motor for an electric two-wheeled vehicle, referenced... Figure 1 and Figure 2 As shown, the external rotor motor for an electric two-wheeled vehicle includes a hub assembly, a stator assembly 20, a rotor assembly 30, and a shaft assembly 40. The hub assembly defines a mounting cavity, the rotor assembly 30 is mounted in the mounting cavity, and the shaft assembly 40 passes through the mounting cavity. The stator assembly 20 includes a stator bracket 22, a stator core 21, and stator windings (not shown). The stator bracket 22 is sleeved on the shaft assembly 40. The rotor assembly 30 is connected to the hub assembly and sleeved on the stator assembly 20. The rotor assembly 30 includes a rotor core 31, on which multiple main magnets 32 and multiple auxiliary magnets 33 are mounted. The multiple main magnets 32 are located on the outer peripheral wall of the rotor core 31 facing the hub assembly and are connected to the hub assembly. The multiple auxiliary magnets 33 are located on the inner peripheral wall of the rotor core 31 facing the stator assembly 20. The main magnets 32 are magnetized radially along the rotor core 31, and the auxiliary magnets 33 are magnetized circumferentially along the rotor core 31. It is understandable that, since the outer peripheral wall of the rotor core 31 of the external rotor motor for electric two-wheeled vehicles in this embodiment is provided with a plurality of main magnets 32 and the inner peripheral wall is provided with a plurality of auxiliary magnets 33, and the main magnets 32 are magnetized radially along the rotor core 31, while the auxiliary magnets 33 are magnetized circumferentially along the rotor core 31, it can be seen from the magnetic field lines and magnetic density cloud diagram of the external rotor motor for electric two-wheeled vehicles in this embodiment (see reference). Figure 3 Because the magnetic reluctance of the d-axis is different from that of the q-axis, the inductance of the q-axis is greater than that of the d-axis. In actual operation, the angle of the rotor assembly 30 can be positioned by directly measuring the back electromotive force of the external rotor motor used in electric two-wheeled vehicles. There is no need to use Hall sensors for control, resulting in low maintenance frequency and high reliability.

[0032] In some embodiments, reference Figure 2 As shown, the outer peripheral wall of the rotor core 31 is provided with multiple first mounting slots 311, and the inner side wall is provided with multiple second mounting slots 312. The first mounting slots 311 and the second mounting slots 312 are used to install the main magnet 32 ​​and the auxiliary magnet 33, respectively. It can be understood that by setting the first mounting slots 311 and the second mounting slots 312 to install the main magnet 32 ​​and the auxiliary magnet 33, the radial dimension of the entire rotor assembly 30 can be reduced. On the one hand, this makes the overall size of the external rotor motor used in electric two-wheeled vehicles smaller, and on the other hand, it can effectively reduce magnetic leakage and improve performance.

[0033] In some specific embodiments, reference is made to Figure 2 As shown, multiple first mounting slots 311 and multiple second mounting slots 312 are staggered in the circumferential direction of the rotor core 31. This further reduces magnetic leakage and improves performance.

[0034] In some specific embodiments, in the circumferential direction of the rotor core 31, the portion of the rotor core 31 located between adjacent first mounting slots 311 and second mounting slots 312 constitutes a magnetic isolation bridge 313, the width of which is 0.5mm-1mm. Optionally, the width of the magnetic isolation bridge 313 can be 0.5mm, 0.51mm, 0.52mm, 0.53mm, 0.54mm, 0.55mm, 0.56mm, 0.57mm, 0.58mm, 0.59mm, 0.6mm, 0.61mm, 0.62mm, 0.63mm, 0.64mm, 0.65mm, 0.66mm, 0.67mm, 0.68mm, 0.69mm, 0.7mm, 0.71mm, 0.72mm, 0.73mm, 0... The widths are 0.74mm, 0.75mm, 0.76mm, 0.77mm, 0.78mm, 0.79mm, 0.8mm, 0.81mm, 0.82mm, 0.83mm, 0.84mm, 0.85mm, 0.86mm, 0.87mm, 0.88mm, 0.89mm, 0.9mm, 0.91mm, 0.92mm, 0.93mm, 0.94mm, 0.95mm, 0.96mm, 0.97mm, 0.98mm, 0.99mm, and 1mm. Optionally, the width of the magnetic bridge 313 can be other values ​​within the range of 0.5mm-1mm, and is not limited to the examples above. If the width of the magnetic isolation bridge 313 is too large, the size of the rotor core 31 will be too large; if it is too small, it will increase magnetic leakage. The width of the magnetic isolation bridge 313 is 0.5mm-1mm, which can control the size of the rotor core 31 and reduce magnetic leakage, thereby improving performance.

[0035] In some specific embodiments, the first mounting slot 311 includes a first slot 3111 and a second slot 3112. Along the circumference of the rotor core 31, the width of the first slot 3111 is greater than that of the second slot 3112. A portion of the main magnet 32 ​​is located within the first slot 3111, and another portion is located within the second slot 3112. It is understood that because the width of the first slot 3111 is greater than that of the second slot 3112 along the circumference of the rotor core 31, in actual installation, it is only necessary to push the main magnet 32 ​​in the radial direction of the rotor core 31, making installation very convenient. Furthermore, the greater length of the first slot 3111 facilitates the installation of the main magnet 32.

[0036] In some specific embodiments, the second mounting slot 312 includes a third slot 3121 and a fourth slot 3122. Along the circumference of the rotor core 31, the width of the third slot 3121 is greater than that of the fourth slot 3122, and all of the auxiliary magnets 33 are located within the third slot 3121. It is understood that, since the width of the first slot 3111 is greater than that of the second slot 3112 along the circumference of the rotor core 31, in actual installation, the width of the third slot 3121 is greater than that of the fourth slot 3122. Therefore, the auxiliary magnets 33 only need to be inserted along the axial direction of the rotor core 31, which avoids the auxiliary magnets 33 from wobbling radially along the rotor core 31, ensuring installation stability.

[0037] In some embodiments, the salient pole ratio of the external rotor motor used in electric two-wheelers is 1.2-1.6. It is understood that the salient pole ratio determines the difference between the magnetic reluctance of the d-axis magnetic circuit and the magnetic reluctance of the q-axis magnetic circuit. Controlling the salient pole ratio of the external rotor motor used in electric two-wheelers within the range of 1.2-1.6 results in a more significant difference between the magnetic reluctance of the d-axis and q-axis magnetic circuits, which in turn leads to a more significant difference between the q-axis inductance and the d-axis inductance, thus facilitating the measurement of back EMF. A preferred salient pole ratio is 1.5.

[0038] In some embodiments, the main magnet 32 ​​is bonded to the inner wall of the hub assembly. It is understood that bonding simplifies the installation of the main magnet 32, facilitating the assembly of the outer rotor motor used in electric two-wheeled vehicles, and also improves the installation stability of the main magnet 32, preventing it from detaching.

[0039] In some embodiments, the hub assembly includes a fixed cover 11, a hub body 12, and an end cover 13 connected in sequence. Thus, the rotor assembly 30, the stator assembly 20, and the shaft assembly 40 can be installed on the hub body 12 first, and then the fixed cover 11 and the end cover 13 can be installed on both sides of the hub body 12, which facilitates assembly.

[0040] In some embodiments, the tooth tips of the rotor core 31 on the air gap side are arc-shaped structures convex toward the air gap side. It is understood that such a structure enables the external rotor motor for electric two-wheelers to have an air gap of unequal width under a salient pole, resulting in a more sinusoidal air gap magnetic flux density. This can reduce back EMF harmonics and torque pulsation, thereby giving the external rotor motor for electric two-wheelers better performance.

[0041] This utility model also discloses an electric two-wheeled vehicle, including a vehicle body and the aforementioned external rotor motor for the electric two-wheeled vehicle, the external rotor motor for the electric two-wheeled vehicle being mounted on the vehicle body. Due to the aforementioned external rotor motor for the electric two-wheeled vehicle, this electric two-wheeled vehicle has a low maintenance frequency and high reliability.

[0042] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0043] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An external rotor motor for an electric two-wheeled vehicle, characterized in that, The assembly includes a hub assembly, a stator assembly (20), a rotor assembly (30), and a shaft assembly (40). The hub assembly defines a mounting cavity, the rotor assembly (30) is mounted in the mounting cavity, the shaft assembly (40) passes through the mounting cavity, the stator assembly (20) is sleeved on the shaft assembly (40), the rotor assembly (30) is connected to the hub assembly and sleeved on the stator assembly (20), and the rotor assembly (30) includes a rotor core (31). The rotor core (31) is equipped with a plurality of main magnets (32) and a plurality of auxiliary magnets (33). The plurality of main magnets (32) are located on the outer peripheral wall of the rotor core (31) facing the hub assembly and are connected to the hub assembly. The plurality of auxiliary magnets (33) are located on the inner peripheral wall of the rotor core (31) facing the stator assembly (20); wherein: The main magnet (32) is magnetized radially along the rotor core (31), and the auxiliary magnet (33) is magnetized circumferentially along the rotor core (31).

2. The external rotor motor for an electric two-wheeled vehicle according to claim 1, characterized in that, The rotor core (31) has a plurality of first mounting slots (311) on its outer peripheral wall and a plurality of second mounting slots (312) on its inner side wall. The first mounting slots (311) and the second mounting slots (312) are used to install the main magnet (32) and the auxiliary magnet (33), respectively.

3. The external rotor motor for an electric two-wheeled vehicle according to claim 2, characterized in that, In the circumferential direction of the rotor core (31), a plurality of first mounting slots (311) and a plurality of second mounting slots (312) are staggered.

4. The external rotor motor for an electric two-wheeled vehicle according to claim 3, characterized in that, In the circumferential direction of the rotor core (31), the portion of the rotor core (31) located between the adjacent first mounting slot (311) and second mounting slot (312) forms a magnetic isolation bridge (313), the width of which is 0.5mm-1mm.

5. The external rotor motor for an electric two-wheeled vehicle according to claim 2, characterized in that, The first mounting slot (311) includes a first slot (3111) and a second slot (3112). Along the circumference of the rotor core (31), the width of the first slot (3111) is greater than that of the second slot (3112). A portion of the main magnet (32) is located in the first slot (3111) and another portion is located in the second slot (3112).

6. The external rotor motor for an electric two-wheeled vehicle according to claim 2, characterized in that, The second mounting slot (312) includes a third slot (3121) and a fourth slot (3122). Along the circumference of the rotor core (31), the width of the third slot (3121) is greater than that of the fourth slot (3122), and all the auxiliary magnets (33) are located in the third slot (3121).

7. The external rotor motor for an electric two-wheeled vehicle according to claim 1, characterized in that, The external rotor motor used in the electric two-wheeler has a salient pole ratio of 1.2-1.

6.

8. The external rotor motor for an electric two-wheeled vehicle according to claim 1, characterized in that, The main magnet (32) is bonded to the inner wall of the hub assembly.

9. The external rotor motor for an electric two-wheeled vehicle according to claim 1, characterized in that, The rotor core (31) has an arc-shaped tooth tip protruding towards the air gap side on the air gap side.

10. An electric two-wheeled vehicle, characterized in that, It includes a vehicle body and an external rotor motor for an electric two-wheeled vehicle as described in any one of claims 1-9, wherein the external rotor motor for the electric two-wheeled vehicle is mounted on the vehicle body.

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