A water cooling device for a motor stator of a two-wheeled electric vehicle

Abstract

This utility model discloses a water-cooling device for the stator of a two-wheeled electric vehicle motor. The device includes a motor comprising a hub, a housing formed by an end cover mounted on the side of the hub, a motor shaft, and a cooling structure. The motor shaft passes through the hub and the end cover, and a stator is fitted into the center of the housing. The hub, along with a magnet seat mounted on its inner wall and the end cover, forms a rotor that rotates relative to the stator. An annular groove is provided on the side of the stator to accommodate the cooling structure. The cooling structure stores a cooling medium and circulates with other cooling media to remove heat generated during operation, thus cooling the motor. This utility model dissipates heat from the motor by using a built-in cooling structure near the stator and rotor close to the hub, preventing excessively high local temperatures during motor operation and ensuring good cooling for the motor under any operating conditions.

Description

Technical Field

[0001] This utility model relates to the field of electric vehicle motor technology, specifically a water-cooling device for the stator of a two-wheeled electric vehicle motor. Background Technology

[0002] As a core component of electric vehicles, the hub motor's main function is to provide continuous and stable power. When riding an electric two-wheeler, especially during starting, uphill, or heavy load conditions, the motor is prone to overheating and may even burn out, seriously affecting its normal operation. Therefore, appropriate measures should be taken to cool the motor.

[0003] Currently, liquid-cooled hub motors are widely used in electric vehicles due to their superior heat dissipation. In related technologies, liquid-cooled hub motors in electric vehicles typically circulate a cooling medium (such as water) into the motor hub, bringing it as close as possible to the rotor and its coils. This requires a high degree of sealing between the cooling medium and the rotor and its coils. However, this increases the structural complexity or number of components in the liquid-cooled hub motor, thereby increasing the difficulty of manufacturing. Utility Model Content

[0004] The purpose of this invention is to provide a water-cooling device for the stator of a two-wheeled electric vehicle motor, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A water-cooling device for the stator of a two-wheeled electric vehicle motor includes a motor. The motor includes a housing consisting of a hub, an end cover mounted on the side of the hub, a motor shaft, and a cooling structure. The motor shaft passes through the hub and the end cover, and a stator located inside the housing is fitted in the middle. The hub, a magnet seat mounted on its inner wall, and the end cover constitute a rotor that rotates relative to the stator. The side of the stator has an annular groove for accommodating the cooling structure. The cooling structure stores a cooling medium and can circulate with a cooling medium outside the cooling structure to remove the heat generated during operation, thereby achieving heat dissipation and cooling of the motor.

[0006] Furthermore, the cooling structure includes a thin-walled housing that is enclosed in an annular groove and fitted onto the motor shaft, the housing serving as a sealed space for storing the cooling medium.

[0007] Furthermore, a gap is reserved between the box body and the end cap, and the wall thickness of the box body is much smaller than the wall thickness of the end cap.

[0008] Furthermore, the housing wall near the motor shaft is sloped from the inside out.

[0009] Furthermore, the housing is fixed to the annular inner groove of the stator or to the motor shaft.

[0010] Furthermore, the motor shaft has an axial channel communicating with the housing.

[0011] Furthermore, the channel includes an inlet channel and an outlet channel that are independent of each other.

[0012] Furthermore, the end cap is mounted to the motor shaft via bearings.

[0013] Furthermore, the inner end of the liquid outlet channel has an extension section.

[0014] Furthermore, the cooling medium is water, ethylene glycol coolant, or propylene glycol coolant.

[0015] Compared with the prior art, the beneficial effects of this utility model are: This invention utilizes a cooling structure within the built-in housing near the stator to dissipate heat from the motor hub, protecting the stator permanent magnet poles from demagnetization and preventing the rotor's excitation windings from burning out. This results in a lower failure rate, reduced operating costs, increased lifespan, and optimal motor efficiency and performance.

[0016] This invention dissipates heat from the motor hub (including the stator and rotor) through a cooling structure located near the stator within the built-in housing. This solves the problem of low efficiency in most existing electric vehicle motor hubs, which rely on air convection for cooling during riding. An appropriate amount of cooling medium is added to the sealed space, and a circulating pump connected to the outside via inlet and outlet channels pumps the cooling medium in and out of the sealed space, forming a cooling medium circulation loop that actively circulates and cools the motor hub. This ensures uniform heat dissipation from the hub, stator, and rotor, preventing localized overheating and ensuring good cooling of the motor under any operating conditions.

[0017] Compared to existing liquid-cooled hub motors, this invention eliminates the need to circulate the cooling medium (such as water) into the motor hub as close as possible to the rotor and its coils. This avoids the need to redesign the piping entering the hub, achieving better heat dissipation and cooling of the motor hub while minimizing or avoiding the addition of structural or component changes that would increase the overall manufacturing difficulty. Furthermore, the cooling structure is built into the housing and within the annular groove reserved in the stator, close to the stator and rotor of the motor. This utilizes the heat absorption of the cooling medium within the housing to dissipate heat and cool the motor. Without increasing design complexity, this invention is suitable for motors used in two-wheeled and three-wheeled vehicles. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the structure of Embodiment 1 of this utility model.

[0019] Figure 2 This utility model Figure 1 A diagram showing the removal of one end cap.

[0020] Figure 3 This utility model Figure 2 A diagram showing the box without its casing.

[0021] Figure 4 This utility model Figure 1 A cross-sectional view along point AA.

[0022] Figure 5 This is a structural schematic diagram of Embodiment 2 of the present invention.

[0023] In the diagram: 1-motor, 2-hub, 3-end cover, 4-motor shaft, 5-stator, 6-magnet, 7-box, 8-channel, 9-annular groove, 10-inlet channel, 11-outlet channel, 12-sloping shape, 13-bearing, 14-extension section, 15-locking screw. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] In the description of this utility model, it should be noted that the terms "upper end," "lower end," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, 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 used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within 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.

[0027] Example 1 Please see Figures 1 to 4 This utility model provides a technical solution: A water-cooling device for the stator of a two-wheeled electric vehicle motor includes a motor 1. The motor 1 includes a housing consisting of a hub 2, an end cover 3 mounted on the side of the hub 2, a motor shaft 4, and a cooling structure. The motor shaft 4 passes through the hub 2 and the end cover 3, and a stator 5 is fitted in the middle of the housing. The hub 2, a magnet 6 seat mounted on its inner wall, and the end cover 3 constitute a rotor that rotates relative to the stator 5. The side of the stator 5 has an annular groove 9 for accommodating the cooling structure. The cooling structure stores a cooling medium and can circulate with a cooling medium outside the cooling structure to remove the heat generated by the motor 1 during operation, thereby achieving heat dissipation and cooling of the motor 1.

[0028] It should be noted that this embodiment adds a cooling structure and an inlet / outlet channel 8 to the motor shaft 4 along the existing hub motor of two-wheeled or three-wheeled electric vehicles, etc. Other parts remain unchanged, and the structural layout is consistent with the existing related hub motor structures. Figure 2 or Figure 4 As shown, for example, magnets 6 are installed around the inside of the hub 2. The hub 2, magnets 6, and end caps 3 on the side serve as the rotor. A stator 5 is fitted in the middle of the motor shaft 4, thereby enabling the rotor to rotate relative to the stator 5.

[0029] When motor 1 is operating, the housing and its internal magnets 6 rotate relative to the motor shaft 4. The hub 2 is used to mount the tire, while the motor shaft 4 is mounted to the rear fork of the frame. During rotation, the stator's excitation windings heat up, causing the entire motor to heat up, especially during starting, uphill driving, and heavy loads. Therefore, cooling is necessary to ensure normal operation. Cooling medium is injected into the cooling structure, which is close to the stator. The cooling medium absorbs heat, thus actively cooling the motor.

[0030] Specifically, the cooling structure comprises a thin-walled box body 7, the box body 7 is wrapped in the annular inner groove 9 and sleeved on the motor shaft 4, and the box body 7 serves as a sealed space for storing cooling medium. A gap is reserved between the box body 7 and the end cover 3, and the wall thickness of the box body 7 is far smaller than that of the end cover 3.

[0031] In this embodiment, an annular inner groove 9 is reserved on one side surface and / or both side surfaces of the stator 5 to serve as a space for adaptively installing and accommodating the box body 7. That is, the shape of the box body 7 is consistent with that of the annular inner groove 9. Of course, the shape of the annular inner groove 9 is not limited to an annular shape, and other shapes can be set according to actual conditions. Moreover, the diameter and depth of the annular inner groove 9 can also be flexibly designed according to actual conditions. For example, for a 10-inch (33.33 cm) hub 2, the stator 5 is in a "匚" shape, with a maximum thickness of 9 cm and a minimum thickness of 3 cm, the annular groove 3 is 6 inches, with a depth of 3 cm, the channel 8 has a diameter of 2 cm, and the liquid inlet channel 10 and the liquid outlet channel 11 have a diameter of 1 cm. Other suitable sizes can also be selected, which will not be repeated herein. The wall of the box body 7 is a thin-walled wall, for example, the wall thickness is 5 mm, which not only reduces the weight of the whole motor, but also enables the cooling medium in the box body to achieve a good heat dissipation effect on the motor on the basis of ensuring the strength.

[0032] In this embodiment, the box body 7 is installed and fixed with the annular inner groove 9 of the stator 5. The two can be fixed by welding or bolt connection. Alternatively, the box body 7 and the motor shaft 4 are installed and fixed. For the fixing mode of the two, the motor shaft 4 can be provided with a square groove, or the two are sleeved together for interference fit, or fixed by bolts. That is to say, in this embodiment, the cooling structure / box body 7 and the motor shaft 4 are relatively fixed and will not rotate. On one hand, the rotation load of the rotor will not be increased, and on the other hand, it is convenient for the cooling structure / box body 7 to circulate with the cooling medium outside the cooling structure / box body through the channel 8. This design will not increase the manufacturing difficulty of the motor, and since the cooling structure / box body 7 does not rotate, it is also easy to realize the internal and external circulation of the cooling medium.

[0033] Specifically, a box wall of the box body 7 close to the motor shaft 4 is in a slope shape 12 inclined from inside to outside. As Figure 4 shown, there is a shaft hole for the motor shaft 4 to penetrate through in the center of the box body 7, the box wall at the shaft hole of the box body 7 is inclined, and is in the slope shape 12 inclined from inside to outside. This design has at least the following advantages: during circulation, the new cooling medium entering the box body 7 through the liquid inlet channel 10 uniformly absorbs heat and then gathers outward, so as to flow to the liquid outlet channel 11, facilitating external discharge through the liquid outlet channel 11 when circulation is required.

[0034] Specifically, the end cap 3 and the motor shaft 4 are mounted together via a bearing 13 equipped with an oil seal. The motor shaft 4 has an axial channel 8 communicating with the housing 7. The channel 8 includes an independent liquid inlet channel 10 and a liquid outlet channel 11. In this embodiment, the bearing 13 enables the housing and magnet 6 to rotate smoothly relative to the motor shaft 4. The channel 8 allows the cooling medium located outside the housing 7 to circulate into the housing 7.

[0035] Specifically, the housing 7 is fixed to the annular inner groove 9 of the stator 5 or to the motor shaft 4. The cooling medium is water, ethylene glycol coolant, or propylene glycol coolant.

[0036] In this embodiment, an appropriate amount of cooling medium can be injected into the sealed space formed by the housing 7. When the motor 1 rotates, the cooling medium absorbs the heat generated by the motor (especially the stator part) and can effectively cool the motor. In this way, the entire motor 1 has a good heat dissipation effect. Even if the motor is running under heavy load, the resistance of the motor windings will not increase and the thermal attenuation will be avoided due to the cooling medium. The temperature of the motor windings will be kept within a stable range so that the magnetic field torque of the motor excitation winding will not decrease, thereby avoiding the reduction of motor efficiency and overall machine performance.

[0037] In this embodiment, cooling medium can be added to the sealed space through channel 8. Channel 8 includes an inlet channel 10 and an outlet channel 11. In this way, cooling medium is added to the sealed space through the inlet channel 10. The added cooling medium enters the sealed space from the outlet of the inlet channel 10. The outlet channel 11 is connected to an external circulation pump. The cooling medium that has absorbed heat and increased in temperature is drawn out from the sealed space from the outlet of the outlet channel 11, so that the cooling medium can form a circulation in the sealed space to achieve cooling and heat dissipation.

[0038] like Figure 3 As shown, since the sealed space formed by the housing 7 is fixed relative to the motor shaft 4, there is no need to consider measures such as sealing rings to prevent leakage of the cooling medium in the housing 7. It is only necessary to use a conventional bearing 13 equipped with an oil seal to enable the housing and rotor to rotate relative to the motor shaft 4. This design makes the production and manufacturing of the entire motor relatively easy under the existing technology, without increasing the need for improvements to the sealing design or adding too many extra motor structures or parts.

[0039] like Figure 1 As shown, the end cap 3 is fixed to the side of the hub 2 by locking screws 15 to form a housing, which is used to surround the sealing stator, etc. A transparent window can be provided on the end cap 3, or the end cap 4 and the housing 7 themselves can be transparent (such as tempered glass or acrylic). This facilitates observation of the cooling medium usage within the sealed space, increasing visibility.

[0040] The cooling medium of this invention can be water, ethylene glycol coolant, propylene glycol coolant, etc., and can be flexibly selected according to the actual situation. This embodiment selects water, which can save production and manufacturing costs.

[0041] In this embodiment, one end of each of the two tubes is inserted into the inlet channel 10 and the outlet channel 11, respectively. The other ends of the two tubes are then connected to an external circulation pump and a circulation tank containing the cooling medium, thus forming a circulation. The circulation pump can be controlled by a controller to pump the cooling medium from the external circulation tank into the sealed space for circulation and cooling. Alternatively, a temperature sensor can be placed in the sealed space to monitor the temperature of the cooling medium. When the temperature exceeds a set value, the controller will control the circulation pump (stopping according to the set running time or stopping when the temperature in the sealed space drops to the set value) to pump the cooling medium from the external circulation tank into the sealed space to form a circulation cooling.

[0042] In this embodiment, only two axial channels can be used, and then the channels are used to insert two pipes as liquid inlet channel 10 and liquid outlet channel 11 for the inlet and outlet of cooling medium.

[0043] Example 2 Please see Figure 5 This utility model provides a technical solution that is basically the same as that in Embodiment 1, except that: The inner end of the liquid outlet channel 11 has an extension section 14. Cooling medium is added to the sealed space through the liquid inlet channel 10. The added cooling medium enters the sealed space through the extension section 14 of the liquid inlet channel 10. The cooling medium, after absorbing heat and increasing in temperature, is drawn out of the sealed space through the liquid outlet channel 11 via an external circulation pump, allowing the cooling medium to circulate within the sealed space for cooling and heat dissipation. The extension section 14 is generally L-shaped, with its bottom extending into the bottom of the sealed space, which can draw out as much of the heated coolant as possible from the sealed space, thereby achieving heat dissipation and cooling of the motor hub 2.

[0044] This invention utilizes a cooling structure within the built-in housing near the stator to dissipate heat from the motor hub, protecting the stator permanent magnet poles from demagnetization and preventing the rotor's excitation windings from burning out. This results in a lower failure rate, reduced operating costs, increased lifespan, and optimal motor efficiency and performance.

[0045] This invention dissipates heat from the motor hub (including the stator and rotor) through a cooling structure located near the stator within the built-in housing. This solves the problem that most existing electric vehicle motor hubs rely on convection airflow for cooling, resulting in low natural heat dissipation efficiency. An appropriate amount of cooling medium is added to the sealed space, and then a circulating pump connected to the outside via the inlet channel 10 and outlet channel 11 pumps the cooling medium in and out of the sealed space, forming a cooling medium circulation loop to actively circulate and cool the motor hub. This ensures uniform heat dissipation from the hub, stator, and rotor, preventing localized overheating and ensuring good cooling of the motor under any operating conditions.

[0046] Compared to existing liquid-cooled hub motors, this invention eliminates the need to circulate the cooling medium (such as water) into the motor hub as close as possible to the rotor and its coils. This avoids the need to redesign the piping entering the hub, achieving better heat dissipation and cooling of the motor hub while minimizing or avoiding the addition of structural or component changes that would increase the overall manufacturing difficulty. Furthermore, the cooling structure is built into the housing and is located within the annular groove 9 reserved in the stator, close to the stator and rotor of the motor. This allows the cooling medium within the housing 7 to absorb heat and cool the motor 1, making it suitable for motors used in two-wheeled and three-wheeled vehicles without increasing design complexity.

[0047] The parts of this utility model not described are existing technology or implemented using existing technology.

[0048] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A water cooling device for a motor stator of a two-wheeled electric vehicle, characterized by, The motor (1) includes a housing consisting of a hub (2), an end cover (3) mounted on the side of the hub (2), a motor shaft (4), and a cooling structure. The motor shaft (4) passes through the hub (2) and the end cover (3), and a stator (5) is installed in the middle of the housing. The hub (2), the magnet (6) seat mounted on its inner wall, and the end cover (3) constitute a rotor that rotates relative to the stator (5). The side of the stator (5) is reserved with an annular inner groove (9) for accommodating the cooling structure. The cooling structure is used to store the cooling medium and can circulate with the cooling medium outside the cooling structure to remove the heat generated by the operation of the motor (1) and realize the heat dissipation and cooling of the motor (1).

2. A water cooling device for the stator of an electric motor of a two-wheeled electric vehicle as claimed in claim 1, characterized in that, The cooling structure includes a housing (7), which is enclosed in an annular inner groove (9) and fitted onto the motor shaft (4). The housing (7) serves as a sealed space for storing the cooling medium.

3. A water-cooling device for the stator of a two-wheeled electric vehicle motor as described in claim 2, characterized in that, A gap is reserved between the box body (7) and the end cap (3), and the wall thickness of the box body (7) is less than the wall thickness of the end cap (3).

4. A water cooling device for the stator of an electric motor of a two-wheeled electric vehicle as claimed in claim 2, characterized in that, The housing (7) near the motor shaft (4) has a sloping wall that slopes from the inside out (12).

5. A water cooling device for the stator of an electric motor of a two-wheeled electric vehicle as claimed in claim 2, characterized in that, The housing (7) is installed and fixed to the annular inner groove (9) of the stator (5) or to the motor shaft (4).

6. A water cooling device for the stator of an electric motor of a two-wheeled electric vehicle, according to any one of claims 2 to 5, characterized in that, The motor shaft (4) has an axial channel (8) that communicates with the housing (7).

7. A water cooling device for the stator of an electric motor of a two-wheeled electric vehicle as claimed in claim 6, characterized in that, The channel (8) includes an inlet channel (10) and an outlet channel (11) that are independent of each other.

8. A water cooling device for the stator of an electric motor of a two-wheeled electric vehicle as claimed in claim 1, characterized in that, The end cap (3) and the motor shaft (4) are mounted together via bearing (13).

9. A water-cooling device for the stator of a two-wheeled electric vehicle motor as described in claim 7, characterized in that, The inner end of the liquid outlet channel (11) has an extension section (14).

10. A water cooling device for the stator of an electric motor of a two-wheeled electric vehicle as claimed in claim 1, characterized in that, The cooling medium is water, ethylene glycol coolant, or propylene glycol coolant.

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