Motor stator, motor, and vehicle power system

Abstract

Provided are a motor stator, comprising a housing (1), an iron core (2), a winding (3), and bobbins (4). The bobbins (4) are attached to the iron core (2), and coils of the winding (3) are wound around winding teeth (2t) of the iron core (2) by means of corresponding bobbins (4). The housing (1), the iron core (2) and the bobbins (4) define an annular flow path (P) extending in the circumferential direction, the end of an axial side of the winding (3) is located in the annular flow path (P), and the housing (1) is provided with an inlet hole (11h), so that a cooling fluid entering the annular flow path (P) through the inlet hole (11h) can flow along winding slots to the end of the other axial side of the winding (3). In this way, the cooling structure of the motor stator is formed in a relatively simple structure, thereby effectively cooling the motor stator. Also provided are a motor comprising the motor stator and a vehicle power system comprising the motor.

Description

Motor stator, motor, and vehicle power system Technical Field

[0001] The present application relates to the field of motors, and in particular to a motor stator with a cooling structure, a motor, and a vehicle power system including the motor. Background Art

[0002] Motors are used to output torque and power, and motor cooling is crucial for achieving these desired outputs. When a motor is operating at high efficiency, much of the energy lost is copper loss. Therefore, the cooling capacity of the motor's cooling structure for the windings is a significant factor influencing the motor's sustained output power under these conditions.

[0003] In existing motors, some cooling structures employ a spray cooling mechanism. For example, the cooling structure may be designed with nozzles that spray cooling fluid (such as cooling oil) directly onto the windings to remove heat. Other cooling structures employ an immersion cooling mechanism. For example, flow paths extending circumferentially and axially are formed within the motor stator, allowing at least a portion of the windings to be immersed in the cooling fluid within the flow paths, thereby cooling the windings. In the latter case, the structure defining the flow paths is typically complex and prone to leakage, resulting in high pumping losses.

[0004] Summary of the Invention

[0005] This application is made in light of the state of the prior art described above. One object of this application is to provide a motor stator and a motor including such a stator. Within the cooling structure of the motor stator, a relatively simple structure is used to implement a flow path for cooling fluid flow, thereby effectively cooling the windings of the motor stator and reducing the adverse effects of excessively high stator temperatures during motor operation. Another object of this application is to provide a vehicle power system including such a motor.

[0006] In order to achieve the above-mentioned purpose of the invention, this application adopts the following technical solutions.

[0007] The present application provides a motor stator as follows, comprising:

[0008] a housing having a cylindrical body and an annular sidewall, wherein the annular sidewall extends radially inward from one axial end portion of the cylindrical body;

[0009] an iron core located radially inward of the cylindrical body and on the other axial side of the annular side wall, the iron core being fixed to the cylindrical body and having a plurality of winding teeth spaced apart and distributed in the circumferential direction of the motor stator, with a winding slot defined between every two adjacent winding teeth;

[0010] a winding comprising a plurality of coils, the coils being wound around corresponding winding teeth so that the winding is mounted on the core; and

[0011] a bobbin attached to the iron core, the coil being wound around the winding teeth via the corresponding bobbin;

[0012] The shell, the iron core and the winding bobbin surround and form an annular flow path extending along the circumferential direction, and one axial end of the winding is located in the annular flow path. The shell is formed with an entry hole so that the cooling fluid entering the annular flow path through the entry hole can flow along the winding groove to the other axial end of the winding.

[0013] In an optional scheme, the cylindrical body constitutes the outer peripheral wall of the annular flow path, the winding drum constitutes the inner peripheral wall of the annular flow path, and the annular side wall constitutes the side wall of the annular flow path. The outer peripheral wall defines the annular flow path from the radial outside, the bottom defines the annular flow path from the radial inside, and the side wall defines the annular flow path from one axial side.

[0014] In another optional solution, the entry hole is formed in the outer peripheral wall and passes through the outer peripheral wall.

[0015] In another optional solution, when the motor stator is installed in place with its axial direction parallel to the horizontal plane, the inlet hole is located at the uppermost part of the outer peripheral wall in the vertical direction.

[0016] In another optional solution, the motor stator is a stator of a concentrated winding motor, the winding bobbin has a first end tooth portion and a second end tooth portion extending toward one side axially relative to the iron core, the first end tooth portion is located radially outside the second end tooth portion, a plurality of the first end tooth portions of the winding bobbin are arranged along the circumferential direction, and a plurality of the second end tooth portions of the winding bobbin are arranged along the circumferential direction.

[0017] The outer peripheral wall is located radially outside the first end tooth portion, and the second end tooth portions of the plurality of bobbins abut against the annular side wall and constitute the inner peripheral wall.

[0018] In another optional solution, the annular side wall is formed with an annular mounting portion protruding toward the winding drum, and the second end teeth of the plurality of winding drums are integrally mounted on the annular mounting portion from the radial outside.

[0019] In another optional solution, the second end teeth of the plurality of winding reels are integrally mounted on the annular mounting portion through clearance fit or transition fit.

[0020] In another optional solution, the second end teeth of the plurality of winding reels abut against the annular side wall from the other axial side.

[0021] The present application also provides the following motor, comprising the motor stator described in any one of the above technical solutions.

[0022] The present application also provides a vehicle power system as follows, comprising the motor described in the above technical solution.

[0023] By adopting the above-mentioned technical solution, the present application provides a motor stator, a motor, and a vehicle power system including the motor. In the motor stator of the present application, an annular flow path for cooling fluid is formed by enclosing the housing, the iron core, and the winding bobbin. One end of the winding can be immersed in the cooling medium in the annular flow path, and the cooling fluid entering the annular cooling flow path can flow from the position of the axial end of the winding on one side to the position of the axial end of the winding on the other side via an axial flow path in the iron core (for example, located between adjacent coils). Thus, in the technical solution of the present application, a cooling structure for the motor stator is formed with a relatively simple structure, thereby effectively cooling the motor stator and reducing the adverse effects that may be caused by excessive temperature during operation of the motor stator. Moreover, effective cooling of the motor stator can increase the continuous output power of the motor and extend the service life of the motor. Furthermore, the cooling fluid is input into the annular flow path from the inlet hole and then discharged through the axial flow path, so that the cooling fluid in the annular flow path can achieve dynamic balance under continuous renewal, thereby improving the cooling effect on the winding. The above-mentioned solution of the present application is particularly suitable for concentrated winding motors with smaller sizes (especially smaller axial sizes). BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1A is a perspective schematic diagram showing a partial structure of a motor according to an embodiment of the present application.

[0025] FIG. 1B is another schematic perspective view showing the structure in FIG. 1A .

[0026] FIG. 1C is a partial cross-sectional schematic diagram showing the structure in FIG. 1A , in which hatching is omitted.

[0027] FIG. 2A is a perspective schematic diagram showing a housing of the motor in FIG. 1A .

[0028] FIG. 2B is a schematic cross-sectional view showing the housing in FIG. 2A , in which hatching is omitted.

[0029] FIG. 3A is a perspective schematic diagram showing an assembly of the core, winding, and bobbin of the motor in FIG. 1A .

[0030] FIG. 3B is an enlarged schematic diagram showing a partial structure of the assembly in FIG. 3A .

[0031] DESCRIPTION OF REFERENCE NUMERALS 1 housing; 11 cylindrical body; 11h entry hole; 12 annular side wall; 12p annular mounting portion; 2 iron core; 2t winding tooth; 3 winding; 4 bobbin; 41 first end tooth portion; 42 second end tooth portion; P annular flow path; A axial direction; R radial direction. DETAILED DESCRIPTION

[0032] The specific embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible methods of the present application, nor to limit the scope of the present application.

[0033] In this application, unless otherwise specified, "axial," "radial," and "circumferential" refer to the axial, radial, and circumferential directions of the motor, respectively. "Axial side" refers to the left side in Figure 1C , and "axial opposite side" refers to the right side in Figure 1C . "Radially outer" refers to the side radially away from the central axis of the motor, such as the upper side in Figure 1C , and "radially inner" refers to the side radially closer to the central axis of the motor, such as the lower side in Figure 1C .

[0034] The motor according to one embodiment of the present application is a centralized winding motor, which mainly includes a housing, a motor stator, a motor rotor and a shaft. The motor stator, the motor rotor and the shaft are coaxially arranged and basically located in the space surrounded by the housing. The motor stator is fixed to the housing, and the motor stator includes an iron core and a winding. The motor rotor is located radially inward of the motor stator and can rotate relative to the motor stator, and there is an air gap between the motor rotor and the motor stator. The shaft and the motor rotor can be fixed together, and the shaft is located radially inward of the motor rotor. Furthermore, the motor according to one embodiment of the present application is provided with a cooling structure for cooling the motor stator. In this cooling structure, cooling oil is used as a cooling fluid to cool the iron core and winding of the motor stator (especially the axial end of the coil of the winding). Therefore, the motor according to one embodiment of the present application is an oil-cooled motor.

[0035] The following will describe the specific structure of a motor according to an embodiment of the present application with reference to the accompanying drawings, and in particular describe a cooling structure for cooling the stator of the motor.

[0036] As shown in Figures 1A to 1C, the motor according to one embodiment of the present application includes a shell 1, an iron core 2, a winding 3 and a bobbin 4 assembled together, and the iron core 2, the winding 3 and the bobbin 4 are all fixed together with the shell 1, wherein the iron core 2, the winding 3 and the bobbin 4 constitute the motor stator.

[0037] In this embodiment, as shown in Figures 1A to 1C and Figures 2A and 2B, the housing 1 includes an integrally formed cylindrical body 11 and an annular sidewall 12. The cylindrical body 11 is cylindrical and positioned radially outward of the core 2, winding 3, and bobbin 4. The cylindrical body 11 and the core 2 can be fixed together via an interference fit. The cylindrical body 11 is formed with an inlet hole 11h extending radially R through the cylindrical body 11, allowing cooling fluid to enter the annular flow path P formed by the housing 1, the core 2, and the bobbin 4 through the inlet hole 11h of the housing 1. The annular sidewall 12 is annular and positioned axially on one side of the core 2, winding 3, and bobbin 4. The annular sidewall 12 extends radially inward for a predetermined distance from one axial end of the cylindrical body 11 and extends continuously along the entire circumference to protect the components within the housing 1. Furthermore, an annular mounting portion 12p is formed on the annular sidewall 12, protruding toward the bobbin 4 (that is, toward the other axial side). This annular mounting portion 12p extends continuously along the entire circumference. The annular mounting portion 12p cooperates with the second end teeth 42 of the bobbin 4, allowing the second end teeth 42 to overlap the annular mounting portion 12p from the radially outer side. Consequently, all second end teeth 42 of the bobbin 4 are integrally fitted onto the annular mounting portion 12p.

[0038] In this embodiment, as shown in Figures 1A to 1C and Figures 3A and 3B, the iron core 2 includes a plurality of winding teeth 2t. The plurality of winding teeth 2t protrude radially inward and are spaced apart in the circumferential direction. A winding slot is defined between every two circumferentially adjacent winding teeth 2t, each winding slot passes through the iron core 2 along the axial direction A and each winding slot has a radial opening open toward the radial inside, and the radial opening is basically closed by the second end tooth portion 42. Furthermore, the iron core 2 is fixed to the cylindrical body 11 of the housing 1 by an interference fit as a whole, and the entire iron core 2 is basically located radially inside the cylindrical body 11.

[0039] In this embodiment, as shown in Figures 1A to 1C and Figures 3A and 3B, the winding 3 is mounted on the iron core 2, with each coil of the winding 3 wound around a corresponding winding tooth 2t. The winding 3 can be composed of a copper conductor coated with an insulating material. During the winding process, the coils of the winding 3 pass through the winding slots adjacent to the winding teeth 2t. Two adjacent coils in the same winding slot can be spaced apart or partially contact each other, thereby forming an axial flow path in the winding slot that extends along the axial direction A through the iron core 2. Cooling fluid in the annular flow path P can flow through the axial flow path to the location of the other axial end of the winding 3.

[0040] In this embodiment, the bobbin 4 (also referred to as a winding frame) is made of an insulating material. The bobbin 4 can be attached to the core 2 by secondary molding, or the bobbin 4 can be manufactured separately and fixedly attached to the core 2 by other mechanical means. As shown in Figures 1B and 1C, each winding tooth 2t corresponds to a bobbin 4, and each bobbin 4 is attached to the corresponding winding tooth 2t. On the one hand, the bobbin 4 is used to support the coil wound on the winding tooth 2t, and on the other hand, the bobbin 4 serves as secondary insulation between the coil and the core 2.

[0041] As shown in Figure 1C, the bobbin 4 has a first end tooth portion 41 and a second end tooth portion 42 that extend axially toward one side relative to the core 2. The first end tooth portions 41 of the bobbin 4 are closely arranged circumferentially, such that there is essentially no gap between adjacent first end tooth portions 41, and all first end tooth portions 41 form a ring-shaped structure extending continuously along the circumference. The second end tooth portions 42 of the bobbin 4 are arranged circumferentially, such that there is essentially no gap between adjacent second end tooth portions 42, and all second end tooth portions 42 form a ring-shaped structure extending continuously along the circumference. The first end tooth portion 41 is located radially outward of the second end tooth portion 42. The first end tooth portion 41 and the second end tooth portion 42 are spaced apart from each other in the radial direction R. The axial end portion of the coil of the winding 3 is located between the first end tooth portion 41 and the second end tooth portion 42 in the radial direction R.

[0042] Furthermore, as shown in Figures 1B and 3A, the second end teeth 42 close the radial opening of the winding slot. Furthermore, as shown in Figures 1C and 3B, the axial length of the second end teeth 42 extending from the core 2 toward one side is greater than the axial length of the first end teeth 41 extending from the core 2 toward the other side. Consequently, each second end tooth 42 can overlap the annular mounting portion 12p of the annular sidewall 12 of the housing 1 from the radially outer side, allowing all second end teeth 42 to be integrally mounted within the annular mounting portion 12p. Furthermore, the second end teeth 42 can abut against the main portion of the annular sidewall 12 from the other axial side. A clearance fit or transition fit can be employed between the second end teeth 42 and the annular mounting portion 12p. Even if a slight gap exists between the second end teeth 42 and the annular mounting portion 12p, this does not affect the filling of the annular flow path P with cooling fluid. This mounting structure requires no additional components, simplifies assembly, and is less prone to loosening, thereby reducing manufacturing and assembly costs.

[0043] By adopting the above arrangement, an annular flow path P is formed by the housing 1, the core 2, and the bobbin 4. The cylindrical body 11 forms the outer circumferential wall of the annular flow path P, the second end teeth 42 of the bobbin 4 form the inner circumferential wall of the annular flow path P, and the annular sidewall 12 forms the side wall of the annular flow path P. The outer circumferential wall is located radially outward of the inner circumferential wall, defining the annular flow path P from the radially outward side, while the inner circumferential wall defines the annular flow path from the radially inward side. The sidewall defines the annular flow path P from one axial direction and extends from the outer circumferential wall toward the inner circumferential wall while also extending obliquely toward one axial direction.

[0044] Furthermore, to allow cooling fluid to enter the annular flow path P through inlet hole 11h and then exit from the other axial side of the core 2 via the aforementioned axial flow path, thereby achieving dynamic equilibrium in the annular flow path P while constantly being refreshed, inlet hole 11h is formed in and extends through the outer peripheral wall. In this embodiment, when the motor is installed with its axial direction A parallel to the horizontal plane, inlet hole 11h is positioned vertically at the uppermost portion of the outer peripheral wall. This further facilitates the smooth filling of the annular flow path P by the cooling fluid entering through inlet hole 11h under the action of gravity.

[0045] By adopting the above-mentioned solution, the motor according to one embodiment of the present application forms an annular flow path P with relatively good sealing performance with a relatively simple structure. The cooling fluid can enter and fill the annular flow path P through the inlet hole 11h, and the cooling fluid can flow out through the axial flow path formed by the winding grooves of the iron core 2, so that the cooling fluid can achieve dynamic balance while being constantly updated, thereby continuously cooling all parts of the winding 3 well. In this way, the adverse effects caused by the excessive temperature of the motor stator during the operation of the motor can be reduced. Moreover, the cooling structure of the motor of the present application is simple in structure, and no additional components need to be designed, thereby reducing the corresponding cost.

[0046] It should be understood that the above embodiments are merely illustrative and are not intended to limit the present application. Those skilled in the art may, based on the teachings of this application, make various modifications and alterations to the above embodiments without departing from the scope of this application. The following is a supplementary explanation of the technical solution of this application.

[0047] i. This application also provides a vehicle power system comprising the motor described herein. This vehicle power system may be an electric bridge drive system, which may further include a transmission mechanism, such as a transmission, with the motor being coupled to the input shaft of the transmission to achieve bidirectional torque transmission. This electric bridge drive system may serve as a drive system for a pure electric vehicle, or it may be used in conjunction with an engine to form a hybrid power system for a hybrid vehicle.

[0048] ii. In the technical solution of the motor of the present application, an oil supply system connected to the inlet hole 11h of the housing 1 may be provided on the outside of the motor housing 1. The oil supply system may include a pump and an oil circuit (oil pipe), etc., so that cooling oil serving as a cooling fluid can be supplied to the cooling structure by using the oil supply system.

[0049] iii. In a modified example of the motor of the present application, the inlet hole 11h may be formed in other locations such as the side wall, and the structures of other components may be appropriately changed so that the cooling fluid can flow into the annular flow path P through the inlet hole 11h and then be discharged.

[0050] iv. It will be appreciated that the technical solution of the present application is particularly suitable for concentrated winding motors, in which the axial dimension of the iron core 2 can be relatively small. This facilitates continuous renewal of the cooling fluid within the annular flow path P, requiring only a relatively small amount of cooling fluid to fill the entire annular flow path P.

[0051] v. In one example, the bobbin 4 can be made of plastic and fixedly connected to the core 2 via an injection molding process, for example, wrapped around the radially intermediate position (of the motor stator) of the winding teeth 2t of the core 2. In one example, the bobbin 4 can be an integral piece (single piece) formed via an injection molding process.

[0052] vi. The motor stator shown in the figures and described above is one of the subjects of this application and can constitute a separate product.

Claims

1. A motor stator, comprising: A housing (1) having a cylindrical main body (11) and an annular side wall (12), the annular side wall (12) extending radially inward from an axial end portion on one side of the cylindrical main body (11); A core (2) located radially inside the cylindrical main body (11) and on the other axial side of the annular side wall (12), the core (2) being fixed to the cylindrical main body (11), and the core (2) having a plurality of winding teeth (2t) spaced apart circumferentially of the motor stator, with a winding slot defined between every two adjacent winding teeth (2t); A winding (3) including a plurality of coils wound around corresponding winding teeth (2t) such that the winding (3) is mounted on the core (2); and A winding bobbin (4) attached to the core (2), the coils being wound around the winding teeth (2t) via corresponding winding bobbins (4), The housing (1), the core (2) and the winding bobbin (4) enclose and form an annular flow path (P) extending along the circumferential direction, an axial end portion on one side of the winding (3) is located in the annular flow path (P), and the housing (1) is formed with an inlet hole (11h) such that the cooling fluid entering the annular flow path (P) via the inlet hole (11h) can flow along the winding slot to the axial end portion on the other side of the winding (3).

2. The motor stator according to claim 1, wherein The cylindrical main body (11) constitutes the outer peripheral wall of the annular flow path (P), the winding bobbin (4) constitutes the inner peripheral wall of the annular flow path (P), the annular side wall (12) constitutes the side wall of the annular flow path (P), the outer peripheral wall defines the annular flow path (P) from the radial outside, the bottom defines the annular flow path (P) from the radial inside, and the side wall defines the annular flow path (P) from one axial side.

3. The motor stator according to claim 2, wherein The inlet hole (11h) is formed in and penetrates the outer peripheral wall.

4. The motor stator according to claim 3, wherein In a state where the motor stator is installed in place with its axis (A) parallel to the horizontal plane, the inlet hole (11h) is located at the uppermost part of the outer peripheral wall in the vertical direction.

5. The motor stator according to any one of claims 2 to 4, wherein The motor stator is a stator of a concentrated winding motor, the winding bobbin (4) has a first end tooth portion (41) and a second end tooth portion (42) protruding axially toward one side with respect to the core (2), the first end tooth portion (41) is located radially outside the second end tooth portion (42), the first end tooth portions (41) of a plurality of winding bobbins (4) are arranged along the circumferential direction, and the second end tooth portions (42) of a plurality of winding bobbins (4) are arranged along the circumferential direction, The outer peripheral wall is located radially outside the first end tooth portion (41), and the second end tooth portions (42) of a plurality of winding bobbins (4) abut against the annular side wall (12) and constitute the inner peripheral wall.

6. The motor stator according to claim 5, wherein The annular side wall (12) is formed with an annular mounting portion (12p) protruding toward the winding bobbin (4), and the second end tooth portions (42) of a plurality of winding bobbins (4) are integrally sleeved on the annular mounting portion (12p) from the radial outside.

7. The motor stator according to claim 6, wherein The second end tooth parts (42) of multiple said winding cylinders (4) are integrally installed on the annular installation part (12p) through clearance fit or interference fit.

8. The motor stator according to claim 6, wherein The second end tooth parts (42) of multiple said winding cylinders (4) abut against the annular side wall (12) from the other axial side.

9. A motor, comprising the motor stator according to any one of claims 1 to 8.

10. A vehicle power system, comprising the motor according to claim 9.

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