A stator fixing structure and axial flux motor

Abstract

The present invention discloses a stator fixing structure and an axial flux motor, belonging to the field of motors. A stator fixing structure includes: a flow channel partition group, an external connection, a stator inner support, a first stator pressure plate and a second stator pressure plate; the stator fixing structure fixes the segmented stator; the first stator pressure plate and the second stator pressure plate are both concavely provided with a plurality of stator fixing grooves and convexly provided with a plurality of coil fixing grooves, the stator fixing grooves are tightly matched with the stator core, and the concave arcs at the bottom of the teeth of the coil fixing grooves clamp the stator coil; the first stator pressure plate and the second stator pressure plate fix and press the stator core and the stator coil, limiting the displacement of the stator core in the axial, radial and tangential directions, and limiting the displacement of the stator coil in the axial direction; the stator inner support has a plurality of positioning grooves to support the stator coil; the stator inner support and the flow channel partition group limit the displacement of the stator coil in the radial and tangential directions. It ensures that the stator has a fixing method in the axial, radial and tangential directions, which greatly improves the reliability of the stator.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and more specifically, relates to a stator fixing structure and an axial flux motor. Background Art

[0002] Axial flux permanent magnet motors (PMMs) have been widely used in recent years in equipment such as electric vehicles and wind turbines due to their flat, compact structure and high power density. To achieve higher power density and efficiency, the yokeless segmented stator (YASA) axial flux motor topology has become a popular choice for motor designers. However, the segmented stator core lacks a yoke connection, making it challenging to securely mount multiple segmented stators in a fixed position and securely connect them to other stator components.

[0003] At present, yokeless segmented armature axial flux permanent magnet motors include two structures: outer rotor and inner rotor. Although the stator core structures of the two motors are basically the same, the stator fixing methods are very different. In the patent application document with application number CN201810024665.4, a stator installation and fixing method for an inner rotor yokeless stator core disc motor is mentioned. Two fixing plates are bonded and fixed to multiple stator cores using epoxy glue. The stator assembly is then fixed in an annular housing and sealed with epoxy glue. However, this solution has the following defects: (1) There is no axial limit, and the end face of the stator core may be staggered; (2) The motor uses thermal conductive fixing glue to conduct heat from the stator core and coil, and the heat dissipation effect is limited, which is not conducive to improving the power density of the motor.

[0004] The patent application document with application number CN202010835768.6 mentions a stator installation and fixation method for an outer rotor yokeless stator core disc motor, which uses a stator bracket and a radial clamping block to fix the stator core and the coil sleeved on the stator core. The advantage of this solution is that the installation of the block stator is simple, and axial positioning parts are provided to ensure that the axial end faces of multiple stator blocks are in the same plane. However, this solution has the following defects: (1) The stator bracket occupies the space of the stator core and winding, limiting the improvement of the motor power density; (2) The stator bracket is made of aluminum alloy, which has high electrical conductivity and large eddy current loss.

[0005] Therefore, how to improve the reliability of the stator fixation of the yokeless segmented armature axial flux motor while ensuring the heat dissipation capacity of the motor stator is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] In view of the defects of the related art, the purpose of the present invention is to provide a stator fixing structure and an axial flux motor, aiming to solve the problem of how to improve the reliability of the stator fixation of the yokeless segmented armature axial flux motor while ensuring the heat dissipation capacity of the motor stator.

[0007] To achieve the above-mentioned object, in a first aspect, the present invention provides a stator fixing structure, comprising a flow channel baffle assembly, an external connection, a stator inner support, a first stator pressure plate, and a second stator pressure plate;

[0008] The stator fixing structure is used to fix the segmented stator, and the segmented stator includes a plurality of stator cores and a plurality of stator coils, and the stator coils are wound on the stator cores;

[0009] The first stator pressure plate and the second stator pressure plate are both circular plates with a central opening. The slotted end surfaces of the first stator pressure plate and the second stator pressure plate are arranged opposite to each other, the outer side surfaces are smooth, and the inner side surfaces are both concavely provided with a plurality of stator fixing slots and convexly provided with a plurality of coil fixing slots. The stator fixing slots and the coil fixing slots are evenly spaced and corresponding to each other along the circumference of the first stator pressure plate and the second stator pressure plate; the profile of the stator fixing slot is trapezoidal and closely matches the stator core; the profile of the coil fixing slot is gear-shaped, and the concave arc at the bottom of the tooth is used to clamp the stator coil;

[0010] The first stator pressure plate and the second stator pressure plate fix and press the stator core, limiting the displacement of the stator core in the axial, radial and tangential directions; at the same time, the first stator pressure plate and the second stator pressure plate fix and press the stator coil, limiting the displacement of the stator coil in the axial direction;

[0011] The stator inner support is cylindrical with a central opening, and its outer circumferential surface is gear-shaped and has multiple positioning grooves for supporting the stator coil; the axial end surface of the stator inner support is fixed to the slotted end surfaces of the first stator pressure plate and the second stator pressure plate by bolts;

[0012] The flow channel baffle assembly includes a plurality of flow channel baffle elements arranged at intervals, the flow channel baffle elements are in a "claw" shape to surround and fix the stator coil, and the flow channel baffle elements are provided with circular through holes for fixing the external wires of the stator coil; the flow channel baffle elements and the external wires are connected to form a circular ring, which is fixed to the outer circumference of the stator coil;

[0013] The stator inner support and flow channel partition assembly are used to limit the displacement of the stator coil in the radial and tangential directions.

[0014] Optionally, the stator fixing structure further includes a casing;

[0015] The housing comprises an inner housing and an outer housing; the inner housing is a cylindrical housing with a housing cooling medium flow channel on its outer surface, a boss slide rail on its inner surface, and a liquid inlet and a liquid outlet on its axial end surface; the outer housing is a round housing covering the inner housing for sealing;

[0016] The first and second stator pressure plates are fixed to the inner surface of the inner casing by radial bolts. The top of the flow channel baffle element is provided with a groove slide, which cooperates with the boss slide on the inner surface of the inner casing to fix the flow channel baffle element to the inner surface of the inner casing. The first stator pressure plate, the second stator pressure plate, the stator inner support, the flow channel baffle assembly and the casing together form a through annular cavity for accommodating multiple segmented stators.

[0017] A plurality of segmented stators are arranged in the annular cavity, and the gap between the stator and the annular cavity forms a stator cooling medium flow channel; the stator cooling medium flow channel and the casing cooling medium flow channel are connected through the through hole on the inner casing; the stator cooling medium flow channel and the casing cooling medium flow channel are used to cool the segmented stators.

[0018] Optionally, the flow channel baffle element includes a main body and a fixing claw, wherein the fixing claw is arranged on the side of the main body and matches the shape of the stator coil; three circular through holes are provided on the main body for fixing the external wiring of the stator coil.

[0019] Optionally, the first stator pressure plate and the second stator pressure plate are glass fiber boards.

[0020] In a second aspect, the present invention further provides an axial flux motor, comprising the stator fixing structure and the segmented stator as described in any one of the first aspects.

[0021] Optionally, sealing rings are provided at the connections between the first stator pressure plate, the second stator pressure plate, the stator inner support and the casing.

[0022] Optionally, the axial end surface of the inner housing is provided with a winding lead terminal hole;

[0023] The winding lead-out terminal holes are used to lead out the three-phase winding wires.

[0024] Compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0025] 1. The present invention provides a stator fixing structure for fixing the segmented stator in an axial flux motor. The stator core is fixed and pressed by two slotted first and second stator pressure plates, limiting the displacement of the stator core in the axial, radial and tangential directions. The slotted stator pressure plate further fixes and presses the stator coil, limiting the displacement of the stator coil in the axial direction. At the same time, the stator internal support and flow channel partition limit the displacement of the stator coil in the radial and tangential directions, thereby achieving all-round fixation of the segmented stator and greatly improving the reliability of the stator. Compared with the technical solutions in the prior art that use stator brackets or fill the annular space with heat-conductive fixing glue, this solution does not use additional structures or materials to occupy the space of the stator core and windings, thereby improving the space utilization of the motor and facilitating the improvement of the motor power density. At the same time, it avoids the eddy current loss generated by the additional structure under the magnetic field, which is beneficial to improving the efficiency of the motor.

[0026] 2. The present invention provides a stator fixing structure, which utilizes the gaps between components such as the stator pressure plate, the stator internal support and the flow channel partition and the winding to form a stator cooling medium flow channel, and a casing cooling medium flow channel is formed between the inner casing and the outer casing. The motor cooling medium flow channel formed by the two greatly enhances the heat dissipation capacity of the motor, which is beneficial to improving the power density of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a three-dimensional exploded view of the stator structure of the axial flux motor provided by an embodiment of the present invention;

[0028] Figure 2 is a cross-sectional view of the stator structure of an axial flux motor provided by an embodiment of the present invention;

[0029] Figure 3 Schematic diagram of a segmented stator provided by an embodiment of the present invention;

[0030] Figure 4 1 is a schematic diagram of a first stator pressure plate provided in an embodiment of the present invention;

[0031] Figure 5 Schematic diagram of the stator inner support provided by an embodiment of the present invention;

[0032] Figure 6 is a schematic diagram of an inner casing provided by an embodiment of the present invention;

[0033] Figure 7 is a schematic diagram of a flow channel baffle provided by an embodiment of the present invention;

[0034] Figure 8 Schematic diagram of the block stator fixing and cooling channel provided by an embodiment of the present invention;

[0035] In all the drawings, the same reference numerals are used to represent the same elements or structures, where: 1—block stator, 11—stator core, 12—stator coil, 2—flow channel partition element, 21—fixing claw, 22—circular through hole, 23—groove slide, 3—external wire, 4—stator inner support, 5—first stator pressure plate, 51—stator fixing groove, 52—coil fixing groove, 6—second stator pressure plate, 7—inner casing, 71—casing cooling medium flow channel, 72—boss slide, 73—lead wire terminal hole, 74—liquid inlet, 8—outer casing. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0037] The contents involved in the above embodiment are described below in conjunction with a preferred embodiment.

[0038] like Figures 1 to 7 As shown, the present invention provides a stator fixing structure, including a flow channel partition plate group, an external connection 3, a stator inner support 4, a first stator pressure plate 5 and a second stator pressure plate 6;

[0039] The stator fixing structure is used to fix the segmented stator 1. The segmented stator 1 includes a plurality of stator cores 11 and a plurality of stator coils 12. The stator coils 12 are wound on the stator cores 11.

[0040] The first stator pressure plate 5 and the second stator pressure plate 6 are both circular plates with a central opening. The slotted end surfaces of the first stator pressure plate 5 and the second stator pressure plate 6 are arranged opposite to each other, the outer side surfaces are smooth, and the inner side surfaces are both concavely provided with a plurality of stator fixing slots 51 and convexly provided with a plurality of coil fixing slots 52. The stator fixing slots 51 and the coil fixing slots 52 are evenly spaced and corresponding to each other along the circumference of the first stator pressure plate 5 and the second stator pressure plate 6. The outline of the stator fixing slot 51 is trapezoidal and fits tightly with the stator core 11. The outline of the coil fixing slot 52 is gear-shaped, and the concave arc at the bottom of the tooth is used to clamp the stator coil 12.

[0041] The first stator pressure plate 5 and the second stator pressure plate 6 fix and press the stator core 11, limiting the displacement of the stator core 11 in the axial, radial and tangential directions; at the same time, the first stator pressure plate 5 and the second stator pressure plate 6 fix and press the stator coil 12, limiting the displacement of the stator coil 12 in the axial direction;

[0042] The stator inner support 4 is cylindrical with a central opening, and its outer circumferential surface is gear-shaped and has multiple positioning grooves for supporting the stator coil 12; the axial end surface of the stator inner support 4 is fixed to the slotted end surfaces of the first stator pressure plate 5 and the second stator pressure plate 6 by bolts;

[0043] The flow channel baffle assembly includes a plurality of flow channel baffle elements 2 arranged at intervals, the flow channel baffle elements 2 are in a "claw" shape to surround and fix the stator coil 12, and the flow channel baffle elements 2 are provided with circular through holes 22 for fixing the external wires 3 of the stator coil 12; the flow channel baffle elements 2 and the external wires 3 are connected to form a ring, which is fixed to the outer circumference of the stator coil 12;

[0044] The stator inner support 4 and the flow channel partition assembly are used to limit the displacement of the stator coil 12 in the radial and tangential directions.

[0045] like Figure 7 As shown, optionally, the flow channel baffle element 2 includes a main body (not shown) and a fixing claw 21, and the fixing claw 21 is arranged on the side of the main body and matches the shape of the stator coil 12; three circular through holes 22 are provided on the main body for fixing the external wiring of the stator coil 12.

[0046] In the technical solution of the present invention, the stator core is fixed and compressed by two first and second stator pressure plates provided with stator core fixing slots, thereby limiting the displacement of the stator core in the axial, radial, and tangential directions. The first and second stator pressure plates are also provided with stator coil fixing slots, which fix and compress the stator coil, thereby limiting the displacement of the stator coil in the axial direction. At the same time, with the assistance of the stator inner support and the flow channel partition, the displacement of the stator coil in the radial and tangential directions is limited. Specifically, the stator inner support limits the radial inward displacement of the stator coil, and the flow channel partition group limits the radial outward displacement of the stator coil. Both the stator inner support and the flow channel partition group have arc surfaces that fit the stator coil, and therefore have the function of limiting tangential displacement. This achieves all-round fixation of the block stator, greatly improving the reliability of the stator. Compared with the existing technical solutions that use stator brackets or fill the annular space with heat-conducting fixing glue, this solution does not use additional structures or materials to occupy the space of the stator core and windings, which improves the space utilization of the motor and is conducive to improving the power density of the motor; at the same time, it avoids the eddy current loss generated by the additional structure under the magnetic field, which is conducive to improving the efficiency of the motor.

[0047] Optionally, the stator fixing structure further includes a casing;

[0048] The housing comprises an inner housing 7 and an outer housing 8. The inner housing 7 is a cylindrical shell having a housing cooling medium flow channel 71 on its outer surface, a boss slide rail 72 on its inner surface, and a liquid inlet 74 and a liquid outlet (not shown) on its axial end surface. The outer housing 8 is a circular shell covering the inner housing 7 for sealing.

[0049] The first stator pressure plate 5 and the second stator pressure plate 6 are fixed to the inner surface of the inner casing 7 by radial bolts. The top of the flow channel baffle element 2 is provided with a groove slide 23, which cooperates with the boss slide 72 on the inner surface of the inner casing 7 to fix the flow channel baffle element 2 to the inner surface of the inner casing 7. The first stator pressure plate 5, the second stator pressure plate 6, the stator inner support 4, the flow channel baffle assembly and the casing together form a through annular cavity for accommodating multiple segmented stators.

[0050] A plurality of segmented stators 1 are arranged in the annular cavity, and the gap between the stator and the annular cavity forms a stator cooling medium flow channel; the stator cooling medium flow channel and the casing cooling medium flow channel are connected through the through hole on the inner casing 7; the stator cooling medium flow channel and the casing cooling medium flow channel are used to cool the segmented stators 1.

[0051] Stator cooling medium flow channel Figure 8 As shown in the figure, the stator cooling channel of the block stator is in the shape of "J"; the cooling medium channel of the casing is as follows Figure 6 As shown. The cooling medium enters the cooling medium flow channel 71 of the casing from the liquid inlet 74, flows in the cooling medium flow channel 71 of the casing, and then enters the stator cooling medium flow channel through the through hole, and flows according to the preset flow channel and flow direction. The cooling medium can flow between the stator coils and circumferentially of the stator coils, fully contacting the stator coils, and efficiently and directly cooling the stator coils of the motor; the cooling medium returns to the cooling medium flow channel 71 of the casing through the through hole again, and finally flows out through the liquid outlet. The combined flow channel of the stator cooling flow channel and the casing cooling flow channel can extend the flow distance of the cooling medium, increase the contact area between the motor and the cooling medium, and thus effectively reduce the temperature rise of the motor. The first stator pressure plate 5, the second stator pressure plate 6, the stator inner support 4, the flow channel partition group and the casing together form a through annular cavity, which limits the overall displacement of multiple segmented stators and improves the reliability of the segmented stator fixation. The formed combined flow channel also enhances the heat dissipation capacity of the motor stator, which is beneficial to improving the power density of the motor.

[0052] Optionally, the first stator pressing plate 5 and the second stator pressing plate 6 are glass fiber boards.

[0053] Glass fiber is an inorganic, non-metallic material with excellent performance, featuring excellent insulation, corrosion resistance, high mechanical strength, low electrical conductivity, and low thermal conductivity. In this embodiment, the first and second stator pressure plates 5 and 6 are constructed from glass fiber sheets, which ensure the fixed strength of the segmented stator 1 while reducing weight, thereby achieving a lightweight motor. Low electrical conductivity reduces eddy current losses generated by the stator pressure plates, reducing motor power loss and thereby improving motor efficiency. Low thermal conductivity also reduces the amount of heat transferred from the stator to the rotor, facilitating heat dissipation in the motor.

[0054] On the basis of the above embodiments, the present invention further provides an axial flux motor, comprising the stator fixing structure and the segmented stator as described in the above embodiments.

[0055] Optionally, sealing rings are provided at the connections between the first stator pressure plate 5 , the second stator pressure plate 6 , the stator inner support 4 and the casing.

[0056] Optionally, the axial end surface of the inner housing 7 is provided with a winding lead-out terminal hole 73;

[0057] The winding lead-out terminal holes 73 are used to lead out the three-phase winding wires.

[0058] After the block stator of the axial flux motor is assembled, the flow channel partition assembly, the stator inner support 4, the first stator pressure plate 5, the second stator pressure plate 6 and the inner housing 7 ensure that the stator is fixed in the axial, radial and tangential directions, which greatly improves the reliability of the stator. At the same time, the gap between the windings can be formed as follows Figure 8 The "J"-shaped cooling medium flow channel shown greatly enhances the heat dissipation capacity of the motor, which helps improve the motor's power density. This results in an axial flux motor with high heat dissipation capacity, power density, and stator reliability. For example, the axial flux motor can be a yokeless, segmented armature axial flux motor.

[0059] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A stator fixing structure, characterized in that: It includes a flow channel partition plate group, an external connection line, a stator inner support, a first stator pressure plate and a second stator pressure plate; The stator fixing structure is used to fix the segmented stator, and the segmented stator includes a plurality of stator cores and a plurality of stator coils, and the stator coils are wound on the stator cores; The first stator pressure plate and the second stator pressure plate are both circular plates with a central opening. The slotted end surfaces of the first stator pressure plate and the second stator pressure plate are arranged opposite to each other, the outer side surfaces are smooth, and the inner side surfaces are both concavely provided with a plurality of stator fixing slots and convexly provided with a plurality of coil fixing slots. The stator fixing slots and the coil fixing slots are evenly spaced and corresponding to each other along the circumference of the first stator pressure plate and the second stator pressure plate; the profile of the stator fixing slot is trapezoidal and closely matches the stator core; the profile of the coil fixing slot is gear-shaped, and the concave arc at the bottom of the tooth is used to clamp the stator coil; The first stator pressure plate and the second stator pressure plate fix and press the stator core, limiting the displacement of the stator core in the axial, radial and tangential directions; at the same time, the first stator pressure plate and the second stator pressure plate fix and press the stator coil, limiting the displacement of the stator coil in the axial direction; The stator inner support is cylindrical with a central opening, and its outer circumferential surface is gear-shaped and has multiple positioning grooves for supporting the stator coil; the axial end surface of the stator inner support is fixed to the slotted end surfaces of the first stator pressure plate and the second stator pressure plate by bolts; The flow channel baffle assembly includes a plurality of flow channel baffle elements arranged at intervals, the flow channel baffle elements are in a "claw" shape to surround and fix the stator coil, and the flow channel baffle elements are provided with circular through holes for fixing the external wires of the stator coil; the flow channel baffle elements and the external wires are connected to form a circular ring, which is fixed to the outer circumference of the stator coil; The stator inner support and flow channel partition assembly are used to limit the displacement of the stator coil in the radial and tangential directions.

2. The stator fixing structure according to claim 1, characterized in that: The stator fixing structure further includes a casing; The housing comprises an inner housing and an outer housing; the inner housing is a cylindrical housing with a housing cooling medium flow channel on its outer surface, a boss slide rail on its inner surface, and a liquid inlet and a liquid outlet on its axial end surface; the outer housing is a round housing covering the inner housing for sealing; The first and second stator pressure plates are fixed to the inner surface of the inner casing by radial bolts. The top of the flow channel baffle element is provided with a groove slide, which cooperates with the boss slide on the inner surface of the inner casing to fix the flow channel baffle element to the inner surface of the inner casing. The first stator pressure plate, the second stator pressure plate, the stator inner support, the flow channel baffle assembly and the casing together form a through annular cavity for accommodating multiple segmented stators. A plurality of segmented stators are arranged in the annular cavity, and the gap between the stator and the annular cavity forms a stator cooling medium flow channel; the stator cooling medium flow channel and the casing cooling medium flow channel are connected through the through hole on the inner casing; the stator cooling medium flow channel and the casing cooling medium flow channel are used to cool the segmented stators.

3. The stator fixing structure according to claim 1, characterized in that: The flow channel partition element includes a main body and a fixing claw. The fixing claw is arranged on the side of the main body and matches the shape of the stator coil. Three circular through holes are arranged on the main body for fixing the external wiring of the stator coil.

4. The stator fixing structure according to claim 1, characterized in that: The first stator pressing plate and the second stator pressing plate are glass fiber plates.

5. An axial flux motor, characterized in that: The invention comprises the stator fixing structure and the segmented stator according to any one of claims 1 to 4.

6. The axial flux motor according to claim 5, characterized in that Sealing rings are provided at the connections between the first stator pressure plate, the second stator pressure plate, the stator inner support and the casing.

7. The axial flux motor according to claim 5, wherein: The axial end surface of the inner housing is provided with a winding lead-out terminal hole; The winding lead-out terminal holes are used to lead out the three-phase winding wires.

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