A hybrid cooling dual-rotor single-stator disc permanent magnet motor

Abstract

The present invention discloses a hybrid cooling dual-rotor single-stator disc permanent magnet motor, which relates to the field of motors. The disc permanent magnet motor has a large power density. At present, materials with good thermal conductivity are widely used as stator cores, or devices such as heat dissipation fans are added. However, this will increase the overall weight of the motor and is not suitable for lightweight applications in electric vehicles and aerospace fields. The present invention includes a stator and left and right double rotors. The stator includes an annular stator support frame and ribs evenly distributed around it. Fan-shaped magnetic poles are arranged between adjacent ribs. The stator support frame is provided with a circumferential cooling channel. Each rib is provided with a radial cooling channel and is connected to the circumferential cooling channel. A continuous cooling pipe is embedded in the cooling channel. The outer periphery of the left and right rotors is provided with an annular cover plate for sealing the motor, and the left and right rotors and the annular cover plate are provided with ventilation holes that penetrate inside and outside. The mixed cooling of air cooling and liquid cooling is adopted, and the overall structure of the motor is compact, the weight of the motor is light, the cooling effect is good, and lightweight applications are effectively realized.

Description

Technical Field

[0001] The invention relates to the field of motors, and in particular to a hybrid cooling double-rotor single-stator disc type permanent magnet motor. Background Art

[0002] At present, traditional motors have disadvantages such as large size and low efficiency, and their selection is limited in some fields. The disc permanent magnet motor has the advantages of small size, light weight, high efficiency, and high torque density. It is suitable for fields such as electric vehicles and aerospace that have strict requirements on motor performance. The disc permanent magnet motor is also called an axial flux motor, and the air gap magnetic field is distributed along the axial direction. In order to overcome problems such as unilateral magnetic pull, the middle stator double-sided rotor and the middle rotor double-sided stator are the most widely used axial disc permanent magnet motor structures. In the fields of electric vehicles and aviation, the motor, as the core of the drive, has attracted widespread attention and research.

[0003] During the operation of the axial motor, the stator core and coil will generate a lot of heat. The disc permanent magnet motor has a high power density, so it places higher requirements on the heat dissipation capacity of the motor. In order to improve the heat dissipation capacity of the motor, the widely used method is to select materials with good thermal conductivity as the stator core, or add devices such as heat dissipation fans. However, this method will increase the overall structural weight of the motor and is not suitable for work areas that require lightweight. Summary of the invention

[0004] The technical problem to be solved and the technical task proposed by the present invention are to improve and perfect the existing technical solutions and provide a hybrid cooling dual-rotor single-stator disc permanent magnet motor, so as to effectively improve the heat dissipation effect while meeting the requirements of lightweight. To this end, the present invention adopts the following technical solutions.

[0005] A hybrid cooling dual-rotor single-stator disc permanent magnet motor comprises a stator, a left rotor located on the left side of the stator, and a right rotor located on the right side of the stator. The stator comprises an annular stator support frame located in the radial middle thereof, and a plurality of radial ribs uniformly distributed around and connected to the outer periphery of the stator support frame. The ribs are made of non-magnetic conductive material, and fan-shaped magnetic poles are arranged between adjacent ribs. The ribs are radially outward and connected to magnetic pole pressure plates. The stator support frame is provided with a circumferential cooling channel, and each rib is provided with a radial cooling channel and communicates with the circumferential cooling channel. The circumferential cooling channel and the radial cooling channel are embedded in a continuous cooling pipeline, and a liquid cooling medium is filled in the cooling pipeline. An annular cover plate for sealing the motor is arranged between the axial directions of the outer peripheries of the left rotor and the right rotor, and a motor running gap exists between the inner side surface of the annular cover plate and the outer periphery of the stator. The left rotor, the right rotor and the annular cover plate are all provided with ventilation holes penetrating inside and outside. The left rotor and the right rotor each comprise a rotor core, a magnetic steel and a fixing member, and the magnetic steel is in close contact with the rotor core through the fixing member. By placing the rotor on both sides of the stator and adopting a mixed cooling method of air cooling and liquid cooling, the rotor and the annular cover plate are provided with ventilation holes, and the air flow can flow into the air gap from the ventilation holes and then flow out from the ventilation holes of the annular cover plate to form a complete air path circulation; the cooling liquid can pass through the cooling channels of the stator support frame and the rib plate, enter the stator support frame through the liquid inlet, flow into the rib plate, and directly cool the fan-shaped magnetic poles. The mixed cooling method improves the cooling efficiency of the motor and also reduces the weight of the motor to a certain extent. The overall structure has a small number of parts and a compact structure. The mixed cooling method has high efficiency and good heat dissipation capacity, which can effectively take away the heat generated inside the rotor and the stator, and effectively improve the cooling effect while meeting the lightweight requirements. The overall structure of the motor is compact and reasonable, and can effectively realize lightweight applications.

[0006] As an optimal technical means: the radial cooling channel on each rib plate is bent several times on both sides of the radial inside and outside of the stator, forming multiple radial cooling channel sections parallel to the stator axis on each rib plate, thereby increasing the flow range of the liquid cooling medium and improving the cooling effect.

[0007] As a preferred technical means: the cooling pipe includes a radial pipe located on the rib plate and a circumferential pipe located on the stator support frame, the circumferential pipe is arranged in the circumferential pipe groove on the side wall of the central hole of the stator support frame, and the radial pipe is arranged in the side pipe groove on the rib plate. The method of injecting liquid cooling medium into the pipe avoids the structural complexity and assembly difficulty caused by directly injecting liquid cooling medium into the inner hole cooling channel of the stator support frame and the rib plate, and reduces the leakage probability of liquid cooling medium.

[0008] As the preferred technical means: the rib plate and the cooling channel therein, the stator support frame and the cooling channel therein are all cast in one piece or 3D printed in one piece. Through the one-piece casting or additive manufacturing method, the processing and manufacturing costs can be effectively reduced, and the degree of integration is high.

[0009] As a preferred technical means: the outer periphery of the stator support frame is provided with rib connection grooves corresponding to the number of ribs, the ribs are positioned and connected in the rib connection grooves at the radial inner side of the stator, the ribs are provided with magnetic pole pressure plates at the radial outer side of the stator to limit the radial outward movement of the sector magnetic poles, and the sector magnetic poles are fixed by the stator support frame at the radial inner side, so as to effectively realize the positioning connection of the ribs and the limiting fixation of the sector magnetic poles.

[0010] As a preferred technical means: the left rotor and the right rotor both include a rotor core, magnets uniformly distributed circumferentially on the rotor core, and fixing parts for fixing the magnets located on the inner and outer sides of the rotor radial direction and the left and right sides of the rotor circumferentially, and the rotor cores of the left rotor and the right rotor are rotatably connected to the bearing blocks at the axial ends of the stator support frame through the central bearing, so as to effectively realize the rotatable structure of the rotor.

[0011] As a preferred technical means: the magnetic steel is provided with an inclination on its radial inner and outer sides, and is pressed by fixing parts on its radial inner and outer sides and circumferential left and right sides, and is fixed to the magnetic steel slot of the rotor core through bolts on the fixing parts. Each magnetic steel is provided with a fixing part on the radial outer side, and each two adjacent magnetic steels share a fixing part on the radial inner side; each two adjacent magnetic steels share a fixing part on both circumferential sides. Structural optimization can effectively reduce the number of fixing parts.

[0012] As a preferred technical means: each magnetic steel is made of multiple small magnetic steel bodies bonded and spliced ​​by insulating glue, which can effectively reduce the eddy current loss of the magnetic steel.

[0013] As a preferred technical means: the motor running clearance is greater than 2mm; the annular cover plate is fixed to the inner step of the rotor core by bolt connection, and the outer peripheral surface of the annular cover plate is flush with the outer peripheral surface of the rotor core. The fixing structure of the annular cover plate can effectively realize the positioning and fixing of the annular cover plate, and the motor running clearance can effectively ensure that the annular cover plate will not touch the outer periphery of the stator when the dual rotors rotate.

[0014] As a preferred technical means: the axial section of the magnetic pole pressure plate is dovetail-shaped, which radially compresses the circumferentially uniformly distributed sector-shaped magnetic poles and ribs, the sector-shaped magnetic poles include a stator core and a stator winding, and the stator core is provided with a dovetail structure on both sides of the stator axial direction; the stator core is formed by laminating silicon steel sheets or by pressing iron powder. The dovetail structure can effectively achieve the limit with adjacent components.

[0015] Beneficial effects: The hybrid cooling structure of internal cooling through liquid cooling medium and air cooling through ventilation holes can effectively remove the heat generated inside the rotor and stator, and can effectively improve the cooling effect without increasing the volume of the motor. The overall structure of the motor is compact and reasonable, with good cooling and heat dissipation effects, and can effectively achieve lightweight applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of an axial cross section of the present invention.

[0017] Figure 2 It is a schematic diagram of the stator structure of the present invention.

[0018] Figure 3 It is a schematic diagram of the connection between the stator support frame and the rib plate of the present invention.

[0019] Figure 4 It is a schematic diagram of the sector-shaped magnetic pole of the present invention.

[0020] Figure 5 It is a partial schematic diagram of the rotor of the present invention.

[0021] Figure 6 It is a structural schematic diagram of the cooling pipeline of the present invention.

[0022] In the figure: 1- stator support frame; 2- rib plate; 3- annular cover plate; 4- circumferential cooling channel; 5- radial cooling channel; 6- pole pressure plate; 7- sector pole; 8- rotor core; 9- magnetic steel; 10- fixing piece; 11- bearing; 12- cooling pipe, 101- rib plate connecting groove; 102- circumferential pipe groove; 201- side pipe groove; 701- stator core; 702- stator winding. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0024] like Figure 1-6 As shown, a hybrid cooling dual-rotor single-stator disc permanent magnet motor comprises a stator, a left rotor located on the left side of the stator, and a right rotor located on the right side of the stator. The stator comprises an annular stator support frame 1 located in the radial middle thereof, and a plurality of radial ribs 2 evenly distributed around and connected to the outer periphery of the stator support frame 1. The ribs 2 are made of non-magnetic conductive material, and fan-shaped magnetic poles 7 are arranged between adjacent ribs 2. The ribs 2 are radially outward and connected to the magnetic pole pressure plate 6. The stator support frame 1 is provided with a circumferential cooling channel 4, and each rib 2 is provided with a radial cooling channel 5 and connected to the magnetic pole pressure plate 6. The circumferential cooling channel 4 is connected, and a continuous cooling pipe 12 is embedded in the circumferential cooling channel 4 and the radial cooling channel 5, and the cooling pipe is filled with a liquid cooling medium; an annular cover plate 3 for sealing the motor is provided between the axial direction of the outer periphery of the left rotor and the right rotor, and a motor operation gap exists between the inner side surface of the annular cover plate 3 and the outer periphery of the stator, and ventilation holes penetrating inside and outside are provided on the left rotor, the right rotor and the annular cover plate 3; the rotor comprises a rotor core 8, a magnetic steel 9 and a fixing part 10, and the magnetic steel 9 is in close contact with the rotor core 8 through the fixing part 10.

[0025] In order to improve the cooling effect, the radial cooling channel 5 on each rib plate 2 is bent multiple times on both sides of the radial inside and outside of the stator, forming four radial cooling channel 5 sections parallel to the stator axis on each rib plate 2. The range of liquid cooling medium flow is increased to improve the cooling effect.

[0026] In order to reduce the complexity of the structure, the cooling pipe 12 includes a radial pipe located on the rib plate 2 and a circumferential pipe located on the stator support frame 1. The circumferential pipe is welded to the circumferential pipe groove 102 on the side wall of the center hole of the stator support frame 1, and the radial pipe is welded to the side pipe groove 201 on the rib plate 2. The method of injecting liquid cooling medium into the pipe avoids the structural complexity and assembly difficulty caused by directly injecting the liquid cooling medium into the inner hole cooling channel of the stator support frame 1 and the rib plate 2, and reduces the leakage probability of the liquid cooling medium.

[0027] In order to realize the positioning connection of the rib plate 2 and the limiting fixation of the sector-shaped magnetic pole 7, the outer periphery of the stator support frame 1 is provided with rib plate connection grooves 101 corresponding to the number of the rib plates 2, the rib plates 2 are positioned and connected in the rib plate connection grooves 101 at the radial inner side of the stator, the rib plates 2 are provided with magnetic pole pressure plates 6 at the radial outer side of the stator to limit the radial outward movement of the sector-shaped magnetic pole 7, and the sector-shaped magnetic pole 7 is limited and fixed at the radial inner side by the stator support frame 1. The positioning connection of the rib plate 2 and the limiting fixation of the sector-shaped magnetic pole 7 are effectively realized.

[0028] In order to realize the rotatable structure of the rotor, the left rotor and the right rotor both include a rotor core 8, magnetic steels 9 uniformly distributed circumferentially on the rotor core 8, and fixing members 10 for fixing the magnetic steels 9 located on both radial inner and outer sides of the magnetic steels 9 and circumferential left and right sides of the rotor. The rotor cores 8 of the left rotor and the right rotor are rotatably connected to the bearings 11 at both axial ends of the stator support frame 1 through the central bearing 11, respectively. The rotatable structure of the rotor is effectively realized.

[0029] In order to reduce the number of fixing parts 10, the magnetic steel 9 is provided with an inclination on its radial inner and outer sides, and is pressed by fixing parts 10 on its radial inner and outer sides and circumferential left and right sides and fixed to the magnetic steel slot of the rotor core 8 through bolts on the fixing parts 10. A fixing part 10 is provided on the radial outer side of each magnetic steel 9, and a fixing part 10 is shared on the radial inner side of every two adjacent magnetic steels 9; and a fixing part 10 is shared on the circumferential sides of every two adjacent magnetic steels 9. The structural optimization can effectively reduce the number of fixing parts 10.

[0030] In order to reduce the eddy current loss of the magnetic steel 9, each magnetic steel 9 is formed by splicing a plurality of small magnetic steel bodies by bonding with insulating glue, which can effectively reduce the eddy current loss of the magnetic steel 9.

[0031] In order to realize the positioning and fixing of the annular cover plate 3, the annular cover plate 3 is fixed to the inner step of the rotor core 8 by bolt connection, and the outer circumference of the annular cover plate 3 is flush with the outer circumference of the rotor core 8. The fixing structure of the annular cover plate 3 can effectively realize the positioning and fixing of the annular cover plate 3.

[0032] In order to achieve the position limiting of the adjacent elements, the axial section of the magnetic pole pressure plate 6 is dovetail-shaped to radially compress the circumferentially uniformly distributed sector-shaped magnetic poles 7 and ribs 2. The sector-shaped magnetic poles 7 include a stator core 701 and a stator winding 702. The stator core 701 is provided with a dovetail structure on both sides of the stator axial direction. The dovetail structure is simple and can effectively achieve the position limiting with the adjacent elements.

[0033] By placing the rotor on both sides of the stator and adopting a mixed cooling method of air cooling and liquid cooling, the iron core and the annular cover plate 3 of the rotor are provided with ventilation holes, and the air flow can flow into the air gap from the ventilation holes, and then flow out from the ventilation holes of the annular cover plate 3 to form a complete air path circulation; the cooling liquid can pass through the cooling channels of the stator support frame 1 and the rib plate 2, enter the stator support frame 1 through the liquid inlet, flow into the rib plate 2, and directly cool the fan-shaped magnetic poles 7. The mixed cooling method improves the cooling efficiency of the motor and also reduces the weight of the motor to a certain extent. The overall structure has a small number of parts and a compact structure. The mixed cooling method has high efficiency and good heat dissipation capacity, and can effectively take away the heat generated inside the rotor and the stator, and effectively improve the cooling effect without increasing the volume of the motor. The overall structure of the motor is compact and reasonable, and can effectively realize lightweight applications.

[0034] In this example, in order to reduce the processing and manufacturing costs, the rib plate 2 and the cooling channel therein, the stator support frame 1 and the cooling channel therein can be replaced by an integral casting or 3D printing additive manufacturing method. The integral casting or additive manufacturing method can effectively reduce the processing and manufacturing costs, and the degree of integration is high.

[0035] In this example, the stator core 701 is formed by laminating silicon steel sheets, and may also be formed by pressing iron powder instead.

[0036] In this example, the magnetic pole pressure plate 6 and the rib plate 2 are fixed by bolts.

[0037] above Figure 1-6 The hybrid cooling dual-rotor single-stator disc permanent magnet motor shown is a specific embodiment of the present invention, which has embodied the outstanding substantial features and significant progress of the present invention. According to actual use needs and under the guidance of the present invention, equivalent modifications in shape, structure, etc. can be made to it, which are all within the protection scope of this scheme.

Claims

1. A hybrid cooling dual-rotor single-stator disc permanent magnet motor, characterized in that: The invention comprises a stator, a left rotor located on the left side of the stator, and a right rotor located on the right side of the stator, wherein the stator comprises an annular stator support frame (1) located in the radial middle thereof, and a plurality of radial ribs (2) evenly distributed around and connected to the outer periphery of the stator support frame (1), wherein the ribs (2) are made of non-magnetic conductive material, and fan-shaped magnetic poles (7) are arranged between adjacent ribs (2), and the ribs (2) extend radially outward and are connected to magnetic pole pressure plates (6); the stator support frame (1) is provided with a circumferential cooling channel (4), and each rib (2) is provided with a radial cooling channel (5) and is connected to the circumferential cooling channel (4), and the circumferential cooling channel (5) is connected to the circumferential cooling channel (4). A continuous cooling pipe (12) is embedded in the cooling channel (4) and the radial cooling channel (5), and a liquid cooling medium is filled in the cooling pipe; an annular cover plate (3) for sealing the motor is provided between the axial directions of the outer peripheries of the left rotor and the right rotor, and a motor operation gap exists between the inner side surface of the annular cover plate (3) and the outer periphery of the stator; the left rotor, the right rotor and the annular cover plate (3) are provided with ventilation holes penetrating inside and outside; the left rotor and the right rotor each include a rotor core (8), a magnetic steel (9) and a fixing member (10), and the magnetic steel (9) is in close contact with the rotor core (8) through the fixing member (10); The cooling pipe (12) comprises a radial pipe located on the rib plate (2) and a circumferential pipe located on the stator support frame (1), the circumferential pipe being arranged in a circumferential pipe groove (102) on the side wall of the center hole of the stator support frame (1), and the radial pipe being arranged in a side pipe groove (201) on the rib plate (2); The outer periphery of the stator support frame (1) is provided with rib connecting grooves (101) corresponding to the number of ribs (2), and the ribs (2) are positioned and connected in the rib connecting grooves (101) at the radial inner side of the stator.

2. A hybrid cooling dual-rotor single-stator disc permanent magnet motor according to claim 1, characterized in that: The radial cooling channel (5) on each rib plate (2) is bent several times on both radial inner and outer sides of the stator, so that a plurality of radial cooling channel (5) sections parallel to the axial direction of the stator are formed on each rib plate (2).

3. A hybrid cooling dual-rotor single-stator disc permanent magnet motor according to claim 2, characterized in that: The rib plate (2) and the cooling channel therein, and the stator support frame (1) and the cooling channel therein are all integrally cast or integrally 3D printed.

4. The hybrid cooling dual-rotor single-stator disc permanent magnet motor according to claim 2, characterized in that: The rib plate (2) is provided with a magnetic pole pressure plate (6) at the radial outer side of the stator to limit the radial outward movement of the sector-shaped magnetic pole (7), and the sector-shaped magnetic pole (7) is fixed at the radial inner side by the stator support frame (1).

5. The hybrid cooling dual-rotor single-stator disc permanent magnet motor according to claim 1, characterized in that: The left rotor and the right rotor both comprise a rotor core (8), magnets (9) uniformly distributed circumferentially on the rotor core (8), and fixing members (10) for fixing the magnets (9) and located on both radial inner and outer sides of the magnets (9) and circumferential left and right sides of the rotor. The rotor cores (8) of the left rotor and the right rotor are both rotatably connected to the bearings (11) at both axial ends of the stator support frame (1) via a central bearing (11).

6. The hybrid cooling dual-rotor single-stator disc permanent magnet motor according to claim 5, characterized in that: The magnetic steel (9) is provided with an inclination on both radial inner and outer sides thereof, and is pressed by fixing members (10) on both radial inner and outer sides thereof and on both circumferential left and right sides thereof, and is fixed in the magnetic steel slot of the rotor core (8) by bolt connection on the fixing members (10), wherein a fixing member (10) is provided on the radial outer side of each magnetic steel (9), and a fixing member (10) is shared on the radial inner sides of every two adjacent magnetic steels (9); and a fixing member (10) is shared on both circumferential sides of every two adjacent magnetic steels (9).

7. The hybrid cooling dual-rotor single-stator disc permanent magnet motor according to claim 6, characterized in that: Each magnetic steel (9) is formed by splicing together a plurality of small magnetic steel bodies by bonding with insulating glue.

8. The hybrid cooling dual-rotor single-stator disc permanent magnet motor according to claim 5, characterized in that: The motor running clearance is greater than 2 mm; the annular cover plate (3) is fixed to the inner step of the rotor core (8) by bolt connection, and the outer peripheral surface of the annular cover plate (3) is flush with the outer peripheral surface of the rotor core (8).

9. The hybrid cooling dual-rotor single-stator disc permanent magnet motor according to claim 4, characterized in that: The axial cross section of the magnetic pole pressure plate (6) is dovetail-shaped, and radially compresses the circumferentially uniformly distributed sector-shaped magnetic poles (7) and ribs (2). The sector-shaped magnetic poles (7) include a stator core (701) and a stator winding (702). The stator core (701) is provided with a dovetail structure on both sides of the stator axial direction. The stator core (701) is formed by laminating silicon steel sheets or by pressing iron powder.

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