Permanent magnet synchronous motor capable of increasing cooling area of magnetic steel

Abstract

The utility model discloses a permanent magnet synchronous motor capable of increasing the cooling area of magnetic steel, which comprises a rotating assembly, the rotating assembly comprises an iron core body and a magnetic steel groove, the magnetic steel groove penetrates through the interior of a single-section iron core along the axial direction, the length direction of the magnetic steel groove is the same as the axial direction of the single-section iron core, and the magnetizing surface of the single-section magnetic steel coincides with the radial side surface of the magnetic steel groove; the cooling oil way is formed in the magnetic steel groove, the cooling oil way comprises an axial oil way in the axial direction of the single-section iron core and a radial oil way in the radial direction of the single-section iron core, and the axial oil way and the radial oil way are communicated to form a small-path oil way surrounding the non-magnetizing face of the single-section magnetic steel. The guide plates with the through holes are arranged between the opposite end faces of the adjacent single-section iron cores, each single magnetic steel groove forms two axial oil ways, the through holes are communicated with the two axial oil ways to form a radial oil way, the radial oil ways make contact with the non-magnetizing face of the single-section magnetic steel, the contact area of cooling oil and the single-section magnetic steel is increased, the heat dissipation effect of the single-section magnetic steel is improved, and the service life of the single-section magnetic steel is prolonged. The operation torque of the permanent magnet synchronous motor is improved.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically to a permanent magnet synchronous motor with increased magnet cooling area. Background Technology

[0002] The rotor of a new energy permanent magnet motor generally adopts a magnet-embedded topology. The magnets need to be fixed in the magnet slot. Existing magnet fixing methods include: glue fixing, injection molding fixing and mechanical fixing. Among them, mechanical fixing is increasingly widely used due to its advantages of low cost and no need for injection molding equipment investment.

[0003] The published patent CN222016290U, "Motor Rotor and Motor," provides a motor rotor and motor. The motor rotor includes a rotating shaft, a rotor core, magnets, a first balance plate, and a second balance plate. The rotating shaft has an axial channel and a radial channel. The magnets are installed in the magnet slots of the rotor core, and a fluid channel is formed between the magnets and the inner wall of the magnet slots. The first balance plate and the second balance plate are respectively provided at both ends of the rotating shaft. The first balance plate has a first flow channel connecting the radial channel and the fluid channel. The second balance plate has a fluid channel and a second flow channel on one end of the second balance plate away from the first balance plate, so that the axial channel, radial channel, first flow channel, fluid channel, and second flow channel are connected to form a channel for coolant flow.

[0004] However, when the inventors implemented this embodiment, they found that the cooling oil only contacts the two small-area sides of the magnet and the sides of the magnet at both ends of the rotor. The small contact area between the cooling oil and the magnet limits its heat dissipation effect. Utility Model Content

[0005] This invention addresses the problem of small contact area between cooling oil and magnets by providing a permanent magnet synchronous motor with increased magnet cooling area. The specific technical solution is as follows:

[0006] This utility model includes a rotating assembly, which includes an iron core body composed of several coaxial single-section iron cores with intersecting axial projections. Each single-section iron core is composed of several coaxial single-piece iron cores. The rotating assembly also includes a magnetic steel groove for placing a single-section magnet. The magnetic steel groove is formed axially through the interior of the single-section iron core, and the length direction of the magnetic steel groove is the same as the axial direction of the single-section iron core. The magnetized surface of the single-section magnet coincides with the radially opposite side of the magnetic steel groove. The permanent magnet synchronous motor also includes a cooling oil passage formed in the magnetic steel groove. The cooling oil passage includes an axial oil passage along the axial direction of the single-section iron core and a radial oil passage along the radial direction of the single-section iron core. The axial oil passage and the radial oil passage are connected to form a small passage oil passage around the non-magnetized surface of the single-section magnet.

[0007] Furthermore, the rotating assembly also includes a guide plate disposed between the opposite end faces of a single iron core section. The guide plate forms a through hole communicating with a single magnet slot. The through hole forms a radial oil passage, and the through hole communicates with an axial oil passage to form a small-passage oil passage.

[0008] Furthermore, the guide plate also includes a limiting protrusion (141) that intersects with the through hole, the projection of which along the axial direction overlaps with the side of the single magnet.

[0009] Preferably, the rotating assembly further includes: a rotating shaft, a single iron core disposed on the circumference of the rotating shaft, the rotating shaft forming a hollow pipe for introducing cooling oil, and end caps disposed at both ends of the iron core, the end caps forming end oil passages for guiding the cooling oil in the hollow pipe to the magnet groove.

[0010] Preferably, the end oil passage and the axial oil passage form a large-passage oil passage, which shares the axial oil passage with the small-passage oil passage.

[0011] As can be seen from the above technical solution, this utility model has the following beneficial effects:

[0012] This invention provides a guide plate with through holes between the opposite end faces of adjacent single iron core sections, and a single magnet slot forms two axial oil passages, so that the through holes connect the two axial oil passages to form a radial oil passage, thereby contacting the non-magnetized surface of the single magnet section, increasing the contact area between the cooling oil and the single magnet section, improving the heat dissipation effect of the single magnet section, and increasing the operating torque of the permanent magnet synchronous motor. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure and the large-pass oil circuit of an embodiment of the present utility model;

[0014] Figure 2 A schematic diagram of a single-section iron core and a single-section magnet structure, as well as a small-circuit oil passage;

[0015] Figure 3 for Figure 2 A magnified view of a portion of the image.

[0016] In the diagram: 1. Rotating assembly; 11. Single iron core; 12. Magnet slot; 13. Single magnet; 14. Guide plate; 141. Limiting protrusion; 15. Shaft; 16. End cover; 2. Cooling oil passage; 21. Axial oil passage; 22. Radial oil passage; 23. Small passage oil passage; 24. Large passage oil passage. Detailed Implementation

[0017] 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.

[0018] In the description of the embodiments of this utility model, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use. They are 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.

[0019] like Figure 1 As shown, this embodiment includes a rotating assembly 1, which includes an iron core body. The iron core body is composed of several coaxial single iron core segments 11 with intersecting axial projections. Each single iron core segment 11 is composed of several coaxial iron core chips.

[0020] As is generally known, a permanent magnet synchronous motor includes a rotating assembly 1 and a stator that is connected to alternating current to generate alternating current. The rotating assembly 1 includes an iron core for concentrating and fixing the magnetic field. The iron core is composed of multiple coaxial single iron core segments 11 spliced ​​together. Adjacent single iron core segments 11 either have staggered rotation angles or no rotation angles to form the iron core, which can reduce the operating noise of the permanent magnet synchronous motor. Each single iron core segment 11 is composed of several coaxial silicon steel sheets spliced ​​together. The silicon steel sheets have through holes for magnets to pass through. The axial projection of the through holes of the several silicon steel sheets that make up the single iron core segment 11 can at least cover the axial projection of the magnet, so that the single iron core segment 11 can form an unobstructed channel along the axial direction for placing the magnet.

[0021] like Figures 2 to 3 As shown, the rotating assembly 1 also includes a magnet slot 12 for placing a single magnet 13. The magnet slot 12 is formed axially through the interior of the single iron core 11. The opposite sides of the magnet slot 12 in the radial direction coincide with the magnetized surface of the single magnet 13 for fixing the single magnet 13. The permanent magnet synchronous motor also includes a cooling oil passage 2 formed in the magnet slot 12. The cooling oil passage 2 includes an axial oil passage 21 along the axis of the single iron core 11 and a radial oil passage 22 along the radial direction of the single iron core 11. The axial oil passage 21 and the radial oil passage 22 are connected to form a small passage oil passage 23 that contacts the non-magnetized surface of the single magnet 13. During rotation, the cooling oil in the axial oil passage 21 flows along the radial oil passage 22 to another axial oil passage 21 in the same magnet slot 12 under the action of centrifugal force, and then flows to the end cover 16.

[0022] Specifically, the magnetized surface of the single magnet 13 is its larger area. A magnetic groove 12 for placing the single magnet 13 is formed along the axial direction of the single core 11. The cross-section of the magnetic groove 12 is elongated, with its long side in close contact with the magnetized surface of the single magnet 13. It also has protrusions that restrict movement in the cross-sectional direction, allowing the magnetic groove 12 to limit the non-axial movement of the single magnet 13. This ensures that the positions of the single magnet 13 and the single core 11 do not change when the single core 11 rotates. Furthermore, the magnetic grooves 12 are arranged in pairs symmetrically about the axial cross-section and are evenly distributed along the axis of the single core 11. This ensures a uniform distribution of the magnetic field lines of the fixed magnetic field, making the interaction force between the fixed magnetic field and the alternating magnetic field always equal, thus preventing vibration during operation of the permanent magnet synchronous motor.

[0023] Secondly, the non-magnetized surface of the single magnet 13 is its smaller side surface. The single magnet 13 is fixed relative to the magnet slot 12 by mechanical fixation, and there is a gap between the short side surface of the magnet slot 12 and the non-magnetized surface of the single magnet 13. This gap is used to improve the performance of the permanent magnet synchronous motor. Cooling oil can pass through this gap to contact the axial non-magnetized surface of the single magnet 13, thereby removing its heat and reducing the temperature of the single magnet 13. This gap is the axial oil passage 21, so that the single magnet slot 12 and the single magnet 13 can form two axial oil passages 21. Secondly, there is a radial oil passage 22 between the end faces of the single magnet 13 for the flow of cooling oil. The radial oil passage 22 connects the two axial oil passages 21 of the single magnet slot 12, so that the cooling oil flowing through the axial oil passage 21 flows radially under the action of centrifugal force and can then flow through the radial oil passage 22, and then contact the non-magnetized surface of the single magnet 13 perpendicular to the axis, thereby carrying away its heat and reducing the temperature of the single magnet 13. The single iron core 11 with radial oil passages 22 at both ends can form a small passage oil passage 23 through the radial oil passage 22 and the axial oil passage 21 connected end to end. The cooling oil flowing through the small passage oil passage 23 can fully contact the non-magnetized surface of the single magnet 13, thereby increasing the contact area with the single magnet 13, thus improving the cooling effect of this embodiment.

[0024] Furthermore, the rotating assembly 1 also includes a guide plate 14 disposed between the opposite end faces of the single iron core 11. The guide plate 14 forms a through hole communicating with the single magnet slot 12. The through hole forms a radial oil passage 22 and communicates with the axial oil passage 21 to form a small passage oil passage 23.

[0025] Specifically, the axial length of the single magnet 13 is the same as the axial length of the single iron core 11, so that the non-magnetized surface of the single magnet 13 perpendicular to the axial direction coincides with the cross-section of the single iron core 11. The guide plate 14 is fixedly connected to the cross-section of the single iron core 11, and it forms an elongated through hole at the single magnet slot 12. The elongated through hole is connected to the two axial oil passages 21 of the single magnet slot 12. When two single iron cores 11 are connected, the guide plate 14 is fixed on their opposite end faces. The two end faces of the through hole are sealed by the end faces of the single iron core 11, so that the through hole forms a radial oil passage 22 connecting the two axial oil passages 21. Then, the cooling oil flows into the single axial oil passage 21 of the single magnet slot 12 and can flow into the other axial oil passage 21 through the through hole, thus forming a small circulating oil passage 23, thereby increasing the contact area between the cooling oil and the single magnet 13, and thus improving the heat dissipation effect of this embodiment.

[0026] The guide plate 14 is composed of several coaxial silicon steel sheets with the same axial projection. The silicon steel sheets are formed with through holes that communicate with the two axial oil passages 21, so that the guide plate 14 can form a radial oil passage 22 that connects the two axial oil passages 21.

[0027] Furthermore, the guide plate 14 also includes a limiting protrusion 141 that intersects with the through hole, and the projection of the limiting protrusion 141 along the axial direction overlaps with the side of the single magnet 13.

[0028] Specifically, the limiting protrusion 141 overlaps with the non-magnetized surface of the single-section magnet 13 perpendicular to the axial direction. It does not block the radial oil passage 22, so that the limiting protrusion 141 can restrict the axial degree of freedom of the single-section magnet 13 without affecting the flow of cooling oil through the radial oil passage 22. This makes the single-section magnet 13 and the single-section iron core 11 completely fixed, so that the distance between the opposite sides of the two single-section magnets 13 remains unchanged, and the radial oil passage 22 always exists, thereby improving the stability of the operation of this embodiment.

[0029] Furthermore, the rotating assembly 1 also includes: a rotating shaft 15, a single iron core 11 disposed on the circumferential surface of the rotating shaft 15, the rotating shaft 15 forming a hollow pipe for introducing cooling oil, and end caps 16 disposed at both ends of the iron core body, the end caps 16 forming end oil passages for guiding the cooling oil in the hollow pipe to the magnet groove 12.

[0030] Specifically, cooling oil enters the hollow pipe through the oil inlet of the rotating shaft 15, and then enters the end caps 16 at both ends. The end caps 16 form end oil passages with open grooves to guide the flow of cooling oil. These end oil passages are respectively connected to individual magnet slots 12, so that the cooling oil flows through the rotating shaft 15, through the end caps 16, and then into the axial oil passage 21 of the magnet slot 12. A portion of the cooling oil flows through the axial oil passage 21 through the non-magnetized surface of the single magnet 13, and a portion of the cooling oil flows through the radial oil passage 22 to form a small passage oil passage 23 that contacts all four non-magnetized surfaces of the single magnet 13, thereby increasing the contact area between the cooling oil and the single magnet 13 and thus improving the heat dissipation effect of this embodiment.

[0031] Furthermore, the end oil passage and the axial oil passage 21 form a large-passage oil passage 24, which shares the axial oil passage 21 with the small-passage oil passage 23.

[0032] Specifically, the cooling oil flowing into the end oil passage flows into the axial oil passage 21. A portion of the cooling oil always flows along the axial oil passage 21 from the left end cover 16 to the right end cover 16 and then out of the right end cover 16. Another portion of the cooling oil flows along the axial oil passage 21 from the right end cover 16 to the left end cover 16 and then out of the left end cover 16. The two portions of cooling oil do not cross each other, which improves the cooling efficiency of the single magnet 13. A portion of the cooling oil flows along the radial oil passage 22 on the non-magnetized surface of the single magnet 13, which increases its contact area with the single magnet 13. The axial oil passage 21 used by the large-passage oil passage 24 and the small-passage oil passage 23 is formed by the gap between the short side surface of the magnet groove 12 and the non-magnetized surface of the single magnet 13 along the axial direction, which reduces the complexity of the cross-section of the single iron core 11, thereby improving the working stability of this embodiment and reducing its processing cost.

[0033] 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.

[0034] The technologies, shapes, and structures not described in detail in this utility model are all known technologies.

Claims

1. A permanent magnet synchronous motor with increased magnet cooling area, the permanent magnet synchronous motor comprising a rotating assembly (1), the rotating assembly (1) comprising an iron core body, the iron core body being composed of several coaxial single iron core segments (11) with interlaced axial projections, the single iron core segment (11) being composed of several coaxial iron core pieces, characterized in that: The rotating assembly (1) further includes a magnet slot (12) for placing a single magnet (13), the magnet slot (12) being formed axially through the interior of the single iron core (11), the length direction of the magnet slot (12) being the same as the axial direction of the single iron core (11), and the magnetized surface of the single magnet (13) coinciding with the radially opposite side of the magnet slot (12); The permanent magnet synchronous motor also includes a cooling oil passage (2) formed in the magnet slot (12). The cooling oil passage (2) includes an axial oil passage (21) along the axis of the single iron core (11) and a radial oil passage (22) along the radial direction of the single iron core (11). The axial oil passage (21) and the radial oil passage (22) are connected to form a small passage oil passage (23) around the non-magnetized surface of the single magnet (13).

2. The permanent magnet synchronous motor according to claim 1, characterized in that: The rotating assembly (1) further includes a guide plate (14) disposed between the opposite end faces of the single iron core (11), the guide plate (14) forming a through hole communicating with a single magnet slot (12), the through hole forming the radial oil passage (22), the through hole communicating with the axial oil passage (21) to form the small passage oil passage (23).

3. The permanent magnet synchronous motor according to claim 2, characterized in that: The guide plate (14) also includes a limiting protrusion (141) that intersects with the through hole, and the projection of the limiting protrusion (141) along the axial direction overlaps with the side of the single magnet (13).

4. The permanent magnet synchronous motor according to claim 3, characterized in that: The rotating assembly (1) further includes: A rotating shaft (15) is provided, wherein the single-section iron core (11) is disposed on the circumferential surface of the rotating shaft (15), and the rotating shaft (15) is provided with a hollow pipe for introducing cooling oil. End caps (16) are provided at both ends of the iron core, and the end caps (16) form end oil passages for guiding the cooling oil in the hollow pipe to the magnet groove (12).

5. The permanent magnet synchronous motor according to claim 4, characterized in that: The end oil passage and the axial oil passage (21) form a large-passage oil passage (24), which shares the axial oil passage (21) with the small-passage oil passage (23).

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