Electric machine rotor and method of manufacturing thereof and self-starting synchronous reluctance machine

Abstract

This application provides a motor rotor, a method for manufacturing the same, and a self-starting synchronous reluctance motor. The motor rotor includes a rotor core with magnetic barrier slots and a central shaft hole. The magnetic barrier slots include a Q-axis magnetic barrier slot located on the outermost side of the Q-axis and a D-axis magnetic barrier slot located between the Q-axis magnetic barrier slot and the central shaft hole, extending along the D-axis. The D-axis magnetic barrier slot includes a non-cast aluminum region and cast aluminum regions located at both ends of the non-cast aluminum region. The Q-axis magnetic barrier slot and the cast aluminum regions are filled with a conductive but non-magnetic material. Rotor baffles are provided at both ends of the rotor core. Each rotor baffle has a shielding portion capable of shielding the non-cast aluminum region. A connecting magnetic barrier slot is provided on the rotor baffle corresponding to the Q-axis magnetic barrier slot and the cast aluminum region. An end ring is provided outside the rotor baffle, at least partially covering the non-cast aluminum region. According to the motor rotor of this application, the volume of the end ring can be increased, improving the motor's starting capability.

Description

Technical Field

[0001] This application relates to the field of motor technology, specifically to a motor rotor and its manufacturing method, and a self-starting synchronous reluctance motor. Background Technology

[0002] Direct-start synchronous reluctance motors combine the structural features of induction motors and synchronous reluctance motors. They achieve starting by generating torque through squirrel-cage induction and constant-speed operation by generating reluctance torque through the rotor inductance difference. They can be directly powered for starting and operation. Compared to direct-start permanent magnet motors, direct-start synchronous reluctance motors do not use rare-earth permanent magnet materials and do not suffer from demagnetization issues, resulting in lower motor costs and higher reliability. Compared to asynchronous motors, they offer higher efficiency and constant speed. Furthermore, direct-start synchronous reluctance motors can self-start without a controller, further reducing costs.

[0003] Self-starting motors generate starting torque by having the rotor bars cut the stator magnetic field. The rotor bars are made of conductive but non-magnetic material, typically pure aluminum, and are filled using a high-pressure casting process. After casting, end rings are formed at both ends of the rotor, short-circuiting all or some of the bars.

[0004] The rotor core has multiple sets of identical air slots, and the number of air slot sets is equal to the number of rotor poles. According to the shape of the air slots, the radial direction parallel to the air slots is called the D-axis, and the radial direction perpendicular to the air slots is called the Q-axis. The air slots are divided into multiple layers along the Q-axis. Each layer of air slots is divided into cast aluminum slots on the D-axis, cast aluminum slots on the Q-axis, and non-cast aluminum slots. The cast aluminum slots and non-cast aluminum slots are separated by an inner magnetic bridge. The air slots and the outer circle of the rotor are separated by an outer magnetic bridge.

[0005] Due to the location of the non-cast aluminum tank, in order to prevent the molten aluminum from entering the non-cast aluminum tank during the casting process, the end ring structure needs to be restricted so that the end ring is only cast in the area of ​​the cast aluminum tank and avoids the area of ​​the non-cast aluminum tank. As a result, the volume of the end ring is restricted, which reduces the starting capability of the motor. Summary of the Invention

[0006] Therefore, the technical problem to be solved by this application is to provide a motor rotor and its manufacturing method, and a self-starting synchronous reluctance motor, which can increase the volume of the end ring and improve the starting capability of the motor.

[0007] To address the aforementioned problems, this application provides a motor rotor, including a rotor core. The rotor core has magnetic barrier slots and a central shaft hole. The magnetic barrier slots include a Q-axis magnetic barrier slot located on the outermost side of the Q-axis and a D-axis magnetic barrier slot located between the Q-axis magnetic barrier slot and the central shaft hole and extending along the D-axis. The D-axis magnetic barrier slot includes a non-cast aluminum region and cast aluminum regions located at both ends of the non-cast aluminum region. The Q-axis magnetic barrier slots and the cast aluminum regions are filled with a conductive but non-magnetic material. Rotor baffles are provided at both ends of the rotor core. The rotor baffles have shielding portions capable of shielding the non-cast aluminum regions. A connecting magnetic barrier slot is provided on the rotor baffles corresponding to the Q-axis magnetic barrier slots and the cast aluminum regions. An end ring is provided outside the rotor baffles, and the end ring at least partially covers the non-cast aluminum regions.

[0008] Preferably, the edge of the connecting magnetic barrier groove corresponding to the D-axis magnetic barrier groove near the Q-axis is aligned with the edge of the non-cast aluminum region away from the Q-axis.

[0009] Preferably, a tooling hole is provided between the cast aluminum zone and the non-cast aluminum zone, penetrating the rotor core axially, and the tooling hole penetrates the rotor baffle and end ring axially.

[0010] Preferably, the cast aluminum area and the non-cast aluminum area are separated by tooling holes.

[0011] Preferably, the tooling hole is symmetrical about the Q axis, the distance between the inner edge of the tooling hole near the Q axis and the Q axis is Lmn, the width of the tooling hole along the Q axis direction is Wmn, Lmn≥Wmn, where n is the layer number of the magnetic barrier groove of the D axis starting from the D axis along the Q axis direction.

[0012] Preferably, the outer diameter of the rotor core is Dr, and the distance Lmn between the inner edge of the tooling hole near the Q-axis and the Q-axis satisfies the following conditions:

[0013] Preferably, the outer diameter of the rotor core is Dr, and the width Wmn of the tooling hole along the Q-axis direction satisfies...

[0014] Preferably, the height of the rotor core is H, and the axial height of the end ring is HT.

[0015] Preferably, the diameter of the central shaft hole is Dsft, the outer diameter of the rotor core is Dr, and the outer diameter of the end ring is D. and

[0016] Preferably, the radial width of one side of the end ring is W3, the diameter of the central shaft hole of the rotor core is Dsft, and the outer diameter of the rotor core is Dr, wherein...

[0017]

[0018] According to another aspect of this application, a self-starting synchronous reluctance motor is provided, including a motor rotor, which is the motor rotor described above.

[0019] According to another aspect of this application, a method for manufacturing the above-mentioned motor rotor is provided, comprising:

[0020] Machining rotor laminations with Q-axis magnetic barrier grooves and D-axis magnetic barrier grooves;

[0021] Machining a rotor baffle with a connecting magnetic barrier groove and a shielding section that blocks the non-cast aluminum area;

[0022] The rotor laminations are stacked to form a rotor core, and rotor baffles are installed at both ends of the rotor core, so that the connecting magnetic barrier grooves of the rotor baffles are aligned with the cast aluminum area of ​​the rotor core, and tooling holes are formed between the shielding part of the rotor baffles and the cast aluminum area of ​​the rotor core.

[0023] Insert the support fixture into the fixture hole;

[0024] The cast aluminum region of the rotor core, the Q-axis magnetic barrier slot, and the connecting magnetic barrier slot of the rotor baffle are filled with conductive and non-magnetic material, and an end ring is formed on the outer side of the rotor baffle along the axial direction. The supporting fixture passes through the end ring along the axial direction.

[0025] Remove the support fixture.

[0026] Preferably, the conductive but non-magnetic material is aluminum or copper.

[0027] The motor rotor provided in this application includes a rotor core with magnetic barrier slots and a central shaft hole. The magnetic barrier slots include a Q-axis magnetic barrier slot located on the outermost side of the Q-axis and a D-axis magnetic barrier slot located between the Q-axis magnetic barrier slot and the central shaft hole and extending along the D-axis. The D-axis magnetic barrier slot includes a non-cast aluminum region and cast aluminum regions located at both ends of the non-cast aluminum region. The Q-axis magnetic barrier slots and the cast aluminum regions are filled with a conductive but non-magnetic material. Rotor baffles are provided at both ends of the rotor core. The rotor baffles have shielding portions that can shield the non-cast aluminum regions. A connecting magnetic barrier slot is provided on the rotor baffles corresponding to the Q-axis magnetic barrier slots and the cast aluminum regions. An end ring is provided outside the rotor baffles, and the end ring at least partially covers the non-cast aluminum regions. The motor rotor has rotor baffles at both ends of the rotor core, which can block the magnetic barrier slots in the non-cast aluminum area of ​​the rotor core. Therefore, when casting the end ring, the support fixture can be used in conjunction with the rotor baffles to prevent the casting liquid from entering the non-cast aluminum area. At the same time, the formation of the end ring is not affected by the magnetic barrier slots in the non-cast aluminum area, and it can have a larger end ring volume, thereby effectively improving the starting capability of the motor. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a motor rotor according to an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of the rotor lamination structure of an electric motor rotor according to an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the rotor baffle structure of an electric motor rotor according to an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the rotor core structure of an electric motor rotor according to one embodiment of this application;

[0032] Figure 5 This is a longitudinal cross-sectional schematic diagram of a motor rotor according to an embodiment of this application;

[0033] Figure 6 The starting capability curve of the motor rotor with 2Lmn / Dr is shown in one embodiment of this application.

[0034] Figure 7 This is a comparison chart of the efficiency of a motor rotor according to one embodiment of this application and a motor rotor with an internal magnetic bridge.

[0035] The reference numerals in the attached figures are as follows:

[0036] 1. Rotor core; 2. Q-axis magnetic barrier slot; 3. D-axis magnetic barrier slot; 4. Central shaft hole; 5. Cast aluminum zone; 6. Non-cast aluminum zone; 7. End ring; 8. Rotor baffle; 9. Connecting magnetic barrier slot; 10. Tooling hole; 11. Shielding part. Detailed Implementation

[0037] See also Figures 1 to 7 As shown, according to an embodiment of this application, the motor rotor includes a rotor core 1. The rotor core 1 has magnetic barrier slots and a central shaft hole 4. The magnetic barrier slots include a Q-axis magnetic barrier slot 2 located on the outermost side of the Q-axis and a D-axis magnetic barrier slot 3 located between the Q-axis magnetic barrier slot 2 and the central shaft hole 4 and extending along the D-axis. The D-axis magnetic barrier slot 3 includes a non-cast aluminum region 6 and cast aluminum regions 5 located at both ends of the non-cast aluminum region 6. The Q-axis magnetic barrier slot 2 and the cast aluminum region 5 are filled with a conductive but non-magnetic material. Rotor baffles 8 are provided at both ends of the rotor core 1. The rotor baffles 8 have shielding portions 11 capable of shielding the non-cast aluminum region 6. Connecting magnetic barrier slots 9 are provided on the rotor baffles 8 corresponding to the Q-axis magnetic barrier slots 2 and the cast aluminum region 5. An end ring 7 is provided outside the rotor baffles 8, and the end ring 7 at least partially covers the non-cast aluminum region 6. In this embodiment, the shielding portion 11 is a flat plate structure between the connecting magnetic barrier slots 9 on the rotor baffles 8.

[0038] The motor rotor has rotor baffles 8 at both ends of the rotor core 1, which can block the magnetic barrier grooves in the non-cast aluminum region 6 of the rotor core 1. Therefore, when casting the end ring 7, the support fixture can be used in conjunction with the rotor baffles 8 to prevent the casting liquid from entering the non-cast aluminum region 6. At the same time, the formation of the end ring 7 is not affected by the magnetic barrier grooves in the non-cast aluminum region 6, and it can have a larger end ring 7 volume, thereby effectively improving the starting capability of the motor.

[0039] In one embodiment, the edge of the connecting magnetic barrier groove 9 near the Q axis, which corresponds to the magnetic barrier groove 3 of the D axis, is aligned with the edge of the non-cast aluminum region 6 away from the Q axis. Alternatively, it can be partially located on the radial outer side of the non-cast aluminum region 6. The connecting magnetic barrier groove 9 can be used to isolate the connecting channel between the cast aluminum region 5 and the non-cast aluminum region 6 by cooperating with the tooling, effectively preventing conductive and non-magnetic materials such as molten aluminum from entering the non-cast aluminum region 6 during the casting process in the cast aluminum region 5.

[0040] In one embodiment, a tooling hole 10 is provided between the cast aluminum region 5 and the non-cast aluminum region 6, penetrating the rotor core 1 axially. The tooling hole 10 also penetrates the rotor baffle 8 and the end ring 7 axially. In this embodiment, the tooling hole 10 penetrates the entire motor rotor axially, including the rotor core 1, the rotor baffle 8, and the end ring 7. This allows the tooling to replace the internal magnetic bridge during the casting process, effectively blocking the communication channel between the cast aluminum region 5 and the non-cast aluminum region 6. This prevents the non-cast aluminum region 6 from entering the cast aluminum, effectively reducing the amount of cast aluminum and the rotor weight while maintaining magnetic barrier strength. Furthermore, after removing the tooling, the end ring 7 retains the clearance hole left by the tooling, providing a heat dissipation channel, improving heat dissipation capacity, reducing the amount of filler material, making the motor lighter, and reducing costs.

[0041] The material filled in the cast aluminum region 5 in this application is a conductive but non-magnetic material. The cast aluminum region 5 is only a name for the filling region and does not limit the filling material. Any conductive but non-magnetic material that can be used as a conductor can be filled into the cast aluminum region 5. For example, the conductive but non-magnetic material is aluminum or copper.

[0042] The motor rotor divides the D-axis magnetic barrier slot 3 of the rotor core 1 into a cast aluminum region 5 and a non-cast aluminum region 6. The cast aluminum region 5 is filled with a conductive but non-magnetic material, which connects the cast aluminum region 5 and the non-cast aluminum region 6. This removes the internal magnetic bridge between the cast aluminum region 5 and the non-cast aluminum region 6, forming a motor rotor without internal magnetic bridges. This effectively reduces rotor leakage magnetism, increases the rotor salient pole ratio, and improves motor efficiency and performance.

[0043] The channel formed between adjacent D-axis magnetic barrier slots 3 is a magnetic channel, which can form a magnetic circuit channel during motor operation, allowing magnetic lines of force to flow through.

[0044] The rotor core 1 has multiple sets of identical air slots as magnetic barrier slots, and the number of air slot sets is the same as the number of rotor poles. Each set of air slots is divided into multiple layers along the Q-axis, and each layer of air slots contains only one slot. Each layer of air slots is adjacent to the magnetic channel along the Q-axis, and the outermost edge along the D-axis is the outer magnetic bridge, which is adjacent to the air gap.

[0045] Because the motor rotor in this application does not have an internal magnetic bridge, the shape of the rotor bars formed by the conductive and non-magnetic material and the end rings 7 at both ends can be flexibly adjusted, enabling the motor's starting capability to be optimized and improving its starting performance. (See also...) Figure 7 As shown, compared to a motor with an internal magnetic bridge, the performance of the motor without an internal magnetic bridge in this application embodiment is improved by at least 1%.

[0046] Furthermore, since the inner magnetic bridge is eliminated, the filling material in the cast aluminum zone 5 can be used to replace the function of the inner magnetic bridge, which can significantly increase the structural strength of the motor rotor.

[0047] In one embodiment, the cast aluminum region 5 and the non-cast aluminum region 6 are separated by a tooling hole 10. In this embodiment, since the tooling hole 10 is used to install tooling during the aluminum casting process, the tooling can be used as a structure to separate the cast aluminum region 5 and the non-cast aluminum region 6. At the same time, since the non-cast aluminum region 6 is an air groove, and the tooling hole 10 is also an air groove after the tooling is removed, in this case, the tooling hole 10 on the rotor core 1 can also be considered to belong to the non-cast aluminum region 6, and the cast aluminum region 5 and the non-cast aluminum region 6 are directly connected.

[0048] In one embodiment, the tooling hole 10 is symmetrical about the Q axis, the distance between the inner edge of the tooling hole 10 near the Q axis and the Q axis is Lmn, the width of the tooling hole 10 along the Q axis direction is Wmn, Lmn≥Wmn, where n is the layer number of the D-axis magnetic barrier groove 3 along the Q axis direction starting from the D axis.

[0049] In one embodiment, the outer diameter of the rotor core 1 is Dr, and the distance Lmn between the inner edge of the tooling hole 10 near the Q-axis and the Q-axis satisfies by Figure 1 For example, Lmn should satisfy

[0050] In one embodiment, the outer diameter of the rotor core 1 is Dr, and the width Wmn of the tooling hole 10 along the Q-axis direction satisfies... by Figure 1 For example, Wmn should satisfy

[0051] In one embodiment, the height of the rotor core 1 is H, and the axial height of the end ring 7 is HT. This ensures that the end ring 7 has sufficient axial height, which reduces resistance and improves starting capability. In this embodiment, within the cross-section passing through the central axis of the rotor core 1, the axial heights of the end ring 7 are HT1, HT2, HT3, and HT4, respectively. These axial heights all meet the aforementioned constraints, thus enabling the overall height of the end ring 7 to provide a larger magnetic conduction channel and lower resistance, thereby improving the motor's starting capability.

[0052] In one embodiment, the diameter of the central shaft hole 4 is Dsft, the outer diameter of the rotor core 1 is Dr, and the outer diameter of the end ring 7 is D. and

[0053] In one embodiment, the end ring 7 is annular, the radial width of one side of the end ring 7 is W3, the diameter of the central shaft hole 4 of the rotor core is Dsft, and the outer diameter of the rotor core is Dr.

[0054] This ensures that end ring 7 has sufficient area, allowing for a larger end ring volume and improved motor starting capability.

[0055] In one embodiment, an outer magnetic bridge is provided on the outer periphery of the magnetic barrier groove, which can improve the structural strength of the rotor core 1.

[0056] In one embodiment, the inner ring of the end ring 7 can be circular or other shapes.

[0057] In one embodiment, the outer ring of the end ring 7 can be circular or other shapes.

[0058] In one embodiment, an outer magnetic bridge is provided on the outer periphery of the magnetic barrier groove, which can improve the structural strength of the rotor core 1.

[0059] According to an embodiment of this application, the self-starting synchronous reluctance motor includes a motor rotor, which is the motor rotor described above.

[0060] According to an embodiment of this application, the above-mentioned method for manufacturing a motor rotor includes: processing rotor laminations having Q-axis magnetic barrier slots 2 and D-axis magnetic barrier slots 3; processing rotor baffles 8 having connecting magnetic barrier slots 9 and shielding portions 11 that shield non-cast aluminum regions; stacking rotor laminations into a rotor core 1, and installing rotor baffles 8 at both ends of the rotor core 1, such that the connecting magnetic barrier slots 9 of the rotor baffles 8 are aligned with the cast aluminum regions 5 of the rotor core 1, and forming a tooling hole 10 between the shielding portions 11 of the rotor baffles 8 and the cast aluminum regions of the rotor core; inserting a support tooling into the tooling hole 10; filling the cast aluminum regions 5 of the rotor core 1, the Q-axis magnetic barrier slots 2, and the connecting magnetic barrier slots 9 of the rotor baffles 8 with conductive and non-magnetic material, and forming an end ring 7 on the axially outer side of the rotor baffles 8, with the support tooling penetrating the end ring 7 axially; and removing the support tooling.

[0061] In this embodiment, the supporting fixture serves to replace the inner magnetic bridge during the casting process to restrict the flow of conductive and non-magnetic materials, separate the cast aluminum zone 5 from the non-cast aluminum zone 6, and cooperate with the shielding part 11 on the rotor baffle 8 to prevent molten aluminum from entering the non-cast aluminum zone 6 during the casting of the end ring 7. In this embodiment, the conductive and non-magnetic material is filled into the D-axis magnetic barrier groove 3, and each layer of D-axis magnetic barrier groove 3 is only filled with conductive and non-magnetic material in the cast aluminum zone 5 at both ends along the D-axis direction, while the non-cast aluminum zone 6 between the two ends of the cast aluminum zone 5 remains air.

[0062] The conductive but non-magnetic material is aluminum or copper.

[0063] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0064] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A motor rotor, characterized in that, The rotor core (1) is provided with magnetic barrier grooves and a central shaft hole (4). The magnetic barrier grooves include a Q-axis magnetic barrier groove (2) located on the outermost side of the Q-axis and a D-axis magnetic barrier groove (3) located between the Q-axis magnetic barrier groove (2) and the central shaft hole (4) and extending along the D-axis. The D-axis magnetic barrier groove (3) includes a non-cast aluminum region (6) and cast aluminum regions (5) located at both ends of the non-cast aluminum region (6). The Q-axis magnetic barrier groove (2) and the cast aluminum region (5) are connected together. The region (5) is filled with a conductive but non-magnetic material. Rotor baffles (8) are provided at both ends of the rotor core (1). The rotor baffles (8) have shielding parts (11) that can shield the non-cast aluminum region (6). A connecting magnetic barrier groove (9) is provided on the rotor baffles (8) corresponding to the Q-axis magnetic barrier groove (2) and the cast aluminum region (5). An end ring (7) is provided outside the rotor baffles (8). The end ring (7) at least partially covers the non-cast aluminum region (6). The edge of the connecting magnetic barrier groove (9) corresponding to the magnetic barrier groove (3) of the D-axis is aligned with the edge of the non-cast aluminum region (6) away from the Q-axis; A tooling hole (10) is provided between the cast aluminum zone (5) and the non-cast aluminum zone (6) and penetrates the rotor core (1) axially. The tooling hole (10) penetrates the rotor baffle (8) and the end ring (7) axially.

2. The motor rotor according to claim 1, characterized in that, The cast aluminum area (5) and the non-cast aluminum area (6) are separated by the tooling hole (10).

3. The motor rotor according to claim 2, characterized in that, The tooling hole (10) is symmetrical about the Q-axis. The distance between the inner edge of the tooling hole (10) near the Q-axis and the Q-axis is Lmn. The width of the tooling hole (10) along the Q-axis direction is Wmn. Wmn, where n is the layer number of the D-axis magnetic barrier groove (3) along the Q-axis direction starting from the D-axis.

4. The motor rotor according to claim 3, characterized in that, The outer diameter of the rotor core (1) is Dr, and the distance Lmn between the inner edge of the tooling hole (10) near the Q-axis and the Q-axis satisfies .

5. The motor rotor according to claim 3, characterized in that, The outer diameter of the rotor core (1) is Dr, and the width Wmn of the tooling hole (10) along the Q-axis direction satisfies .

6. The motor rotor according to claim 1, characterized in that, The height of the rotor core (1) is H, and the axial height of the end ring (7) is HT. .

7. The motor rotor according to claim 1, characterized in that, The diameter of the central shaft hole (4) is Dsft, the outer diameter of the rotor core (1) is Dr, and the outer diameter of the end ring (7) is D. ,and .

8. The motor rotor according to claim 1, characterized in that, The radial width of one side of the end ring (7) is W3, the diameter of the central shaft hole (4) of the rotor core is Dsft, and the outer diameter of the rotor core is Dr. .

9. A self-starting synchronous reluctance motor, comprising a motor rotor, characterized in that, The motor rotor is the motor rotor according to any one of claims 1 to 8.

10. A method for manufacturing a motor rotor as described in any one of claims 1 to 8, characterized in that, include: Machining rotor laminations with Q-axis magnetic barrier grooves (2) and D-axis magnetic barrier grooves (3); A rotor baffle (8) is machined, which has a connecting magnetic barrier groove (9) and a shielding part (11) that shields the non-cast aluminum area. The rotor laminations are stacked to form a rotor core (1), and rotor baffles (8) are installed at both ends of the rotor core (1) so that the connecting magnetic barrier groove (9) of the rotor baffle (8) is aligned with the cast aluminum area (5) of the rotor core (1), and a tooling hole (10) is formed between the shielding part (11) of the rotor baffle (8) and the cast aluminum area of ​​the rotor core. Insert the support fixture into the fixture hole (10); The cast aluminum region (5) of the rotor core (1), the Q-axis magnetic barrier groove (2) and the connecting magnetic barrier groove (9) of the rotor baffle (8) are filled with conductive and non-magnetic materials, and an end ring (7) is formed on the outer side of the rotor baffle (8) along the axial direction. The supporting fixture passes through the end ring (7) along the axial direction. Remove the support fixture.

11. The manufacturing method according to claim 10, characterized in that, The conductive but non-magnetic material is aluminum or copper.

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