A permanent magnet motor with a radially polarized spaced magnetic barrier

Abstract

The present invention provides a permanent magnet motor with a radial pole-spacing magnetic barrier, belonging to the technical field of automotive motor electrical appliances. The rotor core is evenly distributed with an even number of first √-shaped grooves in the circumferential direction. A second √-shaped groove is provided outside the first √-shaped groove, and a third reverse √-shaped groove is provided outside the second √-shaped groove. A first reverse √-shaped groove is provided between two adjacent first √-shaped grooves. A second reverse √-shaped groove is provided outside the first reverse √-shaped groove, and a third √-shaped groove is provided outside the second reverse √-shaped groove. A radial magnetic isolation groove is provided between the short sides of the first √-shaped groove and the first reverse √-shaped groove. A first magnetic isolation groove and a second magnetic isolation groove are respectively provided at the outward extensions of the short sides of the second √-shaped groove and the second reverse √-shaped groove. This motor adopts the method of setting radial magnetic isolation grooves between magnetic poles to reduce magnetic leakage and improve power density. Each layer of permanent magnet is provided with a permanent magnet barrier and permanent magnets of different shapes, reducing the content of magnetic density harmonics, weakening the cogging torque, and improving the motor efficiency.

Description

Technical Field

[0001] The present invention provides a permanent magnet motor with a radial pole-spacing magnetic barrier, belonging to the technical field of automotive motor electrical appliances. Background Art

[0002] Cogging torque is one of the unique problems of permanent magnet motors. Excessive cogging torque will cause fluctuations in the motor speed, affecting the efficiency and stability of the motor. Therefore, weakening the cogging torque is a key issue that must be considered in the design process of permanent magnet motors. Currently, there are many techniques for weakening cogging torque. For example, in the prior art, the published Chinese patent: An interior permanent magnet motor rotor and a permanent magnet motor having the same, application number: 201721891783.2, discloses a rotor structure composed of a first rotor lamination and a second rotor lamination. The radii of the arcs corresponding to the same permanent magnet slot of the first rotor lamination and the second rotor lamination are different, and the cogging torque is effectively weakened without using rotor skewing or stator skewing. The published Chinese patent: A skewed pole rotor structure of a permanent magnet synchronous motor, application number: 201210429721.5, discloses a skewed pole rotor structure of a permanent magnet synchronous motor, including a core segment and a plurality of magnetic tiles. The plurality of magnetic tiles are installed on the side surface of the core to form a plurality of magnetic poles, and a magnetic pole angle is formed between adjacent two magnetic poles, effectively reducing the cogging torque and the operating noise of the motor. When the motor rotor is composed of rotor laminations with different structures, the process is relatively complex and the cost is relatively high. The magnetic tiles are installed on the side surface of the core, and the motor is prone to demagnetization under harsh conditions, affecting the efficiency of the motor. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: on the premise of ensuring no increase in the processing procedures, process difficulty, and no significant change in the motor cost, overcoming the deficiencies of the prior art, providing a permanent magnet motor with a radial pole-spacing magnetic barrier. The structure of the motor is a permanent magnet motor in which each layer of permanent magnets has a magnetic barrier, and the magnetic barriers and permanent magnet steels are alternately distributed, enhancing the anti-demagnetization ability of the motor, weakening the cogging torque, using a radial magnetic barrier between adjacent magnetic poles, improving the power density, and the magnetic fluxes of the two-side pole arcs of each permanent magnet layer are provided by different permanent magnets, which is beneficial to adjusting the magnetic density of different pole arc segments, reducing the harmonic content of the air-gap magnetic density, reducing the motor loss, and improving the efficiency.

[0004] The technical solution adopted by the present invention to solve its technical problem is: a permanent magnet motor with a radial pole-spacing magnetic barrier, including a rotating shaft, a front end cover, a motor housing, a stator, a rear end cover, a rotor core, a first √-shaped groove, a second √-shaped groove, a third reverse √-shaped groove, a first reverse √-shaped groove, a second reverse √-shaped groove, a third √-shaped groove, and permanent magnet steels, characterized in that:

[0005] There are 4 evenly distributed first √-shaped slots on the rotor core. The included angle of the first √-shaped slots is greater than 90°. The short side of the first √-shaped slot is perpendicular to the center line of the magnetic pole where the first √-shaped slot is located, and the proximal ends of the first √-shaped slots are not connected.

[0006] A second √-shaped slot is provided outside the first √-shaped slot. A first magnetic isolation slot is provided at the extension along the short side of the second √-shaped slot. The first magnetic isolation slot is connected to the short side of the second √-shaped slot, and the proximal ends of the second √-shaped slots are not connected.

[0007] A third reverse √-shaped slot is provided outside the second √-shaped slot. The short side of the third reverse √-shaped slot coincides with the center line of the magnetic pole where the third reverse √-shaped slot is located. The proximal ends of the third reverse √-shaped slots are connected, and the included angle of the third reverse √-shaped slots is less than 90°.

[0008] A first reverse √-shaped slot is provided between two adjacent first √-shaped slots. A second reverse √-shaped slot is provided outside the first reverse √-shaped slot. A second magnetic isolation slot is provided at the extension along the short side of the second reverse √-shaped slot. A third √-shaped slot is provided outside the second reverse √-shaped slot.

[0009] A radial magnetic isolation slot is provided between the first reverse √-shaped slot and the first √-shaped slot.

[0010] The first reverse √-shaped slot and the first √-shaped slot are symmetric about the radial magnetic isolation slot. The second reverse √-shaped slot and the second √-shaped slot are symmetric about the radial magnetic isolation slot. The second magnetic isolation slot and the first magnetic isolation slot are symmetric about the radial magnetic isolation slot. The third √-shaped slot and the third reverse √-shaped slot are symmetric about the radial magnetic isolation slot.

[0011] Permanent magnets are placed in the first √-shaped slot, the second √-shaped slot, the first reverse √-shaped slot, and the second reverse √-shaped slot. Permanent magnets are placed in the long sides of the third reverse √-shaped slot and the long sides of the third √-shaped slot.

[0012] There is a 1.5 mm non-connected distance between the outer end of the long side of the first √-shaped slot and the outer circle of the rotor core.

[0013] There is a 1.5 mm non-connected distance between the outer end of the first magnetic isolation slot and the outer circle of the rotor core.

[0014] There is a 1.5 mm non-connected distance between the short side and the long side of the third reverse √-shaped slot and the outer circle of the rotor core.

[0015] There is a 1.5 mm non-connected distance between the proximal ends of the first reverse √-shaped slot and the first √-shaped slot.

[0016] The center line of the magnetic pole passes through the proximal end of the first √-shaped slot, and the center line of the magnetic pole passes through the proximal end of the second √-shaped slot.

[0017] The radial magnetic isolation slot is connected to the proximal end of the first reverse √-shaped slot and the proximal end of the first √-shaped slot.

[0018] The pole arc length between the outer ends of the long sides of the first √-shaped groove and the outer ends of the long sides of the second √-shaped groove is a, the pole arc length between the outer end of the radial magnetic barrier groove and the outer end of the first magnetic barrier groove is b, and the ratio of a to b is equal to the ratio of the length of the long side to the length of the short side of the first √-shaped groove. The pole arc length between the outer end of the long side of the second √-shaped groove and the outer end of the short side of the third reverse √-shaped groove is c, and the pole arc length between the outer end of the first magnetic barrier groove and the outer end of the long side of the third reverse √-shaped groove is d. The ratio of c to d is equal to the ratio of the length of the long side to the length of the short side of the second √-shaped groove.

[0019] Compared with the prior art, the present invention has the following technical effects:

[0020] (1) A radial magnetic barrier is used between adjacent magnetic poles, which reduces magnetic leakage while ensuring mechanical strength and improves power density.

[0021] (2) A magnetic barrier is provided for each layer of permanent magnets, which weakens the effect of the impact current and enhances the demagnetization resistance of the motor.

[0022] Compared with the multi-layer pure permanent magnet rotor structure, the rotor weight is reduced and the cost is lowered.

[0023] (3) The magnetic flux of the pole arcs on the left and right sides of each permanent magnet layer is provided by different permanent magnets, which is beneficial to adjusting the magnetic density of different pole arc segments, reducing the harmonic content of the air-gap magnetic density, reducing the motor loss and improving the efficiency.

[0024] (4) The present invention adopts an arrangement method of alternating magnetic barriers and permanent magnet steels, which weakens the cogging torque and improves the running stability of the motor. Brief Description of the Drawings

[0025] Figure 1 is a schematic diagram of the motor structure of the present invention.

[0026] Figure 2 is a schematic diagram of the rotor structure of the present invention.

[0027] In the figure: 1, rotating shaft; 2, front end cover; 3, machine shell; 4, stator; 5, rear end cover; 6, rotor core; 7, first √-shaped groove; 8, second √-shaped groove; 9, third reverse √-shaped groove; 10, first reverse √-shaped groove; 11, second reverse √-shaped groove; 12, third √-shaped groove. Detailed Embodiments

[0028] The present invention will be further described below with reference to the accompanying drawings.

[0029] A permanent magnet motor with a radial pole interval magnetic barrier includes a rotating shaft 1, a front end cover 2, a machine shell 3, a stator 4, a rear end cover 5, a rotor core 6, a first √-shaped groove 7, a second √-shaped groove 8, a third reverse √-shaped groove 9, a first reverse √-shaped groove 10, a second reverse √-shaped groove 11, a third √-shaped groove 12, and permanent magnet steels, and is characterized in that:

[0030] There are 4 first √-shaped grooves 7 evenly distributed on the rotor core 6. The included angle of the first √-shaped grooves 7 is greater than 90°. The short sides of the first √-shaped grooves 7 are perpendicular to the center line of the magnetic poles where the first √-shaped grooves 7 are located. The proximal ends of the first √-shaped grooves 7 are not connected.

[0031] A second √-shaped groove 8 is provided outside the first √-shaped groove 7. A first magnetic isolation groove is provided at the extension along the short side of the second √-shaped groove 8. The first magnetic isolation groove is connected to the short side of the second √-shaped groove 8. The proximal ends of the second √-shaped grooves 8 are not connected.

[0032] A third reverse √-shaped groove 9 is provided outside the second √-shaped groove 8. The short side of the third reverse √-shaped groove 9 coincides with the center line of the magnetic pole where the third reverse √-shaped groove 9 is located. The proximal ends of the third reverse √-shaped grooves 9 are connected. The included angle of the third reverse √-shaped grooves 9 is less than 90°.

[0033] A first reverse √-shaped groove 10 is provided between two adjacent first √-shaped grooves 7. A second reverse √-shaped groove 11 is provided outside the first reverse √-shaped groove 10. A second magnetic isolation groove is provided at the extension along the short side of the second reverse √-shaped groove 11. A third √-shaped groove 12 is provided outside the second reverse √-shaped groove 11.

[0034] A radial magnetic isolation groove is provided between the first reverse √-shaped groove 10 and the first √-shaped groove 7.

[0035] The first reverse √-shaped groove 10 and the first √-shaped groove 7 are symmetric about the radial magnetic isolation groove. The second reverse √-shaped groove 11 and the second √-shaped groove 8 are symmetric about the radial magnetic isolation groove. The second magnetic isolation groove and the first magnetic isolation groove are symmetric about the radial magnetic isolation groove. The third √-shaped groove 12 and the third reverse √-shaped groove 9 are symmetric about the radial magnetic isolation groove.

[0036] Permanent magnets are placed in the first √-shaped grooves 7, the second √-shaped grooves 8, the first reverse √-shaped grooves 10, and the second reverse √-shaped grooves 11. Permanent magnets are placed in the long sides of the third reverse √-shaped grooves 9 and the long sides of the third √-shaped grooves 12.

[0037] There is a non-connected distance of 1.5 mm between the outer end of the long side of the first √-shaped groove 7 and the outer circle of the rotor core 6.

[0038] There is a non-connected distance of 1.5 mm between the outer end of the first magnetic isolation groove and the outer circle of the rotor core 6.

[0039] There is a non-connected distance of 1.5 mm between the short side of the third reverse √-shaped groove 9, the long side of the third reverse √-shaped groove 9 and the outer circle of the rotor core 6.

[0040] There is a non-connected distance of 1.5 mm between the proximal ends of the first reverse √-shaped groove 10 and the first √-shaped groove 7.

[0041] The center line of the magnetic pole passes through the proximal end of the first √-shaped groove 7, and the center line of the magnetic pole passes through the proximal end of the second √-shaped groove 8.

[0042] The radially magnet isolation slot is connected to the proximal end of the first reverse √-shaped slot 10, and the radially magnet isolation slot is connected to the proximal end of the first √-shaped slot 7.

[0043] The pole arc segment between the outer ends of the long sides of the first √-shaped slot 7 and the outer ends of the long sides of the second √-shaped slot 8 is provided with a magnetic field by the permanent magnet steel inside the long side of the first √-shaped slot 7. The pole arc segment between the outer end of the radially magnet isolation slot and the outer end of the first magnet isolation slot is provided with a magnetic field by the permanent magnet steel inside the short side of the first √-shaped slot 7. The pole arc segment between the outer end of the long side of the second √-shaped slot 8 and the outer end of the short side of the third reverse √-shaped slot 9 is provided with a magnetic field by the permanent magnet steel inside the long side of the second √-shaped slot 8. The pole arc segment between the outer end of the first magnet isolation slot and the outer end of the long side of the third reverse √-shaped slot 9 is provided with a magnetic field by the permanent magnet steel inside the short side of the second √-shaped slot 8.

Claims

1. A permanent magnet motor with a radial pole-spacing magnetic barrier, comprising a rotating shaft (1), a front end cover (2), a motor housing (3), a stator (4), a rear end cover (5), a rotor core (6), a first √-shaped groove (7), a second √-shaped groove (8), a third reverse √-shaped groove (9), a first reverse √-shaped groove (10), a second reverse √-shaped groove (11), a third √-shaped groove (12), and permanent magnet steels, characterized in that: An even number of first √-shaped grooves (7) are evenly distributed on the rotor core (6). The included angle of the first √-shaped grooves (7) is greater than 90°. The short side of the first √-shaped groove (7) is perpendicular to the center line of the magnetic pole where the first √-shaped groove (7) is located, and the proximal ends of the first √-shaped grooves (7) are not connected. A second √-shaped groove (8) is provided outside the first √-shaped groove (7). A first magnetic isolation groove is provided at the extension along the short side of the second √-shaped groove (8). The first magnetic isolation groove is connected to the short side of the second √-shaped groove (8), and the proximal ends of the second √-shaped grooves (8) are not connected. A third reverse √-shaped groove (9) is provided outside the second √-shaped groove (8). The short side of the third reverse √-shaped groove (9) coincides with the center line of the magnetic pole where the third reverse √-shaped groove (9) is located. The proximal ends of the third reverse √-shaped grooves (9) are connected, and the included angle of the third reverse √-shaped grooves (9) is less than 90°. A first reverse √-shaped groove (10) is provided between two adjacent first √-shaped grooves (7). A second reverse √-shaped groove (11) is provided outside the first reverse √-shaped groove (10). A second magnetic isolation groove is provided at the extension along the short side of the second reverse √-shaped groove (11). A third √-shaped groove (12) is provided outside the second reverse √-shaped groove (11). A radial magnetic isolation groove is provided between the first reverse √-shaped groove (10) and the first √-shaped groove (7). The first reverse √-shaped groove (10) and the first √-shaped groove (7) are symmetric about the radial magnetic isolation groove. The second reverse √-shaped groove (11) and the second √-shaped groove (8) are symmetric about the radial magnetic isolation groove. The second magnetic isolation groove and the first magnetic isolation groove are symmetric about the radial magnetic isolation groove. The third √-shaped groove (12) and the third reverse √-shaped groove (9) are symmetric about the radial magnetic isolation groove. Permanent magnet steels are placed in the first √-shaped groove (7), the second √-shaped groove (8), the first reverse √-shaped groove (10), and the second reverse √-shaped groove (11). Permanent magnet steels are placed in the long sides of the third reverse √-shaped groove (9) and the third √-shaped groove (12).

2. The permanent magnet motor with a radial pole interval magnetic barrier according to claim 1, wherein: There is a non-connected distance of 1.5 mm between the outer end of the long side of the first √-shaped groove (7) and the outer circle of the rotor core (6). There is a non-connected distance of 1.5 mm between the outer end of the first magnetic isolation groove and the outer circle of the rotor core (6). There is a non-connected distance of 1.5 mm between the short side and the long side of the third reverse √-shaped groove (9) and the outer circle of the rotor core (6). There is a non-connected distance of 1.5 mm between the proximal ends of the first reverse √-shaped groove (10) and the first √-shaped groove (7).

3. A permanent magnet motor having a radial pole interval magnetic barrier according to claim 1, characterized in that: The center line of the magnetic pole passes through the proximal end of the first √-shaped groove (7). The center line of the magnetic pole passes through the proximal end of the second √-shaped groove (8). The radial magnetic isolation groove is connected to the proximal ends of the first reverse √-shaped groove (10) and the first √-shaped groove (7).

4. A permanent magnet motor having a radial pole interval magnetic barrier according to claim 1, characterized in that: The pole arc length between the outer ends of the long sides of the first √-shaped groove (7) and the outer ends of the long sides of the second √-shaped groove (8) is a, the pole arc length between the outer end of the radial magnetic isolation groove and the outer end of the first magnetic isolation groove is b, and the ratio of a to b is equal to the ratio of the long side length to the short side length of the first √-shaped groove (7). The pole arc length between the outer end of the long side of the second √-shaped groove (8) and the outer end of the short side of the third reverse √-shaped groove (9) is c, and the pole arc length between the outer end of the first magnetic isolation groove and the outer end of the long side of the third reverse √-shaped groove (9) is d. The ratio of c to d is equal to the ratio of the long side length to the short side length of the second √-shaped groove (8).

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