Permanent magnet motor with radial pole spacing magnetic barriers

Abstract

The invention provides a permanent magnet motor with radial pole spacing magnetic barriers, and belongs to the technical field of automobile motor electric appliances. An even number of first V-shaped grooves are evenly distributed in the rotor core in the circumferential direction, second V-shaped grooves are formed in the outer sides of the first V-shaped grooves, third V-shaped grooves are formed in the outer sides of the second V-shaped grooves, first V-shaped grooves are formed between every two adjacent first V-shaped grooves, second V-shaped grooves are formed in the outer sides of the first V-shaped grooves, and third V-shaped grooves are formed in the outer sides of the third V-shaped grooves. A third V-shaped groove is formed in the outer side of the second V-shaped groove, a radial magnetic isolation groove is formed between the short edge of the first V-shaped groove and the short edge of the second V-shaped groove, and a first magnetic isolation groove and a second magnetic isolation groove are formed in the outward extending positions of the second V-shaped groove and the short edge of the second V-shaped groove respectively. The motor adopts a mode that the radial magnetic isolation grooves are arranged between the magnetic poles, magnetic leakage is reduced, power density is improved, each layer of permanent magnet is provided with the permanent magnet barrier and the permanent magnets in different shapes, flux density harmonic content is reduced, cogging torque is weakened, and motor efficiency is improved.

Description

Technical Field

[0001] The invention provides a permanent magnet motor with radial pole spacing magnetic barriers, belonging to the technical field of automobile motors and electrical appliances. Background Art

[0002] Cogging torque is one of the unique problems of permanent magnet motors. If the cogging torque is too large, the motor speed will fluctuate, affecting the efficiency and stability of the motor. Therefore, reducing the cogging torque is a key issue that must be considered in the design process of permanent magnet motors. At present, there are many technologies for reducing cogging torque, such as the prior art, the announced Chinese patent: a built-in permanent magnet motor rotor and a permanent magnet motor having the built-in permanent magnet motor rotor, application number: 201721891783.2, discloses a rotor structure composed of a first rotor lamination and a second rotor lamination, the first rotor lamination and the second rotor lamination have different radii of the arc corresponding to the same permanent magnet slot, and the cogging torque is effectively reduced without using rotor skew poles or stator skew slots. The announced 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, and discloses a rotor structure including a section of iron core and a plurality of magnetic tiles, wherein the plurality of magnetic tiles are installed on the side surface of the iron core to form a plurality of magnetic poles, and the adjacent two magnetic poles form a magnetic pole angle, which effectively reduces the cogging torque and the motor running noise. When the motor rotor is composed of rotor laminations of different structures, the process is more complicated and the cost is higher. The magnetic tiles are installed on the side surface of the iron core, and the motor is prone to demagnetization under harsh conditions, which affects the efficiency of the motor. Summary of the invention

[0003] The technical problem to be solved by the present invention is: under the premise of ensuring that the processing procedures are not increased, the process difficulty and the motor cost are not greatly changed, the shortcomings of the prior art are overcome and a permanent magnet motor with radial pole spacing magnetic barriers is provided. The motor structure is that each layer of permanent magnets has a magnetic barrier, and the magnetic barriers and permanent magnet steel are alternately distributed. The permanent magnet motor enhances the motor's anti-demagnetization ability and weakens the cogging torque. Adjacent magnetic poles use a radial magnetic barrier to improve the power density. The magnetic flux of the pole arcs on both sides of each permanent magnet layer is provided by different permanent magnets, which is conducive to adjusting the magnetic flux of different pole arc segments, reducing the harmonic content of the air gap magnetic density, reducing motor losses and improving efficiency.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a permanent magnet motor with radial pole spacing magnetic barriers, including a rotating shaft, a front cover, a housing, a stator, a rear cover, a rotor core, a first √-shaped slot, a second √-shaped slot, a third inverted √-shaped slot, a first inverted √-shaped slot, a second inverted √-shaped slot, a third √-shaped slot, and permanent magnet steel, characterized in that: Four first √-shaped slots are evenly distributed on the rotor core, the included angle of the first √-shaped slots is greater than 90°, the short sides of the first √-shaped slots are perpendicular to the center line of the magnetic pole where the first √-shaped slots are located, and the proximal ends of the first √-shaped slots are not connected; A second √-shaped groove is provided outside the first √-shaped groove, and a first magnetic isolation groove is provided at the part extending outward along the short side of the second √-shaped groove. The first magnetic isolation groove is connected to the short side of the second √-shaped groove, and the proximal end of the second √-shaped groove is not connected; A third inverted groove is provided on the outer side of the second inverted groove, the short side of the third inverted groove coincides with the center line of the magnetic pole where the third inverted groove is located, the proximal end of the third inverted groove is connected, and the included angle of the third inverted groove is less than 90°; A first inverted groove is provided between two adjacent first inverted grooves, a second inverted groove is provided on the outer side of the first inverted groove, a second magnetic isolation groove is provided along the short side of the second inverted groove, and a third inverted groove is provided on the outer side of the second inverted groove; A radial magnetic isolation groove is provided between the first inverted √-shaped groove and the first √-shaped groove; The first inverted √-shaped groove and the first √-shaped groove are symmetrical about the radial magnetic isolation groove, the second inverted √-shaped groove and the second √-shaped groove are symmetrical about the radial magnetic isolation groove, the second magnetic isolation groove and the first magnetic isolation groove are symmetrical about the radial magnetic isolation groove, and the third √-shaped groove and the third inverted √-shaped groove are symmetrical about the radial magnetic isolation groove; Permanent magnets are placed in the first √-shaped slot, the second √-shaped slot, the first inverted √-shaped slot, and the second inverted √-shaped slot. Permanent magnets are placed in the long side of the third inverted √-shaped slot and the long side of the third √-shaped slot.

[0005] There is a 1.5mm disconnected distance between the outer end of the long side of the first √-shaped slot and the outer circle of the rotor core; There is a 1.5mm disconnected distance between the outer end of the first magnetic isolation slot and the outer circle of the rotor core; There is a 1.5mm disconnected distance between the short side of the third inverted slot, the long side of the third inverted slot and the outer circle of the rotor core; There is a non-connected distance of 1.5 mm between the first inverted √-shaped groove and the proximal end of the first √-shaped groove.

[0006] 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; The radial magnetic isolation groove is connected to the proximal end of the first inverted √-shaped groove, and the radial magnetic isolation groove is connected to the proximal end of the first √-shaped groove.

[0007] The pole arc length between the outer end of the long side of the first √-shaped slot and the outer end of the long side of the second √-shaped slot is a, the pole arc length between the outer end of the radial magnetic isolation slot and the outer end of the first magnetic isolation slot is b, the ratio of a to b is equal to the ratio of the long side length of the first √-shaped slot to the short side length of the first √-shaped slot, the pole arc length between the outer end of the long side of the second √-shaped slot and the outer end of the short side of the third inverted √-shaped slot is c, the pole arc length between the outer end of the first magnetic isolation slot and the outer end of the long side of the third inverted √-shaped slot is d, the ratio of c to d is equal to the ratio of the long side length of the second √-shaped slot to the short side length of the second √-shaped slot.

[0008] Compared with the prior art, the present invention has the following technical effects: (1) Adjacent magnetic poles use a radial magnetic barrier to ensure mechanical strength while reducing magnetic leakage and increasing power density; (2) Each layer of permanent magnets is equipped with a magnetic barrier to reduce the impact of current and enhance the motor's ability to resist demagnetization; Compared with the multi-layer pure permanent magnet rotor structure, it reduces the rotor weight and cost; (3) The magnetic flux of the left and right pole arcs of each permanent magnet layer is provided by different permanent magnets, which is conducive to adjusting the magnetic flux density of different pole arc segments, reducing the harmonic content of the air gap magnetic flux density, reducing motor losses and improving efficiency; (4) The present invention adopts an alternating arrangement of magnetic barriers and permanent magnet steel to weaken the cogging torque and improve the running stability of the motor; BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the motor structure of the present invention.

[0010] Figure 2 It is a schematic diagram of the rotor structure of the present invention.

[0011] In the figure: 1, rotating shaft; 2, front end cover; 3, casing; 4, stator; 5, rear end cover; 6, rotor core; 7, first √-shaped slot; 8, second √-shaped slot; 9, third inverse √-shaped slot; 10, first inverse √-shaped slot; 11, second inverse √-shaped slot; 12, third √-shaped slot. DETAILED DESCRIPTION

[0012] The present invention will be further described below in conjunction with the accompanying drawings.

[0013] A permanent magnet motor with radial pole spacing magnetic barriers, comprising a rotating shaft 1, a front end cover 2, a housing 3, a stator 4, a rear end cover 5, a rotor core 6, a first √-shaped slot 7, a second √-shaped slot 8, a third inverted √-shaped slot 9, a first inverted √-shaped slot 10, a second inverted √-shaped slot 11, a third √-shaped slot 12, and permanent magnet steel, characterized in that: Four first √-shaped slots 7 are evenly distributed on the rotor core 6, the included angle of the first √-shaped slots 7 is greater than 90°, the short sides of the first √-shaped slots 7 are perpendicular to the center line of the magnetic pole where the first √-shaped slots 7 are located, and the proximal ends of the first √-shaped slots 7 are not connected; A second √-shaped groove 8 is provided on the outer side of the first √-shaped groove 7, and a first magnetic isolation groove is provided along the short side of the second √-shaped groove 8 extending outwardly, the first magnetic isolation groove is connected to the short side of the second √-shaped groove 8, and the proximal end of the second √-shaped groove 8 is not connected; A third inverted groove 9 is provided on the outer side of the second inverted groove 8, the short side of the third inverted groove 9 coincides with the center line of the magnetic pole where the third inverted groove 9 is located, the proximal end of the third inverted groove 9 is connected, and the angle of the third inverted groove 9 is less than 90°; A first inverted groove 10 is provided between two adjacent first inverted grooves 7, a second inverted groove 11 is provided on the outer side of the first inverted groove 10, a second magnetic isolation groove is provided along the short side of the second inverted groove 11, and a third inverted groove 12 is provided on the outer side of the second inverted groove 11; A radial magnetic isolation groove is provided between the first inverted √-shaped groove 10 and the first √-shaped groove 7; The first inverted √-shaped groove 10 and the first √-shaped groove 7 are symmetrical about the radial magnetic isolation groove, the second inverted √-shaped groove 11 and the second √-shaped groove 8 are symmetrical about the radial magnetic isolation groove, the second magnetic isolation groove and the first magnetic isolation groove are symmetrical about the radial magnetic isolation groove, and the third √-shaped groove 12 and the third inverted √-shaped groove 9 are symmetrical about the radial magnetic isolation groove; Permanent magnet steel is placed in the first √-shaped slot 7 , the second √-shaped slot 8 , the first inverted √-shaped slot 10 , and the second inverted √-shaped slot 11 , and permanent magnet steel is placed in the long sides of the third inverted √-shaped slot 9 and the long sides of the third √-shaped slot 12 .

[0014] There is a 1.5mm disconnected distance between the outer end of the long side of the first √-shaped slot 7 and the outer circle of the rotor core 6; There is a 1.5mm disconnected distance between the outer end of the first magnetic isolation slot and the outer circle of the rotor core 6; There is a non-connected distance of 1.5 mm between the short side of the third inverted √ slot 9, the long side of the third inverted √ slot 9 and the outer circle of the rotor core 6; There is a non-connected distance of 1.5 mm between the first inverted √-shaped groove 10 and the proximal end of the first √-shaped groove 7.

[0015] The center line of the magnetic pole passes through the proximal end of the first √-shaped slot 7, and the center line of the magnetic pole passes through the proximal end of the second √-shaped slot 8; The radial magnetic isolation groove is connected to the proximal end of the first inverted √-shaped groove 10 , and the radial magnetic isolation groove is connected to the proximal end of the first √-shaped groove 7 .

[0016] The pole arc segment between the outer end of the long side of the first √-shaped slot 7 and the outer end of the long side of the second √-shaped slot 8 is provided with a magnetic field by the permanent magnet steel in the long side of the first √-shaped slot 7, the pole arc segment between the outer end of the radial magnetic isolation slot and the outer end of the first magnetic isolation slot is provided with a magnetic field by the permanent magnet steel in 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 inverted √-shaped slot 9 is provided with a magnetic field by the permanent magnet steel in the long side of the second √-shaped slot 8, and the pole arc segment between the outer end of the first magnetic isolation slot and the outer end of the long side of the third inverted √-shaped slot 9 is provided with a magnetic field by the permanent magnet steel in the short side of the second √-shaped slot 8.

Claims

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

2. A permanent magnet motor with radial pole spacing magnetic barriers according to claim 1, characterized in that: There is a non-connected distance of 1.5 mm between the outer end of the long side of the first √-shaped slot (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 slot and the outer circle of the rotor core (6), there is a non-connected distance of 1.5 mm between the short side of the third inverted √-shaped slot (9), the long side of the third inverted √-shaped slot (9) and the outer circle of the rotor core (6), and there is a non-connected distance of 1.5 mm between the first inverted √-shaped slot (10) and the proximal end of the first √-shaped slot (7).

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

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

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