A permanent magnet motor

Abstract

The present invention relates to the field of permanent magnet motors, and discloses a high power density permanent magnet motor, which includes a housing, a stator core and a rotor core; the stator core is arranged circumferentially along the inner wall of the housing, and the rotor core is installed in the space surrounded by the stator core; the rotor core includes at least two fully connected bridge lamination groups and at least one semi-connected bridge lamination group, wherein the laminations in the fully connected bridge lamination group include a plurality of fully connected bridge punching sheets that are all connected to the first central connection bridge and are distributed circumferentially, and the laminations in the semi-connected bridge lamination group include at least one separated punching sheet that is disconnected from the second central connection bridge and is distributed circumferentially, and the fully connected bridge lamination group and the semi-connected bridge lamination group are stacked axially with each semi-connected bridge lamination group located between two fully connected bridge lamination groups, so that the adjacent sectors of the rotor core are asymmetric. The present invention can improve the power density of the motor.

Description

Technical Field

[0001] The present invention relates to the field of permanent magnet motors, and particularly to a permanent magnet motor. Background Art

[0002] Traditional brushless DC motors adopt surface-mounted magnetic tiles or built-in radially magnetized magnetic steel structures, with relatively low power density. Due to cost factors, the tangentially magnetized parallel magnetic circuit structure is used to increase the magnetic flux per pole of the motor. However, the existing tangentially magnetized structure still has the problem of large magnetic leakage, which limits the improvement of motor performance.

[0003] Patent CN201611226568.0 designs a rotor core, in which at least one tooth sector is disconnected from the rotor collar, and at least one tooth sector is connected to the shaft collar. This suppresses magnetic leakage near the shaft. A positioning convex part is provided outside the shaft collar of the rotor core for positioning and supporting permanent magnets. Through analysis, since there is no fixed support component in the axial direction for the disconnected tooth sectors of the rotor in this solution, the axial structural strength is poor, which is not conducive to large-scale production. At the same time, the above-mentioned positioning protrusions for supporting and positioning permanent magnets will generate self-linkage magnetic leakage, reducing the power density of the motor and being not conducive to performance improvement.

[0004] On the other hand, for motors with built-in tangential magnetization, due to the increase in power density, the stator core is prone to saturation, resulting in higher core losses and reducing motor efficiency. At the same time, the enhancement of electromagnetic force waves leads to an increase in vibration and noise. The existing technology suppresses vibration and noise through methods such as skewed poles and skewed slots. The corresponding methods increase the manufacturing process difficulty and production man-hours. Patent CN201320738896.4 designs a stator core with a bar-shaped bent circle. In this solution, teeth protrude from the inner side of the stator annular yoke, and a slot is formed between two adjacent stator teeth. The stator magnetic circuit is balanced, the magnetic density is moderate and average, local saturation is reduced, the process is simple, and the production efficiency is relatively high. However, the above patent only averages the magnetic density by relying on parameters such as the width of the stator slot opening, the width of the tooth part, and the width of the yoke part, without considering the influence of the stator shape and structure on the motor magnetic field, losses, etc. It is not applicable to high-power density motor structures, nor does it consider reducing the motor vibration and noise through the combination method between the stator core and the machine shell, and does not give a structure that can comprehensively consider power density and suppress vibration and noise reduction.

[0005] Therefore, there is an urgent need for a permanent magnet brushless DC motor with high power density, low vibration and noise, which is suitable for large-scale production, has a simple process, and a reliable structure. Summary of the Invention

[0006] In order to overcome the deficiencies of the existing technology, the technical problem to be solved by the present invention is to provide a permanent magnet motor, which can simplify the production process, and improve the structural strength and power density.

[0007] To solve the above technical problems of the present invention, the present invention provides a permanent magnet motor, including a housing, a stator core, and a rotor core; the stator core is circumferentially arranged along the inner wall of the housing, and the asymmetric hybrid rotor core is installed in the space surrounded by the stator core; the rotor core includes at least two fully connected bridge lamination groups and at least one semi-connected bridge lamination group, wherein the laminations in the fully connected bridge lamination group include a plurality of fully connected bridge punching sheets that are all connected to the first central connection bridge and are circumferentially distributed, and the laminations in the semi-connected bridge lamination group include at least one separated punching sheet that is disconnected from the second central connection bridge and is circumferentially distributed, and the fully connected bridge lamination group and the semi-connected bridge lamination group are axially stacked so that each semi-connected bridge lamination group is located between two fully connected bridge lamination groups, making the adjacent sectors of the rotor core asymmetric.

[0008] Preferably, the fully connected bridge lamination group includes multiple fully connected bridge laminations, and the adjacent fully connected bridge laminations are overlapped and stacked; the semi-connected bridge lamination group includes multiple semi-connected bridge laminations, and the adjacent semi-connected bridge laminations are overlapped and stacked.

[0009] Preferably, the stator core is surrounded by multiple T-shaped tooth yokes, the outer surfaces of the T-shaped tooth yokes are parallel to the bottom of the stator slots, the boundary surfaces between the tooth parts and the yoke parts of the T-shaped tooth yokes are perpendicular, and the number of T-shaped tooth yokes is equal to the number of motor slots.

[0010] Preferably, there are two riveting points with different sizes, an outer riveting point and an inner riveting point, on each T-shaped tooth yoke, and the diameter of the outer riveting point is greater than that of the inner riveting point.

[0011] Preferably, the outer boundary of the stator core is in a regular polygon structure; the stator core and the housing are in contact at the connection points of the T-shaped tooth yokes to form a contact area, and the gaps where the stator core and the housing are not in contact are filled with a filling material to form a filling area.

[0012] Preferably, the fully connected bridge lamination includes a plurality of fully connected bridge punching sheets (311), and there is a support bridge (312) between the adjacent fully connected bridge punching sheets (311); among the two adjacent fully connected bridge punching sheets (311), one protrudes radially outward to form a wide magnetic bridge (313), and the other protrudes radially outward to form a narrow magnetic bridge (314), and the width of the wide magnetic bridge (313) is greater than the width of the narrow magnetic bridge (314).

[0013] Preferably, the semi-connected bridge laminations include a plurality of semi-connected bridge punching sheets (321) and a plurality of separating punching sheets (322). One separating punching sheet (322) is provided between two adjacent semi-connected bridge punching sheets (321), and the separating punching sheet (322) is not in contact with the semi-connected bridge punching sheet (321). There are partitioned support bridges (323) between every two of the plurality of semi-connected bridge punching sheets (321). The semi-connected bridge punching sheet (321) has a narrow magnetic bridge (325), and a partitioned wide magnetic bridge (324) is provided on the first central connecting bridge (H1). The width of the partitioned wide magnetic bridge (324) is greater than the width of the narrow magnetic bridge (325).

[0014] Preferably, in at least one lamination layer, adjacent wide magnetic bridges (313) and narrow magnetic bridges (314) have different lengths and each extends radially outward to form a first sector.

[0015] Preferably, permanent magnets (4) are placed in the slots between adjacent sectors. The polarities of the permanent magnets (4) in two adjacent slots are different, and the corresponding first central connecting bridge (H1) in the slot bulges radially outward to form the support bridge (312). The support bridge (312) is in contact with the permanent magnet (4).

[0016] Preferably, in at least one lamination layer, the second central connecting bridge (H2) extends radially outward to form the narrow magnetic bridge (325).

[0017] Each narrow magnetic bridge (325) extends radially outward to form a second sector. The narrow magnetic bridge (325) is connected to the second sector, and the partitioned wide magnetic bridge (324) is disconnected from the second sector.

[0018] Preferably, the areas of two adjacent second sectors are not equal.

[0019] Preferably, permanent magnets (4) are placed in the slots between adjacent second sectors. The polarities of the permanent magnets (4) in two adjacent slots are different, and the corresponding second central connecting bridge (H2) in the slot extends radially outward to form a bottom bulge of the slot. The bottom bulge of the slot is separated from the permanent magnet (4).

[0020] Preferably, the outer arc surface of each fully-connected bridge punching sheet includes multiple splines for reducing torque ripple. The splines at least include a main arc segment spline and linear segment splines respectively provided on both sides of the main arc segment spline.

[0021] Preferably, the splines include a main arc segment spline, arc segment splines respectively provided on both sides of the main arc segment spline, and linear segment splines respectively provided outside the two arc segment splines.

[0022] Preferably, the outer arc surfaces of each of the semi-connected bridge punching sheets and each of the separation punching sheets each include multiple splines for reducing torque ripple; the splines at least include an arc segment main spline and linear segment splines disposed on both sides of the arc segment main spline; preferably, the splines include an arc segment main spline, arc segment splines disposed on both sides of the arc segment main spline, and linear segment splines disposed outside the two arc segment splines.

[0023] The present invention can simplify the production process of the motor and improve the structural strength of the motor. By designing the partitioned support bridge and the partitioned wide magnetic bridge, the structural strength of the motor rotor is greatly improved. At the same time, the semi-connected bridge type lamination ensures that at least half of the sectors of one lamination of the rotor core can be connected to the bushing, which is easy to position during large-scale production.

[0024] By the present invention, the leakage flux of the rotor slot bottom self-linkage can be greatly reduced, thereby increasing the air-gap magnetic flux. Through the T-shaped tooth-connected yoke stator structure, the saturation degree of the motor can be reduced, maximizing the magnetic flux per pole. Comparing the back electromotive force coefficient of the motor structure of the present invention with that of the traditional full-bridge connection motor structure, it can be seen that the back electromotive force coefficient of the motor adopting this structure is significantly improved. When the motor operates under heavy load, the torque-current curve of the motor has good linearity and no saturation phenomenon, thereby improving the motor performance.

[0025] Through the five-segment spline structure of the rotor, the harmonic distortion rate of the back electromotive force of the motor is low, and the sinusoidality of the air-gap magnetic field is good, thereby reducing the tangential torque pulsation and radial vibration of the motor. At the same time, adopting the T-shaped tooth-connected yoke structure, there is a filling area between the stator and the machine shell, thereby weakening the transmission of vibration between the stator itself and the machine shell and realizing the vibration reduction and noise reduction of the motor.

[0026] Reducing the leakage flux of the rotor slot bottom self-linkage to increase the power density can ensure the high sinusoidality of the air-gap magnetic field and greatly increase the back electromotive force coefficient. The present invention can simplify the production process of the motor and improve the structural strength of the motor. It can be seen from the motor structure that reducing the leakage flux of the rotor slot bottom self-linkage to increase the power density can ensure the high sinusoidality of the air-gap magnetic field and greatly increase the back electromotive force coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0028] Figure 2 is a schematic structural diagram of the rotor core in an embodiment of the present invention;

[0029] Figure 3 is a schematic structural diagram of the T-shaped tooth-connected yoke in an embodiment of the present invention;

[0030] Figure 4 is a schematic structural diagram of the stator assembly in an embodiment of the present invention;

[0031] Figure 5 It is a schematic structural diagram of a semi-connected bridge laminated core in an embodiment of the present invention;

[0032] Figure 6 It is a schematic structural diagram of a fully-connected bridge laminated core in an embodiment of the present invention;

[0033] Figure 7 (a) is the leakage flux distribution of self-linkage at the bottom of the rotor slot in the full-bridge connection type of the prior art, and (b) is a partial enlarged view of the part circled by the square frame in (a);

[0034] Figure 8 (a) is the leakage flux distribution of self-linkage at the bottom of the rotor slot in the non-separated support bridge type of the prior art, and (b) is a partial enlarged view of the part circled by the square frame in (a);

[0035] Figure 9 (a) is the leakage flux distribution of self-linkage at the bottom of the rotor slot in the separated support bridge type of the present invention, and (b) is a partial enlarged view of the part circled by the square frame in (a);

[0036] Figure 10 It is a comparison curve of the leakage flux coefficient of self-linkage at the bottom of the slot near the shaft of three motors with different structures;

[0037] Figure 11 It is a schematic diagram of the inner space of the stator slot with a regular polygon T-shaped tooth connecting yoke in an embodiment of the present invention;

[0038] Figure 12 It is a schematic diagram of the inner space of the stator slot with a traditional structure;

[0039] Figure 13 It is a schematic diagram of the distribution of each section of the spline of the five-section spline rotor punching sheet in an embodiment of the present invention;

[0040] Figure 14 It is the harmonic content of the no-load back electromotive force in an embodiment of the present invention;

[0041] Figure 15 It is a schematic exploded view of the rotor core in an embodiment of the present invention;

[0042] Figure 16 It is a schematic structural diagram of a semi-connected bridge laminated core group in an embodiment of the present invention.

[0043] Description of the reference numerals

[0044] Machine housing 1;

[0045] Stator core 2; Contact area 22; Filling area 23;

[0046] T-shaped tooth connecting yoke 21; yoke part 211; bottom of stator slot 2111; bending point 2112; tooth part 212; beveled shoulder tooth crown slot 2121; outer riveting point 213; inner riveting point 214;

[0047] Rotor core 3;

[0048] Full-connected bridge lamination group 31; full-connected bridge punching sheet 311; outer arc surface 3111; plastic-coated through hole 3112; riveting point 3113; first central connection bridge H1; support bridge 312; wide magnetic bridge 313; narrow magnetic bridge 314;

[0049] Half-connected bridge lamination group 32; half-connected bridge punching sheet 321; outer arc surface of half-connected bridge punching sheet 3211; plastic-coated through hole of half-connected bridge punching sheet 3212; riveting point of half-connected bridge punching sheet 3213; separated punching sheet 322; outer arc surface of separated punching sheet 3221; plastic-coated through hole of separated punching sheet 3222; riveting point of separated punching sheet 3223; second central connection bridge H2; partitioned support bridge 323; partitioned wide magnetic bridge 324; narrow magnetic bridge 325;

[0050] Permanent magnet 4; shaft 5; winding 6; insulating frame 7. Specific embodiments

[0051] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustration and explanation of the present invention, and are not intended to limit the present invention.

[0052] It should be pre-explained that in the description of the present application, "axial direction" generally refers to the axial direction of the motor, that is, the extending direction along the rotation axis of the motor.

[0053] As Figure 1 shown, an embodiment of the present invention is a permanent magnet brushless DC motor, including a motor housing 1, a stator core 2, a rotor core 3, a permanent magnet 4, a shaft 5, a winding 6, and an insulating frame 7.

[0054] As Figure 3 and 4 shown, the stator core 2 is surrounded by 12 T-shaped tooth connecting yokes 21. The stator core 2 contacts the motor housing 1 through the connection points between adjacent T-shaped tooth connecting yokes 21, and the contact area forms a contact domain 22. The outer surface or top surface of the yoke part 211 of each T-shaped tooth connecting yoke 21 is a plane, and the gap between it and the inner wall of the circular motor housing 1 forms a filling domain 23. A variety of materials can be filled in the filling domain 23. In this example, the motor housing 1 is a bulk molding compound, so a bulk molding compound is also injected into the filling domain 23, that is, the motor housing 1 and the filling material are the same material, and the two are mixed to enhance the stiffness of the motor, improve damping, and absorb vibration. The winding 6 adopts fork winding, and the designed stator slot type can effectively avoid fork winding interference and improve the mass production efficiency.

[0055] As Figure 3 shown, the outer surface of the yoke part 211 of the T-shaped tooth-connected yoke 21 is parallel to the bottom of the stator slot 2111. There are two riveting points of different sizes, inner and outer, on the T-shaped tooth-connected yoke 21. The size of the outer riveting point 213 is larger than that of the inner riveting point 214. In this embodiment, the diameter of the outer riveting point 213 is 1.2 mm, and the diameter of the inner riveting point 214 is 1.0 mm; the outer riveting point 213 is located at the center of the yoke part 211, and the inner riveting point 214 is located at the middle of the tooth crown of the tooth part 212; the tooth crown shape of the tooth part 212 is a beveled shoulder type, and the included angle between the inner inclined surface of the beveled shoulder type tooth crown groove 2121 and the radial boundary of the tooth part 212 is an obtuse angle, preferably 120°. The tooth part 212 is perpendicular to the outer surface of the yoke part 211 or the bottom of the stator slot 2111. The slope of the straight line segment of the beveled shoulder type tooth crown groove 2121 is 30°. The width of the narrowest part of the tooth part 212 is 5.2 mm, and the height of the yoke part 211 is 3.5 mm. Considering the production process calculation, in this embodiment, as Figure 11 shown, the theoretical slot-winding area of the stator core 2 is increased by 8.5% compared to the slot-winding area of the traditional circular stator core punching sheet shown in Figure 12 . The bending point 2112 mainly serves to release stress for bending the stator core 2 into a circular shape.

[0056] As Figure 2 , 15 and 16 shown, in this embodiment, the rotor core 3 includes two fully-connected bridge-type lamination groups 31 and one semi-connected bridge-type lamination group 32, which are axially stacked with the semi-connected bridge-type lamination group 32 located between the two fully-connected bridge-type lamination groups 31, that is, the two fully-connected bridge-type lamination groups 31 are respectively located at both ends of the rotor core 3, and the semi-connected bridge-type lamination group 32 is located in the middle of the rotor core 3. This rotor core structure can make the adjacent sectors asymmetric, thereby significantly reducing the self-linkage leakage flux at the bottom of the permanent magnet slot near the axis to improve the power density.

[0057] The semi-connected bridge-type lamination group 32 is formed by stacking multiple semi-connected bridge-type laminations as shown in Figure 5 . The semi-connected bridge-type lamination includes multiple semi-connected bridge punches 321 and multiple separation punches 322. There is one separation punch 322 between two adjacent semi-connected bridge punches 321, and the separation punch 322 does not contact the semi-connected bridge punch 321; there are partitioned support bridges 323 between every two of the multiple semi-connected bridge punches 321; the semi-connected bridge punch 321 has a narrow magnetic bridge 325, and a partitioned wide magnetic bridge 324 is provided on the first central connection bridge H1, and the width of the partitioned wide magnetic bridge 324 is greater than the width of the narrow magnetic bridge 325.

[0058] The fully-connected bridge-type lamination group 31 is formed by stacking multiple fully-connected bridge-type laminations as shown in Figure 6Formed by stacking full-bridge laminated sheets as shown. The full-bridge laminated sheets include a plurality of full-bridge punching sheets 311 with support bridges 312 between adjacent ones; among two adjacent full-bridge punching sheets 311, one bulges radially outwards to form a wide magnetic bridge 313, and the other bulges radially outwards to form a narrow magnetic bridge 314. The width of the wide magnetic bridge 313 is greater than that of the narrow magnetic bridge 314. The full-bridge laminated sheets are axially provided with plastic-coated through holes 3112, and the semi-bridge laminated sheets are axially provided with plastic-coated through holes 3212. A plastic material is passed through the plastic-coated through holes 3112 and 3212 to penetrate and wrap and reinforce the rotor core 3. They are positioned and connected through riveting points 3113, 3213, and 3223. The distance between the edge of the through hole of the punching sheet and the boundary of the adjacent permanent magnet slot is 2.6 mm. The axial stacking structure is A + B + A. A set of full-bridge laminated sheets 31 includes 10 full-bridge laminated sheets, and a set of semi-bridge laminated sheets 32 includes 30 semi-bridge laminated sheets. Compared with the motor with a rotor formed entirely by semi-bridge laminated sheets, the back electromotive force coefficient of the motor in this embodiment is increased by 34.4%.

[0059] As Figure 6 shown, the full-bridge laminated sheet is of a full-bridge structure, and the 10 full-bridge punching sheets 311 included therein are all connected into one body through the first central connection bridge H1. The first central connection bridge H1 includes a plurality of support bridges 312, a plurality of wide magnetic bridges 313, and a plurality of narrow magnetic bridges 314. The first central connection bridge H1 is a continuous whole. The thickness of the permanent magnet 4 selected in this embodiment is 5 mm, the width of the narrow magnetic bridge 314 is 0.8 mm, the width of the wide magnetic bridge 313 is 1.5 mm, the length of the magnetic bridge is 2.8 mm, and the width of the support bridge 312 is 1.2 mm.

[0060] As Figure 5 shown, the semi-bridge laminated sheet is of a semi-bridge structure, and the 5 separated punching sheets 322 included therein are all disconnected from the second central connection bridge H2, that is, the 5 separated punching sheets 322 are not connected to the second central connection bridge H2 and are in a separated state from the second central connection bridge H2. The second central connection bridge H2 includes a plurality of partitioned support bridges 323, a plurality of partitioned wide magnetic bridges 324, and a plurality of narrow magnetic bridges 325. The second central connection bridge H2 is a continuous whole. Of course, the number of the separated punching sheets 322 is not limited to 5, and can be 1 - 4, or other numbers. The width of the narrow magnetic bridge 325 among them is 0.8 mm, and the distance between the partitioned support bridge 323 and the permanent magnet 4 is 2.5 mm. Through the optimization of the above parameters, the self-linkage leakage magnetic flux at the bottom of the permanent magnet slot near the axis of the rotor core 3 is greatly reduced. Keeping other parameters unchanged, the magnetic field distributions of the full-bridge connected rotor structure, the non-partitioned support bridge structure, and this embodiment are respectively compared, and the self-linkage leakage magnetic coefficient is calculated. See Figure 10, it can be obtained that the slot bottom self-linkage leakage magnetic coefficients of the three types of motors with the fully connected bridge type A, the non-separated support bridge type B, and the hybrid bridge type C of the present invention are 0.207, 0.065, and 0.018 respectively, which proves that this embodiment can greatly reduce the slot bottom self-linkage leakage magnetic coefficient, thereby significantly improving the power density of the motor.

[0061] As Figure 5 , Figure 6 and Figure 13 shown, the outer arc surfaces of the fully connected bridge type laminations and the semi-connected bridge type laminations both adopt a five-segment spline structure to reduce torque ripple and improve the vibration and noise of the motor. Each rotor sector adopts this structure, that is, the central arc segment main spline D with a central angle of α concentric with the stator in the middle, two eccentric arc line splines E with central angles of β1 adjacent to the left and right of the arc segment main spline D, and two straight segment splines F with central angles of β2 at the edges, and it should satisfy α + 2β1 + 2β2 = 36°.

[0062] By comparing and analyzing the rotor with a full-circle structure, the rotor with a traditional three-arc structure, and the 5-segment spline type rotor of this embodiment, the optimized no-load back electromotive force distortion rate is only 1.18%, and the corresponding harmonic components are as Figure 14 shown. In this embodiment, the rotor surface is coated and shaped with bulk molding compound, and the highest structural failure speed of the motor is obtained as 19,000 rpm, which is more than 6 times the actual operating speed of the motor, proving that the rotor surface structure design of this embodiment can ensure the high sinusoidality of the air-gap magnetic field and sufficient structural strength.

[0063] The preferred embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0064] In addition, it should be noted that, in the various specific technical features described in the above specific embodiments, they can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0065] In addition, any combination can be made between various different embodiments of the present invention as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A permanent magnet motor, comprising a housing (1), a stator core (2) and a rotor core (3); the stator core (2) is arranged circumferentially along the inner wall of the housing (1), and the rotor core (3) is installed in the space surrounded by the stator core (2); characterized in that, the rotor core (3) includes at least two full-connected bridge lamination groups (31) and at least one half-connected bridge lamination group (32), wherein the laminations in the full-connected bridge lamination group (31) include a plurality of full-connected bridge punching sheets (311) that are all connected to and circumferentially distributed with a first central connection bridge (H1), and the laminations in the half-connected bridge lamination group (32) include at least one separated punching sheet (322) that is disconnected from a second central connection bridge (H2) and circumferentially distributed, and the full-connected bridge lamination group (31) and the half-connected bridge lamination group (32) are axially stacked such that each half-connected bridge lamination group (32) is located between two full-connected bridge lamination groups (31), so that adjacent sectors of the rotor core (3) are asymmetric; the full-connected bridge lamination group (31) includes a plurality of full-connected bridge laminations, and adjacent full-connected bridge laminations are overlapped and stacked; the half-connected bridge lamination group (32) includes a plurality of half-connected bridge laminations, and adjacent half-connected bridge laminations are overlapped and stacked; the stator core (2) is enclosed by a plurality of T-shaped tooth yokes (21), the outer surfaces of the T-shaped tooth yokes (21) are parallel to the stator slot bottom (2111), the tooth parts (212) of the T-shaped tooth yokes are perpendicular to the boundary surfaces of the yoke parts (211), and the number of T-shaped tooth yokes (21) is equal to the number of motor slots.

2. The permanent magnet motor according to claim 1, characterized in that, Each of the T-shaped tooth yokes (21) is provided with two riveting points of different sizes inside and outside, and the diameter of the outer riveting point (213) is greater than the diameter of the inner riveting point (214).

3. The permanent magnet motor according to claim 1, wherein, The outer boundary of the stator core (2) is in a regular polygon structure; The stator core (2) and the housing (1) are in contact at the connection points of the T-shaped tooth yokes (21) to form a contact area (22), and the gaps where the stator core (2) and the housing (1) are not in contact are filled with a filling material to form a filling area (23).

4. The permanent magnet motor according to claim 1, characterized in that, The full-connected bridge lamination includes a plurality of full-connected bridge punching sheets (311), and there is a support bridge (312) between adjacent full-connected bridge punching sheets (311); among two adjacent full-connected bridge punching sheets (311), one protrudes radially outward to form a wide magnetic bridge (313), and the other protrudes radially outward to form a narrow magnetic bridge (314), and the width of the wide magnetic bridge (313) is greater than the width of the narrow magnetic bridge (314).

5. The permanent magnet motor according to claim 1, wherein The semi-connected bridge laminations include a plurality of semi-connected bridge punching sheets (321) and a plurality of separating punching sheets (322). One separating punching sheet (322) is provided between two adjacent semi-connected bridge punching sheets (321), and the separating punching sheet (322) is not in contact with the semi-connected bridge punching sheet (321); there are partitioned support bridges (323) between every two of the plurality of semi-connected bridge punching sheets (321); the semi-connected bridge punching sheet (321) has a narrow magnetic bridge (325), and a partitioned wide magnetic bridge (324) is provided on the first central connection bridge (H1), and the width of the partitioned wide magnetic bridge (324) is greater than the width of the narrow magnetic bridge (325).

6. The permanent magnet motor according to claim 4, wherein, In at least one lamination layer, the adjacent wide magnetic bridges (313) and narrow magnetic bridges (314) have different lengths and each extends radially outward to form a first sector.

7. The permanent magnet motor according to claim 6, wherein Permanent magnets (4) are placed in the slots between adjacent sectors, and the polarities of the permanent magnets (4) in two adjacent slots are different. The corresponding first central connection bridge (H1) in the slot extends radially outward to form the support bridge (312); The support bridge (312) is in contact with the permanent magnet (4).

8. The permanent magnet motor according to claim 5, wherein In at least one lamination layer, the second central connection bridge (H2) extends radially outward to form the narrow magnetic bridge (325); Each narrow magnetic bridge (325) extends radially outward to form a second sector; the narrow magnetic bridge (325) is connected to the second sector, and the partitioned wide magnetic bridge (324) is disconnected from the second sector.

9. The permanent magnet motor according to claim 8, wherein, The areas of two adjacent second sectors are not equal.

10. The permanent magnet motor according to claim 9, characterized in that, Permanent magnets (4) are placed in the slots between adjacent second sectors, and the polarities of the permanent magnets (4) in two adjacent slots are different. The corresponding second central connection bridge (H2) in the slot extends radially outward to form a bottom protrusion of the slot; The bottom protrusion of the slot is separated from the permanent magnet (4).

11. The permanent magnet motor according to claim 4, wherein, The outer arc surface of each full-connected bridge punching sheet (311) includes multiple splines for reducing torque ripple; The splines at least include an arc segment main spline and linear segment splines provided on both sides of the arc segment main spline.

12. The permanent magnet motor according to claim 11, wherein, The splines include an arc segment main spline, arc segment splines provided on both sides of the arc segment main spline, and linear segment splines provided outside the two arc segment splines.

13. The permanent magnet motor according to claim 5, characterized in that, The outer arc surfaces of each semi-connected bridge punching sheet (321) and each separating punching sheet (322) include multiple splines for reducing torque ripple; The splines at least include an arc segment main spline and linear segment splines provided on both sides of the arc segment main spline.

14. The permanent magnet motor according to claim 13, wherein, The splines include an arc segment main spline, arc segment splines provided on both sides of the arc segment main spline, and are provided outside the two arc segment splines.

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