CN110556947B

CN110556947B - A built-in permanent magnet motor

Info

Publication number: CN110556947B
Application number: CN201811459944.XA
Authority: CN
Inventors: 李文瑞; 甘峰; 李虎; 迟闯; 于明湖
Original assignee: Guangdong Welling Motor Manufacturing Co Ltd
Current assignee: Guangdong Welling Motor Manufacturing Co Ltd
Priority date: 2018-05-31
Filing date: 2018-11-30
Publication date: 2025-01-14
Anticipated expiration: 2038-11-30
Also published as: CN113346652B; CN113364183B; CN110556947A; CN113346652A; CN108923560A; CN113364183A

Abstract

The present invention relates to the field of permanent magnet motors, and discloses a built-in permanent magnet motor, comprising a housing, a stator core, a rotor core and a permanent magnet; the rotor core comprises at least two full-bridge lamination groups and at least one half-bridge lamination group, wherein the laminations in the full-bridge lamination group comprise a plurality of full-bridge punchings connected to a first central connecting bridge and distributed circumferentially, the laminations in the half-bridge lamination group comprise at least one separated punching that is disconnected from a second central connecting bridge and distributed circumferentially, and the full-bridge lamination group and the half-bridge lamination group are stacked axially, and each half-bridge lamination group is located between two full-bridge lamination groups, so that adjacent sectors in the same lamination layer of the full-bridge lamination group are asymmetric, and the permanent magnet is placed in the slot between the adjacent sectors. The present invention can simplify the production process of the motor and improve the structural strength of the motor.

Description

Built-in permanent magnet motor

Technical Field

The invention relates to the field of permanent magnet motors, in particular to a built-in permanent magnet motor.

Background

The traditional brushless direct current motor adopts a surface-mounted magnetic shoe or built-in radial magnetizing magnetic steel structure, has lower power density and is limited by cost factors, and the magnetic flux of each pole of the motor is improved through a tangential magnetizing parallel magnetic circuit structure. The existing tangential magnetizing structure still has the problem of large magnetic leakage, and the improvement of motor performance is limited.

The existing rotor core has at least one tooth sector disconnected from the rotor collar while at least one tooth sector is connected to the sleeve. Thereby suppressing leakage at the paraxial region. The rotor core shaft sleeve is provided with a positioning convex part for positioning and supporting the permanent magnet. Through analysis, because the tooth sector of this scheme rotor disconnection is axial does not have fixed support part, axial structural strength is relatively poor, is unfavorable for mass production, simultaneously, foretell location arch that is used for supporting and location permanent magnet will produce the selfing chain magnetic leakage, reduces motor power density, is unfavorable for promoting the performance.

On the other hand, the built-in tangential magnetizing motor is easy to saturate the stator core to generate higher core loss due to the improvement of power density, and the motor efficiency is reduced. While electromagnetic wave enhancement leads to an increase in vibration noise. In the prior art, vibration noise is restrained by a diagonal pole chute and other methods, the manufacturing process difficulty is increased and the production working hour is increased by a corresponding method, for example, a strip-shaped bent round stator core is designed. The stator has balanced magnetic circuit, moderate and average magnetic density, reduced local saturation, simple process and higher production efficiency. However, the above patent only relies on parameters such as the width of the slot opening of the stator, the width of the tooth portion and the width of the yoke portion to average the magnetic density, fails to consider the influence of the shape and structure of the stator on the magnetic field, the loss and the like of the motor, is not applicable to the structure of the motor with high power density, and also considers the reduction of the vibration noise of the motor by the combination method between the stator core and the casing, and does not give a structure capable of comprehensively considering the power density and suppressing vibration and noise.

Therefore, there is a need for a permanent magnet brushless dc motor with simple process, reliable structure, high power density, and low vibration noise, which can be applied to mass production and manufacturing.

Disclosure of Invention

In order to overcome the defects in the prior art, the technical problem to be solved by the invention is to provide the built-in permanent magnet motor which can simplify the production process and improve the structural strength and the power density.

In order to solve the technical problems, the invention provides an interior permanent magnet motor, which comprises a shell (1), a stator core (2), a rotor core (3) and permanent magnets (4), wherein the stator core (2) is circumferentially distributed along the inner wall of the shell (1), the rotor core (3) is arranged in a space surrounded by the stator core (2), the rotor core (3) comprises at least two full-bridge lamination groups (31) and at least one half-bridge lamination group (32), wherein the lamination in the full-bridge lamination groups (31) comprises a plurality of full-bridge lamination sheets (311) which are connected with a first center connection bridge (H1) and distributed along the circumferential direction, the lamination in the half-bridge lamination groups (32) comprises at least one separation lamination sheet (322) which is disconnected with a second center connection bridge (H2) and distributed along the circumferential direction, the full-bridge lamination groups (31) and the half-bridge lamination groups (32) are axially stacked to form a contact point between each half-bridge lamination group (31) and an adjacent lamination group (22), the adjacent lamination groups (31) are in a contact point (4) and the permanent magnets (22) are formed in the same layer, the gap between the stator core (2) and the casing (1) is not contacted, and a filling area (23) is formed by injecting filling materials.

Preferably, the full-bridge lamination group (31) comprises a plurality of full-bridge lamination, adjacent full-bridge lamination are overlapped, the half-bridge lamination group (32) comprises a plurality of half-bridge lamination, and adjacent half-bridge lamination are overlapped.

Preferably, the stator core (2) includes a plurality of T-shaped tooth yokes (21), and each T-shaped tooth yoke (21) is enclosed along an inner wall of the casing (1).

Preferably, the number of the T-shaped tooth connecting yokes (21) is 12, so that the outer boundary of the stator core (2) is in a regular dodecagon shape, the outer surface of each T-shaped tooth connecting yoke (21) is parallel to the stator groove bottom (2111), the tooth parts (212) of the T-shaped tooth connecting yokes are perpendicular to the boundary surface of the yoke parts (211), and the number of the T-shaped tooth connecting yokes (21) is equal to the number of the motor grooves.

Preferably, each T-shaped tooth connecting yoke (21) is provided with an inner rivet point and an outer rivet point which are different in size, the diameter of each outer rivet point (213) is larger than that of each inner rivet point (214), each outer rivet point (213) is arranged at the center of the yoke part (211), each inner rivet point (214) is arranged at the middle part of a tooth crown of each tooth part (212), the tooth crown of each tooth part (212) is in a sloping shoulder shape, and an included angle between an inner inclined surface of each sloping shoulder type tooth crown groove (2121) and the radial boundary of each tooth part is an obtuse angle.

Preferably, the full-bridge lamination comprises a plurality of full-bridge punching sheets (311), a supporting bridge (312) is arranged between every two adjacent full-bridge punching sheets (311), one of the two adjacent full-bridge punching sheets (311) protrudes outwards along the radial direction to form a wide magnetic bridge (313), and the other one protrudes outwards along the radial direction to form a full-bridge narrow magnetic bridge (314), and the width of the wide magnetic bridge (313) is larger than that of the full-bridge narrow magnetic bridge (314).

Preferably, the half-bridge lamination comprises a plurality of half-bridge punching sheets (321) and a plurality of separation punching sheets (322), one separation punching sheet (322) is arranged between two adjacent half-bridge punching sheets (321), the separation punching sheets (322) are not contacted with the half-bridge punching sheets (321), a partition type supporting bridge (323) is arranged between the adjacent half-bridge punching sheets (321), the half-bridge punching sheets (321) are provided with half-bridge narrow magnetic bridges (325), a partition type wide magnetic bridge (324) is arranged on the second center connecting bridge (H2), and the width of the partition type wide magnetic bridge (324) is larger than that of the half-bridge narrow magnetic bridge (325).

Preferably, the second center bridge (H2) extends radially outward forming the half bridge narrow magnetic bridge (325) within at least one lamination of the half bridge lamination stack (32).

Preferably, the polarities of two adjacent permanent magnets (4) are different.

Preferably, adjacent sectors in the same lamination layer of the half-bridge lamination stack (32) are asymmetric, the permanent magnets (4) are placed in grooves between the adjacent sectors, polarities of the permanent magnets (4) in the two adjacent grooves are different, corresponding second center connecting bridges (H2) in the grooves extend outwards in the radial direction to form radial groove bottom protrusions, the supporting bridges (312) are in contact with the permanent magnets (4) and axially coincide with the radial groove bottom protrusions, the supporting bridges (312) are equal to the radial groove bottom protrusions in width on the shaft sleeve side, the radial groove bottom protrusions are separated from the permanent magnets (4), and the distance between the outermost sides of the radial groove bottom protrusions and the permanent magnets (4) is larger than 0.5mm.

Preferably, the outer circular arc surface of each full-bridge punch (311) comprises a plurality of segments of splines for reducing torque ripple;

the spline at least comprises an arc section main spline and straight line section splines which are respectively arranged at two sides of the arc section main spline.

Preferably, the spline comprises an arc section spline body, arc section spline bodies which are respectively arranged at two sides of the arc section spline body, and straight line section spline bodies which are respectively arranged at the outer sides of the two arc section spline bodies.

Preferably, each of the outer arcuate surfaces of the semi-bridge punch (321) and each of the split punches (322) includes a plurality of segments of splines for reducing torque ripple;

Preferably, the ratio of the number of full-bridge laminations in one said full-bridge lamination stack (31) to the number of half-bridge laminations in one half-bridge lamination stack (32) is less than 0.5.

Preferably, the number of segments x of the spline satisfies:

if LCM (2P, s)/2P is odd, x= [ LCM (2P, s)/2P ];

if LCM (2P, s)/2P is even, x= [ LCM (2P, s)/2P ] -1;

Wherein x, LCM, P, S is the number of spline segments, the least common multiple, the pole pair number and the slot number respectively.

Preferably, assuming that the circle center degree of the circular arc section main spline is alpha, and the circle center angles of the rest sections of splines are beta i respectively, the following conditions are satisfied:

The invention can simplify the production process of the motor and can improve the structural strength of the motor. Through design wall formula supporting bridge and wall formula wide magnetic bridge, motor rotor structural strength promotes by a wide margin. Meanwhile, the half-bridge lamination ensures that at least half of the sectors of one lamination of the rotor core can be connected with the shaft sleeve, and the rotor core is easy to position in the mass production process.

The self-crosslinking magnetic flux leakage of the bottom of the rotor groove can be greatly reduced, so that the air gap magnetic flux is improved, and the saturation degree of the motor can be reduced through the T-shaped tooth-connected yoke stator structure, so that the magnetic flux of each pole is maximized. By comparing the counter potential coefficient of the motor structure and the counter potential coefficient of the traditional full-bridge connected motor structure, the counter potential coefficient of the motor adopting the structure is obviously improved, and the torque-current curve of the motor is good in linearity and does not generate saturation phenomenon when the motor is operated repeatedly, so that the motor performance is improved.

Through the five-segment spline structure of the rotor, the counter potential harmonic distortion rate of the motor is low, and the sine degree of the air gap magnetic field is good, so that tangential torque pulsation and radial vibration of the motor are reduced. Meanwhile, a T-shaped tooth connecting yoke structure is adopted, and a filling area is arranged between the stator and the shell, so that the transmission of vibration between the stator and the shell is weakened, and vibration reduction and noise reduction of the motor are realized.

The self-crosslinking magnetic flux leakage at the bottom of the rotor groove is reduced, so that the power density is improved, the high sine of the air gap magnetic field can be ensured, and the counter potential coefficient is greatly improved.

Drawings

FIG. 1 is a schematic diagram of the structure of one embodiment of the present invention;

FIG. 2 is a schematic diagram of a rotor core in accordance with one embodiment of the present invention;

FIG. 3 is a schematic view of the structure of a T-tooth yoke in accordance with one embodiment of the present invention;

FIG. 4 is a schematic illustration of a stator assembly in accordance with one embodiment of the present invention;

FIG. 5 is a schematic view of the structure of a half-bridge lamination in one embodiment of the invention;

FIG. 6 is a schematic view of the structure of a full bridge lamination in one embodiment of the invention;

FIG. 7 (a) is a prior art self-crosslinking leakage flux distribution at the bottom of a full-bridge connected rotor groove, and (b) is a partial enlarged view of the circled part of the square frame in (a);

FIG. 8 (a) is a partial enlarged view of the circled portion of the square frame in (a) showing the self-crosslinking magnetic flux leakage distribution at the bottom of the groove of a non-partitioned support bridge type rotor in the prior art;

FIG. 9 (a) is a partial enlarged view of the encircled portion of the square frame in (a) showing the self-crosslinking leakage flux distribution at the bottom of the slot of the partition support bridge type rotor according to the present invention;

FIG. 10 is a graph showing the comparison of self-linking leakage inductance at the bottom of slots at the paraxial region of three different structure motors;

FIG. 11 is a schematic illustration of the space within a regular polygon T-tooth yoke stator slot in accordance with one embodiment of the present invention;

FIG. 12 is a schematic view of the space within a stator slot of conventional construction;

FIG. 13 is a schematic representation of the spline distribution of the segments of a five-segment spline rotor sheet in one embodiment of the present invention;

FIG. 14 is an idling back emf harmonic content of an embodiment of the invention;

fig. 15 is an exploded view of a rotor core according to an embodiment of the present invention;

fig. 16 is a schematic view of the structure of a half-bridge lamination stack in one embodiment of the invention.

Description of the reference numerals

A housing 1;

a stator core 2, a contact field 22, a fill field 23;

T-tooth yoke 21, yoke 211, stator slot bottom 2111, inflection point 2112, tooth 212, bevel shoulder crown slot 2121, outer rivet point 213, inner rivet point 214;

A rotor core 3;

Full bridge lamination stack 31, full bridge lamination sheet 311, outer arcuate surface 3111, overmolded through hole 3112, rivet point 3113, first center bridge H1, support bridge 312, wide magnetic bridge 313, full bridge narrow magnetic bridge 314;

The semi-bridge lamination stack 32, the semi-bridge lamination 321, the outer circular arc surface 3211 of the semi-bridge lamination, the plastic covered through hole 3212 of the semi-bridge lamination, the rivet point 3213 of the semi-bridge lamination, the separation lamination 322, the outer circular arc surface 3221 of the separation lamination, the plastic covered through hole 3222 of the separation lamination, the rivet point 3223 of the separation lamination, the second center connection bridge H2, the partition type supporting bridge 323, the partition type wide magnetic bridge 324 and the semi-bridge narrow magnetic bridge 325;

permanent magnets 4, shafts 5, windings 6, insulating frames 7.

Detailed Description

The following describes specific embodiments of the present invention in detail with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.

It should be noted that, in the description of the present application, "axial direction" generally refers to the axial direction of the motor, i.e., the extending direction along the rotational axis of the motor.

As shown in fig. 1, 5 and 6, one embodiment of the present invention is a permanent magnet brushless dc motor including a 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. The stator core 2 is circumferentially arranged along the inner wall of the casing 1, the rotor core 3 is arranged in a space surrounded by the stator core 2, the rotor core 3 comprises at least two full-bridge lamination groups 31 and at least one half-bridge lamination group 32, wherein the lamination in the full-bridge lamination group 31 comprises a plurality of full-bridge lamination sheets 311 which are connected with a first central connecting bridge H1 and distributed circumferentially, the lamination in the half-bridge lamination group 32 comprises at least one separation lamination sheet 322 which is disconnected with a second central connecting bridge H2 and distributed circumferentially, and the full-bridge lamination group 31 and the half-bridge lamination group 32 are axially stacked so that each half-bridge lamination group 32 is positioned between the two full-bridge lamination groups 31, adjacent sectors in the same lamination layer of the full-bridge lamination group 31 are asymmetric, permanent magnets 4 are placed in grooves between the adjacent sectors, and polarities of the adjacent two permanent magnets 4 are different, so that the built-in permanent magnet motor is formed. Adjacent sectors in the same laminated layer of the half-bridge lamination stack 32 are asymmetric, permanent magnets 4 are placed in grooves between the adjacent sectors, polarities of the permanent magnets 4 in the adjacent two grooves are different, corresponding half-bridge punching pieces 321 in the grooves extend outwards in the radial direction to form radial groove bottom protrusions, the radial groove bottom protrusions are separated from the permanent magnets 4, and the distance between the outermost sides of the radial groove bottom protrusions and the permanent magnets 4 is larger than 0.5mm.

As shown in fig. 15 and 16, the full bridge lamination stack 31 includes a plurality of full bridge laminations, which are stacked in registration with each other, and the half bridge lamination stack 32 includes a plurality of half bridge laminations, which are stacked in registration with each other.

As shown in fig. 3 and 4, the stator core 2 is formed by enclosing 12T-shaped tooth yokes 21, the stator core 2 is contacted with the casing 1 through the connection points between the adjacent T-shaped tooth yokes 21, the contact parts form contact areas 22, the outer surface or top surface of the yoke part 211 of each T-shaped tooth yoke 21 is a plane, the gap between the yoke part and the inner wall of the circular casing 1 forms a filling area 23, a plurality of materials can be filled in the filling area 23, in this example, the casing 1 is a bulk molding compound, then the bulk molding compound is also filled in the filling area 23, namely, the casing 1 and the filling material are the same material, and the two materials are mixed to play roles of enhancing the rigidity of the motor, improving the damping and absorbing vibration. The winding 6 adopts flying fork winding, and the designed stator slot can effectively avoid the interference of flying fork winding, thereby improving the mass production efficiency.

As shown in fig. 3, the outer surface of the yoke portion 211 of the T-shaped tooth connecting yoke 21 is parallel to the stator groove bottom 2111, two rivet points with different sizes are arranged on the T-shaped tooth connecting yoke 21, the size of the outer rivet point 213 is larger than that of the inner rivet point 214, in this embodiment, the diameter of the outer rivet point 213 is 1.2mm, the diameter of the inner rivet point 214 is 1.0mm, the outer rivet point 213 is arranged in the center of the yoke portion 211, the inner rivet point 214 is arranged in the middle of the crown of the tooth portion 212, the crown of the tooth portion 212 is in a bevel shoulder shape, the included angle between the inner inclined surface of the bevel-shoulder-shaped tooth crown groove 2121 and the radial boundary of the tooth portion 212 is preferably 120 °, the tooth portion 212 is perpendicular to the outer surface of the yoke portion 211 or the stator groove bottom 2111, the slope of the straight line segment of the bevel-shoulder-shaped tooth crown groove 2121 is 30 °, the width of the most position of the tooth portion 212 is 5.2mm, the height of the yoke portion 211 is 3.5mm, and in combination with the calculation of the production process, in this embodiment, as shown in fig. 11, the stator core 2 can be wound around the conventional round iron core 12, and can be wound by 8% compared with the conventional iron core area shown in fig. 8. The inflection point 2112 mainly functions to release stress for the stator core 2 to bend.

As shown in fig. 2, 15 and 16, in the present embodiment, the rotor core 3 includes two full-bridge lamination sets 31 and one half-bridge lamination set 32, and is stacked axially so that the half-bridge lamination set 32 is located between the two full-bridge lamination sets 31, that is, the two full-bridge lamination sets 31 are respectively located at two ends of the rotor core 3, and the half-bridge lamination set 32 is located in the middle of the rotor core 3.

The half bridge lamination stack 32 is formed by stacking a plurality of half bridge laminations as shown in fig. 5, the half bridge laminations comprise a plurality of half bridge punching sheets 321 and a plurality of separation punching sheets 322, one separation punching sheet 322 is arranged between two adjacent half bridge punching sheets 321, the separation punching sheets 322 are not contacted with the half bridge punching sheets 321, a partition type supporting bridge 323 is arranged between the plurality of half bridge punching sheets 321, the half bridge punching sheets 321 are provided with half bridge narrow magnetic bridges 325, a partition type wide magnetic bridge 324 is arranged on the first center connecting bridge H1, and the width of the partition type wide magnetic bridge 324 is larger than that of the half bridge narrow magnetic bridges 325.

The full bridge lamination stack 31 is formed by a full bridge lamination stack as shown in fig. 6, the full bridge lamination comprising a plurality of full bridge punches 311 with support bridges 312 between adjacent ones; two adjacent full-bridge punching sheets 311, one of which protrudes outwards along the radial direction to form a wide magnetic bridge 313, the other of which protrudes outwards along the radial direction to form a full-bridge narrow magnetic bridge 314, the width of the wide magnetic bridge 313 is larger than that of the full-bridge narrow magnetic bridge 314, the full-bridge lamination is axially provided with a plastic coating through hole 3112, the half-bridge lamination is axially provided with a plastic coating through hole 3212, plastic materials are adopted to penetrate through the plastic coating through holes 3112 and 3212 to wrap and reinforce the rotor core 3, the rivet points 3113, 3213 and 3223 are positioned and connected, the boundary distance between the through hole edge of the punching sheet and an adjacent permanent magnet groove is 2.6mm, the axial stacking structure is A+B+A, the ratio of the number of the full-bridge lamination in the full-bridge lamination group 31 to the number of the half-bridge lamination in the half-bridge lamination group 32 is smaller than 0.5, for example, the full-bridge lamination group 31 comprises 10 full-bridge lamination and the half-bridge lamination 32 comprises 30 motor half-bridge lamination, and the counter-lamination coefficient of the rotor is improved by the total rotor is implemented by 4.34%.

As shown in fig. 6, the full bridge lamination is a full bridge structure, wherein 10 full bridge punched sheets 311 are integrally connected through a first central connecting bridge H1, the first central connecting bridge H1 comprises a plurality of supporting bridges 312, a plurality of wide magnetic bridges 313 and a plurality of full bridge narrow magnetic bridges 314, and the first central connecting bridge H1 is a continuous whole. The thickness of the selected permanent magnet 4 in this embodiment is 5mm, the width of the full bridge narrow magnetic bridge 314 is 0.8mm, the width of the wide magnetic bridge 313 is 1.5mm, the length of the magnetic bridge is 2.8mm, and the width of the supporting bridge 312 is 1.2mm. The support bridge 312 is in contact with the permanent magnet 4, the support bridge 312 axially coincides with the radial groove bottom protrusion, and the width of the support bridge 312 and the radial groove bottom protrusion on the sleeve side is equal.

As shown in fig. 5, the half-bridge lamination is a half-bridge structure, in which 5 separate punched sheets 322 are disconnected from the second central connecting bridge H2, that is, the 5 separate punched sheets 322 are not connected to the second central connecting bridge H2 and are separated from the second central connecting bridge H2, and the second central connecting bridge H2 includes a plurality of partition supporting bridges 323, a plurality of partition wide magnetic bridges 324 and a plurality of half-bridge narrow magnetic bridges 325, and the second central connecting bridge H2 is a continuous whole. Of course, the number of separate punches 322 is not limited to 5, and may be 1-4, or other numbers. The width of the half-bridge narrow magnetic bridge 325 is 0.8mm, the distance between the partition type supporting bridge 323 and the permanent magnet 4 is 2.5mm, through the optimization of the parameters, the self-crosslinking leakage flux of the bottom of the permanent magnet tank at the paraxial position of the rotor core 3 is greatly reduced, other parameters are ensured to be unchanged, the full-bridge connected rotor structure, the non-partition type supporting bridge structure and the magnetic field distribution of the embodiment are respectively compared, the self-crosslinking leakage flux coefficients are calculated, and referring to fig. 10, the self-crosslinking leakage flux coefficients of the tank bottom of the three-structure motor of the full-bridge type A, the non-partition type B and the hybrid bridge type C are respectively 0.207, 0.065 and 0.018, so that the embodiment can greatly reduce the self-crosslinking leakage flux coefficient of the tank bottom, and the power density of the motor is greatly improved.

As shown in fig. 5, 6 and 13, the outer arc surfaces of the full-bridge lamination and the half-bridge lamination adopt five-segment spline structures to reduce torque fluctuation and improve motor vibration noise, and each rotor sector adopts the structure, namely an arc segment main spline D with a central angle alpha concentric with a stator, an eccentric arc spline E with a central angle beta 1 adjacent to the arc segment main spline D left and right, and a straight-line segment spline F with a central angle beta 2 at the edge, and the two segments should satisfy alpha+2β1+2β2=36°.

The optimized no-load counter potential distortion rate is only 1.18% by comparing and analyzing the rotor with the full-circle structure, the rotor with the traditional three-segment arc structure and the 5-segment spline rotor of the embodiment, and the corresponding harmonic components are shown in fig. 14. In the embodiment, the bulk molding compound is adopted to carry out plastic coating shaping on the surface of the rotor, and the highest structural failure rotating speed of the motor is 19000rpm which exceeds the actual running rotating speed of the motor by more than 6 times, so that the structural design of the surface of the rotor can ensure the high sine property and enough structural strength of an air gap magnetic field.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention.

In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.

Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.

Claims

1. A built-in permanent magnet motor, comprising a housing (1), a stator core (2), a rotor core (3) and a permanent magnet (4); the stator core (2) is arranged along the circumference of the inner wall of the housing (1), and the rotor core (3) is installed in a space enclosed by the stator core (2); characterized in that:

The rotor core (3) comprises at least two full-bridge lamination groups (31) and at least one half-bridge lamination group (32), wherein the laminations in the full-bridge lamination group (31) comprise a plurality of full-bridge punchings (311) which are all connected to the first central connecting bridge (H1) and distributed along the circumferential direction, and the laminations in the half-bridge lamination group (32) comprise at least one separated punching (322) which is disconnected from the second central connecting bridge (H2) and distributed along the circumferential direction, and the full-bridge lamination group (31) and the half-bridge lamination group (32) are stacked in the axial direction such that each half-bridge lamination group (32) is located between two full-bridge lamination groups (31), so that adjacent sectors in the same lamination layer of the full-bridge lamination group (31) are asymmetric, and the permanent magnets (4) are placed in the slots between the adjacent sectors;

The contact points between the stator core (2) and the housing (1) form a contact region (22), and the gap between the stator core (2) and the housing (1) where no contact is made forms a filling region (23) by injecting a filling material.

2. The interior permanent magnet motor according to claim 1, characterized in that the full-bridge lamination group (31) comprises a plurality of full-bridge laminations, and adjacent full-bridge laminations are overlapped and stacked;

The semi-connected bridge-type lamination group (32) comprises a plurality of semi-connected bridge-type laminations, and adjacent semi-connected bridge-type laminations are overlapped and stacked.

3. The interior permanent magnet motor according to claim 1, characterized in that the stator core (2) comprises a plurality of T-shaped tooth yokes (21), and each of the T-shaped tooth yokes (21) is enclosed along the inner wall of the casing (1).

4. The interior permanent magnet motor according to claim 3, characterized in that the number of the T-shaped tooth yokes (21) is 12, so that the outer boundary of the stator core (2) is a regular dodecagon;

The outer surface of each T-shaped tooth yoke (21) is parallel to the stator slot bottom (2111), the boundary surface between the tooth portion (212) of the T-shaped tooth yoke and the yoke portion (211) is perpendicular, and the number of the T-shaped tooth yokes (21) is equal to the number of motor slots.

5. The interior permanent magnet motor according to claim 4, characterized in that each of the T-shaped tooth yokes (21) is provided with two inner and outer rivet points of different sizes, and the diameter of the outer rivet point (213) is larger than the diameter of the inner rivet point (214);

The outer rivet point (213) is arranged at the center of the yoke (211), and the inner rivet point (214) is arranged at the middle of the tooth crown of the tooth portion (212);

The tooth crown of the tooth portion (212) is in the shape of an oblique shoulder type, and the included angle between the inner inclined surface of the oblique shoulder type tooth crown groove (2121) and the radial boundary of the tooth portion is an obtuse angle.

6. The built-in permanent magnet motor as described in claim 2 is characterized in that the full-bridge type laminations include a plurality of full-bridge punching sheets (311), and a support bridge (312) is provided between adjacent full-bridge punching sheets (311); among two adjacent full-bridge punching sheets (311), one of them protrudes radially outward to form a wide magnetic bridge (313), and the other protrudes radially outward to form a full-bridge narrow magnetic bridge (314), and the width of the wide magnetic bridge (313) is greater than the width of the full-bridge narrow magnetic bridge (314).

7. The built-in permanent magnet motor according to claim 6 is characterized in that the semi-connected bridge type laminations include a plurality of semi-connected bridge laminations (321) and a plurality of separated laminations (322), a separated lamination (322) is provided between two adjacent semi-connected bridge laminations (321), and the separated lamination (322) does not contact the semi-connected bridge lamination (321); a partition type support bridge (323) is provided between adjacent semi-connected bridge laminations (321); the semi-connected bridge laminations (321) have a semi-connected bridge narrow magnetic bridge (325), and a partition type wide magnetic bridge (324) is provided on the second center connecting bridge (H2), and the width of the partition type wide magnetic bridge (324) is greater than the width of the semi-connected bridge narrow magnetic bridge (325).

8. The interior permanent magnet motor according to claim 7, characterized in that, in at least one lamination layer of the semi-bridge type lamination stack (32), the second center connecting bridge (H2) extends radially outward to form the semi-bridge narrow magnetic bridge (325).

9. The interior permanent magnet motor according to claim 1, characterized in that the polarities of two adjacent permanent magnets (4) are different.

10. The interior permanent magnet motor according to claim 8, characterized in that adjacent sectors in the same lamination layer of the semi-bridge type lamination stack (32) are asymmetric, the 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 second center connecting bridge (H2) in the slot extends radially outward to form a radial slot bottom protrusion;

The support bridge (312) contacts the permanent magnet (4) and overlaps with the radial groove bottom protrusion along the axial direction; the width of the support bridge (312) and the radial groove bottom protrusion on the shaft sleeve side are equal;

The radial groove bottom protrusion is separated from the permanent magnet (4), and the distance between the outermost side of the radial groove bottom protrusion and the permanent magnet (4) is greater than 0.5 mm.

11. The interior permanent magnet motor according to claim 6, characterized in that the outer arc surface of each of the full-bridge punching sheets (311) comprises a plurality of splines for reducing torque fluctuations;

The spline at least includes a circular arc segment main spline and straight line segment splines arranged on both sides of the circular arc segment main spline.

12. The interior permanent magnet motor according to claim 11, characterized in that the splines include arc segment main splines, arc segment splines arranged on both sides of the arc segment main splines, and straight segment splines arranged outside the two arc segment splines.

13. The interior permanent magnet motor according to claim 7, characterized in that the outer arc surface of each of the semi-connected bridge punching sheets (321) and each of the separated punching sheets (322) comprises a plurality of splines for reducing torque fluctuations;

14. The interior permanent magnet motor according to claim 13, characterized in that the splines include arc segment main splines, arc segment splines arranged on both sides of the arc segment main splines, and straight segment splines arranged outside the two arc segment splines.

15. The interior permanent magnet motor according to claim 1, characterized in that the ratio of the number of fully connected bridge laminations in a fully connected bridge lamination group (31) to the number of half-connected bridge laminations in a half-connected bridge lamination group (32) is less than 0.5.

16. The interior permanent magnet motor according to any one of claims 11 to 14, characterized in that the number of segments x of the spline satisfies:

If LCM(2P, S)/2P is an odd number, then x=[LCM(2P, S)/2P];

If LCM(2P, S)/2P is an even number, then x=[LCM(2P, S)/2P]-1;

Among them, x, LCM, P, and S are the number of spline segments, the least common multiple, the number of pole pairs, and the number of slots, respectively.

17. The interior permanent magnet motor according to claim 16, characterized in that, assuming that the centrality of the main arc segment spline is α, and the central angles of the remaining segment splines are βi, then: