CN114094737B

CN114094737B - Self-starting permanent magnet auxiliary synchronous reluctance motor rotor and motor

Info

Publication number: CN114094737B
Application number: CN202111356804.1A
Authority: CN
Inventors: 王杜; 肖勇; 李莹; 史进飞; 李霞; 张志东
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-11-16
Filing date: 2021-11-16
Publication date: 2023-05-23
Anticipated expiration: 2041-11-16
Also published as: CN114094737A

Abstract

The invention provides a self-starting permanent magnet auxiliary synchronous reluctance motor rotor and a motor, wherein the self-starting permanent magnet auxiliary synchronous reluctance motor rotor comprises a plurality of rotor punching sheets, a rotor core is formed by laminating the rotor punching sheets, and permanent magnets are arranged on the rotor punching sheets; the permanent magnets comprise an outer permanent magnet which is relatively positioned at the radial outer side, an inner permanent magnet which is relatively positioned at the radial inner side and a third permanent magnet, wherein the coercive force of the outer permanent magnet is equal to that of the inner permanent magnet and is smaller than that of the third permanent magnet, the third permanent magnet is positioned on the d-axis of the motor rotor, and the magnetizing direction of the third permanent magnet is tangential magnetization. According to the invention, the permanent magnet flux linkage of the motor can be effectively increased, the permanent magnet torque of the motor is improved, and the arrangement provides magnetic flux for the q-axis magnetic circuit of the motor rotor, so that the salient pole difference of the motor is further increased, the reluctance torque of the motor is fully utilized, and the torque output capacity of the motor is further improved.

Description

Self-starting permanent magnet auxiliary synchronous reluctance motor rotor and motor

Technical Field

The invention relates to the technical field of motors, in particular to a self-starting permanent magnet auxiliary synchronous reluctance motor rotor and a motor.

Background

The self-starting permanent magnet auxiliary synchronous reluctance motor combines the advantages of an asynchronous motor on the basis of the permanent magnet auxiliary synchronous reluctance motor, can realize self-starting under the condition of no controller, and can also realize high-efficiency operation under the synchronous rotating speed through the combined action of the permanent magnet torque and the reluctance torque. Compared with an asynchronous motor, the motor operates at a synchronous rotating speed, slip loss is eliminated, and the overall efficiency of the motor is obviously improved; compared with an asynchronous starting permanent magnet synchronous motor, the permanent magnet has the advantages of multiple purposes, low cost ferrite and low material cost. However, the output torque of the self-starting permanent magnet auxiliary synchronous reluctance motor is the combined action of the permanent magnet torque and the reluctance torque, and the ferrite magnetic property is weaker, so that the permanent magnet torque of the motor is lower, the torque output capability is ensured, and the reluctance torque part is urgently required to be increased; on the other hand, in the motor starting stage, the resultant magnetic field acting on the ferrite is strong, and the ferrite has the risk of irreversible demagnetization. The rotor structure solves the problem of insufficient torque output capability of the motor, improves the anti-demagnetization capability of ferrite, and increases the economical efficiency and reliability of motor operation.

Because the self-starting permanent magnet auxiliary synchronous reluctance motor in the prior art has small permanent magnet torque, the torque output capability may be insufficient; the invention designs a self-starting permanent magnet auxiliary synchronous reluctance motor rotor and a motor, which are researched and designed by the invention, because ferrite has small coercive force, so that the motor has poor anti-demagnetizing capability and is subjected to strong armature reaction magnetic field action in the starting stage, and the permanent magnet has great demagnetizing risk and other technical problems.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defect that the self-starting permanent magnet auxiliary synchronous reluctance motor in the prior art has small permanent magnet torque, so that the torque output capacity is possibly insufficient, thereby providing a self-starting permanent magnet auxiliary synchronous reluctance motor rotor and a motor.

In order to solve the problems, the invention provides a self-starting permanent magnet auxiliary synchronous reluctance motor rotor, which comprises a plurality of rotor punching sheets, wherein a rotor core is formed by laminating the rotor punching sheets, a permanent magnet is arranged on the rotor punching sheets, and the rotor punching sheets are provided with shaft holes; the permanent magnets comprise an outer permanent magnet which is relatively positioned at the radial outer side, an inner permanent magnet which is relatively positioned at the radial inner side and a third permanent magnet, wherein the coercive force of the outer permanent magnet is equal to that of the inner permanent magnet and is smaller than that of the third permanent magnet, and the third permanent magnet is positioned on the d-axis of the motor rotor and the magnetizing direction of the third permanent magnet is tangential magnetization.

In some embodiments, the third permanent magnet comprises an interlayer neodymium-iron-boron located between the outer layer permanent magnet and the inner layer permanent magnet, and/or an inner layer neodymium-iron-boron located between the inner layer permanent magnet and the shaft hole; the outer permanent magnet is an outer ferrite, and the inner permanent magnet is an inner ferrite.

In some embodiments, when the third permanent magnet includes an interlayer neodymium-iron-boron located between the outer permanent magnet and the inner permanent magnet, the interlayer neodymium-iron-boron is spaced a first predetermined distance from the outer permanent magnet, and the interlayer neodymium-iron-boron is spaced a second predetermined distance from the inner permanent magnet.

In some embodiments, a first preset distance between the interlayer neodymium-iron-boron and the outer permanent magnet is hl, a second preset distance between the interlayer neodymium-iron-boron and the inner permanent magnet is h2, and a distance between the inner neodymium-iron-boron and the inner permanent magnet is h3, and the method comprises the following steps: 0.8σ is equal to or less than h1=h2=h3 is equal to or less than 2σ, and σ is the motor air gap width.

In some embodiments, the third permanent magnet is of rectangular configuration in cross section of the rotor sheet, with a long dimension of the rectangular configuration extending in a radial direction of the rotor sheet and a short dimension of the rectangular configuration extending in a tangential direction of the rotor sheet.

In some embodiments, the outer permanent magnet and/or the inner permanent magnet has a fan-ring structure, the center of the fan-ring is towards one side far away from the center of the rotor, and the thickness of the same permanent magnet near the d-axis is greater than the thickness near the q-axis.

In some embodiments, the thickness d1 of the third permanent magnet in the magnetizing direction satisfies 5σ.ltoreq.d1.ltoreq.10σ, σ being the motor air gap width.

In some embodiments, when the third permanent magnet includes an inner layer neodymium iron boron located between the inner layer permanent magnet and the shaft hole, a magnetism isolating hole is further provided on the rotor punching sheet, and the magnetism isolating hole is located between the inner layer neodymium iron boron and the shaft hole.

In some embodiments, the magnetic isolation hole comprises a first side edge facing the inner layer neodymium iron boron, and the first side edge is an arc-shaped edge protruding towards the shaft hole; and/or the magnetism isolating hole comprises a second side edge facing the shaft hole, and the second side edge is an arc-shaped edge protruding towards the inner layer NdFeB.

In some embodiments, when the magnetic isolation hole comprises a first side facing the inner layer neodymium iron boron, the first side is connected with the inner layer neodymium iron boron, and when the magnetic isolation hole comprises a second side facing the shaft hole, the second side is spaced from the shaft hole by a third preset distance.

In some embodiments, when the magnetism isolating hole includes a second side edge facing the shaft hole, and the second side edge is an arc edge protruding towards the inner layer neodymium iron boron, the shortest distance h4 between the arc edge and the shaft hole satisfies h4 not less than 5 sigma, the circumferential angle beta corresponding to the arc edge satisfies 0.8α not less than β not more than 0.9α, α is a circumferential angle occupied by each pole, and sigma is a motor air gap width.

In some embodiments, the angle between the lines from the center of the rotor to the edges of the permanent magnets is the pole arc angle of the permanent magnets, and the pole arc angle of the ferrite between different layers is gradually reduced along the radial outward direction of the d axis; α1 > α2; α1 and α2 are pole angles of the inner ferrite near the shaft hole side and the outer ferrite near the outer circle side of the rotor respectively;

the radial thickness of the multilayer ferrite is not equal, said ferrite thickness between different layers in the radially outward direction of the d-axis increasing.

In some embodiments, the permanent magnets are arranged radially at least 2 layers under one pole; and/or the motor rotor has 4, 6 or 8 poles.

In some embodiments, the rotor further comprises filling grooves, the filling grooves are distributed along the circumference of the rotor in a radial direction and are arranged in the same layer with the permanent magnets, at least 1 filling groove is arranged at each end part of each layer of permanent magnets, no magnetism isolating groove is arranged between each filling groove and each permanent magnet, reinforcing ribs with the width of b1 are arranged, the width b1 of each reinforcing rib meets 0.8σ.ltoreq.b1.ltoreq.2σ, and σ is the width of an air gap between the inner diameter of the stator and the outer diameter of the rotor.

In some embodiments, the filling groove is a closed groove, an electric conduction and magnetic non-conduction material is filled in the closed groove, the filling groove is connected through an end ring, so that a squirrel cage structure is formed, and the material of the end ring is the same as the material filled in the filling groove.

In some embodiments, the filling grooves are connected with the outer circle of the rotor through a magnetic bridge with the width of b2, b2 is 0.8σ.ltoreq.b2.ltoreq.2σ, and σ is the width of the air gap of the motor.

The invention also provides a motor, which comprises the self-starting permanent magnet auxiliary synchronous reluctance motor rotor.

The self-starting permanent magnet auxiliary synchronous reluctance motor rotor and the motor provided by the invention have the following beneficial effects:

1. according to the invention, the inner permanent magnet, the outer permanent magnet and the third permanent magnet are arranged, the coercive force of the outer permanent magnet is equal to that of the inner permanent magnet and is smaller than that of the third permanent magnet, the third permanent magnet is positioned on the d-axis of the motor rotor, and the magnetizing direction of the third permanent magnet is tangential magnetizing, so that the permanent magnet flux of the motor can be effectively increased, the permanent magnet torque of the motor is improved, and the magnetic flux is provided for the q-axis magnetic circuit of the motor rotor, so that the protruding pole difference of the motor is further increased, the reluctance torque of the motor is fully utilized, and the torque output capability of the motor is further improved.

2. According to the invention, the inner permanent magnet is preferably inner ferrite, the outer permanent magnet is preferably outer ferrite, the third permanent magnet is preferably neodymium iron boron and is arranged on the d axis of the rotor, the placement position is between the ferrite layer or between the innermost ferrite and the shaft hole, the magnetizing direction is tangential, magnetic flux is provided for the q axis magnetic circuit of the motor rotor, the salient pole difference of the motor is further increased, the reluctance torque of the motor is fully utilized, the torque output capacity of the motor is further improved, the permanent magnet flux linkage of the motor is effectively increased, the permanent magnet torque of the motor is improved, the torque output capacity of the motor is improved, the magnetic density of the middle position of the inner ferrite is also enhanced, and the anti-demagnetizing capacity of the motor is improved; the invention provides a hybrid permanent magnet rotor structure of a self-starting permanent magnet auxiliary synchronous reluctance motor, which can improve the anti-demagnetizing capability of ferrite and enhance the operation reliability of the motor.

3. The invention provides a self-starting permanent magnet auxiliary synchronous reluctance motor hybrid permanent magnet rotor structure, wherein a filling groove, a permanent magnet and a shaft hole are formed in a rotor punching sheet, and the permanent magnet comprises ferrite and NdFeB or other materials with permanent magnet characteristics; the filling grooves are distributed along the circumference of the rotor in the radial direction and are arranged on the same layer with the ferrite, and the filling grooves are filled with conductive and non-conductive materials such as aluminum or aluminum alloy, so that the motor can realize self-starting through the combination design of the filling grooves and the permanent magnets, the torque output capacity of the motor is improved, the loss of a controller is omitted, the motor efficiency is improved, and the running economy of the motor is enhanced;

4. according to the invention, the magnetic isolation grooves are not arranged between the filling grooves and the ferrite which are arranged in the same layer, and the filling grooves are separated by the reinforcing ribs with certain width, so that the structural strength of the rotor can be ensured; the squirrel cage asynchronous magnetic field generated by the filling groove plays a role in shielding the armature reaction magnetic field, namely, the squirrel cage magnetic field has a protection effect on the permanent magnet, and the purpose of not arranging the magnetism isolating groove between the filling groove and the ferrite is to reduce the obstruction to the squirrel cage magnetic field, so that the squirrel cage magnetic field can directly act on the ferrite, and the anti-demagnetization capability of the motor is improved;

drawings

FIG. 1 is a block diagram of a rotor punching of a self-starting permanent magnet-assisted synchronous reluctance motor according to a first embodiment of the present invention;

FIG. 2 is an axial view of a rotor of a self-starting permanent magnet assisted synchronous reluctance motor according to a first embodiment of the present invention;

FIG. 3 is a graph of magnetic density contrast of a permanent magnet of the present technology versus a prior art;

fig. 4 is a block diagram of a rotor sheet of a self-starting permanent magnet-assisted synchronous reluctance motor according to a second embodiment of the present invention.

The reference numerals are expressed as:

1. rotor punching; 2. filling the groove; 3. a permanent magnet; 31. an outer permanent magnet; 32. an inner permanent magnet; 4. a third permanent magnet; 41. interlayer NdFeB; 42. inner layer NdFeB; 5. a shaft hole; 6. a magnetism isolating hole; 7. an end ring.

Detailed Description

As shown in fig. 1 to 4, fig. 1 to 3 are first embodiments, and the invention provides a self-starting permanent magnet auxiliary synchronous reluctance motor rotor, which comprises a plurality of rotor punching sheets 1, wherein a plurality of rotor punching sheets 1 are laminated to form a rotor core, and a filling groove 2, a permanent magnet 3 and a shaft hole 5 are arranged on the rotor punching sheet 1; the permanent magnet 3 comprises an outer permanent magnet 31 which is relatively positioned at the radial outer side, an inner permanent magnet 32 which is relatively positioned at the radial inner side and a third permanent magnet 4, wherein the coercive force of the outer permanent magnet 31 and the coercive force of the inner permanent magnet 32 are equal and are smaller than the coercive force of the third permanent magnet 4, the third permanent magnet 4 is positioned on the d axis of the motor rotor, and the magnetizing direction of the third permanent magnet 4 is tangential magnetization.

According to the invention, the inner permanent magnet, the outer permanent magnet and the third permanent magnet are arranged, the coercive force of the outer permanent magnet is equal to that of the inner permanent magnet and is smaller than that of the third permanent magnet, the third permanent magnet is positioned on the d-axis of the motor rotor, the magnetizing direction of the third permanent magnet is tangential magnetizing, the permanent magnet flux linkage of the motor can be effectively increased, the permanent magnet torque of the motor is improved, the magnetic flux is provided for the q-axis magnetic circuit of the motor rotor, the salient pole difference of the motor, namely the value of Lq-Ld, is further increased, and in general, the larger the salient pole difference value is, the larger the reluctance torque is, so that the motor torque output capacity is stronger; lq is quadrature axis inductance, ld is direct axis inductance, so that reluctance torque of the motor is fully utilized, and torque output capacity of the motor is further improved.

The invention provides a mixed permanent magnet rotor structure of a self-starting permanent magnet auxiliary synchronous reluctance motor, which is characterized in that a rotor is provided with a filling groove, and an electric conduction and non-magnetic conduction material is filled in the groove to form a squirrel cage structure, so that the motor has self-starting capability; by arranging neodymium iron boron between two layers of ferrite or between the inner layer of ferrite and the shaft hole, the salient pole difference of the motor is increased, the torque output of the motor is increased, and the motor efficiency is improved; through the shape and the size of the filling groove and the permanent magnet and the design of the specific position, the anti-demagnetizing capability of the ferrite is improved, and the reliable operation of the motor is enhanced.

In the following, a specific embodiment will be described by taking a rotor as an example in conjunction with the accompanying drawings, fig. 1 is a diagram showing a rotor sheet structure of a first embodiment of the present invention, a motor rotor is composed of a rotor sheet 1 with a specific structure and end rings 7 at two ends of a rotor core, and a filling slot 2, a permanent magnet 3, a third permanent magnet 4, a shaft hole 5 matched with a rotating shaft, and a magnetism isolating hole 6 are formed on the rotor sheet 1. And the ferrite is arranged in two layers or more, and each layer of ferrite is arranged close to the outer circle side of the rotor and is provided with filling grooves which are arranged in the same layer with the ferrite, so that the multilayer permanent magnet magnetic barrier structure of the rotor is formed. Wherein no magnetism isolating slot is arranged between each layer of filling slot and ferrite, and only the reinforcing ribs with the width of b1 are used for separation.

In some embodiments, the third permanent magnet 4 comprises an interlayer neodymium iron boron 41 located between the outer layer permanent magnet 31 and the inner layer permanent magnet 32, and/or an inner layer neodymium iron boron 42 located between the inner layer permanent magnet 32 and the shaft hole 5; the outer permanent magnets 31 are outer ferrite and the inner permanent magnets 32 are inner ferrite. The interlayer neodymium iron boron and the inner layer neodymium iron boron are magnetized in a tangential direction, and the magnetizing direction is along the tangential direction of the rotor in the circumferential direction.

The permanent magnets are ferrite and neodymium iron boron or other materials with permanent magnetic properties, and preferably, the permanent magnets are ferrite and neodymium iron boron. Compared with other permanent magnetic materials, the ferrite does not contain noble metal elements such as neodymium, cobalt and the like, has the advantages of low cost and good magnetic performance, and can be widely used in the field of industrial motors; the neodymium iron boron has excellent magnetic performance and high magnetic energy product, and is suitable for providing flux linkage for a q-axis magnetic circuit of the motor in the embodiment.

According to the invention, the inner permanent magnet is preferably inner ferrite, the outer permanent magnet is preferably outer ferrite, the third permanent magnet is preferably neodymium iron boron and is arranged on the d axis of the rotor, the placement position is between the ferrite layer or between the innermost ferrite and the shaft hole, the magnetizing direction is tangential, magnetic flux is provided for the q axis magnetic circuit of the motor rotor, the salient pole difference of the motor is further increased, the reluctance torque of the motor is fully utilized, the torque output capacity of the motor is further improved, the permanent magnet flux linkage of the motor is effectively increased, the permanent magnet torque of the motor is improved, the torque output capacity of the motor is improved, the magnetic density of the middle position of the inner ferrite is also enhanced, and the anti-demagnetizing capacity of the motor is improved; the invention provides a hybrid permanent magnet rotor structure of a self-starting permanent magnet auxiliary synchronous reluctance motor, which can improve the anti-demagnetizing capability of ferrite and enhance the operation reliability of the motor.

In some embodiments, when the third permanent magnet 4 includes an interlayer neodymium iron boron 41 located between the outer layer permanent magnet 31 and the inner layer permanent magnet 32, the interlayer neodymium iron boron 41 is spaced from the outer layer permanent magnet 31 by a first preset distance, and the interlayer neodymium iron boron 41 is spaced from the inner layer permanent magnet 32 by a second preset distance. Through the arrangement that all have the distance between the interlaminar neodymium iron boron and outer permanent magnet and the inlayer permanent magnet, can avoid the direction of magnetizing to reach the third permanent magnet along radial direction from interior, outer permanent magnet effectively, guarantee the direction of magnetizing along tangential direction, further effectively increase output torque.

In some embodiments, the distance between the interlayer neodymium-iron-boron 41 and the inner layer permanent magnet 31 and 32 is h1 and h2, respectively, and the distance between the inner layer neodymium-iron-boron 42 and the inner layer permanent magnet 32 is h3, and the method comprises the following steps: 0.8σ is equal to or less than h1=h2=h3 is equal to or less than 2σ, and σ is the motor air gap width. The arrangement can ensure the mechanical strength of the rotor, and can reduce the magnetic leakage of the NdFeB, thereby improving the flux linkage of the q-axis magnetic circuit.

In some embodiments, the third permanent magnet 4 is of rectangular structure in cross section of the rotor sheet 1, and the long sides of the rectangular structure extend in the radial direction of the rotor sheet 1, and the short sides of the rectangular structure extend in the tangential direction of the rotor sheet 1. The third permanent magnet is a further preferable structural form of the invention, namely the cross section of the third permanent magnet is of a rectangular structure, and the long edge of the third permanent magnet extends along the radial direction, so that the magnetizing degree can be increased to the greatest extent in the radial direction, the magnetic field intensity is effectively improved, and the torque output capability is further improved.

The interlayer NdFeB and the inner layer are arranged at the d-axis position and magnetized in a tangential manner, so that the purpose of the arrangement is to provide a flux linkage of a rotor q-axis magnetic circuit, increase the convex pole difference of the motor, namely the difference value of Xq-Xd is increased, and the increase of the convex pole difference is beneficial to the enhancement of reluctance torque as shown in a formula (1), thereby improving the torque output capacity of the motor.

In some embodiments, the thickness d1 of the third permanent magnet 4 in the magnetizing direction satisfies 5σ.ltoreq.d1.ltoreq.10σ, σ being the motor air gap width. The tangential magnetization mode of the same direction is adopted for the lower interlayer NdFeB and the inner layer NdFeB of the same magnetic pole, the thickness d of the NdFeB magnetization direction can be selected to be equal to or less than 5 sigma and equal to or less than 10 sigma, and the purpose of the arrangement is to ensure the processing technology and simultaneously reduce the dosage of the NdFeB as much as possible.

In some embodiments, the outer permanent magnet 31 and/or the inner permanent magnet 32 have a fan-ring structure, the center of the fan-ring is directed to a side far from the center of the rotor, and the thickness of the same permanent magnet near the d-axis is greater than the thickness near the q-axis. I.e. in the cross section of the rotor punching sheet 1, the ferrite is designed into an arc shape, the thickness of the ferrite near the d-axis position is larger, and the thickness near the q-axis position is slightly smaller.

The ferrite and the filling groove are arranged in the same layer, preferably, the ferrite is designed into an arc shape, the thickness of the ferrite close to the d-axis position is larger, the thickness of the ferrite close to the q-axis position is smaller, the thicknesses of the ferrite between different layers can be flexibly designed in combination with the rotor size, and the purpose of the arrangement is to ensure the smooth q-axis magnetic circuit between the ferrite layers and avoid the condition of torque capacity reduction caused by magnetic circuit saturation.

In some embodiments, when the third permanent magnet 4 includes an inner layer neodymium iron boron 42 located between the inner layer permanent magnet 32 and the shaft hole 5, a magnetism isolating hole 6 is further provided on the rotor sheet 1, and the magnetism isolating hole 6 is located between the inner layer neodymium iron boron 42 and the shaft hole 5. According to the invention, the magnetism isolating holes are arranged at the positions to act as magnetism isolating, so that the situation that the utilization rate of the neodymium iron boron is reduced because the magnetic field of the neodymium iron boron is completely closed with the neodymium iron boron and does not pass through a main magnetic circuit and the magnetism leakage is serious is prevented.

In some embodiments, the magnetic isolation holes 6 include a first side edge facing the inner neodymium-iron-boron 42, and the first side edge is an arc edge protruding toward the shaft hole 5; and/or the magnetism isolating hole 6 comprises a second side edge facing the shaft hole 5, and the second side edge is an arc-shaped edge protruding towards the inner layer neodymium iron boron 42.

In some embodiments, when the magnetic isolation hole 6 includes a first side facing the inner layer neodymium iron boron 42, the first side is connected to the inner layer neodymium iron boron 42, and when the magnetic isolation hole 6 includes a second side facing the shaft hole 5, the second side is spaced from the shaft hole 5 by a third predetermined distance.

In some embodiments, when the magnetism isolating hole 6 includes a second side edge facing the shaft hole 5, and the second side edge is an arc edge protruding toward the inner layer neodymium iron boron 42, the shortest distance h4 between the arc edge and the shaft hole 5 satisfies h4.gtoreq.5σ, the circumferential angle β corresponding to the arc edge satisfies 0.8α.ltoreq.β.ltoreq.0.9α, α is a circumferential angle occupied by each pole, and σ is a motor air gap width. For a 6 pole motor, α is preferably 60 °. The purpose that sets up like this is when guaranteeing rotor structural strength, reduces the magnetic leakage of neodymium iron boron, promotes motor efficiency.

According to the invention, only on the basis of alpha 1 & gtalpha 2, two layers of ferrite can be arranged on the rotor along the radial direction, otherwise, the arrangement is not continued.

According to the motor rotor, the inner permanent magnet and the outer permanent magnet are arranged, the outer permanent magnet comprises the outer ferrite, the inner permanent magnet comprises the inner ferrite and the neodymium iron boron, the neodymium iron boron is positioned on the d axis of the motor rotor and between the outer ferrite and the inner ferrite, so that the magnetic density of the middle position of the inner ferrite can be enhanced, the anti-demagnetizing capability of the motor can be improved, the permanent magnet flux linkage of the motor can be effectively increased, the permanent magnet torque of the motor is improved, and the torque output capability of the motor is improved; the invention provides a hybrid permanent magnet rotor structure of a self-starting permanent magnet auxiliary synchronous reluctance motor, which can improve the anti-demagnetizing capability of ferrite and enhance the operation reliability of the motor.

The invention provides a mixed permanent magnet rotor structure of a self-starting permanent magnet auxiliary synchronous reluctance motor, which is characterized in that a filling groove is formed in a rotor, an electric conduction and non-magnetic conduction material is filled in the groove, and two ends of the filling groove are connected by an end ring to form a rotor squirrel cage structure, so that the self-starting of the motor is realized; by placing neodymium iron boron between ferrite layers, the magnetic density of the middle position of the inner ferrite layer is improved, and meanwhile, the permanent magnetic flux linkage of the motor is increased, so that the output of the motor is increased, and the motor efficiency is improved; through filling groove and permanent magnet structural design, the protection effect of the squirrel cage asynchronous magnetic field to the permanent magnet is maximized to the anti-demagnetizing ability of motor is enhanced, and the reliability of motor operation is improved.

And the filling groove is arranged in the same layer as the ferrite and extends towards the d axis along the direction perpendicular to the d axis. The filling grooves are filled with electric and magnetic-conducting materials such as aluminum or aluminum alloy and the like, and the two ends of the rotor shaft are connected through end rings to form a squirrel cage structure; the conductivity of the aluminum or aluminum alloy material is higher, and the shape of the filling groove is matched, so that the resistance of the squirrel cage rotor is lower, and the synchronous involvement of the motor is facilitated; in the starting stage of the motor, the squirrel cage asynchronous magnetic field generated in the filling groove generates asynchronous torque to drive the motor to rotate, and on the other hand, the asynchronous magnetic field plays a role in shielding the armature magnetic field, namely, the squirrel cage asynchronous magnetic field can protect the demagnetization of the permanent magnet; the ferrite material has low coercive force, is easy to generate armature reaction demagnetization, and has the purpose of reducing the obstruction to the magnetic field of the squirrel cage by not arranging a magnetism isolating groove between the filling groove and the ferrite, so that the ferrite material can directly act on the permanent magnet, and the anti-demagnetization capability of the permanent magnet is improved.

In some embodiments, the permanent magnets 3 are arranged radially at least 2 layers under one pole; and/or the motor rotor has 4, 6 or 8 poles. The permanent magnet under one pole is more than 2 layers, so that the magnetic density strength can be further increased, the anti-demagnetizing capability is improved, and the motor rotor is preferably of a structure with 4 poles, 6 poles or 8 poles uniformly distributed along the circumferential direction, so that the magnetic field strength is further improved, and the torque output capability is improved.

In some embodiments, the rotor further comprises filling grooves 2, wherein the filling grooves 2 are distributed along the circumference of the rotor in a radial direction and are arranged in the same layer with the permanent magnets, at least 1 filling groove is arranged at each end part of each layer of permanent magnets, no magnetism isolating groove is arranged between each filling groove and each permanent magnet, reinforcing ribs with the width of b1 are arranged, the width b1 of each reinforcing rib meets 0.8σ.ltoreq.b1.ltoreq.2σ, and σ is the width of an air gap between the inner diameter of the stator and the outer diameter of the rotor. The purpose of this arrangement is to reduce the leakage of the ferrite itself while ensuring the mechanical strength of the rotor structure.

According to the invention, the magnetic isolation grooves are not arranged between the filling grooves and the ferrite which are arranged in the same layer, and the filling grooves are separated by the reinforcing ribs with certain width, so that the structural strength of the rotor can be ensured; because the squirrel cage asynchronous magnetic field generated by the filling groove plays a role in shielding the armature reaction magnetic field, namely, the squirrel cage magnetic field has a protection effect on the permanent magnet, the purpose of not arranging the magnetism isolating groove between the filling groove and the ferrite is to reduce the obstruction to the squirrel cage magnetic field, so that the squirrel cage magnetic field can directly act on the ferrite, and the anti-demagnetizing capability of the motor is improved.

In the multilayer permanent magnet barrier structure formed by the filling grooves and the ferrite, no magnetism isolating grooves are arranged, and only the reinforcing ribs are used for separation, so that the design aims at ensuring the mechanical structure strength of the rotor and simultaneously fully utilizing the protection effect of a squirrel cage asynchronous magnetic field on the permanent magnet; because current is induced on the squirrel cage bars in the starting stage of the motor, a squirrel cage asynchronous magnetic field generated by the current can shield part of the armature reaction demagnetizing field, so that the permanent magnets on the rotor are protected; the magnetic isolation groove is not arranged, so that the protection effect can be utilized to the maximum extent.

In some embodiments, the filling groove 2 is a closed groove, and the closed groove is filled with an electrically conductive and magnetically non-conductive material, preferably aluminum or aluminum alloy, and the filling groove is connected through an end ring to form a squirrel cage structure, and the material of the end ring is the same as the material filled in the filling groove. Furthermore, the filling groove adopts a closed groove, and the technology of casting aluminum in the closed groove at the present stage is mature, so that the large-scale production is convenient.

In some embodiments, the filling grooves are connected with the outer circle of the rotor through a magnetic bridge with the width of b2, b2 is 0.8σ.ltoreq.b2.ltoreq.2σ, and σ is the width of the air gap of the motor. The purpose of setting like this can guarantee rotor mechanical structure intensity, also can reduce interelectrode magnetic leakage to promote the efficiency of motor operation.

Further, the thickness of the filling groove which is arranged in the same layer with the ferrite is the same as that of the position, close to the q axis, of the ferrite, and the purpose of the arrangement is to ensure the smoothness of the q-axis magnetic flux path and avoid the local saturation of a rotor magnetic circuit.

The invention also provides a self-starting permanent magnet auxiliary synchronous reluctance motor, which comprises the self-starting permanent magnet auxiliary synchronous reluctance motor rotor.

The invention provides a hybrid permanent magnet rotor structure of a self-starting permanent magnet auxiliary synchronous reluctance motor, which realizes the self-starting of the motor through the combination design of a filling groove and a permanent magnet, improves the torque output capacity of the motor and enhances the running economy of the motor.

The invention provides a hybrid permanent magnet rotor structure of a self-starting permanent magnet auxiliary synchronous reluctance motor, which can improve the anti-demagnetizing capability of ferrite and enhance the operation reliability of the motor.

Through the combined design of the filling groove and the permanent magnet, the motor can realize self-starting, the loss of a controller is saved, and the motor efficiency is improved.

Through the structural design of the filling grooves and the permanent magnets, the anti-demagnetizing capability of the motor is improved.

Through the structural design of the permanent magnet, the torque output capacity of the motor is improved.

Embodiment 2:

fig. 4 is a diagram showing a construction of a rotor sheet according to a second embodiment of the present invention. As shown in the figure, the NdFeB is only arranged between ferrite layers, so that the flux linkage in the q-axis direction can be increased, the salient pole ratio is increased, the torque output capacity is enhanced, the dosage of NdFeB can be reduced as much as possible, and the material cost is reduced; because the inner layer NdFeB is omitted, a magnetism isolating hole is not required to be arranged, and therefore the mechanical structure safety of the rotor is greatly improved. The rotor structure may also be used in a 2-pole or multipole motor. The technical scheme can achieve the same technical effects as the first embodiment.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention. The foregoing is merely a preferred embodiment of the present invention, and it should be noted that it will be apparent to those skilled in the art that modifications and variations can be made without departing from the technical principles of the present invention, and these modifications and variations should also be regarded as the scope of the invention.

Claims

1. The utility model provides a self-starting permanent magnetism auxiliary synchronous reluctance motor rotor which characterized in that:

the rotor core comprises a plurality of rotor punching sheets (1), wherein a plurality of rotor punching sheets (1) are laminated to form a rotor core, a permanent magnet (3) is arranged on each rotor punching sheet (1), and each rotor punching sheet (1) is provided with a shaft hole (5); the permanent magnet (3) comprises an outer permanent magnet (31) which is relatively positioned at the radial outer side, an inner permanent magnet (32) which is relatively positioned at the radial inner side and a third permanent magnet (4), wherein the coercive force of the outer permanent magnet (31) and the coercive force of the inner permanent magnet (32) are equal and are smaller than those of the third permanent magnet (4), the third permanent magnet (4) is positioned on the d-axis of the motor rotor, and the magnetizing direction of the third permanent magnet (4) is tangential magnetization;

the third permanent magnet (4) comprises an interlayer neodymium iron boron (41) positioned between the outer layer permanent magnet (31) and the inner layer permanent magnet (32), and/or an inner layer neodymium iron boron (42) positioned between the inner layer permanent magnet (32) and the shaft hole (5); the outer permanent magnet (31) is an outer ferrite, and the inner permanent magnet (32) is an inner ferrite;

when the third permanent magnet (4) comprises an interlayer neodymium iron boron (41) positioned between the outer-layer permanent magnet (31) and the inner-layer permanent magnet (32), the interlayer neodymium iron boron (41) is separated from the outer-layer permanent magnet (31) by a first preset distance, and the interlayer neodymium iron boron (41) is separated from the inner-layer permanent magnet (32) by a second preset distance;

the distance between the interlayer NdFeB (41) and the outer permanent magnet (31) and the distance between the interlayer NdFeB (42) and the inner permanent magnet (32) are h1 and h2 respectively, the distance between the interlayer NdFeB (42) and the inner permanent magnet (32) is h3, and the interlayer NdFeB comprises: 0.8σ is equal to or less than h1=h2=h3 is equal to or less than 2σ, and σ is the motor air gap width.

2. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to claim 1, wherein:

in the cross section of the rotor punching sheet (1), the third permanent magnet (4) is of a rectangular structure, the long edge of the rectangular structure extends along the radial direction of the rotor punching sheet (1), and the short edge of the rectangular structure extends along the tangential direction of the rotor punching sheet (1).

3. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to claim 1, wherein:

the thickness d1 of the third permanent magnet (4) in the magnetizing direction is equal to or more than 5 sigma and equal to or less than 10 sigma, and sigma is the width of an air gap of the motor.

4. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to claim 1, wherein:

the outer-layer permanent magnet (31) and/or the inner-layer permanent magnet (32) are in a fan-ring structure, the circle center of the fan ring faces to one side far away from the center of the rotor, and the thickness of the same permanent magnet, which is close to the d axis, is larger than that of the same permanent magnet, which is close to the q axis.

5. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to claim 1, wherein:

when the third permanent magnet (4) comprises an inner layer NdFeB (42) positioned between the inner layer permanent magnet (32) and the shaft hole (5), the rotor punching sheet (1) is further provided with a magnetism isolating hole (6), and the magnetism isolating hole (6) is positioned between the inner layer NdFeB (42) and the shaft hole (5).

6. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to claim 5, wherein:

the magnetism isolating hole (6) comprises a first side edge facing the inner layer neodymium iron boron (42), and the first side edge is an arc-shaped edge protruding towards the shaft hole (5); and/or the magnetism isolating hole (6) comprises a second side edge which faces the shaft hole (5), and the second side edge is an arc-shaped edge which protrudes towards the inner layer NdFeB (42).

7. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to claim 6, wherein:

when the magnetism isolating hole (6) comprises a first side edge facing the inner layer neodymium iron boron (42), the first side edge is connected with the inner layer neodymium iron boron (42), and when the magnetism isolating hole (6) comprises a second side edge facing the shaft hole (5), the second side edge is spaced from the shaft hole (5) by a third preset distance.

8. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to claim 5, wherein:

when the magnetism isolating hole (6) comprises a second side edge facing the shaft hole (5), and the second side edge is an arc-shaped side edge protruding towards the inner layer neodymium iron boron (42), the shortest distance h4 between the arc-shaped side edge and the shaft hole (5) meets h4 and is more than or equal to 5 sigma, the circumferential angle beta corresponding to the arc-shaped side edge meets 0.8alpha and is less than or equal to 0.9alpha, alpha is the circumferential angle occupied by each pole, and sigma is the width of an air gap of the motor.

9. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to claim 1, wherein:

taking the included angle between the connecting lines from the center of the rotor to the edge of the permanent magnet as the polar arc angle of the permanent magnet, and gradually reducing the polar arc angle of ferrite between different layers along the radial outward direction of the d axis; α1 > α2; α1 and α2 are pole angles of the inner ferrite near the shaft hole side and the outer ferrite near the outer circle side of the rotor respectively;

10. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to any one of claims 1-9, wherein:

-said permanent magnets (3) are arranged radially at least 2 layers under one pole; and/or the motor rotor has 4, 6 or 8 poles.

11. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to any one of claims 1-9, wherein:

the rotor is characterized by further comprising filling grooves (2), wherein the filling grooves (2) are distributed along the circumferential direction of the rotor in the same layer with the permanent magnets, at least 1 filling groove is arranged at each end part of each layer of permanent magnets, no magnetism isolating groove is arranged between each filling groove and each permanent magnet, reinforcing ribs with the width of b1 are arranged, the width b1 of each reinforcing rib is more than or equal to 0.8σ and less than or equal to 2σ, and σ is the width of an air gap between the inner diameter of the stator and the outer diameter of the rotor.

12. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to claim 11, wherein:

the filling groove (2) is a closed groove, the closed groove is filled with conductive and non-magnetic materials, the filling groove is connected through an end ring to form a squirrel cage structure, and the material of the end ring is the same as the material filled in the filling groove.

13. The self-starting permanent magnet assisted synchronous reluctance machine rotor according to claim 11, wherein:

the filling groove is connected with the outer circle of the rotor through a magnetic bridge with the width of b2, b2 is 0.8σ.ltoreq.b2.ltoreq.2σ, and σ is the width of the motor air gap.

14. An electric motor, characterized in that: a rotor comprising the self-starting permanent magnet assisted synchronous reluctance motor of any one of claims 1-13.