CN110739785A

CN110739785A - Permanent magnet motor

Info

Publication number: CN110739785A
Application number: CN201810788716.0A
Authority: CN
Inventors: 朱守昱
Original assignee: AIDELI SCRENCE AND TECHNOLOGY Co Ltd
Current assignee: AIDELI SCRENCE AND TECHNOLOGY Co Ltd; Adlee Powertronic Co Ltd
Priority date: 2018-07-18
Filing date: 2018-07-18
Publication date: 2020-01-31
Anticipated expiration: 2038-07-18
Also published as: CN110739785B

Abstract

The permanent magnet motor comprises an stator provided with a plurality of windings, a rotor provided with a plurality of magnet placing grooves and a plurality of magnetism isolating empty grooves, wherein the plurality of magnet placing grooves comprise a plurality of circumferential magnet placing grooves which are circumferentially arranged and a plurality of radial magnet placing grooves which are radially arranged, each circumferential magnet placing groove and each radial magnet placing groove are circumferentially and alternately arranged, and the plurality of magnetism isolating empty grooves are close to the magnet placing grooves and distributed to the d axis magnetic flux path direction of the rotor.

Description

Permanent magnet motor

Technical Field

The invention belongs to the technical field of motors, and particularly relates to permanent magnet motors.

Background

In order to meet the requirements of different rotation speeds, loads, performances, etc., can obtain the required characteristics by changing the number, position or angle of the magnets arranged in the rotor, taiwan certificate No. 129116 has the characteristic of elastic change, however, the radial magnet only provides a magnetic field for a single magnetic pole, so that two radial magnets are needed between two adjacent magnetic poles, thus causes the cost of the magnet to increase, moreover, distance is left between the two radial magnets, which causes the expansion angle of the magnetic pole to be reduced, which is not favorable for the output characteristics of the motor.

US8044548 discloses that a plurality of circumferential and radial magnet accommodating grooves are formed in a rotor, and magnets are accommodated in the plurality of circumferential and radial magnet accommodating grooves, for example, by arranging magnetic members of different materials in the circumferential and radial magnet accommodating grooves, and arranging different magnetic flux densities or magnetization directions in a d axis and a q axis. In addition, the rotor of the patent may also be provided with a magnetic isolation slot, however, the magnetic isolation slot of the patent cannot compromise the d-axis and q-axis magnetic flux paths, wherein the q-axis magnetic flux path is further blocked, and thus, the rotor cannot obtain better rotation speed and torque force at the same time.

Therefore, there is a need to provide new and improved permanent magnet motors to solve the above problems.

Disclosure of Invention

The invention aims to provide permanent magnet motors, which can plan a desired magnetic flux path to achieve preset performance.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides permanent magnet motors, which comprises a stator provided with a plurality of windings, and a rotor provided with a plurality of magnet placing grooves and a plurality of magnetism isolating empty grooves, wherein the plurality of magnet placing grooves comprise a plurality of circumferential magnet placing grooves which are circumferentially arranged and a plurality of radial magnet placing grooves which are radially arranged, each circumferential magnet placing groove and each radial magnet placing groove are circumferentially and alternately arranged, and the plurality of magnetism isolating empty grooves are close to the magnet placing grooves and are distributed to the d axis magnetic flux path direction of the rotor.

The plurality of circumferential magnet placing grooves contain a plurality of magnets, and the plurality of radial magnet placing grooves do not contain magnets.

The plurality of radial magnet placing grooves contain a plurality of magnets, the magnets in each radial magnet placing groove are positioned on the q axis of the rotor, and the plurality of circumferential magnet placing grooves do not contain magnets.

The plurality of magnet placing grooves contain a plurality of magnets, the plurality of circumferential magnet placing grooves at least partially contain parts of the plurality of magnets, and the plurality of radial magnet placing grooves at least partially contain parts of the plurality of magnets.

The plurality of magnets have different physical characteristics including at least of magnet material shapes and sizes.

The magnet placing grooves contain a plurality of magnets, wherein at least the shape of the magnet is different from the shape of the magnet placing groove containing the magnet.

The magnet placing grooves are provided with a plurality of magnets, and the magnet isolating empty grooves are distributed to the outer periphery of the rotor which is close to the direction pointed by the d-axis magnetic flux path.

The plurality of magnet placing grooves are provided with a plurality of magnets, and compared with the outer periphery of the rotor, the plurality of magnet isolating empty grooves are distributed along the q axis magnetic flux path direction of the rotor in an arc extending way, and the arc openings face outwards in the radial direction.

The plurality of windings of the stator are windings whose current distribution can be adjusted to adjust the proportion of the magnetic flux entering the d-axis and q-axis of the rotor.

The radial magnet placing grooves are provided with a plurality of magnets, and the outer ends of the magnets are retracted inwards relative to the outer periphery of the rotor.

The rotor further comprises a rib part arranged at the outer end of the plurality of radial magnet placing grooves.

The magnet placing grooves are provided with a plurality of magnets, and the expanding angle of magnetic poles formed between the adjacent radial magnet placing grooves of the magnets is smaller than the angle of magnetic poles defined by the central axes of the adjacent radial magnet placing grooves.

The stator further includes a plurality of radially extending teeth around which the plurality of windings are wound, the rotor being closer to the teeth on the outer periphery at the pole spread angle than to the rotor between adjacent pole spread angles on the outer periphery.

The outer periphery of the rotor includes a plurality of segments, at least of which have a different center than the rotor.

The magnet placing grooves are provided with a plurality of magnets, and the outer periphery of the rotor is provided with a inward-contracting surface near the d shaft.

The rotor further comprises a plurality of second magnet placing grooves arranged between the adjacent radial magnet placing grooves.

At least of the second magnet slots are provided with at least magnets.

The plurality of magnetic isolation empty slots comprise straight slots extending along the radial direction of of the rotor and a plurality of non-linear slots positioned at two sides of the straight slots, wherein at least of the plurality of non-linear slots comprises vertical to the end section of the radial magnet placing slot and straight sections extending from the end section towards the radial direction of the rotor.

At least of the plurality of radial magnet placing grooves extend to the space between the opposite end surfaces of two adjacent circumferential magnet placing grooves, and the end surfaces completely correspond to the range of the radial magnet placing grooves.

The invention has the beneficial effects that: the permanent magnet motor can plan a desired magnetic flux path to achieve preset performance, can define better magnetic isolation and magnetic flux paths, and can have output performance and reduce cogging torque.

Drawings

FIG. 1 is a schematic view of the positions of the d-axis and the q-axis.

Fig. 2 is a schematic view of a d-axis flux path.

Fig. 3 is a schematic view of the q-axis flux path.

Fig. 4 is a schematic diagram of armature reaction magnetic axis deviation.

FIG. 5 is a schematic view of a rotor according to an embodiment of the present invention.

Fig. 6 is a partially enlarged view of fig. 5.

Fig. 7-11 are schematic diagrams of different aspects of a partial magnet placement slot arrangement of magnets according to the preferred embodiment of the invention.

Fig. 12-17 are schematic diagrams of various aspects of an preferred embodiment of the invention in which all magnet slots are configured with magnets and wherein adjacent tooth tips of the stator of fig. 17 have a relatively large pitch.

Fig. 18 to 20 are schematic views illustrating another preferred embodiment of the present invention configured with a second magnet placement slot.

FIG. 21 is a schematic view of another preferred embodiment of the present invention, showing different configurations of the magnetic shield slots.

Reference numerals: 10: a stator; 11: a winding; 12: a tooth portion; 13: a stator slot; 20: a rotor; 21: a magnet placing groove; 211: a circumferential magnet placement groove; 212: a radial magnet placement groove; 213: a rib portion; 22: a magnetic isolation empty slot; 221: a straight groove; 222: a non-linear slot; 223: an end segment; 224: a straight section; 23: an arc segment; 24: shrinking the surface inwards; 30: a magnet; 40: a magnetic flux central axis; 50: a magnetic pole central axis; 60: clearance; 70: a second magnet placing groove; a: a magnetic pole spread angle; b: a magnetic pole angle; d-axis: a d-axis; sd: d-axis flux path direction; q-axis: a q-axis; sq: the q-axis flux path direction.

Detailed Description

The following description is given by way of example only, and is not intended to limit the scope of the invention.

Referring to fig. 1 to 6, which show preferred embodiments of the present invention, a permanent magnet motor 1 of the present invention includes a stator 10 and a rotor 20.

The stator 10 has a plurality of windings 11, the rotor 20 has a plurality of magnet slots 21 and a plurality of magnetic isolation empty slots 22, the plurality of magnet slots 21 include a plurality of circumferentially arranged circumferential magnet slots 211 and a plurality of radially arranged radial magnet slots 212, each circumferential magnet slot 211 and each radial magnet slot 212 are circumferentially alternately arranged, and the plurality of magnetic isolation empty slots 22 are close to the magnet slots and distributed to the flux path direction Sd. of d-axis (d-axis) of the rotor 20, thereby being capable of planning a desired flux path to achieve a predetermined performance.

The magnet slots 21 contain magnets 30, the circumferential magnet slots 211 contain magnets 30 at least partially, the radial magnet slots 212 contain magnets 30 at least partially, smooth and stable in this embodiment, for example, magnets may be contained only in or all of the circumferential magnet slots 211, magnets may not be contained in the radial magnet slots 212 (as shown in fig. 7 and 8) to obtain higher rotation speed, or magnets may be contained only in or all of the radial magnet slots 212, magnets may not be contained in the q-axis (q-axis) of the rotor 20, magnets may not be contained in the radial magnet slots 211 (as shown in fig. 9, 10), magnets may not be contained in the radial magnet slots 212, magnets may be contained only in the longitudinal magnet slots 212, magnets may not be contained in the longitudinal magnet slots 211, magnets may be contained in longitudinal slots 211, magnets at least in longitudinal slots 35, magnets may be contained in longitudinal slots, magnets may be contained in longitudinal slots 211, magnets may be contained in longitudinal slots 35, or in longitudinal slots, magnets may be contained in longitudinal slots, magnets may be arranged in longitudinal slots, magnets may be arranged in longitudinal slots, magnets may be arranged in longitudinal slots, or in magnets may be arranged in longitudinal slots, magnets may be arranged in slots, or may be arranged in slots, magnets may be arranged in magnets 211, or may be arranged in magnets, or may be arranged in coils may be arranged in longitudinal slots such as shown in longitudinal slots such as opposed slots such as shown in longitudinal slots such as transverse slots such as opposed slots such as transverse slots 23-8, magnets 211, magnets, and magnet slots.

When there is no armature reaction, central flux axis 40 of the permanent magnet motor is located at central pole axis 50, magnetic fields are generated when the winding 11 of the stator 10 is energized, the magnetic fields interact with the magnetic fields of the magnets 30 and then converge into new central flux axes 40, which is the influence caused by the armature reaction (fig. 4), the new central flux axes 40 deviate from the central pole axis 50, the magnetic isolation slots 22 can generate magnetic resistance, the problem that the central flux axes 40 deviate from the central pole axis 50 caused by the armature reaction is reduced, and the armature reaction can be optimized to be reduced, and the deviation of the central flux axes 40 from the central pole axis 50 can cause the reduction of effective magnetic flux and the reduction of output performance.

The magnets 30 preferably have the same physical characteristics, including at least one of the magnet material shapes and sizes , however, the magnets 30 may have different physical characteristics according to different characteristic requirements, for example, the magnets 30 may have the same or different materials or the same or different shapes and sizes, and the magnets 30 may have the same or different shapes and sizes as the magnet slots 21, for example, at least one of the radial magnet slots 212, extends between the two opposite end faces of the two adjacent circumferential magnet slots 211, the magnet 30 is rectangular, and after the magnet 30 is placed in the magnet slot 21, the end of the magnet slot 21 still has clearance (fig. 5), preferably, the two end faces completely correspond to the range of the radial magnet slot 212, and the clearance 60 can reduce magnetic field leakage.

Compared with the outer periphery of the rotor 20, the plurality of magnetic isolation slots 22 are distributed along the q-axis (q-axis) magnetic flux path direction Sq of the rotor 20 in an arc extending manner with the arc opening facing radially outward, that is, the plurality of magnetic isolation slots 22 are distributed in an arc recessed toward the circumferential magnet accommodating slot 211, so that the q-axis magnetic flux path directions Sq are reserved , and both the q-axis magnetic flux path direction Sq and the armature reaction reduction can be achieved.

The outer ends of the plurality of magnets 30 are recessed relative to the outer periphery of the rotor 20 (as shown in fig. 12-17) to reduce the effect of armature reaction on magnet demagnetization. The deviation of the magnetic flux center axis 40 from the magnetic pole center axis 50 by the armature reaction causes an increase in the magnetic field at the edge of the radially disposed magnets 30 near the outer periphery of the rotor 20, which may cause demagnetization if the increased magnetic field is reversed from the magnetic poles of the radially disposed magnets 30, which may cause saturation of the magnetic circuit if the increased magnetic field is the same as the magnetic poles of the radially disposed magnets 30, both of which may affect the distribution of the magnetic flux.

The plurality of windings 11 of the stator 10 are windings with adjustable current distribution, so as to adjust the flux ratio of d axis and q axis entering the rotor 20, by adjusting the flux ratio of d axis and q axis entering the rotor 20, the offset of the flux center axis 40 from the pole center axis 50 due to armature reaction can be adjusted, which means that the effective flux can be adjusted, i.e. the output performance of the permanent magnet motor can be adjusted, for example, by adjusting the current of the windings, the offset of the flux center axis caused by armature reaction can be compensated in advance, so that the flux center axis 40 overlaps the pole center axis 50, the effective flux is larger, and the output performance is improved.

The radial magnet slots 212 may be directly opened at the outer circumference of the rotor 20 (as shown in fig. 1 to 12) for easy manufacturing and placement of the magnets 30, and the radially disposed magnets 30 may also be flush with or retracted from the radial magnet slots 212 by . however, the rotor 20 may further include ribs 213 (as shown in fig. 13 to 17) disposed at the outer ends of the radial magnet slots 212, or radial magnet slots not completely penetrating the outer circumference of the rotor, thereby increasing the structural strength of the rotor 20 and preventing the magnets 30 from being separated due to centrifugal force, and the ribs 213 may be flush with or retracted from the outer circumference of the rotor 20 by .

The stator 10 further includes a plurality of radially extending teeth 12 around which the plurality of windings 11 are wound, the stator 10 further includes a plurality of stator slots 13 accommodating the plurality of windings 11, slot openings of the stator slots 13 may be necked down, slot opening widths of the stator slots 13 are inversely related to leakage flux amounts, for example, the slot opening widths of fig. 14 and 17 are smaller, the leakage flux amounts are larger, the slot opening widths of fig. 17 are larger, the leakage flux amounts are smaller, the plurality of magnets 30 form a pole spread angle a of between adjacent radial magnet-placement slots 212 that is smaller than a pole angle b defined by a central axis of the adjacent radial magnet-placement slots 212, magnetic flux of each pole may short-circuit to an adjacent pole through the teeth 12 of the stator 10, causing leakage flux, the short circuit fails to interact with the windings 11 of the stator 10, resulting in an effective flux spread affecting output performance, and thus, preferably, the pole spread angle a is smaller, the rotor 20 is preferably located on an outer periphery of the rotor 20 closer to the leakage flux angle a than the rotor 20 located on the rotor.

The outer periphery of the rotor 20 may include or more eccentric segments (as shown in fig. 14-17) or straight segments that provide a gradual increase and decrease in the air gap between the rotor 20 and the stator 10, which in turn provides a gradual increase and decrease in the flux linkage that reduces cogging torque, as illustrated in fig. 15, the outer periphery of the rotor 20 includes a plurality of segments 23, at least (preferably all) of which have different centers than the rotor 20, although the outer periphery of the rotor may include or more concentric segments.

The rotor 20 may have indented surfaces 24 (fig. 16) on its outer periphery near the d-axis the position on the outer periphery of the rotor 20 near the d-axis or the pole center axis 50 where the magnetic flux of the pole is strongest, and for the position where cogging torque is greater, the indented surfaces 24 may be appropriately placed to increase air gaps to increase reluctance to reduce cogging torque.

Referring to fig. 18 to 20, the rotor 20 may further include a plurality of second magnet slots 70 disposed between adjacent radial magnet slots 212, at least one of the plurality of second magnet slots 70, at least one of which , has at least magnets 30 to increase the magnetic flux of the main magnetic pole and increase the torque force, some or all of the second magnet slots 70 may be disposed between adjacent radial magnet slots 212, some or all of the second magnet slots 70 may have the magnets, and the plurality of second magnet slots 70 may be disposed in a single layer (as shown in fig. 18 and 19) or in multiple layers (as shown in fig. 20).

In other embodiments as shown in fig. 21, the plurality of magnetic shielding slots 22 are distributed to the outer periphery of the rotor 20 near the direction Sd (see fig. 2) of the d-axis magnetic flux path. For example, the ends of the plurality of magnetic isolation slots 22 are all close to the outer periphery of the rotor 20 and are distributed along the outer periphery of the rotor 20 in an arc shape, so that the armature reaction can be minimized.

In all the above embodiments, as illustrated in fig. 5 and 6, the plurality of magnetic isolation empty slots 22 include a straight slot 221 extending in a radial direction of the rotor 20 along a side of the rotor, and a plurality of non-linear slots 222 located on both sides of the straight slot 221, at least of the plurality of non-linear slots 222 includes a straight segment 224 extending in a radial direction of the rotor 20 from an end segment 223 of the radial magnet placement slot 212 perpendicular to , so as to define a better magnetic isolation and flux path, achieve both output performance and reduce cogging torque.

Claims

1, A permanent magnet motor, comprising:

stator having multiple windings;

rotor, which has plural magnet placing slots and plural magnetism isolating empty slots, the plural magnet placing slots include plural circumferential magnet placing slots arranged circumferentially and plural radial magnet placing slots arranged radially, each circumferential magnet placing slot and each radial magnet placing slot are disposed alternately circumferentially, the plural magnetism isolating empty slots are close to the magnet placing slots and distributed to the d axis magnetic flux path direction of the rotor.

2. The permanent magnet electric motor of claim 1 wherein said plurality of circumferential magnet receiving slots receive a plurality of magnets and said plurality of radial magnet receiving slots do not receive magnets.

3. The permanent magnet motor of claim 1 wherein said plurality of radial magnet receiving slots receive a plurality of magnets, the magnets in each of said radial magnet receiving slots being located on the q axis of said rotor, said plurality of circumferential magnet receiving slots not receiving magnets.

4. The permanent magnet motor of claim 1 wherein the plurality of magnet receiving slots receive a plurality of magnets, the plurality of circumferential magnet receiving slots at least partially receive portions of the plurality of magnets, and the plurality of radial magnet receiving slots at least partially receive portions of the plurality of magnets.

5. The permanent magnet motor of claim 4 wherein said plurality of magnets have different physical characteristics including at least magnet material shapes and sizes.

6. The permanent magnet motor of claim 1 wherein the plurality of magnet receiving slots receive a plurality of magnets, at least wherein the shape of the magnets is different from the shape of the magnet receiving slots receiving the magnets.

7. The permanent magnet motor of claim 1 wherein said plurality of magnet receiving slots receive a plurality of magnets and said plurality of magnetic isolation slots are disposed proximate an outer periphery of said rotor at which said d-axis flux path is oriented.

8. The permanent magnet motor of claim 1 wherein the plurality of magnet receiving slots receive a plurality of magnets, the plurality of magnetic isolation slots being disposed along an arc of the q axis flux path of the rotor and having radially outward facing arc openings, relative to the outer periphery of the rotor.

9. The permanent magnet motor of claim 8 wherein the plurality of windings of the stator are windings with adjustable current distribution to adjust the proportion of flux entering the d and q axes of the rotor.

10. The permanent magnet electric motor of claim 1 wherein said plurality of radial magnet receiving slots receive a plurality of magnets having outer ends that are recessed relative to an outer periphery of said rotor.

11. The permanent magnet electric motor of claim 1 wherein said rotor further comprises ribs disposed at outer ends of said plurality of radial magnet placement slots.

12. The permanent magnet motor of claim 1 wherein said plurality of magnet receiving slots receive a plurality of magnets forming an pole spread angle between adjacent ones of said radial magnet receiving slots that is less than a pole angle defined by the central axis of adjacent ones of said radial magnet receiving slots.

13. The permanent magnet electric motor of claim 12 wherein the stator further comprises a plurality of radially extending teeth about which the plurality of windings are wound, the rotor being closer to the teeth on the outer periphery at the pole spread angle than to the rotor between adjacent pole spread angles.

14. The permanent magnet motor of claim 1 wherein the outer periphery of the rotor includes a plurality of arc segments, at least of the plurality of arc segments having a different center than the rotor.

15. The permanent magnet motor of claim 1 wherein said plurality of magnet receiving slots receive a plurality of magnets, and said rotor has an outer periphery with a indented surface located near axis d.

16. The permanent magnet motor of claim 1 wherein said rotor further comprises a plurality of second magnet receiving slots disposed between adjacent ones of said radial magnet receiving slots.

17. The permanent magnet motor of claim 16 wherein at least of said plurality of second magnet receiving slots are provided with at least magnets.

18. The permanent magnet motor of claim 1 wherein the plurality of flux-barrier slots include straight slots extending radially of the rotor and a plurality of non-linear slots on either side of the straight slots, at least of the plurality of non-linear slots including an end segment perpendicular to the radial magnet-placement slots and a straight segment extending radially of the rotor from the end segment.

19. The permanent magnet motor of any wherein at least of the plurality of radial magnet slots extend between opposite end faces of two adjacent circumferential magnet slots that correspond entirely within the radial magnet slots.