A magnetic steel arrangement method for a disc motor

Abstract

The present invention discloses a magnetic steel arrangement method for a disk motor, including: a rotor disk, magnetic steel grooves are distributed on the rotor disk, and magnetic steel is embedded in the magnetic steel grooves; the magnetic steel includes: a unit part divided in the radial direction of the rotor disk; a first unit part, spliced ​​between a second unit part and a third unit part, the first unit part closes the magnetic force lines along the axial direction of the motor to form a first magnetic field occurring along the axial direction of the motor; the second unit part closes the magnetic force lines along the radial direction of the motor to form a second magnetic field perpendicular to the splicing surface on the first unit part; the third unit part closes the magnetic force lines along the radial direction of the motor to form a third magnetic field perpendicular to the splicing surface on the first unit part; the magnetic force lines of two adjacent magnetic steels on the rotor disk: the magnetic force lines of the first unit part have opposite closing directions, the magnetic force lines of the second unit part have the same closing directions, and the magnetic force lines of the third unit part have the same closing directions. The magnetic steel segmentation can reduce the eddy current loss of the permanent magnet and reduce the risk of the magnetic steel falling off due to overheating.

Description

Technical Field

[0001] The present invention relates to the technical field of disc motors, and in particular to a magnetic steel arrangement method for disc motors. Background Art

[0002] The permanent magnets of the disc motor rotor are mainly installed by attaching a whole piece of magnetic steel to the rotor back iron. This type of permanent magnet will generate considerable eddy current loss inside when the motor is running at high speed, which will cause the permanent magnet to overheat and demagnetize, or even cause the permanent magnet to fall off. The eddy current loss of this type of permanent magnet is large, and the large-scale use of high-coercivity NdFeB permanent magnets makes the overall manufacturing cost of the motor high.

[0003] The existing permanent magnet segmentation technology simply divides a permanent magnet with the same magnetization direction into several pieces, either equally or unequally. Although it can effectively reduce the eddy current loss of the permanent magnet, this magnetization method has serious magnetic leakage and poor magnetic field enhancement effect.

[0004] At present, the dual-rotor single-stator disc motor has poor heat dissipation effect, which may cause the stator winding to overheat and the winding insulation layer to be damaged. The heat generated by the stator winding overheating is difficult to dissipate. It may also cause the permanent magnets on the rotor to overheat and irreversibly demagnetize, seriously affecting the output performance of the motor. Summary of the invention

[0005] The technical solution of the present invention is: a disk motor magnet arrangement method, which is used to solve the problem that when the permanent magnet of the disk permanent magnet motor rotor is installed with a whole piece of magnet, when the motor runs at high speed, considerable eddy current loss will be generated inside it, resulting in the permanent magnet temperature being too high and demagnetization, or even the permanent magnet falling off.

[0006] A disc motor magnetic steel arrangement method involved in this scheme includes: a rotor disk formed by stacking silicon steel sheets, with magnetic steel slots distributed on the rotor disk, and magnetic steel embedded in the magnetic steel slots; the magnetic steel includes: segmented unit parts; multiple unit parts are spliced ​​along the radial direction of the rotor disk, and the unit parts are contacted and connected through the splicing surface.

[0007] The unit part specifically includes: a first unit part, a second unit part and a third unit part. Among them:

[0008] The first unit part is spliced ​​between the second unit part and the third unit part, and the first unit part closes the magnetic lines of force along the axial direction of the motor to form a first magnetic field generated along the axial direction of the motor;

[0009] The second unit part closes the magnetic lines of force along the radial direction of the motor to form a second magnetic field pointing perpendicularly to the direction in which the first magnetic field is generated;

[0010] The third unit part closes the magnetic lines of force along the radial direction of the motor to form a third magnetic field pointing perpendicularly to the direction in which the first magnetic field is generated;

[0011] For two adjacent magnetic steels on the rotor disk: the closing directions of the magnetic force lines of the first unit part are opposite, the closing directions of the magnetic force lines of the second unit part are the same, and the closing directions of the magnetic force lines of the third unit part are the same.

[0012] Preferably, the magnetic steel has a strip-shaped fan-shaped structure in the transverse cross section, and has a three-section structure in the transverse cross section, namely: the second unit part, the first unit part, and the third unit part are spliced ​​in sequence, and the third unit part is similar in shape to the second unit part and has the same radial length.

[0013] Preferably, the magnetic steel is a permanent magnet, wherein:

[0014] The first unit part is magnetized along the axial direction of the motor to form a first magnetic field;

[0015] The second unit part is magnetized along the radial direction of the motor to form a second magnetic field;

[0016] The third unit portion is magnetized along the radial direction of the motor to form a third magnetic field.

[0017] Specifically, the joint surface of the unit part is basically a plane extending axially, so the joint surface is in the same direction as the first magnetic field. Therefore, the second unit part is magnetized along the radial direction of the motor to form a second magnetic field perpendicular to the joint surface of the first unit part; the third unit part is magnetized along the radial direction of the motor to form a third magnetic field perpendicular to the joint surface of the first unit part.

[0018] Preferably, the unit parts are contact-bonded by coating structural adhesive on adjacent joint surfaces.

[0019] Based on the above structure, a disc motor includes: a stator and rotors on both sides of the stator.

[0020] The rotor comprises a rotor disk, on which magnetic steel grooves are distributed, in which the segmented magnetic steel is embedded, and a rotating shaft is assembled in the shaft hole of the rotor disk by key connection.

[0021] The stator comprises a stator disc, a winding is arranged on the stator disc, and an axial hole of the stator disc is assembled with the rotating shaft through a bearing.

[0022] Preferably, the stator disc is an ironless stator structure.

[0023] Specifically, the stator and the rotor are integrated in the housing, and the housing includes end covers on both sides and a rotating housing between the end covers on both sides. The rotating housing includes a left housing and a right housing, and the left housing and the right housing are butt-jointed to form a butt end.

[0024] The stator is fixedly connected to the butt ends of the left shell and the right shell through a stator disk for assembly connection, and the rotating shaft is assembled with the shaft hole on the end cover through a bearing.

[0025] The advantages of the present invention are:

[0026] The segmentation of permanent magnets can effectively reduce the eddy current loss of permanent magnets and reduce the risk of permanent magnets falling off due to overheating. By optimizing the segmented combination of permanent magnet materials with large intrinsic coercive force and small residual magnetic flux density and permanent magnet materials with small intrinsic coercive force and large residual magnetic flux density, the low-cost NdFeB with large intrinsic coercive force can be used to the minimum while ensuring the anti-demagnetization ability of the motor. While improving the working efficiency of the disc motor, it can also reduce the cost of the segmented magnetic steel structure motor rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0028] Figure 1 is a front view of the rotor disk;

[0029] Figure 2 It is a combined diagram of the positive pole direction of the segmented magnetic steel;

[0030] Figure 3 It is a combined diagram of the reverse polarity of segmented magnetic steel;

[0031] Figure 4 It is a comparison curve of magnetic effect of four arrangement and combination modes of segmented magnetic steel;

[0032] Figure 5 is the front view of the rotating shaft;

[0033] Figure 6 It is a simulation diagram of magnetic field line distribution of segmented permanent magnet;

[0034] Figure 7 It is the segmented magnetic steel torque curve;

[0035] Figure 8 It is a cross-sectional view of a dual-rotor single-stator disc motor;

[0036] Among them, 1. the first bolt; 2. the motor end cover; 3. the rotating shaft; 4. the bearing end cover; 5. the screw; 6. the bearing; 7. the limit block; 8. the flat keyway; 9. the left housing; 10. the stator disk; 11. the second bolt; 12. the right housing; 13. the rotor disk; 14. the second unit; 15. the first unit; 16. the third unit; 17. the winding. DETAILED DESCRIPTION

[0037] Embodiment 1:

[0038] like Figure 4 As shown, there are four basic combinations of segmented magnets: Figure 4The four combinations in the figure are schematic diagrams of the magnetization direction on the longitudinal cross section of the magnetic steel).

[0039] a combination, the magnetization of the three units is upward, the magnetic field strength is relatively uniform but not concentrated, and the amplification effect is not ideal.

[0040] In combination b, the magnetization of the middle unit is upward, and the magnetization of the units on both sides is perpendicular to the magnetic field direction of the middle unit. The magnetic lines of force are dense, the magnetic field amplification is concentrated, and the amplification effect is outstanding.

[0041] In combination c and combination d, the magnetization direction of the two side units and the magnetization direction of the middle unit are opposite to each other, and no magnetic field amplification is generated, and the magnetic lines of force cancel each other out.

[0042] Therefore, it can be seen from the comparison of the magnetic field amplification curves of the four combinations that the magnetic field amplification effect of combination b is the best, that is, the magnetization direction used in the scheme of the present invention can produce a more prominent magnetic field enhancement effect.

[0043] Embodiment 2:

[0044] like Figure 1-8 As shown, a dual-rotor single-stator disc motor includes a rotor and a stator, wherein the rotor includes a rotor disc 13, and the stator includes a stator disc 10. The two rotor discs are respectively located on the left and right sides of the stator disc, and the rotor disc 13 is circular. The rotor disc and the stator disc are both mounted on the rotating shaft 3, and the rotating shaft 3 is provided with a flat key slot 8, and the rotor disc 13 is provided with a key slot of the same size. The rotor discs on the left and right sides of the stator disc are connected to the rotating shaft 3 through flat keys. The shaft hole of the stator disc 10 is supported on the rotating shaft 3 by a bearing, and the outer side of the stator disc is fixedly connected to the rotating housing formed by the left housing 9 and the right housing 12 through a second bolt 11.

[0045] The motor end covers 2 located on the left and right sides of the motor are fixed to the motor shaft 3 through bearings 6, the bearing end covers 4 are fixed to the motor end covers 2 of the motor through screws 5, the bearing end covers 4 and the limit blocks 7 are used for axial positioning of the bearings 6, and the rotating housing is connected to the motor end covers 2 through the first bolts 1.

[0046] like Figure 1 As shown, the rotor disks 13 on both sides of the stator of the dual-rotor single-stator disk motor are formed by laminating silicon steel sheets, and the stator disk 10 is a coreless stator structure composed of a winding 17 and epoxy resin.

[0047] The permanent magnet steel slots are formed on the rotor disk by wire cutting or punching, and the permanent magnet steel slots have the same outer size as the permanent magnets.

[0048] like Figure 2 and 3As shown, the permanent magnets of each pole are distributed radially along the motor from the inside to the outside and are divided into the third unit part 16, the first unit part 15, and the second unit part 14. The first unit part 15 is magnetized along the axial direction of the disc motor. The magnetization directions of the third unit part 16 and the second unit part 14 are perpendicular to the radial end face of the first unit part 15, and the magnetization direction points to the first unit part 15. This magnetization method is used to achieve the axial magnetic flux enhancement effect of the first unit part 15. The third unit part 16, the first unit part 15, and the second unit part 14 are bonded together by high-strength structural adhesive. In order to prevent the permanent magnet from loosening in the permanent magnet steel slot, the contact surface between each segment of the permanent magnet and the disc motor rotor disk 13 is also bonded by high-strength structural adhesive.

[0049] like Figure 5 As shown, of two adjacent permanent magnets on the dual-rotor single-stator disc motor: the third unit portion 16 and the second unit portion 14 have the same magnetization direction, and the first unit portion 15 of the two adjacent permanent magnets have opposite magnetization directions.

[0050] like Figure 6 As shown in the figure, the use of the segmented magnetic steel structure enhances the magnetic induction intensity of the middle magnetic steel corresponding to the effective length of the winding, which is beneficial to improving the motor torque. The measured torque is increased by 5%-18%.

[0051] like Figure 7 As shown in the figure, parametric modeling and simulation of segmented magnetic steel are carried out, and two motor torque curves are obtained. After comparison, it can be found that the torque of the motor is significantly enhanced and the torque pulsation is within a reasonable range.

[0052] Embodiment 3:

[0053] The three sections of permanent magnets in this scheme are distributed in the shape of "1", and each magnetic steel is in the shape of a trapezoid. It adopts a radial segmented structure and is composed of a third unit part 16, a first unit part 15, and a second unit part 14. The third unit part 16 and the second unit part 14 are made of permanent magnetic materials with relatively large intrinsic coercive force and relatively low residual magnetic flux density, and the first unit part 15 is made of permanent magnetic materials with relatively small intrinsic coercive force and relatively high residual magnetic flux density. Among them, the permanent magnetic materials used in the third unit part 16 and the second unit part 14 are the same permanent magnetic materials, and the third unit part and the second unit part have similar shapes and the same radial length. The permanent magnetic materials used in the third unit part 16, the first unit part 15, and the second unit part 14 are neodymium iron boron permanent magnets. The first unit part 14 is magnetized along the axial direction of the disc motor, and the magnetization direction of the third unit part 16 and the second unit part 14 is perpendicular to the radial end face of the first unit part 15.

[0054] like Figure 6As shown, the arrows in the third unit 16, the first unit 15, and the second unit 14 represent the magnetization direction, and the length of the arrows represents the magnitude of the residual magnetic flux density. This disc motor uses segmented magnetic steel to reduce the eddy current loss of the motor permanent magnet, and the design of the cooling structure on the rotor disk makes the temperature rise of this motor low, which can effectively ensure the good use of the motor winding insulation layer and permanent magnet. This structural motor can be used in many fields, such as pure electric vehicles, hybrid vehicles, rail transportation, intelligent manufacturing, shipbuilding industry and many other fields.

[0055] The embodiments of the present invention are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A magnetic steel arrangement method for a disc motor, comprising: The rotor disk is formed by laminating silicon steel sheets, and magnetic steel slots are distributed on the rotor disk, and magnetic steel is embedded in the magnetic steel slots; the characteristic is that the magnetic steel comprises: a segmented unit part; a plurality of unit parts are spliced ​​along the radial direction of the rotor disk; A first unit part is spliced ​​between the second unit part and the third unit part, and the first unit part closes the magnetic lines of force along the axial direction of the motor to form a first magnetic field generated along the axial direction of the motor; The second unit part closes the magnetic lines of force along the radial direction of the motor to form a second magnetic field pointing perpendicularly to the direction in which the first magnetic field is generated; A third unit part closes the magnetic lines of force along the radial direction of the motor to form a third magnetic field pointing perpendicularly to the direction in which the first magnetic field is generated; For two adjacent magnetic steels on the rotor disk, the closing directions of the magnetic force lines of the first unit parts are opposite, the closing directions of the magnetic force lines of the second unit parts are the same, and the closing directions of the magnetic force lines of the third unit parts are the same.

2. The magnetic steel arrangement method of a disk motor according to claim 1 is characterized in that: The magnetic steel is a permanent magnet; The first unit part is magnetized along the axial direction of the motor to form the first magnetic field; The second unit part is magnetized along the radial direction of the motor to form the second magnetic field; The third unit portion is magnetized along the radial direction of the motor to form the third magnetic field.

3. The magnetic steel arrangement method of a disk motor according to claim 2 is characterized in that: The magnetic steel is formed by sequentially splicing the second unit part, the first unit part and the third unit part.

4. The magnetic steel arrangement method of a disk motor according to claim 3 is characterized in that: The third unit portion has the same length as the second unit portion.

5. The magnetic steel arrangement method of a disk motor according to claim 4 is characterized in that: The unit parts are contact-bonded by coating structural adhesive on adjacent joint surfaces.

6. A disk motor magnetic steel arrangement method according to claim 1 or 5, characterized in that: It comprises a stator and a rotor on both sides of the stator; the rotor comprises the rotor disk; a rotating shaft is assembled in the shaft hole of the rotor disk by key connection; the stator comprises a stator disk, and a winding is arranged on the stator disk; the shaft hole of the stator disk is assembled with the rotating shaft by a bearing.

7. The magnetic steel arrangement method of a disk motor according to claim 6 is characterized in that: The stator disc is a coreless stator structure.

8. The magnetic steel arrangement method of a disk motor according to claim 6 is characterized in that: The utility model comprises a shell body, and the shell body comprises end covers on two sides and a rotating shell between the end covers on the two sides.

9. The magnetic steel arrangement method of a disk motor according to claim 8, characterized in that: The stator is fixedly connected to the rotating housing through the stator disk for assembly connection; the rotating shaft is assembled with the shaft hole on the end cover through a bearing.

10. The magnetic steel arrangement method of a disk motor according to claim 2, characterized in that: The permanent magnetic material used in the magnetic steel includes but is not limited to neodymium iron boron permanent magnets.

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