WO2014121466A1

WO2014121466A1 - Disk-type three-phase brushless permanent magnet direct current motor

Info

Publication number: WO2014121466A1
Application number: PCT/CN2013/071464
Authority: WO
Inventors: 杜坤梅
Original assignee: 浙江博望科技发展有限公司
Priority date: 2013-02-06
Filing date: 2013-02-06
Publication date: 2014-08-14

Abstract

A disk-type three-phase brushless permanent magnet direct current motor comprises: a first disk rotor (110) and a second disk rotor (120), which are arranged parallel to and opposite to each other; a first plastic permanent magnet (210) and a second plastic permanent magnet (220), which are arranged on the surfaces of the first disk rotor and the second disk rotor, respectively, and arranged opposite to each other; and a disk stator (300) arranged parallel between the first plastic permanent magnet and the second plastic permanent magnet. The mechanical structures and magnetic structures of the first plastic permanent magnet and the second plastic permanent magnet are the same; the polarities of any one magnetic pole in the first plastic permanent magnet and a magnetic pole in the second plastic permanent magnet right opposite to this magnetic pole are the same to generate an axial air gap field with an electromagnetic air gap of δ; and a first surface (301) and a second surface (302) of the disk stator are both uniformly provided with virtual slots, and a three-phase full pitch winding (310) is mounted in the virtual slots. By adopting plastic permanent magnets, not only is the cost low, but also the aim of being ultrathin can be realized; and the air gap field is a repulsion force field, which can effectively suppress the iron loss of a motor.

Description

Disc three-phase brushless permanent magnet DC motor

Technical field

The present invention relates to a disc type three-phase brushless DC permanent magnet motor, and more particularly to a disc type stator, a disc rotor and an ultra-thin three-phase brushless DC permanent magnet motor constructed using plastic plastic permanent magnets. It can be used for low speed direct drives, such as electric bicycles and electric motorcycles, as well as direct drive power generation.

Background technique

The conventional disc type brushless DC permanent magnet motor adopts a coreless and double magnetic steel structure, and its electromagnetic air gap is large. Although the amount of magnetic steel is large, the magnetic load of the motor is still low. The conventional disc type brushless DC permanent magnet motor can also adopt a core structure. Although the electromagnetic air gap is small, the positioning moment is generated after the core is slotted, which is very disadvantageous for the low speed direct drive, and requires special cogging technology. The winding factor is still low. Moreover, the conventional disc type brushless DC permanent magnet motor solution cannot realize an ultra-thin structure.

Summary of the invention

The technical problem to be solved by the present invention is to provide a disc type three-phase brushless permanent for the disc-type three-phase brushless permanent magnet DC motor of the prior art which is difficult to realize an ultra-thin structure and has high cost and high iron loss. Magnetic DC motor.

The technical solution adopted by the present invention to solve the technical problem thereof is: a disc type three-phase brushless permanent magnet DC motor, characterized in that it comprises:

a first disc rotor and a second disc rotor disposed parallel to each other and face to face;

First and second plastic permanent magnets respectively disposed on surfaces of the first disc rotor and the second disc rotor and facing each other; wherein the first plastic permanent magnet and the The second plastic permanent magnets each include a P-to-N, S-pole magnetic pole with a pole pitch of τ; the first plastic permanent magnet and the second plastic permanent magnet have an outer diameter of D1 and an inner diameter of D2. The number of magnetic poles is 2×P, and the average pole pitch is τ=0.25×π(D1+D2)/P; any one of the first plastic permanent magnets and the second plastic permanent magnet The magnetic poles of the magnetic poles have the same polarity to generate an axial air gap magnetic field with an electromagnetic air gap of δ;

a disc stator disposed in parallel between the first plastic permanent magnet and the second plastic permanent magnet; the first surface and the second surface of the disc stator are uniformly disposed with Z=3×2P virtual a slot in which a three-phase full-length winding is mounted.

In a disc type three-phase brushless permanent magnet DC motor according to an embodiment of the present invention,

The disc stator is a non-magnetically conductive insulator;

An axial distance between a surface of the first plastic permanent magnet and a geometric center line of the disc stator is the electromagnetic air gap δ; a surface of the second plastic permanent magnet and a geometry of the disc stator The axial distance between the center lines is the electromagnetic air gap δ;

An axial distance between a surface of the first plastic permanent magnet and the virtual groove on the first surface opposite thereto is half of the electromagnetic air gap δ; a surface of the second plastic permanent magnet is opposite thereto The axial distance between the virtual grooves on the second surface is half of the electromagnetic air gap δ.

D1 = 400 mm, inner diameter D2 = 150 mm; P = 30; δ = 1.6 mm.

The disc stator is a soft magnetic insulator;

An axial distance between a surface of the first plastic permanent magnet and the first surface opposite thereto is the electromagnetic air gap δ; between a surface of the second plastic permanent magnet and the second surface opposite thereto The axial distance is the electromagnetic air gap δ.

D1 = 200 mm, inner diameter D2 = 100 mm; P = 9; δ = 0.5 mm.

a soft magnet core body having a thickness c is embedded at a geometric center line position of the disc stator;

An axial distance between a surface of the first plastic permanent magnet and a surface of the soft magnet core opposite thereto is the electromagnetic air gap δ; a surface of the second plastic permanent magnet opposite to the soft magnet The axial distance between the surfaces of the core body is the electromagnetic air gap δ;

And satisfy: c ≤ 2 × δ; τ ≥ k × δ, where k is between 4 and 10.

The soft magnet core body is a silicon steel sheet soft magnet core;

The silicon steel sheet soft magnet core is provided with a plurality of micro holes for blocking radial eddy currents.

c is between 0.2mm and 2.0mm;

D1 = 400 mm, inner diameter D2 = 150 mm; P = 30; δ = 1.1 mm.

In the disc type three-phase brushless permanent magnet DC motor according to the embodiment of the invention, the three-phase full-distance winding is a U, V, W three-phase full-length winding.

In the disc type three-phase brushless permanent magnet DC motor according to the embodiment of the present invention, the disc type stator is further provided with a Hall sensor for sensing a change of the air gap magnetic field;

Wherein the disc stator is provided with three switch Hall sensors, three of which are mutually separated by an electrical angle of 120 or 60 degrees, and the sensitive direction of the Hall sensor faces the air gap magnetic field;

Alternatively, the disc stator is provided with two linear Hall sensors, which are spaced apart from each other by an electrical angle of 90, and the sensitive direction of the Hall sensor faces the air gap magnetic field.

The invention has the beneficial effects that the plastic sheet magnetic steel is used as the permanent magnet, which is not only low in cost, but also can achieve ultra-thin purpose; by setting the magnetic pole of any one of the first plastic permanent magnets and the second plastic permanent magnet The magnetic poles of the magnetic poles have the same polarity, so that the air gap magnetic field formed between the two permanent magnets is a repulsive magnetic field, which can effectively suppress the iron loss of the motor.

DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings and embodiments, in which:

1a is a schematic structural view of a disc type three-phase brushless permanent magnet DC motor according to an embodiment of the present invention;

Figure 1b shows an enlarged view of the area A in Figure 1a;

2 is a schematic structural view of a plastic permanent magnet according to an embodiment of the present invention;

Figure 3 is a schematic view showing the structure of the permanent magnet of Figure 2 assembled in a motor;

4 is a schematic view showing the structure of winding a winding on a disc stator according to an embodiment of the present invention;

Figures 5a and 5b respectively show a front view and a rear view of the U-phase winding obtained by the structure winding of Figure 4;

Figure 6 shows a partial perspective view of the U-phase winding of Figures 5a and 5b;

Figure 7 is a block diagram showing the structure of a motor according to a first embodiment of the present invention;

Figure 8 is a block diagram showing the structure of a motor according to a second embodiment of the present invention;

Fig. 9 is a view showing the structure of a motor in accordance with a third embodiment of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Fig. 1a shows a schematic structural view of a disc type three-phase brushless permanent magnet DC motor according to an embodiment of the invention, and Fig. 1b shows an enlarged view of the area A of Fig. 1a. As shown in FIGS. 1a and 1b, the disc type three-phase brushless permanent magnet DC motor (which may be simply referred to as a motor) includes a first disc rotor 110 and a second disc rotor 120, a first plastic permanent magnet 210 and a second plastic. The permanent magnet 220 and the disc stator 300.

Wherein, the first disc rotor 110 and the second disc rotor 120 are parallel to each other and face to face. The first plastic permanent magnet 210 and the second plastic permanent magnet 220 are respectively disposed on the surfaces of the first disc rotor 110 and the second disc rotor 120, and are disposed face to face with each other to generate an axial air gap with an electromagnetic air gap of δ. magnetic field. The disc stator 300 is disposed in parallel between the first plastic permanent magnet 210 and the second plastic permanent magnet 220, preferably disposed on a center line between the first plastic permanent magnet 210 and the second plastic permanent magnet 220. The first surface 301 and the second surface 302 of the disc stator 300 are uniformly provided with Z=3×2P virtual slots in which three-phase full-distance windings 310 (hereinafter simply referred to as windings) are mounted.

In addition, a core may be provided at the geometric centerline (e.g., radial geometric centerline) of the disc stator 300 such that the windings are wound around the surface of the core, thereby producing more axial magnetic field components, the axial magnetic field components. Acting with the drive current in the winding produces a torque that drives the motor.

Preferably, in the motor according to the embodiment of the invention, the disc stator 300 is further provided with a Hall sensor 400 for sensing a change in the air gap magnetic field. Wherein, the disc stator 300 is provided with three switch Hall sensors, and the three are mutually separated by an electrical angle of 120 or 60 degrees, and the sensitive direction of the Hall sensor faces the air gap magnetic field. Alternatively, the disc stator 300 is provided with two linear Hall sensors, which are spaced apart from each other by an electrical angle of 90, and the sensitive direction of the Hall sensor faces the air gap magnetic field.

In addition, motor leads and Hall sensor leads 500 in the motor are drawn from the stator shaft.

Specifically, the first plastic permanent magnet 210 and the second plastic permanent magnet 220 each include a P-to-N, S-pole magnetic pole having a pole pitch of τ; an outer diameter of the first plastic permanent magnet 210 and the second plastic permanent magnet 220; Both are D1, the inner diameter is D2, the number of magnetic poles is 2×P, and the average pole pitch is τ=0.25×π(D1+D2)/P.

2 is a schematic structural view of a plastic permanent magnet according to an embodiment of the present invention. As can be seen from the above description, the first plastic permanent magnet 210 and the second plastic permanent magnet 220 have identical mechanical structures and magnetic structures, and thus 2 is a schematic structural view of the first plastic permanent magnet 210 or a structural schematic view of the second plastic permanent magnet 220. As shown in Fig. 2, the sector poles having the number of poles of 2 × P = 16 are evenly distributed along the outer surface of the disc rotor, and the N and S poles are arranged alternately. Although the process gap between the N pole and the S pole is not shown in FIG. 2, those skilled in the art will appreciate that in the permanent magnet, a process gap of 0.1 to 1 mm may be provided between the N pole and the S pole.

3 is a schematic view showing the structure of the permanent magnet of FIG. 2 assembled in the motor. As shown in FIG. 3, the assembled first permanent magnet 210 and the second permanent magnet 220 are mirror-symmetrical to each other, that is, the first plastic permanent magnet 210. Any one of the magnetic poles has the same polarity as the magnetic pole of the second plastic permanent magnet 220 facing the magnetic pole to generate an axial air gap magnetic field having an electromagnetic air gap of δ.

Specifically, the N-pole magnetic pole in the first permanent magnet 210 is always opposite to the N-pole magnetic pole in the second permanent magnet 220, and the S-pole magnetic pole in the first permanent magnet 210 is always the S-pole magnetic pole in the second permanent magnet 220. relatively. Thus, since the polarities of the face-to-face magnetic poles of the first and second disk rotors 120 are the same, a repulsive magnetic field is formed between the first disk rotor 110 and the second disk rotor 120. At this time, since the axial magnetic fields of the two-sided magnetic poles have the same polarity, the magnetic lines of force are pressed against each other, and a repulsive magnetic field interface is formed at the geometric center line between the first permanent magnet 210 and the second permanent magnet 220 facing each other. Since the magnetic field lines are squeezed, the axial magnetic field enters the surface of the stator vertically, or enters the surface of the core of the stator, and the direction of the axial magnetic field begins to change by 90 degrees, becoming a tangential magnetic field.

4 is a structural view showing winding of a winding on a disc stator according to an embodiment of the present invention, in which an insulating hook frame 340 and an insulating hook line for assisting winding windings provided on the disc stator 300 are shown. Slot 350. In an embodiment of the invention, the three-phase full-scale windings 310 wound on the disc stator 300 may be U, V, W three-phase full-length windings. Figures 5a and 5b show a front view and a rear view, respectively, of a U-phase winding obtained by winding the structure of Figure 4; Figure 6 shows a partial perspective view of the U-phase winding of Figures 5a and 5b.

As shown in FIG. 5a, FIG. 5b and FIG. 6, the first surface and the second surface of the disc stator 300 are uniformly provided with a uniform Z=3×2P=48 virtual slots, and the virtual slots are installed with three-phase full distance. Winding. Although only U-phase windings of the motor are shown in the figure, the V- and W-phase windings have a slot distance in space, so according to the following winding about the U-phase winding, on the basis of no creative work, the field The technician can also obtain the winding of the V and W phase windings.

Insulating hook wire grooves 350 are respectively formed on both sides of the inner circumference of the disk stator 300, and an insulating hook wire frame 340 is formed on the outer dome portion of the disk type stator 300, as shown in FIG. The number of each of the hooking groove 350 and the hooking frame 340 is the same as the number of the virtual grooves D=3×2×P; positioning is performed by these hooking grooves 350 and the hooking frame 340, and wound around the core of the disk stator 300 For the three-phase winding, taking the U phase as an example, the first end of the U-phase winding starts from the 1st groove of the inner circumference of the disc stator 300, and wraps around the outer circle of the 1 slot, and then bypasses the outer dome hook frame 340. The inner groove of the 1 groove on the reverse side, using the hook groove 350 of the inner circle of the opposite side, spans the two virtual grooves, and wraps around the 4 grooves of the inner circle of the opposite side, and wraps around the outer circle of the 4 grooves, and then bypasses the outer dome hook line. The frame 340 is wound around the front 4-slot inner circle, using the front inner circular hook groove 350, spanning the two virtual grooves, and winding around the 7-slot of the front inner circle, and so on, using these hook grooves 350 and hook lines. After the frame 340 is positioned, three-phase windings are wound on both sides of the core of the disc stator 300. Among them, U The phase windings respectively occupy

slots

1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31, 34, 37, 40, 43, and 46 on both sides of the stator core, and a total of 2 × 18 = 36 slots , U, V, W three-phase windings differ from each other by a virtual slot. The traditional winding insulation method is adopted to ensure the insulation between the winding and the core, so that the three-phase full-distance winding is evenly arranged on the core of the disc stator 300.

Fig. 7 is a view showing the structure of a motor according to a first embodiment of the present invention. As shown in Fig. 7, the disc stator 300 is a non-magnetically conductive insulator. The axial distance between the surface of the first plastic permanent magnet 210 and the geometric centerline 303 of the disc stator 300 is the electromagnetic air gap δ; between the surface of the second plastic permanent magnet 220 and the geometric centerline 303 of the disc stator 300 The axial distance is the electromagnetic air gap δ. The axial distance between the surface of the first plastic permanent magnet 210 and the virtual groove on the first surface 301 of the disc stator 300 opposite thereto is half of the electromagnetic air gap δ, ie δ/2; the second plastic permanent magnet 220 The axial distance between the surface and the virtual groove on the second surface 302 opposite thereto is half the electromagnetic air gap δ, i.e., δ/2.

Since the polarities of the magnetic poles facing the surface of the disc rotor are the same, the air gap magnetic field formed between the first permanent magnet 210 and the second plastic permanent magnet 220 is a repulsive magnetic field, and the magnetic fields of the two magnetic poles have the same polarity, and the magnetic lines of force are mutually squeezed. a repulsive magnetic field interface is formed at a geometric center line 303 between the first permanent magnet 210 and the second permanent magnet 220 facing each other. At this time, the distance between the two permanent magnet surfaces and the geometric center line 303 is the electromagnetic of the motor. Air gap δ. At the repulsive magnetic field interface, after the magnetic lines of force are squeezed, the axial magnetic field direction starts at δ/2 of the two permanent magnet surfaces of the motor, that is, at the first surface 301 and the second surface 302 of the disc stator 300. Changing 90 degrees to become a tangential magnetic field, at the position of the stator geometric center line 303, that is, δ from the surface of the two plastic permanent magnets, the axial magnetic field is zero, so when the first surface 301 and the first surface of the disc stator 300 When the axial positions of the dummy grooves on the two surfaces 302 are respectively set at the distance δ/2 from the surface of the respective permanent magnets, the winding conductors in the virtual grooves can cut as many axial magnetic fields as possible and generate torque. The iron loss of the motor is made zero.

In this embodiment, preferably, D1 = 400 mm, inner diameter D2 = 150 mm, thickness of the permanent magnet is 2 mm; P = 30; δ = 1.6 Mm. It should be understood by those skilled in the art that the above-described various parameters are only used as examples and are not intended to limit the invention, and any suitable parameters may be selected without departing from the scope of the invention. For example, the outer diameter of the permanent magnet herein may be 400 mm, and of course other values may be used.

8 is a schematic structural view of a motor according to a second embodiment of the present invention. As shown in FIG. 8, the disc stator 300 is a soft magnetic insulator. For example, the disc stator 300 is made of glass fiber, iron powder, plastic. A soft magnetic insulator composed of a composite material. The axial distance between the surface of the first plastic permanent magnet 210 and its opposite first surface 301 is the electromagnetic air gap δ; the axial distance between the surface of the second plastic permanent magnet 220 and its opposite second surface 302 is electromagnetic Air gap δ.

At this time, the electromagnetic stator has an electromagnetic air gap of δ on both sides of the disc stator 300. Since the polarities of the magnetic poles facing each other are the same, the axial magnetic field of the magnetic pole vertically enters the surface of the soft magnetic core, and the direction changes by 90 degrees to become a tangential direction. In the magnetic field, the axial magnetic field inside the soft magnetic core material is zero. Since the soft magnetic core is an insulator, the iron loss generated by the core is very small and can be ignored.

In this embodiment, preferably, D1 = 200 mm, inner diameter D2 = 100 mm, thickness of the permanent magnet is 2 mm; P = 9; δ = 0.5 Mm. The disc stator 300 has a thickness of 4 mm. It should be understood by those skilled in the art that the above-described various parameters are only used as examples and are not intended to limit the invention, and any suitable parameters may be selected without departing from the scope of the invention. For example, the outer diameter of the permanent magnet herein may be 400 mm, and of course other values may be used.

In the disc type three-phase brushless permanent magnet DC motor of the present embodiment, the two end caps and the bearing chamber of the disc are formed by stamping and drawing of a steel sheet, and the thickness of the steel sheet is 1 mm, so the outer rotor The outer diameter of the large-diameter permanent magnet motor is: 2+3+2δ+5=2+3+1+4=10mm, achieving the purpose of ultra-thin.

Fig. 9 is a view showing the structure of a motor according to a third embodiment of the present invention. As shown in Fig. 9, a soft magnet core having a thickness c is embedded at a position of a geometric center line 303 of the disc stator 300. The axial distance between the surface of the first plastic permanent magnet 210 and the surface of the opposing soft magnetic core body is the electromagnetic air gap δ; the axis between the surface of the second plastic permanent magnet 220 and the surface of the soft magnetic core opposite thereto The distance is the electromagnetic air gap δ. And satisfy: c ≤ 2 × δ; τ ≥ k × δ, where k is between 4 and 10.

In a preferred embodiment of the embodiment, the soft magnetic core is a silicon steel soft magnetic core. For example, the silicon steel soft magnetic core may be attached by two silicon steel sheets having the same thickness (for example, 0.5 mm in thickness). Together. In addition, the silicon steel sheet soft magnet core is provided with a plurality of micropores for blocking radial eddy currents.

In this embodiment, preferably, c is between 0.2 mm and 2.0 mm; D1 = 400 mm, inner diameter D2 = 150 mm, permanent magnet thickness 2 mm; P = 30; δ = 1.1 Mm. For example, when the thickness of the winding is 0.5 mm and the axial physical air gap between the surface of the winding and the surface of the permanent magnet is 0.6 mm, the electromagnetic air gap is δ=0.6+0.5=1.1 mm, τ=0.25π (D1+D2) ) / P = 0.25 π (0.4 + 0.15) / 30 = 14.4 × 10-3 = 14.4 mm. At the same time, it satisfies: (c = 0.5 × 2 = 1.0) ≤ (2δ = 2 × 1.1 = 2.2), (τ = 14.4) ≥ (4 - 10) δ = (4 - 10) × 1.1. It should be understood by those skilled in the art that the above-described various parameters are only used as examples and are not intended to limit the invention, and any suitable parameters may be selected without departing from the scope of the invention. For example, the outer diameter of the permanent magnet herein may be 400 mm, and of course other values may be used.

For the disc type three-phase brushless permanent magnet DC motor of the present embodiment, the two end caps and the bearing chamber of the disc type are formed by stamping and drawing of a steel sheet, and the thickness of the steel sheet is 1 mm, so the outer rotor is large. The thickness of the permanent magnet motor is 2+4+2δ+c=2+4+2.2+1=9.2mm, which achieves ultra-thin. According to the strength requirements, the radial reinforcement can be added to the outside of the steel plate.

A disc type three-phase brushless permanent magnet DC motor according to an embodiment of the present invention can be used for an electric bicycle and an electric motorcycle.

Compared with the disc-type three-phase brushless permanent magnet DC motor of the prior art, the end of the winding is greatly reduced, and the length utilization ratio is improved: (1+D1/D2)=(1+400) /150) = 3.667 times.

The electromagnetic air gap of the motor of the present invention is at least 2 to 5 times less than the electromagnetic air gap of the disc type three-phase brushless permanent magnet DC motor in the prior art. Therefore, although the motor of the present invention uses plastic magnetic steel (permanent magnet), the Br has only 1/2 to 1/3 of the conventional rare earth magnetic steel, but the air gap magnetic density can still reach about 0.45T. Therefore, if the disk three-phase brushless permanent magnet DC motor of the prior art uses plastic magnetic steel, the air gap magnetic density will drop to 0.45/4T, which is not feasible at all. The winding end of the motor of the invention is reduced by several times, and a full-length winding with a pole pitch of τ is used, and the winding coefficient is maximized, which can compensate for the low weakness of the plastic magnetic steel Br.

The invention greatly simplifies the structure and manufacturing process of the motor, is beneficial to the automatic winding, automatic assembly and reduces the process cost. Moreover, since the stator core has no groove, the positioning torque is zero, and the air gap is allowed to be minimized. At the same time, the winding end is reduced to 1/3 to 1/6 or even more of the conventional motor, and the copper loss is greatly reduced.

On the other hand, it can be seen that in the third embodiment of the present invention, the geometric center line position of the disc stator is embedded in two sheets of silicon steel soft magnetic core material having a thickness of 0.5 mm, and the magnetic poles of the disc rotor facing each other have the same polarity. Therefore, the middle surface of the two silicon steel sheets must be an axial zero flux surface. The motor becomes a motor using only one piece of silicon steel sheet. The axial magnetic flux enters the silicon steel sheet and turns 90 degrees into a tangential magnetic flux. The tangential magnetic flux The direction of rotation of the motor is the same, so no eddy current is generated, not to mention the use of plastic permanent magnets. The Br of the plastic permanent magnet is around 0.45T, so the magnetic density of the silicon steel sheet is very low, so the eddy current loss generated by the core is very small, in order to further reduce Small iron loss, micro-pores on the silicon steel sheet, blocking radial eddy current, so the iron loss can be neglected. The main function of the core is to allow more magnetic lines of force to enter the core vertically, resulting in more axial magnetic field components that interact with the drive currents in the windings to produce the torque that drives the motor. The effective length of the windings of the torque that the motor of the present invention is capable of is almost maximized.

However, the radial magnetic field component orthogonal to the axial magnetic field component and the driving current in the winding can also generate a magnetic levitation force that axially repels the magnetic steel. The magnetic levitation force prevents the motor from being fixed and the rotor "broom". The larger the drive current, the greater the magnetic levitation force, which is very valuable.

In the present invention, the pitch coefficient of the winding of the motor is 1, and since the pole pitch is limited to be relatively small, the winding coefficient depends only on the distribution coefficient of about 0.96, and the line back electromotive waveform of the motor winding of the present invention is quite ideal. Sine wave.

The large-diameter ultra-thin permanent magnet motor of the outer rotor realized by the invention has a torque proportional to the square of the diameter of the motor. The invention adopts a large-diameter plastic sheet magnet, which is low in cost and the end of the motor winding tends to be minimum. The utilization of the winding tends to be the highest, so that the copper consumption tends to be the smallest; the repulsive magnetic field effectively suppresses the iron loss of the motor; the motor structure and the manufacturing process are simple, the motor torque is large, and the production cost tends to be the lowest.

It is to be understood that those skilled in the art will be able to make modifications and changes in accordance with the above description, and all such modifications and variations are intended to be included within the scope of the appended claims.

Claims

A disc type three-phase brushless permanent magnet DC motor, characterized in that it comprises:

a first disc rotor and a second disc rotor disposed parallel to each other and face to face;

First and second plastic permanent magnets respectively disposed on surfaces of the first disc rotor and the second disc rotor and facing each other; wherein the first plastic permanent magnet and the The second plastic permanent magnets each include a P-to-N, S-pole magnetic pole with a pole pitch of τ; the first plastic permanent magnet and the second plastic permanent magnet have an outer diameter of D1 and an inner diameter of D2. The number of magnetic poles is 2×P, and the average pole pitch is τ=0.25×π(D1+D2)/P; any one of the first plastic permanent magnets and the second plastic permanent magnet The magnetic poles of the magnetic poles have the same polarity to generate an axial air gap magnetic field with an electromagnetic air gap of δ;

a disc stator disposed in parallel between the first plastic permanent magnet and the second plastic permanent magnet; the first surface and the second surface of the disc stator are uniformly disposed with Z=3×2P virtual a slot in which a three-phase full-length winding is mounted.
A disc type three-phase brushless permanent magnet DC motor according to claim 1, wherein

The disc stator is a non-magnetically conductive insulator;

An axial distance between a surface of the first plastic permanent magnet and a geometric center line of the disc stator is the electromagnetic air gap δ; a surface of the second plastic permanent magnet and a geometry of the disc stator The axial distance between the center lines is the electromagnetic air gap δ;

An axial distance between a surface of the first plastic permanent magnet and the virtual groove on the first surface opposite thereto is half of the electromagnetic air gap δ; a surface of the second plastic permanent magnet is opposite thereto The axial distance between the virtual grooves on the second surface is half of the electromagnetic air gap δ.
A disc type three-phase brushless permanent magnet DC motor according to claim 2, wherein

D1 = 400 mm, inner diameter D2 = 150 mm; P = 30; δ = 1.6 mm.
A disc type three-phase brushless permanent magnet DC motor according to claim 1, wherein

The disc stator is a soft magnetic insulator;

An axial distance between a surface of the first plastic permanent magnet and the first surface opposite thereto is the electromagnetic air gap δ; between a surface of the second plastic permanent magnet and the second surface opposite thereto The axial distance is the electromagnetic air gap δ.
A disc type three-phase brushless permanent magnet DC motor according to claim 4, wherein

D1 = 200 mm, inner diameter D2 = 100 mm; P = 9; δ = 0.5 mm.
A disc type three-phase brushless permanent magnet DC motor according to claim 1, wherein

a soft magnet core body having a thickness c is embedded at a geometric center line position of the disc stator;

An axial distance between a surface of the first plastic permanent magnet and a surface of the soft magnet core opposite thereto is the electromagnetic air gap δ; a surface of the second plastic permanent magnet opposite to the soft magnet The axial distance between the surfaces of the core body is the electromagnetic air gap δ;

And satisfy: c ≤ 2 × δ; τ ≥ k × δ, where k is between 4 and 10.
A disc type three-phase brushless permanent magnet DC motor according to claim 6, wherein

The soft magnet core body is a silicon steel sheet soft magnet core;

The silicon steel sheet soft magnet core is provided with a plurality of micro holes for blocking radial eddy currents.
A disc type three-phase brushless permanent magnet DC motor according to claim 6, wherein

c is between 0.2mm and 2.0mm;

D1 = 400 mm, inner diameter D2 = 150 mm; P = 30; δ = 1.1 mm.
The disc type three-phase brushless permanent magnet DC motor according to any one of claims 1-8, wherein the three-phase full-distance winding is a U, V, W three-phase full-length winding.
The disc type three-phase brushless permanent magnet DC motor according to any one of claims 1 to 8, characterized in that the disc type stator is further provided with a Hall sensor for sensing a change of the air gap magnetic field. ;

Wherein the disc stator is provided with three switch Hall sensors, three of which are mutually separated by an electrical angle of 120 or 60 degrees, and the sensitive direction of the Hall sensor faces the air gap magnetic field;

Alternatively, the disc stator is provided with two linear Hall sensors, which are spaced apart from each other by an electrical angle of 90, and the sensitive direction of the Hall sensor faces the air gap magnetic field.