JPS63124752A - High-efficiency brushless motor - Google Patents

Abstract

PURPOSE:To increase the volumetric ratio of winding per unit volume of a motor and make the motor highly efficient, by a method wherein magnetic flux is concentrated to an inner cylindrical magnetic pole and an outer cylindrical magnetic pole while respective phases are arranged in the areas of plularity of radius of curvatures in the radial direction of a stator. CONSTITUTION:Cylindrical driving coils 28, 30, 32 of plurality of phases, which are provided with different radius of curvatures, are arranged concentrically in a stator 24 while inner cylindrical magnetic poles 34, 38, 42 and outer cylindrical magnetic poles 36, 40, 44 are arranged concentrically at the inside and outside of said driving coils. Magnetic pole teeth, having predetermined phase angles, are formed in front of the inner cylindrical magnetic poles 34, 38, 42 and the outer cylindrical magnetic poles 36, 40, 44 while magnetism intercepting rings 52, 54, 56 are arranged between the magnetic pole teeth of the inner cylindrical magnetic poles 34, 38, 42 and the outer cylindrical magnetic poles 36, 40, 44 in front of the cylindrical driving coils 28, 30, 32 of respective phases. A plurality of magnetic pole teeth is formed on a rotor disc 26 while the magnetic pole teeth are opposed to the magnetic pole teeth of the stator 24 through air gaps.

Description

[Detailed Description of the Invention] [Technical Field] This invention relates to a brushless motor, and more specifically,
This invention relates to a highly efficient brushless motor with increased effective energy density.

Recently talented? Various information If1 equipment, OA equipment or F
A: As equipment becomes more energy efficient, smaller, lighter, and more sophisticated, the need for small, lightweight, high-performance, and energy-saving control motors is increasing. In a conventional stepping motor, which is a type of control motor, firstly, the rotor is placed inside a multi-phase stator, and the magnetic poles of the multiple phases are divided into the same plane, so there is a large number of phases. The disadvantage is that the magnetic pole per unit becomes smaller, the area of the magnetic pole facing the rotor becomes smaller, and the output torque of the motor decreases significantly. Furthermore, in conventional servo motors, a large number of slots are formed inside the stator, multiphase windings are placed in these slots 1-, and the multiphase windings are sequentially switched and controlled in the circumferential direction. Accordingly, a structure is adopted in which a rotor placed inside the stator is rotated. Secondly, in these motors, the drive coil must be arranged within a narrow cross-sectional area divided within the same plane of the stator, and therefore, if you try to increase the number of turns of the coil to increase the output torque, The drawback was that the motor inevitably became larger. Furthermore, these motors have a third drawback in that magnetic leakage between the magnetic poles of the stator is large, and the effective magnetic flux actually used to drive the rotor is small. Furthermore, since the output torque of the motor is proportional to the number of turns of the drive winding (n) and the square of the V dynamic current (1) of this winding (nI),
In order to more effectively improve the performance of the motor, it is necessary to increase the ratio of the drive winding per unit volume of the motor, that is, the ratio of the volume of the V-shaped winding to the total volume of the stator and rotor. Yes, but.

Fourthly, in conventional motors, due to their special structure, it is not possible to increase the ratio of drive windings per unit volume of the motor. This has been a major bottleneck in achieving smaller size, lighter weight, energy savings, and higher performance. This also applies to general-purpose DC motors and AC motors.

[Purpose of the invention]

Therefore, the purpose of this invention is to increase the effective energy density.

The object of the present invention is to provide a brushless motor with high electromagnetic energy conversion efficiency.

Another object of the present invention is to provide a highly efficient brushless motor that can save energy, be ultra-compact, and have high performance.

Another object of the invention is to provide a brushless motor with less magnetic leakage and electromagnetic noise.

Another object of the present invention is to provide a low-cost brushless motor that has a simple structure, is easy to assemble, and can be put to practical use in small to large capacity machines.

Another object of this invention is to reduce the inertia of the rotor, and to reduce the power density (kw/kg) and power rate (kw/kg).
The object of the present invention is to provide a brushless motor with significantly improved speed (w/s).

Other objects of the present invention are that the air gap can be reduced, the starting torque can be high, and the slewing characteristics can be excellent. especially,
The purpose of the present invention is to provide a brushless motor suitable for stepping motors and servo motors.

Another object of the present invention is to provide a brushless motor that has excellent overload resistance in high-speed ranges and environmental resistance against vibrations, shocks, etc., and can be used under any environmental conditions.

Another object of the present invention is to provide a brushless motor that can be used as a general-purpose AC motor, is low cost, has a long life, and is highly efficient.

[Structure of the invention]

In the brushless motor of the present invention, a plurality of phases of cylindrical drive windings having different radii of curvature are arranged concentrically in the stator, and an inner cylindrical magnetic pole and an outer cylindrical magnetic pole are arranged on the outside and inside of the plurality of phases of cylindrical drive windings, respectively. Arrange the magnetic poles concentrically.

Magnetic pole teeth with a predetermined phase angle are formed on the front surfaces of the inner circular magnetic pole and the outer cylindrical magnetic pole, and the inner circular magnetic pole and the outer cylindrical magnetic pole are formed on the front surface of the cylindrical drive winding of each phase. A magnetic isolation ring is disposed between the magnetic pole teeth, forming a plurality of magnetic pole teeth with a predetermined phase angle on the rotor disk, and forming an air gap between each magnetic pole tooth of the rotor disk with respect to the magnetic pole teeth of the stator. It is characterized by being arranged so as to face each other through the middle.

〔Example〕

A preferred embodiment in which the brushless motor according to the present invention is applied to a three-phase brushless motor will be described based on FIGS. 1 to 3. In Figure 1.2, three-phase brushless motor 1
0 comprises a cylindrical casing 12 and end brackets 14,16 arranged at both ends of the casing 12. t
! ? Specifically, the casing 12 and the end bracket 14
．． 16 is made of a non-magnetic metal material that is a good thermal conductor.

End brackets 14 and 16 each have bearings 1
The output 4!1I122 is rotatably supported via the 8.20. Furthermore, the brushless motor 10 has a casing 1
A stator 2 is fixedly supported within the stator 2 concentrically with the output shaft 22.
4, and a rotor 26 fixed to the output l1II22 by welding or other means. The first phase to
A third phase cylindrical drive winding 28, 30.32 is arranged.

A first phase inner cylindrical magnetic pole 34 and an outer cylindrical magnetic pole 36 made of a material with high magnetic permeability are arranged on the inner diameter side and the outer diameter side of the first phase cylindrical drive winding 28, respectively.

The rear portions of the first phase inner cylindrical magnetic pole 34 and outer cylindrical magnetic pole 36 are magnetically coupled by a ring-shaped back yoke 35.

A second phase internal cylindrical magnetic pole 38 made of a material with high magnetic permeability is provided on the inner diameter side and the outer diameter side of the second Aikawa cylindrical drive winding 30, respectively.
and an external cylindrical magnetic pole 40 are arranged. The rear portions of the second phase internal cylindrical magnetic pole 38 and the external cylindrical magnetic pole 4o are magnetically coupled by a ring-shaped back yoke 39. Similarly, a third phase internal cylindrical magnetic pole 42 and external cylindrical magnetic pole 44 made of a material with high magnetic permeability are arranged inside and outside the third Aikawa cylindrical drive winding 32, respectively. The rear portions of the magnetic poles are magnetically coupled by a ring-shaped back yoke 43. A rotating shaft 22 is located inside the third phase internal cylindrical magnetic pole 42.
penetrates. 1st phase to 3rd phase cylindrical drive windings 28 to 32
inside.

All three sides, external and rear, have high permeability internal cylindrical magnetic poles,
Each cylindrical 1ψll! is surrounded by an outer cylindrical pole and a back yoke! Most of the magnetic flux generated by the lJ winding is concentrated by the inner cylindrical pole and the outer cylindrical pole.

In this way, the inner cylindrical magnetic poles and the outer cylindrical magnetic poles of the first to third phases act as magnetic flux concentration members. The ring-shaped back yoke 35, 39.43 has a cylindrical inner magnetic pole and an outer magnetic pole 3.
4, 36.3B, 40, 42.44, respectively, by means of a 7-joint or other means. Furthermore, these back yokes 35, 39° 43 are attached to the end bracket 1.
6 by screws (not shown) or other suitable means to prevent rotation. Back yoke 35, 39.4
3 may be constituted by an integral disc.

Each of the first phase internal cylindrical magnetic pole 34 and the external cylindrical magnetic pole 36 has an arc-shaped magnetic field f41i on the front or axial end surface.
P, 36P and low permeance portions or cutout portions 34C, 36C are formed on the 0-arc-shaped magnetic pole tooth: 3
4P.

36F constitute the N pole and S pole of the first phase, respectively. Second
Arc-shaped a-pole teeth 38P are provided on the front surfaces of the phase internal cylindrical magnetic pole 38 and the external cylinder mt440, respectively.

40P and low permeance part or cutout part 38G
, 40G are formed, and the arc-shaped magnetic pole teeth 38P and 40P constitute the second phase S pole and N pole, respectively. Arc-shaped magnetic pole teeth 42P, 44P and low permeance portions or cut-out portions 42C, 44G are formed on the front surfaces of the third phase internal cylindrical magnetic pole 42 and external cylindrical magnetic pole (4i44), respectively. N pole of third phase.

Configures the south pole. 1st phase to 3rd phase arc-shaped magnetic pole teeth 34P
~44F, and first to third phase cutout portions 34
C to 44C are arranged in a predetermined phase relationship, ie, in FIG. 2 symmetrically in the radial direction with respect to the X axis. However, the cutout part 3 of the first phase
4G, 36G.

The second phase cutout portions 38G, 40G and the third phase cutout portions 42C, 44C have a phase of 1200° with respect to each other.
They may be arranged so as to be shifted one by one.

In this way, when the cylindrical drive winding of the stator consists of multiple phases, the centers of the arc-shaped magnetic pole teeth of each phase may be aligned in the radial direction, or 360°/n (n = phase, number ) may be arranged so as to be shifted.

1st phase to 3rd phase arc-shaped magnetic pole teeth 34P, 3'6P, 38
P, 40F, 42P, 44P have a plurality of thin slits 34S, 36S extending in the radial direction.

385.4O8, 42S, and 443 are formed, respectively. This is due to the magnetic skin effect caused by the fluctuating magnetic flux when the cylindrical quick-acting winding turns on and off.The area of high magnetic flux density that contributes to the magnetic force becomes extremely narrow, increasing magnetic resistance and reducing the total magnetic flux. This is to prevent the output torque of the motor from decreasing.These slits effectively suppress the eddy current, which is the effect of the demagnetizing field on the fluctuating magnetic flux, so that the eddy current that is the effect of the demagnetizing field on the fluctuating magnetic flux is effectively suppressed. This has the effect of uniformly distributing the strong magnetic flux portion throughout.

Furthermore, the slit portions of the arcuate magnetic pole teeth greatly change the strength of the magnetic field and the amount of change in magnetic flux density as the rotor 26 rotates, so they have a significant effect on the output power of the motor.

First phase internal cylindrical magnetic pole 34 and second phase external cylindrical magnetic pole 40
A cylindrical magnetic shielding member 48 made of a conductive material such as copper or aluminum is disposed between the two magnetic poles to block magnetic leakage between these magnetic poles. The front surface of the magnetic shielding member 48 is preferably aligned with the front surface of the adjacent arcuate magnets t434F and 40P. The inner cylindrical magnetic pole 38 of the second phase and the outer inner 1? of the third phase? A cylindrical magnetic shielding member 50 is provided between the i5 magnetic pole 44
are arranged to effectively prevent magnetic leakage between adjacent magnetic poles.

t, t'o to third phase cylindrical Iψ movable gland 28, 30.
Magnetic shielding rings 52, 54, and 56 made of conductive metal such as aluminum or copper are arranged on the front surface of 32. The magnetic shielding rings 52, 54, and 56 are the first phase arc-shaped magnetic pA teeth 34r', 36F, and the second phase arc-shaped magnetic pole teeth 38r, respectively.
', 40F, and third phase arc-shaped magnetic pole teeth 42F, 44
]' is located in the radial gap between the magnetic pole teeth to improve the electromagnetic energy conversion efficiency of the motor by blocking magnetic leakage between the magnetic pole teeth.Especially when the motor is downsized, the mr4 of each phase Since magnetic leakage between teeth is effectively prevented, a highly efficient ultra-compact motor can be obtained. Even more cylindrical 1!
N! It also has the role of effectively preventing radiation of electromagnetic noise to the outside of the motor due to turning on and off of the lJ windings 28, 30, and 32.

The magnetic isolation rings 52, 54, 56 each have an inner projection 52a, 54a, 56a and an outer projection 52b, 54b, 56b, respectively. Inner projections 52a, 54a.

56a is the internal cylindrical magnetic pole 34, 38.4 of the first phase to the third phase.
The outer projections 52b, 54b,
5Gb protrudes into the cutout portions 36G, 40G, 44C of the external cylindrical magnetic poles 3G, 40° 44 of the first to third phases. in this way.

All of the first to third phase cutout portions 34C to 44C are sealed by the projections of conductive magnetic isolation rings 52 to 56, so that these cutout portions 34C to 44C
The cutout portions 34C to 44G are completely prevented from magnetic leakage from C to 44C to the rotor 26 through the air gap.
High reluctance can be achieved with a small area, and the area of the magnetic pole teeth of each phase can be correspondingly increased to increase torque. Moreover, the magnetic flux generated by the cylindrical drive windings 28 to 32 is concentrated between the opposing magnetic pole surfaces of the rotor 26 and the stator 24 only through the arc-shaped magnetic pole teeth of each phase, so that the maximum electromagnetic energy can be obtained. Therefore, the electromagnetic energy conversion efficiency is high, and the maximum output torque can be obtained with a small amount of electrical energy. Furthermore, since the magnetic flux generated by the cylindrical drive winding of each phase is directly concentrated on the inner cylindrical magnetic pole and the outer cylindrical magnetic pole of the single-hole magnetic permeability, and magnetic leakage to the magnetic field other than the magnetic pole teeth is blocked by the magnetic isolation rings 52 to 56, The magnetic flux is concentrated only on the arc-shaped magnetic pole teeth of each phase. Therefore, since there is no wasteful consumption of magnetic flux, the efficiency of the motor is significantly improved, and the miniaturization of light motor vehicles can be achieved. Moreover, four surfaces in the cross section of the cylindrical drive winding of each phase are in contact with a good thermal conductor.

Since these thermal conductors are further thermally coupled to the motor casing and end bracket, the heat conduction area of the N1 moving winding is dramatically expanded, and heat dissipation of the winding is significantly improved. Therefore, there is an effect that the cooling efficiency of the five motors is increased and the overload capacity can be increased. In the embodiment shown in FIGS. 1 and 2, the arc-shaped magnetic poles 34P, 36r', 38P
, 40P, 42F, 44r' are the internal cylindrical magnetic poles 34 of each phase.
, 38.42 and the external cylindrical magnetic poles 3G and 40.44, but these arc-shaped magnetic poles are formed only on either the internal cylindrical magnetic pole or the external circular n magnetic pole of each phase. On the other hand, a circular magnetic pole without a cut-out portion may be formed.

In FIG. 3, the rotor 2G consists of a rotor disk 60 made of a high magnetic permeability material such as soft iron or silicon N4 plate. Rotates in the center of the rotor disk 60! 1122 mounting holes 62 are formed, and the mounting holes 62 of the rotor disk 60
After the rotating shaft 22 is press-fitted into the rotating shaft 22, the rotor disk 60 is fixed to the rotating shaft 22 by welding or other means. The rotor disk 60 has first-phase, second-phase, and third-phase arcuate magnetic pole teeth 64 and 6 in the first to third curvature radius regions, respectively.
6.68. These arcuate magnetic pole teeth 64, 66, 68 for the first to third phases preferably have cutouts 64C, 66G, 68G having low permeance in the first to third radius of curvature regions of the rotor disk 60, respectively.
The cutouts 64G and 66G are formed by simply machining the phases with a phase shift of 20° (360''/n in the case of multiphase, n = number of phases).

The width of 68G is the cutout part 34G of the first phase to the third phase,
36G, 38G.

The widths are selected to be equal to the widths of 40G, 42C, and 44G, respectively. Furthermore, the inner diameter and outer diameter of the cutouts 64G, 66G, and 68G of the rotor disk 60 are the corresponding inner openings f of the first to third phases of the stator. The inner diameter of the i magnetic pole is selected to be approximately equal to the outer diameter of the outer cylindrical magnetic pole.

1st phase, 2nd phase and 3rd phase circular arc magnetic poles @64, 66
．． A plurality of thin slits 648.68 extend in the radial direction.
66S and 68S respectively.

Each of these slits 64S, 66S, 68S corresponds to the slits 34S, 36S, 388.
It is processed to have the same width as 4O8, 42S, and 44S. In FIG. 3, the slits 66S and 688 are integrally formed on the same extension line, but they may be formed independently within each arcuate magnetic pole. Arc-shaped magnet [164, 66, 6
8, the eddy current that occurs when magnetic flux passes in the radial direction is suppressed, and the 1 strong magnetic flux density portion is formed into arc-shaped magnetic pole teeth 64, 66.
．． By uniformly distributing it throughout 68,
It has the effect of reducing magnetic resistance and increasing effective magnetic flux. Moreover, by suppressing the eddy current of the 1-arc magnetic pole tooth 64.6+3.68, it is possible to effectively prevent instability and resonance phenomena caused by a drop in torque characteristics in the motor's mid-range or high-speed range. Stable torque characteristics can be obtained from low speed range to high speed range. Furthermore, in conjunction with the slits in the arc-shaped HpM teeth of the stator, as the rotor disk 60 rotates, the strength of the magnetic field and the amount of change in magnetic flux density between the opposing magnetic pole surfaces of the stator and rotor are greatly changed, thereby increasing the output torque of the motor. A significant increase can be achieved. If you want to further reduce the size and weight of the brushless motor, the first and second phase arc-shaped magnetic poles of the rotor disk 60 may be configured with permanent magnets, although not shown in the figure. Magnetic pole teeth 64, 66, 68 are cutouts 64C, 66C,
Although shown as being formed in the same plane as 68C, an arc-shaped mhtb is formed in the axial convex region in a different plane with a different axial PL of the rotor disk.

The four-part area may be a low permeance part instead of a cutout.

In the above configuration, when the first phase arcuate drive winding 28 is excited, the magnetic flux generated by the coil 28 is transferred to the inner cylindrical magnetic pole 3.
4. Back yoke 35. At this time, the arcuate magnetic pole teeth 34P and 36P are excited as N and S poles, respectively, as indicated by the arrows in FIG. 1, and attract the arcuate magnetic pole teeth 64 of the rotor 26. . At this time, the rotor 26 comes to rest at a stable point where the cutout 64C of the one arc-shaped magnetic pole tooth 64 coincides with the cutout portions 34C and 36C of the first phase. The first phase arcuate magnetic pole teeth 64 of the rotor 26 are the first phase arcuate magnetic poles GI34P, 36P of the stator.
As described above, when moving above, the strength of the magnetic field between the opposing magnetic pole surfaces of the stator and rotor and the amount of change in magnetic flux density vary greatly depending on the slits, so the torque can be significantly increased depending on the number of slits. Moreover, a magnetic isolation ring 52 is installed in each gap between the magnetic pole teeth of each phase of the stator.
56, magnetic leakage between the magnetic pole teeth of the stator is completely blocked, the i-flux is concentrated only in the target magnetic field, and large @magnetic energy acts on the rotor 26. next.

The first phase cylindrical drive winding 28 is turned off and the second phase cylindrical drive winding 28 is turned off.
When the phase cylindrical drive winding 30 is turned on, the arcuate magnetic pole teeth 38P and 40T' of the second phase are excited to the S and N poles, respectively, and attract the arcuate magnetic pole teeth 66 of the rotor 2G. . At this time, the cutout 66C of the arcuate magnetic pole tooth 66 of the rotor 26 moves clockwise, so the rotor 26 rotates 120 degrees clockwise. Further, when the second phase cylindrical drive winding 30 is turned off and the third phase cylindrical drive winding 32 is turned on, the arcuate magnetic pole teeth 68 of the rotor 26 are attracted clockwise. , the rotor 26 rotates 120° clockwise. In this way, the rotor 26 rotates clockwise by sequentially exciting the first to third phase cylindrical drive windings a28 to a32 in the sequence of ■→■→■. The counterclockwise rotation of the rotor 26 is obtained by exciting the first to third phase drive windings in the sequence I→■→■→I→■→■.

4 to 6 show a second three-phase brushless motor according to the present invention.
An embodiment will be described, using the same reference numerals for parts that are the same as those in the first embodiment, and adding an apostrophe (') to the reference numerals of the first embodiment for similar parts. The second embodiment differs from the first embodiment in the following three points.

The first point is that the first phase inner cylindrical magnetic pole 34' and outer cylindrical magnetic pole 36' are symmetrical in a pair of arc-shaped magnetic pole teeth 34P separated by a pair of cut-out portions 34G' and 36C' that are 180 degrees out of phase. ', 36P'. Similarly, the second phase inner cylindrical core 38'
and a pair of cutters 1 part 38G' in which the external cylindrical yoke 40' is 180@out of phase.

A pair of symmetrical arcuate magnetic pole teeth 381'' and 401'' are respectively separated by 40G'. The inner cylindrical magnetic pole 42' and the outer cylindrical GJ & pole 44' of the third phase are 18
A pair of cutout portions -12G' with a 0" phase shift,
Symmetrical arc-shaped magnetic poles 1164 separated by 44C'
2P' and 44P' respectively.

A pair of cutout parts 34C', 36C', 38C
', 40G', 42C', 44G' are each rotation N
22, and a pair of arc-shaped magnetic pole teeth 34F', 36P', 38F', 40P''
, 42F', 44P' are each 180
The 0 position is shifted and placed kl.

The second point is the first phase arcuate magnetic pole tooth 6 of the rotor disk 60'.
4' is divided into two bottles by a pair of symmetrical cutters I-f34c', and further a second phase arc-shaped magnetic tooth t4i 66
' is divided into two poles by a pair of symmetrical cutouts 66G', and the third phase arcuate magnetic pole 68' is further divided by a pair of symmetrical cutouts 68C' to form a six-pole structure. This is what is happening. A pair of arc-shaped magnetic pole teeth 64', 66', and 68' of the first to third phases are arranged with a phase angle of 120° shifted from each other. Note that the slits 64S' and 665' of the rotor disk 60'
, 68S' are formed to be inclined at a constant skew angle with respect to the sleeves 1 to 1 of the arc-shaped magnetic pole teeth of the stator,
This is to ensure smooth rotation of the rotor 26'.

In the above configuration, in the first embodiment, the cylindrical drive windings 28 to 30 of the first to third phases are connected in a +-n-m-r sequence.
When the cylindrical drive windings 28 to 30 of the first to third phases were energized in the same sequence in the second embodiment, the motor rotated clockwise by 120 steps. The rotor 26' rotates counterclockwise in steps of 60''.

When the brushless motors of the first embodiment t9 and the second embodiment are used as stepping motors, they may be driven by one-phase excitation or two-phase excitation.6 A suitable encoder or resolver is connected to the brushless motor of the present invention. , can be used as a servo motor. Note that the first to third phase cylindrical drive coils can be connected to an AC power source and used as a general-purpose AC motor.

``In the first embodiment, the rotor has been described as consisting of a disk with high magnetic permeability, but the rotor may have a structure in which arc-shaped magnetic poles made of high magnetic permeability material or permanent magnets are embedded in a disk of non-magnetic material. Alternatively, the thickness of the rotor disk in the axial direction may be changed so that the convex portion facing the stator constitutes an arc-shaped magnetic pole, and the concave portion may be used as a low permeance portion instead of a cutout.

Note that the arc-shaped magnetic poles of the rotor may be formed of permanent magnets.

〔effect〕

As is clear from the above, in the multiphase brushless motor of the present invention, the magnetic flux generated by the cylindrical drive winding in each phase is concentrated on the internal cylindrical magnetic pole and the external cylindrical magnetic pole, and each phase is divided into multiple radial directions in the stator. Due to the arrangement in the radius of curvature region, the volume ratio of the windings per unit volume of the motor can be significantly increased, and therefore the output I of the motor
- the number of turns n of the winding and NFl + the square of the current ■ (nI)
'', it is possible to achieve high efficiency that could not be achieved in the past.As a result, brushless motors can be made extremely heavy and lightweight, and have high-speed response and high performance.In particular, brushless motors Even if the distance between the arc-shaped magnetic pole teeth of each phase becomes smaller when making the drive winding ultra-heavy and lightweight, the magnetic flux generated by the drive winding is kept close to the arc-shaped magnetic pole teeth because a magnetic isolation ring is placed between the magnetic pole teeth of each phase. The maximum electromagnetic energy is obtained because all the magnetic flux is concentrated between the opposing magnetic pole surfaces of the stator and rotor without leaking into the air gap between them.Therefore, the electromagnetic energy conversion efficiency is extremely high and a large energy saving effect can be obtained. Furthermore, the four sides of the cross section of the cylindrical drive winding of each phase are surrounded by good thermal conductors, and these good thermal conductors are thermally conducted to the casing and end housing, which are also good thermal conductors. Therefore, the heat conduction area of the first winding is significantly increased, and the heat dissipation of the winding is extremely efficient, and the overload capacity of the motor is significantly increased.Moreover, the cylindrical drive winding of each phase is cylindrical. , surrounded by cylindrical magnetic poles, a back yoke and a magnetic isolation ring, which can significantly reduce the radiation of electromagnetic noise from the motor to the outside.In addition, there are a large number of parallel magnetic paths on the rotor disk and stator magnetic pole teeth. Due to the formation of the slit, the magnetic reaction caused by the fluctuating magnetic flux can be effectively prevented, increasing the effective cross-sectional area in the magnetic circuit, and reducing the magnetic resistance, thereby significantly increasing the total magnetic flux. Circular drive winding '6j
& Since slits are formed between the poles and the arc-shaped magnetic poles of the rotor, as the rotor rotates, the amount of change in the magnetic field strength and magnetic flux density between the opposing magnetic pole surfaces of the stator and rotor will change even if the magnetic pole surface is flat. The motor output per herk becomes extremely large. Therefore, a brushless motor that is capable of high-speed response, is smaller, lighter, and has higher performance than ever before is realized. In addition, the rotor disk has a large-area cutout, which significantly reduces the overall weight of the rotor disk.The rotor inertia is extremely low, and the torque per revolution is large, allowing for fast response and precise positioning. It also has excellent slewing characteristics.

The rotor disk is solid and has no brushes or commutators, so it can be used at high speeds. Moreover,
Since the stator and rotor disk can use cheap raw materials, and the structures of the stator, rotor disk, and drive winding are extremely simplified, processing and assembly are simple and can be manufactured at low cost, resulting in a significant cost reduction. Note that the motor of the present invention has a simple structure and is sturdy, so it is suitable for high-speed, large-output applications, and can withstand frequent acceleration/deceleration operations, high humidity,
It has excellent resistance to low-temperature environments, and there is no deterioration in operating performance due to continuous use, making it a long-lasting product.The present invention has been applied to a three-phase brushless motor as an example, but the basic concept of the present invention is a three-phase brushless motor. It is not limited to motors, but can also be applied to 2-phase motors in combination with position sensors, or 4-phase motors if necessary.
Needless to say, the present invention can also be applied to motors with more than one phase.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a three-phase brushless motor according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken from the line ■-■ in FIG.
FIG. 3 is a plan view of the rotor shown in FIG. 1. FIG. 4 is a sectional view of a second embodiment of the three-phase brushless motor of the present invention, FIG. 5 is a sectional view taken from the line ■-■ in FIG. 4, and FIG. Each is shown below. 12...Casing 24...
・・・・・・Stator 2G・・・・・・Rotor 28.30.32・・・・・・Cylindrical drive winding 3
4.38.42...Inner cylindrical magnetic pole 36.
40.44......External cylindrical magnetic pole 341',
34P', 36P, 36P'... 1st
Phase arc-shaped magnetic pole teeth 38T', 38P', 40P, 40P
'......Second phase arcuate magnetic pole teeth 42P, 42
P'', 44P, 44P'......Third phase arcuate magnetic pole teeth 52.54.56......Magnetic isolation ring Patent applicant Hi-Tech Research Co., Ltd. m1G/
group 22 ground 2121

Claims (6)

[Claims] (1) A plurality of phase cylindrical drive windings having different radii of curvature arranged concentrically, and an inner cylindrical magnetic pole and an outer cylindrical magnetic pole concentrically arranged inside and outside each of the cylindrical drive windings. , magnetic pole teeth formed on at least one front portion of the inner cylindrical magnetic pole and the outer cylindrical magnetic pole; and magnetic poles of the inner cylindrical magnetic pole and the outer cylindrical magnetic pole on the front surface of each of the cylindrical drive windings of the plurality of phases. a stator with a magnetic isolation ring disposed in the air gap between the teeth; and a rotor disk with a plurality of phases of magnetic pole teeth, each with a different radius of curvature, formed concentrically in a predetermined phase relationship with respect to each other. A brushless motor characterized in that, in each phase, the magnetic pole teeth of the rotor are opposed to the magnetic pole teeth of the stator via an air gap. (2) The brushless motor according to claim 1, wherein the magnetic pole teeth of the inner cylindrical magnetic pole and the outer cylindrical magnetic pole are arcuate magnetic pole teeth. (3) The brushless motor according to claim 1 or 2, wherein the stator further includes a back yoke connected to rear portions of the inner cylindrical magnetic pole and the outer cylindrical magnetic pole. (4) A patent characterized in that the magnetic pole teeth of the stator are provided with a plurality of eddy current prevention slits extending in the radial direction, and the magnetic pole teeth of the rotor disk are provided with a plurality of eddy current prevention slits extending in the radial direction. A brushless motor according to claim 1 or 2. (5) The brushless motor according to claim 4, wherein the slits of the rotor disk form a constant skew angle with respect to the slits of the magnetic pole teeth of the stator. (6) The brushless brushless according to claim 1 or 2, further comprising a cylindrical magnetic shielding member between the internal cylindrical magnetic pole and the external cylindrical magnetic pole of adjacent phases in the plurality of phases. motor.