JPS63124751A - 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 a plularity of radius of curvatures in the radial direction of a stator. CONSTITUTION:Cylindrical driving coils 28, 30, 32 of plural phases, which are provided with different radius of curvatures, are arranged concentrically in a stator 24. 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 cylindrical driving coils 28, 30, 32. 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 and a plurality of magnetic pole teeth, having predetermined phase angles, is formed on a rotor disc 26 while respective magnetic pole teeth of the rotor disc 26 are arranged so as to oppose to the magnetic pole teeth of the stator 24 with the relation of different phases.

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.

With the recent progress of various information devices, 0∆ devices, and FA devices becoming more energy-saving, smaller, lighter, μ-sized, and higher-performance,
There is a growing need for small, compact, high-performance, energy-saving control motors. 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. This has the drawback that the magnetic pole per unit becomes smaller, and the area of the magnetic pole facing one rotor becomes smaller, resulting in a significant decrease in the output torque of the motor. Also,
In conventional servo motors, a large number of slots are formed inside the stator, multi-phase windings are placed in these slots, and the multi-phase windings are switched and controlled in the normal circumferential direction. A structure is adopted in which a rotor placed inside the child is rotated. Second, in these motors,
In either case, the drive coil must be placed within a narrow cross-sectional area divided within the same plane of the stator, and therefore, if the number of turns of the coil is increased to increase the output torque, the motor will inevitably become larger. was there. 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 a motor is proportional to the number of turns of the drive winding (n) and the square of the drive current (1) of this winding (nI), it is possible 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 drive winding to the total volume of the stator and rotor. Due to the special structure, it is not possible to increase the ratio of quick-acting windings per unit volume of the motor.The first to fourth disadvantages of these are the major drawbacks of further downsizing, weight reduction, energy saving, and high performance of the control motor. This is also true for 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 is simple in structure, 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).
/s) The object of the present invention is to provide a brushless motor with significantly improved speed.

Another purpose of this invention is to reduce the air gap and increase the starting torque.

Excellent slewing characteristics. In particular, it is an object of the present invention 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 a stator, and inside and outside of the plurality of phases of cylindrical drive windings are respectively arranged. A cylindrical magnetic pole and an external cylindrical magnetic pole are arranged concentrically, and magnetic pole teeth with a predetermined phase angle are formed on the front surfaces of the internal cylindrical magnetic pole and the external cylindrical magnetic pole, and a predetermined phase angle is formed on the rotor disk. The present invention is characterized in that a plurality of magnetic pole teeth are formed at different phase angles, and each magnetic pole tooth of the rotor disk is arranged to face the magnetic pole teeth of the stator in a different phase relationship.

〔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 No. 1.21ii11, the three-phase brushless motor 10 includes a cylindrical casing 12 and a casing 12.
and end brackets 14 and 16 located at both ends of the. Preferably, the casing 12 and end brackets 14,16 are formed from a non-magnetic metallic material that is a good thermal conductor. An output shaft 22 is rotatably supported by the end brackets 14, 16 via bearings 18, 20, respectively. Further, the brushless motor 10 includes a stator 24 fixedly supported within the casing 12 concentrically with the output shaft 22, and a rotor 2 fixed to the output shaft 22 by welding or other means.
6. First to third phase cylindrical drive windings 28, 30, 32 are arranged in different curvature radius regions of the stator 24 in order from the outside to the inside in the radial direction.

A first phase internal cylindrical magnetic pole 34 made of a material with a high rate of m is located on the inner diameter side and the outer diameter side of the first phase cylindrical drive winding 28, respectively.
and external cylindrical magnet f! 36 are placed.

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 inner cylindrical magnetic pole 38 and an outer cylindrical magnetic pole 40 made of a material with high magnetic permeability are arranged on the inner diameter side and the outer diameter side of the second Aikawa cylindrical winding 30, respectively. Second phase internal cylindrical magnetic pole 3
8 and the rear part of the external cylindrical magnetic pole 40 is a ring-shaped back yoke 3.
9 magnetically coupled. 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 of the third Aikawa cylindrical winding @32, respectively, and these internal cylindrical magnetic pole and external cylindrical magnetic pole The rear part of the yoke is magnetically coupled by a ring-shaped back yoke 43. The rotating shaft 22 penetrates inside the third phase internal cylindrical magnetic pole 42 . Inside of the first phase to third phase cylindrical quick-acting windings 28 to 32,
All three sides, external and rear, have high permeability internal cylindrical magnetic poles,
Surrounded by the outer cylindrical pole and the back yoke, most of the magnetic flux generated by each cylindrical drive winding is concentrated by the inner cylindrical pole and the outer cylindrical pole. In this way, the internal cylindrical magnetic poles and the external cylindrical 'ij & poles of the first to third phases act as magnetic flux concentration members.

The ring-shaped back yokes 35, 39.43 are fixed to the respective rear portions of the cylindrical inner and outer magnetic poles 34, 36, 38, 40, 42.44 by welding or other means. Furthermore, these back yokes 35, 39, 43 are fixed to the end bracket 16 by screws (not shown) or other suitable means so as not to rotate. The back yokes 35, 39, 43 may be constructed from an integral disc.

The first phase internal cylindrical magnetic pole 34 and the external cylindrical magnetic pole 36 have arcuate magnetic pole teeth 34P and 3 on the front surface or axial end surface, respectively.
6F and low permeance section or cutout section 34C
, 36G are formed.

36P constitute the N pole and S pole of the first phase, respectively. Second
Arc-shaped magnetic pole teeth 38F are provided on the front surfaces of the phase inner cylindrical magnetic pole 38 and the outer cylindrical magnetic pole 40, respectively.

40P and low permeance part or cutout part 38C
, 40C are formed, and the arcuate magnetic pole teeth 3BP and 40P constitute the second phase S pole and N pole, respectively. 3rd phase inner circle a
Arc-shaped magnetic pole teeth 42P, 44F and low permeance portions or cut-out portions 42G, 44G are formed on the front surfaces of the magnetic pole 42 and the external cylindrical magnetic pole 44, respectively.
42F and 44P are the third phase N poles.

Configures the south pole. 1st phase to 3rd phase arc-shaped magnetic pole teeth 34P
~44P, 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
4C, 36C.

The second phase cutout portions 38C, 40G and the third phase cutout portions 42C, 44C are 120' in phase with 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 is composed 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 = number of phases). They may be arranged so as to be shifted one by one.

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

388.4O8, 42S, and 44g are formed, respectively. This is 1 cylindrical Fp1! Due to the magnetic skin effect caused by the fluctuating magnetic flux when the II winding turns on and off, the area of high magnetic flux density that effectively contributes to electromagnetic force becomes extremely narrow, increasing magnetic resistance and reducing the total magnetic flux, which reduces the motor's output torque. This is to prevent a decrease in These slits effectively suppress eddy currents, which are the effects of demagnetizing fields on fluctuating magnetic flux, and thus have the effect of uniformly distributing the strong magnetic flux portion over a wide portion of each arcuate magnetic pole tooth of each phase. Furthermore, the slit portion of one arc-shaped magnetic pole tooth is the rotor 26.
As the motor rotates, the strength of the magnetic field and the amount of change in magnetic flux density change greatly, which has a significant effect on increasing the output 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 arranged between these magnetic poles to block magnetic leakage between the magnetic poles. The front surface of the magnetic shielding member 48 is preferably aligned with the front surface of the adjacent arcuate magnetic poles 34P, 40P. A cylindrical magnetic shielding member 50 is disposed between the second phase internal cylindrical magnetic pole 38 and the third phase external cylindrical magnetic pole 44,
Effectively prevents magnetic leakage between adjacent magnetic poles.

Magnetic isolation rings 52, 54, 56 made of conductive metal such as aluminum or copper are arranged in front of the first to third phase cylindrical drive windings 28, 30, 32. Magnetic blocking ring 5
2, 54, and 56 are the first phase arc-shaped magnetic pole teeth 34F, respectively.
, 36F is located in the radial gap between the second-phase arc-shaped magnetic pole teeth 38P, 40P and the third-phase arc-shaped magnetic pole teeth 42P, 44F to block magnetic leakage between the magnetic pole teeth. Improves electromagnetic energy conversion efficiency. In particular, when the motor is downsized, magnetic leakage between the magnetic pole teeth of each phase is effectively prevented, so a highly efficient ultra-compact motor can be obtained. Furthermore, the cylindrical drive winding 28, 30.32
It also has the role of effectively preventing radiation of electromagnetic wave noise to the outside of the motor due to turning on and off of the motor.

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,
56b is the first to third phase external cylindrical magnetic poles 36,40°4
4 into the cutout portions 36G, 40G, and 44C. In this way, the first to third phase cutout portions 34
C~44G are all conductive magnetic blocking rings 52~56
The rotor 26 is sealed by the projection of the cutout parts 34C to 44G through the gaps.
It is possible to completely prevent magnetic leakage from occurring and to make the cut-out portions 34C to 44G have a small area and high reluctance, and to increase the area of the magnetic pole teeth of each phase accordingly, it is possible to increase torque. Moreover, the cylindrical drive winding 28~
The generated magnetic flux of 32 is more concentrated between the opposing magnetic pole surfaces of the rotor 26 and stator 24 through only the arc-shaped magnetic pole teeth of each phase, and the maximum @magnetic energy is 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, the magnetic flux generated by the cylindrical drive winding of each phase is directly concentrated on the high-permeability inner cylindrical magnetic pole and the outer cylindrical magnetic pole, and magnetic leakage to the magnetic field other than the magnetic pole teeth is blocked by magnetic isolation rings 52 to 56. Because of that,
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 it is possible to further reduce the size and weight of the motor. In addition, four surfaces in the cross section of the cylindrical drive winding of each phase are in contact with a good thermal conductor, and these good thermal conductors are further thermally coupled to the motor casing and end bracket, so the heat conduction area of the drive winding is is dramatically expanded, and the heat dissipation of the windings is significantly improved. Therefore, there is an effect that the cooling efficiency of the motor is increased and the overload capacity can be increased. In addition, the first
In the embodiment shown in FIG. 2, arc-shaped magnetic poles 34P, 36P, 3
8P, 40F, 42P, 44P are internal cylindrical magnetic poles 3 of each phase
4, 38.42 and the external cylindrical magnetic pole w436, 40.44, but these arcuate magnetic poles are formed only on either the internal cylindrical magnetic pole or the external cylindrical magnetic pole of each phase. On the other hand, a circular magnetic pole without a cut-out portion may be formed.

In FIG. 3, rotor 26 comprises a rotor disk 60 made of a high permeability material such as soft iron or silicon steel.

A mounting hole 62 for the rotating shaft 22 is located in the center of the rotor disk 60.
is formed, and the rotating shaft 22 is press-fitted into the mounting hole 62 of the rotor disk 60, and then 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
and third-phase arcuate magnetic pole teeth 64, 66, and 68. These first to third phase arc-shaped magnetic pole teeth 64, 66.
68 preferably has cutouts 64C, 66C, and 68G each having a low permeance in the first to third radius of curvature regions of the rotor disk 60 at a frequency of 1200 (360@/n in the case of multiphase, n = number of phases). They are formed by simply machining each with a phase shift. Cutout 64G, 66C.

The width of 68G is the cutout part 34C 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. Further, the inner diameter and outer diameter of the cutouts 64G, 66C, and 68C of the rotor disk 60 are made to be approximately equal to the inner diameter of the inner cylindrical magnetic pole and the outer diameter of the corresponding outer cylindrical magnetic pole of the first to third phases of the stator. selected.

First phase, second phase, and third phase arc-shaped magnetic pole teeth 64, 66
．． 68 is a plurality of thin slits 64S extending in the radial direction;
66S and 68S respectively.

Each of these slits 64S, 66S, 68S corresponds to the slits 34S, 36S, 38S of the arc-shaped magnetic pole teeth of the stator.
It is processed to have the same width as 40S, 42S, and 44S. In FIG. 3, the slits 66S and 685 are integrally formed on the same extension line, but the slits 66S and 685 may be formed independently in each arcuate magnetic pole.
4S, 66S, 683 are arc-shaped magnetic pole teeth 64, 66.68
In order to suppress the eddy current that occurs when magnetic flux passes in the radial direction within the arc-shaped magnetic pole teeth 64, 66.
Uniform distribution throughout 68 has the effect of reducing magnetic resistance and increasing effective magnetic flux.

Furthermore, by suppressing the eddy currents in the arc-shaped magnetic pole teeth 64, 66, and 68, it is possible to effectively prevent instability and resonance phenomena caused by a drop in torque characteristics in the mid-range or high-speed range of the motor. Stable torque characteristics can be obtained from low speed range to high speed range. Furthermore, in conjunction with the slits in the arc-shaped magnetic pole 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 it is desired to further reduce the size and weight of the brushless motor, the first phase and second phase arc-shaped magnetic poles of the rotor disk 60 may be configured with permanent magnets, although not shown. magnetic pole tooth 6
4.6+3,6B is cutout 64G, 66C, 68
Although shown as being formed in the same circular plane as G, arc-shaped magnetic pole teeth are formed in the axial convex region in a different plane with a different axial thickness of the rotor disk.

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

In the above configuration, when the phase arc drive winding 49t28 is excited, the magnetic flux generated by the coil 28 is transferred to the internal cylindrical magnetic pole 34. Back yoke 35. The outer circle fIi is concentrated by the magnetic pole 36, and at this time, the arc-shaped magnetic pole teeth 34P, 36
P is excited as an N pole and an S pole, respectively, as shown by arrows in FIG. 1, and attracts the arc-shaped magnetic pole teeth 64 of the rotor 26. At this time, the cutout 64 of the arc-shaped magnetic pole tooth 64
The rotor 26 comes to rest at a stable point where C coincides with the first phase cutout portions 34C and 36C. The first phase arcuate magnetic pole tooth 64 of the rotor 26 is the first phase arcuate magnetic pole tooth 34P of the stator.
, 36P, as described 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, since magnetic isolation rings 52 to 56 are arranged in the radial gaps between the magnetic pole teeth of each phase of the stator, magnetic leakage between the magnetic pole teeth of the stator is completely blocked, and the magnetic flux is directed to the intended purpose. A large amount of electromagnetic energy is produced from mouth to evening 26 by being concentrated only in the magnetic field. Next, the first phase cylindrical drive winding 28 is turned off and the second phase cylindrical drive winding 3
0 is turned on, the second phase arc-shaped magnetic pole tooth 38
P and 40P are excited to the S and N poles, respectively, and attract the arcuate magnetic pole @66 of the rotor 26. At this time, the cutout 66G of the arcuate magnetic pole tooth 66 of the rotor 26 moves clockwise, so the rotor 2G rotates 1201 times clockwise.

Furthermore, the second phase cylindrical drive winding 3o is turned off, and the third phase cylindrical drive winding 3o is turned off. When the IIJ winding 32 is turned on, the arcuate magnetic pole teeth 68 of the rotor 26 are attracted clockwise, causing the rotor 26 to rotate 120 degrees clockwise.

In this way, the cylindrical drive windings 28 to 32 of the first to third phases
Sequentially! By excitation in the sequence of →■→■,
The rotor 26 rotates clockwise. The counterclockwise rotation of the rotor 26 rotates the first to third phase drive windings I→■→■→l
This can be obtained by excitation in the sequence →m→■.

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 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 inner cylindrical magnetic pole 34' and the outer cylindrical magnetic pole 36' of the first phase are separated by a pair of cut-out portions 34G' and 36G' with a 1801 phase shift, and a pair of symmetrical arc-shaped magnetic pole teeth 34P' are separated by a pair of cut-out portions 34G' and 36G'. , 36T" respectively. Similarly, the second phase internal cylindrical magnetic pole 38'
and a pair of cutouts 38C' in which the outer cylindrical magnetic poles 40' are 1801 out of phase.

A pair of symmetrical arc-shaped magnetic pole teeth 38F' and 40P' are provided, respectively, separated by 40C'. The third phase internal cylindrical magnetic pole 42' and external cylindrical magnetic pole 44' are 180m
A pair of cutout portions 42G' and 44G that are out of phase.
symmetrical arc-shaped magnetic pole teeth 42P' separated by ',
44P' respectively.

A pair of cutout parts 34G', 36C:, 38C'
, 40G', 42C'', and 44C' are the rotating shaft 2
A pair of arc-shaped magnetic pole teeth 34P', 36P', 38P', 40P',
42P' and 44P' are arranged 180 degrees apart from each other.

The second point is the first phase arcuate magnetic pole tooth 6 of the rotor disk 60'.
4' is divided into two poles by a pair of symmetrical cutouts 640', and the second phase arcuate magnetic pole @66' is further divided into two poles by a pair of symmetrical cutouts 66C', and the third The phase arc-shaped magnetic pole 68' is divided by a pair of symmetrical cutouts 680', forming a so-called six-pole structure. A pair of arc-shaped magnetic pole teeth i teeth 64', 66', and 68' of the first to third phases each have 12
06 are arranged so that the phase angles are shifted. In addition, the rotor disk (30' slits 64S', 66S', 6
8S' is formed to be inclined at a constant skew angle with respect to the slits of the arcuate magnetic pole teeth of the stator, thereby ensuring smooth rotation of the rotor 26'.

In the above configuration, in the first failed embodiment, the cylindrical drive windings 28 to 3o of the first to third phases are connected in the sequence of ■-■-m-f.
In the second embodiment, when the cylindrical drive windings 28 to 30 of the first to third phases were excited in the same sequence, The rotor 26' rotates counterclockwise in steps of 60 degrees.

When the brushless motors of the first and second embodiments are used as stepping motors, one-phase excitation or two-phase excitation is required.
The brushless motor of the present invention, which may be driven by phase excitation, can be used as a servo motor by connecting a suitable encoder or resolver. In addition, the first to third phase cylindrical quick-acting coils can be connected to an AC ffi@ and used as a general-purpose AC motor.

In the above embodiments, the rotor has been described as being made of a disk of high magnetic permeability, but the rotor may also have a structure in which arc-shaped magnetic poles made of a high magnetic permeability material or a permanent magnet 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 arcuate magnetic pole, and the concave portion may be used as a low permeance portion instead of a cutout.

Note that the circular elastic magnetic poles of the rotor may be made 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. Because they are arranged in the radius of curvature region, the volume ratio of the windings per unit body of the motor can be significantly increased. Therefore, the output torque of the motor can be increased by the number of turns n of the windings and the square of the drive current (nI). By significantly increasing in proportion to , it is possible to achieve high efficiency that could not be achieved in the past.As a result, brushless motors can be made ultra-compact and lightweight, with high-speed response and high performance.In particular, brushless motors can be Even if the distance between the arc-shaped magnetic pi teeth of each phase becomes smaller when ultra-compact and lightweight, the magnetic flux generated by the drive winding will remain arc-shaped due to the magnetic isolation ring placed between the magnetic pole teeth of each phase. Maximum electromagnetic energy is obtained because all the magnetic flux is more concentrated between the opposing magnetic pole faces of the stator and rotor without leaking into the air gap between the teeth.Therefore, the electromagnetic energy conversion efficiency is extremely high, resulting in a large energy saving effect. 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 conduct thermally to the casing and end housing, which are also good thermal conductors. Because of this, the heat conduction area of one 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 has an internal cylindrical shape. Surrounded by magnetic poles, external cylindrical magnetic poles, back yokes and magnetic isolation rings, the radiation of electromagnetic noise from the motor to the outside can be significantly reduced.

Furthermore, since a large number of slits are formed in the rotor disk and the magnetic T4i teeth of the stator in parallel with the magnetic path, magnetic reaction due to fluctuating magnetic flux is effectively prevented, the effective cross-sectional area of the magnetic circuit is increased, and magnetic resistance is increased. By decreasing the total magnetic flux, the total magnetic flux can be significantly increased. Because slits are formed in the arc-shaped magnetic poles of the cylindrical drive winding of each phase and the arc-shaped magnetic poles of the rotor, as the rotor rotates, the strength of the magnetic field and the magnetic flux density between the opposing magnetic pole surfaces of the stator and rotor change. The amount of change increases significantly compared to the case of a flat magnetic pole surface, and the output torque of the motor becomes extremely large. Therefore, a brushless motor that is capable of a π-speed response and that is compact, 1 ift, and has high performance, which is unprecedented, is realized. Furthermore, the rotor disc has a large cut-out section, so
The overall weight of the rotor disk is significantly reduced, rotor inertia is extremely low, and the rotational torque is large, allowing for high-speed response and precise positioning.

Excellent slewing characteristics. The rotor disk is solid and has no brushes or commutators, so it can be used at high speeds. Furthermore, the stator and rotor disk can use cheap raw materials, and the structures of the stator, rotor disk, and drive winding are extremely simplified, making processing and assembly easy and inexpensive, resulting in significant cost reductions. can.

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.

The present invention is applicable to a three-phase brushless motor as an example.It can withstand frequent acceleration/deceleration operations and has excellent resistance to high and low temperature environments.Moreover, there is no deterioration in operating performance due to continuous use, and it has a long life. However, it goes without saying that the basic concept of the present invention is not limited to three-phase motors, but can also be applied to two-phase motors in combination with position sensors if necessary, or to four-phase or more phase motors.

[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.
3 is an iTt side 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, and FIG. 5 is a sectional view taken from the line ■-■ in FIG. 4. , 6 respectively show the planar turns of the rotor of FIG. 4. 12...Casing 24...
......Stator 26...Rotor 28.30.32...Cylindrical drive winding 3
4.38.42・・・・・・Internal cylindrical magnetic pole 3G,
40.44......External cylindrical magnetic pole 34P, 34
P', 361', 36P'...First phase arcuate magnetic pole teeth 38P, 38P', 40P, 40P'.
......Second phase arc-shaped magnetic pole teeth 42P, 42P'
, 44P, 44P'......Third phase arcuate magnetic pole teeth 52.54.56...Magnetic isolation ring Patent applicant Hi-Tech Laboratory Hata 2 (21 Qin 3 Leap

Claims (5)

[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. , a stator having magnetic pole teeth formed in at least one front portion of the inner cylindrical magnetic pole and the outer cylindrical magnetic pole, and each having a different radius of curvature formed concentrically with each other in a predetermined phase relationship. 1. A brushless motor comprising a rotor disk having multiple phases of magnetic pole teeth, and in each phase, the magnetic pole teeth of the rotor disk 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.