JP2001352727A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a motor and to increase its energy density. SOLUTION: A rotor 1 that is formed by a magnetic force line guidance material is provided with a plurality of magnets 2 that are arranged on the same circumference. With the plurality of magnets 2, an outer part that is radially outward is surrounded by its magnetic force line guidance material. A stator 5 is provided with a plurality of slots 9-1-9-12 being extended in a radial direction, and a plurality of coils 11-1-11-12 for generating a magnetic field in the plurality of slots. The plurality of magnets 2 are surrounded by the magnetic force line guidance line and are build into the rotor 1 of an iron core, a magnetic path is formed three-dimensionally in the core and a magnetic force system forms salient pole structure, and a reactance torque constituent can be utilized effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor, and more particularly to a motor used as a drive source for industrial robots, machine tools, and factory automation (FA) products, wherein the number of windings and the number of permanent magnet poles are different. Type DC three-phase motor.

[0002]

2. Description of the Related Art In order to reduce the size, increase the output and increase the torque of a motor, it is important that the energy density Edc, which is the volume ratio of the motor to the output, is large. It is important to minimize the number of slots for arranging the armature windings and to increase the workability of the windings.
Such a brushless DC motor is known as having a structure of 14 poles and 12 slots, as shown in FIG.

The 14-pole 12-slot type motor has a permanent magnet group 102 having a 14-pole series structure arranged on a cylindrical surface of a rotor core 101 and twelve slots 103-1 to 103-1.
And a stator core 104 which is a slot forming body radially arranged on the same circumference at equal angular intervals. 12 slots 103-1 to 103-
In a group of six slots composed of two adjacent slots out of the twelve, a set of three-phase electric windings 105 are provided at positions where the phases are shifted from each other by an electrical angle of 120 degrees counterclockwise.
-U1,105-V1,105-W1 and another set of 3
Phase electric winding 105-U2, 105-V2, 105-W2
Are arranged corresponding to the positions. These six three-phase electric windings 105-U1, 105-V1, 105-W1, 10
5-U2, 105-V2, and 105-W2 are respectively shifted by a rotation angle of 30 degrees, and furthermore, six three-phase electric windings 105-U1 ', 105-V1', and 105-W
1 ', 105-U2', 105-V2 ', 105-W
2 'is provided.

It is known that the output torque T of such a motor is expressed by the following equation. T = p {φ · Ia · cos (β) + (Lq−Ld) Ia ² · sin (2β) / 2}. ... (1) p: Number of pole pairs (number of poles / 2) Ia: Armature current
β: current phase Ld: direct-axis inductance Lq: horizontal-axis inductance In a motor with a magnet embedded structure, the value of the direct-axis (d-axis: axis facing the magnetization direction) inductance Ld is calculated from the value of the horizontal-axis (q-axis) inductance Lq. Is also small. Therefore, (Lq−Ld) in equation (1) is a positive value unless Lq = Ld.

In such a surface magnet type motor in which a permanent magnet is arranged on the surface of the iron core 101, the following equation is established from the structural characteristics. Ld = Lq or Ld to Lq. (2) Here, the symbol ~ indicates that Ld and Lq are substantially (substantially or approximately) equal. Therefore, the surface magnet type motor substantially has the following equation: T = p {φ · Ia · cos (β)}. (3) where the output of the second term on the right-hand side of the previous equation is zero, and the output is not output. Therefore, only the magnet torque component, which is the left term on the right side of the equation (1), can be effectively used.
Higher energy density can be suppressed.

It is desired to increase the energy density by effectively utilizing the reluctance torque component, which is the right term on the right side of equation (1).

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to increase the energy density by effectively utilizing a reluctance torque component, in particular, a reluctance torque component which is a right term on the right side of the equation (1). It is to provide a motor that can be used.

[0008]

Means for solving the problem are described as follows. The technical items appearing in the expression are appended with numbers, symbols, and the like in parentheses (). The numbers, symbols, and the like are technical items that constitute at least one embodiment or a plurality of the embodiments of the present invention, in particular, the embodiments or the examples. Corresponds to the reference numerals, reference symbols, and the like assigned to the technical matters expressed in the drawings corresponding to the above. Such reference numbers and reference symbols clarify the correspondence and bridging between the technical matters described in the claims and the technical matters of the embodiments or examples. Such correspondence / bridge does not mean that the technical matters described in the claims are interpreted as being limited to the technical matters of the embodiments or the examples.

A motor according to the present invention comprises a rotor (1),
A stator (5) formed outside of the rotor (1), wherein the rotor (1) is formed of a magnetic field line induction material, and the rotor (1) includes a plurality of magnets (2) arranged on substantially the same circumference. The magnet (2) has a radially outer outer portion surrounded by its magnetic field induction material, and the stator (5) has a plurality of radially extending slots (9) and a plurality of slots (9). A plurality of windings (11) for respectively generating a magnetic field. All or at least the outer part of the plurality of magnets (2) is thus surrounded by the magnetic field induction material and built into the rotor (1) which is an iron core;
Since the magnetic path is formed three-dimensionally in the iron core and the magnetic force system forms a salient pole structure, the reluctance torque component is effectively used. The reluctance torque component is given by the equation (1)
It is represented by Such a pole structure of the motor corresponds to the known pole structure, and the benefits of the known motor can be directly inherited and inherited. The rotor (1) is formed with a hole (4) into which a permanent magnet is inserted in the axial direction, thereby simplifying the assembly.

[0010] A three-phase DC current is passed through the plurality of windings (11) to synchronize them. The winding (11) is composed of a first set of three-phase windings (11-1U, 11-5V, 11-9W) and a second set of three-phase windings (11-1U, 11-5V, 11-9W).
Phase windings (11-7U, 11-11V, 11-3W), and the first set of three-phase windings and the second set of three-phase windings are geometrically arranged substantially in line symmetry. I have. The line of symmetry is
It coincides with the axis of rotation of the rotor (1).

Alternatively, the winding (11) includes a first group three-phase winding and a second group three-phase winding, wherein the first group three-phase winding and the second group three-phase winding are the same. Phase windings (11-1 and 11-1)
2) are adjacent to each other in the same rotational direction, and the first group three-phase windings are the first set three-phase windings (11-1U, 11-5V, 11-
9W) and the second set of three-phase windings (11-7U, 11-11
V, 11-3W), and the first set of three-phase windings and the second set of three-phase windings are preferably geometrically arranged substantially line-symmetrically.

The second group three-phase winding includes another first group three-phase winding and another second group three-phase winding, and the first group three-phase winding and the second group three-phase winding. The windings are geometrically arranged approximately line-symmetrically,
It is further preferable that the other first set three-phase windings and the other second set three-phase windings are arranged geometrically substantially line-symmetrically.

The number of windings is N and the number of permanent magnets is M, where M is greater than N and one of the prime factors of M is greater than any of the prime factors of N. The prime factors of N include 2, 2 and 3, and the prime factors of M include 2 and 7. Such a number M is, for example, 14, and such N is, for example, 12.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Corresponding to the drawings, an embodiment of the motor according to the present invention is provided as a 14-pole, 12-slot type brushless DC motor. As shown in FIG. 1, this 14-pole 12-slot motor has a known phase relationship between a permanent magnet and a slot, and a known relationship shown in FIG. It has the same phase relationship and number relationship, but differs from the known one only in the surface magnet type or the internal magnet type.

The motor has a rotor core 1 as shown in FIG. A 14-pole permanent magnet 2 is embedded and formed in a rotor core 1. The 14-pole permanent magnet 2 corresponds to 14 permanent magnets. The fourteen permanent magnets 2 are inserted and fitted into fourteen columnar holes 4 formed in the rotor core 1 in the axial direction. Pillar hole 4
Is trapezoidal on a section perpendicular to the axis. One bar magnet having a rectangular cross section is fitted into one columnar hole 4 by press-fitting. In each of the permanent magnets 2, the magnetic lines of force from the S pole to the N pole are oriented in the axial direction. Two adjacent magnets are formed at different poles on the same side in the axial direction. The 14 permanent magnets 2 are equiangular (= 3
(60 ° / 14). Magnetic lines of force formed by the 14 magnets arranged in the circumferential direction in this manner are generated by combining magnetic lines of force directed in the circumferential direction and lines of magnetic force directed in the axial direction.

The rotor core 1 includes a stator 5 having a bearing structure.
It has. The stator 5 is formed from a stator-side iron core 6 and band windings 11-1 to 11-12 (a generic reference number is indicated by 11). The stator side core 6
It is formed from a cylindrical ring core 8 and slots 9-1 to 9-12 (general reference numbers are indicated by 9) which are cores extending in the radial direction. Ring core 8 and slot 9
Is an integral object. Between the inner surface in the radial direction of the slot 9 and the cylindrical surface that is the outer peripheral surface of the rotor core 1, two sliding surfaces can be formed. The number of the plurality of slots is twelve.
All the slots 9 are arranged on the same circumference at equal angular intervals (= 360 ° / 12). The center of the ring core 8 coincides with the center of the rotor core 1.

Each of the plurality of slots 9 is wound with twelve armature band windings 11-1 to 11-12 (a generic reference number is indicated by 12). Three armature band windings 11-1 and 1-1 of twelve armature band windings 11
Reference numerals 1-5 and 11-9 denote first set three-phase armature band windings 11-1.
U, 11-5V, and 11-9W. One set of three
Three sets of three-phase armature band windings 11-1U, 11-5V,
11-9W is an equiangular interval (= 120 ° = 360 ° /
In 3), they are arranged on the same circumference.

The other three of the twelve armature strip windings 11
Armature band windings 11-7, 11-11 and 11-3 are:
First set three-phase armature band windings 11-1U, 11-5V, 11
-9W, the second set of three-phase armature band windings 11-7U and 11-11 are arranged in line symmetry with respect to each other.
V, 11-3W. Here, the line of symmetry coincides with the rotation axis of the rotor core 1.

First Set Three-Phase Armature Band Windings 11-1U, 11
-5V, 11-9W and second set three-phase armature band winding 11-7
U, 11-11V, and 11-3W form a first group three-phase armature band winding. The six band windings of the first group three-phase armature band winding are adjacent to each other in the same rotational direction,
Six Strip Windings 11-12 Forming Group Three-Phase Armature Strip Windings
U, 11-4V, 11-8W, 11-6U, 11-10
V, 11-2W. In the figure, the three-phase symbol U,
V, W and U ', V', W 'indicate that the direction of current flow is opposite in the axial direction.

Two band windings located at line-symmetric positions (for example: 1
In 1-1 and 11-7), currents flow in opposite directions when viewed on the same circumferential direction line. The polarities of two permanent magnets (examples: 2-1 and 2-8) arranged corresponding to the rotational angle positions (positions shown) in the two band windings are as follows.
Opposite to each other. Each of the first group three-phase armature band windings and each of the second group three-phase armature band windings adjacent to each other and having the same phase (for example, 11-1 and 11-1)
2), pulse currents flow simultaneously in opposite directions.

The two sets of three-phase band windings U, V, W have 12
A pulse current having an electrical angle phase of 0 ° is applied, and the motor is formed as a brushless DC motor. The time interval between the three-phase pulse currents is controlled (the magnetic field rotational speed is controlled), and the motor is formed as a synchronous motor in which the rotor core 1 rotates at an arbitrary rotational angular speed. Further, the rotor core 1 can be fixed at an angular position that is an integral multiple of 360 ° divided by the least common multiple of 12 and 14.

Equation (1) is expressed as follows. T = p {magnet torque component + reluctance torque component} magnet torque component = φ · Ia · cos (β), reluctance torque component = (Lq−Ld) Ia ² · si
n (2β) / 2.

The fourteen permanent magnets 2-1 to 2-14 are embedded in the rotor core 1, and the magnetic flux line density in which the magnetic path closes in the rotor core 1 is higher than that of the known motor of FIG. Has become. Such differences make them even more asymmetric with respect to the values of Ld and Lq, and positively satisfy the following equation. Lq> Ld. ... (4) Well-known geometrical constants such as the outer size, pole structure, and supply current are the same, but differ only in whether the permanent magnet is a surface-exposed type or an internally embedded type. The motor and the motor of the present invention are compared. When the output torque of the known motor is represented by T ′ and the output torque of the motor of the present invention is represented by T,
According to the condition (4), T ′ <T. ... (5)

FIGS. 2 and 3 show a performance comparison between the known motor and the motor of the present invention. FIG. 2 shows a performance comparison of the relationship between the rotation speed and the output torque, and FIG. 3 shows a performance comparison of the relationship between the rotation speed and the output. The internal magnet type motor of the present invention has both an output torque (unit: Nm) and output (unit: kW conversion J) larger than those of the surface magnet type known motor.

The internal magnet type motor inherits the following advantages of the surface magnet type motor as it is: (1) The winding coefficient is large and the energy density is high. (2) Slots are reduced and productivity is high (cost reduction). (3) Cogging torque generation order (= 7 × 6 × 2 = number of poles 1)
4 and the least common multiple of the number of slots 12) are large, and the torque ripple frequency is increased (the effect of minimizing the influence on the mechanical system normally controlled in the low frequency range is great).

Further, since the internal structuring of the permanent magnet promotes the salient pole structure of the magnetic force system so that Ld does not become equal to Lq, the reluctance torque is effectively used, and further, the energy density, that is, the high energy density is increased. Outputting is possible, and conversely, miniaturization is possible.

[0027]

The motor according to the present invention can effectively utilize the reluctance torque while following the advantages of the known motor.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a motor according to the present invention.

FIG. 2 is a graph showing a performance comparison.

FIG. 3 is a graph showing another performance comparison.

FIG. 4 is a cross-sectional view showing a known motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotor (rotor iron core) 2, 2-1 to 2-14 ... Multiple magnets 4 ... Hole 5 ... Stator 9, 9-1 to 9-12 ... Slot 11-1U, 11-5V, 11-9W ... First Set 3 phase winding 11-7U, 11-11V, 11-3W ... 2nd set 3 phase winding

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[Procedure amendment]

[Submission date] August 30, 2000 (2008.3.
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 3

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

A motor according to the present invention comprises a rotor (1),
A stator (5) formed outside of the rotor (1), wherein the rotor (1) is formed of a magnetic field line induction material, and the rotor (1) includes a plurality of magnets (2) arranged on substantially the same circumference. The magnet (2) has a radially outer outer portion surrounded by its magnetic field induction material, and the stator (5) has a plurality of radially extending slots (9) and a plurality of slots (9). A plurality of windings (11) for respectively generating a magnetic field. All or at least the outer part of the plurality of magnets (2) is thus surrounded by the magnetic field induction material and built into the rotor (1) which is an iron core;
Since the magnetic path is formed three-dimensionally in the iron core and the magnetic force system forms a salient pole structure, the reluctance torque component is effectively used. The reluctance torque component is given by the equation (1)
It is represented by Such a pole structure of the motor corresponds to the known pole structure, and the benefits of the known motor can be directly inherited and inherited. The rotor (1) has multiple
A hole (4) into which the magnet (2) is inserted in the axial direction is formed,
Its assembly is simplified.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiki Kato 1-1-1, Wadazakicho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Masahiro Hirano Wako, Hyogo 1-1-1 Tazakicho Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Isao Baba 6661-9 Miyagawa, Chino-shi, Nagano F-term (reference) 5H619 AA01 BB01 BB06 BB15 BB24 PP01 PP05 PP08 PP14 5H621 AA03 BB10 GA01 GA04 GA16 HH01 JK02 JK05 5H622 AA03 CA02 CA07 CB05 CB06 PP11

Claims (8)

[Claims] 1. A rotor comprising: a rotor; and a stator formed outside the rotor, wherein the rotor is formed of a magnetic field line induction material, the rotor includes a plurality of magnets arranged on a substantially same circumference, An outer portion of the plurality of magnets, which is a radially outer side, is surrounded by the magnetic field induction material, and the stator includes a plurality of slots extending in a radial direction, and a plurality of windings for causing the plurality of slots to respectively generate a magnetic field. . 2. An output torque T according to claim 1, wherein T = p ｛φ 次 Ia ・ cos (β) + (Lq-Ld) Ia
Where p: number of pole pairs (number of poles / 2), Ia: armature current, β: current phase Ld: direct-axis inductance, Lq: horizontal-axis inductance: ² · sin (2β) / 2｝ A motor in which Ld = Lq or Ld to Lq (where the symbol indicates that Ld is approximately equal to Lq) does not hold. 3. The motor according to claim 1, wherein the rotor has a hole into which the permanent magnet is inserted in an axial direction. 4. The motor according to claim 1, wherein a three-phase DC current flows through the plurality of windings. 5. The winding according to claim 4, wherein the windings include a first set of three-phase windings and a second set of three-phase windings, the first set of three-phase windings and the second set of three-phase windings. A winding is a motor that is geometrically arranged approximately line-symmetrically. 6. The winding according to claim 4, wherein the windings include a first group three-phase winding and a second group three-phase winding, wherein the first group three-phase winding and the second group three-phase winding. The same-phase windings of the wires are adjacent to each other in the same rotation direction, and the first group three-phase winding includes a first set three-phase winding and a second set three-phase winding, The set three-phase windings and the second set three-phase windings are geometrically arranged approximately in line symmetry, and the second group three-phase windings are: another first set three-phase windings; A motor including a second set of three-phase windings, wherein the other first set of three-phase windings and the other second set of three-phase windings are geometrically arranged substantially line-symmetrically. 7. The method according to claim 6, wherein the number of windings is N, the number of permanent magnets is M, M is larger than N, and one of the prime factors of M is one of N Motor larger than prime factor. 8. The motor according to claim 7, wherein the prime factor of N includes 2 and 3, and the prime factor of M includes 2 and 7.