JP2006320090A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor in which torque ripples are not generated. <P>SOLUTION: The motor includes: a pair of rotors 12, 14 that are fit and fixed on one and the same rotating shaft 16 and have magnetic poles so formed that their polarities are alternately inverted in the circumferential direction around the axis line; and a stator 13 that is disposed in opposition to the rotor 14 and in which magnetic poles whose polarities are alternately inverted in the circumferential direction around the axis line are excited. When N is taken as the number of poles of the rotors 12, 14, the pair of rotors 12, 14 are fixed on the rotating shaft 16 so that their mounting angles are shifted by only a rotation angle of 180°/N. Thus, the magnetic poles formed in one rotor 12 are shifted in phases with respect to the magnetic poles formed in the other rotor 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a motor provided with at least a pair of rotors fitted and fixed to a rotating shaft.

  Conventionally, in the generator disclosed in Japanese Patent Laid-Open No. 54-116610 and Japanese Patent Laid-Open No. 6-86517, as shown in FIG. 15, the rotating shaft 1 passes through the bracket 2 serving as an outer cylinder through a bearing 3. The field winding 5 is provided on the outer periphery of the yoke 4 that is externally fitted and fixed to the rotary shaft 1, and the claw-shaped magnetic poles 6 and 7 that protrude alternately from the left and right sides of the field winding 5 are provided as a whole. A rotor is formed. On the other hand, the stator 2 is provided on the bracket 2 so as to face the claw-shaped magnetic poles 6 and 7. In addition, the power supply to the field winding 5 is configured to supply power slidably through the slip ring 9.

  According to the above configuration, when a direct current is supplied to the field winding 5 through the slip ring 9, an N pole is generated on the right side of the field winding 5 in the figure and an S pole is generated on the left side of the figure. , The N pole is guided to the claw-shaped magnetic pole 6 protruding from the right side, and the S pole is guided to the claw-shaped magnetic pole 7 protruding from the left side. That is, by providing only one field winding 5 wound around the rotating shaft 1, a plurality of N poles and S poles can be alternately generated in the circumferential direction on the outer peripheral side of the rotor. .

By the way, if the claw-shaped magnetic pole 6 that induces the N pole and the claw-shaped magnetic pole 7 that induces the S pole are too close to each other, a magnetic circuit is formed between the adjacent claw-shaped magnetic poles 6 and 7. The magnetic flux contributing to the torque directed to the stator winding 8 is reduced. Therefore, in order to prevent such magnetic field leakage, it is required to provide a certain amount of gap in the circumferential direction between the claw-shaped magnetic poles 6 and 7. However, when the spacing between the claw-shaped magnetic poles 6 and 7 increases, the rotational torque of the rotating shaft 1 varies depending on the rotational angle as shown in FIG. 16, which causes an unstable torque ripple (cogging torque).
JP 54-116610 A JP-A-6-86517

  The present invention has been made in view of the above problems, and an object thereof is to provide a motor that does not generate torque ripple.

In order to solve the above-described problem, the present invention includes a pair of rotors that are externally fitted and fixed to the same rotating shaft, and are formed with magnetic poles that are alternately opposite in the circumferential direction around the axis,
A stator that is arranged opposite to the rotor and in which magnetic poles having opposite polarities alternately in the circumferential direction around the axis are excited,
When the number of poles of the rotor is N, the magnetic pole formed on the one rotor and the magnetic pole formed on the other rotor are out of phase with each other by a rotation angle of 180 ° / N. A motor characterized by being provided is provided.

  With the above configuration, each of the N magnetic poles of the pair of rotors is shifted in phase by 180 ° / N around the rotation axis, so that the weak part of the magnetic pole generated in one rotor is the magnetic pole generated in the other rotor. The strong part of the magnetic pole produced by the other rotor is complemented by the strong part of the magnetic pole produced by the other rotor. Therefore, even if the torque generated in each rotor varies depending on the rotation angle, the torque of the rotating shaft is flattened as a whole and the occurrence of torque ripple is prevented by shifting the phases of the torques to overlap each other. be able to.

  It is preferable that the pair of rotors be fixed with a rotational angle shifted by 180 ° / N with respect to the rotation axis.

With the above configuration, torque ripple can be prevented only by fixing the mounting angle around the axis of one rotor with respect to the rotation axis by 180 ° / N with respect to the other rotor, and magnetic poles generated in each rotor. Each has the advantage that it only needs to be excited in the same way, and there is no need to perform special control.
The mounting angles of the rotors with respect to the rotating shaft may be the same, and current control or the like may be performed so that the phases of the sinusoidal magnetic poles excited by the respective rotors are shifted by 180 ° / N.

An induction source stator having excitation means for exciting concentric magnetic poles of opposite polarities on the inner and outer peripheral sides around the axis is disposed on one side of the rotor,
The rotor has a first inductor made of a magnetic material having one end face facing the outer peripheral side of the excitation means and the other end face facing the magnetic pole of the stator, and one end face being an inner peripheral side of the excitation means. It is preferable that second inductors made of a magnetic material facing the magnetic poles of the stator and having the other end faces the magnetic poles of the stator are alternately arranged in the circumferential direction.

With the above configuration, since the opposite polarity is excited concentrically on the inner and outer circumferential sides of the induction source stator, even if the rotor rotates, one end surface of the first inductor is fixed to the induction source. Since the end surface of the second inductor moves on the circumference of, for example, the south pole generation point of the induction source stator, the first inductor and the second Constant magnetic poles having opposite polarities are induced on the other end face of the inductor. Therefore, a suction / repulsion force is generated between the first and second inductors and the stator, and a driving force of the rotor is generated.
In addition, if the first inductor and the second inductor are brought too close to each other, a magnetic circuit is formed between the first inductor and the second inductor, magnetic field leakage occurs, and the magnetic flux contributing to the torque toward the stator may be reduced. It is required to provide a certain amount of space between the inductors. Thus, when the adjacent interval between the inductors is increased, torque ripple is likely to occur. Therefore, the above-described device for shifting the phase of each rotor by 180 ° / N becomes more effective.

  It is preferable that the pair of rotors be disposed on both sides of the stator in the axial direction and that the pair of induction source stators be disposed outside the rotor in the axial direction.

  With the above configuration, the axial gap structure in which each rotor and each induction source stator are sandwiched and arranged on both sides of the stator makes it possible to effectively use the magnetic field generated by the stator shared in the center for torque generation. be able to.

The stator preferably excites the magnetic pole by arranging superconducting coils wound with a superconducting wire at regular intervals in the circumferential direction.
That is, by superconducting the coil that generates the magnetic poles of the stator, the magnetic field can be strengthened and the motor torque can be significantly increased.

The exciting means of the induction source stator is preferably a superconducting coil in which a superconducting wire is wound in an annular shape around an axis.
In other words, by superconducting the coil of the induction source stator, a large current can flow, and the number of turns of the coil can be greatly reduced.

  As is clear from the above description, according to the present invention, the N magnetic poles of each rotor are shifted in phase by 180 ° / N around the rotation axis. The weak part is complemented by the strong part of the magnetic pole generated in the other rotor. Therefore, even if the torque generated by the individual rotors varies, the torque of the rotating shaft is flattened by shifting the phases of the torques and superimposing them, thereby preventing the occurrence of torque ripple.

Embodiments of the present invention will be described with reference to the drawings.
1 to 9 show a first embodiment.
The motor 10 of the first embodiment has an axial gap structure, and the induction source stator 11, the rotor 12, the stator 13, the rotor 14, and the induction source stator 15 are arranged in this order, and the rotation shaft 16 is arranged in each order. While being fixed to the rotors 12, 14, the induction source stators 11, 15 and the stator 13 are rotatable. The induction source stators 11 and 15 and the stator 13 are fixed to an installation surface G such as a casing.

  The induction source stators 11 and 15 on both sides are symmetrical and have a yoke 17 and 31 made of a magnetic material fixed to the installation surface G, and a vacuum heat insulating structure embedded in an annular shape around the axis of the yoke 17 and 31. The heat insulating refrigerant containers 19 and 33 and the field coil 18 around the axis made of the superconducting wire housed in the heat insulating refrigerant containers 19 and 33 are provided. The field coils 18 and 32 are made of bismuth-based or yttrium-based superconducting wires.

The yokes 17 and 31 have loose fitting holes 17a and 31a bored at the center larger than the outer diameter of the rotary shaft 16, and a groove portion 17b that is recessed in an annular shape from the inner facing surface around the loose fitting holes 17a and 31a. , 31b.
The adiabatic refrigerant containers 19 and 33 accommodate the field coils 18 and 32 in a state where liquid nitrogen is circulated, and the adiabatic refrigerant containers 19 and 33 are embedded in the grooves 17b and 31b of the yokes 17 and 31, respectively. . A first power feeding device 35 that supplies direct current is connected to the field coils 18 and 32. Further, a liquid nitrogen tank 34 storing liquid nitrogen serving as a refrigerant is connected to the heat insulating refrigerant containers 19 and 33.

The pair of rotors 12 and 14 have the same symmetrical structure. As shown in FIG. 8, the rotation angles are shifted from each other by 45 ° (= 180 ° / number of poles (4)) and fixed on the rotary shaft 16. is doing.
As shown in FIGS. 4A to 4D, the rotors 12 and 14 are disc-shaped and made of a non-magnetic material, and have support portions 20 and 28 having center shaft holes 20a and 28a for fixing the rotary shaft 16, respectively. A pair of N pole inductors 21 and 29 (first inductor) embedded in a point-symmetrical position around the central shaft holes 20a and 28a, and a position rotated 90 ° from the N pole inductors 21 and 29 A pair of south pole inductors 22 and 30 (second inductors).

As shown in FIG. 7B, the end faces 21b and 29b of the N-pole inductors 21 and 29 are arcuately arranged opposite to the outer peripheral sides of the field coils 18 and 32, so that the field coil 18 , And 32 N pole generation positions.
As shown in FIG. 7C, the end faces 22b and 30b of the S-pole inductors 22 and 30, and the field coils 18 and 32 are arcuately arranged opposite to the inner peripheral sides of the field coils 18 and 32. , And 32 S pole generation positions.
The other end surfaces 21a, 22a, 29a, 30a of the N-pole inductors 21, 29 and the S-pole inductors 22, 30 are fan-shaped and equidistant on the same circumference facing the armature coils 25, 26 of the stator 13. Is arranged.

The N-pole inductors 21 and 29 and the S-pole inductors 22 and 30 have the other end faces 21a, 22a, 29a, and the other end faces 21a, 22a, 29a, by changing the cross-sectional shape from the arc-shaped one end faces 21b, 22b, 29b, 30b in the axial direction. In 30a, it is set as the three-dimensional shape used as a fan shape.
The cross-sectional areas orthogonal to the axial direction of the N-pole inductors 21 and 29 and the S-pole inductors 22 and 30 are constant from the one end faces 21b and 29b to the other end faces 22a and 30a. Further, the cross-sectional areas perpendicular to the axial direction of the N-pole inductors 21 and 29 and the S-pole inductors 22 and 30 are the same.

The stator 13 includes a support portion 23 made of a non-magnetic material fixed to the installation surface G, and a vacuum heat insulation structure in which four support portions 23 are embedded in the support portion 23 at equal intervals in the circumferential direction. And armature coils 25 and 26 made of a superconducting wire housed in a heat insulating refrigerant container 24.
The support portion 23 has a loose fitting hole 23a drilled in the center larger than the outer diameter of the rotary shaft 16, and four mounting holes 23b drilled at equal intervals in the circumferential direction on the outer peripheral side. I have. Four heat insulating refrigerant containers 24 having an annular shape and a vacuum heat insulating structure are embedded in the mounting holes 23b in a state where the armature coils 25 and 26 are accommodated therein, and the hollow portion of the heat insulating refrigerant container 24 is made of a magnetic material. A magnetic core 27 is disposed. Further, as shown in FIG. 6, the upper and lower armature coils 25 and the left and right armature coils 26 are reversed in the winding direction so that reverse magnetism is alternately excited in the circumferential direction. A second power feeding device 36 that supplies alternating current is connected to the armature coils 25 and 26. In addition, a liquid nitrogen tank 34 that stores liquid nitrogen serving as a refrigerant is connected to the heat insulating refrigerant container 24.

  The yokes 17 and 31, the inductors 21, 22, 29, and 30 and the magnetic core 27 are formed of a magnetic powder powder or a coating film (phosphoric acid) obtained by heat-bonding magnetic powder (iron powder or the like) with an insulating resin. Magnetic powder (iron powder or the like) covered with a compound film or the like) is bonded with an insulating resin and heat-treated to form a powder magnetic body. A resin such as polyphenylene sulfide or soluble polyimide is preferably used as the resin for binding the dust magnetic material. Further, the support parts 20, 23, 28 are made of a nonmagnetic material such as FRP or stainless steel.

Next, the operation principle of the motor 10 will be described.
When direct current is supplied to the field coils 18 and 32, N poles are generated on the outer peripheral side of the field coils 18 and 32 and S poles are generated on the inner peripheral side. Then, for example, as shown in FIGS. 7A and 7B, the magnetic flux on the N pole side is introduced into the N pole inductor 21 from the one end face 21b, and the N pole magnetic flux appears on the other end face 21a. 7A and 7C, the magnetic flux on the S pole side is introduced into the S pole inductor 22 from the one end face 22b, and the S pole magnetic flux appears on the other end face 22a. Here, since the one end surfaces 21b and 22b of the inductors 21 and 22 are arranged on concentric circles along the inner and outer peripheries of the field coil 18, the other of the N-pole inductor 21 even if the rotor 12 rotates. The N pole always appears on the end face 21a, and the S pole always appears on the other end face 22a of the S pole inductor 22. In FIG. 7, one rotor 12 is described, but the same applies to the other rotor 14.

  When power is supplied to the armature coils 25 and 26 from this state, reverse magnetism is excited in the upper and lower armature coils 25 and the left and right armature coils 26 at a certain timing, as shown in FIG. And magnetism is periodically reversed by making the electric current supplied to the armature coils 25 and 26 into an alternating current. Under the influence of the periodic magnetic pole changes of the armature coils 25 and 26, circumferential attracting / repulsive force is generated in the N pole inductors 21 and 29 and the S pole inductors 22 and 30 of the rotors 12 and 14, The rotating shaft 16 is rotationally driven.

  Further, as a characteristic matter of the present invention, the pair of rotors 12 and 14 are fixed with the mounting angle in the rotation direction being shifted from each other by 45 ° with respect to the rotation shaft 16. 30, each of the four magnetic poles formed on the rotor 12 and the rotor 14 causes a phase shift of 45 ° around the axis. Thereby, the weak part of the magnetic pole generated in one rotor 12 is complemented by the strong part of the magnetic pole generated in the other rotor 14. Therefore, as shown in FIG. 9, even if the torque generated by the individual rotors 12 and 14 varies, the torque of the rotating shaft 16 is flattened by shifting the phases of the torques to overlap each other, resulting in a torque ripple. Is prevented from occurring.

FIG. 10 shows a second embodiment.
The difference from the first embodiment is that the rotors 12, 14, the stator 13, and the induction source stator 15 are added in series in the axial direction to be multistaged.

That is, the motor 40 of the present embodiment has a structure in which two motors 10 of the first embodiment are arranged in series in the left half and the right half of FIG. 10, and the central induction source stator 41 has a right half. Shared with the left half. Note that the rotors 12, 14, the stator 13, and the induction source stator 15 have the same structure as that of the first embodiment, and a description thereof will be omitted.
The induction source stator 41 at the center includes a yoke 42 made of a magnetic material fixed to the installation surface G, a heat insulating refrigerant container 43 having a vacuum heat insulating structure embedded in an annular shape around the axis of the yoke 42, and a heat insulating refrigerant container 43. And a field coil 44 around the axis made of a superconducting wire housed in the housing.
The yoke 42 includes a loose fitting hole 42a formed at the center larger than the outer diameter of the rotating shaft 16, and an attachment hole 42b formed in an annular shape around the loose fitting hole 42a. The adiabatic refrigerant container 43 accommodates a field coil 44 in a state where liquid nitrogen is circulated, and the adiabatic refrigerant container 43 is embedded in the mounting hole 42 b of the yoke 42.
If the motor is multistaged as described above, the magnetic field is strengthened compared to the first embodiment, and the output torque can be increased.

11 and 12 show a third embodiment.
The difference from the first embodiment is that no inductor is used.
The motor 50 of the present embodiment has an axial gap structure in which a pair of rotors 52 and 53 are arranged opposite to each other on both sides in the axial direction of the stator 51, and the rotating shaft 54 is fixed at the center of the rotors 52 and 53.

  The stator 51 has a substantially disc shape, and a loose fitting hole 55a is formed at the center of a support portion 55 made of a non-magnetic material such as FRP fixed to a fixing portion G such as a casing, and the outer peripheral side has a circumferential direction and the like. A plurality of mounting holes 55b are provided at intervals. An annular heat insulating refrigerant container 56 having a vacuum heat insulating structure is embedded in the mounting holes 55b, and an armature coil 57 made of a superconducting wire is accommodated in the heat insulating refrigerant container 56. A magnetic core 64 made of a magnetic material is disposed in the hollow portion of the heat insulating refrigerant container 56. As described above, the plurality of armature coils 57 are attached at intervals in the circumferential direction around the axis, and are arranged so that the magnetic flux direction of each armature coil 57 faces the axial direction. The adiabatic refrigerant container 56 is supplied with cryogenic liquid nitrogen as a refrigerant from a liquid hydrogen tank (not shown). The armature coil 57 is supplied with alternating current from a power supply device (not shown).

The pair of rotors 52 and 53 has a substantially disk shape that is symmetrical to the left and right, and is externally fixed to the rotary shaft 54 with a rotation angle shifted by 45 ° from each other, as shown in FIG.
Specifically, the yokes 58 and 61 of the rotors 52 and 53 have center shaft holes 58a and 61a for attaching a rotating shaft at the center, and the surface facing the stator 51 has a circumferential direction and the like. Coil mounting holes 58b and 61b are provided at intervals, and the coil mounting holes 58b and 61b are respectively embedded with annular heat insulating refrigerant containers 59 and 62 having a vacuum heat insulating structure. The field coils 60 and 63 are housed. As described above, the four field coils 60 and 63 are attached at intervals in the circumferential direction around the axis, and the attachment angle of the field coils 60 and 63 is set between the one rotor 52 and the other rotor 53. The rotating shaft 54 is fixed so as to be shifted by 45 ° in the rotating direction.

  With the above configuration, the pair of rotors 52 and 53 are offset from each other by 45 ° in the rotation direction with respect to the rotation shaft 54, so that each of the four rotor coils 52 and 53 formed in the field coils 60 and 63 is provided. This magnetic pole causes a phase shift of 45 ° around the axis. Thereby, the weak part of the magnetic pole generated in one rotor 52 is complemented by the strong part of the magnetic pole generated in the other rotor 53. Therefore, even if the torque generated by the individual rotors 52 and 53 varies, the torque of the rotating shaft 54 is flattened by shifting the phases of the torques and superimposing them, thereby preventing the occurrence of torque ripple.

13 and 14 show a fourth embodiment.
The difference from the first embodiment is that an inductor is not used and a radial gap structure is used.

The motor 70 of the present embodiment is fixed to the center of the substantially cylindrical stator 71, a pair of rotors 72 and 73 disposed with a gap in the stator 71, and the rotors 72 and 73; The stator 71 is provided with a rotating shaft 74 that is rotatable via a bearing 77.
The stator 71 has four armature coils 81 attached to the inner peripheral surface of a yoke 71 made of a substantially cylindrical magnetic body at equal intervals in the circumferential direction.
The rotors 72 and 73 are yokes 78 and 80 made of a columnar magnetic body that are externally fitted and fixed to the rotary shaft 74, and each of the four rotors 72 and 73 that are attached to the outer peripheral surfaces of the yokes 78 and 80 at equal intervals in the circumferential direction. Two field coils 79 and 81 are provided. As shown in FIGS. 14A and 14B, the respective rotors 72 and 73 are fixed to the rotating shaft 74 so that the mounting angles of the field coils 79 and 81 are shifted from each other by 45 ° in the rotational direction. .

  With the above configuration, each of the four magnetic poles formed in the field coils 79 and 81 of the pair of rotors 72 and 73 causes a phase shift of 45 ° around the axis, so that one rotor 72 The weak part of the magnetic pole generated is complemented by the strong part of the magnetic pole generated in the other rotor 73. Therefore, even if the torque generated by the individual rotors 72 and 73 varies, the torque of the rotating shaft 74 is flattened by shifting the phases of the torques and superimposing them, thereby preventing the occurrence of torque ripple.

It is sectional drawing of the motor of 1st Embodiment of this invention. It is sectional drawing in the position rotated 45 degrees of the motor. It is sectional drawing in the position rotated further 45 degrees of the motor. (A) is a front view of the rotor, (B) is a cross-sectional view taken along line II of (A), (C) is a rear view, and (D) is a cross-sectional view taken along the line II-II of (A). (A) is a front view of an induction source stator, (B) is the II sectional view taken on the line of (A). It is a front view of a stator. (A) is a front view of a state where the rotor and the induction source stator are penetrated by the rotation shaft, (B) is a cross-sectional view taken along line II of (A), and (C) is a cross-sectional view taken along line II-II of (A). FIG. It is drawing explaining the attachment angle to a rotating shaft of a pair of rotor. It is drawing explaining generated torque. It is sectional drawing which shows the motor of 2nd Embodiment. It is sectional drawing which shows the motor of 3rd Embodiment. It is drawing explaining the attachment angle of a pair of rotor. It is sectional drawing which shows the motor of 4th Embodiment. (A) is the II sectional view taken on the line of FIG. 13, (B) is the II-II sectional view taken on the line of FIG. It is drawing which shows a prior art example. It is a graph which shows the conventional problem.

Explanation of symbols

10, 40, 50, 70 Motor 11, 15, 41 Induction source stator 12, 14, 52, 53, 72, 73 Rotor 13, 51, 71 Stator 16, 54, 74 Rotary shaft 18, 32, 60, 63, 79, 81 Field coil (superconducting coil)
19, 24, 33, 56, 59, 62 Insulating refrigerant container 21, 29 N-pole inductor (first inductor)
22, 30 S pole inductor (second inductor)
25, 57, 76 Armature coil (superconducting coil)

Claims (6)

A pair of rotors that are externally fitted and fixed to the same rotating shaft, and in which magnetic poles having opposite polarities alternately in the circumferential direction around the axis are formed;
A stator that is arranged opposite to the rotor and in which magnetic poles having opposite polarities alternately in the circumferential direction around the axis are excited,
When the number of poles of the rotor is N, the magnetic pole formed on the one rotor and the magnetic pole formed on the other rotor are out of phase with each other by a rotation angle of 180 ° / N. A motor characterized by having   2. The motor according to claim 1, wherein the pair of rotors are fixed with a rotation angle of 180 ° / N being shifted from each other with respect to the rotation shaft. An induction source stator having excitation means for exciting concentric magnetic poles of opposite polarities on the inner and outer peripheral sides around the axis is disposed on one side of the rotor,
The rotor has a first inductor made of a magnetic material having one end face facing the outer peripheral side of the excitation means and the other end face facing the magnetic pole of the stator, and one end face being an inner peripheral side of the excitation means. 3. The motor according to claim 1, wherein second inductors made of a magnetic body that face each other and whose other end face faces the magnetic pole of the stator are alternately arranged in the circumferential direction.   4. The axial gap structure according to claim 3, wherein the pair of rotors are arranged on both sides of the stator in the axial direction, and the pair of induction source stators are arranged outside the rotor in the axial direction. 5. motor.   5. The motor according to claim 1, wherein the stator is configured to excite the magnetic poles by arranging superconducting coils around which a superconducting wire is wound at equal intervals in the circumferential direction. 6.   The motor according to any one of claims 3 to 5, wherein the excitation means of the induction source stator is a superconducting coil in which a superconducting wire is wound in an annular shape around an axis.

Images