JP2010110211A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor that efficiently controls both a strong field and a weak field by having both normal and reverse contradicting salient pole characteristics to have a wide range of operation at high torque and high revolution (high output). <P>SOLUTION: The electric motor includes a stator 12 having a field coil and teeth to wind the coil and a rotor 41 having multiple permanent magnets 13 and rotatably mounted on the stator 12 to rotate around the rotary axis being the center. The permanent magnets 13 are arranged on the periphery of the rotary axis being the center in a way that different magnetic poles are linearly arranged. The electric motor further includes a magnetic flux short-circuit mechanism 43 provided between the peripheral side of the rotor 41 and different magnetic poles of the permanent magnets 13 to change the short-circuit magnetic flux amounts in the rotor 41. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric motor, and more particularly to an electric motor having a rotor having a permanent magnet and a stator having a coil, and capable of selecting two types of structures, a forward salient pole structure and a reverse salient pole structure.

  2. Description of the Related Art Conventionally, a permanent magnet (PM) motor having a cylindrical stator provided with a coil and a rotor disposed inside the stator and embedded with a permanent magnet is known. In the PM motor, the rotor is rotated by the interaction between the rotating magnetic field generated in the coil and the magnetic field generated by the permanent magnet of the rotor by passing current sequentially through the plurality of coils arranged in the stator. . In such a PM motor, the number of rotations is controlled in accordance with the speed at which the coils for passing current are sequentially switched.

  That is, in the PM motor, an induced electromotive force is generated in the stator according to the number of rotations of the rotor due to the rotation of the rotor provided with the permanent magnet. This induced electromotive force is generated from the outside in the stator coil. Generated in a direction to cancel the applied voltage. Therefore, the maximum rotation speed of the PM motor is limited so that the induced voltage is equal to or less than the voltage applied to the coil from the outside.

  For example, in the “motor” (see Patent Document 1), which is a conventional PM motor, the induced voltage can be reduced by forming a path through which the magnetic flux flows in the rotor at high speed and reducing the amount of magnetic flux flowing through the stator. The phase difference between the outer rotor and the inner rotor is controlled so that

  By the way, in the control of a motor, there are known a strong field control capable of obtaining a high torque, and a weak field control capable of reducing the back electromotive force to facilitate the flow of a drive current and enabling high rotation. The structure of the salient pole characteristic is suitable for the structure of the salient pole characteristic and the field weakening control. For this reason, if two types of structures, a forward salient pole structure and a reverse salient pole structure, can be arbitrarily selected, both high torque and high rotation (high output) can be achieved.

JP 2004-072978 A

  However, in the “motor” which is a conventional PM motor, it is not possible to arbitrarily select two types of structures, a forward salient pole structure and a reverse salient pole structure. Therefore, it was impossible to achieve both high torque and high rotation (high output).

  The object of the present invention is to enable both strong field control and field weakening control to be efficiently performed by having the opposite forward salient pole characteristics and reverse salient pole characteristics at the same time. It is to provide an electric motor that can be used.

  In order to achieve the above object, an electric motor according to the present invention includes a stator having a field coil and teeth for winding the coil, and a plurality of permanent magnets. The permanent magnet is arranged so that different magnetic poles are arranged in a straight line on the outer peripheral portion around the rotation axis. This electric motor includes a magnetic flux short-circuit mechanism that is provided between the outer peripheral side of the rotor and between different magnetic poles of the permanent magnet, and changes the amount of short-circuit magnetic flux in the rotor.

  According to the present invention, the magnetic path switching unit provided in the rotor in which a plurality of magnets are arranged switches the magnetic path of the rotor so that the strong field control as the forward salient pole structure or the weak field control as the reverse salient pole structure Is selected. For this reason, it becomes possible to efficiently perform strong field control and weak field control by having both the opposite salient pole characteristics and reverse salient pole characteristics, and a wide range of operation that achieves both high torque and high rotation is possible. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing a stator and a rotor by sectioning a motor according to a first embodiment of the present invention in a radial direction. 1A is a plan view showing a forward salient pole characteristic by a magnetic path switching unit, and FIG. 1B is a plan view showing a reverse salient pole characteristic by a magnetic path switching unit. The rotor which concerns on 2nd Embodiment of this invention is shown, (a) is a top view which shows the forward salient pole characteristic by a magnetic path switching part, (b) shows a reverse salient pole characteristic by a magnetic path switching part FIG. It is a top view of the rotor which concerns on 3rd Embodiment of this invention. 4 shows the configuration of the magnetic element of FIG. 4, (a) is an explanatory diagram when a voltage is applied, and (b) is an explanatory diagram when no voltage is applied. FIG. An example of the phase control mechanism of the electric motor which concerns on this invention is shown, (a) is the schematic explanatory drawing which followed the rotating shaft, (b) is a top view explaining a hydraulic mechanism. The other example of the phase control mechanism of the electric motor which concerns on this invention is shown, (a) is the schematic explanatory drawing cut along the rotating shaft, (b) is a top view explaining a hydraulic mechanism. It is the schematic explanatory drawing sectioned along the rotating shaft which shows an example of the short circuit magnetic flux amount variable mechanism of the electric motor which concerns on 5th Embodiment of this invention. The rotor of the electric motor which concerns on 6th Embodiment of this invention is shown, (a) is 180 degree model cross section explanatory drawing at the time of low rotation, (b) is 180 degree model cross section explanatory drawing at the time of high rotation. The rotor of the electric motor which concerns on 7th Embodiment of this invention is shown, (a) is 180 degree model cross section explanatory drawing at the time of low rotation, (b) is 180 degree model cross section explanatory drawing at the time of high rotation. The rotor of the electric motor which concerns on 8th Embodiment of this invention is shown, (a) is 180 degree model cross section explanatory drawing at the time of low rotation, (b) is 180 degree model cross section explanatory drawing at the time of high rotation. The rotor of the electric motor which concerns on 9th Embodiment of this invention is shown, (a) is 180 degree model cross section explanatory drawing at the time of low rotation, (b) is 180 degree model cross section explanatory drawing at the time of high rotation. The rotor of the electric motor which concerns on 10th Embodiment of this invention is shown, (a) is perspective explanatory drawing at the time of low rotation, (b) is perspective explanatory drawing at the time of high rotation. The rotor of the electric motor which concerns on 11th Embodiment of this invention is shown, (a) is 180 degree model cross section explanatory drawing at the time of low rotation, (b) is 180 degree model cross section explanatory drawing at the time of high rotation. The rotor of the electric motor which concerns on 12th Embodiment of this invention is shown, (a) is perspective explanatory drawing at the time of low rotation, (b) is perspective explanatory drawing at the time of high rotation. It is a 180 degree model cross-section explanatory drawing of the rotor which shows an example of the electric power feeding mechanism in 5th Embodiment. It is sectional drawing in alignment with the rotating shaft which shows an example of the phase control mechanism in 10th Embodiment. An example of the phase control mechanism in 12th Embodiment is shown, (a) is the schematic explanatory drawing sectioned along the rotating shaft, (b) is a top view explaining a hydraulic mechanism.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is an explanatory diagram showing a stator and a rotor by sectioning the electric motor according to the first embodiment of the present invention in the radial direction. As shown in FIG. 1, an electric motor (motor) 10 has a rotor (rotor) 11 and a stator (stator) 12. The rotor 11 has a magnet (permanent magnet) 13, and the stator 12 has a field. Magnet coils 14 are provided. The rotor 11 has a rotating shaft 15 arranged orthogonal to the rotor surface, and the rotating shaft 15 is rotatably held in a case (not shown).

  The stator 12 is formed in a cylindrical shape in which laminated steel plates made of a ferromagnetic material formed in an annular shape are stacked along the central axis direction of the rotary shaft 15. On the inner peripheral side of the stator 12, a plurality of slots 16 for winding a coil 14 that generates a rotating magnetic field are arranged at substantially equal intervals in the inner peripheral direction and project toward the rotating shaft 15. It is installed.

  The rotor 11 rotatably mounted on the stator 12 is a cylinder in which laminated steel plates made of a ferromagnetic material formed in an annular shape are stacked in the direction of the central axis of the rotary shaft 15, as with the stator 12. It is configured in shape. A predetermined number (eight in this example) of magnets 13 are spaced apart at substantially equal intervals along the circumferential direction on the outer peripheral portion of the rotor 11, and two N poles and two S poles are alternately arranged. Arranged and secured. An air gap 17 is provided on the outer side in the arrangement direction of the magnets 13 along the radial direction of the rotor, and the air gap 17 is sandwiched between the adjacent air gaps 17, that is, between the adjacent magnets 13 and 13. A magnetic path switching unit 18 is provided.

  The magnetic path switching unit 18 is made of a member having magnetic anisotropy, and by changing the magnetic anisotropy, the magnetic path of the rotor 11 is switched so that a strong field control or a reverse salient pole structure as a forward salient pole structure. Field weakening control can be selected. That is, the magnetic path switching unit 18 is composed of a member having magnetic anisotropy disposed in a magnetic path connecting between the homopolar magnets 13 of the rotor 11 and the magnetic pole connecting between the different polar magnets 13. The forward salient pole structure and the reverse salient pole structure are switched by changing the anisotropy. The member having magnetic anisotropy can be composed of, for example, an electromagnetic steel plate with a slit in the middle. In addition, when switching a magnetic path, all the magnetic path switching parts 18 operate | move synchronously.

  2 shows the rotor of FIG. 1, (a) is a plan view showing the forward salient pole characteristics by the magnetic path switching unit, and (b) is a plane showing the reverse salient pole characteristics by the magnetic path switching unit. FIG. As shown in FIG. 2A, the rotor 11 has an anisotropic magnetic path switching portion 18 between magnets 13 and 13 having the same polarity (N pole and N pole, S pole and S pole). The magnetic path switching unit 18 between the magnets 13 and 13 having different polarities (N pole and S pole) has anisotropy in the circumferential direction of the rotor. For this reason, the rotor 11 has a forward salient pole structure and exhibits forward salient pole characteristics.

  As shown in FIG. 2B, the rotor 11 has an anisotropic magnetic path switching portion 18 between magnets 13 and 13 having the same polarity (N pole and N pole, S pole and S pole). The magnetic path switching unit 18 between the magnets 13 and 13 having different polarities (N pole and S pole) has anisotropy in the rotor radial direction. For this reason, the rotor 11 has a reverse salient pole structure and exhibits reverse salient pole characteristics.

  In this way, the rotor 11 is provided with the magnetic path switching unit 18, and at the time of low-speed rotation, a strong salient pole control is obtained to obtain a high torque as a forward salient pole structure by switching the magnetic path. The field-weakening control can be performed as a reverse salient-pole structure by switching.

  Therefore, since the electric motor 10 having the rotor 11 has both the opposite salient pole characteristics and the opposite salient pole characteristics, and can efficiently perform the strong field control and the weak field control, a wide range of both high torque and high rotation can be achieved. Enable easy operation. Further, since the magnetic flux is increased by the strong field control of the forward salient pole structure, the amount of magnets can be reduced in the case of the same magnetic flux as that of a general interior magnet type (IPM) motor. Furthermore, the reduction in the amount of magnets leads not only to cost reduction but also to higher rotation at a specified speed, enabling a wider range of operation.

(Second Embodiment)
3A and 3B show a rotor according to a second embodiment of the present invention, in which FIG. 3A is a plan view showing forward salient pole characteristics by a magnetic path switching unit, and FIG. 3B is a reverse collision by a magnetic path switching unit. It is a top view which shows the polar characteristic. As shown in FIG. 3, the rotor 20 uses a magnetic path switching unit 21 that is provided so that the magnetic path can be switched along the rotor plane inside the rotor radial direction of each magnet 13. Is going. Corresponding to the magnetic path switching unit 21, both air gaps 17, 17 arranged in parallel between the magnets 13, 13 having the same polarity are extended to the outer peripheral edge of the magnetic path switching unit 21. Other configurations and operations are the same as those of the rotor 11 of the first embodiment.

The magnetic path switching unit 21 has a shape like a rotor of an SR (Switched Reluctance) motor, for example, and is arranged at four positions that are spaced apart at equal intervals on the outer peripheral portion of the disk-like surface of the magnetic path switching unit 21. In addition, it has a substantially fan-shaped air gap 22 having a part of the outer periphery of the magnetic path switching unit 21.
Therefore, the rotor 20 rotates the magnetic path switching unit 21 so that the phase between the magnets 13 of the same polarity and the phase of the salient pole part of the magnetic path switching unit 21 coincide with each other. )), Or a reverse salient pole characteristic (see (b)) in which the phase between the magnets 13 of different polarities and the phase of the salient pole part of the magnetic path switching unit 21 coincide.

  As described above, the magnetic path switching unit 21 is provided in the rotor 11, and is capable of selectively matching the phase with the phase between the homopolar magnets 13 or the phase between the heteropolar magnets 13 of the rotor 11. It consists of a member having a pole part, and the forward salient pole structure and the reverse salient pole structure are switched by changing the matching target of this member. That is, the rotor 20 functions as a first rotor that mainly obtains magnet torque, and the magnetic path switching unit 21 functions as a second rotor that makes the magnetic path variable. And, by switching between the forward salient pole structure and the reverse salient pole structure by phase control between the rotor 20 and the magnetic path switching unit 21 that makes the magnetic path variable, a wide range of operation compatible with both high torque and high rotation is possible. become.

(Third embodiment)
FIG. 4 is a plan view of a rotor according to the third embodiment of the present invention. As shown in FIG. 4, the rotor 25 has a plurality of magnetic elements 26 arranged between the adjacent air gaps 17, 17, and is arranged in the air gap 27 and the air gap 27 instead of the magnetic path switching unit 21. A plurality of magnetic elements 28 are provided. Other configurations and operations are the same as those of the rotor 20 of the second embodiment.

  FIG. 5 shows the configuration of the magnetic element of FIG. 4, (a) is an explanatory diagram when a voltage is applied, and (b) is an explanatory diagram when no voltage is applied. As shown in FIG. 5, the magnetic element 26 and the magnetic element 28 have the same configuration, and the magnetostrictive element 26a (28a) and the two piezoelectric elements 26b sandwiching the magnetostrictive element 26a (28a) from both sides, 26b (28b, 28b).

  When a voltage is applied to the piezoelectric element 26b (28b), the piezoelectric element 26b (28b) is contracted (see (a)). After that, when the voltage application to the piezoelectric element 26b (28b) is stopped, the piezoelectric element 26b (28b) is stopped. The element 26b (28b) returns to its original state before being contracted, and the magnetostrictive element 26a (28a) sandwiched between the piezoelectric elements 26b and 26b (28b and 28b) is pressed from both sides (see (b)). . That is, since the magnetic permeability changes when a stress is applied to the magnetostrictive element 26a (28a), the magnetic permeability can be changed in the magnetic element 26 (28) depending on whether or not a voltage is applied to the piezoelectric element 26b (28b). Become.

  The air gap 27 is formed in an annular shape whose outer periphery is in contact with both air gaps 17, 17 arranged in parallel between the magnets 13, 13 having the same polarity, and between the air gaps 17, 17 of this air gap 27. Magnetostrictive elements 28 a are arranged at positions corresponding to the arranged magnetic elements 26. That is, each magnetic element 26 (28) is arranged so that the polarity is different between a magnetic path connecting adjacent magnets 13 and 13 having the same polarity and a magnetic path connecting adjacent magnets 13 and 13 having different polarities. Then, the piezoelectric element 26b (28b) is fed with a slip ring, a non-contact rotating transformer or the like, and the forward salient pole structure and the reverse salient pole structure are switched according to the change in polarity at the time of feeding. As a result, a wide range of operation that achieves both high torque and high rotation is possible.

  In this way, the magnetic element 26 is disposed in the magnetic path connecting the homopolar magnets 13 of the rotor 11 and the magnetic path connecting the heteropolar magnets 13, and the piezoelectric element 26b (28b) and the piezoelectric element 26b that change in contraction are arranged. (28b) has a magnetostrictive element 26a (28a) that changes the magnetic permeability corresponding to the change of the piezoelectric element 26b (28b), and functions as a magnetic path switching unit. The magnetostrictive element 26a (28a) can switch the forward salient pole structure and the reverse salient pole structure by changing the magnetic permeability.

(Fourth embodiment)
6A and 6B show an example of a phase control mechanism for an electric motor according to a fourth embodiment of the present invention. FIG. 6A is a schematic explanatory view taken along a rotation axis, and FIG. 6B is a plan view for explaining a hydraulic mechanism. It is. 7A and 7B show another example of the phase control mechanism of the electric motor according to the present invention. FIG. 7A is a schematic explanatory view taken along a rotation axis, and FIG. 7B is a plan view for explaining the hydraulic mechanism.

  The magnetic path switching unit 18 of the rotor 11 (see FIG. 2) and the magnetic path switching unit 21 of the rotor 20 (see FIG. 3) according to the present invention, for example, use the hydraulic pressure used in the engine valve timing adjusting device. This can be realized by using the phase control mechanism used (see JP 2004-245192 A).

  As shown in FIG. 6, in the case of the magnetic path switching unit 18 of the rotor 11 (see FIG. 2) rotatably supported by the shaft 31 in the housing 30, the phase operating unit 32 is provided inside the rotor 11. The hydraulic oil 33 is put into the oil chamber 32a of the phase operating section 32, one of the hydraulic oil 33a of the advance oil chamber and the hydraulic oil 33b of the retard oil chamber is supplied, and the other is discharged. As a result, a phase difference is generated between the rotor 11 and the phase operating unit 32. At this time, accurate position control becomes possible by using a position sensor or the like (not shown). When switching between the forward salient pole characteristics (see FIG. 2A) and the reverse salient pole characteristics (see FIG. 2B), the phase operating part 32 and the magnetic path switching part 18 (members having magnetic anisotropy) ) Are attached to gears 34 and 35, respectively, and both gears 34 and 35 are engaged to switch the magnetic path.

  As shown in FIG. 7, in the case of a magnetic path switching unit (second rotor) 21 of a rotor 20 (see FIG. 3) rotatably supported by a shaft 31 inside the housing 30, the rotor 20 Is provided with a phase operating part 36, and the hydraulic oil 33 is put into the oil chamber 36a of the phase operating part 36, and either one of the hydraulic oil 33a for the advance oil chamber or the hydraulic oil 33b for the retard oil chamber is supplied. And discharge the other. Thereby, a phase difference is generated between the rotor 20 and the phase operating unit 36. At this time, accurate position control becomes possible by using a position sensor or the like (not shown). When switching between the forward salient pole characteristic (see FIG. 3A) and the reverse salient pole characteristic (see FIG. 3B), the phase operating unit 36 and the magnetic path switching unit 21 are connected. .

  The effect obtained by the magnetic path switching unit can be further enhanced by providing, for example, one or more slit-shaped flux barriers in the radial direction of the magnet outer side of the rotor shown in the above embodiments. A mechanism capable of changing the amount of short-circuit magnetic flux in the rotor by providing this slit-shaped flux barrier will be described below.

(Fifth embodiment)
FIG. 8 is a schematic explanatory view taken along a rotation axis showing an example of a short-circuit magnetic flux amount varying mechanism for an electric motor according to a fifth embodiment of the present invention. As shown in FIG. 8, the electric motor 40 has a rotor 41 that is rotatably mounted on the stator 12, and a predetermined number (eight in this example) is provided on the outer periphery of the rotor 41. The magnets 13 are arranged in a rectangular shape with an adjacent gap provided between a pair of N poles and S poles arranged in close contact with each other in a straight line.

  A flux barrier (slit) 42 for reducing leakage magnetic flux is provided along the radial direction of the rotor at both ends and joints of the pair of magnets 13 of N and S poles. An air gap 17 is formed between 42 and 42. A coil 43 is disposed in the flux barrier 42 between the magnets having different polarities (N pole and S pole), which is a joint portion of the magnet 13. Other configurations and operations are the same as those of the rotor 11 and the stator 12 (see FIG. 1) of the first embodiment.

  By supplying power to the coil 43 disposed in the flux barrier 42 between the magnets different poles, for example, by a slip ring, and controlling the amount and direction of current flowing through the coil 43 according to the number of rotations of the rotor 41, the amount of magnetic flux The direction of the magnetic pole can be controlled, and high torque and high output can be realized. Furthermore, if the teeth portion of the coil 43 is formed using a permanent magnet having a low coercive force instead of a magnetic body, it is only necessary to pass a current only when changing the direction of the magnetic pole, leading to an improvement in efficiency.

  Further, if the teeth portion of the coil 43 is a magnetic body, an electric current is allowed to flow only during low rotation to make an electromagnet, thereby increasing the amount of magnetic force and obtaining the effect of the flux barrier 42. As a result, the coil 43 becomes a magnetic material and generates a short-circuit current in the rotor 41. For this reason, high torque and high output can be realized by fixing the direction of the current flowing through the coil 43 and controlling only the amount of current. Similarly, if the teeth portion of the coil 43 is a non-magnetic material, by providing a mechanism that increases the amount of power generation according to the number of revolutions, a flux barrier 42 is provided at low speeds and a short circuit within the rotor 41 at high speeds. An electromagnet that generates magnetic flux can be used to passively widen the speed region.

  That is, the coil 43 functions as a magnetic flux short-circuit mechanism that can change the amount of short-circuit magnetic flux in the rotor 41. Accordingly, the coil 43 disposed in the flux barrier 42 has the stator 12 having the coil 14 and the magnet 13, and the magnets have the same polarity from the magnetic paths between the magnets having different polarities (N pole and S pole) and between the different poles. In the electric motor including the rotor 41 having a smaller magnetic resistance, the magnetic path between the N pole and the N pole, and between the S pole and the S pole is a short circuit magnetic flux in the rotor 41 according to the number of rotations. The amount can be varied.

  By the way, in the conventional PM motor described above, the maximum rotational speed of the motor is limited so that the induced voltage is equal to or lower than the voltage applied to the coil from the outside. In Japanese Unexamined Patent Application Publication No. 2004-242462, high rotation speed is realized by short-circuiting a magnetic path interrupted by a flux barrier using a magnetic flux short-circuit member using centrifugal force. However, in the conventional “magnetic flux amount variable magnet rotor”, the reluctance torque may decrease because the inductance ratio decreases as the flux barrier between the different poles blocking the magnetic path is short-circuited. It was inevitable.

  In addition, in the conventional reverse salient pole type electric motor, in order not to demagnetize the magnet, the flux barrier between different poles is short-circuited instead of the field weakening control in which current flows in the demagnetizing direction, but the reluctance torque is obtained. In order to achieve this, after all, it is necessary to pass a current in the demagnetizing direction, and there is a risk of demagnetization.

  On the other hand, by arranging the coil 43 functioning as a magnetic flux short-circuit mechanism in the flux barrier 42, it becomes possible to change the short-circuit magnetic flux amount in the rotor 41 according to the number of rotations, thereby realizing high rotation. be able to. Thereby, although it is not suitable for high rotation, high rotation can be realized by strong field control having characteristics such that it is difficult to demagnetize and is resistant to heat. As a result, a forward salient pole type motor that generates maximum torque with strong field control has a higher inductance ratio when the magnetic path is short-circuited with a magnetic flux short-circuit mechanism than a reverse salient pole type motor that has maximum torque with weak field control. Since the decrease is small, the reluctance torque can be increased even at high speeds.

(Sixth embodiment)
9A and 9B show a rotor of an electric motor according to a sixth embodiment of the present invention, in which FIG. 9A is an explanatory diagram of a 180-degree model cross section during low rotation, and FIG. 9B is an explanatory diagram of a 180-degree model cross section during high rotation. It is. As shown in FIG. 9, the rotor 45 does not include the coil 43, and the flux barrier between the magnets having different polarities is a member capable of changing the magnetic permeability, for example, a magnetostrictive element between a pair of piezoelectric elements 46 a and 46 a. It is formed by a magnetic element 46 sandwiching 46b. Other configurations and operations are the same as those of the rotor 41 (see FIG. 8) of the fifth embodiment. The configuration and operation of the magnetic element 46 are the same as those of the magnetic element 26 or 28 (see FIG. 5).

  When the rotor 45 is rotated at a low speed, the voltage applied to the piezoelectric element 46a is opened or less than the operating voltage, so that the piezoelectric element 46a presses the magnetostrictive element 46b (see (a)). Acts as a barrier. When the rotor 45 rotates at a high speed, an operating voltage is applied to the piezoelectric element 46a, whereby the piezoelectric element 46a contracts and the compressed magnetostrictive element 46b returns (see (b)). For this reason, the magnetic permeability is increased and a short-circuit magnetic path is formed in the rotor 45, so that the induced voltage is reduced and the speed region is widened.

(Seventh embodiment)
10A and 10B show a rotor of an electric motor according to a seventh embodiment of the present invention, in which FIG. 10A is a 180 ° model cross-sectional explanatory diagram at a low rotation, and FIG. 10B is a 180 ° model cross-sectional explanatory diagram at a high rotation. It is. As shown in FIG. 10, the rotor 50 does not include the coil 43, and a flux barrier between magnets having different polarities is formed by a rotating member 51 with a magnet. The rotating member 51 with a magnet is formed by dividing the disk into two parts and forming one side as an N pole and the other side as an S pole, and is rotatably attached to the rotor 50. Other configurations and operations are the same as those of the rotor 41 (see FIG. 8) of the fifth embodiment.

  When the rotor 50 rotates at low speed, the rotating member 51 with magnet is phase-controlled so that the N pole and S pole of the rotating member 51 with magnet are in the same polarity as the main magnet 13 (see (a)). Thereby, the magnetic flux of the magnet 13 increases and a high torque can be obtained. During the high rotation of the rotor 50, the rotating member 51 with magnet is phase-controlled so that the N pole and the S pole of the rotating member 51 with magnet are different from the main magnet 13, respectively (see (b)). As a result, the magnetic flux of the magnet 13 is short-circuited in the rotor 50, the induced voltage is reduced, and the speed region is widened.

(Eighth embodiment)
11A and 11B show a rotor of an electric motor according to an eighth embodiment of the present invention, in which FIG. 11A is an explanatory diagram of a 180-degree model cross section during low rotation, and FIG. It is. As shown in FIG. 11, the rotor 55 does not include the coil 43, and a flux barrier between magnets having different poles is formed by a magnetic anisotropic rotating member 56. Other configurations and operations are the same as those of the rotor 41 (see FIG. 8) of the fifth embodiment.

  When the rotor 55 is rotated at a low speed, the phase is controlled so that the magnetic anisotropic rotating member 56 becomes a flux barrier (see (a)). When the rotor 55 is rotated at a high speed, the magnetic anisotropic rotating member 56 is rotated by the rotor. The phase is controlled so as to form a short-circuit magnetic path within 55 (see (b)). Thereby, the magnetic flux of the magnet 13 is short-circuited in the rotor 55, the induced voltage is reduced, and the speed region is widened.

(Ninth embodiment)
12A and 12B show a rotor of an electric motor according to a ninth embodiment of the present invention, in which FIG. 12A is an explanatory diagram of a 180-degree model cross section during low rotation, and FIG. 12B is an explanatory diagram of a 180-degree model cross section during high rotation. It is. As shown in FIG. 12, the rotor 60 is slid along the flux barrier 42 instead of the coil 43 to the flux barrier 42 between the magnets different poles, which extends to the rotor surface center side beyond the magnet 13. The magnetic body 61 is mounted so as to be movable. The magnetic body 61 is connected to an urging member 62 such as a coil spring, for example, and is always positioned on the rotor surface center side of the flux barrier 42, that is, on the magnet 13 by the urging force of the urging member 62. ing. Other configurations and operations are the same as those of the rotor 41 (see FIG. 8) of the fifth embodiment.

  Since the centrifugal force is small when the rotor 60 rotates at a low speed, the magnetic body 61 is positioned on the rotor surface center side by the biasing force of the biasing member 62 (see (a)), and the short-circuit magnetic path in the rotor 60 Will not form. However, when the centrifugal force increases during the high rotation of the rotor 60, the magnetic body 61 is positioned on the flux barrier 42 against the urging force of the urging member 62 (see (b)), The short circuit magnetic path is formed. Thereby, an induced voltage is reduced and it leads to the widening of a speed area | region.

(Tenth embodiment)
FIGS. 13A and 13B show a rotor of an electric motor according to a tenth embodiment of the present invention. FIG. 13A is a perspective explanatory view at a low rotation, and FIG. 13B is a perspective explanatory view at a high rotation. As shown in FIG. 13, the rotor 65 is not provided with the coil 43, and a flux barrier between magnets having different poles is accommodated in the gap 66 and the gap 66 provided along the vertical axis in the rotor 65. The magnetic fluid 67 and the nonmagnetic fluid 68 are formed by a partition member 69 that partitions the magnetic fluid 67 and the nonmagnetic fluid 68. Other configurations and operations are the same as those of the rotor 41 (see FIG. 8) of the fifth embodiment.

  When the rotor 65 rotates, the partition member 69 moves in the vertical direction in the gap 66 due to the pressure difference between the magnetic fluid 67 and the nonmagnetic fluid 68. For this reason, when the rotor 65 is rotating at a low speed, the gap 66 is filled with the nonmagnetic fluid by applying pressure from the nonmagnetic fluid side to the magnetic fluid side (see (a)), and the short circuit magnet in the rotor 65 is filled. Does not form a road. On the other hand, by applying pressure from the magnetic fluid side to the non-magnetic fluid side at the time of high rotation, the gap 66 is filled with the magnetic fluid (see (b)), and a short circuit magnetic path in the rotor 65 is formed. , The induced voltage is reduced, leading to a wider speed range.

(Eleventh embodiment)
14A and 14B show a rotor of an electric motor according to an eleventh embodiment of the present invention, in which FIG. 14A is a 180-degree model cross-sectional explanatory view during low rotation, and FIG. 14B is a 180-degree model cross-sectional explanatory view during high rotation. It is. As shown in FIG. 14, the rotor 70 is not provided with the coil 43, and is disposed so as to be rotatable inside the first rotor 71 and the first rotor 71 that are spaced apart from each other with no close contact between the different poles of the magnet 13. The second rotor 73 is disposed in close contact with the magnets 72 of the first rotor 71 so as to correspond to the spaced portions of the magnets 13 of the first rotor 71; A flux barrier 74 is provided between each magnet 13 of the first rotor 71 and each magnet 72 of the second rotor 73. Other configurations and operations are the same as those of the rotor 41 (see FIG. 8) of the fifth embodiment.

  That is, the rotor 70 includes a first rotor 71 that is a main for obtaining magnet torque, and a second rotor 73 that generates a short-circuit magnetic flux in the rotor 70. And the phase control of the second rotor 73 is performed. When the rotor 70 is rotated at a low speed, a short circuit magnetic path in the rotor 70 is not formed (see (a)). At a high speed, the short circuit magnetic path between the magnets of the first rotor 71 is a second rotor. 73 (see (b)), the induced voltage is reduced, leading to a wider speed region.

(Twelfth embodiment)
FIGS. 15A and 15B show a rotor of an electric motor according to a twelfth embodiment of the present invention. FIG. 15A is a perspective explanatory view at a low rotation, and FIG. 15B is a perspective explanatory view at a high rotation. As shown in FIG. 15, the rotor 75 is formed by a first rotor 76 and a second rotor 77 that are divided into two in the vertical axis direction without providing the coil 43, and the first rotor 76 and the second rotor. 77 phase control is performed. Other configurations and operations are the same as those of the rotor 41 (see FIG. 8) of the fifth embodiment.

  When the rotor 75 rotates at a low speed, the magnets 13 of the first rotor 76 and the second rotor 77 have the same polarity (see (a)), so a short-circuit magnetic path in the longitudinal direction in the rotor 75 is formed. Not. On the other hand, when the rotor 75 rotates at a high speed, the magnets 13 of the first rotor 76 and the second rotor 77 have different polarities (see (b)). Is formed, the induced voltage is reduced, and the speed region is widened.

  As described above, the electric motor according to the present invention has a rotor in which a plurality of magnets are arranged, and the magnetic path between the magnet poles is smaller in magnetic resistance than the magnetic path between the magnet poles, A magnetic flux short-circuit mechanism is provided that changes the amount of short-circuit magnetic flux in the rotor according to the number of rotations of the rotor. In addition, the magnetic flux short-circuit mechanism has a configuration in which a coil is disposed in a flux barrier between the magnets different poles, or a configuration in which the flux barrier between the magnets different poles is formed by a member capable of changing permeability, or A configuration in which a flux barrier between magnets having different poles is formed by a rotating member with a magnet, a configuration in which a flux barrier between magnets having different poles is formed by a magnetic anisotropic rotating member, or a flux barrier between magnets having different poles A structure in which a magnetic body connected to an urging member is mounted, or a flux barrier between the magnets having different poles is used as a gap in the rotor, a magnetic fluid and a nonmagnetic fluid in the gap, the magnetic fluid and the nonmagnetic A structure formed by a partition member for partitioning the fluid, or a first rotor for obtaining magnet torque, and a short-circuit magnetic flux in the rotor are generated. Having a plurality of rotors of the second rotor for controlling the phase of the first rotor and the second rotor, or having a plurality of rotors divided in the rotor axial direction And a configuration for performing phase control of the plurality of rotors.

(13th Embodiment)
FIG. 16 is a 180-degree model cross-sectional explanatory diagram of a rotor showing an example of a power feeding mechanism in the fifth and sixth embodiments. As shown in FIG. 16, as a mechanism for supplying power in the fifth embodiment (see FIG. 8) and the sixth embodiment (see FIG. 9), a rotor (as an example, the sixth embodiment (FIG. 9) is used. The coil 80 is provided in the magnetic path between the magnets having the same polarity in the rotor 45 shown in FIG. The coil 80 in the rotor 45 does not generate an induced voltage in the fundamental wave component, but generates an induced voltage by applying a component having a higher order than the primary. When the motor is actually operated, a harmonic component is present, so that an induced voltage is generated without applying a harmonic, and power can be supplied by passing through a diode bridge (not shown).

  As a result, the induced voltage increases when the rotor (41, 45) rotates at a high speed. In the fifth embodiment (see FIG. 8), the current flowing through the coil 80 increases and the magnetic force increases. In the sixth embodiment (see FIG. 9), the piezoelectric element 46a operates by exceeding a threshold voltage.

Magnetic path switching of the seventh embodiment (see FIG. 10), the eighth embodiment (see FIG. 11), the eleventh embodiment (see FIG. 14), and the twelfth embodiment (see FIG. 15) described above. Can be realized, for example, by using a phase control mechanism using hydraulic pressure used in an engine valve timing adjusting device (see the fourth embodiment, FIGS. 6 and 7).
In the seventh embodiment (see FIG. 10) and the eighth embodiment (see FIG. 11), the switching between the low rotation and the high rotation is performed by the phase movable unit 32 and the magnetic path switching unit 18 (having magnetic anisotropy). The gears 34 and 35 are respectively attached to the members and the gears 34 and 35 are engaged with each other (see FIG. 6A). Switching between low rotation and high rotation in the eleventh embodiment (see FIG. 14) is performed by connecting the phase movable unit 32 and a second rotor 73 that switches the magnetic path.

  FIG. 17 is a cross-sectional view along the rotation axis showing an example of the phase control mechanism in the tenth embodiment. As shown in FIG. 17, the rotor 65 in which a plurality of gaps 66 forming the magnetic path switching mechanism of the tenth embodiment (see FIG. 13) is formed can be freely rotated by the shaft 31 in the housing 30 of the electric motor. Each gap 66 communicates with both ends of each gap 66 and is connected to each of the upper and lower flow paths 85a and 85b passing through both ends of the shaft 31. The non-magnetic fluid 68 flows in the upper flow path 85a, and the magnetic fluid 67 flows in the lower flow path 85b.

  18A and 18B show an example of a phase control mechanism according to the twelfth embodiment. FIG. 18A is a schematic explanatory view taken along a rotation axis, and FIG. 18B is a plan view illustrating a hydraulic mechanism. As shown in FIG. 18, the rotor 75 is formed by a first rotor 76 and a second rotor 77 that are divided into two in the vertical axis direction, and phase control of the first rotor 76 and the second rotor 77 is performed. In the case of the twelfth embodiment (see FIG. 15), the phase operating unit 36 is provided inside the rotor 75, and the hydraulic oil 33 is placed in the oil chamber 36 a of the phase operating unit 36, so Either one of 33a and retarding oil chamber hydraulic oil 33b is supplied and the other is discharged. Thereby, a phase difference is generated between the rotor 75 and the phase operating unit 36. At this time, accurate position control becomes possible by using a position sensor or the like (not shown). Switching between low rotation and high rotation in the twelfth embodiment (see FIG. 15) is performed by connecting the phase movable unit 32 and the second rotor 77 that switches the magnetic path.

  As described above, according to the present invention, the magnetic path switching unit provided in the rotor having a plurality of magnets is used to switch the magnetic path of the rotor, so that the strong field control or the reverse salient pole structure as the forward salient pole structure is achieved. Field-weakening control is selected, and by combining the opposite forward and reverse saliency characteristics, it becomes possible to efficiently perform the strong field control and the weak field control, resulting in high torque and high rotation (high output) ) Can be operated over a wide range.

  In the above embodiment, the radial gap type motor having the rotor on the inner side has been described. However, the present invention is not limited to this, and the radial gap type motor having the rotor on the outer side, the axial gap type motor, or the like. But it can be realized. In the above embodiment, the embedded magnet type motor has been described. However, the present invention is not limited to this, and can be realized by a surface magnet type motor. Further, the shape of the stator, the number of poles of the rotor, etc. However, it is not limited to this.

10, 40 Electric motors 11, 20, 25, 41, 45, 50, 55, 60, 65, 70, 75 Rotor 12 Stator 13, 72 Magnet 14 Coil 15 Rotating shaft 16 Slots 17, 22, 27 Air gap 18, 21 Magnetic path switching part 26, 28 Magnetic element 26a, 28a, 46b Magnetostrictive element 26b, 28b, 46a Piezoelectric element 30 Housing 31 Shaft 32, 36 Phase operating part 32a, 36a Oil chamber 33 Hydraulic oil 33a Hydraulic oil for advance oil chamber 33b Hydraulic oil 34, 35 gears 42, 74 Flux barrier 43, 80 Coil 46 Magnetic element 51 Rotating member 56 with magnet Magnetic anisotropic rotating member 61 Magnetic body 62 Energizing member 66 Gap 67 Magnetic fluid 68 Non Magnetic fluid 69 Partition members 71, 76 First rotor 73, 77 Second rotor 85a Upper flow path 85b Lower flow path

Claims (9)

A stator having a field coil and teeth for winding the coil;
A rotor having a plurality of permanent magnets and attached to the stator so as to be rotatable around a rotation axis;
An electric motor having
The permanent magnet is arranged so that different magnetic poles are arranged in a straight line on the outer peripheral portion around the rotation axis,
Provided between the outer peripheral side of the rotor and between different magnetic poles of the permanent magnet, provided with a magnetic flux short-circuit mechanism that changes the amount of short-circuit magnetic flux in the rotor,
An electric motor characterized by that.   The electric motor according to claim 1, wherein the magnetic flux short-circuit mechanism has a configuration in which a coil is disposed in a flux barrier between different magnetic poles of the permanent magnet.   The electric motor according to claim 1, wherein the magnetic flux short-circuit mechanism has a configuration in which a flux barrier between different magnetic poles of the permanent magnet is formed by a member capable of changing a magnetic permeability.   The electric motor according to claim 1, wherein the magnetic flux short-circuit mechanism has a configuration in which a flux barrier between different magnetic poles of the permanent magnet is formed by a rotating member with a magnet.   The electric motor according to claim 1, wherein the magnetic flux short-circuit mechanism has a configuration in which a flux barrier between different magnetic poles of the permanent magnet is formed by a magnetic anisotropic rotating member.   The electric motor according to claim 1, wherein the magnetic flux short-circuit mechanism has a configuration in which a magnetic body connected to an urging member is attached to a flux barrier between different magnetic poles of the permanent magnet.   In the magnetic flux short-circuit mechanism, a flux barrier between different magnetic poles of the permanent magnet is formed by a gap in the rotor, a magnetic fluid and a nonmagnetic fluid in the gap, and a partition member that partitions the magnetic fluid and the nonmagnetic fluid. The electric motor according to claim 1, having the configuration described above. The rotor has a first rotor for obtaining magnet torque, and a second rotor for generating a short-circuit magnetic flux in the rotor,
The electric motor according to claim 1, wherein the magnetic flux short-circuit mechanism has a configuration for performing phase control of the first rotor and the second rotor. The rotor has a plurality of rotors divided in the rotor axial direction,
The electric motor according to claim 1, wherein the magnetic flux short-circuit mechanism has a configuration for performing phase control of the plurality of rotors.

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