JP2017070011A - Switched reluctance motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an SR motor which has excellent operation efficiency by making a magnetic path shortest while suppressing the increase in the number of components and the complication of a structure.SOLUTION: An SR motor 1 is driven in three phases and includes: a stator 2 equipped with salient poles 6 and coils 9; and a rotor 3 equipped with salient poles 13. The number of stator salient poles 6 and the rotor salient poles 13 are made to have stator : rotor=6n:7n, 9n:8n or 9n:10n (n is an integer of other than 0). The salient poles 6 of the stator 2 form pole pairs 8 by a plurality of salient poles 6 adjacent to each other and each of the pole pairs 8 constitutes one phase out of three phases. A magnetic circuit of one phase formed by the pole pair 8 is formed in the poles 6 which are adjacent to each other in the pole pair 8. The magnetic path of each phase is formed in the pole pair 8, and a length of the magnetic path is greatly shortened in comparison with a conventional SR motor whose magnetic paths are formed between salient poles opposite to each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a switched reluctance motor (hereinafter abbreviated as SR motor), and more particularly to a technique for improving the operation efficiency of a three-phase SR motor.

  In recent years, SR motors that do not use permanent magnets in the rotor have attracted attention against the background of the rising price of rare earths. Since their structure is simple and robust, their use, such as engine starter drive sources, is expanding. For example, Patent Document 1 describes an SR motor used in an air conditioner, an automobile, or the like, and shows a motor having a configuration in which a rotor having four salient poles is arranged in a stator having six salient poles. In the SR motor, as in Patent Document 1, a stator: rotor = 3: 2 and an even number of salient pole configurations are usually employed, and the coils wound around the salient poles of the stator are energized in sequence to stabilize the stator. A rotating magnetic field is formed in the rotor to continuously rotate the rotor.

JP 2002-272071 A JP 2006-246571 A

  However, the SR motor having the salient pole configuration as described above is formed such that the magnetic path of each phase straddles adjacent phases as shown in FIG. That is, for example, the U phase in FIG. 6 forms a magnetic path between opposing salient poles 51U across the salient poles 51V and 51W of the V and W phases (broken line FP in FIG. 6). For this reason, there has been a problem that the magnetic path of each phase becomes long and the operating efficiency of the motor is deteriorated.

  On the other hand, there is also a segment type SR motor (VR type SR motor) configured to have an independent magnetic path for each pole in order to shorten the magnetic path (Patent Document 2). However, since this type of motor has a large number of parts and a complicated structure, there are problems in that the features of the SR motor, which is simple and robust, cannot be fully utilized, and the product cost increases.

  An object of the present invention is to provide an SR motor having a high operating efficiency by minimizing a magnetic path while suppressing an increase in the number of parts and a complicated structure.

  A switched reluctance motor according to the present invention includes a stator including a plurality of salient poles projecting radially inward and coils wound around the salient poles, and a diameter disposed inside the stator. A rotor having a plurality of salient poles projecting outward in the direction, and supplying a three-phase current to the coil to form a rotating magnetic field in the stator. A switched reluctance motor to be rotated, wherein the number of salient poles of the stator and the salient pole of the rotor is stator: rotor = 6n: 7n, 9n: 8n or 9n: 10n (n is an integer other than 0) The salient poles of the stator form a plurality of pole pairs by a plurality of adjacent salient poles, and each pole pair constitutes one of the three phases, and the one-phase magnetic field Circuit is in each pole pair Characterized in that it is formed.

  In the present invention, the number of stator salient poles (stator salient poles) and rotor salient poles (rotor salient poles) in a three-phase energization SR motor is set as follows: stator: rotor = 6n: 7n, 9n: In addition to 8n or 9n: 10n (n is an integer other than 0), a single-phase pole pair is formed by a plurality of stator salient poles, and salient poles of each phase are concentratedly arranged. Moreover, the magnetic path of each phase is formed in the salient pole adjacent in the pole pair. This significantly reduces the magnetic path length of each phase, improves motor efficiency, reduces input current and reduces output compared to conventional SR motors in which each phase magnetic path is formed between opposing salient poles. Improvement is achieved.

  In the SR motor, the salient poles of the stator are arranged such that an interval between the adjacent salient poles in the pole pair is different from an interval between the adjacent salient poles between the adjacent pole pairs. May be.

  Further, the stator may include a plurality of divided stators including the pole pairs and divided for each phase. In the present invention, since the magnetic path of each phase is formed in the pole pair, there is no magnetic loss even if the stator is divided, and winding work is facilitated by using the divided stator structure. In this case, the divided stators may be dispersedly arranged along the circumferential direction with a space provided between the adjacent divided stators.

  Further, the coil having the same phase in the pole pair may be continuously wound around the salient pole, thereby shortening the winding time.

  According to the present invention, in the SR motor driven by three phases, the number of stator salient poles and rotor salient poles is set as follows: stator: rotor = 6n: 7n, 9n: 8n or 9n: 10n (n is an integer other than 0) In addition, a plurality of pole pairs are formed by a plurality of adjacent stator salient poles, and a single-phase magnetic circuit is formed in each pole pair, so that the magnetic path of each phase is formed in the pole pair. It is possible to minimize the magnetic path length. For this reason, compared with the conventional SR motor, the motor efficiency can be improved, and the input current can be reduced and the output can be improved.

It is explanatory drawing which shows the structure of SR motor which is Embodiment 1 of this invention. It is explanatory drawing which shows the modification of SR motor of FIG. It is explanatory drawing which shows the structure of SR motor which is Embodiment 2 of this invention. It is explanatory drawing which shows the structure of SR motor which is Embodiment 3 of this invention. It is explanatory drawing which shows the structure of SR motor which is Embodiment 4 of this invention. It is explanatory drawing which shows the structure of the conventional SR motor.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing the configuration of the SR motor according to the first embodiment of the present invention. The SR motor 1 shown in FIG. 1 is an inner rotor type brushless motor, and includes a stator 2 fixed in a motor case (not shown) and a rotor 3 rotatably arranged inside the stator 2. The stator 2 has a stator core 4 in which a large number of thin electromagnetic steel plates are laminated. The stator core 4 protrudes radially from the yoke portion 5 toward the radially inner side (center direction). And the salient poles 6 formed. Slots 7 are formed between adjacent salient poles 6. In the SR motor 1, nine salient poles 6 are provided along the circumferential direction.

  In the SR motor 1, the salient poles 6 on the stator 2 side form a pole pair 8 that is a set of three each. The SR motor 1 has three-phase energization driving (hereinafter abbreviated as three-phase driving. The same applies to two-phase driving and four-phase driving), and three pole pairs 8 (8U, 8V, 8W) are provided. Yes. Each pole pair 8U, 8V, 8W is equally arranged at intervals of 120 °. The salient poles 6 in the pole pair 8 are equally arranged at intervals of 36 °. An interval of 48 ° is provided between the adjacent pole pairs 8, and the salient poles 6 of the SR motor 1 are arranged at unequal pitches. A coil 9 is wound around the outer periphery of the salient pole 6. The coil 9 is composed of a plurality of phase coils (here, three sets of a U-phase coil 9U, a V-phase coil 9V, and a W-phase coil 9W), and the coils 9 in each pole pair 8 are in phase. In addition to the three-phase drive, for example, the two-phase drive is difficult to perform forward / reverse drive and the function is limited, and the control is complicated and the driver is expensive at four or more phases. Adopted.

  A rotor 3 is inserted inside the stator 2. The rotor 3 includes a rotating shaft 11 and a rotor core 12 fixed to the rotating shaft 11. The rotor core 12 is also formed by laminating a large number of thin electromagnetic steel plates. On the outer periphery of the rotor core 12, salient poles 13 project from the radial direction. The salient poles 13 are equally divided into 10 pieces along the circumferential direction, and are arranged at the same 36 ° intervals as the salient poles 6 in each pole pair 8. The number of salient poles 6 and 13 of the SR motor 1 is stator: rotor = 9: 10, and the salient poles 6 of the stator 2 are odd numbers.

  In the SR motor 1, the rotation angle of the rotor 3 is detected by a resolver (not shown). Each phase coil 9U, 9V, 9W is sequentially excited in accordance with the angular position of the rotor 3. The salient poles 6 around which the excited coils 9 are wound sequentially become magnetic poles, and a three-phase (U phase, V phase, W phase) rotating magnetic field is formed in the stator 2. The salient poles 13 of the rotor 3 are attracted to the magnetized salient poles 6, whereby the rotor 3 rotates inside the stator 2 and the SR motor 1 operates. In this case, the salient poles of the rotor 3 are arranged uniformly and the salient poles of the stator 2 are arranged unevenly, but the angle between adjacent phases is the same as in the case of the uniform arrangement (at intervals of 120 °). Are equal.

  Since the SR motor 1 having such a configuration has a configuration in which the salient poles of each phase are concentratedly arranged, the magnetic path of each phase is between adjacent salient poles 6 in the pole pair 8 as shown in FIG. Formed. That is, each phase magnetic path is completed within the pole pair 8 and the magnetic path length is minimized. Therefore, the magnetic path length can be greatly reduced as compared with the conventional SR motor (FIG. 6) that straddles the salient poles of the other phases and forms a magnetic path between the opposing salient poles. Therefore, as the magnetic path is shortened, the magnetic resistance decreases and the total magnetic flux also increases, so that the motor operating efficiency increases, and the input current is reduced or the output is improved (the output is increased when the same amount of current is used). .

  Moreover, in the SR motor 1 of FIG. 1, the coils 9 of each phase can be formed by continuous windings. In the conventional SR motor as shown in FIG. 6, winding is performed on the salient poles facing each other, so that each of them is wound individually, and further, a bus wiring for connecting them is required. For this reason, each phase coil cannot be wound continuously, and the wiring becomes long and complicated. On the other hand, the SR motor 1 according to the present invention can be continuously wound and does not require a long bus wiring. Therefore, the winding work is made efficient, and the manufacturing cost can be reduced accordingly.

  Further, in the case of the conventional SR motor, for example, in the case of the configuration of FIG. 6, an attractive force is exerted between the salient poles at the time of excitation, and the stator is deformed in that direction (in an elliptical shape). Distorted). This is the same in the SR motor with 12 salient pole stators and 8 salient pole rotors that is twice that in FIG. 6. In this case, the force acts in all directions and the stator is deformed (distorted into a square shape). As a major problem of the SR motor, there is a problem of sound. In that respect, the SR motor 1 according to the present invention has a three-pole configuration and the radial force is distributed in three directions, so that the magnetostriction of the stator is suppressed. For this reason, noise vibration can be reduced as compared with the conventional SR motor, and the noise and vibration of the SR motor can be reduced.

  On the other hand, in the SR motor 1, each phase is independent and the magnetic path of each phase is formed only in the pole pair 8, so the magnetic paths of each phase do not cross each other. For this reason, even if the stator core 4 is divided | segmented into each phase part along the circumferential direction and the stator 2 is formed with the some division | segmentation stator 14 (14U, 14V, 14W), there is no magnetic loss. Moreover, as shown in FIG. 2, even if the divided stator 14 is not fastened, the motor is established. That is, the divided stators 14 may be distributed along the circumferential direction in a state where the space 15 is provided between the adjacent divided stators 14. Of course, it is also possible to divide the stator 2 as it is and to connect them to form a continuous annular stator.

  In the case of such a divided stator structure, winding of each coil 9 is easy and man-hours can be reduced. Further, in the SR motor 1, it is not necessary to fasten the divided stator 14 in an annular shape, and it is possible to adopt a distributed arrangement form as shown in FIG. As a result, there are no problems such as deformation and dimensional error due to the assembly of the divided stator, and the product yield is improved. Further, since the space between the divided stators 14 is a space 15, leakage of magnetic flux in each phase portion is suppressed, and the motor efficiency is further improved.

(Embodiment 2)
FIG. 3 is an explanatory diagram showing the configuration of the SR motor 21 according to the second embodiment of the present invention. In the following embodiment, the same members and parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The SR motor 21 has a configuration in which the stator 22 has 9 salient poles and the rotor 23 has 8 salient poles (stator: rotor = 9: 8). The SR motor 21 is also driven in three phases, and the salient poles 6 on the side of the stator 2 form a pole pair 8 that is a set of three each. Each pole pair 8U, 8V, 8W is equally arranged at intervals of 120 °. The salient poles 6 in the pole pair 8 are equally arranged at 45 ° intervals. An interval of 30 ° is provided between adjacent pole pairs 8. On the other hand, the salient poles 13 of the rotor 23 are equally divided into eight pieces along the circumferential direction, and are arranged at the same 45 ° intervals as the salient poles 6 in each pole pair 8.

  Similarly to the SR motor 1 of the first embodiment, the SR motor 21 is also provided with each phase magnetic path formed in the adjacent salient pole 6 in the pole pair 8 and the magnetic path length is minimized. Efficiency is improved. As described above, the coils 9 of each phase can be continuously wound, and the winding work is also made efficient. Furthermore, since the SR motor 21 also has a three-pole configuration, the radial force is distributed in three directions, and noise vibration can be reduced. In addition, the SR motor 21 can be configured such that each phase portion is formed as a split core and is not fastened as shown in FIG.

(Embodiment 3)
FIG. 4 is an explanatory diagram showing a configuration of the SR motor 31 according to the third embodiment of the present invention. The SR motor 31 has a configuration in which the stator 32 has 6 salient poles and the rotor 33 has 7 salient poles (stator: rotor = 6: 7). The SR motor 31 is also driven in three phases, and the salient poles 6 on the side of the stator 2 form a pole pair 8 that is a set of three each. Each pole pair 8U, 8V, 8W is equally arranged at intervals of 120 °. The salient poles 6 in the pole pair 8 are equally arranged at an interval of 51 ° 25′43 ″ (360 ° / 7). Between adjacent pole pairs 8, 68 ° 34′17 ″ (120 An interval of ° -360 ° / 7) is provided. On the other hand, the salient poles 13 of the rotor 33 are equally divided into seven pieces along the circumferential direction, and are arranged at the same 51 ° 25′43 ″ interval as the salient poles 6 in each pole pair 8.

  Similarly to the SR motor 1 of the first embodiment, the SR motor 31 can have the shortest magnetic path, so that the operating efficiency of the motor can be improved. As described above, the coils 9 of each phase can be continuously wound, and the winding work is also made efficient. Furthermore, since the SR motor 21 also has a three-pole configuration, the radial force is distributed in three directions, and noise vibration can be reduced. In addition, the SR motor 21 can be configured such that each phase portion is formed as a split core and is not fastened as shown in FIG.

(Embodiment 4)
FIG. 5 is an explanatory diagram showing the configuration of the SR motor 41 according to the fourth embodiment of the present invention. The SR motor 41 is obtained by doubling the number of salient poles of the SR motor 1 of the first embodiment, and the stator 42 has 18 salient poles and the rotor 43 has 20 salient poles (stator: rotor = 18:20). The SR motor 41 is also driven in three phases, and the salient poles 6 on the side of the stator 2 form a pole pair 8 that is a set of three each, but here there are two pole pairs for each phase. It is provided one by one. Accordingly, the pole pairs 8U, 8V, 8W are equally arranged at intervals of 60 °, and the in-phase pole pairs 8 are arranged to face each other by 180 ° (8Ua, 8Va, 8Wa; 8Ub, 8Vb). , 8 Wb). The salient poles 6 in the pole pair 8 are equally arranged at intervals of 18 °. An interval of 24 ° is provided between adjacent pole pairs 8. On the other hand, the salient poles 13 of the rotor 43 are equally divided into 20 pieces along the circumferential direction, and are arranged at the same 18 ° intervals as the salient poles 6 in each pole pair 8.

  In the SR motor 41, the inner periphery of the stator 42 has a substantially hexagonal shape. In the pole pairs 8U, 8V, and 8W of each phase, the bottom surface 44 of the slot 7 is a flat surface, and the bottom surface 44 of the adjacent slot 7 is also flush. In the pole pair 8, the salient poles 6 are erected in parallel, and the side surfaces 45 of the salient poles 6 are also arranged in parallel. By forming each pole pair 8 portion in such a shape, the winding of the coil 9 is further facilitated in addition to the advantages of the SR motor 1 of the first embodiment. Therefore, the coil 9 having the same phase can be continuously wound at once by the flyer winding machine, and the space factor of the coil can be increased. In this case, similarly to the case of FIG. 2, it is also possible to divide and fasten the portions of each pole pair 8 of the stator 42 (distributed arrangement as shown in FIG. 2 is also possible). Further simplification is possible.

It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.
For example, in the above-described embodiment, the example in which the number of salient poles is stator: rotor = 9: 10, 9: 8, 6: 7 has been shown. However, as shown in the fourth embodiment, the ratio between the two is described above. It is possible to obtain the same operation and effect even with an integral multiple of.

  The SR motor according to the present invention can be widely applied not only to a drive source of an engine starter but also to electric equipment using a motor as a drive source, such as household appliances such as a vacuum cleaner and a washing machine, and industrial equipment such as an air conditioner. .

DESCRIPTION OF SYMBOLS 1 SR motor 2 Stator 3 Rotor 4 Stator core 5 Yoke part 6 Salient pole 7 Slot 8 Pole pair 8U U phase pole pair 8V V phase pole pair 8W W phase pole pair 9 Coil 9U U phase coil 9V V phase coil 9W W Phase coil 11 Rotating shaft 12 Rotor core 13 Salient pole 14 Split stator 15 Space 21 SR motor 22 Stator 23 Rotor 31 SR motor 32 Stator 33 Rotor 41 SR motor 42 Stator 43 Rotor 44 Bottom surface 45 Side surface 51U, 51V, 51W Salient pole FP Magnetic path

Claims (5)

A stator having a plurality of salient poles projecting radially inward and a coil wound around each of the salient poles, and being arranged inside the stator and projecting radially outward A switched reluctance motor that rotates the rotor by forming a rotating magnetic field in the stator by supplying a three-phase current to the coil. ,
The number of salient poles of the stator and salient poles of the rotor is stator: rotor = 6n: 7n, 9n: 8n or 9n: 10n (n is an integer other than 0),
The salient poles of the stator form a plurality of pole pairs by a plurality of adjacent salient poles,
Each of the pole pairs constitutes one of the three phases, and the one-phase magnetic circuit is formed in each of the pole pairs. The switched reluctance motor according to claim 1,
The switched salient poles of the stator are configured such that an interval between the adjacent salient poles in the pole pair is different from an interval between the adjacent salient poles between the adjacent pole pairs. Reluctance motor. The switched reluctance motor according to claim 1 or 2,
The switched reluctance motor, wherein the stator includes a plurality of divided stators including the pole pairs and divided for each phase. In the switched reluctance motor according to claim 3,
The switched reluctance motor is characterized in that the divided stators are distributed along the circumferential direction with a space provided between the adjacent divided stators. In the switched reluctance motor according to any one of claims 1 to 4,
The switched reluctance motor, wherein the coil having the same phase in the pole pair is continuously wound around the salient pole.

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