JP2007181306A

JP2007181306A - Switched reluctance motor

Info

Publication number: JP2007181306A
Application number: JP2005376921A
Authority: JP
Inventors: Nobuisa Shiga; 信勇志賀; Masayoshi Ishida; 昌義石田
Original assignee: JFE Steel Corp
Current assignee: JFE Steel Corp
Priority date: 2005-12-28
Filing date: 2005-12-28
Publication date: 2007-07-12

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly perform suction and separation by switching without braking rotation. <P>SOLUTION: An air gap at the generation of magnetic suction and at the starting of the overlapping of a rotor and a stator is made smaller than an air gap at the separation of the rotor and the stator. More concretely, for example, the radial length of a rotor salient pole is made inconstant all over the width in the rotative direction, the radial direction of the width front side end in the rotative direction is made the longest, the radial length of the width rear side end in the rotative direction is made the shortest, and the air gap 5b at the starting of the overlapping of the salient pole 2b and a comb-teeth part 4b is made smaller than the air gap 5c at the separation. As a result, since the air gap 5b becomes the smallest at the starting (X) of the salient pole 2b and the comb-teeth part 4b that requires a suction force, the salient pole 2b and the comb-teeth part 4b most strongly attract each other, and a remaining magnetic field on and after an opposing time (Y), (Z) when a current is cut is rapidly attenuated due to the expansion of the air gap. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、回転子に突極部を有するスイッチトリラクタンスモータに関するものである。 The present invention relates to a switched reluctance motor having a salient pole portion on a rotor.

スイッチトリラクタンスモータは、回転子、固定子とも、通常、電磁鋼板を積層してつくられ、また磁石を用いないため単純かつ堅牢な構造である。そのため、最近、自動車の駆動用モータを初め注目されつつある。このスイッチトリラクタンスモータは、スイッチング電流により固定子に巻線されて形成された各励磁コイルに選択的に通電することで、固定子の櫛歯部が次々と磁化され、固定子の櫛歯部に回転子の突極部が磁気吸引により引き寄せられる（以下、吸引力と称す）ことによって回転子が回転し回転トルクを発生させる構造となっている。この場合、固定子の櫛歯部が通電により磁化され、回転子の突極部が引き寄せられた後、突極部、櫛歯部が対向する時点では、スイッチの電流が切られ、次の櫛歯部へとスイッチされることとなる。 A switched reluctance motor is usually made by laminating electromagnetic steel plates for both a rotor and a stator, and has a simple and robust structure because no magnet is used. For this reason, attention has recently been focused on motors for driving automobiles. In this switched reluctance motor, the comb teeth of the stator are magnetized one after another by selectively energizing each exciting coil formed by winding the stator with a switching current, and the comb teeth of the stator When the salient pole portion of the rotor is attracted by magnetic attraction (hereinafter referred to as attraction force), the rotor rotates to generate a rotational torque. In this case, after the comb tooth portion of the stator is magnetized by energization and the salient pole portion of the rotor is attracted, the current of the switch is cut off at the time when the salient pole portion and the comb tooth portion face each other. It will be switched to the tooth.

すなわち、突極部が櫛歯部に近づく時点では強い吸引力が必要であるが、対向する時点では、速やかに離れることが必要である。突極部と櫛歯部が対向する時点で吸引力が残留すると、回転にブレーキがかかってしまいスムーズに回転せず好ましくない。 That is, a strong suction force is required when the salient pole portion approaches the comb tooth portion, but it is necessary to quickly leave when the salient pole portion faces each other. If the attraction force remains when the salient pole part and the comb tooth part are opposed to each other, the brake is applied to the rotation and the rotation does not smoothly occur.

上記に対して、従来からは、ブレーキをかけずに推進力のみを発生させ、電流のスイッチングのタイミングを最適化させることで吸引と切り離しを円滑に行い回転させている。しかし、この技術は複雑な制御を必要とする。さらには、電流を切った後も残留磁場が減衰しながら存在するため、対向時あるいはそれ以降も回転にブレーキがかかってしまう。そして、これを避けるために早めに電流をスイッチしているのが現状である。 In contrast to the above, conventionally, only the propulsive force is generated without applying a brake, and the current switching timing is optimized, whereby the suction and the separation are smoothly performed and rotated. However, this technique requires complex control. Furthermore, since the residual magnetic field exists after the current is cut off, the rotation is braked at the time of facing or after. In order to avoid this, the current is switched at an early stage.

一方で、吸引と切り離しを円滑に行うために、回転子および固定子の形状を工夫する技術も開示されている（例えば、特許文献１〜５）。しかしながら、特許文献１〜５を持ってしても吸引と切り離しを円滑に行うには未だ不充分である。
特開2004-236369号公報特開2003-32979号公報特開2002-136073号公報特開2001-268868号公報特開2001-186693号公報 On the other hand, in order to perform suction and separation smoothly, techniques for devising the shapes of the rotor and the stator are also disclosed (for example, Patent Documents 1 to 5). However, even if it has patent documents 1-5, it is still inadequate in order to perform suction and isolation | separation smoothly.
JP 2004-236369 A JP 2003-32979 A Japanese Patent Laid-Open No. 2002-136073 Japanese Patent Laid-Open No. 2001-268868 Japanese Patent Laid-Open No. 2001-186693

本発明は、かかる事情に鑑み、スイッチトリラクタンスモータにおいてブレーキをかけずに推進力のみを発生させるための有利な形状となる回転子と固定子を有するスイッチトリラクタンスモータを提案することを目的とする。 In view of such circumstances, an object of the present invention is to propose a switched reluctance motor having a rotor and a stator having an advantageous shape for generating only propulsive force without applying a brake in the switched reluctance motor. To do.

発明者らは、上記課題を解決するために、回転子突極部と固定子櫛歯部との間の空隙に着目し、詳細に調査、検討を行った。その結果、以下の知見を得、本発明を完成するに至った。
１）従来のスイッチトリラクタンスモータにおいて、回転子突極部と固定子櫛歯部の対向時から離れ際において、回転にブレーキがかかってしまうのは、回転子突極部と固定子櫛歯部の間の空隙が重なり初めから離れ際まで一定であることに起因する。
２）回転子突極部と固定子櫛歯部の磁気吸引と切り離しを円滑に行うためには空隙を一定とはせずに、吸引力を必要とする重なり始めにおける空隙を、切り離しすなわち離れ際における空隙より小さくすることが重要である。
３）さらに、回転子の突極部と前記固定子の櫛歯部の形状を工夫することで、適切な空隙が吸引と切り離し時に得られる。 In order to solve the above-mentioned problems, the inventors paid attention to the gap between the rotor salient pole part and the stator comb tooth part, and investigated and examined in detail. As a result, the following knowledge was obtained and the present invention was completed.
1) In a conventional switched reluctance motor, when the rotor salient pole part and the stator comb tooth part are separated from each other, the brakes are applied to the rotor salient pole part and stator comb tooth part. This is due to the fact that the air gap between them is constant from the beginning to the end of the overlap.
2) In order to smoothly perform magnetic attraction and separation of the rotor salient pole part and the stator comb tooth part, the air gap at the beginning of the overlap where the attraction force is required is kept constant without separating the air gap. It is important to make it smaller than the voids in.
3) Furthermore, by devising the shape of the salient pole part of the rotor and the comb tooth part of the stator, an appropriate gap can be obtained at the time of suction and separation.

本発明は、以上の知見に基づきなされたもので、その要旨は以下のとおりである。
［１］4極あるいはそれ以上の極数をもつ回転子および固定子を有するスイッチトリラクタンスモータにおいて、前記回転子の突極部と前記固定子の櫛歯部との間の空隙については、前記回転子と前記固定子の重なり始めにおける空隙が、前記回転子と前記固定子の離れ際における空隙より小さいことを特徴とするスイッチトリラクタンスモータ。
［２］前記［１］において、前記重なり始めにおける空隙が、前記離れ際における空隙の5/6以下であることを特徴とするスイッチトリラクタンスモータ。
［３］前記［１］または［２］において、回転子突極部の回転方向幅前側1/6部分が固定子櫛歯部と重なった場合の空隙が、回転子突極部の回転方向幅後側1/6部分が固定子櫛歯と重なった場合の空隙の5/6以下であることを特徴とするスイッチトリラクタンスモータ。
［４］前記［１］〜［３］のいずれかにおいて、回転子突極部の径方向長さは、回転方向の幅を通じて一定でないことを特徴とするスイッチトリラクタンスモータ。
［５］前記［１］〜［３］のいずれかにおいて、固定子の櫛歯の径方向長さは、回転方向の幅を通じて一定でないことを特徴とするスイッチトリラクタンスモータ。 The present invention has been made based on the above findings, and the gist thereof is as follows.
[1] In a switched reluctance motor having a rotor and a stator having four or more poles, the gap between the salient pole part of the rotor and the comb tooth part of the stator A switched reluctance motor, wherein a gap at the beginning of overlapping of a rotor and the stator is smaller than a gap at the time of separation of the rotor and the stator.
[2] The switched reluctance motor according to [1], wherein the gap at the beginning of the overlap is 5/6 or less of the gap at the time of separation.
[3] In the above [1] or [2], the gap when the front side 1/6 portion of the rotor salient pole portion overlaps the stator comb tooth portion is the width of the rotor salient pole portion in the rotational direction. Switched reluctance motor characterized in that the rear 1/6 portion is 5/6 or less of the gap when it overlaps the stator comb teeth.
[4] The switched reluctance motor according to any one of [1] to [3], wherein the radial length of the rotor salient pole portion is not constant throughout the width in the rotational direction.
[5] The switched reluctance motor according to any one of [1] to [3], wherein the radial length of the comb teeth of the stator is not constant throughout the width in the rotational direction.

本発明によれば、回転子突極部と固定子櫛歯部が対向する時点で、回転にブレーキがかかることなく、スイッチングによる吸引と切り離しを円滑、スムーズに行うことができる。その結果、高いモータ効率を得ることができる。 According to the present invention, when the rotor salient pole part and the stator comb tooth part face each other, suction and separation by switching can be performed smoothly and smoothly without braking. As a result, high motor efficiency can be obtained.

以下、本発明について詳細に説明する。 Hereinafter, the present invention will be described in detail.

まず、本発明において対象とするスイッチトリラクタンスモータとは、4極あるいはそれ以上の極数をもつ回転子および固定子を有するスイッチトリラクタンスモータである。さらに、回転子の突極部と固定子の櫛歯部との間の空隙については、磁気吸引が発生し回転子と固定子が重なり始める時点での空隙が、回転子と固定子の離れ際における空隙より小さいことを本発明の特徴とする。以下、本発明を完成するに至った経緯について説明する。 First, the switched reluctance motor targeted in the present invention is a switched reluctance motor having a rotor and a stator having four or more poles. Furthermore, with respect to the gap between the salient pole part of the rotor and the comb tooth part of the stator, the gap at the time when magnetic attraction occurs and the rotor and the stator start to overlap each other is separated from the rotor and the stator. It is a feature of the present invention that the gap is smaller than the gap. Hereinafter, the background to the completion of the present invention will be described.

図１は従来のスイッチトリラクタンスモータを示す正面図である。図１中、回転子１の突極部２ａと固定子３の櫛歯部４ａはいずれも、回転方向幅に対して径方向の長さが一定となっている。そのため突極部２ａと櫛歯部４ａの間の空隙５ａも一定であった。ここで、固定子３の櫛歯部４ａの吸引力により回転子１が回転する際に吸引力がモータの推力として使えるのは、突極部２ａと櫛歯部４ａが対向する以前の接近している時点である。逆に、突極部２ａと櫛歯部４ａが完全に対向している時点で吸引力が働くと、その場に居留まろうとする力が働き、ましてや突極部２ａと櫛歯部４ａが離れつつある時点で吸引力が働くと、回転とは逆方向に力が発生し回転にブレーキがかかってしまう。この点を考慮すると、図１に示す従来のスイッチトリラクタンスモータにおいて、対向時あるいはそれ以降も回転にブレーキがかかってしまうのは、回転子１の突極部２ａと固定子３の櫛歯部４ａの間の空隙５ａに変化がないためと考えられる。
そこで、本発明では、突極部と櫛歯部の間の空隙を一定とせずに、突極部と櫛歯部が対向する以前の接近している時点と、逆に完全に対向している時点での空隙を変えることに主眼を置き、研究を進めた。そして、突極部と櫛歯部が対向する以前の接近している時点すなわち磁気吸引が発生し前記回転子と前記固定子が重なり始める時点での空隙を、完全に対向した後すなわち離れ際における空隙より小さくすることで、スイッチングにおける吸引と切り離しが円滑に行えることを見出した。さらに、このように空隙に特徴を持たせるための最も確実で簡便な方法として、回転子の突極部と固定子の櫛歯部の形状、構造を工夫することであると考えた。
図２、図３は本発明の一実施形態を示す図であり、回転子の突極部と固定子の櫛歯部の要部拡大図である。なお、実際には、回転子の突極部と固定子の櫛歯部とが向かい合う、それぞれの端面は円筒状の曲面であるが、説明を簡略化するため、図２、図３および後述の図５、図７、図８、図９においては前記それぞれの端面を平面として表している。図２、図３において、図の矢印方向Ａの向きに回転子が回転する。そして、回転するに従い、回転子の突極部２ｂと固定子の櫛歯部４ｂは接近し重なり初めの状態（ア）から回転子の２ｂと固定子の櫛歯部４ｂが対向する状態（イ）そして回転子の突極部２ｂと固定子の櫛歯部４ｂが離れはじめ離れ際の状態（ウ）へと移っていく。ここで、回転子の突極部２ｂは、（ア）→（イ）→（ウ）となるに従い、図４において定義する、中心から突極部端面までの径方向長さが変化しており、（ア）における回転方向幅前側端の径方向長さが最も長く、（ウ）における回転方向幅後側端の径方向長さが最も短くなっている。そのために、突極部２ｂと櫛歯部４ｂの重なり始めにおける空隙５ｂが、離れ際における空隙５ｃよりも小さくなる構造となっている。図２においては、重なり始めで最も空隙５ｂが小さく、その後、空隙が広がり、離れ際で最も空隙５ｃが広がることになる。図３においては、重なり始めからある段階まで空隙５ｂが一定であり、ある段階において、空隙が広がりはじめ、離れ際で最も空隙５ｃが広がることになる。 FIG. 1 is a front view showing a conventional switched reluctance motor. In FIG. 1, the salient pole part 2 a of the rotor 1 and the comb tooth part 4 a of the stator 3 both have a constant radial length with respect to the rotational direction width. Therefore, the gap 5a between the salient pole part 2a and the comb tooth part 4a is also constant. Here, when the rotor 1 is rotated by the suction force of the comb tooth portion 4a of the stator 3, the suction force can be used as the thrust of the motor because the approaching force before the salient pole portion 2a and the comb tooth portion 4a face each other. Is at that point. On the contrary, if the attractive force is applied when the salient pole part 2a and the comb tooth part 4a are completely opposed to each other, a force to stay in place will act, and the salient pole part 2a and the comb tooth part 4a are separated. If a suction force is applied at a certain point, a force is generated in the opposite direction to the rotation, and the rotation is braked. Considering this point, in the conventional switched reluctance motor shown in FIG. 1, the rotation is braked at the time of facing or after that, the salient pole part 2 a of the rotor 1 and the comb tooth part of the stator 3. This is probably because there is no change in the gap 5a between 4a.
Therefore, in the present invention, the gap between the salient pole part and the comb tooth part is not constant, and the point where the salient pole part and the comb tooth part are approaching each other is completely opposite. Research focused on changing the gap at the time. Then, when the salient pole part and the comb tooth part are approaching each other, that is, when the magnetic attraction occurs and the rotor and the stator start to overlap, the gap is completely opposed, that is, at the time of separation. It has been found that by making it smaller than the gap, suction and separation in switching can be performed smoothly. Furthermore, it was considered that the most reliable and simple method for giving the feature to the gap in this way is to devise the shape and structure of the salient pole part of the rotor and the comb tooth part of the stator.
FIG. 2 and FIG. 3 are views showing an embodiment of the present invention, and are enlarged views of a main part of a salient pole part of a rotor and a comb tooth part of a stator. In practice, the salient pole portions of the rotor and the comb teeth portions of the stator face each other, and each end surface is a cylindrical curved surface. However, in order to simplify the description, FIGS. In FIG. 5, FIG. 7, FIG. 8, and FIG. 9, the respective end faces are shown as planes. 2 and 3, the rotor rotates in the direction of arrow A in the figure. As the rotor rotates, the salient pole portion 2b of the rotor and the comb tooth portion 4b of the stator approach and overlap each other from the initial state (a) to the state in which the rotor 2b and the comb tooth portion 4b of the stator face each other (b). Then, the salient pole part 2b of the rotor and the comb tooth part 4b of the stator begin to separate and move to the state (c) at the time of separation. Here, as the salient pole part 2b of the rotor changes in the order of (a) → (b) → (c), the radial length from the center to the end face of the salient pole part changes in FIG. The radial length of the front end in the rotational direction width in (a) is the longest, and the radial length of the rear end in the rotational direction width in (c) is the shortest. Therefore, the gap 5b at the beginning of overlapping of the salient pole part 2b and the comb tooth part 4b is smaller than the gap 5c at the time of separation. In FIG. 2, the gap 5 b is the smallest at the beginning of overlapping, the gap is then widened, and the gap 5 c is widened most away. In FIG. 3, the gap 5b is constant from the beginning of the overlap to a certain stage, and at a certain stage, the gap starts to widen, and the gap 5c spreads most away.

図２、図３によれば、この空隙の変化により、吸引力を必要とする突極部２ｂと櫛歯部４ｂが重なり始め（ア）では空隙５ｂが最も小さくなっているため、突極部２ｂと櫛歯部４ｂが最も強く引き付け合い、電流が切られる対向時以降（イ）（ウ）における残留磁場は、空隙が広がることにより急激に減衰することになる。これにより電流スイッチングのタイミングを従来よりも少し遅らせても、回転にブレーキがかかることがなくなり、より効果的に円滑に吸引力を得、切り離しを行うことができる。 According to FIGS. 2 and 3, due to the change in the gap, the salient pole portion 2b and the comb tooth portion 4b, which require attraction force, begin to overlap (a). 2b and the comb-tooth portion 4b are attracted most strongly, and the residual magnetic field in (a) and (c) after the facing when the current is cut off is abruptly attenuated due to the expansion of the gap. As a result, even if the current switching timing is delayed a little from the conventional timing, the rotation is not braked, and the suction force can be obtained more effectively and smoothly and separated.

図５は本発明の他の一実施形態を示す図であり、回転子の突極部と固定子の櫛歯部の要部拡大図である。図５において、図の矢印方向Ａの向きに回転子が回転する。そして、図２および図３と同様に、回転するに従い、回転子の突極部２ｃと固定子の櫛歯部４ｃは接近し重なり初めの状態（ア）から回転子の突極部２ｃと固定子の櫛歯部４ｃが対向する状態（イ）そして回転子の突極部２ｃと固定子の櫛歯部４ｃが離れはじめ離れ際の状態（ウ）へと移っていく。ここで、固定子の櫛歯部４ｃは、（ア）→（イ）→（ウ）となるに従い、図６において定義する、外周を真円としたときの外周から櫛歯部端面までの径方向長さが変化しており、重なり初めの（ア）の径方向長さが最も長く、離れ際の（ウ）における径方向長さが最も短くなっている。そのために、突極部２ｃと櫛歯部４ｃの重なり始めにおける空隙５ｄが、離れ際における空隙５ｅよりも小さくなる構造となっている。図５においては、重なり始めで最も空隙５ｄが小さく、その後、空隙が広がり、離れ際で最も空隙５ｅが広がることになる。 FIG. 5 is a view showing another embodiment of the present invention, and is an enlarged view of a main part of a salient pole part of a rotor and a comb tooth part of a stator. In FIG. 5, the rotor rotates in the direction of arrow A in the figure. 2 and 3, as the rotor rotates, the rotor salient pole portion 2c and the stator comb tooth portion 4c approach each other and overlap with the rotor salient pole portion 2c from the initial state (a). The child comb teeth 4c face each other (a), and the rotor salient poles 2c and the stator comb teeth 4c begin to move away and move to the separated state (c). Here, the comb tooth portion 4c of the stator has a diameter from the outer periphery to the end surface of the comb tooth portion when the outer periphery is a perfect circle as defined in FIG. 6 as (a) → (b) → (c). The directional length is changed, the radial length of (a) at the beginning of the overlap is the longest, and the radial length at (c) at the time of separation is the shortest. Therefore, the gap 5d at the beginning of the overlap between the salient pole part 2c and the comb tooth part 4c is smaller than the gap 5e at the time of separation. In FIG. 5, the gap 5d is the smallest at the beginning of the overlap, the gap is then widened, and the gap 5e is widened the far away.

そして、図５によれば、図２、図３同様に、この空隙の変化により、吸引力を必要とする突極部と櫛歯部が重なり始め（ア）では空隙５ｄが最も小さくなっているため、突極部２ｃと櫛歯部４ｃが最も強く引き付け合い、電流が切られる対向時以降（イ）（ウ）における残留磁場は、空隙が広がることにより急激に減衰することになる。これにより電流スイッチングのタイミングを従来よりも少し遅らせても、回転にブレーキがかかることがなくなり、より効果的に円滑に吸引力を得、切り離しを行うことができる。 According to FIG. 5, as in FIGS. 2 and 3, due to the change in the gap, the gap 5 d is the smallest at the point where the salient pole part and the comb tooth part that require suction force start to overlap (a). Therefore, the salient pole part 2c and the comb tooth part 4c are attracted most strongly, and the residual magnetic field in (a) and (c) after the facing when the current is cut off is rapidly attenuated by the expansion of the gap. As a result, even if the current switching timing is delayed a little from the conventional timing, the rotation is not braked, and the suction force can be obtained more effectively and smoothly and separated.

以上により、本発明において、回転子の突極部と固定子の櫛歯部との間の空隙については、回転子と固定子の重なり始めにおける空隙は、回転子と固定子の離れ際における空隙より小さいこととする。そして、重なり始めにおける空隙が、離れ際における空隙より小さくするために、回転子の突極部の径方向長さは、回転方向の幅を通じて一定でないことが好ましく、さらに好ましくは回転方向幅前側端の径方向長さが最も長く、後側端の径方向長さが最も短くなる構造とすることが好ましい。あるいは、固定子の櫛歯部の径方向長さは、回転方向の幅を通じて一定でないことが好ましく、さらに好ましくは重なり初めの径方向長さが最も長く、離れ際における径方向長さが最も短くなる構造とすることが好ましい。 As described above, in the present invention, with respect to the gap between the salient pole part of the rotor and the comb tooth part of the stator, the gap at the beginning of the overlap between the rotor and the stator is the gap when the rotor and the stator are separated. Let it be smaller. In order to make the gap at the beginning of overlap smaller than the gap at the time of separation, the radial length of the salient pole part of the rotor is preferably not constant throughout the width in the rotation direction, more preferably the front end in the rotation direction width It is preferable that the structure has the longest radial direction length and the shortest radial end length of the rear end. Alternatively, the radial length of the comb teeth of the stator is preferably not constant throughout the width in the rotational direction, more preferably the longest radial length at the beginning of overlap and the shortest radial length at the time of separation. It is preferable to have a structure as follows.

さらに、より良いモータ効率を得るために、スイッチングによる吸引と切り離しをより円滑、スムーズに行うことができる構造について調査した。その結果、重なり始めの空隙をａ、離れ際の空隙をｂとすると、ａ≦（5/6）ｂの場合に、スイッチングによる吸引と切り離しがスムーズに行われ、より高いモータ効率を示すことがわかった。よって、本発明において、好ましくは重なり始めにおける空隙が、離れ際における空隙の5/6以下とする。詳細は実施例において後述する。 Furthermore, in order to obtain better motor efficiency, we investigated a structure that can perform suction and separation by switching more smoothly and smoothly. As a result, if the gap at the beginning of overlap is a and the gap at the time of separation is b, when a ≦ (5/6) b, suction and separation by switching are performed smoothly, and higher motor efficiency is exhibited. all right. Therefore, in the present invention, the gap at the beginning of the overlap is preferably 5/6 or less of the gap at the time of separation. Details will be described later in Examples.

また、回転子突極部の回転方向幅前側1/6部分が固定子櫛歯部と重なった場合の空隙をａ₁、回転子突極部の回転方向幅後側1/6部分が固定子櫛歯と重なった場合の空隙をｂ₁とした場合、ａ₁≦（5/6）ｂ₁となり、より高いモータ効率を示ことも確認された。よって、好ましくは回転子突極部の回転方向幅前側1/6部分が固定子櫛歯部と重なった場合の空隙が、回転子突極部の回転方向幅後側1/6部分が固定子櫛歯と重なった場合の空隙の5/6以下とする。なお、この場合の本発明の実施態様を図７〜図９に示す。
図７は、回転子の突極部２ｂの回転方向前側端の径方向長さが最も長く、回転方向後側端の径方向長さが最も短くなっており、重なり始めで最も空隙が小さく、その後、空隙が広がり、離れ際で最も空隙が広がる構造をとっている。そして、回転子突極部２ｂの回転方向幅前側1/6部分が固定子櫛歯部４ｂと重なった場合（エ）における空隙５ｆが、回転子突極部２ｂの回転方向幅後側1/6部分が固定子櫛歯部４ｂと重なった場合（オ）の空隙５ｇの５／６以下となっている場合である。
図８は、回転子の突極部２ｂの回転方向前側端の径方向長さが最も長く、回転方向後側端の径方向長さが最も短くなっており、回転子の突極部が重なり始めからある段階まで空隙が一定であり、ある段階において、空隙が広がりはじめ、離れ際で最も空隙が広がる構造をとっている。そして、回転子突極部２ｂの回転方向幅前側1/6部分が固定子櫛歯部４ｂと重なった場合（エ）における空隙５ｆが、回転子突極部２ｂの回転方向幅後側1/6部分が固定子櫛歯部４ｂと重なった場合（オ）の空隙５ｇの５／６以下となっている場合である。
図９は、回転子の突極部２ｃと固定子の櫛歯部４ｃの重なり初めにおける固定子の径方向長さが最も長く、離れ際における固定子の径方向長さが最も短くなっており、重なり始めで最も空隙５ｈが小さく、その後、空隙が広がり、離れ際で最も空隙５ｉが広がる構造をとっている。そして、回転子突極部２ｃの回転方向幅前側1/6部分が固定子櫛歯部４ｃと重なった場合（エ）における空隙５ｈが、回転子突極部２ｃの回転方向幅後側1/6部分が固定子櫛歯部４ｃと重なった場合（オ）の空隙５ｉの５／６以下となっている場合である。 Further, a 1/6 portion of the rotor salient pole front side in the rotational direction width overlaps with the stator comb tooth portion a ₁ , and a rotor salient pole rear side width of 1/6 portion of the rotor salient pole portion is the stator. When the gap when overlapped with the comb teeth is b ₁ , a ₁ ≦ (5/6) b ₁ , and it was confirmed that higher motor efficiency is exhibited. Therefore, preferably the gap when the front side 1/6 portion of the rotor salient pole portion overlaps the stator comb teeth portion is the gap, and the rotor side pole 1/6 portion of the rotor salient pole portion on the rear side in the rotational direction width is the stator. It should be 5/6 or less of the gap when it overlaps with the comb teeth. An embodiment of the present invention in this case is shown in FIGS.
FIG. 7 shows that the radial length of the front end in the rotational direction of the salient pole part 2b of the rotor is the longest, the radial length of the rear end in the rotational direction is the shortest, and the gap is the smallest at the beginning of overlapping, After that, the gap is widened, and the gap is widened most away. Then, the gap 5f in the case where the front side 1/6 portion of the rotor salient pole portion 2b overlaps with the stator comb tooth portion 4b (D) is the rear side width 1 / of the rotor salient pole portion 2b. This is a case where the 6 portion is 5/6 or less of the gap 5g when the portion 6 overlaps with the stator comb tooth portion 4b.
FIG. 8 shows that the radial length of the front end in the rotation direction of the salient pole portion 2b of the rotor is the longest and the radial length of the rear end in the rotation direction is the shortest, and the salient pole portions of the rotor overlap. The gap is constant from the beginning to a certain stage, and at a certain stage, the gap starts to widen, and the gap is widened most away. Then, the gap 5f in the case where the front side 1/6 portion of the rotor salient pole portion 2b overlaps with the stator comb tooth portion 4b (D) is the rear side width 1 / of the rotor salient pole portion 2b. This is a case where the 6 portion is 5/6 or less of the gap 5g when the portion 6 overlaps with the stator comb tooth portion 4b.
In FIG. 9, the radial length of the stator is the longest at the beginning of the overlap of the salient pole portion 2c of the rotor and the comb tooth portion 4c of the stator, and the radial length of the stator is the shortest when separated. The gap 5h is the smallest at the beginning of the overlap, then the gap is widened, and the gap 5i is widened the farthest away. Then, when the 1/6 portion of the rotor salient pole part 2c on the front side in the rotational direction width overlaps the stator comb tooth part 4c (D), the gap 5h is the rear side 1 / of the rotor salient pole part 2c in the rotational direction width. This is a case where the six portions overlap with the stator comb teeth portion 4c (5) or less of the gap 5i.

上述した本発明の実施態様の一つである図２、３、５、７、８、9に示すスイッチトリラクタンスモータを用いて、図２、３、５、７、８、9における空隙５ｂ、５ｄ、５ｆ、５ｈ、および空隙５ｃ、５ｅ、５ｇ、５ｉの値を変化させ、各々の場合のモータ効率を測定した。実験に用いたスイッチトリラクタンスモータは、回転子が固定子の内側に位置するインナーロータ型とし、回転子の中心から突極部先端までの平均距離を20mm、固定子の外径を80mmとし、回転子突極部と固定子櫛歯部との間の空隙の平均を0.20mmとした。回転子、固定子とも0.5mm厚みの無方向性電磁鋼板を打抜き積層したものであり、ともに軸方向長さを50mmとした。モータ効率は、スイッチトリラクタンスモータを回転させながら、これに直結させた負荷モータにより、負荷を与えて測定した。回転数、トルクを測定し出力値を求め、これとパワーメータで測定した入力電力との比によりモータ効率を求めた。本実施例では、回転数3000rpm、トルク0.5Nmにおける効率を測定した。なお、空隙５ｂ、５ｄ、５ｆ、５ｈの値をａ、空隙５ｃ、５ｅ、５ｇ、５ｉの値をｂとし、上記モータ効率はａ＝ｂにおけるモータ効率との比として整理した。得られた結果を図１０に示す。 Using the switched reluctance motor shown in FIGS. 2, 3, 5, 7, 8 and 9, which is one of the embodiments of the present invention described above, the gap 5 b in FIGS. 2, 3, 5, 7, 8 and 9, The values of 5d, 5f, and 5h and the gaps 5c, 5e, 5g, and 5i were changed, and the motor efficiency in each case was measured. The switched reluctance motor used in the experiment is an inner rotor type in which the rotor is located inside the stator, the average distance from the center of the rotor to the tip of the salient pole is 20 mm, and the outer diameter of the stator is 80 mm. The average gap between the rotor salient poles and the stator comb teeth was 0.20 mm. Both the rotor and stator were made by punching and laminating non-oriented electrical steel sheets with a thickness of 0.5 mm, and the axial length was 50 mm. The motor efficiency was measured by applying a load with a load motor directly connected to the switched reluctance motor while rotating it. The rotational speed and torque were measured to determine the output value, and the motor efficiency was determined from the ratio of this to the input power measured with the power meter. In this example, the efficiency was measured at a rotational speed of 3000 rpm and a torque of 0.5 Nm. The values of the gaps 5b, 5d, 5f, and 5h are a, the values of the gaps 5c, 5e, 5g, and 5i are b, and the motor efficiency is arranged as a ratio with the motor efficiency at a = b. The obtained result is shown in FIG.

図１０より、ａ＜ｂの場合において、モータ効率が上がり、吸引と引き離しがスムーズに行われていることがわかる。さらに、この傾向はａ≦（5/6）ｂにおいて顕著である。一方、ｂ＜ａにおいては、空隙が一定である通常のスイッチトリラクタンスモータよりも効率は悪くなっていることがわかる。 FIG. 10 shows that in the case of a <b, the motor efficiency is increased, and the suction and separation are performed smoothly. Furthermore, this tendency is remarkable when a ≦ (5/6) b. On the other hand, when b <a, the efficiency is worse than that of a normal switched reluctance motor having a constant gap.

本発明のスイッチトリラクタンスモータはブレーキがかかることなく回転しトルクを発生させるため、エネルギー効率が高く、圧縮機、自動車の駆動用モータ等、幅広い用途での使用が期待される。 Since the switched reluctance motor of the present invention rotates and generates torque without being braked, it has high energy efficiency and is expected to be used in a wide range of applications such as compressors and automobile drive motors.

従来のスイッチトリラクタンスモータを示す正面図である。It is a front view which shows the conventional switched reluctance motor. 本発明の一実施形態を示す図であり、回転子の突極部と固定子の櫛歯部の要部拡大図である。It is a figure which shows one Embodiment of this invention, and is the principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. 本発明の一実施形態を示す図であり、回転子の突極部と固定子の櫛歯部の要部拡大図である。It is a figure which shows one Embodiment of this invention, and is the principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. 回転子における径方向長さ示す図である。It is a figure which shows the radial direction length in a rotor. 本発明の他の一実施形態を示す図であり、回転子の突極部と固定子の櫛歯部の要部拡大図である。It is a figure which shows other one Embodiment of this invention, and is a principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. 固定子における径方向長さ示す図である。It is a figure which shows the radial direction length in a stator. 本発明の他の一実施形態を示す図であり、回転子の突極部と固定子の櫛歯部の要部拡大図である。It is a figure which shows other one Embodiment of this invention, and is a principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. 本発明の他の一実施形態を示す図であり、回転子の突極部と固定子の櫛歯部の要部拡大図である。It is a figure which shows other one Embodiment of this invention, and is a principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. 本発明の他の一実施形態を示す図であり、回転子の突極部と固定子の櫛歯部の要部拡大図である。It is a figure which shows other one Embodiment of this invention, and is a principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. ａ／ｂとモータ効率（ａ＝ｂにおけるモータ効率との比）との関係を示す図である。（実施例１）It is a figure which shows the relationship between a / b and motor efficiency (ratio with the motor efficiency in a = b). Example 1

Explanation of symbols

１回転子
２ａ、２ｂ、２ｃ突極部
３固定子
４ａ、４ｂ、４c 櫛歯部
５ａ、５ｂ、５ｃ、５ｄ、５ｅ、５ｆ、５ｇ、５ｈ、５ｉ空隙
Ａ回転方向 DESCRIPTION OF SYMBOLS 1 Rotor 2a, 2b, 2c Salient pole part 3 Stator 4a, 4b, 4c Comb tooth part 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i Air gap A Rotation direction

Claims

In a switched reluctance motor having a rotor and a stator having four or more poles, the gap between the salient pole part of the rotor and the comb tooth part of the stator A switched reluctance motor characterized in that a gap at the beginning of overlapping of the stator is smaller than a gap at the time of separation between the rotor and the stator.

2. The switched reluctance motor according to claim 1, wherein a gap at the beginning of the overlap is 5/6 or less of the gap at the time of separation.

When the 1/6 part of the rotor salient pole front side of the rotation direction width 1/6 overlaps with the stator comb teeth, the gap 1/6 part of the rotor salient pole part of the rotation direction width rear side overlaps the stator comb teeth. The switched reluctance motor according to claim 1 or 2, wherein the gap is 5/6 or less.

The switched reluctance motor according to any one of claims 1 to 3, wherein the radial length of the rotor salient pole portion is not constant throughout the width in the rotational direction.

The switched reluctance motor according to any one of claims 1 to 3, wherein the radial length of the stator comb teeth is not constant throughout the width in the rotational direction.