JPH08163803A - Permanent magnet synchronous motor - Google Patents
Permanent magnet synchronous motorInfo
- Publication number
- JPH08163803A JPH08163803A JP6330192A JP33019294A JPH08163803A JP H08163803 A JPH08163803 A JP H08163803A JP 6330192 A JP6330192 A JP 6330192A JP 33019294 A JP33019294 A JP 33019294A JP H08163803 A JPH08163803 A JP H08163803A
- Authority
- JP
- Japan
- Prior art keywords
- permanent magnet
- eddy current
- synchronous motor
- magnet synchronous
- stator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Permanent Field Magnets Of Synchronous Machinery (AREA)
- Permanent Magnet Type Synchronous Machine (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、永久磁石を回転界磁
側に持ち、インバータにて可変速駆動される永久磁石同
期電動機に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet synchronous motor having a permanent magnet on the rotating field side and driven at a variable speed by an inverter.
【０００２】[0002]
【従来の技術】永久磁石同期電動機は、略円環状の固定
子鉄心に複数相の固定子巻線を巻回した固定子と、この
固定子の内周面と同心の回転子鉄心の外径側に配置さ
れ、磁極毎にＮ，Ｓ交互に着磁された永久磁石を備えた
回転子とから構成される。永久磁石同期電動機を回転界
磁形とする場合には、界磁極となる永久磁石を磁性体の
界磁鉄心に固定しなければならない。この固定方法とし
て、磁石に穴を開けることは困難なので、ボルトのよう
な締結部品は使用できないため、接着剤を使用すること
が多い。高速機の場合には、回転に伴う遠心力の作用に
より、接着剤のみでは強度に不安があるので、ガラス
線，金属線または永久磁石を含む回転子全体を金属製の
円筒で被い、永久磁石を固定する方法がとられている。
また、高速回転時に永久磁石が遠心力に耐えられずに破
損した場合、永久磁石の飛散を防止し、回転電機の損傷
を最小限に抑えるためにガラス線，金属線などでバイン
ドすることがある。2. Description of the Related Art A permanent magnet synchronous motor is a stator in which a stator winding having a plurality of phases is wound around a substantially annular stator core, and an outer diameter of a rotor core which is concentric with the inner peripheral surface of the stator. And a rotor provided with permanent magnets that are alternately magnetized for each magnetic pole. When the permanent magnet synchronous motor is of the rotating field type, the permanent magnet serving as the field pole must be fixed to the field iron core of the magnetic body. As this fixing method, since it is difficult to make a hole in the magnet, a fastener such as a bolt cannot be used, and therefore an adhesive is often used. In the case of a high-speed machine, the strength of the adhesive alone is uncertain due to the centrifugal force that accompanies the rotation, so the entire rotor including the glass wire, metal wire or permanent magnet should be covered with a metal cylinder. The method of fixing the magnet is taken.
Also, when the permanent magnet is damaged without being able to withstand the centrifugal force during high-speed rotation, it may be bound with glass wire, metal wire, etc. to prevent the permanent magnet from scattering and to minimize damage to the rotating electrical machine. .
【０００３】[0003]
【発明が解決しようとする課題】ガラス線，金属線によ
るバインドは手間がかかり、かつバインド線の端部の処
理が非常に難しい。金属製の円筒による固定では固定子
側からのスロットリップルや電源となるインバータの搬
送波による渦電流が発生し、効率の低下を招く。図４は
従来の永久磁石同期電動機の回転子の円筒における渦電
流路を示す図である。円筒３上における磁極ピッチをＰ
とすれば、渦電流路６は磁極ピッチＰの長さの範囲で形
成される。渦電流を低減させるためにチタン等の高抵抗
材を用いれば、一般に高価でありコストアップを招く。Binding with glass wire or metal wire is troublesome, and it is very difficult to process the end portion of the binding wire. In the case of fixing with a metal cylinder, slot ripples from the stator side and eddy currents due to the carrier wave of the inverter, which is the power supply, are generated, leading to a decrease in efficiency. FIG. 4 is a diagram showing an eddy current path in a cylinder of a rotor of a conventional permanent magnet synchronous motor. The magnetic pole pitch on the cylinder 3 is P
Then, the eddy current path 6 is formed within the range of the magnetic pole pitch P. If a high resistance material such as titanium is used to reduce the eddy current, it is generally expensive and causes an increase in cost.
【０００４】この発明は、インバータにより可変速駆動
される永久磁石同期電動機において、製作が容易でかつ
渦電流損が小さくなるような永久磁石同期電動機を提供
することを目的とする。An object of the present invention is to provide a permanent magnet synchronous motor that is driven at a variable speed by an inverter and is easy to manufacture and has a small eddy current loss.
【０００５】[0005]
【課題を解決するための手段】略円環状の固定子鉄心に
複数相の固定子巻線を巻回した固定子と、この固定子の
内周面と同心の回転子鉄心の外径側に配置され、磁極毎
にＮ，Ｓ交互に着磁された永久磁石を備えた回転子とか
らなり、インバータにより可変速駆動される永久磁石同
期電動機において、前記永久磁石の軸方向長さを等分す
るように、周方向に刻まれた複数のスリットを有し、前
記永久磁石の外径側を被う非磁性金属からなる円筒を設
けることにより、上記目的を達成する。[Means for Solving the Problems] A stator obtained by winding a plurality of phases of stator windings around a substantially annular stator core, and an outer diameter side of a rotor core concentric with the inner peripheral surface of the stator. In a permanent magnet synchronous motor that is arranged and has a rotor provided with permanent magnets that are alternately magnetized for each magnetic pole, and is driven at a variable speed by an inverter, the axial length of the permanent magnets is equally divided. As described above, the above object is achieved by providing a cylinder made of a nonmagnetic metal having a plurality of slits cut in the circumferential direction and covering the outer diameter side of the permanent magnet.
【０００６】また、円筒のスリットの周方向のピッチを
永久磁石の磁極ピッチの偶数倍とすれば、円筒における
渦電流損を低減させる上に好適である。Further, it is preferable to reduce the eddy current loss in the cylinder by setting the circumferential pitch of the cylindrical slit to be an even multiple of the magnetic pole pitch of the permanent magnet.
【０００７】[0007]
【作用】この発明においては、永久磁石の軸方向長さを
等分するように周方向に刻まれたｎ−１本のスリットを
有する非磁性金属からなる円筒により永久磁石の外径側
を被ったので、スリットにより渦電流の軸方向の流路が
ｎ等分に分断され、１つの渦電流路に渦電流を発生させ
る誘導起電力の値は、従来の場合に比べ１／ｎとなる。
また、軸長／磁極ピッチ＝ｋとし、ｎ−１列のスリット
により円筒を軸方向に等分した場合、渦電流を計算する
と、円筒にスリットがない場合に比べ、渦電流損は（ｋ
＋１）／（ｋ＋ｎ）倍となり、ｎが大きいほど渦電流損
を低減させることができる。このためスリットの本数を
増やせば、渦電流損を大幅に低減させることができる。In the present invention, the outer diameter side of the permanent magnet is covered by the cylinder made of non-magnetic metal having n-1 slits circumferentially cut so as to equally divide the axial length of the permanent magnet. Therefore, the flow path in the axial direction of the eddy current is divided into n equal parts by the slit, and the value of the induced electromotive force for generating the eddy current in one eddy current path is 1 / n as compared with the conventional case.
When the cylinder length is equal to the magnetic pole pitch = k and the cylinder is equally divided in the axial direction by the slits in the row n−1, the eddy current loss is calculated as (k
+1) / (k + n) times, and the larger n is, the more the eddy current loss can be reduced. Therefore, if the number of slits is increased, the eddy current loss can be significantly reduced.
【０００８】また、円筒のスリットの周方向のピッチを
磁極ピッチの偶数倍とすれば、スリットの周りを巡る渦
電流は存在せず、渦電流路は周方向に磁極ピッチの長さ
となり、かつ軸方向に分断されるので、渦電流損を大幅
に低減できる。Further, if the circumferential pitch of the cylindrical slit is an even multiple of the magnetic pole pitch, there is no eddy current circulating around the slit, and the eddy current path has the length of the magnetic pole pitch in the circumferential direction, and Since it is divided in the axial direction, eddy current loss can be greatly reduced.
【０００９】[0009]
【実施例】図１はこの発明の実施例による永久磁石同期
電動機の回転子の斜視図である。図１において永久磁石
１を回転子鉄心２に接着させ、永久磁石１の外径側に軸
方向長さを等分するように周方向の複数の平行なスリッ
ト４が刻まれた非磁性のステンレス製の円筒３を取り付
ける。回転子鉄心２は軸５に取り付けられている。図２
は図１の永久磁石同期電動機の円筒における渦電流路を
示す図である。スリット４の周方向のピッチは磁極ピッ
チＰの２倍とし、円筒表面を５等分する位置に４本のス
リット４が刻まれている。渦電流路６はスリット４によ
って分断されている。実際の渦電流は渦電流路６の方向
に分布して流れるが、１つの破線で代表させている。
計算を簡単にするために、磁極ピッチＰと軸長Ｌを同じ
とすると１つの渦電流路の電気抵抗は、図２の場合には
１＋１＋１／５＋１／５となり、図４の場合には１＋１
＋１＋１となるので、図２の場合は図４の場合に対し、
３／５倍となる。１つの渦電流路の誘導起電力は、図２
の場合は図４の場合の１／５となる。従って渦電流の大
きさは １／５÷３／５＝１／３となり、全体の渦電流
損失は ５×（１／３）2 ×３／５＝１／３となる。次
に一般的な場合について計算する。軸長Ｌ／磁極ピッチ
Ｐ＝ｋ、ｎ−１列のスリットにより金属製の円筒３を軸
方向にｎ分割した場合について計算する。 スリットがない場合 １つの渦電流路の電気抵抗＝２＋
２ｋ スリットがある場合 １つの渦電流路の電気抵抗＝２＋
２×ｋ／ｎ その比 （２＋２ｋ）／（２＋２×ｋ／ｎ）＝（ｎ＋
ｋ）／（ｎ＋ｎｋ） 渦電流の比 １／ｎ÷（ｎ＋ｋ）／（ｎ＋ｎｋ）＝（１
＋ｋ）／（ｎ＋ｋ） 渦電流全体の比 ｎ×（１＋ｋ）2 ／（ｎ＋ｋ）2 ×
（ｎ＋ｋ）／（ｎ＋ｎｋ）＝（１＋ｋ）／（ｎ＋ｋ） 従って、ｎを大きくすれば渦電流損失を大幅に低減でき
る。ステンレス製の円筒３に複数のスリット４を刻んだ
ものを接着剤により永久磁石１の外径側に接着するの
で、製作が容易でかつコストダウンできる。1 is a perspective view of a rotor of a permanent magnet synchronous motor according to an embodiment of the present invention. In FIG. 1, a permanent magnet 1 is adhered to a rotor core 2, and a plurality of circumferential parallel slits 4 are engraved on the outer diameter side of the permanent magnet 1 to divide the length in the axial direction into non-magnetic stainless steel. The cylinder 3 made of metal is attached. The rotor core 2 is attached to the shaft 5. Figure 2
FIG. 2 is a diagram showing an eddy current path in a cylinder of the permanent magnet synchronous motor of FIG. 1. The pitch of the slits 4 in the circumferential direction is twice the magnetic pole pitch P, and four slits 4 are carved at positions that divide the cylindrical surface into five equal parts. The eddy current path 6 is divided by the slit 4. The actual eddy current is distributed in the direction of the eddy current path 6 and flows, which is represented by one broken line.
To simplify the calculation, if the magnetic pole pitch P and the axial length L are the same, the electrical resistance of one eddy current path is 1 + 1 + 1/5 + 1/5 in the case of FIG. 2 and 1 + 1 in the case of FIG.
Since + 1 + 1, the case of FIG. 2 is different from the case of FIG.
It becomes 3/5 times. The induced electromotive force of one eddy current path is shown in Fig. 2.
In the case of, it becomes 1/5 of the case of FIG. Therefore, the magnitude of the eddy current is 1/5 ÷ 3/5 = 1/3, and the total eddy current loss is 5 × (1/3) 2 × 3/5 = 1/3. Next, the general case is calculated. Calculation will be made for the case where the metal cylinder 3 is divided into n in the axial direction by slits of n-1 rows, where the axial length L / the magnetic pole pitch P = k. When there is no slit Electric resistance of one eddy current path = 2+
When there is a 2k slit Electric resistance of one eddy current path = 2+
2 × k / n The ratio (2 + 2k) / (2 + 2 × k / n) = (n +
k) / (n + nk) Eddy current ratio 1 / n / (n + k) / (n + nk) = (1
+ K) / (n + k) Ratio of total eddy current n × (1 + k) 2 / (n + k) 2 ×
(N + k) / (n + nk) = (1 + k) / (n + k) Therefore, if n is increased, the eddy current loss can be significantly reduced. Since a cylinder 3 made of stainless steel, in which a plurality of slits 4 are cut, is adhered to the outer diameter side of the permanent magnet 1 with an adhesive, the manufacture is easy and the cost can be reduced.
【００１０】図２はスリット４の周方向のピッチを磁極
ピッチの２倍としているが、スリット４の周方向のピッ
チを磁極ピッチの偶数倍とすれば、スリット４の周りを
巡る渦電流路は存在しないので渦電流路分断による渦電
流損失の低減効果が大きい。図３はスリット４の周方向
のピッチを磁極ピッチと同一とした場合の渦電流路を示
す図である。図３の例はスリット４の本数は図２と同様
であるが、スリット４の周方向のピッチを磁極ピッチと
同じとしたものである。この場合、渦電流路６は破線の
ごとく形成され、渦電流路分断による渦電流損失の低減
効果は図２の場合より少ない。一般的にスリット４の周
方向のピッチを磁極ピッチの奇数倍とすれば、図３のご
とくスリット４の周りを通る渦電流路６が形成されるの
で、スリット４の周方向のピッチを磁極ピッチの偶数倍
とする場合に比べ渦電流低減の効果は少ない。In FIG. 2, the circumferential pitch of the slit 4 is twice the magnetic pole pitch. However, if the circumferential pitch of the slit 4 is an even multiple of the magnetic pole pitch, the eddy current path around the slit 4 will be. Since it does not exist, the effect of reducing eddy current loss due to eddy current path division is great. FIG. 3 is a diagram showing an eddy current path in the case where the circumferential pitch of the slit 4 is the same as the magnetic pole pitch. In the example of FIG. 3, the number of slits 4 is the same as that of FIG. 2, but the circumferential pitch of the slits 4 is the same as the magnetic pole pitch. In this case, the eddy current path 6 is formed as shown by the broken line, and the effect of reducing the eddy current loss due to the eddy current path division is smaller than that in the case of FIG. Generally, if the pitch of the slits 4 in the circumferential direction is made an odd multiple of the magnetic pole pitch, the eddy current path 6 passing around the slits 4 is formed as shown in FIG. The effect of reducing the eddy current is less than that in the case where it is an even multiple.
【００１１】[0011]
【発明の効果】この発明によれば、永久磁石の軸方向長
さを等分するように、周方向に刻まれた複数のスリット
を有する非磁性金属からなる円筒により、永久磁石の外
径側を被ったので、円筒表面における渦電流路は分断さ
れ、渦電流損失を低減させることができる。なお、スリ
ットの周方向のピッチを磁極ピッチの偶数倍とすれば、
スリットを巡る渦電流路が形成されることなく、かつ円
筒表面の渦電流路を分断させるので、渦電流損失を低減
させることができる。また、複数のスリットを刻んだス
テンレス製の円筒を接着剤により永久磁石の外径側に接
着するので、製作が容易でかつコストダウンできる。According to the present invention, the outer diameter side of the permanent magnet is formed by the cylinder made of nonmagnetic metal having a plurality of slits circumferentially cut so as to equally divide the axial length of the permanent magnet. As a result, the eddy current path on the cylindrical surface is divided, and the eddy current loss can be reduced. If the pitch of the slits in the circumferential direction is an even multiple of the magnetic pole pitch,
Since the eddy current path that surrounds the slit is not formed and the eddy current path on the cylindrical surface is divided, the eddy current loss can be reduced. Further, since a stainless steel cylinder having a plurality of slits is adhered to the outer diameter side of the permanent magnet with an adhesive, the production is easy and the cost can be reduced.
【図１】この発明の実施例による永久磁石同期電動機の
回転子の斜視図である。FIG. 1 is a perspective view of a rotor of a permanent magnet synchronous motor according to an embodiment of the present invention.
【図２】図１の永久磁石同期電動機の円筒における渦電
流路を示す図である。FIG. 2 is a diagram showing an eddy current path in a cylinder of the permanent magnet synchronous motor of FIG.
【図３】永久磁石同期電動機の磁極ピッチと等しい周方
向ピッチのスリットを有する円筒における渦電流路を示
す図である。FIG. 3 is a diagram showing an eddy current path in a cylinder having slits with a circumferential pitch equal to the magnetic pole pitch of a permanent magnet synchronous motor.
【図４】従来の永久磁石同期電動機の回転子の円筒にお
ける渦電流路を示す図である。FIG. 4 is a diagram showing an eddy current path in a cylinder of a rotor of a conventional permanent magnet synchronous motor.
１ 永久磁石 ２ 回転子鉄心 ３ 円筒 ４ スリット ５ 軸 ６ 渦電流路 1 Permanent magnet 2 Rotor iron core 3 Cylindrical 4 Slit 5 Axis 6 Eddy current path
Claims (2)
線を巻回した固定子と、この固定子の内周面と同心の回
転子鉄心の外径側に配置され、磁極毎にＮ，Ｓ交互に着
磁された永久磁石を備えた回転子とからなり、インバー
タにより可変速駆動される永久磁石同期電動機におい
て、前記永久磁石の軸方向長さを等分するように、周方
向に刻まれた複数のスリットを有し、前記永久磁石の外
径側を被う非磁性金属からなる円筒を設けたことを特徴
とする永久磁石同期電動機。1. A stator in which a plurality of phases of stator windings are wound around a substantially annular stator core, and a stator magnetic core is disposed on the outer diameter side of a rotor core concentric with the inner peripheral surface of the stator, and magnetic poles In a permanent magnet synchronous motor which is composed of a rotor having permanent magnets magnetized in alternating N and S for each, and is driven at a variable speed by an inverter, the axial length of the permanent magnets is equally divided. A permanent magnet synchronous motor comprising a cylinder made of non-magnetic metal, which has a plurality of slits cut in the circumferential direction and covers the outer diameter side of the permanent magnet.
て、円筒のスリットの周方向のピッチを永久磁石の磁極
ピッチの偶数倍とすることを特徴とする永久磁石同期電
動機。2. The permanent magnet synchronous motor according to claim 1, wherein the circumferential slit pitch of the cylinder is an even multiple of the magnetic pole pitch of the permanent magnet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6330192A JPH08163803A (en) | 1994-12-06 | 1994-12-06 | Permanent magnet synchronous motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6330192A JPH08163803A (en) | 1994-12-06 | 1994-12-06 | Permanent magnet synchronous motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08163803A true JPH08163803A (en) | 1996-06-21 |
Family
ID=18229867
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6330192A Pending JPH08163803A (en) | 1994-12-06 | 1994-12-06 | Permanent magnet synchronous motor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08163803A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100364705B1 (en) * | 2000-05-18 | 2002-12-16 | 엘지전자 주식회사 | Synchronous Stator of Induction motor |
| JP2013115899A (en) * | 2011-11-28 | 2013-06-10 | Mitsubishi Electric Corp | Rotor of permanent magnet type motor, manufacturing method of the same, and permanent magnet type motor |
| CN103166351A (en) * | 2011-12-19 | 2013-06-19 | 罗伯特·博世有限公司 | Rotor for an electric motor |
| EP3179606A1 (en) * | 2015-12-08 | 2017-06-14 | ABB Schweiz AG | A rotor for an electric machine |
| KR20190033823A (en) * | 2017-09-22 | 2019-04-01 | 엘지이노텍 주식회사 | Motor |
| JP2020520219A (en) * | 2017-05-11 | 2020-07-02 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ | Rotors and electromechanical |
-
1994
- 1994-12-06 JP JP6330192A patent/JPH08163803A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100364705B1 (en) * | 2000-05-18 | 2002-12-16 | 엘지전자 주식회사 | Synchronous Stator of Induction motor |
| JP2013115899A (en) * | 2011-11-28 | 2013-06-10 | Mitsubishi Electric Corp | Rotor of permanent magnet type motor, manufacturing method of the same, and permanent magnet type motor |
| CN103166351A (en) * | 2011-12-19 | 2013-06-19 | 罗伯特·博世有限公司 | Rotor for an electric motor |
| EP3179606A1 (en) * | 2015-12-08 | 2017-06-14 | ABB Schweiz AG | A rotor for an electric machine |
| JP2020520219A (en) * | 2017-05-11 | 2020-07-02 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ | Rotors and electromechanical |
| KR20190033823A (en) * | 2017-09-22 | 2019-04-01 | 엘지이노텍 주식회사 | Motor |
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