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JPS63310358A - Rotary position detecting method for rotor - Google Patents

Rotary position detecting method for rotor

Info

Publication number
JPS63310358A
JPS63310358A JP14397787A JP14397787A JPS63310358A JP S63310358 A JPS63310358 A JP S63310358A JP 14397787 A JP14397787 A JP 14397787A JP 14397787 A JP14397787 A JP 14397787A JP S63310358 A JPS63310358 A JP S63310358A
Authority
JP
Japan
Prior art keywords
magnet
hole
rotor yoke
rotor
magnetic
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
Application number
JP14397787A
Other languages
Japanese (ja)
Inventor
Kazutoshi Ishibashi
和敏 石橋
Kuniyuki Maruyama
丸山 邦行
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Asahi Kasei Electronics Co Ltd
Asahi Chemical Industry Co Ltd
Original Assignee
Asahi Kasei Electronics Co Ltd
Asahi Chemical Industry Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Asahi Kasei Electronics Co Ltd, Asahi Chemical Industry Co Ltd filed Critical Asahi Kasei Electronics Co Ltd
Priority to JP14397787A priority Critical patent/JPS63310358A/en
Publication of JPS63310358A publication Critical patent/JPS63310358A/en
Pending legal-status Critical Current

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  • Transmission And Conversion Of Sensor Element Output (AREA)
  • Brushless Motors (AREA)

Abstract

PURPOSE:To facilitate index without detection without requiring special machining, by making a hole through the side wall of a rotor yoke and detecting flux of a magnet for rotating a motor. CONSTITUTION:A hole 11b is made through the outer wall 11a of a rotor yoke 11. The hole 11b is aligned with a magnet 12. When a magnetic sensor 18 is arranged close to the hole 11b, flux of the magnet 12 leaked through the hole 11b can be detected sufficiently. The rotor yoke 11 absorbs the flux of the magnet 12 and decreases magnetic resistance of magnetic circuit, and when the hole 11b is made, flux of the permanent magnet 12 arranged at the position of the hole 11b is not completely absorbed by the rotor yoke 11 but leaks partially to the outside of the yoke 11. A magnetic focusing member 18A may be provided for the magnetic sensor 18 in order to improve detection sensitivity.

Description

【発明の詳細な説明】[Detailed description of the invention]

[産業上の利用分野] 本発明は磁石回転形のモータのロータの回転位置(以後
インデックスと言う)を検出する方法に関するものであ
る。
[Industrial Application Field] The present invention relates to a method for detecting the rotational position (hereinafter referred to as index) of a rotor of a magnet-rotating motor.

【従来の技術】[Conventional technology]

フロッピーディスクドライブなど各種のモータにおいて
、ロータの位置の検出が行われている。 従来ロータヨークに磁石が係持されている磁石回転形モ
ータのインデックス検出方法としては、第2図に示すよ
うに磁石1を取付けたロータヨーク2の外周に希土類磁
石3を張り付け、その磁石の発生する磁束をホール素子
、ホールIC,磁気抵抗効果素子等の磁気センサ4によ
って検出してインデックス検出を行う方法が知られてい
る。この方法では、インデックス検出用磁石3の取付け
を必要とし、価格の増大を招き、またロータヨークの外
周に検出用磁石を設けるので磁気センサ4の設置のため
に余分の空間が必要で、モータ全体を大型化する欠点が
ある。 第3図は従来のインデックス検出方法の他の例を示す図
で、同図(A)はロータヨークと磁石の部分断面図、同
図(B)はその斜視図である。この従来例においてはロ
ータヨーク2には切り欠き部2^が設けられ、マグネッ
ト1の一部l^がこの切り欠き部2Aからロータヨーク
の外側に突出している。 そしてマグネットの突出部IAによる磁束をコイル、磁
気センサなとで検出してインデックス検出を行う。この
方法では磁石lの加工が必要であり、また磁石1の一部
をロータヨーク2の外側に突出させているので第2図の
従来例と同様にモータの大形化を招く欠点がある。 [発明が解決しようとする問題点] 本発明は上述した従来の方法の欠点である価格増、およ
びモータの大形化を解消し、低価格でかつインデックス
検出のための余分な空間を必要としないインデックス検
出方法を提供することを目的とする。
Detection of the rotor position is performed in various motors such as floppy disk drives. Conventionally, as an index detection method for a magnet rotary motor in which a magnet is attached to a rotor yoke, a rare earth magnet 3 is attached to the outer periphery of a rotor yoke 2 to which a magnet 1 is attached, as shown in Fig. 2, and the magnetic flux generated by the magnet is detected. A method is known in which index detection is performed by detecting the index using a magnetic sensor 4 such as a Hall element, Hall IC, or magnetoresistive element. This method requires the installation of the index detection magnet 3, which increases the cost.Also, since the detection magnet is provided on the outer periphery of the rotor yoke, extra space is required for the installation of the magnetic sensor 4, which reduces the overall motor efficiency. It has the disadvantage of being large. FIG. 3 is a diagram showing another example of the conventional index detection method, in which (A) is a partial sectional view of a rotor yoke and a magnet, and (B) is a perspective view thereof. In this conventional example, the rotor yoke 2 is provided with a notch 2^, and a portion l^ of the magnet 1 protrudes from the notch 2A to the outside of the rotor yoke. Then, index detection is performed by detecting the magnetic flux due to the protruding portion IA of the magnet using a coil, a magnetic sensor, or the like. This method requires machining of the magnet 1, and since a part of the magnet 1 is made to protrude outside the rotor yoke 2, it has the drawback of increasing the size of the motor, similar to the conventional example shown in FIG. [Problems to be Solved by the Invention] The present invention eliminates the disadvantages of the conventional method described above, such as increased cost and increased size of the motor, and provides a method that is low cost and does not require extra space for index detection. The purpose is to provide an index detection method that does not require

【問題点を解決するための手段】[Means to solve the problem]

このような目的を達成するために、複数の永久磁石が取
付けられているロータヨークに、複数の永久磁石のうち
の1個と中心軸が一致する孔を設け、孔より漏洩する磁
束を検出することにより、ロータの回転位置を検出する
ことを特徴とする。 [作 用J 本発明によれば、ロータヨークの側壁に孔を開け、モー
タを回転させるための磁石の磁束を検出してインデック
ス検出を行うのでインデックス検出用の特別の磁石を必
要とせず、また磁石に特別の加工を要せず、さらにイン
デックス検出のための空間を小さくし、モータを小型化
することができる。 [実施例] 以下に図面を参照して本発明の詳細な説明する1゜ 第1図は本発明のインデックス検出方法を適用したモー
タの概要を示す断面図である。ロータヨーク11には複
数個2例えば8個、の永久磁石12が磁化の方向をヨー
クの半径方向に向けてヨーク11の側壁11^に取付け
られている。ロータヨーク11の中心には軸13が固定
されている。ステータ14には軸受15が設けられ、軸
13を回転自由に支えている。ステータ14には磁石1
2と対向して、例えば6個のコイル16が固定され、コ
イル16に流す電流を制御してロータヨーク、従って軸
13を回転させる。17は軸13を支える鋼球、 18
は磁気センサで18^は磁気収束用の磁性体、18Bは
ホール素子。 磁気抵抗素子などのセンサである。 第1図に示した実施例の特徴はロータヨークの外壁ti
^の11所に孔11Bが設けられている点である。孔1
1Bは磁石12と中心が一致するようにするとよい、磁
気センサ18を孔11Bに接近させて設置すると、孔1
1Bから洩れる磁石12の磁束を十分に検出することが
できる。ロータヨーク11は各磁石12の磁束を吸収し
て、磁気回路の磁気抵抗を減少させるものであるが、孔
11Bを設けると、この孔の位置に設置された永久磁石
の磁束はロータヨークに全ては吸収されず、その一部は
ヨーク外に洩れだす、磁束の洩れ量はヨークの側壁!1
Aの厚さ、孔11Bの大きさなどに影響されるが、例え
ばヨーク側壁の厚さ1 ms、孔11Bの直径を41程
度にすれば、通常の磁気センサをロータヨーク側壁から
1〜2■鵬の距離に設ければ、十分に洩れ磁束を検知し
、ロータの位置を検出することができる。 なお、以上の実施例では、周対向形のモータを例として
説明したが、本発明を磁石がロータ側に設けられている
面対向形モータに適用し得ることは言うまでもない、第
1図に示すように、磁気センサに磁気収束用磁性体18
Aを設け、検出感度を向上させることができる。 [発明の効果] 以上説明したように、本発明によれば、ロータヨークの
側壁に孔を開け、モータを回転させるための磁石の磁束
を検出してインデックス検出を行うのでインデックス検
出用の特別の磁石を必要とせず、また磁石に特別の加工
を要せず、さらにインデックス検出のための空間を小さ
くし、モータを小型化することができる。
To achieve this purpose, a hole whose central axis coincides with one of the permanent magnets is provided in the rotor yoke to which a plurality of permanent magnets are attached, and magnetic flux leaking from the hole is detected. It is characterized by detecting the rotational position of the rotor. [Function J] According to the present invention, the index is detected by making a hole in the side wall of the rotor yoke and detecting the magnetic flux of the magnet for rotating the motor, so there is no need for a special magnet for index detection. No special machining is required, and the space for index detection can be reduced, making it possible to downsize the motor. [Embodiments] The present invention will be described in detail below with reference to the drawings. Fig. 1 is a cross-sectional view schematically showing a motor to which the index detection method of the present invention is applied. A plurality of permanent magnets 12, for example eight, are attached to the side wall 11^ of the rotor yoke 11 with the direction of magnetization oriented in the radial direction of the yoke. A shaft 13 is fixed to the center of the rotor yoke 11. A bearing 15 is provided on the stator 14 and supports the shaft 13 in a freely rotatable manner. The stator 14 has a magnet 1
For example, six coils 16 are fixed opposite to the rotor yoke 2, and the rotor yoke, and therefore the shaft 13, is rotated by controlling the current flowing through the coils 16. 17 is a steel ball that supports the shaft 13; 18
is a magnetic sensor, 18^ is a magnetic material for magnetic convergence, and 18B is a Hall element. This is a sensor such as a magnetoresistive element. The feature of the embodiment shown in FIG. 1 is that the outer wall of the rotor yoke
The point is that holes 11B are provided at 11 locations. Hole 1
It is preferable that the center of 1B coincides with the magnet 12.If the magnetic sensor 18 is installed close to the hole 11B,
The magnetic flux of the magnet 12 leaking from 1B can be sufficiently detected. The rotor yoke 11 absorbs the magnetic flux of each magnet 12 and reduces the magnetic resistance of the magnetic circuit, but if the hole 11B is provided, the magnetic flux of the permanent magnet installed at the position of this hole is completely absorbed by the rotor yoke. Some of the magnetic flux leaks out of the yoke.The amount of magnetic flux leaking is from the side wall of the yoke! 1
For example, if the thickness of the yoke side wall is 1 ms and the diameter of the hole 11B is about 41 mm, a normal magnetic sensor can be placed 1 to 2 mm away from the rotor yoke side wall. If it is provided at a distance of , the leakage magnetic flux can be sufficiently detected and the position of the rotor can be detected. In the above embodiments, a circumferentially opposed type motor was explained as an example, but it goes without saying that the present invention can be applied to a surfacely opposed type motor in which magnets are provided on the rotor side, as shown in FIG. As shown in FIG.
A can be provided to improve detection sensitivity. [Effects of the Invention] As explained above, according to the present invention, since index detection is performed by making a hole in the side wall of the rotor yoke and detecting the magnetic flux of the magnet for rotating the motor, a special magnet for index detection is required. , no special processing is required for the magnet, and the space for index detection can be reduced, making it possible to downsize the motor.

【図面の簡単な説明】[Brief explanation of drawings]

第1図は本発明の実施例を示すモータの断面図、 第2図は従来の方法を説明するためのロータの断面図、 第3図(A)は従来の他の方法を説明する部分断面図、
同図(B)はその斜視図である。 1・・・磁石、 l八・・・突出部、 2・・・ロータヨーク、 3・・・インデックス検出用磁石、 4・・・磁気センサ、 11・・・ロータヨーク、 11A・・・側壁、 11B・・・孔、 12・・・磁石、 13・・・軸、 14・・・ステータ、 15・・・軸受、 16・・・コイル、 17・・・鋼球、 18・・・磁気センサ。 13◆由 第1図 第2図 20−タヨーク (A) 第3図
Fig. 1 is a sectional view of a motor showing an embodiment of the present invention, Fig. 2 is a sectional view of a rotor to explain a conventional method, and Fig. 3 (A) is a partial sectional view to explain another conventional method. figure,
Figure (B) is a perspective view thereof. DESCRIPTION OF SYMBOLS 1... Magnet, l8... Projection part, 2... Rotor yoke, 3... Index detection magnet, 4... Magnetic sensor, 11... Rotor yoke, 11A... Side wall, 11B. ... Hole, 12... Magnet, 13... Shaft, 14... Stator, 15... Bearing, 16... Coil, 17... Steel ball, 18... Magnetic sensor. 13 ◆ Figure 1 Figure 2 20- Tayoke (A) Figure 3

Claims (1)

【特許請求の範囲】[Claims] 複数の永久磁石が取付けられているロータヨークに、前
記複数の永久磁石のうちの1個と中心軸が一致する孔を
設け、該孔より漏洩する磁束を検出することにより、ロ
ータの回転位置を検出することを特徴とする回転位置検
出方法。
A hole whose central axis coincides with one of the plurality of permanent magnets is provided in the rotor yoke to which a plurality of permanent magnets are attached, and the rotational position of the rotor is detected by detecting the magnetic flux leaking from the hole. A rotational position detection method characterized by:
JP14397787A 1987-06-10 1987-06-10 Rotary position detecting method for rotor Pending JPS63310358A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14397787A JPS63310358A (en) 1987-06-10 1987-06-10 Rotary position detecting method for rotor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14397787A JPS63310358A (en) 1987-06-10 1987-06-10 Rotary position detecting method for rotor

Publications (1)

Publication Number Publication Date
JPS63310358A true JPS63310358A (en) 1988-12-19

Family

ID=15351446

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14397787A Pending JPS63310358A (en) 1987-06-10 1987-06-10 Rotary position detecting method for rotor

Country Status (1)

Country Link
JP (1) JPS63310358A (en)

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