JPH0797895B2 - Motor with speed detector - Google Patents
Motor with speed detectorInfo
- Publication number
- JPH0797895B2 JPH0797895B2 JP57047438A JP4743882A JPH0797895B2 JP H0797895 B2 JPH0797895 B2 JP H0797895B2 JP 57047438 A JP57047438 A JP 57047438A JP 4743882 A JP4743882 A JP 4743882A JP H0797895 B2 JPH0797895 B2 JP H0797895B2
- Authority
- JP
- Japan
- Prior art keywords
- recording medium
- magnetic
- magnetic recording
- rotor
- fixed
- 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.)
- Expired - Lifetime
Links
- 230000005291 magnetic effect Effects 0.000 claims description 88
- 230000000694 effects Effects 0.000 claims description 24
- 239000000696 magnetic material Substances 0.000 claims description 12
- 239000003302 ferromagnetic material Substances 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 4
- 238000001514 detection method Methods 0.000 description 9
- 239000011295 pitch Substances 0.000 description 9
- 230000004907 flux Effects 0.000 description 7
- 230000005294 ferromagnetic effect Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 230000005415 magnetization Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910003271 Ni-Fe Inorganic materials 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K29/00—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices
- H02K29/06—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with position sensing devices
- H02K29/08—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with position sensing devices using magnetic effect devices, e.g. Hall-plates, magneto-resistors
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Brushless Motors (AREA)
- Permanent Magnet Type Synchronous Machine (AREA)
- Permanent Field Magnets Of Synchronous Machinery (AREA)
Description
【発明の詳細な説明】 本発明は速度検出器を備えたモータに係り、特に磁気抵
抗効果素子を利用した速度検出器を付加するに好適なモ
ータに関する。The present invention relates to a motor equipped with a speed detector, and more particularly to a motor suitable for adding a speed detector using a magnetoresistive effect element.
テープレコーダ,VTR（Video Tape Recorder）に組込ま
れるキャプスタンモータなどには、１回転当り数百パル
ス程度の速度検出信号を発生するような速度検出器がモ
ータ本体と一体的に設置されている。この速度検出信号
は回転速度制御のフィードバック信号に使用されるもの
で、僅かな回転むらでも録画再生時に音質及び画質の低
下を招いてしまうため、微少な回転むらを検出して一定
速の速度制御を行えるように、速度検出器には極めて高
い性能が要求される。さて、このような検出器として発
光ダイオード，フォットトランジスタ，スリット付円板
などを組合わせて、非接触で回転速度信号を出力する方
式がある。しかし、この方式では精度を一層向上させよ
うとすると、スリット付円板の製造が高価となってしま
う。一方、磁気抵抗効果素子を用いた速度検出器は、部
品数，信頼性，精度の点で優れていることがわかり、最
近注目され実用化検討が行われている。さて、磁気抵抗
効果は周知の如く磁界の作用により抵抗が変化する現象
で、材料によってその効果が異なる。磁気抵抗効果素子
は磁気抵抗効果の大きな材料、例えばNi−Fe系など強磁
性材をガラス板上に蒸着して、第１図に示すようなパタ
ーンを形成させたものである。第１図において、電極20
及び20′間に直流電圧を印加すると共に、図中に示すよ
うに電流に対し垂直に磁界を加えると、第２図のように
磁界が増加すると、抵抗は減少する。更に、磁界の方向
を逆転しても同様な結果が得られることが知られてい
る。第３図において、磁気記録媒体15はＮ及びＳ極とを
交互に等ピッチｐで着磁されたもので、γFe2O3或いはC
oOFe2O3などの強磁性体の微粉末を用いて形成したもの
が適している。さて、磁気抵抗効果素子10を磁気記録媒
体15に接近させ、磁極の並んでいる方向に平行移動させ
ると、N,Sの磁界変化を磁気抵抗効果素子10が受け、そ
の結果磁極ピッチに等しい周期の抵抗変化が得られる。
この抵抗変化はブリッジの一辺にすれば、電圧変化とし
て取り出すことができる。更に、コンパレータ，波形成
形回路などを用いてパルス列信号に変換できる。このパ
ルス列信号は磁気記録媒体15に着磁されている磁極ピッ
チに対応したものである。従って、回転子に磁気記録媒
体を固着し、且つ第８図に示すように同一円周上に等ピ
ッチに磁極を交互に着磁すれば、前述の如く磁気抵抗効
果素子によってその状態を読み出すことができ、速度検
出信号とすることが可能である。In a tape recorder, a capstan motor incorporated in a VTR (Video Tape Recorder), and the like, a speed detector that generates a speed detection signal of several hundreds of pulses per rotation is integrally installed with the motor body. This speed detection signal is used as a feedback signal for rotation speed control. Even a slight rotation unevenness will cause deterioration in sound quality and image quality during recording / playback. Therefore, a slight rotation unevenness is detected to control the speed at a constant speed. In order to be able to do so, extremely high performance is required of the speed detector. Now, as such a detector, there is a method of outputting a rotation speed signal in a non-contact manner by combining a light emitting diode, a phototransistor, a disc with a slit and the like. However, in this method, if the accuracy is further improved, the manufacturing of the disc with slits becomes expensive. On the other hand, a speed detector using a magnetoresistive effect element has been found to be excellent in terms of the number of parts, reliability, and accuracy, and has recently received attention and is being studied for practical use. As is well known, the magnetoresistive effect is a phenomenon in which the resistance changes due to the action of a magnetic field, and the effect differs depending on the material. The magnetoresistive element is formed by depositing a material having a large magnetoresistive effect, for example, a ferromagnetic material such as Ni-Fe system on a glass plate to form a pattern as shown in FIG. In FIG. 1, the electrode 20
When a direct current voltage is applied between 20 and 20 'and a magnetic field is applied perpendicularly to the current as shown in the figure, the resistance decreases when the magnetic field increases as shown in FIG. Further, it is known that similar results can be obtained even if the direction of the magnetic field is reversed. In FIG. 3, the magnetic recording medium 15 is one in which N and S poles are alternately magnetized at an equal pitch p. ΓFe 2 O 3 or C
Those formed by using fine powder of ferromagnetic material such as oOFe 2 O 3 are suitable. Now, when the magnetoresistive effect element 10 is brought close to the magnetic recording medium 15 and moved in parallel in the direction in which the magnetic poles are arranged, the magnetoresistive effect element 10 receives a magnetic field change of N and S, and as a result, a period equal to the magnetic pole pitch. The resistance change of is obtained.
This resistance change can be taken out as a voltage change if it is set on one side of the bridge. Further, it can be converted into a pulse train signal using a comparator, a waveform shaping circuit, or the like. This pulse train signal corresponds to the magnetic pole pitch magnetized in the magnetic recording medium 15. Therefore, if the magnetic recording medium is fixed to the rotor and the magnetic poles are alternately magnetized at equal pitches on the same circumference as shown in FIG. 8, the state can be read by the magnetoresistive effect element as described above. And can be used as a speed detection signal.
磁気抵抗効果素子を適用した速度検出器を備えたモータ
の概略構造を第４図に示す。第４図では、回転子ヨーク
７に磁気記録媒体15′を固着し、磁気記録媒体15′に対
向して磁気抵抗効果素子10′が配置される。磁気抵抗効
果素子10′は支持台11によりフレームに固定され、モー
タ本体と一体的な構造である。回転子ヨーク７は鉄など
強磁性体で構成されるため、図示するように磁気記録媒
体15′と回転子ヨーク７は密着して固定されるため、磁
気記録媒体15′に着磁記録されたＮ及びＳ極の磁界が弱
まってしまい、従って十分な信号を得ることができな
い。また、検出しようとすると磁気記録媒体15′と磁気
抵抗効果素子10′とのギャップ即ちスペーシングlsを小
さくする必要があり、組立てに困難を生じた。更に、回
転子ヨーク７から磁気記録媒体10′に磁束が漏れ易く、
信号と雑音の比いわゆるS/N比が低くなってしまう欠点
も持っていた。FIG. 4 shows a schematic structure of a motor provided with a speed detector to which a magnetoresistive effect element is applied. In FIG. 4, the magnetic recording medium 15 'is fixed to the rotor yoke 7, and the magnetoresistive effect element 10' is arranged so as to face the magnetic recording medium 15 '. The magnetoresistive effect element 10 'is fixed to the frame by the support 11 and has a structure integral with the motor body. Since the rotor yoke 7 is made of a ferromagnetic material such as iron, the magnetic recording medium 15 'and the rotor yoke 7 are fixed in close contact with each other as shown in the figure, and thus magnetically recorded on the magnetic recording medium 15'. The magnetic fields of the north and south poles are weakened, so that a sufficient signal cannot be obtained. Further, in order to detect it, it is necessary to reduce the gap between the magnetic recording medium 15 'and the magnetoresistive effect element 10', that is, the spacing l s , which causes difficulty in assembling. Further, magnetic flux easily leaks from the rotor yoke 7 to the magnetic recording medium 10 ',
It also had the drawback of a low signal-to-noise ratio, the so-called S / N ratio.
本発明の目的は、磁気抵抗効果素子を適用した速度検出
器付モータの速度検出信号を高めると共に、S/N比を改
善し信頼性の高い速度検出器付モータを提供するにあ
る。An object of the present invention is to provide a highly reliable motor with a speed detector which enhances the speed detection signal of the motor with a speed detector to which the magnetoresistive effect element is applied and which improves the S / N ratio.
本発明は、固定子と、この固定子に設けられる固定子コ
イルと、前記固定子に軸受を介して回動自在に支持され
るシャフトと、このシャフトに固定支持される回転子と
しての回転子ヨークと、前記固定子コイルに対向して配
置され、かつ前記回転子ヨークに固着される回転子用磁
石と、前記回転子ヨークに固着される磁気記録媒体と、
この磁気記録媒体に近接して対向するように配置される
強磁性体の磁気抵抗効果素子とを備え、前記回転子用磁
石が固着される面とは異なる前記回転子ヨークの面に非
磁性体を設け、この非磁性体の表面に前記磁気記録媒体
を固着し、この非磁性体の厚さを前記磁気記録媒体に着
磁される磁極の記録ピッチよりも大きく設けたことを特
徴とするものである。The present invention relates to a stator, a stator coil provided in the stator, a shaft rotatably supported by the stator via bearings, and a rotor as a rotor fixedly supported by the shaft. A yoke, a rotor magnet arranged to face the stator coil and fixed to the rotor yoke, and a magnetic recording medium fixed to the rotor yoke.
A ferromagnetic magnetoresistive effect element arranged so as to closely face and oppose the magnetic recording medium, and a nonmagnetic material is provided on a surface of the rotor yoke different from a surface to which the rotor magnet is fixed. Is provided, the magnetic recording medium is fixed to the surface of the non-magnetic body, and the thickness of the non-magnetic body is set larger than the recording pitch of the magnetic poles magnetized on the magnetic recording medium. Is.
すなわち、磁気記録媒体を、中間に非磁性体を介して回
転子に固着することにより、磁気記録媒体に着磁記録し
たＮ及びＳ極の磁界を弱めることがなくなり、回転子磁
石からの漏れ磁界の影響が少なくなる。That is, by fixing the magnetic recording medium to the rotor via a non-magnetic material in the middle, the magnetic fields of the N and S poles magnetized and recorded on the magnetic recording medium are not weakened, and the leakage magnetic field from the rotor magnet is eliminated. The effect of is reduced.
本発明による具体的実施例を第５図に示す。同図におい
て、磁気記録媒体15′は非磁性体12を中間に介して回転
子ヨーク７に固着するものである。中間に非磁性体12が
あるため、磁気記録媒体15′を回転子ヨーク７に密着し
た構造に比べ、磁気記録媒体15′に着磁記録された複数
のＮ及びＳ極に対して、Ｎ極からＳ極に回転子ヨーク７
を通じて流れる磁束が大幅に減少し、その結果磁気抵抗
効果素子10′に加わる磁界が強まる。この磁界の強さは
非磁性体12の厚さｔに関係することは自明である。第８
図はこの関係を実験的に調べたものである。図からわか
るように、磁気記録媒体に着磁記録されたＮ及びＳ極の
ピッチｐ以上に非磁性体厚みｔを選ぶことにより、回転
子ヨークの影響が減少し、大きな抵抗変化率ΔR/Rを得
ることができる。更に、非磁性体12を中間に介している
ため、回転子ヨーク７からの磁束が磁気記録媒体15′を
通過しにくくなり、雑音としての回転子磁石の漏れ磁界
の影響が弱まる。A specific embodiment according to the present invention is shown in FIG. In the figure, the magnetic recording medium 15 'is fixed to the rotor yoke 7 with the non-magnetic body 12 interposed therebetween. Since there is the non-magnetic material 12 in the middle, compared with the structure in which the magnetic recording medium 15 'is closely attached to the rotor yoke 7, the N pole is different from the plurality of N and S poles magnetically recorded on the magnetic recording medium 15'. From the S pole to the rotor yoke 7
The magnetic flux flowing therethrough is greatly reduced, and as a result, the magnetic field applied to the magnetoresistive effect element 10 'is strengthened. It is obvious that the strength of this magnetic field is related to the thickness t of the non-magnetic body 12. 8th
The figure is an experimental examination of this relationship. As can be seen from the figure, the influence of the rotor yoke is reduced and the large resistance change rate ΔR / R is selected by selecting the non-magnetic material thickness t to be equal to or more than the pitch p of the N and S poles magnetized and recorded on the magnetic recording medium. Can be obtained. Furthermore, since the non-magnetic body 12 is interposed in the middle, the magnetic flux from the rotor yoke 7 is less likely to pass through the magnetic recording medium 15 ', and the influence of the leakage magnetic field of the rotor magnet as noise is weakened.
第６図は他の実施例である。この構成は磁気記録媒体1
5′を回転子ヨーク７の側面上に固着した場合であり、
第５図の場合と比較すると、磁気記録媒体15′の着磁面
がシャフトに対して垂直と平行の違いがあるが、第５図
と同様、非磁性体12を介して磁気記録媒体15′を固着す
る構成であり、本発明から容易に推定できる実施例であ
る。FIG. 6 shows another embodiment. This structure is a magnetic recording medium 1
5'is fixed on the side surface of the rotor yoke 7,
Compared to the case of FIG. 5, the magnetized surface of the magnetic recording medium 15 'is different from that of the shaft in the direction perpendicular to the shaft. However, as in FIG. This is an embodiment in which is fixed, and can be easily estimated from the present invention.
本発明によれば、検出信号を高めることができると共い
磁石或いはコイルによる磁界の影響を大幅に軽減でき、
速度検出器のS/N比を高める効果がある。大きな検出信
号が得られるため、スペーシングを大きくとることが可
能である。また、コイル４に流れる電流によって発生す
る高調波磁界は、非磁性体12中にうず電流を誘導し、そ
の結果高周波磁界をシールドでき、高調波雑音防止にも
効果がある。磁気記録媒体の表面の磁界が弱められるた
め、磁性粉などが表面に付着しにくくなり、異物のギャ
ップ進入による検出素子の破壊が非常に少なくなる効果
がある。更に、磁気記録媒体と磁気抵抗素子のギャップ
調整を非磁性体の厚さで行うことができ、切削した場
合、切粉が磁気記録媒体に付着せずその処理が簡単にな
る効果がある。その他を効果として、磁気記録媒体にＮ
及びＳ極の着磁が行い易くなる。これは磁気記録媒体の
厚みが極ピッチに対して小さく1/2〜1/10ぐらいの範囲
であるので、着磁の際磁気記録媒体の下側に磁性体があ
る場合、磁束は磁性体に大部分流れてしまい、磁性体が
磁気飽和するまで磁束を流して着磁する必要があるが、
非磁性体を使用すれば、着磁に必要なアンペアターンを
印加するだけでよく、容量の小さな着磁装置で済む。そ
して、確実な着磁を行うことが可能であるため、着磁む
らが無くなり特性の良好な速度検出器が得られる。According to the present invention, although the detection signal can be increased, the influence of the magnetic field due to the magnet or coil can be significantly reduced,
It has the effect of increasing the S / N ratio of the speed detector. Since a large detection signal can be obtained, it is possible to increase the spacing. Further, the harmonic magnetic field generated by the current flowing through the coil 4 induces an eddy current in the non-magnetic body 12, and as a result, the high frequency magnetic field can be shielded, which is also effective in preventing harmonic noise. Since the magnetic field on the surface of the magnetic recording medium is weakened, magnetic powder or the like is less likely to adhere to the surface, and there is an effect that the damage of the detection element due to the entry of a foreign substance into the gap is extremely reduced. Further, the gap between the magnetic recording medium and the magnetoresistive element can be adjusted by the thickness of the non-magnetic material, and when cut, cutting chips do not adhere to the magnetic recording medium and the processing is simplified. As another effect, N is added to the magnetic recording medium.
Also, the S pole can be easily magnetized. This is because the thickness of the magnetic recording medium is smaller than the pole pitch and is in the range of 1/2 to 1/10, so if there is a magnetic substance under the magnetic recording medium during magnetization, the magnetic flux will flow to the magnetic substance. Most of it flows, and it is necessary to magnetize it by flowing magnetic flux until the magnetic substance is magnetically saturated.
If a non-magnetic material is used, it is only necessary to apply the ampere-turn required for magnetization, and a magnetizing device with a small capacity is sufficient. Further, since it is possible to reliably magnetize, it is possible to obtain a speed detector having good characteristics and eliminating unevenness in magnetization.
以上述べたように、本発明は、固定子と、この固定子に
設けられる固定子コイルと、前記固定子に軸受を介して
回動自在に支持されるシャフトと、このシャフトに固定
支持される回転子としての回転子ヨークと、前記固定子
コイルに対向して配置され、かつ前記回転子ヨークに固
着される回転子用磁石と、前記回転子ヨークに固着され
る磁気記録媒体と、この磁気記録媒体に近接して対向す
るように配置される強磁性体の磁気抵抗効果素子とを備
え、前記回転子用磁石が固着される面とは異なる前記回
転子ヨークの面に非磁性体を設け、この非磁性体の表面
に前記磁気記録媒体を固着し、この非磁性体の厚さを前
記磁気記録媒体に着磁される磁極の記録ピッチよりも大
きく設けたことを特徴とする速度検出器付モータにあ
る。As described above, according to the present invention, the stator, the stator coil provided in the stator, the shaft rotatably supported by the stator via the bearing, and the shaft fixedly supported by the shaft. A rotor yoke as a rotor, a rotor magnet that is arranged to face the stator coil and is fixed to the rotor yoke, a magnetic recording medium fixed to the rotor yoke, and a magnetic recording medium A magnetoresistive element of a ferromagnetic material arranged so as to closely face the recording medium, and a non-magnetic material is provided on a surface of the rotor yoke different from a surface to which the rotor magnet is fixed. A velocity detector characterized in that the magnetic recording medium is fixed to the surface of the non-magnetic material, and the thickness of the non-magnetic material is set larger than the recording pitch of magnetic poles magnetized on the magnetic recording medium. Attached to the motor.
この構成によれば、次のような良さが期待できる。According to this configuration, the following advantages can be expected.
（１）．磁気記録媒体の固着される非磁性体の厚さを、
磁気記録媒体に着磁される磁極の記録ピッチよりも大き
くしたので、磁気記録媒体の磁極から発生する磁束は回
転子ヨーク側を通る量が少なくなる。その分、強磁性体
の磁気抵抗効果素子を通る磁束量が増加して磁界強度が
高まるので、大きな速度検知信号が得られ、S/N比の改
善が図られるのである。(1). The thickness of the non-magnetic material to which the magnetic recording medium is fixed,
Since the recording pitch of the magnetic poles magnetized on the magnetic recording medium is made larger, the amount of magnetic flux generated from the magnetic poles of the magnetic recording medium passes through the rotor yoke side. As a result, the amount of magnetic flux passing through the ferromagnetic magnetoresistive effect element increases and the magnetic field strength increases, so that a large speed detection signal is obtained and the S / N ratio is improved.
（２）．大きな速度検知信号が得られるので、近接して
配置される磁気記録媒体と強磁性体磁気抵抗効果素子と
の隙間を多少拡げることができるので、部品の寸法に多
少のバラツキがあっても回転中に磁気記録媒体と強磁性
体磁気抵抗効果素子が擦れ合ってしまうような不具合を
解消させることができるのである。(2). Since a large speed detection signal can be obtained, the gap between the magnetic recording medium and the ferromagnetic magnetoresistive effect element, which are placed close to each other, can be slightly widened. In addition, it is possible to eliminate the problem that the magnetic recording medium and the ferromagnetic magnetoresistive effect element rub against each other.
第１図は磁気抵抗効果素子のパターン、第２図は磁界に
対する抵抗の変化を表わす特性、第３図は速度検出方法
の原理図、第４図は従来例の速度検出器付モータの断面
図、第５図は本発明による一実施例、第６図は他の実施
例、第７図は非磁性体厚みと抵抗変化率の関係、第８図
は回転子ヨークに固着される磁気記録媒体の着磁状態を
示す概念図である。 １……シャフト、２……ベアリング、３……フレーム、
４……コイル、５……ボス、６……回転子磁石、７……
回転子ヨーク、10,10′……磁気抵抗効果素子、11……
支持台、12……非磁性体、15,15′……磁気記録媒体、2
0,20′……電極。FIG. 1 is a pattern of a magnetoresistive element, FIG. 2 is a characteristic showing a change in resistance with respect to a magnetic field, FIG. 3 is a principle diagram of a speed detecting method, and FIG. 4 is a sectional view of a conventional motor with a speed detector. FIG. 5 is an embodiment according to the present invention, FIG. 6 is another embodiment, FIG. 7 is a relationship between the non-magnetic material thickness and the resistance change rate, and FIG. 8 is a magnetic recording medium fixed to the rotor yoke. 3 is a conceptual diagram showing a magnetized state of FIG. 1 ... Shaft, 2 ... Bearing, 3 ... Frame,
4 ... coil, 5 ... boss, 6 ... rotor magnet, 7 ...
Rotor yoke, 10, 10 '... Magnetoresistive effect element, 11 ...
Support base, 12 ... Non-magnetic material, 15,15 '... Magnetic recording medium, 2
0,20 ′ …… Electrode.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 高橋 正 茨城県日立市幸町３丁目１番１号 株式会 社日立製作所日立研究所内 (72)発明者 川又 昭一 茨城県日立市幸町３丁目１番１号 株式会 社日立製作所日立研究所内 (72)発明者 渡邊 充 茨城県日立市幸町３丁目２番１号 日立エ ンジニアリング株式会社内 (56)参考文献 特開 昭55−127874（ＪＰ，Ａ) 特開 昭48−41252（ＪＰ，Ａ) 特開 昭56−142409（ＪＰ，Ａ) 実開 昭57−98164（ＪＰ，Ｕ) 実開 昭55−117184（ＪＰ，Ｕ) 実開 昭48−110602（ＪＰ，Ｕ) 実開 昭53−78409（ＪＰ，Ｕ) 実開 昭55−51797（ＪＰ，Ｕ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Takahashi, 3-1-1 Sachimachi, Hitachi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor, Shoichi Kawamata 3-chome, Hitachi, Hitachi, Ibaraki No. 1 Hitachi Ltd., Hitachi Research Laboratory (72) Inventor Mitsuru Watanabe 3-2-1, Saiwaicho, Hitachi City, Ibaraki Hitachi Engineering Co., Ltd. (56) Reference JP-A-55-127874 (JP , A) JP-A-48-41252 (JP, A) JP-A-56-142409 (JP, A) Actual opening 57-98164 (JP, U) Actual opening Sho-55-117184 (JP, U) Actual opening 48-110602 (JP, U) Actually opened 53-78409 (JP, U) Actually opened 55-51797 (JP, U)
Claims (1)
コイルと、前記固定子に軸受を介して回動自在に支持さ
れるシャフトと、このシャフトに固定支持される回転子
としての回転子ヨークと、前記固定子コイルに対向して
配置され、かつ前記回転子ヨークに固着される回転子用
磁石と、前記回転子ヨークに固着される磁気記録媒体
と、この磁気記録媒体に近接して対向するように配置さ
れる強磁性体の磁気抵抗効果素子とを備え、 前記回転子用磁石が固着される面とは異なる前記回転子
ヨークの面に非磁性体を設け、この非磁性体の表面に前
記磁気記録媒体を固着し、この非磁性体の厚さを前記磁
気記録媒体に着磁される磁極の記録ピッチよりも大きく
設けたことを特徴とする速度検出器付モータ。1. A stator, a stator coil provided on the stator, a shaft rotatably supported by the stator via bearings, and a rotation as a rotor fixedly supported on the shaft. A child yoke, a rotor magnet arranged to face the stator coil and fixed to the rotor yoke, a magnetic recording medium fixed to the rotor yoke, and a magnetic recording medium close to the magnetic recording medium. A magnetoresistive effect element made of a ferromagnetic material arranged so as to face each other, and a nonmagnetic material is provided on a surface of the rotor yoke different from a surface to which the rotor magnet is fixed. A motor with speed detector, wherein the magnetic recording medium is fixed to the surface of the magnetic recording medium, and the thickness of the non-magnetic material is larger than the recording pitch of the magnetic poles magnetized on the magnetic recording medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57047438A JPH0797895B2 (en) | 1982-03-26 | 1982-03-26 | Motor with speed detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57047438A JPH0797895B2 (en) | 1982-03-26 | 1982-03-26 | Motor with speed detector |
Related Child Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5102152A Division JP2539577B2 (en) | 1993-04-28 | 1993-04-28 | Motor with speed detector |
| JP7142902A Division JPH0884457A (en) | 1995-06-09 | 1995-06-09 | Motor with speed detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58165651A JPS58165651A (en) | 1983-09-30 |
| JPH0797895B2 true JPH0797895B2 (en) | 1995-10-18 |
Family
ID=12775151
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57047438A Expired - Lifetime JPH0797895B2 (en) | 1982-03-26 | 1982-03-26 | Motor with speed detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0797895B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62185548A (en) * | 1986-02-07 | 1987-08-13 | Mitsubishi Electric Corp | Rotating apparatus |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5798164U (en) * | 1980-12-05 | 1982-06-16 |
-
1982
- 1982-03-26 JP JP57047438A patent/JPH0797895B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58165651A (en) | 1983-09-30 |
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