JP3605486B2 - Bearing wear monitoring device - Google Patents

Description

【００６３】
前記運転モードＩは、図４の０〜８時及び２０〜２４時における前記第１モータ１の運転状態を示す。
【００６４】
前記運転モードＩは、前記スイッチ５ａによって回路５Ａを接続し、前記第２モータ２の運転を停止して、前記第１モータ１の回転数をインバータ４によって可変に制御して運転する。
【００６５】
前記運転モードＩ＋ＩＩは、図４の８〜１１時における前記第１モータ１及び前記第２モータ２の運転状態を示す。
【００６６】
前記運転モードＩ＋ＩＩは、前記スイッチ５ｂ及び５ｃによって回路５Ａを接続し、前記第１モータ１及び前記第２モータ２を並列運転して、前記第１モータ１の回転数を前記交流電源３によって固定回転数で運転し、前記第２モータ２の回転数をインバータ４によって可変に制御して運転する。
【００６７】
前記運転モードＩＩは、図４の１１〜１８時における前記第２モータ２の運転状態を示す。
【００６８】
前記運転モードＩＩは、前記スイッチ５ｂによって回路５Ａを接続し、前記第１モータ１の運転を停止して、前記第２モータ２の回転数をインバータ４によって可変に制御して運転する。
【００６９】
前記運転モードＩＩ＋Ｉは、図４の１８〜２０時における前記第１モータ１及び前記第２モータ２の運転状態を示す。
【００７０】
前記運転モードＩＩ＋Ｉは、前記スイッチ５ａ及び５ｄによって回路５Ａを接続し、前記第１モータ１及び前記第２モータ２を並列運転して、前記第２モータ２の回転数を前記交流電源３によって固定回転数で運転し、前記第１モータ１の回転数をインバータ４によって可変に制御して運転する。
【００７１】
前記運転モードＩ、Ｉ＋ＩＩ、ＩＩ及びＩＩ＋Ｉにおいては、前記インバータ４によって第１モータ１の回転数、第２モータ２の回転数、第２モータ２の回転数及び第１モータ１の回転数を各々制御することができるので、前記吐出流量を時間帯によって増減する水使用量に応じた最適流量に調節することができる。
【００７２】
更に前記運転モードＩ＋ＩＩ及びＩＩ＋Ｉにおいては、前記交流電源３によって第１モータ１の回転数及び第２モータ２の回転数を固定回転数で運転することができるので、軸受１１ａ及び軸受１１ｂ（図示せず）が摩耗した場合に生じる前記第１モータ１及び第２モータ２におけるロータ９ａ及び９ｂの回転速度、振動、偏心等を総合した回転運動の変化の大きさが各々起電力に変換されて、前記起電力が検出される。前記起電力は各々検出データとして前記モニタ装置７に表示される。
【００７３】
前記０〜８時の運転モードＩにおいて、前記モニタ装置７における第１〜４表示窓を備えた表示画面（図示せず）には新たに検出された検出データの表示はない。
【００７４】
前記８〜１１時の運転モードＩ＋ＩＩにおいて、前記第１モータ１における前記ロータ９ａと前記回転軸１０ａとの回転運動の変化の大きさは前記起電力に変換されて、前記表示画面の第１表示窓（図示せず）に検出データとして表示される。
【００７５】
前記１１〜１８時の運転モードＩＩにおいては、前記第１表示窓の検出データが継続して表示される。
【００７６】
前記１８〜２０時の運転モードＩＩ＋Ｉにおいて、前記第２モータ２における前記ロータ９ｂと前記回転軸１０ｂとの回転運動の変化の大きさは前記起電力に変換されて、前記表示画面の第２表示窓（図示せず）に検出データとして表示され、かつ前記第１表示窓の検出データが継続して表示される。
【００７７】
前記２０〜２４時の運転モードＩにおいては、前記第１表示窓及び第２表示窓の検出データが継続して表示される。
【００７８】
さらに、翌日の０〜８時の運転モードＩにおいては、前記第１表示窓及び第２表示窓の検出データが継続して表示される。
【００７９】
翌日の８〜１１時の運転モードＩ＋ＩＩにおいて、前記第１モータ１における前記ロータ９ａと前記回転軸１０ａとの回転運動の変化の大きさは再度起電力に変換されて、前記表示画面の第３表示窓（図示せず）に検出データとして表示され、かつ前記第１表示窓及び第２表示窓の検出データが継続して表示される。
【００８０】
翌日の１１〜１８時の運転モードＩＩにおいては、前記第１表示窓、第２表示窓及び第３表示窓の検出データが継続して表示される。
【００８１】
翌日の１８〜２０時の運転モードＩＩ＋Ｉにおいて、前記第２モータ２における前記ロータ９ｂと前記回転軸１０ｂとの回転運動の変化の大きさは再度起電力に変換されて、前記表示画面の第４表示窓（図示せず）に検出データとして表示され、かつ前記第１表示窓、第２表示窓及び第３表示窓の検出データが継続して表示される。
【００８２】
前記第１表示窓に表示された検出データと前記第３表示窓に表示された検出データとを比較することによって、前記ロータ９ａに生じる回転運動の変化を２４時間を挟んだ前後に検出した検出データを高精度に、かつ容易に比較することができ、前記軸受１１ａの摩耗によって生じる前記回転運動の変化を監視することができる。
【００８３】
また、前記第２表示窓に表示された検出データと前記第４表示窓に表示された検出データとを比較することによって、前記ロータ９ｂに生じる回転運動の変化を２４時間を挟んだ前後に検出した検出データを高精度に、かつ容易に比較することができ、前記軸受１１ｂの摩耗によって生じる前記回転運動の変化を監視することができる。
【００８４】
前記モニタ装置７は、前記検出データを記憶するメモリー部（図示せず）と、前記検出データを読み出すＣＰＵ（図示せず）と、前記検出データを演算処理するデータ処理部（図示せず）と、前記データ処理部で処理された処理データ及び前記検出データを表示画面（図示せず）たとえばＣＲＴ画面に表示する表示部（図示せず）と、警告表示部（図示せず）たとえば警告ランプと、スピーカ（図示せず）とを有してなる。
【００８５】
前記表示部は、表示画面に前記軸受１１ａの摩耗によって生じる前記回転運動の変化を検出して得られた前記検出データをリアルタイムにリアルタイム表示窓に表示すること、表示画面に前記検出データを演算処理して得られた処理データを処理データ表示窓に表示すること、表示画面に所定時間を挟んだ前後に検出した２点の前記処理データを演算処理して得られた速度データを摩耗速度表示窓に表示すること、表示画面に前記速度データを演算処理して得られた時間データを残り時間表示窓に表示することの少なくともいずれか、あるいはすべてを実行することができるように形成される。
【００８６】
前記データ処理部には、例えば摩耗していない新品の軸受を取り付けた時に得られた初期検出値と、前記軸受の限界摩耗値とを予め設定することができる。
【００８７】
前記初期検出値は、すでに摩耗を生じた軸受を使用して前記回転運動の変化を検出した時に得られた検出値であってもよい。
【００８８】
前記データ処理部は、例えば前記初期検出値を０％、前記限界摩耗値を１００％と認識し、前記検出データを百分率に演算処理して百分率処理データ値を得、前記百分率処理データ値を前記表示部における前記処理データ表示窓に表示することができる。
【００８９】
前記初期検出値として、すでに摩耗を生じた軸受を使用して前記回転運動の変化を検出した時に得られた検出値を設定した場合には、前記データ処理部は前記初期検出値を０％に限らず、すでに前記軸受生じた摩耗に対応した適宜の百分率に認識することもできる。
前記表示部における前記第１〜４表示窓は、第１〜４リアルタイム表示窓（図示せず）、第１〜４処理データ表示窓（図示せず）、第１〜４摩耗速度表示窓（図示せず）及び第１〜４残り時間表示窓（図示せず）を有してなる。
【００９０】
前記データ処理部は、例えば前記第１処理データ表示窓及び前記第３処理データ表示窓に表示された２点の処理データ値を演算処理して速度データ値を得、前記速度データ値を第３摩耗速度表示窓に表示する。
【００９１】
前記データ処理部は、例えば、前記第３摩耗速度表示窓に表示された速度データ値と前記初期検出値と前記限界摩耗値とを演算処理して時間データ値を得、前記時間データ値を第３残り時間表示窓に表示する。
【００９２】
監視作業者は、例えば、前記第３処理データ表示窓に表示された百分率処理データ値から、前記初期検出値に対する前記軸受１１ａの摩耗割合を容易に判断することができる。
【００９３】
また、監視作業者は、例えば、前記第３摩耗速度表示窓に表示された速度データ値から、前記軸受１１ａの摩耗速度を容易に監視することができる。
【００９４】
さらに、監視作業者は、例えば、前記第３残り時間表示窓に表示された時間データ値から、前記軸受１１ａの交換までの残り時間を容易に把握することができる。
【００９５】
さらに、前記データ処理部には、前記摩耗割合が所定の百分率データ値に達した時もしくは前記残り時間が所定時間よりも短くなった時に、前記警告表示部に警告が表示されるように予め警告発信値を設定することもできる。
【００９６】
前記データ処理部は、前記摩耗割合もしくは前記残り時間が前記警告発信値に達した時には、前記警告表示部及び前記スピーカに警告信号を発信するので、前記警告表示部には警告表示のサイン、たとえば警告ランプの点灯が示され、前記スピーカからは警告音が発せられる。
【００９７】
なお、この実施例１においては、前記第１モ−タ１及び第２モ−タ２が本願発明における複数のモ−タに相当し、前記サ−チコイル６ａ、６ｂが本願発明における回転運動変化検出手段に相当し、又、スイッチ５ａ、５ｂ、５ｃ及び５ｄが本願発明における切替手段に相当し、前記モニタ装置７が本願発明における回転運動変化表示手段に相当する。
【００９８】
−その２−
本発明においては、前記実施例１の変更例として給水ポンプの並列台数を前記給水ポンプの性能に応じて適宜に増やすことができる。
【００９９】
例えば複数のポンプを備えたプラントでは、ポンプ全台数の運転時における全揚程が最大揚程になるので、この最大揚程の値を設計揚程とし、キャビテーションの防止、ポンプの始動頻度、流量負荷の変動等を考慮して台数制御をすることができる。
【０１００】
この実施例は３台の給水ポンプを使用する場合について説明する。
【０１０１】
前記３台の給水ポンプを使用すると、例えば図５に示すように、前記実施例１の回路５Ａに回路５Ｂを接続して、第１モータ１、第２モータ２及び第３モータ１２の３台のモータを吐出流量に応じて運転することになる。
【０１０２】
この実施例２においては、表２に示すように運転モードＡ、Ｅ及びＩ以外の各運転モードに固定回転数で運転するモータを有するので、各モータを定期的に固定回転数で運転して前記各モータのロータにおける回転運動の変化の大きさを各々検出データとして検出することができ、よりきめ細かく前記軸受の摩耗量を監視することができる。
【０１０３】
また、前記モータの能力を考慮し、例えばポンプの種類、形式、前記並列台数及び前記最大吐出流量の設定等を最適化することによって、前記モータを効率よく運転することができ、前記モータの寿命を延ばすことができる。
【０１０４】
【表２】

【０１０５】
−その３−
図６及び図７に示すように、前記実施例１におけるサーチコイルとして他の形態を挙げることができる。
【０１０６】
図６におけるサーチコイル１３は、空間角にしてほぼ１２０度隔てて対称に、すなわち、１２０度離れた三相の各相におけるステータ１４の歯部１４ａ、１４ｂ及び１４ｃに巻き付けられた歯部コイル１３ａ、１３ｂ及び１３ｃを有する。
【０１０７】
図７におけるサーチコイル１５は、空間角にしてほぼ９０度隔てて対称にステータ１６の歯部１６ａ、１６ｂ、１６ｃ及び１６ｄに巻き付けられた歯部コイル１５ａ、１５ｂ、１５ｃ及び１５ｄを有する。
【０１０８】
−その４−
図８に示すように、前記回転運動変化検出手段の他の一実施例である磁束密度センサー１７を採用することができる。
【０１０９】
前記磁束密度センサー１７は、例えばステータ１８における、ロータ１９に相対向する適宜の位置に設けられ、ロータ１９に設けられた永久磁石２０とともに、この実施例におけるモータの回転体であるロータ１９及び回転軸２１に生じる回転運動の変化を磁束密度の変化として検出することができる。
【０１１０】
他の一実施例として、磁束密度センサーは、ステータにおける、回転軸に相対向する適宜の位置に設けることもでき、磁束密度センサーに相対向する回転軸に設けられた永久磁石とともに、モータの回転体であるロータ及び回転軸に生じる回転運動の変化を磁束密度の変化として検出することができる。
【０１１１】
前記磁束密度センサーとしては、前記磁束密度の変化を電磁誘導起電力に変換して検出するコイルを有する誘導コイル型磁束密度センサー、前記磁束密度の変化を電流値に変換して検出するホール素子を有するホールＩＣ型磁束密度センサー、前記磁束密度の変化を抵抗値に変換して検出する磁気抵抗型磁束密度センサー等を挙げることができる。
【０１１２】
−その５−
前記回転運動変化検出手段の他の一実施例として、従来から工業計測の分野で用いられている静電容量型センサー（図示せず）を採用することができる。
【０１１３】
前記静電容量型センサーは、この実施例におけるモータにおける静止した部材、すなわち前記モータにおける非回転体に固定され、かつ前記モータにおける回転体であるロータまたはこのロータを貫通する回転軸に相対向する位置に設けることができる。
【０１１４】
前記静電容量型センサーは、前記静電容量型センサーが相対向する前記回転体の一部と前記静電容量型センサーとの間の比誘電率の変化を検出することができる。
【０１１５】
−その６−
前記回転運動変化検出手段の他の一実施例として、従来から工業計測の分野で用いられている加速度センサー（図示せず）を採用することができる。
【０１１６】
前記加速度センサーは、この実施例におけるモータの回転体であるロータ及び回転軸の偏心運動によって生じる振動を検出することができるように、前記回転体における適宜の位置に設けることができる。
【０１１７】
前記加速度センサーは、前記モータにおける前記回転体の振動を起電力に変換して、前記起電力を検出データとして検出することができる。
【０１１８】
【発明の効果】
本発明の軸受摩耗監視装置は、複数のモータへの駆動出力源を切り替えて、各モータの回転軸における回転数を固定回転数での駆動と回転数可変での駆動とに並列運転することによって、回転数可変での駆動するモータの運転を継続しながら、固定回転数で駆動するモータの回転運動の変化によって生じる電気値を回転運動変化検出手段により検出し、回転運動変化表示手段に表示された検出データ及び各種処理データより軸受の寿命を予測することができ、モータの軸受の摩耗量を所定時間毎段階的に又は連続的に検出することができ、モータの軸受の摩耗を監視することができる。
【０１１９】
また、固定回転数で運転するモータにおける回転軸及びロータの回転運動の変化によって生じる起電力の変化を、高精度にかつ容易に比較することができ、軸受の摩耗によって生じる起電力の変化を監視することができる。
【０１２０】
本発明の軸受摩耗監視装置においては、例えばモータを備えたポンプの並列台数及び各ポンプにおける最大吐出流量の設定を最適化することができ、かつ各モータの軸受の摩耗量を監視することができる。
【０１２１】
すなわち本発明の軸受摩耗監視装置においては、必要な吐出流量に応じて種々のポンプを組み合わせることができ、各ポンプの性能を考慮した最適運転ができるので、消費電力を抑えることができ、各モータの寿命を延ばすことができ、かつ各モータの軸受の摩耗量を監視することができる。
【０１２２】
さらに本発明の軸受摩耗監視装置においては、複数のモータを、前記複数のモータよりも少ない台数のインバータの制御により並列運転させ、かつ各モータの軸受の摩耗を監視することができる。
【図面の簡単な説明】
【図１】図１は、本発明の軸受摩耗監視装置の一実施例を示す回路図である。
【図２】図２は、本発明の軸受摩耗監視装置の一実施例に採用することができる給水ポンプの一部断面図である。
【図３】図３は、図２におけるＩＩＩ−ＩＩＩ断面図である。
【図４】図４は、本発明の軸受摩耗監視装置の一実施例における給水ポンプの一日の吐出流量の推移を示すグラフである。
【図５】図５は、本発明の軸受摩耗監視装置の他の一実施例を示す回路図である。
【図６】図６は、本発明の軸受摩耗監視装置の一実施例における回転運動変化検出手段の断面図である。
【図７】図７は、本発明の軸受摩耗監視装置の一実施例における回転運動変化検出手段の断面図である。
【図８】図８は、本発明の軸受摩耗監視装置の他の一実施例における回転運動変化検出検出手段の断面図である。
【符号の説明】
Ａ・・・第１給水ポンプ、１・・・第１モータ、２・・・第２モータ、３・・・交流電源、４・・・インバータ、５Ａ、５Ｂ・・・回路、５ａ、５ｂ、５ｃ、５ｄ・・・スイッチ、６ａ・・・サーチコイル、６ｃ、６ｄ・・・歯部コイル、７・・・モニタ装置、８ａ・・・ステータ、８ｃ、８ｄ・・・歯部、９ａ・・・ロータ、１０ａ・・・回転軸、１１ａ・・・軸受、１２・・・第３モータ、１３・・・サーチコイル、１３ａ、１３ｂ、１３ｃ・・・歯部コイル、１４・・・ステータ、１４ａ、１４ｂ、１４ｃ・・・歯部、１５・・・サーチコイル、１５ａ、１５ｂ、１５ｃ、１５ｄ・・・歯部コイル、１６・・・ステータ、１６ａ、１６ｂ、１６ｃ、１６ｄ・・・歯部、１７・・・磁束密度センサー、１８・・・ステータ、１９・・・ロータ、２０・・・永久磁石、２１・・・回転軸。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bearing wear monitoring device, and more particularly, to a bearing wear monitoring device capable of monitoring the amount of bearing wear without being affected by a change in the number of rotations of a rotating shaft of a motor driven by inverter control. About.
[0002]
[Prior art]
Conventionally, when a bearing of a rotating shaft of a motor wears, the rotating shaft causes eccentric motion caused by abnormal vibration, impact vibration, high-frequency vibration, and the like. There is.
[0003]
For example, when the rotating shaft causes an eccentric motion, a method of notifying wear of the bearing by rupture of a rupture plate provided at a predetermined position near the rotating shaft, that is, mechanical contact of the bearing wear And a method of converting the magnitude of the change in the rotational motion of the rotating shaft into an electrical value and detecting the electrical value, and detecting the eccentric motion of the rotating shaft after a lapse of a predetermined time. A method of monitoring the wear of the bearing by comparing with a measured electric value, that is, a method of detecting the wear of the bearing by a change in an electric value obtained by detecting a change in rotational motion generated in a rotating shaft. Can be.
[0004]
In the method of detecting the wear of the bearing by the mechanical contact, the rupturable plate ruptures to notify the wear of the bearing, so that the wear of the bearing is detected regardless of the rotation speed of the rotating shaft, that is, the rotation speed. be able to.
[0005]
However, in the method of detecting the wear of the bearing by mechanical contact, the life of the bearing is predicted, that is, the wear amount of the bearing is gradually or continuously measured until the rupturable plate ruptures. Not detectable. In other words, the operator can recognize that the rotary shaft has undergone a predetermined eccentric motion only after the rupture disk has ruptured, but cannot predict the rupture of the rupture disk. When the plate is ruptured, there is a problem that a replacement operation of the ruptured plate and the worn bearing causes a delay in a normal operation schedule of the motor.
[0006]
On the other hand, in the method of detecting wear of the bearing by detecting a change in an electric value that detects a change in rotational motion generated in a rotating shaft, a drive output source to the motor is a power supply that drives the motor at a fixed rotation speed. In the case, that is, when the number of rotations of the rotating shaft is constant, a change in the rotating motion generated in the rotating shaft can be detected as an electric value. Until the wear amount reaches the predetermined wear amount, the wear amount of the bearing can be detected stepwise or continuously.
[0007]
For example, when wear deterioration occurs in the bearing, high-frequency vibration is generated. The frequency of the high-frequency vibration is a natural frequency in each part of the bearing, and a vibration waveform obtained by detecting the natural frequency changes from a normal vibration waveform to a characteristic vibration waveform, thereby causing wear deterioration of the bearing. Can be detected.
[0008]
[Problems to be solved by the invention]
However, in the method of detecting the wear of the bearing by a change in an electric value detected by detecting a change in a rotational motion occurring on a rotating shaft, when a drive output source to the motor is an inverter, the inverter controls the motor. Since the number of revolutions of the rotating shaft in the motor changes, the electric value is changed not only by a change in rotating motion generated in the rotating shaft due to abnormal vibration, impact vibration, high-frequency vibration and the like, but also by control of the inverter. Since the value of the change in the rotational motion generated on the rotary shaft due to the change in the rotation speed also becomes a detected value, the amount of wear of the bearing until the wear amount of the bearing reaches a predetermined wear amount. Cannot be detected stepwise or continuously.
[0009]
The electric value is the number of rotations of the rotating shaft caused by the driving of the motor, i.e., the rotation speed, vibration, the magnitude of the change in the rotational motion obtained by integrating the eccentricity, etc. Is converted into an electrical quantity such as the frequency, pulse width, or duration.
[0010]
Therefore, even when the rotation speed changes under the control of the inverter, the rotation speed can be detected without being affected by the rotation speed change. By monitoring the electrical value that has detected the change in motion, the amount of wear of the bearing in the motor can be detected in a stepwise or continuous manner, and the life of the bearing in the motor can be predicted. Bearing wear can be monitored.
[0011]
An object of the present invention is to monitor the wear of a bearing of a motor even when the rotation speed of a rotating shaft in the motor changes by controlling an inverter, to predict the life of the bearing of the motor, An object of the present invention is to provide a bearing wear monitoring device capable of detecting a bearing wear amount stepwise or continuously.
[0012]
Another object of the present invention is to provide a bearing wear that can monitor wear of a bearing by a search coil wound around a tooth portion of a stator of a motor even when the number of rotations of a rotating shaft of the motor changes under the control of an inverter. A monitoring device is provided.
[0013]
Another object of the present invention is to provide an electrostatic capacitance provided at a fixed position opposed to a part of a rotating body of a motor even when the rotation speed of a rotating shaft of the motor is changed by control of an inverter. It is an object of the present invention to provide a bearing wear monitoring device capable of monitoring bearing wear with a mold displacement sensor.
[0014]
Another object of the present invention is to detect a magnetic flux density provided on a permanent magnet provided on a part of a rotating body of a motor and a magnetic flux provided on a stator of the motor even when the rotation speed of a rotating shaft of the motor is changed by control of an inverter. An object of the present invention is to provide a bearing wear monitoring device capable of monitoring bearing wear by a sensor.
[0015]
Another object of the present invention is to adopt a sensor for measuring a change in magnetic flux density, in particular, a coil for detecting electromagnetic induction electromotive force as the magnetic flux density detection sensor, to monitor bearing wear capable of monitoring bearing wear. It is to provide a device.
[0016]
Another object of the present invention is to provide an acceleration sensor that indirectly detects the rotational acceleration of a rotating body of a motor as vibration of the rotating body even when the rotational speed of a rotating shaft of the motor changes under the control of an inverter. It is an object of the present invention to provide a bearing wear monitoring device capable of monitoring the bearing wear.
[0017]
Another object of the present invention is to provide a bearing wear monitoring device capable of operating a plurality of motors in parallel under the control of one inverter and monitoring the wear of the bearings of each motor.
[0018]
Another object of the present invention is to provide a bearing wear monitoring device capable of operating a plurality of motors in parallel by controlling a smaller number of inverters than the plurality of motors and monitoring wear of the bearings of each motor. It is in.
[0019]
[Means for Solving the Problems]
A first means for solving the above problems includes a plurality of motors each having a stator and a rotor, a power supply for driving the motor at a fixed rotation speed, an inverter for driving the motor at a variable rotation speed, and the motor Switching means for switching to one of the power supply and the inverter as a drive output source, and a change in rotational motion occurring on a rotating shaft of a motor driven at a fixed rotation speed by switching the switching means among the plurality of motors. A bearing wear monitoring device, comprising: a rotational movement change detecting means for detecting the rotational movement; and a rotational movement change displaying means for displaying a change in the rotational movement detected by the rotational movement change detecting means. ,
A second means for solving the above-mentioned problem is that the rotational movement change detecting means in the first means is electrically wound around the teeth of the stator, and can detect the eccentricity of the rotating shaft of the motor electrically. It is a bearing wear monitoring device that is a search coil,
A third means for solving the above-mentioned problem is that the search coil in the second means is provided with two tooth portions or a 120-degree rotationally symmetrical positional relationship of 180 degrees about a rotation axis of the motor. Bearing wear monitoring comprising two or three tooth coils wound around three tooth parts in a rotationally symmetrical positional relationship, wherein the two or three tooth coils are connected in series Device
A fourth means for solving the above-mentioned problem is that the rotational movement change detecting means in the first means is provided on a stationary member and faces a rotor in the motor or a rotating shaft passing through the rotor. A bearing wear monitoring device that is provided at a position and is a capacitance type sensor capable of detecting a capacitance that changes due to the eccentricity of the rotating shaft,
A fifth means for solving the above-mentioned problem is that the rotational movement change detecting means in the first means is a permanent magnet provided on a rotating shaft of the motor and a magnetic flux density detecting sensor provided on the stator. It is a bearing wear monitoring device,
A sixth means for solving the above-mentioned problem is a bearing wear monitoring device, wherein the rotational movement change detecting means in the first means is an acceleration sensor for detecting vibration caused by eccentricity of a rotating shaft in the motor.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
(General description)
The bearing wear monitoring device according to the present invention includes a plurality of motors each having a stator and a rotor, a power supply, an inverter, a switching unit, a rotational motion change detecting unit, and a rotational motion change display unit.
[0021]
The motor includes, for example, a rotor as a rotating body and a rotating shaft coupled to the rotor, a stator having, for example, a plurality of teeth at a fixed position near the rotating body, and a bearing that receives the rotating shaft. Have.
[0022]
A field in which the motor needs to be driven in a wide output range from a low output to a high output, for example, a field in which a pump must be operated in a wide discharge flow range from a small discharge flow to a large or large discharge flow. In such a case, a plurality of pumps may be required. In such a case, a plurality of the motors are employed and these are used as drive sources for the pumps. Further, as the plurality of motors, the motors having various output performances and output ranges can be combined according to various purposes to be used.
[0023]
As the power source, a drive output source that outputs power to the motor so that the motor can be driven at a fixed rotation speed, for example, an AC power source having a frequency of 50 to 60 Hz (hereinafter referred to as “AC 50/60” There is).
[0024]
Examples of the inverter include a device that performs frequency conversion of power output from the power supply so as to drive the motor at a variable speed, and a device having a function of driving the motor at a variable speed. There is no particular limitation as long as it exists.
[0025]
Examples of the switching unit include a switch that switches a drive output source to the motor to one of the power supply and the inverter.
[0026]
The rotational movement change detecting means has a function of detecting a change in rotational movement occurring on a rotating shaft of a motor driven at a fixed rotational speed.
[0027]
As the rotational movement change detecting means, a detector for detecting the electric value by converting the magnitude of the change in rotational movement generated on the rotating shaft of the motor driven at a fixed rotational speed to detect the electric value, for example, a detection coil, displacement Examples include a sensor, a magnetic flux density sensor, an acceleration sensor, a thermocouple, a thermistor, and the like.
[0028]
The rotational movement change detecting means has a function of converting industrial quantities such as speed, vibration, temperature, force, light, displacement, flow rate, relative permittivity, and pressure into electric values. Measurement technology can be employed.
[0029]
Examples of the conversion method include an electromagnetic induction electromotive force conversion method, a thermoelectromotive force conversion method, a conversion method using a piezoelectric phenomenon, a conversion method using a photoelectric phenomenon, an electrochemical electromotive force conversion method, a pulse conversion method, and a phase method. , A timed method, a method using a photoelectric tube, a method using a magnetostriction phenomenon, a method using a search coil, and the like.
[0030]
As the conversion method in the present invention, an electromagnetic induction electromotive force conversion method for measuring a change in magnetic flux density, a method for measuring vibration energy, a thermoelectromotive force conversion method for measuring heat energy, and the like are preferable.
When the motor is driven at a fixed number of rotations, the rotational movement change display means generates a change in the rotational movement that occurs on a rotating shaft driven by the drive of the motor and is detected by the rotational movement change detection means. It has the function of displaying as a value.
[0031]
The rotation movement change display means has a function of continuously displaying the electric value obtained by the rotation movement change detection means for a predetermined time, and updates the display of the electric value to a display of a newly detected electric value after a predetermined time has elapsed. Function, a function of comparing the electric value with a newly detected electric value after a predetermined time has elapsed, a function of storing the electric value each time the electric value is detected, a function of displaying the stored electric value again, A function of comparing any two electrical values among the plurality of electrical values stored each time the electrical value is detected, and the first electrical value stored among the plurality of electrical values stored each time the electrical value is detected; A function of comparing a newly detected electric value with a newly detected electric value, a function of comparing the last stored electric value of a plurality of electric values stored each time the electric value is detected with a newly detected electric value, and the like. It is preferred to have.
[0032]
In the present invention, when the motor is driven at a fixed rotation speed, the motor is continuously driven at a fixed rotation speed until a predetermined time elapses after an electric value is detected by the rotation movement change detection unit. Therefore, in the rotational movement change display means, the display can be continuously updated in real time each time an electric value is detected by the rotational movement change detection means.
[0033]
Further, after the electric value is detected by the rotational movement change detecting means when the motor is driven at a fixed rotational speed, the motor can be driven at a variable rotational speed within a predetermined time, While the motor is driven so that the number of rotations is variable, the display on the rotational movement change display means is not updated. When the motor is driven again at a fixed rotation speed after a lapse of a predetermined time and an electric value is detected after a lapse of a predetermined time, the display is continuously updated in real time every time the electric value is detected by the rotational movement change detecting means. be able to.
The fixed rotation speed is a fixed rotation speed, and the rotation speed can be made constant by a commercial power supply, for example, an AC power supply having a frequency of 50 to 60 Hz. By changing the output of the power supply, the fixed rotation speed can be maintained at a desired rotation speed.
[0034]
As the rotational movement change display means, for example, an electric value obtained by detecting the magnitude of the change in rotational movement generated on the rotating shaft of the motor driven at a fixed rotation speed by the rotational movement change detection means, and In addition, a monitor device that performs conversion processing on the electric value and displays converted processing data that is output can be cited.
[0035]
The monitor device preferably has a display unit having a display screen for displaying the electric value as detection data.
[0036]
The monitor function not only displays the electric value, but also stores the electric value as data so that the electric value can be compared with the electric value detected again after a predetermined time has elapsed. And a reading function for reading the stored data.
[0037]
The storage function is realized by, for example, providing a memory unit in the monitor device.
[0038]
The reading function is realized, for example, by providing a CPU in the monitor device.
[0039]
Further, it is preferable that the monitor device has a data processing function such as displaying a difference between the data stored in the storage function and the electric value detected again after a lapse of a predetermined time.
[0040]
The data processing function is realized by, for example, providing a data processing unit in the monitor device.
[0041]
It is preferable that the data processing unit has a function of calculating a degree of wear of the bearing, a wear rate, a prediction of a replacement time of the bearing, and the like by calculating the data.
[0042]
By having the data processing function, the wear amount of the bearing can be monitored accurately and easily.
[0043]
When the difference between the data stored in the storage function and the electric value detected again after a predetermined time has been displayed on the monitor device by the data comparison function is small, it is determined that the wear of the bearing is small. In the case where the difference is large, it can be determined that the wear of the bearing is large.
[0044]
The bearing wear monitoring device of the present invention having the configuration as described above switches a drive output source to the plurality of motors to one of the power supply and the inverter, and changes the number of rotations of the motors on the rotating shaft, By performing a parallel operation of the driving at a fixed rotation speed and the driving at a variable rotation speed, the magnitude of the change in the rotation motion generated on the rotation shaft in the motor driven at the fixed rotation speed is converted into the electric value. Can be detected, and the life of the bearing can be predicted by comparing the electric value with the electric value detected again after a lapse of a predetermined time. Alternatively, it can be detected continuously, and the wear amount of the bearing can be monitored.
[0045]
(Specific explanation)
-Part 1-
Hereinafter, an embodiment of the bearing wear monitoring device of the present invention will be described in detail with reference to the drawings.
[0046]
The case where the bearing wear monitoring device of the present invention is adopted as a bearing wear monitoring device for a canned motor in a water supply cand motor pump will be described.
[0047]
As shown in FIGS. 1, 2 and 3, the bearing wear monitoring device of the present invention includes a first motor 1 in a first water supply pump A, a second motor 2 in a second water supply pump B (not shown), AC power supply 3 having a frequency of 50 to 60, inverter 4, switches 5a, 5b, 5c and 5d provided in circuit 5A, search coil 6a provided in first motor 1, and second motor 2 It has a search coil 6 b (not shown) provided and a monitor device 7.
[0048]
For example, a graph of the amount of water used in one day in a certain section is shown in FIG. As shown in FIG. 4, nighttime water usage is low, while daytime water usage is high. Moreover, even in the daytime, it can be seen that a large amount of water is used between 8:00 and 10:00 in the morning and 6:00 to 8:00 in the evening.
[0049]
Therefore, in the case where water is supplied to the above-mentioned location using the first water supply pump A and the second water supply pump B, as shown in FIG. 4, the first water supply pump A and the second water supply pump B Must be greatly increased or decreased depending on the time of day, so that the operation and the rotation speed of the first motor 1 and the second motor 2 in the first water supply pump A and the second water supply pump B are changed. Controlling the discharge flow rate.
[0050]
If the discharge flow rate does not exceed the maximum discharge flow rate of one water supply canned motor pump, the operation of one of the first water supply pump A and the second water supply pump B is stopped and the remaining one Is operated by controlling the number of revolutions by the inverter 4.
[0051]
When the discharge flow rate exceeds the maximum discharge flow rate of one water supply canned motor pump, the two water supply canned motor pumps of the first water supply pump A and the second water supply pump B are operated in parallel. In this case, one of the units operates by controlling the number of rotations by the inverter 4, and the other unit operates by fixing the number of rotations.
[0052]
The maximum discharge flow rate can be set in advance in consideration of the capacity, economy, and sanitation of the water supply canned motor pump, and is set to 140 [l / min] in this embodiment.
[0053]
The search coil 6a is provided on two teeth 8c and 8d located at opposing poles of the stator 8a of the first motor 1 facing each other.
[0054]
On the other hand, the search coil 6b is provided on a tooth portion (not shown) located at an opposing pole in the stator 8b (not shown) of the second motor 2.
[0055]
In this embodiment, the search coil 6a has two tooth coils 6c and 6d wound around the two tooth portions 8c and 8d at symmetrical positions at a space angle of approximately 180 degrees. The two tooth coils 6c and 6d are connected in series.
The search coil 6b includes two tooth coils (not shown) wound around two tooth parts (not shown) at symmetrical positions at a space angle of about 180 degrees. And the two tooth coils are connected in series.
[0056]
By the search coil 6a, a change in the rotational motion generated in the rotor 9a and the rotating shaft 10a in the first motor 1 is converted into an electromotive force, and the electromotive force is detected. The electromotive force is displayed on the monitor device 7 as detection data.
[0057]
On the other hand, the search coil 6b converts a change in the rotational motion generated on the rotor 9b (not shown) and the rotating shaft 10b (not shown), which are the rotating bodies in the second motor 2, into electromotive force, and Power is detected. The electromotive force is displayed on the monitor device 7 as detection data.
[0058]
The switches 5a, 5b, 5c, and 5d provided in the circuit 5A are configured such that the drive output sources to the first motor 1 and the second motor 2 are the inverter 4 and the output stop, the AC power supply 3 and the inverter 4, The circuit 5A is switched so that output is stopped and any combination of the inverter 4, the inverter 4, and the AC power supply 3 is used.
[0059]
The combination of the drive output sources can be stored as an operation mode in an operation mode selection unit (not shown), and the operation mode selection unit is operated to smoothly select the operation mode and switch the circuit 5A. be able to.
[0060]
The operation mode selection means has a function of operating the switches 5a, 5b, 5c, and 5d so that the circuit 5A is adjusted to a circuit used in each operation mode.
[0061]
The operation modes in this embodiment, the drive output sources to the first motor 1 and the second motor 2 in each operation mode, and the switches used in each operation mode are as shown in Table 1.
[0062]
[Table 1]

[0063]
The operation mode I indicates an operation state of the first motor 1 at 0 to 8 o'clock and 20 to 24 o'clock in FIG.
[0064]
In the operation mode I, the circuit 5A is connected by the switch 5a, the operation of the second motor 2 is stopped, and the rotation speed of the first motor 1 is variably controlled by the inverter 4 for operation.
[0065]
The operation mode I + II indicates an operation state of the first motor 1 and the second motor 2 at 8:00 to 11:00 in FIG.
[0066]
In the operation mode I + II, the circuit 5A is connected by the switches 5b and 5c, the first motor 1 and the second motor 2 are operated in parallel, and the rotation speed of the first motor 1 is fixed by the AC power supply 3. The operation is performed at a rotation speed, and the rotation speed of the second motor 2 is variably controlled by an inverter 4 for operation.
[0067]
The operation mode II indicates an operation state of the second motor 2 at 11 to 18 o'clock in FIG.
[0068]
In the operation mode II, the circuit 5A is connected by the switch 5b, the operation of the first motor 1 is stopped, and the operation is performed by variably controlling the rotation speed of the second motor 2 by the inverter 4.
[0069]
The operation mode II + I indicates an operation state of the first motor 1 and the second motor 2 at 18:00 to 20:00 in FIG.
[0070]
In the operation mode II + I, the circuit 5A is connected by the switches 5a and 5d, the first motor 1 and the second motor 2 are operated in parallel, and the rotation speed of the second motor 2 is fixed by the AC power supply 3. The first motor 1 is operated at a rotational speed, and the first motor 1 is operated while being variably controlled by an inverter 4.
[0071]
In the operation modes I, I + II, II and II + I, the inverter 4 controls the rotation speed of the first motor 1, the rotation speed of the second motor 2, the rotation speed of the second motor 2, and the rotation speed of the first motor 1 respectively. Since it is possible to control the discharge flow rate, it is possible to adjust the discharge flow rate to an optimum flow rate according to the amount of water used which increases or decreases depending on the time zone.
[0072]
Further, in the operation modes I + II and II + I, the AC power source 3 allows the first motor 1 and the second motor 2 to operate at a fixed rotation speed, so that the bearings 11a and 11b (shown in FIG. And the magnitude of the change in the rotational movement of the first motor 1 and the second motor 2 resulting from the rotation speed, vibration, eccentricity, and the like of the rotors 9a and 9b are converted into an electromotive force. The electromotive force is detected. The electromotive force is displayed on the monitor device 7 as detection data.
[0073]
In the operation mode I at 0 to 8 o'clock, there is no display of newly detected detection data on a display screen (not shown) provided with the first to fourth display windows of the monitor device 7.
[0074]
In the operation mode I + II at 8 to 11 o'clock, the magnitude of the change in the rotational motion of the first motor 1 between the rotor 9a and the rotary shaft 10a is converted to the electromotive force, and the first display on the display screen is performed. It is displayed as detection data in a window (not shown).
[0075]
In the operation mode II from 11 to 18 o'clock, the detection data of the first display window is continuously displayed.
[0076]
In the operation mode II + I at 18:00 to 20:00, the magnitude of the change in the rotational motion between the rotor 9b and the rotary shaft 10b in the second motor 2 is converted into the electromotive force, and the second display on the display screen is performed. The detection data is displayed on a window (not shown) as detection data, and the detection data of the first display window is continuously displayed.
[0077]
In the operation mode I at 24:00 to 24:00, the detection data of the first display window and the second display window is continuously displayed.
[0078]
Further, in the operation mode I at 0 to 8:00 on the following day, the detection data of the first display window and the second display window is continuously displayed.
[0079]
In the operation mode I + II at 8 to 11 o'clock of the next day, the magnitude of the change in the rotational movement of the first motor 1 between the rotor 9a and the rotary shaft 10a is converted into an electromotive force again, and The detection data is displayed on a display window (not shown) as detection data, and the detection data of the first display window and the second display window is continuously displayed.
[0080]
In the operation mode II at 11 to 18:00 on the next day, the detection data of the first display window, the second display window, and the third display window are continuously displayed.
[0081]
In the operation mode II + I at 18:00 to 20:00 on the following day, the magnitude of the change in the rotational motion of the second motor 2 between the rotor 9b and the rotating shaft 10b is converted into an electromotive force again, and the fourth screen of the display screen is displayed. The detection data is displayed on a display window (not shown) as detection data, and the detection data of the first display window, the second display window, and the third display window is continuously displayed.
[0082]
By comparing the detection data displayed in the first display window with the detection data displayed in the third display window, a change in the rotational motion occurring in the rotor 9a is detected before and after 24 hours. Data can be compared with high accuracy and easily, and a change in the rotational movement caused by wear of the bearing 11a can be monitored.
[0083]
Further, by comparing the detection data displayed in the second display window with the detection data displayed in the fourth display window, a change in the rotational motion occurring in the rotor 9b is detected before and after 24 hours. The detected data thus obtained can be compared with high accuracy and easily, and a change in the rotational movement caused by wear of the bearing 11b can be monitored.
[0084]
The monitor device 7 includes a memory unit (not shown) for storing the detection data, a CPU (not shown) for reading the detection data, and a data processing unit (not shown) for performing arithmetic processing on the detection data. A display unit (not shown) for displaying the processing data processed by the data processing unit and the detected data on a display screen (not shown), for example, a CRT screen; and a warning display unit (not shown), for example, a warning lamp. , A speaker (not shown).
[0085]
The display unit displays the detected data obtained by detecting a change in the rotational motion caused by wear of the bearing 11a on a display screen in a real-time display window in real time, and processes the detected data on a display screen. Displaying the processed data obtained in the processing data display window on the display screen, and displaying the speed data obtained by performing arithmetic processing on the two processed data detected before and after a predetermined time on the display screen by a wear speed display window. And displaying at least one or all of the time data obtained by arithmetically processing the speed data on the display screen in the remaining time display window.
[0086]
In the data processing unit, for example, an initial detection value obtained when a new unworn bearing is attached and a limit wear value of the bearing can be set in advance.
[0087]
The initial detection value may be a detection value obtained when a change in the rotational motion is detected using a bearing that has already worn.
[0088]
The data processing unit recognizes, for example, the initial detection value as 0% and the marginal wear value as 100%, performs an arithmetic operation on the detection data to obtain a percentage processing data value, and calculates the percentage processing data value as the percentage. The information can be displayed in the processing data display window on the display unit.
[0089]
When the detection value obtained when the change in the rotational motion is detected using a bearing that has already worn is set as the initial detection value, the data processing unit sets the initial detection value to 0%. The present invention is not limited to this, and it is also possible to recognize an appropriate percentage corresponding to the wear caused by the bearing.
The first to fourth display windows on the display unit include a first to fourth real-time display windows (not shown), first to fourth processing data display windows (not shown), and first to fourth wear speed display windows (FIG. (Not shown) and first to fourth remaining time display windows (not shown).
[0090]
The data processing unit obtains a speed data value by performing an arithmetic process on two processing data values displayed in the first processing data display window and the third processing data display window, and converts the speed data value into a third Display on the wear speed display window.
[0091]
The data processing unit obtains a time data value by performing an arithmetic processing on the speed data value, the initial detection value, and the limit wear value displayed in the third wear speed display window, and obtains the time data value. 3 Displayed in the remaining time display window.
[0092]
The monitoring operator can easily determine the wear rate of the bearing 11a with respect to the initial detection value from the percentage processing data value displayed in the third processing data display window, for example.
[0093]
Further, the monitoring operator can easily monitor the wear speed of the bearing 11a from the speed data value displayed in the third wear speed display window, for example.
[0094]
Further, the monitoring operator can easily grasp the remaining time until the replacement of the bearing 11a from the time data value displayed in the third remaining time display window, for example.
[0095]
Further, the data processing unit is provided with a warning so that a warning is displayed on the warning display unit when the wear rate reaches a predetermined percentage data value or when the remaining time is shorter than a predetermined time. You can also set outgoing values.
[0096]
When the wear rate or the remaining time reaches the warning transmission value, the data processing unit transmits a warning signal to the warning display unit and the speaker, so that a warning display sign is provided on the warning display unit, for example, Illumination of a warning lamp is indicated, and a warning sound is emitted from the speaker.
[0097]
In the first embodiment, the first motor 1 and the second motor 2 correspond to a plurality of motors in the present invention, and the search coils 6a and 6b correspond to the rotational motion change in the present invention. The switches 5a, 5b, 5c and 5d correspond to the switching means in the present invention, and the monitor device 7 corresponds to the rotational movement change displaying means in the present invention.
[0098]
-Part 2-
In the present invention, as a modification of the first embodiment, the number of water supply pumps arranged in parallel can be appropriately increased according to the performance of the water supply pump.
[0099]
For example, in a plant equipped with multiple pumps, the total head during operation of all pumps is the maximum head, so this maximum head value is used as the design head to prevent cavitation, start pumps, change the flow load, etc. , The number of units can be controlled.
[0100]
This embodiment describes a case where three water supply pumps are used.
[0101]
When the three water pumps are used, for example, as shown in FIG. 5, a circuit 5B is connected to the circuit 5A of the first embodiment, and the three motors of the first motor 1, the second motor 2 and the third motor 12 are connected. Is operated according to the discharge flow rate.
[0102]
In the second embodiment, as shown in Table 2, each of the operation modes other than the operation modes A, E, and I includes a motor that operates at a fixed rotation speed. The magnitude of the change in the rotational motion of the rotor of each motor can be detected as detection data, and the wear amount of the bearing can be monitored more finely.
[0103]
Further, by considering the capacity of the motor, for example, by optimizing the type, type, number of parallel pumps, and setting of the maximum discharge flow rate, etc., the motor can be operated efficiently, and the life of the motor can be improved. Can be extended.
[0104]
[Table 2]

[0105]
-Part 3-
As shown in FIGS. 6 and 7, other forms can be given as the search coil in the first embodiment.
[0106]
The search coil 13 in FIG. 6 is symmetrical at a space angle of approximately 120 degrees, that is, the tooth coil 13a wound around the teeth 14a, 14b, and 14c of the stator 14 in each of three phases separated by 120 degrees. , 13b and 13c.
[0107]
The search coil 15 in FIG. 7 has tooth coils 15a, 15b, 15c, and 15d symmetrically wound around the teeth 16a, 16b, 16c, and 16d of the stator 16 at a space angle of approximately 90 degrees.
[0108]
-Part 4-
As shown in FIG. 8, a magnetic flux density sensor 17, which is another embodiment of the rotational movement change detecting means, can be employed.
[0109]
The magnetic flux density sensor 17 is provided, for example, at an appropriate position facing the rotor 19 in the stator 18, and together with the permanent magnet 20 provided on the rotor 19, the rotor 19, which is the rotating body of the motor in this embodiment, A change in the rotational movement occurring on the shaft 21 can be detected as a change in the magnetic flux density.
[0110]
As another embodiment, the magnetic flux density sensor can be provided at an appropriate position on the stator opposite to the rotation axis, and together with the permanent magnet provided on the rotation axis opposite to the magnetic flux density sensor, the motor rotates. A change in the rotational movement generated in the rotor and the rotating shaft as a body can be detected as a change in the magnetic flux density.
[0111]
As the magnetic flux density sensor, an induction coil type magnetic flux density sensor having a coil for converting and detecting the change in the magnetic flux density into an electromagnetic induction electromotive force, a Hall element for converting and detecting the change in the magnetic flux density into a current value. A Hall IC type magnetic flux density sensor, a magnetoresistive type magnetic flux density sensor that converts a change in the magnetic flux density into a resistance value and detects the resistance value.
[0112]
-Part 5-
As another embodiment of the rotational movement change detecting means, a capacitance type sensor (not shown) conventionally used in the field of industrial measurement can be adopted.
[0113]
The capacitance-type sensor is fixed to a stationary member of the motor in this embodiment, that is, a non-rotating body of the motor, and faces a rotor that is a rotating body of the motor or a rotating shaft that passes through the rotor. Position.
[0114]
The capacitance-type sensor can detect a change in relative dielectric constant between a part of the rotating body facing the capacitance-type sensor and the capacitance-type sensor.
[0115]
-Part 6-
As another embodiment of the rotational motion change detecting means, an acceleration sensor (not shown) conventionally used in the field of industrial measurement can be employed.
[0116]
The acceleration sensor can be provided at an appropriate position on the rotating body so as to be able to detect vibration caused by eccentric movement of the rotor and the rotating shaft which are the rotating body of the motor in this embodiment.
[0117]
The acceleration sensor may convert the vibration of the rotating body in the motor into an electromotive force and detect the electromotive force as detection data.
[0118]
【The invention's effect】
The bearing wear monitoring device of the present invention switches the drive output source to a plurality of motors, and drives the rotation speed of the rotation shaft of each motor in parallel with driving at a fixed rotation speed and driving at a variable rotation speed. While the operation of the motor driven at a variable rotation speed is continued, an electric value generated by a change in the rotation motion of the motor driven at a fixed rotation speed is detected by the rotation movement change detection means and displayed on the rotation movement change display means. The life of the bearing can be predicted from the detected data and various processing data, the amount of wear of the motor bearing can be detected stepwise or continuously at predetermined time intervals, and the wear of the motor bearing can be monitored. Can be.
[0119]
In addition, it is possible to easily and accurately compare changes in electromotive force caused by changes in the rotational motion of the rotating shaft and the rotor in a motor operating at a fixed rotation speed, and to monitor changes in electromotive force caused by bearing wear. can do.
[0120]
In the bearing wear monitoring device of the present invention, it is possible to optimize, for example, the number of parallel pumps equipped with motors and the setting of the maximum discharge flow rate in each pump, and to monitor the wear amount of the bearing of each motor. .
[0121]
That is, in the bearing wear monitoring device of the present invention, various pumps can be combined according to the required discharge flow rate, and optimal operation can be performed in consideration of the performance of each pump. Can be extended, and the wear amount of the bearing of each motor can be monitored.
[0122]
Further, in the bearing wear monitoring device of the present invention, a plurality of motors can be operated in parallel by controlling a smaller number of inverters than the plurality of motors, and the bearing wear of each motor can be monitored.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing one embodiment of a bearing wear monitoring device of the present invention.
FIG. 2 is a partial cross-sectional view of a water supply pump that can be employed in one embodiment of the bearing wear monitoring device of the present invention.
FIG. 3 is a sectional view taken along a line III-III in FIG. 2;
FIG. 4 is a graph showing a transition of a daily discharge flow rate of a water supply pump in one embodiment of the bearing wear monitoring device of the present invention.
FIG. 5 is a circuit diagram showing another embodiment of the bearing wear monitoring device of the present invention.
FIG. 6 is a sectional view of a rotational motion change detecting means in the bearing wear monitoring device according to one embodiment of the present invention.
FIG. 7 is a sectional view of a rotational motion change detecting means in one embodiment of the bearing wear monitoring device of the present invention.
FIG. 8 is a cross-sectional view of a rotational movement change detection means in another embodiment of the bearing wear monitoring device of the present invention.
[Explanation of symbols]
A: first water supply pump, 1 ... first motor, 2 ... second motor, 3 ... AC power supply, 4 ... inverter, 5A, 5B ... circuit, 5a, 5b, 5c, 5d: switch, 6a: search coil, 6c, 6d: tooth coil, 7: monitoring device, 8a: stator, 8c, 8d: tooth, 9a ...・ Rotor, 10a ・ ・ ・ Rotary shaft, 11a ・ ・ ・ Bearing, 12 ・ ・ ・ Third motor, 13 ・ ・ ・ Search coil, 13a, 13b, 13c ・ ・ ・ Tooth coil, 14 ・ ・ ・ Stator, 14a , 14b, 14c: tooth portion, 15: search coil, 15a, 15b, 15c, 15d: tooth coil, 16: stator, 16a, 16b, 16c, 16d: tooth portion, 17 ... magnetic flux density sensor, 18 ... stator, 19 ... b Motor, 20 ... permanent magnet, 21 ... rotary shaft.

Claims (6)

A plurality of motors each including a stator and a rotor; a power supply for driving the motor at a fixed rotation speed; an inverter for driving the motor at a variable rotation speed; and any one of the power supply and the inverter as a drive output source for the motor. Switching means for switching between the first and second motors, a rotational movement change detecting means for detecting a change in rotational movement occurring on a rotating shaft of a motor driven at a fixed rotational speed by switching the switching means among the plurality of motors, A rotational movement change display means for displaying a change in the rotational movement detected by the change detecting means. The bearing according to claim 1, wherein the rotational movement change detecting means according to claim 1 is a search coil wound around teeth of the stator and capable of electrically detecting the eccentricity of the rotating shaft of the motor. Wear monitoring device. 3. The search coil according to claim 2, wherein the two teeth have a rotationally symmetrical positional relationship of 180 degrees or the three teeth have a rotationally symmetrical positional relationship of 120 degrees about a rotation axis of the motor. 3. The bearing wear monitoring device according to claim 2, further comprising two or three tooth coils wound around the bearing, and wherein the two or three tooth coils are connected in series. 4. The rotational motion change detecting means according to claim 1 is provided on a stationary member, and is provided at a position opposed to a rotor of the motor or a rotating shaft passing through the rotor, and changes due to eccentricity of the rotating shaft. The bearing wear monitoring device according to claim 1, wherein the bearing wear monitoring device is a capacitance type sensor capable of detecting the capacitance of the bearing. The bearing wear monitoring device according to claim 1, wherein the rotational movement change detecting means according to claim 1 is a permanent magnet provided on a rotating shaft of the motor and a magnetic flux density detecting sensor provided on the stator. 2. The bearing wear monitoring device according to claim 1, wherein the rotational movement change detection unit according to claim 1 is an acceleration sensor that detects vibration caused by eccentricity of a rotation shaft of the motor.

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