JP5004219B2 - Oil film dielectric breakdown evaluation system - Google Patents
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Description
本発明は、インバータ駆動モータや鉄道主軸の軸受などで発生する軸受電食の現象解明に用いる装置に関する。 The present invention relates to an apparatus used for elucidating a phenomenon of bearing electric corrosion that occurs in an inverter drive motor, a bearing of a railway main shaft, and the like.
従来の油膜絶縁破壊評価装置の例として、つぎのような動的な試験装置と静的な試験装置がある（例えば、非特許文献１参照）。
まず、第１の従来例として動的な油膜絶縁破壊評価装置の例を図９に示す。図において、２０はボール、２１、２２、２３は内輪、２４はオイルタンク、２５は直流電源、２６はばね、２７はねじである。この装置は、内輪２１と内輪２２が所定の間隔を設けて平行に配置され、この間にボール２０が装着され、さらにこのボール２０の上に内輪２３が載置された構成になっている。そして、内輪２１と内輪２２間に直流電源２５の出力端子が接続されている。
本装置の動作はつぎのようになる。ボール２０と内輪間にオイルタンク２４から油を滴下する。ねじ２７を調整し内輪とボール２０間に負荷を与える。内輪２１を図示しないモータにより回転させ、ボール２０を転がす。その結果、内輪２２、２３が回転する。ボール２０と内輪２１、２２、２３の間に油膜が形成される。この油膜の厚さは内輪２１の回転速度により可変でき、その油膜厚さはＥＨＬ理論（弾性流体潤滑理論）で計算して求める。内輪２１、２２に電圧を印加して、電圧計Ｖ１とＶ２の値を比べ、油膜が絶縁破壊しているかを判定する。油膜が絶縁破壊していないと、内輪２１、２２間の抵抗は１０ＭΩ以上なので、Ｖ２＝Ｖ１になる。油膜が絶縁破壊すると、内輪２１、２２間の抵抗は数ΩになるのでＶ１≒０になる。したがって、このＶ１の値により油膜の絶縁破壊を判定できる。
つぎに、第２の従来例として静的な油膜絶縁破壊評価装置の例を図１０に示す。図において、２８はディスク、２９はアクチュエータ、３０は位置センサである。この装置は、ディスク２８の１個とボール２０の１個で構成し、ディスク２８とボール２０間に油滴を滴下し、アクチュエータ２９により負荷を与える。ディスク２８とボール２０との距離を接触した状態からサブミクロンレベルで離すことで軸受内部の油膜を模擬する。この距離は位置センサ３０で実測する。ここに直流電源２５から電圧を印加して、Ｖ１の値により油膜の絶縁破壊を判定する。
このように、従来の油膜絶縁破壊評価装置は、油膜を隔てた２面間に電圧を印加し、絶縁破壊を評価するものである。
First, FIG. 9 shows an example of a dynamic oil film dielectric breakdown evaluation apparatus as a first conventional example. In the figure, 20 is a ball, 21, 22 and 23 are inner rings, 24 is an oil tank, 25 is a DC power source, 26 is a spring, and 27 is a screw. In this device, an inner ring 21 and an inner ring 22 are arranged in parallel at a predetermined interval, a ball 20 is mounted between them, and an inner ring 23 is placed on the ball 20. An output terminal of a DC power supply 25 is connected between the inner ring 21 and the inner ring 22.
The operation of this device is as follows. Oil is dropped from the oil tank 24 between the ball 20 and the inner ring. The screw 27 is adjusted to apply a load between the inner ring and the ball 20. The inner ring 21 is rotated by a motor (not shown) to roll the ball 20. As a result, the inner rings 22 and 23 rotate. An oil film is formed between the ball 20 and the inner rings 21, 22, 23. The thickness of the oil film can be varied depending on the rotation speed of the inner ring 21, and the oil film thickness is calculated by EHL theory (elastohydrodynamic lubrication theory). A voltage is applied to the inner rings 21 and 22, and the values of the voltmeters V1 and V2 are compared to determine whether the oil film has a dielectric breakdown. If the oil film does not break down, the resistance between the inner rings 21 and 22 is 10 MΩ or more, so V2 = V1. When the oil film breaks down, the resistance between the inner rings 21 and 22 becomes several Ω, so that V1≈0. Therefore, the breakdown of the oil film can be determined from the value of V1.
Next, FIG. 10 shows an example of a static oil film dielectric breakdown evaluation apparatus as a second conventional example. In the figure, 28 is a disk, 29 is an actuator, and 30 is a position sensor. This apparatus is composed of one disk 28 and one ball 20, and an oil droplet is dropped between the disk 28 and the ball 20, and a load is applied by an actuator 29. The oil film inside the bearing is simulated by separating the distance between the disk 28 and the ball 20 from the contacted state at a submicron level. This distance is actually measured by the position sensor 30. A voltage is applied from the DC power supply 25 here, and the dielectric breakdown of the oil film is determined by the value of V1.
Thus, the conventional oil film dielectric breakdown evaluation apparatus applies a voltage between the two surfaces separating the oil film to evaluate the dielectric breakdown.
ところが、従来の絶縁破壊評価装置についてはつぎの問題がある。
［第１の従来例］
（１）本装置は、油膜厚さの計算値が定量値と言えない。油膜厚さの計算には油の粘度の値が必要であり、素性の分かった油であれば油の粘度を高い精度で推定できるが、使用後の油や、混合された油の場合は粘度が不明であり、粘度計測から実施しなくてはいけないからである。
（２）仮に粘度が分かり計算できたとしても、接触域は０．１ｍｍ２程度と比較的大きく、その接触域で油膜厚さが厚いところと薄いところがあり、放電がどの部分で起こっているのか分からないので、計算により油膜厚さを算出してもあまり意味が無い。
（３）また、表面粗さの変化を考慮できない。２面には表面粗さがあり、放電は油膜厚さだけではなく、表面粗さとの比で決まると思われるが、表面粗さは試験時間の経過と共に試料の表面は粗くなる。表面粗さの変化までは計算できない。
（４）さらに、金属接触と放電を混同する。油膜厚さが表面粗さ程度に薄い場合、電圧変化（電流でも同じ）からは金属接触と放電の区別が出来ない。
［第２の従来例］
（１）本装置は、静的な状態で２面を近づけるだけなので、油には荷重がかからず、油の物性が実軸受の場合と大きく異なる。静的な状態で近づけるだけだと油は粘性流体のままの状態である。小さくても荷重を加えると、面圧で言えば１ＧＰａ程度の高面圧が生じ油は粘弾性体や弾塑性固体になる。こうなると粘性流体のときと比べ、体積弾性係数が１桁ほど異なる。実際に絶縁破壊電圧を測定すると、実機モータとは２桁違う値となる。
本発明はこのような問題点に鑑みてなされたものであり、油膜厚さが実測できると共に、表面粗さの変化も見逃すことなく、金属接触と放電を混同せずに、油の物性を実軸受と同じ状態で、油膜の絶縁破壊を評価することができる油膜絶縁破壊評価装置を提供することを目的とする。
However, the conventional dielectric breakdown evaluation apparatus has the following problems.
[First Conventional Example]
(1) In this apparatus, the calculated value of the oil film thickness cannot be said to be a quantitative value. Calculation of the oil film thickness requires the value of the viscosity of the oil, and if it is an oil with known characteristics, the viscosity of the oil can be estimated with high accuracy, but in the case of oil after use or mixed oil, the viscosity This is because it is unknown and must be carried out from viscosity measurement.
(2) Even if the viscosity can be understood and calculated, the contact area is relatively large at about 0.1 mm 2, and there are places where the oil film thickness is thick and thin in that contact area, and where the discharge occurs Since it is not known, it does not make much sense to calculate the oil film thickness by calculation.
(3) Moreover, the change of surface roughness cannot be considered. The two surfaces have surface roughness, and the discharge is determined not only by the oil film thickness but also by the ratio to the surface roughness, but the surface roughness becomes rougher as the test time elapses. It cannot be calculated until the surface roughness changes.
(4) Furthermore, metal contact and discharge are confused. When the oil film thickness is as thin as the surface roughness, it is not possible to distinguish between metal contact and discharge from the voltage change (same for current).
[Second Conventional Example]
(1) Since this device only brings the two surfaces closer in a static state, no load is applied to the oil, and the physical properties of the oil are significantly different from those of the actual bearing. The oil remains in a viscous fluid state when it is brought close to it in a static state. If a load is applied even if it is small, a high surface pressure of about 1 GPa is generated in terms of surface pressure, and the oil becomes a viscoelastic body or an elastoplastic solid. In this case, the bulk modulus differs by an order of magnitude compared to the viscous fluid. When the breakdown voltage is actually measured, the actual motor is two orders of magnitude different.
The present invention has been made in view of such problems. The oil film thickness can be measured, the change in surface roughness is not overlooked, and the physical properties of the oil are realized without confusion between metal contact and discharge. An object of the present invention is to provide an oil film dielectric breakdown evaluation apparatus capable of evaluating the dielectric breakdown of an oil film in the same state as a bearing.
上記課題を解決するため、本発明の一の観点によれば、油膜を挟んだ２つの物体間に電圧を印加して油膜の絶縁破壊を調べる油膜絶縁破壊評価装置であって、前記一方の物体を透明体とし、かつ、前記他方の物体との接触面側に可視光を透過する電極を備え、前記電極は、光干渉により油膜厚さを測定する金属膜とした油膜絶縁破壊評価装置が適用される。
また、前記電極を透明導電膜としてもよい。
また、前記電極を金属膜と透明導電膜とを少なくとも１層ずつ積層してもよい。
また、前記電極を前記透明体の表面から金属膜、透明膜、金属膜の順に積層し、光干渉により接触応力を測定するようにしてもよい。
また、前記電極を前記透明体の表面に、金属膜と透明導電膜とを積層した第１積層膜の領域と、透明な膜が金属膜で挟まれて積層された第２積層膜の領域とを有してもよい。
In order to solve the above-described problem, according to one aspect of the present invention, there is provided an oil film dielectric breakdown evaluation apparatus for examining a dielectric breakdown of an oil film by applying a voltage between two objects sandwiching an oil film, wherein the one object And an electrode that transmits visible light on the contact surface side with the other object, and the electrode is applied to an oil film dielectric breakdown evaluation device that is a metal film that measures the oil film thickness by optical interference. Is done.
In addition, the previous SL electrode may be used as the transparent conductive film.
Also, the pre-Symbol electrode and a metal film and a transparent conductive film may be laminated by at least one layer.
The metal film pre Symbol electrode from the surface of the transparent body, a transparent film, are laminated in this order of the metal film, it may be measured contact stress by optical interference.
Also, the pre-Symbol electrodes on a surface of the transparent body, regions of the second multilayer film and the region of the first multilayer film by laminating a metal film and a transparent conductive film, a transparent film is stacked sandwiched by metal film it may have a door.
本発明によると、可視光を透過または一部反射する電極を用いているので、荷重をかけた状態で接触面の油膜厚さを光干渉法で実測しながら電圧・電流波形が記録でき、表面粗さの変化を見逃すことがない。
また、電極に透明導電膜を用いているので、抵抗値が低く十分な電流が流れ、放電が明瞭な発光現象として観察でき、金属接触と放電を混同せずに油膜の絶縁破壊を評価することができる。
また、透明導電膜を用いているので、発光現象が観察でき、金属膜により光干渉に必要な反射が得られ膜厚測定が確実になる。
また、金属膜と透明膜を積層しているので、ガラスディスクとボールの接触応力による透明膜の弾性変形量を、金属膜同士で生じる光干渉で実測できる。すなわち、油の物性に大きく影響する接触部の応力をモニタしながら油膜の絶縁破壊を評価できる。
また、２つの異なる積層膜の領域を設けたので、膜厚と接触部の応力を測定しながら油膜の絶縁破壊を１試験中に一緒に評価でき、特にグリースの油膜のように潤滑特性が時間の変化と共に変わる材料を評価する際、本発明は効果が大きい。
According to the present invention, since an electrode that transmits or partially reflects visible light is used, the voltage / current waveform can be recorded while measuring the oil film thickness of the contact surface with a light interference method under a load. Never miss a change in roughness.
In addition, since a transparent conductive film is used for the electrode, a sufficient current flows with a low resistance value, and the discharge can be observed as a clear light emission phenomenon, and the dielectric breakdown of the oil film should be evaluated without confusion between metal contact and discharge. Can do.
Further, since the transparent conductive film is used, the light emission phenomenon can be observed, and the reflection necessary for optical interference is obtained by the metal film, and the film thickness measurement is ensured.
Further, since the metal film and the transparent film are laminated, the elastic deformation amount of the transparent film due to the contact stress between the glass disk and the ball can be measured by optical interference generated between the metal films. That is, the dielectric breakdown of the oil film can be evaluated while monitoring the stress at the contact portion that greatly affects the physical properties of the oil.
In addition, since two different laminated film areas are provided, the dielectric breakdown of the oil film can be evaluated together during one test while measuring the film thickness and stress at the contact area. The present invention has a great effect in evaluating a material that changes with the change of.
以下、本発明の実施の形態について図を参照して説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
図１は、本発明の油膜絶縁破壊評価装置を示す断面図である。図において、１はガラスディスク、２は膜電極、３は油、４はボールである。なお、５は支持部材、６はシャフト、７は固定ねじ、８は絶縁物、９はばね、１１は電源、１２はブラシ、１３は光源、１４はプリズム、１５は高速度カメラである。
ガラスディスク１の下面には可視光を透過する膜電極２を被覆している。図２はガラスディスク１と膜電極２としての金属膜２ａを模式的に示した拡大模式図である。
ガラスディスク１の下面には、評価する油３を薄く塗りつけている。油には粘性があるので、評価試験の間はガラスディスク１よりたれ落ちない。ボール４を下方のばね９でガラスディスク１に押しつけ、シャフト６でガラスディスク１と繋がったプーリ１０を図示しないモータで回転させると、ボール４も供回りして自転する。その結果、ボール４とガラスディスク１の間にサブミクロンの油膜が形成される。上部より 高速度カメラ１５で観察すると０．１ｍｍ２程度の円形で、ボール４とガラスディスク１が接触していることが分かる。油膜の厚さは光干渉法で測定できる。絶縁破壊の状況は、シャフトとボール間にブラシを介して印加した電圧Ｖ１または回路に流れる電流Ａ１の測定で判定できる。なお、ガラスディスクは廉価であるが縦弾性係数が鋼と比べ低いので、高価ではあるが縦弾性係数が鋼とほぼ等しいサファイアディスクを使い、軸受内部の応力状態と厳密に等価にすることを狙う場合もある。
本発明が従来技術と異なる本質的な部分は、電極に透明体を使い、接触面を観察できるようにしているところである。
FIG. 1 is a sectional view showing an oil film dielectric breakdown evaluation apparatus according to the present invention. In the figure, 1 is a glass disk, 2 is a membrane electrode, 3 is oil, and 4 is a ball. 5 is a support member, 6 is a shaft, 7 is a fixing screw, 8 is an insulator, 9 is a spring, 11 is a power source, 12 is a brush, 13 is a light source, 14 is a prism, and 15 is a high-speed camera.
The lower surface of the glass disk 1 is covered with a membrane electrode 2 that transmits visible light. FIG. 2 is an enlarged schematic view schematically showing the glass disk 1 and the metal film 2 a as the membrane electrode 2.
A thin oil 3 to be evaluated is applied to the lower surface of the glass disk 1. Since oil is viscous, it does not sag from the glass disk 1 during the evaluation test. When the ball 4 is pressed against the glass disk 1 by the lower spring 9 and the pulley 10 connected to the glass disk 1 by the shaft 6 is rotated by a motor (not shown), the ball 4 also rotates and rotates. As a result, a submicron oil film is formed between the ball 4 and the glass disk 1. When observed with the high-speed camera 15 from above, it can be seen that the ball 4 and the glass disk 1 are in contact with each other in a circular shape of about 0.1 mm 2 . The thickness of the oil film can be measured by optical interferometry. The state of dielectric breakdown can be determined by measuring the voltage V1 applied via a brush between the shaft and the ball or the current A1 flowing through the circuit. Although the glass disk is inexpensive, its longitudinal elastic modulus is lower than that of steel, so it uses a sapphire disk that is expensive but has the same longitudinal elastic modulus as steel, and aims to be exactly equivalent to the stress state inside the bearing. In some cases.
The essential part of the present invention that differs from the prior art is that a transparent body is used for the electrodes so that the contact surface can be observed.
本発明の実施例１について図１、２を用いて説明する。本実施例では、膜電極２として、厚さ７ｎｍのクロムの金属膜２ａを用いた。この膜厚によると可視光の透過率はおよそ４０％、反射率はおよそ２０％である。ボール４は直径２５．４ｍｍ、材質ＳＵＪ２の軸受用鋼球である。ガラスディスク１は板厚１１ｍｍ、直径１８０ｍｍ、材質ＢＫ−７ガラスの円板である。油３は、昭和シェル石油製アルバニア＃２（基油：鉱油、増ちょう剤：Ｌｉせっけん）というグリースを用いた。
つぎに本実施例の動作について述べる。
先ず、ばね９の変位を調整して４０Ｎの力でボール４をガラスディスク１に押し当て、ボール４が２５０ｒｐｍで自転するようにガラスディスク１を回転させた。このとき、油３には実軸受相当の０．５ＧＰａの面圧が負荷されている。上部より高速度カメラ１５で撮影した画像を図３に示す。図中の矢印の先端部の領域が油膜の最も薄い部分である。測定分解能をあげるために、光源１３は、５５５ｎｍ（緑色）と６３０ｎｍ（赤色）の波長の異なる単色光を２色重ねた２色光源を用いている。油膜厚さは、色により測定している。このため、実際の油膜厚さと色との関係をあらかじめ分かっている隙間を用いて検定した関係データを用いている。この図では矢印の先端のところが最小の油膜厚さで、約０．５μｍである。
本発明の装置の特徴は、光干渉法で膜厚が実測できることである。試験時間の経過に伴い表面が粗くなっていくが、この装置を用いると油膜厚さが干渉縞により実測できるので、表面粗さの変化を見逃すことがない。
A first embodiment of the present invention will be described with reference to FIGS. In this example, a chromium metal film 2 a having a thickness of 7 nm was used as the membrane electrode 2. According to this film thickness, the visible light transmittance is about 40% and the reflectance is about 20%. The ball 4 is a steel ball for bearing having a diameter of 25.4 mm and a material SUJ2. The glass disk 1 is a disk of 11 mm in thickness, 180 mm in diameter, and material BK-7 glass. As the oil 3, grease called Albania # 2 (base oil: mineral oil, thickener: Li soap) manufactured by Showa Shell Sekiyu was used.
Next, the operation of this embodiment will be described.
First, the displacement of the spring 9 was adjusted, the ball 4 was pressed against the glass disk 1 with a force of 40 N, and the glass disk 1 was rotated so that the ball 4 was rotated at 250 rpm. At this time, the surface pressure of 0.5 GPa equivalent to a real bearing is applied to the oil 3. An image taken by the high speed camera 15 from above is shown in FIG. The region at the tip of the arrow in the figure is the thinnest part of the oil film. In order to increase the measurement resolution, the light source 13 uses a two-color light source in which two monochromatic lights having different wavelengths of 555 nm (green) and 630 nm (red) are superimposed. The oil film thickness is measured by color. For this reason, relational data obtained by testing using a gap in which the relation between actual oil film thickness and color is known in advance is used. In this figure, the tip of the arrow is the minimum oil film thickness, which is about 0.5 μm.
The feature of the apparatus of the present invention is that the film thickness can be measured by optical interferometry. Although the surface becomes rough as the test time elapses, if this apparatus is used, the oil film thickness can be actually measured by interference fringes, so that the change in surface roughness is not overlooked.
図４は、本発明の実施例２を示す電極部の拡大模式図である。図において、２ｂは膜電極２となる透明導電膜である。実施例１と異なる部分は、膜電極２として透明導電膜であるＩＴＯ（Ｉｎｄｉｕｍ，Ｔｉｎ，Ｏｘｉｄｅ）膜を３００ｎｍの厚さで用いている点である。本実施例で用いたＩＴＯ膜は、実施例１に比べて可視光の透過率が高く、膜厚を厚くでき、抵抗値を下げることが可能である。その結果、放電時の電流値を大きくでき、放電を発光現象として捉えることができる。
なお、本実施例では、透明導電膜としてＩＴＯを使用した例を示したが、ＳｎＯ２，ＺｎＯ、ＩＺＯ（Ｉｎｄｉｕｍ，Ｚｉｎｃ，Ｏｘｉｄｅ）など透明導電膜であれば同じ効果が得られる。
FIG. 4 is an enlarged schematic view of an electrode portion showing Example 2 of the present invention. In the figure, 2b is a transparent conductive film to be the membrane electrode 2. The difference from Example 1 is that an ITO (Indium, Tin, Oxide) film, which is a transparent conductive film, is used as the film electrode 2 with a thickness of 300 nm. The ITO film used in this embodiment has a higher visible light transmittance than that of the first embodiment, can be thicker, and can have a lower resistance value. As a result, the current value at the time of discharge can be increased, and the discharge can be regarded as a light emission phenomenon.
In the present embodiment, an example in which ITO is used as the transparent conductive film is shown, but the same effect can be obtained if it is a transparent conductive film such as SnO 2 , ZnO, or IZO (Indium, Zinc, Oxide).
図５は、本発明の実施例３を示す電極部の拡大模式図である。実施例２と異なる部分は、ガラスディスク１の表面からクロムを７ｎｍ被覆した金属膜２ａ、ＩＴＯ膜を３００ｎｍ被覆した透明導電膜２ｂの順に設け、金属膜２ａにより干渉縞をでき易くした点である。
図６は、本実施例において高速度カメラが捉えた放電による発光である。秒速２０００コマの速度で撮影している。図中の矢印の先端部の白点が発光部分である。つまり５００ｎｓの間に２箇所で絶縁破壊したことが分かる。そして、膜厚が最も薄いところだけで放電しているわけではないことが分かる。また、金属膜２ａを被覆しているので、実施例２に比べて反射率が高く、干渉縞ができ易い。つまり、本実施例の装置では、発光現象の捕捉と干渉縞の判別が同時に可能である。その結果、油膜の絶縁破壊現象の解明がより進む効果がある。
FIG. 5 is an enlarged schematic view of an electrode portion showing Example 3 of the present invention. The difference from Example 2 is that the metal film 2a coated with 7 nm of chromium from the surface of the glass disk 1 and the transparent conductive film 2b coated with 300 nm of ITO film are provided in this order to make interference fringes easier with the metal film 2a. .
FIG. 6 shows light emission by discharge captured by the high-speed camera in this embodiment. Shooting at a speed of 2000 frames per second. The white point at the tip of the arrow in the figure is the light emitting portion. That is, it can be seen that dielectric breakdown occurred at two locations during 500 ns. And it turns out that it is not necessarily discharged only in the place where the film thickness is the thinnest. Moreover, since the metal film 2a is covered, the reflectance is higher than that of the second embodiment, and interference fringes are easily formed. That is, in the apparatus of this embodiment, it is possible to simultaneously capture a light emission phenomenon and discriminate interference fringes. As a result, there is an effect of further elucidating the dielectric breakdown phenomenon of the oil film.
図７は、本発明の実施例４を示す電極部の拡大模式図である。図において、２ｃは透明膜、２ｄは金属膜である。本実施例の膜電極２は、ガラスディスク１の下面にクロムを７ｎｍ被覆した金属膜２ａ、ＳｉＯ２を８００ｎｍ被覆した透明膜２ｃ、最下面にクロムを３００ｎｍ被覆した金属膜２ｄから形成されている。最下面に金属膜２ｄ（３００ｎｍのクロム）を被覆しているので光源からの光は油膜に届かない。油を挟んでボール４をガラスディスク１に押し当てると接触応力によりガラスディスク１および電極膜２が弾性変形する。上部からの光は、金属膜２ａ（７ｎｍのクロムの膜）で一部が反射し、通過した光が金属膜２ｄで反射する。この光干渉により、二つの膜に挟まれた透明膜の弾性変形量が求まり、接触応力がモニタできる。なお、透明膜の弾性変形量は、干渉縞の色により測定している。このため、干渉縞の色と実際の弾性変形量との関係をあらかじめ分かっている荷重を負荷することで検定した関係データを用いている。 FIG. 7 is an enlarged schematic view of an electrode portion showing Example 4 of the present invention. In the figure, 2c is a transparent film and 2d is a metal film. The membrane electrode 2 of this embodiment is formed of a metal film 2a coated with 7 nm of chromium on the lower surface of the glass disk 1, a transparent film 2c coated with 800 nm of SiO2, and a metal film 2d coated with 300 nm of chromium on the lowermost surface. Since the lowermost surface is coated with the metal film 2d (300 nm of chromium), the light from the light source does not reach the oil film. When the ball 4 is pressed against the glass disk 1 with oil interposed therebetween, the glass disk 1 and the electrode film 2 are elastically deformed by contact stress. A part of the light from the upper part is reflected by the metal film 2a (7 nm chromium film), and the passed light is reflected by the metal film 2d. By this optical interference, the elastic deformation amount of the transparent film sandwiched between the two films can be obtained, and the contact stress can be monitored. Note that the amount of elastic deformation of the transparent film is measured by the color of the interference fringes. For this reason, relational data obtained by applying a load whose relation between the interference fringe color and the actual elastic deformation is known in advance is used.
図８は、本発明の実施例５を示す電極部の拡大模式図で、図８（ａ）はガラスディスクを下方から見た平面図、（ｂ）は側断面図である。図において、１６は第１積層膜、１７は第２積層膜である。本実施例は、ガラスディスク１に第１積層膜１６と第２積層膜１７を半分ずつ被覆している。すなわち、第１積層膜１６はガラスディスク１の表面から金属膜２ａ、透明導電膜２ｂの順に形成したものであり、第２積層膜１７は同じくガラスディスク１の表面から金属膜２ａ、透明膜２ｃ、金属膜２ｄの順に形成したものである。
ガラスディスクが１回転する間に、第１積層膜１６により油膜厚さの実測と放電の可視化ができ、第２積層膜１７により接触応力の実測ができる。このように本発明では、一度に２種類の評価ができるという利便性に加え、特にグリースの油膜のように潤滑特性が試験時間の経過と共に刻々と変わる材料を評価する際、一度に多面的に評価できるので、ガラスディスクを取り替えて２回評価する場合と比べ、本発明で得られたデータは信頼性が高い。
8A and 8B are enlarged schematic views of an electrode portion showing Example 5 of the present invention. FIG. 8A is a plan view of the glass disk as viewed from below, and FIG. 8B is a side sectional view. In the figure, 16 is a first laminated film, and 17 is a second laminated film. In this embodiment, the glass disk 1 is covered with the first laminated film 16 and the second laminated film 17 in half. That is, the first laminated film 16 is formed in the order of the metal film 2a and the transparent conductive film 2b from the surface of the glass disk 1, and the second laminated film 17 is similarly formed of the metal film 2a and the transparent film 2c from the surface of the glass disk 1. The metal film 2d is formed in this order.
During one rotation of the glass disk, the first laminated film 16 can measure the oil film thickness and visualize the discharge, and the second laminated film 17 can measure the contact stress. As described above, in the present invention, in addition to the convenience that two kinds of evaluation can be performed at one time, especially when evaluating a material whose lubricating characteristics change every moment as the test time elapses, such as an oil film of grease, it is multifaceted at a time. Since the evaluation can be performed, the data obtained by the present invention is more reliable than the case where the evaluation is performed twice after replacing the glass disk.
１ ガラスディスク
２ 膜電極
２ａ 金属膜
２ｂ 透明導電膜
２ｃ 透明膜
２ｄ 金属膜
３ 油
４、２０ ボール
５ 支持部材
６ シャフト
７ 固定ねじ
８ 絶縁物
９、２６ ばね
１０ プーリ
１１ 電源
１２ ブラシ
１３ 光源
１４ プリズム
１５ 高速度カメラ
１６ 第１積層膜
１７ 第２積層膜
２１、２２、２３ 内輪
２４ オイルタンク
２５ 直流電源
２７ ねじ
２８ レース
２９ アクチュエータ
３０ 位置センサ
DESCRIPTION OF SYMBOLS 1 Glass disk 2 Membrane electrode 2a Metal film 2b Transparent conductive film 2c Transparent film 2d Metal film 3 Oil 4, 20 Ball 5 Support member 6 Shaft 7 Fixing screw 8 Insulator 9, 26 Spring 10 Pulley 11 Power supply 12 Brush 13 Light source 14 Prism 15 High-speed camera 16 First laminated film 17 Second laminated film 21, 22, 23 Inner ring 24 Oil tank 25 DC power supply 27 Screw 28 Race 29 Actuator 30 Position sensor
Claims (5)
前記一方の物体を透明体とし、かつ、前記他方の物体との接触面側に可視光を透過する電極を備え、前記電極は、光干渉により油膜厚さを測定する金属膜としたものであることを特徴とする油膜絶縁破壊評価装置。 An oil film dielectric breakdown evaluation apparatus for examining a dielectric breakdown of an oil film by applying a voltage between two objects sandwiching the oil film,
The one object is a transparent body, and an electrode that transmits visible light is provided on the contact surface side with the other object, and the electrode is a metal film that measures the oil film thickness by light interference. oil film breakdown rating system you wherein a.
The electrode has a first laminated film in which a metal film and a transparent conductive film are laminated on a surface of the transparent body, and a second laminated film in which the transparent film is sandwiched between metal films. The oil film dielectric breakdown evaluation apparatus according to any one of claims 1 to 4 .
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| CN102564329B (en) * | 2011-12-31 | 2014-04-23 | 青岛理工大学 | Lubricating oil film measuring device with fixed skew or deflection angle for finite long line contact pair |
| CN103115846B (en) * | 2013-01-24 | 2014-11-26 | 郑州大学 | Visualization test device for flow form of inner and outer oil films of dynamic-pressure and static-pressure floating ring bearing |
| JP6095108B2 (en) * | 2013-02-07 | 2017-03-15 | 国立大学法人九州工業大学 | Pressure measuring device |
| CN103264256B (en) * | 2013-05-31 | 2015-09-30 | 上海宝冶集团有限公司 | The replacing options of vertical grinder powder concentrator lower bearing |
| JP2017044587A (en) * | 2015-08-27 | 2017-03-02 | 東レエンジニアリング株式会社 | Film thickness distribution measurement device |
| CN105277861A (en) * | 2015-11-19 | 2016-01-27 | 南车株洲电机有限公司 | Method for testing motor bearing dielectric strength |
| CN105865325B (en) * | 2016-04-02 | 2018-10-23 | 上海大学 | Double interference image frequency microscopes adjustable in pitch |
| CN109406878B (en) * | 2016-11-02 | 2020-09-08 | 安徽佳特瑞计量检测科技有限公司 | Intelligent detection system for power switch control cabinet circuit |
| CN106767572A (en) * | 2017-01-10 | 2017-05-31 | 中国科学院烟台海岸带研究所 | A kind of method for observing spilled oil on water surface oil film roughness |
| JP7288271B2 (en) * | 2018-11-29 | 2023-06-07 | 国立大学法人埼玉大学 | Film thickness distribution measuring device |
| TWI814325B (en) * | 2022-03-31 | 2023-09-01 | 國立勤益科技大學 | Oil film estimation device of machine tool feeding system |
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