JP4296611B2 - Rolling device - Google Patents

Description

【００５４】
また、第１及び第２の実施形態で説明した潤滑剤組成物中に上記油状化合物を含有させる場合、油状化合物としては、上記一般式（１）に示す化合物の他に、例えば、下記一般式（２）〜（５）に示す化合物を挙げることができる。なお、下記一般式（２）〜（５）において、ｍ、ｎは正の整数を示す。
【００５５】
【化２】

【００５６】
上記一般式（２）〜（５）に示す化合物において、少なくとも一方の置換基Ｒは、カルボキシル基（−ＣＯＯＨ）、アルコール基、及びイソシアネート基等の極性基である。また、アルコール基及びイソシアネート基としては、例えば下記式（６）〜（９）に示す置換基を挙げることができる。
【００５７】
【化３】

【００５８】
上記一般式（２）〜（５）において、２つの置換基Ｒがともにカルボキシル基、アルコール基、及びイソシアネート基等の極性基である場合、２つの置換基Ｒは互いに等しくてもよく、異なっていてもよい。また、一方の置換基Ｒのみがカルボキシル基、アルコール基、及びイソシアネート基等の極性基である場合、他方の置換基Ｒはフッ素原子とすることが好ましい。
【００５９】
以上説明した本発明の第１〜第３の実施形態に係る転動装置において、潤滑剤組成物には、上記効果を損なわない範囲で、上述の基油等の他に各種添加剤を配合することができる。潤滑剤組成物に配合される添加剤としては、酸化防止剤、防錆剤、耐摩耗剤、分散剤、金属保護剤、及び界面活性剤等を挙げることができる。これら添加物は、その種類により異なるが、全添加剤の合計量として、１５重量％程度まで加えることができる。
【００６０】
【実施例】
以下、本発明の実施例について説明する。
（実施例１）
図１に、軸受回転試験機６に設置された本発明の実施例に係る転がり軸受１の断面図を示す。この図で、転がり軸受１は、外周部に溝状の軌道が設けられた内輪２と内周部に溝状の軌道が設けられた外輪４とが同心上に配置され、転動体であるボール３が、内輪２及び外輪４のそれぞれの軌道上を転動可能に配置されて構成されている。内輪２と外輪４との間には、内輪２、外輪４、及びボール３の接触抵抗を減少し摩耗を防止するために、潤滑剤組成物５が収容されている。
【００６１】
この転がり軸受１について、潤滑剤組成物５の組成を様々に変えて、以下に示す条件下でそれぞれのトルク寿命及び発塵量を調べた。すなわち、転がり軸受１として、内径８ｍｍ、外径２２ｍｍ、幅７ｍｍの日本精工社製玉軸受（型番６０８）を用い、図１に示す軸受回転試験機６により上記特性を測定した。
【００６２】
なお、トルク寿命は、運転を開始してからトルク値が所定の閾値を超えるまでの回転時間とし、下記条件下で測定した。
温度 常温
雰囲気 大気雰囲気
回転速度 １０００ｒｐｍ
アキシアル荷重 １９６Ｎ
ラジアル荷重 １．９６Ｎ
また、発塵量は、所定の運転時間内に転がり軸受１からその外部へと飛散した潤滑剤組成物５の飛散滴等の微粒子の数とし、クラス１００のクリーンベンチ内に軸受回転試験機６を設置して、下記条件下で測定した。
【００６３】
温度 常温
雰囲気 大気雰囲気
回転速度 ３０００ｒｐｍ
アキシアル荷重 １９．６Ｎ
軸受回転試験機６としては、日本精工社製軸受回転試験機を用いた。この軸受回転試験機６によると、転がり軸受１の内輪２はスピンドル７の回転軸に固定され、転がり軸受１へのアキシアル荷重はスプリング８等により調整可能である。スピンドル７には磁性流体シールユニット１５が設けられており、スピンドル７の回転は、モータ９を駆動し、ベルト１０を介してプーリ１１からプーリ１２へ動力を伝達することにより行われる。一方、転がり軸受１の外輪４は、微小荷重変換器１４に接続されたハウジング１３に保持される。したがって、微小荷重変換器１４を用いて転がり軸受１のトルクを測定することができる。
【００６４】
また、転がり軸受１は、容器１６及び隔壁１７により囲まれ、その囲まれた空間の底部はレーザ光散乱式パーティクルカウンタ１８に接続されている。一方、この囲まれた空間の上部には、フィルタ２０を介して空気吸入口１９が設けられており、上記囲まれた空間に、清浄な空気を供給することができる。
【００６５】
したがって、上記囲まれた空間に、清浄な空気を所定の流量で供給することにより、空気吸入口１９からパーティクルカウンタ１８へ向けて気流が生じるため、転がり軸受１から生じる潤滑剤組成物５の飛散滴や摩耗粉の量、すなわち個数がパーティクルカウンタ１８により検出される。
以下の表１に、それぞれの転がり軸受１に用いた潤滑剤組成物５の組成、その封入量、トルク寿命、及び発塵量を示す。
【００６６】
【表１】

【００６７】
上記表１に示すＰＦＰＥ油としてはダイキン工業社製Ｓ−２００を用い、ＰＴＦＥポリマーとしてはダイキン工業社製ルブロンＬ−２を用いた。雲母Ａとして疎水化処理が施された膨潤性を有する雲母であるトピー工業社製合成雲母４Ｃ−ＴＳを用い、雲母Ｂとしては疎水化処理が施されていない膨潤性を有する雲母であるトピー工業社製合成雲母ＤＭＡ−３５０を用いた。雲母Ｃとしては疎水化処理が施された膨潤性を示さない雲母であるトピー工業社製合成雲母ＰＤＭ−９ＷＡを用い、雲母Ｄとしては疎水化処理が施されていない膨潤性を示さない雲母であるトピー工業社製合成雲母ＣＲ−ＴＳを用いた。また、モンモリロナイトとしてはコープケミカル社製合成スメクタイトＳＰＮを用いた。なお、上記雲母Ａ〜Ｄ及びモンモリロナイトは層状鉱物である。また、充填量とは、転がり軸受１に充填された潤滑剤組成物５の量をいう。
【００６８】
表１から明らかなように、本発明の実施例に係るサンプル（１）〜（１５）の転がり軸受はいずれも、従来の転がり軸受である比較用サンプル（１）、（２）に比べて、トルク寿命が長く発塵量が少ない。したがって、液体フッ素化ポリマー油と上記層状鉱物粉末とを含む潤滑剤組成物を用いることにより、トルク寿命特性を向上させ、発塵量を低減することができた。
【００６９】
また、サンプル（１）〜（１５）のそれぞれについてトルク寿命を比較すると、サンプル（１）〜（１２）、（１４）、（１５）は、サンプル（１３）に比べてトルク寿命が長い。これは、サンプル（１３）で用いた潤滑剤組成物５に比べて、サンプル（１）〜（１２）、（１４）、（１５）で用いられる潤滑剤組成物は、いずれも４５重量％以下の増粘剤含有率を有しているためであると考えられる。
【００７０】
サンプル（１）〜（１５）のそれぞれについて発塵量を比較すると、サンプル（１）、（３）〜（１３）は、サンプル（２）、（１４）、（１５）に比べて発塵量が少ない。サンプル（１）、（３）〜（１３）が、サンプル（２）に比べて発塵量が少ないのは、潤滑剤組成物５中に含有される層状鉱物粉末（雲母Ａ、雲母Ｂ、モンモリロナイト）の量に関係していると考えられる。すなわち、層状鉱物粉末の含有量が多い場合、層状鉱物粉末が転がり接触面間或いは滑り接触面間に介在してこれら接触面同士の直接接触を防止するためであると考えられる。
【００７１】
また、サンプル（１）、（３）〜（１３）が、サンプル（１４）、（１５）に比べて発塵量が少ないのは、潤滑剤組成物５の粘度に関係していると考えられる。すなわち、サンプル（１４）、（１５）で用いた潤滑剤組成物５が粘度の低い液状であるのに対し、サンプル（１）、（３）〜（１３）で用いた潤滑剤組成物５はグリース状であるためである。なお、サンプル（１４）、（１５）、及び比較用サンプル（２）における充填量と、他のサンプルにおける充填量との違いは、潤滑剤組成物５がグリース状であるか液状であるかによる。
【００７２】
サンプル（３）〜（７）は、潤滑剤組成物に用いる層状鉱物粉末の種類のみが異なっている。これらを比較すると、雲母Ｃ及びＤを用いた場合に比べ、雲母Ａ、Ｂ及びモンモリロナイトを用いた場合に、トルク寿命及び発塵量の両方で良好な値が得られている。これは、雲母Ｃ及びＤは膨潤性を示さないのに対し、雲母Ａ、Ｂ及びモンモリロナイトは膨潤性を示すため、上記接触面間に常に適量の基油を供給することが可能であるためであると考えられる。
【００７３】
また、雲母Ｂを用いた場合に比べ雲母Ａを用いた場合にトルク寿命及び発塵量の両方で良好な値が得られ、雲母Ｄを用いた場合に比べ雲母Ｃを用いた場合にトルク寿命に関して良好な値が得られている。これは、雲母Ａ及びＣは、雲母Ｂ及びＤとは異なり、疎水化処理されているためであると考えられる。特に、雲母Ａを用いた場合、基油のとり込みがより容易に行われたために、トルク寿命及び発塵量の双方が改善されたものと考えられる。
【００７４】
（実施例２）
次に、上記実施例１で製造したサンプル（３）と同様にして、ＰＦＰＥ油、ＰＴＦＥポリマー、及び雲母の重量比をそれぞれ６７重量％、３０重量％、及び３重量％とし、雲母の粒径を様々に変化させて転がり軸受１を製造した。なお、雲母としては、実施例１で使用した雲母Ａ〜Ｃを使用した。このようにして製造した転がり軸受１について、実施例１と同様にしてトルク寿命を測定した。その結果を図２にグラフにして示す。
【００７５】
図２において、横軸は雲母Ａ〜Ｃの平均粒径を示し、縦軸はトルク寿命を示している。また、図中、曲線２１は雲母Ａを使用した場合に得られたデータを示し、曲線２２は雲母Ｂを使用した場合に得られたデータを示し、曲線２３は雲母Ｃを使用した場合に得られたデータを示している。
【００７６】
このグラフに示すように、雲母Ａ〜Ｃの平均粒径がいずれの範囲にあっても長いトルク寿命が得られている。特に、平均粒径を０．０５μｍ〜２０μｍの範囲内とした場合により良好なトルク寿命が得られ、０．１μｍ〜１０μｍとした場合、例えば雲母Ａを用いた転がり軸受１においては５００時間を超えるほどの良好なトルク寿命を得ることができた。
【００７７】
( 実施例３)
上記実施例１で製造したサンプル（７）と同様にして、潤滑剤組成物中のＰＴＦＥポリマーの含有率を一定とし（２０重量％）、ＰＦＰＥ油及び雲母の含有率を様々に変化させて転がり軸受１を製造した。なお、雲母としては、実施例１で使用した雲母Ａ〜Ｃを使用した。このようにして製造した転がり軸受１について、実施例１と同様にしてトルク寿命を測定した。その結果を図３にグラフにして示す。
【００７８】
図３において、横軸は潤滑剤組成物中の雲母Ａ〜Ｃの含有率を示し、縦軸はトルク寿命を示している。また、図中、曲線３１は雲母Ａを使用した場合に得られたデータを示し、曲線３２は雲母Ｂを使用した場合に得られたデータを示し、曲線３３は雲母Ｃを使用した場合に得られたデータを示している。
【００７９】
このグラフに示すように、雲母Ａ〜Ｃの含有率がいずれの範囲にあっても比較的長いトルク寿命を得ることができるが、雲母Ａの含有率が０．１重量％〜２５重量％の範囲にある場合、すなわち、固体フッ素化ポリマー（ＰＴＦＥポリマー）と雲母Ａとの和である増粘剤の含有率が２０．１重量％〜４５重量％の範囲にある場合により良好なトルク寿命を得ることができた。
【００８０】
（実施例４）
潤滑剤組成物の封入量を３０ｍｇとしたこと以外は実施例１で製造したサンプル（１）と同様にして、ＰＦＰＥ油と雲母Ａとの混合比を様々に変えて転がり軸受１を製造した。すなわち、潤滑剤組成物５にＰＴＦＥポリマーを用いずに、ＰＦＰＥ油と雲母Ａとの混合物を用い、それぞれの含有率を変えて転がり軸受１を製造した。このようにして製造した転がり軸受１について、実施例１と同様にしてトルク寿命及び発塵量を測定した。その結果を図４にグラフにして示す。
【００８１】
図４において、横軸は潤滑剤組成物中の雲母Ａの含有率を示し、縦軸はトルク寿命及び発塵量を示している。また、図中、曲線４１はトルク寿命についてのデータを示し、曲線４２は発塵量についてのデータを示している。
【００８２】
このグラフから明らかなように、雲母Ａの含有率が０．１重量％以上の場合により低い発塵性が得られている。また、トルク寿命に関しては、４５重量％を超えない範囲で雲母Ａの重量比が高いほど良好な値が得られている。すなわち、ＰＦＰＥ油等の基油に対して雲母Ａ等の層状鉱物粉末が０．１重量％〜４５重量％である場合にトルク寿命及び発塵性に関して良好な特性を得ることができた。
【００８３】
また、雲母Ａの含有率が５重量％〜４５重量％である場合により良好な特性を得ることができ、特に１５重量％〜４５重量％である場合には最も良好な特性を得ることができた。これは、５重量％未満の場合、潤滑剤組成物は液状であるが、５重量％以上の場合、グリース状或いはグリース状と液状との中間状態であり、１５重量％以上の場合は、完全にグリース状となるためであると考えられる。
【００８４】
（実施例５）
潤滑剤組成物中に層状鉱物粉末を含有させるかわりに無機物質からなる超微粒子を含有させたこと以外は実施例１に示したのと同様の方法により転がり軸受１を作製し、それぞれの転がり軸受１についてトルク寿命及び発塵量を測定した。下記表２に、それぞれの転がり軸受１に用いた潤滑剤組成物５の組成、その封入量、トルク寿命、及び発塵量を示す。
【００８５】
【表２】

【００８６】
上記表２に示すフラーレン（Ｃ₆₀）としてはマテリアルズ・アンド・エレクトロケミカル・リサーチ社（Materials and Electrochemical Research Corporation）製ピュアＣ６０を用い、ダイヤモンド微粒子（ＣＤ）としてはデュポン社製ＭＹＰＯＭＥＸを用い、表面にグラファイトを化学的にコーティングしたダイヤモンド微粒子（ＣＧＤ）としては平均粒径が２００オングストロームのものを使用した。酸化シリコン（ＳｉＯ₂ ）としては日本アエロジル社製ＡＥＲＯＳＩＬ２００を用い、酸化チタン（ＴｉＯ₂ ）としては出光興産社製出光チタニアＩＴ−ＵＤを用いた。また、酸化ジルコニア（ＺｒＯ）としてはシーアイ化成社製ＺｒＯを用い、酸化マグネシウム（ＭｇＯ）としては宇部興産社製１００Ａを用いた。
【００８７】
表２から明らかなように、本発明の実施例に係るサンプル（１６）〜（２２）の転がり軸受はいずれも、従来の転がり軸受である比較用サンプル（１）、（２）に比べて、トルク寿命が長く発塵量が少ない。したがって、液体フッ素化ポリマー油と上記超微粒子とを含む潤滑剤組成物を用いることにより、トルク寿命特性を向上させ、発塵量を低減することができた。
【００８８】
また、サンプル（１６）〜（２２）のそれぞれについてトルク寿命を比較すると、サンプル（１６）〜（１８）は、サンプル（１９）〜（２２）に比べてトルク寿命が長く、かつ発塵量が低減されている。これは、サンプル（１６）〜（１８）においては、超微粒子としてフラーレン（Ｃ₆₀）、ダイヤモンド微粒子、及び表面にグラファイトを化学的にコーティングしたダイヤモンド微粒子を用いているためであると考えられる。
【００８９】
（実施例６）
上記実施例５で製造したサンプル（１６）〜（２２）と同様にして、潤滑剤組成物中のＰＴＦＥポリマーの含有率を一定とし（２０重量％）、ＰＦＰＥ油及び超微粒子の含有率を様々に変化させて転がり軸受１を製造した。なお、超微粒子としては、実施例５で使用したフラーレン（Ｃ₆₀）、表面にグラファイトを化学的にコーティングしたダイヤモンド微粒子、酸化シリコン、及び酸化チタンを使用した。このようにして製造した転がり軸受１について、実施例１と同様にしてトルク寿命を測定した。その結果を図５にグラフにして示す。
【００９０】
図５において、横軸は潤滑剤組成物中の超微粒子の含有率を示し、縦軸はトルク寿命を示している。図中、曲線５１はフラーレン（Ｃ₆₀）を使用した場合に得られたデータを示し、曲線５２は表面にグラファイトを化学的にコーティングしたダイヤモンド微粒子を使用した場合に得られたデータを示している。また、曲線５３は酸化シリコンを使用した場合に得られたデータを示し、曲線５４は酸化チタンを使用した場合に得られたデータを示している。
【００９１】
このグラフに示すように、超微粒子の含有率がいずれの範囲にあっても比較的長いトルク寿命を得ることができた。特に、超微粒子の含有率が０．１重量％〜２０重量％の範囲にある場合、すなわち、固体フッ素化ポリマー（ＰＴＦＥポリマー）と超微粒子との和である増粘剤の含有率が２０．１重量％〜４０重量％の範囲にある場合により良好なトルク寿命を得ることができた。
【００９２】
（実施例７）
潤滑剤組成物中に油状化合物としてＰＦＰＥ系カルボン酸を含有させて実施例１に示したのと同様の方法により転がり軸受１を作製し、それぞれの転がり軸受１について大気雰囲気下及び真空下（１×１０^-4Ｐａ）でのトルク寿命を測定した。下記表３に、それぞれの転がり軸受１に用いた潤滑剤組成物５の組成、その封入量、及びトルク寿命を示す。
【００９３】
【表３】

【００９４】
なお、上記表３に示す雲母Ａは実施例１で用いたのと同様であり、フラーレン（Ｃ₆₀）、ダイヤモンド微粒子（ＣＤ）、表面にグラファイトを化学的にコーティングしたダイヤモンド微粒子（ＣＧＤ）、酸化シリコン（ＳｉＯ₂ ）、及び酸化チタン（ＴｉＯ₂ ）は、実施例５において用いたのと同様である。また、ＰＦＰＥ系カルボン酸としては、上記一般式（１）に示す化合物（ｎ＝５〜８０）を使用した。
【００９５】
表３から明らかなように、本発明の実施例に係るサンプル（２３）〜（３０）の転がり軸受においては、大気雰囲気下でのトルク寿命に関して、従来の転がり軸受である比較用サンプル（１）、（３）と同等或いはそれ以上の特性が得られている。すなわち、液体フッ素化ポリマー油と上記ＰＦＰＥ系カルボン酸とを含む潤滑剤組成物を用いることにより、大気雰囲気下でのトルク寿命特性を向上させることができた。
【００９６】
また、本発明の実施例に係るサンプル（２３）〜（３０）の転がり軸受においては、真空下でのトルク寿命に関して、従来の転がり軸受である比較用サンプル（１）、（３）に比べて遥かに優れた特性が得られている。すなわち、液体フッ素化ポリマー油と上記ＰＦＰＥ系カルボン酸とを含む潤滑剤組成物を用いることにより、真空下でのトルク寿命特性を大幅に向上させることができた。
【００９７】
（実施例８）
潤滑剤組成物をＰＦＰＥ油とＰＦＰＥ系カルボン酸とで構成し、ＰＦＰＥ系カルボン酸の含有率を様々に変化させて、実施例７に示したのと同様の方法により転がり軸受１を製造した。なお、この場合、潤滑剤組成物の封入量は３０ｍｇとした。また、潤滑剤組成物をＰＦＰＥ油と２０重量％のＰＦＰＥポリマーとＰＦＰＥ系カルボン酸とで構成し、ＰＦＰＥ油及びＰＦＰＥ系カルボン酸の含有率を様々に変化させて、実施例７に示したのと同様の方法により転がり軸受１を製造した。なお、この場合、潤滑剤組成物の封入量は１００ｍｇとした。
【００９８】
このようにして製造した転がり軸受１について、実施例１と同様にして真空下でのトルク寿命と大気雰囲気下での発塵量とを測定した。その結果を図６にグラフにして示す。
【００９９】
図６において、横軸は潤滑剤組成物中のＰＦＰＥ系カルボン酸の含有率を示し、縦軸はトルク寿命及び発塵量を示している。図中、曲線６１は潤滑剤組成物をＰＦＰＥ油とＰＦＰＥ系カルボン酸とで構成した場合に得られたトルク寿命に関するデータを示し、曲線６２はその場合に得られた発塵量に関するデータを示している。また、曲線６３は潤滑剤組成物をＰＦＰＥ油とＰＦＰＥポリマーとＰＦＰＥ系カルボン酸とで構成した場合に得られたトルク寿命に関するデータを示し、曲線６４はその場合に得られた発塵量に関するデータを示している。
【０１００】
このグラフに示すように、ＰＦＰＥ系カルボン酸の含有率がいずれの範囲にあっても発塵量が少なく、かつ比較的長いトルク寿命を得ることができた。特に、超微粒子の含有率が０．１重量％〜１０重量％の範囲にある場合に、発塵量をより低減し、かつより良好なトルク寿命を得ることができた。
【０１０１】
（実施例９）
潤滑剤組成物をＰＦＰＥ油、ＰＦＰＥポリマー、超微粒子、及びＰＦＰＥ系カルボン酸で構成し、ＰＦＰＥ油及びＰＦＰＥ系カルボン酸の含有率を様々に変化させて、実施例７に示したのと同様の方法により転がり軸受１を製造した。なお、ＰＦＰＥポリマー及び超微粒子の含有量はそれぞれ２０重量％及び３重量％とした。また、超微粒子としては、実施例７で用いたフラーレン（Ｃ₆₀）及び表面にグラファイトを化学的にコーティングしたダイヤモンド微粒子を使用した。
【０１０２】
このようにして製造した転がり軸受１について、実施例１と同様にして大気雰囲気下及び真空下でのトルク寿命と大気雰囲気下での発塵量とを測定した。その結果を図７にグラフにして示す。
【０１０３】
図７において、横軸は潤滑剤組成物中のＰＦＰＥ系カルボン酸の含有率を示し、縦軸はトルク寿命及び発塵量を示している。図中、曲線７１，７２は超微粒子としてフラーレン（Ｃ₆₀）を用いた場合に得られた大気雰囲気下及び真空下でのトルク寿命に関するデータをそれぞれ示し、曲線７３はその場合に得られた大気雰囲気下での発塵量に関するデータを示している。また、曲線７４，７５は超微粒子として上記ダイヤモンド微粒子を用いた場合に得られた大気雰囲気下及び真空下でのトルク寿命に関するデータをそれぞれ示し、曲線７６はその場合に得られた大気雰囲気下での発塵量に関するデータを示している。
【０１０４】
このグラフに示すように、ＰＦＰＥ系カルボン酸の含有率が含有率が０．１重量％〜１０重量％の範囲にある場合、真空下及び大気雰囲気下のいずれの条件下においても良好なトルク寿命を得ることができ、かつ発塵量を低減することができた。
【０１０５】
（実施例１０）
潤滑剤組成物をＰＦＰＥ油、ＰＦＰＥポリマー、実施例１で用いた雲母Ａ、及びＰＦＰＥ系カルボン酸で構成し、ＰＦＰＥ油及びＰＦＰＥ系カルボン酸の含有率を様々に変化させて、実施例７に示したのと同様の方法により転がり軸受１を製造した。また、潤滑剤組成物をＰＦＰＥ油、ＰＦＰＥポリマー、酸化シリコン微粒子、及びＰＦＰＥ系カルボン酸で構成し、ＰＦＰＥ油及びＰＦＰＥ系カルボン酸の含有率を様々に変化させて、実施例７に示したのと同様の方法により転がり軸受１を製造した。なお、ＰＦＰＥポリマーの含有率は２０重量％とし、雲母Ａ或いは酸化シリコン微粒子の含有量は３重量％とした。
【０１０６】
このようにして製造した転がり軸受１について、実施例１と同様にして大気雰囲気下及び真空下でのトルク寿命と大気雰囲気下での発塵量とを測定した。その結果を図８にグラフにして示す。
【０１０７】
図８において、横軸は潤滑剤組成物中のＰＦＰＥ系カルボン酸の含有率を示し、縦軸はトルク寿命及び発塵量を示している。図中、曲線８１，８２は雲母Ａを用いた場合に得られた大気雰囲気下及び真空下でのトルク寿命に関するデータをそれぞれ示し、曲線８３はその場合に得られた大気雰囲気下での発塵量に関するデータを示している。また、曲線８４，８５は超微粒子として酸化シリコン微粒子を用いた場合に得られた大気雰囲気下及び真空下でのトルク寿命に関するデータをそれぞれ示し、曲線８６はその場合に得られた大気雰囲気下での発塵量に関するデータを示している。
【０１０８】
このグラフに示すように、ＰＦＰＥ系カルボン酸の含有率が含有率が０．１重量％〜１０重量％の範囲にある場合、真空下及び大気雰囲気下のいずれの条件下においても良好なトルク寿命を得ることができ、かつ発塵量を低減することができた。
【０１０９】
以上、主として、基油としてＰＦＰＥ油を用いた場合について説明したが、他の液体フッ素化ポリマー油を用いた場合についても同様の効果を得ることができる。また、上記実施例では、本発明の転動装置を転がり軸受として用いた場合について説明したが、ボールねじ装置やリニアガイド等のような直動装置として用いた場合においても同様の効果を得ることができる。
【０１１０】
【発明の効果】
以上説明したように、本発明の転動装置においては、潤滑剤組成物として、層状鉱物粉末を含有する増粘剤と液体フッ素化ポリマー油からなる基油との混合物が用いられる。また、本発明の転動装置においては、潤滑剤組成物として、無機物質からなる超微粒子を含有する増粘剤と液体フッ素化ポリマー油からなる基油との混合物が用いられる。さらに、本発明の転動装置においては、潤滑剤組成物として、液体フッ素化ポリマー油からなる基油に分子量１０，０００以下のパーフルオロポリエーテル系カルボン酸を含有してなる潤滑油組成物、或いは液体フッ素化ポリマー油からなる基油と固体フッ素化ポリマーを含有する増粘剤との混合物に分子量１０，０００以下のパーフルオロポリエーテル系カルボン酸を含有してなるグリース組成物が用いられる。
【０１１１】
これら潤滑剤組成物を用いた場合、潤滑剤組成物の飛散や転動体等の摩耗が低減される。したがって、本発明によると、発塵量が少なく、優れたトルク寿命を有する転動装置が提供される。
【図面の簡単な説明】
【図１】本発明の実施例に係る転動装置及び軸受回転試験機を示す断面図。
【図２】本発明の実施例に係る転動装置における、層状鉱物粉末の平均粒径とトルク寿命との関係を示すグラフ。
【図３】本発明の実施例に係る転動装置における、潤滑剤組成物中の層状鉱物粉末の含有率とトルク寿命との関係を示すグラフ。
【図４】本発明の実施例に係る転動装置における、潤滑剤組成物中の層状鉱物粉末の含有率と、トルク寿命及び発塵量との関係を示すグラフ。
【図５】本発明の実施例に係る転動装置における、潤滑剤組成物中の超微粒子の含有率とトルク寿命との関係を示すグラフ。
【図６】本発明の実施例に係る転動装置における、潤滑剤組成物中のＰＦＰＥ系カルボン酸の含有率と、トルク寿命及び発塵量との関係を示すグラフ。
【図７】本発明の実施例に係る転動装置における、潤滑剤組成物中のＰＦＰＥ系カルボン酸の含有率と、トルク寿命及び発塵量との関係を示すグラフ。
【図８】本発明の実施例に係る転動装置における、潤滑剤組成物中のＰＦＰＥ系カルボン酸の含有率と、トルク寿命及び発塵量との関係を示すグラフ。
【符号の説明】
１…転がり軸受
２…内輪
３…転動体
４…外輪
５…潤滑剤組成物
６…軸受回転試験機
７…スピンドル
８…スプリング
９…モータ
１０…ベルト
１１，１２…プーリ
１３…ハウジング
１４…微小荷重変換器
１５…磁性流体シールユニット
１６…容器
１７…隔壁
１８…パーティクルカウンタ
１９…空気吸入口
２０…フィルタ
４１，４２，５１〜５４，６１〜６４，７１〜７６，８１〜８６…曲線[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rolling device, and more particularly to a rolling device using a lubricant composition.
[0002]
[Prior art]
In general, in a rolling device such as a rolling bearing and a linear motion device, a lubricating oil such as mineral oil or poly-α-olefin oil, or a lubricant such as grease is circulated or sealed inside the rolling device, thereby rolling and rolling elements. The wear of the member that comes into contact with is prevented.
[0003]
Such a rolling device is used without problems under normal use conditions, but when driven under high temperature, vacuum, or high speed conditions, the lubricant is scattered to the outside of the rolling device or the gas due to evaporation. Will occur and contaminate the external environment of the rolling device. Therefore, in devices used in a clean room, for example, devices that require a clean environment such as semiconductor manufacturing devices, liquid crystal panel manufacturing devices, and hard disk manufacturing devices, and devices that are used under high temperature and vacuum conditions, Fluorine grease has been frequently used as a lubricant for rolling devices.
[0004]
This fluorinated grease is a mixture of a base oil composed of a liquid fluorinated polymer oil and a thickener composed of a solid fluorinated polymer, and is extremely low in volatility, and the amount of lubricant scattered outside the rolling device, That is, the amount of dust generation is relatively small. Therefore, contamination of the external environment of the rolling device is relatively difficult to occur.
[0005]
However, this fluorine-based grease has poor fluidity and inferior lubrication characteristics as compared with grease using lubricating oil such as mineral oil or poly-α-olefin oil. For this reason, wear of the rolling elements and the members in contact with the rolling elements tends to occur due to the operation of the rolling device. Such wear is particularly serious in a linear motion device used in a positioning device such as a semiconductor or liquid crystal panel manufacturing device because the positioning accuracy is lowered.
[0006]
Moreover, the abrasion powder produced | generated with the above-mentioned abrasion mixes in a lubricant, and causes an increase in torque and seizure in a relatively short time. For this reason, problems such as heat generation due to an increase in torque and overload on the motor may occur.
[0007]
In recent years, the processing speed of semiconductor and liquid crystal panel manufacturing apparatuses has been increased, and rolling devices are also required to operate at high speed. Therefore, in such a rolling device, the increase in torque due to dust generation and wear due to the scattering of the lubricant described above is more likely to occur, and it is required to reduce dust generation and improve the torque life. Yes.
[0008]
[Problems to be solved by the invention]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a rolling device having a small amount of dust generation and an excellent torque life.
[0009]
[Means for Solving the Problems]
The present invention relates to a movable element capable of rotating or linearly moving, a support that supports the movable element, a rolling element that is interposed between the movable element and the support, and rolls in accordance with the movement of the movable element, And a lubricant composition disposed between the movable element on which the rolling element rolls and a support, and the lubricant composition Is a grease-like mixture of a thickener containing mica having swelling properties and polytetrafluoroethylene and a base oil composed of a liquid fluorinated polymer oil, and the average particle size of the mica is from 0.1 μm to 10 m, and the content of the mica in the lubricant composition is 0.1 wt% to 25 wt%. A rolling device is provided.
[0012]
In the present invention, preferred embodiments are:
(1) The lubricant composition contains the thickener at a content of 0.1 wt% to 45 wt%, and the base oil at a content of 55 wt% to 95 wt%,
(2) the interface of the thickener is hydrophobized with a hydrophobizing surfactant;
(3) The layered mineral powder contains at least one of lithium ions and sodium ions as interlayer ions,
(4) The lubricant composition contains the layered mineral powder at a content of 1 wt% to 45 wt%,
(5) The lubricant composition contains the layered mineral powder at a content of 3 wt% to 45 wt%,
(6) The average particle size of the layered mineral powder is in the range of 0.05 μm to 20 μm,
(7) Ultrafine particles made of the inorganic substance are diamond particles, diamond particles whose surface is composed of graphite, fullerene (C ₆₀ ) Particles, silicon oxide (SiO2) ₂ ) Particles, titanium oxide (TiO ₂ ) At least one particle selected from the group consisting of particles, zirconia oxide (ZrO) particles, and magnesium oxide (MgO) particles;
(8) The lubricant composition contains ultrafine particles made of the inorganic substance at a content of 0.1 wt% to 40 wt%,
(9) The lubricant composition contains ultrafine particles composed of the inorganic substance at a content of 0.5 wt% to 30 wt%,
(10) The average particle diameter of the ultrafine particles made of the inorganic substance is 0.1 μm or less,
(11) The lubricant composition has 0.5% by weight of an oily compound having a perfluoropolyether skeleton as a main chain and a molecular weight of 10,000 or less having a polar group at one or both ends of the main chain. Containing 10 to 10% by weight,
(12) The lubricant composition contains 0.5% by weight to 10% by weight of a perfluoropolyether carboxylic acid having a molecular weight of 10,000 or less.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
The rolling device according to the first to third embodiments of the present invention is used as a rolling bearing, a linear motion device, or the like. Here, the linear motion device means a linear motion drive device such as a ball screw device or a linear motion guide device such as a linear guide. Each of these rolling bearings and linear motion devices has a configuration in which a movable element is held on a support via a rolling element, and a lubricant composition is disposed between the support and the movable element. Yes. Hereinafter, the case where the rolling device according to the first to third embodiments of the present invention is applied to a rolling bearing, a linear motion drive device, and a linear motion guide device will be described.
[0014]
When the rolling device according to the first to third embodiments of the present invention is used as a rolling bearing, a cylindrical outer ring is used as a support, and an outer diameter smaller than the inner diameter of the outer ring is used as a mover. An inner ring is used. Further, in this rolling bearing, the inner ring and the outer ring are coaxially arranged, and groove-shaped tracks are provided on the outer peripheral part of the inner ring and the inner peripheral part of the outer ring, respectively. In the gap between the inner ring and the outer ring, the rolling elements are arranged so as to roll on the respective raceways of the inner ring and the outer ring, and further, a lubricant composition is arranged to prevent wear of the rolling elements etc. Has been.
[0015]
In this rolling bearing, the inner ring rotates and moves relative to the outer ring by an external force and does not move in the axial direction. Therefore, the rolling element may be a spherical ball, or may be a cylindrical or conical roller.
[0016]
When the rolling device according to the first to third embodiments of the present invention is used as a linear drive device, a screw shaft having a thread groove on a side wall is used as a support. As the mover, a nut having a thread groove on a surface facing the screw shaft is used, and the rolling element is disposed between the screw shaft and the thread groove of the nut so as to be able to roll.
[0017]
Therefore, since the rolling element moves in the axial direction of the screw shaft by suppressing the rotation of the nut and rotating the screw shaft, the nut can be moved in the axial direction of the screw shaft. In this linear motion drive device, the rolling element is spherical, and the nut is configured so that the rolling element circulates in the thread groove.
[0018]
Next, the case where the rolling device according to the first to third embodiments of the present invention is used as a linear motion guide device will be described. In the linear motion guide device, a guide shaft having no side wall provided with a thread groove or the like is used as the support, and a slider that can move in the axial direction of the guide shaft is used as the mover. In this linear motion guide device, the rolling element is provided between the slider and the guide shaft so as to be able to roll so that the slider can move in the axial direction with respect to the guide shaft by an external force. Alternatively, it may be provided so as to be embedded in the guide shaft.
[0019]
The rolling device described above is configured in the same manner as a general rolling device except that the lubricant composition is different. Accordingly, commonly used materials can be used for the materials used for the support, rolling element, and mover, and are not particularly limited. For example, metal steel such as bearing steel and stainless steel, nitriding Silicon (Si _Three N _Four ), Silicon carbide (SiC), sialon, partially stabilized zirconia (ZrO) ₂ ), And alumina (Al ₂ O _Three ) And the like. These materials can be used alone or in combination.
[0020]
Next, the lubricant composition used in the rolling device according to the first to third embodiments of the present invention will be described. The lubricant composition used in the rolling device of the present invention is movable to prevent wear and reduce contact resistance on the rolling contact surface of the rolling element and the sliding contact surface between the mover and the support. It arrange | positions between a child and a support body. Hereinafter, the lubricant composition used in the rolling device according to the first to third embodiments will be sequentially described.
[0021]
The lubricant composition used in the rolling device according to the first embodiment of the present invention is composed of a thickener containing layered mineral powder and a base oil composed of liquid fluorinated polymer oil. As the layered mineral powder contained in the thickener, powders of mica-based minerals, vermiculite-based minerals, and montmorillonite-based minerals having a layered crystal structure such as graphite and hexagonal boron nitride are used.
[0022]
The physical characteristics common to the layered minerals described above will be described using mica as an example. The main component of mica is SiO ₂ And account for 40-50% of the ingredients. In the mica crystal, Si is coordinated to the oxygen tetrahedron, and Si—O _Four The bond is very strong. A mica crystal is arranged between a pair of layers composed of the tetrahedron and the pair of layers. ³⁺ , Fe ²⁺ , Mg ²⁺ It has a layered structure in which sandwich layers called tablets composed of ions having octahedral coordination, such as, are laminated. Alkali metal or alkaline earth metal ions called interlayer ions are arranged between the tablets, and the interlayer ions and oxygen atoms are ionically bonded. However, the ionic bond between the interlayer ions and oxygen atoms is very weak. Therefore, mica easily peels off on the plane formed by interlayer ions.
[0023]
As described above, the layered mineral used in the rolling device according to the first embodiment of the present invention has a weak binding force between tablets, and when a shearing force is applied, the layered mineral is easily formed on a plane formed by interlayer ions. Cleave. Therefore, by using the layered mineral in the lubricant composition, the friction coefficient on the rolling contact surface and the sliding contact surface of the rolling element, the mover, and the support is reduced. That is, wear on the contact surface can be suppressed, and an increase in torque and seizure can be prevented.
[0024]
As described above, since the lubricant composition is used in the rolling device according to the first embodiment of the present invention, a good lubricating state is maintained over a long period of time. That is, according to the first embodiment of the present invention, a rolling device having a small amount of dust generation and a long torque life is provided.
[0025]
As described above, the thickener used in the lubricant composition contains at least one layered mineral powder of a mica-based mineral, a vermiculite-based mineral, and a montmorillonite-based mineral. The chemical composition of the mica-based mineral has the general formula XMg ₂ Li (Y _Four O _Ten Z ₂ Or XMg _2.5 (Y _Four O _Ten Z ₂ The chemical composition of the vermiculite mineral is represented by the general formula X _2/3 Mg _7/3 Li _2/3 (Y _Four O _Ten Z ₂ The chemical composition of the montmorillonite mineral is represented by the general formula X _1/3 Mg _8/3 Li _1/3 (Y _Four O _Ten Z ₂ Indicated by In the above general formula, X represents K, Na or Li, Y represents Si or Ge, and Z represents F or OH.
[0026]
The layered mineral preferably contains at least one of lithium ions and sodium ions as interlayer ions. Mica-based minerals, vermiculite-based minerals, and montmorillonite-based minerals containing interlayer ions with a small ion radius, when mixed in various solvents such as water and oil, swell up by incorporating the solvent between crystal layers, that is, Swells.
[0027]
When the lubricant composition is prepared by mixing the swellable layered mineral powder and the base oil, a part of the base oil is taken into the layered mineral powder. Therefore, by using such a lubricant composition, the base oil can be supplied when the base oil is insufficient on the contact surface. Moreover, when base oil exists excessively in a contact surface, base oil can be taken in in the said layered mineral powder. Therefore, an appropriate amount of base oil can always be supplied to the contact surface. As a result, a better torque life can be obtained, and it is effective that the base oil is scattered when the rolling device is operated. Can be prevented.
[0028]
Further, the layered mineral powder is preferably used after the interface is hydrophobized with a hydrophobizing surfactant. By hydrophobizing the interface in this way, water can be prevented from being taken in and base oil can be taken in selectively and efficiently. Therefore, a good lubrication state can be maintained for a longer period of time, the torque life of the rolling device can be improved, and the amount of dust generation can be further reduced.
[0029]
The hydrophobizing surfactant used in the hydrophobizing treatment is not particularly limited as long as it is a hydrophobizing surfactant containing an alkyl group having 8 or more carbon atoms, but an ammonium salt compound, -NH ₂ An alkylamine surfactant having a functional group such as a group, —OH group, and —COOH group can be used.
[0030]
The layered mineral powder described above is preferably contained in an amount of 0.1% to 45% by weight, more preferably 1% to 45% by weight, more preferably 3% to Most preferably 45% by weight is contained. When the content of the layered mineral powder is less than the lower limit, it may not be possible to obtain the effect of improving the lubricity and suppressing the leakage and scattering of the lubricant. Further, if the content exceeds the upper limit, the amount of the base oil is reduced and the viscosity of the lubricant composition becomes excessively high, so that sufficient lubricity cannot be obtained, and the above-mentioned wear occurs in a relatively short time. The resulting torque may increase.
[0031]
The layered mineral powder preferably has an average particle size of 0.05 μm to 20 μm, and more preferably 0.1 μm to 10 μm. When the average particle size is less than the lower limit, when preparing a lubricant composition by mixing with a base oil or the like, agglomeration of powder particles occurs and secondary particles are generated, which may reduce dispersibility. is there. On the other hand, when the average particle size exceeds the upper limit value, it becomes difficult to penetrate or bite into the rolling contact surface or the sliding contact surface, so that the torque of the rolling device is greatly increased. May become inoperable.
[0032]
The thickener used in the rolling device according to the first embodiment of the present invention can further contain a solid fluorinated polymer in addition to the layered mineral powder. Examples of the solid fluorinated polymer include polytetrafluoroethylene (hereinafter referred to as PTFE), a copolymer of tetrafluoroethylene and hexafluoropropene, a copolymer of tetrafluoroethylene and perfluoropropyl polyvinyl ether, and a mixture of these polymers. be able to.
[0033]
The thickener described above is preferably contained in an amount of 5% to 45% by weight, more preferably 15% to 40% by weight, based on the lubricant composition. When the content is less than the lower limit, it may not be possible to obtain the effect of improving the lubricity and suppressing the leakage and scattering of the lubricant. When the upper limit is exceeded, the amount of the base oil is reduced and the viscosity of the lubricant composition becomes excessively high, so that sufficient lubricity cannot be obtained and abnormal wear occurs in a relatively short time, resulting in torque. It will increase.
[0034]
The base oil used in the rolling device according to the first embodiment of the present invention is not particularly limited as long as it is a liquid fluorinated polymer oil, but perfluoropolyether (hereinafter referred to as PFPE), trifluoroethylene telomer, And fluorosilicone polymers. This base oil is preferably contained at a content of 55 wt% to 95 wt% with respect to the lubricant composition. When the content of the base oil is less than the lower limit value, the increase in torque described above occurs in a short period of time, and when the content exceeds the upper limit value, it may not be possible to obtain the effect of suppressing the leakage or scattering of the lubricant.
[0035]
Next, the lubricant composition used in the rolling device according to the second embodiment of the present invention will be described.
The lubricant composition used in the rolling device according to the second embodiment of the present invention is composed of a thickener containing ultrafine particles made of an inorganic substance and a base oil made of liquid fluorinated polymer oil. In the rolling device according to the second embodiment, as the base oil, the same liquid fluorinated polymer oil as described in the first embodiment can be used.
[0036]
The ultrafine particles contained in the thickener in the rolling device according to the second embodiment have a small particle size and a rounded surface shape. When a lubricant composition containing such ultrafine particles is used, the ultrafine particles roll on the rolling contact surface and the sliding contact surface of the rolling element, the movable element, and the support when the rolling device is operated. This produces a so-called micro bearing effect. Accordingly, the friction coefficient at the contact surface is reduced. In addition, even when a heavy load is applied, when operated at a low speed, and when the base oil is insufficient between the contact surfaces, the rolling contact or the direct contact or adhesion between the sliding contact surfaces. Etc. are prevented. Therefore, according to the rolling device according to the second embodiment of the present invention, wear and seizure of the contact surface can be prevented, and a good lubrication state can be maintained for a long time.
[0037]
Examples of the ultrafine particles made of an inorganic substance used in the rolling device according to the second embodiment of the present invention include SiO. ₂ Fine particles, MgO fine particles, TrO ₂ Fine particles and Al ₂ O _Three Inorganic compounds such as fine particles, diamond fine particles and fullerenes (C ₆₀ Inorganic substances consisting only of carbon such as These inorganic substances can be formed in a round shape with a very small particle size. Among these ultrafine particles, diamond fine particles or fullerene (C ₆₀ ) Is preferably used.
[0038]
Diamond fine particles are chemically very stable and very hard, and therefore are less likely to break. When the ultrafine particles are destroyed, there is a possibility that a shape having a sharp corner or a sharp fragment may be formed. On the other hand, when diamond fine particles are used as the ultrafine particles, a shape having sharp corners or sharp fragments are hardly formed. Therefore, a good lubricating state can be maintained for a longer period.
[0039]
Furthermore, in this case, it is more preferable to use the diamond fine particles with chemically coated graphite. By coating the surface with graphite, the boundary lubricity of ultrafine particles is improved, so that a good lubrication state can be maintained for a longer period.
[0040]
In addition, fullerene (C ₆₀ ) Can be used to maintain a good lubrication state for a longer period of time. This is due to the following reason. Fullerene (C ₆₀ ) Is a soccer ball-like molecule composed of 60 carbon atoms and having a closed shell structure in which a plurality of 6-membered and 5-membered rings are connected. Fullerene (C ₆₀ ) Is extremely stable to heat and is known not to break down to 1500 ° C. Moreover, since it has a spherical molecular structure, the above-described micro-bearing effect becomes more prominent. Furthermore, fullerene (C ₆₀ ) Itself has lubricity. Therefore, fullerene (C ₆₀ ) Can be used to maintain good lubrication for a longer period of time.
[0041]
The ultrafine particles composed of the inorganic substances described above are preferably contained in an amount of 0.1% to 40% by weight, more preferably 0.5% to 30% by weight, based on the lubricant composition. When the content of the ultrafine particles is less than the lower limit, it may not be possible to obtain the effect of improving the lubricity and suppressing the leakage and scattering of the lubricant. On the other hand, if the content exceeds the upper limit, the amount of the base oil mixed decreases and the viscosity of the lubricant composition becomes excessively high, so that sufficient lubricity may not be obtained. In addition, polishing action may be caused by ultrafine particles. For this reason, the surface roughness increases or abnormal wear occurs in a relatively short time, and as a result, there is a risk of increasing torque and vibration or seizing.
[0042]
The ultrafine particles preferably have an average particle size of 0.1 μm or less. When the average particle diameter exceeds the upper limit value, it may be difficult to enter or bite into the rolling contact surface or the sliding contact surface. In addition, since the polishing action is caused by the ultrafine particles, the surface roughness may increase or abnormal wear may occur in a relatively short time. For this reason, the torque of the rolling device increases significantly, and in some cases, the rolling device may become inoperable.
[0043]
In addition, the shape of the layered mineral powder demonstrated in 1st Embodiment is scale-like, and the thickness is thin compared with an average particle diameter. Further, since the layered mineral powder is easy to cleave and is soft, even if the average particle diameter is 0.1 to 10 μm, it can penetrate between the contact surfaces and does not damage the contact surfaces. However, since the ultrafine particles made of the inorganic substance have a spherical shape, particles having an average particle diameter exceeding 0.1 μm (particles larger than the film thickness of the oil film interposed between the contact surfaces) are contact surfaces. It is difficult to intrude in between. Further, since the ultrafine particles are hard, particles having an average particle size exceeding 0.1 μm may cause wear on the contact surface. Therefore, the preferred range of the particle diameter differs between the layered mineral powder and the ultrafine particles made of the inorganic substance.
[0044]
The thickener used in the rolling device according to the second embodiment of the present invention is the same solid fluorinated polymer as described in the first embodiment, in addition to the ultrafine particles made of the above-mentioned inorganic substance. Can be contained.
[0045]
In the rolling device according to the second embodiment, the above-described thickener is preferably contained in an amount of 5% to 45% by weight, and preferably 15% to 40% by weight, based on the lubricant composition. More preferably. When the content is less than the lower limit, it may not be possible to obtain the effect of improving the lubricity and suppressing the leakage and scattering of the lubricant. When the upper limit is exceeded, the amount of the base oil is reduced and the viscosity of the lubricant composition becomes excessively high, so that sufficient lubricity cannot be obtained and abnormal wear occurs in a relatively short time, resulting in torque. It will increase.
[0046]
Next, the lubricant composition used in the rolling device according to the third embodiment of the present invention will be described.
The lubricant composition used in the rolling device according to the third embodiment of the present invention contains a base oil composed of a liquid fluorinated polymer oil and 0.5 wt% to 10 wt% of an oily compound. Here, the oily compound is an organic compound having a perfluoropolyether skeleton as a main chain and having a polar group at least at one end of the main chain and having a molecular weight of 10,000 or less. Further, in the rolling device according to the third embodiment, as the base oil, the same liquid fluorinated polymer oil as described in the first embodiment can be used.
[0047]
Since the oily compound has the same skeleton as the liquid fluorinated polymer oil used as the base oil, it is not easily dissolved and separated in the base oil. Further, since the vapor pressure of the oily compound is low, the amount of evaporation in a vacuum environment is extremely small.
[0048]
Furthermore, since the oily compound has a substituent having high polarity at the end of the main chain, it is easily adsorbed on the metal surface. That is, the oily compound is physically adsorbed or chemically adsorbed on the rolling contact surface and the sliding contact surface of the rolling element, the movable element, and the support. Therefore, even when the base oil is insufficient on the contact surface, Direct contact between surfaces is prevented. Therefore, according to the rolling device according to the third embodiment of the present invention, the friction coefficient of the contact surface is reduced, and as a result, it is possible to prevent wear and seizure of the contact surface and increase in torque.
[0049]
The oily compound described above has a molecular weight of 10,000 or less. When the molecular weight exceeds the upper limit value, the adsorptivity to the rolling contact surface or the sliding contact surface is lowered, so that the effect of improving the lubricity may not be obtained.
[0050]
The oily compound is preferably contained in an amount of 0.5 to 10% by weight based on the lubricant composition. When the content of the ultrafine particles is less than the lower limit, it may not be possible to obtain the effect of improving the lubricity and suppressing the leakage and scattering of the lubricant. On the other hand, when the content rate exceeds the upper limit value, the viscosity of the lubricant composition may decrease, and the lubricant composition may be easily scattered or leaked.
[0051]
In the rolling device according to the third embodiment of the present invention, a thickener can be contained in the lubricant composition. In that case, the same solid fluorinated polymer as described in the first embodiment can be used as the thickener. Further, as the thickener, the layered mineral powder and ultrafine particles described in the first and second embodiments may be contained in the solid fluorinated polymer. These layered mineral powders and ultrafine particles can be contained in the solid fluorinated polymer at the same content as described in the first and second embodiments.
[0052]
Lubricant composition comprising a lubricating oil composition comprising a base oil comprising a liquid fluorinated polymer oil and the oily compound, or a thickener comprising a base oil comprising a liquid fluorinated polymer oil and a solid fluorinated polymer, and the oil. When comprised with a compound, as the oily compound, for example, a perfluoropolyether carboxylic acid having a molecular weight of 10,000 or less shown in the following general formula (1) can be used. In the following general formula (1), n represents a positive integer.
[0053]
[Chemical 1]

[0054]
Further, when the oily compound is contained in the lubricant composition described in the first and second embodiments, the oily compound includes, for example, the following general formula in addition to the compound represented by the general formula (1). The compound shown to (2)-(5) can be mentioned. In the following general formulas (2) to (5), m and n represent positive integers.
[0055]
[Chemical formula 2]

[0056]
In the compounds represented by the general formulas (2) to (5), at least one substituent R is a polar group such as a carboxyl group (—COOH), an alcohol group, and an isocyanate group. Moreover, as an alcohol group and an isocyanate group, the substituent shown to following formula (6)-(9) can be mentioned, for example.
[0057]
[Chemical 3]

[0058]
In the general formulas (2) to (5), when the two substituents R are polar groups such as a carboxyl group, an alcohol group, and an isocyanate group, the two substituents R may be equal to each other or different. May be. When only one substituent R is a polar group such as a carboxyl group, an alcohol group, and an isocyanate group, the other substituent R is preferably a fluorine atom.
[0059]
In the rolling device according to the first to third embodiments of the present invention described above, the lubricant composition is blended with various additives in addition to the above-described base oil and the like within a range not impairing the above effects. be able to. Examples of the additive compounded in the lubricant composition include an antioxidant, a rust inhibitor, an antiwear agent, a dispersant, a metal protective agent, and a surfactant. These additives vary depending on the type, but can be added up to about 15% by weight as the total amount of all additives.
[0060]
【Example】
Examples of the present invention will be described below.
Example 1
FIG. 1 shows a cross-sectional view of a rolling bearing 1 according to an embodiment of the present invention installed in a bearing rotation tester 6. In this figure, a rolling bearing 1 is a ball that is a rolling element in which an inner ring 2 having a groove-like raceway on the outer periphery and an outer ring 4 having a groove-like raceway on the inner circumference are arranged concentrically. 3 is arranged so as to be able to roll on the respective raceways of the inner ring 2 and the outer ring 4. A lubricant composition 5 is accommodated between the inner ring 2 and the outer ring 4 in order to reduce the contact resistance of the inner ring 2, the outer ring 4, and the ball 3 and prevent wear.
[0061]
About this rolling bearing 1, the composition of the lubricant composition 5 was changed variously, and each torque life and dust generation amount were investigated on the conditions shown below. That is, as the rolling bearing 1, a ball bearing (model number 608) manufactured by NSK Ltd. having an inner diameter of 8 mm, an outer diameter of 22 mm, and a width of 7 mm was used, and the above characteristics were measured by the bearing rotation tester 6 shown in FIG.
[0062]
The torque life was defined as the rotation time from the start of operation until the torque value exceeded a predetermined threshold, and was measured under the following conditions.
Temperature
Atmosphere Air atmosphere
Rotation speed 1000rpm
Axial load 196N
Radial load 1.96N
Further, the dust generation amount is the number of fine particles such as scattered droplets of the lubricant composition 5 scattered from the rolling bearing 1 to the outside within a predetermined operation time, and the bearing rotation tester 6 is installed in a class 100 clean bench. Was measured under the following conditions.
[0063]
Temperature
Atmosphere Air atmosphere
Rotation speed 3000rpm
Axial load 19.6N
As the bearing rotation tester 6, a bearing rotation tester manufactured by NSK Ltd. was used. According to this bearing rotation test machine 6, the inner ring 2 of the rolling bearing 1 is fixed to the rotating shaft of the spindle 7, and the axial load on the rolling bearing 1 can be adjusted by the spring 8 or the like. The spindle 7 is provided with a magnetic fluid seal unit 15. The spindle 7 is rotated by driving a motor 9 and transmitting power from the pulley 11 to the pulley 12 via the belt 10. On the other hand, the outer ring 4 of the rolling bearing 1 is held by a housing 13 connected to a minute load converter 14. Therefore, the torque of the rolling bearing 1 can be measured using the minute load converter 14.
[0064]
The rolling bearing 1 is surrounded by a container 16 and a partition wall 17, and the bottom of the enclosed space is connected to a laser light scattering particle counter 18. On the other hand, an air suction port 19 is provided in the upper part of the enclosed space via a filter 20 so that clean air can be supplied to the enclosed space.
[0065]
Accordingly, when clean air is supplied to the enclosed space at a predetermined flow rate, an air flow is generated from the air inlet 19 toward the particle counter 18, so that the lubricant composition 5 generated from the rolling bearing 1 is scattered. The particle counter 18 detects the amount of droplets and wear powder, that is, the number.
Table 1 below shows the composition of the lubricant composition 5 used for each rolling bearing 1, the amount of the lubricant composition, the torque life, and the amount of dust generation.
[0066]
[Table 1]

[0067]
Daikin Industries, Ltd. S-200 was used as the PFPE oil shown in Table 1 above, and Daikin Industries, Ltd. Lubron L-2 was used as the PTFE polymer. As mica A, synthetic mica 4C-TS made by Topy Industries Co., Ltd., which is a swellable mica subjected to hydrophobic treatment, is used. Synthetic mica DMA-350 manufactured by the company was used. As mica C, synthetic mica PDM-9WA manufactured by Topy Industries Co., Ltd., which is a mica that has been hydrophobized and does not swell, is used. A synthetic mica CR-TS manufactured by certain Topy Industries, Ltd. was used. As the montmorillonite, a synthetic smectite SPN manufactured by Corp Chemical Co. was used. The mica A to D and montmorillonite are layered minerals. The filling amount means the amount of the lubricant composition 5 filled in the rolling bearing 1.
[0068]
As is apparent from Table 1, the rolling bearings of the samples (1) to (15) according to the examples of the present invention are all compared with the comparative samples (1) and (2) that are conventional rolling bearings. Long torque life and low dust generation. Therefore, by using the lubricant composition containing the liquid fluorinated polymer oil and the layered mineral powder, it was possible to improve the torque life characteristics and reduce the amount of dust generation.
[0069]
When comparing the torque life for each of the samples (1) to (15), the samples (1) to (12), (14), and (15) have a longer torque life than the sample (13). This is because the lubricant compositions used in Samples (1) to (12), (14), and (15) are 45% by weight or less compared to the lubricant composition 5 used in Sample (13). It is considered that this is because the content of the thickener is as follows.
[0070]
When the dust generation amount is compared for each of the samples (1) to (15), the sample (1) and (3) to (13) are more dust generation than the samples (2), (14), and (15). Less is. Samples (1), (3) to (13) have a smaller amount of dust generation than sample (2) because the layered mineral powder contained in lubricant composition 5 (mica A, mica B, montmorillonite) ). That is, when the content of the layered mineral powder is large, it is considered that the layered mineral powder is interposed between the rolling contact surfaces or the sliding contact surfaces to prevent direct contact between these contact surfaces.
[0071]
Moreover, it is thought that it is related with the viscosity of the lubricant composition 5 that sample (1), (3)-(13) has little dust generation compared with sample (14), (15). . That is, the lubricant composition 5 used in the samples (14) and (15) is a liquid having a low viscosity, whereas the lubricant composition 5 used in the samples (1) and (3) to (13) is This is because it is grease-like. The difference between the filling amount in the samples (14), (15) and the comparative sample (2) and the filling amount in the other samples depends on whether the lubricant composition 5 is in the form of grease or liquid. .
[0072]
Samples (3) to (7) differ only in the type of layered mineral powder used in the lubricant composition. When these are compared, compared with the case where mica C and D are used, when mica A, B and montmorillonite are used, a favorable value is obtained in both the torque life and the amount of dust generation. This is because mica C and D do not show swelling, whereas mica A, B and montmorillonite show swelling, so that an appropriate amount of base oil can always be supplied between the contact surfaces. It is believed that there is.
[0073]
Further, when mica A is used as compared with the case using mica B, good values are obtained in both the torque life and the dust generation amount, and when mica C is used compared with the case using mica D, the torque life is obtained. Good values are obtained for. This is considered to be because mica A and C are hydrophobized unlike mica B and D. In particular, when mica A is used, it is considered that both the torque life and the amount of dust generation are improved because the base oil is taken in more easily.
[0074]
(Example 2)
Next, in the same manner as in the sample (3) produced in Example 1, the weight ratios of PFPE oil, PTFE polymer, and mica were 67 wt%, 30 wt%, and 3 wt%, respectively, and the mica particle size The rolling bearing 1 was manufactured with various changes. In addition, mica A to C used in Example 1 was used as mica. The torque life of the rolling bearing 1 manufactured as described above was measured in the same manner as in Example 1. The result is shown as a graph in FIG.
[0075]
In FIG. 2, the horizontal axis indicates the average particle diameter of mica A to C, and the vertical axis indicates the torque life. In the figure, curve 21 shows data obtained when mica A is used, curve 22 shows data obtained when mica B is used, and curve 23 is obtained when mica C is used. The obtained data is shown.
[0076]
As shown in this graph, a long torque life is obtained regardless of the range of the average particle diameter of mica A to C. In particular, when the average particle size is in the range of 0.05 μm to 20 μm, a better torque life is obtained, and in the case of 0.1 μm to 10 μm, for example, in the rolling bearing 1 using mica A, it exceeds 500 hours. The good torque life was able to be obtained.
[0077]
(Example 3)
In the same manner as in the sample (7) produced in Example 1 above, the PTFE polymer content in the lubricant composition was kept constant (20% by weight), and the PFPE oil and mica content were varied and rolled. A bearing 1 was manufactured. In addition, mica A to C used in Example 1 was used as mica. The torque life of the rolling bearing 1 manufactured as described above was measured in the same manner as in Example 1. The result is shown as a graph in FIG.
[0078]
In FIG. 3, the horizontal axis indicates the content of mica A to C in the lubricant composition, and the vertical axis indicates the torque life. In the figure, curve 31 shows data obtained when mica A is used, curve 32 shows data obtained when mica B is used, and curve 33 is obtained when mica C is used. The obtained data is shown.
[0079]
As shown in this graph, a relatively long torque life can be obtained regardless of the content of mica A to C, but the content of mica A is 0.1 wt% to 25 wt%. When the content is within the range, that is, when the content of the thickener which is the sum of the solid fluorinated polymer (PTFE polymer) and mica A is in the range of 20.1 wt% to 45 wt%, a better torque life can be obtained. I was able to get it.
[0080]
(Example 4)
A rolling bearing 1 was manufactured in the same manner as in the sample (1) manufactured in Example 1 except that the amount of the lubricant composition was 30 mg, with various mixing ratios of PFPE oil and mica A being changed. That is, the rolling bearing 1 was manufactured by using a mixture of PFPE oil and mica A without changing the PTFE polymer in the lubricant composition 5 and changing the respective contents. With respect to the rolling bearing 1 thus manufactured, the torque life and the amount of dust generation were measured in the same manner as in Example 1. The results are shown in a graph in FIG.
[0081]
In FIG. 4, the horizontal axis represents the content of mica A in the lubricant composition, and the vertical axis represents the torque life and the amount of dust generation. In the figure, a curve 41 shows data on the torque life, and a curve 42 shows data on the dust generation amount.
[0082]
As is apparent from this graph, lower dust generation is obtained when the content of mica A is 0.1% by weight or more. As for the torque life, the higher the weight ratio of mica A is within a range not exceeding 45% by weight, the better the value is obtained. That is, when the layered mineral powder such as mica A was 0.1 wt% to 45 wt% with respect to the base oil such as PFPE oil, good characteristics with respect to torque life and dust generation could be obtained.
[0083]
Further, when the content of mica A is 5% to 45% by weight, better characteristics can be obtained, and when it is 15% to 45% by weight, the best characteristics can be obtained. It was. When the amount is less than 5% by weight, the lubricant composition is in a liquid state, but when the amount is 5% by weight or more, it is in a grease state or an intermediate state between the grease state and the liquid state. This is considered to be due to the grease.
[0084]
(Example 5)
A rolling bearing 1 was produced by the same method as shown in Example 1 except that the lubricant composition contained ultrafine particles made of an inorganic substance instead of containing the layered mineral powder, and each rolling bearing was produced. The torque life and the amount of dust generation were measured for 1. Table 2 below shows the composition of the lubricant composition 5 used for each rolling bearing 1, the amount of sealing, the torque life, and the amount of dust generation.
[0085]
[Table 2]

[0086]
Fullerenes (C ₆₀ ) Using Pure C60 made by Materials and Electrochemical Research Corporation, and using MYPOMEX made by DuPont as the diamond fine particles (CD), the diamond is chemically coated with graphite on the surface. Fine particles (CGD) having an average particle diameter of 200 angstroms were used. Silicon oxide (SiO ₂ ) Is made from Nippon Aerosil Co., Ltd. AEROSIL200, titanium oxide (TiO2) ₂ ) Idemitsu titania IT-UD manufactured by Idemitsu Kosan Co., Ltd. was used. In addition, ZrO manufactured by CI Kasei Co., Ltd. was used as zirconia oxide (ZrO), and 100A manufactured by Ube Industries, Ltd. was used as magnesium oxide (MgO).
[0087]
As is apparent from Table 2, the rolling bearings of the samples (16) to (22) according to the examples of the present invention are all compared with the comparative samples (1) and (2) that are conventional rolling bearings. Long torque life and low dust generation. Therefore, by using the lubricant composition containing the liquid fluorinated polymer oil and the ultrafine particles, it was possible to improve the torque life characteristics and reduce the amount of dust generation.
[0088]
Further, when comparing the torque life for each of the samples (16) to (22), the samples (16) to (18) have a longer torque life and the amount of dust generation than the samples (19) to (22). Has been reduced. In Samples (16) to (18), fullerene (C ₆₀ ), Diamond fine particles, and diamond fine particles whose surface is chemically coated with graphite are considered to be used.
[0089]
(Example 6)
Similar to the samples (16) to (22) produced in Example 5 above, the content of PTFE polymer in the lubricant composition was kept constant (20% by weight), and the content of PFPE oil and ultrafine particles was varied. The rolling bearing 1 was manufactured by changing to In addition, as the ultrafine particles, fullerene (C ₆₀ ), Diamond fine particles with chemically coated graphite, silicon oxide, and titanium oxide were used. The torque life of the rolling bearing 1 manufactured as described above was measured in the same manner as in Example 1. The results are shown in a graph in FIG.
[0090]
In FIG. 5, the horizontal axis represents the content of ultrafine particles in the lubricant composition, and the vertical axis represents the torque life. In the figure, curve 51 is fullerene (C ₆₀ ) Is used, and curve 52 shows the data obtained when diamond fine particles whose surface is chemically coated with graphite are used. A curve 53 shows data obtained when silicon oxide is used, and a curve 54 shows data obtained when titanium oxide is used.
[0091]
As shown in this graph, a relatively long torque life could be obtained regardless of the range of the ultrafine particle content. In particular, when the content of the ultrafine particles is in the range of 0.1% by weight to 20% by weight, that is, the content of the thickener that is the sum of the solid fluorinated polymer (PTFE polymer) and the ultrafine particles is 20. A better torque life could be obtained when it was in the range of 1% to 40% by weight.
[0092]
(Example 7)
Rolling bearings 1 were prepared in the same manner as shown in Example 1 by including a PFPE carboxylic acid as an oily compound in the lubricant composition, and each rolling bearing 1 was subjected to an atmospheric condition and a vacuum (1 × 10 ^-Four The torque life at Pa) was measured. Table 3 below shows the composition of the lubricant composition 5 used in each rolling bearing 1, the amount of sealing, and the torque life.
[0093]
[Table 3]

[0094]
The mica A shown in Table 3 is the same as that used in Example 1, and fullerene (C ₆₀ ), Diamond fine particles (CD), diamond fine particles (CGD) chemically coated with graphite on the surface, silicon oxide (SiO 2) ₂ ) And titanium oxide (TiO) ₂ ) Is the same as that used in Example 5. Moreover, as the PFPE carboxylic acid, a compound (n = 5 to 80) represented by the above general formula (1) was used.
[0095]
As apparent from Table 3, in the rolling bearings of the samples (23) to (30) according to the examples of the present invention, the comparative sample (1) which is a conventional rolling bearing with respect to the torque life in the air atmosphere. The characteristics equivalent to or better than (3) are obtained. That is, by using a lubricant composition containing a liquid fluorinated polymer oil and the PFPE-based carboxylic acid, it was possible to improve torque life characteristics in an air atmosphere.
[0096]
Moreover, in the rolling bearings of the samples (23) to (30) according to the examples of the present invention, the torque life under vacuum is compared with the comparative samples (1) and (3) which are conventional rolling bearings. Much better properties have been obtained. That is, by using a lubricant composition containing a liquid fluorinated polymer oil and the PFPE carboxylic acid, the torque life characteristics under vacuum could be greatly improved.
[0097]
(Example 8)
The rolling bearing 1 was manufactured by the same method as shown in Example 7 by configuring the lubricant composition with PFPE oil and PFPE carboxylic acid and changing the content of PFPE carboxylic acid in various ways. In this case, the amount of the lubricant composition enclosed was 30 mg. In addition, the lubricant composition was composed of PFPE oil, 20% by weight of PFPE polymer, and PFPE carboxylic acid, and the contents of PFPE oil and PFPE carboxylic acid were variously changed. The rolling bearing 1 was manufactured by the same method as described above. In this case, the amount of the lubricant composition enclosed was 100 mg.
[0098]
With respect to the rolling bearing 1 manufactured as described above, the torque life under vacuum and the amount of dust generation under the air atmosphere were measured in the same manner as in Example 1. The results are shown as a graph in FIG.
[0099]
In FIG. 6, the horizontal axis indicates the content of the PFPE carboxylic acid in the lubricant composition, and the vertical axis indicates the torque life and the amount of dust generation. In the figure, a curve 61 shows data on the torque life obtained when the lubricant composition is composed of PFPE oil and PFPE-based carboxylic acid, and a curve 62 shows data on the dust generation obtained in that case. ing. Curve 63 shows data relating to the torque life obtained when the lubricant composition is composed of PFPE oil, PFPE polymer, and PFPE carboxylic acid, and curve 64 is data relating to the amount of dust generated in that case. Is shown.
[0100]
As shown in this graph, the amount of dust generation was small and a relatively long torque life could be obtained regardless of the range of the content of the PFPE carboxylic acid. In particular, when the content of the ultrafine particles is in the range of 0.1 wt% to 10 wt%, the amount of dust generation can be further reduced and a better torque life can be obtained.
[0101]
Example 9
The lubricant composition was composed of PFPE oil, PFPE polymer, ultrafine particles, and PFPE-based carboxylic acid, and the contents of PFPE oil and PFPE-based carboxylic acid were changed variously, and the same as that shown in Example 7 The rolling bearing 1 was manufactured by the method. The contents of the PFPE polymer and the ultrafine particles were 20% by weight and 3% by weight, respectively. In addition, as the ultrafine particles, the fullerene (C ₆₀ ) And fine diamond particles chemically coated with graphite on the surface.
[0102]
With respect to the rolling bearing 1 manufactured as described above, the torque life in the air atmosphere and in the vacuum and the dust generation amount in the air atmosphere were measured in the same manner as in Example 1. The results are shown in a graph in FIG.
[0103]
In FIG. 7, the horizontal axis indicates the content of PFPE carboxylic acid in the lubricant composition, and the vertical axis indicates the torque life and the amount of dust generation. In the figure, curves 71 and 72 are fullerenes (C ₆₀ ) Shows the data on the torque life in the air atmosphere and in the vacuum obtained in the case of using), and the curve 73 shows the data on the dust generation amount in the air atmosphere obtained in that case. Curves 74 and 75 show data on the torque life in the air atmosphere and vacuum obtained when the diamond fine particles are used as the ultrafine particles, respectively, and curve 76 shows the air atmosphere obtained in that case. The data on the amount of dust generated is shown.
[0104]
As shown in this graph, when the content of the PFPE carboxylic acid is in the range of 0.1% by weight to 10% by weight, good torque life is obtained under both vacuum and atmospheric conditions. In addition, the amount of generated dust could be reduced.
[0105]
(Example 10)
The lubricant composition was composed of PFPE oil, PFPE polymer, mica A used in Example 1, and PFPE carboxylic acid, and various contents of PFPE oil and PFPE carboxylic acid were changed to Example 7. A rolling bearing 1 was manufactured by the same method as shown. The lubricant composition was composed of PFPE oil, PFPE polymer, silicon oxide fine particles, and PFPE-based carboxylic acid, and the contents of PFPE oil and PFPE-based carboxylic acid were variously changed. The rolling bearing 1 was manufactured by the same method as described above. The content of PFPE polymer was 20% by weight, and the content of mica A or silicon oxide fine particles was 3% by weight.
[0106]
With respect to the rolling bearing 1 manufactured as described above, the torque life in the air atmosphere and in the vacuum and the dust generation amount in the air atmosphere were measured in the same manner as in Example 1. The result is shown as a graph in FIG.
[0107]
In FIG. 8, the horizontal axis indicates the content of PFPE carboxylic acid in the lubricant composition, and the vertical axis indicates the torque life and the amount of dust generation. In the figure, curves 81 and 82 show the data on the torque life in the atmosphere and vacuum obtained when using mica A, respectively, and curve 83 shows the dust generation in the atmosphere obtained in that case. Data on quantity is shown. Curves 84 and 85 show the data on the torque life in the atmosphere and vacuum obtained when silicon oxide fine particles are used as ultrafine particles, respectively, and curve 86 is in the air atmosphere obtained in that case. The data on the amount of dust generated is shown.
[0108]
As shown in this graph, when the content of the PFPE carboxylic acid is in the range of 0.1% by weight to 10% by weight, good torque life is obtained under both vacuum and atmospheric conditions. In addition, the amount of generated dust could be reduced.
[0109]
As mentioned above, although the case where PFPE oil was mainly used as base oil was demonstrated, the same effect can be acquired also when other liquid fluorinated polymer oil is used. In the above-described embodiment, the case where the rolling device of the present invention is used as a rolling bearing has been described. However, the same effect can be obtained when the rolling device is used as a linear motion device such as a ball screw device or a linear guide. Can do.
[0110]
【The invention's effect】
As described above, in the rolling device of the present invention, a mixture of a thickener containing layered mineral powder and a base oil composed of liquid fluorinated polymer oil is used as the lubricant composition. In the rolling device of the present invention, a mixture of a thickener containing ultrafine particles made of an inorganic substance and a base oil made of liquid fluorinated polymer oil is used as the lubricant composition. Furthermore, in the rolling device of the present invention, as the lubricant composition, a lubricant composition comprising a base oil composed of a liquid fluorinated polymer oil and a perfluoropolyether carboxylic acid having a molecular weight of 10,000 or less, Alternatively, a grease composition containing a perfluoropolyether carboxylic acid having a molecular weight of 10,000 or less in a mixture of a base oil composed of a liquid fluorinated polymer oil and a thickener containing a solid fluorinated polymer is used.
[0111]
When these lubricant compositions are used, scattering of the lubricant composition and wear of rolling elements are reduced. Therefore, according to the present invention, a rolling device having a small amount of dust generation and an excellent torque life is provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a rolling device and a bearing rotation tester according to an embodiment of the present invention.
FIG. 2 is a graph showing the relationship between the average particle diameter of the layered mineral powder and the torque life in the rolling device according to the example of the present invention.
FIG. 3 is a graph showing the relationship between the content of layered mineral powder in a lubricant composition and torque life in a rolling device according to an example of the present invention.
FIG. 4 is a graph showing the relationship between the content of the layered mineral powder in the lubricant composition, the torque life, and the amount of dust generation in the rolling device according to the example of the present invention.
FIG. 5 is a graph showing the relationship between the content of ultrafine particles in the lubricant composition and the torque life in the rolling device according to the example of the present invention.
FIG. 6 is a graph showing the relationship between the content of PFPE carboxylic acid in the lubricant composition, the torque life, and the amount of dust generation in the rolling device according to the example of the present invention.
FIG. 7 is a graph showing the relationship between the content of PFPE carboxylic acid in the lubricant composition, the torque life, and the amount of dust generation in the rolling device according to the example of the present invention.
FIG. 8 is a graph showing the relationship between the content of PFPE carboxylic acid in the lubricant composition, the torque life, and the amount of dust generation in the rolling device according to the example of the present invention.
[Explanation of symbols]
1 ... Rolling bearing
2 ... Inner ring
3 ... rolling element
4 ... Outer ring
5 ... Lubricant composition
6 ... Bearing rotation tester
7 ... Spindle
8 ... Spring
9 ... Motor
10 ... Belt
11, 12 ... pulley
13 ... Housing
14 ... Minute load transducer
15 ... Magnetic fluid seal unit
16 ... container
17 ... Bulkhead
18 ... Particle counter
19 ... Air inlet
20 ... Filter
41, 42, 51-54, 61-64, 71-76, 81-86 ... curve

Claims (5)

A mover that can rotate or move linearly,
A support for supporting the mover,
A rolling element that is interposed between the mover and the support and rolls along with the movement of the mover; and
Comprising a lubricant composition disposed between the movable element and the support on which the rolling element rolls;
The lubricant composition is a grease-like mixture of a thickener containing swellable mica and polytetrafluoroethylene, and a base oil composed of a liquid fluorinated polymer oil,
The average particle diameter of the mica is 0.1 μm to 10 μm,
The rolling device according to claim 1, wherein a content of the mica in the lubricant composition is 0.1 wt% to 25 wt% . The rolling device according to claim 1, wherein the content of the mica is 1% by weight to 20% by weight. The rolling device according to claim 1, wherein the content of the mica is 5% by weight to 20% by weight. The rolling device according to claim 1, wherein the average particle diameter of the mica is 1 μm or more. The rolling device according to any one of claims 1 to 4, wherein the mica is subjected to a hydrophobic treatment.

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