JP2004307986A - Rolling member and rolling device provided therewith - Google Patents

Abstract

[PROBLEMS] To provide excellent corrosion resistance, abrasion resistance and seizure resistance even under a corrosive environment, a non-lubricated condition, a high temperature condition, or a magnetic field environment, and realize non-magnetic and long life. Further, the present invention provides a rolling member capable of suppressing contamination of an external environment and a rolling device including the rolling member.
At least one of an inner ring (1), an outer ring (2) and a rolling element (3) constituting a rolling bearing (10) has a carbon content of 5.7 to 7.3% by weight in WC constituting a hard phase. Formed with cemented carbide.
[Selection diagram] Fig. 1

Description

【００９２】
図３は、ＷＣ−Ｃｏ系超硬合金において、結合相であるＣｏの含有量と、寿命との関係を示す。このとき、ＷＣ中の合金炭素量は、５．９〜６．２重量％の範囲内とした。
図４は、ＷＣ−Ｃｏ系超硬合金において、硬質相であるＷＣ中の合金炭素量と、寿命との関係を示す。このとき、Ｃｏの含有量は一定（１５重量％）とした。表１に示すように、実施例１〜６における転がり軸受においては、比較例１と比べて、無潤滑条件という過酷な潤滑条件下であっても、良好な耐久性を示し、寿命を向上させていることが分かる。
【００９３】
特に、実施例３及び４においては、ＷＣ中の合金炭素量が好ましい範囲内であるが、Ｃｏ含有量が好ましい範囲外であることにより、高い耐久性が得られていないことが分かる。
また、実施例５及び６においては、Ｃｏ含有量が好ましい範囲内であるが、ＷＣ中の合金炭素量は好ましい範囲外であることにより、高い耐久性が得られていないことが分かる。
【００９４】
さらに、図３に示す結果より、ＷＣ−Ｃｏ系超硬合金において、結合相を構成するＣｏ含有量が、６重量％以上、２５重量％以下の範囲であると、非常に優れた耐久性が確保できていることが確認できた。
さらに、図４に示す結果より、ＷＣ−Ｃｏ系超硬合金において、硬質相を構成するＷＣ中の合金炭素量が、５．９重量％以上、６．２重量％の範囲であると、非常に優れた耐久性が確保できていることが確認できた。
【００９５】
以上の結果より、特に、無潤滑条件下或いは過酷な潤滑条件下で適用される転がり軸受において、その構成部材の少なくとも一つを、Ｃｏ含有量を６〜２５重量％とし、且つ、ＷＣ中の合金炭素量を５．９〜６．２重量％としたＷＣ−Ｃｏ系超硬合金から構成するようにすれば、高い耐久性を確保することが可能となる。
〔第二実施例〕
転がり軸受を構成する内輪及び外輪を、Ｃｏからなる結合相を有するＷＣ−Ｃｏ系超硬合金から構成し、表２に示すように、添加剤として添加されるＴｉＣ、ＴｉＮ、ＴａＣ、ＶＣ、Ｃｒ_３ Ｃ_２ をそれぞれ変更させて試験軸受を作製した。
【００９６】
まず、それぞれの粒度が０．５〜２．０μｍの範囲であるＣｏ、Ｃｒ_２ Ｃ_３ 、ＶＣ、ＴｉＣ、ＴｉＮ、ＴａＣと、粒度が１．５〜７．０μｍのＷＣとの原料粉末を、表２に示すように所定量混合し、金型プレスで成形した。
次に、第一実施例と同様の工程を経て、それぞれの試験軸受を完成させた。
なお、この転がり軸受を構成する転動体は、いずれも窒化ケイ素からなるセラミックスから構成するとともに、保持器は、いずれも冠型フッ素系樹脂保持器（ＰＶｄＦ＋２０体積％チタン酸カリウム繊維製）から構成した。
【００９７】
そして、実施例１１〜１８と、比較例１１として添加物を一切含まないＷＣ−Ｎｉ系超硬合金とにおける耐久性を、図５に示す軸受回転試験機（日本精工株式会社製）を用いて、以下の条件下で回転試験を行った。なお、図５中の符号２００は軸受回転試験機、２１はモータ、２２は連結継ぎ手、２３はスピンドル、２４はシャフト、２５は振動計、２６はワイヤ、２７は滑車、２８はおもり、２９はプレート、３０は試験軸受、３１は容器をそれぞれ示し、腐食環境状態が形成された容器３１中で回転試験を行った。
【００９８】
ここで、耐久性は、振動値が初期値の３倍に上昇した時点を転がり軸受の寿命として測定し、各実施例及び比較例における転がり軸受の寿命は、比較例の耐久性を１とした相対値として表２に示す。
【００９９】
【表２】

【０１００】
＜耐久性試験条件＞
・回転速度：２０００ｍｉｎ^−１
・ラジアル荷重：９８Ｎ
・回転条件：塩酸０．５規定水溶液中
図６は、ＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金において、ＴａＣ含有量と、寿命との関係を示す図である。このとき、ＴｉＣ含有量は１０重量％、Ｃｏ含有量は１０重量％の一定とした。
【０１０１】
表２に示すように、実施例１１〜１８の転がり軸受においては、比較例１１と比べて、本発明の添加物を含有したことによって、腐食環境条件下であっても、良好な耐久性を示し、寿命を向上させていることが分かる。
特に、実施例１３〜１５においては、二種の添加物を含有していることによって、一種の添加物を含有している実施例１１、１２、１６、１７よりも、さらに高い耐久性を示していることが分かる。このとき、実施例１８においては、二種の添加物を含有しているが、その含有量が上述した好適範囲外であるため、実施例１３〜１５の耐久性よりも劣っていたことが分かる。
【０１０２】
また、図６に示す結果より、添加剤としてＴａＣの含有量が１〜２０重量％の範囲においては、非常に優れた耐久性が確保できていることが確認された。
以上の結果より、特に、腐食環境下で適用される転がり軸受において、その転動部材の少なくとも一つを、ＴｉＣ、ＴｉＮ、ＴａＣ、ＶＣ、Ｃｒ_３ Ｃ_２ の少なくとも一種が添加されたＷＣ−Ｃｏ系超硬合金から構成するようにすれば、より優れた耐食性を確保することが可能となる。
【０１０３】
〔第三実施例〕
転がり軸受を構成する内輪及び外輪を、Ｃｏからなる結合相を有するＷＣ−Ｃｏ系超硬合金から構成し、表３に示すように、添加剤としてＣｒ_３ Ｃ_２ 及びＶＣの添加量と、硬質相であるＷＣの粒度と、結合相としての機能を有するＣｏの含有量とをそれぞれ変更変更させて、試験軸受を作製した。また、ＴｉＣ−ＴａＣを含有するＷＣ−ＴｉＣ−ＴａＣ系超硬合金を構成し、硬質相であるＷＣの粒度と、結合相としての機能を有するＣｏの含有量をそれぞれ変更させて、試験軸受を作製した。
まず、それぞれの粒度が０．５〜２．０μｍの範囲であるＣｏ、Ｃｒ_２ Ｃ_３ 、ＶＣ、ＴｉＣ、ＴａＣの原料粉末を、表３に示すように、所定量混合し、金型プレスで成形する。
【０１０４】
次に、第一実施例と同様の工程を経て、それぞれの試験軸受を完成させた。具体的には、本発明における実施例２１〜２４のように、結合相としてＣｏを有するとともに、ＷＣの粒度が２μｍ以下で、且つ、Ｃｏ含有量が６重量％以下である超硬合金としては、日本タングステン株式会社製の商品名ＦＮ２０、ＦＮ３０、或いはＦＮ４０などが適用できる。また、本発明における実施例２５及び２６のように、ＴｉＣ、ＴｉＮ、ＴａＣの少なくとも一つを含有するとともに、ＷＣの粒度が２μｍ以下で、且つ、Ｃｏからなる結合相の含有量が１．５重量％以下である超硬合金としては、日本タングステン株式会社製の商品名ＲＣＣＬやＲＣＣＦＮ或いはダイジェット工業株式会社製の商品名ＦＢ０１などが適用される。
【０１０５】
なお、この転がり軸受を構成する転動体は、いずれも窒化ケイ素からなるセラミックスから構成するとともに、保持器は、いずれも冠型フッ素系樹脂保持器（ＰＶｄＦ＋２０体積％チタン酸カリウム繊維製）から構成した。
そして、実施例２１〜２６と、比較例２１〜２４としてそれぞれＷＣの粒度が３〜８μｍの範囲とした、ＷＣ−Ｎｉ系超硬合金、ＷＣ−Ｃｏ系超硬合金、ＷＣ−Ｃｒ_３ Ｃ_２ −ＶＣ−Ｃｏ、及びＷＣ−ＴｉＣ−Ｔａｃ系超硬合金とにおける耐久性を、第二実施例と同様の図５に示す軸受回転試験機を用いて、以下の条件下で回転試験を行った。
【０１０６】
ここで、耐久性は、第二実施例と同様の条件で測定し、結果を表３に示す。
＜耐久性試験条件＞
・回転速度：１０００ｍｉｎ^−１
・ラジアル荷重：９８Ｎ
・回転条件：塩酸２規定水溶液中
【０１０７】
【表３】

【０１０８】
図７は、ＷＣ−Ｃｒ_３ Ｃ_２ −ＶＣ−Ｃｏ系超硬合金において、結合相であるＣｏの含有量と、寿命との関係を示す。ここで、Ｃｒ_３ Ｃ_２ の含有量は２重量％、ＶＣの含有量は０．７重量％、残部ＷＣは一定、ＷＣの粒度は０．５〜１．０μｍの一定とした。
表３に示すように、実施例２１〜２６における転がり軸受においては、比較例２１〜２４と比べて、ＷＣ粒度及びＣｏの含有量を本発明の範囲内としたことによって、腐食環境条件下であっても、良好な耐久性を示し、寿命を向上させていることが分かる。
【０１０９】
特に、実施例２２〜２４においては、ＷＣ−Ｃｏ系超硬合金に添加物としてＣｒ_３ Ｃ_２ 及びＶＣを添加したことによって、これらの添加物が添加されていない実施例２１よりも高い耐久性を示していることが分かる。このうち、実施例２２及び２３においては、ＶＣの添加量を０．２〜１．０重量％の範囲内とし、且つ、Ｃｒ_３ Ｃ_２ の添加量を１．０〜３．０重量％の範囲内としたことによって、その範囲外とした実施例２４よりもさらに高い耐久性が得られていた。
【０１１０】
また、実施例２５及び２６においては、Ｃｏの含有量を１．５重量％以下の範囲内とするのであれば、まったく含有されない場合よりも高い耐久性を示していることが分かる。
さらに、図７に示す結果より、ＷＣ−Ｃｒ_３ Ｃ_２ −ＶＣ−Ｃｏ系超硬合金において、結合相を構成するＣｏ含有量が、６重量％以下の範囲であると、非常に優れた耐久性が確保できていることが確認できた。
【０１１１】
以上の結果より、特に、腐食環境下で適用される転がり軸受において、その転動部材の少なくとも一つを、ＷＣの粒度が２μｍ以下で、且つ、Ｃｏの含有量が６重量％以下であるＷＣ−Ｃｒ_３ Ｃ_２ −ＶＣ−Ｃｏ系超硬合金から構成するようにすれば、より優れた耐食性を確保することが可能となる。
また、同様に、その転動部材の少なくとも一つを、ＷＣの粒度が２μｍ以下で、且つ、Ｃｏの含有量が１．５重量％以下であるＷＣ−ＴｉＣ−ＴａＣ系超硬合金から構成するようにしても、より優れた耐食性を確保することが可能となる。
【０１１２】
〔第四実施例〕
転がり軸受を構成する内輪及び外輪を、Ｃｏからなる結合相を有し、添加剤としてＴｉＣ及びＴａＣを含有するＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金から構成し、このＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金の表面に、ＷＣ−ＴｉＣ−ＴｉＮからなる表面硬化層を１０μｍの厚さで形成した試験軸受を作製した。
まず、結合相となるＣｏ（粒度：１μｍ）を１０重量％と、添加物としてＴｉＣ（粒度：１．５μｍ）を１０重量％及びＴａＣ（粒度：１．５μｍ）を１２重量％と、硬質相となるＷＣ（粒度：１．５μｍ）を６８重量％との原料粉末をアルコール中で混合した後、乾燥し、得られた混合粉末を金型プレスで成型した。
【０１１３】
次に、この成型体を脱脂した後、真空炉内で焼結（１４００℃）し、ＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金を得た。
続いて、０．９気圧、Ｎ_２ 雰囲気中、１２５０℃×４ｈｒ焼結し、ＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金の表面に、厚さ１０μｍ程度のＷＣ−ＴｉＣ−ＴｉＮ表面硬化層を形成した。このとき、表面硬化層の厚さは、Ｎ_２ 雰囲気中での焼結時間で調整する。その後、表面硬化層が形成されたＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金に研削、研磨を行い、実施例１と同様の試験軸受を完成させた。
【０１１４】
そして、上述した図５に示す軸受回転試験機を用いて、以下の条件下で回転試験を行った。ここで、耐久性は、振動値が初期値の３倍に上昇した時点を転がり軸受の寿命として測定し、各実施例及び比較例における転がり軸受の寿命は、比較例の耐久性を１とした相対値として表４に示す。
【０１１５】
【表４】

【０１１６】
＜耐久性試験条件＞
・回転速度：１０００ｍｉｎ^−１
・ラジアル荷重：９８Ｎ
・回転条件：塩酸２規定水溶液中
表４に示すように、実施例３１における転がり軸受においては、比較例３１及び３２と比べて、添加物としてＴｉＣ及びＴａＣが含有され、且つ、ＷＣ−ＴｉＣ−ＴｉＮからなる表面硬化層が形成されていることから、良好な耐久性を示していることが分かる。また、実施例３２は、添加物ＴｉＣ及びＴａＣが含有されていることから比較例３１及び３２よりも良好な耐久性を示しているが、表面硬化層が形成されていないため、実施例３１よりも耐久性が劣っていることが分かる。
【０１１７】
図８は、表面に表面硬化層が形成されたＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金において、表面からの距離と、表面硬化層のビッカース硬さとの関係を示す。ここで、図８は、焼結時間を１時間として、厚さ１６μｍの表面硬化層を形成した試料軸受断面において、その表面からのビッカース硬さ分布（荷重９．８×１０^−１ Ｎ）の場合を示した。
【０１１８】
図８に示す結果より、試料軸受の表面から厚さ２μｍまでの表面硬化層は、ビッカース硬さはＨｖ１４５０〜１５００程度であり、母材であるＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金のビッカース硬さであるＨｖ１３５０よりも若干高くなっていることが分かる。また、試料軸受の表面からの厚さが２μｍを超えると、ビッカース硬さは上昇傾向を示し、厚さが６μｍでのビッカース硬さはＨｖ１６００まで到達している。そして、試料軸受の表面からの厚さが１４μｍを超えると、ビッカース硬さは低下し、厚さが１６μｍの時点で母材であるＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金と同一のビッカース硬さＨｖ１３５０に戻っていることが分かる。すなわち、表面硬化層を２〜１６μｍの厚さで形成すると、母材であるＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金よりも優れた硬さを確保できることが確認できた。
【０１１９】
図９は、表面に表面硬化層が形成されたＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金において、ＷＣ−ＴｉＣ−ＴｉＮからなる表面硬化層の層厚と、寿命との関係を示す。
図９に示す結果より、ＷＣ−ＴｉＣ−ＴｉＮからなる表面硬化層の厚さを、２〜１６μｍの範囲とすることで、優れた耐久性を確保できていることが確認できた。
【０１２０】
〔第五実施例〕
転がり軸受を構成する内輪及び外輪を、Ｃｏからなる結合相を有するＷＣ−Ｃｏ系超硬合金から構成し、このＷＣ−Ｃｏ系超硬合金の表面に、ＴｉＣからなる被膜又はＴｉＣ及びＴｉＮからなる被膜を形成した試験軸受を作製した。
まず、結合相となるＣｏ（粒度：１μｍ）を１０重量％と、硬質相となるＷＣ（粒度：１．５μｍ）を９０重量％との原料粉末をアルコール中で混合した後、乾燥し、得られた混合粉末を金型プレスで成型した。
次に、この成型体を脱脂した後、真空炉内で焼結（１４００℃）し、ＷＣ−Ｃｏ系超硬合金を得る。
【０１２１】
続いて、化学蒸着（ＣＶＤ：Ｃｈｅｍｉｃａｌ ｖａｐｏｒ ｄｅｐｏｓｉｔｉｏｎ）装置を用いて、温度１０００℃、１０^３ 〜１０^４ Ｐａ減圧雰囲気下の条件で、ＷＣ−Ｃｏ系超硬合金の表面に、ＴｉＣからなる被膜とＴｉＮからなる被膜とを総厚さ５μｍとなるように順に形成した。ここで、ＴｉＣからなる被膜を形成する場合には、ＴｉＣｌ_４ ＋Ｈ_２ ＋ＣＨ_４ の混合ガスを使用した。また、ＴｉＮからなる被膜を形成する場合には、ＴｉＣｌ_４ ＋Ｈ_２ ＋Ｎ_２ の混合ガスを使用した。その後、ＴｉＣ及びＴｉＮからなる被膜が形成されたＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金に研削、研磨を行い、表５に示すように、実施例１と同様の試験軸受を完成させた。
【０１２２】
そして、上述した図５に示す軸受回転試験機を用いて、以下の条件下で回転試験を行った。ここで、耐久性は、振動値が初期値の３倍に上昇した時点を転がり軸受の寿命として測定し、各実施例及び比較例における転がり軸受の寿命は、比較例の耐久性を１とした相対値として表５に示す。
【０１２３】
【表５】

【０１２４】
＜耐久性試験条件＞
・回転速度：１０００ｍｉｎ^−１
・ラジアル荷重：９８Ｎ
・回転条件：塩酸２規定水溶液中
表５に示すように、実施例４１及び４２における転がり軸受においては、比較例４１及び４２と比べて、ＴｉＣからなる被膜又はＴｉＣ及びＴｉＮからなる被膜が形成されていることから、良好な耐久性を示していることが分かる。
【０１２５】
図１０は、表面に被膜が形成されたＷＣ−Ｃｏ系超硬合金において、ＴｉＣ及びＴｉＮからなる被膜の膜厚と、寿命との関係を示す。ここで、Ｃｏ含有量は１０重量％、ＷＣ含有量は９０重量％と一定とした。
図１０に示すように、ＴｉＣ及びＴｉＮからなる被膜の厚さを２〜１０μｍの範囲とすることで、優れた耐久性を確保できていることが確認できた。
【０１２６】
なお、本実施例では、ＷＣ−Ｃｏ系超硬合金の表面に、ＴｉＣからなる被膜とＴｉＮからなる被膜とを二層形成するようにしたが、ＴｉＣからなる被膜のみを形成するようにしてもよい。
〔第六実施例〕
転がり軸受を構成する内輪及び外輪を、Ｃｏ及びＮｉからなる結合相を有するＷＣ−Ｃｏ−Ｎｉ系超硬合金から構成し、表６に示すように、添加剤としてＣｒ_３ Ｃ_２ の添加量と、結合相であるＣｏやＮｉの含有量とをそれぞれ変更して試験軸受を作製した。
【０１２７】
まず、それぞれの粒度が０．５〜２．０μｍの範囲であるＣｏ、Ｎｉ、Ｃｒ_２ Ｃ_３ と、粒度が１．５〜７．０μｍであるＷＣとの原料粉末を、表４に示すように、所定量混合し、金型プレスで成形する。
次に、第一実施例と同様の工程を経て、それぞれの試験軸受を完成させた。
なお、この転がり軸受を構成する転動体は、いずれも窒化ケイ素からなるセラミックスから構成するとともに、保持器は、いずれも冠型フッ素系樹脂保持器（ＰＶｄＦ＋２０体積％チタン酸カリウム繊維製）から構成した。
【０１２８】
そして、実施例５１〜５８と、比較例５１であるＮｉの含有量を２０重量％としたＷＣ−Ｎｉ系超硬合金とにおける耐久性を、第一実施例と同様の図２に示す軸受回転試験機を用いて、以下の条件下で回転試験を行った。
ここで、耐久性は、第一実施例と同様に測定し、結果を表６に示す。
＜耐久性試験条件＞
・回転速度：７０００ｍｉｎ^−１
・ラジアル荷重：９８Ｎ
・潤滑条件：無潤滑
【０１２９】
【表６】

【０１３０】
図１１は、ＷＣ−Ｃｏ−Ｎｉ系超硬合金において、Ｎｉの含有量と寿命との関係を示す。このとき、Ｃｏの含有量は６．５重量％、Ｃｒ_３ Ｃ_２ の含有量は０．７重量％の一定とした。
表６に示すように、実施例５１〜５８においては、比較例５１と比べて、Ｃｏ及びＮｉからなる結合相の含有量を１０〜２０重量％とし、且つ、そのうちのＮｉの含有量を１５重量％以下としたことによって、無潤滑条件下であっても、良好な耐久性を示し、寿命を向上させていることが分かる。
特に、実施例５７、５８においては、ＷＣ−Ｃｏ−Ｎｉ系超硬合金中に、添加剤としてＣｒ_３ Ｃ_２ を添加することで、さらに高い耐久性を示していることが分かる。
【０１３１】
また、図１１に示すように、結合相であるＣｏ及びＮｉの合計含有量が１０〜２０重量％の範囲内であると、非常に優れた耐久性が確保できていることが確認できた。
以上の結果より、特に、無潤滑条件下或いは過酷な潤滑条件下で適用される転がり軸受において、その構成部材の少なくとも一つを、結合相であるＣｏ及びＮｉの含有量を１０〜２０重量％とし、且つ、Ｃｒ_３ Ｃ_２ を添加させたＷＣ−Ｃｏ−Ｎｉ系超硬合金から構成するようにすれば、高い耐久性を確保することが可能となる。
【０１３２】
〔第七実施例〕
転がり軸受を構成する内輪及び外輪を、Ｎｉからなる結合相を有するＷＣ−Ｎｉ系超硬合金から構成し、表７に示すように、添加剤としてＣｒ_３ Ｃ_２ 、Ｍｏ_２ Ｃ、ＶＣの添加量と、結合相であるＣｏやＮｉの含有量とをそれぞれ変更して試験軸受を作製した。
まず、結合相となるＮｉ（粒度：１．０〜１．５μｍ）と、添加剤であるＣｒ_３ Ｃ_２ （粒度：０．５〜２．０）、ＶＣ（粒度：０．５〜２．０重量％）、Ｍｏ_２ Ｃ（粒度：０．５〜２．０μｍ）と、硬質相となるＷＣ（粒度：１．０〜１．５μｍ）との原料粉末を、表５に示すように、所定量混合し、金型プレスで成形した。
【０１３３】
次に、第一実施例と同様の工程を経て、それぞれの試験軸受を完成させた。
なお、この転がり軸受を構成する転動体は、実施例６１をＷＣ−Ｎｉ系超硬合金から構成した以外は全て窒化ケイ素からなるセラミックスから構成するとともに、保持器は、いずれも冠型フッ素系樹脂保持器（ＰＶｄＦ＋２０体積％チタン酸カリウム繊維製）から構成した。
【０１３４】
そして、実施例６１〜７３と、比較例６１〜６３とにおける耐久性を、第二実施例と同様の図５に示す軸受回転試験機を用いて、以下の条件下で回転試験を行った。
ここで、耐久性は、第一実施例と同様に測定し、結果を表７に示す。
＜耐久性試験条件＞
・回転速度：３０００ｍｉｎ^−１
・ラジアル荷重：９８Ｎ
・潤滑条件：無潤滑
【０１３５】
また、非磁性が要求される環境下で好適に使用可能であるか否かを評価するために、図１２に示す軸受回転試験機（日本精工株式会社製）を用いて、回転試験を行った。なお、図１２中の符号３００は軸受回転試験機、４１は回転軸、４２は試験軸受、４３は永久磁石、４４はガウスメーターをそれぞれ示し、永久軸受４３を近づけた状態で回転軸４１を回転させ、それに伴い試験軸受４２を回転させた。
【０１３６】
ここで、磁性の有無は、回転の際に生じる磁束密度の変化をガウスメーター４４で測定し、試験軸受４２が回転する際の周辺磁場への影響を評価した。なお、軸受を回転させた際に生じる磁束密度の変化が、０．１ｍＴ以下である場合には磁性（○）とし、それ以外は非磁性（×）として、結果を表７に示す。
【０１３７】
【表７】

【０１３８】
図１３は、ＷＣ−Ｃｒ_３ Ｃ_２ −ＶＣ−Ｎｉ系超硬合金において、Ｎｉの含有量と、寿命との関係を示す。このとき、Ｃｒ_３ Ｃ_２ の含有量は０．８重量％、ＶＣの含有量は０．４重量％、ＷＣ中合金炭素量は６．０５重量％の一定とした。
表７に示すように、実施例６１〜７３においては、比較例６１〜６３と比べて、Ｎｉからなる結合相の含有量を６〜１５重量％とし、且つ、Ｎｉ中に１７重量％以上のＷが固溶させたことによって、腐食条件下であっても、良好な耐久性を示し、寿命を向上させていることが分かる。
特に、実施例６４、６５、７０、７１においては、添加剤として、Ｃｒ_３ Ｃ_２ 、Ｍｏ_２ Ｃ、ＶＣを上述の好適範囲内で添加させたことによって、さらに耐久性を向上させていることが分かる。
【０１３９】
また、実施例６８、６９、７２、７３においては、ＷＣ中の合金炭素量がそれぞれの最適範囲外であることより、非磁性を確保できていないことが分かる。
さらに、図１３に示すように、結合相としてのＮｉの含有量が、６〜１５重量％の範囲内であると、非常に優れた耐久性が確保できていることが確認できた。
以上の結果より、特に、無潤滑条件下や磁場環境下で適用される転がり軸受において、その構成部材の少なくとも一つを、結合相であるＮｉの含有量を６〜１５重量％とし、且つ、Ｃｒ_３ Ｃ_２ 、Ｍｏ_２ Ｃ、ＶＣを添加させたＷＣ−Ｎｉ系超硬合金から構成するようにすれば、非磁性及び高い耐久性を確保することが可能となる。
【０１４０】
〔第八実施例〕
転がり軸受を構成する内輪及び外輪を、下記（１）〜（１１）に示す耐熱性樹脂を用いて、主成分となる耐熱性樹脂がそれぞれ異なる樹脂組成物で構成するとともに、転動体を、本発明の範囲内における超硬合金で構成した試験軸受を作製した。
（１）ＰＰＳ（フィリップスペトローリアム社製ポリフェニレンサルファイド樹脂：ライトンＲ−６
（２）ＰＶＤＦ（呉羽化学工業社製：クレハＫＦポリマーＴ−♯１０００）
（３）ＴＰＩ（三井東圧化学社製：オーラム ４００）
（４）ＰＥＥＫ（ビクトレックス社製：ビクトレックスＰＥＥＫ １５０Ｇ）
（５）ＰＥＥＫ−ＰＢＩ（ヘキストーセラニーズ社製：セラゾール ＴＵ−６０）
（６）ＰＥＮ（出光マテリアル社製：ＩＤ３００）
（７）炭素繊維（呉羽化学工業社製：クレカチョップＭ−１０２Ｓ，繊維径１４．５μｍ，長さ０．２ｍｍ）
（８）チタン酸カリウムウィスカー（大塚化学社製：ティスモＤ−１０１，繊維径０．３〜０．６μｍ，長さ１０〜２０μｍ）
（９）アラミド繊維（群栄化学工業社製：カイノール繊維ＫＦ０２ＢＴ，繊維径１４μｍ，長さ０．２ｍｍ）
（１０）微細炭素繊維（昭和電工社製：気相法炭素繊維ＶＧＣＦ，繊維径１００〜２００ｍｍ，長さ１０〜２０μｍ）
（１１）黒鉛（中越黒鉛工業社製：ＣＬＸ，平均粒径４．５μｍ）
【０１４１】
なお、この転がり軸受を構成する保持器は、いずれも射出成形によって作製した冠型樹脂組成物製保持器（テトラフルオロエチレン・エチレン共重合体（ＥＴＦＥ）樹脂＋２０体積％チタン酸カリウムウィスカー）を用いた。
そして、実施例８１〜８９と、比較例８１及び８２とにおける耐久性を、第二実施例と同様の図５に示す軸受回転試験機を用いて、以下の条件下で回転試験を行った。
ここで、耐久性は、第一実施例と同様に測定し、結果を表８に示す。
＜耐久性試験条件＞
・回転速度：１０００ｍｉｎ^−１
・ラジアル荷重：４９Ｎ
・温度：常温
【０１４２】
【表８】

【０１４３】
表８に示すように、実施例８１〜８９においては、比較例８１及び８２と比べて、内輪及び外輪を耐熱性樹脂を主成分とする樹脂組成物で構成し、且つ、転動体を本発明の範囲における超硬合金で構成したことによって、良好な耐摩耗性及び耐食性を示し、寿命を向上させていることが分かる。
【０１４４】
特に、実施例８１及び８８においては、これらの実施例で転動体を構成している超硬合金で内輪及び外輪を構成した実施例２２や実施例６１よりも、さらに耐久性を向上させていることが分かる。
以上の結果より、特に、潤滑条件が厳しい環境下においても、内輪及び外輪を耐熱性樹脂を主成分とする樹脂組成物で構成し、且つ、転動体を本発明の範囲における超硬合金で構成するようにすれば、より高い耐久性を確保することが可能となる。
【０１４５】
【発明の効果】
以上説明したように、本発明の転動部材によれば、内方部材、外方部材、転動体の少なくとも一つを、硬質相を構成するＷＣ中の合金炭素量が５．７〜７．３重量％となっている超硬合金で構成したことによって、耐摩耗性、耐焼付き性、耐熱性、及び耐食性を向上させることが可能となる。このため、無潤滑条件下、高温環境下、腐食環境下、及び磁場環境下などの過酷な環境であっても好適に利用することが可能となる。
【０１４６】
本発明の第一の転動装置によれば、可動子、支持体、及び転動体の少なくとも一つを、本発明の転動部材で構成することによって、無潤滑条件下、高温環境下、腐食環境下、及び磁場環境下などの過酷な環境であっても好適に利用することが可能となる。
本発明の第二の転動装置によれば、可動子及び支持体の少なくとも一つを、耐熱性樹脂を主成分とする樹脂組成物から構成するとともに、転動体を、本発明の転動部材で構成することによって、潤滑条件が厳しい環境であっても好適に利用することが可能となる。
【０１４７】
本発明の第三の転動装置によれば、可動子、支持体、及び保持器の少なくとも一つを、耐熱性樹脂を主成分とする樹脂組成物で構成するとともに、転動体を、本発明の転動部材で構成することによって、潤滑条件が厳しい環境であっても好適に利用することが可能となる。
【図面の簡単な説明】
【図１】本発明における転動装置の一例として転がり軸受の一構成例を示す断面図である。
【図２】軸受回転試験機を示す断面図である。
【図３】ＷＣ−Ｃｏ系超硬合金において、結合相であるＣｏの含有量と、寿命との関係を示す図である。
【図４】ＷＣ−Ｃｏ系超硬合金において、ＷＣ中の合金炭素量と、寿命との関係を示す図である。
【図５】軸受回転試験機を示す模式図である。
【図６】ＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金において、ＴａＣ含有量と、寿命との関係を示す図である。
【図７】ＷＣ−Ｃｒ_３ Ｃ_２ −ＶＣ−Ｃｏ系超硬合金において、Ｃｏの含有量と、寿命との関係を示す図である。
【図８】表面に表面硬化層が形成されたＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金において、表面からの距離と、表面硬化層のビッカース硬さとの関係を示す。
【図９】表面に表面硬化層が形成されたＷＣ−ＴｉＣ−ＴａＣ−Ｃｏ系超硬合金において、ＷＣ−ＴｉＣ−ＴｉＮからなる表面硬化層の層厚と、寿命との関係を示す。
【図１０】表面に被膜が形成されたＷＣ−Ｃｏ系超硬合金において、ＴｉＣ及びＴｉＮからなる膜厚の膜厚と、寿命との関係を示す。
【図１１】ＷＣ−Ｃｏ−Ｎｉ系超硬合金において、Ｎｉの含有量と寿命との関係を示す図である。
【図１２】軸受回転試験機を示す断面図である。
【図１３】ＷＣ−Ｃｒ_３ Ｃ_２ −ＶＣ−Ｎｉ系超硬合金において、Ｎｉの含有量と、寿命との関係を示す図である。
【符号の説明】
１ 内輪（可動子）
２ 外輪（支持体）
３ 転動体
４ 保持器
１０ 転がり軸受（転動装置）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is applicable to a corrosive environment such as various cleaning devices in a liquid crystal panel manufacturing process, a semiconductor manufacturing process, a hard disk manufacturing process, and a capacitor manufacturing process, steel and steel equipment, a kiln transfer truck, a continuous heat treatment conveyor, and a baking coating machine. Trolleys and other high-temperature furnace-like transfer systems, under non-lubricated conditions such as machine tools, turbines, and various pumps, or electron beam exposure / drawing equipment and inspection equipment for semiconductor manufacturing equipment. The present invention relates to a rolling member suitably usable in such a magnetic field environment and a rolling device including the same.
[0002]
[Prior art]
In rolling devices such as rolling bearings, for example, liquid crystal panels, semiconductors, in order to be suitably usable in a variety of environments such as hard disk manufacturing process, under corrosive environment, high temperature environment, non-lubricated conditions, or Various proposals have been made to withstand a severe environment such as a magnetic field environment.
[0003]
For example, in the above-described manufacturing process, fine particles or gas adhering to the surface of a semiconductor element or the like may adversely affect product performance, reliability, yield, and the like. Therefore, instead of lubricating by lubricating oil or grease that causes particles or gas, the lubrication is not performed by lubricating with a small amount of lubricant or solid lubricant, or without lubrication. Various means using a rolling device have been proposed.
[0004]
In addition, various types of rolling devices that can be suitably used in a corrosive environment such as an atmosphere of the chemicals by using various chemicals in various cleaning processes of the above-described devices have been proposed.
As a rolling bearing applied under such a corrosive environment, the outer ring is made of a ceramic material manufactured by a normal temperature sintering method, and the inner ring is made of a ceramic material manufactured by a gas pressure sintering method or a HIP method. Means have been proposed (for example, see Patent Document 1).
[0005]
Similarly, a means has been proposed in which each of the inner ring, the outer ring, and the rolling elements is made of a ceramic material (silicon carbide) (for example, see Patent Document 2).
Further, in an exposure / drawing apparatus or an inspection apparatus using an electron beam used in the above-described manufacturing process, a rolling device is applied as a means for moving a silicon wafer irradiated with an electron gun. Here, if a magnetic material is used for the rolling members constituting the rolling device, the magnetic field may be disturbed and measurement accuracy and manufacturing accuracy (drawing accuracy) may be reduced. There is a long-awaited need for motion devices.
[0006]
As a rolling bearing applied under such a magnetic field environment, a means has been proposed in which at least one of a bearing ring and a rolling element is made of a Mn-Ni-Cu alloy (for example, see Patent Document 3).
Similarly, a means has been proposed in which the bearing ring is made of beryllium copper and the rolling elements are made of ceramics (silicon nitride, silicon carbide, alumina) (for example, see Patent Document 4).
Similarly, at least one of the inner ring, the outer ring and the rolling elements is made of a WC-Ni (tungsten carbide-nickel) cemented carbide, or the inner and outer rings are made of a WC-Ni cemented carbide. Means in which the moving body is made of ceramics has been proposed (for example, see Patent Document 5).
[0007]
[Patent Document 1]
JP-A-8-112488
[Patent Document 2]
JP-A-10-82426
[Patent Document 3]
JP-A-2000-130439
[Patent Document 4]
JP-A-11-336755
[Patent Document 5]
JP 2000-154825 A
[0008]
[Problems to be solved by the invention]
However, in the means disclosed in Patent Document 1, although the outer ring and the inner ring are made of ceramics, they have excellent corrosion resistance. However, the outer ring is made of ceramics manufactured by a normal temperature sintering method. Therefore, there is a problem that the strength and the fracture toughness are low, and minute cracks are easily propagated based on the surface or internal defect. For this reason, a large amount of abrasion powder is generated, contaminating the external environment, cracking occurs, and the life may be shortened. In particular, when supporting a radial load, the load zone of the outer ring concentrates on the load, so even under a light load, cracks easily propagate to the outer ring manufactured by the room temperature sintering method, and the life is extended. There was a possibility that it would be significantly reduced.
[0009]
Further, in the means disclosed in Patent Document 2, the inner ring, the outer ring, and the rolling elements are each formed of a ceramic material (silicon carbide), thereby providing excellent corrosion resistance. Similarly, the strength and fracture toughness are low, and when a load is applied to some extent, cracks propagate on the surface or the entire surface of the inner ring, the outer ring, and the rolling elements, and there is a problem that peeling or cracking occurs. In particular, in the case where a radial load is supported, there is a possibility that the service life may be significantly reduced as in Patent Document 1.
[0010]
Further, in the means disclosed in Patent Document 3 and Patent Document 4, the race is made of a Mn-Ni-Cu alloy (Hv = about 340) or beryllium copper (Hv = about 400), and the rolling element Is made of ceramics, the hardness of the raceway and the rolling element differs by about 3 times or more. Therefore, under non-lubricated conditions or under severe lubricating conditions using low-viscosity oil, the hard rolling element Abrasion occurs, and the soft bearing ring wears remarkably, shortening the life of the rolling device and contaminating the external environment. In addition, the bearing ring made of a soft alloy such as the above-mentioned Mn-Ni-Cu alloy or beryllium copper causes plastic deformation even at a relatively light load, so that it can be applied only under light load conditions. there were.
[0011]
Furthermore, in the means disclosed in Patent Document 5, there is a possibility that strength, hardness or sinterability may vary depending on the content of Ni, which is a binder phase for binding a hard phase. For this reason, depending on the content of Ni, the hardness and wear resistance are insufficient, and particularly under non-lubricated conditions or severe lubricated conditions, wear significantly progresses or sinterability is deteriorated. Poorly, a large number of pores are generated, and cracks are easily introduced and propagated. For this reason, the service life is significantly reduced, and the external environment may be contaminated by the generated wear powder.
[0012]
In addition, WC-Ni-based cemented carbide has relatively low hardness and wear resistance at high temperatures, and operates in high-temperature environments such as high-temperature furnace transfer systems such as conveyors for continuous heat treatment and trolleys for baking coating machines. If contact occurs or solid contact occurs under severe lubrication conditions such as non-lubrication conditions and the temperature rises significantly locally at the point of contact between the race and the rolling element, adhesion wear or abrasive wear Extreme wear occurs. For this reason, the life of the rolling device may be significantly reduced, the external environment may be contaminated by the generated wear powder, or seizure may occur to make the operation inoperable.
[0013]
Further, WC-Ni-based cemented carbides are not all non-magnetic, and may become ferromagnetic depending on the amount of alloy carbon in WC which is a main component of the hard phase. Therefore, when a WC-Ni-based cemented carbide having ferromagnetism is used in a magnetic field, the magnetic field is disturbed, and there is a possibility that measurement accuracy and manufacturing accuracy (drawing accuracy) may be reduced.
As described above, the gazette disclosed in Patent Document 5 does not disclose the non-magnetic properties and the technical contents necessary to realize the mechanical strength and wear resistance required for the rolling device. There was still room for improvement.
[0014]
The present invention has been made in view of the above circumstances, and has excellent corrosion resistance, abrasion resistance, and seizure resistance even under a corrosive environment, under non-lubricated conditions, under high temperature conditions, or under a magnetic field environment. It is another object of the present invention to provide a rolling member that realizes non-magnetism and has a long life, and that can suppress contamination to an external environment, and a rolling device including the rolling member.
[0015]
[Means for Solving the Problems]
In order to solve such a problem, the present inventors have focused on a cemented carbide as a material constituting a rolling member, and have formed an alloy carbon amount in WC constituting a hard phase thereof and a binder phase. It has been found that the above problem can be solved by examining the metal material and its content and the additive to be added to the cemented carbide.
[0016]
That is, the rolling member of the present invention is a rolling member that constitutes a rolling device, and is made of a cemented carbide made of a hard phase and a binding phase that couples the hard phase, and Is characterized in that the amount of alloy carbon in WC constituting 5.7 to 5.7% by weight.
In the rolling member of the present invention, the cemented carbide may be a WC-Co cemented carbide in which the binder phase is Co.
[0017]
Further, in the rolling member of the present invention, as the WC-Co-based cemented carbide, the carbon content of the alloy in the WC is 5.9 to 6.2% by weight, and the content of the binder phase is 6 to 6%. It is preferably 25% by weight.
Further, in the rolling member of the present invention, it is preferable that the WC-Co-based cemented carbide has a WC particle size of 2 μm or less and a binder phase content of 6% by weight or less.
[0018]
Further, the rolling member according to the present invention includes, as the WC-Co-based cemented carbide, TiC, TiN, TaC, VC, Cr₃C₂It is preferable to contain at least one of the following.
Further, the rolling member according to the present invention includes VC and Cr as the WC-Co-based cemented carbide.₃C₂May be contained together.
[0019]
Further, the rolling member of the present invention contains TiC and TaC as the WC-Co-based cemented carbide, and the surface of the WC-Co-based cemented carbide is rich in WC-TiC-TiN solid solution. The surface hardened layer may be formed with a thickness of 2 to 16 μm.
Further, in the rolling member of the present invention, a film made of TiC or a film made of TiC and TiN may be formed on the surface of the WC-Co cemented carbide.
[0020]
Here, the film made of TiC or the film made of TiC and TiN is preferably formed by a chemical vapor deposition method.
Further, it is preferable that the film made of TiC or the film made of TiC and TiN is formed to have a thickness of 2 to 10 μm.
Furthermore, the rolling member of the present invention contains at least one of TiC, TiN, and TaC as the cemented carbide, and the WC has a particle size of 2 μm or less, and the content of the binder phase composed of Co is 2 μm or less. It may be set to 1.5% by weight or less. However, in this case, the amount of alloy carbon in WC is preferably 6.4 to 6.6% by weight.
[0021]
Further, in the rolling member of the present invention, the cemented carbide may be a WC-Co-Ni-based cemented carbide in which the binder phase is Co-Ni.
Further, in the rolling member of the present invention, it is preferable that the content of the binder phase is 10 to 20% by weight as the WC-Co-Ni-based cemented carbide.
Further, the rolling member of the present invention is characterized in that the WC-Co-Ni-based cemented carbide has a Cr content of 0.5 to 3.0% by weight.₃C₂It is preferred to contain.
[0022]
Further, in the rolling member of the present invention, the cemented carbide may be a WC-Ni-based cemented carbide in which the binder phase is Ni.
Further, in the rolling member of the present invention, it is preferable that the content of the binder phase is 6 to 15% by weight as the WC-Ni-based cemented carbide.
Further, in the rolling member of the present invention, as the WC-Ni-based cemented carbide, it is preferable that 17% by weight or more of W is dissolved in the binder phase.
[0023]
Further, the rolling member according to the present invention is characterized in that, as the WC-Ni-based cemented carbide,₃C₂And 0.7% by weight or less of VC.
Further, the rolling member according to the present invention is characterized in that, as the WC-Ni-based cemented carbide,₃C₂And Mo of 2.0% by weight or less₂C may be contained.
[0024]
The first rolling device of the present invention includes a movable element capable of rotating or linearly moving, a support for supporting the movable element capable of rotating or linearly moving, and a rolling element between the movable element and the support. A plurality of rolling elements movably disposed, wherein at least one of the mover, the support, and the rolling elements is configured by a rolling member of the present invention. Features.
[0025]
In the first rolling device of the present invention, the rolling element may be made of at least one selected from ceramics, cermet, and stainless steel. A second rolling device according to the present invention includes a movable element capable of rotating or linearly moving, a support for supporting the movable element capable of rotating or linearly moving, and a rolling element between the movable element and the support. A plurality of rolling elements movably disposed, and in a rolling device comprising: at least one of the mover and the support body is made of a resin composition containing a heat-resistant resin as a main component; The rolling element is constituted by the rolling member according to any one of claims 1 to 6 or 11 to 19.
[0026]
A third rolling device of the present invention includes a movable element capable of rotating or linearly moving, a support for supporting the movable element capable of rotating or linearly moving, and a rolling element between the movable element and the support. A rolling device, comprising: a plurality of rolling elements movably arranged; and a retainer for rotatably holding the rolling elements, wherein at least one of the movable element, the support, and the retainer is provided. One is made of a resin composition containing a heat-resistant resin as a main component, and the rolling element is made of the rolling member according to any one of claims 1 to 6 or 11 to 19. It is characterized by.
[0027]
According to the rolling member of the present invention, wear resistance and seizure resistance are achieved by using a cemented carbide having a carbon content of 5.7 to 7.3% by weight in the WC constituting the hard phase. , Heat resistance, and corrosion resistance can be improved. Therefore, the present invention can be suitably used for a rolling device used under a non-lubricated condition, a high temperature environment, a corrosive environment, and a magnetic field environment.
[0028]
Note that the amount of alloy carbon in WC constituting the hard phase is defined by the following equation. In the formula, all components refer to the sum of all of the hard phase WC and the binder phase. Further, C is a value including free carbon, and whether or not free carbon was precipitated was determined by observing a cross-sectional structure and measuring the strength (the strength is significantly reduced when free carbon is precipitated).
[0029]
Alloy carbon content (C / WC weight%) = (C / all components) × (all components / WC) × 100 Here, if the alloy carbon content in the WC is less than 5.7% by weight, the η phase (Co₃W₃C phase) or θ phase (Ni₃W₃Because the (C phase) is precipitated, the strength is significantly reduced, and cracks are easily introduced and propagated. For this reason, the service life is significantly reduced, and there is a possibility that cracks may occur even with a relatively light load. On the other hand, if the amount of alloy carbon in WC exceeds 7.3% by weight, free carbon is generated, so that the strength is reduced and the life may be greatly reduced. For this reason, the alloy carbon content in WC is set in the range of 5.7 to 7.3% by weight.
[0030]
Further, according to the rolling member of the present invention, by forming the cemented carbide from a WC-Co-based cemented carbide whose binder phase is Co, it is possible to provide sufficient hardness and improve wear resistance. Becomes possible. Therefore, even under non-lubricated conditions or severe lubricated conditions, abrasive wear at the contact points can be effectively suppressed, so that stable operability can be ensured and contamination of the external environment by wear powder can be suppressed. It becomes possible. The fracture toughness value of the WC-Co cemented carbide having Co as a binder phase is such that cracks hardly propagate on the surface and inside even when used as a component of a rolling device, and peeling and abrasion are likely to occur. 5MPa ・ m^1/2It is preferable that it is above. Here, the fracture toughness value (calculated based on JIS R1607, IF method for a flat surface of a cemented carbide material) is 5 MPa · m.^1/2If it is less than 1, cracks are likely to propagate based on surface or internal defects, and a large amount of abrasion powder may be generated or cracks may occur, which may shorten the life of the rolling device.
[0031]
In particular, as the WC-Co cemented carbide, the carbon content of the alloy in the WC is 5.9 to 6.2% by weight, and the content of the binder phase is 6 to 25% by weight. This makes it possible to provide the required hardness and wear resistance of the rolling device. Here, when the amount of alloy carbon in WC is less than 5.9%, the η phase (Co₃W₃(C phase) is precipitated, the strength is remarkably reduced, and cracks are easily introduced and propagated. Therefore, even under a relatively light load, cracks occur or the life is shortened. On the other hand, if the alloy carbon content in the WC exceeds 6.2% by weight, free carbon is generated, the strength is significantly reduced, and the life is greatly reduced. For this reason, the amount of carbon in the WC constituting the WC-Co cemented carbide is preferably in the range of 5.9 to 6.2% by weight, more preferably 5.95 to 6.15%. . Further, if the content of the binder phase is less than 6% or more than 25%, the durability is reduced. Therefore, the content of the binder phase is set in the range of 6 to 25%.
[0032]
Further, as the WC-Co-based cemented carbide, by setting the particle size of WC to 2 μm or less and the content of the binder phase to 6% by weight or less, the corrosion resistance and the wear resistance of the WC-Co-based cemented carbide are increased. Performance can be further improved. That is, by using WC as fine particles having a particle size of 2 μm or less, the Co binder phase which greatly affects the corrosion resistance of the cemented carbide can be made thinner, and the corrosion resistance is improved and the Co phase as the binder phase is improved. , The strength and wear resistance required for the rolling device can be secured. Here, if the particle size of WC exceeds 2 μm, the Co bonding phase becomes thick, so that it is easily corroded, and the strength and wear resistance required for the rolling device cannot be secured. Further, by setting the content of the binder phase to 6% by weight or less, the corrosion resistance of the cemented carbide can be effectively improved. Here, if the content of the binder phase exceeds 6.0% by weight, it may not be possible to secure sufficient corrosion resistance.
[0033]
Furthermore, TiC, TiN, TaC, VC, Cr₃C₂By containing at least one of the following, among WC-Co cemented carbides, it is possible to further improve not only corrosion resistance, heat resistance, and oxidation resistance, but also hardness and wear resistance. Become. In addition, in order to improve the corrosion resistance and heat resistance required for the rolling device, and to further improve the hardness, abrasion resistance, and seizure resistance, the content of TiC or TiN is 3 to 25% by weight, and the content of TaC is Amount of 1 to 20% by weight, VC content of 0.2 to 5.0% by weight, Cr₃C₂Is preferably 0.2 to 5.0% by weight. Here, if the content of each additive is less than the above range, a sufficient improvement effect on corrosion resistance and heat resistance cannot be obtained. On the other hand, if the content of TiC, TiN, or TaC exceeds the above range, these carbides are agglomerated at the time of sintering, and the strength and wear resistance are reduced, so that the service life may be reduced. In this case, the carbon content of the alloy in WC is preferably 6.9 to 7.3% by weight. In addition, VC and Cr₃C₂If the content exceeds the above range, a coarse crystallization phase (M₇C₃Phase) is crystallized and the strength is significantly reduced, so that cracking may occur even under a relatively light load, or the life may be shortened.
[0034]
The reason that the corrosion resistance and heat resistance are improved is that β oxide is formed at the interface between β phase or βt phase which is a solid solution (for example, WC-TiC or WC-TiC-TaC) of the above-mentioned additive element and WC. This is because the β oxide suppresses diffusion of oxygen. The reason why the hardness and abrasion resistance are improved is that the hardness of the solid solution of TaC (Vickers hardness Hv1900) or TiN (Vickers hardness Hv2000) or TiC (Vickers hardness Hv3200) and WC is WC (Vickers hardness Hv3200). This is because the hardness is higher than the hardness Hv1800) alone, and the presence of these hard particles improves the wear resistance. Therefore, good operability can be ensured even in a more severe corrosive environment or a high-temperature environment. Further, even under non-lubricated conditions or severe lubricated conditions, adhesive wear and abrasive wear can be effectively suppressed, good operability can be ensured, and contamination to the external environment can be suppressed. .
[0035]
Further, as WC-Co-based cemented carbides, VC and Cr₃C₂When WC, which is a hard phase, is contained, the particle growth during sintering is suppressed and the WC particles are refined, so that the corrosion resistance, strength and wear resistance can be further improved. Here, VC is in the range of 0.2 to 1.0% by weight,₃C₂Is preferably in the range of 1.0 to 3.0% by weight. Where VC and Cr₃C₂Is added outside of the above range, M₇C₃Since the phase is crystallized and the strength is remarkably reduced, cracks are generated under a relatively light load, and the life is shortened.
[0036]
Furthermore, by containing TiC and TaC as a WC-Co cemented carbide, a surface hardened layer rich in WC-TiC-TiN solid solution is formed on the surface of the WC-Co cemented carbide. , Hardness, abrasion resistance and seizure resistance can be further improved. The content of Co is preferably in the range of 6 to 25% by weight as described above. However, here, the surface hardened layer is formed on the surface of the WC-Co cemented carbide. Even if the content is within the range of 6 to 18% by weight, sufficient hardness, wear resistance and corrosion resistance as rolling members can be secured. The thickness of the surface hardened layer is preferably in the range of 2 to 16 μm. Here, when the thickness of the surface hardened layer formed on the surface of the WC-Co-based hard metal is out of the above range, the Vickers hardness of the surface hardened layer is essentially the same as that of the WC-Co-based hard metal as the base material. (Vickers hardness Hv about 1350) is not preferred.
[0037]
Furthermore, by forming a coating made of TiC or a coating made of TiC and TiN on the surface of the WC-Co cemented carbide, it is possible to further improve the hardness and wear resistance. In addition, the WC-Co-based cemented carbide has a thermal expansion coefficient close to that of ordinary steel and stainless steel among cemented carbides, and the base material is hard and has a high Young's modulus even under a high load. By using a WC-Co-based cemented carbide as a base material, the coating can be hardly peeled off.
[0038]
In particular, the physical vapor deposition (PVD) method can be performed by forming a film made of TiC or a film made of TiC and TiN formed on the surface of a WC-Co cemented carbide by a chemical vapor deposition method. Since the treatment temperature is higher than that of forming by using a diffusion layer, a diffusion layer is formed, so that the adhesion strength between the WC-Co-based cemented carbide and the coating film can be improved.
[0039]
In addition, the durability is greatly improved by forming the coating made of TiC or the coating made of TiC and TiN on the surface of the WC-Co cemented carbide with a thickness of 2 to 10 μm. Becomes possible. Here, if the thickness of the coating is less than 2 μm, the thickness of the diffusion layer is also reduced, so that the adhesion strength with the WC-Co-based cemented carbide is reduced, and the coating may be peeled off. On the other hand, if the thickness of the coating exceeds 10 μm, the effect of brittleness increases, cracks are more likely to occur in the coating, and the overall strength may be reduced.
[0040]
In addition, the rolling member of the present invention contains at least one of TiC, TiN, and TaC as a cemented carbide, has a WC particle size of 2 μm or less, and has a Co phase content of 1. By setting the content to 5% by weight or less, the hardness and wear resistance required for the rolling device can be secured, and the corrosion resistance can be improved. Here, if the particle size of WC exceeds 2 μm, the Co bonding phase becomes thick, so that it is easily corroded, and the strength and wear resistance required for the rolling device cannot be secured. Further, by reducing the content of the binder phase composed of Co to 1.5% by weight or less, the amount of the binder phase mainly corroded by various chemicals used in the cleaning step or the like is suppressed as much as possible, thereby reducing the corrosion resistance. It is possible to further improve.
[0041]
Further, according to the rolling member of the present invention, by using a WC-Co-Ni-based cemented carbide having a binder phase of Co-Ni as the cemented carbide, the strength and wear resistance required for the rolling device are reduced. Because it can be ensured, it can be suitably used even under non-lubricated conditions or severe lubricated conditions. The fracture toughness value of the WC-Co-Ni-based cemented carbide having Co-Ni as a binder phase is 10 to 15 MPa · m.^1/2Ceramics (in the case of silicon nitride, 7 MPa · m^1/2Very high compared to the degree). Therefore, even under a higher stress, cracks are less likely to be introduced and propagated, and stable operability can be ensured under a higher load.
[0042]
In particular, by setting the content of the binder phase to 10 to 20% by weight as a WC-Co-Ni-based cemented carbide, it is possible to further secure the strength, wear resistance and seizure resistance required for a rolling device. It becomes possible. Here, if the content of the binder phase is less than 10% by weight, the fracture toughness is reduced, and cracks are easily introduced and propagated, so that the life may be shortened. On the other hand, if the content of the binder phase exceeds 20% by weight, the hardness, abrasion resistance and seizure resistance are reduced, and the life is reduced, and a large amount of abrasion powder is generated to contaminate the external environment. There was a risk. For this reason, the content of the binder phase (the total of Co and Ni) constituting the WC-Co-Ni-based cemented carbide is in the range of 10 to 20% by weight, and more preferably, the Ni content is 15% by weight. % By weight or less.
[0043]
Further, as a WC-Co-Ni-based cemented carbide, 0.5 to 3.0% by weight of Cr₃C₂, It is possible to further improve the corrosion resistance. Where Cr₃C₂If the content of is less than 0.5% by weight, a sufficient effect of improving corrosion resistance cannot be obtained.₃C₂If the content exceeds 3.0% by weight, the WC particle size becomes coarse,₇C₃Phase (Cr₇C₃) Is crystallized and the strength and wear resistance are reduced, so that the life may be shortened.
[0044]
Further, according to the rolling member of the present invention, since the cemented carbide is a WC-Ni-based cemented carbide whose bonding phase is Ni, the strength and wear resistance required for the rolling device can be secured. It can be suitably used under no lubrication conditions or severe lubrication conditions. The fracture toughness value of the WC-Ni cemented carbide having Ni as a binder phase is 10 to 20 MPa · m.^1/2Ceramics (in the case of silicon nitride, 7 MPa · m^1/2Very high compared to the degree). Therefore, even under a higher stress, cracks are less likely to be introduced and propagated, and stable operability under a higher load can be secured.
[0045]
In particular, by setting the content of the binder phase to 6 to 15% by weight as a WC-Ni-based cemented carbide, it is possible to further secure the hardness, wear resistance, and corrosion resistance required for a rolling device. Become. Here, when the content of the binder phase is less than 6% by weight, the sinterability is poor and the number of pores is remarkably increased, so that the strength is significantly reduced, cracks are introduced and propagated, and cracks are generated even under relatively light load. It may occur or shorten its life. On the other hand, when the content of the binder phase exceeds 15% by weight, the hardness and wear resistance required for the rolling device are significantly reduced. Therefore, especially when applied under non-lubricated conditions, the abrasive wear or adhesive wear at the contact point sharply increases, contaminating the external environment with a large amount of generated abrasion powder, and the surface roughness increases, causing significant vibration. Occurs, and the life may be shortened. When the content of Ni constituting the binder phase exceeds 15% by weight, the selective dissolution of the binder phase, which causes corrosion to various acids, is significantly increased, and the corrosion resistance may be extremely reduced.
[0046]
Further, as a WC-Ni-based cemented carbide, non-magnetic properties can be reliably ensured by dissolving 17% by weight or more of W in Ni as a binder phase, so that it is preferably used under magnetic field environment conditions. It can be applied.
Further, as a WC-Ni-based cemented carbide, Cr of not more than 2.0% by weight is used.₃C₂And 0.7% by weight or less of VC or 2.0% by weight or less of Cr₃C₂And Mo of 2.0% by weight or less₂By containing C, it is possible to suppress the particle growth of the WC particles and to further improve the hardness and the corrosion resistance because the carbide is dissolved in the binder phase. Where Cr₃C₂, VC, and Mo₂When C exceeds the above range, M₇C₃Since the phase is crystallized and the strength is remarkably reduced, cracking may occur even under a relatively light load, or the life may be shortened.
[0047]
According to the first rolling device of the present invention, by configuring at least one of the mover, the support, and the rolling member with the rolling member of the present invention, the non-lubricated condition, the high temperature environment, the corrosion It can be suitably used under an environment and a magnetic field environment.
Further, according to the first rolling device of the present invention, by forming the rolling element with at least one selected from ceramics, cermet, and stainless steel, sufficient corrosion resistance can be obtained, and By configuring the member, the outer member, and the rolling element with different materials, it is possible to improve wear resistance.
[0048]
According to the second rolling device of the present invention, at least one of the mover and the support is formed of a resin composition containing a heat-resistant resin as a main component, and the rolling element is formed of a surface hardened layer or a coating. By comprising the rolling member of the present invention composed of a cemented carbide not formed on the surface, the resin composition having excellent self-lubricating properties is transferred from at least one of the mover and the support to the rolling element, A lubricating film can be formed on the surface of the rolling element. Therefore, the wear resistance and the corrosion resistance are improved, so that it is possible to secure a long-term stable operation of the rolling device even under an environment where lubrication conditions are severe.
[0049]
According to the third rolling device of the present invention, at least one of the mover, the support, and the retainer is made of a resin composition containing a heat-resistant resin as a main component, and the rolling element has a surface effect. The resin composition having excellent self-lubricating properties can be obtained by forming the resin composition having excellent self-lubricating properties by using at least one of the mover, the support, and the cage by forming the rolling member of the present invention made of a cemented carbide having no layer or coating formed on the surface. From one to the rolling element, and a lubricating film can be formed on the surface of the rolling element. Therefore, the wear resistance and the corrosion resistance are improved, so that it is possible to secure a long-term stable operation of the rolling device even under an environment where lubrication conditions are severe.
[0050]
The rolling member according to the present invention is a member constituting a rolling device, that is, an outer member or an inner member, or a rolling member disposed so as to freely roll between an outer member and an inner member. Refers to the moving body.
Further, the rolling device in the present invention refers to a device that includes a rolling member, and one of an inner member and an outer member rolls relatively to the other by rolling a rolling element, For example, it refers to a device such as a rolling bearing, a linear guide, or a ball screw. Here, when the rolling device is a rolling bearing, the outer member indicates the outer ring, and the inner member indicates the inner ring. When the rolling device is a linear guide, the outer member indicates a slider, and the inner member indicates a guide rail. Further, when the rolling device is a ball screw, the outer member indicates a nut, and the inner member indicates a screw shaft.
[0051]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view showing one configuration example of a rolling bearing as an example of a rolling device according to the present invention.
As shown in FIG. 1, the rolling bearing 10 according to the present embodiment includes an inner ring (movable element) 1, an outer ring (support) 2, and a rolling element that is arranged to be rollable between the inner ring 1 and the outer ring 2. 3 (rolling element) and a retainer 4 that partially surrounds the rolling element 3 and maintains a constant interval in the circumferential direction.
[0052]
At least one of the inner ring 1, the outer ring 2, and the rolling elements 3 is made of a cemented carbide composed of a hard phase and a binder phase for bonding the hard phase, and the alloy carbon in the WC constituting the hard phase. The amount is between 5.7 and 6.2% by weight.
The cemented carbide is not particularly limited. For example, a WC-Co-based cemented carbide in which the binder phase is Co, a WC-Co-Ni-based cemented carbide in which the binder phase is Co-Ni, TiC, For example, a WC-Ti (C, N) -based cemented carbide or a WC-Ti (C, N) -TaC-based cemented carbide containing at least one of TiN and TaC, or WC-Ni having a binding phase of Ni Series hard metal and the like.
[0053]
Here, the WC-Co-based cemented carbide is not particularly limited. For example, WC-Co-based, WC-Cr-based₃C₂-Co system, WC-TaC-Co system, WC-TiC-Co system, WC-NbC-Co system, WC-TaC-NbC-Co system, WC-TiC-TaC-NbC-Co system, WC-TiC-TaC -Co, WC-ZrC-Co, WC-TiC-ZrC-Co, WC-TaC-VC-Co, WC-Cr₃C₂-VC-Co, WC-TiC-Cr₃C₂—Co type and the like.
[0054]
In the case of this WC-Co cemented carbide, it is preferable that the Co content be 6 to 25% by weight in order to improve hardness and wear resistance.
Further, among WC-Co-based cemented carbides, in order to further improve corrosion resistance and wear resistance, the WC particle size is 2 μm or less, and the content of the binder phase is 6% by weight or less. preferable.
[0055]
Further, among WC-Co-based cemented carbides, in order to further improve not only hardness and wear resistance but also corrosion resistance and heat resistance (oxidation resistance), TiC, TiN, TaC, VC, Cr₃C₂It is preferable to include at least one of the following. In particular, VC and Cr are contained in WC-Co-based cemented carbide.₃C₂, It is possible to further improve corrosion resistance, strength and wear resistance.
[0056]
Further, among WC-Co-based cemented carbides, in order to further improve wear resistance in particular, TiC and TaC are contained, and on the surface of the WC-Co-based cemented carbide, a WC-TiC-TiN solid solution is used. It is preferable to form a rich surface hardened layer with a thickness of 2 to 16 μm. Similarly, a coating made of TiC or a coating made of TiC and TiN may be formed on the surface of the WC-Co cemented carbide in a thickness of 2 to 10 μm by a chemical vapor deposition method.
[0057]
The WC-Co-Ni-based cemented carbide is not particularly limited, but may be WC-Co-Ni-based or WC-Cr-based.₃C₂-Co-Ni type and the like.
In the case of the WC-Co-Ni-based cemented carbide, the content of the Co-Ni binder phase may be 10 to 20% by weight in order to further improve the hardness, wear resistance, and seizure resistance. Preferably, more preferably, the content of Ni in the Co—Ni bonded phase is 15% by weight or less.
[0058]
Further, in order to further improve the corrosion resistance, the WC-Co-Ni-based cemented carbide has a Cr content of 0.5 to 3.0% by weight.₃C₂Is preferably contained.
Furthermore, as a WC-Ti (C, N) -based or WC-Ti (C, N) -TaC-based cemented carbide, the hardness and wear resistance required for the rolling bearing 10 are secured, and the corrosion resistance is improved. For this purpose, it is preferable that the particle size of WC is 2 μm or less and the content of the binder phase composed of Co is 1.5% by weight or less.
Further, the WC-Ni-based cemented carbide is not particularly limited, and for example, WC-Ni-based, WC-Cr₃C₂-Ni-based, WC-Mo₂C-Ni, WC-Mo₂C-Cr₃C₂-Ni-based, WC-Cr₃C₂-VC-Ni-based and the like.
[0059]
In this WC-Ni-based cemented carbide, in order to have sufficient strength and ensure non-magnetic properties, it is preferable that the amount of carbon (wt%) in the WC be in the following ranges. For example, 5.7% to 6.06% by weight of WC-10% by weight Ni-based cemented carbide, and 1.5% by weight of WC-Cr₃C₂5.75 to 6.12% by weight for -15% by weight Ni-based cemented carbide, WC-1% by weight Mo₂5.78 to 6.02% by weight of C-15% by weight Ni-based cemented carbide, 0.5% by weight of WC-Mo₂C-1% by weight Cr₃C₂5.90 to 6.12% by weight for -10% by weight Ni-based cemented carbide, WC-0.8% by weight Cr₃C₂-0.4% by weight VC-10% by weight 5.96 to 6.19% by weight for Ni-based cemented carbide, WC-1% by weight Mo₂C-1% by weight Cr₃C₂5.80 to 6.20% by weight for -15% by weight Ni-based cemented carbide, WC-2.5% by weight Mo₂C-3.0% by weight Cr₃C₂5.75 to 6.25% by weight of -10% by weight Ni-based cemented carbide, 0.7% by weight of WC-Cr₃C₂-0.3% by weight VC-15% by weight 5.90 to 6.22% by weight for Ni-based cemented carbide, WC-2.5% by weight Cr₃C₂-1.0% by weight VC-10% by weight Ni-based cemented carbide has a range of 5.85 to 6.25% by weight.
[0060]
In the case of the WC-Ni-based cemented carbide, the content of Ni is set to 6 to 15% by weight in order to further improve hardness, wear resistance, and corrosion resistance, and to ensure non-magnetic properties. Is preferred. Further, it is preferable to dissolve about 17% by weight or more of W in Ni as a binder phase in order to further improve hardness, abrasion resistance, and corrosion resistance, and to ensure nonmagnetic properties. .
[0061]
In order to further improve the hardness and corrosion resistance, the WC-Ni-based cemented carbide has a Cr content of 2.0% by weight or less.₃C₂And 0.7% by weight or less of VC or 2.0% by weight or less of Cr₃C₂And 2.0% by weight or less of Mo₂It is preferable to contain C.
Next, a method for producing the above-mentioned cemented carbide will be described in detail.
[0062]
First, a hard phase forming material, which is a raw material of a cemented carbide, and a binder phase forming material are uniformly mixed so as to have a predetermined composition, and then a small amount of a binder for maintaining the strength of the compact is added. It is put into a mold and molded by hydraulic or mechanical press. At this time, depending on the final shape, machining may be further performed using a lathe or the like.
Next, after the formed body is degreased, it is sintered (at a temperature of about 1350 to 1550 ° C.) in a vacuum furnace. At this time, if more strength is required, it is preferable to perform hot isostatic pressing (HIP) thereafter.
[0063]
Next, in order to make the cemented carbide have a predetermined size and surface roughness applicable to the rolling bearing, grinding and polishing are performed, and at least one of the inner ring 1, the outer ring 2, and the rolling elements 3 is made of a cemented carbide. .
The material for forming the rolling members other than the above-mentioned cemented carbide is not particularly limited, but may be applied in a corrosive environment such as various cleaning processes such as a liquid crystal panel manufacturing process, a semiconductor manufacturing process, and a hard disk manufacturing process. In such a case, it is preferable to be formed of a corrosion resistant material.
[0064]
The corrosion-resistant material is not particularly limited, and examples thereof include various ceramics, cermets, stainless steel, and resins. In particular, it is preferable that the rolling elements are made of ceramics in order to improve the seizure resistance by reducing the weight and hardness of the rolling elements and reducing the power consumption during high-speed rotation.
[0065]
The ceramic is not particularly limited. For example, silicon nitride (Si₃N₄) -Based, zirconia (ZrO)₂) -Based, alumina (Al₂O₃) -Based, silicon carbide (SiC) -based, aluminum nitride (AlN) -based, boron carbide (B₄C), titanium boride (TiB)₂) -Based, boron nitride (BN), titanium carbide (TiC) -based, and titanium nitride (TiN) -based materials alone or in a composite form of ceramics. In particular, it is preferable to use silicon nitride which is lightweight and has a relatively high fracture toughness value. Further, in order to improve specific strength, fracture toughness, and the like, for example, a fibrous filler such as a silicon carbide whisker, a silicon nitride whisker, an alumina whisker, or an aluminum nitride whisker may be blended.
[0066]
The cermet is not particularly limited, but includes TiC-Ni, TiC-Mo-Ni, TiC-Co, and TiC-Mo.₂C-Ni-based, TiC-Mo₂C-ZrC-Ni, TiC-Mo₂C-Co system, Mo₂C-Ni-based, Ti (C, N) -Mo₂C-Ni-based, TiC-TiN-Mo₂C-Ni-based, TiC-TiN-Mo₂C-Co system, TiC-TiN-Mo₂C-TaC-Ni, TiC-TiN-Mo₂C-WC-TaC-Ni system, TiC-WC-Ni system, Ti (C, N) -WC-Ni system, TiC-Mo system, Ti (C, N) -Mo system, boride system (MoB-Ni) System, B₄C / (W, Mo) B₂System). Here, the nonmagnetic cermet is Cr₃C₂-Ni, TiC-Ni, TiC-Mo-Ni, Ti-Mo₂C-Ni, Ti-Mo₂C-ZrC-Ni, Mo₂C-Ni-based, Ti (C, N) -Mo₂C-Ni-based, TiC-TiN-Mo₂C-Ni-based, TiC-TiN-Mo₂C-TaC-Ni, TiC-TiN-Mo₂C-WC-TaC-Ni system, TiC-WC-Ni system, Ti (C, N) -WC-Ni system, boride system (MoB-Ni system, B₄C / (W, Mo) B₂System).
[0067]
Examples of the stainless steel include, but are not particularly limited to, precipitation effect type stainless steel represented by SUS630 and martensitic stainless steel represented by SUS316L and SUS304 as nonmagnetic stainless steel.
Examples of the resin include, but are not particularly limited to, fluorine-containing resin, polyether nitrile (PEN), polyether ether ketone (PEEK), a copolymer of PEEK and polybenzizomidal (PEEK-PBI), and thermoplastic polyimide (TPI). ), A thermoplastic aromatic polyamide-imide, a polyethylene (PE) resin, a polyacetal (POM) resin, a polyarylene sulfide resin represented by a polyphenylene sulfide (PPS) resin, or a combination of two or more selected from the group. Can be.
[0068]
Here, the fluorine-containing resin is not particularly limited, but polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkylvinyl ether copolymer (PFA), tetrafluoroethylene / ethylene copolymer (referred to as ETFE) , Polyvinylidene fluoride (PVDF), tetrafluoroethylene / hexafluoropropylene copolymer (hereinafter, FEP), polychlorotrifluoroethylene (hereinafter, PCTFE), chlorotrifluoroethylene / ethylene copolymer (ECTFE), etc. One selected type or a combination of two or more types can be used.
[0069]
In the above-mentioned resin, a fibrous filler may be blended in order to improve mechanical strength, heat resistance, dimensional stability and the like. The fibrous filler is not particularly limited, but includes, for example, aluminum borate whiskers, potassium titanate whiskers, carbon whiskers, aramid fibers, aromatic polyimide fibers, liquid crystal polyester fibers, graphite whiskers, glass fibers, carbon fibers, and boron fibers. , Silicon carbide whiskers, silicon nitride whiskers, alumina whiskers, aluminum nitride whiskers, wollastonite, and the like.
[0070]
Further, in the above-mentioned resin, in order to improve lubricity, in order to improve lubricity, graphite tetrafluoroethylene resin (PTFE), graphite, hexagonal boron nitride (hBN), fluoromica, melamine cyanurate (MCA), layered crystal structure Amino acid compound (N-lauro-L-lysine) having, graphite fluoride, pitch fluoride, molybdenum disulfide (MoS₂) May be blended in an appropriate amount.
[0071]
As described above, according to the rolling bearing 10 of the present embodiment, at least one of the inner ring 1, the outer ring 2, and the rolling element 3 has a WC alloy carbon content of 5.7 to 7.3% by weight. By being made of a hard alloy, it becomes possible to improve wear resistance and seizure resistance.
Further, by adjusting the content of the metal element constituting the binder phase of the cemented carbide, it becomes possible to improve the corrosion resistance.
[0072]
Further, the corrosion resistance, heat resistance, and abrasion resistance can be further improved by adjusting the additives added to the cemented carbide.
That is, according to the present invention, it is possible to provide the rolling bearing 10 that can be suitably used under a non-lubricated condition, a high temperature environment, a corrosive environment, and a magnetic field environment.
[0073]
In the present embodiment, it is sufficient that at least one of the inner ring 1, the outer ring 2, and the rolling elements 3 is made of the above-mentioned cemented carbide, and all of them may be made of a cemented carbide.
(Second embodiment)
In this embodiment, at least one of the inner ring 1, the outer ring 2, and the retainer 4 of the rolling bearing 10 shown in the first embodiment is made of a resin composition containing a heat-resistant resin as a main component, and a rolling element is used. No. 3 is made of the cemented carbide shown in the first embodiment.
[0074]
Here, the resin composition constituting the inner ring 1 and the outer ring 2 is not particularly limited. For example, polyarylene sulfide resin represented by polyphenylene sulfide (PPS) resin, polyetheretherketone (PEEK), PEEK and Benzoisomidal copolymer (PEEK-PBI), polyether nitrile (PEN), aromatic polyimide (PI), thermoplastic polyimide (TPI), polyamide imide (PAI), aromatic polyester (LCP), and various fluorine-containing compounds One type selected from resins and the like, or a combination of two or more types can be used.
[0075]
Further, the resin composition constituting the retainer 4 is not particularly limited, but for example, a resin represented by polyethylene (PE) resin, polypropylene (PP) resin, polyacetal (POM) resin, polyphenylene sulfide (PPS) resin Arylene sulfide resin, polyetheretherketone (PEEK), copolymer of PEEK and polybenzizomidal (PEEK-PBI), polyethernitrile (PEN), aromatic polyimide (PI), thermoplastic polyimide (TPI), polyamideimide (PAI), an aromatic polyester (LCP), a fluorine-containing resin or the like, or a combination of two or more thereof.
[0076]
The fluorine-containing resin is not particularly limited, and for example, the same material as the resin applied as the corrosion-resistant material in the first embodiment can be used.
In the above-mentioned resin composition, a fibrous filler may be blended in order to improve mechanical strength, heat resistance, dimensional stability and the like. The fibrous filler is not particularly limited. For example, in addition to the materials used for the resins listed as the corrosion-resistant materials in the first embodiment, a vapor-phase method fine carbon fiber or carbon nanofiber can be used. .
[0077]
Here, the aspect ratio of the fibrous filler is preferably from 3 to 200. In the fibrous filler having an aspect ratio of less than 3, the effect of reinforcing the melt-moldable fluororesin is not sufficiently exhibited. On the other hand, when the aspect ratio exceeds 200, uniform dispersion at the time of mixing with the resin composition is not achieved. This is because it may be extremely difficult.
[0078]
The fiber diameter of the fibrous filler is not particularly limited, but preferably has an average fiber diameter of 0.2 to 30 μm, and more preferably 0.3 to 20 μm.
Furthermore, the content of the fibrous filler in the resin composition is not particularly limited, but is preferably 40% by weight or less, and more preferably 5 to 30% by weight. Even if the fibrous filler is contained in an amount exceeding 40% by weight with respect to the resin composition, further improvement in mechanical strength cannot be expected, and fluidity during melt molding of the resin composition is significantly reduced. This is because there is a case where it is lost.
[0079]
Further, in the above-mentioned resin composition, in order to improve lubricity, an appropriate amount of a solid lubricant similar to the material used for the resin mentioned above as the corrosion-resistant material may be blended.
Here, the content of the solid lubricant in the resin composition is preferably 40% by weight or less, more preferably 30% by weight or less. Even if the solid lubricant is contained in an amount exceeding 40% by weight with respect to the resin composition, further improvement in lubricity cannot be expected, and the mechanical strength of the resin composition itself decreases, and the solid composition containing the resin composition is converted. This is because the wear of the moving member increases, which may shorten the life of the bearing.
[0080]
The average particle size of the solid lubricant is not particularly limited, but is preferably 0.1 to 60 μm, more preferably 0.1 to 20 μm, and further preferably 0.1 to 10 μm. If the solid lubricant is small particles having an average particle diameter of less than 0.1 μm, aggregation may occur when the solid lubricant is mixed with the resin composition as the base material, and the dispersion of the particles may be non-uniform. On the other hand, if the solid lubricant is large particles having an average particle size exceeding 60 μm, the smoothness of the surfaces of the inner ring 1, the outer ring 2, and the cage 4, which are formed bodies, is reduced, and the strength is reduced. This is because the life of the device may be shortened.
[0081]
In addition, the total content of the fibrous filler and the solid lubricant with respect to the resin composition is preferably 60% by weight or less, more preferably 5 to 50% by weight. When the total content of the fibrous filler and the solid lubricant with respect to the resin composition exceeds 60% by weight, the fluidity when the resin composition is melt-molded and the mechanical strength of the resin composition are significantly reduced. This is because there are cases.
[0082]
The method of mixing the heat-resistant resin, the fibrous filler, and the solid lubricant constituting the resin composition is not particularly limited. For example, each material may be separately charged into a melt kneader and mixed. Alternatively, these materials may be preliminarily mixed by a mixer such as a Henschel mixer, a tumbler, a ribbon mixer, a ball mill, or the like, and then charged into a melt mixer to be mixed. Here, as the melt mixer, a known melt kneader such as a short axis or twin screw extruder, a kneading roll, a pressure kneader, a Banbury mixer, and a Brabender plastograph can be used. The temperature at which the melt-mixing is performed is not particularly limited, but may be appropriately selected within a temperature range in which the melting of the heat-resistant resin sufficiently proceeds and does not decompose.
[0083]
Furthermore, in the above-mentioned resin composition, various additives may be blended within a range that does not impair the object of the present invention. Examples of additives include antioxidants, heat stabilizers, ultraviolet absorbers, light protectants, flame retardants, antistatic agents, fluidity improvers, non-tackifiers, crystallization accelerators, nucleating agents, Examples include pigments and dyes.
The method for producing at least one of the inner ring 1, the outer ring 2, and the retainer 4 from the resin composition is not particularly limited, but is molded by a normal method such as, for example, injection molding, compression molding, or transfer molding. be able to. In particular, in order to provide an inexpensive rolling bearing, it is preferable to manufacture the bearing by an injection molding method having excellent productivity.
[0084]
As described above, according to the present embodiment, at least one of the inner ring 1, the outer ring 2, and the retainer 4 is made of a resin composition containing a heat-resistant resin as a main component, and the rolling element 3 is made of a first material. The resin composition having excellent self-lubricating properties is applied to the rolling element 3 from the inner ring 1, the outer ring 2 or the cage 4 in addition to the same effects as those of the first embodiment by being formed from the same cemented carbide as in the embodiment. The lubricating film can be formed on the surface of the rolling element 3 by transferring. Therefore, even in an environment where lubrication conditions are severe, such as an environment where water or various cleaning solutions are likely to enter or a dry environment, it is possible to improve wear resistance and corrosion resistance and to improve the bearing life.
[0085]
That is, according to the present embodiment, it is possible to provide a rolling bearing that can operate stably for a long period of time even under severe lubrication conditions as described above.
In the present embodiment, at least one of the inner ring 1, the outer ring 2, and the retainer 4 is made of a resin composition containing a heat-resistant resin as a main component. The inner ring 1, the outer ring 2, and the retainer 4 may all be formed of a resin composition as long as they are made of a cemented carbide within the range described above.
Further, in the first and second embodiments, the rolling bearing 10 has been described as an example of the rolling device. However, the present invention is not limited to this, and can be applied to any rolling device such as a ball screw and a linear guide.
[0086]
【Example】
Next, the effects of the present invention will be verified based on the following examples and comparative examples.
In order to evaluate the durability as a rolling bearing, a rolling bearing (model number: 6000, inner diameter: 10 mm, outer diameter: 26 mm, width: 8 mm) was produced. The constituent materials of the inner ring, the outer ring, and the rolling elements constituting the rolling bearing were variously changed, and the effect of the present invention was verified.
[0087]
(First embodiment)
The inner ring and the outer ring constituting the rolling bearing are made of a WC-Co cemented carbide having a binder phase of Co. As shown in Table 1, the amount of the carbon alloy in the hard phase WC and the binder phase are as shown in Table 1. Test bearings were produced with different Co contents.
First, a predetermined amount of a raw material powder of Co (particle size: 0.5 to 2.0 μm) as a binder phase and WC (particle size: 2.0 to 8.0) as a hard phase are mixed, and a die press is performed. Molded with.
Next, after the molded body was degreased, it was sintered (1350 to 1550 ° C.) in a vacuum furnace, ground and polished to complete a test bearing.
[0088]
Here, the amount of alloy carbon in the WC constituting the hard phase was adjusted by adding tungsten or carbon black. In addition, the amount of alloy carbon in WC is identified by measuring the concentration of gas (CO gas) generated by burning crushed and powdered WC under high temperature conditions in an oxygen stream by an infrared absorption method. Was.
The rolling elements constituting the rolling bearing were all made of ceramics made of silicon nitride, and the cages were all made of crown-type fluororesin cages (PVdF + 20% by volume potassium titanate fiber). .
[0089]
The durability of Examples 1 to 6 and the WC-Ni-based cemented carbide having a binder phase of Ni as Comparative Example 1 was measured using a bearing rotation tester (manufactured by Nippon Seiko Co., Ltd.) shown in FIG. A rotation test was performed under the following conditions. In FIG. 2, reference numeral 100 denotes a bearing rotation tester, 11 denotes a support bearing, 12 denotes a test bearing to be evaluated, and 13 denotes a rotating shaft. The test is performed with the rotation of the rotating shaft 13 supported by the supporting shaft 11. The inner ring of the bearing 12 rotates.
[0090]
Here, the durability was measured as the life of the rolling bearing when the vibration value increased to three times the initial value, and the life of the rolling bearing in each of the examples and the comparative examples was set to 1 as the durability of the comparative example. The relative values are shown in Table 1.
<Durability test conditions>
・ Rotation speed: 3000min^-1
・ Radial load: 98N
・ Lubrication condition: no lubrication
[0091]
[Table 1]

[0092]
FIG. 3 shows the relationship between the content of Co as a binder phase and the life in a WC-Co-based cemented carbide. At this time, the alloy carbon content in the WC was in the range of 5.9 to 6.2% by weight.
FIG. 4 shows the relationship between the amount of carbon in the WC, which is the hard phase, and the life of the WC-Co cemented carbide. At this time, the content of Co was constant (15% by weight). As shown in Table 1, the rolling bearings of Examples 1 to 6 exhibited better durability and improved life even under severe lubricating conditions of no lubrication, as compared with Comparative Example 1. You can see that.
[0093]
In particular, in Examples 3 and 4, although the amount of alloy carbon in WC is within a preferable range, it is understood that high durability is not obtained because the Co content is out of the preferable range.
In Examples 5 and 6, the Co content was within the preferred range, but the high carbon content in the WC was out of the preferred range, indicating that high durability was not obtained.
[0094]
Further, from the results shown in FIG. 3, in the WC-Co cemented carbide, when the Co content constituting the binder phase is in the range of 6% by weight or more and 25% by weight or less, extremely excellent durability is obtained. It was confirmed that it was secured.
Further, from the results shown in FIG. 4, in the WC-Co cemented carbide, if the amount of alloy carbon in the WC constituting the hard phase is in the range of 5.9% by weight or more and 6.2% by weight, the It was confirmed that excellent durability was secured.
[0095]
From the above results, in particular, in a rolling bearing applied under no lubrication conditions or severe lubrication conditions, at least one of the components has a Co content of 6 to 25% by weight, High durability can be ensured by using a WC-Co-based cemented carbide having an alloy carbon content of 5.9 to 6.2% by weight.
(Second embodiment)
The inner race and the outer race constituting the rolling bearing are made of a WC-Co cemented carbide having a binder phase of Co, and as shown in Table 2, TiC, TiN, TaC, VC, Cr₃C₂Were changed to produce test bearings.
[0096]
First, Co, Cr each having a particle size in the range of 0.5 to 2.0 μm.₂C₃, VC, TiC, TiN, TaC and WC having a particle size of 1.5 to 7.0 μm were mixed in a predetermined amount as shown in Table 2, and molded by a die press.
Next, through the same steps as in the first embodiment, each test bearing was completed.
The rolling elements constituting the rolling bearing were all made of ceramics made of silicon nitride, and the cages were all made of crown-type fluororesin cages (PVdF + 20% by volume potassium titanate fiber). .
[0097]
The durability of Examples 11 to 18 and the WC-Ni-based cemented carbide containing no additive as Comparative Example 11 was measured using a bearing rotation tester (manufactured by Nippon Seiko Co., Ltd.) shown in FIG. A rotation test was performed under the following conditions. In FIG. 5, reference numeral 200 denotes a bearing rotation tester, 21 denotes a motor, 22 denotes a coupling joint, 23 denotes a spindle, 24 denotes a shaft, 25 denotes a vibrometer, 26 denotes a wire, 27 denotes a pulley, 28 denotes a weight, and 29 denotes a weight. A plate, 30 indicates a test bearing, and 31 indicates a container, and a rotation test was performed in the container 31 in which a corrosive environment was formed.
[0098]
Here, the durability was measured as the life of the rolling bearing when the vibration value increased to three times the initial value, and the life of the rolling bearing in each of the examples and the comparative examples was set to 1 as the durability of the comparative example. The relative values are shown in Table 2.
[0099]
[Table 2]

[0100]
<Durability test conditions>
・ Rotation speed: 2000min^-1
・ Radial load: 98N
・ Rotating condition: 0.5N aqueous hydrochloric acid
FIG. 6 is a diagram showing the relationship between the TaC content and the life in a WC-TiC-TaC-Co-based cemented carbide. At this time, the TiC content was constant at 10% by weight, and the Co content was constant at 10% by weight.
[0101]
As shown in Table 2, in the rolling bearings of Examples 11 to 18, compared with Comparative Example 11, the inclusion of the additive of the present invention provided good durability even under corrosive environmental conditions. It can be seen that the life is improved.
In particular, in Examples 13 to 15, by containing two kinds of additives, it shows higher durability than Examples 11, 12, 16, and 17 containing one kind of additives. You can see that. At this time, in Example 18, although two kinds of additives were contained, since the content was outside the above-mentioned preferred range, it was found that the durability was inferior to the durability of Examples 13 to 15. .
[0102]
Also, from the results shown in FIG. 6, it was confirmed that when the content of TaC as an additive was in the range of 1 to 20% by weight, extremely excellent durability could be secured.
From the above results, in particular, in a rolling bearing applied in a corrosive environment, at least one of the rolling members is made of TiC, TiN, TaC, VC, Cr₃C₂If it is made of a WC-Co cemented carbide to which at least one of the above is added, more excellent corrosion resistance can be secured.
[0103]
(Third embodiment)
The inner ring and the outer ring constituting the rolling bearing are made of a WC-Co cemented carbide having a binder phase of Co. As shown in Table 3, Cr is used as an additive.₃C₂A test bearing was manufactured by changing and changing the addition amount of VC, the particle size of WC as a hard phase, and the content of Co having a function as a binder phase. Further, a test bearing is formed by forming a WC-TiC-TaC-based cemented carbide containing TiC-TaC, changing the particle size of WC as a hard phase, and the content of Co having a function as a binder phase. Produced.
First, Co, Cr each having a particle size in the range of 0.5 to 2.0 μm.₂C₃, VC, TiC, and TaC are mixed in a predetermined amount as shown in Table 3 and molded by a die press.
[0104]
Next, through the same steps as in the first embodiment, each test bearing was completed. Specifically, as in Examples 21 to 24 in the present invention, a cemented carbide having Co as a binder phase, a WC particle size of 2 μm or less, and a Co content of 6% by weight or less includes , Nippon Tungsten Co., Ltd. product names FN20, FN30, FN40 and the like can be applied. Further, as in Examples 25 and 26 of the present invention, while containing at least one of TiC, TiN, and TaC, the WC particle size is 2 μm or less, and the content of the binder phase of Co is 1.5 μm. As the cemented carbide having a content of not more than% by weight, RCCL or RCCFN (trade name, manufactured by Nippon Tungsten Co., Ltd.) or FB01 (trade name, manufactured by Dijet Industries, Ltd.) is applied.
[0105]
The rolling elements constituting the rolling bearing were all made of ceramics made of silicon nitride, and the cages were all made of crown-type fluororesin cages (PVdF + 20% by volume potassium titanate fiber). .
Then, WC-Ni-based cemented carbide, WC-Co-based cemented carbide, WC-Cr were used as Examples 21 to 26 and Comparative Examples 21 to 24, each having a WC particle size in the range of 3 to 8 μm.₃C₂-VC-Co and WC-TiC-Tac cemented carbide were subjected to a rotation test under the following conditions using a bearing rotation tester shown in FIG. 5 similar to that of the second embodiment. .
[0106]
Here, the durability was measured under the same conditions as in the second example, and the results are shown in Table 3.
<Durability test conditions>
・ Rotation speed: 1000min^-1
・ Radial load: 98N
・ Rotating conditions: 2N aqueous hydrochloric acid
[0107]
[Table 3]

[0108]
FIG. 7 shows WC-Cr₃C₂The relationship between the content of Co, which is a binder phase, and the life of a -VC-Co cemented carbide is shown. Where Cr₃C₂Was 2% by weight, the content of VC was 0.7% by weight, the balance WC was constant, and the particle size of WC was constant at 0.5 to 1.0 μm.
As shown in Table 3, in the rolling bearings in Examples 21 to 26, by setting the WC particle size and the content of Co within the range of the present invention, as compared with Comparative Examples 21 to 24, under corrosive environmental conditions. It can be seen that even with this, good durability was exhibited and the life was improved.
[0109]
Particularly, in Examples 22 to 24, Cr was added as an additive to the WC-Co-based cemented carbide.₃C₂It can be seen that the addition of VC and VC exhibited higher durability than Example 21 in which these additives were not added. Of these, in Examples 22 and 23, the amount of VC added was in the range of 0.2 to 1.0% by weight, and₃C₂By setting the amount of addition within the range of 1.0 to 3.0% by weight, higher durability was obtained than in Example 24, which was out of the range.
[0110]
In addition, in Examples 25 and 26, when the content of Co is within the range of 1.5% by weight or less, it can be seen that the durability is higher than when no Co is contained.
Furthermore, from the results shown in FIG.₃C₂In the case of the -VC-Co based cemented carbide, it was confirmed that when the Co content constituting the binder phase was within the range of 6% by weight or less, extremely excellent durability could be secured.
[0111]
From the above results, in particular, in a rolling bearing used in a corrosive environment, at least one of the rolling members has a WC particle size of 2 μm or less and a Co content of 6% by weight or less. −Cr₃C₂If it is made of a -VC-Co cemented carbide, more excellent corrosion resistance can be secured.
Similarly, at least one of the rolling members is made of a WC-TiC-TaC cemented carbide having a WC particle size of 2 μm or less and a Co content of 1.5% by weight or less. Even if it does so, it becomes possible to ensure more excellent corrosion resistance.
[0112]
(Fourth embodiment)
The inner race and the outer race constituting the rolling bearing are made of a WC-TiC-TaC-Co-based cemented carbide having a binder phase of Co and containing TiC and TaC as additives, and the WC-TiC-TaC- A test bearing was manufactured in which a surface hardened layer made of WC-TiC-TiN was formed on the surface of a Co-based cemented carbide with a thickness of 10 µm.
First, 10% by weight of Co (particle size: 1 μm) as a binder phase, 10% by weight of TiC (particle size: 1.5 μm) and 12% by weight of TaC (particle size: 1.5 μm) as additives, The raw material powder containing 68% by weight of WC (particle size: 1.5 μm) was mixed in alcohol, dried, and the obtained mixed powder was molded by a die press.
[0113]
Next, this molded body was degreased and then sintered (1400 ° C.) in a vacuum furnace to obtain a WC-TiC-TaC-Co-based cemented carbide.
Subsequently, 0.9 atm, N₂It was sintered at 1250 ° C. for 4 hours in an atmosphere to form a WC-TiC-TiN surface hardened layer having a thickness of about 10 μm on the surface of the WC-TiC-TaC-Co-based cemented carbide. At this time, the thickness of the surface hardened layer is N₂It is adjusted by the sintering time in the atmosphere. Thereafter, the WC-TiC-TaC-Co cemented carbide on which the surface hardened layer was formed was ground and polished to complete the same test bearing as in Example 1.
[0114]
Then, a rotation test was performed using the bearing rotation tester shown in FIG. 5 described above under the following conditions. Here, the durability was measured as the life of the rolling bearing when the vibration value increased to three times the initial value, and the life of the rolling bearing in each of the examples and the comparative examples was set to 1 as the durability of the comparative example. The relative values are shown in Table 4.
[0115]
[Table 4]

[0116]
<Durability test conditions>
・ Rotation speed: 1000min^-1
・ Radial load: 98N
・ Rotating conditions: 2N aqueous hydrochloric acid
As shown in Table 4, in the rolling bearing in Example 31, compared with Comparative Examples 31 and 32, a surface hardened layer containing TiC and TaC as an additive and formed of WC-TiC-TiN was formed. It can be seen from the result that good durability was exhibited. Further, Example 32 shows better durability than Comparative Examples 31 and 32 because it contains the additives TiC and TaC, but has no surface hardened layer. It can also be seen that the durability was poor.
[0117]
FIG. 8 shows the relationship between the distance from the surface and the Vickers hardness of the surface hardened layer in a WC-TiC-TaC-Co-based cemented carbide having a surface hardened layer formed on the surface. Here, FIG. 8 shows a Vickers hardness distribution (load of 9.8 × 10 3) from the surface of a sample bearing cross section having a surface hardened layer having a thickness of 16 μm with a sintering time of 1 hour.^-1    N).
[0118]
From the results shown in FIG. 8, the surface hardened layer from the surface of the sample bearing to the thickness of 2 μm has a Vickers hardness of about Hv 1450 to 1500, and the Vickers base material of the WC-TiC-TaC-Co-based cemented carbide. It can be seen that the hardness is slightly higher than Hv1350. When the thickness from the surface of the sample bearing exceeds 2 μm, the Vickers hardness tends to increase, and the Vickers hardness at a thickness of 6 μm reaches Hv1600. When the thickness from the surface of the sample bearing exceeds 14 μm, the Vickers hardness decreases, and at the time when the thickness is 16 μm, the same Vickers hardness as the base metal WC-TiC-TaC-Co-based cemented carbide is used. Hv1350. That is, it was confirmed that when the surface hardened layer was formed to have a thickness of 2 to 16 μm, it was possible to secure hardness superior to that of the WC-TiC-TaC-Co-based cemented carbide as the base material.
[0119]
FIG. 9 shows the relationship between the thickness of the surface hardened layer made of WC-TiC-TiN and the life in a WC-TiC-TaC-Co-based cemented carbide having a surface hardened layer formed on the surface.
From the results shown in FIG. 9, it was confirmed that by setting the thickness of the surface hardened layer made of WC-TiC-TiN in the range of 2 to 16 μm, excellent durability could be secured.
[0120]
(Fifth embodiment)
The inner ring and the outer ring constituting the rolling bearing are composed of a WC-Co-based cemented carbide having a binder phase composed of Co, and the surface of this WC-Co-based cemented carbide is composed of a coating made of TiC or composed of TiC and TiN. A test bearing having a coating formed thereon was manufactured.
First, raw material powders of 10% by weight of Co (particle size: 1 μm) as a binder phase and 90% by weight of WC (particle size: 1.5 μm) as a hard phase are mixed in alcohol, and then dried to obtain a powder. The obtained mixed powder was molded by a mold press.
Next, after this molded body is degreased, it is sintered (1400 ° C.) in a vacuum furnace to obtain a WC-Co cemented carbide.
[0121]
Subsequently, using a chemical vapor deposition (CVD) apparatus, the temperature was set to 1000 ° C. and 10 ° C.³-10⁴Under a condition of a reduced pressure atmosphere of Pa, a coating made of TiC and a coating made of TiN were sequentially formed on the surface of the WC-Co cemented carbide so as to have a total thickness of 5 μm. Here, when forming a film made of TiC, TiCl₄+ H₂+ CH₄Was used. When forming a film made of TiN, TiCl₄+ H₂+ N₂Was used. Thereafter, the WC-TiC-TaC-Co-based cemented carbide on which the film made of TiC and TiN was formed was polished and polished to complete the same test bearing as in Example 1 as shown in Table 5.
[0122]
Then, a rotation test was performed using the bearing rotation tester shown in FIG. 5 described above under the following conditions. Here, the durability was measured as the life of the rolling bearing when the vibration value increased to three times the initial value, and the life of the rolling bearing in each of the examples and the comparative examples was set to 1 as the durability of the comparative example. The relative values are shown in Table 5.
[0123]
[Table 5]

[0124]
<Durability test conditions>
・ Rotation speed: 1000min^-1
・ Radial load: 98N
・ Rotating conditions: 2N aqueous hydrochloric acid
As shown in Table 5, in the rolling bearings of Examples 41 and 42, a film made of TiC or a film made of TiC and TiN was formed as compared with Comparative Examples 41 and 42, so that good durability was obtained. It turns out that it shows.
[0125]
FIG. 10 shows the relationship between the film thickness of the film made of TiC and TiN and the life in a WC-Co-based cemented carbide having a film formed on the surface. Here, the Co content was fixed at 10% by weight, and the WC content was fixed at 90% by weight.
As shown in FIG. 10, it was confirmed that by setting the thickness of the film made of TiC and TiN in the range of 2 to 10 μm, excellent durability could be secured.
[0126]
In the present embodiment, two layers of the film made of TiC and the film made of TiN are formed on the surface of the WC-Co cemented carbide, but only the film made of TiC may be formed. Good.
(Sixth embodiment)
The inner ring and the outer ring constituting the rolling bearing were made of a WC-Co-Ni-based cemented carbide having a binder phase composed of Co and Ni. As shown in Table 6, Cr was used as an additive.₃C₂Test bearings were manufactured by changing the amount of Co and the contents of Co and Ni as binder phases, respectively.
[0127]
First, Co, Ni, and Cr having respective particle sizes in the range of 0.5 to 2.0 μm.₂C₃And a raw material powder of WC having a particle size of 1.5 to 7.0 μm are mixed in a predetermined amount as shown in Table 4, and molded by a die press.
Next, through the same steps as in the first embodiment, each test bearing was completed.
The rolling elements constituting the rolling bearing were all made of ceramics made of silicon nitride, and the cages were all made of crown-type fluororesin cages (PVdF + 20% by volume potassium titanate fiber). .
[0128]
The durability of Examples 51 to 58 and the WC-Ni-based cemented carbide of Comparative Example 51 having a Ni content of 20% by weight is shown in FIG. Using a test machine, a rotation test was performed under the following conditions.
Here, the durability was measured in the same manner as in the first example, and the results are shown in Table 6.
<Durability test conditions>
・ Rotation speed: 7000 min^-1
・ Radial load: 98N
・ Lubrication condition: no lubrication
[0129]
[Table 6]

[0130]
FIG. 11 shows the relationship between the Ni content and the life of the WC-Co-Ni-based cemented carbide. At this time, the content of Co was 6.5% by weight,₃C₂Was constant at 0.7% by weight.
As shown in Table 6, in Examples 51 to 58, as compared with Comparative Example 51, the content of the binder phase composed of Co and Ni was set to 10 to 20% by weight, and the Ni content thereof was set to 15%. It can be seen that by setting the content by weight to not more than 5%, even under non-lubricated conditions, good durability is exhibited and the life is improved.
In particular, in Examples 57 and 58, in the WC-Co-Ni-based cemented carbide, Cr was added as an additive.₃C₂It can be seen that the addition of C. shows higher durability.
[0131]
Further, as shown in FIG. 11, it was confirmed that when the total content of Co and Ni as binder phases was within the range of 10 to 20% by weight, extremely excellent durability could be secured.
From the above results, in particular, in a rolling bearing applied under non-lubricating conditions or severe lubricating conditions, at least one of the constituent members has a Co and Ni content of the binder phase of 10 to 20% by weight. And Cr₃C₂If it is made of a WC-Co-Ni-based cemented carbide to which is added, high durability can be ensured.
[0132]
(Seventh embodiment)
The inner race and the outer race constituting the rolling bearing are made of a WC-Ni cemented carbide having a binder phase of Ni, and as shown in Table 7, Cr is used as an additive.₃C₂, Mo₂Test bearings were prepared by changing the amounts of C and VC and the contents of Co and Ni as binder phases, respectively.
First, Ni serving as a binder phase (particle size: 1.0 to 1.5 μm) and Cr as an additive₃C₂(Particle size: 0.5 to 2.0), VC (particle size: 0.5 to 2.0% by weight), Mo₂A predetermined amount of raw material powder of C (particle size: 0.5 to 2.0 μm) and WC (particle size: 1.0 to 1.5 μm) to be a hard phase are mixed in a predetermined amount as shown in Table 5, and a mold is prepared. It was formed by pressing.
[0133]
Next, through the same steps as in the first embodiment, each test bearing was completed.
The rolling elements constituting this rolling bearing were all made of ceramics made of silicon nitride except that the example 61 was made of a WC-Ni cemented carbide, and the retainers were all crown-type fluororesin. It consisted of a retainer (PVdF + 20% by volume potassium titanate fiber).
[0134]
Then, a rotation test was performed on the durability in Examples 61 to 73 and Comparative Examples 61 to 63 using the same bearing rotation tester shown in FIG. 5 as in the second example under the following conditions.
Here, the durability was measured in the same manner as in the first example, and the results are shown in Table 7.
<Durability test conditions>
・ Rotation speed: 3000min^-1
・ Radial load: 98N
・ Lubrication condition: no lubrication
[0135]
In addition, in order to evaluate whether or not it can be suitably used in an environment where non-magnetism is required, a rotation test was performed using a bearing rotation tester (manufactured by Nippon Seiko Co., Ltd.) shown in FIG. . In FIG. 12, reference numeral 300 denotes a bearing rotation tester, 41 denotes a rotating shaft, 42 denotes a test bearing, 43 denotes a permanent magnet, and 44 denotes a Gauss meter. The rotating shaft 41 rotates with the permanent bearing 43 approached. The test bearing 42 was rotated accordingly.
[0136]
Here, the presence or absence of magnetism was measured by measuring a change in magnetic flux density generated at the time of rotation with a Gauss meter 44 to evaluate the influence on the peripheral magnetic field when the test bearing 42 rotates. In addition, when the change in magnetic flux density generated when the bearing is rotated is 0.1 mT or less, the result is shown in Table 7 as being magnetic (○), and otherwise as non-magnetic (×).
[0137]
[Table 7]

[0138]
FIG. 13 shows WC-Cr₃C₂The relationship between the content of Ni and the life in a VC-Ni-based cemented carbide is shown. At this time, Cr₃C₂Of 0.8% by weight, 0.4% by weight of VC, and 6.05% by weight of alloy carbon in WC.
As shown in Table 7, in Examples 61 to 73, as compared with Comparative Examples 61 to 63, the content of the binder phase composed of Ni was 6 to 15% by weight, and 17% by weight or more in Ni. It can be seen that the solid solution of W shows good durability even under corrosive conditions and improves the life.
In particular, in Examples 64, 65, 70 and 71, Cr was used as an additive.₃C₂, Mo₂It can be seen that the durability was further improved by adding C and VC in the preferred ranges described above.
[0139]
Further, in Examples 68, 69, 72, and 73, it can be seen that non-magnetism could not be secured because the amount of alloy carbon in WC was outside the respective optimum ranges.
Further, as shown in FIG. 13, it was confirmed that when the content of Ni as the binder phase was in the range of 6 to 15% by weight, extremely excellent durability could be secured.
From the above results, in particular, in a rolling bearing applied under a non-lubricated condition or under a magnetic field environment, at least one of the constituent members has a Ni content of 6 to 15% by weight as a binder phase, and Cr₃C₂, Mo₂If it is made of a WC-Ni-based cemented carbide to which C and VC are added, it is possible to ensure non-magnetism and high durability.
[0140]
(Eighth embodiment)
The inner ring and the outer ring constituting the rolling bearing are made of a heat-resistant resin shown in the following (1) to (11) with a resin composition in which the heat-resistant resin as a main component is different from each other. Test bearings made of cemented carbide within the scope of the invention were made.
(1) PPS (Polyphenylene sulfide resin manufactured by Philips Pertrolium: Ryton R-6
(2) PVDF (Kureha Chemical Industry Co., Ltd .: Kureha KF Polymer T- # 1000)
(3) TPI (Mitsui Toatsu Chemicals: Aurum 400)
(4) PEEK (Victrex: Victrex PEEK 150G)
(5) PEEK-PBI (manufactured by Hexto Celanese: Cerazole TU-60)
(6) PEN (ID300, manufactured by Idemitsu Materials Co., Ltd.)
(7) Carbon fiber (Kureha Chemical Industry Co., Ltd .: Crecachop M-102S, fiber diameter 14.5 μm, length 0.2 mm)
(8) Potassium titanate whisker (manufactured by Otsuka Chemical Co., Ltd .: Tismo D-101, fiber diameter 0.3 to 0.6 μm, length 10 to 20 μm)
(9) Aramid fiber (Kinei fiber KF02BT, fiber diameter 14 μm, length 0.2 mm, manufactured by Gunei Chemical Industry Co., Ltd.)
(10) Fine carbon fiber (manufactured by Showa Denko KK: Vapor-grown carbon fiber VGCF, fiber diameter 100 to 200 mm, length 10 to 20 μm)
(11) Graphite (manufactured by Chuetsu Graphite Industry Co., Ltd .: CLX, average particle size 4.5 μm)
[0141]
In addition, as the cage constituting this rolling bearing, a cage made of an crown-shaped resin composition (tetrafluoroethylene / ethylene copolymer (ETFE) resin + 20% by volume potassium titanate whisker) manufactured by injection molding is used. Was.
Then, a rotation test was performed on the durability of Examples 81 to 89 and Comparative Examples 81 and 82 under the following conditions using a bearing rotation tester shown in FIG. 5 similar to that of the second example.
Here, the durability was measured in the same manner as in the first example, and the results are shown in Table 8.
<Durability test conditions>
・ Rotation speed: 1000min^-1
・ Radial load: 49N
・ Temperature: room temperature
[0142]
[Table 8]

[0143]
As shown in Table 8, in Examples 81 to 89, compared with Comparative Examples 81 and 82, the inner ring and the outer ring were formed of a resin composition containing a heat-resistant resin as a main component, and the rolling elements were formed of the present invention. It can be seen that the use of a cemented carbide in the range of (1) shows good wear resistance and corrosion resistance and improves the life.
[0144]
In particular, in Examples 81 and 88, the durability is further improved compared to Examples 22 and 61 in which the inner ring and the outer ring are formed of the cemented carbide forming the rolling elements in these examples. You can see that.
From the above results, in particular, even in an environment where lubrication conditions are severe, the inner ring and the outer ring are formed of a resin composition containing a heat-resistant resin as a main component, and the rolling elements are formed of a cemented carbide within the scope of the present invention. By doing so, it is possible to ensure higher durability.
[0145]
【The invention's effect】
As described above, according to the rolling member of the present invention, at least one of the inner member, the outer member, and the rolling element has an alloy carbon content in the WC constituting the hard phase of 5.7 to 7.0. By using a cemented carbide of 3% by weight, it is possible to improve wear resistance, seizure resistance, heat resistance, and corrosion resistance. For this reason, it is possible to suitably use even under severe environments such as a non-lubricated condition, a high temperature environment, a corrosive environment, and a magnetic field environment.
[0146]
According to the first rolling device of the present invention, by forming at least one of the mover, the support, and the rolling member with the rolling member of the present invention, it is possible to perform corrosion under a high-temperature environment under non-lubricated conditions. It can be suitably used even in severe environments such as an environment and a magnetic field environment.
According to the second rolling device of the present invention, at least one of the mover and the support is made of a resin composition containing a heat-resistant resin as a main component, and the rolling element is a rolling member of the present invention. With such a configuration, it is possible to suitably use even an environment where lubrication conditions are severe.
[0147]
According to the third rolling device of the present invention, at least one of the mover, the support, and the retainer is made of a resin composition containing a heat-resistant resin as a main component, and the rolling element is made of the present invention. By using the rolling members described above, it is possible to suitably use even in an environment where lubrication conditions are severe.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing one configuration example of a rolling bearing as an example of a rolling device according to the present invention.
FIG. 2 is a sectional view showing a bearing rotation tester.
FIG. 3 is a diagram showing the relationship between the content of Co as a binder phase and the life in a WC—Co-based cemented carbide.
FIG. 4 is a diagram showing the relationship between the amount of alloy carbon in WC and the life in a WC-Co-based cemented carbide.
FIG. 5 is a schematic view showing a bearing rotation tester.
FIG. 6 is a diagram showing the relationship between the TaC content and the life of a WC-TiC-TaC-Co-based cemented carbide.
FIG. 7: WC-Cr₃C₂It is a figure which shows the relationship between Co content and life in a -VC-Co cemented carbide.
FIG. 8 shows the relationship between the distance from the surface and the Vickers hardness of the surface-hardened layer in a WC-TiC-TaC-Co-based cemented carbide having a surface hardened layer formed on the surface.
FIG. 9 shows the relationship between the thickness of the surface hardened layer made of WC-TiC-TiN and the life in a WC-TiC-TaC-Co-based cemented carbide having a surface hardened layer formed on the surface.
FIG. 10 shows the relationship between the thickness of a film made of TiC and TiN and its life in a WC-Co-based cemented carbide having a film formed on the surface.
FIG. 11 is a diagram showing the relationship between the Ni content and the life in a WC-Co-Ni-based cemented carbide.
FIG. 12 is a sectional view showing a bearing rotation tester.
FIG. 13: WC-Cr₃C₂It is a figure which shows the relationship between Ni content and life in a -VC-Ni type cemented carbide.
[Explanation of symbols]
1 inner ring (movable element)
2 Outer ring (support)
3 rolling elements
4 cage
10 Rolling bearings (rolling devices)

Claims (23)

A rolling member that constitutes the rolling device, and is made of a cemented carbide that includes a hard phase and a binder phase that couples the hard phase, and the amount of alloy carbon in WC that constitutes the hard phase is reduced. 5.7 to 7.3% by weight. The rolling member according to claim 1, wherein the cemented carbide is a WC-Co-based cemented carbide in which the binder phase is Co. The WC-Co based cemented carbide is characterized in that the alloy carbon content in the WC is 5.9 to 6.2% by weight, and the content of the binder phase is 6 to 25% by weight. The rolling member according to claim 2, wherein The rolling member according to claim 2, wherein the WC-Co cemented carbide has a particle size of the WC of 2 µm or less and a content of the binder phase of 6% by weight or less. . The WC-Co-based cemented carbide, TiC, TiN, TaC, VC , rolling member according to claim 2, characterized by containing at least one of _Cr 3 _{C 2.} The WC-Co-based cemented carbide, rolling member according to claim 2, characterized in that it is containing both VC and _Cr 3 _{C 2.} The WC-Co-based cemented carbide contains TiC and TaC, and a surface hardened layer rich in a WC-TiC-TiN solid solution has a thickness of 2 to 16 µm on the surface of the WC-Co-based cemented carbide. The rolling member according to claim 2, wherein the rolling member is formed by a hook. The rolling member according to claim 2, wherein the WC-Co cemented carbide has a coating made of TiC or a coating made of TiC and TiN formed on a surface thereof. The rolling member according to claim 8, wherein the coating made of TiC or the coating made of TiC and TiN is formed by a chemical vapor deposition method. The rolling member according to claim 8, wherein the coating made of TiC or the coating made of TiC and TiN is formed to have a thickness of 2 to 10 μm. The cemented carbide contains at least one of TiC, TiN, and TaC, has a WC particle size of 2 μm or less, and has a Co binder phase content of 1.5% by weight or less. The rolling member according to claim 1, wherein: The rolling member according to claim 1, wherein the cemented carbide is a WC-Co-Ni cemented carbide in which the binder phase is Co-Ni. The rolling member according to claim 12, wherein the content of the binder phase in the WC-Co-Ni-based cemented carbide is 10 to 20% by weight. The WC-Co-Ni-based cemented carbide, rolling member according to claim 12 or 13, characterized in that it contains 0.5 to 3.0 wt% of _Cr 3 _{C 2.} The rolling member according to claim 1, wherein the cemented carbide is a WC-Ni-based cemented carbide in which the binder phase is Ni. The rolling member according to claim 15, wherein the WC-Ni-based cemented carbide has a content of the binder phase of 6 to 15% by weight. 17. The rolling member according to claim 15, wherein, in the WC-Ni-based cemented carbide, 17 wt% or more of W is dissolved in the binder phase. 18. The WC-Ni-based cemented carbide, 2.0 wt% or less of _Cr 3 _{C 2} with any one of claims 15 to 17, characterized in that it contains 0.7% by weight of VC The rolling member according to Item. The WC-Ni-based cemented carbide, either of claims 15 or 17, characterized in that it contains 2.0 wt% or less of _Cr 3 _{C 2} and 2.0 wt% and less Mo ₂ C The rolling member according to claim 1. A mover capable of rotating or linear movement, a support for supporting the mover for rotational or linear movement, and a plurality of rolling elements rotatably disposed between the mover and the support And a rolling device comprising:
A rolling device, wherein at least one of the mover, the support, and the rolling element is configured by the rolling member according to any one of claims 1 to 19. 21. The rolling device according to claim 20, wherein the rolling element is made of at least one selected from ceramics, cermet, and stainless steel. A mover capable of rotating or linear movement, a support for supporting the mover for rotational or linear movement, and a plurality of rolling elements rotatably disposed between the mover and the support And a rolling device comprising:
At least one of the mover and the support is made of a resin composition containing a heat-resistant resin as a main component,
A rolling device, characterized in that the rolling element is constituted by the rolling member according to any one of claims 1 to 6 or 11 to 19. A mover capable of rotating or linear movement, a support for supporting the mover for rotational or linear movement, and a plurality of rolling elements rotatably disposed between the mover and the support And a retainer that rotatably holds the rolling element,
At least one of the mover, the support, and the retainer is made of a resin composition containing a heat-resistant resin as a main component,
A rolling device, characterized in that the rolling element is constituted by the rolling member according to any one of claims 1 to 6 or 11 to 19.

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