JP3773001B2 - Roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve lubricity of a slide contact portion between the flange part of a bearing ring and the end face of a roller and to reduce the occurrence of wear of the slide contact portion, in a roller bearing, especially a conical roller bearing. SOLUTION: In a roller 1 having a bearing ring 2 having a flange part 2a to guide a roller 4, a lubrication film 6 formed of a fluorine-contained polymer with a functional group is formed at least on one of the inner surface of the flange part 2a of the bearing ring 2 and the end face 4a of the roller 4 guided thereby. This constitution continuously locates the lubrication film 6 at a slide contact portion between the flange part 2a of the bearing ring 2 and the end face 4a of the roller 4 even when an excessive axial load is exerted to provide lubrication operation.

Description

【００２０】
【化２】

【００２１】
【化３】

【００２２】
前述の官能基付きの含ふっ素重合体として、より詳しくは、パーフルオロポリエーテル（ＰＦＰＥ）あるいはその誘導体との混合物、具体的に例えばモンテカチーニ社の商品名フォンブリン（FONBLIN）Ｙスタンダード、フォンブリンエマルジョン（FE20、EM04など）またはフォンブリンＺ誘導体（FONBLIN Z DEAL、FONBLIN Z DIAC、FONBLIN Z DISOC、FONBLIN Z DOL、FONBLIN Z DOLTX2000、FONBLIN Z TETRAOLなど）が好適に用いられる。これら例示したものは、いずれも濃度が濃く、金属に対する親和性がきわめて悪いので、そのままでは膜状に付着させることが困難である。そのため、下記するような方法で形成するのが好ましい。
【００２３】
次に、上述した潤滑膜６の形成方法の一例を説明する。
【００２４】
（ａ） 内輪２の大鍔部２ａおよび円錐ころ４の大端面を除いて、内輪２および円錐ころ４を適当な膜でマスキングしておき、これら単体を用意した溶液中に浸漬することにより、内輪２および円錐ころ４の必要箇所に液状膜を付着させる（付着処理）。この溶液の付着はスプレーを用いて行うこともできる。ここで用意する溶液は、例えばフォンブリンエマルジョンＦＥ２０（フォンブリン濃度２０ｍａｓｓ％）を適当な希釈溶媒でフォンブリン濃度を０．２５ｍａｓｓ％にまで希釈したものである。なお、前述の希釈溶媒は、メタノール溶液、アルコール溶液や水などの揮発性のものとすることができる。
【００２５】
（ｂ） 液状膜を付着した内輪２および円錐ころ４を４０〜５０度で約３分間加熱し、液状膜に含む溶媒を除去する（乾燥処理）。
【００２６】
（ｃ） この後、例えば１２０〜３００℃で１５〜３０分間、加熱する（仕上げ乾燥処理）。このときの加熱温度は、例えば、内輪２および円錐ころ４に対する硬化処理時の焼き戻し温度（例えば１８０℃）よりも低い温度に設定することにより、内輪２および円錐ころ４の性状安定化および寸法精度維持を図るのが好ましい。これにより、円錐ころ軸受１の動作時に溶媒や油成分などの不要な発塵がない流動性を有する潤滑膜６が得られる。
【００２７】
このようにすれば、円錐ころ軸受１の必要部位に潤滑膜６を好適な膜厚で形成することができる。なお、（ａ）、（ｂ）は必要に応じて数回繰り返すようにしてもよく、最終的には、潤滑膜６の膜厚を例えば０．２μｍ以下に設定する。但し、膜形成方法や生成後の膜厚などは、適宜に設定すればよい。
【００２８】
以上説明した円錐ころ軸受１では、内輪２の大鍔部２ａと円錐ころ４の大端面４ａとに発塵性および潤滑性に関して格段に優れていて膜切れを起こさない潤滑膜６を形成しているから、それらが直接的に接触することが無くなる。この潤滑膜６は、過大なアキシャル荷重が作用する状況でも途切れることがないから、両者の摺接部位の潤滑が円滑になり、摩耗を抑制できるようになる。しかも、潤滑膜６そのものが摩耗や発塵がきわめて少ないから、長期にわたって内輪２の大鍔部２ａと円錐ころ４の大端面４ａとの直接的な接触を回避できるようになり、長寿命化を達成できるようになる。
【００２９】
ところで、本発明は上記実施例のみに限定されるものではなく、種々な応用や変形が考えられる。
【００３０】
（１） 上記参考例又は下記実施例では、軸受形式として円錐ころ軸受を引用しているが、例えば円筒ころ軸受など種々なころ軸受に本発明を適用できる。
【００３１】
（２） 上記参考例又は下記実施例では、潤滑膜６を内輪２の大鍔部２ａおよび円錐ころ４の大端面にのみ形成しているが、保持器５の案内面（例えば内輪案内の場合だと内周面、外輪案内の場合だと外周面）や、内・外輪２，３において保持器５と接触しうる位置や、内・外輪２，３の軌道面などにも、任意に形成することができる。内・外輪２，３の軌道面やころの転送面に形成した場合には、デファレンシャル装置７内の潤滑油中の異物を噛み込んでも軌道面や転送面が保護されて摩耗や傷付きが低減される。また、円錐ころ軸受１の全構成要素の外表面に潤滑膜６を形成してもよい。これらの場合、上記（ａ）において、円錐ころ軸受１を完成状態に組み立ててから、用意した溶液をスポイドなどにより数滴、注入して、数回回転させるか、あるいは溶液中に浸漬させればよい。
【００３２】
（３）上記参考例では、流動性を有する潤滑膜６を示しているが下記するような実施例の固体状の潤滑膜６を本発明に含む。図２は、固体状の潤滑膜の構造を模式的に表した構造図、図３は、固体状の潤滑膜の硬化前の状態での性状分析結果を示すグラフ、図４は、固体状の潤滑膜の硬化後の状態での性状分析結果を示すグラフである。
【００３３】
前述の固体状の潤滑膜６は、末端がイソシアネート官能基付き含ふっ素重合体を硬化処理したことで形成された含ふっ素高分子化合物からなる。末端がイソシアネート官能基付き含ふっ素重合体を硬化処理したことで形成された含ふっ素高分子化合物は、−Ｃ_XＦ_2X−Ｏ−という一般式（Ｘは１〜４の整数）で示される単位を主要構造単位とし、いずれも平均分子量が数百万以上で硬化反応により分子間が結合した３次元の網状構造を有している。３次元の網状構造とは、化学構造上の表現であって、膜の断面が網状になっているのではなく、分子間が網状のように連続してつながって密に詰まった均質な構造になっていることを意味している。このような化合物としては、下記化学式４に示すような末端がイソシアネートの官能基付き含ふっ素重合体を用いて、化学構造を変化させたものとすることができる。前述の末端がイソシアネートの官能基付き含ふっ素重合体としては、パーフルオロポリエーテル（ＰＦＰＥ）の誘導体、具体的に例えばモンテカチーニ社の商品名フォンブリンＺ誘導体（FONBLIN Z DISOCなど）が好適に用いられる。
【００３４】
【化４】

【００３５】
次に、上述した潤滑膜６の形成方法の一例を説明する。
【００３６】
（ａ） 固体状の潤滑膜６を得るための溶液を用意し、この溶液を用いて円錐ころ軸受１の任意の必要部位に液状膜を付着させる（付着処理）。ここで用意する溶液は、末端がイソシアネートの官能基付き含ふっ素重合体〔フォンブリンＺ誘導体（FONBLIN Z DISOC）〕を希釈溶媒（ふっ素系溶剤ＳＶ９０Ｄ）で含ふっ素重合体の濃度を１ｍａｓｓ％にまで希釈したものである。
【００３７】
（ｂ） 液状膜を付着した対象あるいは円錐ころ軸受１の全体を４０〜５０℃で約１分間加熱し、液状膜に含む溶媒を除去する（乾燥処理）。この時点では、液状膜のままであり、流動性を有している。
【００３８】
（ｃ） この後、例えば１００〜２００℃で２０時間、加熱する（硬化処理）。これにより、液状膜の化学構造が変化することにより硬化反応して固体状の潤滑膜６が得られる。ちなみに、この硬化処理では、液状膜に存在している官能基付き含ふっ素重合体の個々について、下記化学式５〜８に示すような４種の硬化反応でもって末端のイソシアネート（ＮＣＯ）が消失し、各官能基付き含ふっ素重合体が互いに結合することにより３次元の網状構造となる。結合は、化学式５，６に示すような硬化反応でもって、図２（ａ）に模式的に示すように直線的に架橋するとともに、化学式７，８に示すような硬化反応でもって、図２（ｂ）に模式的に示すように３次元方向で架橋する。なお、図２では、下記化学式９に示すように、上記化学式４を簡略化して模式的に表している。
【００３９】
【化５】

【００４０】
【化６】

【００４１】
【化７】

【００４２】
【化８】

【００４３】
【化９】

【００４４】
このようにすれば、固体状の潤滑膜６を好適な膜厚で形成することができる。なお、（ａ）、（ｂ）は必要に応じて数回繰り返すようにしてもよく、最終的には、潤滑膜６の膜厚を例えば０．２μｍ以下に適宜設定する。
【００４５】
ここで、（ａ）で用意した溶液を濃縮乾燥しただけの状態（流動性がある状態）と、（ａ）で用意した溶液をステンレス鋼板などの試料に付着して硬化した状態とについて、その性状を分析したので説明する。
【００４６】
前者は、ＦＴ−ＩＲ法（フーリエ変換−赤外分光、液膜法）で分析している。その結果は、図３のグラフに示すように、ふっ素系のピーク以外にＮＨ（３３００ｃｍ-1）、Ｎ＝Ｃ＝Ｏ（２２７９ｃｍ-1）、ＮＨＣ＝Ｏ（１７１２ｃｍ-1，１５４６ｃｍ-1）、ベンゼン（１６００ｃｍ-1）などのピークが見られ、ベンゼン環、ＮＨＣ＝Ｏ、イソシアネートが官能基として存在していることが確認できる。ここでは、薄膜と厚膜との場合についてそれぞれ調べているが、膜厚に関係なく分析が行えた。後者は、ＦＴ−ＩＲ法（フーリエ変換−赤外分光、高感度反射法）で分析している。その結果は、図４のグラフに示すように、ベンゼン環やＮＨＣ＝Ｏのピークが見られるが、イソシアネートのピークが見られない。つまり、これらの結果に基づき、上記化学式５〜８に示す硬化反応による官能基の化学構造変化が確認される。
【００４７】
以上説明した固体状の潤滑膜６は、それ自体が３次元の網状構造をもって、被覆対象上に緻密に被覆されるとともに自己潤滑性を有するため、優れた潤滑作用を上記実施例よりもさらに一層長期にわたって発揮できるようになり、内輪２の大鍔部２ａと円錐ころ４の大端面４ａとの直接的な接触を回避できるようになる。この他、固体状であるから、衝撃荷重に対し若干ながらも緩衝作用を発揮するので、耐衝撃性に優れるものとなる。
【００４８】
この実施例において、上記（ｃ）の硬化処理については、加熱に代えて、紫外線、赤外線、γ線、電子線などの電磁波（光）のエネルギーを利用することができる。また、（ｂ）の乾燥処理は、省略してもよい。
【００４９】
この固体状の潤滑膜６の場合、末端がイソシアネート官能基付き含ふっ素重合体を硬化処理したことで形成された含ふっ素高分子化合物中に、フルオロポリエーテルなどの、末端がイソシアネート官能基付き含ふっ素重合体と結合しない含ふっ素重合体を流動可能に分散添加した構造とすることもできる。この場合、具体的に、上記形成方法の（ａ）の付着処理において、用意する溶液を、末端がイソシアネートの官能基付き含ふっ素重合体〔例えば商品名フォンブリンＺ誘導体（FONBLIN Z DISOCなど）〕と、含ふっ素重合体として官能基なし含ふっ素重合体〔例えば商品名フォンブリンＺ誘導体（FONBLIN Z-60など）〕とを所定の割合で混合したものとすればよい。この場合では、（ｃ）の硬化処理において、官能基なし含ふっ素重合体が、官能基付き含ふっ素重合体と結合しないので、これが、固体状の潤滑膜６の内部において流動可能となり、膜表面から滲み出るなどして潤滑作用を発揮することになる。
【００５３】
【発明の効果】
本発明のころ軸受では、軌道輪の鍔部ところの端面との摺接部位に途切れなく介在して潤滑作用を発揮する潤滑膜を形成しているから、過大なアキシャル荷重が作用する状況でも、軌道輪の鍔部ところの端面との摺接部位の潤滑性が良好となり、回転トルクの増大や著しい摩耗の進行を回避できるようになる。
【００５４】
また、潤滑膜を、末端がイソシアネート官能基付き含ふっ素重合体を硬化処理したことで形成された含ふっ素高分子化合物からなる固体状とする場合には、分子間が密に詰まった均質な構造であるので、潤滑作用が長期的に継続できるようになり、軌道輪の鍔部ところの端面との直接接触がより一層起こりにくくなる。しかも、この固体状の潤滑膜に、末端がイソシアネート官能基付き含ふっ素重合体と結合しない含ふっ素重合体を流動可能な状態で分散添加しているため、この末端がイソシアネート官能基付き含ふっ素重合体と結合しない、流動可能な含ふっ素重合体が膜表面から滲み出て潤滑作用に寄与するので、潤滑性の一層の向上に貢献できる。
【００５５】
したがって、本発明のころ軸受を、例えば高予圧による過大なアキシャル荷重が作用するデファレンシャル装置の入出力軸の支持軸受として用いた場合に、動作の安定化に貢献できるようになる。
【図面の簡単な説明】
【図１】本発明の一実施例にかかる円錐ころ軸受の縦断面図
【図２】固体状の潤滑膜の構造を模式的に表した構造図
【図３】固体状の潤滑膜の硬化前の状態での性状分析結果を示すグラフ
【図４】固体状の潤滑膜の硬化後の状態での性状分析結果を示すグラフ
【図５】一般的なデファレンシャル装置の構成を示す縦断面図
【符号の説明】
１ 円錐ころ軸受
２ 内輪
２ａ 内輪の大鍔部
３ 外輪
４ 円錐ころ
４ａ 円錐ころの大端面
５ 保持器
６ 潤滑膜[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a roller bearing. For example, the present invention relates to a roller bearing suitable for use as a support bearing for an input / output shaft of a differential device provided in a driving system of an automobile.
[0002]
[Prior art]
By providing a differential device between the propeller shaft of the automobile and the drive shaft (accelerator shaft) of the wheel, power is transmitted between the propeller shaft and the drive shaft, and the left and right drive wheels accompanying the course change The rotational speed difference is absorbed, and the direction of power is further changed to finally reduce the speed. Such a differential apparatus is configured as shown in FIG. 5, for example.
[0003]
A drive pinion gear 14 fixed to the end of a drive pinion shaft 13 rotatably supported by a pair of tapered roller bearings 11 and 12 is supported at one end of the differential case 10, and is rotatably supported in the differential case 10. By engaging the ring gear 15, the rotational force of the drive shaft (not shown) can be transmitted to the pinion gear 21.
[0004]
Generally, a large axial thrust load is applied to the drive pinion of the differential device 7, and the rotational direction is reversed as the vehicle moves forward and backward. Therefore, in order to prevent the shaft member from moving in the axial direction under load and prevent premature play due to initial wear of the tapered roller bearings 11 and 12, in the assembly process of the differential device 7, the drive pinion An axial force is applied to the inner race of the tapered roller bearing 12 based on the tightening torque of the nut 16 with respect to the front end portion of the shaft 13, whereby both bearings 11, 12 and preload (preload) are applied.
[0005]
Further, the rotational force of the drive pinion gear 14 can be transmitted to the left and right drive shafts 19 and 20 supported on the differential case 10 by the other tapered roller bearings 17 and 18 via the ring gear 15. The differential device configured as described above is a tapered roller bearing that supports the drive pinion shaft 13 and the pinion shaft 22 because each part rotates at a high speed during traveling of the automobile and is constantly given a high preload. 11, 12, 17 and 18 need to be sufficiently lubricated. For this reason, conventionally, the lubricating oil accumulated in the differential case is supplied to each bearing by splashing.
[0006]
[Problems to be solved by the invention]
However, the tapered roller bearings 11, 12, 17, and 18 for differential devices that are configured and act as described above have a high preload imparted, and in particular, the lubricating oil film at the sliding contact portion with the rollers of the inner ring collar portion is easily interrupted, As the rotational torque increases, the raceway surfaces of the inner and outer rings and the surface of the rollers are significantly worn and the service life is shortened.
[0007]
In addition, foreign materials such as wear powder and abrasives (which cannot be removed after finishing the surface of each part) such as wear powder of each part that make up the differential are mixed in the lubricating oil. As a result, the chance of contact between the foreign matter and the tapered roller bearings 11, 12, 17, 18 is increased, the wear of the tapered roller bearings 11, 12, 17, 18 is promoted, the preload is reduced, and the gear meshing noise is increased. Such as inviting. Further, the foreign matters damage not only the sliding contact portions with the flange portions of the tapered roller bearings 11, 12, 17, and 18, but also damage the raceway surface, leading to an increase in sound (race sound) and vibration generated from the bearings.
[0008]
Accordingly, an object of the present invention is to improve the lubricity of a sliding contact portion with an end face of a bearing ring in a roller bearing, particularly a tapered roller bearing, and to reduce wear of the portion. It is said.
[0009]
[Means for Solving the Problems]
[0010]
Bearing Ro saw present invention is a roller bearing having a bearing ring comprising a flange portion for guiding the rollers, and the inner surface of the track Watsuba part, on at least one of the end faces of the rollers are guided to, end A solid lubricating film made of a fluorine-containing polymer compound formed by curing a fluorine-containing polymer having an isocyanate functional group is formed, and the terminal end of the solid lubricating film contains an isocyanate functional group-containing fluorine-containing polymer. A flowable fluorine-containing polymer that does not bind to the fluorine polymer is dispersedly added.
[0011]
Incidentally, the solid lubricating film of the foregoing, has a three-dimensional network structure between molecules is engaged sintering. The flowable fluorine-containing polymer dispersed and added to the solid lubricating film is preferably a fluorine-containing polymer having no functional group, for example, a perfluoropolyether having no functional group.
[0012]
In the present invention, a lubricating film that is remarkably superior in terms of dust generation and lubricity and that does not cause film breakage is interposed in the sliding contact portion with the end face of the buttocks of the race, so that an excessive axial load is applied. Even when it acts, it prevents direct contact with the end face of the buttocks of the race. Thereby, the lubricity of this sliding contact part is maintained well, and wear is also reduced.
[0013]
Further, the lubricating film, where the terminal is a solid consisting of fluorine-containing high molecular compound formed by the curing of the isocyanate functional groups with a fluorine-containing polymer, a homogeneous intermolecular close packed structure Therefore, the lubricating action can be continued for a long period of time, and the direct contact with the end face at the flange portion of the raceway is less likely to occur. Moreover, this solid lubricating film, because the terminal is dispersed and added in a fluorine-containing polymer flowable state that does not bind to the isocyanate functional group with fluorine-containing polymers, fluorine-containing heavy with the terminal isocyanate functional groups A flowable fluorine-containing polymer which does not bind to the coalesces oozes out from the film surface and contributes to the lubricating action.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The details of the present invention will be described based on the embodiment shown in FIGS.
[0015]
FIG. 1 is a longitudinal sectional view of a tapered roller bearing according to an embodiment of the present invention. A tapered roller bearing 1 shown in FIG. 1 includes an inner ring 2, an outer ring 3, a plurality of tapered rollers 4, and a cage 5. Among these, the lubricating film 6 described later in detail is formed on the inner surface of the large collar portion 2 a at one end in the axial direction of the inner ring 2 and the large end surface 4 a of the tapered roller 4. The tapered roller bearing 1 is used, for example, at a required position of the differential device 7 shown in FIG.
[0016]
In such a differential device 7, an excessive axial load acts on the tapered roller bearings 1 and 1 due to high preload. Therefore, in consideration of this point, in the tapered roller bearing 1 according to one embodiment of the present invention, A lubricating film 6 is formed on the inner surface of the large collar portion 2 a at one axial end of the inner ring 2 and the large end surface 4 a of the tapered roller 4.
[0017]
The materials of the inner / outer rings 2, 3 and the tapered roller 4 are carburizing steel such as SAE standard 5120 steel and 4320 steel, and JIS standard SUJ2 (high carbon chromium bearing steel). Then, hardening treatment including subsequent quenching and tempering treatment is appropriately performed.
[0018]
The lubricating film 6 of the reference example is made of, for example, a fluorine-containing polymer with a functional group. In this embodiment, the lubricating film 6 is in a fluid state. As this fluorine-containing polymer with a functional group, a fluoropolyether polymer or a polyfluoroalkyl polymer is preferable. The fluoropolyether polymer has a unit represented by the general formula -C _X F _2X -O- (X is an integer of 1 to 4) as a main structural unit, and each of the polymers has a number average molecular weight of 1,000 to 50,000. To do. Examples of the polyfluoroalkyl polymer include those represented by the following chemical formula 1. In addition, the functional group described above preferably has a high affinity for metals (for example, an epoxy group, an amino group, a carboxyl group, a hydroxyl group, a mercapto group, a sulfone group, or an ester group). What is shown. Such fluorine-containing polymers may be used alone or in combination of two or more. In that case, it is desirable to consider that the combined groups react with each other to increase the molecular weight of the polymer so that a thin film with higher wear resistance can be obtained.
[0019]
[Chemical 1]

[0020]
[Chemical formula 2]

[0021]
[Chemical 3]

[0022]
As the above-mentioned fluorine-containing polymer having a functional group, more specifically, a mixture with perfluoropolyether (PFPE) or a derivative thereof, specifically, for example, a trade name of Fonbrin (FONBLIN) standard of Montecatini, Fonbrin emulsion (FE20, EM04, etc.) or Fomblin Z derivatives (FONBLIN Z DEAL, FONBLIN Z DIAC, FONBLIN Z DISOC, FONBLIN Z DOL, FONBLIN Z DOLTX2000, FONBLIN Z TETRAOL, etc.) are preferably used. All of these exemplified substances have a high concentration and extremely low affinity for metals, so that it is difficult to attach them as they are. Therefore, it is preferable to form by the following method.
[0023]
Next, an example of a method for forming the lubricating film 6 described above will be described.
[0024]
(A) By masking the inner ring 2 and the tapered roller 4 with an appropriate film except for the large flange portion 2a of the inner ring 2 and the large end surface of the tapered roller 4, and immersing these alone in a prepared solution, A liquid film is attached to the necessary portions of the inner ring 2 and the tapered rollers 4 (attachment treatment). This solution can also be deposited using a spray. The solution prepared here is, for example, a fomblin emulsion FE20 (fomblin concentration 20 mass%) diluted with an appropriate diluent solvent to a fomblin concentration of 0.25 mass%. In addition, the above-mentioned dilution solvent can be volatile, such as a methanol solution, an alcohol solution, or water.
[0025]
(B) The inner ring 2 and the tapered roller 4 to which the liquid film is adhered are heated at 40 to 50 degrees for about 3 minutes to remove the solvent contained in the liquid film (drying process).
[0026]
(C) Then, it heats, for example at 120-300 degreeC for 15-30 minutes (finish drying process). The heating temperature at this time is, for example, set to a temperature lower than the tempering temperature (for example, 180 ° C.) during the curing process for the inner ring 2 and the tapered roller 4, thereby stabilizing the properties and dimensions of the inner ring 2 and the tapered roller 4. It is preferable to maintain accuracy. Thereby, the lubricating film 6 having fluidity free from unnecessary dust generation such as solvent and oil component during operation of the tapered roller bearing 1 is obtained.
[0027]
In this way, the lubricating film 6 can be formed with a suitable film thickness on the necessary portion of the tapered roller bearing 1. Note that (a) and (b) may be repeated several times as necessary. Finally, the film thickness of the lubricating film 6 is set to 0.2 μm or less, for example. However, the film forming method and the film thickness after generation may be set as appropriate.
[0028]
In the tapered roller bearing 1 described above, a lubricating film 6 is formed on the large collar portion 2a of the inner ring 2 and the large end surface 4a of the tapered roller 4 which is remarkably superior in terms of dust generation and lubricity and does not cause film breakage. Therefore, they are not in direct contact. Since the lubricating film 6 is not interrupted even in the situation where an excessive axial load is applied, the lubrication of the sliding contact portions of the both becomes smooth and the wear can be suppressed. Moreover, since the lubricating film 6 itself has very little wear and dust generation, direct contact between the large collar portion 2a of the inner ring 2 and the large end surface 4a of the tapered roller 4 can be avoided over a long period of time, thereby extending the service life. Can be achieved.
[0029]
By the way, the present invention is not limited to the above embodiments, and various applications and modifications can be considered.
[0030]
(1) In the above reference example or the following example , a tapered roller bearing is cited as the bearing type, but the present invention can be applied to various roller bearings such as a cylindrical roller bearing.
[0031]
(2) Although the lubricating film 6 is formed only on the large collar 2a of the inner ring 2 and the large end surface of the tapered roller 4 in the above reference example or the following example , the guide surface of the cage 5 (for example, in the case of inner ring guidance) In this case, the inner peripheral surface, the outer peripheral surface in the case of the outer ring guide), the positions where the inner / outer rings 2 and 3 can come into contact with the cage 5, and the raceway surfaces of the inner and outer rings 2 and 3 are arbitrarily formed. can do. When formed on the raceway surface of the inner / outer rings 2 and 3 and the transfer surface of the roller, the raceway surface and transfer surface are protected even if a foreign substance in the lubricating oil in the differential device 7 is caught, thereby reducing wear and damage. Is done. Further, the lubricating film 6 may be formed on the outer surface of all the components of the tapered roller bearing 1. In these cases, if the tapered roller bearing 1 is assembled to the completed state in (a) above, a few drops of the prepared solution are injected with a spoid or the like and rotated several times or immersed in the solution. Good.
[0032]
(3) In the above reference example, the lubricating film 6 having fluidity is shown, but the solid lubricating film 6 of the embodiment as described below is included in the present invention. FIG. 2 is a structural diagram schematically showing the structure of the solid lubricating film, FIG. 3 is a graph showing the result of property analysis of the solid lubricating film before curing, and FIG. It is a graph which shows the property analysis result in the state after hardening of a lubricating film.
[0033]
Lubricating film 6 of the solid described above, the terminal is made of fluorine-containing Motodaka molecular compound is formed by the curing of the isocyanate functional groups with a fluorine-containing polymer. End containing hydrofluoric Motodaka molecular compound is formed by the curing of the isocyanate functional groups with a fluorine-containing polymer represented by -C _X F _2X -O- called general formula (X is an integer of 1 to 4) the unit as a main structural unit, both average molecular weight of between molecules has a 3-dimensional network structure in which combined binding by curing reaction by millions more. The three-dimensional network structure is an expression in terms of chemical structure, and the cross-section of the film is not a network, but a homogeneous structure in which molecules are connected in a continuous manner like a network. It means that As such a compound, the chemical structure can be changed by using a fluorine-containing polymer with an isocyanate functional group at the end as shown in the following chemical formula 4. As the above-mentioned fluorine-containing polymer having an isocyanate-terminated functional group, a derivative of perfluoropolyether (PFPE), specifically, for example, a product name Fomblin Z derivative (FONBLIN Z DISOC, etc.) of Montecatini is preferably used. .
[0034]
[Formula 4]

[0035]
Next, an example of a method for forming the lubricating film 6 described above will be described.
[0036]
(A) A solution for obtaining the solid lubricating film 6 is prepared, and a liquid film is adhered to any necessary portion of the tapered roller bearing 1 using this solution (adhesion treatment). The solution prepared here is a fluorine-containing polymer having a functional group whose end is isocyanate [FONBLIN Z DISOC], and the concentration of the fluorine-containing polymer is reduced to 1 mass% with a diluting solvent (fluorine solvent SV90D). Diluted.
[0037]
(B) The object to which the liquid film is adhered or the entire tapered roller bearing 1 is heated at 40 to 50 ° C. for about 1 minute to remove the solvent contained in the liquid film (drying process). At this time, it remains a liquid film and has fluidity.
[0038]
(C) Then, it heats, for example at 100-200 degreeC for 20 hours (curing process). As a result, the solid lubricating film 6 is obtained through a curing reaction due to a change in the chemical structure of the liquid film. By the way, in this curing treatment, the terminal isocyanate (NCO) disappears in each of the functional fluorine-containing polymers present in the liquid film by four curing reactions as shown in the following chemical formulas 5-8. , each functional group with fluorine-containing polymer is a three-dimensional network structure by binding to each other. Binding is with the chemical formula 5 and 6 show such a curing reaction with linearly crosslinked as schematically shown in FIG. 2 (a), with a curing reaction as shown in Chemical Formula 7 and 8, FIG. Crosslinking is performed in a three-dimensional direction as schematically shown in 2 (b). In FIG. 2, the chemical formula 4 is simplified and schematically shown as the following chemical formula 9.
[0039]
[Chemical formula 5]

[0040]
[Chemical 6]

[0041]
[Chemical 7]

[0042]
[Chemical 8]

[0043]
[Chemical 9]

[0044]
In this way, the solid lubricating film 6 can be formed with a suitable thickness. Note that (a) and (b) may be repeated several times as necessary. Finally, the thickness of the lubricating film 6 is appropriately set to 0.2 μm or less, for example.
[0045]
Here, the state prepared by concentrating and drying the solution prepared in (a) (the state having fluidity) and the state prepared by attaching the solution prepared in (a) to a sample such as a stainless steel plate and curing the I will explain the properties.
[0046]
The former is analyzed by the FT-IR method (Fourier transform-infrared spectroscopy, liquid film method). As a result, as shown in the graph of FIG. 3, NH besides the peak of the fluorine-based (3300cm-1), N = C = O (2279cm-1), NHC = O (1712cm-1,1546cm-1), Peaks such as benzene (1600 cm-1) are observed, and it can be confirmed that a benzene ring, NHC = O, and isocyanate are present as functional groups. Here, the cases of the thin film and the thick film are examined, but the analysis can be performed regardless of the film thickness. The latter is analyzed by the FT-IR method (Fourier transform-infrared spectroscopy, high sensitivity reflection method). As a result, as shown in the graph of FIG. 4, a peak of a benzene ring or NHC═O is seen, but a peak of isocyanate is not seen. That is, based on these results, the chemical structure change of the functional group due to the curing reaction shown in the above chemical formulas 5 to 8 is confirmed.
[0047]
Since the solid lubricating film 6 described above has a three-dimensional network structure and is densely coated on the object to be coated and has a self-lubricating property, it has an even better lubricating action than the above embodiment. It can be demonstrated over a long period of time, and direct contact between the large collar portion 2a of the inner ring 2 and the large end surface 4a of the tapered roller 4 can be avoided. In addition, since it is in a solid state, it exhibits a buffering action with a slight impact load, and therefore has excellent impact resistance.
[0048]
In this embodiment, for the curing process (c), instead of heating, energy of electromagnetic waves (light) such as ultraviolet rays, infrared rays, γ rays, and electron beams can be used. Further, the drying process (b) may be omitted.
[0049]
In this case the solid lubricating film 6, the ends in the fluorine-containing high molecular compound formed by the curing of the isocyanate functional groups with fluorine-containing polymers, such as fluoropolyether terminally including with isocyanate functionality A structure in which a fluorine-containing polymer that is not bonded to the fluorine polymer is dispersed and added so as to be flowable can also be used. In this case, specifically, in the adhesion treatment of (a) in the above formation method, the prepared solution is a fluorine-containing polymer having a functional group having an isocyanate terminal (for example, a trade name fomblin Z derivative (FONBLIN Z DISOC, etc.)). And a fluorine-containing polymer having no functional group (for example, trade name Fomblin Z derivative (FONBLIN Z-60, etc.)) as a fluorine-containing polymer may be mixed at a predetermined ratio. In this case, in the curing process of (c), the fluorine-containing polymer having no functional group is not bonded to the fluorine-containing polymer having a functional group, so that it can flow inside the solid lubricating film 6, and the film surface and such as bleeding out of the ing to exert a lubricating action.
[0053]
【The invention's effect】
In the roller bearing of the present invention, since a lubricating film that exerts a lubricating action is formed without interruption in the sliding contact portion with the end face of the flange portion of the bearing ring, even in a situation where an excessive axial load acts, The lubricity of the slidable contact portion with the end surface of the collar portion of the bearing ring becomes good, and it becomes possible to avoid the increase in rotational torque and the progress of significant wear.
[0054]
Further, the lubricating film, where the terminal is a solid consisting of fluorine-containing high molecular compound formed by the curing of the isocyanate functional groups with a fluorine-containing polymer, a homogeneous intermolecular close packed structure Therefore, the lubricating action can be continued for a long period of time, and the direct contact with the end face at the flange portion of the raceway is less likely to occur. Moreover, this solid lubricating film, because the terminal is dispersed and added in a fluorine-containing polymer flowable state that does not bind to the isocyanate functional group with fluorine-containing polymers, fluorine-containing heavy with the terminal isocyanate functional groups Since the flowable fluorine-containing polymer which does not bind to the coalesce oozes out from the film surface and contributes to the lubricating action, it can contribute to further improvement of the lubricity.
[0055]
Therefore, when the roller bearing of the present invention is used as a support bearing for an input / output shaft of a differential device in which an excessive axial load due to high preload acts, for example, it can contribute to stabilization of operation.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a tapered roller bearing according to an embodiment of the present invention. FIG. 2 is a structural diagram schematically showing the structure of a solid lubricating film. Fig. 4 is a graph showing the result of property analysis in the state of Fig. 4. Fig. 4 is a graph showing the result of property analysis in the solid lubricant film after curing. Fig. 5 is a longitudinal sectional view showing the structure of a general differential device. Explanation of]
DESCRIPTION OF SYMBOLS 1 Tapered roller bearing 2 Inner ring 2a Large collar part of inner ring 3 Outer ring 4 Tapered roller 4a Large end surface of tapered roller 5 Cage 6 Lubricating film

Claims (3)

A roller bearing having a bearing ring having a collar for guiding the roller,
A solid comprising a fluorine-containing polymer compound formed by curing a fluorine-containing polymer having an isocyanate functional group at the terminal on at least one of the inner surface of the bearing ring collar and the end surface of the roller guided thereby The solid lubricating film is dispersed and added with a flowable fluorine-containing polymer that does not bond to the fluorine-containing polymer with an isocyanate functional group at the terminal. Roller bearing. The roller bearing according to claim 1 , wherein the flowable fluorine-containing polymer does not have a functional group. The solid lubricating film has a three-dimensional network structure between molecules are coupled, roller bearing according to claim 1 or 2.

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