JP2014126105A - Rolling bearing unit for supporting wheel - Google Patents

Rolling bearing unit for supporting wheel Download PDF

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JP2014126105A
JP2014126105A JP2012282643A JP2012282643A JP2014126105A JP 2014126105 A JP2014126105 A JP 2014126105A JP 2012282643 A JP2012282643 A JP 2012282643A JP 2012282643 A JP2012282643 A JP 2012282643A JP 2014126105 A JP2014126105 A JP 2014126105A
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seal
seal lip
ring
stationary
rotation
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Yoshio Kamiya
良雄 神谷
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NSK Ltd
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NSK Ltd
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Priority to JP2012282643A priority Critical patent/JP2014126105A/en
Priority to CN2013202397613U priority patent/CN203189535U/en
Publication of JP2014126105A publication Critical patent/JP2014126105A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/72—Sealings
    • F16C33/76—Sealings of ball or roller bearings
    • F16C33/78—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members
    • F16C33/7869—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted with a cylindrical portion to the inner surface of the outer race and having a radial portion extending inward
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/72—Sealings
    • F16C33/76—Sealings of ball or roller bearings
    • F16C33/78—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members
    • F16C33/7816—Details of the sealing or parts thereof, e.g. geometry, material
    • F16C33/782—Details of the sealing or parts thereof, e.g. geometry, material of the sealing region
    • F16C33/7823—Details of the sealing or parts thereof, e.g. geometry, material of the sealing region of sealing lips
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/14—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load
    • F16C19/18—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls
    • F16C19/181—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls with angular contact
    • F16C19/183—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls with angular contact with two rows at opposite angles
    • F16C19/184—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls with angular contact with two rows at opposite angles in O-arrangement
    • F16C19/186—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls with angular contact with two rows at opposite angles in O-arrangement with three raceways provided integrally on parts other than race rings, e.g. third generation hubs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2326/00—Articles relating to transporting
    • F16C2326/01—Parts of vehicles in general
    • F16C2326/02—Wheel hubs or castors

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Rolling Contact Bearings (AREA)
  • Sealing Of Bearings (AREA)
  • Sealing With Elastic Sealing Lips (AREA)
  • Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)

Abstract

PROBLEM TO BE SOLVED: To realize a structure capable of keeping high sealing performance over a long time by suppressing intrusion of foreign matters into an internal space of a combined seal ring and securing movement of a seal lip disposed on the seal ring.SOLUTION: A labyrinth seal 27 is disposed between an outer peripheral edge of a rotation-side circular portion 19 constituting a slinger 16 and a stationary-side circular portion 23 of a core bar 20 constituting a seal ring 17. A thick portion 29 is formed over the whole periphery of a part of an elastic material 21 constituting the seal ring 17, and an auxiliary seal lip 32 having rigidity lower than seal lips 22a-22c is disposed over the whole periphery of the thick portion 29. Movement of the seal lip 22a is prevented from being obstructed due to attachment of foreign matters to the seal lip 22a, by the auxiliary seal lip 32.

Description

本発明は、例えば自動車の車輪を懸架装置に対して回転自在に支持する為の転がり軸受ユニットのうち、軸受内部空間の端部開口を、シールリング或いは組み合わせシールリングにより塞いで成る、車輪支持用転がり軸受ユニットに関する。   The present invention relates to a wheel support comprising, for example, a rolling bearing unit for rotatably supporting a vehicle wheel with respect to a suspension device, wherein an end opening of a bearing internal space is closed with a seal ring or a combination seal ring. The present invention relates to a rolling bearing unit.

自動車の車輪を懸架装置に対して回転自在に支持する為の転がり軸受ユニットとして、例えば特許文献１には、軸受内部空間の端部開口の一方をシールリング、他方を組み合わせシールリングにより密封した車輪支持用転がり軸受ユニットの構造が記載されている。この様な車輪支持用転がり軸受ユニットの耐久性を確保する為には、シールリング及び組み合わせシールリングのシール性を確保する事が重要である。一方、これらシールリング及び組み合わせシールリングは、使用時に泥水等がかかる、厳しい条件で使用される。特に、シール空間に入り込んだ泥水の水分が蒸発し、固形分（泥）だけがこのシール空間に溜まる可能性がある。そして、このシール空間に溜まった固形分は、最も外部側に存在するシールリップに付着し、このシールリップの動きを阻害する可能性がある。この結果、このシールリップの先端縁の一部がシール摺動面から浮き上がり、当該部分を通じて泥水等の異物が、シール空間の内部まで入り込む可能性がある。この様な現象は、水分の蒸発により凝縮し易い粘土質の土を含む泥水に於いて特に著しくなる。   As a rolling bearing unit for rotatably supporting a vehicle wheel with respect to a suspension device, for example, Patent Document 1 discloses a wheel in which one end opening of a bearing internal space is sealed with a seal ring and the other is sealed with a combination seal ring. The structure of the supporting rolling bearing unit is described. In order to ensure the durability of such a wheel-supporting rolling bearing unit, it is important to ensure the sealing performance of the seal ring and the combined seal ring. On the other hand, these seal rings and combination seal rings are used under severe conditions where muddy water or the like is applied during use. In particular, the water in the muddy water that has entered the seal space evaporates, and only solid content (mud) may accumulate in the seal space. Then, the solid content accumulated in the seal space may adhere to the seal lip that is present on the outermost side, and hinder the movement of the seal lip. As a result, a part of the front end edge of the seal lip is lifted from the seal sliding surface, and foreign matters such as muddy water may enter the seal space through the part. Such a phenomenon becomes particularly remarkable in muddy water containing clayey soil that is easily condensed by evaporation of moisture.

組み合わせシールリングのシール性を向上させる為の構造として、特許文献２には、外輪に外嵌した第二のシールリングを構成する第二のシールリップの先端縁を、スリンガの回転側円輪部のうちで、シールリングと反対側の側面に、全周に亙り摺接させた構造が記載されている。この様な構造によれば、シール内部空間内への異物の侵入防止を図れるが、部品点数が増えてコストアップとなる。又、前記第二のシールリングを設ける部分の設置スペースが必要となり、転がり軸受ユニットに隣接して設ける、他の物品との干渉防止の為、設計の自由度が限られる可能性がある。更に、前記第二のシールリップを、組み合わせシールリング側に元々設けられているシールリップに足す状態で設ける為、摺接部が増えて、転がり軸受ユニットの回転抵抗（動トルク）が増大する。   As a structure for improving the sealing performance of the combined seal ring, Patent Document 2 discloses that the tip end edge of the second seal lip constituting the second seal ring fitted on the outer ring is connected to the rotation-side annular portion of the slinger. Among these, a structure is described in which the entire surface is in sliding contact with the side surface opposite to the seal ring. According to such a structure, foreign matter can be prevented from entering the seal internal space, but the number of parts increases and the cost increases. Further, an installation space for the portion where the second seal ring is provided is required, and there is a possibility that the degree of freedom in design may be limited to prevent interference with other articles provided adjacent to the rolling bearing unit. Further, since the second seal lip is provided in a state of being added to the seal lip originally provided on the combined seal ring side, the sliding contact portion is increased, and the rotational resistance (dynamic torque) of the rolling bearing unit is increased.

特開２００７−０８５４７８号公報JP 2007-085478 A 特開２００８−１５１３１１号公報JP 2008-151111 A

本発明は、上述の様な事情に鑑み、転がり軸受ユニットを構成する静止側、回転側両軌道輪同士の間に存在する軸受内部空間の端部開口を塞ぐ、シールリング及び組み合わせシールリング（スリンガとシールリング）のシール内部空間内への異物の侵入を抑えられる構造を実現して、このシールリングに設けたシールリップの動きを確保し、長期間に亙り優れたシール性能を維持できる構造を実現すべく発明したものである。   In view of the circumstances as described above, the present invention provides a seal ring and a combined seal ring (slinger) that closes an end opening of a bearing internal space existing between both stationary and rotating bearing rings constituting a rolling bearing unit. And a seal ring) that can prevent the intrusion of foreign matter into the inner space of the seal, ensuring the movement of the seal lip provided on the seal ring, and maintaining a superior seal performance over a long period of time. It was invented to realize.

本発明に係る車輪支持用転がり軸受ユニットは、互いに同心に配置された状態で相対回転する回転側軌道輪及び静止側軌道輪と、これら回転側軌道輪及び静止側軌道輪の互いに対向する周面にそれぞれ設けられた回転側軌道と静止側軌道との間に転動自在に設けられた複数個の転動体と、前記回転側軌道輪と前記静止側軌道輪との互いに対向する周面同士の間に存在する軸受内部空間の端部開口を塞ぐ、スリンガ及びシールリングから成る組み合わせシールリングとを備えている。
前記スリンガは、断面Ｌ字の円環形状で、回転側円筒部と、この回転側円筒部の軸方向端縁から前記静止側軌道輪に向けて径方向に折れ曲がった回転側円輪部とを備え、前記回転側円筒部を前記回転側軌道輪の周面に嵌合固定しており、
前記シールリングは、芯金と、この芯金に基端部を支持された、複数本のシールリップを有する弾性材とを備え、前記芯金は、断面Ｌ字の円環形状で、静止側円筒部と、この静止側円筒部の軸方向端縁から前記回転側軌道輪に向けて径方向に折れ曲がった静止側円輪部とを備え、前記静止側円筒部を前記静止側軌道輪の周面に嵌合固定し、前記各シールリップの先端部を、前記スリンガの表面に全周に亙り摺接させ、前記回転側円輪部の先端側周縁と前記静止側円筒部の周面との間にラビリンスシールを設けている。 A rolling bearing unit for supporting a wheel according to the present invention includes a rotating raceway and a stationary raceway that rotate relative to each other while being concentrically arranged, and circumferential surfaces of the rotating raceway and the stationary raceway facing each other. A plurality of rolling elements provided between the rotation side raceway and the stationary side raceway respectively provided on the stationary side raceway, and the circumferential surfaces of the rotation side raceway ring and the stationary side raceway which are opposed to each other. And a combined seal ring composed of a slinger and a seal ring, which closes an end opening of a bearing internal space existing therebetween.
The slinger has an annular shape with an L-shaped cross section, and includes a rotation-side cylindrical portion, and a rotation-side annular portion bent in a radial direction from an axial end edge of the rotation-side cylindrical portion toward the stationary-side raceway. Provided, the rotation-side cylindrical portion is fitted and fixed to the peripheral surface of the rotation-side raceway,
The seal ring includes a cored bar and an elastic material having a plurality of seal lips supported at the base end by the cored bar. The cored bar has an annular shape with an L-shaped cross section, and is stationary. A cylindrical portion, and a stationary-side circular ring portion bent in a radial direction from the axial end edge of the stationary-side cylindrical portion toward the rotating-side raceway, and the stationary-side cylindrical portion is arranged around the stationary-side raceway. The front end of each seal lip is slidably contacted with the surface of the slinger over the entire circumference, and the peripheral edge of the front end side of the rotating side annular part and the peripheral surface of the stationary side cylindrical part A labyrinth seal is provided between them.

特に、本発明の車輪支持用転がり軸受ユニットに於いては、前記弾性材の基部で前記各シールリップよりも前記静止側円筒部に寄った部分に、これら各シールリップのうちで、少なくとも前記ラビリンスシールに最も近いシールリップである外部空間寄りシールリップよりも剛性が低い補助シールリップを、前記弾性材と一体に設け、この補助シールリップの先端縁を前記回転側円輪部の軸方向側面に、全周に亙って摺接若しくは近接対向させ、前記各シールリップには前記軸受内部空間に充填されたグリースと同一組成或いはウレア系のグリースが塗布され、前記補助シールリップにはグリースが塗布されていない。   In particular, in the rolling bearing unit for supporting a wheel according to the present invention, at least the labyrinth among the seal lips is formed on a portion of the base of the elastic material that is closer to the stationary cylindrical portion than the seal lips. An auxiliary seal lip having a lower rigidity than the seal lip closer to the outer space, which is the seal lip closest to the seal, is provided integrally with the elastic material, and the tip edge of the auxiliary seal lip is provided on the side surface in the axial direction of the rotating side annular portion. The grease is applied to each seal lip with the same composition or urea grease as the grease filled in the bearing internal space, and grease is applied to the auxiliary seal lip. It has not been.

上述の様に構成する本発明の車輪支持用転がり軸受ユニットによれば、組み合わせシールリングを構成するスリンガとシールリングとの間に存在するシール内部空間のうち、外部空間寄りシールリップに隣接する部分への、泥水等の異物の侵入を効果的に防止できる。即ち、本発明の車輪支持用転がり軸受ユニットの場合には、ラビリンスシールを介して外部空間と連通する外部寄り空間が、補助シールリップにより、径方向に関して２分割される。そして、前記外部空間寄りシールリップと前記ラビリンスシールとの間に、前記補助シールリップが存在する状態となる。   According to the rolling bearing unit for supporting a wheel of the present invention configured as described above, the portion adjacent to the seal lip closer to the external space in the seal internal space existing between the slinger and the seal ring constituting the combined seal ring It is possible to effectively prevent foreign matter such as muddy water from entering. That is, in the case of the rolling bearing unit for supporting a wheel according to the present invention, the outer side space communicating with the outer space through the labyrinth seal is divided into two in the radial direction by the auxiliary seal lip. Then, the auxiliary seal lip exists between the seal lip closer to the outer space and the labyrinth seal.

この結果、前記外部空間寄りシールリップにまで達する泥水等の異物の量を僅少にし、この外部空間寄りシールリップに多量の固形分が付着して、この外部空間寄りシールリップの動きが損なわれる事を防止できる。この結果、長期間に亙り良好なシール性能を発揮させて、車輪支持用転がり軸受ユニットの耐久性を確保できる。
又、前記補助シールリップは、各シールリップよりも剛性が低い為、仮にこの補助シールリップの先端縁が前記スリンガの回転側円輪部と擦れ合っても、擦れ合い部に作用する摩擦力は低く抑えられる。この為、前記補助シールリップを設ける事に伴う、車輪支持用転がり軸受ユニットの回転抵抗の増大は、極く僅少に抑えられる。 As a result, the amount of foreign matter such as muddy water reaching the outer space-side seal lip is reduced, and a large amount of solid matter adheres to the outer space-side seal lip, thereby impairing the movement of the outer space-side seal lip. Can be prevented. As a result, good sealing performance can be exhibited over a long period of time, and the durability of the wheel bearing rolling bearing unit can be ensured.
In addition, since the auxiliary seal lip has lower rigidity than each seal lip, even if the tip edge of the auxiliary seal lip rubs against the rotation-side annular portion of the slinger, the frictional force acting on the rubbed portion is not. It can be kept low. For this reason, the increase in the rotational resistance of the wheel bearing rolling bearing unit due to the provision of the auxiliary seal lip can be suppressed very little.

尚、前記ラビリンスシールを通過した泥水等の異物が前記補助シールリップに付着する事は、或る程度避けられない。但し、前記ラビリンスシールを通過する事で勢いを弱められた異物が、前記補助シールリップを弾性変形させて前記外部空間寄りシールリップにまで達する事は殆どない。従って、この補助シールリップを通過して前記外部空間寄りシールリップにまで達する異物の量は極く僅少に抑えられる。即ち、前記ラビリンスシールを通過する泥水等の異物の侵入速度や勢いが高い場合であっても、この異物がその勢いのまま前記補助シールリップを直撃する事はない。従って、この補助シールリップに異物が付着して、この補助シールリップによるシール性が低下しても、依然として前記外部空間寄りシールリップに達する異物の量を僅少に抑えられる。この為、この外部空間寄りシールリップに、この外部空間寄りシールリップのシール性を低下させる程に多量の異物が付着するまでには、相当の時間がかかる様になる。この結果、車輪支持用転がり軸受ユニットの耐久性を十分に向上させる事ができる。   In addition, it is inevitable that foreign matter such as muddy water that has passed through the labyrinth seal adheres to the auxiliary seal lip. However, the foreign matter whose strength is weakened by passing through the labyrinth seal rarely reaches the seal lip closer to the outer space by elastically deforming the auxiliary seal lip. Therefore, the amount of foreign matter passing through the auxiliary seal lip and reaching the seal lip closer to the outer space can be suppressed to a very small amount. That is, even if the intrusion speed and momentum of foreign matter such as muddy water passing through the labyrinth seal is high, the foreign matter does not directly hit the auxiliary seal lip with that momentum. Therefore, even if foreign matter adheres to the auxiliary seal lip and the sealing performance of the auxiliary seal lip is lowered, the amount of foreign matter that reaches the seal lip closer to the external space can be kept small. For this reason, it takes a considerable amount of time until a large amount of foreign matter adheres to the seal lip closer to the outer space so as to reduce the sealing performance of the seal lip closer to the outer space. As a result, the durability of the wheel bearing rolling bearing unit can be sufficiently improved.

又、補助シールリップの外周面にはグリースを塗布しないことで、グリースと泥とが混ざって補助シールリップに付着することを防止する事ができる。
又、スリンガの表面と摺接する各シールリップには潤滑用のグリースを塗布する必要があるが、軸受内部空間に充填されたグリースと同一組成（基油と増ちょう剤が同一の種類）のグリースを塗布することで、グリースの混合による潤滑性能の劣化を回避できる。また、撥水性に優れるウレア系のグリースをシールリップに塗布すれば、軸受内部空間に充填されたグリース或いはシールリップに塗布されたグリースが外部に漏洩して補助シールリップに付着した場合でも、補助シールリップに泥等が付着する事を抑制できる。 Further, by not applying grease to the outer peripheral surface of the auxiliary seal lip, it is possible to prevent the grease and mud from mixing and adhering to the auxiliary seal lip.
In addition, it is necessary to apply grease for lubrication to each seal lip that is in sliding contact with the surface of the slinger, but the grease has the same composition (the same type of base oil and thickener) as the grease filled in the bearing internal space. By applying, deterioration of lubrication performance due to mixing of grease can be avoided. Also, if urea-based grease with excellent water repellency is applied to the seal lip, even if the grease filled in the bearing internal space or the grease applied to the seal lip leaks outside and adheres to the auxiliary seal lip, It is possible to suppress mud etc. from adhering to the seal lip.

第１実施形態を示す、車輪支持用転がり軸受ユニットの断面図。Sectional drawing of the rolling bearing unit for wheel support which shows 1st Embodiment. 同、組み合わせシールリングの断面図。Sectional drawing of a combination seal ring. 同、シールリングの断面図。Sectional drawing of a seal ring. 第２実施形態を示す、車輪支持用転がり軸受ユニットの断面図。Sectional drawing of the rolling bearing unit for wheel support which shows 2nd Embodiment. 同、組み合わせシールリングの断面図。Sectional drawing of a combination seal ring. 第３実施形態を示す、車輪支持用転がり軸受ユニットの断面図。Sectional drawing of the rolling bearing unit for wheel support which shows 3rd Embodiment. 同、組み合わせシールリングの断面図。Sectional drawing of a combination seal ring. 補助シールリップの先端縁の形状を示す、先端縁の部分拡大図。The elements on larger scale of the front end edge which show the shape of the front end edge of an auxiliary seal lip.

［第１実施形態］
図１〜３は、本発明の第１実施形態を示している。本実施形態の車輪支持用転がり軸受ユニット１は、静止側軌道輪である外輪２と回転側軌道輪であるハブ３とを互いに同心に配置している。そして、この外輪２の内周面に設けた、それぞれが静止側軌道である複列の外輪軌道４、４と、前記ハブ３の外周面に設けた、それぞれが回転側軌道である複列の内輪軌道５、５との間に、それぞれが転動体である玉６、６を、両列毎に複数個ずつ配置している。これら各玉６、６は、それぞれ保持器７、７により、転動自在に保持されている。この様な構成により、外輪２の内径側にハブ３を、回転自在に支持している。外輪２の外周面には静止側フランジ８が設けられており、この静止側フランジ８を図示しない懸架装置にねじ止め固定する。ハブ３の軸方向外端部外周面に形成した回転側フランジ９には円周方向に複数のスタッド６３が圧入固定されており、図示しない車輪のホイール及びディスクロータ等の制動用回転体を回転側フランジ９にねじ止め固定する。尚、軸方向に関して外とは、車両への組み付け状態で車両の幅方向外側を言い、各図の左側となる。これに対して、車両の幅方向内側となる、各図の右側を、軸方向に関して内と言う。 [First Embodiment]
1 to 3 show a first embodiment of the present invention. In the wheel bearing rolling bearing unit 1 of the present embodiment, an outer ring 2 that is a stationary side race ring and a hub 3 that is a rotation side race ring are arranged concentrically with each other. And the double row outer ring raceways 4 and 4 each provided on the inner peripheral surface of the outer ring 2 are stationary side raceways, and the double row each provided on the outer peripheral surface of the hub 3 and each is a rotary side raceway. Between the inner ring raceways 5 and 5, a plurality of balls 6 and 6 each of which is a rolling element are arranged in each row. These balls 6 and 6 are held by rolls 7 and 7 so as to be freely rollable. With such a configuration, the hub 3 is rotatably supported on the inner diameter side of the outer ring 2. A stationary side flange 8 is provided on the outer peripheral surface of the outer ring 2, and the stationary side flange 8 is fixed to a suspension device (not shown) with screws. A plurality of studs 63 are press-fitted and fixed in the circumferential direction to the rotation side flange 9 formed on the outer peripheral surface of the outer end portion in the axial direction of the hub 3, and rotate a rotating wheel for braking such as a wheel of a wheel and a disk rotor (not shown). The side flange 9 is fixed with screws. The outside in the axial direction means the outside in the width direction of the vehicle in the assembled state to the vehicle, and is the left side of each figure. In contrast, the right side of each figure, which is the inner side in the width direction of the vehicle, is referred to as the inner side in the axial direction.

前記外輪２の内周面と前記ハブ３の外周面との間で前記各玉６、６を設置した軸受内部空間１０の両端開口は、それぞれシールリング１１と組み合わせシールリング１２とにより、全周に亙り塞いでいる。軸受内部空間１０の軸方向外端側開口を塞ぐシールリング１１は、図３に示す様に、芯金１３と弾性材１４とから成る。芯金１３は、軟鋼板等の金属板を曲げ形成して成るもので、嵌合筒部５２と、この嵌合筒部５２の外端縁から径方向外方に折れ曲がった円輪部５３と、嵌合筒部５２の軸方向内端縁から径方向内方及び軸方向外方に向けてＵ字形に折り返された折れ曲がり部５４と、円輪部５３の外周縁から軸方向内方に折れ曲がった円筒部５５とを備えている。そして、嵌合筒部５２を、外輪２の軸方向外端部内周面に締め嵌めで内嵌固定すると共に、円輪部５３の軸方向内側面を、外輪２の軸方向外端面に、弾性材１４の一部を介在させた状態で突き当てている。   Both end openings of the bearing internal space 10 in which the balls 6, 6 are installed between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3 are surrounded by a seal ring 11 and a combination seal ring 12, respectively. It is crawling on and blocking. As shown in FIG. 3, the seal ring 11 that closes the axially outer end side opening of the bearing internal space 10 includes a cored bar 13 and an elastic material 14. The cored bar 13 is formed by bending a metal plate such as a mild steel plate, and includes a fitting cylinder part 52 and an annular part 53 bent radially outward from the outer edge of the fitting cylinder part 52. A bent portion 54 folded back in a U shape from the inner end edge in the axial direction of the fitting cylindrical portion 52 toward the radially inner side and the outer side in the axial direction; and bent from the outer peripheral edge of the annular ring portion 53 in the axial direction. And a cylindrical portion 55. Then, the fitting cylinder portion 52 is internally fitted and fixed to the inner peripheral surface of the outer ring 2 in the axial direction outer end portion, and the inner side surface in the axial direction of the annular ring portion 53 is elastically formed on the outer end surface in the axial direction of the outer ring 2. It abuts with a part of the material 14 interposed.

前記弾性材１４は、ゴムの如きエラストマー等の弾性材製で、前記芯金１３に接合固定されており、３本の接触式のシールリップ１５ａ、１５ｂ、１５ｃと、ラビリンスシールを構成する、庇状のラビリンスリップ５１とを備えている。各シールリップ１５ａ〜１５ｃは、それぞれの先端縁を回転側フランジ９の軸方向内側面或いはハブ３の中間部外周面に、全周に亙り摺接させている。尚、弾性材１４の弾性材としては、ＮＢＲ（ニトリルゴム）、アクリルゴム、フッ素ゴム、シリコンゴム等を使用することができる。   The elastic material 14 is made of an elastic material such as an elastomer such as rubber, and is bonded and fixed to the cored bar 13. The elastic material 14 forms a labyrinth seal with three contact-type seal lips 15a, 15b, and 15c. The labyrinth slip 51 is provided. Each of the seal lips 15 a to 15 c is slidably contacted with the entire inner periphery of the front end edge of the seal lip 15 a to the inner peripheral surface of the rotating flange 9 or the outer peripheral surface of the intermediate portion of the hub 3. As the elastic material of the elastic material 14, NBR (nitrile rubber), acrylic rubber, fluorine rubber, silicon rubber, or the like can be used.

又、前記ラビリンスリップ５１は、最も径方向外側に設けられた前記シールリップ１５ａよりも更に径方向外方に設けられており、その先端部をシールリップ１５ａの摺接点よりも軸方向外側まで伸延させている。更に、ラビリンスリップ５１の形成位置は、前記外輪２の軸方向外端部外周面、及び前記回転側フランジ９の軸方向内側面に設けられた段部６０との関係で規制している。尚、段部６０は、回転側フランジ９に加わるモーメント荷重に対する曲げ剛性を確保すべく、この回転側フランジ９の基端寄り部分（根元部分）に設けられた厚肉部６１と、同じく先端寄り部分に設けられた、厚肉部６１よりも肉厚の小さい薄肉部６２とを連続させる部分である。   The labyrinth slip 51 is provided further radially outward than the seal lip 15a provided on the outermost radial direction, and its tip extends to the axially outer side from the sliding contact of the seal lip 15a. I am letting. Further, the formation position of the labyrinth slip 51 is restricted by the relationship between the outer circumferential surface of the outer end portion of the outer ring 2 in the axial direction and the step portion 60 provided on the inner side surface of the rotation side flange 9 in the axial direction. The step portion 60 is also close to the distal end in the same manner as the thick portion 61 provided at the proximal end portion (root portion) of the rotation side flange 9 in order to ensure the bending rigidity with respect to the moment load applied to the rotation side flange 9. This is a portion where a thin portion 62 having a smaller thickness than the thick portion 61 is provided continuously.

前記ラビリンスリップ５１（の先端部乃至基端部）は、前記外輪２の軸方向外端部外周面の外径寸法よりも径方向外方、且つ前記段部６０よりも径方向外方に位置させると共に、ラビリンスリップ５１の先半部と段部６０とを径方向に重畳させている。そして、ラビリンスリップ５１の先端部内周面と段部６０の外周面とを、全周に亙り近接対向させている。これにより、ラビリンスリップ５１の先端縁と回転側フランジ９の軸方向内側面との間に、径方向のラビリンスシールを形成すると共に、ラビリンスリップ５１の先端部内周面と段部６０の外周面との間に、軸方向のラビリンスシールを形成している。
ラビリンスリップ５１の内周面は、先端縁に向かう程径寸法が大きくなる方向に傾斜した部分円錐面形状とし、これによりラビリンスリップ５１の内径側に侵入した泥水等の異物の排出を容易にしている。 The labyrinth slip 51 (the front end portion to the base end portion thereof) is positioned radially outward from the outer diameter of the outer circumferential surface of the outer ring 2 in the axial direction and radially outward from the stepped portion 60. In addition, the leading half of the labyrinth slip 51 and the stepped portion 60 are overlapped in the radial direction. And the front-end | tip part inner peripheral surface of the labyrinth slip 51 and the outer peripheral surface of the step part 60 are made to oppose and approach over the perimeter. Thus, a radial labyrinth seal is formed between the leading edge of the labyrin slip 51 and the axial inner surface of the rotation side flange 9, and the distal inner circumferential surface of the labyrin slip 51 and the outer circumferential surface of the step portion 60 are formed. In between, an axial labyrinth seal is formed.
The inner peripheral surface of the labyrinth slip 51 has a partial conical surface shape inclined in a direction in which the diameter increases toward the leading edge, thereby facilitating the discharge of foreign matter such as muddy water that has entered the inner diameter side of the labyrinth slip 51. Yes.

前記ラビリンスリップ５１の外周面も、先端縁に向かう程径寸法が大きくなる方向に傾斜した部分円錐面形状とし、その外径寸法を、前記外輪２の軸方向外端部外周面の外径寸法よりも、十分に大きくしている。更に、前記シールリング１１を構成する弾性材１４により、止水部５７及び堤部５６を設けている。止水部５７は、ラビリンスリップ５１の基端部から径方向内方に連続する部分により、芯金１３を構成する円輪部５３のうち、外輪２の軸方向外端面外周縁よりも径方向外方に突出した部分を弾性材１４で覆う事により構成している。又、堤部５６は、円輪部５３の外径縁から軸方向内方に折れ曲がった円筒部５５を弾性材１４で覆う事により構成している。堤部５６の内径寸法は、外輪２の軸方向外端部外周面の外径寸法よりも大きくして、堤部５６の内周面と外輪２の外端部外周面との間に環状の隙間空間を、全周に亙り設けている。言い換えれば、外輪２の外端部外周面の全周に亙って、外輪２の外端部外周面と止水部５７と堤部５６とにより三方を囲まれて、軸方向内方が開口した、凹溝を形成している。   The outer peripheral surface of the labyrinth slip 51 is also formed into a partial conical surface shape that is inclined in a direction in which the diameter increases toward the tip edge, and the outer diameter is the outer diameter of the outer peripheral surface in the axial outer end of the outer ring 2. Than big enough. Further, the water stop portion 57 and the bank portion 56 are provided by the elastic material 14 constituting the seal ring 11. The water stop portion 57 is a portion that is continuous radially inward from the base end portion of the labyrin slip 51, and in the circular ring portion 53 that constitutes the core metal 13, it is more radial than the outer peripheral edge in the axial direction outer end surface of the outer ring 2. A portion protruding outward is covered with an elastic material 14. The bank portion 56 is configured by covering the cylindrical portion 55 that is bent inward in the axial direction from the outer diameter edge of the annular ring portion 53 with the elastic material 14. The inner diameter dimension of the bank portion 56 is larger than the outer diameter dimension of the outer peripheral surface in the axial direction outer end portion of the outer ring 2, and an annular shape is formed between the inner peripheral surface of the bank portion 56 and the outer end portion outer peripheral surface of the outer ring 2. A gap space is provided over the entire circumference. In other words, along the entire circumference of the outer peripheral surface of the outer end portion of the outer ring 2, three sides are surrounded by the outer peripheral portion of the outer ring 2, the water stop portion 57 and the bank portion 56, and the inner side in the axial direction is open. A concave groove is formed.

前記止水部５７と堤部５６とにより、前記外輪２の外周面に付着した水分がこの外輪２の外周面を伝って、前記ラビリンスリップ５１の外周面に到達する事を阻止している。即ち、止水部５７に堰き止められた水分は、止水部５７の軸方向内側面と堤部５６の内周面とに案内され、外輪２の外周面を軸方向内方及び下部方向に向って誘導される。更に、ラビリンスリップ５１の外周面を部分円錐面形状とする事により、ラビリンスリップ５１の外周面上部に付着した泥水等を先端部から離れる方向（軸方向内方）に誘導している。
さらに、前記弾性材１４は、ラビリンスリップ５１の基端部から円輪部５３の軸方向内側面までを覆うと共に、前記外輪２の軸方向外端面と当接する円輪部５３の軸方向内側面部分に、全周に亙って突条５９を設けている。これにより、外輪２とシールリング１１との嵌合面から、軸受内部空間１０に泥水等の異物が侵入することを防止している。 The water stop portion 57 and the bank portion 56 prevent moisture adhering to the outer peripheral surface of the outer ring 2 from reaching the outer peripheral surface of the labyrin slip 51 through the outer peripheral surface of the outer ring 2. That is, the water blocked by the water stop portion 57 is guided to the axial inner surface of the water stop portion 57 and the inner peripheral surface of the bank portion 56, and the outer peripheral surface of the outer ring 2 is directed inward and downward in the axial direction. It is guided toward. Furthermore, by making the outer peripheral surface of the labyrin slip 51 into a partial conical surface shape, muddy water or the like adhering to the upper portion of the outer peripheral surface of the labyrin slip 51 is guided in the direction away from the tip (inward in the axial direction).
Further, the elastic member 14 covers from the base end portion of the labyrinth slip 51 to the axially inner side surface of the annular ring portion 53, and the axially inner side surface of the annular ring portion 53 that contacts the axially outer end surface of the outer ring 2. In the portion, a protrusion 59 is provided over the entire circumference. This prevents foreign matter such as muddy water from entering the bearing internal space 10 from the fitting surface between the outer ring 2 and the seal ring 11.

又、前記シールリング１１の芯金１３に前記弾性材１４を加硫成形する際に、金型内で芯金１３を押さえ付けて位置決めするための凹部５８が、前記円輪部５３の軸方向外側面を覆う弾性材１４に形成されている。この凹部５８は、円輪部５３の軸方向外側面を覆う弾性材１４を軸方向に貫通しており、その底面（軸方向外側面）には芯金１３の表面が露出している。そして、前記ラビリンスリップ５１の内径側で、外部空間寄りシールリップであるシールリップ１５ａの基端部とラビリンスリップ５１の基端部との間に凹部５８を設けている。これにより、外部空間の水分等が凹部５８まで到達することを防止している。   Further, when the elastic material 14 is vulcanized and formed on the core metal 13 of the seal ring 11, a concave portion 58 for pressing and positioning the core metal 13 in the mold is provided in the axial direction of the annular portion 53. It is formed in the elastic material 14 which covers an outer side surface. The concave portion 58 penetrates the elastic material 14 covering the outer surface in the axial direction of the annular ring portion 53 in the axial direction, and the surface of the cored bar 13 is exposed at the bottom surface (the outer surface in the axial direction). A recess 58 is provided on the inner diameter side of the labyrin slip 51 between the base end portion of the seal lip 15 a that is a seal lip closer to the outer space and the base end portion of the labyrin slip 51. This prevents moisture or the like in the external space from reaching the recess 58.

一方、軸受内部空間１０の軸方向内端側開口を塞ぐ組み合わせシールリング１２は、図２に示す様に、スリンガ１６とシールリング１７とを組み合わせて成る。スリンガ１６は、金属板を曲げ成形する事により断面Ｌ字形で全体を円環状に構成したもので、回転側円筒部１８と、この回転側円筒部１８の軸方向内端縁から径方向外方に折れ曲がった回転側円輪部１９とから成る。この様なスリンガ１６は、回転側円筒部１８をハブ３（ハブ本体と共にこのハブ３を構成する内輪）の軸方向内端部に締り嵌めで外嵌する事により、ハブ３に固定している。   On the other hand, the combined seal ring 12 that closes the axially inner end side opening of the bearing internal space 10 is formed by combining a slinger 16 and a seal ring 17 as shown in FIG. The slinger 16 is formed by bending a metal plate and is formed into an annular shape with an L-shaped cross section. The slinger 16 is radially outward from the rotation-side cylindrical portion 18 and the axial inner end edge of the rotation-side cylindrical portion 18. And a rotation-side annular ring portion 19 that is bent in a circle. Such a slinger 16 is fixed to the hub 3 by fitting the rotation-side cylindrical portion 18 to the inner end portion in the axial direction of the hub 3 (the inner ring constituting the hub 3 together with the hub body) by an interference fit. .

前記シールリング１７は、金属板製の芯金２０と弾性材２１とを備えている。この弾性材２１は、ゴムの如きエラストマー等の弾性材製で、芯金２０に加硫成形等により接合固定され、複数本（図示の例では３本）のシールリップ２２ａ、２２ｂ、２２ｃを備えている。又、芯金２０は、金属板を曲げ成形する事により断面略Ｌ字形で全体を円環状に構成したもので、静止側円筒部２３と、この静止側円筒部２３の軸方向外端縁から径方向内方に折れ曲がった静止側円輪部２４とから成る。この様な芯金２０を備えたシールリング１７は、静止側円筒部２３を前記外輪２の軸方向内端部に締り嵌めで内嵌する事により、この外輪２に固定している。又、この状態で、シールリップ２２ａの先端縁を前記回転側円輪部１９の軸方向外側面に、各シールリップ２２ｂ、２２ｃの先端縁を前記回転側円筒部１８の外周面に、それぞれ全周に亙り摺接させている。   The seal ring 17 includes a metal core 20 made of a metal plate and an elastic material 21. This elastic material 21 is made of an elastic material such as an elastomer such as rubber, and is joined and fixed to the metal core 20 by vulcanization molding or the like, and includes a plurality of (three in the illustrated example) seal lips 22a, 22b, and 22c. ing. The metal core 20 is formed by bending a metal plate to have a substantially L-shaped cross section, and is formed into an annular shape as a whole. From the stationary side cylindrical portion 23 and the axially outer end edge of the stationary side cylindrical portion 23. The stationary side annular portion 24 is bent inward in the radial direction. The seal ring 17 having such a cored bar 20 is fixed to the outer ring 2 by fitting the stationary-side cylindrical portion 23 to the inner end in the axial direction of the outer ring 2 with an interference fit. Also, in this state, the tip edge of the seal lip 22a is all on the outer surface in the axial direction of the rotary side ring portion 19, and the tip edge of each seal lip 22b, 22c is on the outer peripheral surface of the rotary side cylindrical portion 18, respectively. It touches the circumference.

更に、前記スリンガ１６を構成する回転側円輪部１９の外周縁と、前記シールリング１７の芯金２０を構成する前記静止側円筒部２３の内周面を覆った前記弾性材２１の一部内周面との間に、ラビリンスシール２７を設けている。又、弾性材２１の一部で、静止側円筒部２３の内周面と、静止側円筒部２３と共に芯金２０を構成する前記静止側円輪部２４の軸方向内側面の外径側半部とにより、径方向外側と軸方向外側とを仕切られた部分に、径方向及び軸方向の厚さ寸法が他の部分の厚さ寸法よりも大きくなった厚肉部２９を設けている。弾性材２１のうちで、厚肉部２９の軸方向内端面である円輪状の段差面３０と、静止側円筒部２３の内周面の先端寄り部分（軸方向内半部）を覆う部分とを、断面形状が四分の一円弧状である外径側曲面３１（隅Ｒ）により、滑らかに連続させている。この外径側曲面３１の断面形状の曲率半径Ｒ１は、ラビリンスシール２７の径方向に関する幅寸法Ｗ以上（Ｒ１≧Ｗ）としている。これにより、ラビリンスシール２７を通じて次述する補助シールリップ３２の外径側に存在する空間部分に入り込んだ異物を、ラビリンスシール２７の側に還流させ易くしている。 Further, a part of the elastic member 21 that covers the outer peripheral edge of the rotating-side circular ring portion 19 that constitutes the slinger 16 and the inner peripheral surface of the stationary-side cylindrical portion 23 that constitutes the core metal 20 of the seal ring 17. A labyrinth seal 27 is provided between the peripheral surface. Further, a part of the elastic material 21, the inner peripheral surface of the stationary side cylindrical portion 23 and the outer diameter side half of the axially inner side surface of the stationary side annular portion 24 constituting the cored bar 20 together with the stationary side cylindrical portion 23. A thick-walled portion 29 in which the thickness dimension in the radial direction and the axial direction is larger than the thickness dimension of the other portions is provided in a portion where the radially outer side and the axially outer side are partitioned by the portion. Of the elastic material 21, a ring-shaped stepped surface 30 that is an axially inner end surface of the thick portion 29, and a portion that covers a tip end portion (axially inner half) of the inner peripheral surface of the stationary side cylindrical portion 23 Are smoothly continued by the outer diameter side curved surface 31 (corner R) whose cross-sectional shape is a quarter arc. The radius of curvature R 1 of the cross-sectional shape of the outer diameter side curved surface 31 is not less than the width dimension W in the radial direction of the labyrinth seal 27 (R 1 ≧ W). Thereby, the foreign matter that has entered the space portion existing on the outer diameter side of the auxiliary seal lip 32 described below through the labyrinth seal 27 is easily returned to the labyrinth seal 27 side.

又、前記段差面３０の径方向内端部から前記回転側円輪部１９に向け、補助シールリップ３２を延出（各シールリップ２２ａ〜２２ｃと共に前記弾性材２１に一体に形成）している。又、補助シールリップ３２は、段差面３０を基端として軸方向内方に向かう程直径が大きくなる方向に、末広がりに傾斜して延びる部分円すい筒状である。この様な補助シールリップ３２の基端部外周面と段差面３０とに関しても、断面形状が四分の一円弧状の内径側曲面３３により、滑らかに連続させている。この内径側曲面３３の断面形状の曲率半径Ｒ２は、補助シールリップ３２の基端部に加わる応力を抑えつつ、この補助シールリップ３２を適度に撓み易くする面から、更には、前記ラビリンスシール２７を通じて補助シールリップ３２の外径側に存在する空間部分に入り込んだ異物をこのラビリンスシール２７の側に還流させ易くする面から、適切に規制している。この為に、内径側曲面３３の断面形状の曲率半径Ｒ２を、補助シールリップ３２の基端部の厚さＴと同じか、この厚さＴよりも少しだけ大きく（Ｒ２≧Ｔ）している。 Further, an auxiliary seal lip 32 extends from the radially inner end of the stepped surface 30 toward the rotation-side annular ring portion 19 (formed integrally with the elastic material 21 together with the seal lips 22a to 22c). . The auxiliary seal lip 32 has a partially conical cylindrical shape extending in a slanting manner in a direction in which the diameter increases toward the inner side in the axial direction with the stepped surface 30 as a base end. Such an outer peripheral surface of the base end portion of the auxiliary seal lip 32 and the stepped surface 30 are also smoothly continued by the inner diameter side curved surface 33 whose sectional shape is a quarter arc. The radius of curvature R 2 of the cross-sectional shape of the inner diameter side curved surface 33, while suppressing stress applied to the proximal end portion of the auxiliary seal lip 32, the surface that easily deflected the auxiliary sealing lip 32 adequately, further, the labyrinth seal The foreign matter that has entered the space portion existing on the outer diameter side of the auxiliary seal lip 32 through 27 is appropriately regulated from the viewpoint of facilitating the return to the labyrinth seal 27 side. For this purpose, the curvature radius R 2 of the cross-sectional shape of the inner diameter side curved surface 33 is the same as or slightly larger than the thickness T of the base end portion of the auxiliary seal lip 32 (R 2 ≧ T). ing.

この様な補助シールリップ３２は、この補助シールリップ３２の内径側に存在する、サイドリップと呼ばれる、外部空間寄りのシールリップであるシールリップ２２ａに異物が付着するのを抑える役目を有するものであり、高度のシール性を要求されない。むしろ、補助シールリップ３２を設ける事で、組み合わせシールリング１２を組み込んだ車輪支持用転がり軸受ユニット１の回転抵抗（動トルク）が大きくなるのを抑える事が重要である。この為に、本実施形態の場合には、下記の様な工夫により、補助シールリップ３２を設けた事に基づく摩擦抵抗の増大を抑制している。   Such an auxiliary seal lip 32 has a function of suppressing foreign matter from adhering to the seal lip 22a, which is a side lip, which is located on the inner diameter side of the auxiliary seal lip 32 and is closer to the external space. Yes, high sealing performance is not required. Rather, it is important to suppress an increase in rotational resistance (dynamic torque) of the wheel bearing rolling bearing unit 1 incorporating the combined seal ring 12 by providing the auxiliary seal lip 32. For this reason, in the case of this embodiment, an increase in frictional resistance due to the provision of the auxiliary seal lip 32 is suppressed by the following device.

前記補助シールリップ３２の断面形状は、先端縁に向かう程厚さ寸法が小さくなる、くさび状としている。これにより、補助シールリップ３２の先端部の弾性を低く抑え、摩擦抵抗が大きくならない様にしている。
更に、補助シールリップ３２の厚さ寸法を、前記シールリップ２２ａの厚さ寸法よりも十分に小さくしている。具体的には、補助シールリップ３２のうちで最も厚い部分である基端部の厚さ寸法を、シールリップ２２ａのうちで最も薄い部分である基端部の厚さ寸法の１／２（半分）以下、より好ましくは１／３以下、但し、成形性を考慮して１／５以上としている。これにより、補助シールリップ３２全体の剛性を低く抑え、摩擦抵抗が大きくならない様にしている。
更に、シールリング１７とスリンガ１６とを組み合わせた状態で、補助シールリップ３２の締め代を、シールリップ２２ａの締め代よりも十分に小さくしている。具体的には、図２に示した自由状態において、補助シールリップ３２の軸方向高さ（回転側円輪部１９に向けての軸方向突出量）を、シールリップ２２ａの軸方向高さよりも十分に小さくしている。これにより、シールリング１７とスリンガ１６とを組み合わせた状態で、補助シールリップ３２の弾性変形量（軸方向圧縮量）を、シールリップ２２ａの弾性変形量よりも十分に小さくして、補助シールリップ３２の先端縁と回転側円輪部１９の軸方向外側面との摺接部の面圧を抑え、摩擦抵抗が大きくならない様にしている。
尚、先に述べた様に、補助シールリップ３２には高度のシール性を要求しない為、車両の旋回走行等に伴ってシールリング１７の中心軸とスリンガ１６の中心軸とが傾斜した状態で、補助シールリップ３２の先端縁が回転側円輪部１９の軸方向外側面から僅かに浮き上がっても（締め代が零になったり、僅かに隙間が空いても）良い。又、補助シールリップ３２の先端縁を回転側円輪部１９の軸方向外側面に、全周に亙り微小隙間を介して対向させても良い。 The cross-sectional shape of the auxiliary seal lip 32 has a wedge shape with a thickness dimension that decreases toward the tip edge. Thereby, the elasticity of the front-end | tip part of the auxiliary | assistant seal lip 32 is suppressed low, and it is trying not to increase frictional resistance.
Further, the thickness dimension of the auxiliary seal lip 32 is made sufficiently smaller than the thickness dimension of the seal lip 22a. Specifically, the thickness of the base end that is the thickest portion of the auxiliary seal lip 32 is ½ (half the thickness of the base end that is the thinnest portion of the seal lip 22a. ) Or less, more preferably 1/3 or less, but 1/5 or more in consideration of moldability. As a result, the rigidity of the entire auxiliary seal lip 32 is kept low so that the frictional resistance does not increase.
Further, in a state where the seal ring 17 and the slinger 16 are combined, the tightening allowance of the auxiliary seal lip 32 is sufficiently smaller than the tightening allowance of the seal lip 22a. Specifically, in the free state shown in FIG. 2, the axial height of the auxiliary seal lip 32 (the amount of axial protrusion toward the rotation-side annular ring portion 19) is made larger than the axial height of the seal lip 22a. It is small enough. Thereby, in a state where the seal ring 17 and the slinger 16 are combined, the amount of elastic deformation (axial compression amount) of the auxiliary seal lip 32 is made sufficiently smaller than the amount of elastic deformation of the seal lip 22a. The surface pressure of the sliding contact portion between the tip end edge of 32 and the axially outer side surface of the rotation-side annular ring portion 19 is suppressed so that the frictional resistance does not increase.
As described above, since the auxiliary seal lip 32 does not require a high degree of sealing performance, the center axis of the seal ring 17 and the center axis of the slinger 16 are inclined with the turning of the vehicle. The tip edge of the auxiliary seal lip 32 may be slightly lifted from the outer surface in the axial direction of the rotation-side annular ring portion 19 (even if the tightening margin becomes zero or there is a slight gap). Further, the tip edge of the auxiliary seal lip 32 may be opposed to the outer surface in the axial direction of the rotation-side annular ring portion 19 over the entire circumference with a small gap.

上述した様に、前記シールリップ２２ａよりも径方向外寄り部分に存在してラビリンスシール２７を介して外部空間と連通した外部寄り空間２８を前記補助シールリップ３２により、径方向に関して２分割している。そして、シールリップ２２ａとラビリンスシール２７との間に、補助シールリップ３２が存在する状態としている。言い換えれば、外部寄り空間２８の径方向外端部でラビリンスシール２７と連通する部分に、前記段差面３０と補助シールリップ３２とにより軸方向外端部と内径側とを仕切られた開口寄り小空間３４を設けている。   As described above, the outer space 28 that exists in the radially outer portion than the seal lip 22a and communicates with the outer space via the labyrinth seal 27 is divided into two in the radial direction by the auxiliary seal lip 32. Yes. An auxiliary seal lip 32 exists between the seal lip 22a and the labyrinth seal 27. In other words, at the radially outer end of the outer space 28, the portion that communicates with the labyrinth seal 27 has a small opening portion that is partitioned by the stepped surface 30 and the auxiliary seal lip 32 from the axial outer end and the inner diameter side. A space 34 is provided.

この開口寄り小空間３４の軸方向外端部の内面を構成する、段差面３０の内外両周縁部は、それぞれ前記内径側、外径側両曲面３３、３１により、開口寄り小空間３４の内外両周面と滑らかに連続させている。更に、このうちの内径側曲面３３から連続する、補助シールリップ３２の外周面は、先端に向かう程前記ラビリンスシール２７に向かう方向に傾斜している。この様な構成により、このラビリンスシール２７から開口寄り小空間３４内に、勢い良く吹き込まれた異物の流れを変換し、ラビリンスシール２７に向けて還流する様にしている。従って、前記スリンガ１６と前記シールリング１７との間に存在するシール内部空間２６への、泥水等の異物の侵入を効果的に防止できる。   The inner and outer peripheral edges of the step surface 30 constituting the inner surface of the axially outer end portion of the opening-side small space 34 are inside and outside of the opening-side small space 34 by the both inner diameter side and outer diameter side curved surfaces 33, 31, respectively. Smooth and continuous with both peripheral surfaces. Further, the outer peripheral surface of the auxiliary seal lip 32 that continues from the inner diameter side curved surface 33 is inclined in the direction toward the labyrinth seal 27 toward the tip. With such a configuration, the flow of the foreign matter blown into the small space 34 close to the opening from the labyrinth seal 27 is converted and recirculated toward the labyrinth seal 27. Accordingly, it is possible to effectively prevent foreign matters such as muddy water from entering the seal internal space 26 existing between the slinger 16 and the seal ring 17.

又、前記シールリング１１と同様に、組み合わせシールリング１２を構成するシールリング１７の芯金２０に弾性材２１を加硫成形する際に、金型内で芯金２０を押さえ付けて位置決めするための凹部３６が、前記静止側円輪部２４の軸方向内側面を覆う弾性材２１に形成されている。この凹部３６は、静止側円輪部２４の軸方向内側面を覆う弾性材２１を軸方向に貫通しており、その底面（軸方向内側面）には芯金２０の表面が露出している。そして、補助シールリップ３２よりも内径側に存在する反開口寄り小空間３５で、外部空間寄りシールリップであるシールリップ２２ａの基端部と補助シールリップ３２の基端部との間に凹部３６を設ける事により、外部空間の水分等が凹部３６まで到達することを防止している。   Similarly to the seal ring 11, when the elastic material 21 is vulcanized and formed on the core metal 20 of the seal ring 17 constituting the combined seal ring 12, the core metal 20 is pressed and positioned in the mold. Is formed in the elastic member 21 that covers the inner side surface in the axial direction of the stationary-side annular ring portion 24. The recess 36 passes through the elastic member 21 covering the inner side surface in the axial direction of the stationary ring portion 24 in the axial direction, and the surface of the cored bar 20 is exposed at the bottom surface (the inner side surface in the axial direction). . Then, in the small space 35 near the opening opposite to the inner diameter side of the auxiliary seal lip 32, a recess 36 is provided between the base end portion of the seal lip 22 a that is a seal lip close to the external space and the base end portion of the auxiliary seal lip 32. By providing this, moisture or the like in the external space is prevented from reaching the recess 36.

尚、グリースと泥とが混ざり合って前記補助シールリップ３２に付着することを防止する為に、補助シールリップ３２の外周面及び段差面３０には、グリース等の潤滑剤は塗布されていない。
又、前記シールリップ２２ａ〜２２ｃには、回転トルク低減とシール性維持の為に潤滑用のグリースを塗布する必要があるが、塗布するグリースは、前記軸受内部空間１０に充填された潤滑用のグリースと同一組成（基油と増ちょう剤が同一の種類）としている。これにより、シールリップ２２ａ〜２２ｃに塗布されたグリースと、軸受内部空間１０に充填されたグリースとが混合した場合でも、潤滑性能が劣化する事を回避している。また、撥水性に優れるウレア系のグリースであれば、補助シールリップ３２へ漏洩しても泥水と混合して補助シールリップ３２に付着しないので、シールリップ２２ａ〜２２ｃに塗布する事ができる（含水しやすい金属石鹸系のグリースは好ましくない）。 In order to prevent the grease and mud from mixing and adhering to the auxiliary seal lip 32, a lubricant such as grease is not applied to the outer peripheral surface and the step surface 30 of the auxiliary seal lip 32.
The seal lips 22a to 22c must be lubricated with grease for reducing rotational torque and maintaining sealing performance. The grease to be applied is used for lubrication filled in the bearing internal space 10. It has the same composition as grease (base oil and thickener are the same type). Thereby, even when the grease applied to the seal lips 22a to 22c and the grease filled in the bearing internal space 10 are mixed, deterioration of the lubricating performance is avoided. In addition, urea-based grease having excellent water repellency can be applied to the seal lips 22a to 22c because it mixes with muddy water and does not adhere to the auxiliary seal lip 32 even if it leaks to the auxiliary seal lip 32. Metal soap grease that is easy to do is not preferable.

上述の様に構成する組み合わせシールリング１２を組み込んだ、本実施形態の車輪支持用転がり軸受ユニット１によれば、前記スリンガ１６と前記シールリング１７との間に存在するシール内部空間２６への、泥水等の異物の侵入を効果的に防止できる。
特に、本実施形態の構造によれば、前記各シールリップ２２ａ〜２２ｃのうちで、最も前記ラビリンスシール２７に近い部分に存在するシールリップ２２ａの外周面に異物が付着し、このシールリップ２２ａの挙動が損なわれ、このシールリップ２２ａのシール性能が低下する事を防止できる。 According to the wheel support rolling bearing unit 1 of this embodiment in which the combination seal ring 12 configured as described above is incorporated, the seal inner space 26 existing between the slinger 16 and the seal ring 17, Intrusion of foreign matter such as muddy water can be effectively prevented.
In particular, according to the structure of the present embodiment, foreign matter adheres to the outer peripheral surface of the seal lip 22a present in the portion closest to the labyrinth seal 27 among the seal lips 22a to 22c. It is possible to prevent the behavior from being impaired and the sealing performance of the seal lip 22a from being deteriorated.

近年、懸架装置を構成するナックルは軽量化が図られており、前記静止側フランジ８により外輪２をナックル（不図示）に結合固定する構成に於いては、外輪２の外周面と除肉されたナックルの内周面との間に隙間が存在する場合がある。この様な構成においては、泥水等の異物が前記隙間を通過して容易に外輪２の外周面に到達するので、軸受内部空間１０の端部を塞ぐシール装置は厳しい泥水環境に晒されるが、シールの密封能力を向上させた本発明の車輪支持用転がり軸受ユニット１であれば好適に使用することができる。   In recent years, the knuckle constituting the suspension device has been reduced in weight. In the configuration in which the outer ring 2 is coupled and fixed to the knuckle (not shown) by the stationary flange 8, the outer ring 2 is thinned. There may be a gap between the inner peripheral surface of the knuckle. In such a configuration, since foreign matter such as muddy water easily passes through the gap and reaches the outer peripheral surface of the outer ring 2, the sealing device that closes the end of the bearing inner space 10 is exposed to a severe muddy water environment. If it is the rolling bearing unit 1 for wheel support of this invention which improved the sealing capability of a seal | sticker, it can be used conveniently.

又、鉄等から成るナックルに代えて、アルミニウム合金製のナックルを採用する事で懸架装置の軽量化を図る場合がある。このアルミニウム合金製ナックルに車輪支持用転がり軸受ユニットの外輪２を結合固定した場合、外輪２とナックルとの接触面に雨水等の水分がかかると、電食が発生する。従って、このような組み合わせに於いて使用される外輪では、ナックルと接触する部分（外輪２の外周面及び静止側フランジ８）に、メッキ、或は絶縁処理（例えば塗装や化成処理）を施す事で、電食の発生を防止している。しかし、車輪により跳ね上げられた飛び石等が衝突して、アルミニウム合金製のナックルの表面が傷付き腐食すると、アルカリ化した水と酸化アルミニウム（白錆）粉が発生する。このアルカリ性の水は、シールリングの芯金に弾性材を接合固定している加硫接着剤の接着層を破壊する傾向がある。特に、前述した様な、シールリング（１７及び１１）に弾性材（２１及び１４）を加硫成形する時に芯金を押さえる為の凹部（３６及び５８）に、アルカリ性の水が付着すると、弾性材と芯金の界面剥離を引き起こすおそれがある。又、酸化アルミニウム（白錆）粉は硬く、狭い部分に溜まると固化するので、シールリップを摩耗させる、或はシールリップの近傍で固まり、シールリップの動きを阻害するおそれがある。   In some cases, the weight of the suspension device can be reduced by using an aluminum alloy knuckle instead of a knuckle made of iron or the like. When the outer ring 2 of the wheel support rolling bearing unit is coupled and fixed to the aluminum alloy knuckle, if water such as rainwater is applied to the contact surface between the outer ring 2 and the knuckle, electrolytic corrosion occurs. Therefore, in the outer ring used in such a combination, plating or insulation treatment (for example, coating or chemical conversion treatment) is applied to the portions that contact the knuckle (the outer peripheral surface of the outer ring 2 and the stationary flange 8). Therefore, the occurrence of electric corrosion is prevented. However, when a stepping stone or the like jumped up by a wheel collides and the surface of an aluminum alloy knuckle is damaged and corroded, alkalized water and aluminum oxide (white rust) powder are generated. This alkaline water tends to destroy the adhesive layer of the vulcanized adhesive that bonds and fixes the elastic material to the core metal of the seal ring. In particular, when alkaline water adheres to the recesses (36 and 58) for holding the cored bar when the elastic materials (21 and 14) are vulcanized and formed on the seal rings (17 and 11) as described above, There is a risk of causing interface peeling between the material and the cored bar. Further, the aluminum oxide (white rust) powder is hard and solidifies when it accumulates in a narrow portion, so that the seal lip may be worn out or hardened in the vicinity of the seal lip, thereby hindering the movement of the seal lip.

本実施形態において、軸受内部空間１０の軸方向外側開口を密封する前記シールリング１１の場合、各シールリップ間の空間は比較的広いので、酸化アルミニウム粉が固まり、シールリップの動きを阻害するおそれは少ない。更に、ラビリンスリップ５１の外周面を先端部に向かうに従い大径となる部分円すい面形状とすると共に、外輪２の軸方向外端部に止水部５７及び堤部５６を設ける事により、アルミニウム合金製ナックルからのアルカリ性の水が、外輪２の外周面を伝わって、ラビリンスリップ５１の内径側に形成された凹部５８に到達することを防止している。
一方、軸受内部空間１０の軸方向内側開口を密封する組み合わせシールリング１２の場合、各シールリップ間の間隔が狭く、シールリップ間の空間が狭いので、酸化アルミニウム粉が固まり、シールリップ２２ａの動きを阻害する虞がある。しかし、外部空間寄りのシールリップ２２ａの外径側に、先端部に向かうに従い大径となる部分円すい面形状の補助シールリップ３２を設ける事で、ラビリンスシール２７を通過して開口寄り小空間３４に浸入したアルカリ性の水や酸化アルミニウム粉は、補助シールリップ３２の根元側に誘導された後、下部側に流され、固定側円筒部２３の内周面を覆う弾性材２１に沿って（下部側のラビリンスシール２７を通過して）外部空間に排出される。従って、アルミニウム合金製ナックルからのアルカリ性の水が、補助シールリップ３２の内径側に形成された凹部３６に到達したり、酸化アルミニウム粉がシールリップ２２ａに固着することを防止している。 In the present embodiment, in the case of the seal ring 11 that seals the axially outer opening of the bearing internal space 10, the space between the seal lips is relatively wide, so that the aluminum oxide powder is solidified and obstructs the movement of the seal lip. That is less. Further, the outer peripheral surface of the labyrinth slip 51 is formed into a partial conical surface shape having a diameter increasing toward the tip portion, and a water stop portion 57 and a bank portion 56 are provided at the outer end portion in the axial direction of the outer ring 2 to thereby form an aluminum alloy. Alkaline water from the knuckle made of the product is prevented from reaching the recess 58 formed on the inner diameter side of the labyrin slip 51 through the outer peripheral surface of the outer ring 2.
On the other hand, in the case of the combined seal ring 12 that seals the axially inner opening of the bearing internal space 10, the space between the seal lips is narrow and the space between the seal lips is narrow, so that the aluminum oxide powder is solidified and the seal lip 22a moves. May be disturbed. However, by providing an auxiliary seal lip 32 having a partially conical surface shape that increases in diameter toward the distal end on the outer diameter side of the seal lip 22a near the outer space, the small space 34 near the opening passes through the labyrinth seal 27. Alkaline water and aluminum oxide powder that has entered the base are guided to the base side of the auxiliary seal lip 32 and then flowed to the lower side along the elastic material 21 that covers the inner peripheral surface of the fixed-side cylindrical portion 23 (lower part). It passes through the labyrinth seal 27 on the side and is discharged into the external space. Accordingly, alkaline water from the aluminum alloy knuckle prevents the water from reaching the recess 36 formed on the inner diameter side of the auxiliary seal lip 32 and prevents the aluminum oxide powder from adhering to the seal lip 22a.

又、アルミニウム合金製のホイールが回転側フランジ９に結合固定される場合は、少なくともハブ３の軸方向外端部に設けられたパイロット部４０に、外輪２と同様のメッキ、或は絶縁処理を施す必要がある。そして、飛び石等によりアルミニウム合金製のホイールが傷付き腐食すると、アルミニウム合金製ナックルと同様の問題が発生する虞があるので、本実施形態の様に、補助シールリップ３２を備えた組み合わせシールリング１２とラビリンスリップ５１を備えたシールリング１１とを組み合わせたシール装置の構成が好ましい。   In addition, when an aluminum alloy wheel is coupled and fixed to the rotation side flange 9, at least the pilot portion 40 provided at the outer end in the axial direction of the hub 3 is subjected to the same plating or insulation treatment as the outer ring 2. It is necessary to apply. Then, if the aluminum alloy wheel is scratched and corroded by stepping stones or the like, the same problem as the aluminum alloy knuckle may occur. Therefore, as in this embodiment, the combination seal ring 12 having the auxiliary seal lip 32 is provided. And a seal device 11 in which the seal ring 11 provided with the labyrin slip 51 is combined.

［第２実施形態］
図４〜５は、本発明の第２実施形態を示している。本実施形態の車輪支持用転がり軸受ユニット１ａは、軸受ユニットの大型化を防止しつつ、より大きなモーメント剛性を確保する為に、両列の転動体のピッチ円直径（ＰＣＤ）を異ならせた構造（以下、異径ＰＣＤ構造）としている。即ち、外輪２ａは、内周面に第１の外輪軌道４ａ、第２の外輪軌道４ｂを、それぞれ形成しており、これら両外輪軌道４ａ、４ｂのうち、軸方向外側の第１の外輪軌道４ａの直径は、軸方向内側の第２の外輪軌道４ｂの直径よりも大きくしている。同様に、ハブ３ａは、外周面に第１の内輪軌道５ａ、第２の内輪軌道５ｂを、それぞれ形成しており、これら両内輪軌道５ａ、５ｂのうち、軸方向外側の第１の内輪軌道５ａの直径を、軸方向内側の第２の内輪軌道５ｂの直径よりも大きくしている。 [Second Embodiment]
4 to 5 show a second embodiment of the present invention. The wheel support rolling bearing unit 1a of the present embodiment has a structure in which the pitch circle diameters (PCD) of the rolling elements in both rows are made different in order to ensure a larger moment rigidity while preventing an increase in the size of the bearing unit. (Hereinafter, different diameter PCD structure). That is, the outer ring 2a is formed with a first outer ring raceway 4a and a second outer ring raceway 4b on the inner peripheral surface, respectively. Of these outer ring raceways 4a and 4b, the first outer ring raceway on the outer side in the axial direction. The diameter of 4a is larger than the diameter of the second outer ring raceway 4b on the inner side in the axial direction. Similarly, the hub 3a is formed with a first inner ring raceway 5a and a second inner ring raceway 5b on the outer peripheral surface, respectively. Of these inner ring raceways 5a and 5b, the first inner ring raceway outside in the axial direction. The diameter of 5a is made larger than the diameter of the second inner ring raceway 5b on the inner side in the axial direction.

そして、前記第１の外輪軌道４ａと前記第１の内輪軌道５ａとの間に転動体６ａを、前記第２の外輪軌道４ｂと前記第２の内輪軌道５ｂとの間に転動体６ｂを、それぞれ複数個ずつ設けている。これら複列に配置された各転動体６ａ、６ｂには、予圧と共に背面組み合わせ型の接触角を付与している。又、これら両列の転動体６ａ、６ｂのピッチ円直径は、前記第１、第２の外輪軌道４ａ、４ｂ及び前記第１、第２の内輪軌道５ａ、５ｂの直径の差に応じて互いに異なっている。即ち、軸方向外側の列の転動体６ａ（外側列）のピッチ円直径が、軸方向内側の列の転動体６ｂ（内側列）のピッチ円直径よりも大きくなっている。尚、図示の例では、これら各転動体６ａ、６ｂとして玉を使用しているが、重量の嵩む自動車用の車輪支持用転がり軸受ユニットの場合には、例えば円すいころを使用する場合もある。   A rolling element 6a is provided between the first outer ring raceway 4a and the first inner ring raceway 5a, and a rolling element 6b is provided between the second outer ring raceway 4b and the second inner ring raceway 5b. A plurality of each is provided. The rolling elements 6a and 6b arranged in a double row are provided with a contact angle of the back combination type together with the preload. Further, the pitch circle diameters of the rolling elements 6a and 6b in both rows are mutually different according to the difference in diameter between the first and second outer ring raceways 4a and 4b and the first and second inner ring raceways 5a and 5b. Is different. That is, the pitch circle diameter of the rolling elements 6a (outer row) in the outer row in the axial direction is larger than the pitch circle diameter of the rolling elements 6b (inner row) in the inner row in the axial direction. In the illustrated example, balls are used as the rolling elements 6a and 6b. However, in the case of a rolling bearing unit for supporting a wheel for an automobile, which is heavy in weight, for example, a tapered roller may be used.

又、本実施形態の車輪支持用転がり軸受ユニット１ａは駆動輪用であるので、ハブ３ａの中心部にスプライン孔４１を設け、等速ジョイント用外輪４２の軸方向外端面に固設した駆動軸であるスプライン軸４３を係合している。そして、自動車への組み付け時には、スプライン軸４３をスプライン孔４１に係合させると共に、このスプライン軸４３の先端部に設けた雄ねじ部にナット４４を螺合し、更に締め付けてスプライン軸の先端部に固設する事により、ハブ３ａを、等速ジョイント用外輪４２とナット４４との間で強く挟持し、これらハブ３ａと等速ジョイント用外輪４２とを結合固定する。   Further, since the wheel support rolling bearing unit 1a of the present embodiment is for a drive wheel, a drive shaft provided with a spline hole 41 in the center of the hub 3a and fixed to the outer end surface in the axial direction of the outer ring 42 for the constant velocity joint. The spline shaft 43 is engaged. At the time of assembly to the automobile, the spline shaft 43 is engaged with the spline hole 41, and a nut 44 is screwed into a male screw portion provided at the tip portion of the spline shaft 43, and further tightened to the tip portion of the spline shaft. By fixing, the hub 3a is firmly held between the constant velocity joint outer ring 42 and the nut 44, and the hub 3a and the constant velocity joint outer ring 42 are coupled and fixed.

上述の様な、両列の転動体６ａ、６ｂのピッチ円直径を異ならせた車輪支持用転がり軸受ユニット１ａの場合には、外側列のピッチ円直径を大きくできる分、モーメント剛性を大きくして、旋回走行時の走行安定性向上と、車輪支持用転がり軸受ユニット１ａの耐久性向上とを図る為の設計が容易になる。又、内側列のピッチ円直径を大きくする必要がないので、懸架装置の一部（ナックルの取付孔）を特に大径化する必要はなく、ナックルの軽量化を図れる。従って、懸架装置部分等を特に大型化しなくても、走行安定性、並びに、耐久性向上を図れる。又、外側列の転動体６ａの個数を内側列の転動体６ｂの個数よりも多くできる分、外側列の軸受の剛性、延いては、軸受ユニット全体としての剛性を向上させる事ができる。   In the case of the wheel support rolling bearing unit 1a in which the pitch circle diameters of the rolling elements 6a and 6b of both rows are different as described above, the moment stiffness is increased by the amount that the pitch circle diameter of the outer row can be increased. Thus, the design for improving the running stability during turning and the durability of the wheel bearing rolling bearing unit 1a is facilitated. Further, since it is not necessary to increase the pitch circle diameter of the inner row, it is not necessary to increase the diameter of a part of the suspension device (knuckle mounting hole), and the weight of the knuckle can be reduced. Therefore, it is possible to improve running stability and durability without particularly increasing the size of the suspension device portion. Further, since the number of the rolling elements 6a in the outer row can be made larger than the number of the rolling elements 6b in the inner row, the rigidity of the bearings in the outer row, that is, the rigidity of the entire bearing unit can be improved.

本実施形態の場合には、図５に示す様に、スリンガ１６を構成する回転側円輪部１９の軸方向内側面に、ゴム、合成樹脂等の高分子材料中に磁性粉を分散させて全体を円輪状として成る永久磁石製のエンコーダ２５を、全周に亙り添着している。このエンコーダ２５は、回転側円輪部１９の先端側周縁（外周縁）を覆い、更に、回転側円輪部１９の外周縁を越えて、シールリング１７ａの芯金２０を構成する静止側円輪部２４の側に向け全周に亙り突出させて、環状の突条３７を形成している。この突条３７の内周面は、先端縁に向かう程（軸方向外側程）内径が大きくなる方向に傾斜した、部分円すい面形状の傾斜面としている。そして、突条３７の外周面を含むエンコーダ２５の外周面と静止側円筒部２３の内周面（に被覆した弾性材２１ａの一部）との間に、ラビリンスシール２７ａを構成している。又、シールリング１７ａを構成する弾性材２１ａの一部で、芯金２０を構成する静止側円筒部２３の内周面を覆い、エンコーダ２５の外径端縁及び突条３７の外周面と近接対向してラビリンスシール２７ａを形成する部分を、静止側円輪部２４側に向かう程内径が小さくなる方向に傾斜した、部分円すい面状の傾斜面としている。   In the case of the present embodiment, as shown in FIG. 5, magnetic powder is dispersed in a polymer material such as rubber or synthetic resin on the inner surface in the axial direction of the rotating-side circular ring portion 19 constituting the slinger 16. An encoder 25 made of a permanent magnet having a ring shape as a whole is attached around the entire circumference. The encoder 25 covers the distal end side peripheral edge (outer peripheral edge) of the rotating side annular ring portion 19 and further exceeds the outer peripheral edge of the rotating side circular ring portion 19 so as to constitute the core metal 20 of the seal ring 17a. An annular ridge 37 is formed so as to protrude over the entire circumference toward the ring portion 24. The inner peripheral surface of the ridge 37 is an inclined surface having a partial conical surface shape that is inclined in a direction in which the inner diameter increases toward the tip edge (outward in the axial direction). A labyrinth seal 27 a is formed between the outer peripheral surface of the encoder 25 including the outer peripheral surface of the protrusion 37 and the inner peripheral surface of the stationary-side cylindrical portion 23 (a part of the elastic material 21 a covered with the encoder). Further, a part of the elastic material 21 a constituting the seal ring 17 a covers the inner peripheral surface of the stationary side cylindrical portion 23 constituting the core metal 20, and close to the outer diameter end edge of the encoder 25 and the outer peripheral surface of the protrusion 37. The part which forms the labyrinth seal 27a so as to face each other is a partially conical inclined surface inclined in a direction in which the inner diameter becomes smaller toward the stationary-side circular ring part 24 side.

この様な本実施形態の組み合わせシールリング１２ａの構造によれば、ラビリンスシール２７ａの軸方向の長さを、突条３７の軸方向に関する高さ分を含むエンコーダ２５の厚さ分だけ幅広くできるので、シール効果を高める事ができる。更に、剪断面である回転側円輪部１９の先端側周縁（外周縁）をエンコーダ２５により覆い、表面粗さを向上させて滑らかな表面としているので、ラビリンスシール２７ａの内面部分に泥が引っかかり堆積する事を防止できる。更に、突条３７は、補助シールリップ３２と回転側円輪部１９の軸方向外側面との摺接部若しくは近接対向部を覆う様に突出しているので、車輪が跳ね上げた泥水等の飛沫が、この摺接部乃至は近接対向部に勢い良くぶつかる事を、より確実に防止できる。   According to the structure of the combination seal ring 12a of this embodiment, the length in the axial direction of the labyrinth seal 27a can be increased by the thickness of the encoder 25 including the height in the axial direction of the protrusion 37. The sealing effect can be enhanced. Furthermore, since the tip side peripheral edge (outer peripheral edge) of the rotating side circular ring portion 19 which is a shear surface is covered with the encoder 25 to improve the surface roughness and make the surface smooth, mud gets caught on the inner surface portion of the labyrinth seal 27a. Accumulation can be prevented. Furthermore, since the protrusion 37 protrudes so as to cover the sliding contact portion or the proximity facing portion between the auxiliary seal lip 32 and the axially outer side surface of the rotation-side annular ring portion 19, splashing of muddy water or the like splashed by the wheel. However, it is possible to more reliably prevent the sliding contact portion or the proximity facing portion from colliding with force.

又、静止側円筒部２３の内周面を傾斜面とし、突条３７の内周面も傾斜面とする事で、開口寄り小空間３４の内面に泥等の異物が堆積する事を、より効果的に防止できる。即ち、突条３７の内周面の傾斜面に付着した異物がスリンガ１６の回転に基づく遠心力により外部空間に送り出される際に、静止側円筒部２３の内周面（を覆う弾性材２１ａの傾斜面）に付着した異物を巻き込みながら、ラビリンスシール２７ａを通じて異物を外部空間に排出する。
更に、前記エンコーダ２５を構成する高分子材料として、撥水性が高いポリ四フッ化
エチレン樹脂（ＰＴＦＥ）等のフッ素樹脂、ポリフェニレンサルファイド樹脂（ＰＰＳ）、変性ポリアミド樹脂等を使用すれば、泥等の異物の堆積防止効果をより高められる。 Further, by making the inner peripheral surface of the stationary-side cylindrical portion 23 an inclined surface and the inner peripheral surface of the protrusion 37 also be an inclined surface, foreign matter such as mud is accumulated on the inner surface of the small space 34 near the opening. It can be effectively prevented. That is, when the foreign matter adhering to the inclined surface of the inner peripheral surface of the protrusion 37 is sent out to the external space by the centrifugal force based on the rotation of the slinger 16, the inner peripheral surface of the stationary-side cylindrical portion 23 is The foreign matter is discharged to the external space through the labyrinth seal 27a while the foreign matter adhering to the inclined surface is involved.
Further, as the polymer material constituting the encoder 25, if a fluororesin such as polytetrafluoroethylene resin (PTFE) having high water repellency, polyphenylene sulfide resin (PPS), modified polyamide resin or the like is used, mud etc. The effect of preventing foreign matter accumulation can be further enhanced.

本実施形態の様な、駆動輪用の車輪支持用転がり軸受ユニットの場合は、ハブ３ａの軸方向内端部や等速ジョイント用外輪４２等の回転体から振り切られる水分が問題となる。特に、異径ＰＣＤ構造の車輪支持用転がり軸受ユニットは、ＳＵＶ（スポーツ・ユーティリティ・ビークル）やミニバン等の比較的大型の車両に使用される為、大きな等速ジョイント用外輪４２と組み合わされて使用される。そして、車輪支持用転がり軸受ユニットの軸方向内側面と等速ジョイント用外輪４２の軸方向外側面とナックルとに囲われる空間容積が小さいので、回転体の回転により激しい回転気流が発生する。回転体に振り切られた水滴は、回転気流に乗って回転し、一部はラビリンスシール２７ａを通過して、補助シールリップ３２の外周面に小さな交角で衝突するが、衝突時の力の径方向分力は小さく、補助シールリップ３２の変形は僅かである。この様に、シール性能を向上させた本実施形態の組み合わせシールリング１２ａは、異径ＰＣＤ構造を有する駆動輪用の車輪支持用転がり軸受ユニットに好適に使用できる。
その他の部分の構成及び作用は、前述した第１実施形態と同様であるから、同等部分には同一符号を付して、重複する説明を省略する。 In the case of a wheel support rolling bearing unit for driving wheels as in the present embodiment, moisture that is shaken off from a rotating body such as the axially inner end of the hub 3a or the constant velocity joint outer ring 42 becomes a problem. In particular, the rolling bearing unit for wheel support with different diameter PCD structure is used in combination with a large constant velocity joint outer ring 42 because it is used for relatively large vehicles such as SUVs (Sports Utility Vehicles) and minivans. Is done. And since the space volume enclosed by the axial inner surface of the wheel bearing rolling bearing unit, the axial outer surface of the constant velocity joint outer ring 42, and the knuckle is small, intense rotating air current is generated by the rotation of the rotating body. The water droplets shaken off by the rotating body rotate in a rotating air current, and partly pass through the labyrinth seal 27a and collide with the outer peripheral surface of the auxiliary seal lip 32 at a small angle of intersection. The component force is small, and the deformation of the auxiliary seal lip 32 is slight. Thus, the combination seal ring 12a of the present embodiment with improved sealing performance can be suitably used for a wheel support rolling bearing unit for a drive wheel having a different diameter PCD structure.
Since the configuration and operation of the other parts are the same as those in the first embodiment described above, the same parts are denoted by the same reference numerals, and redundant description is omitted.

［第３実施形態］
図６〜８は、本発明の第３実施形態を示している。本実施形態は従動輪用の車輪支持用転がり軸受ユニット１ｂである為、ハブ本体３ｂが中実体である。又、前述した第２実施形態と同様に、両列の転動体のピッチ円直径を異ならせた異径ＰＣＤ構造としているが、組み合わせシールリング１２ｂ及び回転側フランジ９へホイールを取付ける構造が異なっている。
本実施形態の車輪支持用転がり軸受ユニット１ｂに組み込む組み合わせシールリング１２ｂの場合には、図７に示す様に、弾性材２１ｂの一部に設けた厚肉部２９ａの径方向中間部の円周方向複数箇所に、それぞれがこの厚肉部２９ａの軸方向内端面に開口する凹部３８を形成している。円周方向に関してこれら各凹部３８同士の間部分、並びに、これら各凹部３８よりも径方向内方に位置する、厚肉部２９ａの径方向内端部の厚さ寸法は、補助シールリップ３２ａの基端部の厚さ寸法とほぼ同じとしている。そして、この補助シールリップ３２ａの基端部を、厚肉部２９ａの軸方向内端面のうちの径方向内端部に位置させている。 [Third Embodiment]
6 to 8 show a third embodiment of the present invention. Since this embodiment is a wheel bearing rolling bearing unit 1b for a driven wheel, the hub body 3b is a solid body. In addition, as in the second embodiment described above, the PCD structure has different diameters with different pitch circle diameters of the rolling elements in both rows, but the structure for attaching the wheel to the combined seal ring 12b and the rotation side flange 9 is different. Yes.
In the case of the combination seal ring 12b incorporated in the wheel supporting rolling bearing unit 1b of the present embodiment, as shown in FIG. 7, the circumference of the radial intermediate portion of the thick portion 29a provided in a part of the elastic member 21b. Concave portions 38 that open to the inner end surface in the axial direction of the thick portion 29a are formed at a plurality of locations in the direction. The thickness dimension of the inner end portion in the radial direction of the thick portion 29a located between the concave portions 38 in the circumferential direction and radially inward of the concave portions 38 is determined by the thickness of the auxiliary seal lip 32a. The thickness is almost the same as the thickness of the base end. And the base end part of this auxiliary seal lip 32a is located in the radial direction inner end part among the axial direction inner end surfaces of the thick part 29a.

この様な本実施形態の場合は、前記各凹部３８を設ける分、前記補助シールリップ３２ａとラビリンスシール２７ｂとの間に存在する、開口寄り小空間３４ａの容積を大きくできる。この為、ラビリンスシール２７ｂを通過して開口寄り小空間３４ａ内に入り込んだ異物の勢いを弱める効果が大きくなる。この結果、この異物が補助シールリップ３２ａの先端縁と回転側円輪部１９の軸方向外側面との係合部を通過するのを抑える効果が大きくなる。
又、前記弾性材２１ｂの射出成形時に、補助シールリップ３２ａの基端部が連続している厚肉部２９ａの収縮量を抑えて、射出成形後、この補助シールリップ３２ａの形状の歪みを可及的僅少に抑える様にしている。 In the case of this embodiment as described above, the volume of the small space 34a close to the opening existing between the auxiliary seal lip 32a and the labyrinth seal 27b can be increased by the provision of the respective recesses 38. For this reason, the effect of weakening the momentum of the foreign matter that has passed through the labyrinth seal 27b and entered into the small opening 34a is increased. As a result, the effect of suppressing the foreign matter from passing through the engaging portion between the tip edge of the auxiliary seal lip 32a and the outer side surface in the axial direction of the rotation-side annular ring portion 19 is increased.
Further, during the injection molding of the elastic material 21b, the shrinkage amount of the thick portion 29a where the base end portion of the auxiliary seal lip 32a is continuous is suppressed, and the shape of the auxiliary seal lip 32a can be distorted after the injection molding. I try to keep it as small as possible.

即ち、前記弾性材２１ｂを構成するゴム材料は、射出成形後に１．２〜３．５％程度収縮する、所謂引けが発生する。この為、前記第１〜２実施形態の様に、補助シールリップ３２の基端部を厚肉部２９部分に位置させると、厚肉部２９の引けの影響で、補助シールリップ３２の形状が歪む可能性がある。そして、歪んだ場合には、補助シールリップ３２の先端縁と、スリンガ１６の回転側円輪部１９の軸方向外側面との係合部の状態が不安定になり、この係合部のシール性が不安定になり易い。具体的には、前記シールリング１７の中心軸に対する補助シールリップ３２の傾斜角度が小さくなり（補助シールリップ３２が立ち）、補助シールリップ３２の先端縁が大きく折れ曲がった状態で回転側円輪部１９の軸方向外側面と広い面積で接触する、所謂腹当たりの状態になり易く、安定したシール性能を得難くなる。又、単純に厚肉部２９を無くし、その分補助シールリップを長くすると、補助シールリップの剛性が過度に低下して、やはり安定したシール性能を得難くなる。尚、補助シールリップを長くした分、必要な剛性を確保すべく補助シールリップの厚さを大きくすると、補助シールリップの先端縁と回転側円輪部の軸方向外側面との係合部の面圧が上昇して、車輪支持用転がり軸受ユニットの動トルクが大きくなる。   In other words, the rubber material constituting the elastic material 21b shrinks by about 1.2 to 3.5% after injection molding, so-called shrinkage occurs. For this reason, when the base end portion of the auxiliary seal lip 32 is positioned at the thick portion 29 as in the first and second embodiments, the shape of the auxiliary seal lip 32 is affected by the shrinkage of the thick portion 29. There is a possibility of distortion. In the case of distortion, the state of the engagement portion between the tip edge of the auxiliary seal lip 32 and the outer surface in the axial direction of the rotation-side annular ring portion 19 of the slinger 16 becomes unstable. Tend to be unstable. Specifically, the angle of inclination of the auxiliary seal lip 32 with respect to the central axis of the seal ring 17 is reduced (the auxiliary seal lip 32 stands up), and the rotation-side annular portion is bent in a state where the tip edge of the auxiliary seal lip 32 is bent greatly. It is easy to be in a so-called belly contact state with a large area in contact with the 19 axial outer side surface, and it becomes difficult to obtain a stable sealing performance. Further, if the thick-walled portion 29 is simply eliminated and the auxiliary seal lip is lengthened correspondingly, the rigidity of the auxiliary seal lip is excessively lowered, and it becomes difficult to obtain stable sealing performance. In addition, if the thickness of the auxiliary seal lip is increased in order to ensure the required rigidity by increasing the length of the auxiliary seal lip, the engagement portion between the tip edge of the auxiliary seal lip and the axially outer surface of the rotating side annular ring portion The surface pressure increases, and the dynamic torque of the wheel supporting rolling bearing unit increases.

これに対して本実施形態の構造によれば、前記厚肉部２９ａの径方向中間部の円周方向複数箇所に、それぞれがこの厚肉部２９ａの軸方向内端面に開口する凹部３８を形成している。従って、前記弾性材２１ｂのうちで補助シールリップ３２ａの基端部が連続している部分の厚さ寸法を小さくできる。この結果、この部分に生じる引けの程度を低減して、補助シールリップ３２ａの形状の歪みを低減し、補助シールリップ３２ａの先端縁と、スリンガ１６の回転側円輪部１９の軸方向外側面との係合部の状態を安定させて、この係合部のシール性を良好にできる。   On the other hand, according to the structure of the present embodiment, the concave portions 38 that open to the inner end surface in the axial direction of the thick portion 29a are formed at a plurality of locations in the circumferential direction of the radially intermediate portion of the thick portion 29a. doing. Therefore, the thickness dimension of the portion of the elastic material 21b where the base end portion of the auxiliary seal lip 32a is continuous can be reduced. As a result, the degree of shrinkage occurring in this portion is reduced, the distortion of the shape of the auxiliary seal lip 32a is reduced, the tip edge of the auxiliary seal lip 32a, and the axially outer side surface of the rotation-side annular portion 19 of the slinger 16 The state of the engaging portion can be stabilized, and the sealing performance of the engaging portion can be improved.

又、前記補助シールリップ３２ａの先端縁のうちで、スリンガ１６の回転側円輪部１９の軸方向外側面に摺接する部分の周方向に関する形状を、凹凸形状とし、補助シールリップ３２ａの先端縁を回転側円輪部１９に、周方向に関して間欠的に摺接させている。
前記先端縁の凹凸形状は特に問わない。例えば、図８（Ａ）に示す様な、矩形の凹部と突部とを交互に連続させる形状、（Ｂ）に示す様なサインカーブ状の波形形状、（Ｃ）に示す様な片端縁の形状のみを波形とした形状等を採用できる。何れの形状を採用した場合でも、前記先端縁のうちの各凸部のみが回転側円輪部１９の軸方向外側面と摺接し、各凹部とこの軸方向外側面との間には多数の微小隙間が、円周方向に関して間欠的に存在する状態となる。 In addition, of the tip edge of the auxiliary seal lip 32a, the shape in the circumferential direction of the portion slidably contacting the axially outer surface of the rotation-side annular ring portion 19 of the slinger 16 is an uneven shape, and the tip edge of the auxiliary seal lip 32a Are intermittently brought into sliding contact with the rotation-side annular ring portion 19 in the circumferential direction.
The uneven shape of the tip edge is not particularly limited. For example, as shown in FIG. 8 (A), a rectangular concave portion and a protruding portion are alternately continuous, a sine curve waveform shape as shown in (B), and one end edge as shown in (C). A shape having only a shape as a waveform can be adopted. Regardless of which shape is adopted, only the convex portions of the front end edge are in sliding contact with the outer surface in the axial direction of the rotation-side annular ring portion 19, and there are a large number between the concave portions and the outer surface in the axial direction. A minute gap is intermittently present in the circumferential direction.

この様な構成を採用する事により、仮に反開口寄り小空間３５内に泥水等の異物が入り込んだ場合でも、この異物を排出し易い。即ち、例えば前述の図２に示した第１実施形態では、補助シールリップ３２が回転側円輪部１９の軸方向外側面に軽く摺接している。従って、反開口寄り小空間３５内に泥水等の異物が入り込む可能性を否定できず、仮に入り込んだ場合には外部に排出し難い。これに対して本例の場合には、補助シールリップ３２ａの先端縁を凹凸形状にする事により、この先端縁と摺接面との間に多数の微小通路を設けられる。そして、これら各微小通路を通じて、反開口寄り小空間３５内に入り込んだ異物を、回転側円輪部１９の回転に伴う振り切り効果との兼ね合いで、外部空間に排出できる。この為、長期間に亙る使用によっても、反開口寄り小空間３５内に多量の異物が溜まる事を防止できて、組み合わせシールリング１２ｂの機能を長期間に亙り維持できる。   By adopting such a configuration, even if foreign matter such as muddy water enters the small space 35 near the opposite opening, the foreign matter can be easily discharged. That is, for example, in the first embodiment shown in FIG. 2 described above, the auxiliary seal lip 32 is lightly slidably in contact with the axially outer side surface of the rotation-side annular ring portion 19. Therefore, the possibility that foreign matter such as muddy water enters the small space 35 close to the opening cannot be denied, and if it enters temporarily, it is difficult to discharge it to the outside. On the other hand, in the case of this example, by making the front end edge of the auxiliary seal lip 32a uneven, a large number of minute passages can be provided between the front end edge and the sliding contact surface. Then, the foreign matter that has entered the small space 35 near the anti-opening through each of these micro passages can be discharged into the external space in balance with the swing-off effect associated with the rotation of the rotation-side circular ring portion 19. For this reason, even when used over a long period of time, it is possible to prevent a large amount of foreign matter from accumulating in the small space 35 near the opening, and the function of the combined seal ring 12b can be maintained over a long period of time.

又、前述した各実施形態とは異なり、本実施形態における回転側フランジ９には。前述したスタッド６３の代わりに、内周面に雌ねじが形成された複数のねじ孔６４が設けられている。車輪を構成するホイール（図示せず）を回転側フランジ９に固定する場合には、各ねじ孔６４とホイールの固定用貫通孔とを整合させた状態で、固定用のボルトをホイール側から挿入してねじ孔６４に螺合し、さらに締め付ける。本構造の場合は、スタッドの頭部が回転側フランジ９の軸方向内側面に存在しないので、シールリング１１のラビリンスリップ５１の径方向位置の制約が緩和され、ラビリンスリップ５１をより好適に使用できる。   Moreover, unlike each embodiment mentioned above, the rotation side flange 9 in this embodiment is provided. Instead of the stud 63 described above, a plurality of screw holes 64 in which female threads are formed on the inner peripheral surface are provided. When a wheel (not shown) constituting the wheel is fixed to the rotation side flange 9, a fixing bolt is inserted from the wheel side in a state where the screw holes 64 and the fixing through holes of the wheel are aligned. Then, it is screwed into the screw hole 64 and further tightened. In the case of this structure, since the head portion of the stud does not exist on the inner side surface in the axial direction of the rotation side flange 9, the restriction on the radial position of the labyrinth slip 51 of the seal ring 11 is relaxed, and the labyrinth slip 51 is used more suitably. it can.

ところで、車輪支持用転がり軸受ユニット１ｂを構成するハブ３ｂの軸方向外端部には、図示しないディスクロータ及びホイールをハブ３ｂに取り付ける際の中心合わせの目安となるパイロット部６５が設けられている。このパイロット部６５は、回転側フランジ９よりもさらに軸方向外側に向けて突出して略円筒形状に構成されており、その外周面に前記ディスクロータ及びホイールを嵌合させる。本実施形態においては、このパイロット部６５の外周面、軸方向内端面及び内径面には、防錆（ディスクロータ及びホイールの錆び付き防止）等を目的としてカチオン電着塗装が施されて塗装膜６６を形成している。   By the way, a pilot portion 65 is provided at the axially outer end of the hub 3b constituting the wheel support rolling bearing unit 1b, which serves as a guide for centering when attaching a disk rotor and a wheel (not shown) to the hub 3b. . The pilot portion 65 protrudes further outward in the axial direction than the rotation-side flange 9 and has a substantially cylindrical shape. The disc rotor and the wheel are fitted to the outer peripheral surface of the pilot portion 65. In the present embodiment, the outer peripheral surface, the axial inner end surface, and the inner diameter surface of the pilot portion 65 are subjected to cationic electrodeposition coating for the purpose of rust prevention (preventing rusting of the disk rotor and wheel) and the like. 66 is formed.

本実施形態で用いたカチオン電着塗装膜の形成について簡単に説明する。ハブ３ｂを油脂分を除くため脱脂洗浄等を行った後乾燥する。この乾燥したハブ３ｂに電極を付け、パイロット部６５の周面部及び内径面のみを解離可能な水溶液性塗料を展開した電着槽に浸し、電着槽中に設けられた電極との間に電圧を印加して、陽イオンにイオン化された塗料イオンをパイロット部６５の周面及び内径面に電着させる。塗装部分の見切りをよくするために、電着装置ではポンプにより電着槽内へ塗料を循環させており、電着槽からのオーバーフローを一定にすることで塗装範囲を一定に保っている。これにより塗料液面の波打ちや装置の揺れによる影響を低減している。塗装膜の電着終了後、高温で焼付け、冷却を行い電着塗装膜を硬化して塗装膜６６を完成させる。   The formation of the cationic electrodeposition coating film used in this embodiment will be briefly described. The hub 3b is degreased and washed to remove oil and fat and then dried. An electrode is attached to the dried hub 3b, and only a peripheral surface portion and an inner diameter surface of the pilot portion 65 are immersed in an electrodeposition tank in which an aqueous coating material that can be dissociated is developed, and a voltage is applied between the electrode and the electrode provided in the electrodeposition tank. Is applied, and the coating ions ionized into cations are electrodeposited on the circumferential surface and the inner diameter surface of the pilot portion 65. In order to improve the parting of the coating part, the electrodeposition apparatus circulates the paint into the electrodeposition tank by a pump, and keeps the coating range constant by keeping the overflow from the electrodeposition tank constant. As a result, the influence of the undulation of the coating liquid surface and the shaking of the device is reduced. After the electrodeposition of the coating film is completed, the electrodeposition coating film is cured by baking and cooling at a high temperature to complete the coating film 66.

このようにして作成された塗装膜６６は、塗装膜を薄く、均一に形成することが可能であり、傷、剥がれ等の危険性が少なく、防錆効果が良好である。尚、塗装膜６６は、刷毛塗り塗装や吹き付け塗装された塗料を焼き付けて作成する事も可能である。さらに、アニオン（陰イオン）塗料を用いた、アニオン電着塗装や、帯電した霧状の塗料(イオン微粒子)をハブ３ｂに付着させる静電塗装でも塗装膜６６を形成することができる。
その他の部分の構成及び作用は、第２実施形態と同様であるから、同等部分には同一符号を付して、重複する説明を省略する。 The coating film 66 produced in this way can form a coating film thinly and uniformly, has a low risk of scratches and peeling, and has a good antirust effect. The coating film 66 can also be formed by baking a paint applied by brush painting or spray painting. Furthermore, the coating film 66 can also be formed by anion electrodeposition coating using an anion (anion) coating, or electrostatic coating in which a charged mist coating (ionic fine particles) is attached to the hub 3b.
Since the configuration and operation of the other parts are the same as those of the second embodiment, the same parts are denoted by the same reference numerals, and redundant description is omitted.

本発明の車輪支持用転がり軸受ユニットは、自動車の車輪を懸架装置に対し支持する為の軸受ユニットとして実施する事が好ましい。   The rolling bearing unit for supporting a wheel of the present invention is preferably implemented as a bearing unit for supporting a vehicle wheel with respect to a suspension device.

１，１ａ，１ｂ 転がり軸受ユニット
２，２ａ 外輪
３，３ａ，３ｂ ハブ
４，４ａ，４ｂ 外輪軌道
５，５ａ，５ｂ 内輪軌道
６，６ａ，６ｂ 玉
７ 保持器
８ 静止側フランジ
９ 回転側フランジ
１０ 軸受内部空間
１１，１１ａ シールリング
１２、１２ａ，１２ｂ 組み合わせシールリング
１３ 芯金
１４ 弾性材
１５ａ、１５ｂ、１５ｃ シールリップ
１６ スリンガ
１７、１７ａ，１７ｂ シールリング
１８ 回転側円筒部
１９ 回転側円輪部
２０ 芯金
２１、２１ａ，２１ｂ 弾性材
２２ａ、２２ｂ、２２ｃ シールリップ
２３ 静止側円筒部
２４ 静止側円輪部
２５ エンコーダ
２６ シール内部空間
２７、２７ａ、２７ｂ ラビリンスシール
２８ 外部寄り空間
２９、２９ａ 厚肉部
３０ 段差面
３１ 外径側曲面
３２、３２ａ 補助シールリップ
３３ 内径側曲面
３４、３４ａ 開口寄り小空間
３５ 反開口寄り小空間
３６ 凹部
３７ 突条
３８ 凹部
４０ パイロット部
４１ スプライン孔
４２ 等速ジョイント用外輪
４３ スプライン軸
４４ ナット
５１ ラビリンスリップ
５２ 嵌合筒部
５３ 円輪部
５４ 折れ曲がり部
５５ 円筒部
５６ 堤部
５７ 止水部
５８ 凹部
５９ 突条
６０ 段部
６１ 厚肉部
６２ 薄肉部
６３ スタッド
６４ ねじ孔
６５ パイロット部
６６ 塗装膜 1, 1a, 1b Rolling bearing unit 2, 2a Outer ring 3, 3a, 3b Hub 4, 4a, 4b Outer ring raceway 5, 5a, 5b Inner ring raceway 6, 6a, 6b Ball 7 Cage 8 Stationary side flange 9 Rotation side flange 10 Bearing internal space 11, 11a Seal ring 12, 12a, 12b Combination seal ring 13 Core 14 Elastic material 15a, 15b, 15c Seal lip 16 Slinger 17, 17a, 17b Seal ring 18 Rotating side cylindrical portion 19 Rotating side annular portion 20 Core 21, 21 a, 21 b Elastic material 22 a, 22 b, 22 c Seal lip 23 Stationary side cylindrical part 24 Stationary side annular part 25 Encoder 26 Seal internal space 27, 27 a, 27 b Labyrinth seal 28 External space 29, 29 a Thick part 30 Step surface 31 Outer diameter side curved surface 32, 32a Auxiliary seal lip 33 Inner diameter side curved surface 34, 34a Small space near opening 35 Small space near counter opening 36 Recessed portion 37 Projection 38 Recessed portion 40 Pilot portion 41 Spline hole 42 Outer ring for constant velocity joint 43 Spline shaft 44 Nut 51 Labyrin slip 52 Fitting tube portion 53 Annular part 54 Bent part 55 Cylindrical part 56 Dike part 57 Water stop part 58 Recessed part 59 Projection 60 Step part 61 Thick part 62 Thin part 63 Stud 64 Screw hole 65 Pilot part 66 Coating film

Claims (1)

互いに同心に配置された状態で相対回転する回転側軌道輪及び静止側軌道輪と、これら回転側軌道輪及び静止側軌道輪の互いに対向する周面にそれぞれ設けられた回転側軌道と静止側軌道との間に転動自在に設けられた複数個の転動体と、前記回転側軌道輪と前記静止側軌道輪との互いに対向する周面同士の間に存在する軸受内部空間の端部開口を塞ぐ、スリンガ及びシールリングから成る組み合わせシールリングとを備え、
前記スリンガは、断面Ｌ字の円環形状で、回転側円筒部と、この回転側円筒部の軸方向端縁から前記静止側軌道輪に向けて径方向に折れ曲がった回転側円輪部とを備え、前記回転側円筒部を前記回転側軌道輪の周面に嵌合固定しており、
前記シールリングは、芯金と、この芯金に基端部を支持された、複数本のシールリップを有する弾性材とを備え、前記芯金は、断面Ｌ字の円環形状で、静止側円筒部と、この静止側円筒部の軸方向端縁から前記回転側軌道輪に向けて径方向に折れ曲がった静止側円輪部とを備え、前記静止側円筒部を前記静止側軌道輪の周面に嵌合固定し、前記各シールリップの先端部を、前記スリンガの表面に全周に亙り摺接させ、前記回転側円輪部の先端側周縁と前記静止側円筒部の周面との間にラビリンスシールを設けている車輪支持用転がり軸受ユニットに於いて、
前記弾性材の基部で前記各シールリップよりも前記静止側円筒部に寄った部分に、これら各シールリップのうちで、少なくとも前記ラビリンスシールに最も近いシールリップである外部空間寄りシールリップよりも剛性が低い補助シールリップを、前記弾性材と一体に設け、この補助シールリップの先端縁を前記回転側円輪部の軸方向側面に、全周に亙って摺接若しくは近接対向させ、前記各シールリップには前記軸受内部空間に充填されたグリースと同一組成或いはウレア系のグリースが塗布され、前記補助シールリップにはグリースが塗布されていない事を特徴とする車輪支持用転がり軸受ユニット。 Rotating side raceway and stationary side raceway that rotate relative to each other while being concentrically arranged, and rotation side raceway and stationary side raceway provided on the mutually opposing peripheral surfaces of the rotation side raceway and stationary side raceway, respectively. A plurality of rolling elements provided between the rotating side raceway ring and the stationary side raceway ring, and an end opening of a bearing internal space existing between the mutually opposing peripheral surfaces. A combination seal ring comprising a slinger and a seal ring for closing,
The slinger has an annular shape with an L-shaped cross section, and includes a rotation-side cylindrical portion, and a rotation-side annular portion bent in a radial direction from an axial end edge of the rotation-side cylindrical portion toward the stationary-side raceway. Provided, the rotation-side cylindrical portion is fitted and fixed to the peripheral surface of the rotation-side raceway,
The seal ring includes a cored bar and an elastic material having a plurality of seal lips supported at the base end by the cored bar. The cored bar has an annular shape with an L-shaped cross section, and is stationary. A cylindrical portion, and a stationary-side circular ring portion bent in a radial direction from the axial end edge of the stationary-side cylindrical portion toward the rotating-side raceway, and the stationary-side cylindrical portion is arranged around the stationary-side raceway. The front end of each seal lip is slidably contacted with the surface of the slinger over the entire circumference, and the peripheral edge of the front end side of the rotating side annular part and the peripheral surface of the stationary side cylindrical part In a rolling bearing unit for supporting wheels with a labyrinth seal in between,
A portion of the base of the elastic material that is closer to the stationary cylindrical portion than the seal lips is more rigid than the seal lip closer to the external space, which is at least the seal lip closest to the labyrinth seal. A low auxiliary seal lip is provided integrally with the elastic material, and the tip edge of the auxiliary seal lip is slidably contacted or closely opposed over the entire circumference on the axial side surface of the rotating side annular portion. A rolling bearing unit for supporting a wheel, wherein the seal lip is coated with grease of the same composition or urea type as the grease filled in the bearing internal space, and the auxiliary seal lip is not coated with grease.
JP2012282643A 2012-12-26 2012-12-26 Rolling bearing unit for supporting wheel Pending JP2014126105A (en)

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CN114635915B (en) * 2015-06-12 2024-05-10 Nok株式会社 Sealing device
WO2018097119A1 (en) * 2016-11-28 2018-05-31 Nok株式会社 Dust seal
JP6365806B1 (en) * 2016-11-28 2018-08-01 Nok株式会社 Dust seal
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FR3101925A1 (en) * 2019-10-15 2021-04-16 Ntn-Snr Roulements Assembly comprising a rolling assembly of a motor vehicle and a rotating guide bearing

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