JP5401997B2 - Hub unit for driving wheel support - Google Patents

Hub unit for driving wheel support Download PDF

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Publication number
JP5401997B2
JP5401997B2 JP2009003423A JP2009003423A JP5401997B2 JP 5401997 B2 JP5401997 B2 JP 5401997B2 JP 2009003423 A JP2009003423 A JP 2009003423A JP 2009003423 A JP2009003423 A JP 2009003423A JP 5401997 B2 JP5401997 B2 JP 5401997B2
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Prior art keywords
inner ring
hub
diameter
rolling element
ring raceway
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JP2010159011A (en
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直樹 満江
正 樺山
達男 若林
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NSK Ltd
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NSK Ltd
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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
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/58—Raceways; Race rings
    • 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
    • F16C35/00—Rigid support of bearing units; Housings, e.g. caps, covers
    • F16C35/04—Rigid support of bearing units; Housings, e.g. caps, covers in the case of ball or roller bearings
    • F16C35/06—Mounting or dismounting of ball or roller bearings; Fixing them onto shaft or in housing
    • F16C35/063—Fixing them on the shaft
    • F16C35/0635—Fixing them on the shaft the bore of the inner ring being of special non-cylindrical shape which co-operates with a complementary shape on the shaft, e.g. teeth, polygonal sections
    • 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
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/50—Other types of ball or roller bearings
    • F16C19/505—Other types of ball or roller bearings with the diameter of the rolling elements of one row differing from the diameter of those of another row
    • 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
    • F16C19/52—Bearings with rolling contact, for exclusively rotary movement with devices affected by abnormal or undesired conditions
    • F16C19/527—Bearings with rolling contact, for exclusively rotary movement with devices affected by abnormal or undesired conditions related to vibration and noise
    • 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
    • F16C2240/00—Specified values or numerical ranges of parameters; Relations between them
    • F16C2240/40—Linear dimensions, e.g. length, radius, thickness, gap
    • F16C2240/70—Diameters; Radii
    • F16C2240/80—Pitch circle diameters [PCD]
    • 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)
  • Support Of The Bearing (AREA)
  • Rolling Contact Bearings (AREA)

Description

この発明は、自動車の駆動輪（ＦＦ車の前輪、ＦＲ車及びＲＲ車の後輪、４ＷＤ車の全車輪）を懸架装置に対して回転自在に支持すると共に、上記駆動輪を回転駆動する為に利用する、駆動輪支持用ハブユニットの改良に関する。特に本発明は、複列に配置した転動体のピッチ円直径が互いに異なる駆動輪支持用ハブユニットで、軽量に構成でき、しかも、適切な予圧（所望の予圧）を付与し易くできる構造を実現する事を意図したものである。   The present invention supports the driving wheels of an automobile (front wheels of FF vehicles, rear wheels of FR vehicles and RR vehicles, all wheels of 4WD vehicles) rotatably with respect to a suspension system, and rotationally drives the driving wheels. The present invention relates to an improvement of a hub unit for driving wheel support used in the above. In particular, the present invention is a drive wheel support hub unit in which the pitch circle diameters of the rolling elements arranged in a double row are different from each other, and can realize a structure that can be made light weight and can easily provide an appropriate preload (desired preload). It is intended to do.

自動車の車輪及び制動用回転部材は、車輪支持用ハブユニットにより、懸架装置に対して回転自在に支持する。この様な車輪支持用ハブユニットには、自動車が旋回走行する際に大きなモーメントが加わる為、旋回走行時の安定性を確保する為には、大きなモーメント剛性を確保する必要がある。この為従来から、車輪支持用ハブユニットとして、例えば特許文献１、２等に記載されている様な、転動体を複列に配置すると共に、これら両列の転動体に、予圧並びに背面組み合わせ型（ＤＢ型）の接触角を付与した構造が、一般的に使用されている。更に近年、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、例えば特許文献３〜５に記載されている様な、両列の転動体のピッチ円直径（ＰＣＤ）を異ならせた構造（異径ＰＣＤ構造）が提案されている。   The wheel of the automobile and the rotating member for braking are rotatably supported by the suspension device by the wheel supporting hub unit. Since a large moment is applied to such a wheel support hub unit when the automobile turns, it is necessary to ensure a large moment rigidity in order to ensure stability during turning. For this reason, conventionally, as a wheel support hub unit, for example, as described in Patent Documents 1 and 2, etc., rolling elements are arranged in double rows, and both rows of rolling elements are preloaded and combined with the rear surface. A structure having a contact angle of (DB type) is generally used. Further, in recent years, the pitch circle diameters (PCD) of the rolling elements in both rows have been made different as described in Patent Documents 3 to 5, for example, in order to ensure a larger moment rigidity while preventing an increase in size. A structure (different diameter PCD structure) has been proposed.

図１２は、この様な異径ＰＣＤ構造の車輪支持用転がり軸受ユニットのうち、特許文献５に記載された、駆動輪を支持する為の駆動輪支持用ハブユニットの１例を示している。この駆動輪支持用ハブユニット１は、ハブ２と、内輪３と、外輪４と、複数個の転動体５ａ、５ｂとを備える。このうちのハブ２は、外周面の軸方向外端（軸方向に関して「外」とは、自動車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。反対に、車両の幅方向中央側となる各図の右側を、軸方向に関して「内」と言う。本明細書及び特許請求の範囲全体で同じ。）寄り部分に、車輪及び制動用回転部材を支持する為の取付フランジ６を、同じく中間部には第一の内輪軌道７ａを、同じく内端部にはこの第一の内輪軌道７ａを形成した部分よりも外径寸法が小さくなった小径段部８を、それぞれ形成している。尚、上記取付フランジ６には、複数本のスタッド９、９の基端部を圧入固定し、この取付フランジ６に、上記車輪を構成するホイール及び上記制動用回転部材を支持固定できる様にしている。   FIG. 12 shows an example of a drive wheel support hub unit for supporting a drive wheel described in Patent Document 5 among such wheel support rolling bearing units having a different diameter PCD structure. The drive wheel support hub unit 1 includes a hub 2, an inner ring 3, an outer ring 4, and a plurality of rolling elements 5a and 5b. Of these, the hub 2 is the outer end in the axial direction of the outer peripheral surface ("outside" in relation to the axial direction refers to the outside in the width direction of the vehicle when assembled to the automobile, and the left side of each figure. The right side of each figure on the center side is referred to as “inside” with respect to the axial direction.This is the same throughout the present specification and claims.) The mounting flange 6 for supporting the wheel and the rotating rotating member for braking is provided at the side portion. Similarly, a first inner ring raceway 7a is formed at the intermediate portion, and a small diameter step portion 8 having an outer diameter smaller than that of the portion where the first inner ring raceway 7a is formed is formed at the inner end portion. ing. The mounting flange 6 is press-fitted and fixed to the base end portions of a plurality of studs 9 and 9 so that the wheel constituting the wheel and the brake rotating member can be supported and fixed to the mounting flange 6. Yes.

又、上記内輪３は、外周面に第二の内輪軌道７ｂを有すると共に、上記小径段部８に外嵌している。そして、この様に内輪３を小径段部８に外嵌した状態で、この小径段部８のうちでこの内輪３の内端面から軸方向に突出した部分を、径方向外方に塑性変形させる事によりかしめ部１０を形成して上記内輪３を抑え付け、この内輪３を上記ハブ２に結合固定している。又、上記第一、第二の内輪軌道７ａ、７ｂのうち、軸方向外側の第一の内輪軌道７ａの直径を、同内側の第二の内輪軌道７ｂの直径よりも大きくしている。又、上記外輪４は、外周面に懸架装置に結合固定する為の結合フランジ１１を、内周面に第一、第二の外輪軌道１２ａ、１２ｂを、それぞれ形成している。又、これら両外輪軌道１２ａ、１２ｂのうち、軸方向外側の外輪軌道１２ａの直径は、同内側の外輪軌道１２ｂの直径よりも大きくしている。   The inner ring 3 has a second inner ring raceway 7b on the outer peripheral surface and is externally fitted to the small diameter step portion 8. Then, in a state where the inner ring 3 is externally fitted to the small-diameter step portion 8, the portion of the small-diameter step portion 8 that protrudes in the axial direction from the inner end surface of the inner ring 3 is plastically deformed radially outward. The caulking portion 10 is thereby formed to restrain the inner ring 3 and the inner ring 3 is coupled and fixed to the hub 2. Of the first and second inner ring raceways 7a and 7b, the diameter of the first inner ring raceway 7a on the outer side in the axial direction is made larger than the diameter of the second inner ring raceway 7b on the inner side. The outer ring 4 has a coupling flange 11 for coupling and fixing to a suspension device on the outer peripheral surface, and first and second outer ring raceways 12a and 12b on the inner peripheral surface, respectively. Of these outer ring raceways 12a, 12b, the diameter of the outer ring raceway 12a on the outer side in the axial direction is larger than the diameter of the outer ring raceway 12b on the inner side.

そして、上記第一、第二の各外輪軌道１２ａ、１２ｂと、上記第一、第二の各内輪軌道７ａ、７ｂとの間に、それぞれ複数個ずつの転動体５ａ、５ｂを設けている。これら複列に配置された各転動体５ａ、５ｂ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５ａ、５ｂのピッチ円直径は、上記第一、第二の内輪軌道７ａ、７ｂ及び上記第一、第二の外輪軌道１２ａ、１２ｂの直径の差に応じて互いに異なっている。即ち、軸方向外側の列の各転動体５ａ、５ａ（外側列）のピッチ円直径ＰＣＤＯＵＴが、軸方向内側の列の各転動体５ｂ、５ｂ（内側列）のピッチ円直径ＰＣＤＩＮよりも大きく（ＰＣＤＯＵＴ ＞ＰＣＤＩＮ）なっている。尚、図示の例では、これら各転動体５ａ、５ｂとして玉を使用しているが、重量の嵩む自動車用の駆動輪支持用ハブ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 plurality of rolling elements 5a and 5b are provided between the first and second outer ring raceways 12a and 12b and the first and second inner ring raceways 7a and 7b, respectively. Each rolling element 5a, 5b arranged in a double row is provided with a contact angle of a rear combination type together with a preload. Further, the pitch circle diameters of the rolling elements 5a and 5b in both rows are determined according to the difference in diameter between the first and second inner ring raceways 7a and 7b and the first and second outer ring raceways 12a and 12b. Is different. That is, the pitch circle diameter PCD OUT of each rolling element 5a, 5a (outer row) in the axially outer row is larger than the pitch circle diameter PCD IN of each rolling element 5b, 5b (inner row) in the axially inner row. It is large (PCD OUT > PCD IN ). In the illustrated example, balls are used as the rolling elements 5a and 5b. However, in the case of a driving wheel supporting hub unit for automobiles which is heavy in weight, for example, tapered rollers may be used.

又、図示の例の駆動輪支持用ハブユニット１の場合は、ハブ２の中心部にスプライン孔１３を設け、後述する本発明の実施の形態の第１例を示す図１に表す様な、等速ジョイント用外輪１４の外端面に固設した駆動軸であるスプライン軸１５を係合させられる様にしている。又、この様なハブ２の内周面のうち、上記スプライン孔１３の外端縁の周囲部分に、同じく図１に表す様な、特許請求の範囲に記載した抑え部を構成するナット１６の内側面を突き当てる為の段部１７を設けている。そして、自動車への組み付け時には、上記スプライン軸１５を上記スプライン孔１３に係合させると共に、このスプライン軸１５の先端部に設けた雄ねじ部１８（例えば図１参照）に上記ナット１６を螺合し、更に締め付けて上記スプライン軸の先端部に固設する事により、上記ハブ２を、上記等速ジョイント用外輪１４と上記ナット１６との間で強く挟持し、これらハブ２と等速ジョイント用外輪１４とを結合固定する。   In the case of the hub unit 1 for driving wheel support of the illustrated example, a spline hole 13 is provided at the center of the hub 2, and as shown in FIG. 1 showing a first example of an embodiment of the present invention to be described later. A spline shaft 15 which is a drive shaft fixed to the outer end surface of the constant velocity joint outer ring 14 can be engaged. Further, of the inner peripheral surface of the hub 2 as described above, the nut 16 constituting the holding portion described in the claims as shown in FIG. 1 is also formed around the outer edge of the spline hole 13. A step portion 17 is provided for abutting the inner surface. At the time of assembly in an automobile, the spline shaft 15 is engaged with the spline hole 13 and the nut 16 is screwed into a male screw portion 18 (see, for example, FIG. 1) provided at the tip of the spline shaft 15. The hub 2 is firmly clamped between the outer ring 14 for the constant velocity joint and the nut 16 by tightening and fixing to the tip of the spline shaft, and the hub 2 and the outer ring for the constant velocity joint. 14 and fixed.

上述の様な、両列の転動体５ａ、５ｂのピッチ円直径を異ならせた駆動輪支持用ハブユニット１の場合には、外側列のピッチ円直径ＰＣＤＯＵＴ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、駆動輪支持用ハブユニット１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ＰＣＤＩＮ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い。従って、この懸架装置部分等を特に大型化しなくても、上記走行安定性、並びに、耐久性向上を図れる。又、外側列の各転動体５ａ、５ａの数を内側列の転動体５ｂ、５ｂの数よりも多くできる分、この外側列の軸受の剛性、延いては、車輪支持用ハブ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 drive wheel support hub unit 1 in which the pitch circle diameters of the rolling elements 5a and 5b in both rows are different as described above, the moment stiffness is increased by the amount that the pitch circle diameter PCD OUT in the outer row can be increased. Thus, the design for improving the running stability during turning and the durability of the driving wheel support hub unit 1 is facilitated. Further, since it is not necessary to increase the pitch circle diameter PCD IN of the inner row, it is not necessary to increase the diameter of a part of the suspension device (knuckle mounting hole). Therefore, the traveling stability and the durability can be improved without particularly increasing the size of the suspension device. Further, since the number of the rolling elements 5a, 5a in the outer row can be made larger than the number of the rolling elements 5b, 5b in the inner row, the rigidity of the bearings in the outer row, and as a result, the wheel supporting hub unit as a whole is increased. The rigidity can be improved.

ところで、上述の様な駆動輪支持用ハブユニット１は、軽量に構成する事が、自動車のばね下荷重の低減を図り、乗り心地性や走行安定性を中心とする、この自動車の走行性能の向上を図る面からは好ましい。上述の図１２に示した駆動輪支持用ハブユニット１の場合には、必要以上にハブ２の肉厚が大きく、更なる軽量化を図る余地が残されている。又、上述の図１２に示した構造の場合には、自動車への組み付け時に、スプライン軸１５の先端部の雄ねじ部１８にナット１６（図１参照）を螺合し、更に締め付ける事により、ハブ２と等速ジョイント用外輪１４とを結合した状態で、各転動体５ａ、５ｂに付与される予圧を所望値に規制しにくくなる可能性がある。   By the way, the driving wheel supporting hub unit 1 as described above is light in weight, so that the unsprung load of the automobile is reduced, and the driving performance of the automobile is focused on ride comfort and running stability. This is preferable from the viewpoint of improvement. In the case of the driving wheel supporting hub unit 1 shown in FIG. 12 described above, the hub 2 is thicker than necessary, leaving room for further weight reduction. Further, in the case of the structure shown in FIG. 12 described above, the hub 16 is screwed into the male threaded portion 18 at the tip end portion of the spline shaft 15 and further tightened at the time of assembly to the automobile. In a state where 2 and the constant velocity joint outer ring 14 are coupled, there is a possibility that the preload applied to the rolling elements 5a and 5b may be difficult to be regulated to a desired value.

この理由は、次の通りである。即ち、かしめ部１０により内輪３の軸方向外端面を小径段部８の基端部に設けた段差面１９に抑え付ける事により、上記各転動体５ａ、５ｂに所望の予圧を付与しても、その後に行う、上記ハブ２と上記等速ジョイント用外輪１４との結合作業に伴って、上記ナット１６の締め付けに基づく軸力が、このナット１６と等速ジョイント用外輪１４の端面との間に挟まれた、上記ハブ２の内径側部分並びに内輪３に圧縮荷重（軸力）として加わる。そして、この様な圧縮荷重（軸力）に基づき、このハブ２の内径側部分並びに内輪３が弾性変形すると共に、この内輪３の軸方向に関する位置関係が変化し、上記予圧が所望値からずれる可能性がある。   The reason for this is as follows. That is, by pressing the outer end surface in the axial direction of the inner ring 3 to the stepped surface 19 provided at the base end portion of the small diameter stepped portion 8 by the caulking portion 10, even if a desired preload is applied to each of the rolling elements 5a and 5b. Then, the axial force based on the tightening of the nut 16 is caused between the nut 16 and the end face of the outer ring 14 for constant velocity joints in connection with the connecting operation of the hub 2 and the outer ring 14 for constant velocity joints thereafter. Is applied as a compressive load (axial force) to the inner diameter side portion of the hub 2 and the inner ring 3. Based on such a compressive load (axial force), the inner diameter side portion of the hub 2 and the inner ring 3 are elastically deformed, and the positional relationship in the axial direction of the inner ring 3 changes, so that the preload deviates from a desired value. there is a possibility.

特に、上述の様な両列の転動体５ａ、５ｂのピッチ円直径を異ならせた駆動輪支持用ハブユニット１の場合には、外側列の軸受部分の剛性が高い分、この剛性が低い内側列の軸受部分に、上述の様な予圧のずれに伴う影響が現れ易くなる。具体的には、この内側列の軸受部分の接触角がずれたり、各転動体５ｂ、５ｂが肩部に乗り上げ易くなる等、この内側列の軸受部分の寿命が外側列の軸受部分の寿命に比べて低下する可能性がある。しかも、この内側列の軸受部分は、一般的に寿命が短い（内側列の軸受の方が外側列の軸受に比べて元々寿命性能の点で条件が厳しい）為、この内側列の軸受部分の予圧が上述の様にずれる事は、特に好ましくない。   In particular, in the case of the drive wheel supporting hub unit 1 in which the pitch circle diameters of the rolling elements 5a and 5b in both rows as described above are different, the rigidity of the bearing portion in the outer row is high, and this inner stiffness is low. The influence due to the preload deviation as described above tends to appear in the bearing portion of the row. Specifically, the life of the bearing part in the inner row is reduced to the life of the bearing part in the outer row, for example, the contact angle of the bearing part in the inner row is shifted or each rolling element 5b, 5b can easily ride on the shoulder. There is a possibility of lowering. In addition, the bearing portion of the inner row generally has a shorter life (the inner row bearings are inherently more difficult in terms of life performance than the outer row bearings). It is not particularly preferable that the preload is shifted as described above.

尚、上記ナット１６の締め付け伴う圧縮荷重、即ち、軸力Ｆは、下記の式（１）で表せる。

Figure 0005401997
Ｔ：ナット１６の締め付けトルク［kgf・m］
ｄ２：雄ねじ部１８の有効径［mm］
β：tan−１｛（ｎ×P）／（π×ｄ２）｝
ｎ：ねじ条数（通常は１条、ｎ＝１）
P：ピッチ［mm］
ρ：tan−１（μ／cosα）
α：ねじ山の角度（半角）［drg］
ｒ：ナットの有効座幅［mm］
μ：摩擦係数 The compression load accompanying the tightening of the nut 16, that is, the axial force F can be expressed by the following equation (1).
Figure 0005401997
 T: Tightening torque of nut 16 [kgf · m]
d 2 : Effective diameter [mm] of the male screw portion 18
β: tan −1 {(n × P) / (π × d 2 )}
n: Number of screw threads (usually 1 thread, n = 1)
P: Pitch [mm]
ρ: tan −1 (μ / cos α)
α: Thread angle (half-width) [drg]
r: Effective seat width of nut [mm]
μ: Friction coefficient

前述した様なナット１６の締め付けに伴う予圧のずれを抑えるべく、上述の様な軸力Ｆが付与された状態で、上記各転動体５ａ、５ｂに所望の予圧が付与される様に、駆動輪支持用ハブユニット１の初期隙間等を予め設定する事が行われている。但し、摩擦係数μは不安定である他、雄ねじ部１８とナット１６との嵌め合い（きつさ）やバリ等の影響を受け易く、例えば上記初期隙間や締め付けトルク等を厳密に規制しても、実際に付与される軸力にばらつきを生じ易い（所望の軸力に規制しにくい）。尚、上述の様なナット１６によりスプライン軸１５とハブ２とを不離に結合する構造に代えて、例えば後述する発明の実施の形態の第３例を示す図３に表す様な、特許請求の範囲に記載した抑え部を構成する第二のかしめ部２０や、同じく第４例を示す図４に表す様な、同じく抑え部を構成する止め輪２１により、上記スプライン軸１５とハブ２とを不離に結合する事も考えられる。但し、この様な構造の場合にも、例えばかしめ条件、材料の条件、寸法等に応じて、上記ナット１６を用いる場合と同様に、上記軸力にばらつきを生じる可能性がある。この為、何れの場合にも（ナット１６、第二のかしめ部２０、止め輪２１の何れで結合しても）、上記軸力Ｆを厳密に規制する事により、上記予圧を所望の値に規制する事は、面倒でコストが嵩む等、現実的な解決策とは言えない。   In order to suppress the displacement of the preload accompanying the tightening of the nut 16 as described above, the driving force is applied so that a desired preload is applied to the rolling elements 5a and 5b in the state where the axial force F is applied as described above. An initial gap or the like of the wheel support hub unit 1 is set in advance. However, the friction coefficient μ is unstable and is easily affected by the fit (tightness) between the male threaded portion 18 and the nut 16 and burrs. For example, even if the initial gap and the tightening torque are strictly regulated, for example. The axial force actually applied tends to vary (it is difficult to regulate the desired axial force). It should be noted that, in place of the structure in which the spline shaft 15 and the hub 2 are inseparably coupled by the nut 16 as described above, for example, as shown in FIG. The spline shaft 15 and the hub 2 are connected by the second caulking portion 20 constituting the holding portion described in the range and the retaining ring 21 also constituting the holding portion, as shown in FIG. 4 showing the fourth example. It is also possible to combine indefinitely. However, even in the case of such a structure, there is a possibility that the axial force varies depending on, for example, the caulking conditions, material conditions, dimensions, etc., as in the case where the nut 16 is used. For this reason, in any case (whichever is connected by the nut 16, the second caulking portion 20, and the retaining ring 21), the preload is set to a desired value by strictly regulating the axial force F. Regulating is not a practical solution because it is cumbersome and expensive.

特開２００７−３３１５５６号公報JP 2007-331556 A 特開２００８−１６８７９７号公報JP 2008-168797 A 特開２００７−１４７０６４号公報JP 2007-147064 A 特開２００７−３０３６５１号公報JP 2007-303651 A 国際公開ＷＯ２００５／０６５０７７号パンフレットInternational Publication WO2005 / 065077 Pamphlet

本発明は、上述の様な事情に鑑み、外側列の転動体のピッチ円直径を内側列の転動体のピッチ円直径よりも大きくした駆動輪支持用ハブユニットで、軽量に構成でき、しかも、適切な予圧（所望の予圧）を付与し易く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 is a drive wheel support hub unit in which the pitch circle diameter of the rolling elements in the outer row is larger than the pitch circle diameter of the rolling elements in the inner row, and can be configured to be lightweight. The present invention has been invented to realize a structure capable of easily applying an appropriate preload (desired preload).

本発明の駆動輪支持用ハブユニットは、前述した従来から知られている駆動輪支持用ハブユニットと同様に、外輪と、ハブと、内輪と、複数個の転動体とを備える。
このうちの外輪は、使用時にも回転しないもので、内周面の軸方向外端部に第一の外輪軌道を、同じく内端部に第二の外輪軌道を、それぞれ有する。
又、上記ハブは、外周面の外端寄り部分に車輪を支持する為の取付フランジを、同じく中間部に第一の内輪軌道を、同じく内端部にこの第一の内輪軌道を形成した部分よりも外径寸法が小さくなった小径段部を、中心部に駆動軸であるスプライン軸を係合させる為のスプライン孔を、このスプライン孔の外端縁の周囲部分に上記スプライン軸の先端部に固設した抑え部（例えば、ナット、止め輪、かしめ部等）を当接させる（抑え付ける）為の段部を、それぞれ有する。
又、上記内輪は、上記小径段部に外嵌するもので、外周面に第二の内輪軌道を有する。
又、上記各転動体は、上記第一、第二の各外輪軌道と上記第一、第二の各内輪軌道との間に、それぞれ複数個ずつ転動自在に設けられている。
そして、上記第一の外輪軌道と上記第一の内輪軌道との間に設けた第一の転動体列のピッチ円直径を、上記第二の外輪軌道と上記第二の内輪軌道との間に設けた第二の転動体列のピッチ円直径よりも大きくしている。 The drive wheel support hub unit of the present invention includes an outer ring, a hub, an inner ring, and a plurality of rolling elements, like the conventionally known drive wheel support hub unit.
Of these, the outer ring does not rotate during use, and has a first outer ring raceway at the axially outer end portion of the inner peripheral surface and a second outer ring raceway at the inner end portion.
The hub has a mounting flange for supporting the wheel on the outer end portion of the outer peripheral surface, the first inner ring raceway in the middle portion, and the first inner ring raceway in the inner end portion. A spline hole for engaging the spline shaft, which is the drive shaft, at the center with the small diameter step portion having a smaller outer diameter than the tip end portion of the spline shaft at the peripheral portion of the outer edge of the spline hole Each has a step portion for abutting (holding down) a holding portion (for example, a nut, a retaining ring, a caulking portion, etc.) fixed to the.
The inner ring is fitted on the small-diameter step portion, and has a second inner ring raceway on the outer peripheral surface.
Further, a plurality of rolling elements are provided between the first and second outer ring raceways and the first and second inner ring raceways so as to be capable of rolling.
Then, the pitch circle diameter of the first rolling element row provided between the first outer ring raceway and the first inner ring raceway is set between the second outer ring raceway and the second inner ring raceway. It is larger than the pitch circle diameter of the second rolling element row provided.

特に、本発明の駆動輪支持用ハブユニットに於いては、上記内輪の内端面を上記小径段部の内端部よりも軸方向内方に位置させて、この内輪の内端面に、上記スプライン軸を固設した等速ジョイント用外輪の外端面を直接当接させている。
又、上記段部を、上記ハブの軸方向に関して、上記第一の転動体列の中心と上記第二の転動体列の中心との間に位置させている。尚、この「間に位置させる」には、上記段部と上記第一の転動体列の中心とを一致させる場合を含む。
又、上記段部と上記抑え部との当接部の外径をＡとし、上記内輪の内径をｄとし、この内輪の外端面と上記ハブの段差面との当接部の外径をＢとした場合に、Ｂ＞Ａ＞ｄとしている。
又、上記ハブの内周面のうち、上記取付フランジを設けた部分と対応する部分から上記段部までの部分を、軸方向内方に向かう程内径が小さくなる方向に傾斜した円すい凹面部としている。
更に、この様な本発明の駆動輪支持用ハブユニットを実施する場合により好ましくは、請求項２に記載した発明の様に、上記ハブの内周面のうち、上記第一の内輪軌道を形成した部分の、この第一の内輪軌道の表面の法線方向に関する肉厚の最小値を、上記小径段部の径方向に関する肉厚の最大値よりも小さくする。 In particular, in the drive wheel support hub unit of the present invention, the inner end surface of the inner ring is positioned axially inward from the inner end portion of the small-diameter stepped portion, and the spline is formed on the inner end surface of the inner ring. The outer end face of the constant velocity joint outer ring having a fixed shaft is brought into direct contact.
Further, the stepped portion, in the axial direction of the hub, and is positioned between the centers of the second rolling element row of the first rolling element row. The “positioning between” includes the case where the stepped portion and the center of the first rolling element row are made to coincide.
The outer diameter of the contact portion between the stepped portion and the holding portion is A, the inner diameter of the inner ring is d, and the outer diameter of the contact portion between the outer end surface of the inner ring and the stepped surface of the hub is B. in the case of a, it is set to B>a> d.
Further, a portion from the inner peripheral surface of the hub corresponding to the portion provided with the mounting flange to the stepped portion is a conical concave surface portion inclined in a direction in which the inner diameter becomes smaller toward the inner side in the axial direction. Yes.
Further, when the drive wheel supporting hub unit according to the present invention is implemented, the first inner ring raceway is formed on the inner peripheral surface of the hub as in the invention described in claim 2. The minimum value of the thickness in the normal direction of the surface of the first inner ring raceway of the portion thus made is made smaller than the maximum value of the thickness in the radial direction of the small diameter step portion.

上述の様な構成を有する本発明の駆動輪支持用ハブユニットによれば、軽量に構成でき、しかも、適切な予圧（所望の予圧）を付与し易くできる。
即ち、抑え部と当接する段部を、ハブの軸方向に関して、第一の転動体列の中心と第二の転動体列の中心との間に位置させている。この為、この段部をこのハブの軸方向内側に位置させる事ができ、その分、このハブの内径側部分のうちでこの段部より軸方向外側部分の径方向に関する肉厚を小さくできる。そして、この様に肉厚を小さくできる分、軽量に構成できる。又、上記段部がハブの軸方向内側に位置する分、この段部と等速ジョイント用外輪の端面との軸方向距離を小さくできる。この為、この段部と等速ジョイント用外輪の端面が当接する部分との間｛圧縮荷重（軸力）が加わる部分｝の弾性変形量を小さくできる。そして、この様に弾性変形量を小さくできる分、各転動体に付与される予圧の変化量を小さくでき、適切な予圧（所望の予圧）を付与し易くできる。 According to the hub unit for driving wheel support of the present invention having the above-described configuration, it can be configured to be lightweight, and an appropriate preload (desired preload) can be easily applied.
In other words, the stepped portion that comes into contact with the holding portion is positioned between the center of the first rolling element row and the center of the second rolling element row in the axial direction of the hub. For this reason, this step portion can be positioned on the inner side in the axial direction of the hub, and the thickness in the radial direction of the outer portion in the axial direction from the step portion in the inner diameter side portion of the hub can be reduced accordingly. And since it can reduce thickness in this way, it can comprise lightweight. Further, the axial distance between the stepped portion and the end face of the outer ring for the constant velocity joint can be reduced by the amount of the stepped portion positioned on the inner side in the axial direction of the hub. For this reason, the elastic deformation amount of {the portion where the compressive load (axial force) is applied} between the step portion and the portion where the end face of the outer ring for constant velocity joint abuts can be reduced. And since the amount of elastic deformation can be reduced in this way, the amount of change in preload applied to each rolling element can be reduced, and appropriate preload (desired preload) can be easily applied.

尚、この様に弾性変形量を小さくできる理由は、下記の式（２）から明らかである。

Figure 0005401997
ΔＬ：軸方向変化量
Ｗ：荷重
Ａ：断面積
Ｅ：縦弾性係数
Ｌ：軸方向長さ The reason why the amount of elastic deformation can be reduced in this way is apparent from the following equation (2).
Figure 0005401997
 ΔL: Axial change W: Load A: Cross section E: Longitudinal elastic modulus L: Axial length

即ち、上記式（２）より、荷重Ｗ、即ち、上記段部と上記等速ジョイント用外輪の端面が当接する部分との間に加わる圧縮荷重Ｗ（軸力Ｆ）を同じと考えると、軸方向長さＬが小さい程、軸方向変化量ΔＬが小さくなる事が分かる。又、同じく上記式（２）より、軸方向長さＬが小さい程、荷重Ｗの変化に伴う軸方向変化量ΔＬの変化の程度も小さくなる事が分かる。従って、上述の様に段部と等速ジョイント用外輪の端面との軸方向距離Ｌを小さくする事により、これら段部と等速ジョイント用外輪の端面が当接する部分との間の弾性変形量ΔＬを小さくでき、その分、各転動体に付与される予圧の変化量を小さくできる。又、上記圧縮荷重Ｗ（軸力Ｆ）の変化に対する、上記弾性変形量ΔＬの変化の程度も小さく抑えられる為、この圧縮荷重Ｆ（軸力Ｆ）のばらつきに拘らず、上記各転動体に付与される予圧の変化量を小さくできる。そして、この様に各転動体に付与される予圧の変化量を小さくできる分、これら各転動体に適切な予圧（所望の予圧）を付与し易くできる。   That is, when the load W, that is, the compression load W (axial force F) applied between the step portion and the portion where the end face of the constant velocity joint outer ring abuts is considered to be the same from the above equation (2), It can be seen that the smaller the direction length L, the smaller the axial change amount ΔL. Similarly, from the above equation (2), it can be seen that the smaller the axial length L, the smaller the degree of change in the axial change amount ΔL accompanying the change in the load W. Therefore, by reducing the axial distance L between the stepped portion and the end surface of the constant velocity joint outer ring as described above, the amount of elastic deformation between the stepped portion and the portion where the end surface of the constant velocity joint outer ring abuts. ΔL can be reduced, and accordingly, the amount of change in preload applied to each rolling element can be reduced. In addition, since the degree of change in the elastic deformation amount ΔL with respect to the change in the compression load W (axial force F) can be suppressed to be small, the rolling elements are not affected by variations in the compression load F (axial force F). The amount of change in preload applied can be reduced. And since the amount of change in the preload applied to each rolling element can be reduced in this way, it is possible to easily apply an appropriate preload (desired preload) to each rolling element.

尚、上記段部を、上記ハブの軸方向に関して、上記第一の転動体列の中心よりも軸方向外側に位置させた場合には、このハブの軸方向外側部分のうちで、径方向に関する肉厚を小さくできる部分が小さくなり、十分な軽量化を図れなくなる可能性がある。又、これと共に、上記段部と等速ジョイント用外輪の端面との間部分の軸方向寸法が大きくなり、上記弾性変形量ΔＬを十分に小さくできず、各転動体に付与される予圧の変化量が大きくなる｛各転動体に適切な予圧（所望の予圧）を付与しにくくなる｝可能性がある。一方、上記段部を、上記ハブの軸方向に関して、上記第二の転動体列の中心よりも軸方向内側に位置させた場合には、ハブのうちで径方向の肉厚が小さい部分が大きくなり過ぎ、ハブの強度、剛性、耐久性を十分に確保できなくなる可能性がある。尚、上記段部は、内輪をハブの内端部に設けた小径段部に外嵌支持する面からは、この内輪の外端面よりも軸方向外側に位置させる事がより好ましい。具体的には、これら段部と内輪の外端面との間に、少なくとも上記ハブの強度、剛性、耐久性を十分に確保できるだけの軸方向の厚みが存在する様に、この段部の位置を規制する事が好ましい。   In addition, when the said step part is located in an axial direction outer side rather than the center of said 1st rolling element row | line | column regarding the axial direction of the said hub, it is related to radial direction among the axial direction outer parts of this hub. There is a possibility that the portion where the thickness can be reduced is reduced, and sufficient weight reduction cannot be achieved. At the same time, the axial dimension of the portion between the stepped portion and the end face of the outer ring for the constant velocity joint increases, and the elastic deformation amount ΔL cannot be sufficiently reduced, and the change in the preload applied to each rolling element. There is a possibility that the amount becomes large {it is difficult to give an appropriate preload (desired preload) to each rolling element}. On the other hand, when the stepped portion is positioned axially inside the center of the second rolling element row with respect to the axial direction of the hub, a portion with a small radial thickness in the hub is large. As a result, there is a possibility that sufficient strength, rigidity and durability of the hub cannot be secured. In addition, it is more preferable that the step portion is positioned on the outer side in the axial direction than the outer end surface of the inner ring from the surface that externally supports the inner ring on the small diameter step portion provided at the inner end portion of the hub. Specifically, the position of this step portion is set so that there is an axial thickness between the step portion and the outer end surface of the inner ring so that at least sufficient strength, rigidity, and durability of the hub can be secured. It is preferable to regulate.

又、本発明の様に、段部と抑え部との当接部の外径Ａと、内輪の内径ｄと、この内輪の外端面とこの外端面と当接するハブの段差面との当接部の外径Ｂとを、Ｂ＞Ａ＞ｄに規制した場合には、このハブのうちで内輪の外端面と抑え部の内側面とに挟持される部分に剪断荷重が加わらない様にできる。この為、上述の弾性変形量ΔＬを小さくできると言った効果をより確実に得られると共に、剪断荷重が加わらない分、ハブの強度、剛性、耐久性を確保し易くできる。
又、本発明の場合には、段部を第一の転動体列の中心と第二の転動体列の中心との間に位置させている為、スプライン孔とスプライン軸とのスプライン係合部を、等速ジョイント用外輪に近い位置に、その軸方向寸法を小さくした状態で設けられる。この為、このスプライン係合部に加わるトルク（駆動力）に基づくねじりやたわみの低減も図れ、スティックスリップ音の防止も図れる。 Further, as in the present invention , the outer diameter A of the contact portion between the stepped portion and the holding portion, the inner diameter d of the inner ring, and the contact between the outer end surface of the inner ring and the step surface of the hub that contacts the outer end surface. When the outer diameter B of the portion is restricted to B>A> d, a shear load can be prevented from being applied to a portion of the hub that is sandwiched between the outer end surface of the inner ring and the inner side surface of the holding portion. . For this reason, the effect that the above-described elastic deformation amount ΔL can be reduced can be obtained more reliably, and the strength, rigidity, and durability of the hub can be easily ensured because the shear load is not applied.
In the case of the present invention, since the step portion is positioned between the center of the first rolling element row and the center of the second rolling element row, the spline engaging portion between the spline hole and the spline shaft. Is provided at a position close to the outer ring for the constant velocity joint, with its axial dimension reduced. For this reason, torsion and deflection based on torque (driving force) applied to the spline engaging portion can be reduced, and stick-slip noise can be prevented.

［実施の形態の第１例］
図１は、本発明の実施の形態の第１例を示している。尚、本例の特徴は、各転動体５ａ、５ｂに適切な予圧（所望の予圧）を付与し易くすべく、ハブ２ａ等の構造を工夫した点にある。その他の部分の構造及び作用は、前述の図１２に示した従来構造と同様であるから、同等部分に関する説明は、省略若しくは簡略にし、以下、本例の特徴部分を中心に説明する。尚、本例の場合には、第一の転動体列を構成する各転動体５ａの外径を、第二の転動体列を構成する各転動体５ｂの外径よりも小さくしている。 [First example of embodiment]
FIG. 1 shows a first example of an embodiment of the present invention. The feature of this example is that the structure of the hub 2a and the like is devised so as to easily apply an appropriate preload (desired preload) to the rolling elements 5a and 5b. Since the structure and operation of the other parts are the same as those of the conventional structure shown in FIG. 12, the description of the equivalent parts will be omitted or simplified, and the following will focus on the characteristic parts of this example. In the case of this example, the outer diameter of each rolling element 5a constituting the first rolling element row is made smaller than the outer diameter of each rolling element 5b constituting the second rolling element row.

本例の場合には、抑え部を構成するナット１６の内側面を突き当てる為の段部１７ａを、上記ハブ２ａの軸方向に関して、第一の外輪軌道１２ａと第一の内輪軌道７ａとの間に設けた第一の転動体列の中心Ｘと、第二の外輪軌道１２ｂと第二の内輪軌道７ｂとの間に設けた第二の転動体列の中心Ｙとの間に位置させている。より具体的には、上記段部１７ａを、上記ハブ２ａの軸方向に関して、上記第一の転動体列の中心Ｘと上記第二の転動体列の中心Ｙとのほぼ中央に設けている。又、本例の場合には、上記段部１７ａと上記ナット１６との当接部の外径をＡとし、内輪３の内径をｄとし、この内輪３の外端面と上記ハブ２ａの段差面１９との当接部の外径をＢとした場合に、Ｂ＞Ａ＞ｄとしている。   In the case of this example, the stepped portion 17a for abutting the inner surface of the nut 16 constituting the holding portion is formed between the first outer ring raceway 12a and the first inner ring raceway 7a with respect to the axial direction of the hub 2a. It is located between the center X of the first rolling element row provided in between and the center Y of the second rolling element row provided between the second outer ring raceway 12b and the second inner ring raceway 7b. Yes. More specifically, the stepped portion 17a is provided substantially at the center between the center X of the first rolling element row and the center Y of the second rolling element row in the axial direction of the hub 2a. In this example, the outer diameter of the contact portion between the stepped portion 17a and the nut 16 is A, the inner diameter of the inner ring 3 is d, and the outer end surface of the inner ring 3 and the stepped surface of the hub 2a. B> A> d, where B is the outer diameter of the contact portion with 19.

この様な本例の場合には、前述の図１２に示した従来構造に比べ、上記段部１７ａを上記ハブ２ａの軸方向内側に位置させられる分、このハブ２ａの内径側部分のうちで、この段部１７ａより軸方向外側部分の、径方向に関する肉厚を小さくできる。そして、この様に肉厚を小さくできる分、軽量に構成できる。又、同じく上記段部１７ａを上記ハブ２ａの軸方向内側に位置させられる分、ナット１６の内側面と等速ジョイント用外輪１４の外端面との軸方向距離を小さくできる。この為、このナット１６の内側面と等速ジョイント用外輪１４の端面との間で挟持される（圧縮荷重が加わる）部分の弾性変形量を小さくできる。又、上記ナット１６の締め付けに伴う圧縮荷重（軸力）がばらついたとしても、このばらつきに拘らず、この圧縮荷重が加わる部分の弾性変形量の変化の程度も抑えられる。尚、この様に弾性変形量を小さくでき、しかも、この弾性変形量の変化の程度も抑えられる理由は、前述した［発明の効果］の欄で説明した通りである。そして、この様に弾性変形量を小さくでき、しかも、上記ナット１６の締め付けに伴う圧縮荷重（軸力）のばらつきに拘らず、この弾性変形量の変化の程度も抑えられる為、各転動体５ａ、５ｂに付与される予圧の変化量を小さくでき、適切な予圧（所望の予圧）を付与し易くできる。   In the case of this example, as compared with the conventional structure shown in FIG. 12, the step 17a is positioned on the inner side in the axial direction of the hub 2a. The thickness in the radial direction of the outer portion in the axial direction from the stepped portion 17a can be reduced. And since it can reduce thickness in this way, it can comprise lightweight. Similarly, the axial distance between the inner surface of the nut 16 and the outer end surface of the constant velocity joint outer ring 14 can be reduced by the amount that the stepped portion 17a is positioned on the inner side in the axial direction of the hub 2a. For this reason, the amount of elastic deformation of the portion sandwiched between the inner surface of the nut 16 and the end surface of the constant velocity joint outer ring 14 (applied with a compressive load) can be reduced. Even if the compressive load (axial force) due to tightening of the nut 16 varies, the degree of change in the amount of elastic deformation of the portion to which the compressive load is applied can be suppressed regardless of this variation. The reason why the amount of elastic deformation can be reduced in this way and the degree of change in the amount of elastic deformation can be suppressed is as described above in the section “Effects of the Invention”. Since the amount of elastic deformation can be reduced in this way, and the degree of change in the amount of elastic deformation can be suppressed regardless of variations in the compressive load (axial force) accompanying tightening of the nut 16, each rolling element 5a The amount of change in the preload applied to 5b can be reduced, and an appropriate preload (desired preload) can be easily applied.

又、本例の場合には、上記段部１７ａとナット１６との当接部の外径Ａと、内輪３の内径ｄと、この内輪３の外端面と段差面１９との当接部の外径Ｂとの関係を、Ｂ＞Ａ＞ｄに規制している為、ハブ２ａのうちで上記内輪３の外端面とナット１６の内端面とに挟持される部分に剪断荷重が加わらない様にできる。この為、上述の弾性変形量を小さくできると言った効果をより確実に得られると共に、剪断荷重が加わらない分、上記ハブ２ａの強度、剛性、耐久性を確保し易くできる。   In the case of this example, the outer diameter A of the contact portion between the step portion 17a and the nut 16, the inner diameter d of the inner ring 3, and the contact portion between the outer end surface of the inner ring 3 and the step surface 19 are as follows. Since the relationship with the outer diameter B is regulated as B> A> d, a shear load is not applied to a portion of the hub 2a sandwiched between the outer end surface of the inner ring 3 and the inner end surface of the nut 16. Can be. For this reason, the effect that the amount of elastic deformation can be reduced can be obtained more reliably, and the strength, rigidity, and durability of the hub 2a can be easily ensured because the shear load is not applied.

尚、本例の場合には、上記内輪３の内端面に等速ジョイント用外輪１４の外端面を直接当接させている。即ち、前述の図１２に示した構造の様な、内輪３の内端面をかしめ部１０（図１２参照）により抑え付け、このかしめ部１０の端面に等速ジョイント用外輪１４の端面を当接させると言った構成は採用していない。この様な本例の場合には、かしめ部１０を設けない分、ナット１６の内側面と等速ジョイント用外輪１４の端面との軸方向距離を、より小さくでき、これらナット１６の内側面と等速ジョイント用外輪１４の端面とに挟まれる部分の、更なる弾性変形量の低減を図れる。   In the case of this example, the outer end surface of the constant velocity joint outer ring 14 is brought into direct contact with the inner end surface of the inner ring 3. That is, as in the structure shown in FIG. 12, the inner end surface of the inner ring 3 is suppressed by the caulking portion 10 (see FIG. 12), and the end surface of the constant velocity joint outer ring 14 is brought into contact with the end surface of the caulking portion 10. It does not adopt the structure that said to let you. In the case of this example, since the caulking portion 10 is not provided, the axial distance between the inner surface of the nut 16 and the end surface of the constant velocity joint outer ring 14 can be further reduced. The amount of elastic deformation of the portion sandwiched between the end faces of the constant velocity joint outer ring 14 can be further reduced.

又、本例の場合には、上記ハブ２ａのうち、第一の内輪軌道７ａを形成した部分の、この第一の内輪軌道７ａの表面の法線方向に関する肉厚の最小値Ｔ１を、同じく上記内輪３を外嵌した部分（小径段部８を設けた部分）の径方向に関する肉厚の最大値Ｔ２よりも小さく（Ｔ１＜Ｔ２）している。そして、この様にハブ２ａの肉厚を規制する事でも、このハブ２ａの肉厚を小さくして（第一の内輪軌道７ａを設けた部分の肉厚と小径段部８を設けた部分との肉厚をバランスよく小さくして）、十分な軽量化を図れる様にしている。 Further, in the case of this example, out of the hub 2a, a portion forming a first inner ring raceway 7a, the minimum value T 1 of the thickness concerning the normal direction of the surface of the first inner ring raceway 7a, Similarly, it is smaller (T 1 <T 2 ) than the maximum value T 2 of the thickness in the radial direction of the portion where the inner ring 3 is externally fitted (portion where the small diameter step portion 8 is provided). And even by regulating the thickness of the hub 2a in this way, the thickness of the hub 2a is reduced (the thickness of the portion where the first inner ring raceway 7a is provided and the portion where the small diameter step portion 8 is provided) The wall thickness is reduced in a well-balanced manner) so that the weight can be reduced sufficiently.

［実施の形態の第２例］
図２は、本発明の実施の形態の第２例を示している。本例の場合には、第一の転動体列のピッチ円直径ＰＣＤＯＵＴを第二の転動体列のピッチ円直径ＰＣＤＩＮよりも大きくしている程度を、上述した実施の形態の第１例の場合よりも大きくしている。又、本例の場合、第一の転動体列の各転動体５ａの外径を第二の転動体列の各転動体５ｂの外径よりも小さくする程度を、上述した実施の形態の第１例よりも著しくしている。但し、何れの場合でも、上記各転動体の外径を同じにする事もできる。又、本例の場合は、第一の転動体列の各転動体５ａの数を、第二の転動体列の各転動体５ｂの数よりも多くしている。尚、図示は省略するが、第一の転動体列と第二の転動体列とで（第一の内輪軌道７ａ及び第一の外輪軌道１２ａと第二の内輪軌道７ｂ及び第二の外輪軌道１２ｂとで）、軌道面曲率の玉径比を変える事もできる。又、第一の転動体列の各転動体５ａの接触角と、第二の転動体列の各転動体５ｂの接触角とを異ならせる（例えば第二の転動体列の接触角を第一の転動体列の接触角よりも大きくする）事もできる。又、重量の嵩む自動車用の駆動輪支持用ハブユニットを構成する場合には、各転動体５ａ、５ｂを円すいころとする事もできる。
その他の構成及び作用は、上述した実施の形態の第１例と同様であるから、重複する説明は省略する。 [Second Example of Embodiment]
FIG. 2 shows a second example of the embodiment of the present invention. In the case of this example, the degree to which the pitch circle diameter PCD OUT of the first rolling element row is larger than the pitch circle diameter PCD IN of the second rolling element row is the first example of the embodiment described above. It is bigger than the case. In the case of this example, the extent to which the outer diameter of each rolling element 5a of the first rolling element row is made smaller than the outer diameter of each rolling element 5b of the second rolling element row is the same as that of the above-described embodiment. This is more remarkable than in one example. However, in any case, the outer diameters of the rolling elements can be the same. In this example, the number of rolling elements 5a in the first rolling element row is larger than the number of rolling elements 5b in the second rolling element row. Although not shown, the first rolling element row and the second rolling element row (the first inner ring raceway 7a and the first outer ring raceway 12a, the second inner ring raceway 7b and the second outer ring raceway). 12b), the ball diameter ratio of the raceway surface curvature can be changed. Also, the contact angle of each rolling element 5a in the first rolling element row is made different from the contact angle of each rolling element 5b in the second rolling element row (for example, the contact angle of the second rolling element row is set to the first angle). It is also possible to make the contact angle larger than that of the rolling element row. Further, when a heavy driving wheel support hub unit for automobiles is configured, the rolling elements 5a and 5b can be tapered rollers.
Other configurations and operations are the same as those in the first example of the above-described embodiment, and thus redundant description is omitted.

［実施の形態の第３例］
図３は、本発明の実施の形態の第３例を示している。本例の場合には、スプライン軸１５の先端部で段部１７ａよりも軸方向に突出した部分に、特許請求の範囲に記載した抑え部を構成する第二のかしめ部２０を形成し、この第二のかしめ部２０をこの段部１７ａに直接当接させている。この様な構造の場合には、上述した実施の形態の第１、２例の様なナット１６（図１、２参照）や、後述する実施の形態の第４例の様な止め輪２１（図４参照）を段部１７ａに当接させる構造に比べ、ハブ２ａの内径側部分で、この段部１７ａと等速ジョイント用外輪１４の端面との間に加わる圧縮荷重（軸力）がばらつき易くなる可能性がある。但し、この様に圧縮荷重（軸力）がばらついたとしても、この圧縮荷重（軸力）に伴う弾性変形量の変化の程度を小さくできる為、各転動体５ａ、５ｂに適切な予圧（所望の予圧）を付与し易くできると言った効果を、より有効に得られる。
その他の構成及び作用は、上述した実施の形態の第２例と同様であるから、重複する説明は省略する。尚、本例の場合には、段部１７ａと第二のかしめ部２０との当接部の外径をＡとし、内輪３の内径をｄとし、この内輪３の外端面とハブ２ａの段差面１９との当接部の外径をＢとした場合に、Ｂ＞Ａ＞ｄとしている。 [Third example of embodiment]
FIG. 3 shows a third example of the embodiment of the present invention. In the case of this example, the second caulking portion 20 constituting the restraining portion described in the claims is formed at the tip portion of the spline shaft 15 and protruding in the axial direction from the step portion 17a. The second caulking portion 20 is in direct contact with the stepped portion 17a. In the case of such a structure, the nut 16 (see FIGS. 1 and 2) as in the first and second examples of the embodiment described above, or the retaining ring 21 (as in the fourth example of the embodiment described later) Compared to the structure in which the step 17a is brought into contact with the stepped portion 17a, the compressive load (axial force) applied between the stepped portion 17a and the end face of the constant velocity joint outer ring 14 varies in the inner diameter side portion of the hub 2a. May be easier. However, even if the compressive load (axial force) varies in this manner, the degree of change in the amount of elastic deformation accompanying the compressive load (axial force) can be reduced, so that an appropriate preload (desired to each rolling element 5a, 5b) The effect that it can be easily applied is obtained more effectively.
Other configurations and operations are the same as those of the second example of the above-described embodiment, and thus redundant description is omitted. In this example, the outer diameter of the contact portion between the step portion 17a and the second caulking portion 20 is A, the inner diameter of the inner ring 3 is d, and the step between the outer end surface of the inner ring 3 and the hub 2a. When the outer diameter of the contact portion with the surface 19 is B, B>A> d.

［実施の形態の第４例］
図４は、本発明の実施の形態の第４例を示している。本例の場合には、スプライン軸１５の先端部で、段部１７ａと整合する位置に、このスプライン軸１５の外周面から径方向内方に凹入する状態で全周に亙り凹溝２２を設けている。そして、この凹溝２２に、特許請求の範囲に記載した抑え部を構成する止め輪２１を、この凹溝２２と段部１７ａとの間に掛け渡す状態で設けている。そして、この様に凹溝２２に止め輪２１を係合させた状態で、この止め輪２１の内側面と段部１７ａとを当接させて、上記スプライン軸１５とハブ２ａとを不離に結合している。尚、この様に止め輪２１により不離に結合する場合には、図示は省略するが、例えば内輪３の内端面とこの内端面と対向する等速ジョイント用外輪１４の端面との間に弾性部材を設けたり、上記止め輪２１自体に皿ばねの機能を持たせる事により、等速ジョイント部分で発生するスラスト荷重に拘らず、スプライン軸１５とスプライン孔１３とのスプライン係合部でフレッチング摩耗や異音が生じる事を防止する事が好ましい。
その他の構成及び作用は、前述した実施の形態の第２例と同様であるから、重複する説明は省略する。 [Fourth Example of Embodiment]
FIG. 4 shows a fourth example of the embodiment of the present invention. In the case of this example, at the tip of the spline shaft 15, a groove 22 is formed over the entire circumference in a state where it is recessed radially inward from the outer peripheral surface of the spline shaft 15 at a position aligned with the stepped portion 17a. Provided. And in this concave groove 22, the retaining ring 21 which comprises the holding | suppressing part described in the claim is provided in the state spanning between this concave groove 22 and the step part 17a. Then, with the retaining ring 21 engaged with the concave groove 22 as described above, the inner surface of the retaining ring 21 and the stepped portion 17a are brought into contact with each other so that the spline shaft 15 and the hub 2a are coupled to each other without separation. doing. In the case where the retaining ring 21 is coupled in such a manner as shown in the figure, although not shown, for example, an elastic member is provided between the inner end face of the inner ring 3 and the end face of the constant velocity joint outer ring 14 facing the inner end face. Or the retaining ring 21 itself has the function of a disc spring, regardless of the thrust load generated at the constant velocity joint portion, the fretting wear or the like at the spline engaging portion between the spline shaft 15 and the spline hole 13. It is preferable to prevent the generation of abnormal noise.
Other configurations and operations are the same as those of the second example of the above-described embodiment, and thus redundant description is omitted.

［参考例の第１例］
図５は、本発明に関する参考例の第１例を示している。本参考例の場合には、前述の図１２に示した従来構造と同様に、内輪３の内端面をかしめ部１０により抑え付け、このかしめ部１０の内端面に等速ジョイント用外輪１４の外端面を当接させている。尚、この様なかしめ部１０を形成する際には、この形成に伴うかしめ荷重を段部１７ａで受ける事ができる（段部１７ａを支持面とする事ができる）。そして、この様に段部１７ａでかしめ荷重を受ければ、このかしめ荷重を各転動体５ａ、５ｂで受けにくくして、軌道面に圧痕やフォールスブリネリング（転動面と軌道面との接触部分に生じるブリネル圧痕に似た凹み）が生じる事を防止できる。
その他の構成及び作用は、前述した実施の形態の第２例と同様であるから、重複する説明は省略する。 [ First example of reference example ]
FIG. 5 shows a first example of a reference example relating to the present invention. In the case of this reference example , the inner end surface of the inner ring 3 is held by the caulking portion 10 as in the conventional structure shown in FIG. 12, and the outer end 14 of the constant velocity joint outer ring 14 is fixed to the inner end surface of the caulking portion 10. The end face is in contact. When forming such a caulking portion 10, the caulking load associated with the formation can be received by the step portion 17 a (the step portion 17 a can be used as a support surface). If the caulking load is received by the step portion 17a in this way, the caulking load is made difficult to be received by each of the rolling elements 5a and 5b, so that the raceway surface is indented or false brinelling (contact between the rolling surface and the raceway surface). It is possible to prevent the occurrence of a dent similar to a Brinell impression in a part.
Other configurations and operations are the same as those of the second example of the above-described embodiment, and thus redundant description is omitted.

［実施の形態の第５例］
図６は、本発明の実施の形態の第５例を示している。本例の場合には、内輪３ａの内端部内周面に、他の部分よりも内径が大きい大径部２３を設け、この大径部２３の基端部の段差面２４に、かしめ部１０ａを当接させている。この様な本例の場合には、上記内輪３ａの内端面と等速ジョイント用外輪１４の外端面とが当接する。この為、上記かしめ部１０ａにより上記内輪３ａの非分離を図りつつ、この内輪３ａの内端面と等速ジョイント用外輪１４の外端面との当接面積を確保でき、当該部分の面圧の低下、延いては、スティックスリップ音の防止を図れる。
その他の構成及び作用は、上述した参考例の第１例と同様であるから、重複する説明は省略する。 [ Fifth Example of Embodiment]
FIG. 6 shows a fifth example of the embodiment of the present invention. In the case of this example, a large-diameter portion 23 having an inner diameter larger than the other portions is provided on the inner peripheral surface of the inner ring 3a, and the caulking portion 10a is provided on the stepped surface 24 of the base end portion of the large-diameter portion 23. Are in contact. In the case of this example, the inner end face of the inner ring 3a and the outer end face of the constant velocity joint outer ring 14 come into contact with each other. Therefore, while the inner ring 3a is not separated by the caulking portion 10a, a contact area between the inner end surface of the inner ring 3a and the outer end surface of the constant velocity joint outer ring 14 can be secured, and the surface pressure of the portion is reduced. As a result, stick-slip noise can be prevented.
Other configurations and operations are the same as those of the first example of the reference example described above, and thus redundant description is omitted.

［参考例の第２例］
図７は、本発明に関する参考例の第２例を示している。前述した各例の場合は、ハブ２ａの内周面のうち、取付フランジ６を設けた部分と対応する部分から段部１７ａまで、軸方向内方に向かう程内径が小さくなる方向に傾斜した円すい凹面部２５としている。これに対して本参考例の場合には、段部１７ａの径方向外端縁と円すい凹面部２５の径方向内端縁とを、円筒面部２６により連続させている。この様な本参考例の場合には、この円筒面部２６を、ナット１６を螺合し更に締め付ける為の工具（ソケット）の案内面（ガイド）とする事ができる。尚、ハブ２ａの内周面のうち、段部１７ａよりも軸方向外側部分は、この段部１７を抑え付ける為のナット１６や止め輪２１（図４参照）を取り付ける為の工具、第二のかしめ部２０（図３参照）を形成する為の押圧型等の形状等に応じて、適宜必要な形状とする事ができる。
その他の構成及び作用は、前述した実施の形態の第１例と同様であるから、重複する説明は省略する。 [ Second example of reference example ]
FIG. 7 shows a second example of the reference example relating to the present invention. In the case of each of the above-described examples, a cone inclined in a direction in which the inner diameter decreases from the portion corresponding to the portion provided with the mounting flange 6 to the step portion 17a on the inner peripheral surface of the hub 2a as it goes inward in the axial direction. The concave portion 25 is used. On the other hand, in the case of the present reference example, the radially outer end edge of the step portion 17 a and the radially inner end edge of the conical concave surface portion 25 are made continuous by the cylindrical surface portion 26. In the case of this reference example, the cylindrical surface portion 26 can be used as a guide surface (guide) of a tool (socket) for screwing the nut 16 and further tightening. Of the inner peripheral surface of the hub 2a, the outer side in the axial direction than the step portion 17a is a tool for attaching a nut 16 and a retaining ring 21 (see FIG. 4) for restraining the step portion 17; Depending on the shape of a pressing mold or the like for forming the caulking portion 20 (see FIG. 3), a necessary shape can be appropriately formed.
Other configurations and operations are the same as those in the first example of the above-described embodiment, and thus redundant description is omitted.

［参考例の第３例］
図８は、本発明に関する参考例の第３例を示している。本参考例の場合には、ハブ２ａの軸方向外端部に設けた、車輪及び制動部材（ディスク）の径方向に関する位置決めを図る為のパイロット部２７に加わる応力の低減を図るべく、このハブ２ａの内周面のうち、このパイロット部２７よりも軸方向内側部分に、この内周面から径方向外方に凹入する状態で、全周に亙り凹部２８を設けている。この様な凹部２８を設けた構造の場合には、この凹部２８に雨水等の異物が溜まる事を防止すべく、上記パイロット部２７の内周面にキャップ２９を装着し、このパイロット部２７の開口部（ハブ２ａの外端開口部）を塞ぐ事が好ましい。
その他の構成及び作用は、上述した参考例の第２例と同様であるから、重複する説明は省略する。 [ Third example of reference example ]
FIG. 8 shows a third example of the reference example related to the present invention. In the case of this reference example , in order to reduce the stress applied to the pilot portion 27 for positioning the wheel and the braking member (disk) in the radial direction provided at the axially outer end portion of the hub 2a. Of the inner peripheral surface of 2a, a concave portion 28 is provided on the entire inner periphery of the pilot portion 27 in a state where the inner peripheral surface is recessed radially outward from the inner peripheral surface. In the case of such a structure provided with the recess 28, a cap 29 is attached to the inner peripheral surface of the pilot portion 27 in order to prevent foreign matter such as rainwater from accumulating in the recess 28. It is preferable to close the opening (the outer end opening of the hub 2a).
Other configurations and operations are the same as those of the second example of the reference example described above, and thus redundant description is omitted.

［参考例の第４例］
図９は、本発明に関する参考例の第４例を示している。本参考例の場合には、段部１７ａを、ハブ２ａの軸方向に関して、第一の転動体列の中心Ｘと一致する位置に設けている。又、本参考例の場合も、上記ハブ２ａのうち、第一の内輪軌道７ａを形成した部分の、この第一の内輪軌道７ａの表面の法線方向に関する肉厚の最小値Ｔ１を、同じく内輪３を外嵌した部分（小径段部８を設けた部分）の径方向に関する肉厚の最大値Ｔ２よりも小さく（Ｔ１＜Ｔ２）している。そして、この様にハブ２ａの肉厚を規制する事でも、このハブ２ａの肉厚を小さくして（第一の内輪軌道７ａを設けた部分の肉厚と小径段部８を設けた部分との肉厚をバランスよく小さくして）、十分な軽量化を図れる様にしている。
その他の構成及び作用は、前述した実施の形態の第１例と同様であるから、重複する説明は省略する。 [ Fourth Reference Example ]
FIG. 9 shows a fourth example of the reference example relating to the present invention. In the case of this reference example , the stepped portion 17a is provided at a position that coincides with the center X of the first rolling element row in the axial direction of the hub 2a. Further, in the case of the present reference example, of the hub 2a, a portion forming a first inner ring raceway 7a, the minimum value T 1 of the thickness concerning the normal direction of the surface of the first inner ring raceway 7a, Similarly, it is smaller (T 1 <T 2 ) than the maximum value T 2 of the thickness in the radial direction of the portion where the inner ring 3 is externally fitted (the portion where the small diameter step portion 8 is provided). And even by regulating the thickness of the hub 2a in this way, the thickness of the hub 2a is reduced (the thickness of the portion where the first inner ring raceway 7a is provided and the portion where the small diameter step portion 8 is provided) The wall thickness is reduced in a well-balanced manner) so that the weight can be reduced sufficiently.
Other configurations and operations are the same as those in the first example of the above-described embodiment, and thus redundant description is omitted.

上述の様に、各部の肉厚Ｔ１、Ｔ２を規制する技術は、本発明の対象となる駆動輪支持用ハブユニットに限らず、従動輪支持用ハブユニットにも適用できる。以下に、その具体例（本発明に関する参考例）の２例に就いて説明する。
［本発明に関する参考例の第５例］
図１０は、本発明に関する参考例の第５例を示している。尚、本参考例は、従動輪を支持する為の従動輪支持用ハブユニットに関し、ハブ２ｂの軽量化を図るものである。即ち、本参考例の場合には、このハブ２ｂの中心部に、軸方向の貫通孔３０を形成している。そして、このハブ２ｂのうち、第一の内輪軌道７ａを形成した部分のこの第一の内輪軌道７ａの表面の法線方向に関する肉厚の最小値Ｔ１が、同じく内輪３を外嵌した部分の径方向に関する肉厚の最大値Ｔ２よりも、少しだけ小さく（Ｔ１＜Ｔ２）なる様に、上記貫通孔３０の形状を規制している。言い換えれば、この様な規制を行なう事により、この貫通孔３０の内径寸法を、上記ハブ２ｂのうち上記内輪３を外嵌した小径段部８の内径側部分よりも、同じく上記第一の内輪軌道７ａを形成した大径側部分で十分に大きくしている。これにより、上記ハブ２ｂの肉厚を、上記小径側部分だけでなく上記大径側部分でも、即ち全体的に（バランス良く）、十分に小さくできる様にしている。 As described above, the technology for regulating the thicknesses T 1 and T 2 of each part is applicable not only to the drive wheel support hub unit that is the subject of the present invention but also to the driven wheel support hub unit. Hereinafter, two specific examples (reference examples relating to the present invention) will be described.
[ Fifth Example of Reference Example Related to the Present Invention]
FIG. 10 shows a fifth example of the reference example relating to the present invention. The reference example relates to a driven wheel support hub unit for supporting the driven wheel, and is intended to reduce the weight of the hub 2b. That is, in the case of this reference example, the axial through-hole 30 is formed in the center of the hub 2b. Then, of the hub 2b, partial least value T 1 of the thickness concerning the normal direction of the surface of the first inner ring raceway 7a of the portion forming a first inner ring raceway 7a is, was also fitted to the inner ring 3 The shape of the through hole 30 is regulated so as to be slightly smaller (T 1 <T 2 ) than the maximum thickness value T 2 in the radial direction. In other words, by performing such a restriction, the inner diameter dimension of the through hole 30 is set to be the same as that of the first inner ring than the inner diameter side portion of the small-diameter step portion 8 in which the inner ring 3 is externally fitted in the hub 2b. The large diameter side portion where the track 7a is formed is sufficiently large. Thereby, the thickness of the hub 2b can be sufficiently reduced not only in the small diameter side portion but also in the large diameter side portion, that is, as a whole (with good balance).

尚、本参考例の場合には、上記貫通孔３０の内周面の軸方向内端寄り部分に、軸方向外側に向かう程内径が小さくなるテーパ面部３１を設けている。そして、この様なテーパ面部３１を設ける事により、上記ハブ２ｂのうち、上記小径段部８を設けた部分の径方向に関する肉厚が、この小径段部８の基端縁にほぼ対応する部分で最大（上記Ｔ２）となる様にしている。これにより、上記小径段部８を設けた部分のうち、使用時に最も大きいモーメント荷重が加わる部分である、この小径段部８の基端縁に対応する部分の強度を十分に確保している。又、本参考例の場合には、上記外輪３の外周面のうち、軸方向に関して第一の外輪軌道１２ａと第二の外輪軌道１２ｂとの間に対応する部分に、全周に亙り凹部３２を設けて軽量化を図っている。
その他の構成及び作用は、従動輪を支持する点で異なる以外、前述の図１２に示した従来構造や、図１〜９に示した各例の構造と同様であるから、重複する説明は省略する。 In the case of the present reference example, a tapered surface portion 31 having an inner diameter that decreases toward the outer side in the axial direction is provided at a portion near the inner end in the axial direction of the inner peripheral surface of the through hole 30. By providing such a tapered surface portion 31, a portion of the hub 2 b in which the thickness in the radial direction of the portion where the small diameter step portion 8 is provided substantially corresponds to the base edge of the small diameter step portion 8. And the maximum (the above T 2 ). Thereby, the strength of the portion corresponding to the base end edge of the small diameter step portion 8 which is the portion to which the largest moment load is applied during use among the portions provided with the small diameter step portion 8 is sufficiently secured. Further, in the case of the present reference example, on the outer peripheral surface of the outer ring 3, the recess 32 extends over the entire circumference in a portion corresponding to the axial direction between the first outer ring raceway 12 a and the second outer ring raceway 12 b. To reduce weight.
Other configurations and operations are the same as the conventional structure shown in FIG. 12 and the structures of the examples shown in FIGS. 1 to 9 except that the driven wheel is supported. To do.

［本発明に関する参考例の第６例］
図１１は、本発明に関する参考例の第６例を示している。本参考例の場合には、第一、第二の各転動体列同士の列間距離（軸方向の間隔）を、上述の図１０に示した構造に比べて、短くしている。そして、その分だけ外輪４ａの軸方向寸法を短くして、小型・軽量化を図っている。又、本参考例の場合、第一、第二の各転動体列のピッチ円直径を互いに等しくしている従来構造（鎖線で図示）と比較すると、第一、第二の各転動体列同士の作用点間距離を互いに等しくした場合に、上記列間距離を短くできる。従って、その分だけ軸方向寸法を短くして、小型・軽量化を図れる。又、本参考例の場合、ハブ２ｂのうち小径段部８の中間部に対応する部分の内周面には、径方向内方に突出する補強リブ３３を、全周に亙り設けている。又、図示の例では、この補強リブ３３の内周面を、軸方向外方に向かう程内径が小さくなるテーパ面３４としている。従って、本参考例の場合には、上記ハブ２ｂのうち、上記補強リブ３３の軸方向外端縁に対応する部分の径方向の肉厚が、寸法Ｔ２となる。
その他の構成及び作用は、上述した参考例の第５例と同様であるから、重複する説明は省略する。 [ Sixth Reference Example for the Present Invention]
FIG. 11 shows a sixth example of the reference example relating to the present invention. In the case of this reference example, the distance between the first and second rolling element rows (interval in the axial direction) is shorter than that in the structure shown in FIG. And the axial direction dimension of the outer ring | wheel 4a is shortened by that much, and the size and weight reduction are achieved. Further, in the case of this reference example, the first and second rolling element rows are compared with the conventional structure (shown by chain lines) in which the pitch circle diameters of the first and second rolling element rows are equal to each other. When the distances between the operating points are equal to each other, the distance between the columns can be shortened. Therefore, the axial dimension can be shortened by that much, and the size and weight can be reduced. In the case of this reference example, a reinforcing rib 33 projecting radially inward is provided over the entire circumference on the inner circumferential surface of the hub 2b corresponding to the intermediate portion of the small-diameter stepped portion 8. Further, in the illustrated example, the inner peripheral surface of the reinforcing rib 33 is a tapered surface 34 whose inner diameter decreases toward the outer side in the axial direction. Therefore, in the case of the present embodiment, among the hub 2b, radial thickness of the portion corresponding to the axially outer edge of the reinforcing rib 33, the dimension T 2.
Other configurations and operations are the same as those of the fifth example of the reference example described above, and thus redundant description is omitted.

本発明の実施の形態の第１例を示す半部断面図。FIG. 2 is a half sectional view showing a first example of an embodiment of the present invention. 同第２例を示す半部断面図。Sectional sectional drawing which shows the 2nd example. 同第３例を示す半部断面図。Sectional sectional drawing which shows the 3rd example. 同第４例を示す半部断面図。Sectional sectional drawing which shows the 4th example. 本発明に関する参考例の第１例を示す半部断面図。Sectional drawing which shows the 1st example of the reference example regarding this invention . 本発明の実施の形態の第５例を示す半部断面図。 The half part sectional view showing the 5th example of an embodiment of the invention . 本発明に関する参考例の第２例を示す半部断面図。Sectional drawing of the half part which shows the 2nd example of the reference example regarding this invention . 本発明に関する参考例の第３例を示す半部断面図。Sectional drawing of the half part which shows the 3rd example of the reference example regarding this invention . 本発明に関する参考例の第４例を示す断面図。Sectional drawing which shows the 4th example of the reference example regarding this invention . 本発明に関する参考例の第５例を示す断面図。Sectional drawing which shows the 5th example of the reference example regarding this invention. 本発明に関する参考例の第６例を示す断面図。Sectional drawing which shows the 6th example of the reference example regarding this invention . 従来構造の１例を示す断面図。Sectional drawing which shows an example of a conventional structure.

１ 駆動輪支持用ハブユニット
２、２ａ、２ｂ ハブ
３、３ａ 内輪
４、４ａ 外輪
５ａ、５ｂ 転動体
６ 取付フランジ
７ａ、７ｂ 内輪軌道
８ 小径段部
９ スタッド
１０、１０ａ かしめ部
１１ 結合フランジ
１２ａ、１２ｂ 外輪軌道
１３ スプライン孔
１４ 等速ジョイント用外輪
１５ スプライン軸
１６ ナット
１７、１７ａ、１７ｂ 段部
１８ 雄ねじ部
１９ 段差面
２０ 第二のかしめ部
２１ 止め輪
２２ 凹溝
２３ 大径部
２４ 段差面
２５ 円すい凹面部
２６ 円筒面部
２７ パイロット部
２８ 凹部
２９ キャップ
３０ 貫通孔
３１ テーパ面部
３２ 凹部
３３ 補強リブ
３４ テーパ面 DESCRIPTION OF SYMBOLS 1 Drive wheel support hub unit 2, 2a, 2b Hub 3, 3a Inner ring 4, 4a Outer ring 5a, 5b Rolling element 6 Mounting flange 7a, 7b Inner ring track 8 Small diameter step 9 Stud 10, 10a Caulking part 11 Coupling flange 12a, 12b Outer ring raceway 13 Spline hole 14 Outer ring for constant velocity joint 15 Spline shaft 16 Nut 17, 17a, 17b Stepped portion 18 Male threaded portion 19 Stepped surface 20 Second caulking portion 21 Retaining ring 22 Concave groove 23 Large diameter portion 24 Stepped surface 25 Conical concave part 26 Cylindrical surface part 27 Pilot part 28 Concave part 29 Cap 30 Through hole 31 Tapered surface part 32 Concave part 33 Reinforcement rib 34 Tapered surface

Claims (2)

内周面の軸方向外端部に第一の外輪軌道を、同じく内端部に第二の外輪軌道を、それぞれ有し、使用時にも回転しない外輪と、外周面の外端寄り部分に車輪を支持する為の取付フランジを、同じく中間部に第一の内輪軌道を、同じく内端部にこの第一の内輪軌道を形成した部分よりも外径寸法が小さくなった小径段部を、中心部に駆動軸であるスプライン軸を係合させる為のスプライン孔を、このスプライン孔の外端縁の周囲部分に上記スプライン軸の先端部に固設した抑え部を当接させる為の段部を、それぞれ有するハブと、外周面に第二の内輪軌道を有すると共に、上記小径段部に外嵌した内輪と、上記第一、第二の各外輪軌道と上記第一、第二の各内輪軌道との間にそれぞれ複数個ずつ転動自在に設けた転動体とを備え、上記第一の外輪軌道と上記第一の内輪軌道との間に設けた第一の転動体列のピッチ円直径を、上記第二の外輪軌道と上記第二の内輪軌道との間に設けた第二の転動体列のピッチ円直径よりも大きくした
駆動輪支持用ハブユニットに於いて、
上記内輪の内端面を上記小径段部の内端部よりも軸方向内方に位置させて、この内輪の内端面に、上記スプライン軸を固設した等速ジョイント用外輪の外端面を直接当接させており、
上記段部を、上記ハブの軸方向に関して、上記第一の転動体列の中心と上記第二の転動体列の中心との間に位置させており、
上記段部と上記抑え部との当接部の外径をＡとし、上記内輪の内径をｄとし、この内輪の外端面と上記ハブの段差面との当接部の外径をＢとした場合に、Ｂ＞Ａ＞ｄであり、
このハブの内周面のうち、上記取付フランジを設けた部分と対応する部分から上記段部までの部分を、軸方向内方に向かう程内径が小さくなる方向に傾斜した円すい凹面部としている
事を特徴とする駆動輪支持用ハブユニット。 A first outer ring raceway at the outer end in the axial direction of the inner peripheral surface and a second outer ring raceway at the inner end, respectively, and an outer ring that does not rotate during use, and a wheel near the outer end of the outer peripheral surface The center flange is the same as the first inner ring raceway in the middle part, and the smaller diameter step part whose outer diameter is smaller than the part where the first inner ring raceway is formed in the inner end part. A spline hole for engaging the spline shaft, which is a drive shaft, with a step, and a stepped portion for abutting a holding portion fixed to the tip of the spline shaft around the outer edge of the spline hole. Each having a hub, a second inner ring raceway on the outer peripheral surface, an inner ring fitted on the small-diameter step portion, the first and second outer ring raceways, and the first and second inner ring raceways. A plurality of rolling elements provided in a freely movable manner between each of the first outer and the first outer The second rolling element provided between the second outer ring raceway and the second inner ring raceway with the pitch circle diameter of the first rolling element row provided between the raceway and the first inner ring raceway. In the drive wheel support hub unit that is larger than the pitch circle diameter of the row,
The inner end surface of the inner ring is positioned axially inward from the inner end portion of the small-diameter stepped portion, and the outer end surface of the outer ring for a constant velocity joint, to which the spline shaft is fixed, is directly applied to the inner end surface of the inner ring. Touching,
The step is positioned between the center of the first rolling element row and the center of the second rolling element row with respect to the axial direction of the hub ;
The outer diameter of the contact portion between the stepped portion and the restraining portion is A, the inner diameter of the inner ring is d, and the outer diameter of the contact portion between the outer end surface of the inner ring and the stepped surface of the hub is B. And B>A> d,
Of the inner peripheral surface of the hub, the portion from the portion corresponding to the portion provided with the mounting flange to the stepped portion is a conical concave surface portion inclined in a direction in which the inner diameter becomes smaller as it goes inward in the axial direction. A hub unit for driving wheel support. ハブの内周面のうち、第一の内輪軌道を形成した部分の、この第一の内輪軌道の表面の法線方向に関する肉厚の最小値を、小径段部の径方向に関する肉厚の最大値よりも小さくしている、請求項１に記載した駆動輪支持用ハブユニット。

 Of the inner peripheral surface of the hub, the minimum value of the thickness in the normal direction of the surface of the first inner ring raceway of the portion forming the first inner ring raceway is the maximum thickness in the radial direction of the small diameter step portion. The drive wheel support hub unit according to claim 1, wherein the hub unit is a drive wheel support hub unit.

JP2009003423A 2009-01-09 2009-01-09 Hub unit for driving wheel support Expired - Fee Related JP5401997B2 (en)

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US8616779B2 (en) * 2010-11-29 2013-12-31 Honda Motor Co., Ltd. Shortened driveshaft stem
JP5906021B2 (en) * 2011-04-05 2016-04-20 Ntn株式会社 Wheel bearing device
JP5966851B2 (en) * 2012-10-23 2016-08-10 日本精工株式会社 Wheel support hub unit
JP6212855B2 (en) * 2012-12-03 2017-10-18 株式会社ジェイテクト Wheel bearing device
FR3112825B1 (en) * 2020-07-23 2022-07-15 Ntn Snr Roulements rotating assembly, in particular for guiding a motor vehicle wheel
JP2023529042A (en) * 2020-01-24 2023-07-07 エヌティエヌーエスエヌアール・ルルマン Rotating assemblies, especially for guiding the wheels of motorized vehicles

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AU2004311585B2 (en) * 2003-10-14 2008-11-06 Aktiebolaget Skf Asymmetric hub assembly
JP2007147064A (en) * 2005-10-31 2007-06-14 Ntn Corp Bearing device for wheel
JP2007303651A (en) * 2006-05-15 2007-11-22 Ntn Corp Bearing device for wheel
JP4338095B2 (en) * 2006-06-14 2009-09-30 Ｎｔｎ株式会社 Drive wheel bearing unit
JP2008051272A (en) * 2006-08-25 2008-03-06 Ntn Corp Wheel bearing device
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