JP7487640B2 - Hub unit bearing - Google Patents

Hub unit bearing Download PDF

Info

Publication number
JP7487640B2
JP7487640B2 JP2020181233A JP2020181233A JP7487640B2 JP 7487640 B2 JP7487640 B2 JP 7487640B2 JP 2020181233 A JP2020181233 A JP 2020181233A JP 2020181233 A JP2020181233 A JP 2020181233A JP 7487640 B2 JP7487640 B2 JP 7487640B2
Authority
JP
Japan
Prior art keywords
annular groove
female threaded
threaded hole
hub
radially
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
JP2020181233A
Other languages
Japanese (ja)
Other versions
JP2022072036A (en
JP2022072036A5 (en
Inventor
彩水 鈴木
達男 若林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NSK Ltd
Original Assignee
NSK Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NSK Ltd filed Critical NSK Ltd
Priority to JP2020181233A priority Critical patent/JP7487640B2/en
Publication of JP2022072036A publication Critical patent/JP2022072036A/en
Publication of JP2022072036A5 publication Critical patent/JP2022072036A5/ja
Application granted granted Critical
Publication of JP7487640B2 publication Critical patent/JP7487640B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Rolling Contact Bearings (AREA)

Description

本発明は、自動車の車輪および制動用回転体を懸架装置に対して回転自在に支持するためのハブユニット軸受に関する。 The present invention relates to a hub unit bearing for supporting the wheels and braking rotors of an automobile so that they can rotate freely relative to the suspension system.

自動車の車輪およびディスクやドラムなどの制動用回転体は、ハブユニット軸受により、懸架装置に対して回転自在に支持される。ハブユニット軸受は、内周面に外輪軌道を有する外側部材と、外周面に内輪軌道を有する内側部材と、外輪軌道と内輪軌道との間に転動自在に配置された複数個の転動体とを備える。 Automobile wheels and braking rotors such as discs and drums are supported rotatably relative to the suspension by hub unit bearings. Hub unit bearings have an outer member with an outer ring raceway on its inner circumferential surface, an inner member with an inner ring raceway on its outer circumferential surface, and multiple rolling elements arranged to roll freely between the outer ring raceway and the inner ring raceway.

外側部材と内側部材とのうちの一方は、使用時に懸架装置に支持されて回転しない静止部材として用いられる。外側部材と内側部材とのうちの他方は、使用時に車輪および制動用回転体と一体となって回転する回転部材として用いられる。回転部材は、径方向外側に突出した回転フランジを有する。車輪を構成するホイール、および、制動用回転体は、複数本のハブボルトを用いて、回転フランジに結合固定される。 One of the outer member and the inner member is used as a stationary member that is supported by the suspension device and does not rotate when in use. The other of the outer member and the inner member is used as a rotating member that rotates integrally with the wheel and the braking rotor when in use. The rotating member has a rotating flange that protrudes radially outward. The wheel that constitutes the wheel and the braking rotor are fixed to the rotating flange using multiple hub bolts.

このようなハブユニット軸受では、回転フランジの円周方向複数箇所を軸方向に貫通する圧入孔を有し、かつ、該圧入孔のそれぞれに、ハブボルトの基端部である軸方向内側の端部に備えられたセレーション部を、軸方向内側から圧入するタイプ(以下、ハブボルト圧入タイプという。)が広く知られている。 A widely known type of hub unit bearing has press-fit holes that penetrate the axial direction at multiple points around the circumference of the rotating flange, and the serrations at the axially inner ends (the base ends of the hub bolts) are press-fitted into each of the press-fit holes from the axially inner side (hereafter referred to as the hub bolt press-fit type).

なお、ハブユニット軸受に関して、軸方向内側は、車両への組み付け状態で車両の幅方向中央側であり、軸方向外側は、車両への組み付け状態で車両の幅方向外側である。 Note that with respect to hub unit bearings, the axially inner side is the center side of the vehicle in the width direction when assembled to the vehicle, and the axially outer side is the outer side of the vehicle in the width direction when assembled to the vehicle.

ハブボルト圧入タイプのハブユニット軸受では、ホイールおよび制動用回転体のそれぞれの円周方向複数箇所に備えられた通孔に、ハブボルトの中間部を挿通した状態で、ハブボルトの先端部である軸方向外側の端部に備えられた雄ねじ部にハブナットを螺合し、さらに締め付けることにより、ホイールおよび制動用回転体を回転フランジに結合固定する。 In a hub bolt press-in type hub unit bearing, the middle part of the hub bolt is inserted into the through holes provided at multiple points in the circumferential direction of the wheel and the braking rotor, and then a hub nut is screwed onto the male threaded part at the axially outer end of the hub bolt, which is the tip of the hub bolt, and then tightened to connect and fix the wheel and the braking rotor to the rotating flange.

また、特開2002-370104号公報(特許文献1)や特開2003-175702号公報(特許文献2)などに記載されているように、ハブボルト圧入タイプのハブユニット軸受において、回転フランジの軸方向外側面に、回転部材の中心軸を中心とする円環状の環状溝を形成し、かつ、圧入孔のそれぞれの軸方向外側の端部を、環状溝の底面にのみ開口させた構造が知られている。 As described in JP 2002-370104 A (Patent Document 1) and JP 2003-175702 A (Patent Document 2), in a hub bolt press-in type hub unit bearing, a structure is known in which an annular groove is formed on the axially outer surface of the rotating flange, the annular groove being centered on the central axis of the rotating member, and the axially outer ends of each press-in hole are open only to the bottom surface of the annular groove.

このような構造によれば、圧入孔にハブボルトのセレーション部が圧入されることに伴い、圧入孔の軸方向外側の開口部の周囲が塑性変形して盛り上がった場合でも、この盛り上がりを環状溝内にとどめることで、回転フランジの軸方向外側面の環状溝以外の部分の面振れ精度を向上させることができる。これにより、制動用回転体の面振れ精度を向上させ、制動時にブレーキジャダーと呼ばれる異音を伴った振動の発生を抑制できる。 With this structure, even if the periphery of the axially outer opening of the press-fit hole is plastically deformed and raised as a result of the serration portion of the hub bolt being pressed into the press-fit hole, this bulge can be contained within the annular groove, improving the surface runout accuracy of the portion of the axially outer surface of the rotating flange other than the annular groove. This improves the surface runout accuracy of the braking rotor, and suppresses the occurrence of vibrations accompanied by abnormal noise known as brake judder during braking.

なお、特開2002-370104号公報や特開2003-175702号公報などに記載されているように、ハブボルト圧入タイプのハブユニット軸受において、圧入孔のそれぞれにハブボルトのセレーション部を圧入した後、回転フランジの軸方向外側面の環状溝以外の部分に仕上加工を施すことにより、該部分の面振れ精度を改善する技術も知られている。 As described in JP 2002-370104 A and JP 2003-175702 A, in hub bolt press-in type hub unit bearings, a technique is also known in which the serrations of the hub bolts are press-fitted into the press-in holes, and then the parts of the axial outer surface of the rotating flange other than the annular groove are finished to improve the surface runout accuracy of those parts.

また、ハブユニット軸受では、特開2017-190865号公報(特許文献3)などに記載されているように、ハブナットの省略によって軽量化を図れるタイプ、すなわち、回転フランジの円周方向複数箇所に、軸方向外側の端部を開口させた雌ねじ孔を有し、かつ、該雌ねじ孔のそれぞれに、ハブボルトの雄ねじ部を、軸方向外側から螺合するタイプ(以下、ハブボルト螺合タイプという。)も知られている。 As described in JP 2017-190865 A (Patent Document 3) and elsewhere, there is also a type of hub unit bearing that can be made lighter by omitting the hub nut, that is, a type in which the rotating flange has female threaded holes with open axially outer ends at multiple locations in the circumferential direction, and the male threads of the hub bolt are screwed into each of the female threaded holes from the axially outer side (hereinafter referred to as the hub bolt screw-in type).

ハブボルト螺合タイプのハブユニット軸受では、ホイールおよび制動用回転体のそれぞれの円周方向複数箇所に備えられた通孔にハブボルトを挿通した状態で、ハブボルトの雄ねじ部を、回転フランジの雌ねじ孔に軸方向外側から螺合し、さらに締め付けることにより、ホイールおよび制動用回転体を回転フランジに結合固定する。 In a hub bolt-threaded hub unit bearing, the hub bolt is inserted into through holes provided at multiple locations in the circumferential direction of the wheel and the braking rotor, and the male threads of the hub bolt are threaded into the female threaded hole of the rotating flange from the outside in the axial direction, and then tightened to connect and fix the wheel and the braking rotor to the rotating flange.

このようなハブボルト螺合タイプのハブユニット軸受でも、特開2017-190865号公報などに記載されているように、回転フランジの軸方向外側面に、回転部材の中心軸を中心とする円環状の環状溝を形成し、かつ、雌ねじ孔のそれぞれの軸方向外側の端部を、環状溝の底面にのみ開口させた構造が知られている。 As described in JP 2017-190865 A and other publications, even in this type of hub bolt-threaded hub unit bearing, a structure is known in which an annular groove is formed on the axially outer surface of the rotating flange, the groove being centered on the central axis of the rotating member, and the axially outer ends of each of the female threaded holes are open only to the bottom surface of the annular groove.

このような構造によれば、雌ねじ孔にハブボルトの雄ねじ部を螺合させ、さらに締め付けることに伴い、雌ねじ孔の軸方向外側の開口部の周囲が変形して盛り上がった場合でも、この盛り上がりを環状溝内にとどめることができる。 With this structure, even if the periphery of the axially outer opening of the female threaded hole deforms and bulges as a result of the male thread of the hub bolt being screwed into the female threaded hole and then tightened, this bulge can be contained within the annular groove.

特開2002-370104号公報JP 2002-370104 A 特開2003-175702号公報JP 2003-175702 A 特開2017-190865号公報JP 2017-190865 A

特開2017-190865号公報に記載されているような、従来の環状溝を備えたハブボルト螺合タイプのハブユニット軸受は、ブレーキジャダーを抑制する面から、改良の余地がある。この点について、以下に説明する。 The conventional hub bolt screw-in type hub unit bearing with an annular groove, as described in JP 2017-190865 A, leaves room for improvement in terms of suppressing brake judder. This point is explained below.

従来の環状溝を備えたハブボルト螺合タイプのハブユニット軸受では、図6(A)に示すように、回転フランジ100の軸方向外側面に備えられた環状溝101の底面102は、回転フランジ100の中心軸に対して直交する平坦面により構成されている。また、回転フランジ100の円周方向複数箇所に備えられた雌ねじ孔103の軸方向外側(図中左側)の端部は、環状溝101の底面102の径方向中央部に開口している。 In a conventional hub bolt screw-in type hub unit bearing with an annular groove, as shown in FIG. 6(A), the bottom surface 102 of the annular groove 101 provided on the axially outer surface of the rotating flange 100 is composed of a flat surface perpendicular to the central axis of the rotating flange 100. In addition, the axially outer (left side in the figure) ends of the female threaded holes 103 provided at multiple locations in the circumferential direction of the rotating flange 100 open to the radial center of the bottom surface 102 of the annular groove 101.

このような従来の環状溝を備えたハブボルト螺合タイプのハブユニット軸受では、図6(A)に示すように、不図示のホイールの通孔と制動用回転体104の通孔105とに挿通したハブボルト106の雄ねじ部107を、回転フランジ100の雌ねじ孔103に軸方向外側から螺合する。この状態から、さらにハブボルト106を締め付けると、ハブボルト106の軸力が雌ねじ孔103に集中する。具体的には、雌ねじ孔103に、ハブボルト106の雄ねじ部107から軸方向外側に引き寄せられる方向の軸力が作用する。これにより、図6(B)に誇張して示すように、回転フランジ100および制動用回転体104のハブボルト106の周囲部分が軸方向に曲げ変形する傾向となる。 In such a conventional hub bolt screw-in type hub unit bearing with an annular groove, as shown in FIG. 6(A), the male threaded portion 107 of the hub bolt 106 inserted through the through hole of the wheel (not shown) and the through hole 105 of the braking rotor 104 is screwed into the female threaded hole 103 of the rotating flange 100 from the outside in the axial direction. When the hub bolt 106 is further tightened from this state, the axial force of the hub bolt 106 is concentrated on the female threaded hole 103. Specifically, an axial force acts on the female threaded hole 103 in a direction that pulls it from the male threaded portion 107 of the hub bolt 106 outward in the axial direction. As a result, as shown in an exaggerated manner in FIG. 6(B), the rotating flange 100 and the surrounding portion of the hub bolt 106 of the braking rotor 104 tend to bend and deform in the axial direction.

具体的には、回転フランジ100のハブボルト106の周囲部分のうち、ハブボルト106よりも径方向内側の部分、すなわち、雌ねじ孔103よりも径方向内側の部分は、環状溝101の径方向内側の開口縁部108aを支点として軸方向に曲げ変形、すなわち、径方向内側に向かうにしたがって軸方向内側に向かう方向に曲げ変形する傾向となる。これにより、回転フランジ100の軸方向外側面のうち環状溝101よりも径方向内側の部分が、制動用回転体104の軸方向内側面に対して開口縁部108aで集中的に強く当接するようになる。その結果、制動用回転体104のハブボルト106の周囲部分のうち、ハブボルト106よりも径方向内側の部分も、開口縁部108aを支点として軸方向に曲げ変形、すなわち、径方向内側に向かうにしたがって軸方向外側に向かう方向に曲げ変形する傾向となる。 Specifically, the portion of the rotating flange 100 around the hub bolt 106 that is radially inward of the hub bolt 106, i.e., the portion radially inward of the female threaded hole 103, tends to bend in the axial direction with the radially inner opening edge 108a of the annular groove 101 as a fulcrum, i.e., to bend in the axial direction toward the inside as it moves radially inward. As a result, the portion of the axial outer surface of the rotating flange 100 that is radially inward of the annular groove 101 comes into concentrated strong contact with the axial inner surface of the braking rotor 104 at the opening edge 108a. As a result, the portion of the rotating flange 100 around the hub bolt 106 of the braking rotor 104 that is radially inward of the hub bolt 106 also tends to bend in the axial direction with the opening edge 108a as a fulcrum, i.e., to bend in the axial direction toward the outside as it moves radially inward.

一方、回転フランジ100のハブボルト106の周囲部分のうち、ハブボルト106よりも径方向外側の部分、すなわち、雌ねじ孔103よりも径方向外側の部分は、環状溝101の径方向外側の開口縁部108bを支点として軸方向に曲げ変形、すなわち、径方向外側に向かうにしたがって軸方向内側に向かう方向に曲げ変形する傾向となる。これにより、回転フランジ100の軸方向外側面のうち環状溝101よりも径方向外側の部分が、制動用回転体104の軸方向内側面に対して開口縁部108bで集中的に強く当接するようになる。その結果、制動用回転体104のハブボルト106の周囲部分のうち、雌ねじ孔103よりも径方向外側の部分も、開口縁部108bを支点として軸方向に曲げ変形、すなわち、径方向外側に向かうにしたがって軸方向外側に向かう方向に曲げ変形する傾向となる。 On the other hand, the part of the rotating flange 100 around the hub bolt 106 that is radially outer than the hub bolt 106, i.e., the part radially outer than the female threaded hole 103, tends to bend in the axial direction with the opening edge 108b on the radially outer side of the annular groove 101 as a fulcrum, that is, to bend in the axial direction toward the inside as it moves radially outward. As a result, the part of the axially outer side surface of the rotating flange 100 that is radially outer than the annular groove 101 comes into strong concentrated contact with the opening edge 108b against the axially inner side surface of the braking rotor 104. As a result, the part of the rotating flange 100 around the hub bolt 106 of the braking rotor 104 that is radially outer than the female threaded hole 103 also tends to bend in the axial direction with the opening edge 108b as a fulcrum, that is, to bend in the axial direction toward the outside as it moves radially outward.

以上のような曲げ変形、特に、制動用回転体104のうち環状溝101よりも径方向外側の部分の曲げ変形が生じることに基づいて、制動用回転体104の径方向外側の端部に備えられた、ブレーキパッドを当接させる部分の面振れ精度が低下し、ブレーキジャダーを抑制する効果が低くなる可能性がある。 The above-mentioned bending deformation, particularly the bending deformation of the portion of the braking rotor 104 radially outward from the annular groove 101, may reduce the surface runout accuracy of the portion of the braking rotor 104 at the radially outer end where the brake pads come into contact, potentially reducing the effectiveness of suppressing brake judder.

本発明の一態様のハブユニット軸受は、内周面に外輪軌道を有する外側部材と、外周面に内輪軌道を有する内側部材と、前記外輪軌道と前記内輪軌道との間に転動自在に配置された複数個の転動体とを備える。
前記外側部材と前記内側部材とのうちで使用時に回転する回転部材は、径方向外側に突出した回転フランジを有する。
前記回転フランジは、軸方向外側面に備えられた、前記回転部材の中心軸を中心とする円環状の環状溝、および、円周方向複数箇所のそれぞれに備えられた、軸方向に伸長しかつ軸方向外側の端部が前記環状溝の底面にのみ開口する雌ねじ孔を有する。
前記回転フランジのうち、前記環状溝と軸方向に重畳する部分において、前記雌ねじ孔よりも径方向外側の部分の軸方向の曲げ剛性が、前記雌ねじ孔よりも径方向内側の部分の軸方向の曲げ剛性に比べて高い。
A hub unit bearing of one embodiment of the present invention comprises an outer member having an outer ring raceway on its inner surface, an inner member having an inner ring raceway on its outer surface, and a plurality of rolling elements arranged freely rollable between the outer ring raceway and the inner ring raceway.
Of the outer member and the inner member, the rotating member which rotates during use has a rotating flange protruding radially outward.
The rotating flange has an annular groove provided on its axially outer surface, the annular groove being centered on the central axis of the rotating member, and female threaded holes provided at multiple locations in the circumferential direction, the female threaded holes extending in the axial direction and having their axially outer ends opening only to the bottom surface of the annular groove.
In the portion of the rotating flange that axially overlaps with the annular groove, the axial bending rigidity of the portion radially outer than the female threaded hole is higher than the axial bending rigidity of the portion radially inner than the female threaded hole.

本発明の一態様のハブユニット軸受では、前記環状溝の底面は、径方向外側に向かうにしたがって前記環状溝の軸方向深さが減少する形状を有する。 In one embodiment of the hub unit bearing of the present invention, the bottom surface of the annular groove has a shape in which the axial depth of the annular groove decreases as it moves radially outward.

本発明の一態様のハブユニット軸受では、前記環状溝のうち前記雌ねじ孔よりも径方向外側に位置する部分の径方向幅が、前記環状溝のうち前記雌ねじ孔よりも径方向内側に位置する部分の径方向幅に比べて小さい。 In one embodiment of the hub unit bearing of the present invention, the radial width of the portion of the annular groove located radially outward from the female threaded hole is smaller than the radial width of the portion of the annular groove located radially inward from the female threaded hole.

本発明の一態様によれば、回転フランジの円周方向複数箇所に雌ねじ孔を有し、かつ、ブレーキジャダーの抑制効果を確保しやすいハブユニット軸受を提供できる。 According to one aspect of the present invention, it is possible to provide a hub unit bearing that has female threaded holes at multiple locations in the circumferential direction of the rotating flange and that can easily ensure the effect of suppressing brake judder.

図1は、本発明の実施の形態の第1例のハブユニット軸受の断面図である。FIG. 1 is a cross-sectional view of a hub unit bearing according to a first embodiment of the present invention. 図2は、本発明の実施の形態の第1例のハブを軸方向外側から見た図である。FIG. 2 is a view of a hub according to a first embodiment of the present invention, as viewed from the outside in the axial direction. 図3は、回転フランジのみを取り出して示す、図1の左上部に相当する拡大図である。FIG. 3 is an enlarged view corresponding to the upper left portion of FIG. 1, showing only the rotating flange. 図4(A)および図4(B)は、一部を省略して示す図1の左上部に相当する拡大図であり、図4(A)は、ハブボルトを締め付ける前の状態を示しており、図4(B)は、ハブボルトを締め付けた後の状態を示している。Figures 4(A) and 4(B) are enlarged views corresponding to the upper left portion of Figure 1 with some parts omitted, where Figure 4(A) shows the state before the hub bolt is tightened and Figure 4(B) shows the state after the hub bolt has been tightened. 図5は、本発明の実施の形態の第2例に関する、図3に相当する図である。FIG. 5 is a diagram corresponding to FIG. 3 and relating to a second embodiment of the present invention. 図6(A)および図6(B)は、従来構造に関する、図4(A)および図4(B)に相当する図である。6A and 6B are views corresponding to FIGS. 4A and 4B, but for a conventional structure.

[実施形態の第1例]
本発明の実施の形態の第1例について、図1~図4を用いて説明する。
[First embodiment]
A first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.

本例のハブユニット軸受1は、従動輪用であり、外側部材である外輪2と、内側部材であって、かつ、使用時に回転する回転部材であるハブ3と、複数個の転動体4とを備える。なお、本発明は、駆動輪用のハブユニットにも適用可能である。また、本発明は、外側部材が回転部材であるハブユニット軸受にも適用可能である。 The hub unit bearing 1 in this example is for a driven wheel and comprises an outer ring 2, which is an outer member, a hub 3, which is an inner member and a rotating member that rotates during use, and a number of rolling elements 4. Note that the present invention is also applicable to hub units for driving wheels. The present invention is also applicable to hub unit bearings in which the outer member is a rotating member.

なお、ハブユニット軸受1に関して、軸方向内側は、車両への組付け状態で車両の幅方向中央側である図1の右側であり、軸方向外側は、車両への組付け状態で車両の幅方向外側である図1の左側である。 Note that with respect to the hub unit bearing 1, the axially inner side is the right side in FIG. 1, which is the center side in the width direction of the vehicle when assembled to the vehicle, and the axially outer side is the left side in FIG. 1, which is the outer side in the width direction of the vehicle when assembled to the vehicle.

外輪2は、内周面に、複列の外輪軌道5a、5bを有し、かつ、軸方向中間部に、径方向外側に突出した静止フランジ6を有する。静止フランジ6は、径方向中間部の円周方向複数箇所に、軸方向に貫通する支持孔7を有する。外輪2は、静止フランジ6の支持孔7に螺合した支持ボルトにより、懸架装置に対し支持固定され、車輪が回転する際にも回転しない。 The outer ring 2 has double-row outer ring raceways 5a, 5b on its inner circumferential surface, and a stationary flange 6 that protrudes radially outward at the axially intermediate portion. The stationary flange 6 has support holes 7 that penetrate in the axial direction at multiple circumferential locations at the radially intermediate portion. The outer ring 2 is supported and fixed to the suspension by support bolts that are screwed into the support holes 7 of the stationary flange 6, and does not rotate even when the wheel rotates.

ハブ3は、外輪2の径方向内側に外輪2と同軸に配置されており、外周面に、複列の外輪軌道5a、5bと対向する複列の内輪軌道8a、8bを有する。ハブ3は、外輪2よりも軸方向外側に位置する部分に、径方向外側に突出した回転フランジ9を有し、かつ、軸方向外側の端部に、円筒状のパイロット部10を有する。 The hub 3 is disposed coaxially with the outer ring 2 on the radially inner side of the outer ring 2, and has double row inner ring raceways 8a, 8b facing double row outer ring raceways 5a, 5b on its outer peripheral surface. The hub 3 has a rotating flange 9 that protrudes radially outward in a portion located axially outward from the outer ring 2, and has a cylindrical pilot portion 10 at its axially outer end.

回転フランジ9は、軸方向外側面に備えられた、ハブ3の中心軸Cを中心とする円環状の環状溝11、および、円周方向複数箇所のそれぞれに備えられた、軸方向に伸長し、かつ、軸方向外側の端部が環状溝11の底面12にのみ開口する雌ねじ孔13を有する。 The rotating flange 9 has an annular groove 11 on its axially outer surface, the annular groove 11 being centered on the central axis C of the hub 3, and female threaded holes 13 at multiple locations in the circumferential direction, which extend in the axial direction and whose axially outer ends open only to the bottom surface 12 of the annular groove 11.

すなわち、本例では、回転フランジ9の軸方向外側面は、径方向内側部に備えられた内側突き当て部14と、径方向外側部に備えられた外側突き当て部15と、径方向中間部に備えられた、ハブ3の中心軸Cを中心とする円環状の環状溝11とを有する。 That is, in this example, the axially outer surface of the rotating flange 9 has an inner abutment portion 14 provided on the radially inner portion, an outer abutment portion 15 provided on the radially outer portion, and an annular groove 11 provided on the radially intermediate portion, the annular groove 11 being centered on the central axis C of the hub 3.

内側突き当て部14および外側突き当て部15は、ハブ3の中心軸Cに直交する同一の仮想平面内に存在する平坦面により構成されている。 The inner abutment portion 14 and the outer abutment portion 15 are formed by flat surfaces that exist in the same imaginary plane perpendicular to the central axis C of the hub 3.

環状溝11は、径方向外側を向いた径方向内側周面16と、径方向内側を向いた径方向外側周面17と、軸方向外側を向いた底面12とを有する。 The annular groove 11 has a radially inner peripheral surface 16 facing radially outward, a radially outer peripheral surface 17 facing radially inward, and a bottom surface 12 facing axially outward.

径方向内側周面16の軸方向内側の端部は、底面12の径方向内側の端部に接続されている。径方向内側周面16の軸方向外側の端部は、内側突き当て部14の径方向外側の端部に接続されている。径方向内側周面16の軸方向外側の端部と内側突き当て部14の径方向外側の端部との接続部は、環状溝11の径方向内側の開口縁部30aである。 The axially inner end of the radially inner peripheral surface 16 is connected to the radially inner end of the bottom surface 12. The axially outer end of the radially inner peripheral surface 16 is connected to the radially outer end of the inner abutment portion 14. The connection between the axially outer end of the radially inner peripheral surface 16 and the radially outer end of the inner abutment portion 14 is the radially inner opening edge portion 30a of the annular groove 11.

径方向外側周面17の軸方向内側の端部は、底面12の径方向外側の端部に接続されている。径方向外側周面17の軸方向外側の端部は、外側突き当て部15の径方向内側の端部に接続されている。径方向外側周面17の軸方向外側の端部と外側突き当て部15の径方向内側の端部との接続部は、環状溝11の径方向外側の開口縁部30bである。 The axially inner end of the radially outer peripheral surface 17 is connected to the radially outer end of the bottom surface 12. The axially outer end of the radially outer peripheral surface 17 is connected to the radially inner end of the outer abutment portion 15. The connection between the axially outer end of the radially outer peripheral surface 17 and the radially inner end of the outer abutment portion 15 is the radially outer opening edge portion 30b of the annular groove 11.

図2および図3に示すように、環状溝11の径方向幅Waは、雌ねじ孔13の溝底径Daよりも大きい(Wa>Da)。なお、雌ねじ孔13の溝底径Daとは、雌ねじ孔13のねじ溝底部の直径である。 As shown in Figures 2 and 3, the radial width Wa of the annular groove 11 is larger than the groove bottom diameter Da of the female threaded hole 13 (Wa>Da). Note that the groove bottom diameter Da of the female threaded hole 13 is the diameter of the bottom of the threaded groove of the female threaded hole 13.

雌ねじ孔13のそれぞれは、回転フランジ9の径方向中間部の円周方向等間隔となる複数箇所(図示の例では5箇所)を軸方向に貫通している。すなわち、本例では、雌ねじ孔13のそれぞれは、軸方向内側の端部が回転フランジ9の軸方向内側面に開口し、軸方向外側の端部が回転フランジ9の軸方向外側面に開口している。ただし、本発明を実施する場合には、雌ねじ孔のそれぞれを、軸方向外側の端部のみが回転フランジの軸方向外側面に開口し、軸方向内側の端部が回転フランジの軸方向内側面に開口していない、有底孔とすることもできる。雌ねじ孔13のそれぞれの軸方向外側の端部は、環状溝11の底面12の径方向中央部に開口している。このため、雌ねじ孔13の軸方向外側の開口部の径方向両側に隣接する部分のそれぞれにも、環状溝11の底面12の一部が存在している。 Each female threaded hole 13 axially penetrates a plurality of locations (five locations in the illustrated example) that are equally spaced in the circumferential direction of the radially intermediate portion of the rotating flange 9. That is, in this example, the axially inner end of each female threaded hole 13 opens to the axially inner side surface of the rotating flange 9, and the axially outer end opens to the axially outer side surface of the rotating flange 9. However, when implementing the present invention, each female threaded hole can be a bottomed hole in which only the axially outer end opens to the axially outer side surface of the rotating flange, and the axially inner end does not open to the axially inner side surface of the rotating flange. The axially outer end of each female threaded hole 13 opens to the radial center of the bottom surface 12 of the annular groove 11. Therefore, a part of the bottom surface 12 of the annular groove 11 is also present in each of the portions adjacent to both radial sides of the axially outer opening of the female threaded hole 13.

すなわち、本例では、図3に示すように、環状溝11の内径Diは、ハブ3の中心軸C(図1および図2参照)を中心とする雌ねじ孔13の内接円の直径diよりも小さい(Di<di)。なお、ハブ3の中心軸Cを中心とする雌ねじ孔13の内接円とは、ハブ3の中心軸Cを中心とし、かつ、雌ねじ孔13のねじ溝底部に接する仮想円のうち、直径が最も小さい仮想円のことをいう。また、環状溝11の外径Doは、ハブ3の中心軸Cを中心とする雌ねじ孔13の外接円の直径doよりも大きい(Do>do)。なお、ハブ3の中心軸Cを中心とする雌ねじ孔13の外接円とは、ハブ3の中心軸Cを中心とし、かつ、雌ねじ孔13のねじ溝底部に接する仮想円のうち、直径が最も大きい仮想円のことをいう。 In this example, as shown in FIG. 3, the inner diameter Di of the annular groove 11 is smaller than the diameter di of the inscribed circle of the female threaded hole 13 centered on the central axis C of the hub 3 (see FIG. 1 and FIG. 2) (Di<di). The inscribed circle of the female threaded hole 13 centered on the central axis C of the hub 3 refers to the imaginary circle with the smallest diameter among the imaginary circles centered on the central axis C of the hub 3 and tangent to the bottom of the thread groove of the female threaded hole 13. The outer diameter Do of the annular groove 11 is larger than the diameter do of the circumscribed circle of the female threaded hole 13 centered on the central axis C of the hub 3 (Do>do). The circumscribed circle of the female threaded hole 13 centered on the central axis C of the hub 3 refers to the imaginary circle with the largest diameter among the imaginary circles centered on the central axis C of the hub 3 and tangent to the bottom of the thread groove of the female threaded hole 13.

さらに、本例では、回転フランジ9のうち、環状溝11と軸方向に重畳する部分において、雌ねじ孔13よりも径方向内側の部分(図3で斜格子を付したα部分)の径方向幅Wi(=(di-Di)/2)と、雌ねじ孔13よりも径方向外側の部分(図3で斜格子を付したβ部分)の径方向幅Wo(=(Do-do)/2)とは、互いに等しい(Wi=Wo)。 Furthermore, in this example, in the portion of the rotating flange 9 that axially overlaps with the annular groove 11, the radial width Wi (=(di-Di)/2) of the portion radially inward from the female threaded hole 13 (the α portion marked with diagonal grid in FIG. 3) and the radial width Wo (=(Do-do)/2) of the portion radially outward from the female threaded hole 13 (the β portion marked with diagonal grid in FIG. 3) are equal to each other (Wi=Wo).

なお、回転フランジ9のうち、環状溝11と軸方向に重畳する部分において、雌ねじ孔13よりも径方向内側の部分(α部分)とは、回転フランジ9のうち、環状溝11と軸方向に重畳する部分において、ハブ3の中心軸Cを中心とする雌ねじ孔13の内接円よりも径方向内側の部分である。また、回転フランジ9のうち、環状溝11と軸方向に重畳する部分において、雌ねじ孔13よりも径方向外側の部分(β部分)とは、回転フランジ9のうち、環状溝11と軸方向に重畳する部分において、ハブ3の中心軸Cを中心とする雌ねじ孔13の外接円よりも径方向外側の部分である。 The portion of the rotating flange 9 that overlaps with the annular groove 11 in the axial direction and is radially inward of the female threaded hole 13 (α portion) is the portion of the rotating flange 9 that overlaps with the annular groove 11 in the axial direction and is radially inward of the inscribed circle of the female threaded hole 13 that is centered on the central axis C of the hub 3. The portion of the rotating flange 9 that overlaps with the annular groove 11 in the axial direction and is radially outward of the circumscribed circle of the female threaded hole 13 that is centered on the central axis C of the hub 3 (β portion) is the portion of the rotating flange 9 that overlaps with the annular groove 11 in the axial direction and is radially outward of the circumscribed circle of the female threaded hole 13 that is centered on the central axis C of the hub 3.

また、本例では、回転フランジ9の軸方向内側面のうち、雌ねじ孔13のそれぞれの軸方向内側の開口部の周囲部分は、ハブ3の中心軸Cに対して直交する平坦面18により構成されている。平坦面18の径方向内側の端部は、環状溝11の径方向内側の端部よりも径方向内側に位置している。また、平坦面18の径方向外側の端部は、環状溝11の径方向外側の端部よりも径方向外側に位置している。 In addition, in this example, the axially inner surface of the rotating flange 9, surrounding the axially inner openings of each of the female threaded holes 13, is formed of a flat surface 18 perpendicular to the central axis C of the hub 3. The radially inner end of the flat surface 18 is located radially inward from the radially inner end of the annular groove 11. In addition, the radially outer end of the flat surface 18 is located radially outward from the radially outer end of the annular groove 11.

また、本例では、回転フランジ9のうち、環状溝11と軸方向に重畳する部分において、雌ねじ孔13よりも径方向外側の部分(β部分)の軸方向の曲げ剛性が、雌ねじ孔13よりも径方向内側の部分(α部分)の軸方向の曲げ剛性に比べて高い。 In addition, in this example, in the portion of the rotating flange 9 that axially overlaps with the annular groove 11, the axial bending rigidity of the portion radially outward from the female threaded hole 13 (β portion) is higher than the axial bending rigidity of the portion radially inward from the female threaded hole 13 (α portion).

このために、本例では、環状溝11の底面12は、径方向外側に向かうにしたがって環状溝11の軸方向深さが減少する形状を有する。具体的には、本例では、底面12を、径方向外側に向かうにしたがって軸方向外側に向かう方向に傾斜した部分円すい凹面により構成している。なお、本発明を実施する場合に、環状溝の底面の形状として、径方向外側に向かうにしたがって環状溝の軸方向深さが減少する形状を採用する場合には、たとえば部分球状凹面などの、本例とは異なる形状を採用することもできる。すなわち、以下の説明で明らかになるように、底面の形状の如何にかかわらず、To>Tiを充足しているなら、段付形状など、どのような形状であってもよい。 For this reason, in this example, the bottom surface 12 of the annular groove 11 has a shape in which the axial depth of the annular groove 11 decreases as it moves radially outward. Specifically, in this example, the bottom surface 12 is configured as a partial conical concave surface that is inclined in the axially outward direction as it moves radially outward. When implementing this invention, if a shape in which the axial depth of the annular groove decreases as it moves radially outward is adopted as the shape of the bottom surface of the annular groove, a shape different from this example, such as a partial spherical concave surface, can also be adopted. In other words, as will become clear from the following explanation, regardless of the shape of the bottom surface, any shape, such as a stepped shape, is acceptable as long as To>Ti is satisfied.

本例では、底面12の形状として、径方向外側に向かうにしたがって環状溝11の軸方向深さが減少する形状を採用することによって、雌ねじ孔13よりも径方向外側の部分(β部分)の軸方向の肉厚Toを、雌ねじ孔13よりも径方向内側の部分(α部分)の軸方向の肉厚Tiに比べて大きくしている。なお、肉厚To、Tiのそれぞれは、平坦面18と底面12との間の軸方向幅である。 In this example, the bottom surface 12 is shaped so that the axial depth of the annular groove 11 decreases radially outward, making the axial thickness To of the portion (β portion) radially outward from the female threaded hole 13 greater than the axial thickness Ti of the portion (α portion) radially inward from the female threaded hole 13. Each of the thicknesses To and Ti is the axial width between the flat surface 18 and the bottom surface 12.

すなわち、本例では、雌ねじ孔13よりも径方向外側の部分(β部分)の径方向幅Woと、雌ねじ孔13よりも径方向内側の部分(α部分)の径方向幅Wiとを、互いに等しくする一方で、雌ねじ孔13よりも径方向外側の部分(β部分)の軸方向の肉厚Toを、雌ねじ孔13よりも径方向内側の部分(α部分)の軸方向の肉厚Tiに比べて大きくしている。つまり、本例では、雌ねじ孔13よりも径方向外側の部分(β部分)の断面二次モーメントを、雌ねじ孔13よりも径方向内側の部分(α部分)の断面二次モーメントに比べて大きくしている。これにより、本例では、雌ねじ孔13よりも径方向外側の部分(β部分)の軸方向の曲げ剛性を、雌ねじ孔13よりも径方向内側の部分(α部分)の軸方向の曲げ剛性に比べて高くしている。 That is, in this example, the radial width Wo of the portion (β portion) radially outer than the female threaded hole 13 and the radial width Wi of the portion (α portion) radially inner than the female threaded hole 13 are made equal to each other, while the axial thickness To of the portion (β portion) radially outer than the female threaded hole 13 is made larger than the axial thickness Ti of the portion (α portion) radially inner than the female threaded hole 13. That is, in this example, the second moment of area of the portion (β portion) radially outer than the female threaded hole 13 is made larger than the second moment of area of the portion (α portion) radially inner than the female threaded hole 13. As a result, in this example, the axial bending rigidity of the portion (β portion) radially outer than the female threaded hole 13 is made higher than the axial bending rigidity of the portion (α portion) radially inner than the female threaded hole 13.

すなわち、たとえば片持ち梁では断面二次モーメントが大きい方が曲げ変形しにくいように、本例では、雌ねじ孔13よりも径方向外側の部分(β部分)の方が、雌ねじ孔13よりも径方向内側の部分(α部分)に比べて断面二次モーメントが大きいため、軸方向に曲げ変形しにくい。 In other words, just as a cantilever beam is less prone to bending deformation when its second moment of area is large, in this example, the part radially outward from the female threaded hole 13 (β part) has a larger second moment of area than the part radially inward from the female threaded hole 13 (α part), and is therefore less prone to bending deformation in the axial direction.

なお、図示の例では、径方向内側周面16と径方向外側周面17とのそれぞれは、直径が軸方向にわたり変化しない円筒面により構成されている。ただし、径方向内側周面と径方向外側周面とのそれぞれを、軸方向外側に向かうにしたがって環状溝の径方向幅が大きくなる方向にテーパ状に傾斜した傾斜面により構成することもできる。 In the illustrated example, the radially inner peripheral surface 16 and the radially outer peripheral surface 17 are each formed of a cylindrical surface whose diameter does not change along the axial direction. However, each of the radially inner peripheral surface and the radially outer peripheral surface can also be formed of an inclined surface that is tapered in such a direction that the radial width of the annular groove increases toward the axially outer side.

また、本例では、回転フランジ9は、円周方向複数箇所に、軸方向に貫通する作業孔19をさらに有する。作業孔19のそれぞれは、組立やメンテナンスの際に工具を挿入するなどのために用いられる。本例では、作業孔19は、雌ねじ孔13と同数備えられており、円周方向に関して等間隔に配置されている。また、作業孔19の円周方向に関する配置の位相は、雌ねじ孔13の円周方向に関する配置の位相に対して半ピッチずれている。 In this example, the rotating flange 9 further has work holes 19 penetrating in the axial direction at multiple locations in the circumferential direction. Each of the work holes 19 is used for inserting tools during assembly and maintenance. In this example, the number of work holes 19 is the same as the number of female threaded holes 13, and they are arranged at equal intervals in the circumferential direction. Furthermore, the phase of the circumferential arrangement of the work holes 19 is shifted by half a pitch from the phase of the circumferential arrangement of the female threaded holes 13.

図1に戻り、本例では、ハブ3は、内輪20とハブ輪21とを組み合わせてなる。 Returning to Figure 1, in this example, the hub 3 is made up of an inner ring 20 and a hub wheel 21.

内輪20は、外周面に、軸方向内側の内輪軌道8aを有する。 The inner ring 20 has an inner ring raceway 8a on the outer circumferential surface, which is axially inward.

ハブ輪21は、外周面の軸方向中間部に、軸方向外側の内輪軌道8bを有する。また、ハブ輪21は、軸方向外側の内輪軌道8bよりも軸方向外側に位置する部分に、径方向外側に向けて突出した回転フランジ9を有し、かつ、軸方向外側の端部に、円筒状のパイロット部10を有する。 The hub ring 21 has an axially outer inner ring raceway 8b in the axially middle part of the outer peripheral surface. The hub ring 21 also has a rotating flange 9 that protrudes radially outward in a portion located axially outward of the axially outer inner ring raceway 8b, and has a cylindrical pilot portion 10 at the axially outer end.

ハブ3は、ハブ輪21の軸方向内側部に内輪20を締り嵌めで外嵌し、かつ、ハブ輪21の軸方向内側の端部に備えられたかしめ部22により内輪20の軸方向内側の端面を押さえ付けることで、内輪20とハブ輪21とを結合固定することにより構成されている。 The hub 3 is constructed by fitting the inner ring 20 tightly to the axially inner part of the hub wheel 21, and pressing the axially inner end face of the inner ring 20 with a crimping portion 22 provided at the axially inner end of the hub wheel 21, thereby connecting and fixing the inner ring 20 and the hub wheel 21.

ホイール24および制動用回転体25は、雌ねじ孔13のそれぞれに螺合されたハブボルト26により、回転フランジ9に結合固定される。 The wheel 24 and the braking rotor 25 are fixed to the rotating flange 9 by hub bolts 26 screwed into the female threaded holes 13.

具体的には、制動用回転体25の径方向中央部に備えられた内周面を、パイロット部10の軸方向内側部の外周面に外嵌し、かつ、ホイール24の径方向中央部に備えられた内周面を、パイロット部10の軸方向外側部の外周面に外嵌している。また、この状態で、制動用回転体25およびホイール24のそれぞれの径方向中間部の円周方向複数箇所に備えられた通孔27a、27bにハブボルト26を挿通し、かつ、ハブボルト26の先端部である軸方向内側の端部に備えられた雄ねじ部28を回転フランジ9の雌ねじ孔13に軸方向外側から螺合し、さらに締め付けている。これにより、ホイール24および制動用回転体25を、回転フランジ9とハブボルト26の基端部である軸方向外側の端部に備えられた頭部29とにより軸方向両側から強く挟持することで、ホイール24および制動用回転体25を、回転フランジ9に結合固定している。 Specifically, the inner peripheral surface provided in the radial center of the braking rotor 25 is fitted onto the outer peripheral surface of the axially inner part of the pilot part 10, and the inner peripheral surface provided in the radial center of the wheel 24 is fitted onto the outer peripheral surface of the axially outer part of the pilot part 10. In this state, the hub bolt 26 is inserted into the through holes 27a, 27b provided at multiple circumferential locations in the radial middle parts of the braking rotor 25 and the wheel 24, and the male threaded part 28 provided at the axially inner end, which is the tip part of the hub bolt 26, is screwed into the female threaded hole 13 of the rotating flange 9 from the axially outer side, and further tightened. As a result, the wheel 24 and the braking rotor 25 are firmly clamped from both axial sides by the rotating flange 9 and the head 29 provided at the axially outer end, which is the base end of the hub bolt 26, and the wheel 24 and the braking rotor 25 are fixed to the rotating flange 9.

転動体4は、複列の外輪軌道5a、5bと複列の内輪軌道8a、8bとの間に、それぞれの列ごとに複数個ずつ、保持器23により保持された状態で転動自在に配置されている。これにより、ハブ3は、外輪2の径方向内側に回転自在に支持されている。なお、本例では、転動体4として玉を使用しているが、玉に代えて円すいころを使用することもできる。また、本例では、軸方向外側列の転動体4のピッチ円直径と、軸方向内側列の転動体4のピッチ円直径とを互いに同じとしているが、本発明は、軸方向外側列の転動体のピッチ円直径と、軸方向内側列の転動体のピッチ円直径とが互いに異なる、異径PCD型のハブユニット軸受に適用することもできる。 The rolling elements 4 are arranged between the double row outer ring raceways 5a, 5b and the double row inner ring raceways 8a, 8b, with multiple rolling elements for each row held by a cage 23, so that they can roll freely. As a result, the hub 3 is supported rotatably on the radial inside of the outer ring 2. In this example, balls are used as the rolling elements 4, but tapered rollers can be used instead of balls. In this example, the pitch circle diameter of the rolling elements 4 in the axially outer row and the pitch circle diameter of the rolling elements 4 in the axially inner row are the same, but the present invention can also be applied to a PCD type hub unit bearing with different diameters, in which the pitch circle diameters of the rolling elements in the axially outer row and the rolling elements in the axially inner row are different from each other.

上述したような本例のハブユニット軸受1によれば、ブレーキジャダーの抑制効果を確保しやすい。 The hub unit bearing 1 of this embodiment as described above makes it easier to ensure the effect of suppressing brake judder.

すなわち、本例では、回転フランジ9の軸方向外側面は、径方向中間部に、ハブ3の中心軸Cを中心とする円環状の環状溝11を有する。また、雌ねじ孔13のそれぞれの軸方向外側の端部は、環状溝11の底面12の径方向中央部に開口している。このため、制動用回転体25およびホイール24のそれぞれの通孔27a、27bに挿通したハブボルト26の雄ねじ部28を、回転フランジ9の雌ねじ孔13に軸方向外側から螺合し、さらに締め付けることに伴い、雌ねじ孔13の軸方向外側の開口部の周囲が変形して盛り上がった場合でも、この盛り上がりを環状溝11内にとどめることで、回転フランジ9の軸方向外側面の環状溝11以外の部分の面振れ精度を向上させることができる。これにより、制動用回転体25の径方向外側の端部に備えられた、ブレーキパッドを当接させる部分の面振れ精度を向上させ、制動時にブレーキジャダーの発生を抑制できる。 That is, in this example, the axially outer surface of the rotating flange 9 has, in the radial middle portion, a circular annular groove 11 centered on the central axis C of the hub 3. In addition, the axially outer ends of the female threaded holes 13 open to the radial center of the bottom surface 12 of the annular groove 11. Therefore, even if the male threaded portion 28 of the hub bolt 26 inserted into the through holes 27a, 27b of the braking rotor 25 and the wheel 24 is screwed into the female threaded hole 13 of the rotating flange 9 from the axially outer side and further tightened, the periphery of the axially outer opening of the female threaded hole 13 is deformed and raised, by keeping this raised portion within the annular groove 11, the surface runout accuracy of the portion of the axially outer surface of the rotating flange 9 other than the annular groove 11 can be improved. This improves the surface runout accuracy of the portion that abuts the brake pad, which is provided at the radially outer end of the braking rotor 25, and suppresses the occurrence of brake judder during braking.

また、本例では、図4(A)に示すように、制動用回転体25およびホイール24(図1参照)のそれぞれの通孔27a、27bに挿通したハブボルト26の雄ねじ部28を雌ねじ孔13に螺合した状態で、さらにハブボルト26を締め付けると、ハブボルト26の軸力が雌ねじ孔13に集中する。具体的には、雌ねじ孔13に、ハブボルト26の雄ねじ部28から軸方向外側に引き寄せられる方向の軸力が作用する。これにより、本例では、図4(B)に誇張して示すように、回転フランジ9および制動用回転体25のハブボルト26の周囲部分が軸方向に曲げ変形する傾向となる。 In addition, in this example, as shown in FIG. 4(A), when the male threaded portion 28 of the hub bolt 26 inserted through the through holes 27a, 27b of the braking rotor 25 and the wheel 24 (see FIG. 1) is screwed into the female threaded hole 13 and the hub bolt 26 is further tightened, the axial force of the hub bolt 26 is concentrated on the female threaded hole 13. Specifically, an axial force acts on the female threaded hole 13 in a direction that pulls it axially outward from the male threaded portion 28 of the hub bolt 26. As a result, in this example, as shown in an exaggerated manner in FIG. 4(B), the rotating flange 9 and the surrounding portion of the hub bolt 26 of the braking rotor 25 tend to bend and deform in the axial direction.

具体的には、本例では、回転フランジ9および制動用回転体25のハブボルト26の周囲部分において、ハブボルト26よりも径方向内側の部分では、図6(B)に示した従来構造の場合と同様、環状溝11の径方向内側の開口縁部30aを支点として軸方向に曲げ変形する傾向が大きくなるが、ハブボルト26よりも径方向外側の部分では、図6(B)に示した従来構造の場合と異なり、環状溝11の径方向外側の開口縁部30bを支点として軸方向に曲げ変形する傾向を抑えられる。この理由について、以下に説明する。 Specifically, in this example, in the area around the hub bolt 26 of the rotating flange 9 and the braking rotor 25, the area radially inward of the hub bolt 26 has a greater tendency to bend and deform in the axial direction with the radially inner opening edge 30a of the annular groove 11 as a fulcrum, as in the case of the conventional structure shown in FIG. 6(B). However, in the area radially outward of the hub bolt 26, unlike the case of the conventional structure shown in FIG. 6(B), the tendency to bend and deform in the axial direction with the radially outer opening edge 30b of the annular groove 11 as a fulcrum is suppressed. The reason for this is explained below.

すなわち、本例では、回転フランジ9のうち、環状溝11と軸方向に重畳する部分において、雌ねじ孔13よりも径方向外側の部分(β部分)の軸方向の曲げ剛性が、雌ねじ孔13よりも径方向内側の部分(α部分)の軸方向の曲げ剛性に比べて高い。このため、雌ねじ孔13よりも径方向外側の部分(β部分)は、雌ねじ孔13よりも径方向内側の部分(α部分)に比べて、軸方向に曲げ変形しにくい。 That is, in this example, in the portion of the rotating flange 9 that axially overlaps with the annular groove 11, the axial bending rigidity of the portion (β portion) radially outward from the female threaded hole 13 is higher than the axial bending rigidity of the portion (α portion) radially inward from the female threaded hole 13. Therefore, the portion (β portion) radially outward from the female threaded hole 13 is less susceptible to bending deformation in the axial direction than the portion (α portion) radially inward from the female threaded hole 13.

このため、本例では、回転フランジ9の外側突き当て部15と制動用回転体25の軸方向内側面との当接部に作用するハブボルト26の軸力の分配が、回転フランジ9の内側突き当て部14と制動用回転体25の軸方向内側面との当接部に作用するハブボルト26の軸力の分配に比べて、大きくなる。また、雌ねじ孔13よりも径方向外側の部分(β部分)は、軸方向に曲げ変形しにくいため、回転フランジ9の外側突き当て部15を、制動用回転体25の軸方向内側面に対して面押ししやすい。したがって、本例では、回転フランジ9の外側突き当て部15と制動用回転体25の軸方向内側面とを、広い範囲で強く密接させることができる。 For this reason, in this example, the distribution of the axial force of the hub bolt 26 acting on the contact portion between the outer abutment portion 15 of the rotating flange 9 and the axial inner surface of the braking rotor 25 is greater than the distribution of the axial force of the hub bolt 26 acting on the contact portion between the inner abutment portion 14 of the rotating flange 9 and the axial inner surface of the braking rotor 25. In addition, the portion (β portion) radially outward of the female threaded hole 13 is less susceptible to bending deformation in the axial direction, so the outer abutment portion 15 of the rotating flange 9 is easily pressed against the axial inner surface of the braking rotor 25. Therefore, in this example, the outer abutment portion 15 of the rotating flange 9 and the axial inner surface of the braking rotor 25 can be brought into strong, intimate contact over a wide range.

なお、本例の構造を実施する場合には、たとえば、環状溝11のうち雌ねじ孔13よりも径方向外側の部分(β部分と軸方向に重畳する部分)の軸方向深さを、従来構造と同じ深さにすることもできるし、従来構造に比べて浅くすることもできる。 When implementing the structure of this example, for example, the axial depth of the portion of the annular groove 11 radially outward from the female threaded hole 13 (the portion that overlaps with the β portion in the axial direction) can be the same as that of the conventional structure, or it can be shallower than that of the conventional structure.

すなわち、本例の構造では、環状溝11のうち雌ねじ孔13よりも径方向外側の部分の軸方向深さを従来構造と同じ深さにする、すなわち、雌ねじ孔13よりも径方向外側の部分(β部分)の軸方向の曲げ剛性を従来構造と同じ大きさにする場合でも、回転フランジ9の外側突き当て部15と制動用回転体25の軸方向内側面との当接部に作用するハブボルト26の軸力の分配を大きくできる。このため、外側突き当て部15と制動用回転体25の軸方向内側面とを、広い範囲で強く密接させることができる。 In other words, in the structure of this example, even if the axial depth of the portion of the annular groove 11 radially outward from the female threaded hole 13 is made the same as in the conventional structure, that is, the axial bending rigidity of the portion radially outward from the female threaded hole 13 (β portion) is made the same as in the conventional structure, the distribution of the axial force of the hub bolt 26 acting on the contact portion between the outer abutment portion 15 of the rotating flange 9 and the axial inner surface of the braking rotor 25 can be increased. This allows the outer abutment portion 15 and the axial inner surface of the braking rotor 25 to be brought into strong, intimate contact with each other over a wide range.

また、本例の構造では、環状溝11のうち雌ねじ孔13よりも径方向外側の部分の軸方向深さを従来構造に比べて浅くする、すなわち、雌ねじ孔13よりも径方向外側の部分(β部分)の軸方向の曲げ剛性を従来構造よりも大きくする場合には、回転フランジ9の外側突き当て部15と制動用回転体25の軸方向内側面との当接部に作用するハブボルト26の軸力の分配を、より大きくでき、かつ、雌ねじ孔13よりも径方向外側の部分(β部分)が、より軸方向に曲げ変形しにくくなる。このため、外側突き当て部15と制動用回転体25の軸方向内側面とを、より強く密接させることができる。 In addition, in the structure of this example, if the axial depth of the portion of the annular groove 11 radially outward from the female threaded hole 13 is made shallower than in the conventional structure, that is, if the axial bending rigidity of the portion radially outward from the female threaded hole 13 (β portion) is made greater than in the conventional structure, the distribution of the axial force of the hub bolt 26 acting on the contact portion between the outer abutment portion 15 of the rotating flange 9 and the axial inner surface of the braking rotor 25 can be made greater, and the portion radially outward from the female threaded hole 13 (β portion) becomes less susceptible to axial bending deformation. This allows the outer abutment portion 15 and the axial inner surface of the braking rotor 25 to be brought into closer contact with each other more strongly.

以上のように、本例では、回転フランジ9の外側突き当て部15と制動用回転体25の軸方向内側面とを広い範囲で強く密接させることができる。これにより、制動用回転体25のうち環状溝11よりも径方向外側の部分の軸方向の曲げ変形を抑えられる。この結果、回転フランジ9の外側突き当て部15と制動用回転体25の軸方向内側面との当接部よりも径方向外側に存在する、制動用回転体25の径方向外側の端部に備えられた、ブレーキパッドを当接させる部分の面振れ精度をさらに向上させることができる。この結果、ブレーキジャダーの抑制効果をさらに確保できる。 As described above, in this example, the outer abutment portion 15 of the rotating flange 9 and the axially inner surface of the braking rotor 25 can be brought into strong, intimate contact over a wide range. This suppresses axial bending deformation of the portion of the braking rotor 25 radially outward of the annular groove 11. As a result, it is possible to further improve the surface runout accuracy of the portion that abuts the brake pad, which is provided at the radially outer end of the braking rotor 25 and is located radially outward of the abutment portion between the outer abutment portion 15 of the rotating flange 9 and the axially inner surface of the braking rotor 25. As a result, the brake judder suppression effect can be further ensured.

なお、本例では、制動用回転体25のうち環状溝11よりも径方向内側の部分に、軸方向の曲げ変形が生じる傾向となるが、この部分の軸方向の曲げ変形は、ブレーキジャダーの抑制効果に及ぼす影響が極めて低いため、大きな問題とはならない。 In this example, the braking rotor 25 tends to bend radially inward from the annular groove 11, but this does not pose a major problem because the axial bending deformation in this area has an extremely low effect on the brake judder suppression effect.

[実施形態の第2例]
本発明の実施の形態の第2例について、図5を用いて説明する。
[Second Example of the Embodiment]
A second embodiment of the present invention will be described with reference to FIG.

本例のハブユニット軸受でも、回転フランジ9aのうち、環状溝11aと軸方向に重畳する部分において、雌ねじ孔13よりも径方向外側の部分(図5で斜格子を付したβ部分)の軸方向の曲げ剛性を、雌ねじ孔13よりも径方向内側の部分(図5で斜格子を付したα部分)の軸方向の曲げ剛性に比べて高くすることに基づいて、ブレーキジャダーの抑制効果を確保しやすくしている。 In the hub unit bearing of this example, the axial bending stiffness of the portion of the rotating flange 9a that overlaps with the annular groove 11a in the axial direction is made higher than the axial bending stiffness of the portion radially outward from the female threaded hole 13 (the β portion marked with diagonal grid in Figure 5) compared to the portion radially inward from the female threaded hole 13 (the α portion marked with diagonal grid in Figure 5), making it easier to ensure the suppression effect of brake judder.

すなわち、本例では、環状溝11aの底面12aを、ハブ3aの中心軸に直交する平坦面により構成している。これにより、雌ねじ孔13よりも径方向外側の部分(β部分)の軸方向の肉厚Toと、雌ねじ孔13よりも径方向内側の部分(α部分)の軸方向の肉厚Tiとを、互いに等しくしている(To=Ti)。 That is, in this example, the bottom surface 12a of the annular groove 11a is configured as a flat surface perpendicular to the central axis of the hub 3a. This makes the axial thickness To of the portion radially outward from the female threaded hole 13 (β portion) and the axial thickness Ti of the portion radially inward from the female threaded hole 13 (α portion) equal to each other (To = Ti).

また、本例では、環状溝11aのうち雌ねじ孔13よりも径方向外側に位置する部分の径方向幅を、環状溝11aのうち雌ねじ孔13よりも径方向内側に位置する部分の径方向幅に比べて小さくしている。換言すれば、回転フランジ9aのうち、環状溝11と軸方向に重畳する部分において、雌ねじ孔13よりも径方向外側の部分(β部分)の径方向幅Wo(=(Do-do)/2)を、雌ねじ孔13よりも径方向内側の部分(α部分)の径方向幅Wi(=(di-Di)/2)に比べて小さくしている(Wo<Wi)。
Also, in this example, the radial width of a portion of the annular groove 11a located radially outward from the female threaded hole 13 is made smaller than the radial width of a portion of the annular groove 11a located radially inward from the female threaded hole 13. In other words, in the portion of the rotating flange 9a that axially overlaps with the annular groove 11a , the radial width Wo (=(Do-do)/2) of the portion radially outward from the female threaded hole 13 (β portion) is made smaller than the radial width Wi (=(di-Di)/2) of the portion radially inward from the female threaded hole 13 (α portion) (Wo<Wi).

つまり、本例では、雌ねじ孔13よりも径方向外側の部分(β部分)の軸方向の肉厚Toと、雌ねじ孔13よりも径方向内側の部分(α部分)の軸方向の肉厚Tiとを、互いに等しくする一方で、雌ねじ孔13よりも径方向外側の部分(β部分)の径方向幅Woを、雌ねじ孔13よりも径方向内側の部分(α部分)の径方向幅Wiに比べて小さくしている。これにより、本例では、雌ねじ孔13よりも径方向外側の部分(β部分)の軸方向の曲げ剛性を、雌ねじ孔13よりも径方向内側の部分(α部分)の軸方向の曲げ剛性に比べて高くしている。 In other words, in this example, the axial thickness To of the portion (β portion) radially outer than the female threaded hole 13 and the axial thickness Ti of the portion (α portion) radially inner than the female threaded hole 13 are made equal to each other, while the radial width Wo of the portion (β portion) radially outer than the female threaded hole 13 is made smaller than the radial width Wi of the portion (α portion) radially inner than the female threaded hole 13. As a result, in this example, the axial bending rigidity of the portion (β portion) radially outer than the female threaded hole 13 is made higher than the axial bending rigidity of the portion (α portion) radially inner than the female threaded hole 13.

すなわち、たとえば片持ち梁では梁の長さが短い方が曲げ変形しにくいように、本例では、雌ねじ孔13よりも径方向外側の部分(β部分)の方が、雌ねじ孔13よりも径方向内側の部分(α部分)に比べて径方向幅が短いため、軸方向に曲げ変形しにくい。 In other words, just as a cantilever beam is less susceptible to bending deformation when the beam length is shorter, in this example, the portion radially outward from the female threaded hole 13 (β portion) has a shorter radial width than the portion radially inward from the female threaded hole 13 (α portion), and is therefore less susceptible to bending deformation in the axial direction.

以上のような本例の構造では、回転フランジ9aのうち、環状溝11aと軸方向に重畳する部分において、雌ねじ孔13よりも径方向外側の部分(β部分)の方が、雌ねじ孔13よりも径方向内側の部分(α部分)に比べて、径方向幅が短く、軸方向の曲げ剛性が高い。このため、雌ねじ孔13よりも径方向外側の部分(β部分)は、軸方向に曲げ変形しにくい。 In the structure of this example as described above, in the portion of the rotating flange 9a that overlaps with the annular groove 11a in the axial direction, the portion (β portion) radially outward from the female threaded hole 13 has a shorter radial width and higher axial bending rigidity than the portion (α portion) radially inward from the female threaded hole 13. For this reason, the portion (β portion) radially outward from the female threaded hole 13 is less susceptible to bending deformation in the axial direction.

このため、本例の構造でも、回転フランジ9aの外側突き当て部15と制動用回転体25(図1参照)の軸方向内側面との当接部に作用するハブボルト26(図1参照)の軸力の分配が、回転フランジ9aの内側突き当て部14と制動用回転体25の軸方向内側面との当接部に作用するハブボルト26の軸力の分配に比べて、大きくなる。また、雌ねじ孔13aよりも径方向外側の部分(β部分)は、軸方向に曲げ変形しにくいため、回転フランジ9aの外側突き当て部15を、制動用回転体25の軸方向内側面に対して面押ししやすい。したがって、本例の構造でも、回転フランジ9aの外側突き当て部15と制動用回転体25の軸方向内側面とを、広い範囲で強く密接させることができる。この結果、制動用回転体25のうち環状溝11aよりも径方向外側の部分の軸方向の曲げ変形を抑えられ、ブレーキジャダーの抑制効果を確保できる。
その他の構成および作用効果は、実施の形態の第1例と同じである。
Therefore, even in the structure of this example, the distribution of the axial force of the hub bolt 26 (see FIG. 1) acting on the contact portion between the outer abutment portion 15 of the rotating flange 9a and the axial inner surface of the braking rotor 25 (see FIG. 1) is larger than the distribution of the axial force of the hub bolt 26 acting on the contact portion between the inner abutment portion 14 of the rotating flange 9a and the axial inner surface of the braking rotor 25. In addition, since the portion (β portion) radially outward from the female thread hole 13a is less likely to bend and deform in the axial direction, the outer abutment portion 15 of the rotating flange 9a is easily pressed against the axial inner surface of the braking rotor 25. Therefore, even in the structure of this example, the outer abutment portion 15 of the rotating flange 9a and the axial inner surface of the braking rotor 25 can be strongly and closely contacted over a wide range. As a result, the axial bending deformation of the portion of the braking rotor 25 radially outward from the annular groove 11a is suppressed, and the effect of suppressing brake judder can be ensured.
The other configurations and effects are the same as those of the first embodiment.

なお、本発明は、矛盾が生じない限り、各実施の形態の構造を適宜組み合わせて実施することができる。具体的には、本発明は、環状溝の底面が、径方向外側に向かうにしたがって前記環状溝の軸方向深さが減少する形状を有する構成と、前記環状溝のうち雌ねじ孔よりも径方向外側に位置する部分の径方向幅が、前記環状溝のうち前記雌ねじ孔よりも径方向内側に位置する部分の径方向幅に比べて小さい構成との、双方の構成を備えた構造を採用することもできる。 The present invention can be implemented by appropriately combining the structures of each embodiment, as long as no contradiction occurs. Specifically, the present invention can employ a structure that has both a configuration in which the bottom surface of the annular groove has a shape in which the axial depth of the annular groove decreases as it moves radially outward, and a configuration in which the radial width of a portion of the annular groove located radially outward from the female threaded hole is smaller than the radial width of a portion of the annular groove located radially inward from the female threaded hole.

1 ハブユニット軸受
2 外輪
3、3a ハブ
4 転動体
5a、5b 外輪軌道
6 静止フランジ
7 支持孔
8a、8b 内輪軌道
9、9a 回転フランジ
10 パイロット部
11、11a 環状溝
12、12a 底面
13 雌ねじ孔
14 内側突き当て部
15 外側突き当て部
16 径方向内側周面
17 径方向外側周面
18 平坦面
19 作業孔
20 内輪
21 ハブ輪
22 かしめ部
23 保持器
24 ホイール
25 制動用回転体
26 ハブボルト
27a、27b 通孔
28 雄ねじ部
29 頭部
30a、30b 開口縁部
100 回転フランジ
101 環状溝
102 底面
103 雌ねじ孔
104 制動用回転体
105 通孔
106 ハブボルト
107 雄ねじ部
108a、108b 開口縁部
LIST OF SYMBOLS 1 hub unit bearing 2 outer ring 3, 3a hub 4 rolling elements 5a, 5b outer ring raceway 6 stationary flange 7 support hole 8a, 8b inner ring raceway 9, 9a rotating flange 10 pilot portion 11, 11a annular groove 12, 12a bottom surface 13 female thread hole 14 inner abutment portion 15 outer abutment portion 16 radially inner peripheral surface 17 radially outer peripheral surface 18 flat surface 19 working hole 20 inner ring 21 hub ring 22 crimping portion 23 cage 24 wheel 25 braking rotating element 26 hub bolt 27a, 27b through hole 28 male thread portion 29 head 30a, 30b opening edge portion 100 rotating flange 101 annular groove 102 bottom surface 103 female thread hole 104 Braking rotor 105 Through hole 106 Hub bolt 107 Male threaded portion 108a, 108b Opening edge portion

Claims (1)

内周面に外輪軌道を有する外側部材と、
外周面に内輪軌道を有する内側部材と、
前記外輪軌道と前記内輪軌道との間に転動自在に配置された複数個の転動体とを備え、
前記外側部材と前記内側部材とのうちで使用時に回転する回転部材は、径方向外側に突出した回転フランジを有し、
前記回転フランジは、軸方向外側面に備えられた、前記回転部材の中心軸を中心とする円環状の環状溝、および、円周方向複数箇所のそれぞれに備えられた、軸方向に伸長しかつ軸方向外側の端部が前記環状溝の底面にのみ開口する雌ねじ孔を有しており、
前記環状溝の底面は、径方向外側に向かうにしたがって前記環状溝の軸方向深さが減少する形状を有しており、
前記回転フランジのうち、前記環状溝と軸方向に重畳する部分において、前記雌ねじ孔よりも径方向外側の部分の軸方向の曲げ剛性が、前記雌ねじ孔よりも径方向内側の部分の軸方向の曲げ剛性に比べて高い、
ハブユニット軸受。
an outer member having an outer ring raceway on an inner circumferential surface;
an inner member having an inner ring raceway on an outer circumferential surface;
a plurality of rolling elements disposed between the outer ring raceway and the inner ring raceway for free rolling motion;
A rotating member that rotates during use among the outer member and the inner member has a rotating flange that protrudes radially outward,
the rotating flange has an annular groove formed on an axially outer surface thereof and centered on a central axis of the rotating member, and a plurality of female thread holes formed at each of a plurality of locations in a circumferential direction, the female thread holes extending in the axial direction and having axially outer ends opening only to a bottom surface of the annular groove,
A bottom surface of the annular groove has a shape in which the axial depth of the annular groove decreases toward the radially outer side,
a portion of the rotating flange that overlaps with the annular groove in the axial direction has a bending rigidity in the axial direction that is radially outer than the female threaded hole, the bending rigidity in the axial direction being higher than a portion of the rotating flange that overlaps with the annular groove in the axial direction.
Hub unit bearing.
JP2020181233A 2020-10-29 2020-10-29 Hub unit bearing Active JP7487640B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2020181233A JP7487640B2 (en) 2020-10-29 2020-10-29 Hub unit bearing

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2020181233A JP7487640B2 (en) 2020-10-29 2020-10-29 Hub unit bearing

Publications (3)

Publication Number Publication Date
JP2022072036A JP2022072036A (en) 2022-05-17
JP2022072036A5 JP2022072036A5 (en) 2023-07-06
JP7487640B2 true JP7487640B2 (en) 2024-05-21

Family

ID=81605086

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2020181233A Active JP7487640B2 (en) 2020-10-29 2020-10-29 Hub unit bearing

Country Status (1)

Country Link
JP (1) JP7487640B2 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001334803A (en) 2000-05-29 2001-12-04 Koyo Seiko Co Ltd Bearing device for axle
JP2003175702A (en) 2001-12-13 2003-06-24 Ntn Corp Bearing device for driving wheel
US20050099058A1 (en) 2003-11-07 2005-05-12 Nsk Corporation Wheel supporting roller bearing unit and manufacturing method of the same
WO2017179400A1 (en) 2016-04-12 2017-10-19 日本精工株式会社 Hub unit bearing
JP2019138400A (en) 2018-02-13 2019-08-22 株式会社ジェイテクト Sealing device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001334803A (en) 2000-05-29 2001-12-04 Koyo Seiko Co Ltd Bearing device for axle
JP2003175702A (en) 2001-12-13 2003-06-24 Ntn Corp Bearing device for driving wheel
US20050099058A1 (en) 2003-11-07 2005-05-12 Nsk Corporation Wheel supporting roller bearing unit and manufacturing method of the same
WO2017179400A1 (en) 2016-04-12 2017-10-19 日本精工株式会社 Hub unit bearing
JP2019138400A (en) 2018-02-13 2019-08-22 株式会社ジェイテクト Sealing device

Also Published As

Publication number Publication date
JP2022072036A (en) 2022-05-17

Similar Documents

Publication Publication Date Title
EP1321687B2 (en) Bearing assembly for axle shaft pinion and final reduction gear for vehicle
JP2008100632A (en) Bearing device for wheel
JP5401997B2 (en) Hub unit for driving wheel support
US20190375235A1 (en) Flanged inner ring optimized for orbital forming operation and associated tool
JP7487640B2 (en) Hub unit bearing
JP2010089664A (en) Bearing device for wheel
JP2010060094A (en) Hub unit bearing and manufacturing method therefor
JP4078945B2 (en) Rolling bearing device
JP5087901B2 (en) Rolling bearing device for wheels
JP7487642B2 (en) Hub unit bearing
WO2008018175A1 (en) Bearing device for wheel
JP2013067323A (en) Bearing device for axle
JP4042528B2 (en) Rolling bearing device
JP4134872B2 (en) Rolling bearing device
JP2007292142A (en) Bearing unit for supporting wheel
JP2002187404A (en) Wheel bearing device
JP4023129B2 (en) Rotating member for braking and rolling bearing unit with wheel
JP2007327507A (en) Wheel bearing device
JP4826779B2 (en) Rolling bearing device for wheels
JP2002187403A (en) Wheel bearing device
JP2007314138A (en) Hub unit
JP4940847B2 (en) Manufacturing method of wheel bearing rolling bearing unit
JP2006143071A (en) Hub unit for vehicle
JP2002301532A (en) Method for caulking bearing device
JP2010069926A (en) Hub unit for supporting drive wheel

Legal Events

Date Code Title Description
A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20230628

A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20230628

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20231227

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20240116

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20240131

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20240409

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20240422

R150 Certificate of patent or registration of utility model

Ref document number: 7487640

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150