JP2022074537A - Hub unit bearing - Google Patents

Abstract

To provide a hub unit bearing facilitating design for efficiently discharging water to the external space through the through holes from the gap between the bottom surface of the annular groove and the axial inner surface of the rotating body for braking, while ensuring strength and rigidity of the rotary flange.SOLUTION: A rotary flange 9 has: an annular groove 11 centered on a central axis C in an axial outer surface; female screw holes 13 with an axial outer end being open only in a bottom surface 12, arranged at a plurality of locations in a circumferential direction; and a through hole 14 at least at one place in the circumferential direction. A diameter of an inscribed circle of the through hole 14 centered on the central axis C is smaller than an outer diameter of the annular groove 11, and a diameter of a circumscribed circle of the through hole 14 centered on the central axis C is larger than the outer diameter of the annular groove 11. An axial depth of a portion radially outside a circumscribed circle of the female screw hole 13 centered on the central axis C in the annular groove 11 is deeper than an axial depth of a portion radially inside the circumscribed circle of the female screw hole 13 centered on the central axis C in the annular groove 11.SELECTED DRAWING: Figure 1

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 rotatably supporting an automobile wheel and a rotating body for braking with respect to a suspension device.

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 rotating bodies such as discs and drums are rotatably supported by suspension devices by hub unit bearings. The hub unit bearing includes an outer member having an outer ring track on the inner peripheral surface, an inner member having an inner ring track on the outer peripheral surface, and a plurality of rolling elements rotatably arranged between the outer ring track and the inner ring track. To prepare for.

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 during 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 rotating body for braking during use. The rotating member has a rotating flange protruding radially outward. The wheels constituting the wheels and the rotating body for braking are coupled and fixed to the rotating flange by using a plurality of 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。 Such a hub unit bearing has press-fitting holes that penetrate a plurality of circumferential directions of the rotary flange in the axial direction, and each of the press-fitting holes has an axially inner end portion that is a base end portion of the hub bolt. A type in which the serration portion provided in the above is press-fitted from the inside in the axial direction (hereinafter referred to as a hub bolt press-fit type) is widely known.

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。 Regarding the hub unit bearing, the inside in the axial direction is the center side in the width direction of the vehicle when assembled to the vehicle, and the outside in the axial direction is the outside in the width direction in the assembled state 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 the hub bolt press-fit 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 rotating body for braking, and the tip of the hub bolt is outside in the axial direction. By screwing the hub nut into the male thread provided at the end of the wheel and further tightening it, the wheel and the rotating body for braking are coupled and fixed 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。 Further, as described in JP-A-2002-370104 (Patent Document 1) and JP-A-2003-175702 (Patent Document 2), in a hub bolt press-fit type hub unit bearing, the axial direction of the rotating flange A structure is known in which an annular groove centered on the central axis of the rotating member is formed on the outer side surface, and the axially outer ends of the press-fitting holes are opened only on the bottom surface of the annular groove. ing.

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。 According to such a structure, even when the serration portion of the hub bolt is press-fitted into the press-fitting hole and the circumference of the opening on the axially outer side of the press-fitting hole is plastically deformed and swelled, this swelling is contained in the annular groove. By limiting the amount to, it is possible to improve the surface runout accuracy of the portion other than the annular groove on the outer surface in the axial direction of the rotary flange. As a result, it is possible to improve the surface runout accuracy of the rotating body for braking and suppress the generation of vibration accompanied by an abnormal noise called a brake judder during braking.

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、ハブボルトの先端部である軸方向内側の端部に備えられた雄ねじ部を、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。 Further, as for the hub unit bearing, as described in Japanese Patent Application Laid-Open No. 2017-190865 (Patent Document 3), a type that can reduce the weight by omitting the hub nut, that is, at a plurality of locations in the circumferential direction of the rotary flange. It has a female screw hole with an opening on the outer end in the axial direction, and a male screw portion provided at the inner end in the axial direction, which is the tip of the hub bolt, is screwed from the outer side in the axial direction in each of the female screw holes. A matching type (hereinafter referred to as a hub bolt screw type) is also known.

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 the hub bolt screw type hub unit bearing, the male threaded part of the hub bolt is inserted into the female threaded hole of the rotating flange with the hub bolt inserted into the through holes provided at multiple points in the circumferential direction of the wheel and the rotating body for braking. By screwing from the outside in the axial direction and further tightening, the wheel and the rotating body for braking are coupled and fixed 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。 Even in such a hub bolt screw type hub unit bearing, as described in Japanese Patent Application Laid-Open No. 2017-190865, an annular shape centered on the central axis of the rotating member is formed on the axially outer surface of the rotating flange. A structure is known in which an annular groove is formed and each axially outer end of the female screw hole is opened only at 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。 According to such a structure, even if the male threaded portion of the hub bolt is screwed into the female threaded hole and further tightened, and the periphery of the axially outer opening of the female threaded hole is deformed and swelled, this swelling is annular. Can stay in the groove.

ところで、ハブユニット軸受では、組立またはメンテナンスの際に工具を挿入することや軽量化などを目的として、回転フランジに軸方向に貫通する貫通孔を形成する場合がある。このような貫通孔の軸方向外側の端部のうち、少なくとも径方向一部分は、環状溝の底面に開口するため、軸方向内側からこの貫通孔を通じて、環状溝の底面と制動用回転体の軸方向内側面との間の隙間に、泥水などの水分が侵入する場合がある。 By the way, in the hub unit bearing, a through hole penetrating in the axial direction may be formed in the rotary flange for the purpose of inserting a tool during assembly or maintenance, weight reduction, or the like. Since at least a radial portion of the axially outer end of such a through hole opens to the bottom surface of the annular groove, the bottom surface of the annular groove and the shaft of the rotating body for braking are passed through the through hole from the inside in the axial direction. Moisture such as muddy water may enter the gap between the inner side surface in the direction.

この場合に、たとえば、貫通孔の軸方向外側の端部が、環状溝の底面の径方向中間部に開口していると、環状溝の底面と制動用回転体の軸方向内側面との間の隙間に侵入した水分が、貫通孔から外部空間に完全に排出されず、水分の一部が、隙間のうちで貫通孔よりも径方向外側に位置する部分に残ってしまう可能性がある。そして、隙間内に残った水分が、車輪の回転に伴う遠心力により、回転フランジの軸方向外側面と制動用回転体の軸方向内側面との間に侵入し、回転フランジの軸方向外側面と制動用回転体の軸方向内側面とを錆び付かせるなどの、不都合を生じる可能性がある。 In this case, for example, if the axially outer end of the through hole is opened in the radial intermediate portion of the bottom surface of the annular groove, the space between the bottom surface of the annular groove and the axial inner surface of the rotating body for braking is provided. Moisture that has entered the gap may not be completely discharged from the through hole to the external space, and a part of the water may remain in the portion of the gap located radially outside the through hole. Then, the moisture remaining in the gap enters between the axial outer surface of the rotating flange and the axial inner surface of the rotating body for braking due to the centrifugal force accompanying the rotation of the wheel, and the axial outer surface of the rotating flange is formed. And the inner side surface of the rotating body for braking in the axial direction may be rusted, which may cause inconvenience.

このような不都合を解消するために、特開２０１７－１９０８６５号公報には、回転部材の中心軸を中心とする貫通孔（水抜き孔）の内接円の直径を、環状溝の外径よりも小さくし、かつ、回転部材の中心軸を中心とする貫通孔の外接円の直径を、環状溝の外径よりも大きくした構造が記載されている。 In order to eliminate such inconvenience, Japanese Patent Application Laid-Open No. 2017-190865 states that the diameter of the inscribed circle of the through hole (drainage hole) centered on the central axis of the rotating member is set from the outer diameter of the annular groove. Also described is a structure in which the diameter of the circumscribed circle of the through hole centered on the central axis of the rotating member is made larger than the outer diameter of the annular groove.

このような構造によれば、環状溝の底面と制動用回転体の軸方向内側面との間の隙間に侵入した水分を、車輪の回転に伴う遠心力により、この隙間の径方向外側の端部に集めた後、この端部から貫通孔を通じて外部空間に排出することができる。 According to such a structure, the moisture that has entered the gap between the bottom surface of the annular groove and the axial inner surface of the rotating body for braking is removed by the centrifugal force accompanying the rotation of the wheel to the radial outer end of the gap. After collecting in the portion, it can be discharged to the external space from this end through the through hole.

特開２００２－３７０１０４号公報Japanese Unexamined Patent Publication No. 2002-370104 特開２００３－１７５７０２号公報Japanese Patent Application Laid-Open No. 2003-175702 特開２０１７－１９０８６５号公報Japanese Unexamined Patent Publication No. 2017-190865

上述したような構造、すなわち、回転部材の中心軸を中心とする貫通孔の内接円の直径を、環状溝の外径よりも小さくし、かつ、回転部材の中心軸を中心とする貫通孔の外接円の直径を、環状溝の外径よりも大きくした構造を採用する場合、環状溝の底面と制動用回転体の軸方向内側面との間の隙間から、貫通孔を通じて外部空間に水分を効率良く排出するためには、環状溝の軸方向深さを大きくして、環状溝の底面を、貫通孔の軸方向内側の開口部に近づけることが、効果があると考えられる。 The structure as described above, that is, the diameter of the inscribed circle of the through hole centered on the central axis of the rotating member is made smaller than the outer diameter of the annular groove, and the through hole centered on the central axis of the rotating member. When adopting a structure in which the diameter of the circumscribing circle is larger than the outer diameter of the annular groove, moisture enters the external space through the through hole through the gap between the bottom surface of the annular groove and the axial inner surface of the rotating body for braking. It is considered effective to increase the axial depth of the annular groove and bring the bottom surface of the annular groove closer to the opening inside the axial direction of the through hole in order to efficiently discharge the water.

しかしながら、環状溝全体の軸方向深さを大きくすると、回転フランジのうち、環状溝と軸方向に重畳する部分の軸方向の肉厚が小さくなって、該部分の強度および剛性を確保することが難しくなる。 However, if the axial depth of the entire annular groove is increased, the axial wall thickness of the portion of the rotary flange that overlaps the annular groove in the axial direction becomes smaller, and the strength and rigidity of the portion can be ensured. It gets difficult.

本発明は、回転フランジの強度および剛性を確保しつつ、環状溝の底面と制動用回転体の軸方向内側面との間の隙間から貫通孔を通じて外部空間に水分を効率良く排出するための設計を容易に行えるハブユニット軸受を提供することを目的とする。 The present invention is designed to efficiently discharge moisture to the external space through a through hole through a gap between the bottom surface of the annular groove and the axial inner side surface of the rotating body for braking while ensuring the strength and rigidity of the rotating flange. It is an object of the present invention to provide a hub unit bearing that can easily perform the above.

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、前記回転部材の中心軸を中心とする円環状の環状溝、円周方向複数箇所のそれぞれに、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取付孔、および、円周方向の少なくとも１箇所に、軸方向に貫通する貫通孔を有する。
前記回転部材の中心軸を中心とする前記貫通孔の内接円の直径は、前記環状溝の外径よりも小さくなっており、前記回転部材の中心軸を中心とする前記貫通孔の外接円の直径は、前記環状溝の外径よりも大きくなっている。
前記環状溝のうち、前記回転部材の中心軸を中心とする前記取付孔の外接円よりも径方向外側の部分の軸方向深さは、前記環状溝のうち、前記回転部材の中心軸を中心とする前記取付孔の外接円よりも径方向内側の部分の軸方向深さに比べて深くなっている。 The hub unit bearing of one aspect of the present invention is rotatably arranged between an outer member having an outer ring track on the inner peripheral surface, an inner member having an inner ring track on the outer peripheral surface, and the outer ring track and the inner ring track. It is provided with a plurality of rolling elements.
Among the outer member and the inner member, the rotating member that rotates during use has a rotating flange that protrudes outward in the radial direction.
The rotary flange has an annular groove centered on the central axis of the rotary member on the outer surface in the axial direction, and a plurality of annular grooves in the circumferential direction, each of which extends in the axial direction and has an end portion on the outer side in the axial direction. It has a mounting hole that opens only on the bottom surface of the annular groove, and a through hole that penetrates in the axial direction at at least one position in the circumferential direction.
The diameter of the inscribed circle of the through hole centered on the central axis of the rotating member is smaller than the outer diameter of the annular groove, and the outer circle of the through hole centered on the central axis of the rotating member. The diameter of is larger than the outer diameter of the annular groove.
The axial depth of the portion of the annular groove that is radially outside the circumscribed circle of the mounting hole centered on the central axis of the rotating member is centered on the central axis of the rotating member of the annular groove. It is deeper than the axial depth of the portion inside the radial direction from the circumscribed circle of the mounting 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増大する形状を有する。 In the hub unit bearing of one aspect of the present invention, the bottom surface of the annular groove has a shape in which the axial depth of the annular groove increases toward the outer side in the radial direction.

本発明の一態様のハブユニット軸受では、前記環状溝の底面のうち、前記回転部材の中心軸を中心とする前記取付孔の外接円よりも径方向内側の部分は、前記回転部材の中心軸に直交する平坦面部により構成されており、前記環状溝の底面のうち、前記回転部材の中心軸を中心とする前記取付孔の外接円よりも径方向外側の部分は、前記平坦面部よりも軸方向内側に凹んだ溝部により構成されている。 In the hub unit bearing of one aspect of the present invention, the portion of the bottom surface of the annular groove that is radially inside the outer circle of the mounting hole centered on the central axis of the rotating member is the central axis of the rotating member. A portion of the bottom surface of the annular groove that is radially outer of the circumscribing circle of the mounting hole centered on the central axis of the rotating member is a shaft of the flat surface portion. It is composed of grooves recessed inward in the direction.

本発明の一態様によれば、回転フランジの強度および剛性を確保しつつ、環状溝の底面と制動用回転体の軸方向内側面との間の隙間から貫通孔を通じて外部空間に水分を効率良く排出するための設計を容易に行えるハブユニット軸受を提供できる。 According to one aspect of the present invention, moisture is efficiently transferred to the external space through the through hole through the gap between the bottom surface of the annular groove and the axial inner side surface of the rotating body for braking while ensuring the strength and rigidity of the rotating flange. It is possible to provide a hub unit bearing that can be easily designed for discharge.

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 an 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 the hub of the first example of the 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 taken out. 図４は、図１の左下部に相当する拡大図である。FIG. 4 is an enlarged view corresponding to the lower left of FIG. 1. 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 regarding the second example of the embodiment of the present invention. 図６は、本発明の実施の形態の第２例に関する、図４に相当する図である。FIG. 6 is a diagram corresponding to FIG. 4 regarding the second example of the embodiment of the present invention. 図７は、本発明の実施の形態の第２例の変形例に関する、図４に相当する図である。FIG. 7 is a diagram corresponding to FIG. 4 regarding a modified example of the second example of the embodiment of the present invention.

［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 Example of Embodiment]
A first example of the embodiment of the present invention will be described with reference to FIGS. 1 to 4.

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 of this example is for a driven wheel, has an outer ring 2 which is an outer member, a hub 3 which is an inner member and is a rotating member that rotates during use, and a plurality of rolling elements 4. To prepare for. The present invention can also be applied to a hub unit for drive wheels. The present invention can also be applied to a hub unit bearing in which the outer member is a rotating member.

なお、以下の説明において、特に断らない限り、ハブユニット軸受１に関して、軸方向および径方向は、外輪２およびハブ３の軸方向および径方向をいう。また、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。 In the following description, unless otherwise specified, the axial direction and the radial direction of the hub unit bearing 1 refer to the axial direction and the radial direction of the outer ring 2 and the hub 3. Further, regarding the hub unit bearing 1, the inner side in the axial direction is the right side of FIG. 1 which is the center side in the width direction of the vehicle when assembled to the vehicle, and the outer side in the axial direction is the width of the vehicle when assembled to the vehicle. It is the left side of FIG. 1 which is outside the direction.

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 a double-row outer ring track 5a and 5b on the inner peripheral surface, and has a stationary flange 6 protruding outward in the radial direction at an axial intermediate portion. The stationary flange 6 has support holes 7 penetrating in the axial direction at a plurality of locations in the circumferential direction in the radial intermediate portion. The outer ring 2 is supported and fixed to the suspension device by a support bolt screwed into the support hole 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 arranged coaxially with the outer ring 2 on the inner side in the radial direction of the outer ring 2, and has a double-row inner ring races 8a and 8b facing the double-row outer ring races 5a and 5b on the outer peripheral surface. The hub 3 has a rotary flange 9 projecting radially outward at a portion located axially outward from the outer ring 2, and has a cylindrical pilot portion 10 at an axially outer end.

回転フランジ９は、軸方向外側面に、ハブ３の中心軸Ｃを中心とする円環状の環状溝１１、円周方向複数箇所のそれぞれに、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にのみ開口する取付孔である雌ねじ孔１３、および、円周方向の少なくとも１箇所に、軸方向に貫通する貫通孔１４を有する。 The rotary flange 9 has an annular groove 11 centered on the central axis C of the hub 3 on the outer surface in the axial direction, and a plurality of annular grooves 11 in the circumferential direction, each of which extends in the axial direction and has an end portion on the outer side in the axial direction. It has a female screw hole 13 which is a mounting hole which opens only in the bottom surface 12 of the annular groove 11, and a through hole 14 which penetrates in the axial direction at at least one position in the circumferential direction.

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１５と、径方向外側部に備えられた外側突き当て部１６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 axial outer surface of the rotary flange 9 has an inner abutting portion 15 provided on the radial inner portion, an outer abutting portion 16 provided on the radial outer portion, and a radial intermediate portion. It has an annular groove 11 around the central axis C of the hub 3 provided in the above.

内側突き当て部１５および外側突き当て部１６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 abutting portion 15 and the outer abutting portion 16 are composed of flat surfaces existing in the same virtual plane orthogonal to the central axis C of the hub 3.

環状溝１１は、径方向外側を向いた内側周面１７と、径方向内側を向いた外側周面１８と、軸方向外側を向いた底面１２とを有する。 The annular groove 11 has an inner peripheral surface 17 facing radially outward, an outer peripheral surface 18 facing radially inward, and a bottom surface 12 facing axially outward.

内側周面１７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。内側周面１７の軸方向外側の端部は、内側突き当て部１５の径方向外側の端部に接続されている。 The axially inner end of the inner peripheral surface 17 is connected to the radial inner end of the bottom surface 12. The axially outer end of the inner peripheral surface 17 is connected to the radial outer end of the inner abutting portion 15.

外側周面１８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。外側周面１８の軸方向外側の端部は、外側突き当て部１６の径方向内側の端部に接続されている。 The axially inner end of the outer peripheral surface 18 is connected to the radial outer end of the bottom surface 12. The axially outer end of the outer peripheral surface 18 is connected to the radially inner end of the outer abutment portion 16.

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 FIGS. 2 and 3, the radial width Wa of the annular groove 11 is larger than the groove bottom diameter Da of the female screw hole 13 (Wa> Da). The groove bottom diameter Da of the female screw hole 13 is the diameter of the thread groove bottom portion of the female screw 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 of the female screw holes 13 penetrates a plurality of locations (five locations in the illustrated example) at equal intervals in the circumferential direction of the radial intermediate portion of the rotary flange 9 in the axial direction. That is, in this example, in each of the female screw holes 13, the inner end in the axial direction opens on the inner side surface in the axial direction of the rotary flange 9, and the outer end in the axial direction opens on the outer surface in the axial direction of the rotary flange 9. ing. However, when the present invention is carried out, each of the female screw holes is opened only at the outer end in the axial direction to the outer surface in the axial direction of the rotary flange, and the inner end in the axial direction is the inner surface in the axial direction of the rotary flange. It can also be a bottomed hole that is not open. Each axially outer end of the female screw hole 13 is open 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 sides in the radial direction of the opening on the outer side in the axial direction of the female screw 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（以下、単に「雌ねじ孔１３の内接円」という。）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（以下、単に「雌ねじ孔１３の外接円」という。）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。 That is, in this example, as shown in FIG. 3, the inner diameter Di of the annular groove 11 is from the diameter di of the inscribed circle of the female screw hole 13 centered on the central axis C (see FIGS. 1 and 2) of the hub 3. Is also small (Di <di). The inscribed circle of the female screw hole 13 centered on the central axis C of the hub 3 (hereinafter, simply referred to as “the inscribed circle of the female screw hole 13”) is centered on the central axis C of the hub 3 and is centered on the hub 3. The virtual circle having the smallest diameter among the virtual circles in contact with the bottom of the thread groove of the female screw hole 13. Further, the outer diameter Do of the annular groove 11 is larger than the diameter do of the circumscribed circle of the female screw hole 13 centered on the central axis C of the hub 3 (Do> do). The circumscribed circle of the female screw hole 13 centered on the central axis C of the hub 3 (hereinafter, simply referred to as “the circumscribed circle of the female screw hole 13”) is centered on the central axis C of the hub 3 and is the female screw hole. Of the virtual circles in contact with the bottom of the thread groove of 13, the virtual circle having the largest diameter is referred to.

さらに、本例では、環状溝１１のうち雌ねじ孔１３よりも径方向内側の部分、すなわち、環状溝１１のうち、雌ねじ孔１３の内接円よりも径方向内側の部分の径方向幅Ｗｉ（＝（ｄｉ－Ｄｉ）／２）と、環状溝１１のうち雌ねじ孔１３よりも径方向外側の部分、すなわち、環状溝１１のうち、雌ねじ孔１３の外接円よりも径方向外側の部分の径方向幅Ｗｏ（＝（Ｄｏ－ｄｏ）／２）とは、互いに等しい（Ｗｉ＝Ｗｏ）。 Further, in this example, the radial width Wi (the portion of the annular groove 11 that is radially inner side of the female screw hole 13, that is, the portion of the annular groove 11 that is radially inner side of the inscribed circle of the female screw hole 13). = (Di-Di) / 2) and the diameter of the annular groove 11 that is radially outer of the female screw hole 13, that is, the diameter of the annular groove 11 that is radially outer than the circumscribed circle of the female screw hole 13. The directional width Wo (= (Do-do) / 2) is equal to each other (Wi = Wo).

また、本例では、環状溝１１の軸方向深さは、円周方向に関しては変化していない。本例では、環状溝１１のうち、雌ねじ孔１３の外接円よりも径方向外側の部分（図３において、幅Ｗｏで表示される部分）の軸方向深さは、環状溝１１のうち、雌ねじ孔１３の外接円よりも径方向内側の部分（図３において、幅（Ｄａ＋Ｗｉ）で表示される部分）の軸方向深さに比べて深くなっている。 Further, in this example, the axial depth of the annular groove 11 does not change in the circumferential direction. In this example, the axial depth of the portion of the annular groove 11 that is radially outside the circumscribed circle of the female screw hole 13 (the portion represented by the width Wo in FIG. 3) is the female screw of the annular groove 11. It is deeper than the axial depth of the portion radially inner of the circumscribed circle of the hole 13 (the portion indicated by the width (Da + Wi) in FIG. 3).

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の軸方向深さが増大する形状を有する。より具体的には、本例では、底面１２は、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傾斜した部分円すい凸面により構成されている。 Therefore, 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 increases toward the outer side in the radial direction. More specifically, in this example, the bottom surface 12 is composed of a partial conical convex surface that is inclined in the direction toward the inside in the axial direction toward the outside in the radial direction.

つまり、本例では、底面１２がこのような形状を有することに基づいて、環状溝１１のうち、雌ねじ孔１３の外接円よりも径方向外側の部分の軸方向深さが、環状溝１１のうちの残りの部分の軸方向深さに比べて深くなっている。 That is, in this example, based on the fact that the bottom surface 12 has such a shape, the axial depth of the portion of the annular groove 11 that is radially outside the circumscribed circle of the female screw hole 13 is the annular groove 11. It is deeper than the axial depth of the rest of us.

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増大する形状を採用する場合には、たとえば部分球状凸面などの、本例とは異なる形状を採用することもできる。 In the case of carrying out the present invention, when the shape of the bottom surface of the annular groove is such that the axial depth of the annular groove increases toward the outside in the radial direction, for example, a partially spherical convex surface is used. A shape different from this example can also be adopted.

なお、図示の例では、内側周面１７と外側周面１８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、内側周面と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傾斜した傾斜面、または、軸方向外側に向かうにしたがって環状溝の径方向幅が小さくなる方向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, each of the inner peripheral surface 17 and the outer peripheral surface 18 is composed of a cylindrical surface whose diameter does not change in the axial direction. However, each of the inner peripheral surface and the outer peripheral surface is an inclined surface inclined in a direction in which the radial width of the annular groove increases toward the outer side in the axial direction, or the diameter of the annular groove toward the outer side in the axial direction. It can also be configured by an inclined surface inclined in a direction in which the direction width becomes smaller.

図２から明らかな貫通孔１４は、組立またはメンテナンスの際に工具を挿入することや軽量化などを目的として、回転フランジ９に備えられている。 The through hole 14 apparent from FIG. 2 is provided in the rotary flange 9 for the purpose of inserting a tool during assembly or maintenance, weight reduction, and the like.

本発明において、貫通孔１４の数は任意であるが、本例では、貫通孔１４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。本例では、貫通孔１４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。本例では、貫通孔１４のそれぞれは、回転フランジ９を軸方向に貫通する円孔により構成されている。 In the present invention, the number of through holes 14 is arbitrary, but in this example, the same number of through holes 14 are provided as the number of female screw holes 13, and the through holes 14 are arranged at equal intervals in the circumferential direction. In this example, the phase of the arrangement of the through holes 14 in the circumferential direction is off by a half pitch with respect to the phase of the arrangement of the female screw holes 13 in the circumferential direction. In this example, each of the through holes 14 is composed of circular holes that penetrate the rotary flange 9 in the axial direction.

図４に示すように、本例では、ハブ３の中心軸Ｃを中心とする貫通孔１４の内接円（以下、単に「貫通孔１４の内接円」という。）の直径δｉは、環状溝１１の外径Ｄｏよりも小さくなっており（δｉ＜Ｄｏ）、ハブ３の中心軸Ｃを中心とする貫通孔１４の外接円（以下、単に「貫通孔１４の外接円」という。）の直径δｏは、環状溝１１の外径Ｄｏよりも大きくなっている（δｏ＞Ｄｏ）。 As shown in FIG. 4, in this example, the diameter δi of the inscribed circle of the through hole 14 centered on the central axis C of the hub 3 (hereinafter, simply referred to as “the inscribed circle of the through hole 14”) is annular. It is smaller than the outer diameter Do of the groove 11 (δi <Do), and is the circumscribing circle of the through hole 14 centered on the central axis C of the hub 3 (hereinafter, simply referred to as “the circumscribed circle of the through hole 14”). The diameter δo is larger than the outer diameter Do of the annular groove 11 (δo> Do).

本例では、貫通孔１４のそれぞれは、径方向外側部分が外側突き当て部１６に開口し、径方向内側部分が環状溝１１の底面１２に開口している。本例では、貫通孔１４のそれぞれの内周面は、環状溝１１に対して径方向外側に重畳する部分に、径方向外側に向けて凹んだ部分円筒面状の凹面部１９を有する。凹面部１９の軸方向幅は、後述する面取り部２０が形成されているため、図４に示すように、Ｗｘである。 In this example, each of the through holes 14 has a radial outer portion opened to the outer abutting portion 16 and a radial inner portion opened to the bottom surface 12 of the annular groove 11. In this example, each inner peripheral surface of the through hole 14 has a partially cylindrical concave surface portion 19 recessed toward the radial outer side in a portion overlapping radially outward with respect to the annular groove 11. The axial width of the concave portion 19 is Wx as shown in FIG. 4 because the chamfered portion 20 described later is formed.

また、本例では、貫通孔１４の内周面と、回転フランジ９の軸方向外側面のうち環状溝１１よりも径方向外側の部分との接続部、すなわち、凹面部１９と外側突き当て部１６との接続部に、軸方向外側に向かうにしたがって貫通孔１４の中心軸を中心とする径方向外側に向かう方向に傾斜した面取り部２０を有する。面取り部２０は、外側突き当て部１６の加工の際にバリが発生するのを抑制するために設けられている。面取り部２０の軸方向幅は、図４に示すように、Ｗｙである。図示の例では、面取り部２０は、直線状の断面形状を有するＣ面取り部により構成されている。ただし、本発明を実施する場合には、面取り部を、円弧状の断面形状を有するＲ面取り部により構成することもできる。また、本発明を実施する場合には、凹面部と外側突き当て部との接続部に面取り部を設けるのを省略することもできる。 Further, in this example, the connection portion between the inner peripheral surface of the through hole 14 and the portion of the axial outer surface of the rotary flange 9 that is radially outer than the annular groove 11, that is, the concave surface portion 19 and the outer abutting portion. The connection portion with the 16 has a chamfered portion 20 inclined in a radial direction centered on the central axis of the through hole 14 toward the outer side in the axial direction. The chamfered portion 20 is provided to suppress the generation of burrs during the processing of the outer abutting portion 16. The axial width of the chamfered portion 20 is Wy, as shown in FIG. In the illustrated example, the chamfered portion 20 is composed of a C chamfered portion having a linear cross-sectional shape. However, when the present invention is carried out, the chamfered portion may be configured by an R chamfered portion having an arcuate cross-sectional shape. Further, when the present invention is carried out, it is possible to omit providing a chamfered portion at the connecting portion between the concave surface portion and the outer abutting portion.

また、本例では、環状溝１１の径方向外側の端部の軸方向深さＷｚを、面取り部２０の軸方向幅Ｗｙよりも大きくしている（Ｗｚ＞Ｗｙ）。すなわち、本例では、環状溝１１の底面１２の径方向外側の端部は、面取り部２０よりも軸方向内側に位置している。なお、面取り部２０を省略する場合には、凹面部１９の軸方向幅Ｗｘは、環状溝１１の径方向外側の端部の軸方向深さＷｚと等しくなる。 Further, in this example, the axial depth Wz of the radially outer end of the annular groove 11 is made larger than the axial width Wy of the chamfered portion 20 (Wz> Wy). That is, in this example, the radially outer end of the bottom surface 12 of the annular groove 11 is located axially inside the chamfered portion 20. When the chamfered portion 20 is omitted, the axial width Wx of the concave surface portion 19 becomes equal to the axial depth Wz of the radially outer end portion of the annular groove 11.

なお、本例では、貫通孔１４の内接円の直径δｉは、環状溝１１の内径Ｄｉよりも大きくなっている（δｉ＞Ｄｉ）。ただし、本発明を実施する場合には、貫通孔の内接円の直径を、環状溝の内径よりも小さくすることもできる。この場合には、貫通孔の径方向内側の端部が、内側突き当て部に開口する。 In this example, the diameter δi of the inscribed circle of the through hole 14 is larger than the inner diameter Di of the annular groove 11 (δi> Di). However, when the present invention is carried out, the diameter of the inscribed circle of the through hole may be made smaller than the inner diameter of the annular groove. In this case, the radial inner end of the through hole opens to the inner abutment.

図１に戻って、本例では、ハブ３は、内輪２１とハブ輪２２とを組み合わせてなる。 Returning to FIG. 1, in this example, the hub 3 is a combination of the inner ring 21 and the hub ring 22.

内輪２１は、外周面に、軸方向内側の内輪軌道８ａを有する。 The inner ring 21 has an inner ring track 8a on the outer peripheral surface in the axial direction.

ハブ輪２２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２２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 22 has an inner ring track 8b on the outer side in the axial direction at the intermediate portion in the axial direction of the outer peripheral surface. Further, the hub ring 22 has a rotary flange 9 protruding outward in the radial direction at a portion located on the outer side in the axial direction from the inner ring track 8b on the outer side in the axial direction, and at the end portion on the outer side in the axial direction. It has a cylindrical pilot portion 10.

ハブ３は、ハブ輪２２の軸方向内側部に内輪２１を締り嵌めで外嵌し、かつ、ハブ輪２２の軸方向内側の端部に備えられたかしめ部２３により内輪２１の軸方向内側の端面を押さえ付けることで、内輪２１とハブ輪２２とを結合固定することにより構成されている。 The hub 3 has an inner ring 21 fitted to the inner portion of the hub ring 22 in the axial direction by tightening and fitting, and the hub 3 has a caulking portion 23 provided at the end portion of the inner end of the hub ring 22 in the axial direction to accommodate the inner ring 21 in the axial direction. By pressing the end face, the inner ring 21 and the hub ring 22 are coupled and fixed.

車輪を構成するホイール２５および制動用回転体２６は、雌ねじ孔１３のそれぞれに螺合されたハブボルト２７により、回転フランジ９に結合固定される。 The wheel 25 and the braking rotating body 26 constituting the wheel are coupled and fixed to the rotating flange 9 by hub bolts 27 screwed into the female screw holes 13.

具体的には、制動用回転体２６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２６およびホイール２５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２８ａ、２８ｂにハブボルト２７を挿通し、かつ、ハブボルト２７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２９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２５および制動用回転体２６を、回転フランジ９とハブボルト２７の基端部である軸方向外側の端部に備えられた頭部３０とにより軸方向両側から強く挟持することで、ホイール２５および制動用回転体２６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 portion of the braking rotating body 26 is fitted onto the outer peripheral surface of the axial inner portion of the pilot portion 10 and is fitted in the radial center portion of the wheel 25. The provided inner peripheral surface is fitted onto the outer peripheral surface of the axially outer portion of the pilot portion 10. Further, in this state, the hub bolt 27 is inserted into the through holes 28a and 28b provided at a plurality of circumferential intermediate portions of the braking rotating body 26 and the wheel 25, respectively, and the tip portion of the hub bolt 27 is inserted. The male screw portion 29 provided at the inner end in the axial direction is screwed into the female screw hole 13 of the rotary flange 9 from the outer side in the axial direction and further tightened. As a result, the wheel 25 and the rotating body for braking 26 are strongly sandwiched from both sides in the axial direction by the rotary flange 9 and the head portion 30 provided at the outer end portion in the axial direction, which is the base end portion of the hub bolt 27. The wheel 25 and the braking rotating body 26 are coupled and fixed to the rotating flange 9.

なお、本例では、回転フランジ９の円周方向複数箇所に備えられた取付孔のそれぞれが、ハブボルト２７の雄ねじ部２９を軸方向外側から螺合させる雌ねじ孔１３により構成された、ハブボルト螺合タイプのハブユニット軸受１に、本発明を適用している。ただし、本発明は、回転フランジ９の円周方向複数箇所に備えられた取付孔のそれぞれが、ハブボルトのセレーション部を軸方向内側から圧入する圧入孔により構成された、ハブボルト圧入タイプのハブユニット軸受に適用することもできる。 In this example, each of the mounting holes provided at a plurality of locations in the circumferential direction of the rotary flange 9 is hub bolt screwed, which is composed of female screw holes 13 for screwing the male screw portion 29 of the hub bolt 27 from the outside in the axial direction. The present invention is applied to the type hub unit bearing 1. However, in the present invention, each of the mounting holes provided at a plurality of locations in the circumferential direction of the rotary flange 9 is a hub bolt press-fit type hub unit bearing composed of press-fit holes for press-fitting the serration portion of the hub bolt from the inside in the axial direction. It can also be applied to.

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２４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。 A plurality of rolling elements 4 are rotatably arranged between the double-row outer ring tracks 5a and 5b and the double-row inner ring tracks 8a and 8b in a state of being held by the cage 24. Has been done. As a result, the hub 3 is rotatably supported inward in the radial direction of the outer ring 2. In this example, a ball is used as the rolling element 4, but a tapered roller may be used instead of the ball. Further, in this example, the pitch circle diameter of the rolling element 4 in the outer row in the axial direction and the pitch circle diameter of the rolling element 4 in the inner row in the axial direction are the same as each other. It can also be applied to PCD type hub unit bearings having different diameters in which the pitch circle diameter of the moving body and the pitch circle diameter of the rolling elements in the inner row in the axial direction 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、制動用回転体２６およびホイール２５のそれぞれの通孔２８ａ、２８ｂに挿通したハブボルト２７の雄ねじ部２９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２６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。 According to the hub unit bearing 1 of this example as described above, the male screw portion 29 of the hub bolt 27 inserted into the through holes 28a and 28b of the braking rotating body 26 and the wheel 25, respectively, is inserted into the female screw hole 13 of the rotary flange 9. Even if the circumference of the opening on the outer side of the female screw hole 13 is deformed and swells due to screwing from the outside in the axial direction and further tightening, the swelling is retained in the annular groove 11 to keep the swelling in the annular groove 11. It is possible to improve the surface runout accuracy of the portion other than the annular groove 11 on the outer surface in the axial direction of the above. As a result, it is possible to improve the surface runout accuracy of the portion that comes into contact with the brake pad, which is provided at the radial outer end of the braking rotating body 26, and suppress the occurrence of brake judder during braking.

また、本例のハブユニット軸受１によれば、回転フランジ９の強度および剛性を確保しつつ、環状溝１１の底面１２と制動用回転体２６の軸方向内側面との間の隙間３１から貫通孔１４を通じて外部空間に水分を効率良く排出するための設計を容易に行える。この点について、以下に説明する。 Further, according to the hub unit bearing 1 of this example, while ensuring the strength and rigidity of the rotary flange 9, it penetrates through the gap 31 between the bottom surface 12 of the annular groove 11 and the axial inner side surface of the braking rotating body 26. The design for efficiently discharging water to the external space through the hole 14 can be easily performed. This point will be described below.

車両の走行中には、雨水や泥水などの水分が、貫通孔１４を通じて、隙間３１に侵入することがある。本例では、隙間３１に侵入した水分が、この隙間３１に滞留しにくく、貫通孔１４を通じて外部空間に排出されやすくなっている。 While the vehicle is running, water such as rainwater or muddy water may enter the gap 31 through the through hole 14. In this example, the water that has entered the gap 31 is unlikely to stay in the gap 31, and is easily discharged to the external space through the through hole 14.

すなわち、本例では、貫通孔１４の内接円の直径δｉは、環状溝１１の外径Ｄｏよりも小さくなっており（δｉ＜Ｄｏ）、貫通孔１４の外接円の直径δｏは、環状溝１１の外径Ｄｏよりも大きくなっている（δｏ＞Ｄｏ）。したがって、隙間３１に侵入した水分は、車両の走行時には、車輪の回転に伴う遠心力により、隙間３１の径方向外側の端部まで移動した後、凹面部１９に向けて振り飛ばされる。また、隙間３１に侵入した水分は、車両の停止時には、重力により、隙間３１の下側かつ径方向外側の端部まで移動した後、凹面部１９に向けて滴下する。いずれにしても、凹面部１９に到達した水分は、この凹面部１９から、貫通孔１４のうち凹面部１９よりも軸方向内側に位置する部分を通じて、外部空間へと排出される。 That is, in this example, the diameter δi of the inscribed circle of the through hole 14 is smaller than the outer diameter Do of the annular groove 11 (δi <Do), and the diameter δo of the inscribed circle of the through hole 14 is the annular groove. It is larger than the outer diameter Do of 11 (δo> Do). Therefore, when the vehicle is traveling, the water that has entered the gap 31 moves to the radially outer end of the gap 31 due to the centrifugal force accompanying the rotation of the wheels, and then is shaken off toward the concave portion 19. Further, when the vehicle is stopped, the water that has entered the gap 31 moves to the lower and radial outer ends of the gap 31 due to gravity, and then drops toward the concave portion 19. In any case, the water that has reached the concave surface portion 19 is discharged from the concave surface portion 19 to the external space through the portion of the through hole 14 located axially inside the concave surface portion 19.

特に、本例では、環状溝１１のうち、雌ねじ孔１３の外接円よりも径方向外側の部分の軸方向深さが、環状溝１１のうちの残りの部分の軸方向深さに比べて深くなっている。このため、環状溝１１のうち、雌ねじ孔１３の外接円よりも径方向外側の部分の軸方向深さを十分に深くする、具体的には、たとえば従来構造の環状溝の軸方向深さよりも深くすることにより、隙間３１の径方向外側の端部（外側周面１８）まで移動してきた水分の移動先である凹面部１９を、貫通孔１４の軸方向内側の開口部に近づけることができる。したがって、凹面部１９に到達した水分を、貫通孔１４のうち凹面部１９よりも軸方向内側に位置する部分を通じて、外部空間に効率良く排出することができる。 In particular, in this example, the axial depth of the portion of the annular groove 11 that is radially outside the circumscribed circle of the female screw hole 13 is deeper than the axial depth of the remaining portion of the annular groove 11. It has become. Therefore, of the annular groove 11, the axial depth of the portion radially outer of the circumscribed circle of the female screw hole 13 is sufficiently deepened, specifically, for example, than the axial depth of the annular groove of the conventional structure. By making it deeper, the concave surface portion 19 which is the destination of the moisture that has moved to the radially outer end portion (outer peripheral surface 18) of the gap 31 can be brought closer to the axially inner opening portion of the through hole 14. .. Therefore, the water that has reached the concave surface portion 19 can be efficiently discharged to the external space through the portion of the through hole 14 located axially inside the concave surface portion 19.

また、本例では、環状溝１１の底面１２が、径方向外側に向かうにしたがって環状溝１１の軸方向深さが増大する形状を有する。このため、隙間３１に侵入した水分は、底面１２を伝わりながら、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移動する。また、本例では、環状溝１１の径方向外側の端部の軸方向深さＷｚが、面取り部２０の軸方向幅Ｗｙよりも大きくなっている（Ｗｚ＞Ｗｙ）。このため、底面１２を伝わりながら、隙間３１の径方向外側の端部まで移動した水分を、面取り部２０よりも軸方向内側に位置する凹面部１９に効率良く送ることができる。したがって、その分、隙間３１に侵入した水分を、貫通孔１４を通じて外部空間に効率良く排出できる。 Further, 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 increases toward the outer side in the radial direction. Therefore, the water that has entered the gap 31 moves in the axially inward direction as it goes outward in the radial direction while being transmitted through the bottom surface 12. Further, in this example, the axial depth Wz of the radially outer end of the annular groove 11 is larger than the axial width Wy of the chamfered portion 20 (Wz> Wy). Therefore, the water that has traveled to the radial outer end of the gap 31 while being transmitted through the bottom surface 12 can be efficiently sent to the concave portion 19 located axially inside the chamfered portion 20. Therefore, the water that has entered the gap 31 can be efficiently discharged to the external space through the through hole 14.

また、本例では、環状溝１１のうち、雌ねじ孔１３の外接円よりも径方向外側の部分の軸方向深さが、環状溝１１のうちの残りの部分の軸方向深さに比べて深くなっている。すなわち、本例の構造では、環状溝１１のうち、雌ねじ孔１３の外接円よりも径方向外側の部分の軸方向深さを大きくする一方で、環状溝１１のうち、雌ねじ孔１３の外接円よりも径方向内側の部分の軸方向深さを小さくすることができる。このため、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の外接円よりも径方向内側の部分の軸方向の肉厚、すなわち、強度及び剛性を、十分に確保できる。したがって、本例の構造によれば、回転フランジ９の強度および剛性を確保しつつ、隙間３１から貫通孔１４を通じて外部空間に水分を効率良く排出するための設計を容易に行える。 Further, in this example, the axial depth of the portion of the annular groove 11 that is radially outside the circumscribed circle of the female screw hole 13 is deeper than the axial depth of the remaining portion of the annular groove 11. It has become. That is, in the structure of this example, the axial depth of the portion of the annular groove 11 that is radially outer than the circumscribed circle of the female screw hole 13 is increased, while the circumscribed circle of the female screw hole 13 of the annular groove 11 is increased. It is possible to reduce the axial depth of the inner portion in the radial direction. Therefore, in the portion of the rotary flange 9 that overlaps the annular groove 11 in the axial direction, the thickness, that is, the strength and rigidity of the portion radially inside the circumscribed circle of the female screw hole 13 in the axial direction is sufficiently increased. Can be secured. Therefore, according to the structure of this example, it is possible to easily design to efficiently discharge water from the gap 31 to the external space through the through hole 14 while ensuring the strength and rigidity of the rotary flange 9.

また、以上のように、本例の構造によれば、隙間３１から貫通孔１４を通じて外部空間に水分を効率良く排出できるため、隙間３１内に残った水分が、車輪の回転に伴う遠心力、および／または、重力により、回転フランジ９の内側突き当て部１５および外側突き当て部１６と制動用回転体２６の軸方向内側面との間に侵入することを抑制できる。このため、回転フランジ９の内側突き当て部１５および外側突き当て部１６と制動用回転体２６の軸方向内側面との錆び付きの発生を抑制できる。したがって、メンテナンスの際に、回転フランジ９から制動用回転体２６を容易に取り外すことができる。また、制動用回転体２６の面振れ精度の悪化を抑制して、制動時にブレーキジャダーの発生を抑制できる。 Further, as described above, according to the structure of this example, water can be efficiently discharged from the gap 31 to the external space through the through hole 14, so that the water remaining in the gap 31 is a centrifugal force due to the rotation of the wheel. And / or gravity can prevent entry between the inner abutting portion 15 and the outer abutting portion 16 of the rotating flange 9 and the axial inner side surface of the braking rotating body 26. Therefore, it is possible to suppress the occurrence of rust between the inner abutting portion 15 and the outer abutting portion 16 of the rotary flange 9 and the axial inner side surface of the braking rotating body 26. Therefore, the braking rotating body 26 can be easily removed from the rotating flange 9 during maintenance. Further, it is possible to suppress deterioration of the surface runout accuracy of the braking rotating body 26 and suppress the occurrence of brake judder during braking.

［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および図６を用いて説明する。 [Second Example of Embodiment]
A second example of the embodiment of the present invention will be described with reference to FIGS. 5 and 6.

本例のハブユニット軸受でも、環状溝１１ａのうち、雌ねじ孔１３の外接円（直径ｄｏ）よりも径方向外側の部分の軸方向深さは、環状溝１１ａのうちの残りの部分、すなわち、環状溝１１ａのうち、雌ねじ孔１３の外接円よりも径方向内側の部分の軸方向深さに比べて深くなっている。 Even in the hub unit bearing of this example, the axial depth of the portion of the annular groove 11a that is radially outside the circumscribed circle (diameter do) of the female screw hole 13 is the remaining portion of the annular groove 11a, that is, Of the annular groove 11a, the portion inside the circumscribed circle of the female screw hole 13 in the radial direction is deeper than the axial depth.

このために、本例では、環状溝１１ａの底面１２ａのうち、雌ねじ孔１３の外接円よりも径方向内側の部分は、ハブ３の中心軸Ｃに直交する平坦面部３２により構成されている。これに対して、環状溝１１ａの底面１２ａのうち、雌ねじ孔１３の外接円よりも径方向外側の部分は、平坦面部３２よりも軸方向内側に凹んだ溝部３３により構成されている。 For this reason, in this example, of the bottom surface 12a of the annular groove 11a, the portion radially inner of the circumscribed circle of the female screw hole 13 is composed of a flat surface portion 32 orthogonal to the central axis C of the hub 3. On the other hand, of the bottom surface 12a of the annular groove 11a, the portion radially outside the circumscribed circle of the female screw hole 13 is composed of a groove portion 33 recessed inward in the axial direction from the flat surface portion 32.

本例を実施する場合、溝部３３は、たとえば、軸方向側面と周面との接続部に切削加工で逃げ溝を形成する場合と同様の方法で形成できる。具体的には、環状溝の底面の全体を、鍛造加工や切削加工により、ハブ３の中心軸Ｃを中心とする平坦面に加工した後、この平坦面の径方向外側の端部に切削加工を施すことにより溝部３３を形成し、この平坦面の残りの部分を平坦面部３２とすることができる。ただし、平坦面部３２および溝部３３は、鍛造加工により同時に形成することもできる。 When this example is carried out, the groove portion 33 can be formed by, for example, the same method as in the case of forming a relief groove by cutting at the connection portion between the axial side surface and the peripheral surface. Specifically, the entire bottom surface of the annular groove is machined into a flat surface centered on the central axis C of the hub 3 by forging or cutting, and then cutting is performed on the radial outer end of the flat surface. The groove portion 33 can be formed by applying the above method, and the remaining portion of the flat surface can be used as the flat surface portion 32. However, the flat surface portion 32 and the groove portion 33 can be formed at the same time by forging.

また、本例では、溝部３３の径方向外側に隣接する、環状溝１１ａの外側周面１８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、本発明を実施する場合には、図７に示す実施の形態の第２例の変形例のように、外側周面１８ａを、軸方向内側に向かうにしたがって直径が大きくなる方向に傾斜した傾斜面により構成することもできる。 Further, in this example, the outer peripheral surface 18 of the annular groove 11a adjacent to the radial outer side of the groove portion 33 is formed of a cylindrical surface whose diameter does not change in the axial direction. However, when the present invention is carried out, the outer peripheral surface 18a is inclined in a direction in which the diameter increases toward the inside in the axial direction, as in the modified example of the second example of the embodiment shown in FIG. It can also be configured with an inclined surface.

本例の構造では、雌ねじ孔１３のそれぞれの軸方向外側の端部は、環状溝１１ａの底面１２ａの平坦面部３２に開口している。このため、平坦面部３２を形成した後に、この平坦面部３２を加工の開始点または終了点として雌ねじ孔１３を形成すれば、ハブ３の中心軸Ｃに対して傾斜した傾斜面を加工の開始点または終了点として雌ねじ孔１３を形成する場合に比べて、雌ねじ孔１３を容易に形成することができる。
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。 In the structure of this example, each axially outer end of the female screw hole 13 is open to the flat surface portion 32 of the bottom surface 12a of the annular groove 11a. Therefore, if the female screw hole 13 is formed with the flat surface portion 32 as the start point or end point of machining after the flat surface portion 32 is formed, the inclined surface inclined with respect to the central axis C of the hub 3 can be started at the machining start point. Alternatively, the female screw hole 13 can be easily formed as compared with the case where the female screw hole 13 is formed as the end point.
Other configurations and effects are the same as in the first embodiment of the 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。たとえば、本発明は、環状溝の底面のうち、回転部材の中心軸を中心とする取付孔の外接円よりも径方向内側の部分は、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増大する傾斜面により構成されており、環状溝の底面のうち、回転部材の中心軸を中心とする取付孔の外接円よりも径方向外側の部分は、前記傾斜面よりも軸方向内側に凹んだ溝部により構成されている構造を採用することもできる。 The present invention can be carried out by appropriately combining the structures of the respective embodiments as long as there is no contradiction. For example, in the present invention, the portion of the bottom surface of the annular groove that is radially inner side of the circumscribed circle of the mounting hole centered on the central axis of the rotating member is the axial depth of the annular groove toward the radial outer side. Of the bottom surface of the annular groove, the portion radially outside the circumscribed circle of the mounting hole centered on the central axis of the rotating member is axially inside the inclined surface. It is also possible to adopt a structure composed of a recessed groove.

１ ハブユニット軸受
２ 外輪
３ 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 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 貫通孔
１５ 内側突き当て部
１６ 外側突き当て部
１７ 内側周面
１８、１８ａ 外側周面
１９ 凹面部
２０ 面取り部
２１ 内輪
２２ ハブ輪
２３ かしめ部
２４ 保持器
２５ ホイール
２６ 制動用回転体
２７ ハブボルト
２８ａ、２８ｂ 通孔
２９ 雄ねじ部
３０ 頭部
３１ 隙間
３２ 平坦面部
３３ 溝部 1 Hub unit bearing 2 Outer ring 3 Hub 4 Rolling element 5a, 5b Outer ring track 6 Static flange 7 Support hole 8a, 8b Inner ring track 9 Rotating flange 10 Pilot part 11, 11a Circular groove 12, 12a Bottom surface 13 Female screw hole 14 Through hole 15 Inside Butt part 16 Outer abutment part 17 Inner peripheral surface 18, 18a Outer peripheral surface 19 Concave part 20 Chamfering part 21 Inner ring 22 Hub wheel 23 Caulking part 24 Cage 25 Wheel 26 Braking rotating body 27 Hub bolt 28a, 28b Through hole 29 Male screw part 30 Head 31 Gap 32 Flat surface part 33 Groove part

Claims (4)

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、前記回転部材の中心軸を中心とする円環状の環状溝、円周方向複数箇所のそれぞれに、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取付孔、および、円周方向の少なくとも１箇所に、軸方向に貫通する貫通孔を有しており、
前記回転部材の中心軸を中心とする前記貫通孔の内接円の直径は、前記環状溝の外径よりも小さくなっており、前記回転部材の中心軸を中心とする前記貫通孔の外接円の直径は、前記環状溝の外径よりも大きくなっており、
前記環状溝のうち、前記回転部材の中心軸を中心とする前記取付孔の外接円よりも径方向外側の部分の軸方向深さは、前記環状溝のうち、前記回転部材の中心軸を中心とする前記取付孔の外接円よりも径方向内側の部分の軸方向深さに比べて深くなっている、
ハブユニット軸受。 An outer member having an outer ring track on the inner peripheral surface, and
An inner member having an inner ring track on the outer peripheral surface,
A plurality of rolling elements rotatably arranged between the outer ring track and the inner ring track are provided.
Of the outer member and the inner member, the rotating member that rotates during use has a rotating flange that protrudes outward in the radial direction.
The rotary flange has an annular groove centered on the central axis of the rotary member on the outer surface in the axial direction, and a plurality of annular grooves in the circumferential direction, each of which extends in the axial direction and has an end portion on the outer side in the axial direction. It has a mounting hole that opens only on the bottom surface of the annular groove, and a through hole that penetrates in the axial direction at at least one place in the circumferential direction.
The diameter of the inscribed circle of the through hole centered on the central axis of the rotating member is smaller than the outer diameter of the annular groove, and the outer circle of the through hole centered on the central axis of the rotating member. The diameter of is larger than the outer diameter of the annular groove.
The axial depth of the portion of the annular groove that is radially outside the circumscribed circle of the mounting hole centered on the central axis of the rotating member is centered on the central axis of the rotating member of the annular groove. It is deeper than the axial depth of the portion inside the radial direction from the circumscribed circle of the mounting hole.
Hub unit bearing. 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増大する形状を有する、
請求項１に記載のハブユニット軸受。 The bottom surface of the annular groove has a shape in which the axial depth of the annular groove increases toward the outside in the radial direction.
The hub unit bearing according to claim 1. 前記環状溝の底面のうち、前記回転部材の中心軸を中心とする前記取付孔の外接円よりも径方向内側の部分は、前記回転部材の中心軸に直交する平坦面部により構成されており、前記環状溝の底面のうち、前記回転部材の中心軸を中心とする前記取付孔の外接円よりも径方向外側の部分は、前記平坦面部よりも軸方向内側に凹んだ溝部により構成されている、
請求項１に記載のハブユニット軸受。 Of the bottom surface of the annular groove, the portion radially inside the circumscribed circle of the mounting hole centered on the central axis of the rotating member is composed of a flat surface portion orthogonal to the central axis of the rotating member. Of the bottom surface of the annular groove, a portion radially outer of the circumscribed circle of the mounting hole centered on the central axis of the rotating member is composed of a groove portion recessed inward in the axial direction from the flat surface portion. ,
The hub unit bearing according to claim 1. 前記貫通孔の内周面と、前記回転フランジの軸方向外側面のうち前記環状溝よりも径方向外側の部分との接続部に、面取り部を有し、
前記環状溝の径方向外側の端部の軸方向深さが、前記面取り部の軸方向幅よりも大きい、
請求項１～３のうちのいずれかに記載のハブユニット軸受。 A chamfered portion is provided at a connecting portion between the inner peripheral surface of the through hole and the axially outer surface of the rotary flange, which is radially outer than the annular groove.
The axial depth of the radially outer end of the annular groove is larger than the axial width of the chamfered portion.
The hub unit bearing according to any one of claims 1 to 3.

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