JP2017211076A - Rolling bearing and air turbine bearing unit - Google Patents

Rolling bearing and air turbine bearing unit Download PDF

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JP2017211076A
JP2017211076A JP2016129149A JP2016129149A JP2017211076A JP 2017211076 A JP2017211076 A JP 2017211076A JP 2016129149 A JP2016129149 A JP 2016129149A JP 2016129149 A JP2016129149 A JP 2016129149A JP 2017211076 A JP2017211076 A JP 2017211076A
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inner ring
compressed air
rolling bearing
bearing
seal member
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JP6686738B2 (en
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亨 中原
Toru Nakahara
亨 中原
篤弘 山本
Atsuhiro Yamamoto
篤弘 山本
翔士 宮▲崎▼
Shoji Miyazaki
翔士 宮▲崎▼
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NSK Ltd
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NSK Ltd
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Priority to CN201911379644.5A priority Critical patent/CN111503161B/en
Priority to CN201780016093.9A priority patent/CN108713108A/en
Priority to PCT/JP2017/009102 priority patent/WO2017154935A1/en
Priority to EP17763275.9A priority patent/EP3428468B1/en
Priority to US16/080,490 priority patent/US11564772B2/en
Priority to EP19219903.2A priority patent/EP3667110B1/en
Publication of JP2017211076A publication Critical patent/JP2017211076A/en
Priority to US16/728,014 priority patent/US11540902B2/en
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  • Dental Tools And Instruments Or Auxiliary Dental Instruments (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide an air turbine rolling bearing which can make compatible both high-speed rotation and its quick stop, and an air turbine bearing unit.SOLUTION: A rolling bearing 1 comprises: an outer ring 10; an inner ring 20; a plurality of rolling bodies 3; and a substantially-annular member 30 which is arranged at one end part of a bearing internal space S between the outer ring 10 and the inner ring 20 in an axial direction, and composed of an elastic body having no core grid. An external peripheral part of the substantially-annular member 30 is fixed to a groove part 13 formed at an internal peripheral face of the outer ring 10 at one end part in the axial direction by a snap ring 40, and an internal peripheral part is made elastically changeable. An external peripheral face 21 of the inner ring 20 has an inclined face 23 or a step part which becomes small in a diameter toward an axial end. One end part in the axial direction for installing the substantially-annular member 30 is located at a side opposite to an inlet of compressed air which is supplied to the bearing internal space S.SELECTED DRAWING: Figure 2

Description

本発明は、転がり軸受及びエアタービン用軸受ユニットに関する。   The present invention relates to a rolling bearing and an air turbine bearing unit.

歯科治療においては、小型軽量のエアタービンハンドピースが多用される。
図２２に一例として歯科エアタービンハンドピース１２０を示す。この歯科エアタービンハンドピース１２０は、グリップ部１２１と、グリップ部１２１の先端部に設けられたヘッド部１２２と、を備える。術者は、このグリップ部１２１を持って、例えば歯牙の切削加工を行う。
この種のエアタービンハンドピースは、給気口と排気口とを有するヘッドハウジング（以下、単に「ハウジング」と記す）の内部に、給気口からの圧縮空気を受けるタービンブレードを有する回転軸が回転自在に収納されている。回転軸は、転がり軸受を介して高速回転自在にハウジングに支持される。この回転軸に取り付けられた治療用工具を高速回転させつつ、術者がエアタービンハンドピースを操作することにより、歯牙の切削等が行われる。 In dental treatment, a small and lightweight air turbine handpiece is frequently used.
FIG. 22 shows a dental air turbine handpiece 120 as an example. The dental air turbine handpiece 120 includes a grip part 121 and a head part 122 provided at the tip of the grip part 121. The surgeon holds the grip portion 121 and performs, for example, tooth cutting.
This type of air turbine handpiece has a rotary shaft having a turbine blade that receives compressed air from an air supply port in a head housing (hereinafter simply referred to as “housing”) having an air supply port and an exhaust port. It is stored freely. The rotating shaft is supported by the housing via a rolling bearing so as to be rotatable at high speed. The tooth is cut by the surgeon operating the air turbine handpiece while rotating the treatment tool attached to the rotating shaft at a high speed.

特許文献１には、転がり軸受に耐熱性メカニカルシールを設けたエアタービンハンドピースが記載されている。この耐熱性メカニカルシールは、圧縮空気による圧力が作用しているとき、つまりタービンブレードを有する回転軸が回転しているときには、転がり軸受に接触するように弾性変形して、圧縮空気を遮蔽する。これにより、使用時に作用する圧縮空気の影響で、転がり軸受内部の潤滑油が抜け出てしまうことを防止する。一方、圧縮空気による圧力が作用していないとき、つまり回転軸が回転していないときには、転がり軸受に非接触となるように元の状態に戻る。これにより、回転開始時における耐熱性メカニカルシールと転がり軸受との摩擦抵抗をなくし、回転軸に取り付けられた治療用工具のスムーズな起動を可能としている。   Patent Document 1 describes an air turbine handpiece in which a rolling bearing is provided with a heat-resistant mechanical seal. This heat-resistant mechanical seal is elastically deformed so as to come into contact with the rolling bearing when pressure by compressed air is acting, that is, when the rotating shaft having the turbine blade is rotating, thereby shielding the compressed air. This prevents the lubricating oil inside the rolling bearing from coming out due to the influence of compressed air acting during use. On the other hand, when the pressure by the compressed air is not acting, that is, when the rotating shaft is not rotating, the original state is restored so as not to contact the rolling bearing. This eliminates the frictional resistance between the heat-resistant mechanical seal and the rolling bearing at the start of rotation, and enables a smooth start-up of the therapeutic tool attached to the rotating shaft.

特開２００３−１３５４８６号公報JP 2003-135486 A

エアタービンハンドピースは、約４０万ｍｉｎ−１という超高速回転で使用される。その一方で、回転停止操作がなされたとき、すなわち、圧縮空気の供給が停止されたときには、転がり軸受の回転の早急な停止が求められる。
しかし、特許文献１に記載の転がり軸受は、耐熱性メカニカルシールに圧縮空気による圧力が作用しているとき、つまりタービンブレードが取り付けられた回転軸が回転しているときに、回転軸を支持する転がり軸受に耐熱性メカニカルシールが接触し、転がり軸受の抵抗を大きくする構造になっている。そのため、約４０万ｍｉｎ−１という超高速回転での使用には適さない。また、圧縮空気の供給を停止すると耐熱性メカニカルシールが転がり軸受に接触しなくなり、転がり軸受の摩擦抵抗が小さくなるため、転がり軸受を早急に停止させる上でも不利である。 The air turbine handpiece is used at an ultra-high speed rotation of about 400,000 min −1 . On the other hand, when the rotation stop operation is performed, that is, when the supply of compressed air is stopped, an immediate stop of the rotation of the rolling bearing is required.
However, the rolling bearing described in Patent Document 1 supports the rotating shaft when pressure by compressed air is acting on the heat-resistant mechanical seal, that is, when the rotating shaft to which the turbine blade is attached is rotating. A heat-resistant mechanical seal is in contact with the rolling bearing to increase the resistance of the rolling bearing. Therefore, it is not suitable for use at an ultra high speed rotation of about 400,000 min −1 . Further, when the supply of compressed air is stopped, the heat-resistant mechanical seal does not come into contact with the rolling bearing, and the frictional resistance of the rolling bearing is reduced, which is disadvantageous for quickly stopping the rolling bearing.

本発明は、上述した課題を鑑みてなされたものであり、その目的は、従来よりも更に高速な超高速回転とその迅速な停止とを両立可能な転がり軸受及びエアタービン軸受ユニットを提供することにある。   The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a rolling bearing and an air turbine bearing unit that can achieve both ultra-high-speed rotation at a higher speed than before and quick stop thereof. It is in.

本発明の上記目的は、下記の構成により達成される。
（１） 外輪と、
内輪と、
前記外輪と前記内輪との間に転動自在に配置された複数の転動体と、
前記外輪と前記内輪との間の軸受内部空間の軸方向一端部に設けられ、芯金が無い弾性体からなる略環状部材と、を備え、
前記略環状部材は、前記外輪の前記軸方向一端部の内周面に形成された溝部に外周部が止め輪によって固定されて、内周部が弾性変形可能にされており、
前記内輪の外周面は、軸端に向かって大径から小径となる傾斜面又は段差を有し、
前記軸方向一端部は、前記軸受内部空間に供給される圧縮空気の入口とは反対側であるエアタービン用転がり軸受。
この転がり軸受によれば、内輪の外周面が、軸端に向かって大径から小径となる傾斜面又は段差を有することにより、内外輪間を通過した圧縮空気を低抵抗で軸受外に排出でき、圧縮空気の流れがスムーズになる。そのため、従来よりも更に高速な超高速回転を実現できる。そして、略環状部材に圧縮空気による圧力が作用しない場合、内輪の外周面に略環状部材が接触することで、回転の迅速な停止を実現できる。 The above object of the present invention can be achieved by the following constitution.
(1) outer ring,
Inner ring,
A plurality of rolling elements arranged so as to be freely rollable between the outer ring and the inner ring;
A substantially annular member that is provided at one end in the axial direction of the bearing internal space between the outer ring and the inner ring, and is made of an elastic body without a metal core;
The substantially annular member has an outer peripheral portion fixed to a groove portion formed on an inner peripheral surface of the one axial end portion of the outer ring by a retaining ring, and the inner peripheral portion is elastically deformable.
The outer peripheral surface of the inner ring has an inclined surface or a step that becomes a small diameter from a large diameter toward the shaft end,
The axial end of the rolling bearing for an air turbine, wherein one end of the axial direction is opposite to an inlet of compressed air supplied to the bearing internal space.
According to this rolling bearing, since the outer peripheral surface of the inner ring has an inclined surface or a step difference from the large diameter toward the shaft end, the compressed air that has passed between the inner and outer rings can be discharged out of the bearing with low resistance. , The flow of compressed air becomes smooth. For this reason, it is possible to realize ultra-high speed rotation that is even faster than conventional. And when the pressure by compressed air does not act on a substantially annular member, a rapid stop of rotation is realizable because a substantially annular member contacts the outer peripheral surface of an inner ring | wheel.

（２） 前記略環状部材が前記内輪の外周面に接触する部位は、前記傾斜面又は前記段差である（１）に記載のエアタービン用転がり軸受。
この転がり軸受によれば、傾斜面又は段差に略環状部材が接触することにより、略環状部材と内輪との接触圧が低減し、圧縮空気による略環状部材の開閉をスムーズにできる。よって、従来よりも更に高速な超高速回転とその迅速な停止とを実現できる。 (2) The air turbine rolling bearing according to (1), wherein the portion where the substantially annular member contacts the outer peripheral surface of the inner ring is the inclined surface or the step.
According to this rolling bearing, when the substantially annular member contacts the inclined surface or the step, the contact pressure between the substantially annular member and the inner ring is reduced, and the opening and closing of the substantially annular member by the compressed air can be smoothly performed. Therefore, it is possible to realize an ultra-high speed rotation and a quick stop that are faster than the conventional one.

（３） 前記略環状部材は、前記傾斜面に接触可能なリップ部を有し、
前記リップ部は、径方向内側に向かうに従って、前記圧縮空気の供給方向下流側に傾斜する形状である（１）又は（２）に記載の転がり軸受。
この転がり軸受によれば、略環状部材の内輪との接触部が、より弾性変形しやすい形状となる。この弾性変形しやすいリップ部を、内輪の傾斜面に接触可能に構成することにより、略環状部材の開閉動作をより低い圧力で行える。
（４）前記リップ部は、径方向内側に向かうに従って、径方向からの傾斜角が大きくなる（３）に記載の転がり軸受。
この転がり軸受によれば、略環状部材に圧縮空気の圧力が作用した際に、リップ部が弾性変形しやすくなる。 (3) The substantially annular member has a lip portion that can contact the inclined surface,
The rolling bearing according to (1) or (2), wherein the lip portion has a shape inclined toward the downstream side in the compressed air supply direction as it goes radially inward.
According to this rolling bearing, the contact portion of the substantially annular member with the inner ring has a shape that is more easily elastically deformed. By configuring the lip portion that is easily elastically deformable so as to be in contact with the inclined surface of the inner ring, the opening and closing operation of the substantially annular member can be performed with a lower pressure.
(4) The rolling bearing according to (3), wherein the lip portion has a larger inclination angle from the radial direction as it goes radially inward.
According to this rolling bearing, when the pressure of compressed air acts on the substantially annular member, the lip portion is easily elastically deformed.

（５） 前記略環状部材に前記圧縮空気による圧力が作用しない場合に、前記リップ部が前記傾斜面に全周にわたって接触する（３）又は（４）に記載の転がり軸受。
この転がり軸受によれば、略環状部材に圧縮空気による圧力が作用しない場合に、略環状部材と内輪との摩擦抵抗による大きなブレーキ効果が得られ、回転の迅速な停止を効率よく実現できる。 (5) The rolling bearing according to (3) or (4), wherein when the pressure by the compressed air does not act on the substantially annular member, the lip portion contacts the inclined surface over the entire circumference.
According to this rolling bearing, when pressure by compressed air does not act on the substantially annular member, a large braking effect due to the frictional resistance between the substantially annular member and the inner ring can be obtained, and a quick stop of rotation can be efficiently realized.

（６） 前記略環状部材に前記圧縮空気による圧力が作用しない場合に前記リップ部が前記傾斜面と接触する接触領域は、前記リップ部の内周面全体の１０％以上である（３）又は（４）に記載の転がり軸受。
この転がり軸受によれば、略環状部材に圧縮空気による圧力が作用しない場合に、略環状部材と内輪との摩擦抵抗による十分なブレーキ効果が得られる。 (6) When the pressure by the compressed air does not act on the substantially annular member, the contact area where the lip portion contacts the inclined surface is 10% or more of the entire inner peripheral surface of the lip portion (3) or The rolling bearing according to (4).
According to this rolling bearing, when the pressure by the compressed air does not act on the substantially annular member, a sufficient braking effect due to the frictional resistance between the approximately annular member and the inner ring can be obtained.

（７） 前記略環状部材に前記圧縮空気による圧力が作用する場合に、前記リップ部と前記傾斜面とが互いに完全に非接触の状態になる（３）又は（４）に記載の転がり軸受。
この転がり軸受によれば、略環状部材と内輪との摩擦抵抗がなくなり、超高速回転を実現できる。 (7) The rolling bearing according to (3) or (4), wherein when the pressure by the compressed air acts on the substantially annular member, the lip portion and the inclined surface are completely in non-contact with each other.
According to this rolling bearing, the frictional resistance between the substantially annular member and the inner ring is eliminated, and ultra-high speed rotation can be realized.

（８）前記略環状部材の内周側の先端には、前記内輪の前記傾斜面又は前記段差に面接触する接触面が設けられている（１）〜（７）のいずれか一つに記載の転がり軸受。
この転がり軸受によれば、略環状部材が内輪の傾斜面又は段差に面接触するため、シール部材に作用する面圧が小さくなり、摩耗が軽減される。また、接触面積が増えることでシール性が向上する。 (8) A contact surface that is in surface contact with the inclined surface or the step of the inner ring is provided at an inner circumferential end of the substantially annular member. Rolling bearings.
According to this rolling bearing, since the substantially annular member is in surface contact with the inclined surface or step of the inner ring, the surface pressure acting on the seal member is reduced, and wear is reduced. Further, the sealing performance is improved by increasing the contact area.

（９）前記略環状部材の内周側の先端には、前記内輪の前記傾斜面又は前記段差に線接触する接触面が設けられている（１）〜（７）のいずれか一つに記載の転がり軸受。
この転がり軸受によれば、略環状部材が内輪の傾斜面又は段差に線接触するため、シール部材との摩擦が面接触の場合よりも軽減され、高速回転に有利となる。 (9) The contact surface that is in line contact with the inclined surface or the step of the inner ring is provided at the inner circumferential end of the substantially annular member. Rolling bearings.
According to this rolling bearing, since the substantially annular member is in line contact with the inclined surface or step of the inner ring, the friction with the seal member is reduced compared to the case of surface contact, which is advantageous for high-speed rotation.

（１０）前記略環状部材は、前記圧縮空気が作用するとき、前記内輪の前記傾斜面又は前記段差との間で径方向内側に向かう空気の排出通路を形成する（１）〜（９）のいずれか一つに記載に転がり軸受。
この転がり軸受によれば、軸受内部空間に流れる空気の流動方向が略環状部材の位置で変化するため、圧縮空気による圧力が略環状部材に確実に伝達される。 (10) When the compressed air acts, the substantially annular member forms a discharge passage for air that goes radially inward between the inclined surface or the step of the inner ring. Rolling bearing according to any one of the above.
According to this rolling bearing, since the flow direction of the air flowing in the bearing internal space changes at the position of the substantially annular member, the pressure by the compressed air is reliably transmitted to the substantially annular member.

（１１） 前記外輪の外径がφ１０ｍｍ以下である（１）〜（１０）のいずれか一つに記載の転がり軸受。
この転がり軸受によれば、歯科エアタービン用軸受ユニット等に好適に適用できる。 (11) The rolling bearing according to any one of (1) to (10), wherein an outer diameter of the outer ring is 10 mm or less.
This rolling bearing can be suitably applied to a dental air turbine bearing unit and the like.

（１２） 前記略環状部材は、耐水アクリルゴム又は耐水フッ素ゴムからなる（１）〜（１１）のいずれか一つに記載の転がり軸受。
この転がり軸受によれば、略環状部材が適切な弾性を有することで、耐久性が向上する。 (12) The rolling bearing according to any one of (1) to (11), wherein the substantially annular member is made of water-resistant acrylic rubber or water-resistant fluororubber.
According to this rolling bearing, durability is improved because the substantially annular member has appropriate elasticity.

（１３） 前記略環状部材は、ゴム硬度がショアＡ硬さ６０〜９０である（１２）に記載の転がり軸受。
この転がり軸受によれば、略環状部材が適度なゴム硬度であることで、耐摩擦性能を維持できる。 (13) The rolling bearing according to (12), wherein the substantially annular member has a rubber hardness of Shore A hardness 60 to 90.
According to this rolling bearing, friction resistance can be maintained because the substantially annular member has an appropriate rubber hardness.

（１４） 圧縮空気を受けて回転するタービンブレードと、
前記タービンブレードが一体に固定され、工具を取り付け可能な回転軸と、
前記圧縮空気が作用しないとき、前記略環状部材が前記内輪の外周面に接触し、前記圧縮空気が作用するとき、前記圧縮空気が作用しないときと比べて前記略環状部材と前記内輪の外周面との接触面積が小さくなる、又は非接触となる（１）〜（１３）のいずれか一つに記載のエアタービン用転がり軸受を介して、前記回転軸を回転自在に支持するハウジングと、
を備えるエアタービン用軸受ユニット。
このエアタービン用軸受ユニットによれば、工具を取り付け可能な回転軸のより一層の超高速回転と、回転軸の迅速な停止とが両立可能となる。 (14) a turbine blade that rotates by receiving compressed air;
A rotating shaft to which the turbine blade is fixed integrally and to which a tool can be attached;
When the compressed air does not act, the substantially annular member contacts the outer peripheral surface of the inner ring, and when the compressed air acts, the substantially annular member and the outer peripheral surface of the inner ring compared to when the compressed air does not act. A housing that rotatably supports the rotary shaft via the air turbine rolling bearing according to any one of (1) to (13), wherein the contact area is small or non-contact with
An air turbine bearing unit comprising:
According to this air turbine bearing unit, it is possible to achieve both ultra-high speed rotation of the rotary shaft to which the tool can be attached and quick stop of the rotary shaft.

（１５）グリップ部と、
前記グリップ部の先端部に設けられたヘッド部と、を備え、
前記ヘッド部は、
前記ハウジングと、（１４）に記載のエアタービン用軸受ユニットとを備える、エアタービンハンドピース。
このエアタービンハンドピースによれば、工具を取り付け可能な回転軸のより一層の超高速回転と回転軸の迅速な停止とを両立し、歯牙の切削や研削等、歯科治療時間の短縮が可能となる。 (15) a grip portion;
A head portion provided at a tip portion of the grip portion,
The head portion is
An air turbine handpiece comprising the housing and the air turbine bearing unit according to (14).
According to this air turbine handpiece, it is possible to achieve both ultra-high speed rotation of the rotary shaft to which the tool can be attached and rapid stop of the rotary shaft, and shorten dental treatment time such as tooth cutting and grinding. Become.

本発明の転がり軸受及びエアタービン用軸受ユニットによれば、従来よりも更に高速な超高速回転とその迅速な停止とを両立できる。   According to the rolling bearing and the air turbine bearing unit of the present invention, it is possible to achieve both ultra-high-speed rotation that is faster than conventional and rapid stop thereof.

第１実施形態の歯科エアタービンハンドピースの要部断面図である。It is principal part sectional drawing of the dental air turbine handpiece of 1st Embodiment. 第１実施形態の転がり軸受の停止状態を示す部分断面図である。It is a fragmentary sectional view which shows the stop state of the rolling bearing of 1st Embodiment. 図１に示すシール部材の断面図である。It is sectional drawing of the sealing member shown in FIG. 図３に示すシール部材のリップ部の断面図である。It is sectional drawing of the lip | rip part of the sealing member shown in FIG. 第１実施形態の転がり軸受の動作状態を示す部分断面図である。It is a fragmentary sectional view which shows the operation state of the rolling bearing of 1st Embodiment. 第１実施形態の変形例のシール部材の断面図である。It is sectional drawing of the sealing member of the modification of 1st Embodiment. 第２実施形態の転がり軸受を示す部分断面図である。It is a fragmentary sectional view which shows the rolling bearing of 2nd Embodiment. 第３実施形態の転がり軸受を示す部分断面図である。It is a fragmentary sectional view showing a rolling bearing of a 3rd embodiment. 第４実施形態の転がり軸受を示す部分断面図である。It is a fragmentary sectional view showing a rolling bearing of a 4th embodiment. 第５実施形態の転がり軸受を示す部分断面図である。It is a fragmentary sectional view showing a rolling bearing of a 5th embodiment. その他の実施形態を例示するシール部材の正面図である。It is a front view of the seal member which illustrates other embodiments. その他の実施形態を例示するシール部材の正面図である。It is a front view of the seal member which illustrates other embodiments. その他の実施形態を例示するシール部材の正面図である。It is a front view of the seal member which illustrates other embodiments. その他の実施形態を例示するシール部材の正面図である。It is a front view of the seal member which illustrates other embodiments. その他の実施形態を例示するシール部材の正面図である。It is a front view of the seal member which illustrates other embodiments. その他の実施形態を例示するシール部材の正面図である。It is a front view of the seal member which illustrates other embodiments. その他の実施形態を例示するシール部材の正面図である。It is a front view of the seal member which illustrates other embodiments. その他の実施形態を例示するシール部材の正面図である。It is a front view of the seal member which illustrates other embodiments. その他の実施形態を例示するシール部材の正面図である。It is a front view of the seal member which illustrates other embodiments. 外輪にカウンタボアが形成されたアンギュラタイプの転がり軸受の一部断面図である。It is a partial sectional view of an angular type rolling bearing in which a counterbore is formed on an outer ring. 内輪にカウンタボアが形成されたアンギュラタイプの転がり軸受の一部断面図である。FIG. 3 is a partial cross-sectional view of an angular type rolling bearing in which a counterbore is formed on an inner ring. 歯科エアタービンハンドピースの概略側面図である。1 is a schematic side view of a dental air turbine handpiece. FIG.

以下、本発明に係るエアタービン用転がり軸受及びエアタービン用軸受ユニットの実施形態を図面に基づいて詳細に説明する。   Hereinafter, embodiments of a rolling bearing for an air turbine and a bearing unit for an air turbine according to the present invention will be described in detail with reference to the drawings.

＜第１実施形態＞
図１は第１実施形態の歯科エアタービンハンドピースの要部断面図である。
エアタービン用軸受ユニット１００は、歯科エアタービンハンドピース２００のヘッド部２０１に搭載される。エアタービン用軸受ユニット１００は、圧縮空気を受けて回転するタービンブレード１０３と、タービンブレード１０３が一体に固定され、一端に工具（例えば、歯科処置工具）を取り付け可能な回転軸１０１と、ハウジング１０５に対して回転軸１０１を回転自在に支持する一対のエアタービン用転がり軸受１（以降は、転がり軸受と呼称する）と、を備える。 <First Embodiment>
FIG. 1 is a cross-sectional view of a main part of a dental air turbine handpiece according to the first embodiment.
The air turbine bearing unit 100 is mounted on the head portion 201 of the dental air turbine handpiece 200. The air turbine bearing unit 100 includes a turbine blade 103 that rotates by receiving compressed air, a rotating shaft 101 to which the turbine blade 103 is integrally fixed, and a tool (for example, a dental treatment tool) can be attached to one end, and a housing 105. A pair of air turbine rolling bearings 1 (hereinafter referred to as rolling bearings) that rotatably support the rotating shaft 101 are provided.

各転がり軸受１は、ハウジング１０５の環状凹部１０９，１１１に装着されたゴム製リング１１３を介してハウジング１０５に支持される。また、一方の転がり軸受１は、スプリングワッシャ１１５により他方の転がり軸受１側に付勢される。   Each rolling bearing 1 is supported by the housing 105 via a rubber ring 113 attached to the annular recesses 109 and 111 of the housing 105. Further, one rolling bearing 1 is biased toward the other rolling bearing 1 by a spring washer 115.

歯科エアタービンハンドピース２００に組み込まれるハンドピース用軸受の外径サイズは、一般的に外径φ６．３５ｍｍのものが多用されるが、本構成の転がり軸受１では、タービンヘッドの大きさに応じて、外径φ１０ｍｍ程度まで大きくできる。   Generally, the outer diameter size of the bearing for the handpiece incorporated in the dental air turbine handpiece 200 is that having an outer diameter of φ6.35 mm. In the rolling bearing 1 of this configuration, the outer diameter size depends on the size of the turbine head. Thus, the outer diameter can be increased to about φ10 mm.

図２は第１実施形態の転がり軸受の停止状態を示す部分断面図である。
転がり軸受１は、外輪軌道面１０ａを有する外輪１０と、内輪軌道面２０ａを有する内輪２０と、外輪１０と内輪２０との間に転動自在に配置された複数の玉（転動体）３と、複数の玉３をそれぞれ転動自在に保持する保持器５と、を備える軸受である。なお、図示例の軸受に限らず、アンギュラタイプの軸受であってもよい。外輪１０は、図１に示すゴム製リング１１３を介してハウジング１０５に保持される。内輪２０は、回転軸１０１に固定される。保持器５は、いわゆる冠型保持器であり、略円環状のリム部７が、玉３よりも圧縮空気の供給方向上流側、すなわち、図２における右方側に位置する。図中の矢印Ｐは、圧縮空気の流れる向きを示している。 FIG. 2 is a partial cross-sectional view showing a stopped state of the rolling bearing of the first embodiment.
The rolling bearing 1 includes an outer ring 10 having an outer ring raceway surface 10a, an inner ring 20 having an inner ring raceway surface 20a, and a plurality of balls (rolling elements) 3 disposed between the outer ring 10 and the inner ring 20 so as to be freely rollable. And a cage 5 that holds each of the balls 3 in a rollable manner. The bearing is not limited to the illustrated example, and may be an angular type bearing. The outer ring 10 is held by the housing 105 via a rubber ring 113 shown in FIG. The inner ring 20 is fixed to the rotating shaft 101. The retainer 5 is a so-called crown-shaped retainer, and the substantially annular rim portion 7 is located upstream of the balls 3 in the compressed air supply direction, that is, on the right side in FIG. An arrow P in the figure indicates the direction in which the compressed air flows.

外輪１０と内輪２０との間には、円環状のシール部材（略環状部材）３０が設けられる。シール部材３０は、芯金を備えずに弾性材料のみから構成される弾性体からなる。シール部材３０の外周部は、外輪１０の内周面に形成された溝部１３に止め輪４０によって固定されて、内周部が軸受の軸方向や径方向へ弾性変形可能となっている。   An annular seal member (substantially annular member) 30 is provided between the outer ring 10 and the inner ring 20. The seal member 30 is made of an elastic body made of only an elastic material without a cored bar. The outer peripheral portion of the seal member 30 is fixed to a groove portion 13 formed on the inner peripheral surface of the outer ring 10 by a retaining ring 40 so that the inner peripheral portion can be elastically deformed in the axial direction and the radial direction of the bearing.

シール部材３０を構成する弾性部材としては、例えば、ショアＡ硬さ（ＪＩＳ Ｋ ６２５３）６０〜９０の耐水アクリルゴム、ショアＡ硬さ６０〜９０の一般耐水フッ素ゴム等を使用できる。シール部材３０は、上記材料を用いることで、適切な弾性特性が得られ、耐久性、耐摩耗性も向上する。   As the elastic member constituting the seal member 30, for example, water resistant acrylic rubber having a Shore A hardness (JIS K 6253) of 60 to 90, general water resistant fluororubber having a Shore A hardness of 60 to 90, and the like can be used. By using the above-mentioned material, the sealing member 30 can obtain appropriate elastic characteristics and improve durability and wear resistance.

シール部材３０は、玉３よりも圧縮空気の供給方向下流側、すなわち、図２における左方側に設けられる。つまり、シール部材３０は、軸受内部空間Ｓの圧縮空気供給側（圧縮空気の入口）とは反対側の軸方向一端部に設けられる。外輪１０の内周面１１には、シール部材３０を固定する溝部１３が形成される。溝部１３には、シール部材３０が止め輪４０によって固定される。シール部材３０の形状は、円環状に限らず、後述するように略環状であれば他の形状であってもよい。   The seal member 30 is provided on the downstream side of the ball 3 in the compressed air supply direction, that is, on the left side in FIG. That is, the seal member 30 is provided at one end in the axial direction on the opposite side to the compressed air supply side (compressed air inlet) of the bearing internal space S. A groove 13 for fixing the seal member 30 is formed on the inner peripheral surface 11 of the outer ring 10. A seal member 30 is fixed to the groove 13 by a retaining ring 40. The shape of the seal member 30 is not limited to an annular shape, and may be another shape as long as it is substantially annular as will be described later.

内輪２０の外周面２１は、圧縮空気の供給方向下流側、すなわち、図２における左方側の端部に傾斜面２３を有する。傾斜面２３は、軸方向シール部材側の軸端に向かって大径から小径となるように傾斜した円環形状（円錐面状）に形成される。   The outer peripheral surface 21 of the inner ring 20 has an inclined surface 23 on the downstream side in the compressed air supply direction, that is, on the left side end in FIG. The inclined surface 23 is formed in an annular shape (conical surface shape) that is inclined so as to decrease from a large diameter toward a small diameter toward the axial end on the axial direction seal member side.

図３は図１に示すシール部材の断面図である。
シール部材３０は、径方向に延びる円環形状の基部３１と、基部３１の径方向内側に一体に形成されたリップ部３３と、を有する。シール部材３０の基部３１に対するリップ部３３の傾斜角θ、すなわち、基部３１の径方向と、リップ部３３の延出方向とのなす角は、３０°〜８０°、好ましくは４０°〜７０°、更に好ましくは４５°〜６５°とする。例えば、傾斜角θを上記範囲内の５５°に設定することで、摩擦抵抗と、圧縮空気の流れのバランスが良好となる。傾斜角θが上記範囲より小さい場合には接触抵抗が過大となり、大きい場合には圧縮空気の流動抵抗が過大となり、後述する意図した性能が得られない。 3 is a cross-sectional view of the seal member shown in FIG.
The seal member 30 includes an annular base 31 extending in the radial direction and a lip 33 formed integrally with the base 31 on the radial inner side. The inclination angle θ of the lip portion 33 with respect to the base portion 31 of the seal member 30, that is, the angle formed by the radial direction of the base portion 31 and the extending direction of the lip portion 33 is 30 ° to 80 °, preferably 40 ° to 70 °. More preferably, the angle is 45 ° to 65 °. For example, by setting the inclination angle θ to 55 ° within the above range, the balance between the frictional resistance and the flow of compressed air becomes good. When the inclination angle θ is smaller than the above range, the contact resistance is excessive, and when it is large, the flow resistance of the compressed air is excessive, and the intended performance described later cannot be obtained.

基部３１は、図２に示すように、止め輪４０とともに溝部１３に挿入され、溝部１３に固定される。溝部１３は、軸方向内側に向かうに従って径方向外側に傾斜して拡径して止め輪４０が接するテーパ面１５と、テーパ面１５よりも軸方向内側で、基部３１の軸方向側面が接する軸方向内側面１７と、を有する。テーパ面１５には、止め輪４０の外径側端部が周方向に沿って線接触状態となる。そして、止め輪４０は径方向外側に向けて付勢される弾性部材からなることで、シール部材３０を軸方向内側に押圧する力を発生する。これにより、シール部材３０は、その基部３１が止め輪４０と軸方向内側面１７との間で強く挟まれて、外輪１０に強固に固定される。なお、止め輪４０は、断面矩形状である他、断面円形であってもよい。また、止め輪４０に傾斜面を設け、溝部１３を断面矩形状とし、断面矩形状の溝部１３の角部を止め輪４０の傾斜面に押し当てる構成にしてもよい。   As shown in FIG. 2, the base portion 31 is inserted into the groove portion 13 together with the retaining ring 40 and is fixed to the groove portion 13. The groove portion 13 is inclined radially outward as it goes inward in the axial direction and expands in diameter to contact the retaining ring 40, and an axis that is axially inward of the tapered surface 15 and in contact with the axial side surface of the base 31. Direction inner surface 17. On the tapered surface 15, the outer diameter side end portion of the retaining ring 40 is in a line contact state along the circumferential direction. The retaining ring 40 is made of an elastic member that is urged outward in the radial direction, and generates a force that presses the seal member 30 inward in the axial direction. As a result, the base 31 of the seal member 30 is strongly sandwiched between the retaining ring 40 and the axial inner side surface 17, and is firmly fixed to the outer ring 10. The retaining ring 40 may have a circular cross section in addition to a rectangular cross section. Alternatively, the retaining ring 40 may be provided with an inclined surface, the groove 13 may have a rectangular cross section, and the corner of the groove 13 having a rectangular cross section may be pressed against the inclined surface of the retaining ring 40.

図４は図３に示すシール部材のリップ部の断面図である。
リップ部３３は、径方向内側に向かうに従って圧縮空気の供給方向下流側（軸方向外側）に傾斜し、内輪２０の傾斜面２３に当接可能とされている。図４に示すように、リップ部３３の内周面３５の形状は円環形状（円錐面状）である。このリップ部３３が当接可能な内輪２０の傾斜面２３の形状も円環形状（円錐面状）である。そのため、リップ部３３の内周面３５は、内輪２０の傾斜面に全周にわたって接触可能となる。つまり、シール部材３０は、外輪１０の内周面１１と内輪２０の外周面２１との間の軸受内部空間Ｓを全周にわたってシール可能となっている。 4 is a cross-sectional view of the lip portion of the seal member shown in FIG.
The lip portion 33 is inclined toward the downstream side (axially outer side) in the compressed air supply direction as it goes radially inward, and can contact the inclined surface 23 of the inner ring 20. As shown in FIG. 4, the shape of the inner peripheral surface 35 of the lip portion 33 is an annular shape (conical surface shape). The shape of the inclined surface 23 of the inner ring 20 with which the lip portion 33 can abut is also an annular shape (conical surface shape). Therefore, the inner peripheral surface 35 of the lip portion 33 can contact the inclined surface of the inner ring 20 over the entire periphery. That is, the seal member 30 can seal the bearing inner space S between the inner peripheral surface 11 of the outer ring 10 and the outer peripheral surface 21 of the inner ring 20 over the entire circumference.

図５は第１実施形態の転がり軸受の動作状態を示す部分断面図である。
上記のように構成されたエアタービン用軸受ユニット１００（図１参照）は、歯科エアタービンハンドピース２００の駆動によりタービンブレード１０３に圧縮空気が供給されると、図５に示すように、供給された圧縮空気が軸受内部空間Ｓに流入し、シール部材３０に圧縮空気の圧力が作用する。すると、リップ部３３が圧縮空気の流れの下流側に向かって弾性変形する。その結果、圧縮空気の圧力が作用しない場合と比べて、リップ部３３の内周面３５と内輪２０の傾斜面２３との接触面積が小さくなる。すなわち、リップ部３３は圧縮空気を連通させる開状態となる。 FIG. 5 is a partial cross-sectional view showing an operating state of the rolling bearing of the first embodiment.
When the compressed air is supplied to the turbine blade 103 by driving the dental air turbine handpiece 200, the air turbine bearing unit 100 configured as described above (see FIG. 1) is supplied as shown in FIG. Compressed air flows into the bearing internal space S, and the pressure of the compressed air acts on the seal member 30. Then, the lip portion 33 is elastically deformed toward the downstream side of the flow of compressed air. As a result, the contact area between the inner peripheral surface 35 of the lip portion 33 and the inclined surface 23 of the inner ring 20 is smaller than when the pressure of compressed air does not act. That is, the lip portion 33 is in an open state in which compressed air is communicated.

シール部材３０は、芯金を有さず弾性材料のみからなるので、全体的に弾性変形しやすい構造になっている。特に、リップ部３３は止め輪４０と全く干渉しないため、シール部材３０は、外輪１０に弾性変形容易に支持された状態となる。そのため、圧縮空気がシール部材３０にある特定の圧力を超えて作用すると、シール部材３０の内周部が軸方向外側に向けて弾性変形し、リップ部３３の内周面３５と内輪２０の傾斜面２３との接触面積が小さくなる。   Since the seal member 30 does not have a cored bar and is made of only an elastic material, the seal member 30 has a structure that is easily elastically deformed as a whole. In particular, since the lip portion 33 does not interfere with the retaining ring 40 at all, the seal member 30 is supported by the outer ring 10 so as to be easily elastically deformed. Therefore, when the compressed air acts above a specific pressure on the seal member 30, the inner peripheral portion of the seal member 30 is elastically deformed outward in the axial direction, and the inner peripheral surface 35 of the lip portion 33 and the inner ring 20 are inclined. The contact area with the surface 23 is reduced.

このように、本構成においては、圧縮空気の供給圧力が比較的小さい場合でも、シール部材３０のリップ部３３が確実に弾性変形し、接触面積を低減できる。   Thus, in this configuration, even when the supply pressure of compressed air is relatively small, the lip portion 33 of the seal member 30 is reliably elastically deformed, and the contact area can be reduced.

これにより、スムーズなエアタービンの起動が行え、シール部材３０と内輪２０との摩擦抵抗を小さくでき、回転軸１０１の約４０万ｍｉｎ−１の超高速回転を実現できる。更に、傾斜面２３が内輪２０の外周面２１における圧縮空気の供給方向下流側の端部に設けられることにより、リップ部３３と傾斜面２３との間を通過する圧縮空気の流れがスムーズになり、従来よりも更に高速な超高速回転を実現できる。 As a result, the air turbine can be started smoothly, the frictional resistance between the seal member 30 and the inner ring 20 can be reduced, and an ultrahigh-speed rotation of the rotary shaft 101 of about 400,000 min −1 can be realized. Furthermore, since the inclined surface 23 is provided at the end of the outer peripheral surface 21 of the inner ring 20 on the downstream side in the compressed air supply direction, the flow of compressed air passing between the lip portion 33 and the inclined surface 23 becomes smooth. It is possible to realize ultra-high-speed rotation that is even faster than before.

一方、歯科エアタービンハンドピース２００の駆動停止によりタービンブレード１０３への圧縮空気の供給が停止されると、リップ部３３に作用する圧縮空気の圧力が低下する。すると、リップ部３３は図２に示す状態に戻り、リップ部３３の内周面３５が内輪２０の傾斜面２３に全周にわたって接触した状態になる。すなわち、リップ部３３は閉状態とされ、リップ部３３が内輪２０のブレーキとして機能する。この場合、リップ部３３の内周面３５が内輪２０の傾斜面２３に全周にわたって接触するため、シール部材３０と内輪２０との摩擦抵抗による最も大きなブレーキ効果が得られる。これにより、内輪２０に固定された回転軸１０１を最も迅速に停止させることが可能となる。   On the other hand, when the supply of compressed air to the turbine blade 103 is stopped by stopping the driving of the dental air turbine handpiece 200, the pressure of the compressed air acting on the lip portion 33 decreases. Then, the lip portion 33 returns to the state shown in FIG. 2, and the inner peripheral surface 35 of the lip portion 33 comes into contact with the inclined surface 23 of the inner ring 20 over the entire circumference. That is, the lip portion 33 is closed, and the lip portion 33 functions as a brake for the inner ring 20. In this case, since the inner peripheral surface 35 of the lip portion 33 is in contact with the inclined surface 23 of the inner ring 20 over the entire circumference, the greatest braking effect due to the frictional resistance between the seal member 30 and the inner ring 20 is obtained. Thereby, it becomes possible to stop the rotating shaft 101 fixed to the inner ring 20 most rapidly.

また、シール部材３０の特に弾性変形しやすいリップ部３３が、内輪２０の傾斜面２３と接触する構成にしたため、シール部材３０と傾斜面２３との接触圧を径方向に接触する場合と比較して軽減できる。その結果、圧縮空気によるシール部材３０の開閉動作が、スムーズに且つ高い応答性で実施できる。また、従来の構造よりも少ない圧縮空気の圧力で上記接触圧を軽減でき、回転軸１０１の回転速度の更なる向上と停止時間の短縮とを同時に実現できる。回転軸１０１の回転速度とブレーキ性能とのバランスは、傾斜面２３の傾斜や、シール部材３０の傾斜角の調整によって最適に設定できる。   In addition, since the lip portion 33 of the seal member 30 that is particularly easily deformed is in contact with the inclined surface 23 of the inner ring 20, the contact pressure between the seal member 30 and the inclined surface 23 is compared with that in the radial direction. Can be reduced. As a result, the opening / closing operation of the seal member 30 with compressed air can be performed smoothly and with high responsiveness. Further, the contact pressure can be reduced with a pressure of compressed air that is smaller than that of the conventional structure, and further improvement of the rotation speed of the rotating shaft 101 and reduction of the stop time can be realized at the same time. The balance between the rotation speed of the rotating shaft 101 and the braking performance can be optimally set by adjusting the inclination of the inclined surface 23 and the inclination angle of the seal member 30.

シール部材３０の先端のリップ部３３に、内輪２０の傾斜面２３と面接触する接触面が設けられることで、シール部材３０に作用する面圧が小さくなり、摩耗が軽減される。また、接触面積が増えることでシール性が向上する。
更に、リップ部３３の接触面は、内輪２０の傾斜面２３に線接触する面であってもよい。その場合には、面接触する場合よりも摩擦抵抗が軽減され、高速回転に有利となる。 By providing a contact surface in surface contact with the inclined surface 23 of the inner ring 20 on the lip portion 33 at the tip of the seal member 30, the surface pressure acting on the seal member 30 is reduced and wear is reduced. Further, the sealing performance is improved by increasing the contact area.
Furthermore, the contact surface of the lip portion 33 may be a surface that makes line contact with the inclined surface 23 of the inner ring 20. In that case, the frictional resistance is reduced as compared with the case of surface contact, which is advantageous for high-speed rotation.

特に歯科エアタービンハンドピース２００においては、歯を削る際に極めて高速な回転が求められ、停止時には２秒以内、好ましくは１秒以内の急峻な回転停止性能が求められる。本構成によれば、上記の回転速度の増加と停止時間の短縮効果が安定して得られるため、歯科エアタービンハンドピース２００の使い勝手を格段に向上できる。   In particular, the dental air turbine handpiece 200 requires extremely high-speed rotation when scraping teeth, and requires a sharp rotation stop performance within 2 seconds, preferably within 1 second when stopped. According to this configuration, the above-described increase in the rotational speed and the effect of shortening the stop time can be stably obtained, so that the usability of the dental air turbine handpiece 200 can be significantly improved.

そして、歯科エアタービンハンドピース２００の駆動時には、シールド無しの場合と比べて、圧縮空気が軸受内部から漏れにくくなるため、駆動時の騒音が低減され、高い静粛性が得られる。   When the dental air turbine handpiece 200 is driven, compressed air is less likely to leak from the inside of the bearing than when there is no shield, so that noise during driving is reduced and high silence is obtained.

また、図１に示すように、回転軸１０１に一対配置される転がり軸受１は、シール部材３０が、外輪１０の圧縮空気の入口とは反対側となる軸方向一端部に配置される。これにより、一対の転がり軸受１同士の間から、スプレー注油することで、シール部材３０が配置されない軸受端部側から各転がり軸受１内に潤滑油が供給可能となる。また、スプレー注油側の反対側にはシール部材３０が配置されるため、各転がり軸受１からヘッド部２０１の外部へ液漏れを生じることがない。   Further, as shown in FIG. 1, in the rolling bearing 1 arranged in a pair on the rotating shaft 101, the seal member 30 is arranged at one end in the axial direction on the side opposite to the compressed air inlet of the outer ring 10. Thereby, it becomes possible to supply lubricating oil into each rolling bearing 1 from the bearing end portion side where the seal member 30 is not disposed by spraying oil between the pair of rolling bearings 1. Further, since the seal member 30 is disposed on the side opposite to the spray lubrication side, liquid leakage does not occur from each rolling bearing 1 to the outside of the head portion 201.

通常、歯科エアタービンハンドピース２００は、使用後に高温洗浄・滅菌処理するオートクレーブが施される。この処理によって転がり軸受１内の潤滑油量が減少するが、シール部材３０が転がり軸受１の軸方向一端部にのみ配置されるため、軸方向他端部から潤滑油を容易に供給できる。そのため、転がり軸受１を常に良好な潤滑状態にでき、回転軸１０１の安定した回転駆動が可能となる。   Usually, the dental air turbine handpiece 200 is autoclaved for high temperature cleaning and sterilization after use. Although the amount of lubricating oil in the rolling bearing 1 is reduced by this process, since the seal member 30 is disposed only at one axial end portion of the rolling bearing 1, the lubricating oil can be easily supplied from the other axial end portion. Therefore, the rolling bearing 1 can always be in a good lubrication state, and the rotation shaft 101 can be driven stably.

なお、シール部材３０の寸法は、図３に示すように、径方向内側縁から外側縁までの幅をＷ１、傾斜したリップ部３３の径方向幅をＷ２、基部３１の厚さをｔ１、基部３１から傾斜したリップ部３３の先端までの最大厚さをｔ２とすると、幅の比Ｗ２／Ｗ１は０．２〜０．４、好ましくは０．３〜０．３５であり、厚さの比ｔ１／ｔ２は０．４〜０．７、好ましくは０．５〜０．６である。   As shown in FIG. 3, the dimensions of the seal member 30 are as follows: the width from the radially inner edge to the outer edge is W1, the radial width of the inclined lip 33 is W2, the thickness of the base 31 is t1, and the base When the maximum thickness from 31 to the tip of the inclined lip 33 is t2, the width ratio W2 / W1 is 0.2 to 0.4, preferably 0.3 to 0.35. t1 / t2 is 0.4 to 0.7, preferably 0.5 to 0.6.

また、図５に示すように、内輪２０の傾斜面２３の形状は、傾斜面２３の軸方向長さをＬ１、径方向差をＬ２とすると、長さの比Ｌ２／Ｌ１は０．４〜０．７、好ましくは０．５〜０．６である。また、径方向差Ｌ２はシール部材３０の基部３１の厚さｔ１の０．７〜１．３倍、好ましくは０．９〜１．１倍である。   Further, as shown in FIG. 5, the shape of the inclined surface 23 of the inner ring 20 is such that the length ratio L2 / L1 is 0.4 to L2 when the axial length of the inclined surface 23 is L1 and the radial direction difference is L2. 0.7, preferably 0.5 to 0.6. The radial direction difference L2 is 0.7 to 1.3 times, preferably 0.9 to 1.1 times the thickness t1 of the base 31 of the seal member 30.

更に、断面矩形状の止め輪４０の径方向長さをＬ３、軸方向長さをＬ４とすると、シール部材３０と止め輪４０との寸法比は、Ｗ１／Ｌ３が２〜４、好ましくは２．５〜３．５であり、ｔ１／Ｌ４が０．５〜１．５、好ましくは０．８〜１．２である。   Further, if the length in the radial direction of the retaining ring 40 having a rectangular cross section is L3 and the length in the axial direction is L4, the dimensional ratio between the seal member 30 and the retaining ring 40 is W1 / L3 of 2 to 4, preferably 2. 0.5 to 3.5, and t1 / L4 is 0.5 to 1.5, preferably 0.8 to 1.2.

（変形例）
次に、上記構成のシール部材の変形例を説明する。
図６に第１実施形態の変形例であるシール部材の断面図を示す。
本変形例のシール部材３０Ａは、径方向に延在する円環形状の基部３１と、基部３１の径方向内側に一体に形成されたリップ部３３を有する。リップ部３３は、基部３１に接続される第１リップ部３３Ａと、第１リップ部３３Ａの径方向内側に接続される第２リップ部３３Ｂと、を有する。 (Modification)
Next, a modification of the sealing member having the above configuration will be described.
FIG. 6 shows a cross-sectional view of a seal member which is a modification of the first embodiment.
The seal member 30 </ b> A of the present modification includes an annular base 31 that extends in the radial direction and a lip portion 33 that is integrally formed on the radial inner side of the base 31. The lip portion 33 includes a first lip portion 33A connected to the base portion 31, and a second lip portion 33B connected to the radially inner side of the first lip portion 33A.

第１リップ部３３Ａ、第２リップ部３３Ｂは、基部３１の径方向からの傾斜角がそれぞれ異ならせて形成される。図示例では、第１リップ部３３Ａの径方向からの傾斜角θ１よりも、第２リップ部３３Ｂの径方向からの傾斜角θ２が大きくされている。   The first lip portion 33A and the second lip portion 33B are formed with different inclination angles from the radial direction of the base portion 31. In the illustrated example, the inclination angle θ2 from the radial direction of the second lip portion 33B is made larger than the inclination angle θ1 from the radial direction of the first lip portion 33A.

本構成のシール部材３０Ａは、内周側ほど傾斜角が大きくなる２段階の傾斜角のリップ部３３を有するため、圧縮空気による圧力がリップ部３３に負荷される際に、前述したシール部材３０の場合よりも弾性変形しやすくなる。よって、リップ部３３の柔軟性が増し、更なる高速応答性が得られ、歯科エアタービンハンドピース２００の使い勝手をより向上できる。また、圧縮空気の漏れが更に生じにくくなり、より高い静粛性が得られる。   Since the sealing member 30A of this configuration has the lip portion 33 having two stages of inclination angles with the inclination angle increasing toward the inner peripheral side, when the pressure by the compressed air is applied to the lip portion 33, the sealing member 30 described above. It becomes easier to elastically deform than in the case of. Therefore, the flexibility of the lip portion 33 is increased, a further high-speed response is obtained, and the usability of the dental air turbine handpiece 200 can be further improved. In addition, compressed air leakage is less likely to occur, and higher silence can be obtained.

上記シール部材３０Ａは、２段階の傾斜角を有する構成であるが、これに限らず、３段以上の複数段の傾斜角を有した構成や、径方向内側に向けて連続的に傾斜角が増加する断面湾曲形状の構成であってもよい。   The seal member 30A has a configuration having two-step inclination angles, but is not limited to this, and has a configuration having multiple-step inclination angles of three or more steps, or has an inclination angle continuously inward in the radial direction. An increasing cross-sectional curved configuration may be used.

＜第２実施形態＞
次に、エアタービン用軸受ユニット１００の第２実施形態を説明する。以降の説明においては、同一の部材や部位については、同一の符号を付与することで、その説明を簡単化、又は省略する。 Second Embodiment
Next, a second embodiment of the air turbine bearing unit 100 will be described. In the following description, the same members and parts are denoted by the same reference numerals, and the description thereof is simplified or omitted.

図７は第２実施形態の転がり軸受の動作状態を示す部分断面図である。
本実施形態のシール部材３０Ｂは、圧縮空気が軸受内部空間Ｓに流入し、シール部材３０Ｂに圧縮空気の圧力が作用した場合に、リップ部３３の内周面３５と内輪２０の傾斜面２３とが互いに完全に非接触の状態になる。そして、この非接触の状態が、リップ部３３と傾斜面２３との間を流れる圧縮空気によって維持される。 FIG. 7 is a partial cross-sectional view showing an operating state of the rolling bearing of the second embodiment.
When the compressed air flows into the bearing internal space S and the pressure of the compressed air acts on the seal member 30B, the seal member 30B of the present embodiment has the inner peripheral surface 35 of the lip portion 33 and the inclined surface 23 of the inner ring 20. Are completely in contact with each other. This non-contact state is maintained by the compressed air flowing between the lip portion 33 and the inclined surface 23.

一方、圧縮空気の圧力がシール部材３０Ｂに作用しない場合には、リップ部３３の内周面３５が内輪２０の傾斜面２３に全周にわたって接触する。   On the other hand, when the pressure of the compressed air does not act on the seal member 30B, the inner peripheral surface 35 of the lip portion 33 contacts the inclined surface 23 of the inner ring 20 over the entire periphery.

上記構成のシール部材３０Ｂによれば、圧縮空気の圧力がシール部材３０Ｂに作用する場合に、シール部材３０Ｂと内輪２０との接触による摩擦抵抗が完全になくなるので、前述した第１実施形態の場合よりも更に高速の超高速回転が実現できる。また、圧縮空気の圧力が作用しない場合に、シール部材３０Ｂと内輪２０との接触による摩擦抵抗によって、大きなブレーキ効果が得られ、回転軸１０１を迅速に停止できる。   According to the sealing member 30B having the above configuration, when the pressure of the compressed air acts on the sealing member 30B, the frictional resistance due to the contact between the sealing member 30B and the inner ring 20 is completely eliminated. It is possible to realize ultra-high-speed rotation that is even faster than that. Moreover, when the pressure of compressed air does not act, the big braking effect is acquired by the frictional resistance by contact with the sealing member 30B and the inner ring | wheel 20, and the rotating shaft 101 can be stopped rapidly.

また、第１実施形態と同様に、本構成の転がり軸受１Ｂにおいても、シール部材３０Ｂが内輪２０の傾斜面２３と接触する構成にしたため、シール部材３０Ｂと傾斜面２３との接触圧を軽減できる。その結果、圧縮空気によるシール部材３０Ｂの開閉動作が、スムーズに且つ高い応答性で実施できる。また、従来の構造よりも少ない圧縮空気の圧力で、回転速度の更なる増加と停止時間の短縮とを図れる。   Further, similarly to the first embodiment, also in the rolling bearing 1B of this configuration, the seal member 30B is configured to contact the inclined surface 23 of the inner ring 20, so that the contact pressure between the seal member 30B and the inclined surface 23 can be reduced. . As a result, the opening / closing operation of the sealing member 30B by compressed air can be performed smoothly and with high responsiveness. Further, the rotation speed can be further increased and the stop time can be shortened with a pressure of compressed air that is less than that of the conventional structure.

＜第３実施形態＞
次に、エアタービン用軸受ユニット１００の第３実施形態を説明する。
図８は第３実施形態の転がり軸受を示す部分断面図である。
本実施形態の転がり軸受１Ｃは、内輪２０Ａを外輪１０よりも軸方向外側まで延在させ、シール部材３０Ｃを外輪１０よりも軸方向外側に突出させている。 <Third Embodiment>
Next, a third embodiment of the air turbine bearing unit 100 will be described.
FIG. 8 is a partial cross-sectional view showing the rolling bearing of the third embodiment.
In the rolling bearing 1 </ b> C of the present embodiment, the inner ring 20 </ b> A extends to the outside in the axial direction from the outer ring 10, and the seal member 30 </ b> C is projected to the outside in the axial direction from the outer ring 10.

内輪２０Ａは、第１，第２実施形態と同様に、圧縮空気の供給方向下流側となる外周面２１の端部、つまり、図８における左方側の外周面２１の一端部に傾斜面２３を有する。傾斜面２３は、軸方向シール部材側の軸端に向かって大径から小径となるように傾斜した円環形状（円錐面状）に形成される。   As in the first and second embodiments, the inner ring 20A has an inclined surface 23 at the end of the outer peripheral surface 21 on the downstream side in the compressed air supply direction, that is, at one end of the outer peripheral surface 21 on the left side in FIG. Have The inclined surface 23 is formed in an annular shape (conical surface shape) that is inclined so as to decrease from a large diameter toward a small diameter toward the axial end on the axial direction seal member side.

また、シール部材３０Ｃは、リップ部３３の内周面３５が、外輪１０よりも軸方向外側で内輪２０Ａの傾斜面２３に接触可能に配置される。   Further, the seal member 30 </ b> C is disposed so that the inner peripheral surface 35 of the lip portion 33 can come into contact with the inclined surface 23 of the inner ring 20 </ b> A outside the outer ring 10 in the axial direction.

この構成によれば、リップ部３３の径方向からの傾斜角θ３を、前述の第１、第２実施形態の場合の傾斜角θ，θ１，θ２よりも大きくできる。そのため、圧縮空気によるリップ部３３の開閉動作をよりスムーズに行える。その他の作用効果は、前述の第１、第２実施形態と同様である。
＜第４実施形態＞
次に、エアタービン用軸受ユニット１００の第４実施形態を説明する。
図９は第４実施形態の転がり軸受を示す部分断面図である。
本実施形態の転がり軸受１Ｄは、内輪２０Ｂの圧縮空気の供給方向下流側となる外周面２１の一端部に小径部６１が形成される。外周面２１には、内輪軌道面２０ａに接続される肩部６５と、小径部６１との間に、段差６７が形成される。段差６７は、径方向に切り立った壁面が全周にわたって形成されてなる。 According to this configuration, the inclination angle θ3 from the radial direction of the lip portion 33 can be made larger than the inclination angles θ, θ1, and θ2 in the case of the first and second embodiments described above. Therefore, the opening / closing operation of the lip portion 33 by compressed air can be performed more smoothly. Other functions and effects are the same as those of the first and second embodiments described above.
<Fourth embodiment>
Next, a fourth embodiment of the air turbine bearing unit 100 will be described.
FIG. 9 is a partial cross-sectional view showing the rolling bearing of the fourth embodiment.
In the rolling bearing 1D of the present embodiment, a small-diameter portion 61 is formed at one end portion of the outer peripheral surface 21 that is the downstream side in the compressed air supply direction of the inner ring 20B. On the outer peripheral surface 21, a step 67 is formed between the shoulder portion 65 connected to the inner ring raceway surface 20 a and the small diameter portion 61. The step 67 is formed by a wall that is cut in the radial direction over the entire circumference.

シール部材３０Ｄは、内周側のリップ部３３の側面が段差６７の壁面に接触可能に外輪１０の溝部１３に取り付けられる。なお、図示例ではシール部材３０Ｄは弾性変形可能な平坦円盤状で、段差６７が軸方向に略垂直な壁面となっているが、これに限らない。例えば、シール部材３０Ｄのリップ部３３と段差６７は、いずれか一方が、径方向から僅かに傾斜していてもよい。   The seal member 30 </ b> D is attached to the groove portion 13 of the outer ring 10 so that the side surface of the inner peripheral lip portion 33 can come into contact with the wall surface of the step 67. In the illustrated example, the seal member 30D has a flat disk shape that can be elastically deformed, and the step 67 is a wall surface substantially perpendicular to the axial direction. However, the present invention is not limited to this. For example, one of the lip portion 33 and the step 67 of the seal member 30D may be slightly inclined from the radial direction.

本構成によれば、シール部材３０Ｄのリップ部３３が、内輪２０の段差６７と軸方向に接触する構成にしたため、シール部材３０Ｄと段差６７との接触圧を径方向に接触する場合と比較して軽減できる。これにより、シール部材３０Ｄや内輪２０Ｂの加工が簡単になるため、製造コストを低減でき、更に前述した第１〜第３実施形態と同様の作用効果を得ることができる。   According to this configuration, since the lip portion 33 of the seal member 30D is configured to contact the step 67 of the inner ring 20 in the axial direction, the contact pressure between the seal member 30D and the step 67 is compared to the case where the contact pressure is contacted in the radial direction. Can be reduced. Thereby, since the processing of the seal member 30D and the inner ring 20B is simplified, the manufacturing cost can be reduced, and the same operational effects as those of the first to third embodiments described above can be obtained.

＜第５実施形態＞
次に、エアタービン用軸受ユニット１００の第５実施形態を説明する。
図１０は第５実施形態の転がり軸受を示す部分断面図である。
本実施形態の転がり軸受１Ｅは、保持器７Ａを外輪案内型にした点以外は、第１実施形態の構成と同様である。 <Fifth Embodiment>
Next, a fifth embodiment of the air turbine bearing unit 100 will be described.
FIG. 10 is a partial cross-sectional view showing the rolling bearing of the fifth embodiment.
The rolling bearing 1E of the present embodiment is the same as the configuration of the first embodiment except that the cage 7A is an outer ring guide type.

本構成によれば、保持器７Ａが外輪１０側に配置され、内輪２０の外周面２１と保持器７Ａの内周面と間の内側隙間７１が、外輪１０側の外側隙間７３より広くなる。すると、圧縮空気が軸受内部空間Ｓに流入した際、圧縮空気は、主に内側隙間７１を通ってシール部材３０側に流れ、シール部材３０のリップ部３３に吹き当てられる。   According to this configuration, the cage 7A is disposed on the outer ring 10 side, and the inner gap 71 between the outer circumferential surface 21 of the inner ring 20 and the inner circumferential surface of the cage 7A is wider than the outer gap 73 on the outer ring 10 side. Then, when the compressed air flows into the bearing internal space S, the compressed air mainly flows through the inner gap 71 toward the seal member 30 and is blown against the lip portion 33 of the seal member 30.

シール部材３０は、リップ部３３に圧縮空気が直接吹き当てられることで、圧縮空気の供給圧力が比較的低い場合でも、確実に弾性変形可能となる。これにより、圧縮空気によるシール部材３０の開閉動作が、よりスムーズに且つ高い応答性で実施できる。   Since the compressed air is directly blown onto the lip portion 33, the seal member 30 can be reliably elastically deformed even when the supply pressure of the compressed air is relatively low. Thereby, the opening / closing operation | movement of the sealing member 30 by compressed air can be implemented more smoothly and with high responsiveness.

ここで、圧縮空気の気流について更に詳細に説明する。
軸受内部空間Ｓに供給された圧縮空気は、玉３の間の隙間を通過して軸受外に排気される。内輪２０の外周面２１に傾斜面２３が存在しない場合、圧縮空気の供給方向下流側となる内輪端面側には、気流による空気の剥離が生じ、その結果、カルマン渦が発生する。 Here, the airflow of compressed air will be described in more detail.
The compressed air supplied to the bearing internal space S passes through the gap between the balls 3 and is exhausted outside the bearing. When the inclined surface 23 does not exist on the outer peripheral surface 21 of the inner ring 20, air separation due to the airflow occurs on the inner ring end surface side that is the downstream side in the compressed air supply direction, and as a result, Karman vortex is generated.

また、転がり軸受の内輪２０は、タービンブレード１０３（図１参照）に固定され、タービンブレード１０３の回転軸１０１の回転速度と、内輪２０の回転速度が一致する。しかし、玉３は内輪２０に転動しながら移動するので、玉３の回転速度は回転軸１０１の回転速度より遅くなる。したがって、玉３同士の間の隙間空間の回転速度も回転軸１０１の回転速度より遅くなる。回転軸１０１と玉３間の隙間空間との間に速度差が生じると、隙間空間を通過する圧縮空気によって、隙間空間に隣接する玉３の背面に空気の剥離層が発生する。これが空気流動の抵抗となる。   Further, the inner ring 20 of the rolling bearing is fixed to the turbine blade 103 (see FIG. 1), and the rotation speed of the rotating shaft 101 of the turbine blade 103 and the rotation speed of the inner ring 20 coincide. However, since the ball 3 moves while rolling on the inner ring 20, the rotational speed of the ball 3 is slower than the rotational speed of the rotating shaft 101. Therefore, the rotational speed of the gap space between the balls 3 is also slower than the rotational speed of the rotary shaft 101. When a speed difference is generated between the rotating shaft 101 and the gap space between the balls 3, a compressed air passing through the gap space generates an air peeling layer on the back surface of the ball 3 adjacent to the gap space. This is the resistance to air flow.

しかし、本構成においては、内輪２０に傾斜面２３（又は段差６７）を設けてあるので、シール部材３０と傾斜面２３（又は段差６７）との間の空気流れにガイド効果が生じ、コンバージェント・ノズルの作用が発生する。これにより、空気流れを加速でき、相乗的に空気の排出流速が高められる。よって、剥離する空気層は、強制的に排気されて、空気の排気効率が高められる。その結果、回転軸１０１の高速回転がより安定することになる。   However, in this configuration, since the inner ring 20 is provided with the inclined surface 23 (or step 67), a guide effect is generated in the air flow between the seal member 30 and the inclined surface 23 (or step 67), and the convergence is achieved.・ Nozzle action occurs. Thereby, an air flow can be accelerated and the discharge | emission flow velocity of air can be raised synergistically. Therefore, the air layer to be peeled is forcibly exhausted, and the air exhaust efficiency is increased. As a result, the high speed rotation of the rotating shaft 101 becomes more stable.

また、シール部材３０を捲り上げる際、シール部材３０の弾性力や支点位置が一定だとすると、シール部材３０が外輪１０に固定される支点と、圧縮空気が吹き当てられる力点とが一致又は近い場合には、シール部材３０を弾性変形させるために大きな力が必要となる。しかし、図１０に示すように、圧縮空気が吹き当てられる力点Ｐ１が支点Ｐ２から離れるほど、小さな力でもシール部材３０を容易に弾性変形させられる。また、内輪２０の傾斜面２３とシール部材３０との接触点である作用点は、傾斜面２３の存在によって、内輪２０の外周面２１が一様径である場合の作用点ＱＡから、作用点ＱＢの位置に移る。そのため、支点Ｐ２から作用点までの距離が、ＬＡよりも長いＬＢとなる。よって、少ない力でシール部材３０を捲り上げることができ、スムーズなエアタービンの起動が行える。また、本構成によれば、シールの動作応答性が向上する。   Further, when the seal member 30 is lifted, if the elastic force and the fulcrum position of the seal member 30 are constant, the fulcrum at which the seal member 30 is fixed to the outer ring 10 and the force point to which the compressed air is blown coincide or are close to each other. Requires a large force to elastically deform the seal member 30. However, as shown in FIG. 10, the seal member 30 can be easily elastically deformed with a small force as the force point P1 to which the compressed air is blown is separated from the fulcrum P2. The action point that is the contact point between the inclined surface 23 of the inner ring 20 and the seal member 30 is determined from the action point QA when the outer peripheral surface 21 of the inner ring 20 has a uniform diameter due to the presence of the inclined surface 23. Move to QB position. Therefore, the distance from the fulcrum P2 to the action point is LB longer than LA. Therefore, the seal member 30 can be lifted with a small force, and the air turbine can be started smoothly. Further, according to this configuration, the operation responsiveness of the seal is improved.

ブレーキ性能の向上を目的に、シール部材３０の内輪２０との接触面積を増加させるように、シール部材３０と内輪２０との接触面の軸方向断面長さを延長した場合、傾斜面を有さない従来構造では、ダイバージェント・ノズル効果が生じ、シール部材３０と内輪２０との間を通過する空気の流速を低下させる可能性があった。しかし、本構成のように傾斜面２３や段差６７によってシール部材３０と内輪２０との接触面積を増加させると、高い排気効率がそのまま維持される。その結果、排気に対する影響が少なくなり、高いブレーキ性能の実現と高速な回転駆動との両立が可能となる。   For the purpose of improving braking performance, when the axial cross-sectional length of the contact surface between the seal member 30 and the inner ring 20 is extended so as to increase the contact area between the seal member 30 and the inner ring 20, an inclined surface is provided. In the conventional structure that does not exist, the divergent nozzle effect occurs, and there is a possibility that the flow velocity of the air passing between the seal member 30 and the inner ring 20 is lowered. However, when the contact area between the seal member 30 and the inner ring 20 is increased by the inclined surface 23 or the step 67 as in the present configuration, high exhaust efficiency is maintained as it is. As a result, the influence on the exhaust is reduced, and it is possible to achieve both high brake performance and high-speed rotation drive.

＜その他の実施形態＞
本発明は、上記各実施形態に限定されるものではなく、適宜、変形、改良、等が可能である。 <Other embodiments>
The present invention is not limited to the embodiments described above, and modifications, improvements, and the like can be made as appropriate.

第１〜第４実施形態の転がり軸受１に用いる保持器５は、一端側のリム部７が、玉３よりも圧縮空気の供給方向上流側に配置されているが、これに限らず、リム部７が軸方向反対側のシール部材側に配置された構成であってもよい。   In the cage 5 used in the rolling bearing 1 of the first to fourth embodiments, the rim portion 7 on one end side is arranged on the upstream side in the compressed air supply direction with respect to the ball 3. The structure by which the part 7 is arrange | positioned at the sealing member side of the axial direction opposite side may be sufficient.

また、シール部材は、転がり軸受１の軸方向一端側のみに配置されるため、外輪１０の溝部１３、内輪２０，２０Ａの傾斜面２３，段差６７は、軸方向一端側のみに形成されるが、これに限らず、軸方向他端側にも対称に形成した構成であってもよい。その場合、一対の傾斜面又は段差のうち、一方が使用されないことになるが、転がり軸受の組み立て工程において、組み付け方向を意識する必要がなくなり、作業工程を簡単化できる。   Further, since the seal member is disposed only on one end side in the axial direction of the rolling bearing 1, the groove 13 of the outer ring 10, the inclined surface 23 of the inner rings 20, 20A, and the step 67 are formed only on one end side in the axial direction. However, the present invention is not limited to this, and a configuration in which the other end side in the axial direction is formed symmetrically may also be used. In that case, one of the pair of inclined surfaces or steps is not used, but it is not necessary to be aware of the assembly direction in the assembly process of the rolling bearing, and the work process can be simplified.

また、シール部材は、リップ部の肉厚が一定の厚みであってもよいが、径方向内側に向かって徐々に小さくしてもよい。
また、シール部材のリップ部３３における内周面３５の形状は、図１１、図１２に示すように、略楕円形状でも略三角形状でもよい。以下に説明するシール部材３０の他の例は、前述のシール部材３０Ａ，３０Ｂ，３０Ｃ，３０Ｄについても同様に適用可能である。 Further, the sealing member may have a constant thickness of the lip portion, but may be gradually reduced inward in the radial direction.
Further, the shape of the inner peripheral surface 35 of the lip portion 33 of the seal member may be substantially elliptical or substantially triangular as shown in FIGS. Other examples of the seal member 30 described below can be similarly applied to the above-described seal members 30A, 30B, 30C, and 30D.

また、リップ部３３の内周面３５には、図１３に示すように少なくとも一つの通気孔４１を設けてもよく、図１４〜図１６に示すように少なくとも一つの切り込み４３を設けてもよい。なお、図１３においては、１つの円形の通気孔４１が設けられた例が示されているが、通気孔４１は２つ以上であってもよく、通気孔４１の形状も円形に限定されない。また、図１４〜図１６には、それぞれ２つ、４つ、及び８つの切り込み４３が円周方向等間隔に設けられた例が示されているが、切り込み４３の数や円周方向間隔はこれに限定されない。   Further, the inner peripheral surface 35 of the lip portion 33 may be provided with at least one vent hole 41 as shown in FIG. 13, or may be provided with at least one notch 43 as shown in FIGS. . Although FIG. 13 shows an example in which one circular ventilation hole 41 is provided, two or more ventilation holes 41 may be provided, and the shape of the ventilation hole 41 is not limited to a circle. FIGS. 14 to 16 show examples in which two, four, and eight cuts 43 are provided at equal intervals in the circumferential direction. It is not limited to this.

また、図１７〜図１９に示すように、リップ部３３の先端部が円周方向に連続して切り欠かれ、リップ部３３の内周面３５が、内輪２０の外周面２１に部分的に接触するようにしてもよい。図１７〜図１９では、それぞれリップ部３３の内周面３５、つまり、内輪２０の外周面２１に接触する接触領域（円弧長さ）を、内周面３５の全体の５０％、２５％、１０％を占めるようにしている。   As shown in FIGS. 17 to 19, the tip end of the lip portion 33 is continuously cut in the circumferential direction, and the inner peripheral surface 35 of the lip portion 33 is partially formed on the outer peripheral surface 21 of the inner ring 20. You may make it contact. 17 to 19, the inner peripheral surface 35 of the lip portion 33, that is, the contact area (arc length) contacting the outer peripheral surface 21 of the inner ring 20, is 50%, 25% of the entire inner peripheral surface 35. It accounts for 10%.

このように、リップ部３３の内周面３５の形状を変更することで、当該内周面３５と内輪の外周面との接触面積を適宜変更し、リップ部３３の所望のブレーキ性能や密封性能を満足することが可能となる。   In this way, by changing the shape of the inner peripheral surface 35 of the lip portion 33, the contact area between the inner peripheral surface 35 and the outer peripheral surface of the inner ring is appropriately changed, and desired brake performance and sealing performance of the lip portion 33 are obtained. Can be satisfied.

なお、シール部材がブレーキ機能を果たすためには、図１１〜図１９のシール正面図に示すリップ部３３の内周面３５の接触領域（図１７〜図１９では、接触円弧長）は、圧縮空気の圧力がシール部材に作用しない場合に、シール部材の内周面全体のうち、少なくとも１０％以上の領域で内輪に接触することが望ましい。   In order for the seal member to perform the brake function, the contact area (the contact arc length in FIGS. 17 to 19) of the inner peripheral surface 35 of the lip portion 33 shown in the seal front view of FIGS. When the pressure of air does not act on the seal member, it is desirable to contact the inner ring in an area of at least 10% or more of the entire inner peripheral surface of the seal member.

これは、圧縮空気がシール部材３０，３０Ａ，３０Ｂに当たるときに、シール部材３０，３０Ａ，３０Ｂを、内輪との接触状態から非接触状態に変化しやすくするためである。接触領域がシール部材の内周面全体の１０％未満となると、空気漏れにより、接触状態が変化しにくくなる。また、圧縮空気による圧力が作用しない場合に、リップ部３３の内周面３５と内輪２０との接触が少ないため、ブレーキ機能を十分に果たさない可能性がある。一方、１０％以上であれば、十分なブレーキ性能を発揮できる。   This is to make the sealing members 30, 30A, 30B easily change from a contact state with the inner ring to a non-contact state when the compressed air hits the sealing members 30, 30A, 30B. When the contact area is less than 10% of the entire inner peripheral surface of the seal member, the contact state is unlikely to change due to air leakage. Moreover, when the pressure by compressed air does not act, since there is little contact with the internal peripheral surface 35 of the lip | rip part 33 and the inner ring | wheel 20, there exists a possibility that a brake function may not fully be fulfill | performed. On the other hand, if it is 10% or more, sufficient braking performance can be exhibited.

このように、本発明は上記の実施形態に限定されるものではなく、実施形態の各構成を相互に組み合わせることや、明細書の記載、並びに周知の技術に基づいて、当業者が変更、応用することも本発明の予定するところであり、保護を求める範囲に含まれる。
例えば、上記例では転がり軸受として玉軸受を用いているが、ころ軸受等の他の方式の転がり軸受であってもよい。また、上記例の転がり軸受は内輪回転型であり、シール部材が外輪に固定されているが、シール部材を内輪に固定して、外輪に接触する構成にしてもよい。更に、保持器形状を変更することで、上記例よりも軸受幅を広げた構成にしてもよい。 As described above, the present invention is not limited to the above-described embodiments, and those skilled in the art can make changes and applications based on combinations of the configurations of the embodiments, descriptions in the specification, and well-known techniques. This is also the scope of the present invention, and is included in the scope for which protection is sought.
For example, although ball bearings are used as rolling bearings in the above example, other types of rolling bearings such as roller bearings may be used. The rolling bearing of the above example is an inner ring rotating type, and the seal member is fixed to the outer ring. However, the seal member may be fixed to the inner ring and contact the outer ring. Furthermore, you may make it the structure which expanded the bearing width rather than the said example by changing a holder shape.

また、図２０は外輪にカウンタボア８１が形成されたアンギュラタイプの転がり軸受に本発明の傾斜面２３とシール部材３０を適用したアンギュラタイプの転がり軸受の一部断面図である。
図２１は内輪にカウンタボア８３が形成されたアンギュラタイプの転がり軸受に本発明の傾斜面２３とシール部材３０を適用したアンギュラタイプの転がり軸受の一部断面図である。 FIG. 20 is a partial sectional view of an angular type rolling bearing in which the inclined surface 23 and the seal member 30 of the present invention are applied to an angular type rolling bearing having a counter bore 81 formed on the outer ring.
FIG. 21 is a partial cross-sectional view of an angular type rolling bearing in which the inclined surface 23 and the seal member 30 of the present invention are applied to an angular type rolling bearing having a counter bore 83 formed on the inner ring.

図２０，図２１に示すように、アンギュラタイプの転がり軸受であっても、傾斜面２３にシール部材３０に接触させることで、前述同様の作用効果を奏することができる。なお、図２０，図２１は一例であって、他の形態のアンギュラタイプの転がり軸受であって同様である。   As shown in FIGS. 20 and 21, even in the case of an angular type rolling bearing, the same effect as described above can be achieved by bringing the inclined surface 23 into contact with the seal member 30. 20 and 21 are only examples, and other types of angular type rolling bearings are the same.

１，１Ｂ，１Ｃ，１Ｄ，１Ｅ 転がり軸受
３ 玉（転動体）
５ 保持器
７ リム部
１０，１０Ａ 外輪
１１ 内周面
１３ 溝部
１５ テーパ面
１７ 軸方向内側面
２０，２０Ａ，２０Ｂ，２０Ｃ 内輪
２１ 外周面
２３ 傾斜面
３０，３０Ａ，３０Ｂ，３０Ｃ，３０Ｄ シール部材
３１ 基部
３３ リップ部
３５ 内周面
４０ 止め輪
４１ 通気孔
４３ 切り込み
６７ 段差
１００ エアタービン用軸受ユニット
２００ 歯科エアタービンハンドピース
２０１ ヘッド部
Ｓ 軸受内部空間 1, 1B, 1C, 1D, 1E Rolling bearings 3 balls (rolling elements)
DESCRIPTION OF SYMBOLS 5 Cage 7 Rim part 10, 10A Outer ring 11 Inner peripheral surface 13 Groove part 15 Tapered surface 17 Axial inner side surface 20, 20A, 20B, 20C Inner ring 21 Outer peripheral surface 23 Inclined surface 30, 30A, 30B, 30C, 30D Seal member 31 Base part 33 Lip part 35 Inner peripheral surface 40 Retaining ring 41 Vent hole 43 Notch 67 Step 100 Air turbine bearing unit 200 Dental air turbine handpiece 201 Head part S Bearing internal space

Claims (3)

外輪と、
内輪と、
前記外輪と前記内輪との間に転動自在に配置された複数の転動体と、
前記外輪と前記内輪との間の軸受内部空間の軸方向一端部に設けられ、芯金が無い弾性体からなる略環状部材と、を備え、
前記略環状部材は、前記外輪の前記軸方向一端部の内周面に形成された溝部に外周部が止め輪によって固定されて、内周部が弾性変形可能にされており、
前記内輪の外周面は、軸端に向かって大径から小径となる傾斜面又は段差を有し、
前記軸方向一端部は、前記軸受内部空間に供給される圧縮空気の入口とは反対側であるエアタービン用転がり軸受。 Outer ring,
Inner ring,
A plurality of rolling elements arranged so as to be freely rollable between the outer ring and the inner ring;
A substantially annular member that is provided at one end in the axial direction of the bearing internal space between the outer ring and the inner ring, and is made of an elastic body without a metal core;
The substantially annular member has an outer peripheral portion fixed to a groove portion formed on an inner peripheral surface of the one axial end portion of the outer ring by a retaining ring, and the inner peripheral portion is elastically deformable.
The outer peripheral surface of the inner ring has an inclined surface or a step that becomes a small diameter from a large diameter toward the shaft end,
The axial end of the rolling bearing for an air turbine, wherein one end of the axial direction is opposite to an inlet of compressed air supplied to the bearing internal space. 前記略環状部材が前記内輪の外周面に接触する部位は、前記傾斜面又は前記段差である請求項１に記載のエアタービン用転がり軸受。   The rolling bearing for an air turbine according to claim 1, wherein a portion where the substantially annular member contacts the outer peripheral surface of the inner ring is the inclined surface or the step. 圧縮空気を受けて回転するタービンブレードと、
前記タービンブレードが一体に固定され、工具を取り付け可能な回転軸と、
前記圧縮空気が作用しないとき、前記略環状部材が前記内輪の外周面に接触し、前記圧縮空気が作用するとき、前記圧縮空気が作用しないときと比べて前記略環状部材と前記内輪の外周面との接触面積が小さくなる、又は非接触となる請求項１又は請求項２に記載のエアタービン用転がり軸受を介して、前記回転軸を回転自在に支持するハウジングと、
を備えるエアタービン用軸受ユニット。 Turbine blades that rotate by receiving compressed air;
A rotating shaft to which the turbine blade is fixed integrally and to which a tool can be attached;
When the compressed air does not act, the substantially annular member contacts the outer peripheral surface of the inner ring, and when the compressed air acts, the substantially annular member and the outer peripheral surface of the inner ring compared to when the compressed air does not act. A housing that rotatably supports the rotating shaft via the air bearing rolling bearing according to claim 1, wherein a contact area with the air bearing is reduced or non-contacted.
An air turbine bearing unit comprising:
JP2016129149A 2016-03-07 2016-06-29 Rolling bearings and bearing units for air turbines Active JP6686738B2 (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
CN201780016093.9A CN108713108A (en) 2016-03-07 2017-03-07 Rolling bearing and air turbine bearing unit and dentistry air turbine handpiece
PCT/JP2017/009102 WO2017154935A1 (en) 2016-03-07 2017-03-07 Rolling bearing, bearing unit for air turbine, and air turbine handpiece for dental use
EP17763275.9A EP3428468B1 (en) 2016-03-07 2017-03-07 Rolling bearing, bearing unit for air turbine, and air turbine handpiece for dental use
US16/080,490 US11564772B2 (en) 2016-03-07 2017-03-07 Rolling bearing, bearing unit for air turbine, and air turbine handpiece for dental use
CN201911379644.5A CN111503161B (en) 2016-03-07 2017-03-07 Rolling bearing, bearing unit for air turbine, and dental air turbine handpiece
EP19219903.2A EP3667110B1 (en) 2016-03-07 2017-03-07 Rolling bearing for a roller bearing unit for air turbine and air turbine handpiece for dental use
US16/728,014 US11540902B2 (en) 2016-03-07 2019-12-27 Rolling bearing, bearing unit for air turbine, and air turbine handpiece for dental use

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WO2020195861A1 (en) 2019-03-28 2020-10-01 日本精工株式会社 Roller bearing
WO2021132687A1 (en) 2019-12-27 2021-07-01 日本精工株式会社 Rolling bearing for air turbine
WO2021132688A1 (en) 2019-12-27 2021-07-01 日本精工株式会社 Rolling bearing for air turbine
WO2021182637A1 (en) 2020-03-12 2021-09-16 日本精工株式会社 Rolling bearing

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JP2011117548A (en) * 2009-12-04 2011-06-16 Nsk Ltd Rolling bearing with seal ring, electric motor, and throttle device for automobile
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WO2020195861A1 (en) 2019-03-28 2020-10-01 日本精工株式会社 Roller bearing
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