JP2006138448A - Rolling bearing - Google Patents

Rolling bearing Download PDF

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JP2006138448A
JP2006138448A JP2004330687A JP2004330687A JP2006138448A JP 2006138448 A JP2006138448 A JP 2006138448A JP 2004330687 A JP2004330687 A JP 2004330687A JP 2004330687 A JP2004330687 A JP 2004330687A JP 2006138448 A JP2006138448 A JP 2006138448A
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rolling
rolling bearing
diameter
bearing
rolling element
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Yukio Oura
大浦　　行雄
Shuichi Yano
修一 矢野
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NSK Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing of high moment rigidity capable of maintaining high lubricity over a long period by preventing early seizure. <P>SOLUTION: This rolling bearing 2 rotatably supports various pulleys 10 for winding various belts for transmitting driving force to various driving systems of an automobile or various pulleys for winding the various belts for applying torque to a rotary part of an electromagnetic clutch. The rolling bearing has an inner race 4 and an outer race 6 oppositely arranged so as to be relatively rotatable, and a plurality of rolling bodies 8a and 8b rollingly arranged between raceway surfaces 4s and 6s of the inner-outer races. A plurality of rolling bodies are composed of two kinds or more of rolling bodies having a different diameter. At least at unused time, radial clearance of the rolling body of the largest diameter is set to a negative value, and radial clearance of the rolling body of the smallest diameter is set to a positive value. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、例えば自動車のエンジンのタイミングベルトや補機駆動用ベルトを巻き掛ける各種プーリ、或いは例えば電磁クラッチの回転部分に回転力を与えるベルトを巻き掛ける各種プーリを回転可能に支持する転がり軸受に関する。   The present invention relates to a rolling bearing that rotatably supports, for example, various pulleys around which a timing belt of an automobile engine or an accessory driving belt is wound, or various pulleys around which a belt that applies a rotational force to a rotating portion of an electromagnetic clutch, for example. .

例えば自動車のエンジンのタイミングベルトや補機駆動用ベルトは、転がり軸受で回転可能に支持された各種プーリ(例えば、カムプーリやクランププーリなど)に巻き掛けられており、各種プーリに対するベルトの巻き掛け角度を調節することにより、ベルトに所望の張力が付与されている。このような構成のプーリユニットにおいて、例えば転がり軸受や各種プーリなどの構成部品の取付誤差により、各種プーリに巻き掛けられたベルトの幅方向中央位置と転がり軸受の幅方向中央位置とが一致しない場合がある。この場合、ベルトの張力が転がり軸受の幅方向中央位置からズレた部位に作用する。このため、そのズレ量に応じたモーメント荷重が転がり軸受に加わることにより、内輪中心と外輪中心とが相互に不一致となり内外輪が相対的に傾斜する。   For example, automobile engine timing belts and accessory drive belts are wound around various pulleys (such as cam pulleys and clamp pulleys) that are rotatably supported by rolling bearings. By adjusting the tension, a desired tension is applied to the belt. In the pulley unit configured as described above, for example, when the center position in the width direction of the belt wound around the various pulleys does not match the center position in the width direction of the rolling bearing due to mounting errors of components such as a rolling bearing and various pulleys. There is. In this case, the tension of the belt acts on a portion shifted from the center position in the width direction of the rolling bearing. For this reason, when a moment load corresponding to the amount of deviation is applied to the rolling bearing, the center of the inner ring and the center of the outer ring become inconsistent with each other, and the inner and outer rings are relatively inclined.

かかる状態でベルトを走行させると、ベルトが偏磨耗したり、転がり軸受から異音が発生する場合がある。そこで、このような弊害を防止するために転がり軸受の角すきまを可能な限り小さく設定する要求がされている。なお、“角すきま”とは、内輪又は外輪の一方を固定し他方を傾けたときの傾き量を指す。
このような要求に応える構成として例えば、ラジアル内部すきまを極力小さく設定したり、すきま以外に溝半径(軌道曲率半径)も小さく設定する構成が考えられる。例えば特許文献１の発明では、ラジアル内部すきまを−１０〜＋７μｍに設定する構成が提案されている。 When the belt is run in such a state, the belt may be worn out unevenly or abnormal noise may be generated from the rolling bearing. Therefore, in order to prevent such adverse effects, there is a demand for setting the angular clearance of the rolling bearing as small as possible. The “square clearance” refers to the amount of tilt when one of the inner ring and the outer ring is fixed and the other is tilted.
For example, a configuration in which the radial internal clearance is set as small as possible or the groove radius (orbital curvature radius) is set to be small in addition to the clearance is conceivable as a configuration that meets such requirements. For example, in the invention of Patent Document 1, a configuration is proposed in which the radial internal clearance is set to −10 to +7 μm.

しかしながら、このような構成でベルトを走行させると、転がり軸受の温度上昇に伴って早期に焼き付きが生じる場合がある。具体的に説明すると、転がり軸受の運転中には転動体と内輪と外輪との間の温度差が生じるが、その際、例えば転動体の温度が最も高く、内輪がそれに次ぎ、外輪が最も低い温度になると、外輪よりもその内部の部品(転動体、内輪)の温度が高くなる。このとき部品の熱膨張は外輪よりも大きな値となるため、例えば特許文献１のようにラジアル内部すきまを極力小さく設定する構成にすると、転動体と内外輪との間の接触面圧が高くなり、その結果、早期に焼き付きが生じる場合がある。このような焼き付きを防止するためには、例えば運転条件(例えば、ベルトの走行速度)や使用条件(例えば、転がり軸受のすきま設定値)が制限されてしまうため、満足できるものでは無い。   However, when the belt is run in such a configuration, seizure may occur at an early stage as the temperature of the rolling bearing rises. Specifically, during the operation of the rolling bearing, a temperature difference occurs between the rolling element, the inner ring, and the outer ring. At this time, for example, the temperature of the rolling element is the highest, the inner ring is the next, and the outer ring is the lowest. When the temperature is reached, the temperature of the internal components (rolling elements, inner ring) becomes higher than that of the outer ring. At this time, since the thermal expansion of the component is larger than that of the outer ring, for example, if a configuration in which the radial internal clearance is set as small as in Patent Document 1, the contact surface pressure between the rolling element and the inner and outer rings is increased. As a result, burn-in may occur at an early stage. In order to prevent such seizure, for example, operating conditions (for example, belt running speed) and usage conditions (for example, clearance setting values of rolling bearings) are limited, which is not satisfactory.

また、例えば電磁クラッチの場合には、その構造上の制限からプーリの幅方向中心と転がり軸受の幅方向中心とがオフセットされた構成が一般的であるため、転がり軸受には高いモーメント剛性が要求されている。
かかる要求に応える構成として、例えば特許文献２の発明では４点接触玉軸受を適用すると共に、例えば特許文献３の発明では３点接触玉軸受を適用することにより、所定のモーメント剛性を確保している。 For example, in the case of an electromagnetic clutch, a configuration in which the center in the width direction of the pulley and the center in the width direction of the rolling bearing are offset due to structural limitations is common, so that a high moment rigidity is required for the rolling bearing. Has been.
For example, in the invention of Patent Document 2, a four-point contact ball bearing is applied, and in the invention of Patent Document 3, for example, a three-point contact ball bearing is applied to secure a predetermined moment rigidity. Yes.

しかしながら、転動体と内外輪とを３点又は４点で接触させる構成では、接触点の数が増えるに従ってトルクや発熱量が増加し、このトルクや発熱量の増加に伴って転がり軸受自体の温度も上昇する。転がり軸受の温度が上昇すると、上述したように転動体と内外輪との間の接触面圧が高くなり、早期に焼き付きが生じる場合がある。また、転がり軸受の温度上昇は、転がり軸受に封入された潤滑剤の劣化(潤滑性の低下)を促進し、その結果、早期に焼き付きが生じる場合がある。
特開２００３−４９８３７号公報 特開平１１−３３６７９５号公報 特開平９−１２６３０３号公報 However, in the configuration in which the rolling elements and the inner and outer rings are in contact at three or four points, the torque and the heat generation amount increase as the number of contact points increases, and the temperature of the rolling bearing itself increases as the torque and the heat generation amount increase. Also rises. When the temperature of the rolling bearing rises, as described above, the contact surface pressure between the rolling elements and the inner and outer rings increases, and seizure may occur at an early stage. Further, the temperature rise of the rolling bearing promotes the deterioration of the lubricant enclosed in the rolling bearing (decrease in lubricity), and as a result, seizure may occur early.
JP 2003-49837 A JP-A-11-336795 JP-A-9-126303

本発明は、このような問題を解決するためになされており、その目的は、早期の焼き付けを防止して長期に亘り高い潤滑性を維持可能な高モーメント剛性の転がり軸受を提供することにある。   The present invention has been made to solve such problems, and an object of the present invention is to provide a rolling bearing having a high moment rigidity that can prevent early seizure and maintain high lubricity over a long period of time. .

このような目的を達成するために、本発明は、自動車の各種駆動系に駆動力を伝達する種々のベルトを巻き掛けるための各種プーリ、或いは電磁クラッチの回転部分に回転力を与える種々のベルトを巻き掛けるための各種プーリを回転可能に支持する転がり軸受であって、転がり軸受は、相対的に回転可能に対向配置された内輪及び外輪と、内外輪の軌道面間に転動自在に配列された複数の転動体とを備えており、複数の転動体は、異なる直径を有する２種類以上の転動体で構成されており、少なくとも非使用時において、最も大きな直径の転動体のラジアルすきまは負の値に設定され、且つ、最も小さな直径の転動体のラジアルすきまは正の値に設定されている。   In order to achieve such an object, the present invention provides various belts for wrapping various belts for transmitting driving force to various driving systems of automobiles, or various belts for applying rotational force to a rotating portion of an electromagnetic clutch. A rolling bearing that rotatably supports various pulleys for winding a roller, and the rolling bearing is arranged between an inner ring and an outer ring, which are relatively rotatably opposed to each other, and a raceway surface of the inner and outer rings. The plurality of rolling elements are composed of two or more types of rolling elements having different diameters, and the radial clearance of the largest diameter rolling element is at least when not in use. It is set to a negative value, and the radial clearance of the rolling element with the smallest diameter is set to a positive value.

この発明において、最も大きな直径の転動体と最も小さな直径の転動体とは、線膨張係数及び縦弾性係数の少なくともいずれか一方が互いに異なっている。また、最も大きな直径の転動体は、内外輪構成部の軌道面間に所定の順序で等間隔に配列されている。この場合、最も大きな直径の転動体は、セラミックスで形成されており、一方、最も小さな直径の転動体は、鋼で形成されている。   In the present invention, the rolling element having the largest diameter and the rolling element having the smallest diameter are different from each other in at least one of the linear expansion coefficient and the longitudinal elastic modulus. Further, the rolling elements having the largest diameter are arranged at equal intervals in a predetermined order between the raceway surfaces of the inner and outer ring constituent portions. In this case, the rolling element with the largest diameter is made of ceramics, while the rolling element with the smallest diameter is made of steel.

本発明によれば、内外輪構成部の軌道面間に異なる直径を有する２種類以上の転動体を配列し、少なくとも非使用時において、最も大きな直径の転動体のラジアルすきまを負の値に設定し、且つ最も小さな直径の転動体のラジアルすきまを正の値に設定したことにより、早期の焼き付けを防止して長期に亘り高い潤滑性を維持可能な高モーメント剛性の転がり軸受を実現することができる。   According to the present invention, two or more types of rolling elements having different diameters are arranged between the raceway surfaces of the inner and outer ring components, and at least when not in use, the radial clearance of the rolling element having the largest diameter is set to a negative value. In addition, by setting the radial clearance of the rolling element with the smallest diameter to a positive value, it is possible to achieve a high moment rigidity rolling bearing that can prevent premature seizure and maintain high lubricity over a long period of time. it can.

以下、本発明の一実施の形態に係る転がり軸受について添付図面を参照して説明する。
本実施の形態では、例えば自動車の各種駆動系に駆動力を伝達する種々のベルトを巻き掛けるための各種プーリ、或いは例えば電磁クラッチの回転部分に回転力を与える種々のベルトを巻き掛けるための各種プーリを回転可能に支持する転がり軸受を想定する。 Hereinafter, a rolling bearing according to an embodiment of the present invention will be described with reference to the accompanying drawings.
In the present embodiment, for example, various pulleys for wrapping various belts for transmitting driving force to various driving systems of an automobile, or various belts for wrapping various belts for applying rotational force to a rotating portion of an electromagnetic clutch, for example. Assume a rolling bearing that rotatably supports a pulley.

図１(ｃ)には、上述した各種プーリに転がり軸受２が組み込まれた構成例が示されており、転がり軸受２は、相対的に回転可能に対向配置された内輪４及び外輪６と、内外輪4,6の軌道面4s,6s間に転動自在に配列された複数の転動体(例えば、玉、ころ)とを備えている。この構成において、プーリ１０は外輪６の外周に装着されており、内輪４の内周にはスリーブ(シャフト)１２が装着されている。この場合、プーリ１０はスリーブ１２に対して転がり軸受２を介して相対的に回転可能に支持され、プーリ１０にベルト１４を巻き掛けることにより、当該ベルト１４をプーリ１０の回転に伴って所定方向に走行させることができる。なお、転がり軸受２に封入された潤滑剤(例えば、グリース、油)の漏洩防止と共に、異物(例えば、水、塵埃)の浸入防止を図るために、内外輪4,6間に密封板(図示しない)を配設しても良く、この場合、密封板としては、例えばシールやシールドを適用すれば良い。   FIG. 1 (c) shows a configuration example in which the rolling bearing 2 is incorporated in the above-described various pulleys. The rolling bearing 2 includes an inner ring 4 and an outer ring 6 that are relatively opposed to each other. A plurality of rolling elements (for example, balls and rollers) arranged to freely roll between the raceway surfaces 4s and 6s of the inner and outer rings 4 and 6 are provided. In this configuration, the pulley 10 is mounted on the outer periphery of the outer ring 6, and a sleeve (shaft) 12 is mounted on the inner periphery of the inner ring 4. In this case, the pulley 10 is supported so as to be relatively rotatable with respect to the sleeve 12 via the rolling bearing 2, and the belt 14 is wound around the pulley 10, so that the belt 14 is rotated in a predetermined direction along with the rotation of the pulley 10. Can be run. A sealing plate (not shown) is provided between the inner and outer rings 4 and 6 in order to prevent leakage of lubricant (for example, grease and oil) enclosed in the rolling bearing 2 and to prevent entry of foreign matter (for example, water and dust). In this case, for example, a seal or a shield may be applied as the sealing plate.

このような転がり軸受２において、複数の転動体は、異なる直径を有する２種類以上の転動体(例えば、8a,8b)で構成されており、少なくとも非使用時において、最も大きな直径の転動体８ａのラジアルすきまは負の値に設定され、且つ、最も小さな直径の転動体８ｂのラジアルすきまは正の値に設定されている。この場合、ラジアルすきまの正負の設定値は、転がり軸受２の種類や大きさ、転動体8a,8bの形状や大きさなどに応じて最適な値に設定されるため、ここでは特に数値限定はしない。   In such a rolling bearing 2, the plurality of rolling elements are composed of two or more types of rolling elements (for example, 8a, 8b) having different diameters, and at least when not in use, the rolling element 8a having the largest diameter is used. The radial clearance is set to a negative value, and the radial clearance of the rolling element 8b having the smallest diameter is set to a positive value. In this case, the positive and negative set values of the radial clearance are set to optimum values according to the type and size of the rolling bearing 2 and the shape and size of the rolling elements 8a and 8b. do not do.

なお、転動体の直径寸法差は、生産上のばらつきが１μｍ以下であることから、本実施の形態では、転動体の直径寸法差が１μｍ以下であるものは同一直径とみなす。
また、本実施の形態では一例として、互いに直径が異なる２種類の転動体(大径転動体８ａ、小径転動体８ｂ)を想定し、大径転動体８ａの配置状態を明確化するために、該当する大径転動体８ａにはハッチングを施している。 In addition, since the dispersion | variation in the diameter dimension of a rolling element is 1 micrometer or less in production | generation, in this Embodiment, it is considered that the diameter dimension difference of a rolling element is 1 micrometer or less with the same diameter.
Further, in the present embodiment, as an example, assuming two types of rolling elements (large diameter rolling element 8a and small diameter rolling element 8b) having different diameters, in order to clarify the arrangement state of the large diameter rolling element 8a, The corresponding large-diameter rolling element 8a is hatched.

この場合、内外輪構成部(内外輪)4,6の軌道面4s,6s間に２種類の転動体8a,8bを配列した状態において、内外輪構成部(内外輪)4,6に対して接触面圧を有する大径転動体８ａと接触面圧の無い小径転動体８ｂとが混在することにより、転がり軸受２は周方向に沿って部分的に予圧が付加された状態となる。   In this case, with the two types of rolling elements 8a and 8b arranged between the raceway surfaces 4s and 6s of the inner and outer ring constituent parts (inner and outer rings) 4 and 6, the inner and outer ring constituent parts (inner and outer rings) 4 and 6 By mixing the large-diameter rolling element 8a having the contact surface pressure and the small-diameter rolling element 8b having no contact surface pressure, the rolling bearing 2 is in a state in which preload is partially applied along the circumferential direction.

かかる状態は転がり軸受２の動作中にも維持され、内外輪構成部(内外輪)4,6が転動体8a,8bを介して相対的に回転する際、内外輪構成部(内外輪)4,6に対して接触面圧の無い小径転動体８ｂの位置が周方向に変化することになるが、その間、内外輪構成部(内外輪)4,6に対して接触面圧を有する大径転動体８ａは、内外輪構成部(内外輪)4,6の軌道面4s,6sに常時接した状態を維持する。   Such a state is maintained even during operation of the rolling bearing 2, and when the inner and outer ring constituent parts (inner and outer rings) 4 and 6 relatively rotate via the rolling elements 8a and 8b, the inner and outer ring constituent parts (inner and outer rings) 4 , 6, the position of the small-diameter rolling element 8b having no contact surface pressure changes in the circumferential direction. During this time, the large diameter having the contact surface pressure on the inner and outer ring components (inner and outer rings) 4, 6 The rolling element 8a maintains a state where it is always in contact with the raceway surfaces 4s and 6s of the inner and outer ring components (inner and outer rings) 4 and 6.

また、大径転動体８ａと小径転動体８ｂとは、内外輪構成部(内外輪)4,6の軌道面4s,6s間に所定の順序で等間隔に配列することが好ましい。例えば図１(ａ)では、４個の大径転動体８ａと４個の小径転動体８ｂとを１個ずつ交互に等間隔に配列している。このような配列によれば、転がり軸受２は周方向に沿って等間隔に予圧付加状態となる。   The large-diameter rolling elements 8a and the small-diameter rolling elements 8b are preferably arranged at regular intervals in a predetermined order between the raceway surfaces 4s and 6s of the inner and outer ring constituent parts (inner and outer rings) 4 and 6. For example, in FIG. 1A, four large diameter rolling elements 8a and four small diameter rolling elements 8b are alternately arranged at equal intervals. According to such an arrangement, the rolling bearing 2 is in a preload application state at equal intervals along the circumferential direction.

このような構成によれば、例えば図１(ｂ)に示すように、転がり軸受２の中心Ｔからオフセットされた位置にラジアル荷重Ｆｒが加わってもモーメント剛性の変化を小さくすることができる。この結果、転がり軸受２を安定して且つ滑らかに動作させることが可能となり、トルク制御を安定して行うことが可能となる。   According to such a configuration, for example, as shown in FIG. 1B, even if a radial load Fr is applied to a position offset from the center T of the rolling bearing 2, a change in moment rigidity can be reduced. As a result, the rolling bearing 2 can be operated stably and smoothly, and torque control can be performed stably.

更に、転がり軸受２は周方向に沿って等間隔に予圧付加状態とすることにより、内輪４と外輪６とが相対的に傾斜するのを抑制することができる。この結果、内外輪4,6の軌道面4s,6sと転動体８との間に潤滑剤を引き込み易くなり、潤滑不良による異音や早期の焼き付きも生じない。特に、耐熱性の潤滑剤を用いた転がり軸受２では、低温化での潤滑剤の流動性が低くなるが、この場合でも異音や焼き付きが生じることはない。   Furthermore, the rolling bearing 2 can suppress relative inclination of the inner ring 4 and the outer ring 6 by setting a preload applied state at equal intervals along the circumferential direction. As a result, it becomes easy to draw the lubricant between the raceway surfaces 4s, 6s of the inner and outer rings 4, 6 and the rolling elements 8, and abnormal noise due to poor lubrication and early seizure do not occur. In particular, in the rolling bearing 2 using a heat-resistant lubricant, the fluidity of the lubricant at low temperatures is lowered, but even in this case, no abnormal noise or seizure occurs.

また、本実施の形態の転がり軸受２において、大径転動体８ａと小径転動体８ｂとは、線膨張係数及び縦弾性係数の少なくともいずれか一方が互いに異なるように形成することが好ましい。この場合、大径転動体８ａは、例えば金属元素と非金属元素がイオン結合又は共有結合したセラミックスで形成し、一方、小径転動体８ｂは、例えば２パーセント以下の炭素を含有する鋼で形成すれば良い。なお、線膨張係数とは、例えば応力値が材料により定まる一定値を超えない範囲で、それにより生じる歪との間の比例関係(フックの法則)における比例定数(ヤング率)を示し、一方、縦弾性係数とは、材料が１℃上昇する毎に膨張する長さ方向の割合を示す。   Further, in the rolling bearing 2 of the present embodiment, it is preferable that the large diameter rolling element 8a and the small diameter rolling element 8b are formed so that at least one of the linear expansion coefficient and the longitudinal elastic coefficient is different from each other. In this case, the large-diameter rolling element 8a is made of, for example, a ceramic in which a metal element and a non-metallic element are ion-bonded or covalently bonded, while the small-diameter rolling element 8b is made of, for example, steel containing 2% or less of carbon. It ’s fine. The linear expansion coefficient, for example, indicates a proportionality constant (Young's modulus) in a proportional relationship (Hook's law) with the strain caused by the stress value in a range not exceeding a fixed value determined by the material, The longitudinal elastic modulus indicates a ratio in the length direction in which the material expands every time the material rises by 1 ° C.

この場合、例えば転がり軸受２を高温下で運転する際、２種類の転動体8a,8bの熱膨張量の違いにより、転動体相互の直径差が緩和されるため、転動体回転時の軸受振動を抑制することができると共に、全ての転動体8a,8bが荷重負荷を分担するようになるため、軸受内部の接触面圧が低減され転がり軸受２の転がり疲れ寿命を延命化することができる。   In this case, for example, when the rolling bearing 2 is operated at a high temperature, the difference in diameter between the rolling elements is reduced due to the difference in thermal expansion between the two types of rolling elements 8a and 8b. Since all the rolling elements 8a and 8b share the load, the contact surface pressure inside the bearing can be reduced and the rolling fatigue life of the rolling bearing 2 can be extended.

ここで、ラジアルすきまが負の値に設定された大径転動体８ａと正の値に設定された小径転動体８ｂとを備えた転がり軸受２の軸受温度の変化に対するモーメント剛性(図２(ａ))及び最大接触面圧(図２(ｂ))並びに転がり疲れ寿命(図２(ｃ))の各計算結果について説明する。
この計算では呼び番号(開放形)６２０３の転がり軸受２を適用する。この場合、転がり軸受２は、内径が１７ｍｍ、外径が４０ｍｍ、幅が１２ｍｍであり、玉径は７.９３８ｍｍ、玉数は８個に設定した。なお、ラジアル荷重Ｆｒ(図１(ｂ))を１０００Ｎ、モーメント荷重を１Ｎｍ、軸受初期すきまを０.０２２ｍｍとした。 Here, the moment stiffness with respect to the change in the bearing temperature of the rolling bearing 2 including the large-diameter rolling element 8a in which the radial clearance is set to a negative value and the small-diameter rolling element 8b in which the radial clearance is set to a positive value (FIG. 2 (a )) And maximum contact surface pressure (FIG. 2B) and rolling fatigue life (FIG. 2C) will be described.
In this calculation, the rolling bearing 2 having an identification number (open type) 6203 is applied. In this case, the rolling bearing 2 had an inner diameter of 17 mm, an outer diameter of 40 mm, a width of 12 mm, a ball diameter of 7.938 mm, and the number of balls set to eight. The radial load Fr (FIG. 1B) was 1000 N, the moment load was 1 Nm, and the bearing initial clearance was 0.022 mm.

また、ハウジング１２としては鋼製とし、その直径を４０ｍｍに設定した。この場合、ハウジング穴の交差を交差域クラスＰ７(−0.017/−0.042)とした。一方、回転軸１４としてはアルミニウム製とし、その直径を１７ｍｍに設定した。この場合、軸の交差を交差域クラスｈ６(0/−0.011)とした。   The housing 12 was made of steel and the diameter was set to 40 mm. In this case, the intersection of the housing holes was defined as an intersection area class P7 (−0.017 / −0.042). On the other hand, the rotating shaft 14 was made of aluminum, and its diameter was set to 17 mm. In this case, the intersection of the axes was defined as an intersection area class h6 (0 / −0.011).

更に、転動体8a,8bは、その直径及び線膨張係数が互いに異なったものを用意し、これら転動体8a,8bを図１(ａ)に示すように等配させた。即ち、大径転動体８ａと小径転動体８ｂとを１個ずつ交互に配列させた。この場合、大径転動体８ａの直径を6.747＋0.006ｍｍ、線膨張係数を2.9×10−６に設定し、小径転動体８ｂの直径を6.747±0ｍｍ、線膨張係数を12.5×10−６に設定した。 Furthermore, rolling elements 8a and 8b having different diameters and linear expansion coefficients were prepared, and these rolling elements 8a and 8b were equally arranged as shown in FIG. 1 (a). That is, the large diameter rolling elements 8a and the small diameter rolling elements 8b were alternately arranged one by one. In this case, the diameter of the large diameter rolling element 8a is set to 6.747 + 0.006 mm, the linear expansion coefficient is set to 2.9 × 10 −6 , the diameter of the small diameter rolling element 8b is set to 6.747 ± 0 mm, and the linear expansion coefficient is set to 12.5 × 10 −6 . Set.

まず、転がり軸受２の軸受温度の変化に対するモーメント剛性の変化について、上記の設定条件に従った本発明の転がり軸受２(発明品)と従来の軸受(従来品)とを比較した。この場合、図２(ａ)に示すように、発明品は常温時から高いモーメント剛性を有しており、そのモーメント剛性の変化が従来品に比べて小さくなっていることが分る。これにより、発明品は、例えば取付誤差や取付制限などから生じるオフセット荷重Ｆｒ(図１(ｂ))に対してモーメント剛性比が変化し難いという意味で、従来品よりも高いロバスト性(例えば、安定性、最適性)を有していることが分る。   First, regarding the change in moment stiffness with respect to the change in bearing temperature of the rolling bearing 2, the rolling bearing 2 of the present invention (invention product) and the conventional bearing (conventional product) according to the above set conditions were compared. In this case, as shown in FIG. 2A, it can be seen that the product of the invention has a high moment stiffness from the normal temperature, and the change in the moment stiffness is smaller than that of the conventional product. As a result, the inventive product is more robust than the conventional product in the sense that the moment stiffness ratio is less likely to change with respect to the offset load Fr (FIG. 1 (b)) resulting from, for example, mounting errors or mounting limitations. (Stability, optimality).

次に、転がり軸受２の軸受温度の変化に対する最大接触面圧(図２(ｂ))及び転がり疲れ寿命(図２(ｃ))の変化について、発明品と従来品とを比較した。この場合、発明品は周方向に沿って等間隔に予圧付加状態となっており、負荷を受ける転動体(大径転動体８ａ)の数が少ない。このため、発明品は従来品に比べて接触面圧が増加すると共に、転がり疲れ寿命が低下している。しかしながら、このような変化量は実用上問題の無い範囲であり、特に軸受運転時の軸受温度(１２０℃近辺)では発明品と従来品とは同等レベル値となる。   Next, the invention product and the conventional product were compared with respect to changes in the maximum contact surface pressure (FIG. 2 (b)) and the rolling fatigue life (FIG. 2 (c)) with respect to changes in the bearing temperature of the rolling bearing 2. In this case, the inventive product is in a preloading state at regular intervals along the circumferential direction, and the number of rolling elements (large-diameter rolling elements 8a) receiving the load is small. For this reason, the contact surface pressure of the inventive product is increased as compared with the conventional product, and the rolling fatigue life is reduced. However, such a change amount is in a range where there is no practical problem, and the invention product and the conventional product have the same level value especially at the bearing temperature (around 120 ° C.) during the bearing operation.

ここで、本実施の形態の転がり軸受２を例えば図３(ａ)に示すようなプーリユニット16,18,20に組み込んだ構成例について考察する。かかる構成例において、図中上下２つのプーリユニット16,18は同一平面上に整列され、中央のプーリユニット２０は図中右方向に突出して配置されている。なお、各プーリユニット16,18,20の構成は図１(ｃ)と同様であるため、その詳細な説明は省略する。   Here, a configuration example in which the rolling bearing 2 of the present embodiment is incorporated in pulley units 16, 18, and 20 as shown in FIG. In such a configuration example, the two upper and lower pulley units 16 and 18 in the figure are aligned on the same plane, and the central pulley unit 20 is disposed so as to protrude rightward in the figure. The configuration of each pulley unit 16, 18, 20 is the same as that shown in FIG.

このようなプーリユニット16,18,20にベルト１４を巻き掛けると、プーリユニット２０の突出量に応じて各プーリユニット16,18,20のプーリ１０には、例えば図１(ｂ)に示すようにオフセットされた位置にラジアル荷重Ｆｒが加わることで、転がり軸受２には更にモーメント荷重も作用することになる。
しかしながら、内外輪構成部(内外輪)4,6の軌道面4s,6s間に直径の異なる２種類の転動体8a,8bを配列し、転がり軸受２の周方向に沿って部分的に予圧を付加した状態にしたことにより、モーメント荷重に対して高いモーメント剛性を確保することができる。この場合、転がり軸受２を安定して且つ滑らかに動作させることができるため、早期の焼き付けを防止して長期に亘り高い潤滑性を維持することができる。この結果、各プーリユニット16,18,20を安定して且つ滑らかに動作させることができる。 When the belt 14 is wound around the pulley units 16, 18, and 20, the pulleys 10 of the pulley units 16, 18, and 20 correspond to the protruding amount of the pulley unit 20, for example, as shown in FIG. When the radial load Fr is applied to the position offset to, a moment load further acts on the rolling bearing 2.
However, two types of rolling elements 8a and 8b having different diameters are arranged between the raceway surfaces 4s and 6s of the inner and outer ring components (inner and outer rings) 4 and 6, and preload is partially applied along the circumferential direction of the rolling bearing 2. Due to the added state, it is possible to ensure high moment rigidity with respect to the moment load. In this case, since the rolling bearing 2 can be operated stably and smoothly, early seizure can be prevented and high lubricity can be maintained over a long period of time. As a result, each pulley unit 16, 18, 20 can be operated stably and smoothly.

また、本実施の形態の転がり軸受２を例えば図３(ｂ)に示すような電磁クラッチに組み込んだ構成例について考察する。かかる構成例において、転がり軸受２の外輪６は、磁性体製のロータ22,24を介してプーリ１０に接続され、ロータ22,24には、当該ロータ22,24を磁化させる電磁コイル２６が固定されている。また、ロータ22,24に対向した位置には、転がり軸受２と同心円状に形成されたアーマチュア28a,28b,28cが配設されており、アーマチュア28a,28b,28cは、ロータ22,24を磁化させた際に当該ロータ22,24に吸着するように構成されている。   Further, consider a configuration example in which the rolling bearing 2 of the present embodiment is incorporated in an electromagnetic clutch as shown in FIG. In this configuration example, the outer ring 6 of the rolling bearing 2 is connected to the pulley 10 via the rotors 22 and 24 made of a magnetic material, and the electromagnetic coils 26 that magnetize the rotors 22 and 24 are fixed to the rotors 22 and 24. Has been. Further, armatures 28a, 28b, 28c formed concentrically with the rolling bearing 2 are disposed at positions facing the rotors 22, 24. The armatures 28a, 28b, 28c magnetize the rotors 22, 24. It is configured to be attracted to the rotors 22 and 24 when they are made.

電磁クラッチの場合には、その構造上の制限からプーリ１０の幅方向中心と転がり軸受２の幅方向中心とがオフセットされる場合が一般的であり、そのため、転がり軸受２には高いモーメント剛性が要求される。
そこで、本実施の形態の転がり軸受２を適用して、内外輪構成部(内外輪)4,6の軌道面4s,6s間に直径の異なる２種類の転動体8a,8bを配列し、転がり軸受２の周方向に沿って部分的に予圧を付加した状態にしたことにより、モーメント荷重に対して高いモーメント剛性を確保することができる。この場合、転がり軸受２を安定して且つ滑らかに動作させることができるため、早期の焼き付けを防止して長期に亘り高い潤滑性を維持することができる。この結果、電磁クラッチを安定して且つ滑らかに動作させることができる。 In the case of an electromagnetic clutch, the center in the width direction of the pulley 10 and the center in the width direction of the rolling bearing 2 are generally offset due to structural limitations. For this reason, the rolling bearing 2 has high moment rigidity. Required.
Therefore, by applying the rolling bearing 2 of the present embodiment, two types of rolling elements 8a and 8b having different diameters are arranged between the raceway surfaces 4s and 6s of the inner and outer ring components (inner and outer rings) 4 and 6, and rolling. By providing a state in which a preload is partially applied along the circumferential direction of the bearing 2, a high moment rigidity can be ensured with respect to the moment load. In this case, since the rolling bearing 2 can be operated stably and smoothly, early seizure can be prevented and high lubricity can be maintained over a long period of time. As a result, the electromagnetic clutch can be operated stably and smoothly.

更に、本実施の形態の転がり軸受２は、３点及び４点接触軸受に比べて軸受トルクを小さくすることができるため、運転中の発熱量を軽減することができる。この結果、従来品に比べて、潤滑剤の劣化(潤滑性の低下)を生じさせることが無いため、潤滑不良による異音や早期の焼き付きが生じることも無い。これにより、プーリユニット16,18,20や電磁クラッチの回転安定性及び円滑性を長期に亘って確保することが可能となる。更にまた、転がり軸受２の軸受トルクを小さくすることにより、プーリユニット16,18,20や電磁クラッチの駆動に要する消費馬力の増大を抑えることも可能となる。   Furthermore, since the rolling bearing 2 of the present embodiment can reduce the bearing torque compared to the three-point and four-point contact bearings, the amount of heat generated during operation can be reduced. As a result, there is no deterioration of the lubricant (decrease in lubricity) as compared with the conventional product, and therefore no abnormal noise or early seizure due to poor lubrication will not occur. As a result, the rotational stability and smoothness of the pulley units 16, 18, 20 and the electromagnetic clutch can be ensured over a long period of time. Furthermore, by reducing the bearing torque of the rolling bearing 2, it is possible to suppress an increase in the horsepower consumption required for driving the pulley units 16, 18, 20 and the electromagnetic clutch.

更にまた、高温環境下で使用されるプーリユニット16,18,20や電磁クラッチの転がり軸受２では、その大径転動体８ａの線膨張係数を小径転動体８ｂの線膨張係数よりも小さく設定することが好ましい。高温下で使用される転がり軸受２は、通常、運転時の負のすきまによる軸受焼き付けを防止するため、常温時の残留すきまが正の値に設定されているが、これが軸受ガタの要因となる。しかしながら、本実施の形態の転がり軸受２では、大径転動体８ａにより転がり軸受２の周方向に沿って部分的に予圧付加状態となるため、高温運転時には熱膨張量の違いにより転動体8a,8bの径相互差が緩和される。この場合、転動体回転時の軸受振動を抑制することができると共に、全ての転動体8a,8bが荷重負荷を分担するようになるため、軸受内部の接触面圧が低減され転がり軸受２の転がり疲れ寿命を延命化することができる。この結果、長期に亘ってプーリユニット16,18,20や電磁クラッチを安定して且つ滑らかに動作させることができる。   Furthermore, in the pulley units 16, 18, 20 and the electromagnetic clutch rolling bearing 2 used in a high temperature environment, the linear expansion coefficient of the large diameter rolling element 8a is set smaller than the linear expansion coefficient of the small diameter rolling element 8b. It is preferable. Rolling bearings 2 used at high temperatures usually have a positive residual clearance at room temperature in order to prevent bearing seizure due to negative clearance during operation, which causes bearing backlash. . However, in the rolling bearing 2 of the present embodiment, the preload is partially applied along the circumferential direction of the rolling bearing 2 by the large-diameter rolling element 8a, so that the rolling element 8a, The difference in diameter of 8b is relaxed. In this case, bearing vibration during rotation of the rolling element can be suppressed, and all the rolling elements 8a and 8b share the load load. Therefore, the contact surface pressure inside the bearing is reduced and the rolling bearing 2 is rolled. The fatigue life can be extended. As a result, the pulley units 16, 18, 20 and the electromagnetic clutch can be stably and smoothly operated over a long period of time.

なお、上述した実施の形態では、互いに直径が異なる２種類の転動体8a,8bを想定したが、これに限定されることは無く、互いに直径が異なる３種類又はそれ以上の転動体を備えた転がり軸受２に対して本発明を適用することができることは言うまでも無い。更に、単列及び複列の軸受にも本発明を適用することができることは言うまでも無い。   In the above-described embodiment, two types of rolling elements 8a and 8b having different diameters are assumed. However, the present invention is not limited to this, and three or more types of rolling elements having different diameters are provided. Needless to say, the present invention can be applied to the rolling bearing 2. Furthermore, it goes without saying that the present invention can also be applied to single-row and double-row bearings.

また、上述した実施の形態では、大径転動体８ａと小径転動体８ｂとを１個ずつ交互に配列した転がり軸受２を例示して説明したが、これに限定されることは無く、例えば図４(ａ)に示すように２個の大径転動体８ａの間に１個の小径転動体８ｂを交互に介在させた配列構成や、例えば図４(ｂ)に示すように１個の大径転動体８ａの間に２個の小径転動体８ｂを交互に介在させた配列構成など、転がり軸受２の使用目的や使用環境に応じて任意の配列構成を適用することができる。なお、かかる配列構成でも上述した実施の形態と同様の効果を得ることができることは言うまでも無い。   In the above-described embodiment, the rolling bearing 2 in which the large-diameter rolling elements 8a and the small-diameter rolling elements 8b are alternately arranged one by one has been described as an example. However, the present invention is not limited to this. As shown in FIG. 4 (a), an arrangement configuration in which one small diameter rolling element 8b is alternately interposed between two large diameter rolling elements 8a, or one large diameter rolling element as shown in FIG. 4 (b), for example. Arbitrary arrangement configurations, such as an arrangement configuration in which two small-diameter rolling elements 8b are alternately interposed between the radial rolling elements 8a, can be applied depending on the purpose and environment of use of the rolling bearing 2. It goes without saying that the same effects as those of the above-described embodiment can be obtained with such an arrangement.

(ａ)は、本発明の一実施の形態に係る転がり軸受の断面図、(ｂ)は、同図(ａ)のＹ−Ｙ線に沿う断面図、(ｃ)は、本実施の形態の転がり軸受をプーリに組み込んだ構成例を部分的に示す断面図。(a) is sectional drawing of the rolling bearing which concerns on one embodiment of this invention, (b) is sectional drawing which follows the YY line of the same figure (a), (c) is this Embodiment. Sectional drawing which shows partially the structural example which incorporated the rolling bearing in the pulley. (ａ)は、軸受温度の変化に対するモーメント剛性の変化について発明品と従来品とを比較した結果を示す図、(ｂ)は、軸受温度の変化に対する最大接触面圧の変化について発明品と従来品とを比較した結果を示す図、(ｃ)は、軸受温度の変化に対する転がり疲れ寿命の変化について発明品と従来品とを比較した結果を示す図。(a) is a figure which shows the result of having compared the invention product and the conventional product about the change of the moment rigidity with respect to the change of the bearing temperature, (b) is the product of the invention and the conventional technology about the change of the maximum contact surface pressure with respect to the change of the bearing temperature The figure which shows the result of having compared with the goods, (c) is the figure which shows the result of having compared the invention goods and the conventional goods about the change of the rolling fatigue life with respect to the change of bearing temperature. (ａ)は、本実施の形態の転がり軸受が組み込まれたプーリユニットの構成例を示す図、(ｂ)は、本実施の形態の転がり軸受が組み込まれた電磁クラッチの構成例を示す図。(a) is a figure which shows the structural example of the pulley unit in which the rolling bearing of this Embodiment was integrated, (b) is a figure which shows the structural example of the electromagnetic clutch in which the rolling bearing of this Embodiment was integrated. (ａ)は、２個の大径転動体の間に１個の小径転動体を交互に介在させた転がり軸受の構成例を示す断面図、(ｂ)は、１個の大径転動体の間に２個の小径転動体を交互に介在させた転がり軸受の構成例を示す断面図。(a) is a sectional view showing a configuration example of a rolling bearing in which one small-diameter rolling element is alternately interposed between two large-diameter rolling elements, and (b) is a diagram of one large-diameter rolling element. Sectional drawing which shows the structural example of the rolling bearing which intervened two small diameter rolling elements between them alternately.

符号の説明Explanation of symbols

２ 転がり軸受
４ 内輪
４ｓ 内輪の軌道面
６ 外輪
６ｓ 外輪の軌道面
８ａ 大径転動体
８ｂ 小径転動体
１０ プーリ
2 Rolling bearing 4 Inner ring 4s Inner ring raceway surface 6 Outer ring 6s Outer ring raceway surface 8a Large diameter rolling element 8b Small diameter rolling element 10 Pulley

Claims (4)

自動車の各種駆動系に駆動力を伝達する種々のベルトを巻き掛けるための各種プーリ、或いは電磁クラッチの回転部分に回転力を与える種々のベルトを巻き掛けるための各種プーリを回転可能に支持する転がり軸受であって、
転がり軸受は、相対的に回転可能に対向配置された内輪及び外輪と、内外輪の軌道面間に転動自在に配列された複数の転動体とを備えており、
複数の転動体は、異なる直径を有する２種類以上の転動体で構成されており、少なくとも非使用時において、最も大きな直径の転動体のラジアルすきまは負の値に設定され、且つ、最も小さな直径の転動体のラジアルすきまは正の値に設定されていることを特徴とする転がり軸受。 Roller that rotatably supports various pulleys for wrapping various belts for transmitting driving force to various driving systems of automobiles, or various pulleys for wrapping various belts for applying rotational force to rotating parts of electromagnetic clutches A bearing,
The rolling bearing includes an inner ring and an outer ring that are disposed to face each other so as to be relatively rotatable, and a plurality of rolling elements that are arranged to freely roll between the raceway surfaces of the inner and outer rings,
The plurality of rolling elements are composed of two or more types of rolling elements having different diameters. At least when not in use, the radial clearance of the rolling element having the largest diameter is set to a negative value, and the smallest diameter is set. A rolling bearing characterized in that the radial clearance of the rolling element is set to a positive value. 最も大きな直径の転動体と最も小さな直径の転動体とは、線膨張係数及び縦弾性係数の少なくともいずれか一方が互いに異なっていることを特徴とする請求項１に記載の転がり軸受。   The rolling bearing according to claim 1, wherein the rolling element having the largest diameter and the rolling element having the smallest diameter are different from each other in at least one of a linear expansion coefficient and a longitudinal elastic coefficient. 最も大きな直径の転動体は、内外輪構成部の軌道面間に所定の順序で等間隔に配列されていることを特徴とする請求項１又は２に記載の転がり軸受。   The rolling bearing according to claim 1 or 2, wherein the rolling elements having the largest diameter are arranged at predetermined intervals in a predetermined order between the raceway surfaces of the inner and outer ring constituent portions. 最も大きな直径の転動体は、セラミックスで形成されており、一方、最も小さな直径の転動体は、鋼で形成されていることを特徴とする請求項１〜３のいずれかに記載の転がり軸受。
The rolling bearing according to claim 1, wherein the rolling element with the largest diameter is made of ceramics, while the rolling element with the smallest diameter is made of steel.
JP2004330687A 2004-11-15 2004-11-15 Rolling bearing Pending JP2006138448A (en)

Priority Applications (1)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008164010A (en) * 2006-12-27 2008-07-17 Toyota Motor Corp Rolling bearing
CN117006165A (en) * 2023-08-08 2023-11-07 依必艾传动***(上海)有限公司 Layered array arrangement method for tapered rollers of hub bearing

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008164010A (en) * 2006-12-27 2008-07-17 Toyota Motor Corp Rolling bearing
CN117006165A (en) * 2023-08-08 2023-11-07 依必艾传动***(上海)有限公司 Layered array arrangement method for tapered rollers of hub bearing
CN117006165B (en) * 2023-08-08 2024-03-12 依必艾传动***(上海)有限公司 Layered array arrangement method for tapered rollers of hub bearing

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