JP2021014863A - Cage for needle roller bearing and needle roller bearing - Google Patents

Cage for needle roller bearing and needle roller bearing Download PDF

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Publication number
JP2021014863A
JP2021014863A JP2019128555A JP2019128555A JP2021014863A JP 2021014863 A JP2021014863 A JP 2021014863A JP 2019128555 A JP2019128555 A JP 2019128555A JP 2019128555 A JP2019128555 A JP 2019128555A JP 2021014863 A JP2021014863 A JP 2021014863A
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Japan
Prior art keywords
cage
needle roller
axial direction
cylindrical portion
roller bearing
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
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JP2019128555A
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Japanese (ja)
Inventor
友謹 木村
Tomochika Kimura
友謹 木村
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NTN Corp
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NTN Corp
NTN Toyo Bearing Co Ltd
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Application filed by NTN Corp, NTN Toyo Bearing Co Ltd filed Critical NTN Corp
Priority to JP2019128555A priority Critical patent/JP2021014863A/en
Priority to DE112020003265.5T priority patent/DE112020003265T5/en
Priority to CN202080044342.7A priority patent/CN113993639A/en
Priority to PCT/JP2020/023910 priority patent/WO2021005994A1/en
Publication of JP2021014863A publication Critical patent/JP2021014863A/en
Priority to JP2024006110A priority patent/JP2024045260A/en
Pending legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D28/00—Shaping by press-cutting; Perforating
    • B21D28/02—Punching blanks or articles with or without obtaining scrap; Notching
    • B21D28/14—Dies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D53/00—Making other particular articles
    • B21D53/10—Making other particular articles parts of bearings; sleeves; valve seats or the like
    • B21D53/12—Making other particular articles parts of bearings; sleeves; valve seats or the like cages for bearings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D37/00—Tools as parts of machines covered by this subclass
    • B21D37/10—Die sets; Pillar guides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/22—Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings
    • F16C19/24—Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings for radial load mainly
    • F16C19/26—Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings for radial load mainly with a single row of rollers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/22—Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings
    • F16C19/44—Needle bearings
    • F16C19/46—Needle bearings with one row or needles
    • F16C19/463—Needle bearings with one row or needles consisting of needle rollers held in a cage, i.e. subunit without race rings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/46—Cages for rollers or needles
    • F16C33/4617—Massive or moulded cages having cage pockets surrounding the rollers, e.g. machined window cages
    • F16C33/4623—Massive or moulded cages having cage pockets surrounding the rollers, e.g. machined window cages formed as one-piece cages, i.e. monoblock cages
    • F16C33/4629—Massive or moulded cages having cage pockets surrounding the rollers, e.g. machined window cages formed as one-piece cages, i.e. monoblock cages made from metal, e.g. cast or machined window cages
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/46—Cages for rollers or needles
    • F16C33/467—Details of individual pockets, e.g. shape or roller retaining means
    • F16C33/4676—Details of individual pockets, e.g. shape or roller retaining means of the stays separating adjacent cage pockets, e.g. guide means for the bearing-surface of the rollers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/46—Cages for rollers or needles
    • F16C33/54—Cages for rollers or needles made from wire, strips, or sheet metal
    • F16C33/541—Details of individual pockets, e.g. shape or roller retaining means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/46—Cages for rollers or needles
    • F16C33/54—Cages for rollers or needles made from wire, strips, or sheet metal
    • F16C33/542—Cages for rollers or needles made from wire, strips, or sheet metal made from sheet metal
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/46—Cages for rollers or needles
    • F16C33/54—Cages for rollers or needles made from wire, strips, or sheet metal
    • F16C33/542—Cages for rollers or needles made from wire, strips, or sheet metal made from sheet metal
    • F16C33/543—Cages for rollers or needles made from wire, strips, or sheet metal made from sheet metal from a single part
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/20—Deep-drawing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D28/00—Shaping by press-cutting; Perforating
    • B21D28/02—Punching blanks or articles with or without obtaining scrap; Notching
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D28/00—Shaping by press-cutting; Perforating
    • B21D28/24—Perforating, i.e. punching holes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2220/00—Shaping
    • F16C2220/40—Shaping by deformation without removing material
    • F16C2220/42—Shaping by deformation without removing material by working of thin walled material such as sheet or tube
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2240/00—Specified values or numerical ranges of parameters; Relations between them
    • F16C2240/40—Linear dimensions, e.g. length, radius, thickness, gap
    • F16C2240/60—Thickness, e.g. thickness of coatings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2322/00—Apparatus used in shaping articles
    • F16C2322/39—General build up of machine tools, e.g. spindles, slides, actuators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2361/00—Apparatus or articles in engineering in general
    • F16C2361/61—Toothed gear systems, e.g. support of pinion shafts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C3/00—Shafts; Axles; Cranks; Eccentrics
    • F16C3/04—Crankshafts, eccentric-shafts; Cranks, eccentrics
    • F16C3/06—Crankshafts
    • F16C3/08—Crankshafts made in one piece

Abstract

To enhance the durability of a cage for a needle roller bearing composed of a press molding with respect to a thrust load.SOLUTION: A cage 20 for a needle roller bearing is composed of a metal-plate press molding integrally having a cylinder part 21 having a plurality of column parts 21a and a plurality of pockets 21b, one flange part 23 extending from one end part of the cylinder part 21 in an axial direction to an inside diameter side via a bent part 22, and the other flange part 25 extending from the other end part of the cylinder part 21 in the axial direction to the inside diameter side via a bent part 24. A dimension L1 of the bent part 22 arranged between the cylinder part 21 and one flange part 23 in a radial direction of an outside curved face 22a, and a wall thickness T1 of one end part of the cylinder part 21 in an axial direction satisfy a relation of L1/T1≤1.4.SELECTED DRAWING: Figure 3

Description

本発明は、針状ころ軸受用保持器に関し、特に、プレス加工で形成された針状ころ軸受用保持器に関する。 The present invention relates to a cage for needle roller bearings, and more particularly to a cage for needle roller bearings formed by press working.

例えば特許文献１には、産業用ロボットや工作機械等に組み込まれる偏心揺動型歯車減速機が示されている。この減速機は、筒状のケーシングと、ケーシングに設けられた内歯車と、内歯車と噛み合う遊星ギアと、遊星ギアを遊星運動させるクランク軸とを備え、入力軸の回転が入力されてクランク軸が回転すると、クランク軸の偏心部に取り付けられた遊星ギアが内歯車と噛み合いながら遊星運動し、この遊星運動の公転成分が出力軸の回転として出力される。この減速機では、クランク軸のジャーナル部と出力軸との間、および、クランク軸の偏心部と遊星ギアとの間に、それぞれ針状ころ軸受が組み込まれている。 For example, Patent Document 1 discloses an eccentric swing type gear reducer incorporated in an industrial robot, a machine tool, or the like. This reducer includes a tubular casing, an internal gear provided in the casing, a planetary gear that meshes with the internal gear, and a crank shaft that causes the planetary gear to move planetarily. The rotation of the input shaft is input to the crank shaft. When is rotated, the planetary gear attached to the eccentric portion of the crank shaft makes a planetary motion while meshing with the internal gear, and the revolution component of this planetary motion is output as the rotation of the output shaft. In this reducer, needle roller bearings are incorporated between the journal portion of the crankshaft and the output shaft, and between the eccentric portion of the crankshaft and the planetary gear, respectively.

針状ころ軸受の保持器は、切削加工で形成されることが多いが、製造コストを低減するために、プレス加工で形成されることもある（例えば、下記の特許文献２参照）。 The cage of the needle roller bearing is often formed by cutting, but may also be formed by pressing in order to reduce the manufacturing cost (see, for example, Patent Document 2 below).

特開２０１９−３２０８７号公報JP-A-2019-32087 特開２０１２−５７７５１号公報Japanese Unexamined Patent Publication No. 2012-75751 特開２０１１−１２６９９号公報Japanese Unexamined Patent Publication No. 2011-12399

ところで、産業用ロボットでは、ロボット自体の大型化や可搬重量の増大に伴い、ロボットに組み込まれる減速機の軸受に加わるラジアル荷重が増大し、ラジアル荷重の増大に伴ってスラスト荷重（誘起スラスト荷重）も増大している。特に、上記特許文献１のように、減速機のクランク軸を針状ころ軸受のみで支持する場合は、これらの針状ころ軸受にスラスト荷重が加わりやすい。針状ころ軸受が軸方向に移動して保持器が他部材（他の針状ころ軸受の保持器や、針状ころ軸受の軸方向移動を規制する止め輪等）に当接すると、保持器に応力が加わるため、保持器に強度対策を行うことで信頼性を高めることができる。 By the way, in an industrial robot, the radial load applied to the bearing of the speed reducer incorporated in the robot increases as the robot itself becomes larger and the payload increases, and the thrust load (induced thrust load) increases as the radial load increases. ) Is also increasing. In particular, when the crankshaft of the speed reducer is supported only by needle roller bearings as in Patent Document 1, thrust load is likely to be applied to these needle roller bearings. When the needle roller bearing moves in the axial direction and the cage abuts on another member (such as the cage of another needle roller bearing or the retaining ring that regulates the axial movement of the needle roller bearing), the cage Since stress is applied to the bearing, reliability can be improved by taking measures against the strength of the cage.

例えば、保持器を切削加工で形成する場合は、形状の変更が比較的容易であるため、強度を必要とする部位を局部的に厚肉化する等の対策が可能である。しかし、保持器をプレス加工で形成する場合は、部分的に厚肉化することは容易ではないため、他の対策が必要となる。 For example, when the cage is formed by cutting, it is relatively easy to change the shape, so that it is possible to take measures such as locally thickening the portion requiring strength. However, when the cage is formed by press working, it is not easy to partially thicken the cage, so other measures are required.

例えば、上記の特許文献３には、保持器とこれに軸方向で当接する座金との接触面積を増大させることで、保持器の変形や破損を防止している。しかし、このような対策は、座金を設けない場合や、座金の形状を変更することができない場合には適用することができない。 For example, in Patent Document 3 described above, the cage is prevented from being deformed or damaged by increasing the contact area between the cage and the washer that abuts on the cage in the axial direction. However, such measures cannot be applied when the washer is not provided or when the shape of the washer cannot be changed.

そこで、本発明は、プレス成形品からなる針状ころ軸受用保持器のスラスト荷重に対する耐久性を高めることを目的とする。 Therefore, an object of the present invention is to improve the durability of a cage for needle roller bearings made of a press-molded product against a thrust load.

例えば、図８に示す針状ころ軸受用保持器１２０は、針状ころ１１０を保持するポケット１２１ｂが形成された円筒部１２１と、円筒部１２１の軸方向両端から屈曲部１２２、１２４を介して内径側に延びる一対のフランジ部１２３、１２５とを一体に有するプレス成形品からなる。図９に拡大して示すように、保持器１２０に軸方向一方側（図中右側）から他部材Ｍが当接すると、一方のフランジ部１２３の内径端は軸方向内側に変位するが、外径端は円筒部１２１で支持されているためほとんど変位しない。その結果、フランジ部１２３の外側端面１２３ａの外径端Ｐ（すなわち、屈曲部１２２の外側曲面１２２ａの内径端）が、スラスト荷重Ｆを支持する点となる。 For example, the cage 120 for needle roller bearings shown in FIG. 8 has a cylindrical portion 121 in which a pocket 121b for holding the needle roller 110 is formed, and the cylindrical portions 121 from both ends in the axial direction via bent portions 122 and 124. It is made of a press-molded product having a pair of flange portions 123 and 125 extending on the inner diameter side integrally. As shown enlarged in FIG. 9, when the other member M comes into contact with the cage 120 from one side in the axial direction (right side in the drawing), the inner diameter end of one flange portion 123 is displaced inward in the axial direction, but outside. Since the radial end is supported by the cylindrical portion 121, it hardly displaces. As a result, the outer diameter end P of the outer end surface 123a of the flange portion 123 (that is, the inner diameter end of the outer curved surface 122a of the bent portion 122) becomes a point that supports the thrust load F.

ところで、フランジ部１２３と円筒部１２１との間の屈曲部１２２を曲げ加工により形成する場合、屈曲部１２２が略均一な肉厚で曲げられる。このため、屈曲部１２２の外側曲面１２２ａの半径方向寸法Ｌ１が、円筒部１２１の肉厚Ｔ１と屈曲部１２２の内側曲面１２２ｂの半径方向寸法Ｌ２との合計と略等しくなる（Ｌ１≒Ｔ１＋Ｌ２）。この場合、屈曲部１２２の内側曲面１２２ｂの半径方向寸法Ｌ２を小さくすれば、屈曲部１２２の外側曲面１２２ａの半径方向寸法Ｌ１を小さくすることができるが、屈曲部１２２の内側曲面１２２ｂの半径方向寸法Ｌ２は、製造上の都合からむやみに小さくすることはできない。このため、従来のプレス成形品からなる保持器では、屈曲部１２２の外側曲面１２２ａの半径方向寸法Ｌ１は、円筒部１２１の肉厚Ｔ１の１．５倍程度とされていた。 By the way, when the bent portion 122 between the flange portion 123 and the cylindrical portion 121 is formed by bending, the bent portion 122 is bent with a substantially uniform wall thickness. Therefore, the radial dimension L1 of the outer curved surface 122a of the bent portion 122 becomes substantially equal to the sum of the wall thickness T1 of the cylindrical portion 121 and the radial dimension L2 of the inner curved surface 122b of the bent portion 122 (L1≈T1 + L2). In this case, if the radial dimension L2 of the inner curved surface 122b of the bent portion 122 is reduced, the radial dimension L1 of the outer curved surface 122a of the bent portion 122 can be reduced, but the radial direction of the inner curved surface 122b of the bent portion 122. The dimension L2 cannot be unnecessarily reduced due to manufacturing reasons. For this reason, in the conventional cage made of a press-molded product, the radial dimension L1 of the outer curved surface 122a of the bent portion 122 is about 1.5 times the wall thickness T1 of the cylindrical portion 121.

本発明は、上記のように屈曲部の外側曲面の内径端がスラスト荷重Ｆを支持する点となる点に着目してなされたものであり、屈曲部の外側曲面の半径方向寸法を従来よりも小さくすることにより、スラスト荷重を支持する点を従来よりも外径側に配したことを特徴とするものである。具体的には、屈曲部の外側曲面の半径方向寸法Ｌ１を、円筒部の端部の肉厚Ｔ１の１．４倍以下とした。これにより、フランジ部に加わるモーメント荷重が小さくなり、屈曲部に加わる応力が軽減されるため、保持器の耐久性を向上させることができる。 The present invention has been made by paying attention to the point that the inner diameter end of the outer curved surface of the bent portion is a point supporting the thrust load F as described above, and the radial dimension of the outer curved surface of the bent portion is made larger than before. By making it smaller, the point for supporting the thrust load is arranged on the outer diameter side as compared with the conventional one. Specifically, the radial dimension L1 of the outer curved surface of the bent portion is set to 1.4 times or less of the wall thickness T1 of the end portion of the cylindrical portion. As a result, the moment load applied to the flange portion is reduced, and the stress applied to the bent portion is reduced, so that the durability of the cage can be improved.

以上より、本発明は、複数の柱部および隣接する柱部の周方向間に設けられた複数のポケットを有する円筒部と、前記円筒部の軸方向一方の端部から屈曲部を介して内径側に延びる一方のフランジ部と、前記円筒部の軸方向他方の端部から屈曲部を介して内径側に延びる他方のフランジ部とを一体に有する金属板のプレス成形品からなる針状ころ軸受用保持器であって、前記円筒部と前記一方のフランジ部との間に設けられた屈曲部の外側曲面の半径方向寸法Ｌ１と、前記円筒部の軸方向一方の端部の肉厚Ｔ１とが、Ｌ１／Ｔ１≦１．４を満たす針状ころ軸受用保持器を提供する。 From the above, the present invention has a cylindrical portion having a plurality of pockets provided between a plurality of pillar portions and adjacent pillar portions in the circumferential direction, and an inner diameter from one end of the cylindrical portion in the axial direction via a bent portion. Needle roller bearing made of a press-formed product of a metal plate integrally having one flange portion extending to the side and the other flange portion extending from the other end portion in the axial direction of the cylindrical portion to the inner diameter side via a bending portion. In the cage, the radial dimension L1 of the outer curved surface of the bent portion provided between the cylindrical portion and the one flange portion, and the wall thickness T1 of one end of the cylindrical portion in the axial direction. Provided a cage for needle roller bearings that satisfies L1 / T1 ≦ 1.4.

上記の発明は、ころ充填率が７０％以上の針状ころ軸受の保持器、具体的には、円筒部における前記ポケットの周方向の割合が７０％以上である保持器に主に適用できる。 The above invention is mainly applicable to a cage of a needle roller bearing having a roller filling rate of 70% or more, specifically, a cage in which the ratio of the pocket in the cylindrical portion in the circumferential direction is 70% or more.

上記の保持器は、例えば、屈曲部の外側曲面の半径方向寸法Ｌ１と、屈曲部の内側曲面の半径方向寸法Ｌ２と、円筒部の軸方向一方の端部の肉厚Ｔ１とが、Ｌ１＜Ｔ１＋Ｌ２を満たすように設計される。 In the above cage, for example, the radial dimension L1 of the outer curved surface of the bent portion, the radial dimension L2 of the inner curved surface of the bent portion, and the wall thickness T1 of one end in the axial direction of the cylindrical portion are L1 <. Designed to satisfy T1 + L2.

上記の保持器では、例えば、一方のフランジ部の軸方向外側の端面のうち、少なくとも外径端（屈曲部の外側曲面との境界）を含む領域に研削加工を施すことにより、Ｌ１／Ｔ１≦１．４を満たすことができる。あるいは、円筒部と一方のフランジ部との間の角度が８９．９°以下となるように屈曲させることにより、Ｌ１／Ｔ１≦１．４を満たすことができる。 In the above cage, for example, L1 / T1 ≦ by grinding a region including at least the outer diameter end (the boundary with the outer curved surface of the bent portion) of the axially outer end faces of one flange portion. 1.4 can be satisfied. Alternatively, L1 / T1 ≦ 1.4 can be satisfied by bending the cylinder portion and one flange portion so that the angle is 89.9 ° or less.

上記の保持器では、屈曲部の外側曲面の半径方向寸法Ｌ１と、円筒部の軸方向一方の端部の肉厚Ｔ１とが、０．５≦Ｌ１／Ｔ１≦１．３を満たすことがより好ましい。 In the above cage, the radial dimension L1 of the outer curved surface of the bent portion and the wall thickness T1 of one end of the cylindrical portion in the axial direction satisfy 0.5 ≦ L1 / T1 ≦ 1.3. preferable.

上記の保持器は、金属板に絞り加工を施して円筒成形部およびその軸方向他方の端部を閉塞する底部を一体に有する成形品を形成する工程と、前記底部の軸心を打ち抜いて前記他方のフランジ部を形成する工程と、前記円筒成形部に曲げ加工を施して前記一方のフランジ部を形成する工程と、前記円筒成形部の周方向複数箇所を打ち抜いて前記複数のポケットを形成する工程とを経て製造することができる。 The above-mentioned cage includes a step of forming a molded product having a cylindrical molded portion and a bottom portion that integrally closes the other end in the axial direction thereof by drawing a metal plate, and punching out the axial center of the bottom portion. A step of forming the other flange portion, a step of bending the cylindrical molded portion to form the one flange portion, and a step of punching a plurality of points in the circumferential direction of the cylindrical molded portion to form the plurality of pockets. It can be manufactured through a process.

上記の製造方法において、円筒成形部の軸方向一方の端部を含む領域に、他の領域よりも肉厚が薄い薄肉領域を設け、この薄肉領域に曲げ加工を施せば、曲げ加工が容易になる。こうして形成された保持器は、円筒部の軸方向一方の端部の肉厚が、円筒部の軸方向中央部の肉厚よりも薄くなっているため、本発明を適用して耐久性を高めることが特に好ましい。 In the above manufacturing method, if a thin-walled region having a wall thickness thinner than that of the other region is provided in a region including one end in the axial direction of the cylindrical molded portion and the thin-walled region is bent, the bending can be easily performed. Become. Since the wall thickness of one end of the cylindrical portion in the axial direction of the cage thus formed is thinner than the wall thickness of the axial center portion of the cylindrical portion, the present invention is applied to improve the durability. Is particularly preferred.

以上のように、本発明によれば、プレス成形品からなる針状ころ軸受用保持器のスラスト荷重に対する耐久性を高めることができる。 As described above, according to the present invention, it is possible to improve the durability of a cage for needle roller bearings made of a press-molded product against a thrust load.

減速機に設けられるクランク軸及びこれを支持する針状ころ軸受の断面図である。It is sectional drawing of the crankshaft provided in a reduction gear and the needle roller bearing which supports this. 上記針状ころ軸受の保持器の断面図である。It is sectional drawing of the cage of the needle roller bearing. 上記保持器の一方のフランジ部付近の拡大図である。It is an enlarged view near one flange part of the said cage. 上記保持器の他方のフランジ部付近の拡大図である。It is an enlarged view of the vicinity of the other flange portion of the cage. 保持器の製造工程を示す断面図である。It is sectional drawing which shows the manufacturing process of a cage. 他の実施形態に係る保持器の拡大断面図である。It is an enlarged sectional view of the cage which concerns on another embodiment. 本発明の効果を確認する試験の結果を示すグラフである。It is a graph which shows the result of the test which confirms the effect of this invention. 従来の針状ころ軸受の保持器の断面図である。It is sectional drawing of the cage of the conventional needle roller bearing. 図７の保持器の拡大図である。It is an enlarged view of the cage of FIG.

以下、本発明の実施の形態を図面に基づいて説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

図１は、産業用ロボットの関節部に設けられた偏心揺動型歯車減速機のクランク軸１を示す。クランク軸１は、軸方向に離間した２箇所に設けられた一対のジャーナル部１ａと、一対のジャーナル部１ａの間に設けられた一対の偏心部１ｂと、軸方向一端に設けられたスパーギア取付部１ｃとを有する。一対のジャーナル部１ａの外周面は、回転中心Ｏを中心とした円筒面状に形成される。一対の偏心部１ｂの外周面は、回転中心Ｏからオフセットした軸心を中心とした円筒面状に形成される。各偏心部１ｂの外周面の軸心は、回転中心Ｏに対して異なる位相に配され、例えば１８０°異なる位相に配される。 FIG. 1 shows a crankshaft 1 of an eccentric swing type gear reducer provided at a joint portion of an industrial robot. The crankshaft 1 has a pair of journal portions 1a provided at two positions separated in the axial direction, a pair of eccentric portions 1b provided between the pair of journal portions 1a, and a spur gear attachment provided at one end in the axial direction. It has a part 1c. The outer peripheral surfaces of the pair of journal portions 1a are formed in a cylindrical surface shape centered on the rotation center O. The outer peripheral surfaces of the pair of eccentric portions 1b are formed in a cylindrical surface shape centered on an axis offset from the rotation center O. The axial centers of the outer peripheral surfaces of the eccentric portions 1b are arranged in different phases with respect to the rotation center O, for example, 180 ° different phases.

クランク軸１の各ジャーナル部１ａの外周面は、針状ころ軸受２を介して、キャリア３に取り付けられる。また、クランク軸１の各偏心部１ｂの外周面は、針状ころ軸受２を介して、遊星ギア４の内周面に取り付けられる。クランク軸１は、これらの４つの針状ころ軸受２のみで回転自在に支持されている。クランク軸１のスパーギア取付部１ｃの外周面には、スパーギア５が固定される。尚、偏心揺動型歯車減速機の全体構成は、公知のもの（例えば特許文献１に示されたもの）と同様であるため、詳細な説明は省略する。 The outer peripheral surface of each journal portion 1a of the crankshaft 1 is attached to the carrier 3 via the needle roller bearing 2. Further, the outer peripheral surface of each eccentric portion 1b of the crankshaft 1 is attached to the inner peripheral surface of the planetary gear 4 via the needle roller bearing 2. The crankshaft 1 is rotatably supported only by these four needle roller bearings 2. The spur gear 5 is fixed to the outer peripheral surface of the spur gear mounting portion 1c of the crankshaft 1. Since the overall configuration of the eccentric swing type gear reducer is the same as that of a known one (for example, the one shown in Patent Document 1), detailed description thereof will be omitted.

針状ころ軸受２は、複数の針状ころ１０と、これらを保持する保持器２０とを有する。本実施形態では、針状ころ軸受２の内側軌道面がクランク軸１の外周面に直接形成され、針状ころ軸受２の外側軌道面がキャリア３および遊星ギア４の内周面に直接形成されている。針状ころ軸受２のころ充填率は、例えば７０％以上、好ましくは８０％以上とされる。また、針状ころ軸受２のころ充填率は、保持器２０の強度等に応じて上限が設定され、例えば９０％以下とされる。尚、ころ充填率γは次式で表される。
ころ充填率γ＝（Ｚ・ＤＡ）／（π・ＰＣＤ）
ただし、Ｚ：ころ本数、ＤＡ：ころ直径、ＰＣＤ：ころピッチ円直径 The needle roller bearing 2 has a plurality of needle rollers 10 and a cage 20 for holding them. In the present embodiment, the inner raceway surface of the needle roller bearing 2 is directly formed on the outer peripheral surface of the crankshaft 1, and the outer raceway surface of the needle roller bearing 2 is directly formed on the inner peripheral surface of the carrier 3 and the planetary gear 4. ing. The roller filling rate of the needle roller bearing 2 is, for example, 70% or more, preferably 80% or more. Further, the roller filling rate of the needle roller bearing 2 is set to an upper limit according to the strength of the cage 20 and the like, and is set to 90% or less, for example. The roller filling factor γ is expressed by the following equation.
Roller filling rate γ = (Z ・ DA) / (π ・ PCD)
However, Z: number of rollers, DA: roller diameter, PCD: roller pitch circle diameter

保持器２０は、金属板のプレス成形品からなり、図２に示すように、円筒部２１と、円筒部２１の軸方向一方の端部（図中右端）から屈曲部２２を介して内径側に延びる一方のフランジ部２３と、円筒部２１の軸方向他方の端部（図中左端）から屈曲部２４を介して内径側に延びる他方のフランジ部２５とを一体に有する。保持器２０は、円筒部２１の外周面が軌道面（キャリア３の内周面又は遊星ギア４の内周面）と接触することで案内される、いわゆる外輪案内タイプである。 The cage 20 is made of a press-molded product of a metal plate, and as shown in FIG. 2, the cylindrical portion 21 and the inner diameter side of the cylindrical portion 21 from one end (right end in the drawing) in the axial direction via the bent portion 22. It integrally has one flange portion 23 extending to the inner diameter side and the other flange portion 25 extending from the other end portion (left end in the drawing) of the cylindrical portion 21 in the axial direction to the inner diameter side via the bending portion 24. The cage 20 is a so-called outer ring guide type in which the outer peripheral surface of the cylindrical portion 21 is guided by contacting with the orbital surface (inner peripheral surface of the carrier 3 or inner peripheral surface of the planetary gear 4).

円筒部２１は、周方向等間隔に配された多数の柱部２１ａと、隣接する柱部２１ａの間に設けられた多数のポケット２１ｂとを有する。本実施形態では、円筒部２１におけるポケット２１ｂの周方向の割合が７０％以上とされる。円筒部２１の軸方向一方の端部の肉厚Ｔ１は、円筒部２１の軸方向中央部の肉厚Ｔ２よりも薄い。図示例では、図３に拡大して示すように、柱部２１ａが、肉厚Ｔ２で形成された本体部２１ａ１と、本体部２１ａ１の軸方向一方側に隣接して設けられ、肉厚がＴ２からＴ１まで徐々に小さくなる徐変部２１ａ２とを有する。徐変部２１ａ２の外周面は、本体部２１ａ１の外周面と同一円筒面上に設けられ、徐変部２１ａ２の内周面は、軸方向一方側へ向けて徐々に拡径したテーパ状を成している。円筒部２１の軸方向他方の端部は、軸方向中央部と同じ肉厚Ｔ２を有する。尚、図示例では、柱部２１ａが軸方向に沿った直線状を成しているが、これに限らず、例えば柱部２１ａの軸方向中央部を内径側に配した断面略Ｍ字形状としてもよい。 The cylindrical portion 21 has a large number of pillar portions 21a arranged at equal intervals in the circumferential direction and a large number of pockets 21b provided between the adjacent pillar portions 21a. In the present embodiment, the ratio of the pocket 21b in the cylindrical portion 21 in the circumferential direction is 70% or more. The wall thickness T1 at one end of the cylindrical portion 21 in the axial direction is thinner than the wall thickness T2 at the central portion in the axial direction of the cylindrical portion 21. In the illustrated example, as shown in an enlarged manner in FIG. 3, the pillar portion 21a is provided adjacent to the main body portion 21a1 formed by the wall thickness T2 and the main body portion 21a1 on one side in the axial direction, and the wall thickness is T2. It has a gradual change portion 21a2 that gradually decreases from to T1. The outer peripheral surface of the gradual change portion 21a2 is provided on the same cylindrical surface as the outer peripheral surface of the main body portion 21a1, and the inner peripheral surface of the gradual change portion 21a2 forms a tapered shape whose diameter gradually increases toward one side in the axial direction. doing. The other end of the cylindrical portion 21 in the axial direction has the same wall thickness T2 as the central portion in the axial direction. In the illustrated example, the pillar portion 21a has a linear shape along the axial direction, but the present invention is not limited to this, and for example, the pillar portion 21a has a substantially M-shaped cross section in which the central portion in the axial direction is arranged on the inner diameter side. May be good.

円筒部２１と一方のフランジ部２３との間に設けられた屈曲部２２は、円筒部２１の軸方向一方の端部の外周面と一方のフランジ部２３の外側端面２３ａとを連続する外側曲面２２ａと、円筒部２１の軸方向一方の端部の内周面と一方のフランジ部２３の内側端面２３ｂとを連続する内側曲面２２ｂとを有する。屈曲部２２の外側曲面２２ａの半径方向寸法Ｌ１は、円筒部２１の軸方向一方の端部の肉厚Ｔ１の１．４倍以下（Ｌ１／Ｔ１≦１．４）、好ましくは１．３倍以下（Ｌ１／Ｔ１≦１．３）、より好ましくは１．２倍以下（Ｌ１／Ｔ１≦１．２）、さらに好ましくは１倍以下（Ｌ１／Ｔ１≦１）とされる。図示例では、屈曲部２２の外側曲面２２ａの半径方向寸法Ｌ１が、円筒部２１の軸方向一方の端部の肉厚Ｔ１と内側曲面２４ｂの半径方向寸法Ｌ２との和よりも小さい（Ｌ１＜Ｔ１＋Ｌ２）。また、図示例では、屈曲部２２の外側曲面２２ａの半径方向寸法Ｌ１が、柱部２１ａの本体部２１ａ１の肉厚Ｔ２よりも小さい（Ｌ１＜Ｔ２）。屈曲部２２の外側曲面２２ａの半径方向寸法Ｌ１の下限値は、強度や製造上の都合の観点から設定され、例えば上記肉厚Ｔ１の０．５倍以上（Ｌ１／Ｔ１≧０．５）とされる。 The bent portion 22 provided between the cylindrical portion 21 and one flange portion 23 is an outer curved surface in which the outer peripheral surface of one end portion in the axial direction of the cylindrical portion 21 and the outer end surface 23a of the one flange portion 23 are continuous. It has 22a and an inner curved surface 22b that is continuous with the inner peripheral surface of one end of the cylindrical portion 21 in the axial direction and the inner end surface 23b of one flange portion 23. The radial dimension L1 of the outer curved surface 22a of the bent portion 22 is 1.4 times or less (L1 / T1 ≦ 1.4), preferably 1.3 times the wall thickness T1 of one end in the axial direction of the cylindrical portion 21. Below (L1 / T1 ≦ 1.3), more preferably 1.2 times or less (L1 / T1 ≦ 1.2), still more preferably 1 time or less (L1 / T1 ≦ 1). In the illustrated example, the radial dimension L1 of the outer curved surface 22a of the bent portion 22 is smaller than the sum of the wall thickness T1 at one end of the cylindrical portion 21 in the axial direction and the radial dimension L2 of the inner curved surface 24b (L1 < T1 + L2). Further, in the illustrated example, the radial dimension L1 of the outer curved surface 22a of the bent portion 22 is smaller than the wall thickness T2 of the main body portion 21a1 of the pillar portion 21a (L1 <T2). The lower limit of the radial dimension L1 of the outer curved surface 22a of the bent portion 22 is set from the viewpoint of strength and manufacturing convenience, and is, for example, 0.5 times or more (L1 / T1 ≧ 0.5) of the wall thickness T1. Will be done.

一方のフランジ部２３の外側端面２３ａのうち、少なくとも外径端を含む領域には研削面が設けられ、本実施形態では、一方のフランジ部２３の外側端面２３ａの全域に研削面が設けられる。こうして研削を施した分だけ、一方のフランジ部２３の肉厚Ｔ３は、円筒部２１の軸方向一方の端部の肉厚Ｔ１よりも小さくなっている。 A ground surface is provided in a region including at least the outer diameter end of the outer end surface 23a of the one flange portion 23, and in the present embodiment, the ground surface is provided over the entire outer end surface 23a of the one flange portion 23. The wall thickness T3 of one flange portion 23 is smaller than the wall thickness T1 of one end portion in the axial direction of the cylindrical portion 21 by the amount of grinding in this way.

円筒部２１と他方のフランジ部２５との間に設けられた屈曲部２４は、図４に拡大して示すように、円筒部２１の外周面と他方のフランジ部２５の外側端面２５ａとを連続する外側曲面２４ａと、円筒部２１の内周面と他方のフランジ部２５の内側端面２５ｂとを連続する内側曲面２４ｂとを有する。屈曲部２４の外側曲面２４ａの半径方向寸法Ｌ３は、円筒部２１の軸方向他方の端部の肉厚Ｔ２と内側曲面２４ｂの半径方向寸法Ｌ４との和とほぼ等しい（Ｌ３≒Ｔ２＋Ｌ４）。他方のフランジ部２５の外側端面２５ａには、研削面は設けられておらず、全域がプレス成形面となっている。他方のフランジ部２５の肉厚Ｔ４は、円筒部２１の軸方向他方の端部の肉厚Ｔ２よりも厚い。 The bent portion 24 provided between the cylindrical portion 21 and the other flange portion 25 is continuous with the outer peripheral surface of the cylindrical portion 21 and the outer end surface 25a of the other flange portion 25, as shown in an enlarged manner in FIG. It has an outer curved surface 24a to be formed, and an inner curved surface 24b in which the inner peripheral surface of the cylindrical portion 21 and the inner end surface 25b of the other flange portion 25 are continuous. The radial dimension L3 of the outer curved surface 24a of the bent portion 24 is substantially equal to the sum of the wall thickness T2 of the other end in the axial direction of the cylindrical portion 21 and the radial dimension L4 of the inner curved surface 24b (L3≈T2 + L4). The outer end surface 25a of the other flange portion 25 is not provided with a ground surface, and the entire area is a press-formed surface. The wall thickness T4 of the other flange portion 25 is thicker than the wall thickness T2 of the other end portion in the axial direction of the cylindrical portion 21.

一方のフランジ部２３と円筒部２１との間の屈曲部２２は曲げ加工で形成され、他方のフランジ部２５と円筒部２１との間の屈曲部２４は、絞り加工で形成される（詳細は後述する）。尚、図示例では、フランジ部２３、２５と円筒部２１との間の角度が略９０°に設定されているが、これらの一方又は双方の角度を９０°よりもわずかに小さい値に設定してもよい。 The bent portion 22 between one flange portion 23 and the cylindrical portion 21 is formed by bending, and the bent portion 24 between the other flange portion 25 and the cylindrical portion 21 is formed by drawing. Will be described later). In the illustrated example, the angle between the flange portions 23 and 25 and the cylindrical portion 21 is set to approximately 90 °, but the angle of one or both of these is set to a value slightly smaller than 90 °. You may.

上記の保持器２０に軸方向一方側から他部材が当接すると、図３に示すように、一方のフランジ部２３の外側端面２３ａの外径端Ｐ１（すなわち、フランジ部２３の外側端面２３ａと屈曲部２２の外側曲面２２ａの内径端）にスラスト荷重Ｆ１が加わる。本実施形態では、屈曲部２２の外側曲面２２ａの半径方向寸法Ｌ１が小さくなっている（具体的には、Ｌ１／Ｔ１≦１．４を満たす）ため、スラスト荷重Ｆ１が加わる点Ｐ１が外径側に設けられる。これにより、フランジ部２３に加わるモーメント荷重が軽減されるため、フランジ部２３が傾斜することにより屈曲部２２や円筒部２１の軸方向一方の端部に加わる応力が軽減される。特に、本実施形態では、円筒部２１の軸方向一方の端部の肉厚Ｔ１が薄くなっているため、この部分に加わる荷重が軽減されることで、保持器２０のスラスト荷重に対する耐久性が高められる。 When the other member comes into contact with the cage 20 from one side in the axial direction, as shown in FIG. 3, the outer diameter end P1 of the outer end surface 23a of the one flange portion 23 (that is, the outer end surface 23a of the flange portion 23) A thrust load F1 is applied to the inner diameter end of the outer curved surface 22a of the bent portion 22). In the present embodiment, since the radial dimension L1 of the outer curved surface 22a of the bent portion 22 is small (specifically, L1 / T1 ≦ 1.4 is satisfied), the point P1 to which the thrust load F1 is applied is the outer diameter. It is provided on the side. As a result, the moment load applied to the flange portion 23 is reduced, so that the stress applied to one end of the bent portion 22 and the cylindrical portion 21 in the axial direction due to the inclination of the flange portion 23 is reduced. In particular, in the present embodiment, since the wall thickness T1 of one end of the cylindrical portion 21 in the axial direction is thin, the load applied to this portion is reduced, so that the durability of the cage 20 against the thrust load is improved. Can be enhanced.

一方、上記の保持器２０に軸方向他方側から他部材が当接すると、図４に示すように、他方のフランジ部２５のフランジ部２５の外側端面２５ａの外径端Ｐ２（すなわち、フランジ部２５の外側端面２５ａと屈曲部２４の外側曲面２４ａの内径端）にスラスト荷重Ｆ２が加わる。屈曲部２４の外側曲面２４ａの半径方向寸法Ｌ３は、屈曲部２２の外側曲面２２ａの半径方向寸法Ｌ１よりも大きいため、スラスト荷重Ｆ２が加わる点Ｐ２は、図３に示す点Ｐ１よりも内径側に設けられる。このため、フランジ部２５に加わるモーメント荷重は比較的大きくなるが、円筒部２１の軸方向他方の端部の肉厚Ｔ２やこれに連続する屈曲部２４の肉厚が厚くなっているため、耐久性に問題はない。もちろん、屈曲部２４の外側曲面２４ａの半径方向寸法Ｌ３を、屈曲部２２と同様に小さくしてもよく、この場合、保持器２０の耐久性がさらに高められる。 On the other hand, when another member comes into contact with the cage 20 from the other side in the axial direction, as shown in FIG. 4, the outer diameter end P2 (that is, the flange portion) of the outer end surface 25a of the flange portion 25 of the other flange portion 25 A thrust load F2 is applied to the outer end surface 25a of the 25 and the inner diameter end of the outer curved surface 24a of the bent portion 24). Since the radial dimension L3 of the outer curved surface 24a of the bent portion 24 is larger than the radial dimension L1 of the outer curved surface 22a of the bent portion 22, the point P2 to which the thrust load F2 is applied is on the inner diameter side of the point P1 shown in FIG. It is provided in. For this reason, the moment load applied to the flange portion 25 is relatively large, but the wall thickness T2 at the other end of the cylindrical portion 21 in the axial direction and the wall thickness of the bent portion 24 continuous thereto are thick, so that the durability is high. There is no problem with sex. Of course, the radial dimension L3 of the outer curved surface 24a of the bent portion 24 may be made smaller as in the bent portion 22, and in this case, the durability of the cage 20 is further enhanced.

次に、上記の保持器２０のプレス加工による製造方法を、図５を用いて説明する。 Next, the manufacturing method of the cage 20 by press working will be described with reference to FIG.

まず、平板状の金属板（例えば鋼板）を所定形状に打ち抜いてブランク材Ｗ０を形成する（図５（Ａ）参照）。そして、このブランク材Ｗ０に絞り加工を施して、円筒成形部Ｗ１およびその軸方向一方の端部（図中上端）を閉塞する底部Ｗ２を一体に有するコップ状の成形品Ｗを形成する（図５（Ｂ）参照）。この絞り加工は、複数回に分けて行ってもよい。上記の絞り加工により円筒成形部Ｗ１が引き延ばされるため、円筒成形部Ｗ１の肉厚は底部Ｗ２の肉厚よりも薄くなる。また、上記の絞り加工により、円筒成形部Ｗ１の開口側端部を含む領域には、他の領域よりも肉厚が薄い薄肉部Ｗ１１が形成される。薄肉部Ｗ１１は、例えば金型（ポンチ）の形状を転写して成形される。 First, a flat metal plate (for example, a steel plate) is punched into a predetermined shape to form a blank material W0 (see FIG. 5 (A)). Then, the blank material W0 is drawn to form a cup-shaped molded product W having a cylindrical molded portion W1 and a bottom portion W2 integrally closing one end (upper end in the drawing) in the axial direction thereof (FIG. 5 (B)). This drawing process may be performed in a plurality of times. Since the cylindrical molded portion W1 is stretched by the above drawing process, the wall thickness of the cylindrical molded portion W1 is thinner than the wall thickness of the bottom portion W2. Further, by the above drawing process, a thin portion W11 having a wall thickness thinner than that of other regions is formed in the region including the opening side end portion of the cylindrical molded portion W1. The thin-walled portion W11 is formed by transferring, for example, the shape of a mold (punch).

次に、成形品Ｗの底部Ｗ２の軸心を打ち抜いて、開口部Ｗ２０を形成する（図５（Ｃ）参照）。こうして開口部Ｗ２０が形成された底部Ｗ２が、保持器２０の他方のフランジ部２５となる。 Next, the axial center of the bottom portion W2 of the molded product W is punched out to form the opening W20 (see FIG. 5C). The bottom portion W2 in which the opening portion W20 is formed becomes the other flange portion 25 of the cage 20.

次に、成形品Ｗの円筒成形部Ｗ１の軸方向他方の端部を、曲げ型で複数回に分けてプレスして内径側に屈曲させる（図５（Ｄ）参照）。このとき、円筒成形部Ｗ１の薄肉部Ｗ１１を屈曲させることで、曲げ加工が容易化される。この曲げ加工により、円筒成形部Ｗ１から内径側に延びるフランジ部Ｗ３が形成される。 Next, the other end of the cylindrical molded portion W1 of the molded product W in the axial direction is pressed by a bending die in a plurality of times to bend it toward the inner diameter side (see FIG. 5D). At this time, the bending process is facilitated by bending the thin portion W11 of the cylindrical forming portion W1. By this bending process, a flange portion W3 extending from the cylindrical molded portion W1 to the inner diameter side is formed.

次に、フランジ部Ｗ３の軸心を打ち抜いて、所定径の開口部Ｗ３０を形成する（図５（Ｅ）参照）。こうして開口部Ｗ３０が形成されたフランジ部Ｗ３が、保持器２０の一方のフランジ部２３となる。その後、円筒成形部Ｗ１の周方向複数箇所を半径方向に打ち抜いて、複数の開口部Ｗ１０を形成する（図５（Ｆ）参照）。こうして形成された開口部Ｗ１０が保持器２０のポケット２１ｂとなり、この開口部Ｗ１０を有する円筒成形部Ｗ１が保持器２０の円筒部２１となる。 Next, the axial center of the flange portion W3 is punched out to form an opening W30 having a predetermined diameter (see FIG. 5 (E)). The flange portion W3 in which the opening W30 is formed becomes one flange portion 23 of the cage 20. After that, a plurality of circumferentially formed portions W1 are punched in the radial direction to form a plurality of openings W10 (see FIG. 5 (F)). The opening W10 thus formed becomes the pocket 21b of the cage 20, and the cylindrical molded portion W1 having the opening W10 becomes the cylindrical portion 21 of the cage 20.

こうしてプレス成形された保持器２０の一方のフランジ部２３の外側端面２３ａに研削加工を施す。具体的に、研削加工を施す前の一方のフランジ部２３の外側端面２３ａ’は、図３に点線で示す位置に設けられ、この外側端面２３ａ’と屈曲部２２の外側曲面２２ａとの境界はＰ１’で示す位置に設けられる。この外側端面２３ａ’のうち、少なくとも外径端を含む領域（本実施形態では全域）に研削加工を施すことにより、実線で示す外側端面２３ａが形成されると共に、外側端面２３ａと屈曲部２２の外側曲面２２ａとの境界Ｐ１が、研削前の境界Ｐ１’よりも外径側に移動する。これにより、屈曲部２２の外側曲面２２ａの半径方向寸法Ｌ１が小さくなって、Ｌ１／Ｔ１≦１．４が満たされる。 The outer end surface 23a of one flange portion 23 of the cage 20 press-molded in this way is ground. Specifically, the outer end surface 23a'of one of the flange portions 23 before being subjected to grinding is provided at the position shown by the dotted line in FIG. 3, and the boundary between the outer end surface 23a'and the outer curved surface 22a of the bent portion 22 is defined. It is provided at the position indicated by P1'. Of the outer end surface 23a', by grinding at least the region including the outer diameter end (the entire area in the present embodiment), the outer end surface 23a shown by the solid line is formed, and the outer end surface 23a and the bent portion 22 are formed. The boundary P1 with the outer curved surface 22a moves to the outer diameter side of the boundary P1'before grinding. As a result, the radial dimension L1 of the outer curved surface 22a of the bent portion 22 becomes smaller, and L1 / T1 ≦ 1.4 is satisfied.

本発明は、上記の実施形態に限られない。以下、本発明の他の実施形態を説明するが、上記の実施形態と同様の点については重複説明を省略する。 The present invention is not limited to the above embodiments. Hereinafter, other embodiments of the present invention will be described, but duplicate description will be omitted with respect to the same points as those of the above embodiments.

図６に示す実施形態では、屈曲部２２の曲率半径を小さくすることにより、屈曲部２２の外側曲面２２ａの半径方向寸法Ｌ１を小さくしている。図示例では、一方のフランジ部２３と円筒部２１との間の角度を積極的に小さくする（例えば、８９．９°以下とする）ことにより、屈曲部２２の曲率半径を小さくして外側曲面２２ａの半径方向寸法Ｌ１を小さくし、Ｌ１／Ｔ１≦１．４を満たすようにしている。尚、本実施形態では、外側曲面２２ａが、厳密には、軸方向外側の端部Ｐ１（頂点）よりも内径側の点Ｑまで延びているが、本発明では、外側曲面２２ａの半径方向寸法Ｌ１は、外側曲面２２ａの外径端と軸方向外側の端部Ｐ１との間の半径方向寸法のことを意味するものとする。 In the embodiment shown in FIG. 6, the radius of curvature of the bent portion 22 is reduced to reduce the radial dimension L1 of the outer curved surface 22a of the bent portion 22. In the illustrated example, the radius of curvature of the bent portion 22 is reduced by positively reducing the angle between one of the flange portions 23 and the cylindrical portion 21 (for example, 89.9 ° or less) to reduce the radius of curvature of the bent portion 22, and the outer curved surface. The radial dimension L1 of 22a is reduced to satisfy L1 / T1 ≦ 1.4. Strictly speaking, in the present embodiment, the outer curved surface 22a extends to the point Q on the inner diameter side of the axially outer end P1 (apical), but in the present invention, the radial dimension of the outer curved surface 22a. L1 is assumed to mean the radial dimension between the outer diameter end of the outer curved surface 22a and the axially outer end P1.

本発明に係る保持器及びこれを備えた針状ころ軸受は、産業用ロボットの減速機に限らず、工作機械等の他の機械の回転軸を支持する軸受として組み込むことができる。 The cage according to the present invention and the needle roller bearing provided with the cage can be incorporated as a bearing that supports the rotating shaft of another machine such as a machine tool, not limited to the speed reducer of an industrial robot.

ＦＥＭ解析により、図２に示す保持器２０の屈曲部２２の外側曲面２２ａの半径方向寸法Ｌ１と、円筒部２１の軸方向一方の端部の肉厚Ｔ１とを異ならせた複数の試験片に対し、軸方向一方側から他部材を当接させたときに、破損領域の応力が発生するか否かを確認した。その結果を下記の表１に示す。 By FEM analysis, a plurality of test pieces in which the radial dimension L1 of the outer curved surface 22a of the bent portion 22 of the cage 20 shown in FIG. 2 and the wall thickness T1 of one end in the axial direction of the cylindrical portion 21 are different are obtained. On the other hand, it was confirmed whether or not stress in the damaged region was generated when the other member was brought into contact with the other member from one side in the axial direction. The results are shown in Table 1 below.

表１に示されるように、Ｌ１／Ｔ１が１．４を超えている比較例１及び２には破損領域の応力が発生したのに対し、Ｌ１／Ｔ１が１．４以下である実施例１〜３には破損領域の応力は発生しなかった。 As shown in Table 1, in Comparative Examples 1 and 2 in which L1 / T1 exceeds 1.4, stress in the damaged region is generated, whereas in Example 1 in which L1 / T1 is 1.4 or less. No stress was generated in the damaged region in ~ 3.

次に、Ｌ１／Ｔ１が２．０である複数の従来品と、Ｌ１／Ｔ１が１．３３である複数の本発明品に対し、スラスト荷重を負荷しながら回転試験を行った。その結果、図７に示すように、従来品は何れも短時間で破断した（柱部の軸方向一方の端部が破断した）。これに対し、本発明品は、基準の８．１倍の時間を超えても保持器は破断しなかった（本明細書作成時点で試験継続中）。以上の結果から、Ｌ１／Ｔ１を１．４以下とする本発明により保持器の耐久性が向上することが確認された。 Next, a rotation test was conducted on a plurality of conventional products having L1 / T1 of 2.0 and a plurality of products of the present invention having L1 / T1 of 1.33 while applying a thrust load. As a result, as shown in FIG. 7, all the conventional products broke in a short time (one end of the column in the axial direction broke). On the other hand, in the product of the present invention, the cage did not break even if the time exceeded 8.1 times the standard (test is ongoing at the time of preparation of the present specification). From the above results, it was confirmed that the durability of the cage is improved by the present invention in which L1 / T1 is 1.4 or less.

１ クランク軸
２ 針状ころ軸受
２０ 保持器
２１ 円筒部
２２ 屈曲部
２３ 一方のフランジ部
２４ 屈曲部
２５ 他方のフランジ部
Ｗ 成形品
Ｗ１ 円筒成形部
Ｗ１１ 薄肉部
Ｗ２ 底部
Ｗ３ フランジ部
1 Crankshaft 2 Needle roller bearing 20 Cager 21 Cylindrical part 22 Bending part 23 One flange part 24 Bending part 25 The other flange part W Molded product W1 Cylindrical molded part W11 Thin wall part W2 Bottom part W3 Flange part

Claims (9)

複数の柱部および隣接する柱部の周方向間に設けられた複数のポケットを有する円筒部と、前記円筒部の軸方向一方の端部から屈曲部を介して内径側に延びる一方のフランジ部と、前記円筒部の軸方向他方の端部から屈曲部を介して内径側に延びる他方のフランジ部とを一体に有する金属板のプレス成形品からなる針状ころ軸受用保持器であって、
前記円筒部と前記一方のフランジ部との間に設けられた屈曲部の外側曲面の半径方向寸法Ｌ１と、前記円筒部の軸方向一方の端部の肉厚Ｔ１とが、Ｌ１／Ｔ１≦１．４を満たす針状ころ軸受用保持器。 A cylindrical portion having a plurality of pockets provided between a plurality of pillar portions and adjacent pillar portions in the circumferential direction, and a flange portion extending from one end of the cylindrical portion in the axial direction to the inner diameter side via a bent portion. A cage for needle roller bearings, which is a press-molded product of a metal plate integrally having a flange portion extending from the other end portion in the axial direction of the cylindrical portion to the inner diameter side via a bent portion.
The radial dimension L1 of the outer curved surface of the bent portion provided between the cylindrical portion and the one flange portion and the wall thickness T1 at one end in the axial direction of the cylindrical portion are L1 / T1 ≦ 1. .. A cage for needle roller bearings that satisfies 4. 前記円筒部における前記ポケットの周方向の割合が７０％以上である請求項１に記載の針状ころ軸受用保持器。 The cage for needle roller bearings according to claim 1, wherein the ratio of the pocket in the cylindrical portion in the circumferential direction is 70% or more. 前記屈曲部の外側曲面の半径方向寸法Ｌ１と、前記屈曲部の内側曲面の半径方向寸法Ｌ２と、前記円筒部の軸方向一方の端部の肉厚Ｔ１とが、Ｌ１＜Ｔ１＋Ｌ２を満たす請求項１又は２に記載の針状ころ軸受用保持器。 Claim that the radial dimension L1 of the outer curved surface of the bent portion, the radial dimension L2 of the inner curved surface of the bent portion, and the wall thickness T1 of one end of the cylindrical portion in the axial direction satisfy L1 <T1 + L2. The cage for needle roller bearings according to 1 or 2. 前記一方のフランジ部の軸方向外側の端面のうち、少なくとも外径端を含む領域に研削面が設けられた請求項１〜３の何れか１項に記載の針状ころ軸受用保持器。 The cage for needle roller bearings according to any one of claims 1 to 3, wherein the ground surface is provided in a region including at least the outer diameter end of the axially outer end surface of the one flange portion. 前記円筒部と前記一方のフランジ部との間の角度が８９．９°以下である請求項１〜３の何れか１項に記載の針状ころ軸受用保持器。 The cage for needle roller bearings according to any one of claims 1 to 3, wherein the angle between the cylindrical portion and one of the flange portions is 89.9 ° or less. 前記屈曲部の外側曲面の半径方向寸法Ｌ１と、前記円筒部の軸方向一方の端部の肉厚Ｔ１とが、０．５≦Ｌ１／Ｔ１≦１．３を満たす請求項１〜５の何れか１項に記載の針状ころ軸受用保持器。 Any of claims 1 to 5 in which the radial dimension L1 of the outer curved surface of the bent portion and the wall thickness T1 of one end of the cylindrical portion in the axial direction satisfy 0.5 ≦ L1 / T1 ≦ 1.3. The cage for needle roller bearings according to item 1. 前記円筒部の軸方向一方の端部の肉厚Ｔ１が、前記円筒部の軸方向中央部の肉厚Ｔ２よりも薄い請求項１〜６の何れか１項に記載の針状ころ軸受用保持器。 The holding for a needle roller bearing according to any one of claims 1 to 6, wherein the wall thickness T1 at one end of the cylindrical portion in the axial direction is thinner than the wall thickness T2 at the axial center portion of the cylindrical portion. vessel. 請求項１〜７の何れか１項に記載の針状ころ軸受用保持器と、前記針状ころ軸受用保持器の複数のポケットに収容された複数の針状ころとを有する針状ころ軸受。 Needle roller bearing having the cage for needle roller bearing according to any one of claims 1 to 7 and a plurality of needle rollers housed in a plurality of pockets of the cage for needle roller bearing. .. ころ充填率が７０％以上である請求項８に記載の針状ころ軸受。 The needle roller bearing according to claim 8, wherein the roller filling rate is 70% or more.
JP2019128555A 2019-07-10 2019-07-10 Cage for needle roller bearing and needle roller bearing Pending JP2021014863A (en)

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DE112020003265.5T DE112020003265T5 (en) 2019-07-10 2020-06-18 Cage for a needle roller bearing and needle roller bearing
CN202080044342.7A CN113993639A (en) 2019-07-10 2020-06-18 Needle roller bearing retainer and needle roller bearing
PCT/JP2020/023910 WO2021005994A1 (en) 2019-07-10 2020-06-18 Needle roller bearing retainer, and needle roller bearing
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