JP2008196582A - Tapered roller bearing for planetary rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of wear or seizure on a guided face by guiding the cage of a tapered roller bearing supporting a planetary rotor which are revolved while rotating on its axis, along the guided face having low contact bearing pressure. <P>SOLUTION: On a small annular portion 5a of the cage 5, a disc portion 5d is provided which is bent from the outer end and extends to the outer diameter side. At the outer periphery end thereof, an annular portion 5e is provided which is bent to the axial inside at a right angle. The inner diameter face of the annular portion 5e is formed as the radial guided face 6 to be guided to a stepped small diameter face 3b provided on the outer diameter face of an outer ring 3. Thus, the contact area of the guided face 6 is increased to prevent the occurrence of wear or seizure on the guided face 6 of the cage 5 of the tapered roller bearing 1 for supporting a planetary gear 15 as the planetary rotor which is revolved while rotating on its axis. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tapered roller bearing for a planetary rotating body that rotatably supports a planetary rotating body that revolves while rotating.

  In a tapered roller bearing in which a plurality of tapered rollers are arranged in the circumferential direction between the raceway surfaces of the inner ring and the outer ring, each of the arranged tapered rollers is connected in an annular shape on the small end face side and the large end face side of the tapered roller. And a circular ring part are connected by a plurality of column parts, and held by a conical cylindrical retainer in which a pocket for accommodating each tapered roller is formed.

  For such a tapered roller bearing retainer, a press retainer formed by pressing a metal plate such as a steel plate or a machined retainer formed by cutting a metal such as steel or brass is used. In many cases, these cages are of a roller guide type in which a column portion forming a pocket is guided by a tapered roller. In some cases, a protruding portion that bends and protrudes from the small ring portion is provided, and this protruding portion is guided in the radial direction on the raceway surface of the inner ring or the outer circumferential surface of the gavel, or the raceway surface of the outer ring. There is also a raceway guide type (see, for example, Patent Document 1).

  On the other hand, a planetary speed reducer is known as a speed reducer capable of obtaining a large reduction ratio, and a planetary gear speed reducer is a typical one. The planetary gear reducer revolves while rotating a plurality of planetary gears rotatably supported by carrier pins between a sun gear provided on an input shaft and an internal gear fixed to a housing or the like. The revolving motion of the planetary gear is output to the output shaft through the carrier (see, for example, Patent Document 2). There is also a planetary roller speed reducer that uses a sun gear, an internal gear, and a planetary gear as a planetary rotating body as rollers (see, for example, Patent Document 3).

  As the rolling bearing for supporting the planetary gear or the planetary roller on the carrier pin, needle roller bearings are often used in small planetary reduction gears, and tapered roller bearings and self-aligning roller bearings are used in medium and large planetary reduction gears. Cylindrical roller bearings are used.

JP 2004-293730 A JP-A-7-103320 Japanese Patent Laid-Open No. 8-130853

  In addition to centrifugal force from the bearing center due to rotation, the cage of the planetary roller tapered roller bearing that supports the planetary rotating body that revolves while rotating, such as the planetary gears and planetary rollers of the planetary reducer described above, Centrifugal force from the center of the speed reducer due to. Since the centrifugal force due to revolution acts to decenter the cage from the bearing center, when the revolution speed increases and the centrifugal force increases, in the roller guide type, some columns are conical due to the eccentricity of the cage. There is a risk that the column part is worn by the roller, and the column part is worn out, or the column part is broken by a bending moment concentrated on the root part connected to the annular part.

  In the raceway guide type described in Patent Document 1, there is no fear of such wear or breakage of the column portion, but the inner raceway surface or small corrugation is provided at the tip of the projection portion protruding from the annular portion. Since a guided surface guided by the outer peripheral surface or the raceway surface of the outer ring is provided, the contact surface pressure of the guided surface with a small contact area increases, and there is a problem that the guided surface is likely to be worn or seized. . When guiding on the raceway surface of the inner ring or the outer surface of the gavel, the circumference of the guided surface becomes shorter and the contact area becomes smaller.Lubricant such as grease moves to the outer ring side by centrifugal force due to rotation. The lubricant on the guided surface tends to be insufficient, and wear and seizure are more likely to occur on the guided surface.

  In addition, when guiding on the raceway surface of the inner ring or the outer ring, the guided surface of the protruding portion inserted between the tapered rollers is restricted to a part in the circumferential direction, and the contact area of the guided surface is considerably reduced. Since the raceways of the inner and outer rings are inclined in the axial direction, a component force in the axial direction acts on the guided surface of the cage, and the inner end face of the annular part forming the pocket is pressed against the end face of the tapered roller. There is also a problem. Thus, when the inner end surface of the annular portion is pressed against the end surface of the tapered roller, the torque cross of the bearing becomes large.

  Accordingly, an object of the present invention is to guide a tapered roller bearing retainer that supports a planetary rotating body that revolves while rotating with a guided surface having a low contact surface pressure, and wear or seizure occurs on the guided surface. It is to avoid.

  In order to solve the above-mentioned problem, the present invention holds a plurality of tapered rollers arranged between the raceway surfaces of an inner ring and an outer ring with a cage, and a planetary rotating body that revolves while rotating, and has an outer diameter of the outer ring. In a tapered roller bearing for a planetary rotating body that is externally fitted to a surface and is rotatably supported, the outer diameter surface of the outer ring or the inner diameter surface of the planetary rotating body that is externally fitted to the outer diameter surface of the outer ring. The structure which provided the guided part of the radial direction guided all around is adopted.

  That is, by providing the cage with a radially guided portion that is guided around the entire circumference by the outer diameter surface of the outer ring or the inner diameter surface of the planetary rotating body fitted on the outer diameter surface of the outer ring. The circumference of the guided surface is lengthened to increase the contact area, and the cage of the tapered roller bearing that supports the planetary rotating body that revolves while rotating is guided by the guided surface with a low contact surface pressure. The guide surface was not worn or seized. In addition, since the outer surface of the outer ring and the inner surface of the planetary rotor are not inclined in the axial direction, the axial component acts on the guided surface of the cage, and the inner side of the annular part forming the pocket The end face is not pressed against the end face of the tapered roller.

  By forming the guided portion in the radial direction of the cage in an annular shape, the contact area of the guided surface can be further increased.

  By providing the cage with the guided portion in the axial direction that is guided in the axial direction, it is possible to reliably prevent the inner end surface of the annular portion forming the pocket from being pressed against the end surface of the tapered roller.

  The wear resistance of the guided surface can be improved by forming the cage from steel and forming a hardened surface layer on the guided surface of the guided portion. As means for forming the surface hardened layer, tuftride treatment, partial quenching treatment, or the like can be employed.

  By forming the cage with resin, it is possible to reduce the frictional resistance on the guided surface and reduce the trocross of the bearing. As the resin forming the cage, polyamide resin such as nylon, fluorine resin such as polytetrafluoroethylene, polyether ketone resin such as polyether ether ketone, polyamide imide resin, polyimide resin, polyphenylene sulfide resin, and these Mixtures can be used. If necessary, these resins may be added to fibrous reinforcing materials such as carbon fibers and glass fibers, scale-like reinforcing materials such as mica and talc, microfiber reinforcing materials such as potassium titanate whiskers, polytetrafluoroethylene, and graphite. Also, a solid lubricant such as molybdenum disulfide, a sliding reinforcing material such as calcium phosphate and calcium sulfate, and the like can be blended.

  By forming the cage with high-strength brass, the frictional resistance on the guided surface can be reduced and the trocross of the bearing can be reduced.

  Each of the above-described tapered roller bearings for a planetary rotating body is suitable for the planetary rotating body in which the planetary rotating body is a planetary gear or a planetary roller of a planetary speed reducer.

  The tapered roller bearing for a planetary rotator of the present invention has a radial bearing that is guided around the entire circumference by the outer diameter of the outer ring or the inner diameter surface of the planetary rotator fitted on the outer diameter of the outer ring. Since the guide section is provided, the circumference of the guided surface of the cage is increased to increase its contact area, and the cage of the tapered roller bearing that supports the planetary rotating body that revolves while rotating, has a low contact surface pressure. It is possible to prevent wear and seizure from occurring on the guided surface. Moreover, this cage can also reduce the torque cross of a bearing, without the inner end surface of the annular part which forms a pocket being pressed against the end surface of a tapered roller.

  By forming the guided portion in the radial direction of the cage in an annular shape, the contact area of the guided surface can be further increased.

  By providing the cage with the guided portion in the axial direction that is guided in the axial direction, it is possible to reliably prevent the inner end surface of the annular portion forming the pocket from being pressed against the end surface of the tapered roller.

  The wear resistance of the guided surface can be improved by forming the cage from steel and forming a hardened surface layer on the guided surface of the guided portion.

  By forming the cage with resin, it is possible to reduce the frictional resistance on the guided surface and reduce the trocross of the bearing.

  By forming the cage with high-strength brass, the frictional resistance on the guided surface can be reduced and the trocross of the bearing can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment. In this planetary rotor tapered roller bearing 1, a plurality of tapered rollers 4 arranged between raceway surfaces 2a and 3a of an inner ring 2 and an outer ring 3 are connected to a small end surface side and a large end surface side in a small ring shape. An annular portion 5a and a large annular portion 5b are held by a cage 5 connected by a plurality of column portions 5c, and a planetary gear reducer as a planetary rotating body, which will be described later, is arranged on the outer diameter surface of the outer ring 3. A gear 15 is externally fitted. On one side of the raceway surface 2a of the inner ring 2, a large collar 2b for guiding the large end surface of the tapered roller 4 is provided.

  The cage 5 is formed by pressing a steel plate, bent from the outer end of the small ring portion 5a and bent to the outer diameter side of the disk portion 5d and bent at right angles in the axial direction. The annular portion 5e is provided as a radially guided portion guided by a step small diameter surface 3b provided on the outer diameter surface of the outer ring 3, and the inner diameter surface thereof is guided. Surface 6 is designated. Further, the disk portion 5d is a guided portion in the axial direction guided by the end face of the outer ring 3, and the inner side surface thereof is a guided surface 7, and these guided surfaces 6 and 7 are subjected to tuftride processing. A soft-nitrided hardened surface layer is formed.

  2 and 3 show a planetary gear speed reducer that supports the planetary gear 15 as a planetary rotating body by the tapered roller bearing 1 described above. In this planetary gear reducer, a plurality of planetary gears 15 are meshed between a sun gear 12 attached to an input shaft 11 and an internal gear 14 fixed to a housing 13, and pins of a carrier 17 connected to an output shaft 16. The planetary gears 15 are rotatably supported by a pair of tapered roller bearings 1, and the revolving motion of the planetary gears 15 that revolve while rotating between the sun gear 12 and the internal gear 14 is carried through the carrier 17. Output to the output shaft 16.

  FIG. 4 shows a second embodiment. The planetary roller body tapered roller bearing 1 has the same basic configuration as that of the first embodiment, the cage 5 is formed of high-strength brass, and the guided in the axial direction. The difference is that the surface 7 is the tip surface of the annular portion 5e, and the guided surface 7 is guided by the step surface 3c forming the step small diameter surface 3b of the outer ring 3.

  FIG. 5 shows a third embodiment. The planetary roller bearing 1 for a planetary rotor has a retainer 5 formed by injection molding of a nylon resin, and a disc portion 5d that is bent from the outer end of the small annular portion 5a and extends to the outer diameter side. A circular plate portion 5f that is bent from the outer end of the large annular portion 5b and extends toward the outer diameter side is provided, and an annular portion 5g that is bent at a right angle inward in the axial direction is provided at the outer peripheral end. The annular portion 5g is inserted into a gap between the step small diameter surface 3d provided on the outer diameter surface of the outer ring 3 and the inner diameter surface of the planetary gear 15, and the outer diameter surface of the annular portion 5g is the planetary gear. The guided surface 6 in the radial direction is guided by the inner diameter surface of the gear 15. Further, the inner side surfaces of the respective disc portions 5d and 5f are guided surfaces 7 in the axial direction guided by the end surfaces of the outer ring 3. Other parts are the same as those of the first embodiment.

  In each of the embodiments described above, the planetary rotating body supported by the tapered roller bearing is a planetary gear of a planetary gear speed reducer, but the planetary roller bearing for a planetary rotating body according to the present invention includes a planetary roller of a planetary roller speed reducer, It can also be applied to the support of other planetary rotating bodies that revolve while rotating.

The longitudinal cross-sectional view which shows the tapered roller bearing for planetary rotating bodies of 1st Embodiment 1 is a longitudinal sectional view showing a planetary gear reducer using the tapered roller bearing of FIG. Sectional view along line III-III in FIG. The longitudinal cross-sectional view which shows the tapered roller bearing for planetary rotating bodies of 2nd Embodiment The longitudinal cross-sectional view which shows the tapered roller bearing for planetary rotating bodies of 3rd Embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tapered roller bearing 2 Inner ring 2a Raceway surface 2b Large ring 3 Outer ring 3a Raceway surface 3b, 3d Step small diameter surface 3c Step surface 4 Tapered roller 5 Cage 5a Small ring part 5b Large ring part 5c Column part 5d, 5f Disc Portions 5e, 5g Ring portions 6, 7 Guided surface 11 Input shaft 12 Sun gear 13 Housing 14 Internal gear 15 Planetary gear 16 Output shaft 17 Carrier 17a Pin

Claims (7)

  A planetary rotation that holds a plurality of tapered rollers arranged between the raceways of the inner ring and the outer ring with a cage and rotatably supports a planetary rotating body that revolves while rotating on the outer diameter surface of the outer ring. In a tapered roller bearing for a body, a radially guided portion is guided by the retainer on an outer diameter surface of the outer ring or an inner diameter surface of the planetary rotating body fitted on the outer diameter surface of the outer ring. A tapered roller bearing for a planetary rotating body.   The tapered roller bearing for a planetary rotating body according to claim 1, wherein the radial guided portion of the cage is formed in an annular shape.   The tapered roller bearing for a planetary rotating body according to claim 1 or 2, wherein the cage is provided with a guided portion in the axial direction guided in the axial direction.   The tapered roller bearing for a planetary rotating body according to any one of claims 1 to 3, wherein the cage is made of steel, and a hardened surface layer is formed on a guided surface of the guided portion.   The tapered roller bearing for a planetary rotor according to any one of claims 1 to 3, wherein the cage is made of resin.   The tapered roller bearing for a planetary rotating body according to any one of claims 1 to 3, wherein the cage is made of high-strength brass.   The tapered roller bearing for a planetary rotating body according to any one of claims 1 to 6, wherein the planetary rotating body is a planetary gear or a planetary roller of a planetary reduction gear.

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