JP2008249108A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing for reducing stress concentration on portions of a cage at the bottoms of pockets. <P>SOLUTION: The cage 14 of the rolling bearing 10 is an annular member which has the pockets 23 at a plurality of peripheral positions, passing therethrough in the radial direction and opened to one axial end. Balls 13 are stored in the pockets 23, respectively. The rotation of the cage 14 is guided by an outer ring 11, and the cage 14 is engaged with the outer ring 11, thereby restricting the movement of the cage 14 along the axial direction to the opposite side to the side of opening the pockets 23. Opening widths W1-W3 of the pockets 23 which appear on the outer and inner peripheral faces of the cage and at one axial end are larger than the diameters of the balls 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing, and more particularly to a rolling bearing suitable for high-speed rotation.

  In the rolling bearing, a plurality of balls are arranged so as to be freely rollable in the circumferential direction between an outer ring and an inner ring arranged coaxially, and these balls are arranged at substantially equal intervals in the circumferential direction. It is held by a cage. As shown in FIG. 9, the conventional cage has a plurality of pockets 102 formed in an annular shape as a whole, penetrating in the radial direction and opened to one end side in the axial direction at a plurality of locations in the circumferential direction. A so-called crown-shaped cage 101 is known in which balls are accommodated in the respective pockets 102 (see, for example, Patent Document 1).

  Some crown-shaped cages are formed by injection molding a synthetic resin such as a polyamide resin containing glass fibers. Crown type cages made of synthetic resin can reduce the weight of rolling bearings and are often used in rolling bearings that require high-speed rotation. The inner surface 103 of the pocket 102 of the crown-shaped cage 101 is generally formed in a spherical shape slightly larger in diameter than the ball to be accommodated, but the pocket appears on the outer circumferential surface and inner circumferential surface of the cage 101 and one end in the axial direction. The width of the opening 102 is smaller than the diameter of the ball.

In the crown-shaped cage 101 configured in this manner, the ball elastically deforms the claw portion 104 of the cage that defines the opening of the pocket 102 that appears at one end of the cage 101 in the axial direction, thereby opening the ball. Is accommodated in the pocket 102 while spreading. The ball accommodated in the pocket 102 is held by the holder 101 without coming out of the pocket 102, and the holder 101 is guided to rotate by a ball rolling in the circumferential direction in the pocket 102.
Japanese Utility Model Publication No. 06-008821

  A rolling bearing rotated at high speed is likely to generate vibrations, and the axial and radial vibrations of the cage incorporated in the bearing are also large. Here, in the above crown-shaped cage 101, the width of the opening of the pocket 102 appearing on the outer peripheral surface and the inner peripheral surface and one end in the axial direction is smaller than the diameter of the accommodated ball. When the cage 101 swings in the axial direction or the radial direction, the balls collide with the outer peripheral surface and the inner peripheral surface of the cage 101 and the cage portion corresponding to the edge of the opening of the pocket 102 that appears on one end in the axial direction. Stress is applied to the cage portion corresponding to the bottom of the container. As a result, the pocket 102 may be deformed.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a rolling bearing capable of reducing stress concentration on a cage portion corresponding to the bottom of a pocket.

The object of the present invention is achieved by the following rolling bearing (1).
(1) A pair of raceways arranged coaxially, a plurality of balls arranged so as to be freely rollable in the circumferential direction between the raceways, and an annular member arranged between the raceways. A pocket that penetrates in the radial direction and is open at one end in the axial direction at a plurality of locations in the circumferential direction, and each retains the balls in these pockets. The rotation is guided by the raceway, and the movement to the side opposite to the side where the pocket is opened is restricted along the axial direction by engaging with the raceway, and the outer peripheral surface of the cage And the width of the opening of the pocket appearing at one end in the axial direction and the inner peripheral surface is formed to be larger than the diameter of the ball.

  According to the rolling bearing of the present invention, the cage is guided to the side opposite to the side where the pocket is opened along the axial direction by guiding the rotation of the cage by the raceway and engaging the cage with the raceway. In addition, the width of the opening of the pocket appearing at one end in the axial direction is formed larger than the diameter of the ball. Thereby, even when the cage is swung in the axial direction or the radial direction, it is possible to prevent the balls from colliding with the cage portion corresponding to the edge of the opening of the pocket. Thereby, the stress concentration on the cage portion corresponding to the bottom of the pocket can be reduced.

  Hereinafter, preferred embodiments of the rolling bearing of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view showing a partially broken outer ring according to a first embodiment of a rolling bearing of the present invention, FIG. 2 is a sectional view of the rolling bearing of FIG. 1, and FIG. 3 is incorporated in the rolling bearing of FIG. FIG. 4 is a sectional view showing a modification of the rolling bearing of FIG.

  As shown in FIG. 1 to FIG. 3, the rolling bearing 10 of the present embodiment is arranged in a circumferential direction between an outer ring 11 and an inner ring 12 that are a pair of raceways arranged coaxially, and between the outer ring 11 and the inner ring 12. There are provided a plurality of balls 13 arranged to be freely rollable, and a cage 14 for holding these balls 13 at equal intervals in the circumferential direction.

  An outer ring raceway groove 21 is recessed in the axially central portion of the inner peripheral surface of the outer ring 11, and an inner ring raceway groove 22 is recessed in the axially central portion of the outer peripheral surface of the inner ring 12. The plurality of balls 13 are disposed between the raceway grooves 21 and 22 facing each other, and roll in the circumferential direction.

  The retainer 14 is an annular member disposed between the outer ring 11 and the inner ring 12, and has pockets 23 penetrating in the radial direction and opened to one end side in the axial direction at a plurality of locations in the circumferential direction. Have. The cage 14 accommodates the balls 13 in the pockets 23 and holds the balls 13 at substantially equal intervals in the circumferential direction.

  The cage 14 includes an annular portion 24 and a plurality of column portions 25 extending in the axial direction from one end surface of the annular portion 24 in the axial direction. These column portions 25 are arranged at substantially equal intervals in the circumferential direction. A pocket 23 is defined by being surrounded on three sides by a pair of adjacent column portions 25 and an annular portion 24.

  The widths W1 and W2 of the openings of the pockets 23 appearing on the outer peripheral surface and the inner peripheral surface of the cage 14 are both formed larger than the diameter of the ball 13. That is, the balls 13 can pass through the pockets 23 defined by the pillars 25 in the radial direction without contacting the adjacent pairs of pillars 25.

  Furthermore, the width W3 of the opening of the pocket 23 that appears on one end face of the cage 14 in the axial direction is formed larger than the diameter of the ball 13. That is, the ball 13 can enter the pocket 23 defined by the pillars 25 in the axial direction without coming into contact with a pair of adjacent pillars 25, and can come out from the pockets 23 in the axial direction. it can.

  The cage 14 which is not relatively restrained by the balls 13 as described above even when the balls 13 are accommodated in the pockets 23 is guided to rotate by the outer ring 11 or the inner ring 12. In the present embodiment, the retainer 14 is in sliding contact with the outer peripheral surface of the annular portion 24 on one of the shoulder portions 26 of the outer ring 11 formed on both sides of the outer ring raceway groove 21. Is guided by the outer ring 11 and positioned in the radial direction. In the present invention, the cage 14 may be guided by the inner ring 12.

  Furthermore, the retainer 14 is restricted from moving to the side opposite to the side where the pocket 23 is opened along the axial direction by engaging the outer ring 11 or the inner ring 12. In the present embodiment, an engagement recess 27 is formed in one shoulder 26 of the outer ring 11 slidably in contact with the annular portion 24, and the outer diameter is formed at the tip of the column 25 of the retainer 14. An engagement protrusion 28 protruding to the side is formed, and the cage 14 is restricted from moving in the axial direction by engaging the engagement protrusion 28 with the engagement recess 27. In the illustrated example, the engagement protrusions 28 are formed on all the column parts 25, but the engagement protrusions 28 need not be formed on all the column parts 25. The engagement protrusions 28 only need to be formed on the plurality of column parts 25 so as to be distributed substantially evenly in the circumferential direction. When configured in this way, the engagement protrusions 28 are formed on all the column parts 25. Compared to the above, it is possible to reduce the weight and cost of the retainer 14, which is preferable.

  The cage 14 is formed, for example, by injection molding synthetic resin. Although it does not specifically limit about synthetic resin, For example, polyamide-type resin, such as 46 nylon and 66 nylon, polybutylene terephthalate, polyphenylene sulfide (PPS), polyamideimide (PAI), thermoplastic polyimide, polyetheretherketone (PEEK), And polyether nitrile (PEN). Further, for example, 10 to 50% by weight of a fibrous filler such as glass fiber or carbon fiber may be appropriately added to the above resin. Thereby, the rigidity and dimensional accuracy of the cage 14 can be improved.

  The rolling bearing 10 is held between the outer ring 11 and the inner ring 12 such that a plurality of balls 13 are inserted between the outer ring 11 and the inner ring 12 and a column part 25 is inserted between a pair of adjacent balls 13. The instrument 14 is inserted and assembled. Here, the retainer 14 abuts the engagement protrusion 28 of the column portion 25 against the shoulder portion 26 of the outer ring 11, and moves the distal end side of the column portion 25 whose base end portion is supported by the annular portion 24 only. The column part 25 is inserted between the outer ring 11 and the inner ring 12 while being elastically deformed so as to be displaced toward the inner diameter side. Therefore, the tip of the engaging protrusion 28 that contacts the shoulder 26 is formed in an R shape. Thereby, the holder | retainer 14 can be inserted smoothly. As shown in FIG. 4, the cage 14 can also be smoothly inserted by inclining the tip of the engagement protrusion 28.

  As described above, in the rolling bearing 10 according to this embodiment, the rotation of the cage 14 is guided by the outer ring 11 and the cage 23 is engaged with the outer ring 11 so that the pocket 23 is opened along the axial direction. The movement of the cage to the opposite side is restricted, and the outer and inner circumferential surfaces of the cage 14 and the widths W1 to W3 of the opening of the pocket 23 appearing at one end in the axial direction are all the diameters of the balls 13. It is formed larger than. Therefore, even when the cage 14 swings in the axial direction or the radial direction, it is possible to avoid the balls 13 from colliding with the edge portion of the column portion 25 of the cage 14 corresponding to the edge of the opening of the pocket 23. Thereby, the stress concentration on the annular portion 24 of the cage 14 corresponding to the bottom of the pocket 23 can be relaxed.

(Second Embodiment)
Next, a second embodiment of the rolling bearing of the present invention will be described with reference to FIGS.
FIG. 5 is a perspective view showing a part of an outer ring according to a second embodiment of the rolling bearing of the present invention, FIG. 6 is a sectional view of the rolling bearing of FIG. 5, and FIG. 7 is incorporated in the rolling bearing of FIG. FIG. 8 is a sectional view showing a modification of the rolling bearing of FIG. In addition, about the part which overlaps with the rolling bearing 10 of 1st Embodiment mentioned above, description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  As shown in FIG. 5 to FIG. 7, the rolling bearing 30 of the present embodiment is arranged in the circumferential direction between the outer ring 11 and the inner ring 12, which are a pair of raceways arranged coaxially, and between the outer ring 11 and the inner ring 12. There are provided a plurality of balls 13 which are arranged to be freely rollable, and a cage 34 which accommodates these balls 13 in a pocket 23 and holds them at equal intervals in the circumferential direction.

  The widths W1, W2, and W3 of the opening of the pocket 23 appearing on the outer peripheral surface and inner peripheral surface of the cage 34 and one end surface in the axial direction are all formed larger than the diameter of the ball 13. Therefore, the retainer 34 is not restrained by the balls 13 accommodated in the pockets 23, and the retainer 34 that is not restrained by the balls 13 is guided to rotate by the outer ring 11 or the inner ring 12.

  In the present embodiment, the retainer 34 slides the outer peripheral surface of the annular portion 24 against one of the shoulder portions 26 of the outer ring 11 formed on both sides of the outer ring raceway groove 21, and further engages with the column portion 25. A step portion 29 that bulges to the outer diameter side is formed at a position adjacent to the protrusion 28, and the step portion 29 is slidably brought into contact with the other shoulder portion 26 of the outer ring 11 and guided by the outer ring 11. As described above, if the cage 34 is guided by the outer ring 11 at the two locations of the annular portion 24 and the stepped portion 29 which is the tip side of the column portion 25 when viewed in the axial direction, the attitude of the cage 34 at the time of rotation. Can be stabilized.

  The tip of the engagement protrusion 28 of the retainer 34 has an R shape. Thereby, the retainer 34 can be smoothly inserted between the outer ring 11 and the inner ring 12. In addition, as shown in FIG. 8, the holder | retainer 34 can be smoothly inserted also by making the front-end | tip of the engagement protrusion 28 incline. Other functions and effects are the same as those of the rolling bearing 10 of the first embodiment described above, and thus the description thereof is omitted.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

It is a perspective view which fractures | ruptures and shows a part of outer ring concerning 1st Embodiment of the rolling bearing of this invention. It is sectional drawing of the rolling bearing of FIG. It is a single-piece | unit perspective view of the holder | retainer integrated in the rolling bearing of FIG. It is sectional drawing which shows the modification of the rolling bearing of FIG. It is a perspective view which fractures | ruptures and shows a part of outer ring concerning 2nd Embodiment of the rolling bearing of this invention. It is sectional drawing of the rolling bearing of FIG. It is a single-piece | unit perspective view of the holder | retainer integrated in the rolling bearing of FIG. It is sectional drawing which shows the modification of the rolling bearing of FIG. It is a perspective view of the holder | retainer integrated in the conventional rolling bearing.

Explanation of symbols

10 Rolling bearings 11 Outer ring (Raceway ring)
12 Inner ring (Raceway)
13 ball 14 cage 21 outer ring raceway groove 22 inner ring raceway groove 23 pocket 24 ring part 25 pillar part 26 shoulder part 27 step part 28 engaging protrusion

Claims (1)

A pair of raceways arranged coaxially, a plurality of balls arranged so as to be able to roll in the circumferential direction between the raceways, and an annular member arranged between the raceways, in the radial direction A plurality of pockets opened in one end side in the axial direction in the circumferential direction, and cages each containing the balls in these pockets,
The cage is guided to rotate by the raceway, and is restricted from moving to the side opposite to the side where the pocket is opened along the axial direction by engaging the raceway,
A rolling bearing characterized in that the width of the opening of the pocket appearing on the outer peripheral surface and inner peripheral surface of the cage and one end in the axial direction is formed larger than the diameter of the ball.

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