JP2006170276A - Ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the deformation of claws when a synthetic resin crown type cage used for a ball bearing is released and assembled. <P>SOLUTION: The pockets of the half of the crown type cage 4 are formed to have the claws 6 curved along balls 3 at the axial one end thereof, and the pockets 5a with the claws and the pockets 5b without the claws are alternately disposed in the circumferential direction. Accordingly, when the cage 4 is injection-molded and released from a mold M forming its pockets 5a and 5b, the peripheral parts 8 of the claws become easily deformable to the pockets 5b without the claws and the deformation of the claws 6 can be reduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a ball bearing provided with a crown-shaped cage formed by injection molding of synthetic resin.

  In ball bearings such as deep groove ball bearings and angular contact ball bearings, a plurality of balls that are arranged to freely roll between inner and outer rings are accommodated in a plurality of pockets that are open on one side in the axial direction at equal intervals in the circumferential direction. Some have a crown-shaped cage to hold. As the crown-shaped cage, those formed by injection molding of synthetic resin are often used. In such a synthetic resin crown-shaped cage, a pawl that curves along the ball is provided at one end of each pocket (see Patent Document 1), and these pawls move to the other end in the axial direction. Many are regulated so that they do not fall out of the bearing.

  However, in the ball bearing provided with the crown-shaped cage having the claw, as shown in FIG. 4A, the entrance width of the pocket 52 of the cage 51 is set so that the pocket 52 is formed during the injection molding of the cage 51. Since the diameter of the spherical portion of the mold M to be formed is narrower, as shown in FIGS. 4B and 4C, the side between the adjacent claws 53 of the cage 51 from the state of FIG. When the end face 54 is pushed in the axial direction by the push pin P and the cage 51 is released from the mold M, the claw 53 is deformed by the mold M, and a whitening phenomenon occurs in the base 53a of the claw 53 where particularly large stress is generated. And cracks may occur. The whitening phenomenon and cracks are more likely to occur as the interval between the pockets 52 is narrower (the more balls are present). As shown in FIG. 4 (c), when the mold is released, the peripheral portion 55 of the nail receives force symmetrically from both sides in the circumferential direction to suppress the deformation, so that the deformation of the nail 53 is increased and its base portion This is because the stress generated in 53a tends to increase.

  Also, during bearing assembly work, when the retainer is press-fitted into the balls arranged between the inner and outer rings, the retainer claws are deformed by the balls, which causes whitening and cracks at the base. There is a case.

If the bearing is used with the whitening phenomenon or cracks occurring at the base of the claw of the cage, the claw may break during use and may be caught between the inner ring or the outer ring and the ball, resulting in poor rotation of the bearing. . For this reason, after the mold release work and assembly work, the base of the claw is checked, but there are many things that are removed as defective products at that time, which reduces the bearing productivity and costs. It is a factor that invites up.
JP 2001-248647 A (FIGS. 2 and 3)

  An object of the present invention is to reduce the deformation of the claws when releasing and assembling a crown-shaped cage made of a synthetic resin used for a ball bearing.

  In order to solve the above-described problems, the present invention is formed by injection molding of an inner ring, an outer ring, a plurality of balls that are freely rollable between the inner and outer rings, and a synthetic resin. A ball bearing including a crown-shaped cage that is accommodated in a plurality of opened pockets and is held at equal intervals in the circumferential direction. As one having a claw that curves along the ball at one side end, a configuration is adopted in which pockets having these claws are arranged so as not to be adjacent to each other in the circumferential direction.

  In other words, by making some pockets of the crown-shaped cage have nails, other pockets without nails, and making the pockets with nails not adjacent to each other in the circumferential direction, when releasing and assembling the cage, The peripheral part of the nail is easily deformed toward the non-nail pocket and the deformation of the nail is reduced.

  In the present invention, as described above, only some of the pockets of the crown-shaped cage are provided with claws, and these pockets with claws are not adjacent to each other in the circumferential direction. By reducing the deformation of the nail at the time, the stress generated at the base can be reduced, and the whitening phenomenon and the crack can be made difficult to occur. As a result, the occurrence rate of defective products of the cage can be kept low, which can contribute to improvement of bearing productivity and cost reduction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the ball bearing of this embodiment includes an inner ring 1, an outer ring 2, and a plurality of balls 3 that are arranged to freely roll between the inner and outer rings 1 and 2,
It is a deep groove ball bearing provided with a crown-shaped cage 4 that holds these balls 3.

  The crown-shaped cage 4 is formed by injection molding of a synthetic resin. As shown in FIGS. 2A and 2B, pockets 5a and 5b opened on one side in the axial direction are circumferentially equal. Provided at intervals, the balls 3 are accommodated and held in the pockets 5a and 5b. Each pocket 5a, 5b has a concave spherical surface whose inner surface is along the ball 3, and has a claw 6 curved along the ball 3 at one end in the axial direction (5a), and has no claw 6. Things (5b) are alternately arranged in the circumferential direction. And since the claw 6 is provided in half the pockets 5a in this way, the movement of the cage 4 to the other end side in the axial direction is restricted by the balls 3 even in a state of non-contact with the inner and outer rings 1, 2. It is designed not to fall off the bearing.

  In the injection molding of the crown-shaped cage 4, as shown in FIG. 3A, a mold M having a spherical portion having a diameter larger than the entrance width of the pocket 5 a with claws is used as in the conventional case. However, as shown in FIGS. 3B and 3C, the side end surface 7 provided with the claw 6 of the retainer 4 is pushed in the axial direction by the push pin P from the state of FIG. When the mold 4 is released from the mold M, the claw peripheral portion 8 is deformed to the clawless pocket 5b side, so that the deformation of the claw 6 becomes smaller than the conventional one. For this reason, the stress which arises in the base 6a of the nail | claw 6 is small, and a whitening phenomenon and a crack are hard to generate | occur | produce.

  Moreover, as shown in FIG. 3 (b), the side end surface 7 of the retainer 4 is wider than that of the prior art so that a large-diameter push pin P can be used. Therefore, the contact surface between the retainer 4 and the pin P The pressure is small and problems such as the pin P penetrating the retainer 4 are less likely to occur.

  Although illustration is omitted, when the retainer 4 is press-fitted into the balls 3 arranged between the inner and outer rings 1 and 2 in the bearing assembly work, as in the above-described mold release work, The deformation of the nail 6 is smaller than in the prior art, and whitening and cracks are less likely to occur.

  This ball bearing is configured as described above, and the deformation of the claw is small when the crown-shaped cage is released and assembled, whitening and cracking are unlikely to occur, and the extrusion pin penetrates when the cage is released. Therefore, it can be manufactured more efficiently and at a lower cost.

  In the embodiment described above, the pockets with claws and the pockets without claws of the crown-shaped cage are alternately arranged in the circumferential direction, but the number of pockets with claws is the number of the claws with the claws toward the other end in the axial direction of the cage. Any range can be set as long as the movement can be reliably regulated.

  The present invention is not limited to the deep groove ball bearing described in the embodiment, and can be widely applied to a ball bearing provided with a crown-shaped cage.

Front sectional view of the ball bearing of the embodiment a is a side view of the cage shown in FIG. 1, and b is a developed view of a cross section taken along line BB of a. “a”, “b”, and “c” are explanatory views of the releasing operation of the cage in FIG. a, b, and c are explanatory drawings of the release operation of the conventional ball bearing cage, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 3 Ball 4 Crown-shaped cage 5a, 5b Pocket 6 Claw 6a Base 7 Side end surface 8 Claw peripheral part M Mold P Extrusion pin

Claims (1)

  An inner ring, an outer ring, a plurality of balls that are freely rollable between the inner and outer rings, and a synthetic resin injection molding, the balls are accommodated in a plurality of pockets that are open on one side in the axial direction. In the ball bearing provided with a crown-shaped cage that is held at equal intervals, a claw that curves a part of each pocket of the crown-shaped cage along the ball at one axial end thereof A ball bearing characterized in that the pockets having these claws are arranged so as not to be adjacent to each other in the circumferential direction.

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