JP2005325884A - Roller bearing cage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing for which there is no limit to the number of balls that can be inserted, the insertion load can be reduced, the possibility of indentations on inner and outer ring grooves and balls is reduced, and deformation of the cage can be prevented. A cage is provided.
A counter bore type rolling bearing retainer used in a pivot bearing device for a swing arm of a hard disk drive device, comprising a ball, a retainer, and a sealing plate, and at least one of an inner ring and an outer ring has no engagement allowance. The cage is made of plastic, and the cage has a claw pocket portion and a clawless pocket portion that are annularly arranged for inserting balls, and between the claw pocket portion and the clawless pocket portion. A recess is provided on the upper surface of the column part, and at least one nail-less pocket part is provided between the nail pockets.
[Selection] Figure 2

Description

  The present invention relates to an improvement of a cage used in a pivot arm pivot bearing of a hard disk drive device (hereinafter referred to as “HDD device”).

  In a conventional swing arm bearing device, a bearing is composed of inner and outer rings, balls, a cage, a sealing plate, a shaft, and a housing, and two bearings having the sealing plate are used with preload applied thereto. Further, the bearing device is provided with caps on both end faces of the housing.

  An example of such a bearing is disclosed in Patent Document 1, for example. Patent Document 1 proposes a configuration in which two balls are accommodated in one pocket in order to improve the cage strength and increase the number of balls to be accommodated.

  Further, Patent Document 2 discloses a thin cage that prevents deformation of a column portion between pockets. In this document, the dimensions such as the opening width of the pocket are set to be predetermined, thereby preventing the cage pillar portion from being deformed when the ball is inserted.

  Patent Document 3 discloses a cage in which the number of balls loaded is increased by reducing the pitch of the pockets in order to reduce the thickness of the pillar portion between the non-claw pocket and the claw pocket, that is, the partition wall. ing.

Prior art document information related to the invention of this application includes the following.
Japanese Patent Laid-Open No. 7-208483 (2nd page, FIG. 1 etc.) Japanese Unexamined Patent Publication No. 2003-83335 (page 3, FIG. 1, etc.) Japanese Utility Model Publication No. 4-111920 (second page, FIG. 4 etc.)

  However, the conventional deep groove ball bearings have a problem in that there is a limit to the ball diameter and the number of balls in assembling, and improvement in rigidity cannot be expected. Furthermore, in conventional ball bearings having a counter bore, since there is generally a retaining margin in the groove having the counter bore, there is a limit to the number of balls that can be inserted, and high-frequency shrinkage fitting must be performed during assembly. It was necessary to use a cage made of a phenol material having high temperature durability.

  Therefore, the object of the present invention is that there is no limit to the number of balls that can be inserted, the insertion load can be reduced, the possibility of indentations on the inner and outer ring grooves and balls, and the deformation of the cage can also be prevented. It is providing the cage | basket for rolling bearings.

In order to achieve the above object, the rolling bearing cage of the present invention comprises:
In a counter bore type rolling bearing retainer used in a pivot bearing device for a swing arm of a hard disk drive device, comprising a ball, a retainer, and a sealing plate, and at least one of an inner ring and an outer ring has no allowance. The vessel is made of plastic, and the cage has a claw pocket portion and a clawless pocket portion arranged in an annular shape for inserting the ball, and between the claw pocket portion and the clawless pocket portion. A concave portion is provided on the upper surface of the pillar portion, and at least one clawless pocket portion is provided between the claw pockets.

  By providing at least one clawless pocket between the claw pockets, the following effects occur.

  (1) The number of bearing balls can be increased. In the conventional plastic cage, the balls are held by providing the claw portions in all the pockets. Therefore, if the claw portions cannot be designed, it is impossible to insert more balls. However, by providing at least one or more non-claw pocket portions between the claw pockets, it is possible to reduce the wall thickness between the pockets and increase the number of balls.

  (2) It is possible to reduce the load applied to the ball-inner / outer ring when the cage is inserted. In conventional plastic cages, all the pockets are provided with claws, so that excessive insertion load is applied to the balls, inner and outer rings, and cage when inserting the cage, and there is a possibility that indentations will be formed on the inner and outer ring grooves and balls. Yes, the cage could also be deformed. By providing at least one clawless pocket between the claw pockets, it is possible to reduce the insertion load, reduce the possibility of indentations on the inner and outer ring grooves and balls, and deform the cage. Prevention becomes possible.

  (3) Grease can be filled in the pillar plane between the non-claw pockets. In the conventional plastic cage, balls are held by providing claw portions in all the pockets. Therefore, when the number of balls increases, the space between the claws of the cage column portions is narrowed, and a space for placing grease cannot be secured. However, by providing at least one clawless pocket portion between the claw pockets, it is possible to provide a sufficient space for putting grease on the columnar plane by providing the clawless column.

  The nail pocket is a spherical pocket, the nailless pocket is a cylindrical pocket, or the nail pocket is a cylindrical pocket, and the nailless pocket is a spherical pocket. It becomes possible to insert a ball into the. Further, when the number of balls is large at the time of assembling the bearing, it becomes difficult to separate the balls. However, it is easy to divide the number of balls for the spherical pocket in the same way as normal ball bearings. Furthermore, it becomes possible to insert a ball from the outer ring (inner ring), the cage, and the ball inner side (outer side).

  By providing the concave portion on the upper surface of the pillar portion of the nailless pocket, it becomes possible to stabilize the grease filling. In addition, the grease becomes difficult to move when the bearing rotates.

  By making the cage from a material containing 10-35% glass fiber in nylon fat, it is possible to use a cage in which glass fiber is contained in a resin material not having high heat resistance. In conventional ball bearings with counterbore, it is necessary to expand and assemble the outer ring, and it is necessary to raise the temperature during the assembly process. Therefore, it is necessary to use a machined cage made of highly heat-resistant phenol resin. There were high costs, product size limitations, and shape limitations. However, for ball bearings with counterbore and no allowance, there is no need to raise the temperature during the assembly process, so a molded cage containing glass fiber in a resin such as nylon with low heat resistance can be used. It becomes.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same parts are denoted by the same reference numerals. In addition, each Example demonstrated below demonstrates this invention as an illustration, and it cannot be overemphasized that this invention is not limited in any meaning.

  FIG. 1 is a perspective view showing a cage according to a first embodiment of the present invention. The cage 1 is a counter bore type of a swing bearing pivot bearing device 20 (see FIG. 4) of an HDD device (not shown) in which at least one of the inner ring and the outer ring does not have a dependency, and includes a ball, a cage, and a sealing plate. It is a cage for a rolling bearing constructed. The same applies to second and third embodiments described later.

  In FIG. 1, the substantially annular cage 1 has a plurality of pockets opened at one end in the axial direction. A pocket in which a ball (see FIG. 4) that is a rolling element is rotatably fitted includes a claw pocket 3 and a clawless pocket 2 having claw portions 4 protruding radially outward on both sides of the opening, They are provided alternately in the circumferential direction. As can be seen from FIG. 5, the clawd pocket 3 and the clawless pocket 2 are provided so as to have substantially the same diameter, but may be provided slightly differently.

  The nail | claw part 4 is curving so that the opening part of the pocket 3 with a nail | claw may be covered, and is extended from the opening part both ends of the pocket 3 with a nail | claw. Between the pocket 3 with the nail and the pocket 2 without the nail, a column part 6 that separates both pockets is formed. A part of the upper surface 5 of the column part 6 is formed with the nail part 4, and the rest is The surface is a substantially flat surface, and a recess 9 having a predetermined depth is formed there.

  The recess 9 is filled with lubricating oil such as grease. Since the grease is accommodated in the recess 9, the grease hardly flows out (moves) out of the recess when the bearing rotates, and a good lubricating performance is obtained. Although the recessed part 9 can also be provided in the upper surface 5 of all the pillar parts 6, what is necessary is just to provide a required number in order to obtain desired lubricity.

  FIG. 2 is a perspective view showing a cage according to a second embodiment of the present invention. In the first embodiment, the nail pockets 3 and the non-nail pockets 2 are alternately arranged, that is, one nail-less pocket 2 is arranged between the nail pockets 3. Two nailless pockets 2 are arranged on the left side.

  In the second embodiment, as shown in FIG. 2, since the two nailless pockets 2 are arranged side by side between the nailless pockets 3, the column part 7 is also formed between the nailless pockets 2. Since the pillar portion 7 is not provided with the claw portion 4, the upper surface 10 of the pillar portion 7 is a substantially flat surface.

  The upper surface 10 is provided with a recess 8 in which grease is enclosed. Since the concave portion 8 is larger than the concave portion 9, a sufficient amount of grease can be enclosed, so that the lubricity is further improved. In FIG. 2, the recesses 8 are provided in all the column parts 7, but it is not always necessary to do so, and it goes without saying that the number can be arbitrarily selected according to the required lubricity. Further, in the second embodiment, the column portion 6 between the claw pocket 3 and the clawless pocket 2 is not provided with a recess, but may be provided as in the first embodiment.

  FIG. 3 is a perspective view showing a cage according to a third embodiment of the present invention. In this embodiment, as in the second embodiment, a plurality of nailless pockets 2 are arranged between the nail pockets 3. In the third embodiment, three nailless pockets 2 are arranged between the nail pockets 3.

  In the third embodiment, as shown in FIG. 3, the three clawless pockets 2 are arranged between the clawless pockets 3, so that the two column portions 7 are formed between the clawless pockets 2. . Similar to the second embodiment, since the claw portion 4 is not provided in the column portion 7, the upper surface 10 of the column portion 7 is a substantially flat surface.

  The upper surface 10 is provided with a recess 8 in which grease is enclosed. Since the concave portion 8 is larger than the concave portion 9, a sufficient amount of grease can be enclosed, so that the lubricity is further improved. In addition, since the number of recesses is larger than that in the second embodiment, the lubricity can be further improved. In FIG. 3, the recesses 8 are provided in all the column parts 7, but it is not always necessary to do so, and it goes without saying that the number can be arbitrarily selected according to the required lubricity. For example, it can also be provided on either one of the adjacent column portions 7. Further, in the second embodiment, the column portion 6 between the claw pocket 3 and the clawless pocket 2 is not provided with a recess, but may be provided as in the first embodiment.

  Here, with reference to FIG. 4, the bearing 20 and the bearing device 30 in which the cage 1 of the present invention is used will be described. The ball bearing 20 includes an annular outer ring 11 and an annular inner ring 12 disposed concentrically with the outer ring 11, and a plurality of balls 13 are held by the cage 1 between the outer ring 11 and the inner ring 12. Arranged. A bearing device 30 which is a pivot bearing for a swing arm of a HDD device (not shown) is fitted to the outer ring 11 of the ball bearing 20 and the shaft 14 rotatably supported at both ends in the axial direction by two ball bearings 20. And a swing arm 16 fixed to the housing 15. The ball bearing 20 is sealed from the outside by a sealing plate 17.

  In the first to third embodiments described above, the inner surfaces of the clawd pocket 3 and the clawless pocket 2 can be combined as follows. The claw-equipped pocket 3 is a spherical surface, and the clawless pocket is a cylinder. On the contrary, the pocket 3 with a claw is a cylinder, and the pocket 2 without a claw is a spherical surface. In this way, it is possible to assemble balls only in the number of spherical pockets when assembling the inner and outer rings and balls, and then insert the balls into the cylindrical pockets.

  Further, the inner surfaces of all the pockets can be made spherical or cylindrical without distinction between the pockets with nails and the pockets without nails. Moreover, in each Example, the holder | retainer 1 is made from the material which contained 10-35% of glass fibers in the nylon resin. As a result, it is possible to use a cage in which glass fiber is contained in a resin material that is not heat resistant.

  As mentioned above, although each Example of this invention was described, this invention is not limited to the above-mentioned structure, For example, the following changes are possible. Each pocket is provided only at one end in the axial direction of the cage 1, but may be provided at both ends in the axial direction, that is, doubled to hold two rows of balls in the axial direction.

  Although the concave portion 9 of the first embodiment and the concave portion 8 of the second and third embodiments are illustrated in a rectangular shape, other shapes such as a circular shape are of course possible. Moreover, the recessed parts 8 and 9 can also be provided as a single groove or a plurality of grooves. In each embodiment, the bearing is a ball bearing, but other types of rolling bearings can of course be used.

1 is a perspective view showing a cage according to a first embodiment of the present invention. It is a perspective view which shows the holder | retainer of 2nd Example of this invention. It is a perspective view which shows the holder | retainer of 2nd Example of this invention. It is an axial sectional view of a bearing device using a rolling bearing to which the cage of each embodiment of the present invention can be applied. It is a partial side view of the holder | retainer of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cage 2 Pocket without nail | claw 3 Pocket with nail | claw 4 Claw part 5 Upper surface 6 Column part 7 Column part 8 Recessed part 9 Recessed part 10 Upper surface 20 Ball bearing 30 Bearing device

Claims (7)

In a counter bore type rolling bearing retainer that is used in a pivot bearing device for a swing arm of a hard disk drive device and is composed of a ball, a retainer, and a sealing plate, and at least one of the inner ring and the outer ring has no allowance. The container is made of plastic, and the retainer has a claw pocket portion and a clawless pocket portion that are annularly arranged for inserting the balls, and is between the claw pocket portion and the clawless pocket portion. The retainer is characterized in that a recess is provided on the upper surface of the pillar portion, and at least one clawless pocket portion is provided between the claw pockets. The retainer according to claim 1, wherein the pocket with the claw has a spherical inner surface, and the pocket without the claw has a cylindrical inner surface in a radial direction. The cage according to claim 1, wherein the clawd pocket has a cylindrical inner surface in the radial direction, and the clawless pocket has a spherical inner surface. The retainer according to any one of claims 1 to 3, wherein a concave portion is provided on an upper surface of the column portion between the clawless pockets. The cage according to any one of claims 1 to 4, wherein the cage is made of a material containing 10 to 35% glass fiber in a nylon resin. The rolling bearing which has a holder | retainer of any one of Claims 1-5. A bearing device using the rolling bearing according to claim 6.

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