JP2015169315A - Rolling bearing, rolling bearing device, and information recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable seizure at an inner ring and generation of oil mist to be prevented concurrently.SOLUTION: This invention provides a rolling bearing 10 comprising coaxially arranged inner ring 11 and outer ring 13; a plurality of rollers 15 spaced apart in an annular space between these inner ring 11 and outer ring 13 in a circumferential direction; and a ring-shaped retainer 17 arranged in the annular space in coaxial with the inner ring 11 and the outer ring 13 and having a plurality of ball pockets at positions spaced apart in a circumferential direction for use in holding each of the rollers 15. The retainer 17 has grease pockets 19 formed between adjoining ball pockets in a circumferential direction so as to hold grease G therein. The grease pockets 19 have openings 19a, 19b at both inner and outer circumferential surfaces of the retainer 17, and in each of the grease pockets 19, the grease G is held at a position displaced toward the inner ring 11 so as not to contact with at least the outer ring 13.

Description

  The present invention relates to a rolling bearing, a rolling bearing device, and an information recording device.

  Conventionally, a rolling bearing device used for an information recording device such as a magnetic recording device (HDD) is known (for example, see Patent Document 1). This rolling bearing device includes a rolling bearing having an inner ring and an outer ring arranged coaxially, and a plurality of rolling elements arranged at intervals in the circumferential direction in an annular space between the inner ring and the outer ring. And a grease is held by a retainer that rotatably supports the rolling element in the annular space. By supplying this grease to the rolling elements over time, the relative motion between the rolling elements and the inner and outer rings can be lubricated to prevent seizure of the inner and outer rings.

Japanese Patent No. 3651541

  However, the conventional rolling bearing device has the following problems. That is, since the rolling element is inscribed in the outer ring, but in contact with the inner ring, the contact area with the rolling element is smaller in the inner ring than in the outer ring, and the inner ring is separated from the rolling element. The pressure received is increased. Therefore, seizure due to friction with the rolling elements occurs more significantly in the inner ring than in the outer ring.

  On the other hand, in the rotational operation of the rolling bearing, the rotational speed in the circumferential direction differs between the inner ring and the outer ring, and the relative speed between the outer ring and the rolling element is faster than the relative speed between the inner ring and the rolling element. Therefore, the amount of oil mist generated when the grease is atomized with the rotation operation is larger on the outer ring side than on the inner ring side. If this oil mist adheres to a recording medium or a magnetic head, it causes read / write errors and malfunctions, so that the amount of oil mist generated is required to be reduced as much as possible.

  Since the rolling bearing device of Patent Document 1 supplies the same amount of grease to both the inner ring and the outer ring as described above, both prevention of seizure of the inner ring and prevention of oil mist are achieved. Difficult to do.

  The present invention has been made in view of the above-described circumstances, and provides a rolling bearing, a rolling bearing device, and an information recording device capable of achieving both prevention of seizure of the inner ring and prevention of generation of oil mist. Objective.

In order to achieve the above object, the present invention provides the following means.
The present invention relates to an inner ring and an outer ring that are arranged coaxially, a plurality of rolling elements that are arranged in an annular space between the inner ring and the outer ring at intervals in the circumferential direction, and the inner ring that is disposed in the annular space. And a retainer having a plurality of ball pockets which are arranged coaxially with the outer ring and are spaced apart in the circumferential direction, each holding the rolling elements, the retainer in the circumferential direction. The grease pocket is formed between the adjacent ball pockets and holds the grease inside, and the grease pocket has openings on both the inner peripheral surface and the outer peripheral surface of the retainer, and the grease pocket A rolling bearing is provided in which the grease is held at a position biased toward the inner ring so as not to contact at least the outer ring.

  According to the present invention, two rolling bearings are used, and a shaft member is fitted inside each inner ring of these two rolling bearings, and an outer frame member is fitted outside each outer ring. And the outer frame member can be supported by two rolling bearings so as to be rotatable about the axis. In addition, the grease in the grease pocket provided between the ball pockets of the retainer is continuously supplied to the outer ring and the inner ring through the opening, thereby maintaining the lubrication state of the rolling elements for a long period of time. Can do.

  In this case, the amount of grease supplied to the inner ring and the outer ring is different because the grease is held at a position biased toward the inner ring in the grease pocket, and the grease is supplied to the inner ring where seizure is likely to occur. Although promoted, the supply of grease to the outer ring that is likely to generate oil mist is reduced. Thereby, it is possible to achieve both prevention of seizure of the inner ring and prevention of generation of oil mist.

  The present invention also provides an inner ring and an outer ring arranged coaxially, a plurality of rolling elements arranged in an annular space between the inner ring and the outer ring at intervals in the circumferential direction, and the annular space. A retainer having a plurality of ball pockets arranged in the same direction as the inner ring and the outer ring and having a plurality of ball pockets respectively holding the rolling elements at intervals in the circumferential direction. Formed between the ball pockets adjacent to each other in a direction, and having a grease pocket for retaining grease therein, the grease pocket having openings on both an inner peripheral surface and an outer peripheral surface of the retainer, A rolling bearing is provided in which the opening on the inner peripheral surface is larger than the opening on the outer peripheral surface.

  According to the present invention, of the two openings of the grease pocket, the opening facing the inner ring is larger than the opening facing the outer ring, so that the grease is applied to the inner ring and the outer ring. Although the supply amount is different and the supply of grease is promoted to the inner ring where seizure is likely to occur, the supply of grease is reduced to the outer ring where oil mist is likely to occur. Thereby, it is possible to achieve both prevention of seizure of the inner ring and prevention of generation of oil mist.

In the above invention, the grease pocket may be formed so that a dimension in the circumferential direction gradually increases from the outer peripheral surface toward the inner peripheral surface, and the dimension in the axial direction may be larger than the outer peripheral surface. You may form so that it may become large gradually toward an internal peripheral surface.
By doing so, the cross-sectional area of the grease pocket increases as it goes from the outer ring side to the inner ring side, so that the amount of grease in the grease pocket is biased to gradually increase from the outer ring side toward the inner ring side. . Thereby, the supply of grease to the outer ring can be further effectively reduced while the supply of grease to the inner ring is further effectively promoted.

Further, the present invention provides the two rolling bearings according to any one of the above, which are arranged at intervals in the axial direction, the shaft member fitted to the inner rings of the two rolling bearings, and the outer rings. There is provided a rolling bearing device including at least one of outer fitting members having fitting holes for fitting them.
Further, the present invention provides a recording medium for recording information, the rolling bearing device described above, a base portion for supporting the recording medium and the rolling bearing device, and the rolling bearing device for the base portion. Provided is an information recording apparatus comprising: an arm portion supported so as to be swingable about an axis of the rolling bearing; and a head portion attached to the arm portion and recording information on the recording medium.

  According to the present invention, it is possible to achieve both prevention of seizure of the inner ring and prevention of oil mist generation.

It is a schematic block diagram of an information recording device provided with the rolling bearing apparatus which concerns on one Embodiment of this invention. It is a top view of the 1st rolling bearing with which the rolling bearing apparatus of FIG. 1 is provided. It is a longitudinal cross-sectional view of the rolling bearing apparatus of FIG. It is the partial side view which looked at the retainer with which the 1st rolling bearing of FIG. 2 is provided from the outer peripheral surface side. It is a top view of the 1st rolling bearing of FIG. 2 with which the grease was mounted in the grease pocket. It is a top view of the 1st rolling bearing with which the rolling bearing apparatus which concerns on other embodiment of this invention is provided. It is a partial longitudinal cross-sectional view of the rolling bearing apparatus which concerns on other embodiment of this invention.

Hereinafter, a rolling bearing, a rolling bearing device, and an information recording device according to an embodiment of the present invention will be described with reference to the drawings.
An information recording apparatus 100 according to the present embodiment is a hard disk drive device, and has a substantially rectangular box-shaped base housing (base portion) 2, and a swing arm (arm portion) 4 that can swing relative to the base housing 2. A rolling bearing device 1 that swingably supports the swing arm 4 and a drive unit 8 such as a voice coil motor that swings the swing arm 4 are provided. In FIG. 1, reference numeral 6 denotes a magnetic recording medium.

A magnetic head (head unit) 5 for writing magnetic information on the magnetic recording medium 6 and reading magnetic information recorded on the magnetic recording medium 6 is attached to the tip of the swing arm 4.
The rolling bearing device 1 is fixed to the base housing 2 and fitted in a bearing fitting hole (not shown) of the swing arm 4.

  As shown in FIGS. 2 and 3, the rolling bearing device 1 includes a first rolling bearing 10 and a second rolling bearing 20 that are coaxially arranged with an interval in the axial direction, and these rolling bearings 10 and 20. A shaft (shaft member) 31 to be fitted and a spacer 33 sandwiched between the rolling bearings 10 and 20 in the axial direction are provided. FIG. 2 is a view of the first rolling bearing 10 as viewed from the upper side in the axial direction, and FIG. 3 is a cross-sectional view of the rolling bearing device 1 cut in the axial direction at the position of line II-II in FIG. In FIG. 2, only one of the rolling elements, protrusions, and grease pockets shown in the figure is represented by reference numerals 15, 17 b, and 19.

The first rolling bearing 10 includes a plurality of annular inner rings 11 and outer rings 13 that are coaxially arranged, and a plurality of annular bearings that are incorporated in an annular space between the inner ring 11 and the outer ring 13 at intervals in the circumferential direction. A rolling element 15 and a retainer 17 that is disposed in the annular space and rotatably supports each rolling element 15 are provided.
The second rolling bearing 20 has the same configuration and dimensions as the first rolling bearing 10, and includes an inner ring 21 and an outer ring 23, a plurality of rolling elements 25, and a retainer 27.

In these rolling bearings 10 and 20, a shaft 31 fixed to the base housing 2 is fitted to the inner rings 11 and 21, and the outer rings 13 and 23 are fitted to bearing fitting holes of the swing arm 4, respectively. It is like that.
In the following description, the axial direction, the circumferential direction, and the radial direction of the inner rings 11, 21 and the outer rings 13, 23 are simply referred to as “axial direction”, “circumferential direction”, and “radial direction”, respectively.

  As shown in FIG. 4, the retainer 17 of the first rolling bearing 10 includes a ring-shaped main body 17a disposed coaxially with the inner ring 11 and the outer ring 13, and a plurality of sets protruding in the axial direction from the end surface of the main body 17a. And a pair of claw-shaped protrusions 17b. The pair of protrusions 17b hold the rolling element 15 in a ball pocket formed between the pair of protrusions 17b by sandwiching the rolling element 15 between them.

  Further, the retainer 17 is provided between the protrusions 17b that are adjacent to each other in the circumferential direction and hold different rolling elements 15 (that is, between the ball pockets that are adjacent to each other in the circumferential direction). A grease pocket 19 is formed. That is, the grease pocket 19 is demarcated by the outer surface of two adjacent protrusions 17b and the end surface of the main body 17a serving as the bottom surface 19c. Each grease pocket 19 penetrates in the radial direction of the retainer 17, and has a first opening 19 a and a second opening 19 b on the inner peripheral surface and the outer peripheral surface of the retainer 17, respectively.

  The retainer 27 of the second rolling bearing 20 has the same configuration and dimensions as the retainer 17 of the first rolling bearing 10, and includes a main body 27a and a plurality of pairs of protrusions 27b, and holds different rolling elements 25. A grease pocket 29 is formed between the protruding protrusions 27b.

  The grease G is placed on the bottom surfaces 19c and 29c of the grease pockets 19 and 29. As shown in FIG. 5, the grease G does not come into contact with the outer rings 13 and 23, and the inner ring 11 is closer to the inner rings 11 and 21 than the distance to the outer rings 13 and 23. , 21 is placed at a position biased to the side. Preferably, the grease G is placed so as to contact the inner rings 11 and 21.

  In addition, a flange-like shield (not shown) that protrudes radially inward from the inner peripheral surface outside the rolling elements 15 and 25 is fixed to the inner peripheral surfaces of the outer rings 13 and 23. . The annular space between the inner rings 11 and 21 and the outer rings 13 and 23 is covered by the shield so that the atomized grease (so-called oil mist) is prevented from flowing out of the rolling bearing device 1. It has become.

Hereinafter, operations of the rolling bearings 10 and 20, the rolling bearing device 1, and the information recording device 100 configured as described above will be described.
The rolling bearing device 1 according to the present embodiment is fixed to the shaft 31 by rolling the rolling elements 15 and 25 between the inner rings 11 and 21 and the outer rings 13 and 23 of the rolling bearings 10 and 20, respectively. The outer rings 13 and 23 are rotated with respect to the inner rings 11 and 21, respectively.

  Thereby, in the information recording apparatus 100 according to the present embodiment, the swing arm 4 fixed to the outer rings 13 and 23 of the rolling bearings 10 and 20 by the operation of the drive unit 8 is fixed to the base housing 2 in which the shaft 31 is fixed. Is swung around the central axis C. As the swing arm 4 swings, the magnetic head 5 is reciprocated on the magnetic recording medium 6.

  For example, when the swing arm 4 is operated at high speed by the drive unit 8, the magnetic head 5 is instantaneously moved to data recorded at a predetermined position on the magnetic recording medium 6, and recording is performed on the magnetic recording medium 6 by the magnetic head 5. Reading magnetic information and writing magnetic information can be performed.

  According to the rolling bearings 10 and 20, the rolling bearing device 1, and the information recording device 100 according to the present embodiment, the grease G held in the grease pockets 19 and 29 of the retainers 17 and 27 is the first. The rolling elements 15 and 25 are supplied to the inner rings 11 and 21 through the openings 19a and 29a and the outer rings 13 and 23 from the second openings 19b and 29b. The lubrication state between the inner rings 11, 21 and the outer rings 13, 23 is maintained over a long period of time.

  In this case, since the grease G is held at a position closer to the inner rings 11, 21 than the outer rings 13, 23, supply of the grease G to the inner rings 11, 21 is promoted, while The supply amount of the grease G is reduced. Thereby, in the inner ring | wheels 11 and 21, the lubrication effect by the grease G can be heightened and seizure can be prevented effectively. At the same time, generation of oil mist can be effectively prevented in the outer rings 13 and 23.

  Furthermore, especially seizure occurring in the inner rings 11 and 21 can be prevented by increasing the total amount of grease G. In this case, however, the supply amount of grease G to the whole becomes excessive and rotation occurs. Problems such as excessive torque increase and increased oil mist generation occur. On the other hand, with respect to oil mist, it is possible to reduce the amount of oil mist generated by reducing the total amount of grease G. In this case, however, the supply amount of grease G to the inner ring 11 is particularly insufficient. Seizure is likely to occur.

  Therefore, in the present embodiment, the grease G is disposed closer to the inner rings 11 and 21 so that the amount of the grease G is larger on the inner rings 11 and 21 side than on the outer rings 13 and 23 side, and the grease G to the outer rings 13 and 23 is increased. The supply amount of grease G to the inner rings 11 and 21 is increased while reducing the supply amount of. Accordingly, an appropriate amount of grease G required by each of the inner rings 11 and 21 and the outer rings 13 and 23 can be supplied while suppressing the total amount of the grease G.

  In the present embodiment, in the grease pockets 19 and 29, the grease G is placed at a position biased toward the inner rings 11 and 21, thereby increasing the supply amount of the grease G to the inner rings 11 and 21. Instead of reducing the supply amount of grease G to the grease pockets 19 and 23, the grease pockets 19 and 19 are replaced so that the grease G is distributed in the grease pockets 19 and 29 toward the inner rings 11 and 21. The shape of 29 may be asymmetric in the radial direction.

Specifically, as shown in FIG. 6, each grease pocket 19, 29 faces the circumferential direction so that the inner diameter in the circumferential direction gradually increases from the outer ring 13, 23 side toward the inner ring 11, 21 side. The inner side surface may be formed to be inclined with respect to the radial direction.
In this configuration, since the first openings 19a and 29a on the inner rings 11 and 21 side are larger than the second openings 19b and 29b on the outer rings 13 and 23 side, the grease G is supplied to the inner rings 11 and 21. The amount increases, and the amount of grease G supplied to the outer rings 13, 23 decreases.

Further, due to the inner shape of the grease pockets 19 and 29, when the grease pockets 19 and 29 are filled with the grease G, the amount of the grease G increases from the outer rings 13 and 23 side toward the inner rings 11 and 21 side. A gradient is formed in the amount of grease G in the grease pockets 19 and 29. Thereby, supply of the grease G to the outer rings 13 and 23 can be further reduced while further promoting the supply of the grease G to the inner rings 11 and 21.
In the configuration of FIG. 6 as well, as shown in FIG. 5, the grease G may be placed at a position biased toward the inner rings 11 and 21 in the grease pockets 19 and 29.

Alternatively, as shown in FIG. 7, each of the grease pockets 19 and 29 has bottom surfaces 19c and 29c in the axial direction so that the axial dimension gradually increases from the outer ring 13 and 23 side toward the inner ring 11 and 21 side. It may be inclined with respect to.
Also in this configuration, since the first openings 19a and 29a are larger than the second openings 19b and 29b, the amount of grease G supplied to the inner rings 11 and 21 is increased, and the outer rings 13 and 23 are greased. The supply amount of G decreases.

Further, since the bottom surfaces 19c and 29c of the grease pockets 19 and 29 are inclined, when the grease pockets 19 and 29 are filled with the grease G, the grease is directed from the outer rings 13 and 23 toward the inner rings 11 and 21. A gradient is formed in the amount of grease G in the grease pockets 19 and 29 so that the amount of G increases. Thereby, supply of the grease G to the outer rings 13 and 23 can be further reduced while further promoting the supply of the grease G to the inner rings 11 and 21.
In the configuration of FIG. 7 as well, as shown in FIG. 5, the grease G may be placed at a position biased toward the inner rings 11 and 21 in the grease pockets 19 and 29.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included. For example, the present invention is not limited to one applied to the above-described embodiment and modification, but may be applied to an embodiment appropriately combining these one embodiment and modification, and is particularly limited. is not.

  For example, in the above embodiment, each of the rolling bearings 10 and 20 has been described by exemplifying a configuration that does not include an outer fitting member. However, the rolling bearings 10 and 20 have fitting holes for fitting the outer rings 13 and 23 of the rolling bearings 10 and 20. A substantially cylindrical sleeve (an outer fitting member, not shown) may be provided.

In this case, the first rolling bearing 10 is fitted to one side in the axial direction with the spacer member interposed between the fitting holes of the sleeve, and the second rolling bearing 20 is fitted to the other axial direction. That's fine. Further, the sleeve may be fitted into the bearing fitting hole of the swing arm 4.
Further, the rolling bearing device 1 is provided with a sleeve (outer fitting member, not shown) without the shaft 31, and between the inner rings 11 and 21 instead of between the outer rings 13 and 23 and having the same diameter as the inner rings 11 and 21. An annular spacer may be arranged.

1 Rolling bearing device 2 Base housing (base part)
4 Swing arm 5 Magnetic head (head part)
10, 20 Rolling bearings 11, 21 Inner ring 13, 23 Outer ring 15, 25 Rolling element 17, 27 Retainer 19, 29 Grease pocket 19a, 19b, 29a, 29b Opening 19c, 29c Bottom surface 31 Shaft (shaft member)
100 Information recording device G Grease

Claims (6)

An inner ring and an outer ring arranged coaxially;
A plurality of rolling elements disposed in the annular space between the inner ring and the outer ring at intervals in the circumferential direction;
A retainer having a ring shape disposed coaxially with the inner ring and the outer ring in the annular space, and having a plurality of ball pockets respectively holding the rolling elements at circumferentially spaced positions;
The retainer is formed between the ball pockets adjacent to each other in the circumferential direction, and has a grease pocket for holding grease inside,
The grease pocket has openings on both the inner and outer peripheral surfaces of the retainer;
A rolling bearing in which the grease is held at a position biased toward the inner ring so as not to contact at least the outer ring in the grease pocket. An inner ring and an outer ring arranged coaxially;
A plurality of rolling elements disposed in the annular space between the inner ring and the outer ring at intervals in the circumferential direction;
A retainer having a ring shape disposed coaxially with the inner ring and the outer ring in the annular space, and having a plurality of ball pockets respectively holding the rolling elements at circumferentially spaced positions;
The retainer is formed between the ball pockets adjacent to each other in the circumferential direction, and has a grease pocket for holding grease inside,
The grease pocket has openings on both the inner and outer peripheral surfaces of the retainer;
A rolling bearing in which the opening on the inner peripheral surface is larger than the opening on the outer peripheral surface.   The rolling bearing according to claim 2, wherein the grease pocket is formed so that a dimension in the circumferential direction gradually increases from the outer peripheral surface toward the inner peripheral surface.   The rolling bearing according to claim 2, wherein the grease pocket is formed so that a dimension in the axial direction gradually increases from the outer peripheral surface toward the inner peripheral surface. Two rolling bearings according to any one of claims 1 to 4, arranged at intervals in the axial direction;
A rolling bearing device comprising: at least one of a shaft member fitted to each inner ring of the two rolling bearings and an outer fitting member having a fitting hole for fitting each outer ring. A recording medium for recording information;
A rolling bearing device according to claim 5;
A base for supporting the recording medium and the rolling bearing device;
An arm portion supported by the rolling bearing device with respect to the base portion so as to be swingable about an axis of the rolling bearing;
An information recording apparatus comprising: a head unit attached to the arm unit and configured to record information on the recording medium.

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