JP2566504Y2 - Double row angular contact ball bearing and hard disk drive using the same - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-row angular ball bearing suitable for use as an arm bearing, a spindle bearing, and the like in a hard disk drive, and a hard disk drive using the same.

[0002]

2. Description of the Related Art A double-row angular contact ball bearing is the same as one in which an inner ring (including a shaft) and an outer ring are integrated with two single-row ball bearings in a rear combination or a front combination. The structure is suitable for receiving the combined load of thrust load and radial load. Although the bearing width can be smaller than that of a combined angular contact ball bearing in which two single-row ball bearings are combined, the range of use is limited because accuracy is generally lower than that of a single-row ball bearing.

[0003] A conventional double row angular contact ball bearing will be described in detail with reference to Fig. 7. The inner ring 1 has two rows of raceways on the outer periphery of which two rows are not dropped on both shoulders (hereinafter referred to as deep grooves). 1A and 1B, and the outer race 2 also has two rows of deep groove raceway grooves 2A and 2B on its inner periphery. Between the inner ring 1 and the outer ring 2, a plurality of balls 3 forming one ball row, a plurality of balls 4 forming the other ball row 4,
And crown type retainers 5 and 6 for holding these ball rows, respectively, and shield bodies 7 and 8 are provided on both sides thereof. The track grooves 1A and 1B and the track grooves 2A and 2B of these deep grooves are placed in a state where a preload is applied between the inner rings 1 and 2 and the balls 3 and 4 when assembled, so that a desired contact angle θ is obtained. Designed and formed to be formed.

In such double-row angular contact ball bearings, it is necessary to eliminate a radial clearance and an axial clearance after assembling, and to provide a negative clearance of 0.5 to 2 μm (depending on the type) in order to facilitate rotation. is there. For that purpose, it is necessary to measure the diameter and interval of the raceway grooves of the inner ring and the outer ring in submicron, and assemble them in combination. However, if such double-row angular contact ball bearings have high accuracy and are relatively inexpensive, they are suitable for use as arm bearings, spindle bearings, and the like in hard disk drive devices.

[0005]

However, in such a conventional double-row angular contact ball bearing, two single-row race grooves 1A and two deep-row race grooves 1A and 1B are provided in a single inner ring and an outer ring, respectively.
B and the track grooves 2A and 2B are processed, and each track groove 1A and 1B
And the dimensions of the raceway grooves 2A and 2B were measured and assembled from the beginning with sufficient matching with the balls 3 and 4. Therefore, to assemble while maintaining a predetermined preload applied to each ball row, The groove diameters and depths of the two rows of deep grooves 1A and 1B of the inner ring 1, and the groove diameters and depths of the two rows of deep grooves 2A and 2B of the outer ring 2 and the two rows of track grooves 1
Since accuracy on the order of submicrons is required in general, such as the positional relationship between A and 1B, extremely high measurement accuracy, matching accuracy, and assembly accuracy are required, and assembly is extremely difficult and cost is extremely high. .

[0006] Such an extremely expensive double-row angular contact ball bearing has a problem that it is difficult to use it for an arm bearing, a spindle bearing, and the like in a hard disk drive even though the accuracy is high. Therefore, it is extremely difficult to assemble a double-row angular contact ball bearing having such a high-precision structure.

An object of the present invention is to provide an inexpensive double-row angular contact ball bearing that can be easily manufactured and has relatively high accuracy.

[0008]

Means for Solving the Problems A double row angular contact ball bearing according to the present invention is a double row angular contact ball bearing having a plurality of ball rows between an inner ring and an outer ring and a retainer holding the ball rows. Each of the raceways formed on the inner race and the outer race for rolling the row is a groove in which both shoulders are not dropped (also referred to as a deep groove in the present invention), and the inner race or the outer race for rolling the other ball row. The raceway groove formed in the inner ring is a deep groove, and the distance between the outer wall of the inner race and the inner wall of the outer race where the other ball row is located is smaller than the distance between the outer wall of the inner race and the inner wall of the outer race where the one ball row is located. The gap is formed to be large, and the inner ring member or the outer ring member is fixed to the inner ring outer surface or the outer ring inner surface on the side of the larger gap while pressing in the thrust direction, and the other ball row is aligned with the raceway groove of the deep groove. The inner race member or the outer race member is adapted to roll between the raceway groove on which one shoulder is dropped.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a double-row angular contact ball bearing according to the present invention will be described with reference to FIG. The same symbols as the reference symbols shown in FIG. 7 indicate the corresponding members.

[0010] The inner ring 1 and the outer ring 2 are similar to the conventional one,
The raceway grooves 1A and 2A for rolling the balls 3 constituting one ball row are deep grooves. However, the inner race 1 does not have a raceway for rolling the balls 4 constituting the other ball row.

The inner surface of the outer ring 2 where the ball 4 having the same diameter as the ball 3 is located is shaved to form a large inner diameter surface 2X having a large inner diameter at the position where the ball 3 is located. The space between the outer surfaces of the inner ring 1 is wide.
In this embodiment, the spacing is greater than the diameter of the ball 4.
And a track groove 2B 'of a deep groove is formed in the large inner diameter surface 2X portion.

The inner ring member 9 is a cylindrical member having an inner diameter slightly larger than the outer diameter of the inner ring 1, and one outer surface thereof is cut or polished to give a raceway groove 9 B with one shoulder dropped. . The inner ring member 9 is attached to the outer surface of the inner ring 1 in a state where the balls 4 and the like are arranged as shown in the figure. At this time, the adhesive may be applied to the inner surface of the inner ring member 9 or the outer surface of the inner ring 1 in advance. The position of the inner ring member 9 is fixed at a position where the contact angle θ is equal to the contact angle on the ball 3 side.

As described above, since the raceway grooves of the inner and outer rings for rolling one of the double row of ball rows are deep grooves, one of the ball rows is assembled in the same manner as a single row ball bearing, and Since the inner ring member 9 that provides the other raceway groove of the shoulder drop is pushed in the thrust direction along the outer surface of the inner ring 1 later, it is possible to easily obtain a double-row angular ball bearing that eliminates backlash and operates stably. The contact angle θ can be easily adjusted simply by changing the inner ring member 9.

FIG. 2 is a view showing another embodiment of the double-row angular contact ball bearing according to the present invention, in which an annular outer ring member 10 is fixed to a large inner diameter surface 2X of the outer ring 2 on the ball 4 side. I have. The outer ring member 10 is an annular member having an outer diameter slightly smaller than the diameter of the large inner diameter surface 2 </ b> X of the outer ring 2, and is preferably made of the same material as the outer ring 2. The portion of the outer race member 10 that comes into contact with the ball 4 is the outer race 2
A track groove 10B with one shoulder falling corresponding to the track groove 2B 'of the second embodiment is provided.

A spring body 11 such as a leaf spring is provided between the balls 3 and 4 so as not to come into contact with them, and a preload is applied between the inner ring 1 and the outer ring 2. Therefore,
The outer ring member 10 is fixed to the large inner diameter surface 2X of the outer ring 2 with an adhesive while a constant pressure preload is applied between the inner ring 1 and the outer ring 2.

In this embodiment, similarly to the above, since the raceway groove for rolling one of the double rows of balls is a deep groove, one of the rows of balls is assembled in the same manner as a single row of ball bearings. A double row angular contact ball bearing that operates stably without any backlash by simply adhering the outer ring member 10 providing the other raceway groove of one shoulder drop to the large inner diameter surface 2X of the outer ring 2 while applying a force in the thrust direction. Can be easily obtained, and the contact angle θ can be easily adjusted only by changing the outer ring member 10.

Next, in the double row angular contact ball bearing according to another embodiment of the present invention shown in FIG. 3, the outer diameter of the inner ring 1 on which the ball 4 is located is cut and removed to reduce the outer diameter. The inner ring member 9 is fixed to the small outer diameter surface 1Y, and at this time, the spring body 11 is engaged with the inner ring 1 and the inner ring member 9 to apply a preload to the inner ring 1. That is, the inner ring member 9 is bonded and fixed to the small outer diameter surface 1Y of the inner ring 1 while applying a preload to the inner ring 1.

In this embodiment, as described above, since the raceway groove for rolling one of the double rows of balls is a deep groove, one ball row is assembled in the same manner as a single row ball bearing. By simply bonding the inner ring member 9 providing the other raceway groove with one shoulder dropped to the outer surface of the inner ring 1 corresponding to the large inner diameter surface 2X of the outer ring 2, a double row angular ball that operates stably without any backlash. Bearings can be easily obtained. Also,
On the single row ball bearing side, the radial clearance is managed, and the contact angle θ can be easily adjusted only by replacing the outer ring member 10 with an appropriate one.

In each of the above embodiments, the balls 3 and 4 in the plurality of ball rows are equal. Next, an embodiment in which the diameters of the balls 3 and 4 are different will be described.

In FIG. 4, the diameter of each ball 3 in one ball row is smaller than the diameter of each ball 4 in the other ball row. On the outer surface of the inner ring 1, there are formed deep groove race grooves 1A and 1B suitable for the balls 3 and 4, respectively. On the inner surface of the outer ring 2, there are formed deep groove race grooves 2B suitable for the balls 4. The outer ring member 10 is fixed to the inner surface of the outer ring 2 at the position where the small-diameter ball 3 is located while applying a force in the thrust direction from behind. The outer ring member 10 is the same as that described with reference to FIG. 2, and has a raceway groove 10 </ b> A with one shoulder suitable for the ball 3 on its inner surface.

Next, a double-row angular contact ball bearing according to another embodiment of the present invention shown in FIG. 5 has an inner ring member 9 fixed to the outer surface of the inner ring 1 on the side where the small-diameter ball 3 is located.
On the outer surface of the inner race 1, there is formed a raceway groove 9A having a shoulder which is suitable for the ball 3.

In these embodiments, as described above, since the raceway groove for rolling one of the double rows of balls is a deep groove, one ball row is assembled in the same manner as a single row ball bearing. The inner race member or the outer race member providing the other raceway groove of one shoulder drop is only stuck to the outer surface of the inner race 1 or the inner diameter surface of the outer race while applying a preload in the thrust direction. A double-row angular contact ball bearing can be easily obtained. In particular, since the ball diameter of the ball row rolling in the deep groove raceway groove is larger than the other,
A double-row angular contact ball bearing that operates more stably against external force can be obtained.

Next, FIG. 6 shows a part of a hard disk drive using the double-row angular contact ball bearing as described above.

In FIG. 1, reference numeral 20 denotes one of the double-row angular ball bearings described above, which is fixed to the substrate 22 by screws 21 through the inner ring thereof.
A swing arm 24 having a head 23 at the tip is fixed to the outer ring 20 of the double row angular contact ball bearing, and a coil 25 is provided on the opposite side of the swing arm 24, that is, on the side opposite to the head 23. . A magnet 26 is mounted at a position on the substrate 22 facing the coil 25. In addition, 27 is a disk.

A hard disk drive using such a double-row angular contact ball bearing can perform precise driving and is economically advantageous.

The other ball row is
Since the retainer containing the ball and the outer ring member or the inner ring member are incorporated, a ribbon-type retainer that has little effect on rotation can be used. Further, in general bearings, a shaft (shaft) is often used as the inner ring, but the shaft can be used in the same manner in this bearing.

[0027]

As described above, according to the present invention, the raceway groove for rolling one of the double rows of balls is a deep groove, and the inner race member or the outer race which provides the other raceway groove of one shoulder drop. The structure is such that members are incorporated later to function as a part of the inner or outer ring, so the matching accuracy is about 1/6 compared to the conventional one, and the measurement accuracy is micron order compared to the conventional submicron order. Double-row angular contact ball bearings with equivalent accuracy can be easily assembled.

Further, not only can a double row angular contact ball bearing having a different ball diameter of a ball row be produced, but also a crown type retainer has to be used in the past due to assembly restrictions. Since it is possible to use a ribbon-type one having little influence on the rotation, it is also advantageous in obtaining high-precision rotation in this aspect as well.

Therefore, the double-row angular contact ball bearing according to the present invention is easier to manufacture than conventional ones, and can be operated stably with little backlash, as well as greatly reducing the cost.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

FIG. 2 is a view for explaining another embodiment of the present invention.

FIG. 3 is a view for explaining another embodiment of the present invention.

FIG. 4 is a view for explaining another embodiment of the present invention.

FIG. 5 is a view for explaining another embodiment of the present invention.

FIG. 6 is a diagram illustrating an example of a hard disk drive using the double row angular contact ball bearing according to the present invention.

FIG. 7 is a diagram for explaining a conventional example.

[Explanation of symbols]

 1 ····· Inner ring 1A, 1B ··· Track groove 2 ······ Outer ring 2A, 2B ··· Track groove 3,4 ··· Ball 5,6 ···· Retinaa 7, 8 Shield body 9 Inner ring member 10 Outer ring member 11 Spring body

Claims (5)

(57) [Scope of request for utility model registration] 1. A double row angular contact ball bearing comprising a plurality of ball rows between an inner ring and an outer ring and a retainer holding the ball rows, a track formed on each of the inner ring and the outer ring for rolling one of the ball rows. Each of the grooves is a deep groove, and the raceway groove formed in the inner ring or the outer ring that rolls the other ball row is a deep groove, and the gap between the outer wall of the inner ring where the one ball row is located and the inner wall of the outer ring is On the other hand, the distance between the outer wall of the inner race and the inner wall of the outer race where the other row of balls is located is increased, and the inner race member is added and fixed to the outer surface of the inner race on the side with the larger distance, so that the other row of balls is A double row angular contact ball bearing characterized in that it rolls between a raceway groove of a deep groove of the outer race and a raceway groove of one shoulder of the inner race member. 2. A double-row angular contact ball bearing comprising a plurality of ball rows between an inner ring and an outer ring and a retainer for holding the ball rows, the tracks respectively formed on the inner ring and the outer ring for rolling one of the ball rows. Each of the grooves is a deep groove, and the raceway groove formed in the inner ring or the outer ring that rolls the other ball row is a deep groove, and the gap between the outer wall of the inner ring where the one ball row is located and the inner wall of the outer ring is In comparison, the distance between the outer wall of the inner race and the inner wall of the outer race where the other row of balls is located is made larger, and an outer ring member is added and fixed to the inner surface of the outer race on the side of the larger distance, so that the other row of balls is A double row angular contact ball bearing rolling between a raceway groove of a deep groove of the inner race and a raceway groove of one shoulder of the outer race member. 3. A double-row angular contact ball bearing comprising a plurality of ball rows and an retainer for holding the same between an inner ring and an outer ring, wherein the ball diameter of one ball row is smaller than the ball diameter of the other ball row. An outer ring member is added to and fixed to the inner wall surface of the outer ring corresponding to the ball row having a smaller ball diameter, so that the other ball row rolls between the inner ring and the outer ring member. Double row angular contact ball bearing. 4. A double-row angular contact ball bearing having a plurality of ball rows between an inner ring and an outer ring and a retainer holding the plurality of ball rows, a ball diameter of one ball row is larger than a ball diameter of the other ball row. An inner ring member is added to and fixed to the outer wall surface of the inner ring corresponding to the ball row having a smaller ball diameter, so that the other ball row rolls between the outer ring and the inner ring member. Double row angular contact ball bearing. 5. A vehicle comprising: a plurality of rows of balls between an inner ring and an outer ring; and a retainer for holding the plurality of rows of balls, and a member provided between the inner ring and the outer ring to contact one of the rows of balls so as to provide one raceway groove. A hard disk drive, wherein a swing arm having a head at a tip is fixed to the outer ring of the double row angular contact ball bearing.