Double seal bearing

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a double-seal bearing characterized in that two non-contact seal plates are provided on at least one side of the bearing, and particularly to a double-seal ball bearing suitable for a spindle motor for a hard disk drive or the like.

【0002】

[Conventional technology and its problems]

1. Figure 10 shows a bearing with a conventional non-contact seal structure. This conventional seal structure is a non-contact type in which the outer periphery of one seal plate 11 is fixed to the end surface of the outer ring 2 and a small gap is provided between the inner peripheral edge of the seal plate and the outer peripheral edge of the inner ring 1.

【0003】

In non-contact type bearings, when the inner ring or outer ring rotates, the grease sealed inside the bearing, or dust and other dirty substances remaining inside the bearing, pass through the gaps in the non-contact part of the seal plate. There is a problem that it flows out to the outside of the bearing.

【0004】

In order to prevent these problems, the following measures are taken as general conventional measures. (1) One means is to have a contact-type seal structure in which the inner peripheral edge 12a of the seal plate 12 is in contact with the outer periphery of the inner ring 1 as shown in FIG. (2) An oil seal (contact type seal) is provided on the outside of the bearing, or a non-contact type labyrinth seal mechanism is provided, and grease, dust, etc. are blocked by the oil seal or the labyrinth seal mechanism.

【0005】

However, all of these have the following problems and drawbacks. (1) In the case of a bearing having a contact type seal structure, the inner peripheral edge of the seal plate is in contact with the inner ring, so that the following problems occur. (a) Friction torque is generated at the contact part. (b) Wear occurs on the contact part (particularly the inner peripheral edge of the seal plate) over the course of use, and particles such as grease leaks and dust due to wear are generated. (c) The sealing material may be restricted to rubber or resin materials, which may limit its use. (2) One of the biggest common problems in the case of a structure in which an oil seal (contact type seal) is provided outside the bearing or a non-contact type labyrinth seal mechanism is provided is to install the seal mechanism. This is a point that requires a separate space, which poses a big problem for equipment that requires miniaturization and space reduction, and also leads to an increase in cost.

【0006】

2. In addition, in bearings used for spindle motors of hard disk drives, if particles such as wear particles generated during rotation flow out to the magnetic disk section, the function of the magnetic disk will be fatally adversely affected. For this reason, various sealing means are currently used to prevent the particles generated in the bearing from flowing out to the outside.

【0007】

In this case, the sealing effect may be a bearing with a contact-type seal plate, but particles are generated by friction at the seal contact portion, and therefore the use of a bearing with a contact-type seal plate is inappropriate and cannot be adopted.

【0008】

For this, A means of using a bearing having one non-contact seal plate on one side and an external labyrinth mechanism together. A means for using a bearing having one non-contact seal plate on one side and a magnetic fluid seal mechanism on the outside. A means for using a bearing having one non-contact seal plate on one side and a labyrinth mechanism in addition to a magnetic fluid seal mechanism on the outside. Etc. are currently adopted, but a means for providing a labyrinth mechanism and a magnetic fluid sealing mechanism on the outside requires a space for the mechanism. However, since the distance between bearings (bearing span) cannot be increased, there are problems with resonance vibration caused by the rotational accuracy and assembly rigidity of the motor hub, as well as problems with rotational stability, and inside the bearing. It is hard to say that there is sufficient reliability to block the outflow of particles to the disc.

【0009】

[Purpose of the present invention]

In the present invention, a conventional non-contact type seal plate is incorporated into a bearing having one on one side, and a labyrinth seal mechanism previously assembled to the outside is incorporated in the bearing, and two labyrinth mechanisms are provided to provide non-contact. The purpose is to improve the mold sealing function and ensure that it is smoothed.

【0010】

In addition, the sealing effect can be appropriately achieved with either the inner ring rotation bearing or the outer ring rotation bearing, and it is possible to provide a bearing that can be used for various purposes.

【0011】

Means of the present invention

In order to achieve the above object, the bearing of the present invention has an annular inner seal plate and an outer seal having a hole in the center on at least one side of the bearing in which the rolling elements are arranged between the inner ring and the outer ring, respectively. The plate is attached so as to have a non-contact labyrinth seal function having a slight gap between the inner ring or the outer ring.

【0012】

Moreover, the embodiment is as follows.

【0013】

<Embodiment 1> The outer peripheral portion of the inner seal plate is fixed to the end face of the small-diameter inner recess portion in the two-stage recess formed on the end face of the outer ring, and the inner peripheral portion of the seal plate is the end face of the inner ring. The outer seal plate has a labyrinth seal function by making it non-contact with the inner ring so that a slight gap is formed between the two large-diameter inner steps formed in the above. Is fixed to the end face of the small-diameter outer step portion of the inner ring with an adhesive, and the outer peripheral portion is designed so that a slight gap is formed between the outer ring and the large-diameter outer recess portion of the outer ring. It has a labyrinth seal function as a non-contact.

【0014】

<Embodiment 2> The inner peripheral portion of the inner seal plate is fixed to the end surface of the large-diameter inner step portion in the inner ring, and a slight gap is formed between the outer peripheral portion and the small-diameter inner recess portion in the outer ring. The outer peripheral part is fixed to the end face of the large-diameter outer recess in the outer ring, and the inner peripheral part is the small-diameter outer step part in the inner ring. It has a labyrinth seal function by making it non-contact so that there is a slight gap between the two.

【0015】

<Embodiment 3> The outer peripheral portion of the inner seal plate is fixed to the end surface of the inner recess portion having a small diameter of the outer ring, and a slight gap is formed between the inner peripheral portion and the inner step portion having a large diameter of the inner ring. The outer peripheral part of the outer seal plate is fixed to the end face of the large-diameter outer recess of the outer ring, and the inner peripheral part is connected to the small-diameter outer step of the inner ring. It is designed to have a labyrinth seal function by making it non-contact so that there is a slight gap between them.

【0016】

<Embodiment 4> If the inner peripheral portion of the inner seal plate is fixed to the end surface of the large-diameter inner step portion of the inner ring, and the outer peripheral portion is non-contact so as to form a slight gap with the inner recess portion having a small diameter of the outer ring. The outer seal plate is also fixed to the end face of the small diameter outer step of the inner ring, and the outer peripheral part has a slight gap with the large outer recess of the outer ring. It is made non-contact so that it has a labyrinth seal function.

【0017】

<Embodiment 5> The inner peripheral portion of the inner sealing plate is fixed to the end surface of the step portion of one wheel formed on the end surface of the inner ring, and a slight gap is formed between the outer peripheral portion and the inner recessed portion having a small diameter of the outer ring. The outer sealing plate has a labyrinth sealing function by making it non-contact, and the diameter of the inner peripheral edge is the same as or slightly larger than the diameter of the shaft hole of the inner ring, and the outer peripheral part is the large diameter of the outer ring. It is fixed to the end face of the outer recessed portion, and the inner peripheral portion has a labyrinth seal function by leaving a slight gap e in the axial direction between the end face and the inner peripheral portion to make it non-contact.

【0018】

<Embodiment 6> A labyrinth seal is formed by fixing the outer peripheral portion of the inner seal plate to the end surface of the inner recess portion having a small diameter of the outer ring, and making the inner peripheral portion non-contact with the step portion of the inner ring with a slight gap a. The outer seal plate has a function, and the diameter of the inner peripheral edge is the same as or slightly larger than the diameter of the shaft hole of the inner ring, and the outer peripheral part is fixed to the end face of the large diameter outer recess of the outer ring. The inner peripheral part has a labyrinth seal function by making it non-contact with a slight gap in the axial direction from the end face of the inner ring.

【0019】

<Embodiment 7> A single recess is provided on the end surface of the outer ring, the outer peripheral portion of the inner seal plate is fixed to the end surface of the recess, and the inner peripheral portion of the inner seal plate is a large-diameter inner step portion of the inner ring. A slight gap a is left between the two to provide a labyrinth seal function, and the outer diameter of the outer seal plate is the same as or slightly smaller than the outer diameter of the outer ring. Is fixed to the end face of the small-diameter outer step portion of the inner ring, and the outer peripheral portion is made non-contact with a slight gap f in the axial direction with respect to the end face of the outer ring to have a labyrinth seal function.

【0020】

<Embodiment 8> A recessed portion of one wheel is provided on the end surface of the outer ring, the outer diameter of the outer sealing plate 6 is the same as or slightly smaller than the outer diameter of the outer ring, and the inner peripheral portion of the inner sealing plate is the inner ring. It is fixed to the end face of the large-diameter inner step part, and the outer peripheral part has a labyrinth seal function by leaving a slight gap c with respect to the recessed part 2c of the outer ring and making it non-contact, and the outer seal plate has a labyrinth seal function. The inner peripheral part is fixed to the end face of the small diameter outer step part of the inner ring, and the outer peripheral part is made non-contact with a slight gap f in the axial direction with respect to the end face of the outer ring to have a labyrinth seal function. is there.

【0021】

[Features of the present invention]

The present invention exhibits the following features by assembling two non-contact seal plates on the end face of the bearing itself. (a) Compared with the conventional bearing having one non-contact type sealing plate, the sealing effect is greatly improved. (b) It is improved that the internal grease leaks from the non-contact part of the seal plate, and the life of the bearing rotation performance is extended. (c) In order to accommodate the two double seal plates inside the bearing, the labyrinth mechanism previously incorporated outside can be eliminated. (d) By not requiring an external labyrinth mechanism, it is possible to design with high efficiency such as miniaturization, space reduction and cost reduction of equipment. (e) As a countermeasure against the drawbacks of the contact type seal plate, it can be replaced depending on the purpose for the application using the conventional contact type seal plate, and the reliability of the equipment can be improved. (f) When the non-contact type double seal bearing of the present invention is incorporated into a motor for a hard disk drive, particles in the bearing are sufficiently prevented from flowing out to the magnetic disk by the double labyrinth seal function, so that an external labyrinth and a magnetic fluid seal are not required. In addition, it is possible to increase the shaft span, and it is possible to solve the above-mentioned conventional problems of the hard disk drive motor at once.

【0022】

[Example]

FIGS. 1 and 2 show a first embodiment of the bearing according to the present invention. In the figure, the side surface portion between the inner and outer rings of the bearing provided with the ball 3 which is a rolling element held by the retainer 4 between the inner ring 1 and the outer ring 2 has two annular seal plates having a hole in the center. It is blocked by 5 and 6. That is, the outer peripheral portion of the inner seal plate 5 is fixed to the end faces of the two-stage recessed portions 2a and 2b formed on the end surface of the outer ring 2 with an adhesive, and the seal plate is fixed to the end surface of the small diameter inner recessed portion 2a. The inner peripheral portion of 5 is different from the inner ring because a slight gap a is formed between the outer peripheral surface and the end surface of the two stepped portions 1a and 1b having a large diameter inner stepped portion 1a formed on the end face of the inner ring 1. It has a labyrinth seal function by making contact.

【0023】

Further, in the outer seal plate 6, the inner peripheral portion is fixed to the end surface of the small-diameter outer step portion 1b in the inner ring 1 with an adhesive, and the outer peripheral portion is the inner peripheral surface of the large-diameter outer recess portion 2b in the outer ring 2. A slight gap b is formed between the surface and the end face so that the outer ring is not in contact with the outer ring to provide a labyrinth seal function.

【0024】

In the second embodiment shown in FIG. 3, the inner peripheral portion of the inner sealing plate 5 is fixed to the end surface of the large-diameter inner step portion 1a in the inner ring 1 with an adhesive, and the outer peripheral portion has a small diameter in the outer ring 2. A slight gap c is formed between the inner peripheral surface and the end surface of the inner recessed portion 2a of the above, and the labyrinth seal function is provided by making it non-contact with the outer ring. Further, the outer peripheral portion of the outer seal plate 6 is fixed to the end surface of the large-diameter outer recess 2b in the outer ring 2 with an adhesive, and the inner peripheral portion is the outer peripheral surface and the end surface of the small-diameter outer step portion 1b in the inner ring. A slight gap d is formed between the two, and the labyrinth seal function is provided by making the inner ring non-contact.

【0025】

In the third embodiment shown in FIG. 4, the inner peripheral portion of the inner sealing plate 5 is fixed to the end face of the inner recess 2a having a small diameter of the outer ring 2 with an adhesive, and the inner peripheral portion is the large diameter inner portion of the inner ring 1. The labyrinth seal function is provided as a non-contact that creates a slight gap a between the outer peripheral surface and the end surface of the step portion 1a. Further, the outer peripheral portion of the outer seal plate 6 is also fixed to the end face of the large-diameter outer recess 2b of the outer ring 2 with an adhesive, and the inner peripheral portion is the outer peripheral surface and the end face of the small-diameter outer step portion 1b of the inner ring 1. The labyrinth seal function is provided as a non-contact with a slight gap d between the two.

【0026】

In the fourth embodiment shown in FIG. 5, the inner peripheral portion of the inner sealing plate 5 is fixed to the end surface of the large-diameter inner step portion 1a of the inner ring 1 with an adhesive, and the outer peripheral portion is a small-diameter inner recess of the outer ring 2. The labyrinth seal function is provided as a non-contact that creates a slight gap c between the inner peripheral surface and the end surface of the portion 2a. Further, the inner peripheral portion of the outer seal plate 6 is also fixed to the end surface of the small diameter outer step portion 1b of the inner ring 1 with an adhesive, and the outer peripheral portion is the inner peripheral surface and the end surface of the large diameter outer recessed portion 2b of the outer ring 2. The labyrinth seal function is provided as a non-contact with a slight gap b between the two.

【0027】

The inner ring and the outer seal plate of the fifth embodiment shown in FIG. 6 are different from those of the first to fourth embodiments. That is, the inner ring 1 has only one step portion 1c, and the inner peripheral portion of the inner sealing plate 5 is fixed to the end surface of this step portion with an adhesive, and the outer peripheral portion is the small diameter inner recess portion 2a of the outer ring 2. A labyrinth seal function is provided by leaving a slight gap c between the inner peripheral surface and the end surface to prevent contact.

【0028】

Further, the diameter of the inner peripheral edge of the outer seal plate 6 is the same as or slightly larger than the diameter of the shaft hole of the inner ring 1, and the outer periphery is used as an adhesive on the end face of the large diameter outer recess 2b of the outer ring 2. The inner peripheral portion is provided with a labyrinth seal function by leaving a slight gap e in the axial direction between the inner peripheral portion and the end surface of the inner ring 1 to make it non-contact.

【0029】

In the sixth embodiment shown in FIG. 7, the outer peripheral portion of the inner seal plate 5 is fixed to the end face of the inner recess 2a having a small diameter of the outer ring 2 with an adhesive, and the inner peripheral portion is the step portion 1c of the inner ring. A labyrinth seal function is provided by leaving a slight gap a between the outer peripheral surface and the end surface to prevent contact. Further, the diameter of the inner peripheral edge of the outer seal plate 6 is the same as or slightly larger than the diameter of the shaft hole of the inner ring 1, and the outer periphery is used as an adhesive on the end face of the large diameter outer recess 2b of the outer ring 2. The inner peripheral portion is provided with a labyrinth seal function by leaving a slight gap e in the axial direction between the inner peripheral portion and the end surface of the inner ring 1 to prevent contact.

【0030】

In the seventh embodiment shown in FIG. 8, a single recess 2c is provided in the outer ring 2, and the outer peripheral portion 5 of the inner sealing plate is fixed to the end face of the recessing portion with an adhesive to seal the inner ring. The inner peripheral portion of the plate is provided with a labyrinth sealing function by making a slight gap a between the outer peripheral surface and the end surface of the large-diameter inner step portion 1a of the inner ring 1 so as to be non-contact. Further, the outer diameter of the outer seal plate 6 is the same as or slightly smaller than the outer diameter of the outer ring, and the inner peripheral portion is fixed to the end surface of the small diameter outer step portion 1b of the inner ring 1 with an adhesive, and the outer diameter is fixed. A labyrinth seal function is provided by leaving a slight gap f in the axial direction between the peripheral portion and the end face of the outer ring 2 to make it non-contact.

【0031】

In the case of the eighth embodiment shown in FIG. 9, the outer ring 2 is provided with a recessed portion 2c of one wheel, and the outer diameter of the outer seal plate 6 is the same as or slightly smaller than the outer diameter of the outer ring. The inner peripheral portion of the inner sealing plate 5 is fixed to the end surface of the large-diameter inner step portion 1a of the inner ring 1 with an adhesive, and the outer peripheral portion is slightly between the inner peripheral surface and the end surface of the recessed portion 2c of the outer ring 2. A labyrinth seal function is provided by leaving a gap c to make it non-contact. Further, in the outer sealing plate 6, the inner peripheral portion is fixed to the end face of the small diameter outer step portion 2 of the inner ring 1 with an adhesive, and the outer peripheral portion is provided with a slight axial gap f between the outer peripheral portion and the end face of the outer ring 2. It has a labyrinth seal function by opening and making it non-contact.

【0032】

In the above embodiment, the two inner and outer seal plates 5 and 6 are provided on both sides of the bearing body, but the inner and outer seal plates 5 and 6 are provided on only one side of the bearing body and the opposite side is the conventional one. In some cases, one contact type seal plate, a non-contact type seal plate is provided, or no seal plate is provided and the bearing is not closed. Further, although a ball bearing using a ball is shown as the rolling element, there is also a case of a roller bearing in which the rolling element is a roller, and there is also a case of a needle bearing. There is also the case of fluid bearings.

【0033】

The bearing of the present invention can be effectively used for bearings of rotating parts of various motors, particularly motors of hard disk drive devices, or for bearings of rotating shafts of swing arms of the device.

[Simple explanation of drawings]

[Figure 1]

The front view which shows 1st Example of the double seal bearing which concerns on this invention.

[Figure 2]

The vertical sectional view of the same as above.

[Fig. 3]

The vertical sectional view which shows the 2nd Example of the double seal bearing which concerns on this invention.

[Fig. 4]

The vertical sectional view which shows the 2nd Example of the double seal bearing which concerns on this invention.

[Fig. 5]

The vertical sectional view which shows the 2nd Example of the double seal bearing which concerns on this invention.

[Fig. 6]

The vertical sectional view which shows the 2nd Example of the double seal bearing which concerns on this invention.

[Fig. 7]

The vertical sectional view which shows the 2nd Example of the double seal bearing which concerns on this invention.

[Fig. 8]

The vertical sectional view which shows the 2nd Example of the double seal bearing which concerns on this invention.

[Fig. 9]

The vertical sectional view which shows the 2nd Example of the double seal bearing which concerns on this invention.

[Fig. 10]

The vertical sectional view which shows an example of the conventional bearing which has a non-contact type seal structure.

[Fig. 11]

The vertical sectional view which shows an example of the conventional bearing which has a contact type seal plate structure.

[Explanation of symbols]

1 Inner ring 1a, 1b, 1c steps 2 outer ring 2a, 2b, 2c dents 3 balls 4 retainer 5 Inner seal plate 6 Outer seal plate a d Gap e, f Axial gap