JPH0988981A - Bearing seal and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To capacitate a bearing seal to secure its sealability to the full, and also capable of surely preventing any nonconformity such as deformation or the like in a bearing outer ring from occurring as well as to make an improvement in production efficiency and a reduction in manufacturing cost promotable, especially usable for a small-sized bearing so well. SOLUTION: This bearing seal is constituted with a ring laminated plate 20, where an elastic coating layer 22 consisting of an elastic member is formed on one surface of a metal core plate 21, and further it is so constituted that an outer circumferential edge part is bent to the other face side, forming an edge bending part 30 there, and in a state of being attached to a bearing 1, a specified area of the elastic coating layer 22 is stuck close to an inner circumferential step part 1f formed in a bearing outer ring 1a, while a tip of the edge bending part 30 is made so as to be pressed to the inner surface of an inner circumferential groove 1d formed in this bearing outer ring 1a by dint of elastic repulsion od the metal core plate 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing seal mounted in an annular opening between inner and outer rings of a bearing and a method for manufacturing the same, and particularly to a small size in a precision device such as a hard disk drive or a video tape recorder. The present invention relates to a bearing seal that can be suitably used for miniature bearings and a method for manufacturing the seal.

[0002]

2. Description of the Related Art As shown in FIGS. 7 and 8, a hermetically sealed rolling bearing (1) includes an outer ring (1a) and an inner ring (1).
The annular opening (1c) between b) is sealed by an annular bearing seal (2).

There are many types of such bearing seals, but the small size bearing seal (2) to be mounted on a small diameter bearing (1) such as a miniature bearing is mainly made of a metal plate. This bearing seal (2) is formed by punching a metal plate in an annular shape and bending the outer peripheral edge of the annular metal plate to form an edge bending portion (2a), as shown by an imaginary line in FIG. Is what you get.

As shown by the solid line in FIG. 9, the seal (2) is caulked at the edge bending portion (2a) and is fitted into the inner peripheral groove (1d) of the outer ring (1a) in a pressure contact state, whereby the bearing ( It is attached to 1).

However, since the bearing seal (2) is made of a metal having high rigidity, it is caulked when the edge bent portion (2a) is caulked and fitted into the inner circumferential groove (1d) of the outer ring (1a). The accompanying strong force is applied to the outer ring (1a), and the outer ring (1a) is deformed, and the dimensional accuracy such as the roundness of the outer ring (1a) is reduced and the quality is deteriorated. Further, the metal seal (2) has insufficient adhesion to the outer ring (1a), resulting in grease leakage between the two and other drawbacks such that sufficient sealing performance cannot be ensured.

On the other hand, as shown in FIG. 10, as a commonly used bearing seal (10), an annular metal core plate (3) is used.
a) a coating layer (3) made of an elastic member by vulcanization compression molding
What formed b) is known. This seal (3)
The outer peripheral seal part (3c) is made of an elastic member, and the seal part (3c) is the inner peripheral groove (1d) of the bearing outer ring (1a).
Since it is fitted and fixed in a compressed state,
It can be sufficiently brought into close contact with the outer ring (1a), and grease leakage and the like can be reliably prevented.

However, the bearing seal (3) has a punching step and a bending step for obtaining the core plate (3a).
A large number of steps are required, such as a step of arranging the core plate (3a) in a mold and vulcanization compression molding to form an elastic coating layer, and a step of removing an excessive elastic portion (burr). However, there was a problem of causing an increase in cost. Above all, in vulcanization compression molding, the work of arranging the core plates in the mold with high positional accuracy or carefully tearing out fine burrs requires a great deal of labor and an enormous amount of time. The work load increases, and when manufacturing a small-sized seal for a miniature bearing or the like, there is a problem that production efficiency is further reduced and cost is increased.

<Background of the Invention> Therefore, the applicant of the present application has proposed a bearing seal suitable for a small size bearing in Japanese Patent Application No. 7-34861.

As shown in FIG. 11, this bearing seal is composed of an annular laminated plate (4) having an elastic coating layer (4b) formed on one surface of a metal core plate (4a). The outer peripheral edge portion of () is bent to the other surface side to form a rising edge bent portion (4c) substantially parallel to the axial direction. This bearing seal (5) is provided with an edge bending portion (4c).
In the state where the coating layer (4b) in the vicinity is brought into close contact with the inner peripheral stepped portion (1f) of the bearing outer ring (1a), the edge bent portion (4c) is moved by the elastic repulsion force of the core plate (4a) to the bearing outer ring (4a). The inner peripheral end face (1e) of 1a) is pressure-contacted and mounted on the bearing (1).

In the bearing seal (5), the elastic coating layer (4b) is provided on the inner peripheral step (1) of the bearing outer ring (1a).
Since it is brought into close contact with f), sufficient sealing performance can be secured. Further, since the seal (5) can be basically manufactured by two pressing steps including a step of punching out the laminated plate (4) and a step of bending the outer peripheral edge portion, the production efficiency is improved and the cost is reduced. Can be achieved. Moreover, since these steps can be realized only by the pressing step, which is less disadvantageous even when handling small-sized products, high production efficiency can be maintained at low cost even when manufacturing small-sized seals for miniature bearings and the like.

[0011]

By the way, in the bearing seal (5) of this proposed example, in order to secure a sufficient hermeticity, the elastic coating layer (4b) in the vicinity of the edge bending portion (4c) is internally sealed. Although it is closely attached to the peripheral step portion (1f), this close contact force is secured by the frictional force between the edge bent portion (4c) and the inner peripheral end surface (1e). Therefore, in order to obtain a predetermined adhesive force, the rim bending portion (4c) should be attached to the bearing outer ring (1
The bearing outer ring (1a) may be deformed due to the strong pressure contact force with a). In particular, the roundness is low for low strength products such as the outer ring (1a) of small size bearings. There is a risk that the dimensional accuracy of such items will decrease and the quality will deteriorate.

The present invention has been made in view of the above circumstances, and it is possible to secure sufficient sealing performance, to reliably prevent defects such as deformation of the bearing outer ring, and to improve production efficiency and reduce costs. It is an object of the present invention to provide a bearing seal that can be achieved, and can be suitably used particularly for a small size bearing, and a manufacturing method thereof.

[0013]

In order to achieve the above object, the first invention of the present application is a bearing seal to be mounted on an annular open portion between inner and outer rings of a bearing, wherein at least one surface of a metal core plate is provided. An annular laminated plate having an elastic covering layer formed of an elastic member formed on the outer peripheral edge portion of which is bent to the other surface side to form an edge bending portion, and the elastic covering layer is attached to the bearing. A predetermined region of the inner peripheral step portion formed on the bearing outer ring, and the edge of the rim bending portion,
A gist of the present invention is that it is configured to be pressed against the inner surface of the inner peripheral groove formed in the bearing outer ring by the elastic repulsive force of the metal core plate.

In the bearing seal according to the first aspect of the present invention, the elastic coating layer is required when the end of the rim bending portion is pressed against the inner surface of the inner peripheral groove of the bearing outer ring by the elastic repulsive force of the core plate and mounted on the bearing. Since the portion comes into close contact with the inner peripheral step portion of the bearing outer ring, sufficient sealing performance can be secured and grease leakage can be reliably prevented. Further, the force applied to the bearing outer ring is mainly an elastic repulsive force of the core plate, and it is possible to prevent a large amount of force from being applied to the outer ring and prevent harmful outer ring deformation.

Moreover, since the tip of the edge bending portion having a bending angle of about 5 ° to 60 ° is pressed against the inner circumferential groove of the bearing outer ring, the pressing force in the outer radial direction which adversely affects the bearing outer ring is reduced. Therefore, the outer ring deformation can be prevented more reliably.

Further, in the first aspect of the present invention, when the edge bending portion is formed with a plurality of notches along the circumferential direction, the edge bending portion can be flexed moderately and reasonably over the entire circumference. Yes, the work of fitting into the bearing can be done smoothly.

On the other hand, in the method of manufacturing a bearing seal according to the second aspect of the present invention, an annular laminated plate is obtained by punching out a laminated plate having an elastic coating layer made of an elastic member formed on at least one surface of a metal core plate. It includes a punching step and a bending step of bending the outer peripheral edge portion of the seal to the other surface side to form an edge bending portion having a bending angle of 5 ° to 60 °.

Since the second invention specifies the manufacturing process of the bearing seal of the first invention, it is possible to manufacture the bearing seal having the above-described effects.

Further, in the second aspect of the present invention, when the above-mentioned two steps to be carried out are simultaneously performed, the production efficiency can be further improved.

[0020]

1 to 3 are views showing a bearing seal (10) according to an embodiment of the present invention. As shown in these figures, the bearing seal (10) is composed of an annular laminated plate (20) having an elastic coating layer (22) formed on one surface of a metal core plate (21) and having an outer peripheral edge. The part is bent to the other surface side to form an edge bent part (30), and the inner peripheral edge part is bent to the one surface side to reinforce the part (3).
5) is formed, and further, a plurality of cutout portions (40) are formed in the edge bending portion (30) at predetermined intervals along the circumferential direction.

The bearing seal (10) is replaced with the bearing (1).
In order to install the bearing seal (10) on the bearing (1), the seal (10) is pushed into the annular opening (1c) between the outer ring (1a) and the inner ring (1b) of the bearing (1), and the edge seal of the bearing seal (10) is bent. It suffices to fit the inner ring groove (1d) of the outer ring (1a) while bending the part (30). In this mounted state,
Due to the elastic repulsive force of the core plate (21), the edge bending portion (30) is biased in the bending direction, and the edge portion of the core plate (21) at the tip of the edge bending portion (30) is the bearing outer ring (1a). While being pressed against the inner surface of the inner peripheral groove (1d), the elastic coating layer (22) near the edge bending portion (30) is in close contact with the inner peripheral stepped portion (1f) of the bearing outer ring (1a).

The structure of the bearing seal (10) will be described in detail below.

As the core plate (21) of the laminated plate (20),
A material made of a rigid metal can be used, for example, a material made of stainless steel, aluminum, a cold-rolled steel sheet or the like can be preferably used, and among them, a material made of a cold-rolled steel sheet can be particularly preferably used.

The elastic coating layer (22) on one surface of the laminated plate (20) may be made of any elastic material such as nitrile rubber (NBR), acrylic rubber, fluororubber, Those made of synthetic rubber such as urethane rubber, and those made of synthetic resin such as polyamide, polyacetal, polybutylene terephthalate, thermoplastic elastomer and thermoplastic urethane can be preferably used, and particularly those made of NBR are more preferable. Can be used.

The other surface of the laminated plate (20) is preferably coated with resin or the like in order to improve durability such as rust prevention.

The laminate (20) has a thickness of 0.2 to 0.5.
mm can be preferably used, and especially for small size miniature bearings, those of 0.1 to 0.3 mm,
Above all, those having a thickness of 0.15 to 0.25 mm can be more preferably used. That is, if the thickness of the laminated plate (20) is too thin, sufficient rigidity cannot be obtained and deformation or the like is likely to occur, which is not preferable. On the other hand, if the thickness is too thick, the rigidity becomes too high, which makes it difficult to mount the bearing (1) and may increase the material cost, which is not preferable.

The thickness of the core plate (21) is 0.1 to 0.3 m.
In the case of a miniature bearing, particularly 0.1 mm to 0.15 mm can be used more preferably. That is, if the thickness of the core plate (21) is too thin, the rigidity is lowered, and if it is too thick, the rigidity is too high, and the same problems as described above occur, which is not preferable.

The coating layer (22) has a thickness of 0.03 to 0.
A 10 mm one can be preferably used, and particularly for a miniature bearing, a 0.05 to 0.10 mm one can be used.
It can be used more preferably. That is, if the coating layer (22) becomes too thin, the outer ring (1
There is a case where it does not adhere sufficiently to a) and a good sealing property cannot be secured. Conversely, if it becomes too thick, the core plate (2
The thickness of 1) becomes thin, the rigidity decreases, and the same problems as described above occur, which is not preferable.

On the other hand, the inner peripheral groove (1d) of the bearing outer ring (1a)
As shown in FIG. 4, the seal pressure contact area (1g) from the one end position (P1) to the bottom vicinity position (P2) is formed in a flat area having an inclination angle of about 45 ° with respect to the axis. It is preferable that the tip of the edge bending portion (30) of the bearing seal (10) is brought into pressure contact with the region. That is, when the press-contacting position of the tip of the edge bending portion deviates from the press-contacting region (1g), not only a good mounting force cannot be obtained but also the mounting may not be possible in some cases, which is not preferable. The bearing (1) of the bearing seal (10)
In consideration of the workability of mounting on, the edge bending portion (30) is more preferably configured so as to be in pressure contact with the position (P1) rather than the midpoint of the positions (P1) and (P2).

Further, the edge bending portion (3) of the bearing seal (10) is
The bending angle (α) of 0) is 5 ° to 60 °, preferably the lower limit is 10 ° or more and the upper limit is 40 ° or less, more preferably
It is preferable to set the lower limit to 20 ° or more and the upper limit to 40 ° or less. That is, if the bending angle (α) is too large or too small, the bearing outer ring (1a) at the tip of the edge bending portion (30)
It is not preferable because the position of pressure contact with can not be set within the seal pressure contact region (1g) described above, and the same problem as described above occurs.

Further, when the bearing seal (10) is mounted on the bearing (1), the elastic coating layer (22) is in close contact with the inner peripheral step (1f). The thickness of 22) is 1/4 to 1 as compared with that in the natural state.
It is preferable to secure the adhesive force to such an extent that it is compressed by 1/2.

The bearing seal (10) having the above-described structure has an annular punching step and a bending step for finishing into a predetermined shape with respect to a laminated plate having a coating layer formed on one surface of a metal core plate. Can be manufactured by carrying out. In this case, it is common to perform the bending process on the punched product after performing the punching process. However, in order to improve work efficiency, etc., the combined machining method is used to perform the pressing process once. It is possible to perform the above two steps at the same time. As shown in FIG. 6, in the method of sequentially performing the two steps, the tip end surface of the edge bending portion (30) is inclined with respect to the axial direction, but in the method of simultaneously performing the two steps, As shown in FIG. 2, the tip of the edging portion (30) is parallel to the axial direction.

As described above, according to the bearing seal (10) of the present embodiment, the tip of the rim bending portion (30) is brought into pressure contact with the inner surface of the inner peripheral groove (1d) of the bearing outer ring (1a) to form a bearing. When mounted on (1), the predetermined area of the elastic coating layer (22) is in close contact with the inner peripheral stepped portion (1f) of the outer ring (1a), so that sufficient sealing performance can be ensured and grease leakage etc. can be ensured. It can be prevented.

When mounted on the bearing (1), the outer ring (1a)
The force applied to the outer ring (1a) is mainly an elastic repulsive force of the core plate (21), and unlike the conventional metal seal described above, a large amount of force due to the caulking process is not applied to the outer ring (1a). Therefore, even when the outer ring (1a) having a small size and low rigidity is fitted, quality deterioration due to deformation of the outer ring can be reliably prevented.

Further, the bearing seal (10) of this embodiment
Can be basically manufactured by only two steps, that is, a step of punching the laminated plate (20) into an annular shape and a bending step of forming the annular laminated plate (20) into a predetermined shape. Since it can be done by pressing once, it is possible to improve the production efficiency and reduce the cost. Further, since these processes have few disadvantages even when handling small-sized products, even when manufacturing small-sized seals for miniature bearings, etc., high production efficiency can be maintained at low cost.

Further, in the bearing seal (10) of the present embodiment, the edge of the edge bending portion (30) is brought into pressure contact with the inner surface of the inner peripheral groove (1d) of the outer ring (1a) so that the inner portion of the elastic coating layer (22) is Since the adhesion force to the circumferential step portion (1f) is ensured, when compared with the conventional proposal example shown in FIG. 11, the external force to the outer ring (1a) is reduced and the coating layer (22 It is possible to secure a large adhesive force. That is, as shown in FIG. 4, in the bearing seal (10) of the present embodiment, the force (pressing force) that pushes in the seal press contact region (1g) of the inner circumferential groove (1d) at the tip position of the edge bending portion (30). F _1A ) acts. This pressure contact force F _1A is an axial component F _1Y parallel to the axial direction.
And the outer radial component F _1X that adversely affects the outer ring (1a). Here, the inclination angle β with respect to the axis of the seal pressure contact region (1g) of the inner peripheral groove (1d) is 45.
When the angle is 0, both the outer radial direction component F _1X and the axial direction component F _1Y are equal, and the axial direction component F _1Y corresponds to the adhesive force F _1B of the elastic coating layer (22). . That is, the relational expressions F _1X = F _1Y and F _1Y = F _1B are established.

Therefore, if the adhesion force F _1B is a [N], the outer radial direction component F _1X that adversely affects the outer ring (1a) is a [N].

On the other hand, in the bearing seal (3) of the proposed example shown in FIG. 11, the force exerting a bad influence on the outer ring (1a) is the pressure contact force to the inner peripheral end face (1e) of the edge bending portion (4c). However, this pressure contact force is “F _2X ”, the frictional force between the edge bending part (4 c) and the inner peripheral end face (1 e) is “F _2Y ”, the static friction coefficient between them is “μ”, and the elastic coating layer (4 b ) Inner peripheral step (1
F _2Y = F _2B , F when the adhesion force to f) is “F _2B ”
The relational expression _2Y = F _2X × μ holds.

At this time, assuming that the adhesion force F _2B is a [N] as in the above embodiment, the outer ring (1
Force (pressure contact force) F _2X that adversely affects a) is a / μ [N]
Becomes Here, since the static friction coefficient between the steel plate (outer ring) and the rubber (elastic coating layer) is usually 0.4 to 0.6, assuming that the static friction coefficient μ is 0.5, the pressing force F _2X is a /
0.5 [N] = 2a [N].

Even in the case where the adhesion forces (sealing properties) are equal as described above, in the bearing seal (10) of the present embodiment, the force F _1X that adversely affects the outer ring (1a) is F _{2X of the} proposed example.
Compared with the above, it is possible to reduce the roundness to about half, and it is possible to more reliably prevent a decrease in roundness due to the deformation of the outer ring, and it is possible to further improve the quality.

On the other hand, the bearing seal (10) of this embodiment
In the above, since the plurality of cutout portions (40) are formed in the edge bending portion (30) at predetermined intervals, the edge bending portion (30) is formed.
Can be flexed moderately over the entire circumference,
The work of fitting the bearing (1) can be done smoothly.

Further, in the bearing seal (10) of this embodiment, since the inner peripheral edge portion is bent to form the reinforcing portion (35), the rigidity of the inner peripheral edge portion of the seal and thus the rigidity of the entire seal can be increased. Yes, seal (1) when mounting on the bearing (1)
The deformation of 0) can be prevented, and in this respect, the quality of the product can be further improved.

The bearing seal of the present invention has a simplified bearing outer ring (1a) shape, for example, as shown in FIG. 5, from the inner peripheral step (1f) to the outer ring (1a) of the outer ring (1a).
a) It can also be applied to an outer ring (1a) having a seal pressure contact region (1h) that is inclined with respect to the axial direction toward the end. In this case, the inner peripheral groove (1d) is formed by the seal pressure contact region (1h) and the inner peripheral stepped portion (1f).

[0044]

As described above, according to the bearing seal of the first invention of the present application, sufficient sealing performance can be ensured, defects such as deformation of the bearing outer ring can be reliably prevented, and the production efficiency can be improved. It is possible to reduce the cost, and it is possible to obtain an effect that it can be suitably used particularly for a small size bearing.

In the first aspect of the invention, when the bending angle of the edge bending portion is set to 5 ° to 60 °, there is an advantage that the above effect can be obtained more reliably.

Further, in the first aspect of the present invention, when a plurality of notches are formed along the circumferential direction at the edge bending portion, there is an advantage that the work of mounting on the bearing can be easily performed.

The method of manufacturing the bearing seal according to the second aspect of the present invention specifies the manufacturing process of the bearing seal of the first aspect of the present invention, so that the bearing seal having the above effects can be manufactured.

Further, in the above-mentioned second invention, when two steps to be executed are simultaneously performed, there is an advantage that the production efficiency can be further improved.

[Brief description of drawings]

FIG. 1 is a plan view showing a bearing seal according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a cross-sectional view showing one side portion of the bearing seal of the embodiment in a bearing mounted state.

FIG. 4 is an enlarged cross-sectional view showing a periphery of an edge bending portion of the bearing seal of the embodiment in a bearing mounted state.

FIG. 5 is a cross-sectional view showing one side portion of the bearing seal of the embodiment mounted on another bearing.

FIG. 6 is a cross-sectional view showing one side portion of a bearing seal that is a modified example of the present invention.

FIG. 7 is a cross-sectional view showing the vicinity of one side of a seal in a conventional bearing.

FIG. 8 is a schematic perspective view showing a conventional bearing seal.

FIG. 9 is a cross-sectional view showing one side portion of a conventional bearing seal in a bearing mounted state.

FIG. 10 is a cross-sectional view showing one side portion of another conventional bearing seal in a bearing mounted state.

FIG. 11 is a cross-sectional view showing one side portion of a conventional bearing seal in a bearing mounting state.

FIG. 12 is an enlarged cross-sectional view showing a rim bent portion of a bearing seal of the proposed example in a bearing mounted state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Bearing 1a ... Outer ring 1b ... Inner ring 1d ... Inner circumferential groove 1f ... Inner circumferential step 10 ... Bearing seal 20 ... Laminated plate 21 ... Core plate 22 ... Elastic coating layer 30 ... Edge bending part 40 ... Notch part .. Bending angle

Claims (5)

[Claims] 1. A bearing seal to be mounted in an annular open portion between an inner ring and an outer ring of a bearing, which comprises an annular laminated plate in which an elastic coating layer made of an elastic member is formed on at least one surface of a metal core plate. The outer peripheral edge portion is bent to the other surface side to form an edge bending portion, and in a state of being mounted on the bearing, a predetermined region of the elastic coating layer is in close contact with an inner peripheral step portion formed on the outer ring of the bearing. At the same time, the seal for a bearing is configured such that the tip of the edge bending portion is pressed against the inner surface of the inner peripheral groove formed in the bearing outer ring by the elastic repulsive force of the metal core plate. 2. The bending angle of the bent portion is 5 ° to 60 °.
The bearing seal according to claim 1, wherein the seal is set at °. 3. The bearing seal according to claim 1, wherein a plurality of notches are formed in the rim bent portion along the circumferential direction. 4. A punching step of punching a laminated plate having an elastic coating layer made of an elastic member formed on at least one surface of a metal core plate to obtain an annular laminated plate, and a seal outer peripheral edge portion on the other surface side. Bend and bend angle is 5 °
A method of manufacturing a bearing seal, including a bending step of forming an edge bend portion of -60 °. 5. The method for manufacturing a bearing seal according to claim 4, wherein the punching step and the bending step are performed simultaneously.