JPH08326765A - Sealed bearing and manufacture thereof - Google Patents

Abstract

PURPOSE: To provide sufficient sealing performance by simple constitution by forming a very small gap in a seal gap against either a rotary side member and a stationary side member, and interposing a seal member formed by solidifying a fluid substance. CONSTITUTION: A shield plate 5 is mounted on the inner diameter of the end part of an outer ring, so that a seal gap 6 is formed between the extreme end part 5a and the outer diameter of the end part of an inner ring 1. Next, the seal gap 6 is filled with a seal member made of resin in fluid state, the member is turned round up to the upper part inside the extreme end 5a, and the member is dried and solidified while rotating the inner ring 1, so as to form a sealing member 7. In this process, shear fracture is generated on the contact part between the sealing member 7 and the inner ring 1, and hence a very small gap 8 is formed. Because the very small gap 8 is remarkably smaller than a gap by general machining, sealing performance is improved, and not only outflow of lubricant to the outside but invasion of a foreign substance such as dust or water from the outside can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed bearing device suitable for use in an atmosphere / environment where foreign matter enters from the outside of the bearing and affects bearing performance, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Generally, in a hermetically sealed bearing, rolling elements are equidistantly arranged in a circumferential direction between a inner ring and an outer ring via a cage, and a seal is attached to an end of the inner ring or the outer ring to seal the inside of the bearing. It is configured to do.

Seals are roughly classified into contact seals and non-contact seals. In either seal, a lubricant such as grease flows out or foreign matter such as dust or water enters from the outside. Can be prevented.
Therefore, the durability of the bearing can be improved and deterioration of the lubricant of the bearing can be suppressed.

[0004]

By the way, when the above-mentioned contact seal is adopted, sliding friction heat is generated at the contact portion with the bearing ring, resulting in torque loss. In particular, when using a rubber seal, there is a problem that the contact state (sealed state) becomes unstable depending on the operating temperature and the number of rotations.

On the other hand, when a non-contact seal is adopted,
Although the sealing property is inferior to the contact seal, the above-mentioned problems can be overcome. However, when used in a harsh environment such as in-furnace transportation in glass manufacturing, there is also a problem that glass powder or the like enters the bearing through the seal gap and lubricity is significantly impaired.

Therefore, it is an object of the present invention to provide a hermetically-sealed bearing device and a method for manufacturing the same, which can obtain a sufficient sealability with a relatively simple structure.

[0007]

Therefore, in order to achieve the above-mentioned object, the present invention provides a labyrinth by making a rotating side member and a stationary side member face each other through a seal gap at an end of a bearing. In a sealed bearing device in which a seal is formed, a seal is formed by solidifying a fluid such that a minute gap is formed between the rotating side member and the stationary side member in the seal gap. A member is interposed.

According to a second aspect of the present invention, an inner ring, an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, a retainer for holding the rolling elements at equal circumferential intervals, and an inner ring and an outer ring In a sealed bearing device having a seal member mounted so that a seal gap is formed between the end portion of one bearing ring and the end portion of the other bearing ring, It is characterized in that a sealing member formed by solidifying resin or grease is interposed so that a minute gap is formed between the end portion and the end portion.

According to a third aspect of the invention, a box-shaped housing having caliber portions at both ends, a shaft body inserted through the caliber portion of the housing, and an inner diameter portion of the housing are fitted to rotatably support the shaft body. In a sealed bearing device having a bearing, a housing-side labyrinth member provided in the bore of the housing, and a shaft-body-side labyrinth member provided on the shaft with a seal gap between the housing-side labyrinth member and
It is characterized in that a sealing member formed by solidifying resin or grease is interposed so that a minute gap is formed between any one of the labyrinth members in the seal gap.

A fourth invention is characterized in that an oil-based lubricant is interposed in the minute gap.

A fifth aspect of the invention is characterized in that carbon is added to the grease.

According to a sixth aspect of the present invention, the sealing member is fluidly filled in the seal gap between the rotating side member and the stationary side member facing each other at the end of the bearing to form a labyrinth seal, and then the rotating side. By solidifying the sealing member while relatively rotating the member and the stationary member, a minute gap is formed between the sealing member and either one of the rotating member and the stationary member. It is what

In a seventh aspect of the present invention, of the inner ring and the outer ring, resin or grease is provided in the seal gap formed between the seal member mounted on the end of one race ring and the end of the other race. After filling the sealing member made of the material in a fluid state, the sealing member is solidified while rotating the inner ring or the outer ring to form a minute gap between the sealing member and the end of the other race. Is characterized by.

An eighth invention is characterized in that an oil-based lubricant is interposed in the minute gap.

A ninth aspect of the invention is characterized in that carbon is added to the grease.

[0016]

According to this structure, the sealing member formed by solidifying the fluid is interposed between the rotating member and the stationary member, and the sealing member, the rotating member and the stationary member are also provided. Since a minute gap is formed between one of the members and the rotating side member so that the rotating side member can rotate, the lubricant may flow out or foreign matter may enter from the outside. It can be prevented. In particular, if an oil-based lubricant is interposed in the minute gap, further sealing performance can be obtained.

When carbon is contained in the grease, the proportion of the oil content in the grease is reduced, so that the solidification of the sealing member is promoted. Further, due to the self-lubricating property of carbon, the resistance at the time of contact with the counterpart member can be reduced.

Further, the minute gap between the sealing member and any one of the rotating side member and the stationary side member is the rotating side member and the stationary side member in the process of solidification of the fluidized sealing member. It is formed by shearing caused by relative rotation of the members. In this case, a surface treatment (for example, oil coating) for preventing sticking may be performed on the contact surface of either one of the members with the sealing member to form a minute gap with the sealing member. The gap formed in this way is much smaller than the gap formed by general machining, so the sealability is improved, but especially if an oil-based lubricant is interposed in the minute gap, The sealing property of is obtained.

As the sealing member, a solidified resin or a solidified grease can be used.

[0020]

Next, a first embodiment of the present invention will be described with reference to FIGS. In the figure, 1 is an inner ring, and an outer ring 2 is concentrically arranged on the outer peripheral portion thereof. A plurality of rolling elements (balls) 3 are arranged between the raceway surface 1a of the inner ring 1 and the raceway surface 2a of the outer ring 2, and are held by a cage 4 at equal intervals around the circumference. A seal member, for example, shield plates 5 and 5 made of a metal plate, and a seal gap 6 functioning as a labyrinth seal are formed between the tip 5a and both ends of the inner ring 1 at the inner diameters of both ends of the outer ring 2. Is installed as.

A resin sealing member 7 is provided in the seal gap 6.
Is intervening. Then, a minute gap 8 is formed between the sealing member 7 and the outer diameter of the end portion of the inner ring 1. In particular, the tip portion 5a of the shield plate 5 is bent toward the inside of the bearing, and the sealing member 7 is solidified in a state of embracing the tip portion 5a. For this reason, the sealing member 7 does not easily come off from the tip portion 5a. The inner ring 1, the outer ring 2,
The sealed space formed by the shield plate 5 and the sealing member 7 is filled with an oil-based lubricant (not shown) such as grease, but a solid lubricant may be used. Specifically, a coating of a solid lubricant is formed on the raceways 1a and 2a of the inner ring 1 and the outer ring 2 and on the surfaces of the rolling elements 3. As this solid lubricant, for example, polytetrahydrofuran having an average molecular weight of 5000 or less is used. Fluoroethylene (low molecular weight PTFE) is preferred.

Next, a method of manufacturing the sealed bearing according to the present invention will be described with reference to FIG. First, as shown in FIG. 4A, the shield plate 5 is attached to the inner diameter of the end portion of the outer ring 2 so that a seal gap 6 is formed between the tip portion 5a of the outer ring 2 and the outer diameter of the end portion of the inner ring 1. . The seal gap 6 corresponds to the seal gap in a normal non-contact seal. Next, as shown in FIG. 8B, the sealing gap 6 is filled with a resin sealing member 71 in a fluid state, and the sealing gap 6 is made to wrap around to the upper inside of the tip 5a. After that, the sealing member 71 is dried and solidified while rotating the inner ring 1. As a result, the sealing member 71 becomes the solidified sealing member 7. During this drying and solidification process, shear fracture occurs in the contact portion between the sealing member and the inner ring 1, and a minute gap 8 as shown in FIG. 2 is formed.

According to this method, since the minute gap 8 formed between the inner ring 1 and the first sealing member 7 is much smaller than the gap formed by general machining, the sealing property is improved and the lubrication is improved. In addition to the outflow of the agent to the outside, invasion of foreign matter such as dust and water from the outside can be suppressed. In addition, since the minute gap 8 is formed so small that the inner ring 1 can rotate, the minute gap 8 has low torque, and the original function of the bearing is not impaired.

The inventors of the present invention have used the above-mentioned low molecular weight PTFE as a lubricant, and the sealing member 7 of the present invention, which uses, for example, the trade name "Polycoke" manufactured by Cemedine Co., Ltd., and "Polycoke". When a durability test was conducted on a conventional bearing that was not used in a high temperature and dust environment of 250 ° C., it was confirmed that the product of the present invention was twice as durable as the conventional product. After the durability test, each bearing was disassembled, and it was found that the product of the present invention had a significantly smaller amount of foreign matter entering than the conventional product.

Next, a method of manufacturing different sealed bearings according to the present invention will be described with reference to FIG. First, as shown in the figure, a shield plate 5 is attached to the ends of the inner ring 1 and the outer ring 2 so that a seal gap 6 is formed between the tip 5 a and the inner ring 1. Next, both ends of the inner ring 1 are treated to prevent sticking to the sealing member, and the curable caulking agent "polycoke" that is in a fluid state in the seal gap 6 is introduced to the inner upper part of the tip 5a. Apply to. Then dry
The inner ring 1 is rotated during the solidification process. As a result, a minute gap 8 is formed between the caulking agent 7 and the inner ring 1. After that, when an oil-based lubricant 9 such as grease or oil is injected into the minute gap 8, the oil-based lubricant 9 is intervened in the entire minute gap 8 by a capillary phenomenon. This allows
It is possible to seal the minute gap 8 and obtain a better sealing property while suppressing an increase in the rotation torque to the minimum. still,
It is also possible to apply the caulking agent 7 and then apply the oil-based lubricant 9 on the surface thereof.

According to this embodiment, the same effect as that of the above-mentioned embodiment is obtained, but the same effect can be obtained even if it is used for an axle bearing of a vehicle, an automobile, etc., in addition to a conveyer conveyor used outdoors. You can expect an effect. In particular, by coating the surface of the caulking agent 7 with the oil-based lubricant 9 such as grease, the solidification of the sealing member 7 is suppressed, and a gap is generated during the use due to the solidification of the caulking agent. Also,
Since the oil content of the grease is trapped in the minute gaps, good sealability can be secured.

The shield plate 5 is attached to the outer ring 2,
It can be mounted on the inner ring, and its mounting structure and shape are not limited to the illustrated example. Of course, it is applicable not only to the inner ring rotating bearing described above, but also to the outer ring rotating bearing.

The sealing member 7 is not limited to the resin material such as the above-mentioned "polycoke" as long as it has such a fluidity that it can surely flow into the narrow seal gap 6 and is solidified thereafter. Various materials can be applied. Hereinafter, a case where grease is used will be described as an example.

The grease contains a base oil and a thickener as main components, and when the base oil is evaporated, a solid substance containing the thickener as a main component is produced. Therefore, the seal gap 6
If grease is filled as a sealing member 71 in a fluid state, for example, “Demnum Grease” manufactured by Daikin Co., Ltd., and then the bearing is operated or the inner ring is rotated to evaporate the oil, the sealing material 71 is solidified. Thus, the solid encapsulant 7 is formed. Since the minute gap 8 formed between the sealing material 7 and the inner ring 1 is significantly smaller than the gap formed by general machining, similar to the bearing shown in FIG. 2, while maintaining a good sealability, It is possible to realize low torque. of course,
Similar to that shown in FIG. 4, an oil-based lubricant 9 may be interposed in the minute gap 8. If high-temperature grease is used as this sealing grease, heat resistance can be improved.

Since the grease (demnum grease) used here has been widely used for lubricating the inside of the bearing, there is no problem in terms of hygiene, and it is also special in the fields of food and the like. It can be used as is without any measures.

If carbon is added to the sealing grease, the proportion of the oil content in the grease is reduced, so that its solidification can be promoted. Further, since the carbon itself has self-lubricating property, even when the sealing member 7 and the inner ring 1 are lightly contacted, the frictional resistance at that time can be reduced.

FIG. 5 shows the present invention applied to a plummer type bearing device. Plummer type bearing devices are generally used in pairs, one on the fixed side and the other on the free side, and have the function of automatically correcting the deviation of the shaft center caused by shaft mounting error, deflection, dimensional change (thermal expansion), etc. It has a box-shaped housing 11, a self-aligning bearing 12 fitted in the inner diameter portion of the housing 11, and a sealing device 13 provided in the bore portions 11a at both ends of the housing 11 (only one is shown in the drawing. Do)
And are the main components.

The sealing device 13 is, for example, an axial labyrinth in which a rotary side labyrinth member 16 fitted to the shaft body 15 and a stationary side labyrinth member 17 fixed to the housing 11 are opposed to each other with a seal gap 6 therebetween. . Similar to FIG. 1, a sealing member 7 (which may be either resin solidified or grease solidified) is interposed in the seal gap 6, and the sealing member 7 and the rotation side labyrinth member are disposed. 16
A minute gap 8 is formed between and. The minute gap 8 is formed by applying a sticking prevention oil or fat to the mating surface of the rotary labyrinth member 16 and then filling the seal gap 6 with the sealing material 7 (which is preferably degreased and washed in advance). It is formed by rotating the shaft body 15 in the process of drying and solidifying the sealing member 7.

With this structure, as described above, since the minute labyrinth gap 8 which cannot be obtained by the normal machining is formed, the improvement of the sealing performance is achieved. Further, similarly to FIG. 4, if an oil-based lubricant (not shown) is interposed in the minute gap, further improvement in sealing performance can be expected.

The embodiments in which the present invention is applied to various bearings have been described above. However, the present invention is not limited to this, and a non-contact type sealing in which a labyrinth seal is formed by facing a rotary member and a stationary member. The bearing device can be applied to all bearing devices. Here, the rotating member refers to the inner ring 1 and a member that rotates integrally with the inner ring 1 in a bearing device that rotates the inner ring, and the stationary member refers to a member that is stationary with the outer ring and the outer ring. On the contrary, in the bearing device for rotating the outer ring, the inner ring or the like serves as the stationary side member and the outer ring or the like serves as the rotating side member.

Of course, the present invention may be used in combination with other types of sealing devices (oil seals, etc.).
Since the structure of the oil seal and the like can be simplified, cost reduction can be achieved.

[0037]

As described above, according to the present invention, the sealing member formed by solidifying the fluid is interposed in the sealing gap between the rotary member and the stationary member, and the sealing member is also provided. Since there is a minute gap between the rotating side member and the stationary side member so that the rotating side member can rotate, the lubricant inside the bearing may flow out or foreign matter may enter from the outside. It can be suppressed with a simple structure.

Further, the minute gap between the sealing member and the rotating side member or the stationary side member is formed by shearing due to relative rotation of both members in the process of drying and solidifying the sealing member in a fluid state. Therefore, the gap is extremely smaller than the gap formed by general machining, and the sealability can be greatly improved.

In particular, by interposing an oil-based lubricant in the minute gap, it is possible to further improve the sealing property while suppressing an increase in rotational torque.

Furthermore, by filling the seal gap with a fluid sealing member and then applying an oil-based lubricant to the surface thereof, deterioration of the sealing member can be suppressed.

If carbon is added to the sealing grease, the proportion of the oil content in the grease is reduced, so that its solidification can be promoted. Further, since the carbon itself has self-lubricating property, it is possible to reduce the frictional resistance when the sealing member and the mating member are in contact with each other.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of FIG.

FIG. 3 is an enlarged sectional view of an essential part for explaining the method of the present invention.

FIG. 4 is an enlarged cross-sectional view of an essential part showing a different embodiment of the present invention.

FIG. 5 is a sectional view showing an embodiment in which the present invention is applied to a plummer type bearing device.

[Explanation of symbols]

 1 Inner ring 2 Outer ring 3 Rolling element 4 Cage 5 Shield plate (seal member) 6 Seal gap 7 Sealing member 8 Small gap 9 Oil-based lubricant 11 Housing 11a Diameter 12 Bearing 13 Seal device 15 Shaft body 16 Rotation side labyrinth member 17 Stationary side labyrinth member

Claims (9)

[Claims] 1. At the end of the bearing, the rotating side member and the stationary side member are opposed to each other through a seal gap,
In a sealed bearing device having a labyrinth seal, a minute gap is formed in the seal gap between the rotary side member and the stationary side member.
A sealed bearing device, wherein a sealing member formed by solidifying a fluid is interposed. 2. An inner ring, an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, a cage for holding the rolling elements at equal circumferential intervals, and one race ring of the inner ring and the outer ring. In a sealed bearing device having a seal member attached to the end of the other bearing ring so that a seal gap is formed between the end of the other bearing ring and the end of the other bearing ring, A sealed bearing device comprising a sealing member formed by solidifying resin or grease so that a minute gap is formed therebetween. 3. A box-shaped housing having caliber portions on both ends, a shaft body inserted through the caliber portion of the housing, a bearing fitted to the inner diameter portion of the housing and rotatably supporting the shaft body, and a housing. In a sealed bearing device having a housing-side labyrinth member provided in the bore portion and a shaft-side labyrinth member provided on the shaft body with a seal gap interposed between the housing-side labyrinth member, A sealed bearing device comprising a sealing member formed by solidifying resin or grease so that a minute gap is formed between the labyrinth member and one of the labyrinth members. 4. The sealed bearing device according to claim 1, wherein an oil-based lubricant is interposed in the minute gap. 5. The sealed bearing device according to claim 2, wherein carbon is added to the grease. 6. The rotary member and the stationary side are filled with a sealing member in a fluid state in a seal gap between the rotary member and the stationary member facing each other at the end of the bearing to form a labyrinth seal. By sealing the sealing member while rotating the member relative to each other, a minute gap is formed between the sealing member and one of the rotating side member and the stationary side member. Device manufacturing method. 7. A seal made of resin or grease in a seal gap formed between a seal member attached to an end of one race ring and an end of the other race of the inner race and the outer race. After the member is filled in a fluid state, the sealing member is solidified while rotating the inner ring or the outer ring, thereby forming a minute gap between the sealing member and the end of the other race. Manufacturing method of sealed bearing device. 8. The method for manufacturing a hermetically sealed bearing device according to claim 6, wherein an oil-based lubricant is interposed in the minute gap. 9. The method of manufacturing a sealed bearing device according to claim 6, wherein carbon is added to the grease.