JP2003254343A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-priced rolling bearing to be used for a machinery to be exposed with liquid and necessary to prevent the generation of leak of grease with the simple structure for preventing a leak of grease even in the environment to be exposed with liquid such as water. <P>SOLUTION: This standard seal type rolling bearing is formed by installing a seal 5, of which lip 52a is slid to be brought in contact with a track ring (an inner ring 1) of a counter side, in both axial directional sides of any one of track rings (for example, an outer ring 2) of the inner ring 1 and the outer ring 2. A second seal 6 is attached to an outside surface of each seal 5, and the lip 52 of the second seal 6 is slid to be brought in contact with an end surface 1b of the counter side track ring (the inner ring 1) to protect the seal 5 by using the second seal 6 without preparing a special track ring, and intrusion of the liquid from outside to the seal 5 is prevented to prevent a leak of the grease inside of the bearing. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a rolling bearing,
Particularly, the present invention relates to a rolling bearing suitable for use in food machines and the like.

[0002]

2. Description of the Related Art Generally, a rolling bearing is arranged between an inner ring and an outer ring in such a manner that a plurality of rolling elements are rotatably held by both of them on a cage. Among such rolling bearings, what is called a sealed type or a sealed type has a plurality of ball bearings between the inner ring 1 and the outer ring 2 as shown in the axially parallel sectional view of the ball bearing in FIG. The rolling elements (balls) 3 are arranged in a state of being held by a cage 4, and sealing seals 5 are attached to both axial ends of the bearing. Such a sealed type rolling bearing is used in a state where grease is sealed inside the bearing, that is, in the annular space between the inner ring 1 and the outer ring 2.

The hermetic seal 5 is formed by integrally forming an elastic material 52 such as rubber on a cored bar 51. The example shown in FIG. 3 shows a ball bearing used for inner ring rotation. The outer peripheral portion is attached and fixed to the seal groove 21 formed on the inner periphery of the outer ring 2 which is a fixed ring, and the lip 52a formed on the inner peripheral portion is configured to slidingly contact the shoulder portion 11 of the inner ring 1. ing.

Further, among the above-mentioned sealed type rolling bearings, a rolling bearing called a double seal type is known as a rolling bearing having a further improved sealing performance. In this double seal type rolling bearing, double seal grooves for fixing the seal are formed on both axial sides of the inner ring or the outer ring, or one seal groove is formed on each of the inner ring and the outer ring. A hermetic seal 5 as illustrated in FIG. 3 is double mounted on each side of the bearing.

[0005]

By the way, rolling bearings used in, for example, food machines are often exposed to water, hot water, or liquids such as cleaning liquids, and are particularly required to have corrosion resistance. In the normal sealed type rolling bearing shown in FIG. 3, the durability of the seal has a problem in such an environment, and the sealed grease may leak out. Food grease may be filled as grease, but even if the safety of the grease for humans is secured, grease leakage is not allowed because it impairs the commercial value.

[0006] Therefore, conventionally, in such an environment, measures such as using a ceramic rolling bearing without lubrication or using the double seal type rolling bearing described above have been taken.

However, when a ceramic rolling bearing is used without lubrication, not only is it expensive, but since the ceramic bearing does not have a lubricating function itself, the wear life is reached relatively early. There was a problem that sometimes.

Further, the double seal type rolling bearing is required to have a large width size for the inner ring and the outer ring, and also to have a dedicated shape and structure respectively, which is a so-called special bearing, which is expensive. There's a problem.

The present invention has been made in view of the above circumstances, and has a simple structure and prevents grease from leaking out even when used in an environment exposed to water, hot water, or a liquid such as a cleaning liquid. It is an object of the present invention to provide a rolling bearing that can be used and is inexpensive and that can be used in a machine or the like that is exposed to a liquid and in which grease leakage is not allowed.

[0010]

In order to achieve the above object, in the rolling bearing of the present invention, between the inner ring and the outer ring, a plurality of rolling elements which are freely rotatable with respect to both of them are held by a cage. Rolling bearings that are installed in a fixed state, and seal seals whose lips are in sliding contact with the mating bearing rings are attached and fixed to both axial sides of either the inner ring or the outer ring. In, the second seal is attached and fixed to the outer surface of each of the hermetic seals, and each of the second seals is configured such that its lip is in sliding contact with the end surface of the other bearing ring. (Claim 1).

In the present invention, preferably, the peripheral portion of the second seal opposite to the lip is in pressure contact with the shoulder portion of the one bearing ring (claim 2). be able to.

Further, in the present invention, it is preferable in view of corrosion resistance that the material of the second seal is silicon rubber (claim 3).

Further, in the present invention, it is also possible to adopt a structure in which a peripheral groove into which the lip of the second seal is fitted is formed on the end surface of the other raceway ring (claim 4).

In the present invention, a standard sealed type rolling bearing is used (claims 1 to 3), or a rolling bearing in which one of the bearing rings of the standard sealed type rolling bearing is slightly modified. (Claim 4), the second seal is adhered and fixed to the hermetic seal, thereby significantly improving the hermeticity and achieving the intended purpose.

That is, the conventional general sealing type rolling bearing illustrated in FIG. 3 is used, and the second seals are attached to the outer surfaces of the sealing seals on both sides thereof and the lip thereof is attached to the inner ring or the outer ring (usually). If it is configured to make sliding contact with the end surface of the rotating wheel), the hermetic seal (original seal) is protected by this second seal and is hardly exposed to the liquid from the outside, so that the grease inside the bearing is prevented. It will not leak. Further, even if some grease leaks from the hermetic seal (original seal), the grease is prevented from leaking to the outside by the second seal.

The above-mentioned structure of the invention according to claim 1 is the same as the double seal type because the second seal is attached afterwards to the standard sealed type rolling bearing provided with the hermetic seal. Although it has a function, it can be made cheaper than the case where the inner and outer rings have a special special shape such as this double seal type rolling bearing.

According to the invention of claim 2, the second
By adopting a structure in which the peripheral part of the seal lip of the side opposite to the lip is pressed against the shoulder part of the outer ring or inner ring (usually a fixed ring), the seal seal (original seal) can be attached to the outer ring or inner ring It is possible to effectively prevent the infiltration of the liquid, and it is possible to further secure the above effects.

Further, as in the invention according to claim 3, the second
When the material of the seal of (1) is silicon rubber, it is possible to exhibit corrosion resistance to most solvents.

Further, as in the invention according to claim 4, by the addition of simple processing, a peripheral groove into which the lip of the second seal is fitted is formed on the end surface of the bearing ring with which the lip of the second seal is in sliding contact. The liquid permeation resistance at the lip portion of the second seal can be improved.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an axially parallel sectional view of an embodiment of the present invention. In this example, the conventional standard sealed type ball bearing shown in FIG. 3 is used as a basic structure, and the second seals 6 are attached to the sealed seals 5 on both sides thereof with an adhesive.

That is, between the inner ring 1 and the outer ring 2, a plurality of balls 3 are held on a cage 4 and formed on the raceway surface 1a formed on the outer periphery of the inner ring 1 and on the inner periphery of the outer ring 2. The ring-shaped hermetic seal 5 is mounted on the outer circumference of the seal groove 21 formed on the inner circumferences of both ends of the outer ring 2 while being rollably arranged on both the raceways 2a.
Fixed, inner ring 1 and outer ring 2, and hermetic seals 5 on both sides
The grease is filled in the annular space surrounded by. The hermetic seal 5 is formed by integrally forming an elastic material 52 such as NBR or silicon rubber on a cored bar 51, and a lip 52 a formed on the inner periphery of the core metal 51 is in sliding contact with the shoulder portion 11 on the outer periphery of the inner ring 1. Is configured to.

The inner ring 1, the outer ring 2 and the balls 3 can be made of bearing steel, stainless steel, ceramics or the like, but when used in an environment exposed to a liquid such as water,
This type of rolling bearing is often used, for example, SU
It is preferable to use S630, SUS304, or the like. The cage 4 can be made of a pressed product of carbon steel, or a plastic material such as SUS304, polyamide (PA66), or polyphenylene sulfide (PPS).

A second seal 6 is attached to the outer surface of each hermetic seal 5 of such a standard hermetic type ball bearing by a suitable adhesive. This second
The seal 6 is a ring-shaped molded body entirely made of an elastic material such as NBR or silicon rubber, and its side surface is tightly adhered over the entire flat portion of the outer surface of the hermetic seal 5. The outer peripheral portion is bent toward the bearing side, and the fitting portion 6 is fitted and press-fitted to the protrusion 22 on the outer side of the seal groove 21 on the inner periphery of the outer ring 2 with a predetermined interference.
Make up one. The inner peripheral portion of the second seal 6 constitutes a lip 62, and the lip 62 is constituted so as to be in sliding contact with the end surface 1b of the inner ring 1. Since the side surface of the second seal 6 is attached to the entire flat portion of the outer surface of the hermetic seal 5, the lip 62 can be strongly contacted with the end surface 1b of the inner ring 1.

The inner diameter of the second seal 6, that is, the inner diameter at the tip of the lip 62 is larger than the diameter D passing through the center of the radial dimension W of the end face 1b of the inner ring 1, and thus the end face of the inner ring 1 is formed. It is possible to fix the bearing by bringing other parts such as a sleeve and a collar into contact with 1b.

According to the above-described embodiment of the present invention, the hermetic seal 5 originally mounted on the rolling bearing is the second seal.
Even when used in an environment exposed to a liquid such as water, the sealed seal 5 is protected by the liquid 6 from the outside, and therefore the lip 5 of the sealed seal 5 is protected.
The liquid does not enter the bearing through the space between the inner ring 1 and the inner ring 1. As a result, the grease filled in the bearing does not leak beyond the hermetic seal 5. Further, even if some grease leaks beyond the hermetic seal 5, the presence of the second seal 6 can prevent the grease from reaching the outside of the bearing.

Further, since the fitting portion 61 formed on the outer circumference of the second seal 6 is fitted and pressure-contacted with the inner circumference of the outer ring 2, the liquid can enter from this portion as well. Therefore, it is possible to effectively prevent liquid from entering between the hermetic seal 5 and the seal groove 21 of the outer ring 2.

Here, if the inner ring 1 and the outer ring 2 are made of stainless steel such as SUS630 as described above and the second seal 6 is made of silicon rubber, all the parts exposed to the external liquid have corrosion resistance and almost all parts are exposed to liquid. It can be a rolling bearing capable of exhibiting corrosion resistance against the solvent.

Next, another embodiment of the present invention will be described. FIG. 2 is a sectional view parallel to the axis. The feature of this example is that the lip 6 of the second seal 6 is provided on the end surface 1b of the inner ring 1.
It is characterized in that a peripheral groove 12 into which 2 is fitted is formed. That is, in this example, the portion of the tip of the lip 62 of the second seal 6 facing the end surface 1c side of the inner ring 1 is formed into an R shape, while the end surface 1c of the inner ring 1 is fitted with the R shaped portion 62a. A peripheral groove 12 is formed so as to fit in.

By adopting such a configuration, it is possible to more reliably prevent the external liquid from entering between the lip 62 of the second seal 6 and the end surface 1c of the inner ring 1.

In the above embodiment, the lip 52a of the hermetic seal 5 and the lip 62 of the second seal 6 are configured to be in sliding contact with the inner ring 1, respectively. It is suitable for use in rotating the inner ring, and when used in rotating the outer ring, the lips 52a, 62 of the hermetic seal 5 and the second seal 6 are configured to be in sliding contact with the outer ring 2, respectively. Is preferred.

In each of the above embodiments, the present invention is applied to ball bearings, but the present invention can be applied to bearings other than ball bearings as long as the bearing can be fitted with a hermetic seal. Can be applied.

[0032]

As described above, according to the present invention, the second seal is adhered to the outer surface of each hermetic seal of the hermetically sealed rolling bearing having hermetically sealed seals at both ends. Since the seal lip of No. 2 is configured to be in sliding contact with the end surface of the bearing ring on which the lip of the hermetic seal is in sliding contact, the hermetic seal can be used even in an environment exposed to liquid such as water. Is protected by the second seal, and the hermetic seal is hardly exposed to the liquid from the outside, so that it is possible to prevent the hermetic seal from penetrating into the inside of the bearing beyond the hermetic seal. It is possible to prevent the internal grease from leaking to the outside. Therefore, the rolling bearing of the present invention can be used in food machines and the like that are often used in a state of being exposed to a liquid such as water, and the rolling bearing of the present invention is substantially standard. Since it can be manufactured by attaching the second seal to the sealed type rolling bearing afterwards, compared to the case of using a bearing ring with a special shape and structure like the conventional double seal type. Therefore, the cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 is an axially parallel sectional view of an embodiment of the present invention.

FIG. 2 is an axially parallel sectional view of another embodiment of the present invention.

FIG. 3 is an axially parallel sectional view showing a configuration example of a conventional sealed type ball bearing.

[Explanation of symbols]

1 inner ring 2 outer ring 21 seal groove Three balls 4 cage 5 hermetic seal 52a lip 6 Second seal 62 lips

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akira Yamamoto             3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka               Koyo Seiko Co., Ltd. F term (reference) 3J016 AA01 BB03 CA02 CA03

Claims (4)

[Claims] 1. A plurality of rolling elements, which are rollable with respect to both of the inner ring and the outer ring, are arranged in a state of being held by a cage, and one of the inner ring and the outer ring is arranged. Rolling bearings, in which lip seals are mounted and fixed on both sides in the axial direction of the bearing ring, the second seal is attached to the outer surface of each of the above seals. A rolling bearing, wherein each of the second seals is fixed, and the lip of each of the second seals is in sliding contact with the end surface of the other bearing ring. 2. The rolling bearing according to claim 1, wherein a peripheral portion of the second seal opposite to the lip is in pressure contact with a shoulder portion of the one bearing ring. 3. The rolling bearing according to claim 1, wherein the material of the second seal is silicon rubber. 4. The second member is formed on the end surface of the other party race ring.
The rolling bearing according to claim 1, 2 or 3, wherein a circumferential groove into which the lip of the seal is fitted is formed.