JP2000310337A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device capable of improving in sealability and exhibiting excellent sealing performance. SOLUTION: This device is provided with a first ring 2 having a seal lip 3 with slidably and closely contacting to a mating member 21 mounted, a second and a third rings 5, 6 holded by the first ring 2 and provided with a pair of flange parts 5b, 6b opposing with each other in an axial direction, an elastic body 8 placed between the pair of flange parts 5b, 6b, and a sliding ring 9 supported by the elastic body 8 and slidably and closely contacted to the mating member 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device.

[0002]

2. Description of the Related Art In the field of a centrifuge or the like, when a housing rotates at a high speed, a sealing device shown in FIG. 3 or 4 is conventionally known as a sealing device for sealing the circumference of the housing shaft.

That is, the sealing device 51 of FIG. 3 has a seal lip 54 made of Rare Freon sandwiched between two rings 52 and 53 as an inner seal, and the sealing device 55 of FIG. A seal lip 57 made of a rubber-like elastic material is baked on 56.

However, in the sealing device 51 shown in FIG. 3, since a large centrifugal force acts on the seal lip 54 at the time of high-speed rotation, the seal lip 54 is opened, and the seal lip 54 is a shaft which is a mating member. There is a possibility that the seal lip 57 may be separated from the shaft 58, and the sealing lip 57 may be worn out by the sealing device 55 shown in FIG. In some cases, the sealing performance may be reduced due to the shortage.

[0005]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a sealing device capable of improving the sealing performance as compared with the above-mentioned prior art, and thereby exhibiting excellent sealing performance. The purpose is to provide.

[0006]

In order to achieve the above object, a sealing device according to a first aspect of the present invention has a first sealing lip made of a rubber-like elastic material which is slidably in close contact with a mating member. A ring, a second and a third ring provided with a pair of flange portions which are held by the first ring and are axially opposed to each other, and a rubber-like elastic material disposed between the pair of flange portions. And a sliding ring supported by the elastic body and slidably in close contact with the counterpart member.

According to a second aspect of the present invention, there is provided a sealing device according to the first aspect, wherein a cut-out or groove-shaped flow path is provided at a fitting portion between the second and third rings. And a grease supply path for supplying grease to the seal lip side through the grease is provided.

In the sealing device according to the first aspect of the present invention, the sliding ring functions as a primary seal and the seal lip functions as a secondary seal or a dust seal. Even if a centrifugal force acts on the supporting elastic body, the opening thereof is suppressed by the ring supporting the elastic body. Therefore, the support of the sliding ring by the elastic body is continued, and the close contact of the sliding ring with the mating member is continued, so that it is possible to suppress a decrease in sealing performance.

In addition to the above, in the sealing device according to the second aspect of the present invention having the above-described structure, the cut-out or groove-shaped flow path provided at the fitting portion between the second and third rings is provided. Since the grease is supplied to the seal lip side through the grease supply path including the above, it is possible to improve the lubricity of the sliding portion of the seal lip with respect to the mating member. Further, when the seal lip is a dust seal and grease is supplied at a predetermined pressure, grease is discharged to the outside from the sliding portion, thereby forming a grease-out type sealing device. (The grease-out type sealing device is a type that prevents intrusion of external dust such as water and scale while discharging grease to the outside, whereas the grease-in type sealing device It is a completely sealed type that does not emit).

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

First Embodiment As shown in FIG. 1, a sealing device 1 according to this embodiment is an oil seal used in a portion where a housing and a shaft rotate at high speed, such as a centrifuge. This is a type of sealing device, and is configured as follows.

That is, first, a seal lip (also referred to as a rubber lip) 3 and an outer peripheral seal portion 4 made of a rubber-like elastic material are provided.
Is provided, and a second ring 5, a third ring 6, and a fourth ring 7 are held on the inner peripheral side of the first ring 2; An elastic body (also referred to as a rubber ring) 8 made of a rubber-like elastic material is disposed between the flange portion 5b of the second ring 5 and the flange portion 6b of the third ring 6;
A sliding ring (also referred to as a Teflon ring or a Teflon seal) 9 made of Teflon or resin is arranged on the inner peripheral side of the elastic body 8.

The first ring 2 first has a cylindrical portion 2a, and a flange portion 2b is formed radially inward at one axial end (downward in the figure) of the cylindrical portion 2a. It is integrally molded. The cylindrical portion 2a is integrally provided with a small-diameter portion 2c, a tapered step portion 2d, a large-diameter portion 2e, and a swaged portion 2f from one end in the axial direction to the other end (upper side in the drawing). The seal lip 3 is fixed to the inner peripheral end of the flange portion 2b by being baked obliquely inward (obliquely inward toward the other side in the axial direction), and the outer peripheral seal portion 4 is fixed to the cylindrical portion 2b.
a, the seal lip 3 and the outer peripheral seal portion 4 are fixed to the outer peripheral surface of the small-diameter portion 2c and the step portion 2d through the connecting portion 10 fixed to the outer end surface of the flange portion 2b. It is molded integrally.

The second ring 5 has a cylindrical portion 5a fitted on the inner peripheral side of the large-diameter portion 2e of the first ring 2, and a radially opposite end of the cylindrical portion 5a in the axial direction. It has a flange portion 5b integrally formed inward, and the bent portion at the boundary between the cylindrical portion 5a and the flange portion 5b is held by the caulked portion 2f of the first ring 2. It is axially positioned with respect to the first ring 2.

The third ring 6 has a cylindrical portion 6a fitted on the inner peripheral side of the cylindrical portion 5a of the second ring 5, and a radial end portion at one axial end of the cylindrical portion 6a. And a flange portion 6b integrally formed inwardly.
Is positioned in the axial direction with respect to the second ring 5 by abutting against the flange portion 5b.

The fourth ring 7 includes a cylindrical portion 7a fitted on the inner peripheral side of the small diameter portion 2c of the first ring 2 and a cylindrical portion 7c.
a flange portion 7b integrally formed radially inward at the other end in the axial direction of a, and the flange portion 7b abuts against the flange portion 6b of the third ring 6 and has a cylindrical shape. The portion 7a is positioned in the axial direction with respect to the first and third rings 2, 6 by abutting the flange portion 2b of the first ring 2.

The first to fourth rings 2, 5, 6 and 7 are all made of metal and are formed by pressing a sheet metal. 6 are fitted together, and then the second and fourth rings 5 and 7 are collectively fixed together by the first ring 2.

The elastic body 8 is formed into a ring shape with a predetermined rubber, and has a rectangular cross section that is long in the radial direction. The elastic body 8 has a third ring 6 on its outer peripheral surface.
Are always in contact with the inner peripheral surface of the cylindrical portion 6a, but clearances are respectively set between the second and third rings 5 and 6 from the viewpoint of the filling rate.

The sliding ring 9 is formed in an annular shape from Teflon having excellent slidability, and has a rectangular cross section that is long in the axial direction. The outer periphery of the sliding ring 9 is always in contact with the inner periphery of the elastic body 8, but the second and third rings 5, 5 are not worn by contact with the rings 5, 6. 6, a gap is set between them.

The sealing device 1 having the above structure is fitted on the inner periphery of a housing (not shown) with a first ring 2 having an outer peripheral surface to which an outer peripheral sealing portion 4 is baked, and a sealing lip 3 and a sliding ring are provided. 9 is a shaft 2 which is a sliding partner.
1, which seals the space between the housing and the shaft 21 in close contact with the peripheral surface of the housing 1 (the sealing fluid is present on one side in the axial direction of the sealing device 1). It has features.

That is, first, as described above, the double sealing structure including the seal lip 3 and the sliding ring 9 can improve the sealing performance,
Even if a centrifugal force acts on the sliding ring 9 and the elastic body 8 supporting the sliding ring, the opening thereof is suppressed by the second and third rings 5 and 6 supporting the elastic body 8. Therefore, the support of the sliding ring 9 by the elastic body 8 is continued, and the close contact of the sliding ring 9 with the shaft 21 is continued, so that a decrease in sealing performance is suppressed. Therefore, excellent sealing performance can be exhibited even in a situation where a large centrifugal force acts during high-speed rotation.

Second Embodiment As shown in FIG. 2, a sealing device 1 according to this embodiment is an oil seal type used for equipment with severe external dust conditions, such as a continuous casting machine for steel production. And is configured as follows.

First, there is provided a first ring 2 to which a seal lip (also referred to as a rubber lip) 3 made of a rubber-like elastic material and functioning as a dust lip and a peripheral seal portion 4 are baked. A second ring 5 and a third ring 6 are held on the inner peripheral side of the elastic member, and a rubber-like elastic material is provided between a flange portion 5b of the second ring 5 and a flange portion 6b of the third ring 6. An elastic body (also referred to as a rubber ring) 8 is disposed, and a sliding ring (also referred to as a Teflon ring or a Teflon seal) 9 made of Teflon or resin is disposed on the inner peripheral side of the elastic body 8.

The first ring 2 first has a tubular portion 2a, and a first U-shaped bent portion 2g is provided at one axial end (left side in the figure) of the tubular portion 2a. Thus, the flange portion 2b is integrally formed radially inward. The cylindrical portion 2a has a small-diameter portion 2c, a tapered step portion 2d, and a large-diameter portion 2e from one end in the axial direction to the other end (right side in the figure).
And a caulking portion 2f. The seal lip 3 is fixed by baking near the inner peripheral end of the flange portion 2b in an obliquely inward direction (obliquely inward in one axial direction), and the outer peripheral seal portion 4 is fixed to the cylindrical portion 2a. The seal lip 3 and the outer peripheral seal 4 are fixed to the outer peripheral surface of the small diameter portion 2c, the stepped portion 2d, and the large diameter portion 2e by baking. It is integrally formed via a connecting portion 10 fixed to the outer end surfaces of the flange 11 and the flange portion 2b by baking.

The second ring 5 has a cylindrical part 5a fitted on the inner peripheral side of the cylindrical part 2a of the first ring 2 and a radially opposite end of the cylindrical part 5a in the axial direction. It has a flange portion 5b integrally molded inward, and the bent portion at the boundary between the cylindrical portion 5a and the flange portion 5b is held by the caulked portion 2f of the first ring 2 and The shape portion 5a is positioned in the axial direction with respect to the first ring 2 by abutting against the bent portion 2g of the first ring 2.

The third ring 6 has a cylindrical portion 6a fitted on the inner peripheral side of the cylindrical portion 5a of the second ring 5, and a radial end portion at one axial end of the cylindrical portion 6a. And a flange portion 6b integrally formed inwardly.
And the flange portion 6b is abutted against the flange portion 2b of the first ring 2 to be axially positioned with respect to the first and second rings 2 and 5.

Each of the first to third rings 2, 5, and 6 is made of a metal and is formed by pressing a sheet metal. The two rings 5 are fitted together, and then the second ring 5 is crimped with the first ring 2.

The elastic body 8 is formed in a ring shape with a predetermined rubber, and has a rectangular cross section that is long in the radial direction. The elastic body 8 has a third ring 6 on its outer peripheral surface.
Are always in contact with the inner peripheral surface of the cylindrical portion 6a, but clearances are respectively set between the second and third rings 5 and 6 from the viewpoint of the filling rate.

The sliding ring 9 is formed in an annular shape from teteron having excellent slidability, and has a rectangular cross section that is long in the axial direction. The outer periphery of the sliding ring 9 is always in contact with the inner periphery of the elastic body 8, but the second and third rings 5, 5 are not worn by contact with the rings 5, 6. 6, a gap is set between them.

Further, the sealing device 1 is provided with a grease supply path 12 for supplying grease G present on one side in the axial direction to the seal lip 3 side when the sealing apparatus 1 is mounted. It is configured as follows.

That is, first, the flange portion 5 of the second ring 5
b is provided with a required number of hole-shaped flow paths (also simply referred to as holes) 13, and a cut-out flow path (first flow path) is provided at the other axial end of the cylindrical portion 6 a of the third ring 6. (Also called a slit) 14
A groove-shaped flow path (also referred to as a second slit) 15 is provided on the outer peripheral surface of the cylindrical portion 6 a of the third ring 6, and a flanged portion 6 b of the third ring 6 is provided. A groove-shaped flow path (also referred to as a third slit) on one end face in the axial direction.
16 are provided. A plurality of hole-shaped flow paths 13 are provided in an evenly distributed manner. Notched or grooved flow path 14, 1
Plural 5, 5 and 16 are respectively provided in an equal arrangement (for example, four equal arrangements), and are provided so that the positions on the circumference may be aligned. The outer peripheral end of the other end in the axial direction of the cylindrical portion 6a of the third ring 6 is cut into a tapered shape, and the bent portion at the boundary between the cylindrical portion 6a and the flange portion 6b of the third ring 6 is formed. The outer corners are also tapered. Therefore, the above-mentioned hole-shaped flow path 1
3 and the notched flow path 14 and the grooved flow path 1
A series of grease supply paths 12 extending to the space 17 on the back side of the seal lip 3 via the seals 5 and 16 are formed. Grease G is supplied to the seal lip 3 through the grease supply path 12. ing.

The sealing device 1 having the above-described structure is fitted on the inner periphery of a housing (not shown) with the first ring 2 having an outer peripheral surface on which an outer peripheral sealing portion 4 is baked, and is provided with a seal lip 3 and a sliding ring. 9 is a shaft 2 which is a sliding partner.
1, which seals the space between the housing and the shaft 21 in close contact with the peripheral surface of the shaft 1, and is characterized in that the following functions and effects are achieved by the above configuration.

That is, first, as described above, the double sealing structure including the seal lip 3 and the sliding ring 9 can improve the sealing performance,
Even if a centrifugal force acts on the sliding ring 9 and the elastic body 8 supporting the sliding ring, the opening thereof is suppressed by the second and third rings 5 and 6 supporting the elastic body 8. Therefore, the support of the sliding ring 9 by the elastic body 8 is continued, and the close contact of the sliding ring 9 with the shaft 21 is continued, so that a decrease in sealing performance is suppressed. Therefore, excellent sealing performance can be exhibited even in a situation where a large centrifugal force acts during high-speed rotation.

In addition to this, a notch-shaped or groove-shaped flow channel 13 provided in a hole-shaped flow channel 13 provided in the second ring 5 and a fitting portion of the second and third rings 6, 7 with each other. Roads 14, 15,
Since the grease G is supplied to the seal lip 3 via the grease supply path 12 including the grease 16, the grease G
Thereby, the lubricity of the sliding portion of the seal lip 3 with respect to the shaft 21 can be improved. Further, when the grease G is filled with a predetermined pressure due to grease up or the like, the grease G that has reached the space 17 is released from the sliding portion to the outside at any time. Is formed, and the sealing performance against external dust can be improved. Therefore, from these, it is possible to provide the sealing device 1 exhibiting excellent durability and sealing properties.

[0035]

The present invention has the following effects.

That is, first, in the sealing device according to the first aspect of the present invention having the above-described structure, the sliding ring as a component thereof functions as a primary seal and the seal lip functions as a secondary seal or a dust seal. Since the seal structure is employed, the sealing performance can be improved. Even if a large centrifugal force acts on the sliding ring and the elastic body supporting the sliding ring due to the high-speed rotation of the housing, etc., these are prevented from opening by the second and third rings supporting the elastic body. Can be Therefore, the support of the sliding ring by the elastic body is continued and the close contact of the sliding ring with the partner member is continued,
Therefore, a decrease in sealing performance is suppressed. Therefore, it is possible to provide a sealing device that exhibits excellent sealing performance even in a situation where a large centrifugal force acts during high-speed rotation.

In addition to the above, in the sealing device according to the second aspect of the present invention having the above-mentioned structure, the cut-out or groove-shaped flow passage provided at the fitting portion of the second and third rings is provided. Since the grease is supplied to the seal lip side through the grease supply path including the grease, the lubrication of the sliding portion of the seal lip with respect to the mating member of the seal lip can be improved. Further, when the seal lip is a dust seal and grease is supplied at a predetermined pressure, the grease is discharged to the outside from the sliding portion, thereby forming a grease-out type sealing device.
The sealing performance against external dust can be improved. Therefore, from these, a sealing device exhibiting excellent durability and sealing properties can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a sealing device according to a first embodiment of the present invention.

FIG. 2 is a half sectional view of a sealing device according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a sealing device according to a conventional example.

FIG. 4 is a sectional view of a main part of a sealing device according to another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing device 2 1st ring 2a, 5a, 6a, 7a Cylindrical part 2b, 5b, 6b, 7b Flange part 2c Small diameter part 2d Step part 2e Large diameter part 2f Caulking part 2g Bent part 3 Seal lip 4 Peripheral seal part Reference Signs List 5 second ring 6 third ring 7 fourth ring 8 elastic body 9 sliding ring 10 connecting part 11 end face seal part 12 grease supply path 13, 14, 15, 16 flow path 17 space 21 axis (partial member) G grease

Claims (2)

[Claims] 1. A first ring (2) to which a seal lip (3) made of a rubber-like elastic material is slidably in close contact with a mating member (21), and is held by the first ring (2). Between the second and third rings (5) and (6) provided with a pair of flange portions (5b) and (6b) opposed to each other in the axial direction, and the pair of flange portions (5b) and (6b). An elastic body (8) made of a rubber-like elastic material, and a sliding ring (9) supported by the elastic body (8) and slidably in contact with the counterpart member (21). A sealing device. 2. The sealing device according to claim 1, wherein the second and third rings (5) and (6) have cutout or groove-shaped flow paths (14), (15) ( A grease supply path (12) for supplying grease (g) to the seal lip (3) side via 16).