JP4116298B2 - mechanical seal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mechanical seal used for a rotating part of a construction machine, an industrial machine or the like.
[0002]
[Prior art]
For example, on a rotating part of a device that operates in an environment with a lot of foreign matter such as earth and sand, such as track rollers, idlers, sprockets of construction machines equipped with crawler type traveling bodies such as hydraulic excavators, or guide rings of industrial machines such as belt conveyors. In order to prevent foreign matter from entering the internal rotating sliding part from the outside through between the rotating part and the fixed part, and to prevent the internal lubricating oil from leaking to the outside, further between the rotating part and the fixed part. A mechanical seal is provided so as to cope with fluctuations in the direction of the rotation axis that occur. In this mechanical seal, a pair of seal rings having annular seal surfaces that are in sliding contact with each other are formed of metal, for example, and this is held by a pair of annular elastic seals between the rotating portion and the fixed portion. By doing so, it is possible to deal with foreign matters, fluctuations, and the like.
[0003]
A typical example of a mechanical seal is disclosed in Japanese Patent Laid-Open No. 9-60733. As shown in FIG. 4 (the figure corresponding to FIG. 1 of the same publication), this mechanical seal includes a pair of seal rings 32 and 32 and a pair of O-ring seals 34 and 34 which are a pair of elastic seals holding and holding them. I have. Further, in the technique disclosed in the publication, the mounting position of the O-ring seal 34 is prevented from moving due to foreign matters such as earth and sand and muddy water that have entered the space S outside the radial O-ring seal 34 from the outside. An annular recess 33 for seating the ring seal 34 is provided in each of the inner seal ring 32 and the outer seal mounting member.
[0004]
[Problems to be solved by the invention]
The conventional mechanical seal of the form as described above has the following problems to be solved that are desired to be improved.
[0005]
That is, foreign matters such as earth and sand and muddy water that have entered the annular space S outside the pair of O-ring seals 34 and 34 shown in FIG. 4 are compacted and accumulated over time, and are repeatedly expanded and contracted by freezing and thawing. As a result, the O-ring seal 34 is pushed in the direction of the inner lubricating oil enclosure chamber L, and foreign matter enters the lubricating oil enclosure chamber L, causing a sealing problem in the mechanical seal.
[0006]
The present invention has been made in view of the above-mentioned facts, and its technical problem is to minimize the intrusion and accumulation of foreign matter such as earth and sand and muddy water from the outside into the space of the outer peripheral portion of the mechanical seal, resulting in a poor sealing performance. It is an object of the present invention to provide a mechanical seal that does not cause the occurrence of the problem.
[0007]
[Means for Solving the Problems]
In the present invention, as a mechanical seal that solves the above technical problem, a pair of seal rings having annular seal surfaces that are in sliding contact with each other, and a pair of seals in which relative rotation of the seal rings is freely arranged to nip pressure held between the mounting member, and a pair of annular elastic seal interposed between each of the respective the seal mounting member of the seal ring, the elastic seal has a cross section of rectangular shape, the seal The ring includes a cylindrical wall having an L-shaped cross section that fits with the inner diameter portion of the rectangular cross section and an outer peripheral groove having an orthogonal wall, and the seal mounting member has an L-shaped cross section that fits with the outer diameter portion of the rectangular cross section. An annular space having a rectangular cross section formed by a pair of the seal mounting members opposed to each other on the outer periphery of the seal ring and on the outside thereof, and an inner peripheral groove having a cylindrical wall and an orthogonal wall In Includes an annular member set has been rectangular-shaped cross section, a mechanical seal is provided, characterized in that.
[0008]
And, by arranging an annular member in the space where foreign matter such as earth and sand and muddy water enters, the space where foreign matter accumulates is minimized, the accumulation of foreign matter is reduced, and the factors that cause the sealing failure of the mechanical seal are eliminated. Like that.
[0009]
In a preferred embodiment, the annular member is provided integrally with one each or one of the pair of elastic seal.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The mechanical seal constructed in accordance with the present invention will now be described in more detail with reference to the accompanying drawings illustrating preferred embodiments.
[0011]
Referring to FIG. 1, the mechanical seal denoted by reference numeral 2 as a whole has a pair of seal rings 4, 4 having annular seal surfaces F that are in sliding contact with each other, and the seal ring 4 can be relatively rotated. A pair of annular elastic seals 8, 8 interposed between the seal rings 4, 4 and the seal attachment members 6, 7. The seal rings 4 and 4 are disposed in the annular space S formed by the seal mounting members 6 and 7 and the elastic seals 8 and 8 which are opposed to each other on the outer periphery and the outer periphery thereof, and are integrally formed with the elastic seals 8 and 8 respectively. The provided annular members 10 and 10 are provided.
[0012]
The mechanical seal 2 is lubricated to lubricate the rotating portion of the seal mounting member 7 between one seal mounting member 6 fixed to the shaft 12 and the seal mounting member 7 rotatably mounted to the shaft 12. The oil enclosure chamber L is maintained. The seal rings 4 and 4, the elastic seals 8 and 8, and the annular members 10 and 10 of the mechanical seal 2 are symmetric with respect to the seal surface F in the direction of the rotation axis 13, as is apparent from FIG. 1. And the same thing is attached symmetrically.
[0013]
The seal ring 4 has an L-shaped cross section extending in the axial direction of the rotation axis 13 and radially outward, and is formed of a special alloy cast iron with high wear resistance and strength. Inside the two sides of the cross-section L, a cross-section L-shaped having a cylindrical wall 4a and an orthogonal wall 4b extending radially outward from the cylindrical wall 4a, which are fitted into an inner diameter portion of a rectangular cross-section of the elastic seal 8 described later. The outer peripheral groove 4c is formed. On the back surface of the orthogonal wall 4b, on the outer peripheral side of the surface extending in the radial direction, the above-described sealing surface F is formed in a ring shape and a mirror surface.
[0014]
The seal attachment member 6 has a cylindrical portion 6a and an L-shaped annular portion 6b extending radially outward from the cylindrical portion 6a. The cylindrical portion 6 a is fitted to the shaft 12, one end portion is fixed to the shaft 12 by the through pin 14, and the other end portion extends through the inner diameter portions of the pair of seal rings 4 and 4. The outer peripheral surface 6 c of the annular portion 6 b is substantially formed into a perfect circle, and is positioned at an interval inside the inner peripheral surface 7 a of the other seal mounting member 7. The annular portion 6b has an inner circumferential groove 6f having a L-shaped cross section having a cylindrical wall 6d fitted to the outer diameter portion of the rectangular cross section of the elastic seal 8 and an orthogonal wall 6e extending radially inward from the cylindrical wall 6d. Is formed. An O-ring seal 16 is attached to an annular groove formed on the inner periphery of the cylindrical portion 6a at the fitting portion between the shaft 12 and the cylindrical portion 6a.
[0015]
The other seal mounting member 7 is rotatably supported on the shaft 12 via a sleeve bearing 18. At the opposite end of the seal mounting member 6 side, the above-mentioned inner peripheral surface 7a positioned outside the outer peripheral surface of the annular portion 6b of the seal mounting member 6 and a smaller diameter than the inner peripheral surface 7a, the seal mounting member A cylindrical wall 7b, which is formed to face the inner circumferential groove 6f in the same shape as the inner circumferential groove 6f and is fitted to the outer diameter portion of the rectangular cross section of the elastic seal 8, and extends radially inward from the cylindrical wall 7b. An inner circumferential groove 7d having an L-shaped cross section having an orthogonal wall 7c is formed.
[0016]
Elastic seal 8 is provided with a cross section of rectangular shape, and is formed of an elastic material such as oil-resistant synthetic rubber. The inner diameter portion of the rectangular cross section is compressed and fitted into the outer circumferential groove 4c of the seal ring 4 and the outer diameter portion is compressed and fitted into the inner circumferential groove 6f of the seal mounting member 6 and the inner circumferential groove 7d of the seal mounting member 7, respectively. Has been. The elastic seal 8 is also provided with an annular lip portion 8a at a portion that contacts the orthogonal wall 6e of the seal mounting member 6 and the orthogonal wall 7c of the seal mounting member 7.
[0017]
The aforementioned annular space S is defined by the outer periphery of the seal rings 4, 4, the seal mounting members 6, 7 facing the outside, and the elastic seals 8, 8.
[0018]
The annular member 10 is provided integrally with the elastic seal 8 so as to protrude into the annular space S. The annular member 10 has a rectangular cross section and is integrally formed of the same material as that of the elastic seal 8, or is formed separately from the same material and bonded together. The annular member 10 extends to a position close to the annular member 10 provided in the other elastic seal 8 in the space S.
[0019]
Thus, the lubricating oil enclosure chamber L filled with the above-described lubricating oil is provided between the pair of seal mounting members 6 and 7 by the shaft 12, the seal mounting members 6 and 7, the seal rings 4 and 4, and the elastic seals 8 and 8. Comparted and regulated.
[0020]
The annular member 10 provided integrally with each of the elastic seals 8 and 8 is an annular member having a cross section of a size corresponding to two annular members 10 only in one of the elastic seals 8 as shown in FIG. The member 20 may be integrally provided.
[0021]
The operation of the mechanical seal 2 configured as described above will be described with reference to FIG.
[0022]
(1) Sealability:
Since the annular member 10 is disposed in the outer annular space S of the mechanical seal 2, the space S in which foreign matter such as earth and sand and muddy water enters and accumulates can be reduced and minimized. It is possible to prevent deterioration of the sealing performance of the mechanical seal due to foreign matter.
[0023]
(2) Sealability:
Furthermore, since the elastic seal 8 and the annular member 10 can greatly increase the volume of the cross-sectional area as compared with the conventional O-ring seal 34 (FIG. 4), the volume change due to intrusion of earth and sand, freezing, etc. It becomes possible to absorb easily, and also from this point, deterioration of the sealing performance of the mechanical seal can be prevented.
[0024]
(3) Elastic seal:
In addition, since the elastic seal 8 has a rectangular cross section, as in the conventional O ring seal 34 (FIG. 4), rolling at the mounting portion due to the circular cross section causes twisting of the O ring seal 34. Etc. can also be prevented. Further, in the case of the O-ring seal 34, the space S in which foreign matters such as earth and sand and muddy water enter and accumulate from the circular cross-section tends to increase (FIG. 4), but the rectangular cross-section passes through this space S. Can be small.
[0025]
(4) Annular member:
If the elastic seal 8 and the annular member 10 are integrally formed, the assembly of the mechanical seal 2 can be facilitated without incorporating them separately.
[0026]
As described above, the present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications or corrections may be made within the scope of the present invention, for example, as described below. It is something that can be done.
[0028]
( 1 ) Annular member:
In the embodiment of the present invention, the annular member 10 is provided integrally with each of the elastic seals 8, 8, and the other form of the annular member 20 is provided integrally with only one elastic seal 8, but as shown in FIG. 3. It is good also as the annular member 22 which consists of the same material separate from the elastic seal 8, and has a cross section of the magnitude | size for two annular members 10. As shown in FIG.
[0029]
( 2 ) Annular member:
The annular members 10 and 20 and the annular member 22 in the embodiment of the present invention are formed of the same synthetic rubber as that of the elastic seal 8, but may be formed of other materials such as a synthetic resin and a metal material. .
[0030]
【The invention's effect】
According to the mechanical seal constructed in accordance with the present invention, entry of foreign matter such as earth and sand and muddy water from the outside into the space of the outer peripheral portion of the mechanical seal, accumulation is minimized, and a problem in sealing performance is not caused. A mechanical seal is provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an embodiment of a mechanical seal constructed in accordance with the present invention.
FIG. 2 is a cross-sectional view showing another embodiment of the annular member in FIG.
3 is a cross-sectional view showing still another embodiment of the annular member in FIG. 1. FIG.
FIG. 4 is a cross-sectional view of a conventional mechanical seal.
[Explanation of symbols]
2: mechanical seal 4: seal ring 4c: outer peripheral groove 6: seal mounting member 6f: inner peripheral groove 7: seal mounting member 7d: inner peripheral groove 8: elastic seal 10: annular member 20: annular member 22: annular member 32: Seal ring 34: O-ring seal F: Seal surface L: Lubricating oil sealing chamber S: Annular space

Claims (2)

A pair of seal rings having annular seal surfaces that are in sliding contact with each other, and each seal ring and seal that hold the seal ring between a pair of seal mounting members that are arranged to freely rotate relative to each other. A pair of annular elastic seals interposed between each of the mounting members,
Elastic seal has a cross section of rectangular shape,
The seal ring includes an outer peripheral groove having an L-shaped cylindrical wall and an orthogonal wall fitted to the inner diameter portion of the rectangular cross section,
The seal mounting member includes an inner circumferential groove having an L-shaped cylindrical wall and an orthogonal wall that are fitted to the outer diameter portion of the rectangular cross-section.
The outer periphery of the seal ring, and a pair of the seal attachment member facing at its outward, and a pair of elastic sealing rectangular cross section of the annular ring member disposed a rectangular shaped cross-section in the space formed by the A mechanical seal characterized by comprising. The mechanical seal according to claim 1, wherein the annular member is provided integrally with each of or one of the pair of elastic seals.

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