JP3849862B2 - Seal chain - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention prevents the lubricating oil (for example, grease) sealed between the outer peripheral surface of the pin and the inner peripheral surface of the bush from leaking to the outside and between the outer peripheral surface of the pin and the inner peripheral surface of the bush. The present invention relates to a seal chain having an annular seal member made of an elastic material that prevents foreign matter from entering the outside.
[0002]
[Prior art]
The seal chain generally has a seal structure A in the gap S between the inner plate 21 and the outer plate 22 as shown in FIG.
Conventionally, various seal structures have been proposed. For example, as shown in FIG. 6, both of the first and second rigid seal members 34 and 31 facing each other at positions near the outer periphery of the end of the bush 24 that is loosely fitted to the pin 23. A required taper side surface is formed on the taper, and an O-ring elastic seal member 35 having elasticity is interposed between the both taper side surfaces.
Then, by utilizing the elasticity of the respective tapered side surfaces and the O-ring elastic seal member, the first rigid seal member 34 is provided on the outer surface of the inner plate 21 and the second rigid seal member 31 is provided on the outer plate 22. There is known a full-float type seal structure that is arranged so as to be pressed on the inner surface of each of them (see Japanese Utility Model Laid-Open No. 6-76218).
[0003]
In order to further improve the sealing performance, as shown in FIG. 7, a second O-ring is provided between the second rigid seal member 31 and the inner plate 21 and between the first rigid seal member 34 and the outer plate 22. A double-seal type seal chain is also proposed in which an elastic seal member 32 and a V-shaped elastic seal member 33 are interposed (see Japanese Patent Application Laid-Open No. 2000-136848).
[0004]
[Problems to be solved by the invention]
However, in the full float type sealing structure, since the sealing is substantially performed by one O-ring-shaped elastic sealing member 35, the fine powder easily enters and a sufficient sealing effect cannot be obtained.
In the double seal type seal chain, the first rigid seal member 34 and the second rigid seal member 31, the first O-ring elastic seal member 35 and the second O-ring elastic seal member 32, From the grease reservoir formed in the space surrounded by the plate 21, the lubricant (grease) flows out to the outside, and the sealing function is deteriorated.
As a result of the intensive studies by the inventors of the present invention on the cause of the deterioration of the sealing function, when a stress is applied that reduces the distance between the inner plate 21 and the outer plate 22 due to some cause when the chain is bent. The lubricant flows out of the grease reservoir. Thereafter, the stress is relieved and the interval is restored, but the volume of the grease reservoir is reduced by the amount of the lubricating oil that has flowed out, so that a tensile force is generated in each member constituting the grease reservoir. A gap is generated between the plate and each member constituting the seal. As a result, it was clarified that the sealing function is lowered.
[0005]
Accordingly, an object of the present invention is to prevent the fine powder from penetrating, the contact pressure between the first rigid seal member and the inner plate against the relative displacement between the inner plate and the outer plate, and the second rigid seal member and the outer plate. It is an object of the present invention to provide a seal chain that can maintain a high sealing function over a long period of time without lowering the contact pressure with the nozzle.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a seal chain according to claim 1 is a chain formed by connecting a plurality of link assemblies, wherein one of adjacent link assemblies is perpendicular to the longitudinal direction of the chain. A pair of inner plates that are spaced apart from each other and a hollow cylindrical bush press-fitted to the pair of inner plates, and the other of the adjacent link assemblies is disposed on the outside of the pair of inner plates on the length of the chain. A pair of outer plates spaced apart in a direction orthogonal to the direction, and a pin that is press-fitted into the pair of outer plates through the bush, and between the opposing surfaces of the inner plate and the outer plate, A first rigid seal member whose rear surface is in contact with the inner plate and a second rigid seal member whose rear surface is in contact with the outer plate are interposed, and the tapered side surface of the first rigid seal member and the first The first rigid seal member is configured such that an O-ring elastic seal member is gripped between tapered side surfaces of the rigid seal member, and two spaces formed with the O-ring elastic seal member as a boundary communicate with each other. And a lubricating oil communication passage is formed in at least one of the second rigid seal members.
Here, the shape and the like of the communication path for the lubricating oil are not particularly limited as long as they communicate with the two spaces, and the slits formed in the radial direction and the side walls are penetrated in the radial direction. It may be a hole.
[0007]
[Action]
Since the present invention has the above-described configuration, the following effects specific to the present invention are exhibited.
[0008]
According to the seal chain according to claim 1, the first rigid seal member whose rear surface is in contact with the inner plate and the second surface whose rear surface is in contact with the outer plate are disposed between the opposed surfaces of the inner plate and the outer plate. And an O-ring elastic seal member is gripped between the tapered side surface of the first rigid seal member and the tapered side surface of the second rigid seal member. Since the communication passage for lubricating oil is formed in at least one of the first rigid seal member and the second rigid seal member so as to communicate two spaces formed with the elastic seal member as a boundary, The lubricant (grease) moves smoothly with respect to the relative displacement with the outer plate, and the contact pressure between the first rigid seal member and the inner plate and / or the second rigid seal member and the outer plate decreases. It is not, sealing effect is sustained over a long period of time.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Example 1 which is a preferred embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows the overall structure of the seal chain, and FIG. 2 is an enlarged cross-sectional view of the seal structure that is a characteristic part of the seal chain according to the first embodiment of the present invention. This corresponds to the portion shown in FIG.
[0010]
The seal chain 20 of the present invention is a chain formed by connecting a plurality of link assemblies, and one of the adjacent link assemblies is separated from each other in a direction perpendicular to the longitudinal direction of the chain, 21 and a hollow cylindrical bush 24 that is press-fitted to the pair of inner plates 21, 21, and the other of the adjacent link assemblies is outside the pair of inner plates 21, 21. It has a pair of outer plates 22 and 22 that are separated in a direction orthogonal to the longitudinal direction, and a pin 23 that is loosely fitted to the bush 24 and press-fitted to the pair of outer plates 22 and 22.
And between the opposing surfaces of the inner plate 21 and the outer plate 22, the first rigid seal member 34 having a L-shaped cross section whose back surface is in contact with the inner plate 21, and the back surface is in contact with the outer plate 22. And a second rigid seal member 31 having an O-ring insertion groove 31a on the front surface, and a second rigid member 31 that is inserted into the O-ring insertion groove 31a and biases the second rigid seal member 31 against the outer plate 22. The O-ring elastic seal member 32, and the first O-ring elastic seal held between the tapered side surface of the first rigid seal member 34 and the tapered side surface of the second rigid seal member 31. An elastic seal having a V-shaped cross section located between the member 35, the first rigid seal member 34 and the outer plate 22 and biasing the first rigid seal member 34 against the inner plate 21. It is constituted by a wood 33.
[0011]
Further, on the side wall having the tapered side surface of the first rigid seal member 34, as shown in FIG. 3, a predetermined number of slit-shaped lubricating oil communication paths 34a are provided in the radial direction.
3A is a plan view of the first rigid seal member 34, and FIG. 3B is a cross-sectional view taken along line BB of FIG. 3A. In FIG. 3, the number of the lubricating oil communication paths 34a is four, but the number is not particularly limited to four. The shape is not limited to the slit shape and may be a hole shape.
[0012]
The space 36 and the space 37 formed between the inner plate 21 and the outer plate 22 are communicated with each other through the lubricating oil communication passage 34a with the first O-ring elastic seal member 35 as a boundary. Therefore, the lubricant (grease) filled in the space 36 can move to the space 37 through the lubricating oil communication passage 34a, and the interval between the inner plate 21 and the outer plate 22 changes to form a grease reservoir. Even if the volume of the space 36 to be changed changes, no tensile stress acts on each member constituting the seal.
[0013]
Next, Example 2 which is another embodiment of the present invention will be described with reference to FIGS.
FIG. 4 is an enlarged cross-sectional view of a seal structure that is a characteristic part of the seal chain according to the second embodiment of the present invention. This corresponds to the portion shown in FIG.
[0014]
In the seal chain according to this embodiment, a trapezoidal groove having a cross section that is in contact with the inner plate 21 between the opposed surfaces of the inner plate 21 and the outer plate 22 and expands toward the outer plate 22 on the front surface. A first rigid seal member 14 having a trapezoidal groove in the cross section of the first rigid seal member 14 and spaced apart from the inner wall of the trapezoidal groove, and a back surface of the first rigid seal member 14 and the outer plate 22. A second rigid seal member 11 having a trapezoidal cross section in contact, and a first O-ring elastic seal disposed between opposing side wall surfaces of the cross-sectional trapezoidal groove and the second rigid seal member having the cross-sectional trapezoidal shape. Positioned between the member 15 and the second O-ring elastic seal member 16, the first rigid seal member 14 and the outer plate 22, the first rigid seal member 14 is connected to the inner plate 2. And a V-shaped cross-section elastic seal member 13 urged against.
[0015]
The first rigid seal member 14 has a flat plate donut shape in which a trapezoidal groove having a tapered side surface 14b, 14c as an inner surface is formed on one side, and the second rigid seal member 11 has a tapered side surface 11b. , 11c is a ring shape having a trapezoidal cross section.
Then, the first and second O-ring elasticities are held by the tapered side surfaces 14b and 14c of the first rigid seal member 14 and the tapered side surfaces 11b and 11c of the second rigid seal member 11. Seal members 15 and 16 are disposed.
The first rigid seal member is formed by the elastic action of the first O-ring elastic seal member 15 and the second O-ring elastic seal member 16 and the action of the tapered side faces 11b and 11c and the tapered side faces 14b and 14c. 14 d is biased toward the outer surface of the inner plate 21, and the one rear surface 11 a of the second rigid seal member 11 is biased toward the inner surface of the outer plate 22.
As a result, even if a relative displacement occurs between the inner plate 21 and the outer plate 22 due to the bending of the chain, the first rigid seal member 14 is pressed against the inner plate 21 and the second rigid seal member 11. The first O-ring elastic seal member 15 and the second O-ring elastic seal member 16 are always connected to the inner plate 21 and the outer plate 22 from the tapered side surface. Since it receives a force that stays in the approximate center, it does not come into contact with both the plates.
[0016]
A space 17 surrounded by the first rigid seal member 14, the second rigid seal member 11, and the two O-ring elastic seal members 15 and 16 is filled with a lubricant such as grease. Has a grease reservoir.
By this grease pool, the surfaces of the first O-ring elastic seal member 15 and the second O-ring elastic seal member 16 can be always kept wet by the lubricant, and slide with the rigid seal member. Wear due to can be reduced.
Further, an elastic seal member 13 having a V-shaped cross section is interposed between the end of the first rigid seal member 14 and the outer plate 22, and the first O-ring elastic seal member 15, A grease reservoir is also formed in a space 18 surrounded by the first rigid seal member 14, the V-shaped elastic seal member 13, the outer plate 22, and the second rigid seal member 11, and the second rigid seal member is formed. The wear due to sliding between the outer plate 22 and the outer plate 22 can be further reduced, and the first O-ring elastic seal member 15, the first rigid seal member 14, and the second rigid seal member 11. Wear due to sliding between the two can be further reduced.
[0017]
Moreover, a predetermined number of slit-shaped lubricating oil communication passages 14a are provided in the radial direction on the side wall having the tapered side surface of the first rigid seal member 14 as shown in FIG. 5A is a plan view of the first rigid seal member 14, and FIG. 5B is a cross-sectional view taken along the line CC of FIG. 5A.
Although FIG. 5 shows four lubricating oil communication passages 14a, the number is not particularly limited to four. Further, the shape of the lubricating oil communication passage 14a is not limited to the slit shape, and may be a hole shape.
[0018]
These lubricating oil communication passages 14 a are formed in the trapezoidal groove in section and between the outer plate 22 and the first rigid seal member 14 with the first O-ring elastic seal member 15 as a boundary. The space 17 and the space 18 are communicated.
Therefore, the lubricant (grease) filled in the space 17 can move to the space 18 through the lubricating oil communication path 14a, and the interval between the inner plate 21 and the outer plate 22 changes, and the volume of the space 17 increases. Even if it changes, a tensile stress does not act on each member which comprises a seal | sticker.
[0019]
Further, a recess 11d serving as a grease reservoir is formed on the back surface of the second rigid seal member 11, and wear due to sliding between the second rigid seal member 11 and the outer plate 22 is reduced, and Intrusion of fine powder from the outside S between the second rigid seal member 11 and the outer plate 22 can be suppressed.
[0020]
Here, the material of each O-ring elastic seal member and the V-shaped elastic seal member used in the present invention is not particularly limited as long as it has sufficient elasticity, but nitrile rubber (NBR) is particularly preferable because it is excellent in oil resistance, heat resistance, and wear resistance. Moreover, when using in a high temperature atmosphere, the fluororubber excellent in heat resistance can be used conveniently.
[0021]
The seal chain 20 according to the embodiment of the present invention has been described as a roller chain having a roller. However, the present invention can also be applied to a bush chain having no roller.
[0022]
【The invention's effect】
As described above, the seal chain according to the present invention has the above-described configuration, and therefore has the following effects specific to the present invention.
[0023]
First, according to the seal chain of the first aspect, the first rigid seal member whose rear surface is in contact with the inner plate and the rear surface is in contact with the outer plate between the opposed surfaces of the inner plate and the outer plate. A second rigid seal member is interposed, and an O-ring elastic seal member is gripped between the tapered side surface of the first rigid seal member and the tapered side surface of the second rigid seal member. Since the communication passage for lubricating oil is formed in at least one of the first rigid seal member and the second rigid seal member so as to communicate two spaces formed with the ring-shaped elastic seal member as a boundary, The lubricant (grease) moves smoothly with respect to the relative displacement between the plate and the outer plate, and the contact pressure between the first rigid seal member and the inner plate and / or the second rigid seal member and the outer plate is reduced. Without having to lower, sealing effect is sustained over a long period of time.
As a result, even when used in a dusty atmosphere, the sealing function is maintained for a long period of time, and smooth operation becomes possible.
[Brief description of the drawings]
FIG. 1A is a plan view illustrating the structure of a seal chain, and FIG. 1B is a side view thereof.
FIG. 2 is a cross-sectional view of a main part of a seal chain according to a first embodiment of the present invention.
3A is a plan view showing a first rigid seal member used in the seal chain shown in FIG. 2, and FIG. 3B is a cross-sectional view thereof.
FIG. 4 is a cross-sectional view of a main part of a seal chain according to a second embodiment of the present invention.
5A is a plan view showing a first rigid seal member used in the seal chain shown in FIG. 4, and FIG. 5B is a cross-sectional view thereof.
FIG. 6 is a cross-sectional view of a main part of a conventional full float type seal chain.
FIG. 7 is a cross-sectional view of a main part of a conventional double seal type seal chain.
[Explanation of symbols]
11, 31 ... second rigid seal member 11d ... recess 13, 33 ... V-shaped elastic seal member 14, 34 ... first rigid seal members 14a, 34a ... lubricating oil Communicating passages 15, 35 ... first O-ring elastic seal members 16, 32 ... second O-ring elastic seal members 17, 18, 36, 37 ... space 20 ... seal chain 21 ... Inner plate 22 ... Outer plate 23 ... Pin 24 ... Bush 25 ... Roller 26 ... Split pin 31a ... O-ring insertion groove

Claims (1)

A chain formed by connecting a plurality of link assemblies,
One of the adjacent link assemblies has a pair of inner plates spaced in a direction orthogonal to the longitudinal direction of the chain, and a hollow cylindrical bush press-fitted to the pair of inner plates,
The other of the adjacent link assemblies is press-fitted to the pair of outer plates through a pair of outer plates spaced apart in the direction perpendicular to the longitudinal direction of the chain on the outside of the pair of inner plates. And having a pin
Between the opposing surfaces of the inner plate and the outer plate, a first rigid seal member whose back surface is in contact with the inner plate and a second rigid seal member whose back surface is in contact with the outer plate are interposed. ,
An O-ring elastic seal member is gripped between the tapered side surface of the first rigid seal member and the tapered side surface of the second rigid seal member,
A communication passage for lubricating oil is formed in at least one of the first rigid seal member and the second rigid seal member so as to communicate two spaces formed with the O-ring elastic seal member as a boundary. A seal chain characterized by that.

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