JPS6252120B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a seal that is housed in an annular seal accommodating portion formed between a shaft member and a relative rotation member that rotates relatively around the axis of the shaft member, and seals between the two members. In particular, the present invention relates to a seal that is suitably used in devices such as roller bits in which a large seal accommodating portion cannot be secured and heat resistance and vibration resistance are required.

For example, in the case of roller bits for excavating high-temperature rock bodies, a seal is placed between the bearing shaft of the lug, which is a shaft member, and the cutter, which is a relatively rotating member rotatably supported by the lug, to shield the lubricating oil side from the muddy water side. I need to let it happen.

By the way, in order to perform such a seal well, it is necessary to use a seal that satisfies the following conditions.

Firstly, because of the structure of the lug and the cutter, it is not possible to secure a large seal accommodating area for accommodating the seal, so the design is made smaller so that it can be accommodated in a small seal accommodating area. Second, since considerable vibration is generated during rock excavation, it must be vibration resistant. Thirdly, when the roller bit goes up and down, the cooling action of the cooling water is stopped, so the temperature rises to approximately the same temperature as the rock body, and even during excavation, although the cooling action of the cooling water is performed, Since roller rabbits are in direct contact with high-temperature rock bodies and reach considerable high temperatures, they must be heat resistant.

However, in the past, the first to third
The reality is that no seal has been proposed to date that satisfies all of these conditions. In other words, in devices where a large seal accommodating portion cannot be secured, seals made of elastomer materials such as rubber O-rings have been commonly used, but this does not satisfy the first and second conditions. However, the third condition cannot be satisfied. On the other hand, in the past, there are various seals that satisfy the third condition, but none of these seals can satisfy the first condition (and even the second condition).

In view of the above circumstances, the present invention provides a new seal that has heat resistance and vibration resistance and can be made compact so that it can be accommodated in a small seal housing.

The seal of the present invention that solves this problem has a base body, each of which is formed into an annular shape from a heat-resistant material and is fitted and fixed to the shaft member, and an annular seal surface formed on the relative rotation member, which is capable of relative rotation. It consists of a sealing body that slides into contact with the sealing body, and an elastic pressing body that integrally connects the two bodies and presses the sealing body against the sealing surface.

Hereinafter, the embodiment will be described in detail based on the drawings.

FIG. 1 shows the main parts of a roller bit 1 for excavating high-temperature rock bodies, in which a cutter 3 with digging blades 3a, 3a, . The lug 2
and the cutter 3 have a radial width l (for example, approximately
An annular seal accommodating portion S having a small rectangular cross section with an axial width h (for example, 4 to 4.4 mm) is formed. An annular sealing surface 3b is formed on the end surface of the cutter 3 facing the seal accommodating portion S, which is perpendicular to the axis of the support shaft portion 2a. Also, the contact portion 7 between the support shaft portion 2a and the cutter 3 (including the contact portion with support members such as the support rollers 4, 4, etc.)
The lubricating oil is supplied from an oil passage 6 formed in the lug 2, and this lubricating oil is intended to allow the cutter 3 to rotate smoothly around the support shaft 2a.

A seal 8 is attached to the seal accommodating portion S to prevent the lubricating oil supplied to the contact portion 7 from leaking to the outside, that is, a seal 8 for shielding and sealing the lubricating oil side A from the muddy water side B. has been done.

As shown in FIG. 2, each seal 8 is made of a heat-resistant material, that is, an appropriate metal material having heat resistance and corrosion resistance, and is formed into an annular shape.
the base body 9 fitted and fixed to a, and the sealing surface 3b
a seal body 10 that can be relatively rotatably slidably contacted with the body, and a seal body 10 that integrally connects both bodies 9 and 10 and
0 to the sealing surface 3b. In the cross-sectional shape, the radial width (thickness) and axial thickness of each seal component member 9 to 11 are such that the radial width and axial thickness of the entire seal 8 are equal to the radial width l of the seal housing portion S and It is appropriately set to be smaller than the axial width h.

The base body 9 has a cylindrical shape, and the support shaft portion 2a
They are firmly fitted and fixed by shrink fitting. This shrink-fitting is performed at a higher temperature than the maximum temperature (for example, 350°C) (hereinafter referred to as the "maximum usage temperature") expected when using the roller bit 1, and even under the maximum usage temperature, the support of the base body 9 is maintained. It is designed so that the degree of fitting to the shaft portion 2a does not change. The thickness of the base body 9 in the radial direction is made as thin as possible so that the base body 9 can be fitted to the support shaft portion 2a by shrink fitting in a good and uniform manner in the circumferential direction. Furthermore, when performing shrink fitting, if necessary, a polymer resin material such as a polymer resin adhesive may be applied to the inner circumferential portion of the base body 9. The polymer resin is carbonized and the support shaft portion 2a and the base body 9
This is advantageous because it functions as a gasket between the two. Further, a heat-resistant adhesive may be applied to the inner peripheral portion of the base body 9. Furthermore,
As shown in FIG. 2, a detent pin 12 may be interposed between the lug 2 and the base body 9.

The seal body 10 includes a seal portion 10a and a retainer portion 10 formed into an annular plate shape having a larger diameter than the base body 9.
b are integrally joined. Seal part 10a
As a constituent material of With this in mind, tungsten carbide has been selected. by the way,
In general seals, the tungsten carbide member and the base material are joined by shrink fitting, but in the seal body 10 described above, the seal portion 10a
(and the retainer part 10b) is thin in the axial direction, so if it is shrink-fitted at a high temperature higher than the maximum operating temperature, the shrink-fitting stress will be large and there is a risk of large distortion. Although the seal portion 10a and the retainer portion 10b are joined and integrated by high-temperature silver brazing without melting, they may be fused metallurgically in some cases.

The elastic pressing body 11 is formed into an annular plate shape with a corrugated cross section, and has an inner peripheral edge 11a and an outer peripheral edge 1.
1b are bonded to the outer peripheral edge of the base 9 and the outer peripheral edge of the retainer portion 10b of the sealing body 10 by high-temperature silver brazing or welding that does not melt even at the maximum operating temperature, thereby bonding the base 9 and the sealing body. 10 are integrally connected. The elastic pressing body 11 presses the sealing portion 10a of the sealing body 10 against the sealing surface 3b, forming an annular sealed end surface 13 having a predetermined width L, which is a relatively rotational sliding contact surface between the sealing portion 10a and the sealing surface 3b. It is made to be done. Therefore, as the constituent material of the elastic pressing body 11, a metal material is selected that has predetermined spring characteristics even at the maximum operating temperature. By the way, the elastic pressing body 11
Although the radial width cannot be made extremely small in order to ensure a predetermined pressing force, as described above, the outer peripheral edge 11b is bonded to the outer peripheral edge of the retainer portion 10b instead of the inner peripheral edge, so that the elastic pressing body 11 By overlapping the outer peripheral side of the seal body 10 with the seal body 10, the radial width of the seal portion 10a can be adjusted to the sealed end surface 13 of a predetermined width L.
The radial width of the elastic pressing body 11 is made large enough to ensure the above-mentioned pressing force while making the radial width of the entire seal 8 smaller than the radial width l of the seal accommodating portion S. You can set it to Furthermore, by making the cross-sectional shape of the elastic pressing body 11 waveform, elasticity of the elastic pressing body 11 in the axial direction and the radial direction can be more effectively ensured.

Next, the operation will be explained with respect to the above example.
The seal portion 10a of the seal body 10 is given an initial pressing force to press against the sealing surface 3b due to the elasticity of the elastic pressing body 11, so this initial pressing force and the muddy water pressure (lubricating oil Due to the differential pressure (with respect to the oil pressure on side A), the seal portion 10a and the seal surface 3b
They are pressed against each other and rotated relative to each other.

Therefore, the lubricating oil side A and the muddy water side B are shielded and sealed by the sealing end surface 13 due to the relative rotational sliding contact between the two sides 3b and 10a. At this time, the sealed end surface 13 is lubricated by the lubricating oil on the lubricating oil side A, and there is no fear that the sealing portion 10a and the sealing surface 3b will seize.

Furthermore, since the constituent members 9 to 11 of the seal 8 are molded from a heat-resistant material, the seal 8 is highly heat resistant and can satisfactorily exhibit the above-mentioned sealing function even at the maximum operating temperature.

Moreover, even if vibrations occur during rock excavation, the vibrations are absorbed and alleviated by the elastic pressing body 11.
Can exhibit vibration resistance function. In particular, if the cross-sectional shape of the elastic pressing body 11 is wave-shaped, its elasticity will further increase, and the vibration resistance can be further improved.
In connection with this, even when the differential pressure between the lubricating oil side A and the muddy water side B fluctuates, the elastic pressing body 11 applies pressure to the seal surface 3b of the seal portion 10a regardless of this fluctuation. Sufficient pressing force can be secured and the sealing function can be kept stable.

Note that the structure of the seal according to the present invention is not limited to the above embodiment, and each seal component 9
The shape, material, and integration means of items 1 to 11 can be changed as appropriate, taking into consideration various conditions such as the shape of the seal accommodating portion S and the maximum operating temperature. For example, the elastic pressing body 11 may have a linear cross-sectional shape instead of a waveform.

Further, the seal according to the present invention can be used not only in the roller bit 1 for excavating a high-temperature rock body as in the embodiment described above, but also in various types of equipment that require heat resistance and vibration resistance and in which a large seal housing cannot be secured. Suitably used.

As can be easily understood from the above explanation, the seal of the present invention is formed by integrating a base body and a seal body, each of which is annular, via an elastic pressing body, so that It can be downsized to
Therefore, it can be conveniently equipped even in equipment where only a small seal accommodating space can be secured. In addition, all of the above-mentioned bodies, which are the seal constituent members, are made of heat-resistant materials, and the elastic force of the elastic pressing body presses the sealing body against the sealing surface for sealing, so it has excellent heat resistance and vibration resistance. It has excellent sealing properties and can exhibit good sealing performance even under harsh conditions where high temperatures and vibrations occur.

Therefore, according to the seal of the present invention, only a small seal accommodating space can be secured, where conventionally only seals made of elastomer materials could be used, and furthermore, seals made of elastomer materials cannot withstand use. Even in equipment used under high temperature conditions, it can be sealed well, and its practical value is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing the main parts of a roller bit equipped with a seal according to the present invention, and FIG. 2 is an enlarged view showing the main parts of FIG. 1 in detail. 1... Roller bit, 2... Lug, 2a... Lug support shaft portion (shaft member), 3... Cutter (relative rotation member), 3b... Seal surface, 8... Seal,
9... Base body, 10... Seal body, 10a... Seal portion, 10b... Retainer portion, 11... Elastic pressing body, 13... Sealed end surface, A... Lubricating oil side, B...
Muddy water side, S... Seal housing section.

Claims (1)

[Claims] 1 A seal that is housed in an annular seal accommodating portion formed between a shaft member and a relative rotating member that rotates relatively around the axis thereof, and seals between the two members, each of which is made of a heat resistant material and has an annular shape. A base body that is fitted and fixed to the shaft member molded in A seal characterized in that the sealing body comprises an elastic pressing body that presses the sealing body against the sealing surface.