JPS59117957A - Mechanical seal - Google Patents

Abstract

PURPOSE:To prevent the seizure of a mechanical seal and eliminate the undesirable influence due to adhesion and obtain the superior sealing performance by preparing the seat ring of a mechanical seal and the trailing ring from carbon material. CONSTITUTION:When the rotary shaft 2 of a water pump is revolution driven, a rotor 10 is revolved, and water is sealed by sealing members 7 and 8, and sealed by the slidable surface between the trailing ring 4 and the seat ring 5 of a mechanical seal 3. When the trailing ring 4 and the seat ring 5 are made of carbon material, seizure and the undesirable influence due to adhesion are not generated, and leak of fluid is prevented furthermore, and the frictional torque can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical seal used in water pumps, compressors for car coolers, and the like.

The mechanical seal is a seal in which a seat ring and a driven link are brought into close contact with each other, and the sliding surface provides a seal between the rotating shaft and the casing. By the way, in general, in contact parts that slide against each other, such as between a cylinder and a piston, dissimilar materials are used to prevent adhesion of similar materials (roughening of the sliding surface and seizure caused by this). In the case of homogeneous materials, consideration was given to forming an appropriate surface layer so that the different materials would eventually come into contact.Conventionally, no consideration was given to the seat ring and driven ring of the mechanical seal mentioned above. The same idea has been made, and normally the seat ring is made of a carbon material and the driven ring is made of a 4Δ material such as sintered alumina or stainless steel, so that different materials come into contact.

The present inventor also assumes the combination of different materials,
We have conducted various performance experiments combining seat rings and driven rings made of various materials, but we have not been able to find a combination that comprehensively satisfies various performances such as sealing properties, low friction properties, and seizure resistance. . Experiments have also been conducted on combinations of similar materials, but as mentioned above, most of them cause roughness due to adhesion, reducing sealing performance and increasing frictional torque. had reached the point of burn-in.

However, even if the materials are of the same type, if it is a combination of carbon material and carbon material, roughness will occur even if T't is ≧%<, L/Therefore, the sealing performance It has been found that there is no decrease in the performance or seizure, and in addition, it has been found that better results can be obtained in terms of sealing properties and (IL friction properties) than with the combination of different types of lA.

In other words, the present invention not only eliminates the adverse effects of adhesion and seizure when the seat ring and driven ring of a mechanical seal are made of the same type of carbon material, which was generally avoided in the past, but also achieves the above-mentioned different 1ift hA advantage. This was done based on the knowledge that superior sealing performance could be obtained when using the same method.

The following drawings explain the present invention with reference to an embodiment. In FIG. 1, (1) shows a water pump casing, (2
) is a rotating shaft inserted into the cylindrical part (la) of the casing (1) and rotatably supported by a bearing (not shown) provided in the cylindrical part a). 2) no/
T: The end portion is linked to an engine as a drive unit via a pulley, a sill, and a bell (not shown).

A mechanical seal (
3), and this mechanical seal (3) is provided with a driven link (4) that can be displaced in the axial direction of the rotating shaft (2) and a driven link (4) that rotates together with the rotating shaft (2) but is fixed in the axial direction. It is equipped with a seat ring (5). The above driven ring [
4) is fitted to the optical outer circumferential portion of the inner cylindrical portion (6a) constituting a part of the support portion IA'(6) so as to be able to reciprocate along the axial direction thereof, and the driven ring (4) By engaging the axial protrusion (6b) provided on the outer periphery of the inner cylindrical part (6a) with the axial groove [/ra] provided on the inner periphery of the inner cylindrical part (6a), relative rotation between the two is prevented. ing. The support member (6) includes a wall portion 16c extending radially outward from the left end of the inner cylindrical portion (6a), an outer cylindrical portion [6d] folded back to the right from the outer periphery of this wall portion (6C), and a flange portion (6) bent radially outward from this outer cylindrical portion (6d).
e), the outer cylindrical part (6d) is connected to the cylindrical part i l of the casing (1) via the sealing member (7).
By fitting into the inside of a), the hermeticity of that part is maintained and the driven ring (4) is fixed in the direction of rotation.

Before gluing part -41111 of Sealpa November (8) on the wall part T6C)8 of support part (6) f)J
By gluing the other end of this seal portion 4A (8) to the left end of the driven ring (4) with the intermediate rt++ curved by 1J, the supporting ring 1 (old 6) and Seat ring (maintains Ijl property between 4J and 4J.And between image &7+f part of this sealing member (8)
The driven link (4) is brought into elastic contact with the seat ring (5). This seal 1-ring (
5) is attached via a floating paragine (II) within the four parts (tOa) formed in the rotor (10) for performing a pumping action, which is fixed to the rotating shaft (2). It rotates together with the rotating shaft (2) as one body. Note that, contrary to the illustrated embodiment, the rotation axis (
A driven ring (4) that can be displaced in the axial direction with respect to 2) is provided on the rotating shaft (2) so that it can rotate integrally therewith, and a seal ring (5) is attached to the casing (1) to secure it. You can also make it look like a crab.

In the water pump having the above configuration, when the rotary shaft (2) is rotationally driven by an engine (not shown), the rotor (1o) integrated therewith rotates and supplies water to each cooling section in the engine. At this time, water is sealed by the seal parts 8 (7) and (8), and also by the sliding surface of the driven ring (4) and seat ring (5) of the mechanical seal (3). Become.

However, in the present invention, the driven link (4).

The seat ring (5) and the seat ring (5) are both made of carbon material, which is the same kind of material that has been avoided in the past. This seal is designed to prevent fluid leakage to a greater extent than known mechanical seals, and also to reduce the friction torque by 1φ.

FIG. 2 shows the experimental results of measuring changes in the excitation coefficient when both the driven ring (4) and the seat ring (5) are made of carbon iA'B and are brought into sliding contact. In the same figure, (A) shows the result of the combination according to the present invention, (
B) and (C) show the results of conventional combinations, and in both FB) and (C) carphone material is used as the driven ring, but (
13) stainless steel 47 (sus-304), (C
) uses alumina sintered body.

This experiment was conducted under the following experimental conditions (experimental conditions) ○Test rock: Mechanical laboratory type thrust testing machine ○Revolution speed: 2
000 rpm ○ Test time = 60 minutes ■ Load: 51 (g ○ Moisture γ)"): In water volume (80°C) Q Test piece surface roughness: 0.4 to 1.6 Rz ○ Carbon 4A' PI Composition: Carbon 65wt%: Binder (phenol) 25wt% Nijilica 10wt% As shown in the experimental results in Figure 2, the combination of the present invention has a lower coefficient of friction than the conventional combination. I
SM rub is 1-lux. This shows that even if adhesion occurs on the sliding surface, it does not cause roughness (lower friction torque than before can be maintained), and seizure does not occur. There is.

Next, FIG. 3 shows the amount of water leakage measured for each of the above combinations [A) to fc) under the following experimental conditions. This experiment shows the results of seven experiments conducted for each of the combinations (A) to (C).

(Experiment conditions) ○Testing machine: Physical testing machine 0 rotation speed 711000 rpm 0 hours: 100 hours ○Sealing fluid: Water (80℃) 10 antifreeze ○Sealing pressure Crab 1.5Kg/ctlt As shown in the experimental results in Figure 3 The combination of the invention iA) is
Compared to other conventional combinations TB) and IC), the maximum leakage amount, average leakage amount, and range of the maximum and minimum values of the leakage claws are all small, and excellent sealing performance is obtained.

Although a general carbon IFA material can be used as it is as a Naori-bon material, a desirable composition is 30 to 80 (more preferably 40 to 70) wt% carbon, 15 to 45 (more preferably 25 wt%) ~4o)wt
% binder, 2 to 15 wt % silica or silicate, and optionally 0.5 to 3 wt.
L% lead and 0+5 to 15 wt% boron nitride may be added. As the above-mentioned binder, a conventionally known binder may be used, but especially when a mechanical seal is used in a water pump, it is desirable to use a phenolic resin as the binder.
4) and the seat ring (5), it is desirable to reduce the wear resistance of the force with a small sliding contact area.

As described above, according to the present invention, even though similar materials are in sliding contact, there is no adverse effect or seizure due to adhesion, and
In addition, compared to conventional devices, it is possible to improve sealing performance and reduce frictional torque.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a view showing the results of measuring the coefficient of friction, and FIG. 3 is a view showing the results of measuring the leakage (1).・・Casing (2)・・Rotating shaft (34)・
・Mechanical seal (4)... Driven ring (5)...
Seat ring 11!1 Figure 2 Figure 2 Test B time (minutes) - 1

Claims (1)

[Claims] In a mechanical seal that includes a seat ring and a driven link that slides in contact with the seat ring, and prevents fluid leakage at the sliding contact surface between the seat ring and the driven ring, both the seat ring and the driven link are made of carbon. A mechanical seal characterized by being constructed from materials.