JP2020085036A - mechanical seal - Google Patents

Abstract

To provide a mechanism seal with high versatility capable of being used without selecting fluid to be sealed.SOLUTION: Mechanical seals 10A, 10B comprise a stationary element 30 having a stationary seal ring 35 and attached to a housing 3, a rotary side element 20 having a rotary seal ring 25 and attached to a rotational shaft 3, and energization means 38A, 38B of energizing the stationary seal ring 35 and the rotary seal ring 25 in opposite directions, and has partition means 32, 33, 34, 36, 39 that hermetically partition back surface 25b, 35b side of the stationary seal ring 35 or the rotary seal ring 25 into an inner diameter side and an outer diameter side. On the inner diameter side and the outer diameter side of the partitioning means 32, 33, 34, 36, 39, installation spaces C1 and C2 are provided, in which the energization means 38A and 38B can be individually installed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a mechanical seal that seals a rotating shaft.

A mechanical seal, such as a water pump or a stirrer, which seals a space between a fixed-side structure and a rotary shaft when mounting the rotary shaft so as to be rotatable relative to the fixed-side structure (housing) is known. ..

For example, the mechanical seal shown in Patent Document 1 is applied to a water pump, and includes a stationary seal ring, a bellows externally fitted to the stationary seal ring, and a static seal ring disposed on the outer diameter side of the bellows. A stationary side element having a wave spring (biasing means) for urging the rotary seal ring side and a rotary side element having a rotary seal ring are provided. The sealed fluid is sealed by utilizing the pressure of the sealed fluid such as water or LLC (Long Life Coolant) guided to the radial side.

Japanese Patent No. 5099009 (page 2, FIG. 8)

The mechanical seal disclosed in Patent Document 1 can keep the stationary seal ring and the rotary seal ring in close contact with each other by the urging force of the wave spring even if the pressure of the sealed fluid is weakened. When such a mechanical seal is used for general purposes, the wave spring may be clogged or corroded when the fluid to be sealed is a high-concentration slurry or corrosive.

The present invention has been made in view of these problems, and an object thereof is to provide a mechanical seal with high versatility that can be used without selecting a fluid to be sealed.

In order to solve the above problems, the mechanical seal of the present invention,
A stationary element having a stationary seal ring attached to the housing, a rotating element having a rotary seal ring attached to the rotating shaft, and a biasing force for biasing the stationary seal ring and the rotary seal ring in opposite directions. A mechanical seal comprising:
The stationary sealing ring or the rotary sealing ring has a partition means for sealingly partitioning the back side into an inner diameter side and an outer diameter side, and the biasing means is provided on the inner diameter side and the outer diameter side of the partition means, respectively. It is characterized by having an installation space that can be installed.
According to this feature, it is possible to appropriately select one of the installation spaces provided on the inner diameter side and the outer diameter side of the partition means to arrange the biasing means, and thus it is possible to provide a mechanical seal with high versatility. it can. For example, the urging means can be arranged by selecting an installation space that is not affected by the sealed fluid from installation spaces provided on the inner diameter side and the outer diameter side of the partition means.

Suitably, the stationary element has a case attached to the housing, the partition means is arranged so as to be movable in the axial direction relative to the case, and the installation space is the case. It is formed between the partition means.
According to this, since the case and the partitioning means can move relative to each other in the axial direction, the assembly of the biasing means is easy.

Preferably, the partitioning means includes a tubular member partitioning the stationary sealing ring and the case, and an annular secondary seal, and the tubular member is provided with the case by the secondary seal. They are connected in a sealed manner and are relatively movable in the axial direction.
According to this, since the case and the partitioning means can move relative to each other in the axial direction, the assembling is easy.

Preferably, the tubular member is formed with a support portion that holds the biasing means in the radial direction.
According to this, the urging means can be held in the installation space with high accuracy because the urging means can be held in the state where the tubular member is in contact with the radial direction.

Suitably, the said case is formed with the support part which hold|maintains the said biasing means in a radial direction.
According to this, since the case can hold the biasing means in a state of being abutted in the radial direction, the biasing means can be accurately positioned in the installation space.

Preferably, the rotation-side element and the stationary-side element are formed into a cartridge with their movements restricted in the axial direction.
According to this, the mechanical seal can be easily attached to the housing and the rotary shaft.

It is a sectional side view which shows the mechanical seal in Example 1 of this invention. (A)-(c) is a sectional side view which shows the assembly procedure of a mechanical seal. (A), (b) is a sectional side view which shows the assembly procedure of a mechanical seal following FIG. It is a sectional side view which shows the mechanical seal which changed the arrangement position of the biasing means from FIG. It is a sectional side view which shows the mechanical seal in Example 2 of this invention. It is a sectional side view which shows the mechanical seal in Example 3 of this invention. It is a sectional side view which shows the mechanical seal in Example 4 of this invention. It is a sectional side view which shows the mechanical seal in Example 5 of this invention. It is a sectional side view which shows the mechanical seal in Example 6 of this invention.

The mechanical seal according to the first embodiment will be described with reference to FIGS. 1 to 4.

In the present embodiment, the back surfaces of the rotary seal ring and the stationary seal ring are end faces located on the opposite side of the sliding surface in the rotary seal ring and the stationary seal ring.

As shown in FIG. 1, a mechanical seal 10A according to an embodiment of the present invention is provided between a housing 3 of a rotary machine such as a pump or a stirrer, and a rotary shaft 2 inserted into a shaft hole H of the housing 3. Thus, the interior of the housing 3 is partitioned into a sealed fluid side L1 that is the outer diameter side of the mechanical seal 10A and an atmosphere side A1 that is the inner diameter side of the mechanical seal 10A, and the space between the housing 3 and the rotary shaft 2 is divided. Is used as a so-called inside type for preventing the sealed fluid inside the housing 3 from leaking to the outside.

The mechanical seal 10A is mainly composed of a rotary side element 20 mounted on the rotary shaft 2 and a stationary side element 30 mounted on the housing 3, and the rotary side element 20 and the stationary side element 30 are made into a cartridge. It was done.

First, the rotating element 20 will be described. The rotating side element 20 includes a collar 21 fixed to the rotating shaft 2 with a set screw, a sleeve 22 arranged on an inner diameter side of the collar 21, a gasket 24 internally fitted on the inner diameter side of the sleeve 22, and a gasket 24. It is mainly composed of a rotary seal ring 25 which is fitted in the inner diameter side, and an O-ring 26 which is arranged between the collar 21, the sleeve 22 and the rotary shaft 2.

The collar 21 is formed in a stepped cylindrical shape, and a peripheral wall of the collar 21 is provided with a recessed portion 21a that is open to the right side and the inner diameter side of the paper at a part of the end portion on the right side of the paper that is the housing 3 side. It is formed into 6 equal parts in the direction. In addition, the recessed portions 21a may be formed in a configuration other than the equal distribution of 6.

The sleeve 22 is formed in a laterally-viewed J-shaped annular shape, and has an outer diameter side tubular portion 22b extending axially on the outer diameter side and an inner diameter side tubular portion 22c extending axially on the inner diameter side. is doing. Further, on the outer diameter side tubular portion 22b, claw portions 22a extending in the outer diameter direction are formed at equal intervals in the circumferential direction at the right end portion of the drawing, and each claw portion 22a has a concave portion of the collar 21. It is locked to the installation portion 21a. Further, the inner diameter side tubular portion 22c is formed with an annular flange portion 22d which extends in the outer diameter direction substantially orthogonal to the end portion on the right side of the drawing. In addition, the claw portions 22a may be formed in a manner other than the equal distribution of 6.

The gasket 24 is formed in a laterally L-shaped annular shape in cross section. The rotary seal ring 25 is formed in an annular shape having a rectangular cross section.

Next, the stationary element 30 will be described. The stationary-side element 30 is inserted into the shaft hole H of the housing 3, a middle holder 32 as a tubular member arranged on the inner diameter side of the case 31, and an inner fitting side of the middle holder 32. Of the inner holder 33 as a tubular member, the gasket 34 fitted inside the inner holder 33, the stationary seal ring 35 fitted inside the gasket 34, the case 31 and the middle holder 32. An O-ring 36 and a spacer 37 arranged between them, a wave spring 38A as a biasing means arranged between the case 31 and the inner holder 33, and a sheet packing 39 interposed between the housing 3 and the case 31. , And are mainly composed of.

The case 31 is formed in an annular shape, and in order from the outer diameter side, a flange portion 31a extending in the radial direction, and a U-shaped portion opening to the rotary element 20 side substantially orthogonal to the inner diameter side end portion of the flange portion 31a. 31b, a wall-shaped portion 31c extending substantially in the inner diameter direction of the U-shaped portion 31b on the inner diameter side and on the left side of the paper surface, and substantially orthogonal to the inner diameter side end portion of the wall portion 31c on the left side of the paper surface in the axial direction. It has an inner diameter side tubular portion 31d extending to.

Further, in the inner diameter side tubular portion 31d, concave portions 31e which are open to the left side of the paper surface are formed at six end portions on the left side of the paper surface in the circumferential direction. In addition, the concave portions 31e may be formed in other than 6 equal arrangements.

The middle holder 32 is formed in a cylindrical shape having two steps, and the outer diameter side cylindrical portion 32a extending in the axial direction and the outer diameter side cylindrical portion 32a are substantially formed at the right end of the drawing in the order from the outer diameter side. The outer diameter side wall-shaped portion 32b that extends orthogonally to the inner diameter direction, the central cylindrical portion 32c and the central cylindrical portion 32c that extend to the right side in the axial direction substantially orthogonal to the inner diameter side end of the outer diameter side wall portion 32b. An inner diameter side wall-shaped portion 32d that extends in the inner diameter direction substantially orthogonal to the end portion on the right side of the paper, and an inner diameter side tubular portion 32e that extends to the right side in the axial direction substantially orthogonal to the inner diameter side end portion of the inner diameter side wall portion 32d. Have

Further, the inner diameter of the inner diameter side tubular portion 32e of the middle holder 32 is substantially the same as the outer diameter of the inner diameter side tubular portion 31b2 of the U-shaped portion 31b of the case 31.

The inner holder 33 is formed in an L shape facing downward in cross section, and extends in the inner diameter direction from the outer diameter side in order from the outer diameter side in a direction substantially orthogonal to the tubular portion 33a extending in the axial direction and the end portion of the tubular portion 33a on the right side of the drawing. It has an existing wall-shaped portion 33b. Further, the wall-shaped portion 33b is formed with claw portions 33c extending in the left side of the drawing on the inner diameter side end portion in the circumferential direction at equal intervals, and the claw portions 33c are locked to the concave portions 31e of the case 31. There is. Note that the claw portions 33c may be formed in other than 6 equal arrangements.

The gasket 34 is formed in an annular shape having an L-shape facing downward in cross section. The stationary seal ring 35 is formed in an annular shape having a rectangular cross section. The spacer 37 is formed in a rectangular annular shape with one end chamfered in cross section. The seat packing 39 is formed in an annular shape that is long in the axial direction and has a flat plate shape in cross section.

Next, assembly of the mechanical seal 10A will be described with reference to FIGS. The assembling procedure described below may be changed as appropriate. As shown in FIG. 2A, the rotation-side element 20 is assembled by sequentially fitting a gasket 24 and a rotary seal ring 25 inside the sleeve 22 on the inner diameter side.

Next, the assembly of the stationary element 30 will be described. As shown in FIG. 2B, in a state where the gasket 34 and the stationary seal ring 35 are fitted inside the inner holder 33, the inner holder 33 is press-fitted and fixed to the inside diameter of the middle holder 32, After that, the O-ring 36 is fitted onto the inner diameter side tubular portion 32e of the middle holder 32. A sealant is applied between the outer diameter side tubular portion 32a of the middle holder 32 and the tubular portion 33a of the inner holder 33 to improve the adhesion. Further, the middle holder 32 and the inner holder 33 may be fixed by welding.

As shown in FIG. 2C, the spacer 37 is fitted into the bottom of the U-shaped portion 31b of the case 31. The outer diameter of the spacer 37 is substantially the same as the inner diameter of the outer diameter side tubular portion 31b1 of the U-shaped portion 31b, and the inner diameter of the spacer 37 is larger than the outer diameter of the inner diameter side tubular portion 31b2 of the U-shaped portion 31b. Since it is formed, a gap S is formed between the inner diameter side tubular portion of the U-shaped portion 31b and the spacer 37. The size of the gap S in the radial direction is longer than the plate thickness of the inner diameter side tubular portion 32e of the middle holder 32.

Further, the wave spring 38A is fitted onto the inner diameter side tubular portion 31d of the case 31. The inner diameter side tubular portion 31d of the case 31 prevents the wave spring 38A from moving in the radial direction. That is, the inner diameter side tubular portion 31d is a support portion of the biasing means in the present embodiment.

Referring to FIG. 3A, by inserting the inner diameter side tubular portion 32e of the middle holder 32 into the gap S of the case 31, the case 31 and the middle holder 32 are temporarily fixed. At this time, a gap is formed between the central tubular portion 32c of the middle holder 32 and the outer diameter side tubular portion 31b1 of the U-shaped portion 31b of the case 31, and the slurry is unlikely to stay in this void. The central tubular portion 32c of the middle holder 32 and the outer diameter side tubular portion 31b1 of the U-shaped portion 31b of the case 31 may be in radial contact with each other.

Next, referring to FIG. 3B, the inner diameter side tubular portion 22c of the sleeve 22 of the rotation side element 20 is inserted into the inner diameter side of the stationary side element 30 to insert the rotary seal ring 25 and the stationary seal ring 35. In the abutted state, the end portion on the right side of the drawing of the inner diameter side tubular portion 22c indicated by the two-dot chain line is bent to the outer diameter side to form the flange portion 22d. As a result, the relative movement of the sleeve 22 and the case 31 in the axial direction is restricted, and the mechanical seal 10A is formed into a cartridge, and the assembly is completed.

In the mechanical seal 10A, a case 31 and a middle holder 32 are hermetically connected via an O-ring 36, and a middle holder 32, an inner holder 33, and a gasket are provided between a back surface 35b of the stationary seal ring 35 and the case 31. 34 and an O-ring 36 partition the inner diameter side and the outer diameter side in a sealed manner.

Further, on the inner diameter side of the middle holder 32 and the O-ring 36, an annular inner diameter side installation space C1 defined by the wall-shaped portion 31c of the case 31, the inner diameter side tubular portion 31d, and the wall-shaped portion 33b of the inner holder 33 is provided. Since the wave spring 38A is formed and the wave spring 38A is disposed in the installation space C1 on the inner diameter side, not only the wave spring 38A can be easily assembled but also the wave spring 38A can be accurately positioned.

In the mechanical seal 10A before being mounted on the housing 3 and the rotary shaft 2, the sliding surface 35a of the stationary seal ring 35 is in close contact with the sliding surface 25a of the rotary seal ring 25 by the urging force of the wave spring 38A. The wall-shaped portion 31c of the case 31 is in contact with the flange portion 22d of the sleeve 22.

Further, the mechanical seal 10A resists the urging force of the wave spring 38A by applying an external force in the axial direction, and at the bottom of the U-shaped portion 31b of the case 31, the inner diameter side tubular portion 32e of the middle holder 32 is on the right side of the drawing. It is movable until the ends of the contact.

Next, the attachment of the mechanical seal 10A to the housing 3 and the rotary shaft 2 will be described with reference to FIG. First, the sleeve 22 is externally inserted onto the rotary shaft 2, and the mechanical seal 10A is moved in the axial direction until the flange portion 31a of the case 31 contacts the housing 3. At this time, the U-shaped portion 31b of the case 31 is press-fitted into the shaft hole H of the housing 3 through the sheet packing 39 in a sealed manner.

Next, the collar 21 is fixed to the rotary shaft 2 with a set screw in a state where the case 31 is further pushed to the right side in the axial direction by a predetermined dimension, whereby the attachment of the mechanical seal 10A to the housing 3 and the rotary shaft 2 is completed. In this attached state, the flange portion 22d of the sleeve 22 and the wall-shaped portion 31c of the case 31 are separated from each other, and the wave spring 38A is compressed by a predetermined dimension in the axial direction.

As described above, since the mechanical seal 10A is formed into a cartridge, it can be easily attached to the housing 3 and the rotary shaft 2.

In addition, the mechanical seal 10A attached to the rotary shaft 2 and the housing 3 utilizes the pressure of the sealed fluid so that the sliding surfaces 25a and 35a of the rotary seal ring 25 and the stationary seal ring 35 are slidably brought into close contact with each other. At the same time, the stationary portion is sealed by the gaskets 24 and 34, the O-rings 26 and 36, and the seat packing 39 that are secondary seals.

That is, the middle holder 32, the inner holder 33, the gasket 34 and the O-ring 36, and the sheet packing 39 are on the back surface 35b side of the stationary seal ring 35 between the stationary seal ring 35 and the case 31, and between the case 31 and the housing. The partitioning means in this embodiment is for partitioning the space between 3 and 3 into the inner diameter side and the outer diameter side in a sealed manner.

Further, the sealed fluid flows up to the balance line B1 shown by the alternate long and short dash line and presses the middle holder 32 to the left side of the drawing. The mechanical seal 10A is a so-called balance type in which the balance line B1 is arranged between the outer diameter side end and the inner diameter side end of the sliding surfaces 25a, 35a of the rotary seal ring 25 and the stationary seal ring 35 in the radial direction. The balance rate in this embodiment is about 76%. The balance rate is not limited to about 76% and may be changed as appropriate. The same applies to the subsequent numerical values.

In addition to this, in the mechanical seal 10A, since the middle holder 32 is axially movable relative to the case 31, when the rotary shaft 2 tries to move to the right side of the drawing relative to the housing 3, Within the range of movement of the case 31 and the middle holder 32 in the axial direction, the stationary seal ring 35 is pressed by the rotary seal ring 25 driven by the rotary shaft 2 to the right side of the drawing while the static seal ring 35 is in close contact with the rotary seal ring 25. It is movable together with the middle holder 32.

Similarly, when the rotary shaft 2 tries to move to the left side of the drawing relative to the housing 3, the mechanical seal 10A has a pressure of the sealed fluid within a range of axial movement between the sleeve 22 and the case 31. Also, the stationary seal ring 35 is pressed to the left side of the drawing while being in close contact with the rotary seal ring 25 by the urging force of the wave spring 38B, and is movable together with the middle holder 32.

Further, in the mechanical seal 10A, since the inner diameter side tubular portion 32e has a movement allowance in the gap S to be movable in the radial direction, the rotary shaft 2 may be moved in the radial direction or tilted relative to the housing 3. Then, within the range of radial movement between the sleeve 22 and the case 31, the stationary seal ring 35, which is in close contact with the rotary seal ring 25, moves in accordance with the radial movement or tilt of the rotary seal ring 25. It is movable together with the holder 32.

As a result, the mechanical seal 10A can allow the rotary shaft 2 to move in the axial direction and the radial direction, and to tilt relative to the housing 3.

Further, in the stationary element 30, since the movement of the O-ring 36 to the right side in the axial direction of the drawing is restricted by the spacer 37, the bottom portion of the U-shaped portion 31b of the case 31, the inner cylindrical portion 31b2, and the middle holder. The O-ring 36 is prevented from being caught between the inner diameter side tubular portion 32e of 32. As a result, the middle holder 32 can be stably moved relative to the case 31 in the axial direction.

Further, in the mechanical seal 10A, the claw portion 22a of the sleeve 22 is locked to the recessed portion 21a of the collar 21 in the rotation side element 20, so that the sleeve 22 reliably follows the rotation shaft 2.

Further, in the mechanical seal 10A, in the stationary side element 30, since the claw portion 33c of the inner holder 33 is locked to the concave portion 31e of the case 31, the inner holder 33 is relatively circumferential with respect to the case 31. It is prevented from rotating.

As described above, in the mechanical seal 10A, since the wave spring 38A is arranged in the inner diameter side installation space C1 arranged on the atmosphere side A1, the wave spring 38A is prevented from being exposed to the sealed fluid. There is. That is, even if the sealed fluid is a high-concentration slurry or a corrosive fluid, the wave spring 38A can be used stably without being clogged or corroded.

Here, the mechanical seal 10A can configure the mechanical seal 10B by disposing the wave spring 38B in the outer diameter side installation space C2 provided on the outer diameter side of the inner diameter side installation space C1 (FIG. 4). reference). The outer diameter side installation space C2 is an annular shape defined on the outer diameter side of the middle holder 32 and the O ring 36 by the flange portion 31a of the case 31, the central cylindrical portion 32c of the middle holder 32, and the outer diameter side wall portion 32b. Is the space of. The wave spring 38B has a larger diameter than the wave spring 38A (see FIG. 4).

In the outer diameter side installation space C2, the outer diameter side wall-shaped portion 32b of the middle holder 32 is arranged on the axial right side of the wall-shaped portion 33b of the inner holder 33 by the plate thickness, and the flange portion 31a of the case 31 is provided. The case 31 is arranged with a difference in axial position from the wall-shaped portion 31c. In other words, in the inner diameter side installation space C1, the wall-shaped portion 33b of the inner holder 33 is arranged on the left side of the outer diameter side wall-shaped portion 32b of the middle holder 32 in the plate thickness direction, and the wall-shaped portion 31c of the case 31 The case 31 is arranged with a difference in axial position from the flange portion 31a. The axial position of the flange portion 31a of the case 31 and the wall-shaped portion 31c of the case 31 may be the same.

As a result, the dimension D2 (see FIG. 1) between the outer diameter side wall-shaped portion 32b of the middle holder 32 and the flange portion 31a of the case 31 facing each other is determined by the wall-shaped portion of the inner holder 33 facing the inner diameter side installation space C1. It is substantially the same as the dimension D1 (see FIG. 1) between 33b and the wall-shaped portion 31c of the case 31 (D1=D2). Note that D1 and D2 do not have to be substantially the same.

In constructing the mechanical seal 10B, the wave spring 38B is supported by the central tubular portion 32c, so that not only the assembly is easy, but also the wave spring 38B can be accurately positioned. Further, the central cylindrical portion 32c is a supporting portion of the biasing means in this embodiment that supports the wave spring 38B and prevents the wave spring 38B from being pulled out in the radial direction.

Further, as shown in FIG. 4, the mechanical seal 10B is used as a so-called outside type. The sealed fluid flows up to the balance line B2 indicated by the alternate long and short dash line and presses the middle holder 32 to the left side of the drawing. The mechanical seal 10B is a balance type in which the balance line B2 is arranged between the outer diameter side end and the inner diameter side end of the sliding surfaces 25a, 35a of the rotary seal ring 25 and the stationary seal ring 35 in the radial direction. The balance rate in this example is about 83%.

Further, a gap is formed between the inner diameter side tubular portion 32e of the middle holder 32 and the inner diameter side tubular portion 31b2 of the U-shaped portion 31b of the case 31, and the slurry is unlikely to stay in this void. The inner diameter side tubular portion 32e of the middle holder 32 and the inner diameter side tubular portion 31b2 of the U-shaped portion 31b of the case 31 may abut in the radial direction.

Further, in the mechanical seal 10B, since the wave spring 38B is arranged in the outer diameter side installation space C2 located on the atmosphere side A2, the wave spring 38B is exposed to the sealed fluid guided to the sealed fluid side L2. Is prevented. That is, even if the sealed fluid is a high-concentration slurry or a corrosive fluid, the wave spring 38B can be used stably without being clogged or corroded. This makes it possible to provide a highly versatile mechanical seal that can be used without selecting a fluid to be sealed.

If the sealed fluid is water, LLC, or the like, the wave spring 38B will not be clogged or corroded, so the mechanical seal 10B can also be used as an inside type. Similarly, the mechanical seal 10A can also be used as an outside type. That is, the mechanical seals 10A and 10B of the present invention can be used as an inside type and an outside type, respectively.

Further, in the mechanical seals 10A and 10B, since the pressure receiving surfaces of the inside type or the outside type are partially overlapped with each other on the inner diameter side wall portion 32d of the middle holder 32 and the O-ring 36, each balance rate is 50%. It can be configured as a double-balanced mechanical seal that exceeds.

Although the restricting means for cartridge-forming the rotating side element and the stationary side element has been described as the flange portion 22d of the annular sleeve 22, the present invention is not limited to this, and the regulating means may be formed in six equal intervals in the circumferential direction. Good. Incidentally, the respective regulation means may be arranged in a manner other than the equal distribution.

Next, a mechanical seal according to the second embodiment will be described with reference to FIG. The same components as those shown in the first embodiment are designated by the same reference numerals, and the duplicated description will be omitted. The second embodiment is different from the first embodiment in the urging means and the construction of the cartridge.

Referring to FIG. 5, in mechanical seal 110, six coil springs 138 as biasing means are arranged in the inner diameter side installation space C1 or the outer diameter side installation space C2 in the circumferential direction at 6 equal intervals, and a wall of case 31 is provided. The cylindrical portion 31c and the wall portion 33b of the inner holder 33, or the flange portion 31a of the case 31 and the outer diameter side wall portion 32b of the middle holder 32 are fixed by welding. In addition, the coil springs 138 may be arranged at a position other than the six equal distributions. Furthermore, each coil spring 138 may be externally or internally fitted to and fixed to a convex portion or a concave portion formed on the case 31, the middle holder 32, and the inner holder 33.

Next, a mechanical seal according to the third embodiment will be described with reference to FIG. The same components as those shown in the first and second embodiments are designated by the same reference numerals, and the duplicate description will be omitted. The third embodiment differs from the first and second embodiments in the configuration of the tubular member.

6, in the mechanical seal 210, the central cylindrical portion 132c of the middle holder 132 as a cylindrical member is slidably contacted with the outer diameter side cylindrical portion 31b1 of the U-shaped portion 31b of the case 31 in the circumferential direction. As much as possible, the inner diameter side tubular portion 132e of the middle holder 132 is separated from the inner diameter side tubular portion 31b2 of the U-shaped portion 31b of the case 31. Accordingly, when used as the outside type, it is possible to prevent the middle holder 32 from being largely deformed to the outer diameter side due to the pressure of the sealed fluid. The central cylindrical portion 132c of the middle holder 132 may be configured such that the radially protruding portion is in contact with the outer diameter side cylindrical portion 31b1 of the U-shaped portion 31b of the case 31. In this case, the stagnation of the slurry can be prevented by the voids formed in the non-projecting portion.

Next, a mechanical seal according to the fourth embodiment will be described with reference to FIG. The same components as those shown in the first to third embodiments are designated by the same reference numerals, and the duplicated description will be omitted. The fourth embodiment is different from the first to third embodiments in the configuration of the tubular member and the supporting portion of the biasing means.

Referring to FIG. 7, in the mechanical seal 310, the central cylindrical portion 232c of the middle holder 232 as a cylindrical member is located from the inner diameter side end portion of the outer diameter side wall portion 232b to the inner left side end portion of the paper surface of the inner diameter side cylindrical portion 232e. It is formed in a taper shape that inclines toward. Accordingly, since a large space can be secured between the outer diameter side tubular portion 31b1 of the U-shaped portion 31b of the case 131 and the central tubular portion 232c, the outer diameter side tubular portion 31b1 of the U-shaped portion 31b of the case 131 can be secured. The slurry is unlikely to stagnate between the central cylindrical portion 232c and the central cylindrical portion 232c.

Further, the support portion of the biasing means of the outer diameter side installation space C2 is configured by a flange 131a of the case 131 and a pair of ribs formed on the outer diameter side wall portion 232b of the middle holder 232. As described above, the support portion of the biasing means is not limited as long as it can support the biasing means.

Next, a mechanical seal according to the fifth embodiment will be described with reference to FIG. The same components as those shown in the first to fourth embodiments are designated by the same reference numerals, and the duplicated description will be omitted. The fifth embodiment differs from the first to fourth embodiments in the configuration of the tubular member.

Referring to FIG. 8, the mechanical seal 410 is configured such that the middle holder 332 as a cylindrical member is vertically symmetrical with respect to the first to fourth embodiments and expands from the inner diameter side to the outer diameter side toward the right side of the paper surface. The case 231 and the inner holder 133 as a tubular member are also formed in accordance with the above. As described above, the cylindrical member may have any shape as long as it can be used in combination with the secondary seal to hermetically partition the back surface 35b side of the stationary sealing ring 35 into the inner diameter side and the outer diameter side, and the same applies to the case. is there.

Next, a mechanical seal according to the sixth embodiment will be described with reference to FIG. The same components as those shown in the first to third embodiments are designated by the same reference numerals, and the duplicated description will be omitted. The fifth embodiment differs from the first to fourth embodiments in the configuration of the partitioning means.

Referring to FIG. 9, mechanical seal 510 employs bellows 432 having an outer diameter side end portion or an inner diameter side end portion fixed to case 31 and inner holder 33 as partitioning means. In this way, the partitioning means may be capable of hermetically partitioning the back surface 35b side of the stationary sealing ring 35 into the inner diameter side and the outer diameter side. The secondary seal forming the partition means is not limited to the gasket 34, the O-ring 36 in the first to fifth embodiments and the bellows 432 in the sixth embodiment, and may be appropriately changed to an elastic member such as a lip packing.

The embodiments of the present invention have been described above with reference to the drawings. However, the specific configuration is not limited to these embodiments, and any modifications or additions within the scope of the present invention are included in the present invention. Be done.

For example, in the above-described embodiment, the mechanical seal has been described as a so-called fixed type in which the biasing means is provided in the stationary side element 30, but the mechanical seal is not limited to this, a so-called rotary type in which the biasing means is provided in the rotating side element. May be configured as. That is, the back surface 25b side of the rotary seal ring 25 may be hermetically divided into the outer diameter side and the inner diameter side to form the inner diameter side installation space C1 and the outer diameter side installation space C2.

Further, although the mechanical seal has been described as a mode in which it can be used both as an inside type and an outside type, the mechanical seal is not limited to this, and may be a dedicated inside type or an outside type. For this reason, the both-balanced type may not be used, and the unbalanced type may be used.

Further, the mechanical seal has been described as a cartridge form, but it may not be a cartridge form, and the stationary side element and the rotating side element may be separately attached to the housing 3 or the rotating shaft 2. .. For example, even in a mode in which the case 31 is not provided and the middle holder 32 is axially movable relative to the housing 3 and is sealed in an outer diameter side and an inner diameter side by an O-ring 36. Good.

Further, the inner diameter side installation space C1 and the outer diameter side installation space C2 may be formed between the middle holder 32, the inner holder 33, and the O-ring 36, which are partitioning means, and the case 31. A separate member for forming an installation space may be interposed between the middle holder 32 and the case 31.

Further, the inner diameter side installation space C1 may be formed between the inner holder 33 and the flange portion 22d of the sleeve 22, or may be formed between the inner holder 33 and the housing 3 and is limited. Not a thing. The same applies to the outer diameter side installation space C2.

Further, the middle holder 32 and the inner holder 33, which are tubular members, have been described as being separate bodies, but the present invention is not limited to this, and they may be integrally molded and are not limited. In addition, the stationary seal ring 35 and the case 31 are directly prevented from rotating, and if the urging means can be arranged between the stationary seal ring 35 and the case 31, the inner holder 33 is not provided. Good.

Further, although the middle holder 32 has been described as having a stepped cylindrical shape, it may have a linearly extending cylindrical shape, a bottomed cylindrical shape, or an annular shape. .. This also applies to the inner holder 33.

Further, although the biasing means has been described as the wave springs 38A, 38B or the coil spring 138, the biasing means is not limited to this, and can be continuously arranged in the inner diameter side installation space C1 or the outer diameter side installation space C2 in the circumferential direction. It may be a coil spring or a metal bellows having a biasing force, and is not limited.

Further, the rotation-side element has been described as an aspect including the collar 21, but the invention is not limited to this, and if the rotation stopper with respect to the rotation shaft 2 is sufficient only by externally inserting the sleeve 22 onto the rotation shaft 2, the collar is not limited to this. 21 may not be included.

Further, the recessed portion 21a, the claw portion 22a, the recessed portion 31e, the claw portion 33c, the coil spring 138, and the restricting means have been described as a mode in which they may be arranged in a manner other than 6 equal distributions. It may be provided only in one place, or may be unevenly arranged in plural.

2 rotary shaft 3 housing 10A, 10B mechanical seal 20 rotary side element 25 rotary seal ring 25b back surface 30 stationary side element 31 case 32 middle holder (partitioning means, tubular member)
33 Inner holder (partitioning means, tubular member)
34 Gasket (compartment means, secondary seal)
35 stationary seal ring 35b rear surface 36 O-ring (compartment means, secondary seal)
38A, 38B Wave spring (biasing means)
39 Seat packing (secondary seal)
110 mechanical seal 131 case 132 middle holder (partitioning means, tubular member)
133 Inner holder (partitioning means, tubular member)
138 Coil spring (biasing means)
210 mechanical seal 231 case 232 middle holder (partitioning means, tubular member)
310 Mechanical seal 332 Middle holder (partitioning means, tubular member)
410 Mechanical seal 432 Bellows (compartment means)
510 mechanical seal A1, A2 atmosphere side B1, B2 balance line C1, C2 outer diameter side installation space D1, D2 dimension H shaft hole L1, L2 sealed fluid side S gap

Claims (6)

A stationary element having a stationary seal ring attached to the housing, a rotating element having a rotary seal ring attached to the rotating shaft, and a biasing force for biasing the stationary seal ring and the rotary seal ring in opposite directions. A mechanical seal comprising:
The stationary sealing ring or the rotary sealing ring has a partition means for sealingly partitioning the back side into an inner diameter side and an outer diameter side, and the biasing means is provided on the inner diameter side and the outer diameter side of the partition means, respectively. A mechanical seal characterized by having an installation space where it can be installed. The stationary element has a case attached to the housing, the partition means is arranged so as to be relatively movable in the axial direction with respect to the case, and the installation space is the case and the partition means. The mechanical seal according to claim 1, which is formed between the two. The partitioning means includes a tubular member that partitions the stationary seal ring and the case, and an annular secondary seal, and the tubular member is hermetically connected to the case by the secondary seal. The mechanical seal according to claim 2, wherein the mechanical seal is axially movable. The mechanical seal according to claim 3, wherein the tubular member is formed with a support portion that holds the biasing means in a radial direction. The mechanical seal according to any one of claims 2 to 4, wherein the case is formed with a support portion that holds the biasing means in a radial direction. The mechanical seal according to any one of claims 1 to 5, wherein movements of the rotation-side element and the stationary-side element are restricted in a direction in which they are separated from each other in the axial direction.

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