JPH0227717Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is used to improve mechanical seals that have a relatively large axial movement, such as upper seals for turbo drills, which are used as balance pistons. This is related.

[Conventional technology]

Conventional mechanical seals used as balance pistons, such as upper seals for turbo drills, generally consist of seal members on the non-rotating side and seal members on the rotating side. A sealing mechanism configured by disposing a sealing surface on the side is provided, and this sealing mechanism is interposed between the casing on the fixed side and the rotating shaft on the rotating side so as to be movable in the axial direction, For example, the lubricating oil chamber side and mud muddy water side, which are subject to pressure fluctuations, are hermetically sealed, and the pressure difference between these two chambers is followed to achieve the desired sealing action. .

In the case of this conventional configuration, the sealing material held by each seal member is provided between the stationary side casing and each seal member on the non-rotating side, and between the rotary side rotating shaft and each seal member on the rotating side. By pressing O-rings and the like against their respective mating surfaces and changing their compression margins, appropriate tension and friction forces are obtained to achieve the function of preventing rotation in the circumferential direction.

[Problem that the invention attempts to solve]

However, in the case of the above-mentioned conventional configuration, since the tension force and frictional force as a rotation prevention function are obtained by the pressure-welded sealing O-ring, etc., there was a problem that this rotation prevention function did not work effectively. .

In other words, the tension force and frictional force caused by this type of sealing O-ring etc. are inherently extremely unstable, and may be affected by wear and deterioration of the intervening sealing O-ring, torque fluctuations on the sealing surface, etc. As a result, the anti-rotation function is easily lost, causing slip rotation between the fixed and rotating casings and rotating shafts and each sealing member on the non-rotating and rotating sides, in this case the sealing O-ring. This is undesirable because the sealing O-ring is immediately damaged and rapidly worn, leading to seal leakage.

In addition, in conventional mechanical seals of this type, the seal ring is movable in the axial direction, as disclosed in, for example, Japanese Utility Model Application Publication No. 48-6452. However, with this configuration, if the seal spring that presses the seal ring cannot absorb pressure fluctuations on the lubricating oil chamber side and the muddy water side, the seal mechanism will have to move significantly in the axial direction. There was also the problem of not being able to respond to changes.

This idea was developed in view of the above-mentioned circumstances, and allows the entire seal mechanism to be moved significantly in the axial direction. At the same time, the stationary side member of the seal mechanism is prevented from rotating relative to the casing side, and the seal It is an object of the present invention to provide a mechanical seal in which a rotating member of a mechanism is prevented from rotating with respect to a rotating shaft side.

[Means for solving problems]

In order to achieve the above purpose, the mechanical seal of this invention is interposed between the casing on the fixed side and the rotating shaft on the rotating side so as to be movable in the axial direction, and is used for applications such as the lubricating oil chamber side where pressure fluctuates. In a mechanical seal that tightly seals the mat muddy water chamber side, each row of cylinders on the fixed side and rotating side are stacked in multiple stages with gaps in the circumferential direction, and the cylinders adjacent to each other in each stage are axially At the same time, one of the first-stage and final-stage cylinders on the fixed side and rotating side is placed on the casing side or the rotating shaft side, and the other is placed on the rotating shaft side. It is characterized in that it is provided so as to be appropriately engaged with the stationary side member and the rotating side member, respectively.

〔Example〕

Hereinafter, one embodiment of the mechanical seal according to this invention will be described in detail with reference to FIGS. 1 to 3.

FIG. 1 shows the general structure of this embodiment of the balanced piston type mechanical seal, and FIGS. 2 and 3 show the detailed structure at the arrows shown above.

In each of these figures, reference numeral 1 denotes a casing with a fixed sleeve 2 provided on its inner wall, 3 a rotary shaft mounted within the casing 1 and a rotary sleeve 4 provided on the shaft, and 5 these fixed sleeves 2. A balanced piston type mechanical seal mechanism is provided between the rotary sleeve 4 and the rotary sleeve 4 so as to be freely movable in the axial direction. and muddy water side B. Further, the mechanical seal mechanism 5 includes a rotation prevention mechanism 20 provided to obtain a rotation prevention effect in the rotation direction.

Here, the mechanical seal mechanism 5 as one specific example includes a seal ring retainer 6 pressed against the inner peripheral surface of the stationary sleeve 2 via O-rings 7, 7', and a seal ring retainer 6 of the rotary sleeve 4. It has a piston sleeve 8 which is pressed against the inner circumferential surface via O-rings 9, 9'.

A thrust ring 10, which mainly functions as a thrust bearing, is fixed to the inner peripheral surface of the retainer 6 on the lubricating oil chamber side A, and a thrust ring 10, which mainly functions as a thrust bearing, is fixed on the inner peripheral surface of the retainer 6, and a thrust ring 10, which mainly functions as a thrust bearing, is fixed on the inner peripheral surface of the retainer 6. A stationary sealing ring 11 is elastically held via a sealing spring 12 and is attached to the sleeve 8.
A floating seat 13 and a rotary seal ring 14, which press and receive the rings 10 and 11, are provided at both ends of the outer peripheral surface of the support ring 1, respectively.
5,16.

Therefore, in the case of the mechanical seal mechanism 5 having the configuration of the one specific example, the stationary seal ring 11 is
is pressed against the rotary seal ring 14 at a predetermined pressure,
In addition to forming the intended seal between the lubricating oil chamber side A and the mat muddy water side B, the thrust ring 10 is also pressed against the floating seat 13 and functions as a thrust bearing on the pressure receiving surface.

Also, there is a communication groove 17 between the ring 10 and the seat 13, a retainer 6 and a sleeve 8.
are formed with communication holes 18 and 19, respectively, and through these communication grooves 17 and communication holes 18 and 19,
Pour the lubricating oil in the lubricating oil chamber side A into each of the O-rings 7, 7'.
By supplying between 9 and 9′,
As described above, the axial movement of the seal mechanism 5 itself is carried out smoothly as a result of the pressure difference between the lubricating oil pressure and mud mud water pressure.

However, the mechanical seal mechanism 5 of the above embodiment
The anti-rotation mechanism 20 provided in the lubricating oil chamber side A
Inside, the seal ring retainer 6 on the fixed side and between the rotary sleeve 4 and the piston sleeve 8 on the rotary side are interposed in a laminated state with a slight gap in the circumferential direction. The cylinders 21 to 23 on the fixed side and the cylinders 2 on the rotating side are equipped with multiple stages, each of which has three stages.
It has 7 to 29 columns.

and the first stage (initial stage) to the third stage on the fixed side.
The cylinders 21, 22, and 23 of the stage (final stage) are set at a predetermined angle θ to prevent them from overlapping each other.
Keyholes (or keyways) 21a, 22a, 23a parallel to the axial direction are provided at multiple locations (only one location is shown in the figure) at angular intervals of
At the same time, a pin (or key) 24 implanted in the holding member 2a fixed to the fixed sleeve 2 is inserted into the key hole 21a of the first stage cylinder 21,
The pin 25 implanted in the first stage cylinder 21 is inserted into the key hole 22a of the second stage cylinder 22, and the pin 26 implanted in the second stage cylinder 22 is inserted into the key hole 23a of the third stage cylinder 23.
are sequentially loosely inserted and engaged with each other, and the end portion of the third stage cylinder 23 is appropriately fixed to the seal ring retainer 6. Similarly, on the rotating side, key holes 27a, 28a,
29a and the rotating sleeve 4
The pin 30 of the holding member 4a fixed to the key hole 2
7a, insert the pin 31 of the cylinder 27 into the key hole 28a,
The pins 32 of the cylinder 28 are sequentially slowly inserted into and engaged with the key holes 29a, and the ends of the cylinder 29 are appropriately fixed to the support ring 15 of the piston sleeve 8.

Therefore, in the mechanical seal mechanism 5 equipped with the rotation prevention mechanism 20 as described above, each keyhole 21a,
By loosely inserting and engaging the pins 24, 25, 26 and 30, 31, 32 into the fixed side cylinders 21, 22, 22a, 23a, 27a, 28a, 29a,
23 and the cylinders 27, 28, and 30 on the rotating side are each held together in the rotational direction, and are movable only in the axial direction and can be expanded and contracted. Without interfering with the axial movement that follows the pressure difference between the hydraulic pressure and mud mud water pressure, only the rotational movement in the circumferential direction can be effectively contained, and a rotation prevention function can be obtained. Since each cylindrical row on the rotating side is arranged on the lubricating oil chamber side, it receives an abundant supply of lubricating oil and can smoothly operate in the axial direction.

In addition, in the above embodiment, the rotation prevention mechanism 2
Although each row of cylinders on the fixed side and rotating side of 0 is configured in three stages, it is sufficient to have two or more stages.
The method is not necessarily limited to loose insertion or engagement of the pin into the keyhole.

[Effect of idea]

As detailed above, according to this invention, in a mechanical seal mechanism that forms a hermetic seal movably in the axial direction, the fixed side consisting of multiple stages,
Each cylinder row on the rotating side is connected to the casing side, the rotating shaft side,
Since it is attached to the fixed side member and rotating side member of the seal mechanism and is movable in the axial direction between adjacent cylinders, the sealing spring that presses the seal ring is attached to the lubricating oil chamber side and the muddy water side. When pressure fluctuations cannot be absorbed completely, the entire mechanical seal mechanism, that is, both the rotating side and the stationary side, can be moved significantly in the axial direction. In addition, the pin or key that guides the movement in the axial direction can reliably and effectively restrain the rotational movement in the circumferential direction, thereby achieving a rotation prevention function that never changes from beginning to end, and preventing wear of O-rings, etc. It has various practical effects such as being able to suppress damage as much as possible, improving durability, and having a simple structure and being able to be provided easily and inexpensively.

[Brief explanation of the drawing]

FIG. 1 is a half-cut sectional view showing the general structure of a balance piston type mechanical seal to which an embodiment of the anti-rotation device according to the invention is applied, and FIG.
Figure 3 is a cross-sectional view and a partial plan view at the same point as the arrow. DESCRIPTION OF SYMBOLS 1... Casing, 2... Fixed sleeve of casing, 3... Rotating shaft, 4... Rotating sleeve of rotating shaft, 5... Mechanical seal mechanism, 6... Seal ring retainer, 8... Piston sleeve, 1
0... Thrust ring, 11... Stationary seal ring, 12... Seal spring, 13... Floating seat, 15, 16... Support ring. 20...
... Detent devices, 21-23 and 27-29...
...Cylinder on fixed side and rotating side consisting of multiple layers, 21
a to 23a and 27a to 29a...keyholes (key grooves) of the fixed side and rotating side cylinders, 24 to 26 and 30 to 32...pins (keys) on the fixed side and rotating side. A...Lubricating oil chamber side, B...Matsudo muddy water side.

Claims (1)

[Scope of utility model registration request] A mechanical seal is installed between a casing on the fixed side and a rotating shaft on the rotating side so as to be movable in the axial direction, and seals the lubricating oil chamber side and mud muddy water chamber side, which are subject to pressure fluctuations, for example. Multiple rows of cylinders on the fixed side and rotating side stacked with gaps in the direction are held together using pins or keys so that the adjacent cylinders in each stage can only be moved in the axial direction. At the same time, one of the first-stage and final-stage cylinders on the fixed side and rotating side is appropriately engaged with the casing side and the rotating shaft side, and the other with the fixed side member and the rotating side member, respectively. A mechanical seal characterized by being provided with a