JPS6324293Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention mainly relates to a sealing device for a rotating shaft.

Technical background of the invention and its problems Conventionally, the rotary shaft has been sealed by installing a sealing element in a box formed between the casing and the rotary shaft. A sealing element having a basic structure in which an annular plate-shaped sealing piece A is bent in the fluid pressure direction, the tip B of the sealing piece is brought into close contact with the rotating shaft C, and the other end is fixed to the casing side is often used. In the seal element of this structure, the tip of the seal piece slides closely against the rotating shaft to seal the pressure fluid, but this seal piece has a tension margin that compresses against the shaft. The tip has a large sliding surface pressure against the rotating shaft. Therefore, at the beginning of operation, the tip of the seal piece wears rapidly, and then the sliding part becomes accustomed to sealing, but it takes time to achieve the necessary conformation for sealing. teeth,
The sealing performance was unstable. That is, there were problems in that the sliding torque was large at the beginning of operation, and it took time to obtain stable sealing performance.

In addition, in this seal element, when the fluid pressure increases during operation, the seal piece A moves backward along the shaft due to the fluid pressure, and the seal piece A first moves between the tip of the seal piece A and the rotating shaft C. The sliding part that has been moved will move. As a result, the tip of the seal piece must form a fit necessary for sealing at the sliding portion of the new rotating shaft, and the tip of the seal piece is also worn out. That is, when the fluid pressure fluctuates, there is a problem in that the sliding parts cannot be quickly adapted to each other and the sealing performance becomes unstable.

Purpose of the invention and its outline The present invention attempts to solve the technical problems associated with the prior art as described above, and has the following purposes.

(a) To provide a shaft sealing device that exhibits small changes in sliding torque during the initial stage of operation immediately after the shaft sealing device is mounted on a rotating shaft.

(b) To provide a shaft sealing device that can immediately obtain stable sealing performance even when fluid pressure fluctuates.

The shaft sealing device according to the present invention is provided with an annular space that is open to the outside when viewed from the pressure fluid side in a thick-walled cylindrical inner adapter ring that is fitted onto the rotating shaft, and a ring that is bent toward the pressure fluid side in this space. the base, bent to the side wall of the inner adapter ring;
An annular plate-shaped sealing auxiliary piece consisting of a diagonal part and a sealing part and a sealing piece are arranged one on top of the other so that the sealing piece faces the rotating shaft side, and the tip of the sealing part of the sealing auxiliary piece has a A protrusion is provided so that the protrusion comes into pressure contact with the thick side wall of the inner adapter ring, and a cylindrical seal part that makes sliding contact with the rotating shaft of the seal piece is provided, and a pressing means such as a coil spring is provided in the space. The seal part of the seal piece is brought into pressure contact with the rotating shaft, the outer adapter ring is provided on the outside when viewed from the pressure fluid of the inner adapter ring, and the seal piece and the seal auxiliary piece are placed between the inner adapter ring and the outer adapter ring. The present invention is characterized in that the outer adapter ring is provided with a support portion for holding the seal piece from the outside of the diagonal portion of the seal piece.

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to embodiments shown in the drawings, but the present invention is not limited to these embodiments.

As shown in FIG. 2, the shaft sealing device 1 according to the present invention includes an inner adapter ring 3 fitted to the rotating shaft 2, and a pressure fluid side fitted to the rotating shaft 2. and an outer adapter ring 4 positioned on the outer side when viewed from the center.

The inner adapter ring 3 is provided with an annular space 5 that is open to the outside when viewed from the pressure fluid side.
In this space 5, a seal piece 7 and a seal auxiliary piece 8, which are bent toward the pressure fluid side and reach the side wall 6 of the inner adapter ring 3, are placed one on top of the other so that the seal piece 7 faces the rotating shaft 2 side. It is arranged as follows. The seal piece 7 consists of a base portion 9a, a diagonal portion 10a, and a seal portion 11a, and the seal portion 11a is formed in a cylindrical shape, and the shaft sealing device 1 according to the present invention is connected to the rotating shaft 2 in this seal portion 11a. There is a sliding contact. Further, like the seal piece 7, the auxiliary seal piece 8 also has a base part 9b, a diagonal part 10b, and a seal part 11.
A protrusion 12 is provided at the tip of the seal portion 11b so as to protrude in a direction parallel to the rotation axis, and the protrusion 12 is pressed against the side wall 6 of the inner adapter ring 3. As a result, The seal portion 11a of the seal piece 7 is brought into closer contact with the rotating shaft 2. This protrusion 12 is preferably provided at the tip of the auxiliary seal piece 8, but in some cases, the protrusion 12 may not be provided.

Since the seal piece 7 may generate heat due to close sliding contact with the rotating shaft, it is preferable that the seal piece 7 is made of a heat-resistant material, and for example, it is preferably made of a fluororesin or the like. preferable.
On the other hand, the auxiliary seal piece 8 is not necessarily required to be heat resistant, so it is preferably made of a rubber material or the like.

The annular space 5 is provided with a pressing means 13 such as a coil spring. As a result, the seal portion 11a of the seal piece is brought into close contact with the rotating shaft 2.

As mentioned above, the outer adapter ring 4 is provided on the outside of the inner adapter ring 3, and this outer adapter ring 4 plays the role of holding the seal piece 7 and the seal auxiliary piece 8 from the back side.
Therefore, on the pressure fluid side of the outer adapter ring 4, a support part 14 for holding the diagonal part 10a of the seal piece 7 and the like is provided.
It is shaped so that it fits into the space formed between the In this way, the seal piece 7 and the auxiliary seal piece 8 are held between the inner adapter ring 3 and the outer adapter ring 4.

This outer adapter ring 4 is attached to the pressing flange 1
5, and is prevented from moving outward by the pressure of the liquid.

Moreover, between the inner adapter ring 3 or outer adapter ring 4 and the casing 16, an O-
A groove 18 for mounting the ring 17 may be formed. This O-ring 17 serves to prevent pressure fluid from leaking between the casing 16 and the inner adapter ring 3 or outer adapter ring 4. Other conventional sealing means may be used for this purpose.

Optionally, the side wall 6 of the inner adapter ring 3 may be provided with a through hole 19 through which pressurized fluid can be introduced into the annular space 5.

Next, a modification of the shaft sealing device according to the present invention will be described.

In FIG. 3, the seal portion 11b of the auxiliary seal piece 8 is shown.
2 shows a modification in which a protrusion 20 is further provided in a direction perpendicular to the rotation axis in addition to the protrusion 12 described above. The convex portion 20 is pressed against the upper wall 21 forming the annular space 5 of the inner adapter ring, and thereby the seal portion 11a of the seal piece 7 is pressed against the rotating shaft. Thus, in this modification, the convex portion 20 provided on the seal portion 11b of the auxiliary seal piece 8 serves as a means for pressing the seal portion 11a of the seal piece 7 against the rotating shaft 2.

Further, in FIG. 4, an annular space 5 is formed in the outer adapter ring 4, and a seal piece 7 and a seal auxiliary piece 8 are attached to the inner adapter ring 3 in this annular space 5.
A modified example is shown, which is arranged in the same way as in the case of . In this case, the outer adapter ring 4
Seal piece 7 and seal auxiliary piece 8 arranged on the outer adapter ring on the outside when viewed from the pressure fluid side of
It is necessary to provide a second outer adapter ring 22 for holding the .

Optionally, an annular space 5 is further formed in the second outer adapter ring 22, which annular space 5
The sealing piece 7 and the auxiliary sealing piece 8 may be provided on the outer side, and in this case, it is necessary to provide a third outer adapter ring outside the second outer adapter ring 22. In this way, by providing the outer adapter ring 4 with the function of the inner adapter ring 3, the sealing elements may be overlapped.

Further, in the above specific example, the seal piece 7 and the seal auxiliary piece 8 are provided in the annular space 5 provided in the inner adapter ring 3, but the annular space 5 is provided on the pressure fluid side of the outer adapter ring 4, A seal piece 7 and a seal auxiliary piece 8 may be arranged in this annular space 5.

Effects of the invention The shaft sealing device according to the invention has the following effects.

(a) Since the seal part of the seal piece is formed in a cylindrical shape, the sliding area between the seal part and the rotating shaft is constant from the end of the movement, and therefore the change in sliding torque is small. The seal part and the rotating shaft quickly become compatible, and the wear of the seal part is further reduced.

(b) The seal portion of the seal piece is pressed against the rotating shaft by the auxiliary seal piece, the protrusion provided at its tip, and a pressing means such as a coil spring, so even if fluid pressure fluctuates, ,
Stable sealing performance can be obtained immediately. In other words, when the fluid pressure is low, the fluid does not enter the space formed by the inner adapter ring and the auxiliary seal piece, and the sealing part of the seal piece is kept constant with respect to the rotation axis by a pressing means such as a coil spring. are in contact with the pressing force of On the other hand, when the fluid pressure increases, even if fluid enters the space against the pressing force of the protrusion of the auxiliary seal piece, the diagonal part of the seal piece is held by the support part of the outer adapter ring. Therefore, the diagonal part of the seal piece does not deform, and the seal part of the seal piece also does not move in the direction of the rotation axis, so the sliding part formed at the beginning of operation remains almost constant. It is.

In addition, if a through hole is provided in the side wall of the inner adapter ring, pressure fluid is supplied from the through hole into the space, and it is possible to always obtain a constant sliding torque almost unaffected by the fluid pressure. can.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional shaft sealing device, and the second
The figure is a cross-sectional view of the shaft sealing device according to the present invention.
The figure is a sectional view of a main part of another shaft sealing device according to the present invention, and FIG. 4 is a sectional view of another embodiment of the shaft sealing device according to the present invention. DESCRIPTION OF SYMBOLS 1... Shaft sealing device, 2... Rotating shaft, 3... Inner adapter ring, 4... Outer adapter ring, 7...
... Seal piece, 8 ... Seal auxiliary piece, 12 ... Protrusion, 13 ... Pressing means.

Claims (1)

[Claims for Utility Model Registration] 1. An annular space opened to the outside when viewed from the pressure fluid side is provided in the thick-walled cylindrical inner adapter ring that is fitted to the rotating shaft, and this space is folded toward the pressure fluid side. An annular plate-shaped seal piece consisting of a base, a diagonal part, and a seal part, which bends to reach the side wall of the inner adapter ring, and an auxiliary seal piece are placed one on top of the other so that the seal piece faces the rotating shaft side. The seal portion that comes into sliding contact with the rotating shaft of the seal piece is formed into a cylindrical shape, and a pressing means such as a coil spring is provided in the space to press the seal portion of the seal piece against the rotating shaft, and the inner adapter ring is pressed against the rotating shaft. An outer adapter ring is provided on the outside when viewed from the pressure fluid, and a seal auxiliary piece and a seal piece are sandwiched between the inner adapter ring and the outer adapter ring, and a seal is attached to the outer adapter ring from the outside of the diagonal part of the seal piece. A shaft sealing device characterized in that a support portion for holding the piece is provided. 2. The shaft sealing device according to claim 1, wherein a protrusion is provided at the tip of the sealing portion of the auxiliary sealing piece.