JPH0222526Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] "Field of Industrial Application" This invention relates to a split-type floating seal used, for example, in a blower with a split casing.

"Prior art" For example, a split type that can be disassembled and reassembled without disassembling the impeller as a leakage prevention device between the casing of a blower, where the rotating shaft is inserted along the mating surfaces of the upper and lower casings, and the rotating shaft. A floating ring seal is used.

An example of a conventional floating seal is shown in FIG. 3, which is a vertical cross-sectional view. Two floating seal rings 1 having exactly the same shape are arranged facing each other in the axial direction in an upper and lower halves of a casing 3. A spring 5 is present between the seal rings 1 and presses each seal ring 1 against the casing 3. The area of the contact portion of each seal ring 1 with the casing 3 is usually made as small as possible in order to reduce sliding resistance. Also, the seal ring 1 is connected to the rotating shaft 7.
The outer periphery of the seal ring 1 is pressed toward the center by a garter spring 4. Seal ring 1 and casing 3
A detent pin 6 is provided across both sides.
The portion of the detent pin 6 through which the garter spring 4 passes is a groove. The pressure is high in the central space formed by both seal rings 1 and low outside the casing 3. Leakage of pressurized fluid is kept to a minimum even in the narrow gap between the floating seal ring 1 and the shaft 7. Further, since the seal ring 1 is required to be lightweight and to have low contact sliding resistance (in the direction perpendicular to the axis) with the casing 3, carbon is often used as its material.

However, since the seal ring 1 is divided along the radial dividing plane, a step tends to occur between the inner and outer circumferences of adjacent seal rings 1 at the position of the dividing plane, which has the disadvantage of increasing leakage loss. It was hot. For example, such drawbacks can be seen in the
As shown in Publication No. 9, the problem is solved by providing a means for pressing the retainer against the seal ring, in which the retainer is in contact with the surface obtained by cutting off the outer periphery of the seal ring across the dividing surface of the seal ring. .

``Problem to be solved by the invention'' However, in the conventional example shown in FIG. It was hot. Therefore, in the conventional example shown in Fig. 3, even if a retainer is provided as in Japanese Patent Publication No. 29-9, a locking pin is provided in the seal ring, so the same accident in which the seal ring is damaged when an impact is applied can be avoided. I can't.

The object of this invention is to eliminate the above-mentioned drawbacks and provide a split type floating seal in which no step is formed between the inner and outer circumferences of the seal ring and the seal ring is not damaged by the rotation stopper pin.

[Structure of the idea]

``Means for solving the problem'' This invention is a split type floating ring seal in which a means is provided to press the seal ring dividedly arranged around the rotating shaft toward the casing in the axial direction. A retainer whose outer periphery is cut off to intersect with the radial dividing surface and abuts on the cut off surface over an adjacent seal ring, a means for urging the retainer toward the seal ring, and a retainer. This is a split type floating ring seal that has a retainer rotation prevention member between it and the casing.

``Example'' An example of this invention will be described below with reference to the drawings. Figure 1 is a front view perpendicular to the axis, Figure 2 is a front view of the
It is an AA sectional view of the figure. A rotating shaft 7 is inserted along the dividing surface of the casing 3, which is divided into upper and lower halves, and a split seal ring 1 is arranged around the rotating shaft 7. The seal ring 1 is usually made of carbon. The seal ring 1 is equally spaced on the circumference and divided by a radial dividing surface 8, completely surrounding the rotating shaft 7,
With the dividing surfaces 8 in close contact, there is a very small gap between the inner diameter of the seal ring 1 and the rotating shaft 7, and this gap seals the sealing fluid in the shaft sealing chamber 9.

The seal ring 1 is cut off into a plane perpendicular to the dividing surface 8 of the seal ring 1, and a cut surface 11 is formed.

A retainer 12 whose outer periphery is an arcuate segment whose outer periphery is an extension of the outer periphery of the seal ring 1 is disposed on the cut-off surface 11 extending over the adjacent seal ring 1.
The planes that are the chords of are in contact. Retainer 1
2 is made of light and strong metal such as aluminum. Rotating shaft 7
A groove 13 in the circumferential direction is provided in the seal ring 1 and the retainer 12 on the same circle with the center as the center, and the garter spring 4 is fitted into the groove 13 and tensioned. is assisted by. A radial pin 6 is inserted between the retainer 12 and the casing 3.
is provided. The pin 6 is a rotation preventing member that stops the retainer 12 from moving in the circumferential direction but allows the retainer 12 to move in the radial direction. The portion of the pin 6 that interferes with the garter spring 4 is cut out.

The above configurations are arranged equally around the rotating shaft 7.

The divided seal rings 1 face each other in pairs in the axial direction, and a compression spring 5 is inserted between the seal rings 1 to press the seal rings 1 against the casing 3.

The sealing fluid in the shaft sealing chamber 9 is such that the seal ring 1 is energized directly toward the rotating shaft 7 by the pressure of the garter spring 4 and the sealing fluid, and is also energized toward the rotating shaft 7 via the retainer 12. As a result, the dividing surfaces 8 are brought into close contact with each other, and an extremely small gap is maintained between the seal ring 1 and the rotating shaft 7, and the seal ring 1 is pressed against the casing 3 by the pressure of the compression spring 5 and the sealing fluid, thereby sealing the seal ring 1.

When the seal ring 1 moves along the dividing surface 8 and a step is created on the cut-off surface 11, the cut-off surface 11 that tries to come out to the outer diameter side is pressed by the pressure of the garter spring 4 and the sealing fluid. Since the cut surfaces 11 of the adjacent seal rings 1 are kept in one plane while being pressed by the retainer 12, the rotating shaft 7
The gap between the seal ring 1 and the seal ring 1 is maintained, and the dividing surface 8 does not separate.

Even if the seal ring 1 is in contact with the rotary shaft 7 and the rotary shaft 7 is activated, the seal ring 1 undergoes sudden rotation, the rotational force is transferred to the retainer 12 which is prevented from rotating by the pin 6 and the wide cut. falling face 1
1 contact surface. Therefore, even if the seal ring 1 is made of carbon, it does not generate notch stress and is not damaged. Further, due to such rotation of the seal ring 1, the cut-off surface 11 of the adjacent seal ring 1 follows the retainer 12, so that it is immediately restored to its normal position.

In the embodiment, the dividing surface 8 is in the radial direction, but it may be inclined in the radial direction, although there is a limit. Further, the cutting surface 11 does not necessarily need to be perpendicular to the dividing surface 8, and may intersect with it. Furthermore, although it is preferable for the cut-off surface 11 to be a flat surface as in the embodiment, it may be a curved surface convex toward the rotating shaft 7.

Note that the seal ring 1 and retainer 12 are connected to the rotating shaft 7.
The means for biasing toward is not limited to the garter spring 4.

[Effect of idea]

This idea is based on a split type floating seal in which a seal ring arranged in parts around a rotating shaft is provided with a means for pushing it toward the casing in the axial direction. is cut off, a retainer is disposed in contact with the cut off surface across the adjacent seal ring, and a retainer rotation preventing member is provided between the means for biasing the retainer toward the seal ring and the retainer and the casing. Since the split type floating ring seal is provided, the seal ring will not be damaged even if an impact force is applied due to twisting around the rotating shaft.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of this invention at right angles to the axis;
FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a vertical sectional view of the conventional example. 1... Seal ring, 3... Casing, 4...
... Garter spring, 5 ... Spring, 6 ... Stopping pin, 7 ... Rotating shaft, 8 ... Dividing surface, 9 ... Shaft sealing chamber, 11 ... Cutting surface, 12 ... Retainer, 1
3...Groove.

Claims (1)

[Scope of utility model registration request] In a split type floating ring seal, in which a seal ring is divided and arranged around the rotating shaft and is provided with a means for pushing it toward the casing in the axial direction, the outer periphery is cut across the radial dividing surface of the seal ring. A retainer is disposed to abut the cut surface across adjacent seal rings, and a retainer rotation prevention member is provided between the retainer and the casing and a means for biasing the retainer toward the seal ring. Split type floating ring seal.