JPH1130335A - Segment seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate practical leakage by eliminating possibility of causing a gap neither in radius nor in axial directions by making a first and a second segments closely adhered constantly to a sealed shaft with both segments mutually sliding together by garter spring tightening force and to provide favorable weight and cost as well as to lessen required space by dispensing with the necessity of using a plural number of segments by combining them in the axial direction. SOLUTION: This segment seal is provided with a plural number of first segments 1 whose outer circumferential tapers are longer than the inner circumferential tapers and which are arranged in the circumferential direction of a seal shaft 4 with their inner circumferential surfaces sliding on the outer circumferential surfaces of the seal shaft 4, a plural number of second segments 2 whose outer circumferential tapers are shorter than those of the inner circumferences, heights lower than that of the first segments 1, which are fitted between the first segments 1 with their inner circumferential surfaces sliding on the outer circumference of the seal shaft 4, and whose tapered surfaces are mutually in contact with that of the first segments 2, and is also provided with garter springs 3 for tightening the outer circumference of the first segments 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a segment seal applied to a shaft seal of a rotating shaft in a pump, a water turbine, a turbine, and the like.

[0002]

2. Description of the Related Art FIGS. 2 and 3 are explanatory views of a conventional segment seal used for a shaft seal of a rotary shaft in a pump, a water turbine, a turbine, and the like. In FIG. 2, the segment 11 of the present segment seal is divided into four parts having the same shape and the same size.
A gap 12 is provided in the circumferential direction so as to make close contact.

[0003]

As described above, in the conventional segment seal, even if the inner periphery is worn, the rotating shaft 4 is not used.
A gap 12 is provided in the circumferential direction so as to make close contact.
In order to prevent leakage from the gap 12, a plurality of sets of segment seals are used in the axial direction by changing the circumferential position of the gap 12 in combination with each other, which requires space and is disadvantageous in weight and cost. .

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a segment seal having a tapered outer periphery longer than an inner periphery and an inner peripheral surface which is in sliding contact with the outer periphery of a shaft to be sealed. A plurality of first segments arranged in the circumferential direction of the sealed shaft, and the outer periphery is tapered shorter than the inner periphery, and the inner peripheral surface of the sealed shaft is lower than the first segment. A plurality of second segments which are mounted between the first segments in sliding contact with the outer periphery and which are in contact with the first segments by a tapered surface; and a garter spring for tightening the outer periphery of the first segment. I have.

[0005] As described above, in the present segment seal, the second segment 2 whose outer periphery is shorter than the inner periphery, and the first segment whose diameter is slightly larger than the second segment 2 and whose outer periphery is longer than the inner periphery. Are alternately arranged in the circumferential direction of the shaft to be sealed so as to make planar contact with the outer periphery of the shaft to be sealed, and even if the inner periphery of the segment seal is worn, the garter spring mounted on the outer periphery of the first segment is tightened. Due to the force, the first and second segments slide with each other and are always in close contact with the shaft to be sealed, so that there is no gap in either the radial direction or the axial direction. Therefore, it is not necessary to use a plurality of sets of segment seals in combination in the axial direction.

[0006]

FIG. 1 is an explanatory view of a segment seal according to an embodiment of the present invention. In the figure, the segment seal according to the present embodiment is used for a shaft seal of a rotary shaft in a pump, a water turbine, a turbine, or the like.Even when the inner periphery of each segment is newly installed, the segment seal wears due to friction with the rotary shaft. However, no gap is always generated in the axial direction and the radial direction. In the figure, reference numeral 1 denotes a first segment whose outer periphery is formed in a wedge shape longer than the inner periphery, 2 denotes a second segment whose outer periphery is formed in a wedge shape shorter than the inner periphery, and 3 denotes a garter that tightens the outer periphery of the segment 1. spring,
Reference numeral 4 denotes a rotating shaft (sealed shaft).

As shown in the figure, a plurality of (six in the present segment seal) segments 1 each having a wedge shape (taper shape) whose outer periphery is longer than the inner periphery are slidably in contact with the rotating shaft 4 as shown in FIG. Are evenly arranged. A plurality of (six in this segment seal) segments 2 having a wedge shape (tapered shape) lower than the segment 1 and slightly smaller in outer diameter than the segment 1 are arranged between the segments 1, In close contact with each other. The outer circumference of the segment 1 is tightened by a garter spring 3, and the inner circumferences of the segment 1 and the segment 2 are in close contact with the rotating shaft 4.

Thus, in the present segment seal, the segment 2 whose outer periphery is shorter than the inner periphery and the segment 1 whose diameter is slightly larger than this segment 2 and whose outer periphery is longer than the inner periphery are arranged in the circumferential direction of the rotary shaft 4. The inner circumference of each of the segments 1 and 2 is brought into planar contact with the rotating shaft 4 and the outer circumference of the segment 1 having a diameter slightly larger than that of the segment 2 is tightened by the garter spring 3, thereby forming the segments 1 and 2 The inner circumference is in close contact with the rotating shaft 4, so that no gap is formed in the axial direction or the radial direction. Even if the inner circumferences of the segments 1 and 2 are worn, the segments 1 and 2 are always slid by the garter spring 3 on the outer circumference of the segment 1 and are in close contact with the rotating shaft 4, so that there is a gap in both the radial and axial directions. Does not occur.

In the conventional segment seal, a gap is provided in the circumferential direction so that even if the inner periphery is worn, the segment seal is in close contact with the rotating shaft. In order to prevent leakage from the gap, a plurality of sets of segment seals are used in the axial direction in combination with changing the circumferential position of the gap, which is disadvantageous in terms of space and weight and cost.

On the other hand, in the present segment seal, the outer periphery of a plurality of tapered segments 1 and 2 divided in the circumferential direction is tightly attached to the rotating shaft 4 by a garter spring 3 so that the outer periphery is inward. A structure in which segments 2 that are shorter than the circumference and segments 1 that are slightly larger in diameter than the segments 2 and whose outer circumference is longer than the inner circumference are alternately arranged in the circumferential direction of the rotation shaft 4 and are brought into planar contact with the outer circumference of the rotation shaft 4 Therefore, even if the inner circumference of the segment seal is worn, the inner circumference of each of the segments 1 and 2 is always in close contact with the rotating shaft 4 so that no gap is generated in the axial direction and the radial direction. I have.
As described above, even when the inner periphery of the present segment seal is worn even when newly installed, no gap is formed in the axial direction and the radial direction, so that there is almost no leakage. Further, there is no need to use a plurality of sets of segment seals in combination in the axial direction.

[0011]

The segment seal according to the present invention is configured as described above. Even if the inner periphery of the segment seal is worn, the first and second garter springs are mounted on the outer periphery of the first segment. Since the second segments slide with each other and are always in close contact with the shaft to be sealed, and there is no gap in the radial direction or the axial direction, there is almost no leakage. Further, since it is not necessary to use a plurality of sets of segment seals in combination in the axial direction, no space is required and the weight and cost are advantageous.

[Brief description of the drawings]

FIG. 1A is a sectional view of a segment seal according to an embodiment of the present invention, and FIG. 1B is a detailed view of a main part in FIG. 1A.

FIG. 2A is a sectional view of a conventional segment seal, and FIG. 2B is a detailed view of a main part in FIG. 2A.

[Explanation of symbols]

 1 segment 2 segment 3 garter spring 4 rotating shaft

Claims (1)

[Claims] A plurality of first segments whose outer periphery is tapered and longer than the inner periphery and whose inner peripheral surface is in sliding contact with the outer periphery of the shaft to be sealed and which is arranged in the circumferential direction of the shaft to be sealed; The outer periphery has a taper shape shorter than the inner periphery and is lower than the first segment, and the inner peripheral surface is slidably in contact with the outer periphery of the sealed shaft and is mounted between the first segments and the first segment. A segment seal comprising: a plurality of second segments that are in contact with each other at a tapered surface; and a garter spring that tightens an outer periphery of the first segment.