JPH0868393A - Shaft seal expansion fixing device - Google Patents

Abstract

PURPOSE: To prevent leakage of gas from a fixing part due to an internal pressure exerted on a shaft seal expansion. CONSTITUTION: The ends on both sides of shaft seal expansion 5 are fixed. A plurality of grooves 14 and 15 in a semicircular shape in cross section are formed in the outer peripheral surfaces of a first end pipe 12 arranged at a shaft seal labyrinth 6 and a second end pipe 13, respectively, arranged at a casing 3. Stopper rings 16 are disposed on both sides of the innermost grooves 15 of the first and second end pipes 12 and 13 positioned facing each other. The first and second end pipes 12 and 13 are covered with the two end parts of the shaft seal expansion 5, and the outer surface of the shaft seal expansion 5 with which the upper sides of the grooves 14 and 15 are covered is securely fastened by external bands 9 and 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft seal expansion fixing device for fixing a shaft seal expansion for a blower such as a centrifugal fan between a casing and a shaft seal labyrinth.

[0002]

2. Description of the Related Art FIG. 2 shows a schematic structure of a centrifugal fan.
The centrifugal fan compresses the gas 7 flowing from the inflow port 31 of the casing 3 with the blade shaft 4 fixed to the central outer peripheral surface of the main shaft 1 whose both ends are supported by the bearing 2, and outputs the desired gas from the discharge port 32. I try to drain it to the place. In the case where the pumped gas 7 is a hot gas such as a high-temperature gas that causes a problem when flowing out to the outside of the casing 3, the main shaft 1 penetrates the casing 3 and leaks out of the casing 3 from a through-hole gap 8. To prevent, the side plate 33 of the casing 3
A shaft-sealed labyrinth 6 is installed around the shaft end portion of the main shaft 1 that penetrates through the shaft. Further, the shaft-sealing labyrinth 6 is supported from the bearing 2 side so as not to be affected by the thermal expansion of the casing 3.

Therefore, thermal expansion of the casing 3 occurs due to the difference in temperature of the high-temperature gas 7 passing through the casing 3, and along with this thermal expansion, the side plate 33 of the casing 3 provided with the through gap 8 and the shaft seal. The distance from the labyrinth 6 varies. The side plate 3 of the peripheral casing 3 of the shaft-sealing labyrinth 6 and the penetrating gap 3 is provided in order to absorb the fluctuation of the space and prevent the gas leaking out from this part in the radial direction.
It is connected to 3 by a shaft-sealing expansion made of a heat resistant cloth or the like and configured to absorb thermal expansion, thereby performing gas sealing.

FIG. 3 (A) is a detailed view of a portion B in FIG. 2 for showing a conventionally used shaft-sealing expansion 05 and its fixing (sealing) structure. As shown in the figure, the conventional shaft-sealing expansion 05 is attached to the outer peripheral side of the shaft-sealing labyrinth 06 by bolts and nuts 03 on the outer peripheral surface 02 of the first end pipe 01 having an L-shaped cross section. A second end having an L-shaped cross-section, in which one end is fixed and the other end is fixed to the outer surface of the side plate 33 of the casing 3 at the peripheral edge of the penetrating gap 8 with bolts and nuts 07. It is fixedly attached to the outer peripheral surface 010 of the end tube 09 of.

Further, stopper rings 0 are provided on the outer peripheral surfaces 02, 010 of the tubular portions of the end tubes 01, 09, respectively.
4, 011 is attached to the stopper ring 04,
011 over shaft expansion (heat resistant cloth etc.) 0
5, so that both end portions of the shaft-sealing expansion 05 are sandwiched between the stopper rings 04 and 011 and wound on the outer peripheral surface of the shaft-sealing expansion 05 with the outer bands 08 and 012, Installed by tightening. At that time, a heat-resistant adhesive is applied to the contact surface between the outer peripheral surfaces of the end pipes 01 and 09 and the inner peripheral surface of the shaft sealing expansion 05 to improve the sealing property.

Further, the outer bands 08 and 012 are divided into two as shown in FIG. 3B showing the AA cross section of FIG. 3A in order to give a pressing force to the shaft sealing expansion 05. Molded and divided flange 1
The shaft seal expansion 05 is pressed against the end pipes 01 and 09 and fixed by closely contacting the end pipes 01 and 09 by tightening and pulling 3 by bolts and nuts 14 so that gas leakage does not occur.

Further, both ends are sandwiched between the stopper rings 04, 011 and the outer bands 08, 012 to prevent the fixed shaft seal expansion 05 from being pulled out by the gas 7 internal pressure. Stoppers 015 are wound around and attached to the ends of the shaft-sealing expansion 05 at both ends.

However, in this way, in the shaft seal expansion fixing device in which both end portions of the shaft seal expansion 05 are fixed to the outer peripheral surfaces of the end pipe 01 and the end pipe 09,
There were the following problems. (1) Connect both ends of the shaft seal expansion 05 to the end pipe 0
1 and the outer band 08 pressed against the outer peripheral surface of the end tube 09,
When 012 is a round bar, since the outer peripheral surface, which is the bonding surface of the end pipes 01, 09 to be attached, is a flat surface on the circumference, the contact portion between the shaft sealing expansion 05 and the end pipes 01, 09 is a line contact, The pressing area by the outer bands 08 and 012 becomes smaller. Therefore, the gas is easily leaked by applying it to the contact portion to prevent gas leakage, peeling of the adhesive, and insufficient tightening force of the outer bands 08 and 012. Also,
When the plate-shaped outer band 08,012 is used, the tightening force of the outer band 08,012 is 0.
5 and the entire contact surface between the first and second end tubes 01, 09,
It is difficult to tighten so as to generate uniformly, and the pressing area cannot be increased as in the case of the round bar, and gas leakage may occur due to peeling of the adhesive or insufficient tightening. (2) Since only one outer band 08,012 is provided on each side of the first and second end tubes 01,09, the shaft sealing expansion 05 is
When pulled outward, this pulling force is
Since it is directly applied to the part which is pressed and adhered with 8,012, the adhesive applied to this part is easily peeled off,
It is easy for gas to leak from the peeling part.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned inconveniences that occur in a conventional shaft seal expansion fixing device, the present invention provides a contact area between both end portions of the shaft seal expansion and the first and second end pipes. It is an object of the present invention to provide a shaft-sealing expansion fixing device capable of increasing gas flow and reducing gas outflow from the contact portion.

Further, according to the present invention, the contact portions, to which the internal pressure acting on the shaft seal expansion does not directly act, are provided.
An object of the present invention is to provide a shaft-seal expansion fixing device that is provided on an end pipe and that prevents an adhesive agent applied to the contact portion from peeling off and reliably prevents gas outflow from the contact portion.

[0011]

Therefore, the shaft seal expansion fixing device of the present invention has the following means. (1) Fixed to both ends of the shaft seal expansion,
A groove having an arcuate cross section was provided around the outer peripheral surfaces of the first end pipe and the second end pipe. (2) An external band that presses both ends of the shaft-sealing expansion covering the groove from the upper side of the groove provided around the first end tube and the second end tube in conformity with the shape of the groove to bring them into close contact with each other. Was set up.

Further, another shaft sealing expansion fixing device of the present invention has the following means in addition to the above means (1) and (2). (3) A plurality of grooves are provided around the outer peripheral surfaces of the first end pipe and the second end pipe. (4) A stopper ring is provided around at least the outer peripheral surfaces of both sides of the groove provided at the ends of the first end tube and the second end tube on the opposite sides.

[0013]

According to the shaft seal expansion fixing device of the present invention, by means of the above (1) and (2), (1) a groove having an arcuate cross section such as a semicircle is provided in the first and second end pipes, and the circle An outer band with a cross-section that is approximately the same shape as the groove, where the tightening force is evenly generated in the groove with an arcuate cross section, presses both ends of the shaft-sealed expansion into close contact, and The pressing area is provided, and the contact area between the outer peripheral surfaces of the first and second end tubes and the shaft-sealing expansion is increased, so that gas outflow from the contact portion can be reduced.

In addition to the above-mentioned (1), the shaft-sealing expansion fixing device according to another aspect of the present invention includes (2) the outer peripheral surfaces of the first and second end tubes by the means of (3) and (4). A plurality of grooves are provided on the both sides, and stopper rings are arranged at least on both sides of the grooves at the ends on the opposite sides of the first and second end tubes, respectively, and the outer surface of the shaft sealing expansion Since both ends are pressed and fixed with external bands, the tensile force of shaft sealing expansion due to the gas internal pressure is received by the groove contact portion where the stopper ring is provided, and almost no tensile force is applied to the other groove contact portions. It does not hang. Therefore, it is possible to prevent peeling of the adhesive applied to the contact portion where tensile force is not applied at all, and to completely prevent outflow of gas.

[0015]

EXAMPLES The shaft seal expansion fixing device of the present invention will be described below based on examples. FIG. 1A is a cross-sectional view showing the details of the B part of FIG. 2 for explaining the schematic structure of the centrifugal fan, and FIG. 1B is a detailed cross-sectional view of the A part of FIG. 1A. In FIG. 1, the same reference numerals as those in FIG.
The description of the same or very similar to those will be omitted.

In FIG. 1, a shaft-sealing labyrinth 6 supported by a bearing 2 is provided at the shaft end of the main shaft 1 to prevent leakage of gas 7 in the main shaft 1 direction. Inside the shaft-sealed labyrinth 6, a side plate 33 of the casing 3 is installed upright which partitions the gas 7 operated by the centrifugal fan 10 from the outside air.

A flanged end pipe 12 as a first end pipe, whose flange portion 121 is fastened with bolts and nuts 11, is fixed to the outer peripheral edge portion of the shaft-sealing labyrinth 6 which is provided around the main shaft 1. Has been done. In addition, the flange 131 is a bolt and a nut 11 ′ at a position facing the flanged end tube 12 on the outer surface of the peripheral portion of the through gap 8 where the main shaft 1 penetrates the casing 3, and the side plate 33 of the casing 3 is provided.
Flanged end tube 13 as the second end tube, fastened to
Is stuck. Flange portion 1 of flanged end tube 12
The distal end of the pipe portion 122 provided orthogonal to the pipe 21 and the distal end of the pipe portion 132 of the flanged end pipe 13 are spaced apart from each other and face each other. Then, on the outer peripheral surfaces 123 and 133 of the tube portions 122 and 132, two semicircular grooves 14 and 15 are provided, respectively, as shown in FIG.
It is provided around one round.

Outer peripheral surfaces 123 of the pipe portions 122, 132 on both sides of the groove (hereinafter referred to as an inner groove) 15 provided at the tip side of the pipe portions 122, 132 of the grooves, that is, at the end portion on the opposite side. , 133 has the stopper ring 16 in the groove 15
The pipe parts 122 and 132 are provided so as to make one round in parallel with the above. The flanged end tube 12, formed in this way,
Outer peripheral surfaces 123, 133 of 13, and outer peripheral surfaces 123, 1
The upper surface of the shaft-sealing expansion 5 in which the outer groove 14 and the inner groove 15 are covered by covering both ends of the shaft-sealing expansion 5 formed of a heat-resistant cloth or the like from above the stopper ring 16 arranged in 33. From the above, an outer outer band 9 and an inner outer band 18 each having a circular cross section with a curvature substantially the same as that of the grooves 14 and 15 are respectively wound and tightened, and both end portions of the shaft seal expansion 5 are connected to the flanged end pipe. 1
It is fixed to the outer peripheral surfaces 123 and 133 of the Nos. 2 and 13.

In this fixing, the two stopper rings 16 and the inner outer band 18 are attached so that both ends of the shaft-sealing expansion 5 are sandwiched, and the inner outer band 18 and the outer outer band are attached. 9
Is the inner groove 15 at both ends of the shaft seal expansion 5.
Push into each of the outer grooves 14 to form the grooves 14, 1
It adheres to the inner surface of 5.

Also, the inner and outer outer bands 9, 1
Each of 8 is of a two-part type as shown in FIG. 3 (B) in order to give a pressing force to the shaft-sealing expansion 5, and the flange 13 of the divided part is similar to the conventional example.
The shaft seal expansion 5 is pressed against and closely fixed to the flanged end pipes by tightening and pulling with the bolts and nuts 14 to improve the sealing property and prevent gas leakage.

Further, both end portions are sandwiched between the stopper ring 16 and the inner outer band 18, and the fixed shaft seal expansion 5 is prevented from being pulled out by the internal pressure of the gas 7 on both side ends of the shaft seal expansion 5. A ring-shaped stopper 17 is wound around the portion by the shaft-sealing expansion 5 and is pressed and attached by the outer band 9 on the outside.

A heat-resistant adhesive is applied to the contact surfaces between the outer peripheral surfaces 123 and 133 of the flanged end tubes 12 and 13 and the inner peripheral surfaces of the grooves 14 and 15 and the inner peripheral surface of the shaft-sealing expansion 5. , The sealing property is improved.

As described above, in this embodiment, the outer peripheral surfaces 123 and 133 of the flanged end tubes 12 and 13 have a semicircular shape,
By providing the outer grooves 14 and 15 and pressing the shaft-sealing expansion 5 with the inner and outer outer bands 9 and 18 to the semi-circular portions, the semi-circular parts of the round bars of the inner and outer outer bands 9 and 18 are formed. Is the pressing area, the sealing area is expanded, the sealing performance is improved, and gas leakage from the sealing portion is reduced.

Also, the inner and outer outer bands 9 and 18,
The outer peripheral surface 123 of each of the flanged end tubes 12, 13,
By adding the stopper ring 16 provided in 133 to two (two-stage tightening type), the tensile force acting on the shaft sealing expansion 5 due to the gas internal pressure is generated by the inner groove 15 portion pressed by the inner outer band 18. Since it is received, tensile force is not applied to the outer groove 14 portion pressed by the outer band 9 on the outer side. Therefore, the adhesive applied to the groove 14 on the outer side, which is pressed by the outer band 9 on the outer side, is not peeled off, and by dedicating this portion to the gas seal,
The sealing property is further improved and the problem of gas leakage is completely solved.

[0025]

As described above, according to the shaft-sealing expansion fixing device of the present invention, it is possible to achieve (1) the first and second end pipes for fixing the shaft-sealing expansion. The contact portion changes from line contact to surface contact, the contact area can be expanded, and gas leakage from the contact portion can be effectively reduced.

Further, according to the structure of claim 2, (2) the shaft sealing expansion tensile force due to the gas internal pressure is received by the contact portion of the inner groove provided with the stopper ring, and acts on the contact portion of the groove provided outside thereof. The pulling force is almost gone.

As a result, the adhesive applied to the contact portion of the groove on the outside can be prevented from peeling off, and gas leakage from the contact portion can be completely prevented.

[Brief description of drawings]

1A and 1B are views showing an embodiment of a shaft seal expansion fixing device of the present invention, FIG. 1A is a side sectional view, and FIG. 1B is a side sectional view showing details of a portion A;

FIG. 2 is a side view showing a schematic structure of a centrifugal fan,

3A and 3B are views showing an example of a conventional shaft seal expansion fixing device, FIG. 3A is a side sectional view, and FIG. 3B is FIG.
It is an arrow AA cross-sectional view of (A).

[Explanation of symbols]

 1 main shaft 2 bearing 3 casing 31 (gas) inflow port 32 (gas) discharge port 33 side plate 4 impeller 5 shaft seal expansion 6 shaft seal labyrinth 7 gas 8 penetration gap 9,18 outer band 10 centrifugal fan 11, 11 'bolt , Nut 12 end pipe with flange as first end pipe 121 flange portion 122 pipe portion 123 outer peripheral surface 13 end pipe with flange as second end pipe 131 flange portion 132 pipe portion 133 outer peripheral surface 14, 15 groove 16 stopper Ring 17 stopper

Claims (2)

[Claims] 1. A shaft-sealing expansion for preventing gas outflow, which is interposed between a casing enclosing a blower and a shaft-sealing labyrinth penetrating the casing and installed at an end of a main shaft for driving the fan. In the shaft seal expansion fixing device, the first end pipe fixed to the outer periphery of the shaft seal labyrinth and the second end pipe fixed to the side plate of the casing at the peripheral edge of the penetrating portion of the main shaft are fixed to the first end pipe. A shaft seal comprising: a groove having an arcuate cross-section formed on the outer circumference of the pipe and the second end pipe, and an external band for pressing both end portions of the shaft seal expansion into close contact with the groove. Expansion fixing device. 2. A plurality of the grooves are respectively provided on the outer circumferences of the first end pipe and the second end pipe, and are formed at least at opposite ends of the first end pipe and the second end pipe. 2. The shaft seal expansion fixing device according to claim 1, wherein stopper rings are provided on both sides of the groove to be formed.