JPS6235002A - Shut-down seal - Google Patents

Abstract

PURPOSE:To make a device to be compact, by setting a seal member which can be broken or dissolved, on a narrow route between a rotary shaft and a casing, in a closed cycle turbo machine. CONSTITUTION:A shut-down seal 600 is set in a narrow route 610 between a turbine rotor 100 and a bearing housing 310. A holder 630 of this shut-down seal 600 is filled up with a seal member 620 which can be dissolved at a low temperature or broken by a weak force. When a rotary shaft 130 starts to rotation, the seal member 620 is broken or dissolved, and the shut-down seal is released. In this way, a space necessary for the shut-down seal can be made smaller, and the device can be made compact.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an improvement in a down seal for sealing a rotating shaft portion with an inert gas fluid in a turbomachine of a closed cycle engine or the like.

[Conventional technology]

When turbo machinery is not rotating, rust may form on the shaft of one revolution.
Inert fluid such as nitrogen gas is sealed in the rotating shaft support to prevent dust from entering. Therefore, a shutdown seal is attached to the rotating shaft support to prevent fluid such as inert nitrogen gas from leaking to the outside.

Hereinafter, purchasing of a conventional shutdown seal will be explained with reference to FIG. Shutdown Sea/l/
Seal 210 . Bellows 220. The ring fixing piece 240 is purchased from the turbine rotor 100, the LD end face 110K, the seal ring 210, and the entire bellows 220 is pressed with high pressure gas sent through the gas passage 230 to seal the shaft support A for one rotation. There is. Therefore, when high pressure gas is removed from inside the bellows 220, the restoring force of the bellows 220 causes the gas to be released.

Seal ring 210 and end face 110 are separated from each other.

[Problem that the invention seeks to solve]

Conventional Shutdown Sea) I/2oo Har Bellows 220. Gas flow path 230. Ring fixed beef 240
Therefore, there was a problem in that the distance from the bearing 300 to the turbine rotor 100 had to be increased.

Furthermore, there were also drawbacks such as the need for high pressure gas for sealing.

[Means for solving problems]

Shutdown seals, which seal inert fluid such as nitrogen gas in the rotating shaft support, are usually used when turbomachinery is not being driven, and there are few startups and shutdowns.

We focused on the fact that the shutdown seal is often released at startup and not used until a periodic inspection, etc. one to two years later.

The present invention is applied between the rotating shaft and the casing of a rotating machine.

This is a soto-down seal that has a passageway and seals the passageway with a sealant that can be melted or destroyed.

[Effect]

Therefore, when the turbomachine is stopped, the rotating shaft support inside the turbomachine is completely sealed with an inert fluid such as nitrogen gas by the sealing material installed in the joint between the rotating shaft and the casing, and it starts one rotation. The C/l/goods are then melted or destroyed, and the shaft rotates smoothly.

〔Example〕

FIG. 1 shows a groove construction according to a first embodiment of the present invention.

Shutdown Sea in this Actual Case/' 600 H + The passage 610 provided between the turbine rotor 100 and the bearing housing 310 is filled with solder, raw materials, etc. that melt at relatively low temperatures or break with weak force. Le material 6
20.

Therefore, when the one-rotation machine is not rotating, inert fluids such as nitrogen gas are sealed by the sealing material 620 filled in the joint 610, but when the one-rotation machine is driven, steam, combustion gas, etc. The fluid flows through the turbine housing 500
It passes from the inner scroll 510 through the nozzle/11520, acts on the rotor blades 120 attached to the outer periphery of the turbine rotor 100, and rotates the turbine rotor 100. Once the turbine rotor 100 starts rotating, shear acts on the sealing material 620 between the holter 630 and the turbine rotor 100, and the sealing material 620 is destroyed or melted by the heat of the working fluid such as steam. is blown to the outer circumferential side by centrifugal force and enters the cavity 640. Since there is a gap in the rotating shaft support A between the rotating shaft 130 and the bearing housing 810, the working fluid flows inside the bearing housing 300. The shutdown seal is released.

Note that the turbine rotor 100 is supported by a bearing 300 and is able to rotate smoothly without contacting any other parts.

Next, a description will be given with reference to FIG. 2 showing the purchase of a second practical example. The seal plate 700 in this embodiment is connected to a bearing housing 810 on the outer diameter side.

The inner ff 111 is attached to the end face 110 of the turbine rotor 100 to hermetically define a passage between the turbine rotor 100 and the bearing housing 310. Note that the seal plate 700 is made of a synthetic resin plate, vinyl, planutic, or the like.

Therefore, these seal plates 700 are destroyed by the rotation of the turbine rotor 100 at the weakest seal plate intermediate portion 710, thereby releasing the shutdown seal.

In addition to the actual examples shown above, electric heaters, explosives, chemicals, etc. can be used to destroy or melt the sealing material 620 and the sealing plate 700.

〔Effect of the invention〕

With the above purchase, the subane required for the shutdown seal in a 9-rotation machine becomes smaller.

Turbomachinery becomes more compact. Furthermore, the shaft length of the turbine rotor can be shortened, improving the stability of the shaft system. In addition, high-pressure gas and controls are not required, making it a 1-section price.

In particular, the present invention greatly contributes to the development of industry, as it is most suitable for engines such as engines for underwater vehicles, which are overhauled after each use and need to be made smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the invention, and FIG. 2 is a sectional view of a second embodiment of the invention. FIG. 3 is a sectional view showing a conventional example. 100... Turbine rotor, 110... End face, 12
0...Dynamic g, 130...Rotary axis, 300...
Bearing, 310...Bearing housing, 500...
・Turbine housing 510...Scroll, 520
... Noz/l/, 600... Shutdown seal, 610... Passageway, 620... Seal material, 6
30...Holder, 640...Cavity, 700...Seal plate, 710...Seal plate intermediate portion. Agent: Kyou Sakama+, j1. , :,,, :. (ζ,;n@1 Figure 2 Figure 30

Claims (1)

[Claims] A shutdown seal characterized in that a passage between a rotating shaft of a rotating machine and a casing is hermetically divided with a sealing material that can be destroyed or melted.