JPS6093102A - Spring type locking ring - Google Patents

Abstract

PURPOSE:To improve the effect of preventing a sealing ring from coming out by supporting the sealing ring of an expansible pipe for main steam of a steam turbine by a locking ring. CONSTITUTION:Sealing rings 11 are arranged between an expansible pipe 10 for main steam of a steam turbine and spindle chambers 1, 2 to be supported by a locking ring 14 which is previously prepared to have the diameter larger than that D of the spindle chambers 1, 2 and cut out one portion to be contracted. Then the locking ring is released from the contraction to be fixed after it is inserted into the spindle chambers 1, 2. Thus, the seal rings 11 can be securely prevented from coming out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention is provided with a sealing function for sealing steam at the flat part of the expansion pipe joint at the main steam inlet of a steam turbine.

This invention relates to a locking ring used as a measure to prevent a sealing ring from coming out.

[Background of the invention]

The structure of a conventional steam turbine telescopic tube will be explained with reference to FIGS. 1 to 4.

Current steam turbines have high temperature and high pressure steam conditions.
The turbine casing has a double structure: a high-pressure outer casing and a high-pressure inner casing.

Especially in high-pressure train compartments under high-temperature, high-pressure steam conditions.

Steam must be guided from the high-pressure inner compartment to the nozzle box without leaking.

FIG. 1 shows the high-temperature compartment, and FIG. 2 shows details of the expandable pipe joint flat part 13 of FIG. 1.

In Fig. 2, high-temperature, high-pressure steam generated in the boiler flows smoothly and efficiently from the high-pressure outer casing 1 and the high-pressure inner casing 2 to the nozzle box 6 with less loss.

The steam path leading to the rotor blade 8 is shown, and the expansion pipe 10 of the expansion pipe joint 9 represents its introduction pipe.

This telescopic pipe 10 is connected from the high pressure external compartment 1 to the nozzle box 6.
Used to prevent steam leakage.

Since a difference in thermal expansion occurs in the high-pressure external compartment 1, the high-pressure internal compartment 2, and the nozzle box 6 depending on the temperature, the high-pressure external compartment 1. A gap is maintained between the high-pressure internal compartment 2 and the nozzle box 6 so that they can freely expand and contract.

Because of this gap, the expansion pipe 10 and the high pressure external compartment 1.
A sealing ring 11 is interposed between the high-pressure internal compartment 2 and the nozzle box 6, and in order to prevent steam leakage and further enhance the sealing effect, the sealing ring 1 has different diameters.
1 are placed alternately.

Also, to prevent the sealing ring 11 from being pulled out, the entire circumference is stopped by a locking ring 12 which is divided into several pieces, and the locking ring 12 is connected to the retaining ring 1.
It is held down by 3.

This retaining ring 13 is caulked to the high-pressure outer casing 1, the high-pressure inner casing 2, and the nozzle box 6, as shown in part 2 in FIG. 3, to fix the retaining ring 13. Also, the sealing ring 13 and the high pressure external compartment 1. High pressure internal compartment 2. A gap Y is provided to absorb the difference in elongation between the nozzle box 6 and the nozzle box 6 due to thermal expansion.

FIG. 4 shows a plan view of the caulking part.The caulking is done at several places and fixed.

However, when the retaining ring 13 is caulked, the gap Y for absorbing the difference in expansion is pushed by the retaining ring 11, and the gap Y between the locking ring 12 and the sealing ring 1 is pushed by the retaining ring 11.
A problem occurred in which the gap Y between the
High-frequency vibrations are generated due to the high-pressure steam, and the weight of the sealing ring 11 and locking 12 is applied to the crimped part Z, causing wear, and the retaining ring 13 may come out, potentially causing a serious accident. There is.

[Purpose of the invention]

The purpose of the present invention is to eliminate the retaining ring so that the retaining ring does not wear out due to vibration and the retaining ring does not come out. There are tubes to provide.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 5 to 8.

FIG. 5 shows an embodiment of the present invention of a telescopic pipe joint, and FIG.
The figure is a plan view of FIG. 5.

To prevent the sealing ring 11 from being removed/high pressure external compartment 1. High pressure internal compartment 2. The retaining ring 13 is removed from the nozzle box 6, and the retaining ring 13
It also has a locking ring 140 function. Insert and secure the spring type locking ring 14.

The spring-loaded locking ring 14 is attached to the high pressure outer compartment 1. High pressure internal compartment 2. The diameter of the insertion part of the locking ring 14 of the nozzle box 6 is made to be rounded in advance,
In order to insert the locking ring 14 using a material with a large reaction force, it is necessary to cut out a part as shown in Fig. 7, contract it in the direction of arrow "M" as shown in Fig. 8, and release the contraction after insertion. , a reaction force acts in the direction of arrow N in FIG. After insertion, by attaching the bolt 16 to the stopper 15, removal can be completely prevented.

〔Effect of the invention〕

According to the present invention, since it is possible to completely prevent the retaining ring from coming out, a highly reliable expansion pipe joint structure can be obtained, and since the retaining ring is abolished and the force is applied only to the locking ring, it is possible to completely prevent the retaining ring from coming out. It also makes regular inspections easier and quicker.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the structure of the expansion pipe joint at the main steam inlet, Figure 2 is a detailed view of the expansion pipe joint, Figure 3 is a cross-section of the conventional glued tening ring, and Figure 4 is a sectional view of the expansion pipe joint. Figure IV-
FIG. 5 is a sectional view of an embodiment of the present invention, and FIG.
The figure is a view taken along the line ■--■ in FIG. 5, and FIGS. 7 and 8 are plan views of the locking ring of the present invention. 1... High pressure external compartment, 2... High pressure internal compartment, 6...
- Nozzle box, 10... telescopic tube, 11... sealing ring, 14... spring type locking ring. Agent Patent Attorney Akio Takahashi

Claims (1)

[Scope of Claims] 1. In a steam turbine, sealing of a flat part of a main steam expansion pipe that leads high-temperature, high-pressure steam for operation to a nozzle box through a high-pressure outer casing and a high-pressure inner casing. A spring-type locking ring characterized by a structure that prevents the ring from being pulled out.