JPH0524461Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a jig for extracting parts that are tightly fitted into shafts, such as impellers, shaft couplings, gears, bearings, propellers, shaft sleeves, etc. of pumps that are installed in, for example, nuclear power plants and are contaminated by radiation.

[Conventional technology]

Fig. 2 is a cross-sectional view of a conventional extracting jig. In the figure, 7 is the impeller of a vertical pump tightly fitted, 8 is the shaft, 10 is the extracting jig, 9 is a hydraulic jack, and the impeller 7 is shown as a shaft. The installed state in which the is removed from the shaft 8 is shown. 12 is a gas burner, which is used to heat the impeller 7. Reference numeral 11 denotes a cradle, which supports the impeller 7 and extraction jig 10 that fall off.

When removing the impeller 7 from the shaft 8, first attach the hook rod 10a to the impeller 7 while holding the shaft 8 vertically using a lifting device (not shown), and then attach the extraction jig 10 to the hook rod 10 with a nut 10b.
Conclude in a. Next, the extraction jig 10 and the floor surface 1
A pedestal 11 is installed between the impeller 7 and the impeller 7, and its height is adjusted appropriately so that the impact when the impeller 7 falls off does not become large. Further, a hydraulic jack 9 is installed between the shaft 8 and the extraction jig 10, and hydraulic pressure is applied from the hydraulic pressure introduction pipe 9b to move the impeller 7 to the shaft 8.
When a force is applied in the direction of pulling out the impeller 7 and the gas burner 12 uniformly heats and expands the impeller 7, the interference fit with the shaft 8 loosens and the impeller 7 falls out.

[Problem that the invention attempts to solve]

Such conventional extraction jigs have the following problems. That is, since the impeller 7 contaminated with radioactivity is heated by the gas burner 12, radioactive dust is generated and the working environment deteriorates. Also,
Since the impeller 7, which has a large mass, is heated, the working time is long, and the time required for the worker to be close to the radioactively contaminated pump is also long, so the worker is exposed to a large amount of radiation.

[Means for solving problems]

The extraction device according to the present invention aims to solve the above-mentioned problems, and is a jack that is installed between fitting objects that fit inside and outside of each other, and extracts one fitting object from the other fitting object. and an adapter fluid-tightly connected to a hole drilled in the inner fitting for supplying and recovering a coolant into the hole.

[Effect]

That is, in the extraction device according to the present invention,
A jack for extracting one fitted object from the other fitting object is installed on the fitting objects that fit inside and outside of each other, and an adapter is fluid-tightly connected to a hole drilled in the inner fitting object. Coolant is supplied into the hole and collected, and the coolant cools and contracts the fitting inside while remaining in a sealed state, loosening the fitting and causing the operator to be exposed to the coolant atmosphere. The mutually fitted objects can be safely and easily removed by remote control without being exposed or close to each other.

〔Example〕

An embodiment of the present invention will be described based on FIG. FIG. 1 is a sectional view of a extractor according to an embodiment of the present invention, in which 7 is an impeller, and 7a is an impeller 7.
8a is the shaft, 8
A bolt hole b is provided at the lower end of the shaft 8a to fix the impeller 7 to the shaft 8a, and is hollow at the back. Reference numeral 1 denotes an adapter, the tip of which is screwed into the bolt hole 8b. An O-ring packing 2 is attached to the mounting surface of the adapter 1 and the shaft 8a to seal the coolant.
Further, the shape of the adapter 1 is tubular so that the coolant can be introduced deep into the bolt hole 8b.
Reference numeral 3 denotes a shock absorbing rubber seat, which has a ring shape and is fitted into a shoulder provided on the outer periphery of the adapter 1 to receive the impeller 7 that falls out without damaging it. Reference numeral 4 denotes a hydraulic jack, which has a hollow cylindrical shape and is composed of a hydraulic cylinder 4a and a hydraulic pressure introduction pipe 4b, into which the adapter 1 can be inserted.
Reference numeral 5 denotes a pull-out collar, to which a hydraulic cylinder 4a is fixed with a bolt 4c, and is connected to a pull-out screw hole 7a of the impeller 7 with a pull-out rod 5a and a nut 5b, and the force generated by the hydraulic jack 4 is transferred to the pull-out rod 5a. The signal is transmitted to the impeller 7 via the signal. Reference numeral 6 denotes a double pipe adapter, which is connected and fixed to the adapter 1 with screws, and a coolant injection pipe 6a and a discharge pipe 6b are connected to the lower end, and the coolant supplied from the injection pipe 6a passes through the inside of the adapter 1. Bolt hole 8 of shaft 8a
b, and is discharged from the discharge pipe 6b through the inner pipe of the double pipe adapter 6.

When removing the impeller 7 from the shaft 8a using the present invention, first attach the O-ring packing 2 and the cushioning rubber seat 3 to the adapter 1, fix it to the bolt hole 8b of the shaft 8a, and then remove the extraction rod 5a from the impeller 7. After fixing it to the extraction screw hole 7a,
Pull-out collar 5 with built-in hydraulic jack 4
is inserted into the adapter 1 and fixed to the pull-out rod 5a with a nut 5b. Next, double pipe adapter 6
Attach it to the adapter 1 and connect the injection pipe 6a and the discharge pipe 6.
b is connected, and the hydraulic jack 4 is pressurized from the hydraulic pressure introduction pipe 4b to maintain a constant pressure. Here, when a coolant such as liquid nitrogen or a cryogen is continuously supplied from the injection pipe 6a, the shaft 8a is gradually cooled and contracts, and the grip force of the impeller 7 is reduced. When the pulling force of the hydraulic jack 4 exceeds the gripping force, the impeller 7 moves to the shaft 8a.
However, the fallen impeller 7 is caught by the cushioning rubber seat 3 without damage.

[Effect of idea]

The extraction device according to the present invention is constructed as described above, and after it is set on the object to be extracted, it can be extracted by supplying hydraulic pressure and coolant by remote control, thereby saving labor and radiation exposure of the worker. The system reduces radiation exposure, and since only the shaft with a small mass is locally cooled, it can be removed in a short time, and there is no generation of radioactive dust due to heat, which improves the working environment. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a extraction device according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional extraction jig. 4... Hydraulic jack, 6... Coolant injection pipe,
6b... Coolant discharge pipe, 7... Impeller, 8a...
...Shaft, 8b...Bolt hole.

Claims (1)

[Scope of utility model registration request] a jack that is installed between the fittings that fit inside and outside of each other and extracts one fitting from the other fitting; and a jack that is fluid-tightly connected to a hole drilled in the inner fitting. An extraction device characterized by comprising an adapter for supplying and recovering a coolant inside.