JPH0227199Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a centrifugal pump.

[Prior Art] In general, a centrifugal pump, as shown in Fig. 3,
An impeller 3 is attached near the tip of a drive shaft 2 that passes through the casing cover 1, and is normally configured so that the gap 4 between the casing cover 1 and the impeller 3 is as narrow as possible. The reasons for this are (a) to shorten the overall length of the pump, (b) to lower the pressure in space 4 during movement and reduce the thrust load, and (c) in slurry pumps etc. This is to reduce the amount of slurry that enters the shaft seal 5.

By the way, when attempting to remove the impeller 3 from the drive shaft 2 for disassembly or repair of the pump, it is necessary to use an extraction tool, especially if the impeller 3 is rusted to the drive shaft 2. However, as mentioned above, the narrow gap 4 made it difficult to apply the tool.

For this reason, the conventional
The method described in "Publication No. 1" is proposed. This has a groove in which a claw of an extraction tool can be hooked, in a boss portion of the impeller that corresponds to the fitting portion of the liner ring.

According to this, the impeller can be taken out by hooking the claw part of the extraction tool into the groove part.

[Problem to be solved by the invention] However, in the case of the prior art described in the above publication, the boss part of the impeller in which the groove is formed is a part that slides on the liner ring, and such a sliding part When forming concave grooves, there is a risk of scratches or deformation unless the generation of burrs is avoided, and since it is a rotating part, it is necessary to take into account rotational balance.For these reasons, casting processing is not possible. First, the machining accuracy must be set extremely high, resulting in high costs.

Further, the boss portion is a location where the pressure difference is large in the pump, and there is also the problem that pressure leakage that forms a groove at such a location is likely to occur.

The present invention was developed based on the above circumstances, and the impeller can be easily taken out, there is no need to make the gap between the impeller and the pump casing particularly large, and it is easy to process and prevents pressure leaks. The aim is to provide a centrifugal pump that does not cause this problem and can also reduce costs.

[Means for Solving the Problems] In the present invention, in a centrifugal pump in which a drive shaft passes through the casing cover and an impeller is attached to the tip of the drive shaft, the center of the drive shaft is attached to the casing cover. The present invention is characterized in that a plurality of recesses are provided, which are opened at positions symmetrical with respect to a line and at positions facing the outer peripheral portion of the impeller, and allow the claws of the extraction tool to be inserted into the back side of the impeller.

[Function] According to the present invention, since the casing cover is provided with a plurality of recesses opening at positions facing the outer circumference of the impeller at symmetrical positions with respect to the center line of the drive shaft, the casing cover and the impeller are Even if the distance between the pump and the pump is set to be sufficiently narrow so as not to impair the pump characteristics, the claw of the extraction tool can be inserted into the recess, and the impeller can therefore be easily extracted.

[Embodiment of the invention] Hereinafter, the present invention will be described with reference to an illustrated embodiment. In FIG. 1, the pump section 10 includes a pump chamber 13 formed by a casing body 11, a casing cover 12, and the like. A drive shaft 15 of a drive unit (for example, an electric motor, etc.) 14 is provided with a pump chamber 13 that passes through the casing cover 12 in a fluid-tight manner.
An impeller 16 is located near the inwardly protruding tip and is detachably attached via a nut 18 so as to rotate together with the impeller 16 via a key 17. Further, the gap 19 between the casing cover 12 and the impeller 16 is set to be sufficiently narrow so that the internal pressure during operation is below a desired level, and so that less slurry or the like enters the shaft seal 20. .
The general configuration described above may be the same as the conventional example shown in FIG.
3 to the outside via a discharge flow path 22.

In the present invention, the casing cover 12
In addition, a plurality of recesses 23 (only two are shown in the figure) are opened at positions symmetrical with respect to the center line of the drive shaft 15 and facing the outer circumference of the impeller 16.
is formed.

When removing the impeller 16, as shown in FIG. 2, with the casing body 11, nut 18, etc. removed, the claw portion 25 of the extraction tool 24 is inserted into the recess 23, and thereby the claw portion 25 is removed from the impeller. car 16
It can be hung on the back of the outer edge. bolt 2
6, the extraction tool 24 is pulled out, so that the impeller 16 receives an even force from the claw portion 25 and is pulled out in the axial end direction.

According to the above configuration, by providing the recess 23, the impeller 16 can be easily removed from the drive shaft 15, and the casing cover 12 and the impeller 1 can be easily removed.
Since the gap 19 between the pump and the pump 6 can be set sufficiently narrow, the pump performance will not be impaired.

Moreover, the recess 23 into which the claw portion 25 is inserted
is formed on the front surface of the casing cover 12, so no special processing is required on the impeller 16 on the rotating side, and even if there is a slight burr in the recess 23,
Problems such as scratches and poor assembly are prevented. Since the casing cover 12 is a non-rotating part, there is no need to worry about rotational balance. Therefore, since the molding accuracy may be low, it can be formed even by casting, and high-precision machining is not required, making it possible to reduce costs.

Furthermore, no pressure or fluid leakage occurs, and deterioration of pump characteristics can be prevented.

[Effects of the invention] As explained above, according to the invention, the casing cover is provided with a plurality of recesses into which the claws of the extraction tool can be inserted, and the impeller is removed by inserting the claws into the recesses. The impeller can be easily removed from the drive shaft by hooking it on the back. Also,
The space between the casing cover and the impeller can be set sufficiently narrow, and by providing the recess in a position that avoids the sliding part of the impeller, leakage of fluid and pressure can be prevented. There is no loss in performance.

Furthermore, since the recess is formed in the casing cover, there is no need to worry about machining accuracy or rotational balance, making manufacturing easier and reducing costs.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention;
FIG. 2 is an explanatory diagram of the operation of the same example, and FIG. 3 is a partial sectional view showing the conventional example. 10... Pump part, 12... Casing cover, 15... Drive shaft, 16... Impeller, 19...
〓 between, 23... recess, 24... extraction tool, 25...
...Claw part, 26...bolt.

Claims (1)

[Scope of Claim for Utility Model Registration] In a centrifugal pump in which a drive shaft passes through the casing cover and an impeller is attached to the tip of the drive shaft, the casing cover is located at a symmetrical position with respect to the center line of the drive shaft. A centrifugal pump characterized in that a plurality of recesses are provided that are open at positions facing the outer periphery of the impeller and allow claws of an extraction tool to be inserted into the back side of the impeller.