JPH0626499A - Pump and assembling method therefor - Google Patents

Abstract

PURPOSE:To form a pump in a simple structure, and position and install a casing in a casing cover. CONSTITUTION:An impeller 8a is stored between a casing 9a and a casing cover 4 so as to install the impeller on a driving shaft 10 guided to penetrate the casing cover 4. In a pump provided in such constitution that a mechanical seal 13 for maintaining liquid density while being push-pressed by a spring member 14 is provided between the impeller 8a and the casing cover 4, and also the impeller 8a is between the mechanical seal 13 and a fastening nut screwed around the driving shaft 10, a sliding contact part 30 fitted detachably to the suction port outer circumference 8aa of the impeller 8a is provided on the liner part of the casing 9a. It is thus possible to position the casing 9a against the impeller 8a by fitting the sliding contact part 30 of the casing 9a on the suction port of the impeller 8a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump having a positioning structure for mounting a pump casing on a casing cover, and a pump assembling method using this positioning structure.

[0002]

2. Description of the Related Art Generally, in a spiral pump or the like, a casing cover is fixed to a bracket connected to a motor casing, the pump casing is connected to the casing cover to form a pump chamber, and a drive shaft extending from the motor casing is connected to the casing. The casing cover is penetrated and introduced into the pump chamber, an impeller is attached to the drive shaft, and the impeller is covered with the casing cover and the pump casing.

When the pump casing is attached to the casing cover, it is fixed by bolts. In this case, it is necessary to position the casing with respect to the impeller, and the pump casing is circumferentially and radially arranged with respect to the casing cover. The casing is aligned with the impeller by adjusting the position in the direction. However, the work of positioning the pump casing with respect to the casing cover is troublesome. That is, the positioning structure of the inner casing is shown in FIG.
I will explain based on this.

In the figure, 1 is a motor casing for housing a motor, 2 is a bracket, 3 is an outer casing, and 4 is a casing cover. In the illustrated example, both the outer casing 3 and the casing cover 4 are made of sheet metal and are pressed products.

The casing cover 4 is fixed to the bracket 2 connected to the motor 1 via a bolt (not shown), and the outer casing 3 is fastened to the casing cover 4 by a bolt (not shown). A pump chamber 5 is formed between the external pump casing 3 and the casing cover 4, and the pump chamber 5 has a pump suction port 6 opened on the front surface of the external pump casing 3.
It also communicates with the outer casing 3 and a pump discharge port 7 which is open on the circumference.

A drive shaft 10 projects from the motor 1, and the drive shaft 10 penetrates the bracket 2 and is inserted into the casing cover 4 to be introduced into the pump chamber 5. The pump chamber 5 has a plurality of impellers 8a, 8b, 8c.
Are housed in the inner casings 9a, 9b, 9c, respectively. The impellers 8a, 8b, 8c are attached to the drive shaft 10 in a stacked state along the axial direction, and the impellers 8a, 8b, 8c are spaced by a sleeve-shaped spacer 11 ... There is. In addition, these impellers 8
The a, 8b, 8c and the spacers 11 are fixed by a tightening nut 12 that is screwed into the tip of the drive shaft 10.

A mechanical seal 13 for liquid-tightly sealing the drive shaft 10 is provided between the last-stage impeller 8a and the casing cover 4. The mechanical seal 13 is liquid-tightly sealed by the sliding contact between the pressing plate 15 pressed by the spring 14 and the sliding contact plate 16.

These impellers 8a, 8b, 8c are housed in inner casings 9a, 9b, 9c, and these inner casings 9a, 9b, 9c are also stacked in the axial direction. The inner casings 9a, 9b and 9c
Are sandwiched between the outer casing 3 and the casing cover 4. In this case, the inner casing 9a at the final stage is fixed to the casing cover 4a through the bolts 17 ... However, the other inner casings 9b and 9c are positioned at the stepped portion 18 with respect to the inner casings 9a and 9b at the rear stage, respectively. Are stacked in the axial direction in a state of being positioned by ..., and held by being pressed by the outer casing 3 on the front surface of the innermost casing 9c at the frontmost stage. An O-ring 19 keeps the liquid tightness between the front surface of the innermost casing 9c and the outer casing 3.

In the multistage spiral pump having such a structure, when assembling it, the drive shaft 10 extending from the motor casing 1 and penetrating the bracket 2 is
This casing cover 4 is inserted through the casing cover 4.
Is fixed to the bracket 2. The mechanical seal 13 is inserted into the drive shaft 10 and the impeller 8 at the final stage is inserted.
Insert a. The impeller 8a is covered with the inner casing 9a at the final stage, and the inner casing 9a is fixed to the bolt 17 ...
It is fixed to the casing cover 4 using.

Next, spacers 11 and 2 are attached to the drive shaft 10.
The second stage inner casing 9b is covered by inserting the second stage impeller 8b, and the inner casing 9b is positioned on the final stage inner casing 9a by the positioning step portion 18 and laminated in the axial direction. . Further, the spacer 11 and the frontmost impeller 8c are inserted through the drive shaft 10, the frontmost inner casing 9c is covered on the impeller 8c, and the inner casing 9c is inserted into the second inner casing 9b by the positioning step portion 18. And stack in the axial direction.

In this state, the spacer 11 is further inserted into the drive shaft 10, and the tightening nut 12 is screwed into the tip of the drive shaft 10 and tightened. Then, each impeller 8a, 8b,
8c is the tightening nut 12 and the mechanical seal 13
It is sandwiched between and and positioned on the step portion 10a of the drive shaft 10, and is attached to the drive shaft 10. The impellers 8a, 8b, and 8c are each prevented from rotating with respect to the drive shaft 10 by using a key or the like (not shown).

After that, the outer casing 3 is put on the inner casings 9a, 9b and 9c, and the outer casing 3 is fastened to the pump cover 4 with bolts (not shown). As a result, the inner casings 9a, 9b, 9c are axially pushed and held between the outer pump casing 3 and the pump cover 4. This completes the assembly of the pump.

Reference numeral 20 designates each inner casing 9a, 9
A partition plate 21 for partitioning b and 9c in the axial direction is provided at the front opening of each of the inner casings 9a, 9b and 9c, and has a predetermined gap with the outer circumference of the suction ports of the impellers 8a, 8b and 8c. Liner rings facing each other.

In the multistage pump having such a structure,
When the inner casing 9a at the final stage is fixed to the casing cover 4 using the bolts 17 ..., It is necessary to align the inner casing 9a with the impeller 8a. This alignment is troublesome because it is necessary to shift the position of the inner casing 9a in the radial direction and the circumferential direction to adjust the position. In order to facilitate this alignment, for example, as shown in FIG. 4, a plurality of positioning stoppers 23 ... Are provided on the casing cover 4 at intervals in the circumferential direction, and the circumferential surface of the inner casing 9a at the final stage is projected. It is conceivable that the position in the radial direction is regulated by engaging with the positioning stoppers 23 ...

In this way, the inner casing 9a at the final stage is positioned in the radial direction by the stoppers 23, so that the inner casing can be easily aligned with the impeller and the assembling work can be carried out efficiently. .

[0016]

However, the positioning stoppers 23 ... As described above are provided in the casing cover 4.
Special processing is required, and in the case of casting, special processing is required for the mold, and particularly when the above-mentioned positioning stopper 23 ... Is provided on the casing cover 4 made of sheet metal, it is integrally pressed. Alternatively, there is no choice but to use welding, and in such press working and welding work, there is a problem that molding becomes impossible and the number of working processes increases.

Further, such a positioning stopper 23
Since it is used only when the inner casing 9a is assembled to the casing cover 4, it is rather an obstacle at other times, and there is a concern that it may become a resistance to the discharge flow, for example.

The present invention has been made in view of the above circumstances. The object of the present invention is to provide a pump having a simple structure, which allows the casing to be positioned and attached to the casing cover, thereby improving the assembling efficiency. And an assembling method thereof.

[0019]

SUMMARY OF THE INVENTION A pump according to the present invention accommodates an impeller between a casing and a casing cover, and the casing has a liner facing the suction port outer periphery of the impeller with a predetermined gap. The impeller is attached to the drive shaft that penetrates through the casing cover, and the impeller and the casing cover are pressed against each other by a spring member so as to be in sliding contact with each other to ensure liquid tightness. A mechanical seal is installed to hold the impeller, and the mechanical seal and a tightening nut screwed to the drive shaft hold the impeller to attach it to the drive shaft. It is characterized in that a slidable contact portion is provided so that the outer periphery of the mouth can be inserted and removed.

According to the assembling method of the present invention, the drive shaft is inserted into the casing cover which is fastened to the casing, and the mechanical seal for keeping the liquid tightness is inserted into the drive shaft by being pressed by the spring member and slidingly contacting with the blade. This casing is positioned by the impeller by inserting the wheel, covering the impeller with the casing, and fitting the sliding contact portion formed on the liner portion of the casing to the outer circumference of the suction port of the impeller. Then, the casing is fixed to the casing cover, and then a tightening nut is screwed onto the drive shaft, and the tightening nut causes the impeller to move axially against the spring member of the mechanical seal. The suction port outer circumference of the impeller is separated from the sliding contact portion of the casing to secure a predetermined gap between the liner portion and the impeller suction port outer circumference. And it said that there was Unishi.

[0021]

According to the present invention, since the sliding contact portion is provided between the liner portion of the casing and the outer circumference of the suction opening of the impeller so that the suction opening of the impeller can be inserted and removed. The casing can be positioned with respect to the impeller by fitting into the suction port of the impeller. Therefore, the position of the casing can be restricted in the radial direction with respect to the casing cover. Moreover, when the tightening nut is tightened, the impeller is pushed and moved against the spring member of the mechanical seal, and the outer circumference of the suction port of the impeller is axially disengaged from the sliding contact portion of the casing. A predetermined gap can be secured between the outer circumference and the liner portion of the casing, and the outer circumference of the suction port of the impeller is not worn.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in FIGS. This embodiment shows an example applied to a multi-stage spiral pump, and in FIGS. 1 to 3, the same members as those of the conventional structure shown in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. Then, the present embodiment shows an example in which the casing of the present invention is applied to the final stage inner casing.

The present embodiment differs from the conventional one in that the positioning stoppers 23 formed on the casing cover 4 ...
Instead, the liner portion of the inner casing 9a at the final stage is provided with a small-diameter sliding contact portion 30 as shown in detail in FIGS. 3 (a) and 3 (b) so as to cover the front surface of the liner ring 21. It is a point. As shown in FIG. 3A, the small-diameter sliding contact portion 30 can be slidably contacted with the suction port outer peripheral portion 8aa formed in the front portion of the last stage impeller 8a so as to be insertable and removable. .

With such a structure, when the final stage inner casing 9a is covered on the final stage impeller 8a, the suction port outer peripheral portion 8aa of the impeller 8a is fitted to the small-diameter sliding contact portion 30 formed on the liner portion. The inner casing 9
a is positioned with respect to the impeller 8a, and as a result, the inner casing 9a is positioned with respect to the casing cover 4. This point will be described in more detail based on the assembly procedure.

That is, in the multistage spiral pump having the above-mentioned structure, when assembling the pump, the drive shaft 10 extending from the motor casing 1 and penetrating through the bracket 2 has a casing cover 4 as in the conventional case. And the casing cover 4 is fixed to the bracket 2. Next, the mechanical seal 13 is inserted into the drive shaft 10 and the impeller 8a at the final stage is inserted. Then, as shown in FIG. 2, the impeller 8a is covered with a final stage inner casing 9a.

In this case, as shown in FIG. 3A, the inner peripheral surface of the small-diameter sliding contact portion 30 formed in the inner casing 9a at the final stage is the outer periphery of the suction port outer peripheral portion 8aa of the impeller 8a at the final stage. Fit them so that they are in sliding contact with the surface. By this fitting, the sliding contact portion 30 and the suction port outer peripheral portion 8aa positionally regulate, and the casing 9a is positioned with respect to the impeller 8a. Since the position of the impeller 8a is restricted by the drive shaft 10, the inner casing 9a is positioned with respect to the casing cover 4 in the radial direction. In such a fitted state, the inner casing 9a is rotated in the circumferential direction to align the bolt holes, and the bolts 17 are inserted into the bolt holes to fix the inner casing 9a to the casing cover 4.

In this case, the impeller 8a is pushed by the force of the spring 14 of the mechanical seal 13 in the direction of the arrow in FIG. 2 from the predetermined mounting position, and the inner casing 9a is covered by the bolts 17 ... When fixed to 4, the impeller 8a also moves in the direction opposite to the arrow against the biasing force of the spring 14 of the mechanical seal 13 as the inner casing 9a approaches the casing cover 4. However, even if the inner casing 9a is fixed to the casing cover 4 by the bolts 17 ..., The slidable contact portion 30 and the suction port outer peripheral portion 8aa are kept in a fitted state.

In this way, the final stage inner casing 9
When a is fixed to the casing cover 4, the spacer 11 and the second-stage impeller 8b are inserted into the drive shaft 10, and the impeller 8b is covered with the second-stage inner casing 9b. In this case, the inner casing 9b of the second stage has the positioning step portion 18
Thus, the inner casing 9a at the final stage is positioned and laminated in the axial direction. Further, the other spacer 11 and the impeller 8c at the frontmost stage are inserted into the drive shaft 10, and the impeller 8
c is covered with the innermost casing 9c at the front stage, and in this case also,
The inner casing 9c is positioned on the inner casing 9b of the second stage by the positioning step portion 18 and stacked in the axial direction.

In this state, another spacer 11 is inserted into the drive shaft 10 and the tightening nut 12 is attached to the tip of the drive shaft 10.
Screw it in and tighten it. When the tightening nut 12 is tightened, the impellers 8a, 8b, 8
.. and the spacers 11 are pushed in the axial direction, so that the impellers 8a, 8b, 8c are clamped between the tightening nut 12 and the mechanical seal 13. That is, since the spring 14 of the mechanical seal 13 pushes the impellers 8a, 8b, 8c in the axial direction, the impellers 8a, 8b, 8c are sandwiched between the tightening nut 12 and the mechanical seal 13, and the drive shaft The shaft step portion 10a of 10 is positioned and mounted.

At this time, the impeller 8a at the final stage is pushed in the direction opposite to the direction of the arrow in FIG. 2, while the inner casing 9a at the final stage is fixed to the casing cover 4, so the impeller 8a is fixed. The outer peripheral portion 8aa of the suction port is shown in FIG.
As shown in FIG. 5, the inner casing 9a axially slips out from the small-diameter sliding contact portion 30. As a result, the suction inlet outer peripheral portion 8aa does not come into sliding contact with the liner portion, and a predetermined gap t is secured between the suction inlet outer peripheral portion 8aa and the liner ring 21. Therefore, the outer peripheral portion 8aa of the suction port does not cause sliding friction and wear is prevented. In addition, each impeller 8a, 8b, 8
Each of the keys c is prevented from rotating with respect to the drive shaft 10 by using a key or the like (not shown).

After that, the outer pump casing 3 is put on the inner casings 9a, 9b and 9c, and the outer pump casing 3 is fastened to the pump cover 4 with bolts (not shown). This allows each inner casing 9a, 9b, 9
c is pushed in the axial direction by the outer pump casing 3 and the pump cover 4 and held. This completes the assembly of the pump.

According to such an embodiment, the positioning of the inner casing 9a at the final stage is performed by the inner casing 9a.
Since the small-diameter sliding contact portion 30 formed on the above and the suction port outer peripheral portion 8aa of the impeller 8a at the final stage are slidably fitted, only the small-diameter sliding contact portion 30 is formed on the inner casing 9a. Therefore, it is not necessary to form a special positioning stopper 23 ... As in the conventional case. Therefore, the processing is easy, and particularly when the casing cover 4 made of sheet metal as in this embodiment is used, the positioning stoppers 23 ...
Since it is not necessary to form the structure, there is no restriction on processing, strength, or working process.

In order to attach the inner casing 9a to the casing cover 4, it is necessary to cover the impeller 8a without fail. In this covering work, the sliding contact portion 30 of the inner casing 9a and the suction port outer peripheral portion 8aa of the impeller 8a are covered. Since the positioning is performed by the fitting, the extra troublesome work for this positioning is not required. Therefore, the positioning work is easy.

Furthermore, after such positioning, a tightening nut 12 is screwed into the tip of the drive shaft 10 and tightened to prevent the impellers 8a, 8b, 8c from resisting the force of the spring 14 of the mechanical seal 13. And push it in the axial direction, and thereby it is mounted on the drive shaft 10. At this time,
The suction port outer peripheral portion 8aa of the final stage impeller 8a comes out in the axial direction from the small-diameter sliding contact portion 30 of the final stage inner casing 9a, as shown in FIG. 3B.

Therefore, when the impellers 8a, 8b and 8c are fixed by the tightening nut 12, the outer peripheral portion 8a of the suction port is accompanied.
A predetermined gap t can be secured between a and the liner ring 21, and the gap t can be easily obtained. In addition,
The present invention is not limited to the above embodiments, but various modifications and applications are possible within the scope of the gist thereof.

For example, in the case of the above-mentioned embodiment, the outer casing 3 and the inner casings 9a, 9a as the pump casings are used.
The case of the double casing structure of b and 9c has been described, but the double structure is not limited to the single structure, and the casing and the casing cover are not limited to sheet metal and may be cast. Good.

Furthermore, in the above embodiment, the case of the multi-stage spiral wound pump has been described, but the structure in which the casing is positioned and attached to the casing cover is a structure that is generally adopted in general pumps. The invention can be practiced with pumps having these general structures.

[0038]

As described above, according to the pump and the assembling method of the present invention, the slide in which the suction port of the impeller is removably fitted between the liner portion of the casing and the outer circumference of the suction port of the impeller. Since the contact portion is provided, the casing can be positioned with respect to the impeller by fitting the sliding contact portion of the casing into the suction port of the impeller. Therefore, the position of the casing can be restricted in the radial direction with respect to the casing cover. Therefore, although the structure is simple, the pump casing can be positioned and attached to the casing cover, and the assembling efficiency is improved. Moreover, when the tightening nut is tightened on the drive shaft, the impeller is pushed and moved against the spring member of the mechanical seal and the suction port outer periphery of the impeller is axially separated from the sliding contact portion of the casing. A predetermined gap can be secured between the outer circumference and the liner portion of the casing, wear is not generated on the outer circumference of the suction port of the impeller, and the life characteristics are improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a multistage spiral wound pump showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in the middle of assembly in the same embodiment.

3A and 3B are enlarged cross-sectional views of a portion A of FIG. 1 in the same embodiment, FIG. 3A is a cross-sectional view during assembly, and FIG. 3B is a cross-sectional view after assembly is completed.

FIG. 4 is a cross-sectional view of a conventional multistage spiral pump.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motor casing, 2 ... Bracket, 3 ... Outer casing, 4 ... Casing cover, 8a ... Final stage impeller, 9a ... Final stage inner casing, 10 ... Drive shaft, 1
2 ... Tightening nut, 13 ... Mechanical seal, 14 ... Spring, 17 ... Bolt, 21 ... Liner ring, 8aa ...
Outer periphery of suction port of impeller, 30 ... Sliding contact part of inner casing.

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[Procedure amendment]

[Submission date] November 12, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art Generally, in a spiral pump or the like, a casing cover is fixed to a bracket connected to a motor and a pump casing is connected to the casing cover to form a pump chamber, and a drive shaft extending from the motor. Is introduced into the pump chamber through the casing cover, an impeller is attached to the drive shaft, and the impeller is covered with the casing cover and the pump casing.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

In the figure, 1 is a motor, 2 is a bracket,
Reference numeral 3 is an outer casing, and 4 is a casing cover. In the illustrated example, both the outer casing 3 and the casing cover 4 are made of sheet metal and are pressed products.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

The casing cover 4 is fixed to the bracket 2 connected to the motor 1 via a bolt (not shown), and the outer casing 3 is fastened to the casing cover 4 by a bolt (not shown). Outside
A pump chamber 5 is formed between the part casing 3 and the casing cover 4, and the pump chamber 5 is an external casing.
Leads to pump inlet 6 pump outlet 7 and which opens on the circumference of the outer casing 3, opened in the front surface of the ring 3.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

These impellers 8a, 8b, 8c are housed in inner casings 9a, 9b, 9c, and these inner casings 9a, 9b, 9c are also stacked in the axial direction. The inner casings 9a, 9b and 9c
Are sandwiched between the outer casing 3 and the casing cover 4. In this case, the inner casing 9a at the final stage is fixed to the casing cover 4 through the bolts 17 ... However, the other inner casings 9b and 9c are positioned at the stepped portion 18 with respect to the inner casings 9a and 9b at the rear stage, respectively. Are stacked in the axial direction in a state of being positioned by ..., and held by being pressed by the outer casing 3 on the front surface of the innermost casing 9c at the frontmost stage. An O-ring 19 keeps the liquid tightness between the front surface of the innermost casing 9c and the outer casing 3.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

In the multistage spiral pump having such a structure, when assembling it, the casing cover 4 is inserted into the drive shaft 10 extending from the motor 1 and penetrating the inside of the bracket 2, and the casing cover 4 is inserted. Fix it to the bracket 2. Then, the mechanical seal 13 is inserted into the drive shaft 10 and the final stage impeller 8a is inserted. The impeller 8a is covered with a final stage inner casing 9a, and the inner casing 9a is fixed to the casing cover 4 by using bolts 17 ...

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

After that, the outer casing 3 is covered on the inner casings 9a, 9b, 9c, and the outer casing 3 is fastened to the casing cover 4 with bolts (not shown). Thus the inner casing 9a, 9b, 9c outside
The casing 3 and the casing cover 4 are pushed and held in the axial direction. This completes the assembly of the pump.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

That is, in the multistage spiral pump having the above-mentioned structure, when assembling the same, the casing cover 4 is attached to the drive shaft 10 extending from the motor 1 and penetrating the bracket 2 as in the conventional case. The casing cover 4 is inserted and fixed to the bracket 2. Next, the mechanical seal 13 is inserted into the drive shaft 10 and the impeller 8a at the final stage is inserted. And this impeller 8a
Then, as shown in FIG. 2, the inner casing 9a at the final stage is covered.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

In this case, as shown in FIG. 3A, the inner peripheral surface of the small-diameter sliding contact portion 30 formed in the inner casing 9a at the final stage is the outer periphery of the suction port outer peripheral portion 8aa of the impeller 8a at the final stage. Fit them so that they are in sliding contact with the surface. By this fitting, the sliding contact portion 30 and the suction port outer peripheral portion 8aa regulate the position, and the inner casing 9a is positioned with respect to the impeller 8a. Since the position of the impeller 8a is regulated by the drive shaft 10, the inner casing 9a is attached to the casing cover 4a.
On the other hand, radial positioning is performed. In such a fitted state, the inner casing 9a is rotated in the circumferential direction to align the bolt holes, and the bolts 17 are inserted into the bolt holes to fix the inner casing 9a to the casing cover 4.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

After that, the outer casing 3 is covered on the inner casings 9a, 9b, 9c, and the outer casing 3 is fastened to the casing cover 4 with bolts (not shown). Thus the inner casing 9a, 9b, 9c outside
The casing 3 and the casing cover 4 are pushed and held in the axial direction. This completes the assembly of the pump.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] Explanation of code

[Correction method] Change

[Correction content]

[Explanation of Codes] 1 ... Motor , 2 ... Bracket, 3 ... External casing, 4
... Casing cover, 8a ... Final stage impeller, 9a ... Final stage inner casing, 10 ... Drive shaft, 12 ... Tightening nut, 13 ... Mechanical seal, 14 ... Spring, 17
... bolts, 21 ... liner ring, 8aa ... outer periphery of suction port of impeller, 30 ... sliding contact portion of inner casing.

Claims (4)

[Claims] 1. An impeller is housed between a casing and a casing cover, and a liner portion is provided in the casing so as to face the outer periphery of the suction port of the impeller with a predetermined gap therebetween. Attached to the drive shaft introduced through the casing cover, between the impeller and the casing cover, a mechanical seal is installed to maintain liquid tightness by sliding contact by being pressed by a spring member. In a pump in which the impeller is clamped and attached to the drive shaft by a mechanical seal and a tightening nut screwed onto the drive shaft, the outer periphery of the suction port of the impeller can be inserted into and removed from the liner portion of the casing. A pump provided with a sliding contact portion that is fitted to the pump. 2. The pump is a multi-stage pump, wherein the sliding contact portion is formed on a liner portion of a casing at the final stage, and the outer periphery of the suction port of the impeller at the final stage is removably fitted into the sliding contact portion. The pump according to claim 1, wherein: 3. A drive shaft is inserted through a casing cover that is fastened to the casing, and a mechanical seal that keeps liquid-tightness is inserted through the drive shaft by being pressed by a spring member and slidingly contacting the drive shaft. This impeller is covered with the casing, and the sliding contact portion formed on the liner portion of the casing is fitted to the outer circumference of the suction port of the impeller to position the casing with the impeller. Fixed to the cover,
After that, a tightening nut is screwed onto the drive shaft, and the tightening nut axially pushes the impeller against the spring member of the mechanical seal to move the outer circumference of the suction port of the impeller to the casing. A method of assembling a pump, characterized in that a predetermined gap is secured between the liner portion and the outer circumference of the suction port of the impeller by separating from the sliding contact portion. 4. The pump is a multi-stage pump, wherein the sliding contact portion is formed on a liner portion of a final stage casing, and an outer periphery of a suction port of an impeller of the final stage is removably fitted into the sliding contact portion. The method for assembling a pump according to claim 3, wherein: