JP2003343499A - Multistage motor pump and its assembly method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multistage motor pump capable of making a vertical multistage pump to a horizontal multistage pump, making the horizontal multistage pump to the vertical multistage pump only by exchanging one part, and reducing the installation cost as a whole. <P>SOLUTION: The multistage motor pump is equipped with an outer cylinder 6 provided on the outside of a motor frame 2, a first pump part increasing a pressure of the treated liquid by at least one impeller 14, and a second pump part increasing a pressure of the treated liquid by at least one impeller 15. The suction direction of the impeller 14 of the first pump part and that of the impeller 15 are reversed each other. A delivery side casing 3 having a delivery nozzle 3a toward the perpendicular direction to an axis can be mounted on the one end of the outer cylinder 6. Both a first suction side casing 1 having a suction nozzle 1a toward the perpendicular direction to the axis and a second suction side casing 101 having a suction nozzle 101a toward the axial direction can be mounted on the other end of the outer cylinder 6. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multistage motor pump and a method for assembling the pump, and more particularly to a multistage motor pump having impellers at both ends of a main shaft and a method for assembling the pump.

[0002]

2. Description of the Related Art Conventionally, there has been known an all-circumferential-type multistage pump in which an annular space through which a liquid to be handled flows is formed on the outer periphery of a motor frame. Such a full-circulation multi-stage pump is a kind of canned motor pump, and the rotor of the canned motor is rotatably supported by bearings. The liquid to be handled is guided from the suction section to the first-stage impeller to be boosted in pressure, further pressurized by the next-stage impeller, and finally discharged from the discharge port.

As such a multi-stage pump, there are a vertical multi-stage pump and a horizontal multi-stage pump. However, when only a flat installation space is considered, the installation space can be reduced, and thus the vertical pump. Is suitable.

As shown in FIGS. 1 and 2, a check valve 200 and a sluice valve 210 are provided in the pipe connected to the discharge port of the pump. These check valve 200 and the sluice valve 210 are arranged in the vertical direction. Connected to. In the horizontal type pump, as shown in FIG. 1, since the discharge port 220 is oriented in the vertical direction with respect to the axis (extending in the horizontal direction), when considering a planar installation space including the pipe, A horizontal (end-top) pump is suitable.

In order to make the installation space equivalent to that of the horizontal pump in the vertical type pump, as shown in FIG. 2, an elbow 240 is connected to the discharge port 230, and a vertical direction is provided through the elbow 240. It is necessary to connect to the check valve 200 and the sluice valve 210 arranged in As a result, the following problems occur. (1) Since the piping load on the discharge side acts as a bending load on the shaft of the pump and causes damage to the bearing, expansion joints and appropriate piping support are required, or rigidity of the casing needs to be increased. . (2) A vertical space is required as compared with the horizontal type (end top type).

[0006]

As described above, a more appropriate pump is selected and installed from the vertical multi-stage pump and the horizontal multi-stage pump due to the installation space. Conventionally, in order to meet such a demand, it is necessary to prepare two types of pumps, a vertical multi-stage pump and a horizontal multi-stage pump, which causes an increase in cost.

The present invention has been made in view of the above problems of the prior art. A vertical multi-stage pump can be formed into a horizontal multi-stage pump or a horizontal multi-stage pump can be set up by replacing only one component. It is an object of the present invention to provide a multi-stage motor pump and a method for assembling the pump, which can be a multi-stage pump of a type and can reduce the installation cost as a whole.

[0008]

In order to solve the problems in the prior art, the first aspect of the present invention is
An outer cylinder provided on the outer side of the motor frame, a first pump section for increasing the pressure of the handling liquid introduced from the suction section by at least one impeller, and at least one handling liquid discharged from the first pump unit. A multi-stage motor pump, comprising: a second pump portion for boosting pressure by individual impellers, wherein the impellers of the first pump portion and the impeller of the second pump portion have suction directions opposite to each other. A discharge side casing having a discharge nozzle oriented in the direction perpendicular to the shaft can be attached to one end of the outer casing, and a suction nozzle oriented in the direction perpendicular to the shaft is attached to the other end of the outer casing. It is a multi-stage motor pump capable of mounting both the first suction side casing and the second suction side casing having a suction nozzle oriented in the axial direction.

According to a second aspect of the present invention, an outer cylinder provided on the outer side of the motor frame, a first pump section for pressurizing the liquid to be handled introduced from the suction section by at least one impeller, and the first aspect described above. A second pump part for pressurizing the handling liquid discharged from the pump part by at least one impeller, and the suction directions of the impeller of the first pump part and the impeller of the second pump part. And a discharge-side casing having a discharge nozzle oriented in the direction perpendicular to the shaft is attached to one end of the outer cylinder, and a suction nozzle oriented in the direction perpendicular to the shaft is provided. A first suction side casing and a second suction side casing having a suction nozzle oriented in the axial direction are prepared, and the first suction side casing is attached to the other end of the outer cylinder to form a vertical multi-stage motor pump. , Above The suction-side casing is an assembly method of the multi-stage motor pump, characterized in that a horizontal multistage motor pump installed in the other end of the outer tube.

In a preferred aspect of the present invention, the outer cylinder forms an annular space through which the liquid to be handled flows, the first pump portion is arranged on one shaft end side, and the second pump portion is formed on the other shaft end side. It is characterized by arranging the pump part of.

According to the present invention, a first suction side casing having a suction nozzle oriented in the direction perpendicular to the axis and a second suction side casing having an suction nozzle oriented in the axial direction can be prepared. The vertical multi-stage pump can be changed to a horizontal multi-stage pump, or the horizontal multi-stage pump can be changed to a vertical multi-stage pump simply by replacing the suction side casing. Therefore, it is not necessary to separately prepare two types of pumps, and it is possible to reduce the installation cost as a whole.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a multi-stage motor pump according to the present invention will be described in detail below with reference to FIGS. 3 and 4. FIG. 3 is a vertical cross-sectional view showing a multistage motor pump according to an embodiment of the present invention, which is an example in which the multistage motor pump is configured as a vertical pump. As shown in FIG. 3, the multi-stage motor pump according to the present embodiment has (first
The suction side casing 1, the motor frame 2, the discharge side casing 3, the casing cover 4, and the canned motor 5 are basically configured.

The motor frame 2 is formed of stainless cast steel so as to be integrated with an outer cylinder 6 and a rib 7 provided on the outer side thereof. Furthermore, on the outer peripheral portion of the outer cylinder 6,
A plane seat 8 for mounting the frequency converter is integrally provided. An annular space S1 through which the handled liquid flows is formed between the motor frame 2 and the outer cylinder 6.

The stator 9 of the canned motor 5 is housed in the motor frame 2 by shrink fitting or press fitting. Inside the stator 9, a rotor 11, which is shrink-fitted and fixed to the main shaft 10, is rotatably accommodated.
A motor frame side plate 12 formed of stainless cast steel is hermetically welded to the axially upper end of the motor frame 2. The flat seat 8 has a flat surface, and a case 13 for accommodating a frequency converter (not shown) is attached to the flat seat 8.

At both ends of the main shaft 10 of the canned motor 5,
One impeller 14 and 15 are fixed,
The impellers 14 and 15 are formed with suction portions 14a and 15a that are open outward in the axial direction. These impellers 14 and 15 are housed inside the suction side casing 1 and the discharge side casing 3, respectively. For the impellers 14 and 15, cast-molded articles made of stainless cast steel are appropriately selected,
A high lift (pressure) of 100 m per stage is generated.

The main shaft 10 is supported at its both ends by bearings provided on the motor frame 2. In the bearing portion below the main shaft 10 (first stage), the bearing bracket 20 is provided with a radial bearing 21, and the sleeve 23 that abuts the washer 22 forms a sliding portion with the radial bearing 21. The bearing bracket 20 is in contact with the end of the motor frame 2.

In the bearing portion above the main shaft 10 (second stage), a bearing bracket 30 is provided with a radial bearing 31 and a fixed thrust bearing 32. The end surface of the radial bearing 31 also has a function as a fixed-side thrust sliding member, and the rotation-side thrust bearing 34 held by the thrust disk 33 is in sliding contact with the end surface of the radial bearing 31. A rotary thrust bearing 35 is provided so as to face the fixed thrust bearing 32. The rotary thrust bearing 35 is held by a thrust disk 36.
The sleeve 37 forms a sliding portion with the radial bearing 31.

The above-mentioned radial bearings 21, 31,
Thrust bearings 32, 34, 35 and sleeves 23, 3
The material of No. 7 is silicon carbide which is a kind of ceramic material, and the materials of the bearing brackets 20, 30 and the thrust disks 33, 36 are stainless steel. In addition, the thrust bearing 3 that supports the axial thrust load
Reference numerals 2, 34, and 35 are plain bearings.

The canned motor 5 is a two-pole three-phase induction motor, and is operated at a high speed of about 7,500 revolutions per minute by electric power (for example, 125 Hz, 200 V) supplied from the frequency converter. As a result, the impellers 14, 1
A miniaturization of the pump including 5 has been achieved. At this time,
The handling liquid flowing in the flow path S1 between the motor frame 2 and the outer cylinder 6 shields noise having a relatively high frequency generated as the speed increases, and also effectively causes the canned motor 5 and the frequency converter that generate heat. Cooling.

Here, a suction side casing 1 and a discharge side casing 3 are fixed to both axial sides of an outer cylinder 6 provided outside the motor frame 2. Also,
A casing cover 4 is attached to the upper portion of the discharge side casing 3. The first suction side casing 1 is a main shaft 10
Is provided with a suction nozzle 1a oriented in a direction perpendicular to the axial direction, and a flow path S2 is formed from the suction nozzle 1a to the suction portion 14a of the first-stage impeller 14. Further, the wall forming the flow path S2 forms a flow path S3 that connects the suction portion 14a of the impeller 14 and the above-described flow path S1. As a result, the fluid sucked into the flow path S2 from the suction nozzle 1a of the suction side casing 1 passes through the suction portion 14a of the first-stage impeller (first pump portion) 14 and is pressurized by the impeller 14. . Then, the pressurized fluid flows into the flow path S1 through the flow path S3.

The discharge side casing 3 has a flow path S4 communicating with the flow path S1 and a flow path S5 extending from the discharge portion of the second stage impeller 15 to the discharge nozzle 3a. The discharge nozzle 3 a of the discharge-side casing 3 faces in a direction perpendicular to the axial direction of the main shaft 10. The casing cover 4 is provided with a space S6 communicating with the flow path S4 formed in the discharge side casing 3, and the central portion of the discharge side casing 3, that is, the suction portion 15a of the second-stage impeller 15 is positioned. The part to be opened is open. A distance piece 40 for ensuring a distance between the impeller 15 and the thrust disk 36 is disposed between the second-stage impeller 15 and the thrust disk 36. It is fitted into the main shaft 10.

Therefore, the fluid whose pressure has been increased by the first-stage impeller 14 and which has flowed into the flow path S1 is introduced into the flow path S4 of the discharge side casing 3 and the space S of the casing cover 4.
Up to 6. The fluid is the space S of the casing cover 4.
6 through the suction portion 15a of the impeller 15 to the impeller (second
The pressure is increased by the pump portion 15) and is discharged from the discharge nozzle 3a of the discharge side casing 3 through the flow path S5. As shown in FIG. 3, in the present embodiment, since the impellers 14 and 15 arranged at both shaft ends of the main shaft 10 have suction directions opposite to each other, the axial thrust can be balanced.

Here, instead of the above-mentioned first suction side casing 1, a second suction side casing having a suction nozzle oriented in the axial direction is prepared. If this is attached to the outer cylinder 6 and a leg for horizontal placement is provided, the vertical multi-stage motor pump can be changed to a horizontal (end-top) multi-stage motor pump. FIG. 4 is an example in which the multi-stage motor pump shown in FIG. 3 is configured as a horizontal pump. As shown in FIG. 4, the outer cylinder 6 has a suction nozzle 101 oriented in the axial direction.
A second suction side casing 101 having a is attached, and a leg 102 for horizontal placement is provided at the bottom of the pump. Note that, in FIG. 4, the plane seat (reference numeral 8 in FIG. 3) and the case of the frequency converter (reference numeral 13 in FIG. 3) are not shown.

As described above, at one end of the outer cylinder 6, the first suction side casing 1 having the suction nozzle 1a oriented in the direction vertical to the axis and the second suction side having the suction nozzle 101a oriented in the axial direction are provided. Any of the side casings 101 can be attached. Therefore, by preparing the first suction side casing 1 and the second suction side casing 101 and replacing these suction side casings, the vertical multi-stage pump becomes a horizontal multi-stage pump,
Alternatively, the horizontal multi-stage pump can be changed to a vertical multi-stage pump. As described above, according to the present invention, it is not necessary to separately prepare two types of pumps, so that it is possible to reduce the installation cost as a whole.

In the present embodiment, a two-stage motor pump has been described as an example, but the present invention is not limited to this, and the present invention can be applied to a motor pump having three or more stages.

Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above embodiment and may be implemented in various different forms within the scope of the technical idea thereof.

[0027]

As described above, according to the present invention, the first suction side casing having the suction nozzle oriented in the direction perpendicular to the axis and the second suction side casing having the suction nozzle oriented in the axial direction are provided. If it is prepared, the vertical multi-stage pump can be changed to a horizontal multi-stage pump or the horizontal multi-stage pump can be changed to a vertical multi-stage pump simply by replacing these suction side casings. Therefore, it is not necessary to separately prepare two types of pumps, and it is possible to reduce the installation cost as a whole.

[Brief description of drawings]

FIG. 1 is a schematic front view showing a piping configuration of a horizontal type multi-stage motor pump.

FIG. 2 is a schematic front view showing a piping configuration of a vertical multi-stage motor pump.

FIG. 3 is a vertical cross-sectional view showing a multistage motor pump according to an embodiment of the present invention, which is an example configured as a vertical pump.

FIG. 4 is an example in which the multi-stage motor pump shown in FIG. 3 is configured as a horizontal pump.

[Explanation of symbols] 1 First suction side casing 1a Suction nozzle 2 motor frame 3 Discharge side casing 4 casing cover 5 canned motor 6 outer cylinder 7 ribs 8 plane 9 stator 10 spindles 11 rotor 12 Motor frame side plate 13 cases 14,15 Impeller 20,30 Bearing bracket 21,31 radial bearing 22 washer 23,37 Sleeve 32 Fixed thrust bearing 33,36 thrust disk 34,35 Rotation side thrust bearing 101 Second suction side casing 101a suction nozzle 102 legs

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F04D 29/42 F04D 29/42 G 29/44 29/44 A E 29/46 29/46 A F term (reference) 3H034 AA01 AA12 BB01 BB06 BB11 CC03 CC07 DD01 DD02 DD05 DD12 DD16 DD20 DD22 DD26 DD27 DD30 EE05 EE12

Claims (4)

[Claims] 1. An outer cylinder provided on the outer side of a motor frame, a first pump section for boosting the handling liquid introduced from a suction section by at least one impeller, and a first pump section discharged from the first pump section. A multi-stage system comprising: a second pump unit that pressurizes the liquid to be handled by at least one impeller, and the suction directions of the impeller of the first pump unit and the impeller of the second pump unit are opposite to each other. A motor pump, wherein a discharge side casing having a discharge nozzle oriented in a direction perpendicular to the shaft can be attached to one end of the outer casing, and the other end of the outer casing is oriented in a direction perpendicular to the shaft. A multistage motor pump, wherein both a first suction side casing having a suction nozzle and a second suction side casing having an axially oriented suction nozzle can be attached. 2. The outer cylinder forms an annular space through which the liquid to be handled flows, and the first pump portion is arranged on one shaft end side and the second pump portion is arranged on the other shaft end side. The multistage motor pump according to claim 1, wherein 3. An outer cylinder provided on the outer side of the motor frame, a first pump section for boosting the handling liquid introduced from the suction section by at least one impeller, and a first pump section discharged from the first pump section. A multi-stage system comprising: a second pump unit that pressurizes the liquid to be handled by at least one impeller, and the suction directions of the impeller of the first pump unit and the impeller of the second pump unit are opposite to each other. A method for assembling a motor pump, comprising: a discharge side casing having a discharge nozzle oriented in a direction perpendicular to a shaft is attached to one end of the outer cylinder; and a first suction side casing having a suction nozzle oriented in a direction perpendicular to the shaft. A second suction side casing having a suction nozzle oriented in the axial direction is prepared, and the first suction side casing is attached to the other end of the outer cylinder to form a vertical multi-stage motor pump, and the second suction side is provided. casing Is attached to the other end of the outer cylinder to form a horizontal type multi-stage motor pump. 4. The outer cylinder forms an annular space through which the liquid to be handled flows, and the first pump portion is arranged on one shaft end side and the second pump portion is arranged on the other shaft end side. The method for assembling a multi-stage motor pump according to claim 3, wherein.