JPH09222098A - Pump casing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate an assembly work and to provide a high-reliable pump casing. SOLUTION: A pump casing comprises an inner casing 65 to contain impellers 8A and 9A; an outer casing 1 arranged at the outer peripheral part of the inner casing 65; a seal member 75 arranged to prevent leakage of handling liquid through a gap between the inner and outer casings; and fastening members 72 and 73 to fix the inner casing 65 to fix a member, such as a motor. A seal member 75 is previously located between the inner and outer casings 65 and 1 and thereafter by functioning the fastening members 72 and 73, the seal member 75 is axially compressed and radially expanded to prevent leakage of handling liquid through a gap between the inner and outer casings 65 and 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump casing, and more particularly to a pump casing having an inner casing for accommodating an impeller and an outer casing provided on an outer peripheral portion of the inner casing.

[0002]

2. Description of the Related Art An all-circumferential flow type pump, in which a liquid to be handled flows around the outer periphery of a motor, has been known. In all circumferential flow pumps, there are many examples in which a seal member is provided between the outer casing and the inner casing. For example, in Japanese Patent Application No. 6-54861 (Japanese Patent Application Laid-Open No. 7-158594), a seal member is provided between an outer cylinder forming an outer casing and an outer peripheral portion of a partition wall which is a kind of inner casing. The seal member has a tightening margin in the radial direction in order to prevent leakage from a gap between a partition wall corresponding to the inner casing and an outer cylinder corresponding to the outer casing. However, due to this interference, it was difficult to insert the inner casing into the outer casing, and the workability of assembling was poor. Therefore, JP-A-7-
In No. 158594, the end portion side of the outer cylinder is expanded in diameter to provide the expanded tube portion, thereby facilitating the insertion work of the seal member.

[0003]

However, in the method proposed in JP-A-7-158594 for providing the pipe expanding portion on the outer cylinder, a pipe expanding step is required after the outer cylinder is formed, which impairs the productivity. There was a problem. The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a pump casing which is easy to assemble and has high reliability.

[0004]

In order to solve the above problems, the present invention provides an inner casing for accommodating an impeller, an outer casing provided on an outer peripheral portion of the inner casing, and a space between the inner casing and the outer casing. In a pump casing including a seal member provided to prevent leakage of the handled liquid and a fastening member for fixing the inner casing to a member such as a motor, a seal member is previously provided between the inner casing and the outer casing. By interposing it and then causing the fastening member to function, the seal member is compressed in the axial direction and expanded in the radial direction to prevent the handling liquid from leaking from the gap between the inner casing and the outer casing. Characterize.

According to the present invention, it is not necessary to previously provide the seal member with a radial tightening allowance, but it is sufficient to provide a sealing allowance allowing for the radial deformation in the axial direction. As a result, after the inner casing is inserted into the outer casing, the seal member can have a sealing function between the two. Even when the seal member is fitted in the inner casing, there is no interference in the radial direction, so that the inner casing can be easily inserted into the outer casing.

Further, since the axial tightening margin is deformed in the radial direction for sealing, an extremely reliable sealing performance can be secured by setting the axial tightening margin to an appropriate value.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An all-circumferential double-suction pump equipped with a pump casing according to the present invention will be described below with reference to FIGS. FIG. 1 is a vertical sectional view of a full-circulation double-suction pump, FIG.
2 is a sectional view taken along the line II-II in FIG. 1. The full-circulation double-suction pump shown in FIGS. 1 and 2 is constructed as a vertical pump. Both suction pumps are provided with a canned motor 6 in the center of the outer casing 1, and impellers 8A, 9A; 8B having suction portions axially outwardly open at both shaft ends of a main shaft 7 of the canned motor 6. , 9B are fixed.

The outer casing 1 comprises an outer cylinder 2 made of stainless steel plate, and covers 63A, 63B made of stainless steel plate connected to both ends of the outer cylinder 2 by flanges 51, 52 and flanges 53, 54, respectively. There is. The flange 54 has a leg 5 for standing the pump.
4a are integrally formed. A plug 100 for venting air is attached to the upper cover 63A.

On the other hand, the canned motor 6 includes a stator 13
A motor frame outer case 14 fitted to the outer peripheral part of the stator 13, motor frame side plates 15 and 16 welded and fixed to both open ends of the motor frame outer case 14, and an inner peripheral part of the stator 13. Is attached to the motor frame side plate 15,
A can 17 that is welded and fixed to 16 is provided. A rotor 18 rotatably housed in the stator 13 is shrink-fitted and fixed to the main shaft 7. An annular passage 40 is formed between the motor frame outer case 14 and the outer cylinder 2.

A terminal case 20 (see FIG. 2) is fixed to the outer casing 14 of the motor frame. The canned motor 6 and the outer cylinder 2 are the terminal case 20 and the stay 4.
It is fixed integrally with 3. The outer cylinder 2 has suction windows 2a and 2b near both ends, and these suction windows 2a and 2b are provided.
Are connected by a suction cover 55. On the suction cover 55, a pump suction port 55a is formed and a suction nozzle 56 is fixed.

A case 77 for housing the inverter 76 is welded and fixed to the outside of the outer cylinder 2. Wiring for power supply is provided from the inverter 76 to the stator 13 via the terminal case 20. Inside the outer cylinder 2, inner casing assemblies 65, 65 for accommodating the impellers 8A, 9A; 8B, 9B are arranged. The inner casing assemblies 65 and 65 are formed in one side of the cylindrical members 65a and 65a by forming cylindrical members 65a and 65a having a small diameter portion and a large diameter portion and flat plate-shaped covers 65b and 65b into a substantially cylindrical container shape. Collars 65c and 65c and support ring 7
Seal member 75, 75 made of an elastic material
Is pinched. Suction opening 6 in the covers 65b, 65b
5e and 65e are formed. Seal member 75, 75
By this, the gap between the inner casing assembly 65 and the outer cylinder 2 is tooled to prevent the handling liquid on the discharge side from leaking to the suction side.

The inner casing assemblies 65 and 65 have studs 72 that are planted in the motor frame side plates 15 and 16, respectively, and nuts 73 that are screwed into the studs 72.
It is fixed to the motor frame side plates 15 and 16 by. Support rings 71, 71 and covers 65b, 65b
Distance pieces 74, 74 are respectively interposed between and. Then, in each inner casing assembly 65, the holding members 46 and 46 holding the liner rings 45 and 45, respectively, and the fluid discharged from the first stage impeller 8A or 8B, the second stage impeller. Return vanes 47, 47 leading to 9A or 9B and guide devices 48, 48 guiding the fluid discharged from the second stage impeller 9A or 9B from the radial direction to the axial direction are provided.

FIG. 3 is an exploded view of the inner casing assembly 65, FIG. 3 (a) is a sectional view, and FIG. 3 (b) is a plan view. As shown in FIG. 3, the seal member 75 is inserted into the brim 65c of the cylindrical member 65a, and then the support ring 7 is inserted.
The inner casing assembly 65 is pushed into the outer cylinder 2 while the cylindrical member 65a is covered with 1, and the distance piece 74 and the cover 65b are attached. At this time, even when the seal member 75 is fitted in the cylindrical member 65a, there is no interference in the radial direction, so that the seal member 75 can be easily inserted into the outer cylinder 2.
Thereafter, by screwing the nut 73 into the stud 72, the seal member 75 is axially compressed and radially expanded, and the handling liquid is discharged from the gap between the inner casing assembly 65 and the outer cylinder 2 forming the outer casing. Can be prevented from leaking.

An annular flow passage 40 is formed between the outer cylinder 2 and the motor frame outer case 14. Further, as shown in FIGS. 1 and 2, a discharge window 2c is formed in the outer cylinder 2 and a discharge nozzle 68 is connected thereto.

Next, the bearing peripheral portion on one side of the main shaft will be described. The bearing bracket 21 includes a radial bearing 2
2 and a fixed thrust bearing 23 are provided. The end surface of the radial bearing 22 also has a function as a fixed-side thrust sliding member. A rotary thrust bearing 24 and a rotary thrust bearing 25, which are rotary thrust sliding members, are provided on both sides of the radial bearing 22 and the fixed thrust bearing 23, respectively. The rotary thrust bearing 24 is fixed to the thrust disk 26, and the rotary thrust bearing 25 is fixed to the thrust disk 27.

The bearing bracket 21 is inserted into a spigot provided on the motor frame side plate 16 via an O-ring 29 made of an elastic material. Reference numeral 31 in the drawing denotes a sleeve which forms a sliding portion with the radial bearing 22.

Next, the peripheral portion of the bearing on the other side of the main shaft will be described. The bearing bracket 32 is provided with a radial bearing 33. In the figure, 34 is a sleeve that forms a sliding portion with the radial bearing 32, and the sleeve 34 contacts the washer 35, and this washer 35 is the impeller 9A and the sleeve 4.
It is fixed by a screw and a nut 36 provided at the end of the main shaft 7 via 2 and the impeller 8A. The bearing bracket 32 is inserted into a spigot provided on the motor frame side plate 15 via an O-ring 37 made of an elastic material. The bearing bracket 32 is in contact with the motor frame side plate 15.

Next, the operation of the full-circulation type double suction pump constructed as described above will be described. The fluid sucked from the pump suction port 55a is branched left and right by the suction cover 55 and flows into the pump portion through the suction windows 2a and 2b. The fluid that has flowed into the pump portion is the inner casing assembly 65, 65.
Through the suction openings 65e, 65e formed in the impeller 8
Boosted by A, 8A; 9B, 9B. Impeller 9A,
The fluid discharged from 9B is guided by the guide devices 48, 4 respectively.
After the flow direction is changed from the centrifugal direction to the axial direction via 8, the fluid flows into an annular flow passage 40 formed between the outer cylinder 2 and the motor frame 14 of the canned motor 6, and this flow passage 40
While flowing through the discharge tube 2c of the outer cylinder 2 through the discharge nozzle 68 to be discharged from the discharge port.

[0019]

According to the present invention, the seal member interposed between the inner casing and the outer casing is previously provided with
It is not necessary to provide a tightening allowance in the radial direction, and it is sufficient to provide a tightening allowance that allows for radial deformation in the axial direction. As a result, after inserting the inner casing into the outer casing, the seal member can be provided with a sealing function between them, and the pipe expanding step of the outer casing is not required. Even when the seal member is fitted in the inner casing, there is no interference in the radial direction, so that the inner casing can be easily inserted into the outer casing.

Further, in the seal member of the present invention, since the axial tightening margin is deformed in the radial direction for sealing, the axial tightening margin is set to an appropriate value, so that the sealing performance is extremely reliable. Can be secured.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a full-circulation double-suction pump including a pump casing according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

3 is an exploded view showing an inner casing assembly in a pump casing according to the present invention, FIG. 3 (a) is a sectional view and FIG. 3 (b) is a plan view.

[Explanation of symbols]

 1 Outer Casing 2 Outer Cylinder 6 Canned Motor 7 Main Spindle 8A, 8B, 9A, 9B Impeller 13 Stator 14 Motor Frame Outer Body 15,16 Motor Frame Side Plate 17 Can 18 Rotor 20 Terminal Case 21,32 Bearing Bracket 22,33 Radial bearing 23 Fixed side thrust bearing 24 Rotation side thrust bearing 40 Annular flow path 43 Stay 45 Liner ring 47, 48 Return vane 55 Suction cover 63 Cover 65 Inner casing assembly 65a Cylindrical member 65b Cover 71 Support ring 72 Plant bolt 73 Nut 74 Distance piece 75 Seal member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Isemoto 4-2-1 Honfujisawa, Fujisawa City, Kanagawa Prefecture Ebara Research Institute Ltd. (72) Inventor Kaoru Yagi 4-Fujisawa, Fujisawa City, Kanagawa Prefecture No. 1 Incorporated EBARA Research Institute (72) Inventor Keita Uei 4-2-1 Motofujisawa, Fujisawa-shi, Kanagawa Prefecture Incorporated EBARA Research Institute (72) Incorporator Yoshiaki Miyazaki, Fujisawa Fujisawa, Kanagawa 4-2-1 Incorporated EBARA Research Institute (72) Inventor Katsuji Iijima 4-2-1 Motofujisawa, Fujisawa-shi, Kanagawa Incorporated EBARA Research Institute (72) Inventor Junya Kawabata Ota, Tokyo 11-1 Haneda-machi, Haneda-ku Ebara Corporation

Claims (2)

[Claims] 1. An inner casing for accommodating an impeller, an outer casing provided on an outer peripheral portion of the inner casing, and a seal member provided between the inner casing and the outer casing for preventing leakage of a handling liquid. In a pump casing provided with a fastening member for fixing the inner casing to a member such as a motor, a seal member is previously interposed between the inner casing and the outer casing, and then the fastening member is made to function, thereby providing a seal. A pump casing characterized in that the member is axially compressed and radially expanded to prevent the handling liquid from leaking through a gap between the inner casing and the outer casing. 2. An inner casing is provided with a brim that axially supports the seal member, and a support ring that engages with the outer side of the inner casing and corresponds to the seal member is provided. The support ring functions as the fastening member. The pump casing according to claim 1, wherein the pump casing is moved in the axial direction to compress the seal member in the axial direction and expand in the radial direction.