NZ198423A

NZ198423A - Submersible pump: pump casing formed as curved tube with integral motor casing

Info

Publication number: NZ198423A
Application number: NZ198423A
Authority: NZ
Inventors: K Nakata
Original assignee: Shin Meiwa Ind Co Ltd
Priority date: 1980-09-24
Filing date: 1981-09-21
Publication date: 1984-05-31
Also published as: DE3152367T1; AU7536281A; AU541379B2; JPS6410678B2; WO1982001039A1; DE3152367C2; JPS5759097A

Abstract

An axial or oblique flow type underwater pump improved to reduce the load on the connection to a discharge tube due to vibration in operation. A motor casing (16) is formed integrally with a pump casing coaxially with the central axis of the lower opening (15) of the pump casing with the pump casing (11) formed in a bent tube. The motor casing has an end face (17) opened externally of the pump casing through the tubular wall of the pump casing. A motor (18) is provided in the motor casing, and a guide blade unit (29), an impeller (34) and an intake piece (35) are sequentially disposed under the motor casing (16).

Description

<div class="application article clearfix" id="description"> Czxr-% e? CI&xF9MlWtfM?.^PPS.Fo&BfaOi ^ . |51 MAY 984 - UtCiivia t J e- ... ^ ^...J a B ■ • • B ■ • ■ •!■■•■■ I ?.e. J cur ? ' p," • I$-58 198423 NEW ZEALAND Patents Act 1953 N.Z. No. \ M II COMPLETE SPECIFICATION AXIAL/MIXED FLOW TYPE SUBMERSIBLE MOTOR PUMP » We, SHIN MEIWA INDUSTRY CO., LTD, of 5-25 Kosone-cho 1-chome, Nishinomiya-shi, Hyogo-ken, Japan <\~ JajpA.v\Q-S<2- Cfcr|r\oro.|j c^\, hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement - 1 - (followed by la) 1984 23 This invention relates to a submersible motor pump and particularly, to improvements in a submersible motor pump constructed by using an axial flow or mixed flow pump. Description of the prior art Figure 1 shows, in section, the construction of a conventional axial flow type submersible motor pump. Referring to Figure 1, a submersible motor 1 is disposed within a suction member 2. Disposed in series above the submersible motor 1 are an inlet guide vane 3, an impeller 4 and an outlet guide vane 5. A discharge channel is formed above the outlet guide vane 5. This discharge channel is formed typically of a discharge pipe (not shown) extending upwardly from the bottom of a tank to which this submersible motor pump is attached. In some cases, the submersible motor pump is connected directly to the lower end of the discharge pipe, but in other cases, as shown in Fig. 1, a bent pipe 6 is first connected to the submersible motor pump. A pipe-like connector 7 leading to the discharge pipe is fixed on the bottom of the tank and the submersible motor pump is adapted for automatic connection to the connector 7 through the bent pipe 6. A motor driving cable 8 for feedinc -la- 1984 23 power to the submersible motor 1 is led to the latter, e.g. by passing laterally through the suction member 2. In such axial flow type submersible motor pump, unlike the centrifugal pump, in consideration of the fact that a flow is 5 formed on a cylindrical surface concentric with the shaft 9 of the submersible motor 1, the submersible motor 1 must of necessity be located in said flow. As a result, there is a danger of the motor driving cable 8 being damaged by the flowing water or being drawn into the impeller 4. Further, the 10 connection of the front end of the cable 8 to the motor 1 may sometimes be difficult since the motor 1 is located inside the pump or the discharge pipe. Further, as shown in Fig. 1, when the pump is to be automatically connected to the connector 7 fixed on the bottom 15 of the tank, the distance between the center line C of this connecting section and the operating section of the pump including the motor 1 and impeller 4 becomes longer. Therefore, during operation, the moment arm from the centerline C .of the vibration which is produced in the operating section 20 of the submersible motor pump becomes longer. As a result, the load on the support section of this submersible motor pump, i.e. the section for connection between the bent pipe 6 and the connector. 7 increases. This necessitates increasing the structural strength of the connecting section and results in 25 various inconveniences including water leakage in the 2 198 4 23 connecting section due to the vibration of the pump during operation. In addition, in the case of the centrifugal type submersible motor pump, since the motor can be disposed outside the flow, as described above, the problems with the axial flow type submersible motor pump described above can be easily solved. Examples which disclose such centrifugal type submersible motor pump includes U S Patent Specification No 3,656,871, and U S Patent Specification No 3,018,925. The problems with the axial flow type submersible motor pump described above can also occur in the mixed flow type submersible motor pump requiring the motor to be placed in the flow. This invention eliminates the above-described various inconveniences encountered in the axial flow or mixed flow type submersible motor pump. According to a broad aspect of the invention there is provided a submersible motor pump of the axial or mixed flow type comprising: a pump casing in the form of a bent pipe elbow having a lower end defining a lower opening having a first central axis extending substantially vertically in an operating portion of the pump and a lateral end defining a lateral opening having a second central axis extending substantially horizontally in said operating position of the pump, said lateral end having a connecting flange surrounding said lateral opening, a motor casing formed internally of and integrally with 3 198423 said elbow pump casing and concentrically witji said lower opening, said motor casing having an upper end surface which extends through the pump casing and opens outwardly of the pump casing upwardly in the direction of said first central axis, a motor mounted with said motor casing with its shaft extending substantially coaxially with said first central axis, said motor being held in such a position that an intersection between said first and central axes is located substantially within said motor, said shaft having a downward extension, a guide vane device connected to the lower end of the motor casing below said lower opening, an impeller arranged below said guide vane device and attached to said extension of said shaft, a suction member surrounding said impeller connected to the lower end of the guide vane device and defining a suction port, cover means removably attached to said upper end surface of said motor casing, electrically conductive means including a cable extending through said cover means for feeding power to said motor, and connecting means adapted to be vertically guided while in engagement with vertical guide members for enabling a connection between said connecting flange of said pump casing and a further flange of a discharge path section through a wedging action on said further flange of the discharge path section when said further flange and said connecting flange abut against each other. 1984 23 According to the invention, the bent formation of the pump casing, coupled with the positional relation of the motor casing to the pump casing, makes it possible to reduce the distance between the operating section of the pump 5 including the motor and impeller and the centerline of the discharge connecting section of the pump,. Further, the overall length of the pump is also reduced. Therefore, there is no need for special reinforcement in the connecting section on the discharge side of the pump, and reliable 10 automatic connection can be effected. Further, since the cable is led in through the cover member attached to the end surface of the motor casing, protection and maintenance of the cable are facilitated. These objects and other objects, features, aspects and 15 advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, in which Figure 1 shows, in section, the construction of a 20 conventional axial flow type submersible motor pump; Figure 2 shows an embodiment of the present invention, illustrating, in section, of an automatically connectible, axial flow type submersible motor pump; and Figure 3 shows another embodiment of the invention, 25 illustrating, in section, the construction of an automatically connectible, mixed flow type submersible motor pump. 1984 23 Referring to Fig. 2 illustrating an axial flow pump, a pump casing 11 is constructed in the form of a bent pipe as a whole. A lateral end 13 defining a lateral opening 12 in the pump casing 11 is formed with a flange 14. A motor casing 16 is constructed concentrically with the centerline of a lower opening 15 and integrally with the pump casing 11. The motor casing 16 has an end surface 17 which extends through the wall of the pump casing 11 on the side opposite to the lower opening 15 and which opens outwardly of the pump casing 11. A motor 18 is disposed in the motor casing 16, with its shaft 19 coaxial with the centerline of the lower opening 15. The shaft 19 has an extension which extends downwardly to serve as a pump shaft. The lower end of the shaft 19 is rotatably supported in two bearings 21 and 22 installed in a bearing box 20 fixed to the lower end of the motor casing 16. The upper end of the shaft 19 is rotatably supported in a bearing 24 installed in a bearing box 2 3 attached to the end surface of the motor casing 16. The upper surface of the bearing box 23 is provided with an electric wire connector 25 for electrical connection to the motor 18. A cover member 26 is removably installed above the bearing box 23. A cable 27 is led in through the cover member 26, said cable 27 being held in water-tight relation to the cover member 26. Fixed to the lower end 28 defining the lower opening 15 in the pump casing 11 and to the lower surface of the bearing box 1984 23 20 is an outlet guide vane device 29. The outlet guide vane device 29 supports a conical partition wall 31 at the center thereof by a plurality of vane members 30 extending from the inner wall surface thereof. The partition wall 31 cooperates with the lower surface of the bearing box 20 to define a lubricating oil chamber 32. The lubricating oil chamber 32 enables lubrication of a mechanical seal 33 which supports the shaft 19. An axial flow type impeller 34 is attached to the front end of the shaft 19 adjacent the partition wall 31. Surrounding the impeller 34, a suction member 35 which defines a suction port is fixed to the lower end of the outlet guide vane device 29. The suction member 35 has a plurality of inlet guide vanes 35 opposed to the impeller 34. Attached to the lower end of the suction member 35 is a strainer 37 having lattice openings in the outer periphery and in the bottom thereof. A guide-equipped connector 38 is fixed to the back of the flange 14 on the lateral end 13 of the pump casing 11. A discharge member 40 in the form of a bent pipe is fixed on a step-like bed 39 formed on the bottom of a tank to which this submersible motor pump is attached. The upwardly directed opening in the discharge member 40 is adapted to be connected to a discharge pipe (not shown). Two vertically extending guide pipes 42 (only one of which is shown) are installed 1984 23 between the discharge member 40 and the upper portion 41 of the tank. The guide-equipped connector 38 is formed with semi-circular engaging portions 43 and 44, disposed one above the other, which engage the guide pipes 4 2 to guide the guide-equipped connector 38 vertically along the guide pipes 42. The guide-equipped connector 38 is formed with a connecting pawl 45. The connecting pawl 45 is adapted to engage a vertical flange 46 formed on the discharge member 10. The back of the vertical flange 4 6 is formed with an inclined portion 4 7 to ensure that such engagement is effected with a wedge action to establish strong connection between the vertical flange 46 and the flange 14 on the pump casing 11. The upper surface of the cover member 26 is provided with a pair of opposed hanger rings 48. Connected to the hanger rings 48 is the bifurcated front end portion of a chain 49 suspended from a lift (not shown) installed above the tank. The submersible motor pump described above and shown in Fig. 2 is lowered from above the tank to the bottom of the tank as it is suspended by the chain 49. During this lowering, the pump is guided through engagement between the semi-circular engaging portions 43 and 44 and the guide pipe 42 until the flanges 14 and 46 come in contact with each other. Thereupon, the connecting pawl 45 engages the inclined portion 47 of the flange 46, so that the submersible motor pump is held with respect to the discharge member 40 fixed on the step-like bed 8 1 984 23 39, thus completing the installation of the submersible motor pump. That is, the submersible motor pump has been automatically connected. In this installed state, the pump is operated. In this 5 case, the distances from the centerline CI of the connection between the pump casing 11 and the discharge member 4 0 to such parts as the motor 18 and impeller 34, which may be a cause of vibration, are relatively short. That is, such distances are reduced to the extent that the motor 18 is positioned on an 10 extension of the centerline CI. Therefore, the load on the connecting portion causing vibration is extremely small as compared with the prior art, so that water leakage due to pulsating action of the connecting portion which accompanies vibration is eliminated. Thus, special reinforcement in the 15 connecting portion is not needed. Further, according to this embodiment, since the electric wire connection 25 can be disposed outside the pump casing 11 and is easily accessible, protection of the cable 27 can be attained and moreover the inspection and repair of the pump can 20 be extremely simply and easily effected. As for the position where the chain 49 is attached, whereas in the conventional arrangement shown in Fig. 1 the chain is attached to an intermediate region of a vertically extending long object, causing some unstability, in this 25 embodiment the chain 49 is attached to the top of a vertically 9 1 984 23' extending relatively short object (the upper surface of the cover member 26), providing improved stability. Fig. 3 shows an embodiment of the invention applied to a mixed flow type submersible motor pump. Only the portions different from the axial flow type submersible motor pump shown in Fig. 2 will be described. A guide vane device 129 supports a partition wall 131 at the center thereof by a plurality of vanes 130 projecting from the inner wall thereof. The partition wall 131 cooperates with the lower surface of a bearing box 120 to define a lubricating oil chamber 132. The lubricating oil chamber 132 enables lubrication of a mechanical seal 133 supporting a motor shaft 119. The lower end of the shaft 119 has a mixed flow type impeller 134. Surrounding the lower portion of the impeller 134, a suction member 135 is connected to the lower end of the guide vane device 129. This invention is not limited to automatic connection type submersible motor pumps shown in Figs. 2 and 3, but is applicable to other types of submersible motor pumps. For example, the guide-equipped connector 38 may be replaced by other means for connection to the discharge pipe or the pump may be connected directly to some other device. Although the present invention has been described and illustrated in detail, it will" be appreciated that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the present 10 1 984 23 invention being limited only by the terms of the appended claims. 11 </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 198423 WHAT WE CLAIM IS:

1. A submersible motor pump of the axial or mixed flow type comprising: a pump casing in the form of a bent pipe elbow having a lower end defining a lower opening having a first central axis »-A &-v extending substantially vertically in an operating portion of the pump and a lateral end defining a lateral opening having a second central axis extending substantially horizontally in said operating position of the pump, said lateral end having a connecting flange surrounding said lateral opening, a motor casing formed internally of and integrally with said elbow pump casing and, concentrically with said lower opening, said motor casing having an upper end surface which extends through the pump casing and opens outwardly of the pump casing upwardly in the direction of said first central axis, a motor mounted with said motor casing with its shaft extending substantially coaxially with said first central axis, said motor being held in such a position that an intersection between said first and jcentral axes is located substantially within said motor, said shaft having a downward extension, a guide vane device connected to the lower end of the motor casing below said lower opening, an impeller arranged below said guide vane device and attached to said extension of said shaft, 198-23 a suction member surrounding said impeller connected to the lower end of the guide vane device and defining a suction port, cover means removably attached to said upper end surface of said motor casing, electrically conductive means including a cable extending through said cover means for feeding power to said motor, and connecting means adapted to be vertically guided while in engagement with vertical guide members for enabling a connection between said connecting flange of said pump casing and a further flange of a discharge path section through a wedging action on said further flange of the discharge path section when said further flange and said connecting flange abut against each other.

2. A submersible motor pump as set forth in claim 1, wherein the cover means includes a bearing box which supports the shaft of the motor.

3. A submersible motor pump as set forth in claim 2 wherein the electrically conductive means includes an electric wire connector attached to the bearing box.

4. A submersible motor pump substantially as herein defined with reference to and as illustrated in Figures 2 and 3 of the drawings. SHIN MEIWA INDUSTRY CO., LTD By Their Attorneys 13 - HENRY HUGHES LIMITED </div>