JPH0424158Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Field of Industrial Application) The present invention relates to a sheet metal intermediate casing for a multi-stage pump or a multi-stage blower.

(Prior art) Generally, the intermediate casing of a multistage pump is
As shown in FIGS. 4 and 5, a plurality of notched passages 5 are provided in the outer diameter portion of a partition plate 4 that partitions an impeller chamber 2 in which an impeller 1 is installed and a return passage 3, and A plurality of guide vanes 6 are provided on the outer diameter portion of the plate 4 on the impeller chamber 2 side, and each notch passage 5 is connected to the vortex chamber 18 formed on the outer diameter side of the impeller 1 of the impeller chamber 2.
A plurality of differential user passages 7 are formed which are connected to each other, and the partition plate 4 on the opposite side from the differential user passages 7 is formed.
A plurality of guide vanes 8 are provided in each notch passage 5.
An intermediate casing 10 is known that has a configuration in which the return passage 3 is formed to connect to the suction port 9 of the next stage.

In this intermediate casing 10, the swirl chamber 18
The diameter of the intermediate casing 10 is increased by the size required for the differential user passage 7 formed on the outer circumferential side of the pump, which increases the size and weight of the pump.The provision of the differential user passage 7 makes the structure complex, and the disadvantage is that it is expensive. There is.

On the other hand, as shown in FIG. 6 and FIG. A return passage inlet 16 in the shape of an arcuate groove that extends from the rear wall of the vortex chamber 19, which is an annular passage formed on the outer diameter side of the impeller chamber 12, to each of the return passages 14 and gradually becomes deeper is provided in the diameter portion. An intermediate casing 17 is known in which the return passage inlet 16 is also used as a differential user passage 20. According to this intermediate casing 17, the differential user passage 7 is not formed on the outer circumferential side of the vortex chamber 12, so that the intermediate casing 17 has a small diameter. As a result, the pump can be made smaller and lighter, and the structure is simple and inexpensive.

(Problems to be Solved by the Invention) However, in any of the intermediate casings 10, 17 shown in FIGS. 4, 5, 6, and 7, the vortex chamber 18 is , 19 as well as the differential user passage 7,
The dimensional accuracy and surface roughness of flow paths such as casings 20 and return passages 3 and 14 must not be rough, but if the intermediate casings 10 and 17 are made of cast metal, their shapes are complicated, so the dimensional accuracy and surface roughness described above must not be rough. Cutting to improve the surface roughness is practically impossible, and precision casting is therefore expensive, and if the intermediate casings 10 and 17 are made of resin, the dimensional accuracy and surface roughness described above are satisfied, but extremely difficult. Since an expensive mold is required, the cost is high in the case of small-scale production, and the temperature of the pump handling liquid is limited due to the heat resistance of the resin, and the pump pressure resistance is limited to a low level due to the strength of the resin, and it is necessary to improve the pressure resistance. Therefore, if only the bodies of the intermediate casings 10 and 17 are made of metal,
There is a problem in that the types of liquids handled by the pump are narrowly limited to those that do not corrode both metals and resins.

The present invention was devised in view of the above, and has a small diameter and is easy to process and manufacture, allows a multi-stage pump or multi-stage blower to be constructed in a small, lightweight, and inexpensive manner, and allows sufficient dimensional accuracy and surface roughness of the flow path to be ensured. Provided is a sheet metal intermediate casing for a multi-stage pump or multi-stage blower that improves the efficiency or blower efficiency and does not limit the temperature of the handled fluid or the pressure resistance of the pump or blower to be low, or narrowly limit the type of fluid handled. It is something to do.

[Structure of the idea]

(Means for Solving the Problems) The structure of the sheet metal intermediate casing of the multistage pump or multistage blower of the present invention includes a return passage formed by arranging a plurality of guide vanes of the same shape and an impeller. An adjacent guide is placed on the outer diameter of the partition plate that partitions the impeller chamber from the vicinity of the intersection of the outer periphery of the partition plate and each of the guide vanes, approximately perpendicular to each guide vane, toward the center of the partition plate. The same number of notches as the guide vanes are provided, each of which is formed by a substantially L-shaped cutting line that reaches the blade and extends halfway toward the outer periphery of the partition plate while following the adjacent guide vane. The notch portion is bent along the guide vane toward the return passage, and the passage cross-sectional area is gradually expanded from the vortex chamber, which is an annular passage formed on the outer diameter side of the impeller of the impeller chamber. and a differential user passage connected to the return passage.

(Function) In this invention, each intermediate casing does not have a differential user passage on the outer periphery of the vortex chamber, the diameter thereof is small, and the sheet metal structure maintains sufficient dimensional accuracy of flow passages such as return passages and differential user passages. It is possible to form a smooth surface.

(Example) Next, an example in which the present invention is applied to a 12-stage barrel type multi-stage canned motor pump will be described with reference to FIGS. 1 to 3.

In FIG. 3, 30 is a multistage canned motor pump formed by combining a multistage pump 31 and a canned motor 32, and the multistage pump 31 is sequentially and fluid-tightly attached to one side of the canned motor 32 with bolts or the like. Rear barrel body 33, discharge casing 3
4. Front barrel body 35 and suction casing 36
, intermediate casings 37 and impellers 38 arranged in the front barrel body 35 and constituting each stage pump from the first stage to the sixth stage from the suction casing 36 side to the discharge casing 34 side, and the rear barrel body Intermediate casings 37 are arranged in the middle casing 33 and constitute each stage pump from the seventh stage to the final stage from the canned motor 32 side to the discharge casing 34 side.
and each impeller 38, and each stage pump from the first stage to the sixth stage and each stage pump from the seventh stage to the final stage have intermediate casings 37 and Impeller 38
are arranged in opposite directions, and each impeller 38 is fixed to a rotating shaft 39 of a canned motor 32 extending into the multistage pump 31.

Next, the configuration of each intermediate casing 37 is changed to the first one.
2 and 2 will be explained.

Each of the intermediate casings 37 includes a flat cylindrical metal ball 40 and a plurality of notches 43 on the outer diameter portion.
a metal partition plate 44 provided with a metal partition plate 44, and the notch portion 43 fixed to the partition plate 44 by spot welding or by caulking a protrusion into an engagement hole of the partition plate 44 (not shown). Same number of guide vanes 45
The partition plate 44 and the guide blade 45 that are fixed together are disposed within the ball 40 with the other end edge of the guide blade 45 abutting against the side plate portion 46 of the ball 40. The outer peripheral edge of the partition plate 44 excluding the notch 43 is fixed to the body 47 of the ball 40 by welding, and the adjacent guide vanes 45, the partition plate 44 and the ball 40
The spaces surrounded by the side plate portions 46 are respectively formed as return passages 41.

A plurality of notches 43 of the partition plate 44
The partition plate 44 extends from the vicinity of the intersection of the outer peripheral edge of the partition plate 44 and each guide vane 45 at a substantially right angle to this guide vane 45.
It is formed by a substantially L-shaped cutting line 43a that extends toward the center of the partition plate 44, reaches the adjacent guide blade 45, and runs along this neighboring guide blade 45 toward the outer periphery of the partition plate 44. Guide blade 4 with a cutting line 43a of
5 approaches the side plate portion 46 of the ball 40 as it moves toward the center, and the portion along the cutting line 43a approaches the side plate portion 46 of the ball 40.
The portion substantially perpendicular to each guide vane 45 is the ball 4.
0, and so that the outer peripheral edge of the cutting line 43a abuts the inner peripheral surface of the body 47 of the ball 40, and the inner peripheral edge contacts the side surface of the guide vane 45, respectively. The plurality of notches 43 are bent toward each return passage 41 side, and the vortex chamber 42 is an annular passage on the outer diameter side of the impeller 38 of the impeller chamber 57 in which the impeller 38 is disposed. A differential user passage 58 is formed as a return passage introduction port 49 whose passage cross-sectional area gradually increases and is connected to each return passage 41 .

Further, the body portion 47 of the ball 40 has a female thread 50 on the inner periphery of the front side and a male thread 51 on the outer periphery of the rear side.
The intermediate casings 37 of each stage are screwed and fixed to each other by both screws 50 and 51, and the vortex chamber 42 is formed between the partition plate 44 of the intermediate casing 37 of each stage and the intermediate casing 37 of the preceding stage. is formed.

Note that in order to fix the intermediate casings 37 of each stage to each other, for example, the intermediate casings 37 that are adjacent to each other are
Although it is possible to adopt a method of tightening bolts for each stage, it is better to use the method of this embodiment.
The thickness of the body portion 47 of No. 7 can be reduced, and the diameter of the intermediate casing 37 can be reduced accordingly.

In addition, in Fig. 3, 52 and 53 are multistage pumps 3.
The tip and intermediate bearing portions 54 and 54 of 1 are bearing portions of the canned motor 32.

55 is each intermediate casing 3 from the seventh stage to the final stage
7 and a flow path using the gap between the rear barrel body 33,
56 is the passage 55 and the intermediate casing 3 of the sixth stage.
A flow path is provided in the discharge casing 34 so as to communicate with the flow path 7, through which the pump handling liquid sucked from the suction casing 36 and energized by each stage pump from the first stage to the sixth stage passes through the flow paths 56 and 55. Guided to the seventh stage pump closest to the canned motor 32 side,
It is further energized by the pumps from the seventh stage to the final stage and is discharged from the discharge casing 34.

In addition, each stage pump from the first stage to the sixth stage and the seventh stage pump
Each stage pump from stage to final stage means each impeller 3.
The winding directions of the blades No. 8 and the guide vanes 45 of each intermediate casing 37 are opposite to each other.

According to the embodiment configured as described above, since each intermediate casing 37 does not have a differential user passage on the outer circumferential side of the vortex chamber 42, the diameter thereof is small and manufacturing is easy, and the entire pump is small, lightweight, and inexpensive. In addition, since it has a sheet metal structure, the dimensional accuracy of the flow paths such as the return passage 41 and the differential user passage 58 can be maintained sufficiently compared to a cast intermediate casing, and the surfaces thereof can be formed smoothly, improving pump efficiency. Moreover, it is not as expensive as precision casting, does not require extremely expensive molds compared to resin intermediate casing, is suitable for small-scale production, and has low pump handling liquid temperature and pump pressure resistance. The type of fluid handled by the pump is not narrowly limited, as is the case when only the body of the intermediate casing is made of metal.

Although an embodiment in which the present invention is applied to a barrel-type multistage canned motor pump has been described above, it can also be applied to multistage pumps and multistage blowers other than barrel-type and canned motor driven.

[Effect of idea]

According to the sheet metal intermediate casing of the multi-stage pump or multi-stage blower of the present invention, the diameter is small and easy to process, and sufficient dimensional accuracy and surface roughness of the flow path are ensured, so the product is small, lightweight, and inexpensive. In addition, the pump efficiency or blower efficiency is improved, and it is possible to obtain a multi-stage pump or a multi-stage blower in which the temperature of the fluid to be handled, the pressure resistance of the pump or the blower is not limited to low, and the type of fluid to be handled is not narrowly limited. .

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the intermediate casing of a barrel-type multi-stage canned motor pump showing an embodiment of the present invention, Fig. 2 is a partially cutaway perspective view of the same, and Fig. 3 is a cross-sectional view of the same canned motor pump. 4 is a sectional view of the intermediate casing of a conventional multistage pump, FIG. 5 is a partially cutaway perspective view of the same as above, FIG. 6 is a sectional view of the intermediate casing of another conventional multistage pump, and FIG. 7 is a partially cutaway perspective view of the same as above. 41... Return passage, 42... Vortex chamber, 43... Notch, 44... Partition plate, 45... Guide vane, 5
8...Deaf user passage.

Claims (1)

[Scope of utility model registration request] At the outer diameter part of the partition plate that partitions the return passage formed by arranging a plurality of guide vanes of the same shape and the impeller chamber in which the impeller is arranged, the outer peripheral edge of this partition plate and the Approximately L extending from the vicinity of the intersection approximately perpendicularly to each guide vane toward the center of the partition plate to the next guide vane and along the adjacent guide vane halfway toward the outer periphery of the partition plate. The same number of notches as the guide vanes are formed by a letter-shaped cutting line, and each of the notches is bent toward the return passage along the guide vanes, thereby forming the impeller chamber. A sheet metal intermediate casing for a multi-stage pump or a multi-stage blower, characterized in that a passage cross-sectional area gradually expands from a vortex chamber, which is an annular passage formed on the outer diameter side of the impeller, to form a diffuser passage connected to the return passage. .