JPS6123676Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the structure of a multi-stage pump made of sheet metal.

The sheet metal multistage pump related to Utility Model Application Publication No. 181573/1983, which aims to develop a compact and highly efficient sheet metal multistage pump, has achieved the effects of these objectives; The casing and casing cover are fastened together in the axial direction to form a return flow path between the front impeller and the subsequent impeller in the pump chamber. It has an integrated sheet metal structure consisting of a flat plate-shaped part that enters the inner casing and a cylindrical part that covers the outer periphery of the impeller in the previous stage, and the flat plate-shaped part of the inner casing before the final stage contacts the casing cover on the final stage impeller side. The volute casing of the elastic body collides, and the cylindrical end of each inner casing is sequentially brought into contact with the inner casing of the previous stage through a sealed conveyor, and the end of the inner casing between the first stage impeller and the second stage impeller is sealed. The transport is made by contacting the outer casing, and sealed transport is often used. In the case of special applications involving the use of high-temperature water, it is necessary to use a heat-resistant material such as fluoro rubber for the sealed container, volute, etc., which is expensive. Also, because of the volute casing, the final stage impeller is different and there are many parts.

Therefore, the purpose of this invention is to provide a sheet metal multi-stage pump that is small, lightweight, versatile, and inexpensive by minimizing the number of parts that must handle high-temperature water, such as sealed pumps and volutes. It is.

This idea is based on a multi-stage pump in which the main part of the pump casing is made of sheet metal.The outer casing and the casing cover are fastened together in the axial direction to form a return flow path between the front impeller and the subsequent impeller in the pump chamber. The inner casing that forms the front-stage impeller is an integral sheet metal structure consisting of a flat plate-shaped part that fits between the impeller of the previous stage and the impeller of the subsequent stage, and a cylindrical part that covers the outer periphery of the impeller of the previous stage. The flat plate portion of the previous inner casing has a mounting portion for a cylindrical spacer that is core-fitted to the casing cover on the final stage impeller side, and a liquid sealant is applied to the end of the cylindrical portion of each inner casing. A spigot is provided on the outer periphery of the flat plate-like part of the cylindrical part of the inner casing of the previous stage through the casing, and the sealing ring at the end of the inner casing between the first stage impeller and the second stage impeller comes into contact with the outer casing. This is a multi-stage pump made of sheet metal.

Embodiments of the sheet metal multi-stage pump of this invention will be described below with reference to the drawings. The first to be described is a two-stage sheet metal pump. FIG. 1 is a side view partially shown in longitudinal section.

A spigot 1b is formed on the flange 1a of the motor 1, into which a casing cover 2 is fitted. A mechanical seal 3 is provided at the center of the casing cover 2, and the main shaft 4, which is integral with the motor 1 and the shaft, is sealed.

The end of the main shaft 4 consists of a circular impeller mounting part 4a having a cross-sectional width across flats, and a male threaded part at the tip (not shown in the figure). The second impeller 7 is inserted, and the impeller nut 8 is attached to the male thread at the tip of the main shaft 4.
is screwed in, and the final stage impeller 5 and first stage impeller 7 are fixed to the main shaft 4.

An inner casing 11 in which a return blade 9 is formed is disposed between the first stage impeller 7 and the last stage impeller 5, and the inner casing 11 is provided with an inlet 10, as shown in a perspective view in FIG. A spacer 12 having an annular shape and having a discharge hole 13 is fitted therein. Discharge hole 13
is aligned with the discharge port 15 provided in the outer casing 14, and the spacer 12 is also aligned with the discharge port 15 provided in the outer casing 14.
It is fitted into the spigot 16 provided in the. Therefore, the spacer 12 has a spigot 16 centered on the pump axis.
Since the inner casing 11 is fitted with the spacer 12 at one end in the axial direction, the inner casing 11 can be accurately centered without being supported from the periphery of the outer casing 14.

A liner ring holder 17 is welded to the center side of the inner casing 11, and a liner ring 18 that provides a water seal between the inner casing 11 and the final stage impeller 5 is fitted and fixed into the liner ring holder 17. The inner casing 11 is narrowed into a cylindrical shape at the outer periphery from the flat plate-shaped portion to which the return vane 9 is welded, and a sealed container 19 having the cross-sectional shape shown in the figure is used to ensure watertightness of the elastic body at the cylindrical end surface.
is fitted into the outer casing 14 which clamps the casing cover 2 via a seal 19 and is fitted into the spigot 1b of the motor flange, and the inner side forms a first stage pressure chamber. The first stage pressure chamber serves as a return passage for the return vane 9.

The outer casing 14 is provided with an inlet flange 21 that opens on an extension of the main shaft 4, and an air vent device 22 is attached thereto. In addition, a liner ring holder 23 is welded to the outer casing 14 near the suction port, and a liner ring 24 is fitted and fixed to the liner ring holder 23 to provide a water seal between it and the first stage impeller 7. As shown, on the discharge side, a discharge port 15 is fitted and welded into the outer casing 14 at the position of the discharge hole 13 of the spacer 12.

The suction port flange 21 has a bipin mounting hole 26 arranged on the circumference of the end face of the flange portion 25, and is attached to the outer casing 14 via a suction port mounting portion 27. 25, it is made thinner than the outer casing 14. That is, the suction port mounting portion 27 is designed to prevent deformation of the suction port mounting portion 27 and the deformation of the outer casing 14, particularly the liner ring holder 23, when an external force is applied to the flange portion 25.

Machine screws 28 inserted through machine screw holes in the motor flange 1a, casing cover 2, and outer casing 14
Screw the nut 29 into the casing cover 2,
The outer casing 14 is fastened together, and at this time, the outer casing 14 presses the sealing member 19, the inner casing 11, and the spacer 12 toward the casing cover 2. As a result, the inner casing 11 and the spacer 12 are not allowed to shift in the direction perpendicular to the axis, increasing their rigidity in the assembled state.

When the motor 1 is energized, the main shaft 4 rotates, and the first stage impeller 7 and the final stage impeller 5 rotate. Water is sucked in through the suction port of the suction port flange 21, and is pressurized and accelerated by the first stage impeller 7.

The pressure of the water discharged from the first stage impeller 7 is efficiently recovered by the inner casing 11 having return vanes 9, and the pressure of the pressure water discharged from the last stage impeller 5 is recovered by the spacer 12 attached to the other side of the inner casing 11. While being collected, it passes through the discharge hole 13 and is guided to the discharge port 15.

A sealed pipe 19 made of an elastic material such as rubber is attached to the tip of the cylindrical part of the inner casing 11, and is strongly pressed against the inside of the outer casing 14, so that the pressure water boosted by the two impellers flows inside to the suction side. There is no turning back.

Figure 3 shows another embodiment of this invention, and this embodiment is constructed as a three-stage pump made of sheet metal, and the first stage and final stage are constructed in two stages. is the same as The second row is a new addition. Describe the structure, excluding the first and final stages.

A final stage impeller 5, a distance piece 6, a second stage impeller 31, a distance piece 32, and a first stage impeller 7 are fitted onto the main shaft 4, and the impeller nut 8 is attached to the end of the main shaft 4. It is screwed into the male thread and fixed.

The inner casing 11', which is the same as the inner casing 11, is therefore located between the final stage impeller 5 and the second stage impeller 31, and its end is fitted into the spigot 10 of the inner casing 11 with liquid packing, and the inner casing 11 A spacer 12 is fitted into the spigot 10'.

A seal 19 fitted into the end of the inner casing 11 is in contact with the outer casing 14. In this way, the inner casings 11, 11' and the spacer 12 are stacked, and the outer casing 14 is attached to the casing cover 2.
The screw 28 is inserted into the spigot 1b of the motor flange 1a through the screw 28, and then tightened with the nut 29 in the axial direction.

The inner casing 11' has a liner ring holder 1
A liner ring 18' is fitted into the liner ring holder 17' to provide a water seal between the liner ring holder 17 and the final stage impeller 5.
A liner ring 18 is fitted between the first impeller 31 and the second impeller 32 to provide a water seal.

A return vane 33 is further provided in the return flow path between the inner casing 11' and the second stage impeller 31.

As in the first embodiment, when the outer casing 14 is tightened with the nut 29, the sealing tube 19 is pressed against the outer casing 14 and the inner casing 11 to seal that part.

According to this embodiment, the pressure of the water that has been pressurized and accelerated by the first stage impeller 7 is efficiently recovered by the inner casing 11 having return vanes 9, and the water is further pressurized and accelerated by the second stage impeller 31. Similarly, the pressure is efficiently recovered by the inner casing 11' having the return vanes 33, and the pressure water discharged from the final stage impeller 5 is guided to the discharge port while the pressure is recovered by the spacer 12.

When increasing the number of stages, further attach an impeller to the main shaft 4 between the impellers 5 and 31 or between the impellers 7 and 31,
The same inner casing as the inner casing 11 is arranged between them.

As described above, the inner casing 11' is fitted with the spigot 10' into the spacer 12 which is fitted into the spigot 16 of the casing cover 2, and the inner casing 11 is fitted into the inner casing 11' with the spigot 10. By simply inserting the casing cover 2 between the outer casing 14 and the motor flange 1a and tightening them, the inner casings 11 and 1 can be removed.
The position of 1' is determined, and the rigidity in the direction perpendicular to the axis is increased in the assembled state. In the case of four or more stages, the number of inner casings is further increased, but the position of the inner casings is determined in the same way. Although it is possible that the lack of a final stage volute would theoretically cause a decrease in performance, experimental results showed that there was almost no decrease in efficiency.

In the sheet metal multi-stage pump of this invention, the inner casing is provided with a fitting part so that the adjacent inner casing or spacer 12 is fitted into it, and the spacer 12 is fitted into the spigot 16 of the casing cover mounting part, so that the inner casing can be positioned. There is no need for any work, and the stacked inner casing, spacer 12, etc. can be fixed simply by pressing between the outer casing and the casing cover, and the sealing can be achieved by simply applying a liquid seal to the fitting part.

Since the centering work during assembly does not involve fixing the inner casing to each other separately from the outer casing, there are no bolt holes, bolts, or accompanying sealing means, so there is no assembly work involved, so assembly time is short and assembly is easy and accurate. Moreover, the number of parts is reduced.

Since the volute casing is removed from the conventional example, all impellers including the final stage impeller can be made the same, and centering work of the volute casing is not required. In addition, the bolts used to attach the volute casing are no longer necessary, and it can be used for high-temperature liquid conveyance without using large amounts of expensive fluorine rubber.

As described above, the sheet metal pump of this invention is small, highly efficient, low cost, and easy to assemble.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of this invention, FIG. 2 is a perspective view of the parts shown in FIG. 1, and FIG. 3 is a longitudinal sectional view of another embodiment of this invention. 1...Motor, 2...Casing cover, 3...
... Mechanical seal, 4 ... Main shaft, 5 ... Last stage impeller, 6 ... Distance piece, 7 ... First stage impeller, 8 ... Impeller nut, 9 ... Return vane, 10 ... Inlet, 11...Inner casing, 1
2...Spacer, 13...Discharge hole, 14...Outer casing, 15...Discharge hole, 16...Inro, 1
7... Liner ring holder, 18... Liner ring, 19... Sealed transport, 21... Inlet flange,
22...Air vent device, 23...Liner ring holder, 24...Liner ring, 25...Flange section, 26...Pipin mounting hole, 27...Suction port mounting section, 28...Machine screw, 29...Nut , 31
...Second stage impeller, 32...Distance piece, 33...Return impeller.

Claims (1)

[Scope of utility model registration request] In a multi-stage pump where the main part of the pump casing is made of sheet metal, the outer casing and casing cover are fastened together in the axial direction to form a return flow path by partitioning the front-stage impeller and the subsequent-stage impeller in the pump chamber. The inner casing has an integral sheet metal structure consisting of a front-stage impeller, a flat plate-shaped part that enters the rear stage, and a cylindrical part that covers the outer periphery of the front-stage impeller. It has a mounting part for a cylindrical spacer that is centrally fitted to the casing cover on the side, and the ends of the cylindrical part of each inner casing are sequentially engaged with the spigots provided in the previous inner casing, and are connected to the first stage impeller. A multi-stage pump made of sheet metal, in which the seal ring at the end of the inner casing between the second stage impellers is in contact with the outer casing.