JPS6143999Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the structure of a multi-stage pump made of sheet metal, and its purpose is to provide a small and highly efficient pump.

The structural features of the sheet metal multi-stage pump of this invention are that multiple impellers are mounted on the motor extension shaft, the final stage impeller is the same size or smaller than the other impellers, and the inner casing is This is a multi-stage pump made of sheet metal that has a return vane and a rubber volute casing at the final stage.The inner casing that partitions the casing cover and the outer casing and forms the final stage impeller chamber has an elastic body volute casing. The inner casings are stacked together via a sealing ring, and the inner casing is press-fitted between the inner casing and outer casing following the first stage via the sealing ring.

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 flange 1a of the motor 1 is formed with an annular ring 1b, into which a casing cover 2 is fitted. A mechanical seal 3 is provided at the center of the casing cover 2, and a main shaft 4 that is integral with the shaft of the motor 1 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 fitted, and a nut 8 is screwed into the male thread at the tip of the main shaft 4, thereby fixing the final stage impeller 5 and the first stage impeller 7 to the main shaft 4.

An inner casing 11 on which a return blade 9 is formed is disposed between the first stage impeller 7 and the last stage impeller 5, and an elastic body, for example, a volute casing 12 made of rubber, is in contact with or vulcanized. The inner casing 11,
By passing nuts 24 through the bolt holes of the volute casing 12 and screwing them into several tightening bolts 13 welded to the casing cover 2 at positions where they do not touch the final stage impeller 5 and the liner ring 15 (described later), the casing cover 2 At the same time, the casing cover 2 and the volute casing 12 are watertight. A liner ring holder 14 is welded to the center side of the inner casing 11, and the liner ring 1 provides a water seal between the inner casing 11 and the final stage impeller 5.
5 is fitted and fixed into the liner ring holder 14. The inner casing 11 is narrowed into a cylindrical shape at its outer periphery from the flat plate-shaped portion to which the return vane 9 is welded, and a sealing ring 16 having the cross-sectional shape shown in the figure is fitted into the cylindrical end face to ensure watertightness of the elastic body. It is fitted into the cylindrical part of the outer casing 17 which holds the cover 2 and is fitted into the spigot 1b of the motor flange, and is in contact with the end surface of the outer casing 17, so that the inner side forms the first stage pressure chamber. The first stage pressure chamber serves as a return flow path for the return vane 9.

A suction port flange 18 that opens on the extension of the main shaft 4 is fitted and welded to the outer casing 17, and an air vent device 25 is attached to the outer casing 17. A liner ring holder 19 is welded to the outer casing 17 near the suction port.
A liner ring 21 that provides a water seal between the first stage impeller 7 and the first stage impeller 7 is fitted and fixed into the first stage impeller 7, while a discharge port flange 20 is fitted and welded to the outer periphery of the volute casing 12 on the discharge side.

Machine screws 22 inserted through machine screw holes in the motor flange 1a, casing cover 2, and outer casing 17
Screw the nut 23 into the casing cover 2,
The outer casing 17 is fastened together, and at this time, the outer casing 17 presses the sealing ring 16, the inner casing 11, and the volute casing 12 toward the casing cover 2.

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 flange 18, 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 water discharged from the last stage impeller 5 is collected by the elastic body volute attached to the other side of the inner casing 11. The pressure is recovered by the casing 12 and guided to the discharge port.

A sealing ring 16 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 17, so that the pressure water boosted by the two impellers is internally transferred to the suction side. I can't get away from it.

If the first stage impeller 7 and the final stage impeller 5 have different outer diameters as in the embodiment, the first stage impeller 7 has a larger outer diameter and the final stage impeller 5 has a smaller outer diameter.
It is effective to do so. In other words, the first stage is the return blade 9
Since the velocity energy output from the first stage impeller 7 is effectively recovered, the difference between the outer diameter of the first stage impeller 7 and the inner diameter of the cylindrical part of the inner casing 11 (which is almost the inner diameter of the outer casing 17) is small. good.
On the other hand, since the velocity energy of the water coming out of the final stage impeller 5 is recovered by a single volute, a large difference is required between the outer circumference of the final stage impeller 5 and the inner diameter of the outer casing 17. Therefore, a large impeller is used as the first stage,
By using a small impeller as the final stage, the outer diameter of the pump can be effectively reduced.

Further, since the rubber volute casing 12 is firmly fastened to the casing cover 2 with bolts 13, there is no leakage of water from the end face of the volute chamber. This, together with the sealing ring 16 at the tip of the inner casing 11, prevents internal leakage, resulting in a highly efficient two-stage pump.

Fig. 3 shows another embodiment of this invention, and this embodiment is constructed as a four-stage pump made of sheet metal, and the first stage and final stage are constructed in two stages. is the same as The second and third rows are new additions. Describe the structure, excluding the first and final stages.

The main shaft 4 is fitted with a final stage impeller 5, a distance piece 6, a third stage impeller 26, a distance piece 27, a second stage impeller 28, a distance piece 29, and a first stage impeller 7. A nut 8 is screwed into the male thread at the end of the main shaft 4 to fix it.

The inner casing 11 is therefore located between the final stage impeller 5 and the third stage impeller 26, and the sealing ring 31 fitted into the end thereof is located between the second stage impeller 28 and the third stage impeller 26. Casing 32 and outer casing 1
The seal ring 33, which is fitted into the end of the inner casing 32, is in contact with the inner casing 34 and the outer casing 17, which are located between the first stage impeller 7 and the second stage impeller 28. A sealing ring 16 fitted into the end of the inner casing 34 is in contact with the outer casing 17. In this way, the inner casing 11, 3
2 and 34 are stacked on top of each other, and a bolt is passed through them in the axial direction near their outer peripheries. That is, bolts 13' are welded to the casing cover 2,
The inner casing 11 is fitted into the stepped portion of the bolt 13' so as to be in contact with the stepped portion, and then the inner casing 1 is inserted into the stepped portion of the bolt 13'.
A collar 35 inserted into the bolt 13' is fitted between 1 and 32, a collar 36 inserted into the bolt 13' is fitted between the inner casings 32 and 34, and the end of the bolt 13' passes through the inner casing 34.
These are fixed by a nut 24 screwed into the tip.

Liner ring holders 37 and 38 are provided in the inner casings 32 and 34, and a liner ring 39 is fitted into the liner ring holder 37 to provide a water seal between the liner ring holder 37 and the third stage impeller 26. A liner ring 41 is fitted into the second stage impeller 38 to provide a water seal between the second stage impeller 28 and the second stage impeller 28.

Return vanes 42 and 43 are provided in the return channels between the inner casing 32 and the second-stage impeller 28 and between the inner casing 34 and the first-stage impeller 7, respectively.

As in the first embodiment, the sealing ring 16 is pressed against the outer casing 17 and the inner casing 34 when the outer casing 17 is tightened with the nut 23 to seal that part.

According to this embodiment, the pressure of the water that has been pressurized and sped up by the first stage impeller 7 is efficiently recovered by the inner casing 34 having the return vanes 43, and the water is further pressurized and sped up by the second stage impeller 28. , the pressure is similarly efficiently recovered by the inner casing 32 having the return vane 42, and the pressure is increased by the third stage impeller 26,
Further pressure is efficiently recovered in the inner casing 11 having the return vane 9, and the pressure water discharged from the final stage impeller 5 is discharged while being recovered by the elastic body volute casing 12 attached to the other side of the inner casing 11. guided to the mouth.

Elastic sealing rings 31 and 33 are attached to the ends of the inner casings 11 and 32, and pressure is applied in the axial direction to ensure sealing between the inner casings 11, 32 and 34, respectively. is strongly pressed against the inside of the outer casing 17, so that the water pressurized by the impellers 7, 28, 26, and 5 does not leak toward the suction side.

The operation of the final stage is similar to the first embodiment.

Although this embodiment has four stages, the number of stages can be similarly increased, although there is a limit.

In addition, in each example, the volute casing 1
Alternatively, even if the volute casing 12 is provided, the outer diameter of the final stage impeller 5 is made larger than that of the front stage impeller. When the outer diameters are the same, only the portion constituting the final stage of the outer casing 17 can be constructed with a larger diameter.

As described above, according to the sheet metal multi-stage pump of this invention, the pump is compact. The inner casing before the final stage is equipped with an elastic volute casing and fixed to the casing cover, and the inner casing ends are all fitted with elastic sealing rings that fit into the outer casing, and the inner casings are overlapped to continue to the first stage. Since the inner casing is in pressure contact with the outer casing, there is no water leakage, resulting in a highly efficient pump. In addition, since the volute casing is in pressure contact with the casing cover and the inner casing is in pressure contact with the outer casing via the sealing ring, the damping performance is increased and the steel plate structure has a vibration isolation effect.

[Brief explanation of drawings]

Fig. 1 is a side view showing a partial vertical sectional view of an embodiment of this invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1 or Fig. 3, and Fig. 3 is a side view showing another embodiment of this invention. FIG. 3 is a side view partially shown in longitudinal section. 1...Motor, 2...Casing cover, 4...
...Main shaft, 5...Final stage impeller, 7...First stage impeller, 9...Return vane, 11...Inner casing, 1
2...Voluyute casing, 16...Sealing ring,
17...Outer casing, 18...Suction port flange, 20...Discharge port flange, 26...Second stage impeller, 28...First stage impeller, 31...Sealing ring, 32...Inner casing, 33...Sealing ring, 3
4...Inner casing, 35, 36...Color, 4
2,43...Return feather.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a multi-stage pump where the main part of the pump casing is made of sheet metal, the space between the impeller at the front stage and the impeller at the rear stage in the pump chamber formed by axially fastening the outer casing and the casing cover. The inner casing, which partitions the air and forms the return flow path, has an integral sheet metal structure consisting of a flat plate-shaped part that fits between the impeller at the front stage and the impeller at the rear stage, and a cylindrical part that covers the outer periphery of the impeller at the front stage. The volute casing, which is an elastic body in contact with the casing cover, is brought into contact with the final stage impeller side of the flat plate-shaped part of the inner casing before the final stage, and the cylindrical end of each inner casing is inserted through a sealing ring that fits into the outer casing. A multistage pump made of sheet metal, in which the sealing ring at the end of the inner casing between the first stage impeller and the second stage impeller contacts the outer casing. 2. A multi-stage pump made of sheet metal according to claim 1, wherein a return vane is provided in the flat plate-shaped portion of the inner casing.