JPS6221759Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention provides a sealing ring at the edge of the inner casing provided between the first stage impeller and the second stage impeller, and the sealing ring is in contact with the pump casing. Regarding the adjacent sheet metal multi-stage pump.

Such a multi-stage pump made of sheet metal is described in Japanese Utility Model Application Publication No. 191890/1983 by the present applicant. In this type of multistage pump, a plurality of impellers are housed in the pump casing, and two adjacent impellers, for example, a first stage impeller and a second stage impeller, are installed inside the pump casing. They are separated by an inner casing. The inner casing is comprised of a partition wall portion that extends radially outward from the liner ring, and a cylindrical portion that is bent from the outer periphery of the partition wall portion and extends in the axial direction.
In pumps made of sheet metal, the sheet metals to be joined after forming are hermetically fixed to each other, for example by spot welding. However, since the inner casing is sequentially inserted into the pump casing together with the impeller during assembly, disassembly and assembly becomes impossible if the inner casing and the pump casing are fixed to each other by welding or the like. Normally, the discharge pressure of the final stage impeller is applied between the cylindrical portion of the inner casing and the pump casing. This is because the discharge port of the pump is provided in the pump casing. Therefore, a considerable pressure difference occurs at the portion where the axial end edge of the cylindrical portion of the inner casing engages with the axial end wall surface of the pump casing, so a sealing ring is provided here to reduce the pressure. This prevents water from flowing into the chamber of the first stage impeller.

However, in such conventional technology, since the sealing ring is exposed in the first stage impeller chamber, it is easily deteriorated by friction and collision with liquid flowing into the chamber and foreign objects contained in the liquid. Therefore, it had the disadvantage of being easily damaged. Furthermore, as mentioned above, while the pump is operating, the hydraulic pressure acting on the space between the inner casing and the outer casing is higher than the hydraulic pressure inside the first stage impeller chamber, so if the sealing ring deteriorates, the first stage impeller There was a problem with the impeller being pushed out into the interior of the impeller chamber.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a multi-stage pump made of sheet metal with a structure in which the sealing ring does not deteriorate due to collision with liquid or foreign matter and is not pushed out into the first stage impeller chamber.

According to the present invention, a ring-shaped sealing ring retainer that holds the sealing ring at the end edge of the cylindrical portion of the inner casing is provided on the radially inner side of the cylindrical portion.

Therefore, the sealing ring holder protects the sealing ring from the liquid flowing inside the first stage impeller chamber in the radial direction, so it is less likely to deteriorate, and even if it deteriorates, it can be supported by the sealing ring holder. Therefore, it is not pushed out toward the first stage impeller chamber due to the pressure difference.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but in order to better understand the present invention, the prior art will first be described with reference to FIG. 1.

The pump casing, designated as a whole by the reference numeral 1 in FIG. 1, has a suction port 2 at its axial end and a discharge port 3 radially outwardly. A motor 4 is fixed to the opposite side of the pump casing 1 from the suction port 2 with a bolt device 5. The rotating shaft 6 rotated by the motor 4 has a plurality of shafts, that is, in the illustrated embodiment, a first stage to a third stage.
Three stage impellers 7, 8, and 9 are attached.

A first inner casing 10 is housed in the pump casing 1 so as to surround the first stage impeller 7, and the first inner casing 10 has a partition wall portion that extends outward in the radial direction. 10a, and a cylindrical portion 10b that is bent from the outer periphery of the partition wall portion 10a and extends in the axial direction, and surrounds the first stage impeller 7. An impeller chamber 11 is defined. A sealing ring 1 is provided at the axial end edge of the cylindrical portion 10b.
2 is provided to seal between the gap S between the pump casing 1 and the inner casing 10 and the impeller chamber 11. Guide vanes 13 are provided on the partition wall portion 10a of the first inner casing 10.

A second inner casing 14 is similarly provided for the second stage impeller 8. In the figure, 15 is a pump cover, and 16 is a liner ring. Components such as the casing, cover, impeller, and guide vanes are made by sheet metal processing. In operation, when the motor is driven to rotate the rotary shaft 6, the impellers 7, 8, and 9 rotate, sucking in liquid from the suction port 2 and discharging it from the discharge port 3.

Now, in such conventional technology, as described above, the sealing ring 12
FIG. 2 shows an embodiment of the present invention that solves this problem. In FIG. 2, the same parts as in FIG. 1 are designated by the same reference numerals.

Next, an embodiment of the present invention will be described with reference to FIG.

In FIG. 2, a sealing ring 12 provided at the axial end of the cylindrical portion 10b of the first inner casing 10
A ring-shaped sealing ring holder 17 is provided on the radially inward side of the first impeller chamber 11. This seal ring presser 17 is fixed inside the cylindrical portion 10b. In the illustrated example, the sealing ring presser 17 is the sealing ring 1
Although the sealing ring holder 17 has a crank-shaped cross section so as to be well engaged with the sealing ring 12, the sealing ring holder 17 can have any shape as it protects and supports the sealing ring 12.

Therefore, while the liquid is sucked in from the suction port 2 by the first stage impeller 7 and flows into the second stage impeller 8 through the guide vanes 13, it collides with the sealing ring presser 17, but the sealing Since it does not collide with the ring 12, the sealing ring 12
deterioration can be prevented.

As described above, according to the present invention, the sealing ring retainer prevents deterioration of the sealing ring and also prevents the sealing ring from deteriorating.
This prevents the sealing ring from being pushed out toward the impeller chamber, which extends the life of the sealing ring, and greatly reduces the need for disassembly and assembly of the pump to replace the sealing ring, which is required with conventional products. can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view of a conventional sheet metal multistage pump, and FIG. 2 is a partially sectional side view of a sheet metal multistage pump embodying the present invention. DESCRIPTION OF SYMBOLS 1... Pump casing, 7... First stage impeller, 10... First inner casing, 10a... Partition wall part, 10b... Cylindrical part, 12... Sealing ring,
17...Sealing ring presser.

Claims (1)

[Scope of utility model registration request] A multi-stage pump made of sheet metal in which a sealing ring is provided at the edge of the cylindrical part of the inner casing provided between the first stage impeller and the second stage impeller, and the sealing ring is in contact with the pump casing. A multi-stage pump made of sheet metal, characterized in that a ring-shaped seal ring retainer for holding the seal ring is provided inside the cylindrical portion in the radial direction.