JPH0633789B2 - Multistage pump - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multi-stage pump suitable for pumping water.

[Conventional technology]

As a conventional multi-stage pump, as shown in Japanese Patent Laid-Open No. 61-179396, a plurality of intermediate cases having a built-in impeller fixed to the rotary shaft are attached to the rotary shaft with tightening nuts. Alternatively, as shown in JP-A-52-103701, a plurality of intermediate casings, in which an impeller chamber, a volute chamber, a communication passage and a water passage are integrally provided on a suction / discharge casing, are sequentially stacked. Things are known.

[Problems to be Solved by the Invention]

In the conventional example shown in JP-A-61-179396, it is necessary to form a key groove in the rotary shaft and fix the impeller to the rotary shaft by using a key in this key groove, increasing the number of parts, And,
Since the number of steps for processing the rotary shaft is increased, it has a drawback of low productivity.

In the conventional example shown in JP-A-52-103701, an intermediate casing integrally formed with an impeller chamber, a volute chamber, a communication passage and a conduction passage is formed for each impeller. Since they are stacked one by one, the axial length of the rotating shaft becomes long, and the pump becomes large in size.

In view of the above drawbacks, the object of the present invention is to
It is an object of the present invention to provide a multistage pump capable of easily performing maintenance and inspection without increasing the size of the pump, having high productivity, and suppressing runout of the impeller.

[Means for Solving the Problems]

The above-mentioned object is a multi-stage pump in which a first-stage guide vane and a first-stage impeller and a second-stage guide vane and a second-stage impeller are sequentially arranged in the axial direction, and a disc is provided at one end of one impeller shaft. Part is formed so that the rear shroud of the second-stage impeller comes into surface contact with this disc part.
The second stage impeller is attached to a flat portion formed on the impeller shaft, and a spacer interposed between the first stage impeller and the second stage impeller is a rear surface of the first stage impeller. By attaching the first-stage impeller to a flat portion formed on the impeller shaft so as to make surface contact with the shroud, the impeller shaft, the both impellers, and the spacer become one rotating portion, and The first and second step guide vanes are connected to each other to form one impeller unit as one fixed portion, and the impeller shaft that constitutes the impeller unit is screwed to a rotary shaft of an electric motor, and This is achieved by fixing the fixing portion to the bracket that forms the fluid path and the housing.

[Action]

According to such a multi-stage pump, each impeller is attached to the impeller shaft to form a rotating portion, and each guide vane is connected to each other to form a fixed portion. By combining these rotating portions and the fixed portion, One impeller unit is configured, the impeller shaft that constitutes this impeller unit is detachably screwed to the rotating shaft of the electric motor, and the fixing part is fixed between the bracket and the housing. The impeller unit can be removed from the motor with one operation for maintenance and inspection at a convenient location.

Furthermore, a disc portion is formed at one end of the impeller shaft, and the rear shroud of the second-stage impeller is attached to the disc portion such that the rear shroud of the second-stage impeller comes into surface contact with the first-stage impeller and the second-stage impeller. Since the spacer interposed therebetween comes into surface contact with the rear shroud of the first-stage impeller, the runout of both impellers can be suppressed.

Further, the second-stage impeller is attached to the flat part of the impeller shaft so that the rear shroud of the second-stage impeller comes into surface contact with the disc part of the impeller shaft, and the first-stage impeller and the second-stage impeller are attached. By mounting the first-stage impeller on the flat part of the impeller shaft so that the spacer interposed between the impeller and the first-stage impeller makes surface contact with the rear shroud of the first-stage impeller, the impeller shaft, both impellers and the spacer Since the and are one rotating part, it is not necessary to form a key groove in the impeller shaft and to provide a key for fixing both impellers to the impeller shaft, which improves the productivity of the impeller unit. In addition to being achieved, the axial length of the rotating portion can be set to the required minimum dimension, so that the impeller unit can be downsized.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

First, an installation example of a pump device including the pump of the present invention will be described with reference to FIG. The pump device 5 includes a first pump 6, a second pump 7, a control box 8, a water reservoir 9, and the like. Water tank 1 from water pipe 1 via ball tap 2
Water is stored in the water receiving tank 3 and is connected to the first pump 6 and the second pump 7 by the water supply pipe 4. The first pump 6 and the second pump 7 are connected in parallel. The discharge sides of the first pump 6 and the second pump 7 are connected to a large number of discharge faucets 11 via a discharge pipe 10. The water storage 9 is communicated with the inlet side of the discharge pipe 10.

Then, when the use is started in a state where the amount of water used from the discharge water tap 11 is small, the first pump 6 is first operated. When the use from the discharge faucet 11 is stopped, the first pump 6 is stopped. Then, when the amount of water used is restarted again, the second pump 7 operates, and when the use is stopped, the second pump 7 stops. The operation in which this is repeated is called alternate operation. Further, when a large number of discharge faucets 11 are opened and a large amount of water is used, both the first pump 6 and the second pump 7 operate, and parallel operation is performed. These controls are performed by the control box 8. The first pump 6 and the second pump 7 having the same performance are generally used. The pump device 5 is used for repairing the first pump 6 and the second pump 7,
If the maintenance and inspection are not performed in a short time, many discharge faucets 11 cannot be used during that time.

The first pump 6 or the second pump 7 of the pump device 5 is configured as shown in FIGS. A rotary shaft 22 is projected from a bracket 23 that constitutes one side surface of the electric motor 21. An impeller shaft 37, which constitutes a part of the rotating part of the impeller unit 15, is screwed and attached to the tip of the rotating shaft 22. The shaft sealing device 24 is interposed between the bracket 23 and the impeller shaft 37 that constitutes a part of the impeller unit 15 on the rotating portion side. On the fixed portion side of the impeller unit 15, packing 3 is provided between the housing 31 and the bracket 23.
Held through 9,40.

The impeller unit 15 will be described. A disk portion 37a is formed at one end of the tubular portion 37b of the impeller shaft 37, and
The step impeller 26 comes into surface contact with the rear shroud to reduce the runout. A threaded portion 37c is formed on the outer circumference of the multi-end portion of the tubular portion 37b, and a nut 38 is screwed onto the threaded portion 37c. The flat portion 37 is provided on the outer peripheral surface of the tubular portion 37b.
d (Fig. 2) is formed, and the fitting portion 26 of the second stage impeller 26 is formed.
b and the fitting holes 30b of the first-stage impeller 30 are fitted in a shape that matches the rotational force of the impeller shaft 37,
I am going to tell 27. A guide portion 37e and a screw portion 37f for screwing and fixing the rotary shaft 22 are formed on the inner circumference of the tubular portion 37b. The second stage guide blade 27
The discharge water guide vane portion 27a of the second-stage impeller 26 is provided on one side thereof.
Is formed, a water passage 27b for guiding the discharge water of the first-stage impeller 30 to the suction side of the second-stage impeller 26 is formed on the other side, a guide pin 27d is formed on one side of the outermost periphery, and a partition wall is formed on the other side. A guide cylinder portion 27c for coaxially fitting the plate 28 and the first stage guide blade 29 is formed, and a circular hole 27e is formed in the center. The spacer 44 is formed with a disk portion 44a that comes into surface contact with the rear surface shroud 30a of the first-stage impeller 30. The partition plate 28 has a water passage 28a for communicating the discharge water from the first-stage guide blade 29 with the water passage 27b of the second-stage guide blade 27, a circular hole 28b formed at the center, and an axially extending projection on the outer periphery. An appropriate number of 28c are formed. A circular hole 29a is formed in the center of the first-stage guide blade 29, and an appropriate number of projections 29b extending in the axial direction are formed on the outer circumference. The holding plate 25 is a protrusion 25 that extends in the axial direction on the outer circumference.
a is formed.

Thus, when assembling the impeller unit 15, the impeller shaft 37 is fitted with the second-stage impeller 26. Next, a second-stage guide vane 27 is arranged so as to surround the second-stage impeller 26, and a partition plate is provided in the guide cylindrical portion 27c of the second-stage guide vane 27 so as to be concentric with the second-stage guide vane 27. Protrusion 2 on the outer periphery of 28
Fit using 8c. Providing the protrusion 28c can solve the problem of dimensional accuracy even if the separator 28c is made of synthetic resin, and a porous material can be used. If a porous material is used, the weight is reduced and noise can be reduced.
Next, the spacer 44 is fitted to the impeller shaft 37, and the first-stage impeller 30 is also fitted to the impeller shaft 37.
The nut 38 is screwed into the screw portion 37c of the
8 and the disk portion 37a of the impeller shaft 37, the first-stage impeller 3
0, the spacer 44, and the second-stage impeller 26 are sandwiched therebetween, and these constitute the rotating part of the impeller unit 15. Then, the guide cylindrical portion 27c of the second-stage guide vane 27 is arranged so that the first-stage guide vane 29 surrounds the first-stage impeller 26.
The outer peripheral projection 29 is used for fitting. Further, the pressing plate 25 is moved to the second position via the guide pin 27d of the second-stage guide blade 27.
The first guide blade 29, the partition plate 28, and the second guide blade 2 are contacted with the second guide blade 27 while the through guide 42 is abutted.
7 are arranged so as to pass through, and the thread guide 42 and the pressing plate 25 are fixed by machine screws 43 so that the rotating portion and the fixed portion of the impeller unit 15 are combined with each other. The impeller unit 15 is configured.

The second guide blade 27, the partition plate 28, and the first guide blade 29 are fitted to each other by the guide cylindrical portion 27 of the second guide blade 27.
Although it is performed via c, the partition wall 28 or the first stage guide vane 29 may be provided with a guide cylindrical portion. Further, the pressing plate 25 can be omitted.

When the electric motor 21 is energized and the rotating shaft 22 is rotated, the first-stage impeller 30 and the second-stage impeller 26 rotate, and the frame 3
The first-stage impeller 30
Then, the pressure is increased by way of the water passage 28a to reach the water passage 27b, and the pressure is further increased by the second stage impeller 26 so that predetermined pumping can be performed.

According to such a multi-stage pump, in the multi-stage pumps 6 and 7 in which a plurality of impellers 26 and 30 and guide vanes 27 and 29 are arranged in the axial direction, the impellers 26 and 30 are attached to the impeller shaft 37 to form a rotating portion. And guide vanes 27, 29
The impeller unit 15 is formed by combining the rotating part and the fixing part by connecting the parts to each other, and the impeller shaft 37 is attached to the rotating shaft 22 of the electric motor 21. The unit 15 can be removed from the rotary shaft 22 by one operation, and maintenance and inspection can be performed at a convenient place.

Further, since the partition wall plate 28 made of a porous material having the water passage 28a is interposed between the guide blades 27, 29 to connect the guide blades 27, 29, it is possible to reduce the weight and reduce the noise.

Further, a disk portion 37a is formed at one end of the impeller shaft 37,
The rear shroud 26a of the second-stage impeller 26 is mounted on the disc portion 37a so that the rear shroud 26a of the second-stage impeller 26 is in surface contact, and the spacer 44 is interposed between the first-stage impeller 30 and the second-stage impeller 26. The disk part 44a of the first stage impeller 30
Since the rotor shroud 30a is formed so as to be in surface contact with the rear shroud 30a and the rotating portion is formed including the spacer 44, both impellers 26,
The shake of 30 can be suppressed, and the impellers 30 and 26 can be shared.

〔The invention's effect〕

As described above, according to the present invention, the impeller unit is downsized to reduce the size of the entire apparatus, and the key groove and key are not required to improve the productivity, and the impeller unit is detached from the electric motor. Since maintenance and inspection of the impeller unit can be performed in this state, the rear surface shroud of the second-stage impeller comes into surface contact with the disc portion of the impeller shaft, and the spacer is Since the rear shroud of the first-stage impeller is in surface contact, a multi-stage pump capable of suppressing the runout of the first-stage impeller and the second-stage impeller was obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a multistage pump of the present invention, FIG. 2 is an exploded perspective view of the multistage pump, FIG. 3 is a cross sectional view of an impeller unit used in the multistage pump, and FIG. It is an installation explanatory view. 6, 7 ... Pump, 15 ... Impeller unit, 21 ...
Electric motor, 22 ... Rotary shaft, 26 ... Second stage impeller, 26
a: rear shroud, 27: second stage guide vane, 28
...... Partition plate, 29 ...... 1st stage guide blade, 30 ...... 1st stage impeller, 30a ...... Rear shroud, 31 ...... Housing, 3
7 ... Impeller shaft, 37a ... Disk part, 44 ... Spacer.

Claims (1)

[Claims] 1. A multi-stage pump in which a first-stage guide vane and a first-stage impeller and a second-stage guide vane and a second-stage impeller are sequentially arranged in an axial direction, and a circle is provided at one end of one impeller shaft. A plate portion is formed so that the rear shroud of the second-stage impeller comes into surface contact with the disc portion.
The second stage impeller is attached to a flat portion formed on the impeller shaft, and a spacer interposed between the first stage impeller and the second stage impeller is a rear surface of the first stage impeller. By attaching the first-stage impeller to a flat portion formed on the impeller shaft so as to make surface contact with the shroud, the impeller shaft, the both impellers, and the spacer become one rotating portion, and The first and second step guide vanes are connected to each other to form one impeller unit as one fixed portion, and the impeller shaft that constitutes the impeller unit is screwed to a rotary shaft of an electric motor, and A multi-stage pump characterized in that a fixing part is fixed to a bracket forming a fluid path and a housing.