JPH0448958B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a self-priming pump that retains self-priming water necessary for restarting the pump next time after the pump has stopped operating.

[Prior art]

In self-priming pumps, a siphoning cut mechanism is provided in order to save the effort of injecting priming water when operating the pump, and to secure the self-priming water necessary for restarting the pump next time after the pump has stopped operating.

Various structures have been proposed for this type of self-priming pump. One of them is that a suction chamber and a discharge chamber are separated by a partition wall in the main body, and a vortex chamber is formed by communicating with the lower part of both chambers. An impeller is installed in the vortex chamber, and a back blade is provided on the top surface of the impeller, and a rotary disk provided around the impeller is placed in the gap between the bottom plate of the main body and the partition plate provided above the vortex chamber. A self-priming pump has been proposed in which a shaft seal gap with a U-shaped cross section is formed.

In the self-priming pump configured as described above, the siphon cut mechanism that interrupts the backflow of water that occurs from the discharge chamber to the suction chamber via the vortex chamber due to siphon action when the pump stops operating is a siphon cut mechanism that partitions the suction chamber and discharge chamber. Some have siphon-acting cut holes in the upper part of the partition wall that communicate the suction chamber and the discharge chamber.

With this pump, when you stop pump operation,
Due to the siphon action, water flows back from the discharge chamber to the suction chamber via the vortex chamber, lowering the water level in the discharge chamber and exposing the siphon cut hole to the water surface. Air enters and floats to the suction port, which is the highest point in the pump, interrupting the water flow (cutting the siphon effect).In this way, the water remaining below the siphon cut hole is removed from the pump next time. It is used for self-priming water when restarting operation.

During pump operation, the rotary disk of the impeller rotates into the shaft seal gap, which has a U-shaped cross section, and the centrifugal force generated by the rotation of the back blade and rotary disk fills the shaft seal gap with high-pressure water, causing the impeller to move. It provides a sealing effect by preventing air from entering from the attached rotating shaft side.

[Problem to be solved by the invention]

However, as mentioned above, when a siphoning cut hole is provided in the partition wall that separates the discharge chamber and suction chamber to communicate the two chambers, at the beginning of the next pump operation, that is, during self-priming, A portion of the water mixed with air flowing in the discharge chamber flows back into the suction chamber where the pressure is low, and the water helps the self-priming action, but the air hinders the self-priming action.

In addition, even after the pump starts normal operation, a small amount of water continues to flow back from the discharge chamber to the suction chamber through the siphon cut hole due to the pressure difference between the discharge chamber and the suction chamber, which reduces pump efficiency. become the cause.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a self-priming pump with high pump efficiency that can secure a sufficient amount of self-priming water necessary for restarting the operation of the pump.

[Means to solve the problem]

The gist of the present invention to achieve the above object is that a casing is integrally connected to the lower part of the main body in which a suction chamber and a discharge chamber are formed, and the suction chamber and the discharge chamber are communicated between the main body bottom plate and the casing. A vortex chamber is provided in the vortex chamber, an impeller having a pumping blade and a back blade is arranged in the vortex chamber, and a rotary disk provided around the outer periphery of the impeller is installed in the gap between the bottom plate of the main body and a partition plate provided at the top of the vortex chamber. In a self-priming pump having a shaft seal gap with a U-shaped cross-section facing the discharge chamber, the lower end communicates with the vortex chamber and the upper end opens at the upper part of the discharge chamber, and the flowing water from the vortex chamber is connected to the discharge port. A guide path is defined to guide the water to the vicinity, and a siphoning cut hole is provided in the upper part of the circumferential wall of the vortex chamber so that the suction chamber and the vortex chamber communicate with each other in a tangential direction of the vortex chamber, which is opposite to the flowing water in the vortex chamber. The feature is the self-priming pump.

[Operation] During pump operation, water flowing from the vortex chamber is guided near the discharge port by a guide path defined in the discharge chamber and is discharged from the discharge port.

When the pump stops operating and the impeller stops, water flows back from the guideway to the suction chamber via the vortex chamber due to siphon action, and the water level in the guideway drops to the vortex chamber, causing the siphon action cut hole. When exposed to the water surface, air enters the flowing water filling the suction chamber through this siphoning cut hole, cutting off the siphoning effect. In this way, the water remaining in the pump is used as self-priming water when the pump resumes operation next time.

〔Example〕

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

FIG. 1 is a schematic partial sectional view of a self-priming pump of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a sectional view taken along line BB in FIG. 1.

In the figure, 1 is a main body, and in this main body 1 there is a suction chamber 3 having a suction port 2 by a partition wall 1a,
A discharge chamber 5 having a discharge port 4 is partitioned.

A casing 6 is integrally connected to the lower part of the main body 1. A vortex chamber 7 is formed between the casing 6 and the bottom plate 1b of the main body, and a suction chamber is formed below the vortex chamber 7 in the casing 6 by a partition wall 6a. A lower chamber 3a of No. 3 and a lower chamber 5a of discharge chamber 5 are partitioned.

8 is an impeller arranged in the vortex chamber 7, and this impeller 8 is connected to the rotating shaft 10 of the motor 9 mounted on the upper part of the main body 1.
The impeller 8 is attached to the pumping blade 8a and the back blade 8.
b, and a rotary disk 8c is provided around the impeller 8, and this rotary disk 8c is located at the upper part of the vortex chamber 7, facing the gap between the partition plate 11 which is provided to protrude into the vortex chamber 7, and the main body bottom plate 1b. This forms a shaft sealing gap 12 having a U-shaped cross section. The lower central portion 8d of the impeller 8
is in communication with the lower chamber 3a of the suction chamber 3.

13 communicates the inside of the suction chamber 3 and the whirlpool chamber 7 to form the whirlpool chamber 7.
A siphoning cut hole 13 is provided in the upper part of the circumferential wall, and the siphoning cut hole 13 is oriented tangentially to the vortex chamber 7, against the water flow flowing in the vortex chamber 7.

Reference numeral 14 denotes a guide path defined in the discharge chamber 5 by a partition wall 5b, whose lower end communicates with the vortex chamber 7, and whose upper end is opened 14a above the discharge chamber 5, and which directs the water flow from the vortex chamber 7 to the discharge port. 4, and together with the siphon cut hole 13 constitutes a siphon cut mechanism.

Reference numeral 15 denotes a rectifying plate provided at an intermediate position of the discharge chamber 5 outside the guide path 14, which has a large number of rectifying holes and divides the inside of the discharge chamber 5 into upper and lower parts.

Reference numeral 16 denotes a lower chamber 5a of the discharge chamber 5, which is a self-priming hole that communicates with the inside of the vortex chamber 7 and is provided in the lower wall of the vortex chamber 7.

In addition, 17 in the figure is a guide path defined by the partition wall 3b in the suction chamber 3, and this guide path 17 is for guiding the flowing water from the suction port 2 to the lower chamber 3a of the suction chamber 3. , the upper part of the guideway 17 communicates with the suction chamber 3 through a through hole 17a provided in the partition wall 3b, and the guideway 17
The lower part is an opening 17b provided in the partition wall 3b and the suction chamber 3
is connected to.

The operation of the above configuration will be described with reference to FIGS. 4 to 7.

When operating the pump for the first time, self-priming water (priming water) is injected into the pump. (See Figure 4) When the impeller 8 rotates when the motor 9 is started, water in the suction chamber 3 is sucked into the vortex chamber 7 from the lower chamber 3a and pressurized, and then flows through the guide path 14 into the discharge chamber 5. leaks to. The self-suction water in the suction chamber 3 decreases and the suction chamber 3
When the pressure in the suction chamber 3 decreases and the water level in the suction chamber 3 drops to the lower part of the vortex chamber 7, the air in the suction chamber 3 is mixed with the self-suction water and sucked into the vortex chamber 7 together. , and the pressure in the suction chamber 3 further decreases. During this self-priming, some of the self-priming water in the discharge chamber 5 is absorbed into the self-priming hole 1.
6 into the vortex chamber 7 to help the self-priming effect.
(See Figure 5) As the pressure in the suction chamber 3 decreases due to self-priming, water will eventually be sucked in from the suction port 2, and the air in the suction chamber 3 will disappear, filling the pump with water. Start normal operation. Here, the water flowing from the vortex chamber 7 flows through the guide path 14 and is guided to near the discharge port 4. (See FIG. 6) Next, when the motor 9 is stopped and the impeller 8 is stopped, water flows back from the discharge chamber 5 to the suction chamber 3 via the vortex chamber 7 due to the siphon effect.

At this time, in the discharge chamber 5, water in the guide path 14 whose lower end communicates with the vortex chamber 7 passes through the vortex chamber 7 to the suction chamber 3, and the water level in the guide path 14 decreases. When this water level drop reaches the vortex chamber 7 and the siphoning cut hole 13 is exposed to the water surface, air enters the flowing water filling the suction chamber 3 upward through the siphoning cut hole 13, causing the suction port It floats to two parts and the water flow is interrupted. That is, the siphon effect is cut off. During this time, some of the water remaining in the discharge chamber 5 outside the guideway 14 escapes to the vortex chamber 7 through the self-priming hole 16, but the size of the self-priming hole 16 is determined by the cross-sectional area of the guideway 14. Since it is extremely small compared to the self-priming hole 16, the amount of water that escapes through the self-priming hole 16 is extremely small. (Refer to Fig. 7) In this way, immediately after the siphon effect is cut, water that reaches almost the vicinity of the suction port 2 remains in the suction chamber 3, and water that reaches almost the vicinity of the suction port 2 remains in the discharge chamber 5 outside the guideway 14 and almost reaches the discharge port 4.
Water that reaches the vicinity remains, and water remains in the vortex chamber 7 below the siphoning cut hole 13, and this water gradually eliminates the water level difference and becomes self-priming water that will be used for the next restart of pump operation. Become.

〔Effect of the invention〕

According to the self-priming pump of the present invention configured as described above, the following effects are achieved.

(1) At the time of siphon action cutting, the water in the guide path defined in the discharge chamber drains out and cooperates with the siphon action cut hole to cut the siphon action.
Due to the siphon effect, the amount of water flowing out from inside the pump is reduced, leaving a large amount of water inside the pump, which is effectively used as self-priming water for the next pump operation.

(2) During siphon action cutting, the water level in the vortex chamber does not fall below the siphon action cut hole provided on the upper part of the vortex chamber peripheral wall, so a large amount of water remains in the vortex chamber, making it sufficient for self-suction. The amount of water can be secured.

(3) The siphon effect cut holes face the water flow flowing into the vortex chamber during pump operation, so the water in the vortex chamber does not flow back into the suction chamber during pump operation, and the siphon effect is prevented during pump operation. The presence of cut holes does not affect pump efficiency.

(4) The guide path defined in the discharge chamber guides the flowing water from the vortex chamber to the vicinity of the discharge port during pump operation, so there is almost no dynamic influence on the water filling the discharge chamber outside the guide path. This also improves pump efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic partial cross-sectional view of a self-priming pump of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1, and FIG. 7 to 7 are operation explanatory diagrams. 1...Main body, 2...Suction port, 3...Suction chamber, 4
...Discharge port, 5...Discharge chamber, 6...Casing,
7... Vortex chamber, 8... Impeller, 9... Motor, 10
...rotating shaft, 11 ... partition plate, 12 ... shaft sealing gap, 13 ... siphon action cut hole, 14 ... guideway, 15 ... rectifier plate, 16 ... self-priming hole.

Claims (1)

[Claims] 1. A casing is integrally connected to the lower part of the main body where a suction chamber and a discharge chamber are formed, a vortex chamber is provided between the main body bottom plate and the casing by communicating the suction chamber and the discharge chamber, and a pumping vane and a back vane are installed in the vortex chamber. A shaft sealing gap having a U-shaped cross section is formed by disposing an impeller having a rotary disk provided on the outer periphery of the impeller and facing the gap between the bottom plate of the main body and a partition plate provided at the upper part of the vortex chamber. In the suction type pump, a guide path is defined in the discharge chamber, the lower end of which communicates with the vortex chamber, and the upper end of which opens above the discharge chamber to guide flowing water from the vortex chamber to the vicinity of the discharge port, and the guide path is connected to the suction chamber. A self-priming pump characterized in that a siphoning cut hole is provided in the upper part of the circumferential wall of the vortex chamber in a direction tangential to the vortex chamber, which is opposite to the inflowing water in the vortex chamber.