JPH0435639B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a self-priming or non-self-priming centrifugal pump.

[Conventional technology]

FIG. 3 shows an example of a conventional self-priming centrifugal pump.

In this figure, 1 is a housing, 2 is a cover fixed to one side of the housing 1 by means of bolts, etc., and a shaft 4 is driven by a motor (not shown) through a bearing 3 provided on the cover 2. The shaft 4 is supported and kept watertight by a mechanical seal 5, and an impeller 6 is fixed to the inner end of the shaft 4.

A casing 7 surrounds the impeller 6, and a spiral chamber 8 surrounding the outer periphery of the impeller 6 is formed on its inner periphery. FIG. 4 is a perspective view of the casing 7,
9 is a discharge port at the end of the swirl chamber 8. In addition, the spiral chamber 8
A communication hole 10 for self-priming circulating water is provided in the middle.

Inside the housing 1 is a water storage chamber 12, and the communication hole 10 communicates the lower part of the water storage chamber 12 with the swirl chamber 8. On the other side of the housing 1 is a check valve 1.
A suction pipe connection port 15 having a diameter of 4 is provided, and this connection port 15 and a suction port 16 at the center of the casing 7 are communicated through a communication passage 17 integral with the housing 1. Further, a pumping pipe connection port 18 is provided in the upper part of the housing 1.

In the case of this conventional self-priming pump, water stored in the water storage chamber 12 and the casing 7 is circulated through the communication hole 10 by the rotation of the impeller 6, thereby performing a self-priming action.

[Problem that the invention seeks to solve]

In the conventional pump as described above, the swirl chamber 8 is provided so as to surround the outer periphery of the impeller 6. Therefore, the outer diameter of the pump casing 7 is larger than the outer diameter of the impeller 6 by the addition of the radial width of the volute chamber 8. It becomes considerably large, and the pump itself becomes large.

Further, in the case of a turbine pump in which a swirl chamber having guide vanes is provided around the outer periphery of the impeller, there is a similar problem in that the entire pump is large and heavy compared to the diameter of the impeller.

[Means for solving problems]

In order to solve the above problems, the present invention makes the impeller in the casing of a centrifugal pump an open type, and also provides an outer peripheral wall of the casing close to the outer periphery of the impeller. A slight gap is provided between the inner circumferential surface of the outer circumferential wall and the outer circumferential surface of the impeller to allow rotation of the impeller, and the side wall of the casing is placed outside along the outer circumference of the open side of the impeller. The outer diameter of the pump is made to match the outer diameter of the impeller as much as possible by expanding the outer diameter of the pump toward the outer diameter of the impeller by expanding it toward the outer circumference of the impeller. It's a close one.

〔Example〕

In the embodiment shown in FIG. 1, 21 is a housing, 22 is a cover fixed to one side of the housing 21 by means of bolts, etc.
A bearing 23 provided at 2 supports a shaft 24 driven by a motor (not shown), and a mechanical seal 25 maintains watertightness. Also,
An open type impeller 26 having a shroud on one side is fixed to the inner end of this shaft 24.

27 is a casing provided on the side of the impeller 26, and its outer peripheral wall is attached to the impeller 26 as shown in FIG.
There is only a small gap between the inner peripheral surface of the peripheral wall of the casing 27 and the outer peripheral surface of the impeller 26 to allow rotation of the impeller 26, and the side wall of the casing 27 is A spiral chamber 28 that gradually bulges outward along the outer periphery of the impeller 26 and communicates with the outer periphery of the impeller 26 on the open side.
is formed.

FIG. 2 is a perspective view of the casing 27,
29 is a discharge port at the end of the swirl chamber 28. Further, a communication hole 30 for self-priming circulating water is provided in the middle of the swirl chamber 28.

The inside of the housing 21 becomes a water storage chamber 32, and the communication hole 30 connects the lower part of this water storage chamber 32 to the spiral chamber 2.
It leads to 8. A suction pipe connection port 35 having a check valve 34 is provided on the other side of the housing 21, and this connection port 35 and the suction port 36 at the center of the casing 27 are communicated through a communication passage 37 integrated with the housing 21. . Further, a pumping pipe connection port 38 is provided in the upper part of the housing 21.

In the case of the self-priming pump of this embodiment as well, the water stored in the water storage chamber 32 and the casing 27 circulates through the communication hole 30 due to the rotation of the impeller 26, thereby performing a self-priming action.

In this way, self-priming action is performed, and when pumping starts, the pumped water is turned by the impeller 26 and discharged outward by centrifugal force, collides with the inner surface of the peripheral wall of the casing 27, changes direction almost at right angles, and enters the spiral chamber. 28 converts the velocity energy into pressure energy, which is then discharged from the discharge port 29.

Although the above embodiment shows a self-priming pump, there are also non-self-priming pumps, that is, pumps that do not have a water storage chamber and require priming water for operation. In the case of a pump, the communication hole 30 of the casing 27 is eliminated, and the suction port 36 of the casing 27 is removed.
Since the suction pipe is directly connected to the casing 27 and the pumping pipe is connected to the discharge port 29 of the casing 27, it becomes even more compact and lightweight.

〔effect〕

In this invention, as described above, the vortex chamber provided in the casing is provided near the outer periphery of the open side of the open type impeller, so it is different from conventional pumps in which the guide means is provided on the outer periphery of the impeller. In comparison, the outer diameter of the casing can be reduced to the minimum necessary, which is equal to the outer diameter of the impeller plus some play and wall thickness of the casing, thereby providing a small and lightweight centrifugal pump.

In addition, in the centrifugal pump of this invention, the water that is rotated inside the casing and discharged outward at high speed due to centrifugal force collides with the inner surface of the peripheral wall of the casing, and the velocity energy is converted into pressure energy and the water is turned at right angles while becoming high pressure. Since the flow changes direction and flows into the vortex chamber, high performance can be achieved despite the small size.

In addition, as a result of operating a conventional type centrifugal pump having an impeller of the same diameter and shape and the type of centrifugal pump of the present invention under the same conditions and measuring their performance, it was found that the pump of the present invention was superior to the conventional type. It was found that although the pump was much smaller, it was able to achieve almost the same performance as conventional pumps.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing one embodiment of the pump of the present invention, FIG. 2 is a perspective view of the same casing,
FIG. 3 is a vertical side view showing an example of a conventional pump;
FIG. 4 is a perspective view of the casing same as above. 26... impeller, 27... casing, 28...
...A spiral chamber as an example of a guiding means.

Claims (1)

[Claims] 1. In a centrifugal pump in which a casing housing an impeller is provided with a spiral chamber, the impeller is of an open type, and the outer peripheral wall of the casing is provided close to the outer periphery of the impeller, thereby making the casing more compact. A slight gap is provided between the inner circumferential surface of the outer circumferential wall and the outer circumferential surface of the impeller to allow rotation of the impeller, and the side wall of the casing is placed outside along the outer circumference of the open side of the impeller. The outer diameter of the pump is made to match the outer diameter of the impeller as much as possible by expanding the outer diameter of the pump toward the outer diameter of the impeller by expanding it toward the outer circumference of the impeller. A centrifugal pump characterized by its close proximity.