Centrifugal pump

Abstract

To provide an efficient centrifugal pump.SOLUTION: A centrifugal pump 1 includes: an impeller 7; a pump casing 3 which encloses the impeller 7 and has a suction port 4 and a discharge port 5; and a motor 2 configured to rotate the impeller 7. The pump casing 3 has a water passage 3a through which water flows from the suction port 4 into the impeller 7. The centrifugal pump 1 has a rectifier tube 12 for flowing water smoothly at the inner side of the suction port of the impeller 7. Accordingly, the centrifugal pump is obtained that inhibits occurrence of turbulence of water flow when water flows thereinto.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a centrifugal pump. [Background technology]

[0002] A centrifugal pump is known that rotates a disk-shaped impeller disposed inside a pump casing and connected to a rotating shaft of a motor to discharge water drawn in through a suction port radially outward (see, for example, Patent Document 1). A conventional centrifugal pump 101 includes a pump casing 102 and a motor 103. The power of the motor 103 is transmitted to an impeller 104 disposed inside the pump casing 102 through a rotating shaft, causing the impeller 104 to rotate and generate a water flow. In this case, the impeller 104 is generally fixed to the rotating shaft with bolts and nuts 105. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7161341 Summary of the Invention [Problem to be solved by the invention]

[0004] In such conventional centrifugal pumps, a minute gap is provided between the impeller and the pump casing, and water flows into the gap, resulting in a problem of reduced pump efficiency.

[0005] SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems of the conventional art, and aims to provide an efficient centrifugal pump with a structure that allows water flowing in from the suction port to flow smoothly. [Means for solving the problem]

[0006] In order to achieve this object, one aspect of the present invention provides a volute pump comprising an impeller, a pump casing containing the impeller and having an inlet and an outlet, and a motor for rotating the impeller, wherein the pump casing has a water passage through which water flows from the inlet to the impeller, and has a straightening pipe that allows water to flow smoothly inside the inlet of the impeller, thereby achieving the desired object. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an efficient centrifugal pump. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an exploded perspective view of a centrifugal pump according to a first embodiment of the present invention; [Figure 2] Cross-sectional view of the same centrifugal pump [Figure 3] Cross-sectional view of the impeller inside the same centrifugal pump [Figure 4] Schematic diagram showing a conventional pump DETAILED DESCRIPTION OF THE INVENTION

[0009] A centrifugal pump according to one aspect of the present invention is a centrifugal pump including an impeller, a pump casing containing the impeller and having a suction port and a discharge port, and a motor for rotating the impeller, wherein the pump casing has a water passage through which water flows from the suction port to the impeller. The impeller has a flow straightening pipe inside the suction port to allow water to flow smoothly.

[0010] According to this configuration, the flow of water flowing in from the suction port can be rectified, and a highly efficient pump can be provided.

[0011] The flow straightening pipe may have an inner curve having the same curvature as the curve of the impeller.

[0012] This configuration allows the water flowing in from the suction port to flow smoothly, making it possible to provide an efficient pump.

[0013] The flow straightening pipe may overlap the inside of the suction port of the impeller, and the overlap dimension may be the same as the length of the suction port cylindrical portion of the impeller.

[0014] This configuration makes it possible to provide a pump that is efficient and has little loss by preventing water from flowing into minute gaps.

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (Embodiment 1) 1 and 2 show a centrifugal pump according to a first embodiment of the present invention.

[0016] As shown in FIGS. 1 and 2, the centrifugal pump 1 includes a motor 2 and a pump casing 3.

[0017] The pump casing 3 has a suction port 4 and a discharge port 5. The suction port 4 is cylindrical and serves as an inlet through which liquid is drawn into the centrifugal pump 1, while the discharge port 5 serves as an outlet through which the liquid is discharged from the centrifugal pump 1. The pump casing 3 has a water passage 3a that connects the suction port 4 and the discharge port 5.

[0018] The motor 2 has a rotating shaft 6. An impeller 7 is disposed on a protruding portion at one end of the rotating shaft 6 and is fixed with bolts and nuts 8. The impeller 7 is disposed so as to be enclosed within the pump casing 3. The impeller 7 is disposed within the water passage 3a of the pump casing 3.

[0019] The power of the motor 2 is transmitted to the impeller 7 via the rotating shaft 6, causing the impeller 7 to rotate. As the impeller 7 rotates, the water (liquid) sucked in from the suction port 4 is given pressure and velocity energy by centrifugal force and is discharged from the discharge port 5 in the radial outward direction.

[0020] A cooling fan 11 is provided on the protruding portion of the other end of the rotary shaft 6, opposite to one end to which the impeller 7 is fixed. A fan cover 10 is fixed to the motor 2 and covers the cooling fan 11.

[0021] A terminal cover 9 is provided on the top of the motor 2. The terminal cover 9 is fixed to the motor 2.

[0022] The impeller 7 has a plurality of spirally formed cylindrical flow passages 7d defined by a plurality of adjacent vane plates 7a, a front shroud 7b, and a rear shroud 7c. The inner peripheral end of each cylindrical flow passage 7d of the impeller 7 forms an inlet 7e, and the outer peripheral end of each vane plate 7a forms an outlet 7f. The impeller 7 has a cylindrical portion 7h on the side of the suction port 4 of the pump casing 3, i.e., at the inlet 7e of the impeller 7, and has a flow straightening pipe 12 inside the cylindrical portion 7h. The flow pipe 12 has the effect of rectifying the flow of water flowing from the suction port 4 into the impeller 7. In other words, the water that flows in from the suction port 4 of the pump casing 3 flows through the flow passage 7d in the impeller 7 through the flow pipe 12, and is then caused by centrifugal force to flow to the outlet 7f at the end of the outer periphery of the blades 7a. This allows the water that flows in from the suction port 4 to be rectified.

[0023] FIG. 3 shows a perspective view of the rectifier pipe 12 according to this embodiment. As shown in FIGS. 1, 2, and 3, the rectifier pipe 12 is cylindrical with openings on both sides. One open end of the rectifier pipe 12 is fixed within the cylindrical suction port 4 of the pump casing 3. The other open end of the rectifier pipe 12 extends into the cylindrical portion 7h, leaving a small gap between the outer surface of the rectifier pipe 12 and the inner surface of the cylindrical portion 7h. This gap extends from within the flow passage 7d of the impeller 7 to the tip of the cylindrical portion 7h of the impeller 7. Water flowing in from the suction port 4 of the pump casing 3 flows through the rectifier pipe 12 into the flow passage 7d in the impeller 7 and, due to centrifugal force, flows to the outlet 7f at the outer peripheral end of the blade plate 7a, making it difficult for water to flow from the flow passage 7d of the impeller 7 into the gap. As a result, the inflow of water into the minute gap between the impeller 7 and the pump casing 3 can be suppressed.

[0024] Furthermore, the cross-sectional area of ​​the approximately cylindrical hole inside the rectifier tube 12 gradually decreases from both ends toward the center. In other words, when viewed from a direction perpendicular to the central axis of the rectifier tube 12, the inner surface of the rectifier tube 12 is a curved surface that convexes inward. By forming the cross section of the plane including the central axis of the rectifier tube 12 into a shape that includes a curve inside the rectifier tube 12 with the same curvature as the curve of the impeller 7, the water that flows in from the suction port 4 flows along the curve of the impeller 7, and the occurrence of turbulence in the water flow can be suppressed.

[0025] This allows the water flowing in from the suction port 4 to flow smoothly, making it possible to provide an efficient centrifugal pump.

[0026] Furthermore, the flow straightening pipe 12 overlaps the inside of the cylindrical portion 7h of the impeller 7, and the overlap dimension is set to the same dimension as the length of the cylindrical portion 7h of the impeller 7, which makes it more difficult for water to flow from within the flow path 7d of the impeller 7 into the gap between the outer surface of the flow straightening pipe 12 and the inner surface of the cylindrical portion 7h, thereby suppressing water from flowing into the tiny gap between the impeller 7 and the pump casing 3.

[0027] This makes it possible to provide a pump with low loss and high efficiency.

[0028] Although the centrifugal pump according to the present invention has been described above based on the embodiments, the present invention is not limited to these embodiments. As long as they do not deviate from the spirit of the present invention, various modifications that a person skilled in the art can make to the present embodiments and configurations constructed by combining components of different embodiments are also included within the scope of the present invention. [Industrial Applicability]

[0029] The centrifugal pump of the present invention prevents water flowing in from the suction port from flowing into the tiny gap between the impeller and the pump casing, suppressing the occurrence of turbulence in the water flow, allowing the water flowing in from the suction port to flow smoothly, making it effective as an efficient centrifugal pump. [Explanation of symbols]

[0030] 1 Centrifugal pump 2 motors 3 Pump casing 3a waterway 4 Intake port 5 Outlet 6 Rotation Axis 7 impeller 7a Slats 7b Front shroud 7c Rear shroud 7d Flow path 7e Inlet 7f Outlet 7h Cylindrical part 8 bolts and nuts 9 Terminal cover 10 Fan cover 11 Cooling fan 12 Rectifier tube

Claims

1. The impeller and a pump casing containing the impeller and having a suction port and a discharge port; A centrifugal pump including a motor that rotates the impeller, the pump casing has a water passage through which water flows from the suction port to the impeller, A centrifugal pump characterized by having a flow straightening pipe inside the suction port of the impeller to allow water to flow smoothly.

2. 2. The centrifugal pump according to claim 1, wherein the flow straightening pipe has an inner curve having the same curvature as the curve of the impeller.

3. 3. The centrifugal pump according to claim 2, wherein the flow straightening pipe overlaps the inside of the suction port of the impeller, and the overlap dimension is the same as the length of the suction port cylindrical portion of the impeller.

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