JP2018100603A - Centrifugal pump - Google Patents

Abstract

A centrifugal pump that suppresses occurrence of a short circuit and suppresses adhesion of impurities to an electric motor. A centrifugal pump (10) includes a blade (3) having a plurality of blades (3a) disposed on a peripheral portion of a disk (3b), a shaft (4a), an electric motor (4) for rotating the blade (3) attached to the shaft (4a), and a fluid (A). The suction port 1 for sucking in and the blowout port 2 for blowing out the fluid A are provided, the blade 5 is surrounded with the back surface 5a facing the disk 3b, and the fluid A sucked from the suction port 1 by the rotation of the blade 3 is supplied to the blowout port 2. The back surface 5a of the casing 5 has the same position as the peripheral edge of the disk 3b in the axial direction of the shaft 4a of the edge 5d of the portion 5c that does not overlap the disk 3b. It is closer to the tip of the shaft 4a than the periphery. [Selection] Figure 2

Description

  The present invention relates to a centrifugal pump that feeds fluid by centrifugal force generated by rotation of an impeller.

  As disclosed in Patent Document 1, a centrifugal pump includes a multi-blade fan type in which a blade having a plurality of blades arranged on a peripheral portion of a disk is rotated in a scroll casing. In a multiblade fan type centrifugal pump, power consumption and noise increase unless the fluid is sucked efficiently from the suction. Therefore, there has been a disk opening type in which an opening for ventilation or water flow is provided in the disk, and the fluid that has turned around the disk is blown out again.

Japanese Utility Model Publication No. 60-22258

  However, in a conventional disk-opening centrifugal pump, a so-called short circuit state occurs in which a part of the blown-out fluid turns to the back surface, and efficiency is lowered. There is also an electric motor for rotating the blades on the back side. Impurities contained in the fluid, for example, oil smoke and dust contained in the air adhere to the motor surface and disturb the heat dissipation of the electric motor. As a result, the service life of the centrifugal pump is shortened and the centrifugal pump is shortened.

  The present invention has been made in view of the above, and an object of the present invention is to provide a centrifugal pump that suppresses the occurrence of a short circuit and suppresses adhesion of impurities to the electric motor on the back surface.

  In order to solve the above-described problems and achieve the object, the present invention includes a blade having a plurality of blades arranged on the peripheral edge of a disk, a motor having a shaft, and rotating the blade attached to the shaft, A suction port for sucking fluid and a blow-out port for blowing out the fluid are provided, and the casing surrounds the blade with the back face facing the disk, and a casing for guiding the fluid sucked from the suction port by the rotation of the blade to the blow-out port. In the rear surface of the casing, the position along the axial direction of the shaft at the edge of the portion that does not overlap the disk is the same as the periphery of the disk, or closer to the tip of the shaft than the periphery of the disk.

  According to the present invention, it is possible to provide a centrifugal pump that suppresses the occurrence of a short circuit and suppresses the adhesion of impurities to the motor on the back surface.

The top view of the centrifugal pump which concerns on Embodiment 1 of this invention Sectional drawing of the centrifugal pump which concerns on Embodiment 1. FIG. Sectional drawing of the centrifugal pump which concerns on Embodiment 2 of this invention Sectional drawing of the centrifugal pump which concerns on Embodiment 3 of this invention.

  Below, the centrifugal pump which concerns on embodiment of this invention is demonstrated in detail based on drawing. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a plan view of a centrifugal pump according to Embodiment 1 of the present invention. 2 is a cross-sectional view of the centrifugal pump according to the first embodiment, showing a cross section taken along line II-II in FIG. The centrifugal pump 10 according to the first embodiment includes a blade 3 having a plurality of blades 3a disposed on a peripheral portion of a disk 3b, a motor 4 having a shaft 4a, and rotating the blade 3 attached to the shaft 4a. It has a suction port 1 for sucking fluid A and a blow-out port 2 for blowing out fluid A, and a casing 5 for guiding the fluid A sucked from the suction port 1 to the blow-out port 2 when the blade 3 rotates. The fluid A is blown out from the suction port 1 through the blades 3 in the circumferential direction of the blades 3, and is blown out from the blowout port 2 provided in a part of the casing 5.

  The position of the back surface 5a of the casing 5 along the axial direction of the shaft 4a at the edge 5d of the portion 5c that does not overlap the disk 3b is the same as the periphery of the disk 3b. Since the fluid A exiting from the blade 3 in the radial direction is blown out along the back surface 5 a of the casing 5, the flow of the fluid A around the back surface of the blade 3 is eliminated. Or even if the flow of the fluid A which rotates around the back surface of the blade 3 is generated in the casing 5, it is pushed back by the flow of the fluid A blown out from the blade 3.

  The reason why the gap is provided between the disk 5 b and the portion 5 b that overlaps the disk 3 b on the back surface 5 a of the casing 5 is to avoid contact between the blade 3 and the casing 5.

  According to the centrifugal pump 10 according to the first embodiment, since the flow of the fluid A that rotates around the back surface of the blade 3 is eliminated, the blowout is efficiently performed from the suction, and impurities are not easily attached to the electric motor 4. Therefore, the centrifugal pump 10 according to Embodiment 1 can suppress an increase in the amount of operating power and noise, and can extend the life. Thus, the centrifugal pump 10 according to the first embodiment can suppress the occurrence of a short circuit and suppress the adhesion of impurities to the electric motor on the back surface.

Embodiment 2. FIG.
FIG. 3 is a cross-sectional view of the centrifugal pump according to the second embodiment of the present invention, and shows a cross section corresponding to a cross section taken along the line II-II in FIG. The centrifugal pump 11 according to the second embodiment has a protrusion 6 disposed on the back side of the casing 5.

  In FIG. 3, the protrusion 6 is arrange | positioned in the part 5c of the back surface 5a of the casing 5 which does not overlap with the disk 3b. The tip 6 a of the protrusion 6 forms an edge 5 d of a portion 5 c that does not overlap the disk 3 b on the back surface 5 a of the casing 5. The position of the tip 6a of the protrusion 6 along the axial direction of the shaft 4a is the same position as the periphery of the disk 3b, and the protrusion 6 has a ring shape to surround the periphery of the blade 3. Also in the centrifugal pump 11 according to the second embodiment, as in the first embodiment, the fluid A that has come out from the blade 3 in the radial direction is blown along the upper surface of the protrusion 6 and flows around the rear surface of the blade 3. The flow of is lost. Alternatively, even if the flow of the fluid A rotating around the back surface of the blade 3 occurs in the casing 5, the direction is changed upward by the protrusion 6, and then pushed back by the flow of the fluid A blown from the blade 3. At this time, the back surface 5a of the casing 5 has a simple planar shape, and the casing 5 is formed with a simple structure, so that the manufacturing cost can be suppressed. Moreover, since the protrusion 6 should just be additionally arranged in the ready-made casing 5, it can apply to a ready-made product, without newly producing the casing 5. FIG.

  As described above, according to the centrifugal pump 11 according to the second embodiment in which the protrusions 6 are added, the same effect as the centrifugal pump 10 according to the first embodiment can be utilized at low cost and in a short period by diverting an existing product. It is feasible.

Embodiment 3 FIG.
FIG. 4 is a cross-sectional view of the centrifugal pump 12 according to Embodiment 3 of the present invention, and shows a portion corresponding to the IV portion surrounded by a broken line frame in FIG. In the centrifugal pump 12 according to the third embodiment, the blowing direction of the fluid A on the back side of the blade 3 is inclined in the opposite direction.

  In Embodiment 3, the disk 3b of the blade 3 is inclined in the direction away from the back surface 5a at the peripheral edge, and the blowing direction of the fluid A from the blade 3 is from the back surface 5a along the inclination of the peripheral edge of the disk 3b. The direction is to leave. Therefore, as shown in FIG. 4, the position along the axial direction of the shaft 4a of the tip 6a of the protrusion 6 is located on the tip of the shaft 4a from the peripheral edge of the disk 3b and does not collide with the flow of the fluid A Can be. For this reason, even if the height dimension of the protrusion 6 or the mounting position dimension of the blade 3 varies, the fluid A surely blows out along the upper surface of the protrusion 6, and the flow of the fluid A that rotates around the rear surface of the blade 3 by the protrusion 6. It can be lost.

  As described above, the centrifugal pump 12 according to the third embodiment has the centrifugal pump 10 according to the first embodiment or the second embodiment because the blowing direction of the fluid A on the back side of the blade 3 is inclined in the opposite direction. It is possible to obtain the centrifugal pump 12 having the same effect as the centrifugal pump 11 according to the present invention with high reliability.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

  1 suction port, 2 outlet port, 3 blades, 3a wing, 3b disk, 4 motor, 4a shaft, 5 casing, 5a back surface, 5b portion overlapping the disk, 5c portion not overlapping the disk, 5d edge, 6 protrusion, 6a tip Part 10, 11, 12 Centrifugal pump.

Claims (3)

A blade having a plurality of wings arranged on the periphery of the disk;
An electric motor having a shaft and rotating the blades attached to the shaft;
A casing comprising a suction port for sucking fluid and a blow-out port for blowing out the fluid, and enclosing the blade with a back surface facing the disk, and guiding the fluid sucked from the suction port by rotation of the blade to the blow-out port And
The rear surface of the casing has a position along the axial direction of the shaft at the edge of the portion that does not overlap with the disk, or is closer to the tip of the shaft than the periphery of the disk. A centrifugal pump characterized by being. The casing includes a protrusion on a portion of the back surface that does not overlap the disk,
The centrifugal pump according to claim 1, wherein a tip portion of the protrusion forms an edge of a portion of the back surface of the casing that does not overlap with the disk.   3. The centrifugal pump according to claim 1, wherein the disk is inclined in a direction in which the peripheral edge portion is separated from the back surface of the casing.

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