Booster pump

Abstract

To provide a booster pump that can ease component accuracy regarding accuracy of gap dimension between an impeller and a housing accommodating the impeller, and is easily assembled.SOLUTION: A biasing member 13 is interposed between an axially inside end surface 12g of a pump housing 12 of a booster pump 1 and a first housing 12a, to constantly bias the first housing 12a toward a second housing 12b.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a booster pump provided, for example, in a building with low water supply pressure.

Background Art

[0002] In water supply facilities such as apartment buildings, offices, and schools, a cascade pump that is small and has a high discharge pressure is used. The cascade pump is a pump in which an impeller having a number of blades similar to gears rotates at high speed in a case having an annular passage formed concentrically, sucks in from an outer peripheral side suction port communicating with the annular passage, increases the pressure while rotating, and discharges from an outer peripheral side discharge port communicating with the annular passage.

[0003] As an example of a cascade pump, a side channel pump described below has been proposed. This side channel pump includes an impeller rotatable within a pump housing. The impeller is connected to the rotating shaft of an electric motor. The pump housing includes two housing portions and one casing held at intervals by a ring element. The ring element has dimensions such that the housing portions face the casing with a slight interval from the end face of the impeller. The impeller has a ring-shaped passage portion having a ring of annular rotor chambers partitioned by guide vanes. The ring-shaped passage portion, together with the rotor chambers, communicates from an inlet passage to an outlet passage and is configured to form a conveyance chamber for conveying a medium when the impeller is rotationally driven (see Patent Document 1; Japanese Patent Application Laid-Open No. 2010-509543).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the side channel pump of the above-mentioned Citation Document 1, it is necessary to reduce the gap between the two housing parts held at intervals by the impeller and the ring element (0.05 mm or less). For this reason, since dimensional accuracy of the two housing parts arranged so as to surround the impeller and the ring element is required, there has been a problem that the manufacturing cost increases and the assembly work becomes difficult.

Means for Solving the Problems

[0006] The present invention has been made to solve these problems, and an object thereof is to provide a booster pump that can improve the accuracy of the gap dimension between the impeller and the housing that houses the impeller, relax the component accuracy of the housing, and is easy to assemble.

[0007] In order to achieve the above object, the present invention has the following configuration. A booster pump comprising: an impeller having a plurality of blades formed along an outer peripheral edge of a disk-shaped main board; a first housing and a second housing directly overlapped radially outward so that the impeller is rotatably accommodated between the first housing and the second housing; a pump housing in which a pressure increasing flow path along an outer peripheral edge of the impeller and a suction flow path and a discharge flow path communicating with the pressure increasing flow path via a partition wall are formed; a rotating shaft connected to an axial end of the impeller; a rotor connected to the rotating shaft; and a motor having a stator disposed opposite to the rotor, wherein a biasing member that constantly biases the first housing toward the second housing is interposed between an axially inner end surface of the pump housing and the first housing.

[0008] Thus, since the first housing and the second housing are directly overlapped on the radially outer side and the impeller is rotatably accommodated between the first housing and the second housing, a ring element is not required between the first housing and the second housing as in the prior art documents, and the number of components is reduced, so that the accuracy of the clearance dimension between the impeller and the first housing and the second housing can be improved. Further, since a biasing member that constantly biases the first housing toward the second housing is interposed between the axially inner end surface of the pump casing and the first housing, there is no need to form the axially inner end surface of the pump housing at an axial height such that the first housing and the second housing are directly overlapped on the radially outer side, so that the component accuracy of the pump housing can be relaxed, and the assembling work can be easily performed.

[0009] It is preferable that the biasing member has a bottomed cylindrical portion that fits into the concave portion of the first housing at the central portion and accommodates the axial end portion of the rotating shaft, and a disc portion that extends radially outward from the bottom of the bottomed cylindrical portion is sandwiched between the pump housing and the first housing. Thereby, by fitting the bottomed cylindrical portion into the concave portion of the first housing, displacement of the biasing member can be prevented.

Advantages of the Invention

[0010] It is possible to provide a booster pump capable of adjusting the accuracy of the clearance dimension between the impeller and the housing that accommodates the impeller without depending on the accuracy of the component itself and facilitating the assembling work.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Best Mode for Carrying Out the Invention

[0012] Hereinafter, an embodiment of the booster pump according to the present invention will be described with reference to the accompanying drawings. First, the configuration of the booster pump 1 will be described with reference to FIG. 1. Hereinafter, as an example of the booster pump 1, a water supply pump connected to the water supply pipe of a condominium or apartment, such as an apartment building, will be exemplified. As shown in FIG. 1(B), the booster pump 1 is provided with a water inlet 3a to which a water pipe is connected on the side surface of the exterior cover 2 and a drain outlet 3b from which the pressurized tap water is discharged.

[0013] The booster pump 1 has the following configuration accommodated in a case body in which the bottom plate 4 is covered with the exterior cover 2. A cascade pump 5 is provided on the bottom plate 4. The cascade pump 5 is driven by a motor 6 provided above it. The tap water pressurized by the cascade pump 5 is temporarily stored in the accumulator 7. Thereby, the instantaneous change of the water pressure such as the pulsation and impact of the tap water is alleviated.

[0014] A self-cooling fan 8 is provided above the motor 6 to cool the heat generated by the motor coil of the stator. An air inlet 10 for sending air into the self-cooling fan 8 is provided above the self-cooling fan 8. The electronic board 9 includes a control unit (MPU) for controlling the operation of the device, a ROM for storing an operation program, and a storage unit such as a RAM for temporarily storing input / output data and reading the operation program for use as a work area of the CPU. Further, a display 11 is provided on the upper part of the exterior cover 2. The display 11 is provided with an input key, input data, a display unit for displaying the operation status, and the like.

[0015] The cascade pump 5 includes an impeller 5a having a plurality of blades standing upright along the outer peripheral edge of a disc-shaped main board and blade grooves partitioned by the plurality of blades. The impeller 5a is axially prevented from coming off by an impeller stopper 5b near the axial end (lower end) of the rotating shaft 6a of the motor 6 and is assembled. The motor 6 that drives the cascade pump 5 includes a rotating shaft 6a to which the impeller 5a is connected at the axial end, a rotor 6b connected to the rotating shaft 6a, and a stator 6c disposed opposite to surround the rotor 6b.

[0016] As shown in FIG. 2, a pump housing 12 is mounted on the bottom plate 4. Inside the pump housing 12, a first housing 12a and a second housing 12b are assembled by being directly overlapped in the radial outer side. A ring element is not required between the first housing 12a and the second housing 12b as in the prior art document, and since the number of parts is reduced, the accuracy of the clearance dimension between the impeller 5a, the first housing 12a, and the second housing 12b can be improved. Further, the impeller 5a is rotatably accommodated by providing an extremely small clearance (for example, 0.05 mm or less) between the first housing 12a and the second housing 12b.

[0017] As shown in FIG. 3, the cascade pump 5 has a pressure-raising flow path 12c along the outer peripheral edge of the impeller 5a, a suction flow path 12e communicating with the pressure-raising flow path 12c via a partition wall 12d, and a discharge flow path 12f formed in the pump housing 12, respectively. The suction flow path 12e communicates with the water supply port 3a, and the discharge flow path 12f communicates with the accumulator 7 (see FIG. 1(A)).

[0018] An urging member 13 is interposed between the axial inner end face (lower end face) 12g of the pump housing 12 and the first housing 12a. As shown in FIGS. 4(A) to 4(C), this urging member 13 has a bottomed cylindrical portion 13a that houses the axial end portion of the rotating shaft 6a at the center, and a disc portion 13b that extends radially outward from the bottom of the bottomed cylindrical portion 13a is sandwiched between the pump housing 12 (lower end face 12g) and the first housing 12a. An elastic member such as fluororubber is used for the urging member 13. The inside of the bottomed cylindrical portion 13a is hollow, and by housing the axial end portion of the rotating shaft 6a and the impeller stopper 5b assembled thereto in this portion, the rotating shaft 6a and the urging member 13 do not interfere with each other, and the rotational operation of the impeller 5a is not affected. Further, the bottomed cylindrical portion 13a is fitted into the recess 12h of the first housing 12a, so that the displacement of the urging member 13 can be prevented (see FIG. 2). In this way, since the urging member 13 constantly urges the first housing 12a toward the second housing 12b, it is not necessary to form the axial inner end face 12g of the pump housing 12 at an axial height such that the first housing 12a and the second housing 12b are directly overlapped on the radially outer side. Therefore, the component accuracy of the pump housing 12 can be relaxed, and the assembly work can be easily performed.

[0019] A mechanical seal 14 is provided on the rotating shaft 6a extending between the second housing 12b and the impeller 5a. Specifically, one end of a cylindrical sliding member 14a fitted coaxially with the rotating shaft 6a is fixed to the second housing 12b. This mechanical seal 14 can prevent leakage from the water pressure increasing flow path 12c of the tap water to the rotating shaft 6a side.

[0020] The above-described pressure increasing pump 1 can be applied not only to water supply facilities in apartment houses such as condominiums but also to water supply facilities in offices, schools, etc. It is possible to improve the accuracy of the clearance dimension between the impeller and the pump housing that houses it, relax the component accuracy of the pump housing, and provide a pressure increasing pump that is easy to assemble.

Explanation of Reference Numerals

[0021] 1 Boost pump 2 Outer cover 3a Water inlet 3b Drain outlet 4 Bottom plate 5 Cascade pump 5a Impeller 5b Impeller stopper 6 Motor 6a Rotating shaft 6b Rotor 6c Stator 7 Accumulator 8 Self-cooling fan 9 Electronic board 10 Heat dissipation rib 11 Display 12 Pump housing 12a First housing 12b Second housing 12c Boost flow path 12d Partition wall 12e Suction flow path 12f Discharge flow path 12g Axial inner end face (lower end face) 12h Recess 13 Biasing member 13a Bottomed cylindrical portion 13b Disk portion 14 Mechanical seal 14a Sliding member 14b Coil spring

Claims

1. An impeller having a plurality of blades formed along an outer peripheral edge of a disk-shaped main board, A first housing and a second housing are overlapped radially outward, and the impeller is rotatably accommodated between the first housing and the second housing. A pump housing in which a pressure increasing flow path along an outer peripheral edge of the impeller and a suction flow path and a discharge flow path communicating with the pressure increasing flow path via a partition wall are formed respectively, A pressure increasing pump comprising a rotating shaft connected to an axial end of the impeller, a rotor connected to the rotating shaft, and a motor having a stator disposed opposite to the rotor, A pressure increasing pump, characterized in that a biasing member for constantly biasing the first housing toward the second housing is interposed between an axially inner end face of the pump housing and the first housing.

2. The pressure increasing pump according to claim 1, wherein the biasing member has a bottomed cylindrical portion that fits into a concave portion of the first housing at a central portion and accommodates an axial end portion of the rotating shaft, and a disk portion extending radially outward from a bottom of the bottomed cylindrical portion is sandwiched between the pump casing and the first housing and biases toward the second housing.

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