pump

Abstract

To provide a pump that offers a high degree of flexibility in placement and can be manufactured at low cost. [Solution] The pump 1 comprises a rotor 10 including an impeller 12, a pump housing 40 having an opening 41 communicating with the inlet 12A of the impeller 12 and extending radially outward from the opening 41 so as to cover the impeller 12, and an inlet passage forming member 60 attached to the pump housing 40 and having an inlet passage 62 on its inside that communicates with the opening 41 of the pump housing 40. The pump housing 40 includes a stopper 50 provided at a radial position overlapping with the center of the opening 41 on the radially inner side of the impeller 12 for restricting the axial position of the rotor 10, and a support 44 extending radially inward from the inner circumferential wall of the opening 41 for supporting the stopper 50.

Description

Technical Field

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[0001] The present disclosure relates to a pump.

Background Art

[0002] Conventionally, a pump including a rotor having an impeller and a pump housing covering the impeller has been known. In this type of pump, a thrust load caused by a pressure difference between the inlet side and the outlet side of the impeller can act on the rotor. Therefore, a stopper for regulating the axial position of the rotor is required. For example, Patent Document 1 describes a pump device in which the axial position of a rotor is regulated by a cylindrical portion (stopper) provided integrally with a case (pump housing) covering an impeller.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when manufacturing the pump device described in Patent Document 1, if the cylindrical portion (stopper) is integrally formed with the case (pump housing) using a mold, cost reduction due to reduction in the number of parts can be expected. However, in this case, there are restrictions related to mold design, and the suction pipe portion of the case (pump housing) is limited to a simple shape such as a straight shape, and the degree of freedom in arranging the pump device is reduced. Even if the restrictions in mold design can be satisfied, if one tries to accommodate various forms of suction pipe portions in order to improve the degree of freedom in arranging the pump device, it is necessary to prepare a mold for integral molding of the pump housing for each form of the suction pipe portion, which increases the manufacturing cost.

[0005] In view of the above circumstances, at least some embodiments of the present invention aim to provide a pump that offers a high degree of freedom in arrangement and can be manufactured at low cost. [Means for solving the problem]

[0006] Pumps according to at least some embodiments of the present invention are The rotor, including the impeller, A pump housing having an opening that communicates with the inlet of the impeller and extending radially outward from the opening so as to cover the impeller, An inlet channel forming member is attached to the pump housing and has an inlet channel on its inside that communicates with the opening in the pump housing, Equipped with, The pump housing is A stopper is provided on the radially inner side of the impeller at a radial position that coincides with the center of the opening, for restricting the axial position of the rotor, A support extending radially inward from the inner circumferential wall of the opening, for supporting the stopper, Includes.

[0007] In this specification, the "inlet channel forming member" is a component of the pump located upstream of the pump housing. The "inlet channel forming member" may be, for example, a straight inlet pipe, a non-straight inlet pipe having bends or branches, or a reservoir tank other than a pipe. [Effects of the Invention]

[0008] In at least some embodiments of the present invention, a structure is adopted in which the inlet channel forming member is attached to the pump housing, so the inlet channel forming member is separated from the pump housing. Therefore, the variations of the inlet channel forming member can be increased without affecting the design of the pump housing. Thus, by selecting an appropriate one from among the variations of the inlet channel forming member, the degree of freedom in pump placement can be improved. Furthermore, because the inlet channel forming member is separated from the pump housing, it is easier to integrally mold the pump housing, including a stopper for restricting the axial position of the rotor and a support for supporting the stopper, while satisfying mold design constraints. Here, when integrally molding the pump housing including the stopper and support, a common mold can be used regardless of the shape of the inlet channel forming member. Therefore, the manufacturing cost of the pump can be reduced. [Brief explanation of the drawing]

[0009] [Figure 1A] This is a cross-sectional view showing the schematic configuration of a pump according to one embodiment. [Figure 1B] This is a cross-sectional view showing a schematic configuration of a pump according to another embodiment. [Figure 1C] This is a cross-sectional view showing a schematic configuration of a pump according to yet another embodiment. [Figure 1D] Figures 1B and 1C are cross-sectional views showing the configuration around the pump stopper. [Figure 2] This is a plan view of a pump in one embodiment, viewed from the axial direction. [Figure 3] This is a partial cross-sectional perspective view showing the structure around the stopper of a pump in one embodiment. [Figure 4A] This is a cross-sectional view showing an example of the structure of the connection part of a pump housing. [Figure 4B] This is a cross-sectional view showing another example of the structure of the connection part of the pump housing. [Figure 5A] This is an exploded perspective view showing an inlet channel forming member and a pump housing according to one embodiment. [Figure 5B] This is an exploded perspective view showing an inlet channel forming member and pump housing according to another embodiment. [Figure 5C] This is an exploded perspective view showing an inlet channel forming member and pump housing according to yet another embodiment. [Figure 5D] This is an exploded perspective view showing an inlet channel forming member and pump housing according to yet another embodiment. [Figure 5E]A cross-sectional view showing an inlet flow path forming member and a pump housing according to yet another embodiment. [Figure 6A] A cross-sectional view showing the configuration around a filter provided in the inlet flow path of a pump according to one embodiment. [Figure 6B] A cross-sectional view showing the configuration around a filter provided in the inlet flow path of a pump according to another embodiment. [Figure 6C] A cross-sectional view showing the configuration around a filter provided in the inlet flow path of a pump according to yet another embodiment. [Figure 7A] A partial cross-sectional perspective view showing an example configuration of a filter. [Figure 7B] A partial cross-sectional perspective view showing another example configuration of a filter. [Figure 7C] A partial cross-sectional perspective view showing yet another example configuration of a filter. [Figure 7D] A partial cross-sectional perspective view showing yet another example configuration of a filter.

MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.

[0011] FIG. 1A is a cross-sectional view along the axial direction (hereinafter, axial cross-sectional view) showing the schematic configuration of a pump 1A according to one embodiment. FIG. 1B is an axial cross-sectional view showing the schematic configuration of a pump 1B according to another embodiment. FIG. 1C is an axial cross-sectional view showing the schematic configuration of a pump 1C according to yet another embodiment. FIG. 1D is a cross-sectional view showing the configuration around a stopper 50 of the pumps shown in FIGS. 1B and 1C. FIG. 2 is a plan view of the pumps 1 (1A to 1C) shown in FIGS. 1A to 1C viewed from the axial direction. In FIG. 2, an inlet flow path forming member 60 described later is omitted. Figure 3 is a partial cross-sectional perspective view showing the structure around the stopper 50 of the pump housing 40 in one embodiment.

[0012] Hereinafter, when referring to pumps according to several embodiments of the present invention that include at least one of pumps 1A to 1C, they may simply be referred to as pump 1, or, for the purpose of clarifying the included embodiments, as pump 1(1A to 1C), pump 1(1A), pump 1(1B, 1C), etc. In Figures 1A to 1C and Figure 2, the "axial direction" is the direction along the rotational axis of the impeller 12 of pump 1 (1A to 1C), and the "radial direction" is the radial direction centered on the rotational axis of the impeller 12 of pump 1 (1A to 1C).

[0013] The pump 1 (1A to 1C) shown in Figures 1A to 1C is a centrifugal pump that uses the centrifugal force generated by the rotation of the impeller 12 to pressurize the fluid flowing in from the inlet 2 and discharge it from the outlet 3 (see Figure 2). The pump 1 (1A to 1C) may also be a volute pump having a vortex chamber 11 on the radially outer side of the impeller 12. Furthermore, pump 1A, shown in Figure 1A, is driven by the output shaft 4 of an external motor (not shown). In contrast, pumps 1B and 1C, shown in Figures 1B and 1C, are driven by internal motors 5, respectively.

[0014] In some embodiments, as shown in Figures 1A to 1C, the pump 1 (1A to 1C) includes a rotor 10 including an impeller 12, a pump housing 40 covering the impeller 12, and an inlet flow path forming member 60 attached to the pump housing 40. The inlet channel forming member 60 has an inlet channel 62 on its inside. The inlet channel forming member 60 also has an inlet 2 for the pump 1 (1A~1C) at its upstream end. The inlet channel 62 communicates with the inlet 2. The fluid taken into the pump 1 (1A~1C) from the inlet 2 is guided to the impeller 12 via the inlet channel 62, passes through the impeller 12, and finally flows out from the outlet 3 (see Figure 2) of the pump 1 (1A~1C).

[0015] As shown in Figures 1A to 1C and Figure 2, the impeller 12 of the rotor 10 includes a hub surface 13 and a plurality of blades 14 arranged circumferentially on the hub surface 13. An inlet 12A (see Figure 2) of the impeller 12 is formed between the leading edges of adjacent blades 14, and an outlet 12B (see Figure 2) of the impeller 12 is formed between the trailing edges of adjacent blades 14. Fluid flowing into the impeller 12 from the inlet 12A is given kinetic energy by the rotating impeller 12. As shown in Figures 1A to 1C, the outlet 12B of the impeller 12 communicates with an annular vortex chamber 11 provided on the outer circumference of the impeller 12. After passing through the impeller 12, the fluid flows radially outward through the outlet 12B and flows into the vortex chamber 11, where it flows circumferentially. At this time, the fluid is decelerated due to the gradual expansion of the flow path in the vortex chamber 11, and the kinetic energy is converted into static pressure. The vortex chamber 11 is connected to the outlet 3 (see Figure 2) of the pump 1 (1A-1C), and the fluid pressurized by the pump 1 (1A-1C) flows out from the outlet 3. Furthermore, a thrust load acts on the impeller 12 due to the pressure difference between the inlet 12A and the outlet 12B. This thrust load is a force that causes the impeller 12 to lift axially towards the inlet flow path forming member 60. For this reason, the pump 1 (1A to 1C) includes a stopper 50, which will be described later, and the axial position of the rotor 10 is restricted by the stopper 50 against the thrust load.

[0016] The impeller 12 may have a shroud 15 that faces the hub surface 13 in the axial direction, sandwiching the blades 14. In the exemplary embodiments shown in Figures 1A to 1C, the impeller 12 is a closed impeller and includes a shroud 15 covering the blades 14. In other embodiments, the impeller 12 is an open impeller without a shroud covering the blades 14.

[0017] In some embodiments, the pump 1(1A) is driven by an external motor. In this case, the rotor 10 includes an impeller 12 connected to the output shaft 4 of the external motor and rotating together with the output shaft 4, as shown in Figure 1A.

[0018] In some other embodiments, the pump 1(1B,1C) includes an internal motor 5, and the impeller 12 is driven by the internal motor 5. In this case, as shown in Figures 1B and 1C, the rotor 10 includes the impeller 12 and a motor rotor 20 which constitutes the rotating part of the internal motor 5. The motor rotor 20 includes a magnet 22 and a holder 24 which holds the magnet 22. In the exemplary embodiments shown in Figures 1B and 1C, the rotor 10, including the impeller 12 and motor rotor 20, is rotatably supported on a stationary shaft 21 via a radial bearing 28. The radial bearing 28 is a sliding bearing, which may be made of metal or carbon, for example. As shown in Figure 1D, the radial bearing (sliding bearing) 28 has an inner circumferential surface 28A and one axial end surface 28B as sliding surfaces. The inner circumferential surface 28A of the radial bearing (sliding bearing) 28 slides against the outer circumferential surface of the stationary shaft 21. The one axial end surface 28B of the radial bearing (sliding bearing) 28 slides against a thrust bearing 29, which will be described later. The radial bearing (sliding bearing) 28 may be integrally molded with the resin rotor 10, including the impeller 12 and motor rotor 20, by insert molding.

[0019] In the exemplary embodiments shown in Figures 1B and 1C, the built-in motor 5 is a radial gap motor in which a radial magnetic gap is formed between the magnet 22 and the stator 30, and is an inner rotor type motor in which the motor rotor 20 is located radially inward of the stator 30. Therefore, in Figures 1B and 1C, the holding portion 24 is a cylindrical member, and the magnet 22 held on the outer circumferential surface of the holding portion 24 faces the stator 30 located radially outward from the motor rotor 20. The holding portion 24, as a cylindrical member, is connected to the hub side of the impeller 12 via a neck portion 26, which has a smaller diameter than the holding portion 24.

[0020] In other embodiments, the built-in motor 5 is a radial gap motor in which a radial magnetic gap is formed between the magnet 22 and the stator 30, and is an outer rotor type motor in which the motor rotor 20 is located radially outward from the stator 30. In this case, the holding portion 24 is a hollow cylindrical member extending axially from the outer peripheral end of the impeller 12, and the magnet 22 is held on the inner circumferential surface of the holding portion 24. The magnet 22 held on the inner circumferential surface of the holding portion 24 faces the stator 30, which is located radially inward from the motor rotor 20. In yet another embodiment, the built-in motor 5 is an axial gap motor in which an axial magnetic gap is formed between the magnet 22 and the stator 30. In this case, the holding portion 24 forms the axial end face of the rotor 10 that is opposite to the hub surface 13 of the impeller 12, and holds the magnet 22 on the axial end face of the rotor 10 formed by the holding portion 24. As a result, the magnet 22 faces the stator 30, which is located in the axial direction on the opposite side of the motor rotor 20 from the inlet flow path forming member 60.

[0021] As shown in Figures 1B and 1C, the stator 30 of the built-in motor 5 includes a stator core 32 and a stator coil 34. The stator core 32 forms a magnetic path through which the magnetic flux generated by energizing the stator coil 34 flows. The stator coil 34 may be wound around the teeth of the stator core 32 so as to be housed in slots provided in the stator core 32.

[0022] In the exemplary embodiments shown in Figures 1B and 1C, the pump 1 (1B, 1C) includes a control board 6 for controlling a built-in motor 5, which is composed of a motor rotor 20 and a stator 30 as described above. The control board 6 includes a printed circuit board 6A and one or more electronic components 6B mounted on the printed circuit board 6A.

[0023] The rotor 10 in the above configuration is at least partially covered by the pump housing 40, as shown in Figures 1A to 1C. The pump housing 40 may, together with other housing members 8 (8A to 8C), form a housing that accommodates each element of the pump 1 (1A to 1C). In some embodiments, as shown in Figure 1A, the pump 1(1A) includes a back plate 8A as another housing member 8. The pump housing 40 is attached to the back plate 8A. The pump housing 40, together with the back plate 8A, forms a pump chamber in which the impeller 12 is housed. In some other embodiments, as shown in Figures 1B and 1C, the pump 1(1B,1C) includes a motor cover 8B and a circuit board cover 8C as other housing members 8. The pump housing 40 is attached to the motor cover 8B. Together with the motor cover 8B, the pump housing 40 forms a pump motor chamber in which the rotor 10, including the impeller 12 and motor rotor 20, is housed. The circuit board cover 8C is attached to the motor cover 8B so as to be located on the opposite side of the pump housing 40 from the motor cover 8B in the axial direction. Together with the motor cover 8B, the circuit board cover 8C forms a circuit board chamber in which the control board 6 is housed.

[0024] As shown in Figures 1A to 1C and Figure 2, the pump housing 40 has an inlet passage 62 inside the inlet passage forming member 60 and an opening 41 that communicates with the inlet 12A of the impeller 12. The pump housing 40 extends radially outward from the opening 41 so as to cover the impeller 12 of the rotor 10. The opening 41 is a through-hole provided in the pump housing 40 along the axial direction, and has a cross-sectional shape defined by a circle centered on the rotation axis of the impeller 12. The fluid that passes through the opening 41 axially via the inlet 2 and the inlet passage 62 is deflected to flow radially outward along the hub surface 13 of the impeller 12. The fluid that has passed through the impeller 12 flows into the radially outward vortex chamber 11.

[0025] In some embodiments, as shown in Figures 1A to 1C and Figure 2, the pump housing 40 includes a main body 42 that covers the impeller 12, a stopper 50 for restricting the axial position of the rotor 10, and a support 44 for supporting the stopper 50. The pump housing 40 is a single molded resin product including the main body 42, the stopper 50, and the support 44.

[0026] The main body portion 42 is the part that fulfills the above-mentioned function of the pump housing 40 by forming the opening 41 and extending radially outward from the opening 41 to cover the impeller 12. In the exemplary embodiments shown in Figures 1A to 1C and Figure 2, the main body 42 includes an inner rim portion 42A that forms an opening 41, a disk portion 42B that extends radially outward on the outer circumference of the inner rim portion 42A, and a scroll portion 42C that forms a spiral chamber 11 on the outer circumference of the disk portion 42B. The inner rim portion 42A protrudes axially from the disk portion 42B toward the inlet flow path forming member 60. The impeller 12 is covered by the inner rim portion 42A and the disk portion 42B of the main body 42. The scroll portion 42C is located radially outward of the impeller 12. In the example shown in Figures 1A to 1C, the inner rim portion 42A has an inward-facing flange 43 that protrudes radially inward. The opening 41 is defined by the inner circumferential surface of the inward-facing flange 43 of the inner rim portion 42A.

[0027] The stopper 50 is located radially inside the impeller 12, at a position that coincides with the center of the opening 41 of the pump housing 40. In the exemplary embodiments shown in Figures 1A to 1C and Figure 2, the central axis of the stopper 50 is concentric with the center of the opening 41 and the center of rotation of the impeller 12.

[0028] The stopper 50 has a flow path forming surface 51 that forms a flow path from the inlet flow path 62 inside the inlet flow path forming member 60, through the opening 41 of the pump housing 40, toward the impeller 12. The flow path forming surface 51 is a curved surface (a so-called streamlined surface) that smoothly connects with the hub surface 13 of the impeller 12. The stopper 50 includes an upstream end 52 located upstream of the support 44. The upstream end 52 of the stopper 50 has a shape that gradually narrows in diameter toward the upstream side (a so-called streamlined shape) so as to form part of the flow path forming surface 51. In this way, when the upstream end 52 of the stopper 50 gradually narrows in diameter toward the upstream side, a hydrodynamic effect occurs in which the fluid flowing through the inlet flow path 62 flows smoothly along the upstream end 52 of the stopper 50, reducing the loss of flow toward the impeller 12.

[0029] In order to enjoy the hydrodynamic effects of the upstream end 52 of the stopper 50 as described above, it is necessary to position the upstream end 52 sufficiently upstream from the impeller 12, and the direct way to do this is to extend the pump housing 40, which includes the stopper 50, upstream. If the pump housing 40 (main body 42) is extended upstream toward the inlet 2 of the pump 1, the area where the stopper 50, which is part of the pump housing 40, is located will expand upstream, and as a result, the upstream end 52 of the stopper 50 will move further upstream from the impeller 12. However, in this case, under the condition that the position of the inlet 2 of the pump 1 remains unchanged, the inlet flow path forming member 60 becomes shorter by the amount that the housing 40 (main body portion 42) is extended, and the effect of improving the degree of freedom in positioning of the pump 1 by the inlet flow path forming member 60 separated from the pump housing 40 cannot be fully obtained.

[0030] Therefore, in some embodiments, as shown in Figures 1A and 1B, the tip 53 of the upstream end 52 of the stopper 50 is positioned in the axial direction opposite to the support 44, straddling the opening end of the opening 41 on the outer surface of the pump housing 40 (in the examples shown in Figures 1A and 1B, the upper surface of the inner rim portion 42A). In this case, the stopper 50 penetrates the inlet passage 62 inside the inlet passage forming member 60, beyond the opening end of the opening 41 on the outer surface of the pump housing 40 in the axial direction. In another embodiment, as shown in Figure 1C, the tip 53 of the upstream end 52 of the stopper 50 is located in the same position in the axial direction as the opening end of the opening 41 on the outer surface of the pump housing 40 (the upper surface of the inner rim portion 42A in the example shown in Figure 1C). In this case, the stopper 50 extends in the axial direction to the position of the opening end of the opening 41 on the outer surface of the pump housing 40. This makes it possible to position the upstream end 52 of the stopper 50 sufficiently upstream of the impeller 12 while suppressing excessive shortening of the inlet channel forming member 60 (while ensuring the length of the inlet channel forming member 60).

[0031] Furthermore, the stopper 50 includes a downstream end 54 that receives a thrust load from the rotor 10. The stopper 50 restricts the axial position of the rotor 10 by having the downstream end 54 directly or indirectly receive the thrust load acting on the rotor 10 (impeller 12).

[0032] In some embodiments, as shown in Figures 1A to 1C, the downstream end 54 of the stopper 50 receives the thrust load via thrust bearings 29 (29A, 29B). In the exemplary embodiment shown in Figure 1A, the thrust bearing 29A is a disc-shaped bearing provided in a recess 16 formed in the rotor 10 on the radially inner side of the impeller 12, and supports the rotor 10 against the thrust load that would cause the impeller 12 to lift towards the inlet passage 62. The downstream end 54 of the stopper 50 is located axially on the opposite side of the rotor 10 from the disc-shaped thrust bearing 29A, and receives the thrust load acting on the rotor 10 via the thrust bearing 29A. In contrast, in the exemplary embodiments shown in Figures 1B and 1C, the thrust bearing 29B is provided opposite the axial end face 28B of the radial bearing (sliding bearing) 28. As shown in Figure 1D, the thrust bearing 29B is an annular member provided in an annular shape around the tip of the stationary shaft 21. The downstream end 54 of the stopper 50 is located in the axial direction opposite the radial bearing 28, with the annular thrust bearing 29B in between, and receives the thrust load acting on the rotor 10 via the thrust bearing 29A and the radial bearing 28.

[0033] The stopper 50 in the above configuration is supported on the main body 42 of the pump housing 40 by one or more supports 44. As shown in Figures 1A to 1C and Figure 2, the one or more supports 44 extend radially inward from the inner circumferential wall of the opening 41 of the main body 42 (inner rim portion 42A). In the exemplary embodiment shown in Figure 2, three supports 44 are arranged radially. The three supports 44 are arranged at equal intervals (120-degree intervals) in the circumferential direction. The number of supports 44 is not limited to three; two supports 44, or four or more supports 44, may be arranged in the circumferential direction.

[0034] Each support 44 includes a radially outer end 44A connected to the inner circumferential wall of the opening 41 of the main body portion 42 (inner rim portion 42A), and a radially inner end 44B connected to the flow path forming surface 51 of the stopper 50. The radially inner end 44B of the support 44 is connected to the portion of the flow path forming surface 51 downstream of the upstream end 52 of the stopper 50, so that it is located downstream of the upstream end 52 in the axial direction.

[0035] Here, we will define the various dimensions (L1 to L3 and L) related to the stopper 50 and support 44 of the pump housing 40, and then explain the relationships between these dimensions. For the sake of explanation, we will refer to Figure 3, but the definitions of the various dimensions (L1 to L3 and L) and the relationships between these dimensions are not limited to the example shown in Figure 3, and can be applied to any embodiment of the pump 1 described herein.

[0036] In Figure 3, the length L of the stopper 50 is the length of the portion of the stopper 50 facing the flow path (the portion of the stopper 50 that forms the flow path forming surface 51) in the axial direction. L1 is the distance in the axial direction from the upstream end face of the support 44 to the tip 53 of the upstream end 52 of the stopper 50. L2 is the distance in the axial direction from the downstream end face of the support 44 to the position of the downstream end of the flow path forming surface 51 of the stopper 50. L3 is the distance in the axial direction from the opening end of the opening 41 on the outer surface of the pump housing 40 (the upper surface of the inner rim portion 42A in the example shown in Figure 3) to the tip 53 of the upstream end 52 of the stopper 50. In the exemplary embodiment shown in Figure 3, a rib 45 is provided that connects the downstream end face of a support 44 extending radially from the inner circumferential wall of the opening 41 of the pump housing 40 to the flow path forming surface 51 of the stopper 50. In this case, L2 is defined as the axial distance from the downstream end face of the support 44 to the position of the downstream end of the flow path forming surface 51 of the stopper 50, excluding the rib 45.

[0037] In some embodiments, the upstream end 52 of the streamlined stopper 50 is positioned sufficiently upstream of the support 44 to reduce the influence of the stopper 50 and support 44 on the flow. Therefore, the distance L1 is at least 0.2 times the length L of the stopper 50 (L1 / L ≥ 0.2). The distance L1 may also satisfy 0.3 ≤ L1 / L ≤ 0.6, or for example, 0.4 ≤ L1 / L < 0.5. In some embodiments, within the axial range occupied by the flow path forming surface 51 of the stopper 50, the support 44 is positioned sufficiently downstream of the upstream end 52 of the stopper 50 to reduce the influence of the support 44 on the flow. Therefore, the distance L2 may be 0.55 times or less of the length L of the stopper 50 (L2 / L ≤ 0.55). The distance L2 may also satisfy 0.35 ≤ L2 / L ≤ 0.5, for example, 0.4 ≤ L2 / L < 0.5. In some embodiments, the upstream end 52 of the streamlined stopper 50 is positioned sufficiently upstream from the impeller 12 to reduce the influence of the stopper 50 on the flow. Therefore, the distance L3 is 0.2 times the length L of the stopper 50 (L3 / L ≥ 0.2). The distance L3 may also satisfy 0.3 ≤ L3 / L ≤ 0.6, or for example, 0.4 ≤ L3 / L < 0.5.

[0038] In some embodiments, as shown in Figures 1A to 1C, the pump housing 40 (main body portion 42) has a connection portion 46 with an inlet flow path forming member 60. The inlet flow path forming member 60 is connected to the connection portion 46 of the pump housing 40. The connection portion 46 is the portion of the pump housing 40 (main body portion 42) located in the axial direction opposite to the impeller 12. The connection structure of the inlet flow path forming member 60 to the connection portion 46 of the pump housing 40 (structure of the connection portion 46) is not particularly limited, and any structure can be adopted.

[0039] Figure 4A is a cross-sectional view showing an example of the structure of the connection portion 46 of the pump housing 40. Figure 4B is a cross-sectional view showing another example of the structure of the connection portion 46 of the pump housing 40. In the embodiment shown in Figure 4A, the connection portion 46 of the pump housing 40 is a fastening portion 46A with the inlet flow path forming member 60. In this case, the inlet flow path forming member 60 is fastened to the connection portion 46 (fastening portion 46A) of the pump housing 40 using fastening means 47, which may be screws or bolts. Furthermore, a seal ring 48 is provided radially inside the fastening portion 46A to seal the gap between the pump housing 40 and the inlet flow path forming member 60. The seal ring 48 may be, for example, an O-ring. In the embodiment shown in Figure 4B, the connection portion 46 of the pump housing 40 is a welded portion 46B with the inlet channel forming member 60. The welding of the inlet channel forming member 60 to the connection portion 46 (welded portion 46B) of the pump housing 40 is performed by partially melting the pump housing 40 and the inlet channel forming member 60 by irradiation with a laser or ultrasonic waves, and then solidifying the molten portion 49 formed. In yet another embodiment, the connection portion 46 of the pump housing 40 is a heat-sealed portion or a mating portion. If the connection portion 46 is a mating portion, the inlet flow path forming member 60 may be attached to the pump housing 40 by snap-fit.

[0040] Figure 5A is an exploded perspective view showing an inlet channel forming member 60A and pump housing 40 according to one embodiment. Figure 5B is an exploded perspective view showing an inlet channel forming member 60B and pump housing 40 according to another embodiment. Figure 5C is an exploded perspective view showing an inlet channel forming member 60C and pump housing 40 according to yet another embodiment. Figure 5D is an exploded perspective view showing an inlet channel forming member 60D and pump housing 40 according to yet another embodiment. Figure 5E is a cross-sectional view showing an inlet channel forming member 60E and pump housing 40 according to yet another embodiment.

[0041] In some embodiments, as shown in Figures 5A to 5D, the inlet flow path forming member 60 is an inlet pipe 60A to 60D connected to the peripheral edge of the opening 41 of the pump housing 40. The inlet pipes 60A to 60D include a hose connection portion 64 located at the end of the pump 1 on the inlet 2 side, and an axial pipe portion 66 connected to the periphery of the opening 41 of the pump housing 40. The hose connection portion 64 has an annular convex shape (bulge shape), and a hose (not shown) is connected to the hose connection portion 64 using a hose clamp. The axial pipe portion 66 extends along the axial direction to form the downstream end of the inlet pipes 60A to 60D. The axial pipe portion 66 has an inner diameter approximately the same as the opening 41 of the pump housing 40. In the exemplary embodiment shown in Figure 5A, the inlet flow path forming member 60 is a straight inlet pipe 60A including a hose connection portion 64 and an axial pipe portion 66. In contrast, in the exemplary embodiments shown in Figures 5B and 5C, the inlet flow path forming member 60 is an elbow-shaped inlet pipe 60B, 60C that includes a hose connection portion 64 and an axial pipe portion 66, as well as an upstream pipe portion 68 connected to the axial pipe portion 66 via a bend portion 67. The upstream pipe portion 68 of the inlet pipe 60B is an oblique pipe portion having a bend angle of less than 90 degrees with respect to the axial pipe portion 66. The upstream pipe portion 68 of the inlet pipe 60C is an orthogonal pipe portion having a bend angle of approximately 90 degrees with respect to the axial pipe portion 66. Furthermore, in the exemplary embodiment shown in Figure 5D, the inlet flow path forming member 60 is a T-shaped inlet pipe 60D that includes a hose connection portion 64 and an axial pipe portion 66, as well as a branch pipe portion 69 connected to the axial pipe portion 66. Inlets 2 and hose connection portions 64 are provided at both ends of the branch pipe portion 69, respectively. Fluid flowing into the pump 1 from the pair of inlets 2 merges in the branch pipe portion 69 and flows axially toward the opening 41 via the axial pipe portion 66. Note that the inlet flow path forming member 60 may be a Y-shaped inlet pipe in which the branch pipe portion 69 has a bent shape, instead of a T-shaped inlet pipe 60D.

[0042] In some embodiments, as shown in Figure 5E, the inlet channel forming member 60 is a reservoir tank 60E to which the connection portion 46 (fastening portion 46A) of the pump housing 40 is fastened using fastening means 47. The joint surface between the pump housing 40 (main body portion 42) and the reservoir tank 60E is a plane aligned radially. The reservoir tank 60E as the inlet channel forming member 60 has an inlet 2 that communicates with the inlet channel 62 (internal space of the tank) inside the reservoir tank 60E.

[0043] As described above, since the inlet channel forming member 60 is separated from the pump housing 40, the variations of the inlet channel forming member 60 (for example, inlet pipes 60A to 60D and reservoir tank 60E) can be increased without affecting the design of the pump housing 40. Therefore, by selecting an appropriate one from among the variations of the inlet channel forming member 60, the degree of freedom in the arrangement of the pump 1 can be improved.

[0044] Furthermore, in the pump 1 (1A to 1C) with the above configuration, the inlet channel forming member 60 is a separate component separated from the pump housing 40, and the design freedom of the inlet channel forming member 60 is relatively high. For this reason, other functions other than the formation of the inlet channel 62 may be added to the inlet channel forming member 60. For example, in order to protect the internal components of pump 1 (1A to 1C), a filter for removing foreign matter may be provided in the inlet passage 62 of the inlet passage forming member 60.

[0045] Figure 6A is a cross-sectional view showing the configuration around a filter provided in the inlet channel 62 of a pump 1 according to one embodiment. Figure 6B is a cross-sectional view showing the configuration around a filter provided in the inlet channel 62 of a pump 1 according to another embodiment. Figure 6C is a cross-sectional view showing the configuration around a filter provided in the inlet channel 62 of a pump 1 according to yet another embodiment. Figure 7A is a partial cross-sectional perspective view showing an example of filter configuration. Figure 7B is a partial cross-sectional perspective view showing another example of filter configuration. Figure 7C is a partial cross-sectional perspective view showing yet another example of filter configuration. Figure 7D is a partial cross-sectional perspective view showing yet another example of filter configuration. In Figures 7A to 7D, "flow direction" refers to the flow direction of the fluid passing through the filter when each filter is assembled to pump 1.

[0046] In some embodiments, as shown in Figures 6A to 6C, the pump 1 includes a filter 70 provided in the inlet channel 62 inside the inlet channel forming member 60. The filter 70 has numerous small holes 71 through which fluid can pass, allowing fluid in the inlet passage 62 to pass through the small holes 71 of the filter 70. On the other hand, foreign matter 72 that enters the inlet passage 62 from the inlet 2 cannot pass through the small holes 71 and is captured by the filter 70. This prevents malfunctions in the pump 1 caused by foreign matter 72 entering gaps between the impeller 12 and the pump housing 40, bearing gaps between bearings 28 and 29, and magnetic gaps between the motor rotor 20 and the stator 30.

[0047] In some embodiments, as shown in Figure 6A, the filter 70 is integrally provided with the inlet channel forming member 60. The filter 70 may also be an insert part integrally molded with the resin inlet channel forming member 60. In this case, by insert molding with the filter 70 as an insert part, an integrally molded product can be obtained in which the filter 70 is held in the inlet channel forming member 60. In the exemplary embodiment shown in Figure 6A, a disc-shaped filter 70A is integrally provided with a straight-shaped inlet pipe 60A. The filter 70A is provided in the inlet flow path 62 inside the inlet pipe 60A, upstream of the upstream end 52 of the stopper 50.

[0048] In some other embodiments, as shown in Figures 6B and 6C, the filter 70 is sandwiched between the inlet channel forming member 60 and the pump housing 40. Specifically, it is held within the inlet channel 62 inside the inlet channel forming member 60 by being sandwiched between an annular stepped portion 61 provided on the inner surface of the inlet channel forming member 60 and an annular protrusion 42D or peripheral wall portion 42E of the pump housing 40. In the exemplary embodiment shown in Figure 6B, a disc-shaped filter 70A is held between an annular stepped portion 61 provided on the inner surface of a straight inlet pipe 60A and an annular projection 42D that protrudes axially from the inner rim portion 42A of the main body portion 42 of the pump housing 40. The annular projection 42D is inserted into the inlet pipe 60A. The inlet passage 62 inside the inlet pipe 60A is formed by the inlet pipe 60A alone on the upstream side of the filter 70A, while on the downstream side of the filter 70A, it is formed by a double pipe consisting of the inlet pipe 60A and the annular projection 42D. In the exemplary embodiment shown in Figure 6C, the dome-shaped filter 70B is held between an annular stepped portion 61 provided on the inner surface of the downstream end 65 of the inlet pipe 60F and a peripheral wall portion 42E provided on the main body portion 42 of the pump housing 40.

[0049] In some embodiments, as shown in Figure 6C, the pump housing 40 includes a peripheral wall portion 42E that protrudes from the surface of the pump housing 40 (main body portion 42) opposite to the surface facing the impeller 12 and surrounds the opening 41, and the inlet flow path forming member 60 has a downstream end portion 65 that has a flow path cross-sectional area larger than the opening 41. The annular peripheral wall portion 42E of the pump housing 40 is inserted into the enlarged downstream end portion 65 of the inlet flow path forming member 60. As a result, the downstream end portion 65 of the inlet flow path forming member 60 and the peripheral wall portion 42E of the pump housing 40 form an inlet chamber 63 that communicates with the opening 41 as part of the inlet flow path 62. The filter 70 is provided in the inlet chamber 63 of the inlet flow path 62, which has a flow path cross-sectional area larger than the opening 41. For this reason, a large-area filter 70 can be used. In the example shown in Figure 6, a dome-shaped filter 70B is used to further increase the area of ​​the filter 70 compared to a disc-shaped filter 70A. In the exemplary embodiment shown in Figure 6C, the inlet flow path forming member 60 is an inlet pipe 60F in which an upstream pipe section 68 having a hose connection section 64 and a downstream end section 65 are connected via a bend 67. The downstream end section 65 has a larger flow path cross-sectional area than the upstream pipe section 68 and the bend 67. The main body 42 of the pump housing 40 includes a peripheral wall section 42E located on the outer circumference side of the scroll section 42C. The peripheral wall section 42E is an annular projection that protrudes axially toward the inlet pipe 60F. The peripheral wall section 42E of the main body 42 is inserted inside the downstream end section 65 of the inlet pipe 60F. The gap between the outer surface of the peripheral wall section 42E and the inner surface of the downstream end section 65 of the inlet pipe 60F is sealed by a seal ring 48. The pump housing 40 has a connection section 46 (fastening section 46A) on the outer circumference side of the peripheral wall section 42E. The pump housing 40 is fastened to the inlet pipe 60F by fastening means 47 at the fastening portion 46A.

[0050] In yet another embodiment, a filter 70 is provided in the reservoir tank 60E (see Figure 5E), which serves as the inlet channel forming member 60.

[0051] The configuration of the filter 70 is not particularly limited, as long as it has small holes 71 through which fluid can pass and is capable of capturing foreign matter 72. The filter 70 may be, for example, a mesh filter having a large number of mesh-like small holes 71, or a perforated metal plate with a large number of small holes 71.

[0052] Furthermore, the shape of the filter 70 is not particularly limited and may be any shape such as a disc, hat, tube, or dome. In the exemplary embodiment shown in Figure 7A, the filter 70 is a disc filter 70A having an outer diameter corresponding to the inner diameter of the inlet flow path forming member 60. When assembled to the pump 1, the filter 70A is oriented along a direction perpendicular to the flow direction. In the exemplary embodiment shown in Figure 7B, the filter 70 is a dome-shaped filter 70B having an outer diameter corresponding to the inner diameter of the inlet channel forming member 60. The dome-shaped filter 70B includes a flange 74 that forms the outer periphery and a dome portion 75 located on the inner circumferential side of the flange 74. The dome portion 75 has a number of small holes 71. The dome portion 75 protrudes upstream in the flow direction from the flange 74. The flange 74 is used to fix the dome-shaped filter 70B inside the inlet channel forming member 60. In the exemplary embodiment shown in Figure 7C, the filter 70 is a hat-shaped filter 70C having a hat-shaped cross-section. The hat-shaped filter 70C includes a flange 74 and a bottomed cylindrical portion 76 that protrudes downstream from the flange 74 in the flow direction. The cylindrical portion 76 has a number of small holes 71. In the exemplary embodiment shown in Figure 7D, the filter 70 is a tubular filter 70D. The tubular filter 70D includes a flange 74, an annular ridge 77 rising upstream from the flange 74 in the flow direction, and a bottomed tube portion 78 extending downstream from the annular ridge 77 in the flow direction. The tube portion 78 is provided on both sides of the flange 74, passing inside the flange 74 in the flow direction. The tube portion 78 has a number of small holes 71.

[0053] Figures 7A to 7D illustrate the orientation of each filter 70 (70A to 70D) with respect to the direction of fluid flow passing through the filter 70 when the filters 70 are assembled to the pump 1. However, the orientation of the filters 70 is not limited to this example. For example, filters 70B to 70D may be assembled to the pump 1 with orientations opposite to those shown in Figures 7B to 7D.

[0054] The characteristic configurations of the pump 1 according to some of the embodiments described above can be summarized as follows:

[0055] [1] Pumps (1) according to at least some embodiments of the present invention are A rotor (10) including an impeller (12), The pump housing (40) has an opening (41) that communicates with the inlet (12A) of the impeller (12), and extends radially outward from the opening (41) so as to cover the impeller (12), An inlet channel forming member (60) is attached to the pump housing (40) and has an inlet channel (62) on its inside that communicates with the opening (41) of the pump housing (40), Equipped with, The pump housing (40) is A stopper (50) is provided on the radially inner side of the impeller (12) at a radial position that coincides with the center of the opening (41), and is used to restrict the axial position of the rotor (10). A support (44) extends radially inward from the inner circumferential wall of the opening (41) and supports the stopper (50), Includes.

[0056] According to the configuration described in [1] above, since the inlet channel forming member (60) is attached to the pump housing (40), the inlet channel forming member (60) is separated from the pump housing (40). Therefore, the variations of the inlet channel forming member (60) can be increased without affecting the design of the pump housing (40). Thus, by selecting an appropriate one from the variations of the inlet channel forming member (60), the degree of freedom in the placement of the pump (1) can be improved. Furthermore, since the inlet channel forming member (60) is separated from the pump housing (40), it is easier to integrally mold the pump housing (40), including a stopper (50) for restricting the axial position of the rotor (10) and a support (44) for supporting the stopper (50), while satisfying mold design constraints. Here, when integrally molding the pump housing (40), including the stopper (50) and the support (44), a common mold can be used regardless of the shape of the inlet channel forming member (60). Therefore, the manufacturing cost of the pump (1) can be reduced.

[0057] [2] In some embodiments, in the configuration of [1] above, The pump housing (40) has a connection portion (46) with the inlet flow path forming member (60) on the side opposite to the impeller (12) in the axial direction.

[0058] According to the configuration described in [2] above, even after the rotor (10) including the impeller (12) has been assembled to the pump housing (40), the inlet flow path forming member (60) can be easily attached to the pump housing (40).

[0059] [3] In some embodiments, in the configuration of [2] above, The connection portion (46) of the pump housing (40) is one of the following: a welded portion (46B), a heat-crimped portion, a mating portion, or a fastening portion (46A) with the inlet flow path forming member (60).

[0060] According to the configuration described in [3] above, the inlet flow path forming member (60) can be easily attached to the pump housing (40) using commonly available component connection methods.

[0061] [4] In some embodiments, in any of the configurations described in [1] to [3] above, The stopper (50) includes an upstream end (52) that gradually decreases in diameter toward the upstream side, located upstream of the support (44). The tip (53) of the upstream end (52) of the stopper (50) is located in the axial direction at the same position as the opening end of the opening (41) on the outer surface of the pump housing (40), or at a position on the opposite side of the support (44) from the opening end of the opening (41).

[0062] In the configuration described in [4] above, the upstream end (52) of the stopper (50) has a hydrodynamically advantageous shape (a shape that gradually narrows in diameter towards the upstream side), thus reducing flow loss toward the impeller (12). That is, the fluid flowing through the inlet channel (62) flows smoothly along the upstream end (52) of the stopper (50) and can reach the impeller (12). In order to enjoy the hydrodynamic effects of the upstream end (52) of the stopper (50) as described above, it is necessary to position the upstream end (52) sufficiently far upstream from the impeller (12), and the direct way to do this is to extend the pump housing (40), which includes the stopper (50), upstream. If the pump housing 40 is extended upstream, the area in which the stopper (50), which is part of the pump housing (40), is located will expand upstream, and as a result, the upstream end (52) of the stopper (50) will move further upstream from the impeller (12). However, in this case, under the condition that the position of the inlet (2) of the pump (1) remains unchanged, the inlet flow path forming member (60) becomes shorter by the amount that the housing (40) is extended, and the effect of improving the degree of freedom in positioning the pump (1) by the inlet flow path forming member (60) being separated from the pump housing (40) is not sufficiently obtained. In this regard, in the configuration of [4] above, the tip (53) of the upstream end (52) of the stopper (50) is in the same position in the axial direction as the opening end of the opening (41) on the outer surface of the pump housing (40), or on the opposite side of the support (44) with the opening end of the opening (41) in between. This makes it possible to position the upstream end (52) of the stopper (50) sufficiently upstream of the impeller (12) while ensuring the length of the inlet flow path forming member (60).

[0063] [5] In some embodiments, in any of the configurations [1] to [4] above, The pump (1) includes a filter (70) provided in the inlet channel (62) of the inlet channel forming member (60).

[0064] As described in [1] above, the inlet channel forming member (60) is a component separated from the pump housing (40). Therefore, there is a relatively high degree of design freedom for the inlet channel forming member (60), and it is easy to add functions other than the formation of the inlet channel (62) to the inlet channel forming member (60). For example, as in the configuration described in [5] above, if a filter (70) is provided in the inlet channel (62) of the inlet channel forming member (60), the filter (70) can capture foreign matter (72) and protect the internal components of the pump (1) from foreign matter (72). Since the filter (70) built into the pump (1) is less expensive than an external filter installed upstream of the pump (1), cost reduction effects can also be expected.

[0065] [6] In some embodiments, in the configuration of [5] above, The filter (70) is an insert component integrally molded with the resin inlet channel forming member (60).

[0066] According to [6] above, by integrally molding the filter (70) and the inlet channel forming member (60) as insert parts using an insert molding method, it is possible to enjoy cost reduction effects by reducing the number of parts.

[0067] [7] In some embodiments, in the configuration of [5] above, The filter (70) is sandwiched between the inlet flow path forming member (60) and the pump housing (40).

[0068] As described in [1] above, the inlet channel forming member (60) is a separate component from the pump housing (40), and the inlet channel forming member (60) is attached to the pump housing (40). Therefore, by sandwiching the filter (70) between the inlet channel forming member (60) and the pump housing (40), as in the configuration described in [7] above, the filter (70) can be assembled at the same time as the inlet channel forming member (60) is attached to the pump housing (40). Thus, the work process required for manufacturing the pump (1) can be simplified.

[0069] [8] In some embodiments, in any of the configurations described in [5] to [7] above, The pump housing (40) includes a peripheral wall portion (42E) that protrudes from the surface of the pump housing (40) opposite to the surface facing the impeller (12) and surrounds the opening (41). The inlet channel forming member (60) has a downstream end (65) with a larger channel cross-sectional area than the opening (41), The downstream end (65) of the inlet channel forming member (60) together with the peripheral wall portion (42E) of the pump housing (40) forms an inlet chamber (63) that communicates with the opening (41). The filter (70) is installed in the inlet chamber (63).

[0070] According to the configuration described in [8] above, the filter (70) is installed in the inlet chamber (63) of the inlet flow path (62), where the flow path cross-sectional area is larger than that of the opening (41). Therefore, a large-area filter (70) can be used, and the increase in pressure loss due to the installation of the filter (70) can be suppressed. In addition, by using a large-area filter (70), the amount of foreign matter (72) that can be collected increases, so the frequency of filter (70) replacement can be reduced. [Explanation of symbols]

[0071] 1 (1A~1C): Pump 10: Rotor 12: Impeller 12A: Entrance 40: Pump Housing 41 :Aperture 42E: Peripheral wall part 44: Support 46: Connection part 46A: Fastening part 46B: Welded part 50: Stopper 52: Upstream end 53: Tip 54: Downstream end 60 (60A~60F): Inlet channel forming member 62: Inlet channel 63: Entrance Chamber 65: Downstream end 70 (70A~70D): Filter

Claims

1. The rotor, including the impeller, A pump housing having an opening that communicates with the inlet of the impeller and extending radially outward from the opening so as to cover the impeller, An inlet channel forming member is attached to the pump housing and has an inlet channel on its inside that communicates with the opening in the pump housing, Equipped with, The pump housing is A stopper is provided on the radially inner side of the impeller at a radial position that coincides with the center of the opening, for restricting the axial position of the rotor, A support extending radially inward from the inner circumferential wall of the opening, for supporting the stopper, including pump.

2. The pump housing has a connection portion with the inlet flow path forming member on the side opposite to the impeller in the axial direction. The pump according to claim 1.

3. The connection portion of the pump housing is one of the following: a welded portion, a heat-crimped portion, a mating portion, or a fastening portion with respect to the inlet flow path forming member. The pump according to claim 2.

4. The stopper includes an upstream end that gradually decreases in diameter toward the upstream side, located upstream of the support. The tip of the upstream end of the stopper is provided in the axial direction at the same position as the opening end of the opening on the outer surface of the pump housing, or at a position on the opposite side of the support, with the opening end in between. The pump according to any one of claims 1 to 3.

5. The pump according to any one of claims 1 to 3, further comprising a filter provided in the inlet channel of the inlet channel forming member.

6. The filter is an insert component integrally molded with the resin inlet channel forming member. The pump according to claim 5.

7. The filter is sandwiched between the inlet flow path forming member and the pump housing. The pump according to claim 5.

8. The pump housing includes a peripheral wall portion that protrudes from the surface of the pump housing opposite to the surface facing the impeller and is provided to surround the opening. The inlet channel forming member has a downstream end with a channel cross-sectional area larger than the opening, The downstream end of the inlet channel forming member, together with the peripheral wall portion of the pump housing, forms an inlet chamber that communicates with the opening. The filter is provided in the inlet chamber. The pump according to claim 5.

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