centrifugal pump

Abstract

An object of the present invention is to provide a centrifugal pump that can easily have a small overall height while maintaining strength at the connection between the main body case and the joint. [Solution] A centrifugal pump (1) includes a rotating impeller member (20), a main body case (10) that houses the rotating impeller member (20), and a suction joint (60) that communicates with the main body case (10). The centrifugal pump (1) also includes a suction-side attachment (70) that connects the main body case (10) and the suction joint (60). The suction-side attachment (70) is made of a material that has greater fracture strength than the material that makes up the suction joint (60), and includes a suction-side insertion part (71) that connects to the main body case (10), and a joint connection part (73) that connects to the suction joint (60). At least the suction-side insertion part (71) has a thickness that is smaller than the suction joint (60), and a height dimension (H1) that is smaller than the outer diameter (D1) of the suction joint (60).

Description

[Technical Field]

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

[0002] Conventionally, centrifugal pumps that are installed in a circulation circuit of a fluid such as cooling water and circulate the fluid are known (see, for example, Patent Document 1). As shown in FIG. 1 of Patent Document 1, the centrifugal pump described in Patent Document 1 includes a main body case 34, a rotary vane member 12 housed in the main body case 34, and a suction-side coupling member 42 and a discharge-side coupling member 46 (hereinafter sometimes referred to as coupling members) that communicate with the inside and outside of the main body case 34. In this centrifugal pump, the fluid that flows into the main body case 34 from the suction-side coupling member 42 is sent to the discharge-side coupling member 46 by the rotary vane member 12 and flows out from the discharge-side coupling member 46. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6151294 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional centrifugal pumps such as those described above, a space larger than the diameter of the coupling member must be secured in the mounting portion of the main body case 34 to accommodate the coupling member, making it difficult to reduce the height of the case. One possible solution to this problem would be to reduce the space by reducing the outer diameter of the coupling member, but this would result in a smaller inner diameter of the coupling member, potentially reducing the flow rate within the coupling member. On the other hand, increasing the inner diameter of the coupling member would reduce the wall thickness of the coupling member, making it difficult to maintain the strength of the coupling member.

[0005] An object of the present invention is to provide a centrifugal pump that can easily have a small overall height while maintaining strength at the connection between the main body case and the joint. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the object, the centrifugal pump of the present invention is a centrifugal pump comprising: a rotary vane member that rotates around the axis of a shaft member to flow a fluid; a main body case that houses the rotary vane member; and a coupling member that communicates with the main body case, and further comprising an attachment member that connects the main body case and the coupling member, the attachment member being made of a material that has greater fracture strength than a material that constitutes the coupling member, and comprising: a main body connecting part that is connected to the main body case; and a coupling connecting part that is connected to the coupling member, and at least the main body connecting part has a thickness that is thinner than the coupling member and a height that is smaller than the outer diameter of the coupling member.

[0007] According to the present invention, the coupling member and the main body case are connected via an attachment member, which is connected to the main body case by a main body connection portion having a height smaller than the outer diameter of the coupling member. Therefore, compared to a structure in which the coupling member is directly connected to the main body case, the space required for connecting the coupling member in the height direction in the main body case can be reduced. This facilitates reducing the height dimension of the main body case, contributing to the miniaturization of the centrifugal pump. Furthermore, with this configuration, when reducing the height dimension of the main body case, it is not necessary to change the shape or size of the coupling member. That is, it is not necessary to intentionally reduce the outer diameter or thickness of the coupling member. Conversely, it is possible to increase the outer diameter or thickness of the coupling member. Furthermore, the attachment member is made of a material with greater fracture strength than the coupling member. This facilitates maintaining the strength of the connection portion between the main body case and the coupling portion including the coupling member and the attachment member. Furthermore, because the main body connection portion has a smaller thickness than the coupling member, a decrease in flow rate at that portion can be suppressed. Therefore, it is possible to provide a centrifugal pump in which the overall height dimension can be easily reduced while maintaining the strength of the connection between the main body case and the joint portion.

[0008] In this case, it is preferable that the main body connection portion of the attachment member constitutes a pump main body insertion portion that is inserted into the main body case, and that the pump main body insertion portion has a flat structure with a width dimension larger than its height dimension. With this configuration, the main body connection portion of the attachment member serves as the pump main body insertion portion, and the pump main body insertion portion has a flat structure, allowing the main body connection portion to be flat. This makes it easier to reduce the space required for connecting the coupling member in the main body case in the height direction. Furthermore, with this configuration, the pump main body insertion portion has a width dimension larger than its height dimension, making it easier to increase the flow rate of fluid through the attachment member compared to a pump main body insertion portion of the same height dimension that is formed in a cylindrical shape.

[0009] Preferably, the coupling connection portion is configured with a coupling insertion portion into which the end of the coupling member can be inserted. With this configuration, the coupling member and the attachment member can be connected by inserting the end of the coupling member into the coupling insertion portion, so there is no need to change the shape or size of the end of the coupling member when connecting the coupling member and the attachment member. This makes it possible to suppress changes in the flow rate within the coupling member.

[0010] Furthermore, it is preferable that a communication space be provided between the main body connection portion and the joint connection portion in the attachment member, the communication space being in communication with the main body connection portion and the joint connection portion and defining the relative positions of the main body connection portion and the joint connection portion. According to this configuration, the provision of the communication space in the attachment member allows the relative positions of the main body connection portion and the joint connection portion to be freely defined. This significantly increases the degree of freedom in selecting the position of the joint connection portion relative to the main body connection portion, making it possible to obtain a centrifugal pump that can accommodate a variety of joint member layouts.

[0011] Preferably, the coupling member comprises a suction coupling through which fluid flowing into the main body case flows and a discharge coupling through which fluid flowing out of the main body case flows, the attachment member comprises a suction-side attachment connecting the suction coupling to the main body case and a discharge-side attachment connecting the discharge coupling to the main body case, a blade case accommodating the rotary blade member is disposed within the main body case, and the main body connection portion of at least one of the suction-side attachment and the discharge-side attachment is inserted through a side wall extending in a height direction of the main body case and a vertical wall extending in the height direction of the blade case and welded to the side wall and the vertical wall. With this configuration, the main body connection portion of at least one of the suction-side attachment and the discharge-side attachment is fixed in a state where it is inserted through the side wall of the main body case and the vertical wall of the blade case. Therefore, compared to a structure in which the main body connection part is not fixed to the blade case or is not inserted into the main body case or the blade case, the coupling member can be firmly fixed to the main body case, and the state in which the coupling member is connected to the main body case can be stably maintained. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a centrifugal pump in which the overall height dimension can be easily reduced while maintaining the strength of the connection portion between the main body case and the joint portion. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a plan view of a centrifugal pump according to an embodiment of the present invention, viewed from above; [Figure 2] 2 is a cross-sectional view taken along line AA in FIG. 1. [Figure 3] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 4] 3 is a cross-sectional view taken along line CC in FIG. 2. [Figure 5] 10A and 10B are cross-sectional views showing variations of the attachment member. [Figure 6](A) is an oblique view of the attachment member according to the second embodiment as seen from the main body connection part side, (B) is an oblique view of the attachment member according to the second embodiment as seen from the joint connection part side, and (C) is a cross-sectional view of the attachment member according to the second embodiment cut along the axial direction. [Figure 7] 10A is a perspective view of an attachment member according to a third embodiment as seen from the main body connection part side, and FIG. 10B is a perspective view of an attachment member according to the third embodiment as seen from the joint connection part side. [Figure 8] FIG. 10 is a plan view of a centrifugal pump according to a fourth embodiment, as viewed from above. DETAILED DESCRIPTION OF THE INVENTION

[0014] A first embodiment of the present invention will be described below with reference to FIGS. 1 to 4. In the following description, the direction along the axis L of a shaft member (described later) is referred to as the height direction, and is referred to as the "height direction Z." One side of the height direction Z is referred to as the "upper side Z1," and the other side is referred to as the "lower side Z2." One of the radial directions perpendicular to the height direction Z is referred to as the "width direction X." The radial direction perpendicular to the height direction Z, which is perpendicular to the width direction X, is referred to as the "front-rear direction Y." In the width direction X and the front-rear direction Y, the direction approaching the axis L is referred to as the inward side, and the direction away from the axis L is referred to as the outward side. These definitions of directions are provided for convenience of description and do not limit the directions during manufacture and use of the centrifugal pump 1 according to this embodiment.

[0015] A centrifugal pump 1 is installed, for example, in a closed circuit in which a fluid circulates, and causes the fluid to flow. As shown in FIG. 1, the centrifugal pump 1 includes a main body case 10, a suction-side joint 50 (joint), and a discharge-side joint 80 (joint). Fluid that flows into the main body case 10 via the suction-side joint 50 flows out of the main body case 10 via the discharge-side joint 80. The main body case 10 is formed into a substantially cylindrical shape from a metal material such as stainless steel (SUS). As shown in FIG. 2, the main body case 10 includes a lower main body case 11. The lower main body case 11 includes a bearing receiving portion 11a that forms the lower end of the main body case 10. The bearing receiving portion 11a is formed into a cylindrical shape with a bottom that opens upward, and a cylindrical bushing 12 is fixed inside the bearing receiving portion 11a by press-fitting or the like.

[0016] The lower end of a shaft member 13 extending in the height direction Z is press-fitted or otherwise fixed into the center of the bushing 12 so as to be unrotatable about the axis L. A rotor accommodating portion 11b is formed above the bearing accommodating portion 11a. The rotor accommodating portion 11b is formed in a cylindrical shape with a bottom and a larger diameter than the bearing accommodating portion 11a, and is continuous with the upper end of the bearing accommodating portion 11a. A rotor magnet 30 that rotates integrally with the rotating blade member 20 is accommodated in the rotor accommodating portion 11b. A bracket 11c that protrudes outward is fixed to the upper outer peripheral surface of the rotor accommodating portion 11b. The bracket 11c engages with a protrusion 42a of the coil case 40, which will be described later. An extension portion 11d that extends radially outward about the axis L is formed at the upper end of the rotor accommodating portion 11b. The extension portion 11d is formed in a plate shape, and its outer edge is bent downward to form a flange-shaped outer peripheral connecting portion 11e.

[0017] An upper main body case 14 made of a metal material is disposed above the lower main body case 11. The upper main body case 14 has a top wall 14a extending in the intersecting direction. A bulging portion 14b bulges upward and extends in the intersecting direction at the center of the top wall 14a. The inner wall surface of the bulging portion 14b forms part of a fluid introduction flow path S1, which will be described later. A side wall 14c is formed at the outer edge of the top wall 14a, bending downward and extending in the direction of the axis L. The lower end of the side wall 14c is fixed to an outer peripheral connection portion 11e of the lower main body case 11 by welding or the like.

[0018] The side wall 14c is formed with an inlet 14d and an outlet 14e that communicate with the inside and outside of the main body case 10. In this embodiment, as shown in Fig. 2, the inlet 14d penetrates in the width direction X, and an inlet-side attachment 70 (attachment member) of the inlet-side joint 50 (described later) is connected to its inner peripheral surface. As shown in Fig. 3, the outlet 14e penetrates in the front-rear direction Y, and an outlet-side attachment 100 (attachment member) of the outlet-side joint 80 (described later) is connected to its inner peripheral surface.

[0019] The blade case 15 is disposed between the lower case body 11 and the upper case body 14. The blade case 15 includes a horizontal wall 15a disposed below the top wall 14a of the upper case body 14. The horizontal wall 15a faces the bulging portion 14b of the top wall 14a across a gap in the height direction Z and extends along the inner wall surface of the top wall 14a in a direction intersecting the axis L. A flow path opening 15b penetrating in the direction of the axis L is formed in the center of the horizontal wall 15a. A vertical wall 15c is formed continuously from the outer edge of the horizontal wall 15a. The vertical wall 15c bends from the outer edge of the horizontal wall 15a and extends downward Z2. As shown in FIG. 4, the vertical wall 15c faces the inner surface of the side wall 14c of the upper case body 14 and extends circumferentially around the axis L.

[0020] A portion of the outer peripheral surface of the vertical wall 15c abuts a portion of the inner peripheral surface of the side wall 14c, and an attachment port 15e communicating with the inside and outside of the main body case 10 is formed in this abutting portion 15d. In this embodiment, the attachment port 15e is penetrating in the front-rear direction Y and communicates with the above-mentioned discharge port 14e, and a discharge-side attachment 100 (attachment member) of the discharge-side joint, which will be described later, is connected to its inner peripheral surface. In addition, a control wall 15f extending radially inward around the axis L is formed at one circumferential end of the abutting portion 15d. The control wall 15f blocks the fluid flowed by the rotary vane member 20, thereby increasing the pressure near the attachment port 15e. This increases the discharge pressure of the fluid and ensures a sufficient flow rate.

[0021] 3, a flange 15g is formed at the lower end of the vertical wall 15c. The flange 15g protrudes radially outward around the axis L and has its protruding end bent downward Z2. The flange 15g is fixed by welding or the like while being sandwiched between the outer circumferential surface of the outer circumferential connecting portion 11e of the lower main body case 11 and the inner wall surface of the side wall 14c of the upper main body case 14 in a direction intersecting the axis L. By installing the blade case 15, a fluid introduction flow path S1 surrounded by the upper main body case 14 and the blade case 15 is formed inside the main body case 10. Furthermore, a blade accommodating space S2 surrounded by the lower main body case 11 and the blade case 15 is formed inside the main body case 10.

[0022] The blade housing space S2 accommodates a rotary blade member 20. The rotary blade member 20 rotates about the axis L of the shaft member 13, which is fixed non-rotatably by the bush 12, to cause a fluid to flow about the axis L. As shown in FIG. 3, the rotary blade member 20 includes a cylindrical bearing portion 21 extending in the direction of the axis L. The lower end of the bearing portion 21 is supported by the upper end of the bush 12 via an annular thrust bearing 22, and the shaft member 13 is inserted through the center of the bearing portion 21. A groove portion 21a is formed on the outer peripheral surface of the bearing portion 21, recessed radially inward about the axis L, and an annular snap ring 21b is installed in the groove portion 21a. A rotor magnet 30 is installed around the bearing portion 21.

[0023] The rotor magnet 30 is cylindrically formed with a thick, disc-shaped upper wall portion 31 and a side wall portion 32 that extends from the outer peripheral edge of the upper wall portion 31 to the lower side Z2 and circumferentially surrounds the bearing portion 21. The lower end surface of the upper wall portion 31 of the rotor magnet 30 is supported by a snap ring 21b installed in the bearing portion 21, thereby integrating the rotary vane member 20 and the rotor magnet 30. A cylindrical flange portion 23 with a larger diameter than the bearing portion 21 is formed at the upper end of the bearing portion 21, and blade portions 24 are connected to the flange portion 23. As shown in FIG. 4, the blade portions 24 are erected on an upper flange surface 23a, which is the surface on the upper side Z1 of the flange portion 23, and extend radially outward around the axis L, centered on the axis L.

[0024] The main body case 10 thus formed is housed in a coil case 40. As shown in FIG. 3, the coil case 40 is formed in a generally box-like shape with a base portion 41 that forms the lower Z2 portion and a coil cover 42 that is attached to the base portion 41 and forms a part of the side wall. A through-hole 41a that penetrates the base portion 41 in the direction of the axis L is formed in the center of the base portion 41, and the bearing housing portion 11a of the lower main body case 11 is disposed within the through-hole 41a. A protrusion 42a that protrudes inward toward the axis L is formed at the upper end of the coil cover 42. The protrusion 42a engages with a bracket 11c fixed to the rotor housing portion 11b of the main body case 10. A plurality of coil portions 43 are disposed within the coil case 40. The plurality of coil portions 43 are disposed at intervals along the circumferential direction of the rotor housing portion 11b.

[0025] The coil section 43 includes a stator core 44 extending in the transverse direction, a bobbin case 45 arranged around the axis of the stator core 44, and a coil 46 wound around the axis of the stator core 44 via the bobbin case 45. In FIG. 3, reference numeral 47 denotes a circuit board, 47a denotes a terminal pin, 48 denotes a cable insertion hole, 49 denotes a cable, and 49a denotes a connector. With this configuration, when a current flows through the coils 46 via the cable 49, connector 49a, terminal pin 47a, and circuit board 47, the multiple coils 46 are excited, generating a magnetic force around the rotor accommodating section 11b. This magnetic force then acts on the rotor magnet 30, causing the rotating blade member 20 to rotate around the axis L.

[0026] Next, the suction-side joint 50 will be described. The suction-side joint 50 is a joint that communicates with the main body case 10 and allows fluid to flow between the inside and outside of the main body case 10. As shown in FIG. 2, it includes a suction joint 60 (joint member) and a suction-side attachment 70 (attachment member). The suction joint 60 is formed in a tubular shape using a metal material such as phosphorus-deoxidized copper, and allows fluid to flow inside. The suction-side attachment 70 is a member that connects the main body case 10 and the suction joint 60 and is made of a material, such as SUS (stainless steel), that has greater fracture strength than the suction joint 60. The suction-side attachment 70 can be formed, for example, by press processing, header processing, MIM (Metal Injection Molding) processing, or the like. The suction-side attachment 70 includes a suction-side insertion portion 71 (pump main body insertion portion, main body connection portion), an intermediate portion 72, and a joint connection portion 73. Suction side insertion portion 71 is a portion that connects to suction port 14d of main body case 10, and in this embodiment is formed in a cylindrical shape, and is inserted into suction port 14d of side wall 14c and then welded and fixed to main body case 10. Note that the fixing means for suction side insertion portion 71 is not limited to this and can be selected appropriately; for example, suction side insertion portion 71 may be fixed to main body case 10 by brazing, laser welding, or the like.

[0027] As shown in FIG. 2 , the suction-side insertion portion 71 has a smaller wall thickness than the suction joint 60. Furthermore, the height dimension H1 of the suction-side insertion portion 71 is smaller than the outer diameter D1 of the suction joint 60. That is, the suction-side insertion portion 71 has a smaller wall thickness than the suction joint 60 and a smaller height than the outer diameter of the suction joint 60. The intermediate portion 72 extends radially outward from the suction-side insertion portion 71 around the axis L. In this embodiment, the intermediate portion 72 has the same wall thickness as the suction-side insertion portion 71 and a tapered shape that increases in diameter radially outward. However, the thickness and shape are not limited to this, and can be adjusted as appropriate. The interior of the intermediate portion 72 defines a communication space 74 that connects the suction-side insertion portion 71 and the joint connection portion 73. In this embodiment, the intermediate portion 72 extends in the width direction X, making the suction side insertion portion 71 and the suction joint 60 coaxial, but this is not limited to this. By adjusting the shape of the intermediate portion 72, etc., the relative positions of the suction side insertion portion 71 and the joint connection portion 73 can be freely determined.

[0028] The joint connection portion 73 is a portion for connecting the suction joint 60 and is formed in a cylindrical shape. In this embodiment, the joint connection portion 73 is configured as a joint insertion portion 75 into which the suction joint 60 can be inserted. This joint insertion portion 75 is formed in a cylindrical shape with the same wall thickness as the suction side insertion portion 71 and an inner diameter larger than the outer diameter D1 of the suction joint 60. Note that the wall thickness and shape of the joint insertion portion 75 are not limited to these and can be adjusted as appropriate to match the shape of the suction joint 60, etc. The end of the suction joint 60 is inserted and fixed in the joint insertion portion 75. In this manner, the main body case 10 and the suction joint 60 are connected via the suction side attachment 70.

[0029] Next, the discharge-side joint 80 will be described. Like the suction-side joint 50 described above, the discharge-side joint 80 is a joint that communicates with the main body case 10 and allows fluid to flow between the inside and outside of the main body case 10. The discharge-side joint 80 differs from the suction-side joint 50 in the connection location with the main body case 10, but its structure is substantially the same as that of the suction-side joint 50. Therefore, the configuration of the discharge-side joint 80 will be mainly described here, and detailed descriptions of the structure other than those that differ from the suction-side joint 50 will be omitted. As shown in FIG. 3 , the discharge-side joint 80 includes a discharge joint 90 (joint member) and a discharge-side attachment 100 (attachment member). The discharge-side attachment 100 includes a discharge-side insertion portion 101 (pump main body insertion portion, main body connection portion), an intermediate portion 102 having a communication space portion 104, and a joint insertion portion 105 (joint connection portion 103).

[0030] As shown in Fig. 4, the discharge-side insertion part 101 of the discharge-side attachment 100 is inserted into the discharge port 14e formed in the side wall 14c of the main body case 10, and is also inserted into the mounting port 15e formed in the vertical wall 15c of the impeller case 15. In this inserted state, the discharge-side insertion part 101 is fixed to the main body case 10 by brazing or the like. Note that the fixing means for the discharge-side insertion part 101 can also be selected appropriately, similar to the fixing means for the suction-side insertion part 71 described above. For example, the discharge-side insertion part 101 may be fixed to the main body case 10 by brazing, laser welding, or the like. With this configuration, the discharge-side insertion part 101 is fixed to both the side wall 14c and the vertical wall 15c, and therefore the state in which it is fixed to the main body case 10 is more likely to be maintained stably. In the present embodiment, the discharge-side insertion portion 101 of the discharge-side attachment 100 is fixed to the side wall 14c of the main body case 10 and the vertical wall 15c of the blade case 15. However, the present invention is not limited to this structure, and the suction-side insertion portion 71 of the suction-side attachment 70 may be fixed to the side wall 14c of the main body case 10 and the vertical wall 15c of the blade case 15. That is, the main body connecting portion (suction-side insertion portion 71 or discharge-side insertion portion 101) of at least one of the suction-side attachment 70 and the discharge-side attachment 100 may be inserted through the side wall 14c extending in the height direction Z of the main body case 10 and the vertical wall 15c extending in the height direction Z of the blade case 15, and may be welded (by brazing, laser welding, or the like) to the side wall 14c and the vertical wall 15c.

[0031] The operation of the centrifugal pump 1 configured as described above will now be described. First, in the assembled state shown in FIG. 2, when current is passed through the coil portion 43, the coil 46 is excited, generating a magnetic force around the rotor housing portion 11b. This magnetic force acts on the rotor magnet 30 of the rotating blade member 20, causing the rotating blade member 20 to rotate around the axis of the shaft member 13. This generates a fluid flow around the axis L within the main body case 10. As a result, the fluid flows from the inside of the suction joint 60 through the joint insertion portion 75, intermediate portion 72, and suction side insertion portion 71 of the suction side attachment 70 in this order, and then flows into the fluid introduction flow path S1 via the suction port 14d of the main body case 10.

[0032] The fluid then flows toward the center of the main body case 10 and into the blade housing space S2 from the flow path opening 15b of the blade case 15. The fluid that has flowed into the blade housing space S2 flows in a predetermined direction (e.g., counterclockwise) around the axis L shown in FIG. 4, passes through the discharge port 14e, flows out of the main body case 10, and flows through the discharge-side insertion part 101 of the discharge-side attachment 100. At this time, the fluid is blocked to some extent by the control wall 15f, which increases the pressure near the discharge port 14e, and the fluid flows out with sufficient discharge pressure. The fluid then flows through the intermediate part 102 and the joint insertion part 105 of the discharge-side attachment 100 and into the discharge joint 90.

[0033] According to the above-described embodiment, the suction joint 60 and the case body 10 are connected via the suction-side attachment 70, which is connected to the case body 10 by the suction-side insertion portion 71 (main body connection portion) having a height dimension H1 (height) smaller than the outer diameter D1 of the suction joint 60 (joint member). The discharge joint 90 and the case body 10 are also connected via the discharge-side attachment 100, which is connected to the case body 10 by the discharge-side insertion portion 101 (main body connection portion) having a height dimension H1 (height) smaller than the outer diameter D1 of the discharge joint 90 (joint member). Therefore, compared to a structure in which the suction joint 60 and the discharge joint 90 are directly connected to the case body 10, the space required for connecting the suction joint 60 and the discharge joint 90 in the case body 10 can be reduced in the height direction Z. Therefore, even if there is not enough space in the case body 10 to directly connect the suction joint 60 and the discharge joint 90, the suction joint 60 and the discharge joint 90 can be connected to the case body 10. Therefore, the height dimension of the main body case 10 can be easily reduced, which contributes to making the centrifugal pump 1 more compact.

[0034] Furthermore, with this configuration, when the height dimension of the main body case 10 is reduced, there is no need to change the shape or size of the suction joint 60 and the discharge joint 90. That is, there is no need to intentionally reduce the outer diameter D1 of the suction joint 60 and the discharge joint 90 or to reduce the wall thickness of the suction joint 60 and the discharge joint 90. Conversely, it is possible to increase the outer diameter D1 of the suction joint 60 and the discharge joint 90 or to increase the wall thickness of the suction joint 60 and the discharge joint 90. Furthermore, the suction-side attachment 70 and the discharge-side attachment 100 are made of a material with greater fracture strength than the suction joint 60 and the discharge joint 90. This makes it easier to maintain the strength of the connection between the suction-side joint 50 (joint) and the discharge-side joint 80 (joint) and the main body case 10. Furthermore, since the suction side insertion portion 71 and the discharge side insertion portion 101 have a smaller wall thickness than the suction joint 60 and the discharge joint 90, a decrease in flow rate at these portions can be suppressed. Therefore, it is possible to provide a centrifugal pump 1 that can easily reduce the overall height while maintaining the strength of the connection portions between the suction side joint 50 and the discharge side joint 80 and the main body case 10.

[0035] Furthermore, according to this embodiment, the joint connection portion 73 of the suction side attachment 70 constitutes a joint insertion portion 75 into which the end of the suction joint 60 can be inserted. Furthermore, the joint connection portion 103 of the discharge side attachment 100 constitutes a joint insertion portion 105 into which the end of the discharge joint 90 can be inserted. Therefore, when connecting the suction joint 60 to the suction side attachment 70 or the discharge joint 90 to the discharge side attachment 100, it is not necessary to change the shape or size of the end of the suction joint 60 or the discharge joint 90. Therefore, changes in the flow rate inside the suction joint 60 and the discharge joint 90 can be suppressed.

[0036] Furthermore, according to this embodiment, the discharge-side insertion part 101 of the discharge-side attachment 100 is fixed in a state in which it is inserted into the side wall 14c of the main body case 10 and the vertical wall 15c of the blade case 15. Therefore, compared to a structure in which the discharge-side insertion part 101 is not fixed to the blade case 15 or a structure in which the discharge-side insertion part 101 is not inserted into the main body case 10 and the blade case 15, the discharge joint 90 can be firmly fixed to the main body case 10, and the state in which the discharge joint 90 is connected to the main body case 10 can be stably maintained.

[0037] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configurations are not limited to these, and the present invention also includes design changes and the like that do not deviate from the gist of the present invention.

[0038] 5(A) and (B) are cross-sectional views showing variations of the attachment member. In the figures, suction-side joint 50A and suction-side joint 50B are shown as examples of the attachment member to explain suction-side attachment 70A or suction-side attachment 70B, but a similar configuration can also be applied to discharge-side joint 80. As shown in FIG. 5(A), suction-side attachment 70A of suction-side joint 50A includes joint connecting portion 73A. An end of joint connecting portion 73A forms inserted portion 75A that is connected to suction joint 60 when inserted into the end of suction joint 60. As shown in FIG. 5(B), suction-side attachment 70B of suction-side joint 50B includes joint connecting portion 73B. An end of joint connection portion 73B forms abutment portion 75B that is connected by welding (brazing, laser welding, etc.) in a butt-to-butt state to the end face of suction joint 60. In this way, even in a configuration in which joint connection portion 73A is connected to suction joint 60 in an inserted state, or a configuration in which joint connection portion 73B is connected to suction joint 60 in an abutting state, it is possible to provide a centrifugal pump 1 that can easily reduce the overall height dimension while maintaining the strength of the connection portion between suction joint 60 and main body case 10.

[0039] Next, a second embodiment of the present invention will be described. A centrifugal pump 1 according to the second embodiment includes a suction-side attachment 70C. FIG. 6(A) is a perspective view of the suction-side attachment 70C according to the second embodiment, viewed from the suction-side insertion portion 71C side. FIG. 6(B) is a perspective view of the suction-side attachment 70C, viewed from the joint insertion portion 75c side. FIG. 6(C) is a cross-sectional view of the suction-side attachment 70C taken along the axis L1. As shown in FIG. 6(A), the suction-side attachment 70C includes a cylindrical, bottomed, tubular attachment main body 76. The bottom of the attachment main body 76 is formed with a suction-side insertion portion 71C that protrudes outward. The suction-side insertion portion 71C is coaxial with the attachment main body 76 and has a smaller diameter than the attachment main body 76.

[0040] As shown in FIG. 6(B), a fitting insertion portion 75c that opens in the axial direction is formed at the end opposite the bottom of the attachment main body 76. The end of a suction fitting 60 (not shown) is inserted into the fitting insertion portion 75c. As shown in FIG. 6(C), a communication space 74c that connects the suction side insertion portion 71C and the fitting insertion portion 75c is formed inside the attachment main body 76. The communication space 74c is formed in a tapered shape that increases in diameter toward the fitting insertion portion 75c, for example, by cutting the inner wall surface of the attachment main body 76. In the second embodiment, the thickness of the suction side insertion portion 71C is smaller than the thickness of the fitting insertion portion 75c.

[0041] Although not shown, the thickness of the suction-side insertion portion 71C is smaller than the thickness of the suction joint 60. In this manner, in the suction-side attachment 70C, the thickness of at least the suction-side insertion portion 71C may be smaller than the thickness of the suction joint 60, while the thickness of the remaining portions may be larger. Even with a configuration including such a cylindrical attachment body 76, the same effects and advantages as those of the above-described embodiment can be achieved. Furthermore, according to this embodiment, the appearance of the suction-side attachment 70C is determined only by the shapes of the attachment body 76 and the suction-side insertion portion 71C, so the appearance of the suction-side attachment 70C can be simplified compared to the above-described embodiment. While the second embodiment has been described with respect to the suction-side attachment 70C, this configuration can also be applied to the discharge-side attachment 100.

[0042] Next, a third embodiment of the present invention will be described. Fig. 7(A) is a perspective view of a suction-side attachment 70D according to the third embodiment, as viewed from the suction-side insertion portion 71D, and Fig. 7(B) is a perspective view of the suction-side attachment 70D as viewed from the coupling insertion portion 75D side. As shown in Fig. 7(A), the suction-side attachment 70D includes a cylindrical attachment main body 77 with a bottom. A suction-side insertion portion 71D protruding in the axial direction is formed at the bottom of the attachment main body 77. Unlike the above-described embodiments, the suction-side insertion portion 71D of the third embodiment has a flat structure in which the width dimension W1 is large relative to the height dimension H2. As shown in Fig. 7(B), a coupling insertion portion 75D opening in the axial direction is formed at the end of the attachment main body 77 opposite the bottom. An end of a suction coupling 60 (not shown) is inserted into the coupling insertion portion 75D.

[0043] According to the third embodiment, suction-side insertion section 71D (main body connection section, pump main body insertion section) of suction-side attachment 70D has a flat structure. That is, suction-side insertion section 71D is flat. This makes it easier to reduce the space required for connecting suction joint 60 in main body case 10 in the height direction Z. Furthermore, according to this configuration, suction-side insertion section 71D has a large width dimension W1 relative to height dimension H2, which increases the flow rate of fluid flowing through suction-side attachment 70 compared to a case in which a suction-side insertion section of the same height dimension is formed in a cylindrical shape. Note that while the third embodiment has been described with respect to suction-side attachment 70D, this configuration can also be applied to discharge-side attachment 100.

[0044] Next, a fourth embodiment of the present invention will be described. FIG. 8 is a plan view of a centrifugal pump 1 according to the fourth embodiment, viewed from the upper side Z1. The centrifugal pump 1 of the fourth embodiment includes a suction-side attachment 70E and a discharge-side attachment 100E. The suction-side attachment 70E corresponds to the suction-side attachment 70 described above, and the discharge-side attachment 100E corresponds to the discharge-side attachment 100 described above. The suction-side attachment 70E includes a suction-side insertion portion 71, an intermediate portion 72E, and a fitting connection portion 73. The intermediate portion 72E includes an enlarged diameter pipe portion 72e that is continuous with the suction-side insertion portion 71 and extends outward while expanding in diameter, and a bent portion 72d that is continuous with the enlarged diameter pipe portion 72e and bent in the front-rear direction Y. Although not shown, the interiors of the enlarged diameter pipe portion 72e and the bent portion 72d form a communicating space. By providing such intermediate portion 72E, the axis of suction joint 60 connected to suction side attachment 70E extends in a direction intersecting the axis of suction side insertion portion 71.

[0045] On the other hand, the discharge side attachment 100E includes a discharge side insertion portion 101, an intermediate portion 102E, and a joint connection portion 103. Similar to the suction side attachment 70E, the intermediate portion 102E includes an expanded diameter pipe portion 102e and a bent portion 102d. Although not shown, the interiors of the expanded diameter pipe portion 102e and the bent portion 102d form a communicating space. By providing such an intermediate portion 102E, the axis of the discharge joint 90 connected to the discharge side attachment 100E extends in a direction intersecting the axis of the discharge side insertion portion 101.

[0046] As described above, according to the fourth embodiment, by providing the intermediate portion 72E (communicating space portion) in the suction-side attachment 70E, the relative positions of, for example, the suction-side insertion portion 71 (main body connection portion) and the joint connection portion 73 in the front-to-rear direction Y can be freely determined. Furthermore, by providing the intermediate portion 102E (communicating space portion) in the discharge-side attachment 100E, the relative positions of, for example, the discharge-side insertion portion 101 (main body connection portion) and the joint connection portion 103 in the front-to-rear direction Y can be freely determined. Note that the relative positions are not limited to the front-to-rear direction Y, and may be set appropriately in the height direction Z, width direction X, or other directions. This configuration significantly improves the degree of freedom in selecting the position of the suction joint 60 relative to the suction-side insertion portion 71 and the position of the discharge joint 90 relative to the discharge-side insertion portion 101. Therefore, a centrifugal pump 1 can be obtained that is compatible with various layouts of the suction joint 60 and the discharge joint 90. [Explanation of symbols]

[0047] D1 Outer diameter H1 Height dimension (height) 1. Centrifugal pump 10 Main unit case 13 Shaft member 20 Rotating blade member 60 Suction joint (joint part) 70 Suction side attachment (attachment part) 71 Suction side insertion part (main body connection part) 73 Fitting connection 90 Discharge joint (joint part) 100 Discharge side attachment (attachment member) 101 Discharge side insertion part (main body connection part) 103 Fitting connection part

Claims

1. A centrifugal pump comprising: a rotary vane member that rotates around the axis of a shaft member to cause a fluid to flow; a main body case that houses the rotary vane member; and a coupling member that communicates with the main body case, an attachment member that connects the main body case and the joint member; the attachment member is made of a material having a greater breaking strength than a material constituting the joint member, and includes a main body connecting portion connected to the main body case and a joint connecting portion connected to the joint member, A centrifugal pump, characterized in that at least the main body connection portion has a wall thickness smaller than that of the coupling member and a height smaller than an outer diameter of the coupling member.

2. In the attachment member, the main body connection portion constitutes a pump main body insertion portion to be inserted into the main body case, 2. The centrifugal pump according to claim 1, wherein the pump body insertion portion has a flat structure in which the width dimension is larger than the height dimension.

3. 2. The centrifugal pump according to claim 1, wherein the joint connection portion is configured as a joint insertion portion into which an end of the joint member can be inserted.

4. 2. The centrifugal pump according to claim 1, wherein a communication space is provided between the main body connection portion and the joint connection portion in the attachment member, the communication space communicating with the main body connection portion and the joint connection portion and defining the relative positions of the main body connection portion and the joint connection portion.

5. The coupling member includes a suction coupling through which fluid flows into the main body case and a discharge coupling through which fluid flows out of the main body case, the attachment member includes a suction side attachment that connects the suction joint and the main body case, and a discharge side attachment that connects the discharge joint and the main body case, a blade case that houses the rotary blade member is disposed within the main body case; 2. The centrifugal pump according to claim 1, wherein the main body connection portion of at least one of the suction-side attachment and the discharge-side attachment is inserted through a side wall extending in a height direction of the main body case and a vertical wall extending in the height direction of the impeller case, and is welded to the side wall and the vertical wall.

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