Pump device

Abstract

To restrain upsizing of a case and a housing for a motor when forming a pump chamber having an involute shape by welding the case to the housing.SOLUTION: In a pump device 1, a pump chamber 20 is formed between a housing 10 for a motor 3 for rotating an impeller 4 and a case 2. The pump chamber 20 has a shape in which the width of a flow passage F extending in a circumferential direction on an outer periphery of the impeller 4 increases as going toward one side R1 in the circumferential direction. The housing 10 comprises a first flange part 16 protruding to an outer peripheral side from a trunk part 14 covering an outer periphery of a stator 5. The case 2 comprises a second fixing surface 33 opposed to a first fixing surface 19 of the first flange part 16. The second fixing surface 33 comprises a welding rib 42 extending along the outline of the pump chamber 20 when viewed from an axial direction. The first fixing surface 19 comprises a welding concave part 41 to which the welding rib 42 is welded.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a pump device that sucks fluid into a pump chamber and discharges it by rotating an impeller. [Background technology]

[0002] Patent Documents 1 and 2 describe pump devices that circulate cooling water. In the pump device of Patent Document 1, a pump chamber is formed between a housing (a resin sealing member) that covers an annular stator and a case that is fixed to an end of the housing. The impeller rotates integrally with a rotor that is disposed on the inner periphery of the stator. The case includes a suction pipe that is connected to the radial center of the pump chamber and a discharge pipe that is connected to the outer periphery of the pump chamber.

[0003] In Patent Document 1, a pump chamber is formed by axially abutting an annular flange provided at the end of a case against an annular flange provided at the end of a housing (a resin sealing member) and fixing them by vibration welding. The welded portion extends in a circular shape along the outer periphery of the flange. Therefore, there is little variation in weld strength.

[0004] In a pump device in which an impeller rotates in the center of a pump chamber, a fluid intake port is provided in the center of the pump chamber, and a fluid discharge port is provided on the outer periphery of the pump chamber, the shape of the pump chamber may be such that the width of the flow path surrounding the impeller increases toward one side in the circumferential direction (for example, an involute shape). Patent Document 2 describes a pump device with an involute-shaped pump chamber. In the pump device of Patent Document 2, a housing (pump base) and a case (pump mounting portion) are fastened together by bolts on the outer periphery of the pump chamber. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-020102 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-089776 Summary of the Invention [Problem to be solved by the invention]

[0006] When the pump chamber is shaped so that the flow path width increases toward one side in the circumferential direction and the housing and case are welded together to form the pump chamber as in Patent Document 1, providing a circular flange to reduce variations in weld strength and providing a weld along the outer periphery of the flange increases the outer diameter of the flange when viewed from the axial direction, resulting in larger case and housing sizes. As a result, the amount of resin required to manufacture the case and housing increases.

[0007] In view of the above problems, an object of the present invention is to prevent the case and housing from becoming large when a pump chamber that is non-circular when viewed in the axial direction is formed by welding the case to the housing of a motor. [Means for solving the problem]

[0008] In order to solve the above problems, the pump device of the present invention includes a motor including a rotor and a stator surrounding the outer periphery of the rotor, a housing that seals the stator, a case that includes a pump chamber forming portion that is fitted over the housing from one side in the axial direction along the rotation axis of the rotor and forms a pump chamber between the housing and the case, and an impeller that is disposed in the pump chamber and rotates integrally with the rotor, and the shape of the pump chamber as viewed from the axial direction is such that the width of a flow path extending circumferentially around the outer periphery of the impeller becomes wider as it goes towards one side in the circumferential direction. the housing includes a first partition wall portion covering one side of the stator in the axial direction, a body portion covering the outer periphery of the stator, and a first flange portion protruding from the body portion toward the outer periphery, the first flange portion including a first fixing surface facing one side in the axial direction, the pump chamber forming portion including a second fixing surface opposing the first fixing surface, one of the first fixing surface and the second fixing surface including a welding rib extending along the outer shape of the pump chamber as seen from the axial direction, and the other of the first fixing surface and the second fixing surface including a welding recess to which the welding rib is welded.

[0009] According to the present invention, the housing and the case are welded together to form a pump chamber between the housing and the case, in which the width of a flow path extending circumferentially around the outer periphery of the impeller increases toward one side in the circumferential direction. When forming a non-circular pump chamber, the welding rib used to weld the housing and the case is shaped to extend along the outer shape of the pump chamber as viewed from the axial direction, eliminating the need to provide flanges on the case and the housing that protrude significantly toward the outer periphery. This prevents the case and the housing from becoming too large, and reduces the amount of resin required to manufacture the case and the housing.

[0010] In the present invention, it is preferable that one of the first and second fixed surfaces includes an additional welding rib located on the outer periphery of the welding rib, and the other of the first and second fixed surfaces includes an additional welding recess to which the additional welding rib is welded. This makes it possible to reinforce areas where the welding strength of the welding portion extending along the outer shape of the pump chamber is insufficient. Therefore, it is possible to suppress a decrease in durability due to variations in the welding strength of the welding portion or the stress applied to the welding portion. Furthermore, in this case, it is only necessary to extend the case and housing toward the outer periphery only at the areas where the additional welding portion is provided. Therefore, it is possible to suppress an increase in the size of the case and housing.

[0011] In the present invention, the additional welding rib is preferably disposed on the outer periphery of the linearly extending portion of the welding rib. The linearly extending portion of the welding rib is more likely to collapse than the arcuately extending portion, making it difficult to ensure sufficient welding strength. Therefore, by providing the additional welding rib and additional welding recess at this portion, the portion where the welding strength is insufficient can be reinforced.

[0012] In the present invention, when the angular position at which the width of the flow passage extending circumferentially around the outer periphery of the impeller is the widest is defined as a first angular position, and the angular position at which the width of the flow passage is the smallest is defined as a second angular position, the pump chamber forming portion preferably includes an inlet port provided at the radial center of the pump chamber and an outlet port provided at the first angular position, the welding rib includes a first reinforced portion disposed within a first angular range from the first angular position to the second angular position in the circumferential direction, and the additional welding rib and the additional welding recess are preferably disposed on the outer circumferential side of the first reinforced portion. As described above, the shape of the pump chamber of the present invention has a portion where the outer shape of the pump chamber is not arc-shaped in the range (first angular range) from the downstream end position (first angular position T1) of the flow passage F back to the upstream end position (second angular position T2). Therefore, since there is a risk that the welding strength at this portion may not be sufficient, the portion with insufficient welding strength can be reinforced by providing an additional welding portion at this portion.

[0013] In the present invention, the suction port and the discharge port open to one side in the axial direction. In this case, the direction of the fluid flowing circumferentially changes toward one side in the axial direction near the discharge port. Therefore, the direction and magnitude of the fluid pressure applied to the inner circumferential surface of the pump chamber differs from that in other areas, which may result in insufficient welding strength. Therefore, by providing an additional welding rib and an additional welding recess in this area, the area where the welding strength is insufficient can be reinforced.

[0014] In the present invention, the additional welding rib and the additional welding recess are provided outside the first reinforced portion. It is preferable that the additional welding ribs and additional welding recesses are disposed on the circumferential side of the first reinforced portion and on the outer circumferential side of the second reinforced portion that is radially opposite the first reinforced portion. The inventors have confirmed through analysis that when the portion with the lowest welding strength (the first reinforced portion) is reinforced, the portion radially opposite the reinforced portion (the second reinforced portion) will have the next lowest welding strength. Therefore, by providing the additional welding ribs and additional welding recesses in this portion, it is possible to reinforce the portion with insufficient welding strength.

[0015] In the present invention, it is preferable that the additional welding rib has a first portion extending from the outer periphery of the welding rib in a direction intersecting the welding rib, and a gap is provided between the inner periphery end of the first portion and the welding rib. In this way, the first portion can make the welding rib less likely to collapse. Therefore, the welded portion can be effectively reinforced. Furthermore, by providing a gap between the first portion and the welding rib, space can be secured to accommodate welding flash.

[0016] In the present invention, the additional weld rib preferably includes the first portions disposed at two circumferentially separated locations and a second portion connecting the outer peripheral ends of the two first portions. This allows the weld rib to be reinforced at two locations and makes the additional weld rib itself less likely to collapse. Therefore, the reinforcing effect can be enhanced.

[0017] In the present invention, it is preferable that the case includes an attachment portion disposed on the outer periphery of the pump chamber-forming portion, the pump chamber-forming portion including a sidewall portion surrounding the outer periphery of the pump chamber and a protrusion portion protruding from the sidewall portion toward the outer periphery, the attachment portion being disposed on the outer periphery of the protrusion, the second fixing surface including a first region consisting of an end face on the other side in the axial direction of the sidewall portion and a second region consisting of an end face on the other side in the axial direction of the protrusion, the welding rib or the welding recess being provided in the first region, and the additional welding rib or the additional welding recess being provided in the second region. In this way, when an attachment portion for fixing the pump device to a mating member is provided on the case, a structure for connecting the attachment portion and the pump chamber-forming portion (the protrusion portion protruding from the sidewall portion of the pump chamber-forming portion) can be used to ensure space for arranging the additional welding rib or the additional welding recess for reinforcement.

[0018] In the present invention, the housing preferably includes a reinforcing rib connecting the outer circumferential surface of the body portion and the first flange portion, and the reinforcing rib preferably overlaps the welding rib when viewed from the axial direction. In this way, the reinforcing rib can reinforce areas where the welding strength is insufficient. For example, the reinforcing rib can suppress deformation of the first flange portion and suppress a decrease in welding strength due to the welding rib being unable to make sufficient contact with the welding recess.

[0019] In the present invention, it is preferable that the reinforcing rib extends from a position overlapping the welding rib to a position overlapping the additional welding rib when viewed from the axial direction. By providing the reinforcing rib so as to straddle two welding portions in this way, the reinforcing effect can be enhanced. [Effects of the Invention]

[0020] According to the present invention, the housing and the case are welded together to form a pump chamber between the housing and the case, in which the width of a flow path extending circumferentially around the outer periphery of the impeller increases toward one side in the circumferential direction. When forming a non-circular pump chamber, the welding rib used to weld the housing and the case is shaped to extend along the outer shape of the pump chamber as viewed from the axial direction, eliminating the need to provide flanges on the case and the housing that protrude significantly toward the outer periphery. This prevents the case and the housing from becoming too large, and reduces the amount of resin required to manufacture the case and the housing. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view of a pump device to which the present invention is applied. [Figure 2] FIG. 10 is a plan view of the case as viewed from the other side in the axial direction. [Figure 3] FIG. 10 is a perspective view of the case as seen from the other axial side. [Figure 4] FIG. 2 is an exploded perspective view of the rotor and the housing as viewed from one side in the axial direction. [Figure 5] FIG. 4 is a perspective view of the pump device as seen from the other axial side. [Figure 6] FIG. 10 is an explanatory diagram showing the arrangement of the welding ribs, the additional welding ribs, and the reinforcing ribs. DETAILED DESCRIPTION OF THE INVENTION

[0022] A pump device 1 according to an embodiment of the present invention will be described below with reference to the drawings. In the following description, the axial direction refers to the direction in which the rotation axis L of the motor 3 extends (the direction along the rotation axis L), the radial direction refers to the radial direction centered on the rotation axis L, and the circumferential direction refers to the rotation direction centered on the rotation axis L. The direction in which the rotation axis L extends is referred to as the axial direction, with one side of the axial direction referred to as L1 and the other side of the axial direction referred to as L2. One side of the circumferential direction is referred to as R1 and the other side of the circumferential direction referred to as R2.

[0023] (Overall composition) Fig. 1 is a cross-sectional view of a pump device 1 to which the present invention is applied, taken along a plane including a rotation axis L. As shown in Fig. 1, the pump device 1 has a case 2 provided with an intake port 21 and a discharge port 22 that open on one axial side L1, a motor 3 disposed on the other axial side L2 of the case 2, and an impeller 4 disposed in a pump chamber 20 provided between a housing 10 of the motor 3 and the case 2.

[0024] The impeller 4 is driven to rotate around the rotation axis L by the motor 3. In the pump device 1 of this embodiment, the fluid flowing through the pump chamber 20 is liquid. The fluid supplied to the pump chamber 20 from an intake port 21 provided in the radial center of the case 2 moves circumferentially through the pump chamber 20 as the impeller 4 rotates, and is discharged from an outlet port 22 provided on the outer periphery of the pump chamber 20. The intake port 21 and the outlet port 22 open at an end face of the case 2 on one side L1 in the axial direction.

[0025] The motor 3 includes an annular stator 5, a rotor 6 arranged inside the stator 5, a support shaft 7 that rotatably supports the rotor 6, a substrate 8 arranged on the other axial side L2 of the stator 5, a housing 10 that covers the stator 5, and a resin cover 9 that covers the substrate 8. The support shaft 7 is made of metal or ceramic. The housing 10 is a resin sealing member that covers the stator 5 from both radial and axial sides. The housing 10 is made of polyphenylene sulfide (PPS). The stator 5 is integrated with the housing 10 by insert molding.

[0026] The stator 5 includes an annular stator core 51, an insulator 52 overlapping the stator core 51 from one axial side L1, an insulator 53 overlapping the stator core 51 from the other axial side L2, and a plurality of coils 50 wound around a plurality of salient poles provided on the stator core 51 via the insulators 52 and 53. The motor 3 is a three-phase motor. Therefore, the plurality of coils 50 are composed of a U-phase coil, a V-phase coil, and a W-phase coil.

[0027] The housing 10 is a partition member having a first partition 11 covering one axial side L1 of the stator 5, a second partition 12 covering the inner circumferential side of the stator 5, and a bottom wall 13 provided at the end of the second partition 12 on the other axial side L2. The housing 10 also includes a cylindrical body 14 covering the stator 5 from the outside in the radial direction, a cylindrical connector housing 15 extending radially outward from the body 14 on the radial outside of the stator 5, and a first flange 16 expanding radially outward from the end of the body 14 on the one axial side L1. The first flange 16 is connected to the connector housing 15.

[0028] The cover 9 is fixed to the end of the body 14 of the housing 10 on the other side L2. A circular opening 90 is provided in the center of the cover 9, and the opening 90 is covered from one axial side L1 by a metal heat dissipation member 91. Metal winding terminals 55, which penetrate the bottom wall 13 of the housing 10 from the stator 5 and protrude to the other axial side L2, are connected to the circuit board 8, which is disposed between the cover 9 and the bottom wall 13 of the housing 10. When an external power supply connector (not shown) is connected to the connector housing 15, a drive current generated by a circuit mounted on the circuit board 8 is supplied to each coil 50 via the winding terminals 55. As a result, the rotor 6 and impeller 4 rotate together, creating a negative pressure inside the pump chamber 20. Fluid is sucked into the pump chamber 20 through the suction port 21 and discharged from the discharge port 22.

[0029] The rotor 6 includes a rotor member 60 made of resin and a cylindrical magnet 61 held by the rotor member 60. The rotor member 60 includes a cylindrical portion 62 extending in the axial direction and a disk-shaped flange portion 63 extending from an end of one side L1 in the axial direction of the cylindrical portion 62 toward the outer periphery. The magnet 61 is fixed to the outer periphery of the cylindrical portion 62. The magnet 61 faces the stator 5 on the inside in the radial direction. The magnet 61 is made of, for example, a neodymium bonded magnet.

[0030] A radial bearing 70 is held inside the cylindrical portion 62. The rotor 6 is rotatably supported on the support shaft 7 via the radial bearing 70. The end of the support shaft 7 on the other axial side L2 is held in a shaft hole 71 formed in the bottom wall 13 of the housing 10. The case 2 has three support portions 72 extending from the inner circumferential surface of the suction port 21 toward the motor 3, and at the tip of the support portions 72 is provided a cylindrical portion 73 into which the end of the support shaft 7 on one axial side L1 fits. A thrust bearing 74 attached to the end of the support shaft 7 on one axial side L1 is arranged between the cylindrical portion 73 and the radial bearing 70.

[0031] A plurality of blades 64 protrude from the flange 63 of the rotor member 60 toward one side L1 in the axial direction, and a resin plate 65 is fixed to the tips of the blades 64 from the one side L1 in the axial direction. The plurality of blades 64 extend radially outward while curving in an arc and are arranged at equal angular intervals. The flange 63, blades 64, and plate 65 form the impeller 4. Three support members 72 provided on the case 2 are arranged inside a circular hole 66 provided in the center of the plate 65, and are connected to a tubular member 73 arranged inside the cylindrical member 62 of the rotor member 60.

[0032] (case) FIG. 2 is a plan view of the case 2 as viewed from the other axial side L2. FIG. 3 is a perspective view of the case 2 as viewed from the other axial side L2. As shown in FIG. 1, the case 2 covers the housing 10 from one axial side L1. As shown in FIGS. 1, 2, and 3, the case 2 includes a pump chamber forming portion 23 that forms the pump chamber 20 between the case 2 and the housing 10, and a mounting portion 24 with a hole that is located on the outer periphery of the pump chamber forming portion 23. The pump device 1 is fixed to a mating member (not shown) via the mounting portions 24 at three locations on the case 2. In this case, the suction port 21 and the discharge port 22 provided in the case 2 are positioned so that they can be connected to flow paths such as holes or pipes provided in the mating member.

[0033] 1, 2, and 3, the pump chamber forming portion 23 includes an upper wall portion 25 through which the suction port 21 and the discharge port 22 pass in the axial direction, and a side wall portion 26 that protrudes from the upper wall portion 25 to the other axial side L2 and surrounds the outer periphery of the pump chamber 20. The upper wall portion 25 is provided with a circular first recess 27 that is recessed to one axial side L1 about the rotation axis L, and a second recess 28 that is recessed to one axial side L1 on the outer periphery of the first recess 27. The second recess 28 has a substantially semicircular cross section when cut in the radial direction, and the side wall portion 26 extends along the outer periphery of the second recess 28.

[0034] As shown in Fig. 1, in the pump chamber 20, the upper part of the impeller 4 is disposed in the first recess 27, and a flow path F surrounded by the second recess 28 and the side wall portion 26 extends in the circumferential direction around the outer periphery of the impeller 4. As shown in Figs. 2 and 3, the second recess 28 has a shape in which the radial width increases toward one circumferential side R1. Therefore, the pump chamber 20 has a shape in which the width of the flow path F extending in the circumferential direction around the outer periphery of the impeller 4 increases toward one circumferential side R1. An example of such a shape is an involute shape.

[0035] 2, the second recess 28 has an end portion on one circumferential side R1 located at a first angular position T1, and an end portion on the other circumferential side R2 located at a second angular position T2. ​​The flow path F, which extends circumferentially around the inner periphery of the pump chamber 20, extends from the second angular position T2 to the one circumferential side R1 to the first angular position T1. The second angular position T2 is the angular position where the width of the flow path F is smallest, and the first angular position T1 is the angular position where the width of the flow path F is largest.

[0036] 2 and 3, the discharge port 22 opens to the bottom of the second recess 28 at the first angular position T1. In a range from one circumferential side R1 of the first angular position T1 to the second angular position T2 (hereinafter referred to as the first angular range θ), a convex portion 29 is provided that protrudes from the inner circumferential surface of the side wall portion 26 and the bottom surface of the second recess 28 toward the inside of the pump chamber 20. Therefore, the fluid flowing through the pump chamber 20 toward the one circumferential side R1 collides with the convex portion 29 at the first angular position T1 and heads toward the discharge port 22.

[0037] As shown in Figures 2 and 3, the pump chamber forming portion 23 has two protrusions 31, 32 that protrude from the side wall portion 26 toward the outer periphery. The protrusion 31 is provided in the first angle range θ and is disposed on the outer periphery of the discharge port 22 and the convex portion 29. The protrusion 32 is provided at a position radially opposite the protrusion 31. Two of the three mounting portions 24 provided on the case 2 are disposed on the outer periphery of the protrusions 31, 32. Therefore, the mounting portion 24 is reinforced by the protrusions 31, 32.

[0038] (welded part) Fig. 4 is an exploded perspective view of the rotor 6 and the housing 10 as viewed from one side L1 in the axial direction. As shown in Fig. 4, the first flange portion 16 is provided around the entire circumference of the body portion 14. The outer shape of the first flange portion 16 substantially matches the outer shape of the pump chamber forming portion 23 as viewed from the axial direction. The first flange portion 16 has protrusions 17 and 18 that overlap with two protrusions 31 and 32 provided on the pump chamber forming portion 23 as viewed from the axial direction.

[0039] As shown in FIGS. 1 and 4, first flange portion 16 has a first fixed surface 19 facing one side L1 in the axial direction. As shown in FIGS. 1 and 3, pump chamber forming portion 23 has a second fixed surface 33 which is an end face of side wall portion 26 and protrusions 31, 32 on the other side L2 in the axial direction. First fixed surface 19 and second fixed surface 33 face each other in the axial direction. Case 2 and housing 10 are joined by welding ribs 42 provided on second fixed surface 33 to welding recesses 41 provided on first fixed surface 19 by vibration welding. Welding portion 40 (see FIG. 1), in which welding ribs 42 are welded to welding recesses 41, surrounds pump chamber 20 all around.

[0040] When joining the case 2 and the housing 10 by vibration welding, for example, the pump chamber forming portion 23 is overlapped with the first flange portion 16 from one axial side L1, and pressure is applied to the first flange portion 16 from the other axial side L2. Because the axial height of the welding rib 42 is greater than the depth of the welding recess 41, the tip of the welding rib 42 inserted into the welding recess 41 is crushed by the bottom surface of the welding recess 41. Because the radial thickness of the welding rib 42 is smaller than the width of the welding recess 41, welding flash (not shown) is accommodated in the gap around the welding rib 42 inserted into the welding recess 41.

[0041] Furthermore, the first flange portion 16 is provided with an additional welding recess 43 on the outer periphery of the welding recess 41 on the first fixing surface 19, and the case 2 is provided with an additional welding rib 44 on the outer periphery of the welding rib 42 on the second fixing surface 33. The additional welding recess 43 and the additional welding rib 44 are each provided at two locations on opposite sides in the radial direction. When the case 2 is joined to the housing 10 by vibration welding, additional welds formed by welding the additional welding recess 43 and the additional welding rib 44 to the outer periphery of the welded portion 40 are formed at two locations on opposite sides in the radial direction. This reinforces the welded portion 40 at two locations.

[0042] As shown in Fig. 4, the welding recess 41 extends on the first fixing surface 19 in a shape that follows the outer shape of the pump chamber 20 when viewed from the axial direction. One of the two additional welding recesses 43 extends along the outer peripheral edge of the protruding portion 17, and both ends of the additional welding recess 43 are connected to the welding recess 41. The other additional welding recess 43 is provided on the protruding portion 18. On the protruding portion 18, the additional welding recess 43 extends over the entire protruding portion 18 and is integrated with the welding recess 41.

[0043] 2 and 3, the welding rib 42 extends on the second fixing surface 33 in a shape that follows the outer shape of the pump chamber 20 when viewed from the axial direction. More specifically, the welding rib 42 includes a curved portion 420 that extends while curving from the second angular position T2 to one circumferential side R1 to the first angular position T1, a first straight portion 421 that bends inward at the first angular position T1 and extends linearly, and a second straight portion 422 that bends on the one circumferential side R1 of the first straight portion 421 in a direction that forms an obtuse angle with the first straight portion 421 and extends linearly to the second angular position T2.

[0044] As described above, in this embodiment, by providing the welded portion 40 along the outer shape of the pump chamber 20, a portion of the welded portion 40 extends linearly without being curved within the first angle range θ. The first linear portion 421 and the second linear portion 422 of the welded rib 42 are more likely to collapse than the curved portion 420 when subjected to fluid pressure. Therefore, the welded portion 40 has the lowest weld strength at the location where the first linear portion 421 and the second linear portion 422 are welded to the welded recess 41. One of the two additional welded portions is located on the outer periphery of the first reinforced portion, with the first linear portion 421 and the second linear portion 422 serving as the first reinforced portion, and therefore reinforces the location of the welded portion 40 where the weld strength is lowest.

[0045] Here, it was confirmed by analysis that when additional welded portions are provided on the outer periphery of the first straight portion 421 and the second straight portion 422, the portion with the lowest weld strength is the portion radially opposite the first straight portion 421 and the second straight portion 422. Therefore, the portion radially opposite the first straight portion 421 and the second straight portion 422 is set as the second reinforced portion, and additional welded portions (additional welding recess 43, additional welding rib 44) are also arranged on the outer periphery of the second reinforced portion.

[0046] As shown in FIGS. 2 and 3 , the second fixing surface 33 includes a first region 34 that is an end face on the other axial side L2 of the side wall portion 26 and completely surrounds the outer periphery of the pump chamber 20, and a welding rib 42 is arranged in the first region 34. The second fixing surface 33 also includes two second regions 35, 36 that are end faces on the other axial side L2 of the protrusions 31, 32 and are provided on the outer periphery of the first region 34. The second region 35 extends outward from the first straight portion 421 and the second straight portion 422. The second region 36 extends outward from the curved portion 420 at a position radially opposite the first straight portion 421 and the second straight portion 422. An additional welding rib 44 is arranged in the second regions 35, 36.

[0047] The additional welding ribs 44 extend continuously along the outer peripheries of the second regions 35, 36. Each additional welding rib 44 extends linearly toward the outer periphery of the welding rib 42, then curves in the opposite direction, and extends linearly toward the welding rib 42. In other words, each of the two additional welding ribs 44 has first portions 441 at two circumferentially spaced locations, each of which extends linearly from the outer periphery of the welding rib 42 in a direction intersecting with the welding rib 42. The two first portions The outer peripheral end of 441 is connected by a second portion 442 that curves and extends in the circumferential direction.

[0048] In this embodiment, a gap S is provided between the first portion 441 of the additional welding rib 44 and the welding rib 42 arranged on the inner periphery thereof, and the additional welding rib 44 is not connected to the welding rib 42. By providing the gap S between the additional welding rib 44 and the welding rib 42, a space is secured to accommodate welding burrs that are generated when the additional welding rib 44 is welded.

[0049] (reinforcement rib) FIG. 5 is a perspective view of the pump device 1 as viewed from the other side L2 in the axial direction. In the following description, the first direction X is a direction perpendicular to the axial direction, and the second direction is a direction perpendicular to both the axial direction and the first direction X. As shown in FIGS. 4 and 5 , the housing 10 includes reinforcing ribs 46 at multiple positions that connect the body 14 and the first flange 16. The reinforcing ribs 46 protrude in the first direction X from the outer peripheral surface of the body 14 and are connected to the surface of the first flange 16 on the other side L2 in the axial direction. Each reinforcing rib 46 has a shape in which the radial length increases toward the one side L1 in the axial direction and extends to the outer peripheral edge of the first flange 16. The reinforcing ribs 46 are arranged in the second direction Y and extend parallel to the first direction X. In this embodiment, a plurality of reinforcing ribs 46 protrude in parallel from the outer peripheral surface of the body 14 on one side in the first direction X (the side on which the protrusions 31 and 17 are provided) and on the other side in the first direction X (the side on which the protrusions 32 and 18 are provided).

[0050] 6 is an explanatory diagram showing the arrangement of the welded ribs 42, the additional welded ribs 44, and the reinforcing ribs 46, and is a partial cross-sectional view of the pump device 1 as viewed from the other axial side L2. Each of the multiple reinforcing ribs 46 overlaps with the welded rib 42 as viewed from the axial direction. Of the multiple reinforcing ribs 46, one reinforcing rib 461 connected to the protruding portion 17 of the first flange portion 16 and two reinforcing ribs 462 and 463 connected to the protruding portion 18 of the first flange portion 16 each overlap with both the welded rib 42 and the additional welded rib 44 as viewed from the axial direction.

[0051] The reinforcing rib 461 connected to the protruding portion 17 of the first flange portion 16 is disposed in the first angle range θ, and is provided at a position overlapping with the discharge port 22 when viewed from the axial direction. The reinforcing rib 461 extends from a position overlapping with the second linear portion 422 of the welding rib 42 to a position overlapping with the additional welding rib 44 extending along the outer peripheral edge of the protruding portion 17.

[0052] The two reinforcing ribs 462, 463 connected to the protruding portion 18 of the first flange portion 16 are arranged at positions on opposite sides in the radial direction with respect to the first angle range θ. The reinforcing ribs 462, 463 extend from a position overlapping in the axial direction with the second reinforced portion of the welding rib 42 (i.e., the portion on the radially opposite side from the first straight portion 421 and the second straight portion 422) to a position overlapping with the additional welding rib 44 extending along the outer peripheral edge of the protruding portion 18.

[0053] (Main effects of this embodiment) As described above, the pump device 1 of this embodiment includes the rotor 6, the stator 5 surrounding the outer periphery of the rotor 6, the housing 10 sealing the stator 5, the case 2 including the pump chamber forming portion 23 that covers the housing 10 from one side L1 in the axial direction along the rotational axis L of the rotor 6 and forms the pump chamber 20 between the case 2 and the housing 10, and the impeller 4 that is disposed in the pump chamber 20 and rotates integrally with the rotor 6. When viewed from the axial direction, the shape of the pump chamber 20 is such that the width of the flow path F extending circumferentially around the outer periphery of the impeller 4 increases toward the one side R1 in the circumferential direction. The housing 10 includes a first partition wall portion 11 that covers the one side L1 in the axial direction of the stator 5, a body portion 14 that covers the outer periphery of the stator 5, and a first flange portion 16 that protrudes from the body portion 14 toward the outer periphery. The first flange portion 16 has a first fixing surface 19 facing one side L1 in the axial direction, and the pump chamber forming portion 23 has a second fixing surface 33 facing the first fixing surface 19. The second fixing surface 33 is provided with a welding rib 42 that extends along the outer shape of the pump chamber 20 when viewed from the axial direction, and the first fixing surface 19 is provided with a welding recess 41 to which the welding rib 42 is welded.

[0054] In this embodiment, the housing 10 and the case 2 are welded together to form a pump chamber 20 between the housing 10 and the case 2, in which the width of a flow path F extending circumferentially around the outer periphery of the impeller 4 increases toward one circumferential side R1. The welding rib 42 used to weld the housing 10 and the case 2 is shaped to extend along the contour of the pump chamber 20 as viewed from the axial direction. This eliminates the need for a flange portion on the case 2 that protrudes outward, and the first flange portion 16 on the housing 10 does not need to protrude significantly outward to form a circular shape. This prevents the case 2 and the housing 10 from becoming too large, and reduces the amount of resin required to manufacture the case 2 and the housing 10.

[0055] In this embodiment, the second fixing surface 33 provided on the case 2 includes an additional welding rib 44 located on the outer periphery of the welding rib 42, and the first fixing surface 19 provided on the housing 10 includes an additional welding recess 43 to which the additional welding rib 44 is welded. This allows for partial reinforcement of areas in the welding portion 40 where the welding strength is insufficient, thereby preventing a decrease in the durability of the pump device 1 due to partial insufficient welding strength. Furthermore, the case 2 and the housing 10 only need to be extended far outward in areas where the additional welding rib 44 and the additional welding recess 43 are provided. This prevents the case 2 and the housing 10 from becoming larger in size.

[0056] In this embodiment, the additional welding rib 44 is disposed on the outer periphery of the linearly extending portion of the welding rib 42 (the first linear portion 421 and the second linear portion 422). The linearly extending portion of the welding rib 42 is more likely to collapse than the arcuately extending portion, making it difficult to ensure sufficient welding strength. Therefore, by providing the additional welding rib 44 and the additional welding recess 43 at this location to reinforce it, the portion where the welding strength is insufficient can be reinforced.

[0057] In this embodiment, the angular position at which the width of the flow path F extending circumferentially around the outer periphery of the impeller 4 is widest is defined as the first angular position T1, and the angular position at which the width of the flow path F is narrowest is defined as the second angular position T2. ​​The pump chamber forming portion 23 includes an intake port 21 provided at the radial center of the pump chamber 20 and an outlet port 22 provided at the first angular position T1. The welded rib 42 has a portion (first reinforced portion) arranged in a first angular range θ from one circumferential side R1 of the first angular position T1 to the second angular position T2, which is not arc-shaped, but is composed of a first linear portion 421 and a second linear portion 422. As described above, in this embodiment, a linear portion of the welded portion 40 is formed in the range (first angular range θ) from the downstream end position (first angular position T1) of the flow path F back to the upstream end position (second angular position T2), which may result in insufficient weld strength. Therefore, by providing additional welding ribs 44 and additional welding recesses 43 on the outer periphery of this area (first reinforced portion) to reinforce it, it is possible to reinforce the area where the welding strength is insufficient.

[0058] In this embodiment, the intake port 21 and the discharge port 22 open to one side L1 in the axial direction. In this case, near the discharge port 22, the direction of the fluid flowing in the circumferential direction changes to the direction toward one side L1 in the axial direction. Therefore, the direction and magnitude of the fluid pressure applied to the inner circumferential surface of the pump chamber 20 differs from that in other areas, and there is a risk that the required welding strength may not be ensured. Therefore, by reinforcing this area with the additional welding rib 44 and the additional welding recess 43, it is possible to reinforce the area where the welding strength is insufficient.

[0059] In this embodiment, the additional welding ribs 44 and the additional welding recesses 43 are arranged on the outer periphery of the first linear portion 421 and the second linear portion 422 (first reinforced portion) and on the outer periphery of the portion (second reinforced portion) on the radially opposite side of the first linear portion 421 and the second linear portion 422 (first reinforced portion). Analysis confirmed that when reinforcement is performed, the area radially opposite the reinforced area (second reinforced area) becomes the area with the next lowest welding strength. Therefore, by designating this area as the second reinforced area and providing additional welding ribs 44 and additional welding recesses 43 on its outer periphery, the area with insufficient welding strength can be reinforced.

[0060] In this embodiment, the additional welding rib 44 has a first portion 441 that extends from the outer periphery of the welding rib 42 in a direction that intersects with the welding rib 42. Therefore, the first portion 441 makes it difficult for the welding rib 42 to collapse. Also, a gap S is provided between the inner periphery end of the first portion 441 and the welding rib 42, so that space can be secured to accommodate welding burrs that may occur from the additional welding portion.

[0061] In this embodiment, the additional weld rib 44 includes first portions 441 arranged at two circumferentially spaced locations, and a second portion 442 connecting the outer peripheral ends of the two first portions 441. By reinforcing the weld rib 42 at two locations in this way, the weld rib 42 can be made less likely to collapse. Furthermore, by connecting the two additional weld ribs (first portions 441) with the second portion 442, the additional weld rib 44 as a whole can be made less likely to collapse. Therefore, the strength of the additional welded portion can be increased, thereby improving the reinforcing effect.

[0062] In this embodiment, the case 2 includes an attachment portion 24 disposed on the outer periphery of the pump chamber-forming portion 23. The pump chamber-forming portion 23 includes a sidewall portion 26 that surrounds the outer periphery of the pump chamber 20 and protrusions 31 and 32 that protrude from the sidewall portion 26 toward the outer periphery, with the attachment portion 24 disposed on the outer periphery of the protrusions 31 and 32. The second fixing surface 33 includes a first region 34 formed by an end face on the other axial side L2 of the sidewall portion 26 and second regions 35 and 36 formed by end faces on the other axial sides L2 of the protrusions 31 and 32. A welding rib 42 or a welding recess 41 is provided in the first region 34, and an additional welding rib 44 or an additional welding recess 43 is provided in the second regions 35 and 36. Therefore, the provision of the protrusions 31 and 32 reinforces the attachment portion 24 and also ensures space for arranging the additional reinforcing welding rib 44 on the end faces of the protrusions 31 and 32.

[0063] In this embodiment, the housing 10 includes a reinforcing rib 46 that connects the outer peripheral surface of the body 14 and the first flange 16, and the reinforcing rib 46 overlaps the welding rib 42 when viewed in the axial direction. This reinforces the welding portion 40. The reinforcing rib 46 also suppresses deformation of the first flange 16, thereby suppressing a decrease in welding strength that would occur if the welding rib 42 were unable to make sufficient contact with the welding recess 41 as a result of deformation of the first flange 16. In this embodiment, the reinforcing rib 46 and additional welding portion are provided so that the joint strength between the case 2 and the first flange 16 is uniform at all angle positions.

[0064] In this embodiment, the reinforcing rib 46 extends from a position overlapping the welding rib 42 to a position overlapping the additional welding rib 44 when viewed from the axial direction. Therefore, the reinforcing rib 46 is provided so as to straddle two welding portions, and therefore it is possible to reinforce not only the welding portion 40 but also the additional welding portion, thereby enhancing the reinforcing effect. Furthermore, since the additional welding rib 44 is provided on the protruding portions 17, 18 that protrude significantly toward the outer periphery, extending the reinforcing rib 46 to the additional welding rib 44 can reinforce the protruding portions 17, 18 that protrude significantly. Therefore, it is possible to prevent a decrease in welding strength caused by deformation of the protruding portions 17, 18 preventing the additional welding rib 44 from making sufficient contact with the additional welding recess 43.

[0065] (Other embodiments) (1) In the above embodiment, welding ribs 42 are provided on second fixing surface 33 and welding recesses 41 are provided on first fixing surface 19, but the projections and recesses may be reversed. That is, welding ribs 42 may be provided on first fixing surface 19 and welding recesses 41 may be provided on second fixing surface 33.

[0066] (2) In the above embodiment, the additional welded portions (additional weld recess 43, additional welded rib 44) are provided in two locations, but the locations and number of the additional welded portions are not limited to the locations and number of the present invention. For example, the additional welded portion may be provided in only one location on the outer periphery of the discharge port 22. Alternatively, the stress applied to each part of the welded portion 40 can be analyzed, and the additional welded portion can be provided appropriately in locations where reinforcement is required. Note that it is also possible to provide only the welded portion 40 without providing any additional welded portions.

[0067] (3) In the above embodiment, the reinforcing rib 46 overlaps with the welding rib 42 and the additional welding rib 44, but the reinforcing rib 46 does not have to overlap with the additional welding rib 44. Also, a configuration in which the reinforcing rib 46 is not provided is also possible.

[0068] (4) In the above embodiment, the discharge port 22 provided in the pump chamber 20 faces in the same direction as the suction port 21 (toward one side L in the axial direction), but the direction of the discharge port 22 is not limited to this. For example, the direction of the discharge port 22 may be a tangential direction to the downstream end of the flow path F. [Explanation of symbols]

[0069] 1...pump device, 2...case, 3...motor, 4...impeller, 5...stator, 6...rotor, 7...support shaft, 8...board, 9...cover, 10...housing, 11...first partition wall portion, 12...second partition wall portion, 13...bottom wall, 14...body portion, 15...connector housing, 16...first flange portion, 17, 18...protrusion portion, 19...first fixing surface, 20...pump chamber, 21...suction port, 22...Discharge port, 23...Pump chamber forming portion, 24...Mounting portion, 25...Upper wall portion, 26...Side wall portion, 27...First recess, 28...Second recess, 29...Convex portion, 31, 32...Protruding portion, 33...Second fixing surface, 34...First region, 35, 36...Second region, 40...Welded portion, 41...Welded recess, 42...Welded rib, 43...Additional welding recess, 44...Additional welding rib, 46, 461, 462, 4 63...reinforcing rib, 50...coil, 51...stator core, 52, 53...insulator, 55...winding terminal, 60...rotor member, 61...magnet, 62...cylindrical portion, 63...flange portion, 64...blade portion, 65...plate, 66...circular hole, 70...radial bearing, 71...shaft hole, 72...support portion, 73...cylindrical portion, 74...thrust bearing, 90...opening, 91...heat dissipation Member, 420...curved portion, 421...first straight portion, 422...second straight portion, 441...first portion, 442...second portion, F...flow path, L...rotation axis, L1...one side in the axial direction, L2...other side in the axial direction, R1...one side in the circumferential direction, R2...other side in the circumferential direction, S...gap, T1...first angular position, T2...second angular position, X...first direction, Y...second direction, θ...first angular range

Claims

1. a rotor and a stator surrounding the outer periphery of the rotor; a housing that seals the stator; a case including a pump chamber forming portion that is fitted over the housing from one side in an axial direction along a rotation axis of the rotor to form a pump chamber between the housing and the pump chamber forming portion; an impeller disposed in the pump chamber and rotating integrally with the rotor; a shape of the pump chamber as viewed from the axial direction such that a width of a flow path extending in a circumferential direction around an outer periphery of the impeller increases toward one side in the circumferential direction, the housing includes a first partition wall portion covering one side of the stator in the axial direction, a body portion covering an outer periphery of the stator, and a first flange portion protruding from the body portion toward the outer periphery, The first flange portion includes a first fixing surface facing one side in the axial direction, The pump chamber forming portion includes a second fixing surface facing the first fixing surface, one of the first fixing surface and the second fixing surface includes a welding rib extending along an outer shape of the pump chamber as viewed from the axial direction; The other of the first fixing surface and the second fixing surface is provided with a welding recess to which the welding rib is welded.

2. The one of the first fixing surface and the second fixing surface includes an additional welding rib arranged on an outer circumferential side of the welding rib, The pump device according to claim 1 , wherein the other of the first fixing surface and the second fixing surface includes an additional welding recess to which the additional welding rib is welded.

3. The pump device according to claim 2, wherein the additional welding rib is disposed on an outer circumferential side of a portion where the welding rib extends linearly.

4. When an angular position at which the width of the flow passage extending in a circumferential direction around the outer periphery of the impeller is the largest is defined as a first angular position, and an angular position at which the width of the flow passage is the smallest is defined as a second angular position, the pump chamber forming portion includes an intake port provided at a radial center of the pump chamber and an exhaust port provided at the first angular position, the welding rib includes a first reinforced portion disposed within a first angular range up to the second angular position on one side in the circumferential direction of the first angular position, The pump device according to claim 2 , wherein the additional welding rib and the additional welding recess are disposed on an outer circumferential side of the first reinforced portion.

5. 5. The pump device according to claim 4, wherein the suction port and the discharge port open to one side in the axial direction.

6. The pump device according to claim 4, characterized in that the additional welding rib and the additional welding recess are arranged on the outer circumferential side of the first reinforced portion and on the outer circumferential side of a second reinforced portion radially opposite the first reinforced portion.

7. The additional welding rib has a first portion extending in a direction intersecting with the welding rib on an outer circumferential side of the welding rib, 3. The pump device according to claim 2, wherein a gap is provided between an inner peripheral end of the first portion and the welding rib.

8. The pump device according to claim 7, characterized in that the additional welding rib comprises the first portions arranged at two circumferentially separated locations, and a second portion connecting the outer peripheral ends of the two first portions.

9. the case includes an attachment portion disposed on an outer circumferential side of the pump chamber forming portion, the pump chamber forming portion includes a side wall portion surrounding an outer periphery of the pump chamber and a protruding portion protruding from the side wall portion toward the outer periphery, the attachment portion being disposed on the outer periphery of the protruding portion, the second fixing surface includes a first region formed by an end face on the other side in the axial direction of the side wall portion, and a second region formed by an end face on the other side in the axial direction of the protruding portion, The welding rib or the welding recess is provided in the first region, The pump device according to claim 2 , wherein the additional welding rib or the additional welding recess is provided in the second region.

10. the housing includes a reinforcing rib that connects an outer circumferential surface of the body portion and the first flange portion, 3. The pump device according to claim 2, wherein the reinforcing rib overlaps with the welding rib when viewed in the axial direction.

11. The pump device according to claim 10, wherein the reinforcing rib extends from a position overlapping the welding rib to a position overlapping the additional welding rib when viewed in the axial direction.

Images