Closed impeller, electric pump, and method for manufacturing closed impeller

Abstract

To provide a closed impeller, an electric pump, and a method for manufacturing a closed impeller, which can relax restrictions on materials for constituting the closed impeller and can control the gap between a shroud and a hub with high precision.SOLUTION: A closed impeller 100 (100A to 100C) comprises blades 102, a shroud 104 that covers the blades 102, and a hub 106 that is located on the opposite side of the shroud 104 across the blades 102 in the axial direction. A first part 110, which includes one of the shroud 104 and the hub 106, has a crimping projection 112. A second part 120, which includes the other of the shroud 104 and the hub 106, has an opening 122 for receiving the crimping projection 112 of the first part 110. The first part 110 has a retaining portion 114 formed of a portion of the crimping projection 112 that protrudes outside the opening 122 and is deformed by crimping.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] The present disclosure relates to a closed impeller, an electric pump, and a method for manufacturing a closed impeller. [Background technology]

[0002] Conventionally, a closed impeller in which blades are covered by a shroud has been known.

[0003] For example, Patent Document 1 describes a closed impeller made of resin in which vanes (blades) and a shroud are joined by welding, as an impeller used in an electric fluid pump used in an automobile cooling system or the like.

[0004] Furthermore, Patent Document 2 describes a closed impeller used in a pump of a vehicle thermal management system, in which vanes (blades) and a lower plate (hub) are assembled by ultrasonic welding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-31329 [Patent Document 2] Patent No. 6333313 specification Summary of the Invention [Problem to be solved by the invention]

[0006] However, welding and deposition are basically limited to joining materials of the same kind, and cannot be used to join dissimilar materials, such as metal and resin, which places restrictions on the materials that can be used to form the closed impeller. Furthermore, as described in Patent Document 1, when assembling a closed impeller by welding using an ultrasonic vibration device, the resin is melted using heat generated by ultrasonic waves while the shroud is pressed against the blades. During this process, variations occur in the amount of melted resin, making it difficult to precisely control the gap between the shroud and hub of the assembled closed impeller, and there are cases where a pump equipped with this impeller does not exhibit the desired performance.

[0007] In view of the above circumstances, at least some embodiments of the present invention aim to provide a closed impeller, an electric pump, and a method for manufacturing a closed impeller that can relax restrictions on the constituent materials of the closed impeller and that can control the gap between the shroud and the hub with high precision. [Means for solving the problem]

[0008] [1] In at least some embodiments of the present invention, a closed impeller comprises: Blade and A shroud that covers the blade; a hub located on the opposite side of the shroud across the blade in the axial direction; Equipped with the first component including either the shroud or the hub has a caulking projection; the second part including the other of the shroud and the hub has an opening for receiving the crimping projection of the first part; The first component has a retaining portion formed by deformation of the portion of the crimping projection that protrudes out of the opening due to crimping.

[0009] [2] In some embodiments, in the configuration of [1] above, The retaining portion is located on the opposite side of the flow passage space between the shroud and the hub, with the second component sandwiched therebetween.

[0010] [3] In some embodiments, in the configuration of [2] above, The retaining portion is located on the opposite side of the flow path space with the shroud, which serves as the second component, in between.

[0011] [4] In some embodiments, in any of the configurations [1] to [3] above, The blades are integrally mounted to either the shroud or the hub.

[0012] [5] In some embodiments, in any of the configurations [1] to [4] above, The first part having the crimping protrusion is made of resin, The second part is made of metal.

[0013] [6] In some embodiments, in any of the configurations [1] to [5] above, the first part is a resin part including a blade and a hub, The shroud as the second part is a pressed metal product having a thickness thinner than that of the hub.

[0014] [7] In some embodiments, in any of the configurations [1] to [6] above, the first part includes a blade; The crimping projection is provided on the surface of the blade that comes into contact with the second component.

[0015] [8] In some embodiments, in any of the configurations [1] to [5] above, the second part includes a blade; the first component has a flow straightening portion that protrudes toward the second component so as to be adjacent to the trailing edge of the blade in a flow passage space between the shroud and the hub; The crimping protrusion is provided on the contact surface of the flow rectifying portion with the second component.

[0016] [9] In at least some embodiments of the present invention, an electric pump includes: A support shaft; a rotor including an impeller and a magnet and supported by the support shaft on the radially outer side of the support shaft; a stator including a stator core disposed with a magnetic gap between it and the magnet, the stator facing the rotor without contact with the rotor across an air gap within the range where the magnetic gap is formed; Equipped with The impeller is a closed impeller having any of the above configurations [1] to [8].

[0017]

[10] A method for manufacturing a closed impeller according to at least some embodiments of the present invention includes: Blade and A shroud that covers the blade; a hub located on the opposite side of the shroud across the blade in the axial direction; A method for manufacturing a closed impeller, comprising: a crimping projection of a first component including one of the shroud and the hub is fitted into an opening of a second component including the other of the shroud and the hub; The portion of the crimping projection that protrudes outside the opening is deformed by crimping to form a retaining portion, and the first component and the second component are joined together. [Effects of the Invention]

[0018] According to at least some embodiments of the present invention, unlike welding or welding, the method can be used to bond dissimilar materials, such as metal and resin, thereby easing restrictions on the materials that can be used to construct the closed impeller. Furthermore, compared to welding, in which variations in the amount of melted resin can affect the gap between the shroud and the hub, the gap between the shroud and the hub in the assembled closed impeller can be controlled with high precision. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is an axial cross-sectional view showing a schematic configuration of an electric pump according to an embodiment. [Figure 2A] FIG. 2 is a cross-sectional view schematically illustrating a configuration of a portion of a closed impeller according to one embodiment. [Figure 2B] FIG. 2B is a perspective view showing the closed impeller of FIG. 2A in an unassembled state. [Figure 3] FIG. 10 is a cross-sectional view schematically showing a configuration of a portion of a closed impeller according to another embodiment. [Figure 4A] FIG. 10 is a cross-sectional view schematically showing a configuration of a portion of a closed impeller according to yet another embodiment. [Figure 4B] FIG. 4B is a perspective view showing the closed impeller of FIG. 4A in an unassembled state. [Figure 4C] FIG. 4B is a plan view of the closed impeller of FIG. 4A without the shroud. [Figure 5A] FIG. 2 is a diagram showing a step of a manufacturing method for a closed impeller. [Figure 5B] FIG. 2 is a diagram showing a step of a manufacturing method for a closed impeller. [Figure 5C] FIG. 2 is a diagram showing a step of a manufacturing method for a closed impeller. [Figure 6A] 4A and 4B are diagrams illustrating how a first part and a second part are resin-caulked together in one embodiment. [Figure 6B] 10A and 10B are diagrams illustrating how a first component and a second component are resin-caulked together in another embodiment. [Figure 6C] 10A and 10B are diagrams illustrating how a first component and a second component are resin-caulked together in still another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0021] Fig. 1 is an axial cross-sectional view showing a schematic configuration of an electric pump 1 according to one embodiment. The electric pump 1 shown in Fig. 1 is an example of an electric pump including a closed impeller according to some embodiments of the present invention.

[0022] Hereinafter, the overall configuration of the electric pump 1 including the closed impeller 100 will be described, and then the closed impeller 100 will be described in detail.

[0023] As shown in FIG. 1, in some embodiments, electric pump 1 includes a casing 2 and a motor portion 6 and a pump portion 8 at least partially disposed within casing 2. The casing 2 includes a front casing 2A and a rear casing 2B. The front casing 2A has a fluid inlet 3 and a fluid outlet 4. The casing 2 defines an interior space for at least partially accommodating a motor unit 6 and a pump unit 8. Electric power is supplied to the motor unit 6 via a terminal (not shown), and the motor unit 6 drives and rotates a closed impeller 100 of the pump unit 8. A region (pump chamber) in the internal space of the casing 2 where the pump section 8 is provided communicates with a fluid inlet 3 and a fluid outlet 4. The fluid taken into the pump chamber from the fluid inlet 3 is pressurized as it passes through a closed impeller 100 of the pump section 8, and is discharged from the fluid outlet 4. In the exemplary embodiment shown in FIG. 1 , the fluid is guided axially to the closed impeller 100 via the fluid inlet 3, and after passing through the closed impeller 100, the fluid is guided to the fluid outlet 4 via a volute chamber 9 radially outside the closed impeller 100. The flow path of the volute chamber 9 gradually expands toward the circumferential position of the fluid outlet 4.

[0024] 1, the pump section 8 is a centrifugal pump that utilizes centrifugal force caused by the rotation of a closed impeller 100. Specifically, the pump section 8 is a volute pump that has a volute chamber 9 radially outside the closed impeller 100. The pump section 8 may be any other type of centrifugal pump as long as it includes a closed impeller 100. In another embodiment, the pump section 8 is a turbine pump having guide vanes. When the pump section 8 is a turbine pump, the volute 9, whose flow path cross-sectional area gradually increases, is an optional configuration.

[0025] As described above, when focusing on the function of the electric pump 1, the components of the electric pump 1 are mainly classified into a motor section 6 that functions as a motor, and a pump section 8 that functions as a pump. On the other hand, the electric pump 1 can also be classified into a plurality of elements from the viewpoint of physical components. The components of the electric pump 1 will be described below.

[0026] In some embodiments, as shown in FIG. 1, the electric pump 1 includes a support shaft 10, a rotor 20 supported by the support shaft 10, and a stator 40 facing the rotor 20 without contacting it.

[0027] The support shaft 10 is a hollow or solid shaft member that extends along the central axis of the closed impeller 100. The support shaft 10 is at least partially housed in the casing 2. 1, the support shaft 10 is a stationary shaft (fixed shaft) fixed to the casing 2 or the stator 40. In another embodiment, the support shaft 10 is a rotating shaft rotatably supported by the casing 2 or the stator 40 via a bearing.

[0028] The rotor 20 is supported by the support shaft 10 on the radially outer side of the support shaft 10. When the support shaft 10 is a stationary shaft, the rotor 20 is rotatably supported by the support shaft 10 via bearings 12, as shown in FIG.

[0029] The rotor 20 includes a closed impeller 100 that is arranged axially facing the fluid inlet 3 of the casing 2, a magnet 26 that is located on the opposite side of the fluid inlet 3 in the axial direction across the closed impeller 100, and a rotor main body 21 that supports the closed impeller 100 and the magnet 26.

[0030] In some embodiments, as shown in FIG. 1, the rotor body 21 extends cylindrically in the axial direction from the back side of the closed impeller 100 and supports the magnets 26 so that they are positioned on the inner circumferential side of the stator 40 with the magnets 26 facing radially outward. In another embodiment, the rotor body 21 extends cylindrically in the axial direction from the outer periphery of the closed impeller 100 and supports the magnet 26 so that the magnet 26 is positioned on the outer periphery of the stator 40 with the magnet 26 facing radially inward. In yet another embodiment, the rotor body 21 extends radially outward from the support shaft 10 in a disk shape and supports the magnets 26 so that the magnets 26 are arranged radially facing away from the closed impeller 100 in the axial direction.

[0031] The closed impeller 100 includes blades 102, a shroud 104 that covers the blades 102, and a hub 106 that is located on the opposite side of the shroud 104 across the blades 102 in the axial direction.

[0032] A plurality of blades 102 are arranged in the circumferential direction in a flow passage space 108 formed between a shroud 104 and a hub 106 . An intake port 102A is formed between the leading edges of adjacent blades 102, and an outlet port 102B is formed between the trailing edges of adjacent blades 102. The intake port 102A of the closed impeller 100 is connected to the fluid inlet 3, and velocity energy is imparted to the fluid that flows in from the fluid inlet 3 by the rotating closed impeller 100. The outlet port 102B of the closed impeller 100 is connected to the volute chamber 9, and the fluid that has passed through the closed impeller 100 flows radially outward through the outlet port 102B and flows into the volute chamber 9, and then flows circumferentially through the volute chamber 9 toward the fluid outlet 4. At this time, the fluid is decelerated due to the gradual expansion of the flow path of the volute chamber 9, and the velocity energy is converted into static pressure. In another embodiment, the pump section 8 is a turbine pump, and the fluid after passing through the closed impeller 100 is decelerated in guide vanes (diffusers) arranged radially outside the closed impeller 100, and the velocity energy is converted into static pressure.

[0033] The magnet 26 is a permanent magnet that is disposed facing the stator 40. In the embodiment shown in FIGS. 1 to 3, the magnet 26 is provided so as to be exposed on the surface of the rotor 20 that faces the stator 40.

[0034] In some embodiments, as shown in FIG. 1, the rotor 20 has a neck 28 axially between the hub 106 of the closed impeller 100 and the magnet 26 . The neck 28 refers to a portion of the rotor 20 that is constricted radially inward from the outer circumferential surface of the closed impeller 100 and the outer circumferential surface of the magnet 26. The neck 28 of the rotor 20 is formed by a recess 27 of the rotor body 21. 1, the rotor 20 has a shoulder 31 whose outer diameter is larger than that of the neck 28. The shoulder 31 is located on the opposite side of the neck 28 from the closed impeller 100 in the axial direction. The shoulder 31 holds the magnet 26 on the outer peripheral surface side of the shoulder 31.

[0035] In some embodiments, as shown in FIG. 1, the stator 40 is disposed on the outer circumferential side of the magnet 26 of the rotor 20 and includes a stator core 42 and a stator coil 44 . The stator core 42 forms a magnetic path through which magnetic flux flows when current is applied to the stator coil 44. The stator coil 44 may be wound around the teeth of the stator core 42 so as to be housed in slots provided in the stator core 42.

[0036] The stator 40 may further include a resin molding material 46 that covers the stator core 42 and the stator coil 44 .

[0037] The stator core 42 is disposed with a magnetic gap G between it and the magnet 26 of the rotor 20. The magnetic gap G is formed across the area where the stator core 42 and the magnet 26 face each other. The magnetic gap G extends in an annular shape along the axial direction of the closed impeller 100.

[0038] The stator 40 faces the rotor 20 without contacting it, with an air gap 48 between them, within the range where the magnetic gap G is formed. In embodiments in which magnets 26 are exposed on the surface of rotor 20 and stator 40 includes molding material 46, an air gap 48 is formed between magnets 26 and molding material 46, as shown in FIG.

[0039] Next, the closed impeller 100 will be described in detail. FIG. 2A is a cross-sectional view schematically showing a partial configuration of a closed impeller 100A according to one embodiment, and FIG. 2B is a perspective view showing the closed impeller 100A of FIG. 2A in a state before assembly. FIG. 3 is a cross-sectional view schematically showing a partial configuration of a closed impeller 100B according to another embodiment. FIG. 4A is a cross-sectional view schematically showing a partial configuration of a closed impeller 100C according to yet another embodiment, and FIG. 4B is a perspective view showing the closed impeller 100C of FIG. 4A in a state before assembly. FIG. 4C is a plan view of the closed impeller of FIG. 4A with the shroud omitted.

[0040] Hereinafter, when referring to the closed impeller according to some embodiments of the present invention including the closed impellers 100A to 100C, it will be referred to as the closed impeller 100 (100A to 100C).

[0041] As shown in FIGS. 2A, 3, and 4A, the closed impeller 100 (100A to 100C) includes a first part 110 and a second part 120 that are joined by caulking. The first part 110 includes either the shroud 104 or the hub 106. In contrast, the second part 120 includes the other of the shroud 104 or the hub 106. In other words, the shroud 104 belongs to either the first part 110 or the second part 120, and the hub 106 belongs to the part, either the first part 110 or the second part 120, to which the shroud 104 does not belong. In this way, the shroud 104 and the hub 106 are each separate parts (the first part 110 and 2 parts 120).

[0042] In some embodiments, the blades 102 are integrally mounted to either the shroud 104 or the hub 106. That is, the blades 102 belong to either the first part 110 or the second part 120. Here, being "integrally" provided means that the blades 102 are provided seamlessly and made of the same material as the shroud 104 or the hub 106. For example, the blades 102 and either the shroud 104 or the hub 106 may be integrally formed by injection molding of resin, or a metal part including the blades 102 and either the shroud 104 or the hub 106 may be formed by machining.

[0043] When assembling the closed impeller 100 (100A to 100C), the first part 110 and the second part 120 are joined by caulking. This alleviates restrictions on the materials that can be used to construct the closed impeller 100 compared to when the closed impeller is assembled by welding or deposition. For example, first component 110 may be made of plastic and second component 120 may be made of metal. In other embodiments, both first component 110 and second component 120 are made of plastic. In yet other embodiments, both first component 110 and second component 120 are made of metal.

[0044] 2A, 3, and 4A, the first part 110 has a protrusion (crimping protrusion) 112 used to crimp the first part 110 and the second part 120. On the other hand, the second part 120 has an opening 122 for receiving the crimping protrusion 112 of the first part 110. 2B and 4B show the state before first component 110 and second component 120 are assembled. In this state, crimping protrusion 112 has a cross-sectional shape corresponding to the shape of opening 122, and the length of crimping protrusion 112 is set to be greater than the depth of opening 122. Therefore, when crimping protrusion 112 of first component 110 is aligned with opening 122 of second component 120, crimping protrusion 112 is fitted into opening 122 with substantially no gap, and the tip of crimping protrusion 112 protrudes from opening 122. The portion of crimping protrusion 112 protruding from opening 122 (the tip of crimping protrusion 112) is deformed by crimping to form retaining portion 114. Retaining portion 114 of first component 110 prevents crimping protrusion 112 from coming out of opening 122. In this way, the first part 110 and the second part 120 are joined by caulking, and the closed impeller 100 (100A to 100C) is obtained.

[0045] In some embodiments, the crimping protrusions 112 and the openings 122 are provided at a plurality of locations in the circumferential direction. 2B and 4B, one set of crimping protrusions 112 and openings 122 is provided for each blade 102. In other embodiments, multiple sets of crimping protrusions 112 and openings 122 are provided for each blade 102.

[0046] In some embodiments, the opening 122 is a through hole extending along the axial direction in the second part 120. The through hole may be a circular hole or a non-circular hole. In another embodiment, the opening 122 is a slit (notch) in the outer periphery of the second part 120 .

[0047] In some embodiments, as shown in FIGS. 2A, 3, and 4A, the retaining portion 114 is located on the opposite side of the second part 120 from the flow space 108 between the shroud 104 and the hub 106. In the embodiment shown in FIGS. 2A and 4A, the retaining portion 114 of the first part 110 including the shroud 104 is located on the opposite side of the flow path space 108 with the second part 120 including the hub 106 in between. In contrast, in the embodiment shown in FIG. 3, the retaining portion 114 of the first part 110 including the hub 106 is located on the opposite side of the flow path space 108 with the second part 120 including the shroud 104 in between.

[0048] In some embodiments, as shown in FIGS. 2A and 3, first component 110 includes blade 102, and crimping protrusions 112 are provided on abutment surfaces 103A and 103B of blade 102 that come into contact with second component 120. 2A, blade 102 included in first part 110 has abutment surface 103A with hub 106 as second part 120. Crimping protrusion 112 is provided to protrude from abutment surface 103A of blade 102 toward hub 106 so as to pass through opening 122 of hub 106 as second part 120. 3, blade 102 included in first component 110 has a contact surface 103B with shroud 104 as second component 120. Crimping protrusion 112 is provided to protrude from contact surface 103B of blade 102 toward shroud 104 so as to pass through opening 122 of shroud 104 as second component 120.

[0049] In some other embodiments, as shown in FIGS. 4A and 4C, the first part 110 includes a flow straightening portion 130 that protrudes toward the second part 120 so as to be located within the flow path space 108. The flow straightening portion 130 is provided at a predetermined circumferential position and radial position in the assembled closed impeller 100C so as to be adjacent to the trailing edge 105 of the blade 102 included in the second part 120. The flow straightening portion 130 has an opposing surface 132 that faces the trailing edge 105 of the blade 102 within the flow path space 108. The opposing surface 132 of the airflow control portion 130 may have a shape complementary to the trailing edge 105 of the blade 102. In the example shown in Fig. 4C, the trailing edge 105 of the blade 102 and the opposing surface 132 of the airflow control portion 130 are both flat surfaces. 4C, the opposing surface 132 of the airflow control portion 130 may contact the trailing edge 105 of the blade 102. In other embodiments, the opposing surface 132 of the airflow control portion 130 is disposed along the trailing edge 105 of the blade 102 with a small gap between them.

[0050] The flow rectifying portion 130 of the first component 110 has an abutting surface 134 that abuts against the second component 120. The crimping protrusion 112 is provided on the abutting surface 134 of the flow rectifying portion 130. 4A to 4C, the first part 110 including the shroud 104 includes a rectifying portion 130 that protrudes toward the hub 106, which serves as the second part 120, and a crimping protrusion 112 is provided on an abutment surface 134 of the rectifying portion 130 that abuts against the hub 106. In this case, the crimping protrusion 112 is provided to protrude from the abutment surface 134 of the rectifying portion 130 toward the hub 106 so as to pass through an opening 122 of the hub 106, which serves as the second part 120. In another embodiment, the first part 110 including the hub 106 includes the flow straightening part 130 that protrudes toward the shroud 104 serving as the second part 120, and the crimping protrusion 112 is provided on the abutment surface 134 of the flow straightening part 130 that abuts against the shroud 104. In this case, the crimping protrusion 112 is provided to protrude from the abutment surface 134 of the flow straightening part 130 toward the shroud 104 so as to pass through the opening 122 of the shroud 104 serving as the second part 120.

[0051] 4A to 4C, the flow straightening portion 130 has a shape in which the thickness gradually decreases radially outward. Specifically, at the upstream end of the flow straightening portion 130, the thickness of the flow straightening portion 130 is approximately the same as the thickness of the trailing edge 105 of the blade 102, but the thickness of the flow straightening portion 130 decreases toward the downstream end. As a result, the blades 102 and the flow straightening portion 130 form a streamlined shape as a whole, and are able to smoothly guide the fluid flow within the flow path space 108 .

[0052] As described above, in the closed impeller 100 (100A to 100C), the first part 110 and the second part 120 are joined by caulking, and therefore various combinations of materials for the first part 110 and the second part 120 are possible. In some embodiments, the first component 110 is a resin component including the blades 102 and the hub 106, and the second component 120 constituting the shroud 104 is a pressed metal component having a thickness thinner than that of the hub 106. Such a combination of materials for the first component 110 and the second component 120 is applicable to, for example, the closed impeller 100B shown in FIG. 3. In this case, the shroud 104 may be a pressed metal component having a three-dimensional shape corresponding to the inlet shape of the flow path space 108, obtained by, for example, raising the inner peripheral edge of an annular metal plate by press working. In another embodiment, the first part 110 is a resin part including the shroud 104, and the second part 120 including the blades 102 and the hub 106 is a metal part. Such a combination of materials for the first part 110 and the second part 120 is applicable to, for example, the closed impeller 100C shown in Figures 4A and 4C. In this case, the resin part as the first part 110 including the shroud 104 and the flow control part 130 may be obtained by injection molding, while the metal part as the second part 120 including the blades 102 and the hub 106 having a desired three-dimensional shape may be obtained by machining.

[0053] Next, a manufacturing method for the closed impeller 100 (100A to 100C) will be described. In the following, reference will be made to FIGS. 5A to 5C showing a manufacturing method for the closed impeller 100A, but the same applies to the manufacturing methods for the closed impellers 100B and 100C.

[0054] As shown in FIG. 5A, first part 110 is positioned relative to second part 120 so that the position of crimping protrusion 112 of first part 110 coincides with the position of opening 122 of second part 120. Here, the crimping protrusion 112 has a cross-sectional shape corresponding to the opening 122 and can be fitted into the opening 122 with substantially no gap. The length L1 of the crimping protrusion 112 is set to be greater than the depth (length) L2 of the opening 122.

[0055] 5B, crimping protrusion 112 of first part 110 is fitted into opening 122 of second part 120. At this time, since length L1 of crimping protrusion 112 is greater than depth (length) L2 of opening 122, the tip of crimping protrusion 112 protrudes from opening 122. In this state, the crimping device 200 is moved relatively close to the tip of the crimping protrusion 112 from the opposite side of the first component 110 with the second component 120 sandwiched therebetween, and the tip of the crimping protrusion 112 is crimped by the crimping device 200.

[0056] In this way, as shown in FIG. 5C, the tip of the crimping protrusion 112 is deformed by crimping to form a retaining portion 114, thereby joining the first part 110 and the second part 120 and completing the assembly of the closed impeller 100A.

[0057] As will be described below with reference to FIGS. 6A to 6C, the crimping device 200 may be a resin crimping (resin staking) device that crimps the crimping protrusion 112 of the first component 110 formed from a resin component.

[0058] In some embodiments, as shown in FIG. 6A, the resin crimping protrusion 112 is crimped using a thermal crimping device 200A including a punch 202 and a heater (not shown). When the thermal crimping device 200A is used, the punch 202 heated by a heater is pressed against the tip of the crimping protrusion 112 to thermally deform the tip of the crimping protrusion 112, thereby forming the retaining portion 114.

[0059] In another embodiment, as shown in FIG. 6B, the resin crimping protrusion 112 is crimped using an ultrasonic crimping device 200B including a horn 204. When using the ultrasonic crimping device 200B, ultrasonic waves from the horn 204 are applied to the tip of the crimping protrusion 112, and the tip of the crimping protrusion 112 is heated and deformed by ultrasonic vibration, thereby forming the retaining portion 114.

[0060] In yet another embodiment, as shown in FIG. 6C, the resin crimping protrusion 112 is crimped using an infrared crimping device 200C including a punch 206 and a cover 210. When the infrared crimping device 200C is used, infrared rays 212 irradiated from an infrared light source (not shown) are reflected by the inner surface of the cover 210 and collected at the tip of the crimping protrusion 112. The tip of the crimping protrusion 112 heated by the infrared rays 212 is pressed by the punch 206 and deformed to form the retaining portion 114.

[0061] Among the above-described embodiments, some configurations and their corresponding advantageous effects will be described.

[0062] [1] The closed impeller 100 (100A to 100C) includes a blade 102, a shroud 104 that covers the blade 102, and a hub 106 that is located on the opposite side of the shroud 104 across the blade 102 in the axial direction. A first part 110 including either the shroud 104 or the hub 106 has a crimping protrusion 112. A second part 120 including the other of the shroud 104 or the hub 106 has an opening 122 for receiving the crimping protrusion 112 of the first part 110. The first part 110 has a retaining portion 114 formed by deformation of the portion of the crimping protrusion 112 that protrudes out of the opening 122 due to crimping.

[0063] The configuration [1] above can be used to join dissimilar materials, such as metal and resin, unlike welding or adhesion, which alleviates restrictions on the materials that can be used to form the closed impeller 100 (100A to 100C). Furthermore, compared to welding, in which variations in the amount of melted resin can affect the gap between the shroud and the hub, the gap between the shroud 104 and the hub 106 in the assembled closed impeller 100 (100A to 100C) can be controlled with high precision.

[0064] [2] As shown in FIGS. 2A, 3, and 4A, the retaining portion 114 is located on the opposite side of the flow passage space 108 between the shroud 104 and the hub 106, with the second part 120 sandwiched therebetween.

[0065] According to the configuration [2] above, the fluid can be guided to flow more smoothly through the closed impeller 100 (100A to 100C) than when the retaining portion 114 is located inside the flow path space 108. Therefore, the hydrodynamic performance of the closed impeller 100 (100A to 100C) is improved.

[0066] [3] As shown in FIG. 3, the retaining portion 114 is located on the opposite side of the flow passage space 108 across the shroud 104 as the second component 120.

[0067] In the case of [3] above, when manufacturing the closed impeller 100B, the crimping protrusion 112 is crimped from the opposite side of the flow path space 108 across the shroud 104. Therefore, even if a part of the motor unit 6 of the electric pump 1 is integrated into the hub 106 of the closed impeller 100B, a sufficient space for the crimping work can be secured. Furthermore, when a part of the motor section 6 of the electric pump 1 is integrated with the hub 106 of the closed impeller 100B, heat input due to crimping may adversely affect the components (such as the magnet 26) of the motor section 6. In this regard, by moving the heat input point due to crimping (the crimping protrusion 112) away from the motor section 6 as described in [3] above, it is possible to suppress the temperature rise of the components of the motor section 6.

[0068] [4] The blades 102 are integrally mounted to either a shroud 104 or a hub 106, as shown in Figures 2A, 3 and 4A. In the case of [4] above, the manufacturing cost of the closed impeller 100 (100A to 100C) can be reduced by reducing the number of parts.

[0069] [5] The first component 110 having the crimping projection 112 is made of resin, and the second component 120 having the opening 122 is made of metal.

[0070] As described in [1] above, by joining the first part 110 and the second part 120 by crimping, restrictions on the constituent materials of the closed impeller 100 (100A to 100C) are alleviated. Therefore, as described above in [5], the first part 110 having the crimping protrusion 112 can be made of resin, which is easy to crimp, while the second part 120 can be made of metal, taking into account mechanical properties and processing costs.

[0071] [6] The first component 110 is a resin component including the blades 102 and the hub 106, and the shroud 104 as the second component 120 is a pressed metal component having a thickness thinner than that of the hub 106.

[0072] According to the configuration [6] above, the second part 120 does not include the blades 102 but only the shroud 104, so the shape of the second part 120 is simplified and it becomes possible to realize the second part 120 as a pressed metal part. On the other hand, the first part 110 (the blades 102 and the hub 106) having the crimping protrusions 112 is made of a resin part that is easy to crimp. In this way, it is possible to achieve both improved workability in crimping first component 110 and second component 120 and reduced processing costs for second component 120.

[0073] [7] As shown in FIGS. 2A and 3, the first part 110 includes the blade 102, and the crimping projections 112 are provided on the abutment surface 103 (103A, 103B) of the blade 102 that abuts against the second part 120.

[0074] According to the configuration [7] above, the retaining portion 114 is located outside the flow path space 108 between the shroud 104 and the hub 106, thereby realizing a closed impeller 100 (100A, 100B) that can exhibit excellent hydrodynamic performance with a simple structure.

[0075] 4A to 4C, the second component 120 includes the blades 102 and the hub 106, and the first component 110 includes the shroud 104 and the flow straightening portion 130. The flow straightening portion 130 protrudes toward the second component 120 so as to be adjacent to the trailing edge 105 of the blade 102 in the flow passage space 108 between the shroud 104 and the hub 106. The crimping protrusion 112 is provided on the abutment surface 134 of the flow straightening portion 130 that contacts the second component 120.

[0076] According to the configuration [8] above, the retaining portion 114 is located outside the flow path space 108 between the shroud 104 and the hub 106, thereby realizing a closed impeller 100C that can exhibit excellent hydrodynamic performance with a simple structure. Furthermore, the structure that supports the crimping protrusion 112 of the first component 110 on the second component 120 side is exposed to the flow path space 108, and if this structure is not the blade 102, it may have an adverse effect on the flow of fluid. In this regard, in the configuration [8] above, the crimping protrusion 112 is provided on the flow straightening portion 130 of the first component 110, so that the flow of fluid downstream of the blade 102 is straightened by the flow straightening portion 130 adjacent to the trailing edge 105 of the blade 102.

[0077] In this specification, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement strictly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions representing shapes such as a rectangular shape or a cylindrical shape not only represent rectangular shapes or cylindrical shapes in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components. [Explanation of symbols]

[0078] 1: Electric pump 10: Support shaft 20: Rotor 40: Stator 42: Stator core 44: Stator coil 100 (100A~100C): Closed impeller 102: Blade 103(103A,103B): Contact surface 104: Shroud 105: Trailing edge 106: Hub 108: Flow path space 110: First part 112: Convex part for caulking 114: Retaining part 120: Second part 122:Aperture 130: Rectifier 134: Contact surface

Claims

1. Blade and a shroud covering the blade; a hub located on the opposite side of the shroud with the blades in the axial direction; Equipped with a first component including one of the shroud and the hub has a caulking projection; a second component including the other of the shroud and the hub has an opening for receiving the crimping protrusion of the first component; The first component has a retaining portion formed by deformation of the crimping protrusion that protrudes out of the opening due to crimping. Closed impeller.

2. The closed impeller according to claim 1 , wherein the retaining portion is located on an opposite side of the flow passage space between the shroud and the hub, with the second component sandwiched therebetween.

3. The closed impeller according to claim 2 , wherein the retaining portion is located on an opposite side of the flow passage space with the shroud as the second component interposed therebetween.

4. The blades are integrally mounted on either the shroud or the hub.

3. The closed impeller according to claim 1 or 2.

5. the first component having the crimping protrusion is made of resin, The second part is made of metal.

3. The closed impeller according to claim 1 or 2.

6. the first component is a resin component including the blade and the hub, 3. The closed impeller according to claim 1, wherein the shroud as the second part is a pressed metal part having a thickness thinner than that of the hub.

7. the first part includes the blade; The crimping protrusion is provided on a surface of the blade that comes into contact with the second component.

3. The closed impeller according to claim 1 or 2.

8. the second part includes the blade; the first component has a flow straightening portion that protrudes toward the second component so as to be adjacent to the trailing edge of the blade in a flow passage space between the shroud and the hub, The crimping protrusion is provided on a contact surface of the flow rectifying portion with the second component.

3. The closed impeller according to claim 1 or 2.

9. A support shaft; a rotor including an impeller and a magnet and supported by the support shaft on the radially outer side of the support shaft; a stator including a stator core disposed with a magnetic gap between it and the magnet, the stator facing the rotor without contact with the rotor across an air gap within a range where the magnetic gap is formed; Equipped with The impeller is configured as a closed impeller according to claim 1 or 2. Electric pump.

10. Blade and a shroud covering the blade; a hub located on the opposite side of the shroud with the blades in the axial direction; A method for manufacturing a closed impeller, comprising: a crimping projection of a first component including one of the shroud and the hub is fitted into an opening of a second component including the other of the shroud and the hub; A portion of the crimping projection that protrudes outside the opening is deformed by crimping to form a retaining portion, thereby joining the first component and the second component. A manufacturing method for a closed impeller.

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