Water jacket and method of manufacturing the water jacket

Abstract

To provide a water jacket that can improve cooling efficiency of a heat generating part.SOLUTION: A cooling liquid channel inside a housing arranged on an outer surface of a heat generating part includes: a plurality of main channel pipe parts which are arranged in the vicinity of the outer surface of the heat generating part, extend linearly, and are arranged along the outer surface of the heat generating part; an inflow side collection pipe part which is collectively connects upstream side ends of the main channel pipe part and causes a cooling liquid to flow in; and an outflow side collection pipe part which collectively connects downstream side ends of the main channel pipe part and causes the cooling liquid to flow out. The main channel pipe part has a vortex generating part which deflects the flow of the cooling liquid toward a circumferential direction of the main channel pipe part to generate a vortex flow inside the vicinity of an end portion of the upstream side. The vortex generating part has a plurality of protruding parts which are arranged along the circumferential direction on an inner wall surface of the main channel pipe part and protrude toward a radial center of the main channel pipe part. Tips of the plurality of protruding parts are separated from each other, and the tip side of the plurality of protruding parts has a penetration flow passage part capable of making the cooling liquid flow along the radial center of the main channel pipe pat.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water jacket and a method for manufacturing a water jacket. [Background technology]

[0002] Conventionally, a water jacket provided on the peripheral surface of a stator housing of an electric motor is known (see, for example, Patent Document 1). This water jacket is provided with a turbulence generating member at the coolant inlet to the coolant jacket. The turbulence generating member generates turbulence in the coolant flowing toward the coolant jacket, and causes the coolant to flow into the coolant jacket approximately evenly, thereby improving cooling efficiency. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-119019 Summary of the Invention [Problem to be solved by the invention]

[0004] In the water jacket of the above-mentioned conventional technology, the wide coolant jacket extends around the circumferential direction of the stator housing, which is a heat-generating part. Therefore, even if turbulence is generated in the coolant flowing into the coolant jacket using a turbulence generating member, the effect of the turbulence is reduced as the coolant flows through the flow path of the coolant jacket, which is curved around the circumferential direction of the stator housing. Therefore, there is room for improvement in terms of efficient cooling throughout the entire coolant jacket.

[0005] An object of the present invention is to provide a water jacket that can further improve the cooling efficiency of a heat-generating portion, and a method for manufacturing such a water jacket. [Means for solving the problem]

[0006] (1) The water jacket according to the present invention is a water jacket (e.g., the water jacket 1) having a coolant flow path (e.g., the coolant flow path 3 described later) inside a housing (e.g., the housing 2 described later) disposed on the outer surface of a heat generating part (e.g., the stator core 101 described later), and the coolant flow path is disposed near the outer surface of the heat generating part, and includes main flow path pipe sections (e.g., the main flow path pipe sections 31 described later) that extend linearly and are arranged along the outer surface of the heat generating part, and upstream ends (e.g., the upstream ends 31a described later) of the main flow path pipe sections are connected together to form an inlet-side collecting pipe section (e.g., the inlet-side collecting pipe section 32 described later) through which the coolant flows, and downstream ends (e.g., the downstream ends 31b described later) of the main flow path pipe sections are connected together to form an outlet-side collecting pipe section through which the coolant flows out. and a pipe section (e.g., an outlet-side collecting pipe section 33 described later), the main flow path pipe section having a vortex generating section (e.g., vortex generating section 4 described later) inside near the upstream end section that deflects the flow of the coolant in a circumferential direction of the main flow path pipe section to generate a vortex flow, the vortex generating section having a plurality of protrusions (e.g., deflector plates 41 described later) that are arranged along the circumferential direction (e.g., a D4 direction described later) of an inner wall surface (e.g., an inner wall surface 31c described later) of the main flow path pipe section and protrude toward the center in a radial direction (e.g., a D5 direction described later) of the main flow path pipe section, the tips (e.g., tips 41a described later) of the plurality of protrusions being spaced apart from each other, and a through flow path section (e.g., a through flow path section 41e) that allows the coolant to flow along the radial center of the main flow path pipe section on the tip side of the plurality of protrusions.

[0007] (2) In the water jacket described above in (1), each of the plurality of protrusions may be formed in a tapered shape from the inner wall surface of the main flow path pipe portion toward the tip.

[0008] (3) In the water jacket described in (1) or (2) above, the vortex generating portion may have a gap flow path portion (e.g., gap flow path portion 41f described below) between adjacent protrusions in the circumferential direction of the main flow path pipe portion, which connects the upstream side and downstream side of the vortex generating portion along the extension direction of the main flow path pipe portion and connects with the through flow path portion.

[0009] (4) In the method for manufacturing a water jacket according to the present invention, the water jacket according to any one of (1) to (3) above is integrally molded by additive manufacturing using a metal material. [Effects of the Invention]

[0010] According to the above (1), a plurality of protrusions protruding from the inner wall surface of the main flow passage pipe toward the center can generate a vortex within the main flow passage pipe. This improves the heat transfer in the coolant flow path and further improves the cooling efficiency of the heat-generating part. Furthermore, since the tips of the plurality of protrusions are spaced apart from each other, a through-flow path through which the coolant can flow is formed at the radial center of the main flow passage pipe. This allows the coolant to flow smoothly within the main flow passage pipe, and stress is less likely to concentrate on the protrusions due to, for example, external forces acting on the housing itself. This makes it possible to provide a high-quality water jacket with high durability.

[0011] According to the above (2), the protrusion is formed in a tapered shape toward the center of the main flow path pipe, which reduces the flow resistance of the coolant when passing through the vortex generating section, allowing the coolant to flow more smoothly through the main flow path pipe.

[0012] According to the above (3), by providing the gap flow passages that communicate with the through flow passages between the circumferentially adjacent protrusions of the main flow passage pipe section, the flow resistance of the coolant passing through the vortex generating section can be reduced, allowing the coolant to flow more smoothly through the main flow passage pipe section.

[0013] According to the above (4), a water jacket that can further improve the cooling efficiency of heat-generating parts can be easily manufactured using a 3D printer. The vortex generated by the vortex generator in the main flow path pipe also improves the removability of metal material remaining in the coolant flow path after molding. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a vertical cross-sectional view showing an electric motor equipped with a water jacket according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing only the cooling water flow path in the water jacket according to the embodiment. [Figure 3] 2 is a perspective view showing a partly cutaway vortex generating section in a main flow path pipe section at part A in FIG. 1. FIG. [Figure 4] FIG. 4 is a plan view of a vortex generating section in a main flow path pipe section, as viewed from the upstream side of the main flow path pipe section. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 shows an electric motor 100 equipped with a water jacket 1 according to this embodiment. The direction D1 indicated by the arrow in Fig. 1 is the axial direction of the electric motor 100, and the direction D2 is the radial direction of the electric motor 100.

[0016] The electric motor 100 has a substantially cylindrical stator core 101 extending in the axial direction, and a rotor 102 rotatably supported in an axial hole 101a of the stator core 101. The stator core 101 is made of an iron-based metal material, and houses coils 103 in a plurality of slots 101b.

[0017] When the electric motor 100 is driven, heat from the coil 103 is transferred to the stator core 101, causing the stator core 101 to generate heat. The water jacket 1 cools the coil 103 through the stator core 101. In this embodiment, the stator core 101 is a heat-generating part to be cooled by the water jacket 1.

[0018] The water jacket 1 is disposed radially outside the stator core 101 of the electric motor 100. The water jacket 1 has a housing 2 disposed on the outer periphery of the stator core 101, and a tubular coolant flow path 3 provided inside the housing 2 and through which a coolant for cooling the stator core 101 flows.

[0019] The housing 2 is formed from a metal material such as aluminum or copper that has good thermal conductivity, and has a shape that surrounds the entire outer periphery of the stator core 101. The housing 2 is thermally connected to the outer peripheral surface 101c of the stator core 101. In this embodiment, the housing 2 is in direct contact with the outer peripheral surface 101c of the stator core 101. However, the housing 2 may be connected to the outer peripheral surface 101c of the stator core 101 via a heat-conductive material, such as a heat-conductive medium containing metal fine particles.

[0020] 2, a coolant flow path 3 through which the coolant flows is formed inside the housing 2. The coolant flow path 3 has a plurality of main flow path pipe sections 31, at least one inlet collecting pipe section 32, and at least one outlet collecting pipe section 33.

[0021] The main flow path pipe section 31 is disposed near the outer peripheral surface 101c of the stator core 101. In this embodiment, the multiple main flow path pipe sections 31 each extend linearly along the axial direction of the stator core 101. However, the multiple main flow path pipe sections 31 may each be provided to extend along the circumferential direction of the stator core 101. Inside the housing 2, the multiple main flow path pipe sections 31 are arranged in parallel at regular intervals in the direction D3 along the outer periphery of the stator core 101 so as to surround the stator core 101. The main flow path pipe sections 31 in this embodiment are configured to pass the coolant along the axial direction of the stator core 101 from top to bottom in FIGS. 1 and 2 .

[0022] The inlet collecting pipe section 32 is provided in an annular shape along the outer periphery of the stator core 101. The inlet collecting pipe section 32 connects the upstream ends 31a of all the main flow path pipe sections 31 together so that they are in communication with the interiors of the main flow path pipe sections 31. As shown in FIG. 2 , the inlet collecting pipe section 32 is connected to at least one inlet pipe 321 that allows the coolant to flow into the coolant flow path 3.

[0023] Like the inlet-side collecting pipe 32, the outlet-side collecting pipe 33 is provided in an annular shape along the outer periphery of the stator core 101. The outlet-side collecting pipe 33 connects the downstream ends 31b of all the main flow path pipes 31 together so that each is in communication with the interior of the main flow path pipes 31. As shown in FIG. 2 , the outlet-side collecting pipe 33 is connected to at least one outlet pipe 331 that causes the coolant to flow out of the coolant flow path 3.

[0024] A vortex generating section 4 is provided inside each of all main flow path pipe sections 31, for generating a vortex in the coolant flowing through the main flow path pipe section 31. As shown in FIGS. 1 and 2, the vortex generating section 4 is disposed inside the main flow path pipe section 31 near the upstream end section 31a. By providing this vortex generating section 4 in the main flow path pipe section 31, a vortex can be easily generated inside the main flow path pipe section 31, thereby improving the heat transferability of the coolant flow path 3. This significantly reduces the temperature gradient inside the main flow path pipe section 31, and further improves the cooling efficiency of the stator core 101, which is a heat-generating section.

[0025] 3 and 4, the vortex generating section 4 of this embodiment has a plurality of blade-shaped deflection plates 41 that deflect the flow of the coolant in the circumferential direction of the main flow path pipe section 31 (direction D4 in FIGS. 3 and 4) to generate a vortex flow. The deflection plates 41 are protrusions that protrude from the inner wall surface 31c of the main flow path pipe section 31 toward the center of the main flow path pipe section 31 in the radial direction (direction D5 in FIG. 4). The vortex generating section 4 of this embodiment has four deflection plates 41, but the number of deflection plates 41 is not limited to four.

[0026] The deflection plates 41 are arranged on the inner wall surface 31c of the main flow path pipe section 31 along the circumferential direction of the main flow path pipe section 31. More specifically, the four deflection plates 41 are arranged at intervals of approximately 90° along the circumferential direction of the inner wall surface 31c and are provided integrally with the inner wall surface 31c. Each of the four deflection plates 41 protrudes from the inner wall surface 31c toward the center of the main flow path pipe section 31 in the radial direction.

[0027] As shown in Fig. 4, the deflector plate 41 is formed in a tapered shape from the inner wall surface 31c to which the base end 41b is connected toward the tip 41a. More specifically, the deflector plate 41 is formed in a triangular or fan shape in which the base end 41b connected to the inner wall surface 31c is wider than the tip 41a located toward the center in the radial direction of the main flow path pipe section 31. Both side edges 41c, 41d of the deflector plate 41 gradually approach each other from the base end 41b toward the tip 41a and are integrated at the tip 41a. Because the deflector plate 41 is connected to the inner wall surface 31c of the main flow path pipe section 31 on the wider base end 41b side, it is stably and firmly attached to the main flow path pipe section 31.

[0028] The surfaces of the four deflection plates 41 are curved or inclined in the same circumferential direction of the main flow path pipe section 31 from the base end 41b to the tip end 41a. More specifically, a side edge 41c of the deflection plate 41 is arranged on one circumferential side (direction D41 in FIG. 4) of the main flow path pipe section 31, while a side edge 41d of the deflection plate 41 is arranged on the other circumferential side (direction D42 in FIG. 4) of the main flow path pipe section 31 is arranged slightly downstream of the main flow path pipe section 31. As a result, the four deflection plates 41 deflect the flow of the coolant inside the main flow path pipe section 31 in the same circumferential direction of the main flow path pipe section 31, as shown by the arrows in FIG. 3.

[0029] 4, the tips 41a of the four deflection plates 41 are spaced apart from one another and do not contact one another. Therefore, the vortex generating section 4 has a through-flow passage 41e on the side of the tips 41a of the four deflection plates 41, through which the coolant can flow along the radial center of the main flow path pipe section 31. The through-flow passage 41e linearly connects the upstream side and downstream side of the vortex generating section 4 inside the main flow path pipe section 31.

[0030] 4, when the vortex generating section 4 is viewed from above, gap flow passage sections 41f are formed between the deflection plates 41, 41 adjacent to each other in the circumferential direction of the main flow passage pipe section 31. The gap flow passage sections 41f linearly connect the upstream side and downstream side of the vortex generating section 4 inside the main flow passage pipe section 31 along the extension direction of the main flow passage pipe section 31 (direction D1 in FIGS. 2 and 3, the direction perpendicular to the paper surface in FIG. 4). Each gap flow passage section 41f communicates with a respective through flow passage section 41e.

[0031] The coolant that flows from the inlet collecting pipe 32 of the coolant flow path 3 into the main flow path pipe 31 collides with the four deflection plates 41 of the vortex generating section 4. The coolant that collides with the deflection plates 41 is guided by the surfaces of the deflection plates 41 and becomes a vortex that swirls in the same circumferential direction of the main flow path pipe 31 (in this embodiment, the direction D42 in FIG. 4 ), and passes through the vortex generating section 4. Because the vortex generating section 4 is disposed near the upstream end 31a of the main flow path pipe 31, the coolant that flows into the main flow path pipe 31 flows toward the outlet collecting pipe 33 over the entire length of the main flow path pipe 31 while maintaining a vortex state.

[0032] Such a water jacket 1 can be manufactured by additive manufacturing using the same metal material (powdered metal, metal wire, etc.) to form the housing 2 and the coolant flow path 3 having the vortex generating portion 4 inside the main flow path pipe portion 31. According to this manufacturing method, the housing 2 and the coolant flow path 3 having the vortex generating portion 4 inside the main flow path pipe portion 31 can be easily molded integrally using a 3D printer. As the metal material, an aluminum-based, copper-based, or other metal material with good thermal conductivity can be used.

[0033] In additive manufacturing using a 3D printer, for example, when powdered metal is used as the metal material, the water jacket 1 is three-dimensionally additively manufactured along the direction D1, which is the longitudinal direction of the main flow path pipe section 31, by repeatedly irradiating the powdered metal spread on a base plate with a laser or electron beam as a heat source to melt and solidify the part to be formed, and then moving the base plate and spreading new powdered metal.

[0034] The water jacket 1 according to the present embodiment described above provides the following functions and advantages. Specifically, this embodiment provides a water jacket 1 having a coolant flow path 3 inside a housing 2 disposed on the outer peripheral surface of a stator core 101, which is a heat-generating part. The coolant flow path 3 is disposed near the outer peripheral surface of the stator core 101 and includes a plurality of main flow path pipe sections 31 that extend linearly and are arranged along the outer peripheral surface of the stator core 101, an inlet-side collecting pipe section 32 that connects together upstream ends 31a of the main flow path pipe sections 31 and allows the coolant to flow in, and an outlet-side collecting pipe section 33 that connects together downstream ends 31b of the main flow path pipe sections 31 and allows the coolant to flow out. The main flow path pipe section 31 has a vortex generating section 4 near the upstream end 31a that deflects the flow of coolant in the circumferential direction of the main flow path pipe section 31 to generate a vortex. The vortex generating section 4 has deflection plates 41 consisting of multiple protrusions arranged circumferentially around the inner wall surface 31c of the main flow path pipe section 31 and protruding toward the radial center of the main flow path pipe section 31, and the tips 41a of the multiple deflection plates 41 are spaced apart from each other, and on the side of the tips 41a of the multiple deflection plates 41, there is a through flow path section 41e through which the coolant can flow along the radial center of the main flow path pipe section 31.

[0035] According to this, the coolant that has passed through the vortex generating section 4 becomes a vortex flow, and flows through the main flow path pipe section 31 while swirling alternately between the side closer to the stator core 101 and the side farther from the stator core 101. Therefore, the coolant can efficiently exchange heat with the stator core 101, which is a heat-generating section, over the entire length of the main flow path pipe section 31. Inside the main flow path pipe section 31, the temperature gradient between the side closer to the stator core 101 and the side farther from the stator core 101 is significantly reduced, which improves the heat transferability of the coolant flow path 3 and further improves the cooling efficiency of the stator core 101, which is a heat-generating section.

[0036] Furthermore, because the vortex generating unit 4 has through-flow passages 41e on the tip ends 41a of the four deflection plates 41, the center of the vortex flow of the coolant passing through the vortex generating unit 4 can flow smoothly from the upstream side to the downstream side in the through-flow passages 41e. Because the flow resistance of the coolant passing through the vortex generating unit 4 is reduced, even if an external force is applied to the housing 2 itself, for example, stress is less likely to concentrate on the deflection plates 41, improving the durability of the deflection plates 41. Therefore, a highly durable and high-quality water jacket 1 can be provided.

[0037] In this embodiment, each of the deflection plates 41 is formed in a tapered shape from the inner wall surface 31c of the main flow path pipe section 31 toward the tip 41a. This further reduces the flow path resistance of the coolant when passing through the vortex generating section 4. This allows the coolant to flow through the main flow path pipe section 31 more smoothly.

[0038] In this embodiment, the vortex generating section 4 has a gap flow path section 41f between adjacent deflection plates 41, 41 in the circumferential direction of the main flow path pipe section 31. The gap flow path section 41f connects the upstream side and downstream side of the vortex generating section 4 along the extension direction of the main flow path pipe section 31 and also connects with the through flow path section 41e. This further reduces the flow path resistance of the coolant when passing through the vortex generating section 4. This allows the coolant to flow through the main flow path pipe section 31 more smoothly.

[0039] The manufacturing method for the water jacket 1 of this embodiment involves integral molding using a metal material through additive manufacturing. This allows the water jacket 1, which can further improve the cooling efficiency of the stator core 101, to be easily manufactured using a 3D printer. The vortex generated by the vortex generating section 4 in the main flow path pipe section 31 also improves the removability of metal material remaining in the coolant flow path 3 after manufacturing.

[0040] The water jacket 1 shown in the above embodiment is provided in only one set on the outer peripheral surface of the heat-generating part, the stator core 101. However, for example, if the stator core 101 is longer in the axial direction, two or more sets of water jackets 1 may be stacked along the axial direction of the stator core 101.

[0041] The water jacket 1 shown in the above embodiment is provided in the electric motor 100 whose heat-generating part is the stator core 101, but the heat-generating part is not limited to the electric motor 100. The water jacket 1 can be provided in various heat-generating parts that require cooling by a coolant. [Explanation of symbols]

[0042] 1 water jacket 2. Housing 3 Coolant flow path 31 Main flow pipe section 31a Upstream end 31b Downstream end 31c Inner wall 32 Inflow side collecting pipe section 33 Outlet side collecting pipe section 4 Vortex generator 41 Deflection plate (protrusion) 41a Tip 41e Through-flow passage section 41f Gap flow path section 101 Stator core (heat generating part)

Claims

1. A water jacket having a coolant flow path inside a housing arranged on the outer surface of a heat generating part, The coolant flow path is a plurality of main flow path pipe sections arranged in the vicinity of an outer surface of the heat generating section, extending linearly and arranged along the outer surface of the heat generating section; an inlet collecting pipe portion that connects upstream ends of the main flow path pipe portions together and allows the coolant to flow in; an outflow collecting pipe portion that connects downstream ends of the main flow path pipe portions together and allows the coolant to flow out; and the main flow path pipe portion has, inside the upstream end portion thereof and a vortex generating portion that deflects the flow of the coolant in a circumferential direction of the main flow path pipe portion to generate a vortex, the vortex generating section has a plurality of protrusions arranged along the circumferential direction of the inner wall surface of the main flow path pipe section and protruding toward the radial center of the main flow path pipe section, the plurality of protrusions have tips spaced apart from one another, and a through-flow passage portion is provided on the tip side of the plurality of protrusions, through which the coolant can flow along a radial center of the main flow passage pipe portion; A water jacket, wherein base ends of the plurality of protrusions are connected to the inner wall surface, and the base ends of adjacent protrusions in the circumferential direction of the inner wall surface are spaced apart from each other.

2. The water jacket according to claim 1 , wherein each of the plurality of protrusions is formed in a tapered shape from the inner wall surface of the main flow passage pipe portion toward the tip end.

3. 3. The water jacket according to claim 1, wherein the vortex generating portion has a gap flow path portion between adjacent protrusions in the circumferential direction of the main flow path pipe portion, the gap flow path portion connecting the upstream side and downstream side of the vortex generating portion along the extension direction of the main flow path pipe portion and connecting with the through flow path portion.

4. A water jacket described in any one of claims 1 to 3, wherein the protrusion consists of a deflector plate, and the surfaces of the deflector plates are curved or inclined in the same circumferential direction of the main flow path pipe section from the base end to the tip end.

5. A method for manufacturing a water jacket, comprising integrally molding the water jacket according to any one of claims 1 to 4 by additive manufacturing using a metal material.

6. A water jacket having a coolant flow path inside a housing arranged on the outer surface of a heat generating part, The coolant flow path is a plurality of main flow path pipe sections arranged in the vicinity of an outer surface of the heat generating section, extending linearly and arranged along the outer surface of the heat generating section; an inlet collecting pipe portion that connects together upstream ends of all of the main flow path pipe portions and into which the coolant flows; an outlet-side collecting pipe section that connects together downstream end portions of all of the main flow path pipe sections and through which the coolant flows out, all of the main flow path pipe sections have a vortex generating section located downstream of the inlet-side collecting pipe section and inside the main flow path pipe sections near the upstream end sections, the vortex generating section deflecting the flow of the coolant in a circumferential direction of the main flow path pipe sections to generate a vortex flow, the vortex generating section has a plurality of protrusions arranged along the circumferential direction of the inner wall surface of the main flow path pipe section and protruding toward the radial center of the main flow path pipe section, and the tips of the plurality of protrusions are spaced apart from each other, and a through flow path section is provided on the tip side of the plurality of protrusions so that the coolant can flow along the radial center of the main flow path pipe section.

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