Inverter-integrated motor

Abstract

To achieve downsizing of a motor case and improve cooling performance of a motor.SOLUTION: An inverter-integrated motor (1) is provided with: a motor case (10) in which an inner case (21) is accommodated inside an outer case (11); a motor (31) installed inside the inner case and having a motor shaft protruding to the outside of the case; an inverter (39) installed inside the outer case and configured to control rotation of the motor; and a heat sink (41) installed inside the outer case and configured to cool the inverter. A plurality of cooling ribs (22) are provided on an outer circumferential surface of the inner case, and a plurality of cooling fins (42) are provided on a lower surface of the heat sink. The lower surface of the heat sink faces the outer circumferential surface of the inner case, and a common flow path (52) is formed by the plurality of cooling ribs and the plurality of cooling fins.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an inverter-integrated motor. [Background technology]

[0002] Conventionally, an inverter-integrated motor in which a motor and an inverter are housed in a single motor case is known (see, for example, Patent Document 1). In the inverter-integrated motor described in Patent Document 1, the motor is housed in the lower case of the motor case, and the inverter is housed in the upper case of the motor case. A first cooling flow path is formed in the lower case so as to surround the stator of the motor, and a second cooling flow path is formed in the upper case so as to follow the underside of the inverter. The second cooling flow path is connected to the downstream side of the first cooling flow path, and the motor and inverter share a common cooling flow path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6589095 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the inverter-integrated motor described in Patent Document 1, the upper case is stacked on the lower case, and the cooling channels are formed in each case, which increases the size of the motor case. Also, in the lower case, the first cooling channel cannot completely surround the stator, which deteriorates the cooling performance of the motor.

[0005] The present invention has been made in view of the above points, and has as its object to provide an inverter-integrated motor that can reduce the size of the motor case and improve the cooling performance of the motor. [Means for solving the problem]

[0006] One embodiment of the inverter-integrated motor of the present invention comprises a motor case in which an inner case is housed inside an outer case, a motor installed inside the inner case with the motor shaft protruding outside the case, an inverter installed inside the outer case to control the rotation of the motor, and a heat sink installed inside the outer case to cool the inverter, wherein the outer surface of the inner case is provided with a plurality of cooling ribs, the underside of the heat sink is provided with a plurality of cooling fins, the underside of the heat sink faces the outer surface of the inner case, and a common flow path is formed by the plurality of cooling ribs and the plurality of cooling fins, thereby solving the above-mentioned problem. [Effects of the Invention]

[0007] According to an inverter-integrated motor of one aspect of the present invention, a common flow path is formed between the inner case and the heat sink, which allows the motor and inverter to be closer to each other, thereby making the motor case more compact. Also, as cooling water flows through the common flow path, heat from the motor is transferred to the inner case and dissipated into the cooling water from the multiple cooling ribs, and heat from the inverter is transferred to the heat sink and dissipated into the cooling water from the multiple cooling fins, thereby improving the cooling performance of the motor and inverter. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a side view of the inverter-integrated motor of the present embodiment. [Figure 2] FIG. 2 is a front view of the inverter-integrated motor of the present embodiment. [Figure 3] 2 is a cross-sectional view of the inverter-integrated motor of FIG. 1 taken along line AA. [Figure 4] 3 is a cross-sectional view of the inverter-integrated motor of FIG. 2 taken along line BB. [Figure 5] 2A and 2B are a side view and a top view of the inner case of the present embodiment. [Figure 6] FIG. 2 is a perspective view of the heat sink of the present embodiment. [Figure 7]2 is an explanatory diagram of a cooling structure for a motor and an inverter according to the embodiment; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] An inverter-integrated motor according to one aspect of the present invention includes a motor case in which an inner case is housed inside an outer case. A motor is installed inside the inner case, and the motor shaft of the motor protrudes outside the case. An inverter and a heat sink are installed inside the outer case, with the inverter controlling the rotation of the motor and the heat sink cooling the inverter. A plurality of cooling ribs are provided on the outer peripheral surface of the inner case, and a plurality of cooling fins are provided on the underside of the heat sink of the inverter. The underside of the heat sink faces the outer peripheral surface of the inner case, and the plurality of cooling ribs and fins form a common flow path, bringing the motor and inverter closer together and reducing the size of the motor case. Furthermore, as cooling water flows through the common flow path, heat from the motor is transferred to the inner case and dissipated into the cooling water from the plurality of cooling ribs, and heat from the inverter is transferred to the heat sink and dissipated into the cooling water from the plurality of cooling fins, improving the cooling performance of the motor and inverter. [Example]

[0010] In a typical inverter-integrated motor, the motor unit and inverter unit are formed separately. The motor unit and inverter unit each have a cooling channel, and the units are fixed together, connecting the cooling channels in each unit in series. Because the cases and cooling channels of each unit are formed independently, the motor size of the inverter-integrated motor is disadvantageously large. Therefore, in this embodiment, the motor and inverter are housed in a single motor case, and some of the cooling channels for the motor and inverter are shared, thereby reducing the motor size.

[0011] The inverter-integrated motor of this embodiment will be described below with reference to the accompanying drawings. Fig. 1 is a side view of the inverter-integrated motor of this embodiment. Fig. 2 is a front view of the inverter-integrated motor of this embodiment. Fig. 3 is a cross-sectional view of the inverter-integrated motor of Fig. 1 taken along line AA. Fig. 4 is a cross-sectional view of the inverter-integrated motor of Fig. 2 taken along line BB. In the following figures, arrow Fr indicates the front, arrow Re indicates the rear, arrow L indicates the left, and arrow R indicates the right.

[0012] As shown in Figures 1 and 2, the inverter-integrated motor 1 has a motor 31 and an inverter 39 installed inside a single motor case 10. The motor case 10 is configured by accommodating an inner case 21 inside an outer case 11. The lower side of the outer case 11 is a cylindrical portion 12 with an open front, and the upper side of the outer case 11 is a box-shaped portion 13 with an open top. The bottom of the box-shaped portion 13 has a large opening, and a heat sink 41 is installed in the opening of the box-shaped portion 13. The opening of the box-shaped portion 13 is closed by the heat sink 41, so that the inside of the box-shaped portion 13 and the inside of the cylindrical portion 12 are separated by the heat sink 41.

[0013] A cylindrical inner case 21 is installed inside the cylindrical portion 12, and a motor 31 is installed inside the inner case 21. A stator 32 of the motor 31 is shrink-fitted inside the inner case 21, and a rotor 33 is rotatably installed inside the stator 32. A motor shaft 34 is fixed to the center of the rotor 33, and the motor shaft 34 protrudes forward from the inner case 21 (motor case 10). An inverter 39 is installed inside the box-shaped portion 13, and the rotation of the motor 31 is controlled by the inverter 39. The inverter 39 is supported on the upper surface of a heat sink 41, and the heat sink 41 cools the inverter 39.

[0014] A cooling flow path 51 (see FIGS. 3 and 4) is formed between the inner case 21 and the outer case 11 so as to surround the motor 31. An inlet pipe 14 and an outlet pipe 15 are attached to one side of the cylindrical portion 12 of the outer case 11. Cooling water is supplied from the inlet pipe 14 to the inlet of the cooling flow path 51, and the cooling water is discharged from the outlet of the cooling flow path 51 to the outlet pipe 15. The cooling flow path 51 is formed around the inner case 21 and below the heat sink 41, and the motor 31 and inverter 39 are effectively cooled while the cooling water passes around the inner case 21 and the underside of the heat sink 41.

[0015] 3 and 4, a plurality of cooling ribs 22 are provided on the outer peripheral surface of the inner case 21, and the top surfaces of the plurality of cooling ribs 22 contact the inner peripheral surface of the cylindrical portion 12 of the outer case 11. A heat sink 41 is provided in the opening at the top of the cylindrical portion 12, and the underside of the heat sink 41 faces the outer peripheral surface of the inner case 21. A plurality of cooling fins 42 are provided on the underside of the heat sink 41, and the top surfaces of the plurality of cooling fins 42 protrude toward the inner case 21. The plurality of cooling ribs 22 form a cooling flow path 51 around the inner case 21, and the plurality of cooling ribs 22 and the plurality of cooling fins 42 form a common flow path 52 in part of the cooling flow path 51.

[0016] Note that most of the cooling ribs 22 extend along the circumferential direction of the inner case 21, but some of the cooling ribs 22 that face the heat sink 41 extend along the axial direction of the inner case 21. Also, most of the cooling fins 42 extend along the circumferential direction of the inner case 21, but some of the cooling fins 42 extend along the axial direction of the inner case 21. These some of the cooling ribs 22 and some of the cooling fins 42 are arranged with misalignment in the circumferential direction. Therefore, in the common flow path 52 between the inverter 39 and the motor 31, coolant flows back and forth between the inner case 21 and the heat sink 41.

[0017] In this way, a common flow path 52 that simultaneously cools the motor 31 and inverter 39 is formed between the inner case 21 and the heat sink 41. Separate flow paths are no longer necessary for the inner case 21 and the heat sink 41, and the motor 31 and inverter 39 are brought closer together, thereby reducing the size of the motor case 10. The common flow path 52 is divided into inter-rib flow paths 53 on the inner case 21 side and inter-fin flow paths 56 on the heat sink 41 side. In the common flow path 52, the cooling performance of the motor 31 and inverter 39 is adjusted by the heights of the multiple cooling ribs 22 and multiple cooling fins 42, and the height dimension of the flow path does not become larger than necessary, thereby reducing the size of the motor case 10.

[0018] A partition wall 25 that separates the cooling flow path 51 into upper and lower sections is provided on one side of the outer peripheral surface of the inner case 21. The partition wall 25 extends along the axial direction of the inner case 21, and the top surface of the partition wall 25 contacts the inner peripheral surface of the tubular portion 12. The inlet pipe 14 is located above the partition wall 25, and the side above the partition wall 25 is the upstream section of the cooling flow path 51. The outlet pipe 15 is located below the partition wall 25, and the side below the partition wall 25 is the downstream section of the cooling flow path 51. In this way, the cooling flow path 51 is formed in which the cooling water flows clockwise in a cross-sectional view (rear view).

[0019] The inner case and the heat sink will be described with reference to Figures 5 and 6. Figure 5 is a side view and a top view of the inner case of this embodiment, and Figure 6 is a perspective view of the heat sink of this embodiment.

[0020] As shown in Figures 5(A) and 5(B), a plurality of cooling ribs 22 are provided on the outer peripheral surface of the inner case 21. The plurality of cooling ribs 22 includes a plurality of vertical ribs 23 aligned in the motor axial direction and a plurality of horizontal ribs 24 aligned in a circumferential direction perpendicular to the motor axial direction. The plurality of vertical ribs 23 extend in the circumferential direction, and the plurality of horizontal ribs 24 are perpendicular to the plurality of vertical ribs 23. The plurality of vertical ribs 23 are formed around substantially the entire circumference of the inner case 21 except for the vicinity of the inlet 16 and the outlet 17 of the inner case 21, and the plurality of horizontal ribs 24 are formed only on the upper part of the inner case 21 facing the heat sink 41 (see Figure 6).

[0021] The inner case 21 is formed with a plurality of inter-rib flow paths 53, branch flow paths 54, and confluence flow paths 55 as cooling flow paths 51. The plurality of inter-rib flow paths 53 allow cooling water to circulate along the longitudinal ribs 23, and the entire circumference of the motor 31 (see FIG. 2) is cooled via the inner case 21. At the upstream portion of the cooling flow path 51, branch flow paths 54 extend in the motor axial direction, and cooling water that has entered from the inlet 16 is branched by the branch flow paths 54 into the plurality of inter-rib flow paths 53. At the downstream portion of the cooling flow path 51, a confluence flow path 55 extends in the motor axial direction, and the cooling water from the plurality of inter-rib flow paths 53 is joined by the confluence flow path 55 and discharged from the outlet 17.

[0022] The vertical ribs 23 and horizontal ribs 24 are formed at a constant height that is the same as the outermost diameter of the inner case 21. By making the vertical ribs 23 and horizontal ribs 24 constant in height, the cross-sectional area of ​​the flow path around the motor is constant, stabilizing cooling of the motor 31, which has a large amount of heat. In the upper part of the inner case 21, the vertical ribs 23 and horizontal ribs 24 are arranged in a lattice pattern, and the multiple inter-rib flow paths 53 are partially blocked by the multiple horizontal ribs 24. The upper part of the inner case 21 faces the heat sink 41, and the interrupted parts of the multiple inter-rib flow paths 53 communicate with the multiple inter-fin flow paths 56 (see FIG. 6) on the heat sink 41 side.

[0023] In the branch flow passages 54 and the merging flow passages 55, a plurality of reinforcing ribs 26 that are lower than the vertical ribs 23 are provided on the outer peripheral surface of the inner case 21 instead of the vertical ribs 23. The plurality of reinforcing ribs 26 extend circumferentially, continuing from the vertical ribs 23, and are formed to have the same width as the vertical ribs 23. Because the inner case 21 is provided with ribs around the entire periphery, the difference in thickness between the inner case 21 with and without ribs is reduced, and stress concentration due to shrink fitting of the stator 32 is alleviated. In addition, the surface area of ​​the inner case 21 is increased by the plurality of reinforcing ribs 26, improving the cooling performance of the motor 31.

[0024] By forming the multiple reinforcing ribs 26 low, a sufficient gap is secured between the multiple reinforcing ribs 26 and the cylindrical portion 12 of the outer case 11, and the flow of cooling water in the branch flow passages 54 and the merging flow passages 55 is less likely to be obstructed by the reinforcing ribs 26. The top surfaces of the multiple vertical ribs 23 and the multiple horizontal ribs 24 are formed flat in a side view so as to contact the inner circumferential surface of the outer case 11, and the top surfaces of the multiple reinforcing ribs 26 are formed rounded in a cross-sectional view so as not to obstruct the flow of cooling water. The flow passage width of the multiple inter-rib flow passages 53 is formed to be equal to or less than the width of the vertical ribs 23. Increasing the number of flow passages in the inter-rib flow passages 53 improves cooling performance, and it is easier to maintain the rigidity of the inner case 21 even when the number of flow passages is increased.

[0025] A partition wall 25 extending in the motor axial direction is provided on the outer peripheral surface of the inner case 21, and a branch flow passage 54 and a junction flow passage 55 are adjacent to each other in the circumferential direction, with the partition wall 25 sandwiched between them. Cooling water flows from the branch flow passage 54 on the upper side of the partition wall 25 through multiple inter-rib flow passages 53 to the junction flow passage 55 on the lower side of the partition wall 25, thereby cooling the entire circumference of the motor 31. An inlet 16 is formed in the cylindrical portion 12 of the outer case 11 (see FIG. 1 ) at one end in the motor axial direction, and an outlet 17 is formed at the other end in the motor axial direction. One end of the branch flow passage 54 in the motor axial direction is connected to the inlet 16, and the other end of the junction flow passage 55 in the motor axial direction is connected to the outlet 17.

[0026] The partition wall 25 is formed in a crank shape so that the flow path width of the branch flow path 54 is wider at a location corresponding to the inlet 16 and the flow path width of the confluence flow path 55 is wider at a location corresponding to the outlet 17. More specifically, the wide portion of the branch flow path 54 is adjacent to the narrow portion of the confluence flow path 55 in the circumferential direction, with the partition wall 25 in between, and the narrow portion of the branch flow path 54 is adjacent to the wide portion of the confluence flow path 55 in the circumferential direction, with the partition wall 25 in between. Because the flow path widths of the branch flow path 54 and the confluence flow path 55 are wider near the inlet 16 and the outlet 17, the inflow and outflow of coolant are less likely to be obstructed even if multiple reinforcing ribs 26 are provided in the branch flow path 54 and the confluence flow path 55.

[0027] The wide portions of the branch flow passages 54 are adjacent to the narrow portions of the merging flow passages 55, and the narrow portions of the branch flow passages 54 are adjacent to the wide portions of the merging flow passages 55, so that the total area of ​​the branch flow passages 54 and the merging flow passages 55, i.e., the area A1 where the multiple reinforcing ribs 26 are formed, is narrowed in the circumferential direction. The narrowing of the area A1 where the multiple reinforcing ribs 26 are formed reduces differences in thickness of the inner case 21. The branch flow passages 54 and the merging flow passages 55 are formed point-symmetrically with respect to the center O of the partition wall 25. The symmetrical shapes of the branch flow passages 54 and the merging flow passages 55 alleviate stress concentration. The flow deviation between the inlet 16 and the outlet 17 is reduced, so that even if the partition wall 25 is crank-shaped, the coolant flows smoothly and cooling performance is not impaired.

[0028] The flow path width of the branch flow path 54 narrows at a location spaced from the inlet 16 on the other side in the motor axial direction, and the flow path width of the confluence flow path 55 narrows at a location spaced from the outlet 17 on one side in the motor axial direction. The narrow portion of the branch flow path 54 is located directly beside the inlet 16, and the outlet 17 is located directly beside the narrow portion of the outlet 17. Cooling water flows straight from the inlet 16 to the narrow portion of the branch flow path 54, and cooling water also flows straight from the narrow portion of the confluence flow path 55 to the outlet 17. Therefore, even though the partition wall 25 is crank-shaped, the branching to the multiple inter-rib flow paths 53 and the merging from the multiple inter-rib flow paths 53 are not obstructed.

[0029] As shown in Fig. 6, a plurality of cooling fins 42 are provided on the underside of the heat sink 41. The plurality of cooling fins 42 includes a plurality of vertical fins 43 aligned in the motor axial direction and a plurality of horizontal fins 44 aligned in a direction perpendicular to the motor axial direction. The plurality of vertical fins 43 extend along the plurality of vertical ribs 23, and the plurality of horizontal fins 44 are perpendicular to the plurality of vertical fins 43. The heat sink 41 is formed with a plurality of inter-fin flow paths 56 as cooling flow paths 51. The inter-fin flow paths 56 allow cooling water to circulate along the vertical fins 43, and the entire surface of the inverter 39 (see Fig. 2) is cooled via the heat sink 41.

[0030] The multiple vertical fins 43 are formed to increase in height from the middle toward both ends in the extension direction so as to fit along the outer peripheral surface of the inner case 21 (see FIG. 5). By fitting the top surfaces of the multiple vertical fins 43 along the outer peripheral surface of the inner case 21, the heat sink 41 is brought closer to the inner case 21, thereby reducing the size of the motor case 10. The multiple vertical fins 43 and multiple horizontal fins 44 are arranged in a lattice pattern, and the multiple inter-fin flow paths 56 are partially blocked by the multiple horizontal fins 44. The interrupted portions of the multiple inter-fin flow paths 56 communicate with the multiple inter-rib flow paths 53 (see FIG. 5). The height of the multiple horizontal fins 44 is the same as the multiple vertical fins 43 at the intersections with the vertical fins 43.

[0031] The cooling structure for the motor and inverter will be described with reference to Fig. 7. Fig. 7 is an explanatory diagram of the cooling structure for the motor and inverter of this embodiment.

[0032] As shown in Fig. 7, between the motor 31 and the inverter 39, the opening at the top of the outer case 11 is closed by a heat sink 41, and the heat sink 41 faces the top of the inner case 21. The motor 31 is installed inside the inner case 21, and the inverter 39 is installed on the heat sink 41. A plurality of vertical ribs 23 and a plurality of horizontal ribs 24 protrude from the outer peripheral surface of the outer case 11, and a plurality of vertical fins 43 and a plurality of horizontal fins 44 protrude from the underside of the heat sink 41. When viewed from the motor axial direction, the top surfaces of the plurality of vertical fins 43 and horizontal fins 44 are recessed in an arc shape so as to follow the top surfaces of the plurality of vertical ribs 23 and horizontal ribs 24.

[0033] In the inner case 21, a plurality of inter-rib flow paths 53 are formed by a plurality of vertical ribs 23, and in the heat sink 41, a plurality of inter-fin flow paths 56 are formed by a plurality of vertical fins 43. In the inner case 21, a plurality of inter-rib flow paths 53 are partially blocked by a plurality of horizontal ribs 24, and in the heat sink 41, a plurality of inter-fin flow paths 56 are partially blocked by a plurality of horizontal fins 44. The plurality of horizontal ribs 24 and the plurality of horizontal fins 44 are arranged alternately in the circumferential direction, and a serpentine common flow path 52 is formed between the inner case 21 and the heat sink 41, in which the plurality of inter-rib flow paths 53 and the plurality of inter-fin flow paths 56 are connected.

[0034] Furthermore, the top surfaces of the multiple horizontal ribs 24 are formed flush with the top surfaces of the multiple vertical ribs 23, and the top surfaces of the multiple horizontal fins 44 are formed flush with the top surfaces of the multiple vertical fins 43. The multiple horizontal ribs 24 fit into the multiple inter-rib flow paths 53, and the multiple horizontal ribs 24 do not enter the multiple inter-fin flow paths 56 on the heat sink 41 side. The multiple horizontal fins 44 fit into the multiple inter-fin flow paths 56, and the multiple horizontal fins 44 do not enter the multiple inter-rib flow paths 53 on the inner case 21 side. By reducing the height of the multiple horizontal ribs 24 and the multiple horizontal fins 44, pressure loss of the coolant passing through the multiple inter-rib flow paths 53 and the multiple inter-fin flow paths 56 is reduced.

[0035] When cooling water enters the branch flow channel 54 from the inlet pipe 14, the cooling water is diverted from the branch flow channel 54 to the plurality of inter-rib flow channels 53 (see FIG. 5(A)). In the plurality of inter-rib flow channels 53, the cooling water flows along the plurality of vertical ribs 23. In the upper part of the inner case 21, the plurality of inter-rib flow channels 53 and the plurality of inter-fin flow channels 56 are connected to each other. The plurality of horizontal ribs 24 guide the cooling water from the plurality of inter-rib flow channels 53 to the plurality of inter-fin flow channels 56, and the plurality of horizontal fins 44 guide the cooling water from the plurality of inter-fin flow channels 56 to the plurality of inter-rib flow channels 53, so that the cooling water flows back and forth between the inner case 21 side and the heat sink 41 side.

[0036] The multiple vertical ribs 23 and multiple horizontal ribs 24 increase the contact area between the inner case 21 and the cooling water, and the multiple vertical fins 43 and multiple horizontal fins 44 increase the contact area between the heat sink 41 and the cooling water. Heat from the motor 31 is transferred to the inner case 21 and dissipated into the cooling water from the multiple vertical ribs 23 and multiple horizontal ribs 24, thereby cooling the motor 31. Heat from the inverter 39 is transferred to the heat sink 41 and dissipated into the cooling water from the multiple vertical fins 43 and multiple horizontal fins 44, thereby cooling the inverter 39. The branch flow path 54 is closer to the heat sink 41 than the merged flow path 55, and the inverter 39 is cooled by the cooling water immediately after it flows in.

[0037] The cooling water passes below the heat sink 41 and through the multiple inter-rib channels 53 around the inner case 21, thereby cooling the entire motor 31. The cooling water then flows from the multiple inter-rib channels 53 into the junction channel 55, and the junction of the cooling water in the junction channel 55 is discharged to the outlet pipe 15 (see FIG. 5(A)). The multiple inter-rib channels 53 and the multiple inter-fin channels 56 do not branch, and the cooling water flows in one direction from the branch channel 54 to the junction channel 55, resulting in less pressure loss in the multiple inter-rib channels 53 and a smoother flow of the cooling water, improving the cooling performance of the motor 31 and the inverter 39.

[0038] As described above, according to the inverter-integrated motor 1 of this embodiment, the common flow path 52 is formed between the inner case 21 and the heat sink 41, thereby bringing the motor 31 and the inverter 39 closer to each other and reducing the size of the motor case 10. Furthermore, as the cooling water flows through the common flow path 52, heat from the motor 31 is conducted to the inner case 21 and dissipated into the cooling water from the multiple cooling ribs 22, and heat from the inverter 39 is conducted to the heat sink 41 and dissipated into the cooling water from the multiple cooling fins 42, improving the cooling performance of the motor 31 and the inverter 39.

[0039] In this embodiment, the outer case has a cylindrical portion and a box-shaped portion, but the outer case may be formed to be able to house the inner case.

[0040] In addition, in this embodiment, a plurality of vertical ribs and a plurality of horizontal ribs are provided on the outer peripheral surface of the inner case as a plurality of cooling ribs, but it is sufficient if a plurality of ribs are provided on the outer peripheral surface of the inner case. For example, the outer peripheral surface of the inner case may be provided with only vertical ribs or only horizontal ribs as a plurality of cooling ribs.

[0041] In addition, in this embodiment, a plurality of vertical fins and a plurality of horizontal fins are provided as the plurality of cooling fins on the underside of the heat sink, but it is sufficient that a plurality of fins are provided on the underside of the heat sink. For example, the underside of the heat sink may be provided with only vertical fins or only horizontal fins as the plurality of cooling fins.

[0042] In addition, in this embodiment, the top surfaces of the multiple horizontal ribs are formed flush with the top surfaces of the multiple vertical ribs, but the top surfaces of the multiple horizontal ribs may also be formed lower than the top surfaces of the multiple vertical ribs so that the multiple horizontal ribs fit into the multiple inter-rib flow paths.

[0043] In addition, in this embodiment, the top surfaces of the multiple horizontal fins are formed flush with the top surfaces of the multiple vertical fins, but the top surfaces of the multiple horizontal fins may also be formed lower than the top surfaces of the multiple vertical fins so that the multiple horizontal fins fit into the multiple inter-fin flow paths.

[0044] In addition, in this embodiment, the vertical fins are formed along the outer peripheral surface of the inner case, increasing in height from the middle to both ends in the extension direction, but the shape of the vertical fins is not particularly limited.

[0045] Furthermore, the inverter-integrated motor of this embodiment may be used in other devices as well as in vehicles.

[0046] As described above, the first aspect includes a motor case (10) in which an inner case (21) is housed inside an outer case (11), a motor (31) installed inside the inner case and having a motor shaft (34) protruding outside the case, an inverter (39) installed inside the outer case and controlling the rotation of the motor, and a heat sink (41) installed inside the outer case and cooling the inverter, wherein a plurality of cooling ribs (22) are provided on the outer peripheral surface of the inner case, a plurality of cooling fins (42) are provided on the underside of the heat sink, the underside of the heat sink faces the outer peripheral surface of the inner case, and a common flow path (52) is formed by the plurality of cooling ribs and the plurality of cooling fins. With this configuration, the common flow path is formed between the inner case and the heat sink, so that the motor and the inverter are close to each other, thereby making it possible to reduce the size of the motor case. In addition, by having cooling water flow through the common flow path, heat from the motor is transferred to the inner case and dissipated into the cooling water from multiple cooling ribs, and heat from the inverter is transferred to the heat sink and dissipated into the cooling water from multiple cooling fins, thereby improving the cooling performance of the motor and inverter.

[0047] In the second aspect, in the first aspect, the common flow path is divided into a plurality of inter-rib flow paths (53) on the inner case side and a plurality of inter-fin flow paths (56) on the heat sink side. With this configuration, the cooling performance of the motor and inverter is adjusted by the height of the plurality of cooling ribs and the plurality of cooling fins, and the height dimension of the flow path does not become larger than necessary, allowing the motor case to be made smaller.

[0048] In a third aspect, in the first or second aspect, the cooling ribs include a plurality of vertical ribs (23) aligned in the motor axial direction and extending in the circumferential direction, and the cooling fins include a plurality of vertical fins (43) aligned in the motor axial direction and extending along the plurality of vertical ribs. With this configuration, the motor can be cooled over the entire circumference, and the inverter can be cooled over the entire surface. By allowing the cooling water to flow in one direction, pressure loss can be reduced, thereby improving the cooling performance of the motor and the inverter.

[0049] In a fourth aspect, in the third aspect, the vertical ribs are formed at a uniform height, and the vertical fins are formed along the outer peripheral surface of the inner case, increasing in height from the middle to both ends in the extension direction. With this configuration, the top surfaces of the vertical fins are aligned along the outer peripheral surface of the inner case, allowing the heat sink to be placed closer to the inner case, making the motor case more compact. Furthermore, since the vertical ribs have a uniform height, the cross-sectional area of ​​the flow path around the motor is uniform, stabilizing cooling of the motor, which generates a large amount of heat.

[0050] In a fifth aspect, in the third or fourth aspect, the cooling ribs include horizontal ribs (24) perpendicular to the vertical ribs, and the cooling fins include horizontal fins (44) perpendicular to the vertical fins, with the horizontal ribs and horizontal fins arranged alternately in the circumferential direction. With this configuration, cooling water flows back and forth between the inner case side and the inverter side. The vertical ribs and horizontal ribs increase the contact area between the inner case and the cooling water, and the vertical fins and horizontal fins increase the contact area between the heat sink and the cooling water, thereby improving the cooling performance of the motor and the inverter.

[0051] In a sixth aspect, in the fifth aspect, a plurality of inter-rib flow passages are formed between the plurality of vertical ribs, a plurality of inter-fin flow passages are formed between the plurality of vertical fins, a plurality of horizontal ribs are contained in the plurality of inter-rib flow passages, and a plurality of horizontal fins are contained in the plurality of inter-fin flow passages. This configuration reduces pressure loss of the cooling water passing through the common flow passage. In addition, the motor and inverter are located close to each other, preventing the motor case from becoming larger.

[0052] Although the present embodiment has been described, other embodiments may be made by combining the above-described embodiments and modifications in whole or in part.

[0053] Furthermore, the technology of the present invention is not limited to the above-described embodiments, and various changes, substitutions, and modifications may be made without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way due to technological advances or other derived technologies, it may be implemented using that method. Therefore, the claims cover all embodiments that may fall within the scope of the technical idea. [Explanation of symbols]

[0054] 1: Inverter integrated motor 10: Motor case 11: Outer case 21: Inner case 22: Cooling rib 23: Vertical rib 24: Horizontal rib 31: Motor 39: Inverter 41: Heat sink 42: Cooling fin 43: Vertical fin 44: Horizontal fin 51: Cooling channel 52: Common flow path 53: Flow passage between ribs 56: Flow passage between fins

Claims

1. a motor case in which an inner case is housed inside an outer case; a motor installed inside the inner case and having a motor shaft protruding outside the case; an inverter installed inside the outer case to control the rotation of the motor; a heat sink disposed inside the outer case to cool the inverter, a plurality of cooling ribs are provided on the outer peripheral surface of the inner case, and a plurality of cooling fins are provided on the lower surface of the heat sink; an outer peripheral surface of the inner case, the lower surface of the heat sink facing the outer peripheral surface of the inner case, and a common flow path formed by the plurality of cooling ribs and the plurality of cooling fins;

2. 2. The inverter-integrated motor according to claim 1, wherein the common flow path is divided into a plurality of inter-rib flow paths on the inner case side and a plurality of inter-fin flow paths on the heat sink side.

3. the plurality of cooling ribs include a plurality of longitudinal ribs aligned in the motor axial direction and extending in the circumferential direction, 3. The inverter-integrated motor according to claim 1, wherein the plurality of cooling fins include a plurality of vertical fins aligned in the motor axial direction and extending along the plurality of vertical ribs.

4. The inverter-integrated motor according to claim 3, characterized in that the plurality of vertical ribs are formed at a constant height, and the plurality of vertical fins are formed higher from the middle of the extension direction toward both ends so as to follow the outer peripheral surface of the inner case.

5. the plurality of cooling ribs include a plurality of horizontal ribs perpendicular to the plurality of vertical ribs, the plurality of cooling fins include a plurality of horizontal fins orthogonal to the plurality of vertical fins, 4. The inverter-integrated motor according to claim 3, wherein the plurality of horizontal ribs and the plurality of horizontal fins are arranged alternately in the circumferential direction.

6. A plurality of inter-rib flow paths are formed between the plurality of longitudinal ribs, and a plurality of inter-fin flow paths are formed between the plurality of vertical fins, 6. The inverter-integrated motor according to claim 5, wherein the plurality of horizontal ribs are accommodated in the plurality of inter-rib flow passages, and the plurality of horizontal fins are accommodated in the plurality of inter-fin flow passages.

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