Rotating electric machines

Abstract

To provide a rotary electric machine with high heat radiation.SOLUTION: In one aspect of a rotary electric machine of the present invention, the rotary electric machine comprises: a rotational shaft that is extended to a shaft direction; a motor unit that includes a rotor fixed to a peripheral surface of the rotational shaft and an annular stator arranged to the circumference of the rotor; a resin cylinder case 10 of which one side of the shaft direction is opened, and that houses the motor unit; a metal lid body 20 that blocks the open part of the cylinder case 10; and a metal motor housing 30 that is fixed to the inner wall of the cylinder case 10, and supports the stator so as to surround and contact the stator. The motor housing 30 includes a flange part 35 that is extended to a radial direction so as to be positioned to one side of the shaft direction, and the flange part 35 is thermally contacted to the lid body 20 in a surface.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a rotating electric machine. [Background technology]

[0002] BACKGROUND ART Rotating electric machines equipped with a motor having a rotor and a stator are known. For example, Patent Document 1 discloses a motor in which the stator is resin-molded. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-076407 Summary of the Invention [Problem to be solved by the invention]

[0004] In rotating electrical machines, when a motor body made of resin is used, the heat generated by the stator assembly is dissipated to the outside air by heat transfer through the resin material, which has poor thermal conductivity, and this insufficient heat dissipation can be a factor in performance degradation. On the other hand, it is also possible to use a special resin with high thermal conductivity for the resin case itself, but this would create new issues such as cost.

[0005] The present invention has been made in consideration of the above points, and has an object to provide a rotating electric machine with high heat dissipation properties. [Means for solving the problem]

[0006] One aspect of the rotating electric machine of the present invention comprises a motor unit having a rotating shaft extending in the axial direction, a rotor fixed to the circumferential surface of the rotating shaft, and an annular stator arranged around the rotor, a cylindrical resin case that is open on one axial side and houses the motor unit, a metal lid that closes the opening of the cylindrical case, and a metal motor housing that is fixed to the inner wall of the cylindrical case and surrounds the stator, contacting and supporting the stator, wherein the motor housing has a flange portion located on one axial side and extending radially, and the flange portion is in thermal surface contact with the lid. [Effects of the Invention]

[0007] According to one aspect of the present invention, it is possible to provide a rotating electric machine with high heat dissipation properties. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing a rotating electric machine according to this embodiment. [Figure 2] FIG. 2 is a perspective view showing the cylindrical case of this embodiment. [Figure 3] FIG. 3 is a perspective view showing the motor housing of the present embodiment. [Figure 4] FIG. 4 is a partially enlarged view of the periphery of the flange portion of this embodiment. [Figure 5] FIG. 5 is a plan view showing the lid of this embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a modified example of the rotating electric machine of this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a rotating electric machine according to an embodiment of the present invention will be described with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiments, and can be modified as desired within the scope of the technical concept of the present invention. In addition, in the following drawings, the scale and number of each structure may differ from the actual structure in order to make each configuration easier to understand.

[0010] In each drawing, a central axis J of a rotating electric machine according to an embodiment to be described below is virtually shown. In the following description, the axial direction of the central axis J will be simply referred to as the "axial direction." The radial direction centered on the central axis J will be simply referred to as the "radial direction." The circumferential direction centered on the central axis J will be simply referred to as the "circumferential direction." The Z axis shown in each drawing indicates the direction in which the central axis J extends. In the following description, the side of the axial direction toward which the arrow of the Z axis points (+Z side) will be referred to as the "upper side," and the side of the axial direction opposite to the side toward which the arrow of the Z axis points (-Z side) will be referred to as the "lower side."

[0011] In this embodiment, the lower side corresponds to "one axial side," and the upper side corresponds to "the other axial side." Note that the terms "upper side" and "lower side" are simply names used to describe the relative positional relationships of the various components, and the actual positional relationships may be other than those indicated by these names. For the sake of explanation, FIG. 1 shows cross sections at different circumferential positions on both the left and right sides of the central axis J.

[0012] As shown in FIG. 1, the rotating electrical machine 100 includes a motor unit 1, a cylindrical case 10, a cover 20, and a motor housing 30. The motor unit 1 includes a rotating shaft 40, a rotor 50, a stator 70, and a control board 80.

[0013] The rotating shaft 40 has a cylindrical shape extending in the axial direction around the central axis J. The rotating shaft 40 is rotatably supported around the central axis J by bearings 5a and 5b. The rotor 50 is rotatable around the central axis J. The rotor 50 is fixed to the circumferential surface of the rotating shaft 40. The rotor 50 has a rotor core 51 and a magnet 52. The rotor core 51 is annular and surrounds the central axis J. The rotating shaft 40 passes axially through the radially inner side of the rotor core 51. The magnet 52 is fixed to the rotor core 51. Although not shown in the figure, a plurality of magnets 52 are provided, for example, spaced apart in the circumferential direction.

[0014] The stator 70 is located radially outside the rotor 50. The stator 70 is arranged around the rotor 50. The stator 70 is annular and surrounds the rotor 50. The stator 70 has a stator core 71, an insulator 72 attached to the stator core 71, and a plurality of coils 73 attached to the stator core 71 via the insulator 72.

[0015] The stator core 71 surrounds the rotor core 51. The stator core 71 includes an annular core back 71a surrounding the rotor core 51 and, although not shown, multiple teeth extending radially inward from the core back 71a. The multiple teeth are arranged side by side in the circumferential direction. The core back 71a, excluding its upper end, is press-fitted and fixed into a first peripheral wall portion 32 (described later) of the motor housing 30. This secures the stator 70 to the motor housing 30. The radially inner ends of the multiple teeth face the outer peripheral surface of the rotor 50 with a small gap between them. In other words, in this embodiment, the stator 70 is arranged without contacting the outer peripheral surface of the rotor 50. The insulator 72 and the coil 73 protrude axially from the stator core 71 on both sides.

[0016] The control board 80 is disposed above the rotor 50 and the stator 70. As will be described in detail later, the control board 80 is in thermal surface contact with the lid 20. The control board 80 is positioned in the cylindrical case 10 by fitting into a fitting protrusion 14c (described in detail later). As shown in FIG. 1 , one ends of a plurality of terminals 83 are connected to the control board 80. Although not shown, the other ends of the plurality of terminals 83 are provided in the connector unit 19. When an external power supply (not shown) is connected to the connector unit 19, power from the external power supply is supplied from the terminals 83 to the control board 80. Although not shown, the control board 80 is electrically connected to the coil 73. Power supplied to the control board 80 from the external power supply (not shown) is supplied to the coil 73.

[0017] The cylindrical case 10 is located below the lid 20. The cylindrical case 10 is cylindrical and open at the top. In this embodiment, the cylindrical case 10 is made of resin. As shown in FIG. 2 , the cylindrical case 10 has a bottom wall portion 11, an outer peripheral wall 12, a rib wall 12b, an inner wall 14, and a connector portion 19. The bottom wall portion 11 is annular and surrounds the central axis J. The bottom wall portion 11 is located below the stator 70.

[0018] The outer peripheral wall 12 is cylindrical and extends upward from the edge of the bottom wall 11. The upper surface of the outer peripheral wall 12 is the joining surface to which the lid 20 is joined. The upper surface of the outer peripheral wall 12 has a groove 12a. The groove 12a is provided around the entire circumference. Although not shown, a sealing material is provided in the groove 12a. The outer peripheral wall 12 has a protruding wall 13. The protruding wall 13 protrudes radially outward from the outer peripheral wall 12. Multiple protruding walls 13 (six in Figure 2) are arranged at intervals in the circumferential direction. The protruding wall 13 has a cavity 13a that opens upward. The cavity 13a extends in the axial direction. With the sealing material provided in the groove 12a, a tapping screw 13b (see Figure 1) can be screwed into the cavity 13a from above via the lid 20, thereby fixing the cylindrical case 10 and the lid 20 in a sealed state. The outer peripheral wall 12 is provided with a connector portion 19 .

[0019] The rib walls 12b protrude radially inward from the outer peripheral wall 12. The rib walls 12b extend upward from the bottom wall portion 11. A plurality of the rib walls 12b (six in FIG. 2) are arranged at intervals in the circumferential direction. The upper surfaces of the rib walls 12b are located below the upper surface of the outer peripheral wall 12.

[0020] The inner wall 14 protrudes upward from the bottom wall portion 11. More specifically, the inner wall 14 protrudes upward from the radially outer peripheral edge portion of the bottom wall portion 11. The inner wall 14 is annular and surrounds the central axis J. As shown in FIG. 1 , the inner wall 14 is located radially outside the stator 70. The inner wall 14 surrounds the stator 70 from the radially outside. The inner wall 14 is located radially inside the outer peripheral wall 12. The upper surface of the inner wall 14 is located below the upper surface of the outer peripheral wall 12.

[0021] A mating protrusion 14c is provided between the outer peripheral wall 12 and the inner wall 14 in the radial direction. A plurality of mating protrusions 14c (six in FIG. 2) are arranged at intervals in the circumferential direction. The mating protrusions 14c protrude upward. The mating protrusions 14c are connected to the outer peripheral wall 12 and the inner wall 14 by a rib 14d extending in the radial direction. The rib 14d protrudes upward from the bottom wall portion 11. Although not shown in the figure, the mating protrusions 14c fit into a through-hole in the control board 80 to position the control board 80.

[0022] The motor housing 30 is made of metal. The motor housing 30 is made of a heat-dissipating material such as iron, aluminum, or copper. The motor housing 30 is made, for example, by pressing a metal sheet. That is, in this embodiment, the motor housing 30 is a pressed product. The motor housing 30 is fixed to the upper side of the cylindrical case 10. The motor housing 30 has a bottom plate portion 31, a first peripheral wall portion 32, a step portion 33, a second peripheral wall portion 34, and a flange portion 35.

[0023] The bottom plate portion 31 has an annular shape centered on the central axis J. The bottom plate portion 31 is fixed to the bottom wall portion 11 of the cylindrical case 10 by screwing in fastening members 31a (see FIG. 1 ), such as tapping screws, machine screws, or bolts. The first circumferential wall portion 32 extends upward from the outer edge of the bottom plate portion 31. The first circumferential wall portion 32 is cylindrical. An upper end of the first circumferential wall portion 32 is located above the upper surface of the inner wall 14. The first circumferential wall portion 32 is press-fitted into the inner wall 14 of the cylindrical case 10 and fixed thereto. The first circumferential wall portion 32 surrounds the stator 70 from the radially outer side. The first circumferential wall portion 32 contacts and supports a stator core 71 of the stator 70 from the radially outer side.

[0024] The first circumferential wall portion 32 contacts and supports the stator core 71 of the stator 70 from the radially outer side, so that heat generated in the coils 73 of the stator 70 is transferred to the first circumferential wall portion 32 and dissipated.

[0025] The step portion 33, the second peripheral wall portion 34, and the flange portion 35 are arranged in plurality (six of each in FIG. 2 ) at intervals in the circumferential direction. The step portion 33, the second peripheral wall portion 34, and the flange portion 35 are arranged at positions away from the fitting protrusion 14c, the terminal 83, etc. of the cylindrical case 10. The step portion 33 extends radially outward from the upper end of the first peripheral wall portion 32. The radially outer position of the step portion 33 is radially outer than the control board 80 and radially inner than the outer peripheral wall 12. The second peripheral wall portion 34 extends upward from the radially outer end of the step portion 33. The upper end of the second peripheral wall portion 34 is located below the upper surface of the outer peripheral wall 12.

[0026] The flange portion 35 extends radially outward from the upper end of the second circumferential wall portion 34. The flange portion 35 is located above the rib wall 12b. The flange portion 35 faces the rib wall 12b in the axial direction. The circumferential position of the rib wall 12b is the circumferential center position of the flange portion 35. Because the flange portion 35 faces the rib wall 12b in the axial direction, the rib wall 12b can support the flange portion 35 from below when the flange portion 35 bends downward.

[0027] As shown in FIG. 4, the motor housing 30 has a ridge portion 36. The ridge portion 36 extends in the circumferential direction. The ridge portion 36 is disposed radially inward of the flange portion 35. The ridge portion 36 protrudes upward beyond the flange portion 35. The ridge portion 36 is formed by curving the flange portion 35. Heat generated in the coil 73 in the stator 70 is transferred to the flange portion 35 via the first circumferential wall portion 32, the step portion 33, and the second circumferential wall portion 34.

[0028] As shown in FIG. 1, the lid body 20 is disposed on the upper side of the cylindrical case 10. As shown in FIG. 5, the lid body 20 is disk-shaped. The lid body 20 closes the opening of the cylindrical case 10. In this embodiment, the lid body 20 is made of metal. The material constituting the lid body 20 is, for example, iron. The lid body 20 is made, for example, by pressing a sheet metal member. That is, in this embodiment, the lid body 20 is a pressed product.

[0029] The lid 20 has a disk portion 21, a protrusion 22, an insertion hole 23, and a groove portion 24. The radial end of the disk portion 21 contacts the upper surface of the outer peripheral wall 12 of the cylindrical case 10 from above. The protrusion 22 protrudes radially outward from the outer edge of the disk portion 21. A plurality of the protrusions 22 (six in FIG. 2 ) are arranged at intervals in the circumferential direction. The insertion hole 23 penetrates the protrusion 22 in the axial direction. The insertion hole 23 is arranged at a position overlapping with the cavity 13a of the cylindrical case 10 in the axial direction. As described above, with a sealant provided in the groove portion 12a of the cylindrical case 10, the tapping screw 13b (see FIG. 1 ) inserted from above through the insertion hole 23 of the lid 20 can be screwed into the cavity 13a of the cylindrical case 10 to fix the cylindrical case 10 and the lid 20 in a sealed state. The sealing material is, for example, an O-ring.

[0030] As shown in FIG. 4 , the groove 24 is recessed upward from the lower surface of the disk portion 21. The groove 24 extends in the circumferential direction. The groove 24 is provided around the entire circumference. The groove 24 is located radially outward of the protrusion 36. The radial end of the disk portion 21 located radially outward of the protrusion 36 is located above the flange portion 35 and the protrusion 36. In other words, when the lid 20 closes the opening of the cylindrical case 10, the protrusion 36 and the groove 24 are spaced apart. The protrusion 36 and the groove 24 form the storage portion 25. The storage portion 25 is a space. The storage portion 25 stores a heat-dissipating gel member G1. By storing the heat-dissipating gel member G1 in the storage portion 25, heat from the flange portion 35 is transferred to the lid 20. That is, the flange portion 35 is in thermal surface contact with the lid body 20 via the heat-dissipating gel member G1. Because the flange portion 35 is in thermal surface contact with the lid body 20 via the heat-dissipating gel member G1, heat generated in the coil 73 of the stator 70 is transferred to and dissipated in the lid body 20 via the first circumferential wall portion 32, the step portion 33, the second circumferential wall portion 34, and the flange portion 35. That is, the heat generated in the coil 73 of the stator 70 is dissipated to the metal lid body 20 via the metal motor housing 30 and the heat-dissipating gel member G1. Therefore, deterioration in performance of the motor unit 1 due to high temperatures can be suppressed.

[0031] When the lid 20 closes the opening of the cylindrical case 10, the ridges 36 and the grooves 24 are separated, and the heat-dissipating gel member G1 deforms when a load is applied. Therefore, even if the heat-dissipating gel member G1 is housed in a volume larger than the capacity of the housing portion 25, the heat-dissipating gel member G1 deforms due to the pressure applied when fixing the cylindrical case 10 and the lid 20, and for example, protrudes radially inward from the gap between the ridges 36 and the disk portion 21. Therefore, the cylindrical case 10 and the lid 20 can be fixed together while maintaining a tight seal.

[0032] The material of the heat dissipating gel member G1 is not particularly limited as long as it is a gel material that has high thermal conductivity and can transfer heat.

[0033] In this embodiment, the control board 80 is in thermal surface contact with the lid body 20. The control board 80 is in thermal surface contact with the lid body 20 via the second heat-dissipating gel member G2. Because the control board 80 is in thermal surface contact with the lid body 20 via the second heat-dissipating gel member G2, heat generated in the control board 80 is transferred to the metal lid body 20 via the second heat-dissipating gel member G2 and dissipated. Therefore, performance degradation of the control board 80 due to high temperatures can be suppressed.

[0034] The second heat-dissipating gel member G2 is made of the same material as the heat-dissipating gel member G1. Using the same material for the heat-dissipating gel member G1 and the second heat-dissipating gel member G2 eliminates the need to prepare multiple types of materials for the heat-dissipating gel members, which contributes to improving manufacturing efficiency and reducing manufacturing costs.

[0035] As described above, according to the rotating electrical machine 100 of this embodiment, the flange portion 35 of the motor housing 30 is in thermal surface contact with the cover 20, thereby improving heat dissipation.

[0036] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0037] In the above embodiment, the flange portion 35 is in thermal surface contact with the lid 20 via the heat dissipating gel member G1, but the present invention is not limited to this configuration. For example, as shown in FIG. 6, the flange portion 35 may be in direct contact with the lid 20, thereby providing thermal surface contact.

[0038] When this configuration is adopted, the flange portion 35 is sized to extend up to the upper surface of the projecting wall 13, and the cover 20 and the flange portion 35 can be fastened together to the projecting wall 13 of the cylindrical case 10 by tapping screws (screws) 13b, thereby fixing them to each other. Therefore, the cover 20 and the flange portion 35 can be fixed together to the projecting wall 13 by the tapping screws 13b. This makes it easier to fix the motor housing 30 and the cover 20 together. When this configuration is adopted, the cylindrical case 10 and the lid body 20 are sealed via the flange portion 35, so from the viewpoint of ensuring sealing between the cylindrical case 10 and the lid body 20, it is preferable to adopt a configuration in which the flange portion 35 is in thermal surface contact with the lid body 20 via the heat dissipation gel member G1.

[0039] The application of the rotating electric machine to which the present invention is applied is not particularly limited. The rotating electric machine may be mounted on any type of equipment. The rotating electric machine may be mounted on an actuator equipped with a speed reduction mechanism. The rotating electric machine may be a generator. The application of the pump to which the present invention is applied is not particularly limited. The pump may be mounted on any type of equipment. The pump may be mounted on a vehicle, for example. The pump may be a pump that pumps any type of fluid. The pump may be an oil pump that pumps oil. Note that the configurations described above in this specification can be combined as appropriate within a range that does not contradict each other. [Explanation of symbols]

[0040] DESCRIPTION OF SYMBOLS 1...motor unit, 10...cylindrical case, 13b...tapping screw (fastening member), 20...lid, 24...concave portion, 25...accommodating portion, 30...motor housing, 35...flange portion, 36...convex portion, 40...rotating shaft, 50...rotor, 70...stator, 80...control board, 100...rotating electric machine, G1...heat dissipation gel member, G2...second heat dissipation gel member, J...central axis

Claims

1. a motor unit including a rotating shaft extending in an axial direction, a rotor fixed to a circumferential surface of the rotating shaft, and an annular stator disposed around the rotor; a cylindrical resin case that is open on one axial side and that houses the motor unit; a metal lid that closes the opening of the cylindrical case; a metal motor housing fixed to an inner wall of the cylindrical case, surrounding the stator and in contact with and supporting the stator; Equipped with the motor housing has a flange portion located on one axial side and extending in a radial direction, the flange portion is in thermal surface contact with the lid body via a heat dissipation gel member; the motor housing has a protruding ridge portion located radially inside the flange portion and protruding axially further toward one side than the flange portion, the cover has a recessed ridge portion recessed from the surface on the other axial side to the one axial side, a radial center position of the recessed streak portion is located radially outward of a radial center position of the protruding streak portion, The convex ridge portion and the concave ridge portion constitute a housing portion that houses the heat dissipation gel member.

2. a control board disposed on one axial side of the rotor and the stator; the control board is in thermal surface contact with the lid via a second heat dissipation gel member; The rotating electric machine according to claim 1 .

3. The heat-dissipating gel member and the second heat-dissipating gel member are made of the same material. The rotating electric machine according to claim 2 .

4. the flange portion is in surface contact with a surface on the other axial side of the lid body, The lid body and the flange portion are fastened together to the cylindrical case by a fastening member, and are fixed to each other. The rotating electric machine according to claim 1 .

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