motor

Abstract

To provide a motor that can be cooled to contribute to an improvement in output.SOLUTION: A motor 1 comprises a rotatable rotor 3, and a stator 10 that faces the rotor in a radial direction with a gap therebetween. The stator has a stator core that has an annular core back and teeth, and coils 30 that are wound around the teeth. The motor has a cover 51 that has, on its inside, coil end spaces for accommodating the coils projecting on both sides in an axial direction of the stator core and covers the coils, one or more first pipes 61 and one or more second pipes 62 that each connect the inside and the outside of the cover, and passages that penetrate the stator core in the axial direction and connect the coil end spaces on both ends in the axial direction. A coolant circulates inside the cover. A first opening surface surrounded by an end face at the tip of the first pipe inside the cover does not face a second opening surface surrounded by an end face at the tip of the passage located in the same coil end space as the tip of the first pipe.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a motor. [Background technology]

[0002] In motors, the heat generated by the coil cannot be sufficiently dissipated through the motor housing, etc., and the upper limit of motor output is limited by the rise in coil temperature due to heat generation. Therefore, by reducing the thermal resistance, it is possible to increase the output of a motor of the same size.

[0003] Patent Document 1 discloses cooling a coil using a cooling pipe and a heat pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-046975 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the configuration disclosed in Patent Document 1, it is difficult to bring the cooling pipes or heat pipes into contact with all of the coils for cooling, and when the motor output is increased, there is a risk that insufficiently cooled areas will overheat and break down, which is a bottleneck in improving output.

[0006] The present invention has been made in consideration of the above points, and an object of the present invention is to provide a motor that can contribute to improving output. [Means for solving the problem]

[0007] One aspect of the motor of the present invention comprises a rotor rotatable about a central axis and a stator radially opposed to the rotor via a gap, wherein the stator has a stator core having an annular core back surrounding the central axis and teeth extending radially from the core back to one side, and coils wound around the teeth, and has coil end spaces on the inside that accommodate the coils protruding on both axial sides of the stator core, a cover that covers the coils, at least one first pipe and at least one second pipe that respectively connect the inside and outside of the cover, and a passage that penetrates the stator core in the axial direction and connects the coil end spaces on both axial sides, wherein a coolant circulates inside the cover, and a first opening surface surrounded by the end face of the tip of the first pipe on the inside of the cover does not face a second opening surface surrounded by the end face of the tip of the passage that is located in the same coil end space as the tip of the first pipe. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to contribute to improving the output of a motor. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a motor according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view schematically showing the motor of the first embodiment. [Figure 3] FIG. 3 is an external perspective view showing a part of the stator of the first embodiment. [Figure 4] FIG. 4 is an external perspective view showing a part of the stator of the first embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing a part of the stator of the first embodiment, taken along line II-II in FIG. [Figure 6] FIG. 6 is an enlarged view of the hole HL and the stator core 20 in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line III-III in FIG. [Figure 8] FIG. 8 is a cross-sectional view schematically showing a motor according to the second embodiment. [Figure 9] FIG. 9 is a cross-sectional view schematically showing a motor according to the third embodiment. [Figure 10] FIG. 10 is a cross-sectional view schematically showing a motor according to the fourth embodiment. [Figure 11] FIG. 11 is a cross-sectional view schematically showing a motor according to a fifth embodiment. [Figure 12] FIG. 12 is a cross-sectional view schematically showing a motor according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, motors according to embodiments 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 components may differ from the actual structure in order to make each component easier to understand.

[0011] The Z-axis direction, as shown appropriately in each figure, is the up-down direction, with the positive side being the "upper side" and the negative side being the "lower side." The central axis J, as shown appropriately in each figure, is a virtual line that is parallel to the Z-axis direction and extends in the up-down direction. In the following description, the axial direction of the central axis J, i.e., the direction parallel to the up-down direction, 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," and the circumferential direction centered on the central axis J will be simply referred to as the "circumferential direction." In the "axial direction," the lower side will be referred to as the "one side," and the upper side will be referred to as the "other side." In the circumferential direction, the clockwise direction when viewed from above will be referred to as the "one side," and the counterclockwise direction will be referred to as the "other side."

[0012] Note that the terms "upper direction," "upper side," and "lower side" are simply names used to explain the relative positions of the various parts, and the actual relative positions may be other than those indicated by these names.

[0013] First Embodiment A first embodiment of the motor 1 will be described with reference to FIGS. As shown in FIG. 1, the motor 1 of the first embodiment is provided in an electric airplane 100. The electric airplane 100 includes a main body 110, a rotary wing device 120, and an attachment part 130. The attachment part 130 extends from the main body 110 in a direction perpendicular to the axial direction. The rotary wing device 120 is attached to the attachment part 130. The rotary wing device 120 is a device that generates a propulsive force for the electric airplane 100 in an upward direction. In this embodiment, multiple rotary wing devices 120 are provided.

[0014] The rotary blade device 120 has a motor 1, a front cone portion 101, a rotary blade portion 102, and a rear cone portion 103. The rotary blade portion 102 is provided on the axially upper side of the housing 2 with a gap therebetween. The rotary blade portion 102 has an annular shape centered on the central axis J. The rotary blade portion 102 has a through hole 102a and a propeller 102b.

[0015] The through-hole 102a passes through the rotor portion 102 in the axial direction. The through-hole 102a is coaxial with the central axis J. The upper end of a shaft 3a of the motor 1, which will be described later, is inserted into the through-hole 102a. The shaft 3a inserted into the through-hole 102a is fixed to the rotor portion 102. The rotor portion 102 fixed to the shaft 3a rotates in synchronization with a rotor body 3b of the motor 1, which will be described later. The propellers 102b extend radially outward from the outer circumferential surface of the rotor portion 102. Multiple propellers 102b are provided at intervals in the circumferential direction.

[0016] The housing 2 of the motor 1 is attached to the upper side of the attachment portion 130. The attachment portion 130 has a through hole 132. The through hole 132 passes through the attachment portion 130 in the axial direction. The through hole 132 axially overlaps with a through hole 8a of a bottom plate portion 8 of the motor 1, which will be described later.

[0017] 2, the motor 1 of the first embodiment is an inner rotor type motor. The central axis of the motor 1 is a central axis J. The motor 1 includes a housing 2, a rotor 3, a stator 10, bearings 5a and 5b, covers 51 and 52, a first pipe 61, a second pipe 62, a third pipe 63, a circulation pump 81, and a radiator 82.

[0018] The covers 51 and 52, the first pipe 61, the second pipe 62, the third pipe 63, the circulation pump 81, and the radiator 82 constitute the cooling device 50.

[0019] The housing 2 accommodates the rotor 3, the stator 10, bearings 5a and 5b, covers 51 and 52, a portion of the first pipe 61, a portion of the second pipe 62, and a third pipe 63. The rotor 3 is rotatable about a central axis J. The rotor 3 has a shaft 3a and a rotor body 3b.

[0020] The housing 2 has a cover portion 7 and a bottom plate portion 8. The bottom plate portion 8 has a through hole 8a. The through hole 8a passes through the bottom plate portion 8 in the axial direction. A plurality of the through holes 8a are provided at intervals in the circumferential direction.

[0021] The shaft 3a extends in the axial direction along the central axis J. The shaft 3a is, for example, cylindrical and extends in the axial direction around the central axis J. The shaft 3a is supported by bearings 5a and 5b so as to be rotatable about the central axis J. The bearings 5a and 5b are held in bearing holders 4a and 4b of the housing 2. The rotor body 3b is fixed to the outer circumferential surface of the shaft 3a. Although not shown, the rotor body 3b has a rotor core fixed to the outer circumferential surface of the shaft 3a and a magnet fixed to the rotor core.

[0022] The stator 10 faces the rotor 3 in the radial direction via a gap. In this embodiment, the stator 10 is located radially outward of the rotor 3. FIG. 3 shows a state in which covers 51 and 52 are provided on the stator 10. FIG. 4 shows a state in which the covers 51 and 52 are not provided on the stator 10. As shown in FIGS. 3 and 4, the stator 10 has a stator core 20, a plurality of coils 30, and an insulator 40 (see FIG. 5). As shown in FIG. 4, the stator core 20 has an annular core back 21 surrounding the central axis J and a plurality of teeth 22 extending radially inward, i.e., on one radial side, from the core back 21. The core back 21 is, for example, cylindrical and centered on the central axis J.

[0023] The teeth 22 are arranged at intervals along the circumferential direction. For example, the teeth 22 are arranged at equal intervals around the circumference along the circumferential direction. In this embodiment, the teeth 22 are molded integrally with the core back 21. Each tooth 22 has a substantially rectangular parallelepiped shape that extends linearly along the radial direction. The circumferential dimension of the teeth 22 is substantially constant throughout the entire radial direction.

[0024] Note that the radially inner ends of the teeth 22 may be provided with umbrella portions that protrude on both circumferential sides. The teeth 22 may also be separate members from the core back 21. In this case, the teeth 22 may be fixed to the core back 21, for example, by press-fitting protrusions provided on the radially outer ends of the teeth 22 into recesses provided on the radially inner surfaces of the core back 21.

[0025] The multiple coils 30 are attached to the multiple teeth 22, respectively. In this embodiment, the coils 30 are attached to the teeth 22 via insulators 40. Each tooth 22 passes radially inside each coil 30. The radially inner ends of the teeth 22 protrude radially inward beyond the coils 30.

[0026] As an example, the coil 30 is constructed by winding a rectangular wire. This allows for a higher space factor of the coil 30 than when a round wire is used. In this specification, "rectangular wire" refers to a wire having a rectangular or approximately rectangular cross section. In this specification, "approximately rectangular shape" includes a rectangular shape with rounded corners. Although not shown in the figures, the rectangular wire that constitutes the coil 30 in this embodiment is an enameled wire having an enamel coating on its surface.

[0027] 3 and 4 show the tooth 22 and core back 21 on which two circumferentially adjacent coils 30 are attached. In this embodiment, two circumferentially adjacent coils 30 are treated as a unit to be cooled by the cooling device 50. In the following description, one of the two circumferentially adjacent coils 30 may be referred to as coil 30A, the tooth 22 on which coil 30A is attached may be referred to as tooth 22A, the other of the two circumferentially adjacent coils 30 may be referred to as coil 30B, and the tooth 22 on which coil 30B is attached may be referred to as tooth 22B.

[0028] As shown in FIG. 5, the stator core 20 has at least one hole HL and a slit SL. The hole HL penetrates the stator core 20 in the axial direction. The holes HL are arranged at intervals along the circumferential direction. The holes HL are arranged, for example, at equal intervals around the circumference along the circumferential direction. The holes HL are arranged in the core back 21. The holes HL overlap with the teeth 22 in the radial direction, respectively. A hole HL is provided for each tooth 22. The circumferential center position of the hole HL is the same as the circumferential center position of the tooth 22. The radially outermost position of the hole HL is located radially inward from the outer periphery of the stator core 20.

[0029] A third pipe 63 is held in the hole HL, which is located at the same circumferential center position as the tooth 22A. As shown in Fig. 4, a second pipe 62 is held in the hole HL, which is located at the same circumferential center position as the tooth 22B. The radially outermost position of the hole HL is located radially inward from the outer periphery of the stator core 20, which shortens the distance between the coil 30A and the third pipe 63 and the distance between the coil 30B and the second pipe 62. This allows the coolant CL to be efficiently supplied to the coils 30A, 30B or the coolant CL that has absorbed heat generated by the coils 30A, 30B to be efficiently collected.

[0030] The slits SL are spaces that connect the holes HL and the radial outside of the stator core 20. The slits SL extend in the axial direction. The circumferential width of the slits SL is smaller than the diameter of the second pipe 62 or the third pipe 63. Because the circumferential width of the slits SL is smaller than the diameter of the second pipe 62 or the third pipe 63, the second pipe 62 or the third pipe 63 held in the holes HL can be prevented from slipping out radially to the outside through the slits SL. In this embodiment, the second pipe 62 and the third pipe 63 have the same inner diameter and outer diameter. The second pipe 62 and the third pipe 63 may have different inner diameters or outer diameters.

[0031] The stator core 20 of this embodiment has 12 poles. The holes HL and slits SL are arranged in groups of 12 at equal intervals (30° intervals) in the circumferential direction. As shown in FIG. 6, adhesive 23 is filled between the third pipe 63 and the hole HL. An adhesive with high thermal conductivity is used as the adhesive 23. Although not shown in the figure, adhesive 23 is also filled between the second pipe 62 and the hole HL.

[0032] When the second pipe 62 or the third pipe 63 is fixed with the adhesive 23 to the hole HL of the stator core 20, which does not have a slit SL, it is difficult to fill the gap between the hole HL and the second pipe 62 or the third pipe 63 with the adhesive 23, which may result in a gap. For example, if the adhesive 23 is applied to the inner circumferential surface of the hole HL in advance and the second pipe 62 or the third pipe 63 is inserted into the hole HL, the adhesive 23 may be squeezed out. For example, if the adhesive 23 is applied to the outer circumferential surface of the second pipe 62 or the third pipe 63 and then inserted into the hole HL, the adhesive 23 may be scraped off by being handled at the insertion end of the hole HL. As a result, the adhesive 23 cannot be sufficiently filled between the second pipe 62 or the third pipe 63 and the hole HL. In this case, the retention of the second pipe 62 or the third pipe 63 to the stator core 20 is reduced, and air with a higher thermal resistance is present between the hole HL and the second pipe 62 or the third pipe 63 than when adhesive 23 is filled, resulting in a decrease in the efficiency of heat transfer.

[0033] In contrast to this, in the present embodiment, slits SL are provided that connect the holes HL and the radially outer side of the stator core 20, and by applying the adhesive 23 through the slits SL to the second pipe 62 or the third pipe 63 inserted into the holes HL, the adhesive 23 can be easily and sufficiently spread and filled between the holes HL and the second pipe 62 or the third pipe 63. Filling the gaps between the holes HL and the second pipe 62 or the third pipe 63 with the adhesive 23 reduces thermal resistance and improves heat transfer efficiency.

[0034] The cover 51 covers the upper side of the coil 30. The cover 51 covers the coil 30 protruding above the stator core 20. The cover 51 has an outer wall 51a, an inner wall 51b, and an upper wall 51c. The outer wall 51a is located radially outside the coil 30. The outer wall 51a extends in the circumferential direction. The outer wall 51a is provided around the entire circumference. The lower end of the outer wall 51a contacts the upper surface of the core back 21. The lower end of the outer wall 51a contacts the core back 21 around the entire circumference. The lower end of the outer wall 51a contacting the core back 21 also includes the case where an adhesive is interposed between the lower end of the outer wall 51a and the core back 21.

[0035] The outer wall 51a has a protruding wall 51d. The protruding wall 51d protrudes radially outward from the outer wall 51a. When viewed in the axial direction, the protruding wall 51d has a semicircular shape. As shown in Fig. 7, the inner peripheral surface of the protruding wall 51d contacts and is held by the outer peripheral surface of the upper side of the second pipe 62.

[0036] The inner wall 51b of the cover 51 is located radially inside the coil 30. The inner wall 51b extends in the circumferential direction. The inner wall 51b is provided around the entire circumference. A portion of the lower end of the inner wall 51b contacts the upper surface of the tooth 22. The upper wall 51c of the cover 51 connects the upper end of the outer wall 51a and the upper end of the inner wall 51b. The upper wall 51c extends in the circumferential direction. The upper wall 51c is provided around the entire circumference.

[0037] The lower end of the outer wall 51a is fixed in a sealed state to the upper surface of the stator core 20 using an adhesive. The lower end of the inner wall 51b is fixed in a sealed state to the upper surface of the stator core 20 (teeth 22) and the radially inner side of the coils 30 using an adhesive. Therefore, the cover 51 has a coil end space 53 that covers the coils 30 protruding above the stator core 20. The coil end space 53 is a sealed space that houses the coils 30 protruding above the stator core 20. The coil end space 53 is provided around the entire circumference in the circumferential direction. The coil end space 53 is a sealed space that houses the upper sides of the 12-pole coils 30.

[0038] The cover 52 covers the underside of the coil 30. The cover 51 covers the coil 30 protruding below the stator core 20. The cover 52 has an outer wall 52a, an inner wall 52b, and a lower wall 52c. The outer wall 52a is located radially outside the coil 30. The outer wall 52a extends in the circumferential direction. The outer wall 52a is provided around the entire circumference. The upper end of the outer wall 52a contacts the lower surface of the core back 21. The lower end of the outer wall 52a contacts the core back 21 around the entire circumference. The upper end of the outer wall 52a contacting the core back 21 also includes the case where an adhesive is interposed between the upper end of the outer wall 52a and the core back 21.

[0039] The outer wall 52a has a protruding wall 52d. The protruding wall 52d protrudes radially outward from the outer wall 52a. The circumferential position at which the protruding wall 52d is arranged is the same as the circumferential center position of the tooth 22 around which the coil 30 is wound. Therefore, 12 protruding walls 52d are provided. When viewed in the axial direction, the protruding wall 52d has a semicircular shape. When viewed in the axial direction, the center of the arc of the protruding wall 52d is the same as the center of the hole HL.

[0040] The inner wall 52b of the cover 52 is located radially inside the coil 30. The inner wall 52b extends in the circumferential direction. The inner wall 52b is provided around the entire circumference. A portion of the upper end of the inner wall 52b contacts the lower surface of the tooth 22. The lower wall 52c of the cover 52 connects the lower end of the outer wall 52a and the lower end of the inner wall 52b. The lower wall 52c extends in the circumferential direction. The lower wall 52c is provided around the entire circumference.

[0041] The upper end of the outer wall 52a is fixed to the lower surface of the stator core 20 in a sealed state using an adhesive. The upper end of the inner wall 52b is fixed to the lower surface of the stator core 20 (teeth 22) and the radially inner side of the coils 30 in a sealed state using an adhesive. Therefore, the cover 52 has a coil end space 54 that covers the coils 30 protruding below the stator core 20. The coil end space 54 is a sealed space that houses the coils 30 protruding below the stator core 20. The coil end space 54 is provided around the entire circumferential direction. The coil end space 54 is a sealed space that houses the lower sides of the 12-pole coils 30.

[0042] As shown in FIG. 2 , lead wires 31 from coil 30 extend downward and are drawn out to the outside of cover 52. Lead wires 31 are liquid-tightly sealed to cover 52 with an adhesive. Lead wires 31 drawn out to the outside of cover 52 are connected to bus bar 32. Bus bar 32 is disposed outside cover 52. Lead wires 33 are connected to bus bar 32. Power is supplied to coil 30 via lead wires 33 and bus bar 32.

[0043] The first pipe 61 connects the inside and outside of the cover 52. The first pipe 61 is cylindrical and extends in the axial direction. The circumferential position at which the first pipe 61 is arranged is the same as the circumferential center position of the tooth 22A around which the coil 30A is wound. Therefore, six first pipes 61 are arranged in the circumferential direction. As shown in FIG. 4, the first pipe 61 has an axial portion 61a and a curved portion 61b.

[0044] The shaft-shaped portion 61a has a shaft shape extending in the axial direction. The shaft-shaped portion 61a is located below the first pipe 61. The first pipe 61 is inserted inside the cover 52 at the shaft-shaped portion 61a. The first pipe 61 is held by the protruding wall 52d at a part of the outer circumferential surface of the shaft-shaped portion 61a inserted inside the cover 52. The first pipe 61 is liquid-tightly sealed to the cover 52 by an adhesive at the shaft-shaped portion 61a inserted inside the cover 52.

[0045] The curved portion 61b is located above the first pipe 61. The curved portion 61b has a bent tip. The curved portion 61b is bent from the upper end of the shaft-shaped portion 61a toward one side in the circumferential direction. The first pipe 61 opens into the coil end space 54 at the curved portion 61b at its tip, facing one side in the circumferential direction. A first opening surface 61c surrounded by the end surfaces of the tips of the curved portions 61b that open into the coil end space 54 faces one side in the circumferential direction. The tips of the six first pipes 61 are all bent toward the same side in the circumferential direction and open into the coil end space 54 toward one side in the circumferential direction. By bending the tips of the first pipes 61 toward the same side in the circumferential direction and facing one side in the circumferential direction, the flow of the coolant CL can be restricted to one side in the circumferential direction when the coolant CL is discharged from the first pipe 61 into the coil end space 54.

[0046] The motor 1 has at least two passages 72, 73. The passages 72, 73 each pass through the stator core 20 in the axial direction. The circumferential position at which the passage 72 is arranged is the same as the circumferential center position of the tooth 22B around which the coil 30B is wound. The circumferential position at which the passage 73 is arranged is the same as the circumferential center position of the tooth 22A around which the coil 30A is wound. Therefore, six passages 72, 73 are provided.

[0047] In this embodiment, the passage 72 is the second pipe 62. That is, at least one of the passages 72 and 73 is the second pipe 62. Therefore, six second pipes 62 are provided. The second pipe 62 connects the inside and outside of the cover 52. The second pipe 62 is cylindrical and extends in the axial direction. As shown in FIG. 7 , a portion of the outer circumferential surface of the second pipe 62 is held inside the cover 52 in contact with the inner circumferential surface of the protruding wall 52d and exposed to the coil end space 54. The first pipe 61 inserted inside the cover 52 is liquid-tightly sealed to the cover 52 with an adhesive. The second pipe 62 is inserted through the hole HL of the stator core 20 above the area exposed to the coil end space 54. The upper end of the second pipe 62 protrudes upward from the stator core 20 and opens upward into the coil end space 53.

[0048] The passage 73 in this embodiment is the third pipe 63. At least one of the passages 72, 73 is the second pipe 62. In other words, at least one of the passages 72, 73 that is different from the second pipe 62 is the third pipe 63. Therefore, six third pipes 63 are provided. As shown in FIG. 4 , the third pipe 63 is inserted through the hole HL. The upper side of the third pipe 63 protrudes upward from the stator core 20 and opens into the coil end space 53. In other words, the third pipe 63 is not connected to the outside of the covers 51, 52. The lower side of the third pipe 63 protrudes downward from the stator core 20 and opens into the coil end space 54. The third pipe 63, as the passage 73, connects the coil end space 53 and the coil end space 54 on both axial sides.

[0049] The center position of the hole HL through which the third pipe 63 is inserted is the same as the center position of the shaft-shaped portion 61a of the first pipe 61. Therefore, the third pipe 63 and the shaft-shaped portion 61a of the first pipe 61 are arranged coaxially. Because the tip of the first pipe 61 is bent toward one side in the circumferential direction, a first opening surface 61c surrounded by the end face of the tip of the first pipe 61 on the inside of the cover 52 does not face a second opening surface 63c surrounded by the end face of the tip of the passage 73 formed by the third pipe 63, which is located in the same coil end space 54 as the tip of the first pipe 61. Because the first opening surface 61c at the tip of the first pipe 61 does not face the second opening surface 63c at the tip of the passage 73, it is possible to prevent the coolant CL that flows from one of the first pipe 61 and the passage 73 into the coil end space 54 from flowing out to the other of the first pipe 61 and the passage 73 before it has sufficiently spread throughout the coil end space 54.

[0050] The first pipe 61 and the second pipe 62 are connected to a circulation pump 81. The circulation pump 81 circulates the coolant CL in the cooling device 50. The circulation pump 81 sends the coolant CL toward one of the first pipe 61 and the second pipe 62. The coolant CL is cooled by the radiator 82 and then flows into one of the first pipe 61 and the second pipe 62. The coolant CL that flows out from the other of the first pipe 61 and the second pipe 62 is cooled by the radiator 82 and then returns to the circulation pump 81.

[0051] The coolant CL is not particularly limited and is appropriately selected based on the expected maximum temperature of the coil 30. For example, if the expected maximum temperature of the coil 30 exceeds 100°C, oil or the like with a boiling point exceeding 100°C can be selected. The radiator 82 can have, for example, a configuration with multiple layers of fins arranged in the axial direction.

[0052] Cooling of the coil 30 by the cooling device 50 in the motor 1 having the above configuration will now be described. For example, when the circulation pump 81 pumps the coolant CL toward the first pipe 61, the coolant CL flows from the curved portion 61b at the tip of the first pipe 61 into the coil end space 54 in one circumferential direction. Because the tips of the multiple first pipes 61 all face in one circumferential direction, the coolant CL flows smoothly in one circumferential direction through the coil end space 54 and is sufficiently distributed throughout the coil end space 54. The coolant CL removes heat through heat exchange when it comes into contact with the coil 30 exposed in the coil end space 54.

[0053] The coolant CL that has removed heat from the coil 30 in the coil end space 54 flows into the third pipe 63 from below, and then flows into the coil end space 53 from above the third pipe 63. The coolant CL that has flowed into the coil end space 53 removes heat through heat exchange when it comes into contact with the coil 30 exposed in the coil end space 53. The coolant CL that has removed heat from the coil 30 in the coil end space 53 flows into the second pipe 62 from above, dissipates heat in the radiator 82, and then returns to the circulation pump 81. As described above, the continuous circulation of the coolant CL effectively removes heat from the coil 30, thereby cooling it.

[0054] In the above cooling method, the circulation pump 81 sends out the cooling liquid CL toward the first pipe 61 and returns it from the second pipe 62, but the same effects and advantages can be obtained even if the circulation pump 81 sends out the cooling liquid CL toward the second pipe 62 and returns it from the first pipe 61.

[0055] In this embodiment, the coolant CL comes into direct contact with the coil 30 exposed in the coil end spaces 53, 54 to remove heat, thereby effectively dissipating the heat generated in the coil 30. If the heat generated in the coil 30 cannot be sufficiently dissipated, the upper limit of the output of the motor 1 would be limited by the temperature rise of the coil 30. In this embodiment, by sufficiently dissipating the heat generated in the coil 30, the limit due to the temperature rise of the coil 30 is alleviated, which can contribute to improving the output of a motor 1 of the same size and specifications.

[0056] Second Embodiment Next, a second embodiment of the motor 1 will be described with reference to FIG. In these figures, the same elements as those in the first embodiment shown in FIGS. 1 to 7 are denoted by the same reference numerals, and their description may be omitted.

[0057] In the second embodiment, a configuration will be described that takes into consideration the fact that air is less likely to remain in the coil end spaces 53, 54 when the coil end spaces 53, 54 are filled with the coolant CL. In FIG. 8, the lead wire 31 of the coil 30 is pulled out to the upper side, and first pipes 61A, 61B and second pipes 62A, 62B are inserted into the inside of the cover 51 from above. The coolant CL in the second embodiment flows from a circulation pump 81 (not shown in FIG. 8) into the upper sides of the second pipes 62A, 62B, as shown by the arrows in FIG.

[0058] The tips of the second pipes 62A, 62B protrude downward from the stator core 20. The tips of the multiple second pipes 62A, 62B are bent to the same circumferential side. The tips of the second pipes 62A, 62B all face the other circumferential side and open into the coil end space 54. By bending the tips of the second pipes 62A, 62B to the same circumferential side and facing the other circumferential side, when the coolant CL is discharged from the second pipes 62A, 62B into the coil end space 54, the flow of the coolant CL can be restricted to the other circumferential side.

[0059] Sub-pipes 64A and 64B are provided on the cover 51. The sub-pipes 64A and 64B connect the inside and outside of the cover 51. The first pipes 61A and 61B are inserted into and fixed to the sub-pipes 64A and 64B from above. The sub-pipes 64A and 64B have sub-flow passages 65A and 65B. The sub-flow passages 65A and 65B form part of the flow passages of the first pipes 61A and 61B. In other words, part of the sub-pipes 64A and 64B form part of the first pipes 61A and 61B. One end of each of the sub-flow passages 65A and 65B faces the other circumferential side and opens into the coil end space 53. The other end of each of the sub-flow passages 65A and 65B faces upward and communicates with the first pipes 61A and 61B. The axial positions at which the sub-flow passages 65A and 65B open into the coil end space 53 are near the upper wall 51c. That is, the sub-flow paths 65A and 65B open at the upper end of the coil end space 53.

[0060] Because the sub-flow paths 65A, 65B open at the upper ends of the coil end spaces 53, air remaining in the coil end spaces 53 can be easily discharged via the sub-flow paths 65A, 65B and the first pipes 61A, 61B when the coil end spaces 53 are filled with coolant CL. The first pipes 61A, 61B are inserted into the sub-pipes 64A, 64B and communicate with the sub-flow paths 65A, 65B that open into the coil end spaces 53 facing the other circumferential side, eliminating the need to bend the tips of the first pipes 61A, 61B toward the other circumferential side. This reduces the work and costs required to prepare the first pipes 61A, 61B.

[0061] The lower ends of the third pipes 63A, 63B, which are not connected to the covers 51, 52, are flush with the underside of the stator core 20. Therefore, the lower ends of the third pipes 63A, 63B open at the upper end of the coil end space 54. Since the lower ends of the third pipes 63A, 63B open at the upper end of the coil end space 54, air remaining in the coil end space 54 can be easily discharged via the third pipes 63A, 63B when the coil end space 54 is filled with the coolant CL.

[0062] The upper ends of the third pipes 63A, 63B are inserted into and fixed to the sub-pipes 64A, 64B from below. The sub-pipes 64A, 64B have sub-flow passages 66A, 66B. The sub-flow passages 66A, 66B form part of the flow passages of the third pipes 63A, 63B. In other words, part of the sub-pipes 64A, 64B form part of the third pipes 63A, 63B. One end of each of the sub-flow passages 66A, 66B faces one side in the circumferential direction and opens into the coil end space 53. The other end of each of the sub-flow passages 66A, 66B faces downward and communicates with the third pipes 63A, 63B. The axial positions at which the sub-flow passages 66A, 66B open into the coil end space 53 are lower than the axial positions at which the sub-flow passages 65A, 65B open into the coil end space 53.

[0063] The axial positions at which the sub-flow paths 66A, 66B open into the coil end space 53 are lower than the axial positions at which the sub-flow paths 65A, 65B open into the coil end space 53, which prevents the flow of coolant CL from flowing from the sub-flow paths 66A, 66B into the coil end space 53 from impeding the discharge of air remaining in the coil end space 53 via the sub-flow paths 65A, 65B. The third pipes 63A, 63B are inserted into the sub-pipes 64A, 64B and communicate with the sub-flow paths 66A, 66B that open into the coil end space 53 facing one circumferential side, which eliminates the need to bend the upper ends of the third pipes 63A, 63B toward one circumferential side. This reduces the work and costs required to prepare the third pipes 63A, 63B.

[0064] As described above, in this embodiment, in a configuration in which the lead wire 31 of the coil 30 is pulled out upward and the first pipes 61A, 61B and the second pipes 62A, 62B are inserted into the inside of the cover 51 from above, when the coil end spaces 53, 54 are filled with the coolant CL, it is possible to smoothly discharge air remaining in the coil end spaces 53, 54.

[0065] Third Embodiment Next, a third embodiment of the motor 1 will be described with reference to FIG. In these figures, the same elements as those in the first embodiment shown in FIGS. 1 to 7 are denoted by the same reference numerals, and their description may be omitted.

[0066] In the second embodiment, a configuration was described in which the lead wire 31 of the coil 30 is drawn out to the upward side, and the first pipes 61A, 61B and the second pipes 62A, 62B are inserted into the inside of the cover 52 from the upper side, whereas in the third embodiment, the lead wire 31 of the coil 30 is drawn out to the downward side, and the first pipes 61A, 61B and the second pipes 62A, 62B are inserted into the inside of the cover 52 from the lower side.

[0067] As indicated by the arrows in FIG. 9 , the coolant CL in the third embodiment flows from a circulation pump 81 (not shown in FIG. 9 ) into the lower sides of the second pipes 62A, 62B. The tips of the second pipes 62A, 62B protrude upward from the stator core 20. The tips of the multiple second pipes 62A, 62B are bent toward the same circumferential side. The tips of the second pipes 62A, 62B all face the other circumferential side and open into the coil end space 53. By bending the tips of the second pipes 62A, 62B toward the same circumferential side and facing the other circumferential side, when the coolant CL is discharged from the second pipes 62A, 62B into the coil end space 53, the flow of the coolant CL can be restricted to the other circumferential side.

[0068] The axial position at which the upper ends of the third pipes 63A, 63B, which are not connected to the covers 51, 52, open into the coil end space 53 is near the upper side wall 51c. In other words, the third pipes 63A, 63B open near the upper end of the coil end space 53. By having the third pipes 63A, 63B open near the upper end of the coil end space 53, air remaining in the coil end space 53 can be more easily discharged via the third pipes 63A, 63B when the coil end space 53 is filled with the coolant CL.

[0069] The axial position where the upper ends of the third pipes 63A, 63B open into the coil end space 53 is higher than the axial position where the tips of the second pipes 62A, 62B open into the coil end space 53. Since the axial position where the upper ends of the third pipes 63A, 63B open into the coil end space 53 is higher than the axial position where the tips of the second pipes 62A, 62B open into the coil end space 53, it is possible to prevent the flow of coolant CL flowing from the tips of the second pipes 62A, 62B into the coil end space 53 from interfering with the discharge of air remaining in the coil end space 53 via the upper ends of the third pipes 63A, 63B.

[0070] The lower ends of the third pipes 63A, 63B are both bent toward the same side in the circumferential direction. The lower ends of the third pipes 63A, 63B both face toward one side in the circumferential direction and open into the coil end space 54. By bending the ends of the third pipes 63A, 63B toward the same side in the circumferential direction and facing that side, when the coolant CL is discharged from the third pipes 63A, 63B into the coil end space 54, the flow of the coolant CL can be restricted to one side in the circumferential direction.

[0071] The first pipes 61A, 61B are positioned on the other circumferential side of the third pipes 63A, 63B. The tips of the first pipes 61A, 61B are located near the lower surface of the stator core 20. In other words, the first pipes 61A, 61B open near the upper end of the coil end space 54. Since the first pipes 61A, 61B open near the upper end of the coil end space 54, air remaining in the coil end space 54 can be easily discharged via the first pipes 61A, 61B when the coil end space 54 is filled with the coolant CL.

[0072] The axial position where the tips of the first pipes 61A, 61B open into the coil end space 54 is higher than the axial position where the lower ends of the third pipes 63A, 63B open into the coil end space 54. Since the axial position where the tips of the first pipes 61A, 61B open into the coil end space 54 is higher than the axial position where the lower ends of the third pipes 63A, 63B open into the coil end space 54, it is possible to prevent the flow of coolant CL flowing from the lower ends of the third pipes 63A, 63B into the coil end space 54 from interfering with the discharge of air remaining in the coil end space 54 via the tips of the first pipes 61A, 61B.

[0073] As described above, in this embodiment, in a configuration in which the lead wire 31 of the coil 30 is pulled out downward and the first pipes 61A, 61B and the second pipes 62A, 62B are inserted into the inside of the cover 52 from the bottom, when the coil end spaces 53, 54 are filled with the coolant CL, it is possible to smoothly discharge air remaining in the coil end spaces 53, 54.

[0074] <Fourth embodiment> Next, a fourth embodiment of the motor 1 will be described with reference to FIG. In this figure, the same elements as those in the first embodiment shown in FIGS. 1 to 7 are denoted by the same reference numerals, and their description may be omitted.

[0075] In the fourth embodiment, a configuration will be described in which the tip of the second pipe 62 inserted into the cover 52 opens into the coil end space 54. In Fig. 10, the covers 51 and 52 are shown by two-dot chain lines to make it easier to understand the inside of the covers 51 and 52.

[0076] 10, the second pipe 62 inserted inside the cover 52 is bent so that its tip faces one side in the circumferential direction. A third opening surface 62c of the second pipe 62, which is surrounded by the end surface of the tip of the second pipe 62 inside the cover 52, faces one side in the circumferential direction and opens into the coil end space 54.

[0077] In this embodiment, the passage 72 is the third pipe 63B. The third pipe 63B is cylindrical and extends in the axial direction. The third pipe 63B protrudes upward and downward from the stator core 20. The passage 72 formed by the third pipe 63B does not face a fourth opening surface 63d surrounded by the end surface of the tip of the second pipe 62, which is located in the same coil end space 54 as the tip of the second pipe 62. Because the fourth opening surface 63d at the tip of the passage 72 formed by the third pipe 63B does not face the third opening surface 62c at the tip of the second pipe 62, it is possible to prevent the coolant that flows into the coil end space 54 from one of the second pipe 62 and the passage 72 from flowing out to the other of the second pipe 62 and the passage 72 before the coolant has sufficiently spread throughout the coil end space 54.

[0078] The cover 52 has a partition wall 52e. The partition wall 52e defines a coil end space 54 below the stator core 20 inside the cover 52. The partition wall 52e extends in the axial direction and is located between the first pipe 61 and the second pipe 62 in the circumferential direction.

[0079] Because the cover 52 has the partition wall 52e, the coolant that flows into the coil end space 54 from the tip of the first pipe 61 removes heat from the lower side of the coil 30A and then flows into the coil end space 53 via the third pipe 63A. The coolant that flows into the coil end space 53 sequentially removes heat from the upper sides of the coil 30A and the coil 30B. Because the third pipe 63B is provided and the tip of the second pipe 62 opens into the coil end space 54, the coolant that has removed heat from the upper sides of the coil 30A and the coil 30B flows back into the coil end space 54 via the third pipe 63B and removes heat from the lower side of the coil 30B. By the coolant flowing back into the coil end space 54 via the third pipe 63B and removing heat from the lower side of the coil 30B, more heat can be removed from the coil 30B than when the passage 72 is the second pipe 62 and the coolant flows from the coil end space 53 to the outside of the cover 52 via the second pipe 62.

[0080] Fifth Embodiment Next, a fifth embodiment of the motor 1 will be described with reference to FIGS. In the fifth embodiment, a configuration will be described in which coolant CL is circulated in series or parallel to a 12-pole coil 30. In Fig. 11, the first pipe, second pipe, and third pipe described in the above embodiments will be simply described as a circulation path 90. The coolant, cover, etc. are not shown in Figs. 11 and 12.

[0081] FIG. 11 shows a circuit 90 in a series cooling configuration. As shown in Figure 11, the circulation path 90 on the coolant discharge side connected to the circulation pump 81 circulates the coolant by passing through two circumferentially adjacent coils 30 and then dissipating heat in a radiator 82, which is repeated in sequence.

[0082] FIG. 12 shows a circuit 90 in a parallel cooling configuration. The circulation path 90 has a high-pressure side collecting pipe 91, a low-pressure side collecting pipe 92, and a communicating pipe 93. The high-pressure side collecting pipe 91 and the low-pressure side collecting pipe 92 are provided on the mounting portion 130 and extend circumferentially. The high-pressure side collecting pipe 91 is connected to the discharge side of the circulation pump 81. The low-pressure side collecting pipe 92 is connected to the suction side of the circulation pump 81. One end of the communicating pipe 93 is connected to the high-pressure side collecting pipe 91. The other end of the communicating pipe 93 is connected to the low-pressure side collecting pipe 92. In other words, the communicating pipe 93 communicates between the high-pressure side collecting pipe 91 and the low-pressure side collecting pipe 92.

[0083] One end of the communicating pipe 93 passes through two circumferentially adjacent coils 30. The other end of the communicating pipe 93 passes through the radiator 82. Six communicating pipes 93 are provided, one for each pair of coils 30.

[0084] Therefore, the coolant discharged from the circulation pump 81 flows from the high-pressure side collecting pipe 91 into one end of the communicating pipe 93. The coolant that flows into one end of the communicating pipe 93 removes heat from two circumferentially adjacent coils 30, and then dissipates heat in the radiator 82. The coolant in the communicating pipe 93 that has dissipated heat in the radiator 82 flows into the low-pressure side collecting pipe 92 and circulates. In this way, in the circulation path 90 shown in FIG. 12, the coolant circulates in parallel between two coils 30.

[0085] 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.

[0086] For example, in the first embodiment, the third pipe 63 is used as the passage 73, but the present invention is not limited to this configuration. For example, the slit SL may not be provided, and the hole HL may be used as the passage 73. In this case, the gaps between the electromagnetic steel plates that make up the stator core 20 may be treated to be liquid-tight and leak-proof.

[0087] Furthermore, as explained in the fourth embodiment above, when the tip of the second pipe 62 opens in the coil end space 54, the hole HL may be used as the passage 72 without using the third pipe 63B as the passage 72. In this case as well, the gaps between the electromagnetic steel plates that make up the stator core 20 may be treated to be liquid-tight and leak-proof. [Explanation of symbols]

[0088] DESCRIPTION OF SYMBOLS 1...motor, 2...housing, 3...rotor, 10...stator, 20...stator core, 21...core back, 22...teeth, 30, 30A, 30B...coil, 51, 52...cover, 52e...partition wall, 53, 54...coil end space, 61, 61A, 61B...first pipe, 61c...first opening surface, 62, 62A, 62B...second pipe, 62c...third opening surface, 63, 63A, 63B...third pipe, 63c...second opening surface, 63d...fourth opening surface, 72, 73...passage, 81...circulation pump, CL...coolant, HL...hole, J...central axis, SL...slit

Claims

1. a rotor rotatable about a central axis; a stator that faces the rotor in a radial direction with a gap therebetween; Equipped with The stator includes: a stator core having an annular core back surrounding the central axis and teeth extending radially from the core back to one side; a coil wound around the tooth; and a cover that covers the coils and has coil end spaces therein that accommodate the coils protruding on both axial sides of the stator core; at least one first pipe and at least one second pipe, each connecting the inside and outside of the cover; a passage that axially penetrates the stator core; and the passage includes a first passage connecting the coil end spaces on both axial sides, A coolant circulates inside the cover, a first opening surface surrounded by an end surface of the first pipe at the tip end of the cover on the inside thereof and a second opening surface surrounded by an end surface of the first passage located in the same coil end space as the tip end of the first pipe are not opposed to each other; At least one of the end of the first pipe and the end of the first passage, which are located in the same coil end space, is bent.

2. A plurality of the passages are provided, The plurality of passages includes a second passage formed by the second pipe. The motor according to claim 1 .

3. The second pipe is arranged in plurality in the circumferential direction, The ends of the second pipes located inside the cover are bent to the same side in the circumferential direction. The motor according to claim 2 .

4. The plurality of passages includes the first passage formed by a third pipe not connected to the outside of the cover.

4. The motor according to claim 2 or 3.

5. a third opening surface surrounded by an end surface of the inner tip of the cover of the second pipe and a fourth opening surface surrounded by an end surface of the tip of the first passage located in the same coil end space as the tip of the second pipe do not face each other; The motor according to claim 1 .

6. The passage includes the first passage formed by a third pipe that is not connected to the outside of the cover. The motor according to claim 5.

7. The tip of the second pipe is bent.

7. The motor according to claim 5 or 6.

8. the first pipe and the second pipe are connected to one axial side of the cover, a partition wall that partitions the inside of the cover on one axial side of the stator core, The motor according to claim 7 , wherein the partition wall extends in the axial direction and is located between the first pipe and the second pipe in the circumferential direction.

9. The second pipe is arranged in plurality in the circumferential direction, The tip ends of the second pipes are bent to the same side in the circumferential direction. The motor according to claim 7.

10. The tip of the first pipe is bent. A motor according to any one of claims 1 to 9.

11. The first pipe is a plurality of pipes arranged in the circumferential direction, The tip ends of the plurality of first pipes are bent to the same side in the circumferential direction. The motor according to claim 10.

12. the first pipe and the second pipe are connected to a circulation pump; A motor according to any one of claims 1 to 11.

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