Motors and aircraft

Abstract

To improve a heat radiation performance of a motor.SOLUTION: A motor 100 comprises a rotor 1 and a stator 2. The rotor 1 is rotatable around a central axis extending in an axial direction. The stator 2 has an annular stator core 21 surrounding the central axis. The rotor 1 has a cylinder part 12, a first plate part 131, a second plate part 132, and a hole part 15. The cylinder part 12 is located on a radially outer side than the stator 2 and extends in the axial direction. The first plate part 131 is located further on one axial side than the stator 2 and extends radially inward from one axial end of the cylinder part 12. The second plate part 132 is located further on the other axial side than the stator 2 and extends radially inward from the other axial end of the cylinder part 12. The hole part 15 penetrates at least either one of the cylinder part 12, the first plate part 131, and the second plate part 132.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, a technique for dissipating heat from a motor by providing holes in the cover of the rotor is known. For example, the rotor is rotatably connected to a base to which the stator is fixed. By providing holes in the cover placed on the rotor, air circulation inside the motor is promoted (see, for example, the specification of Chinese Utility Model No. 205602145). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Utility Model No. 205602145 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional motors, the base does not rotate, so there is a risk that air may not circulate sufficiently on the fixed portion side of the stator, which may result in the heat inside the motor not being dissipated sufficiently.

[0005] An object of the present invention is to improve the heat dissipation performance of a motor. [Means for solving the problem]

[0006] An exemplary motor of the present invention includes a rotor and a stator. The rotor is rotatable about a central axis extending in the axial direction. The stator has an annular stator core surrounding the central axis. The rotor has a cylindrical portion, a first plate portion, a second plate portion, and a hole portion. The cylindrical portion is disposed radially outward from the stator and extends in the axial direction. The first plate portion is disposed on one axial side from the stator and extends radially inward from one axial end of the cylindrical portion. The second plate portion is disposed on the other axial side from the stator and extends radially inward from the other axial end of the cylindrical portion. The hole portion penetrates at least one of the cylindrical portion, the first plate portion, and the second plate portion.

[0007] An exemplary aircraft of the present invention includes the motor described above. [Effects of the Invention]

[0008] According to the exemplary motor and aircraft of the present invention, the heat dissipation performance of the motor can be improved. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the configuration of a motor according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing the appearance of the motor according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing an example of an aircraft equipped with a motor. [Figure 4A] FIG. 4A is a cross-sectional view showing an example of the arrangement of holes on one axial side of the rotor. [Figure 4B] FIG. 4B is a cross-sectional view showing an example of the arrangement of holes on the other axial side of the rotor. [Figure 5A] FIG. 5A is a perspective view showing an example of the configuration of the first groove portion. [Figure 5B] FIG. 5B is a perspective view showing an example of the configuration of the second groove portion. [Figure 6] FIG. 6 is a cross-sectional view showing an example of the configuration of a motor according to a modified example of the first embodiment. [Figure 7] FIG. 7 is a perspective view showing the appearance of a motor according to a modified example of the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing an example of the configuration of the stator holder as viewed from the axial direction. [Figure 9] FIG. 9 is a cross-sectional view showing an example of the configuration of a motor according to the second embodiment. [Figure 10] FIG. 10 is a perspective view showing the appearance of the motor according to the second embodiment. [Figure 11] FIG. 11 is a perspective view showing the other axial end of the motor according to the second embodiment. [Figure 12] FIG. 12 is a cross-sectional view showing an example of the configuration of a motor according to a modified example of the second embodiment. [Figure 13] FIG. 13 is a perspective view showing the appearance of a motor according to a modified example of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Exemplary embodiments will now be described with reference to the drawings.

[0011] In this specification, in motor 100, the direction parallel to the central axis CX is referred to as the "axial direction." Furthermore, the direction perpendicular to a specific axis such as the central axis CX is referred to as the "radial direction," and the direction of rotation around the specific axis is referred to as the "circumferential direction." Within the radial direction, the direction approaching the specific axis is referred to as the "radially inward direction," and the direction away from the specific axis is referred to as the "radially outward direction."

[0012] In this specification, the term "annular" includes not only a shape that is continuous and uninterrupted throughout the entire circumferential area centered on the central axis CX, but also a shape that has one or more interruptions in a portion of the entire area centered on the central axis CX. It also includes a shape that describes a closed curve on a curved surface that intersects with the central axis CX, centered on the central axis CX.

[0013] Furthermore, in the positional relationship between one of a direction, a line, and a plane and another, "parallel" includes not only a state in which they do not intersect at all no matter how far they are extended, but also a state in which they are substantially parallel. Furthermore, "perpendicular" and "orthogonal" each include not only a state in which they intersect at 90 degrees, but also a state in which they are substantially perpendicular and a state in which they are substantially orthogonal. In other words, "parallel," "perpendicular," and "orthogonal" each include a state in which there is an angular deviation in the positional relationship between the two to an extent that does not deviate from the spirit of the present invention.

[0014] It should be noted that these are names used merely for the purpose of explanation and are not intended to limit the actual positional relationships, directions, names, etc.

[0015] 1. First Embodiment Fig. 1 is a cross-sectional view showing an example configuration of a motor 100 according to the first embodiment. Fig. 2 is a perspective view showing the exterior of the motor 100 according to the first embodiment. Fig. 3 is a diagram showing an example of an aircraft 500 equipped with the motor 100. Note that Fig. 2 shows the cross-sectional structure of the motor 100 when cut along an imaginary plane including the central axis CX.

[0016] As shown in FIG. 3, the aircraft 500 includes a motor 100. The aircraft 500 also includes a battery 501 and a propeller 503. The motor 100 is a driving source for the aircraft 500, such as a drone. For example, the motor 100 receives power from the battery 501 and drives the propeller 501 to rotate. In the aircraft 500 of FIG. 3, the heat dissipation performance of the motor 100 can be improved, as will be described later. Note that the use of the motor 100 is not limited to the example shown in FIG. 3.

[0017] As shown in FIGS. 1 and 2, the motor 100 includes a rotor 1, a stator 2, a stator holder 3, and a base portion 4.

[0018] <1-1. Rotor 1> The rotor 1 is rotatable about a central axis CX extending in the axial direction. As described above, the motor 100 includes the rotor 1. The rotor 1 has a cylindrical shaft 10, a rotor hub 11, a cylindrical portion 12, a first plate portion 131, a second plate portion 132, a rotor core 141, a magnet 142, a hole portion 15, a first groove portion 161, and a second groove portion 162. Note that, hereinafter, the first plate portion 131 and the second plate portion 132 may be collectively referred to as "plate portion 13."

[0019] <1-1-1. Shaft 10> The shaft 10 extends axially along a central axis CX.

[0020] <1-1-2. Rotor hub 11> The rotor hub 11 is annular and surrounds the central axis CX, and is fixed to the radially outer surface of the shaft 10.

[0021] <1-1-3.Cylinder part 12> The cylindrical portion 12 is disposed radially outward of the stator 2 and extends in the axial direction. As described above, the rotor 1 has the cylindrical portion 12. The cylindrical portion 12 has a first cylindrical portion 121 and a second cylindrical portion 122. The first cylindrical portion 121 and the second cylindrical portion 122 are cylindrical and surround the central axis CX, and extend in the axial direction.

[0022] The first cylindrical portion 121 has a plurality of recesses 1211 arranged in the circumferential direction. Each recess 1211 is recessed from the end of the first cylindrical portion 121 on the other axial direction Da2 side toward the one axial direction Da1 side, and penetrates the first cylindrical portion 121 in the radial direction.

[0023] The second cylindrical portion 122 is disposed closer to the other axial direction Da2 than the first cylindrical portion 121, and in this embodiment, is aligned with the first cylindrical portion 121 in the axial direction with a gap therebetween. The second cylindrical portion 122 has a plurality of recesses 1221 aligned in the circumferential direction. Each recess 1221 is recessed from the end of the second cylindrical portion 122 on the one axial direction Da1 side toward the other axial direction Da2 side and penetrates the second cylindrical portion 122 in the radial direction.

[0024] <1-1-4.First plate part 131> The first plate portion 131 is disposed closer to one axial direction Da1 than the stator 2, and extends radially inward from the end of the cylindrical portion 12 on the one axial direction Da1 side. As described above, the rotor 1 has the first plate portion 131. The first plate portion 131 faces the stator 2 in the axial direction. The radially outer end of the first plate portion 131 is connected to the first cylindrical portion 121. The radially inner end of the first plate portion 131 is connected to the radially outer end of the rotor hub 11.

[0025] <1-1-5.Second plate part 132> The second plate portion 132 is disposed closer to the other axial direction Da2 than the stator 2, and extends radially inward from the end of the cylindrical portion 12 on the other axial direction Da2 side. As described above, the rotor 1 has the second plate portion 132. The second plate portion 132 faces the stator 2 in the axial direction. The radially outer end of the second plate portion 132 is connected to the second cylindrical portion 122. The radially inner end of the second plate portion 132 faces the stator holder 3 in the radial direction, with a gap therebetween.

[0026] Since the rotor 1 has both the first plate portion 131 and the second plate portion 132, when the rotor 1 rotates, the rotation of the first plate portion 131 can circulate air in the first space 101. Furthermore, the rotation of the second plate portion 132 can circulate air in the second space 102. The first space 101 is the space between the first plate portion 131 and the end of the stator 2 on one axial direction Da1. The second space 102 is the space between the second plate portion 132 and the end of the stator 2 on the other axial direction Da2. This promotes heat dissipation from both axial ends of the stator 2, thereby suppressing temperature increases. This improves the heat dissipation performance of the motor 100.

[0027] <1-1-6. Rotor core 141 and magnet 142> The rotor core 141 is cylindrical and surrounds the central axis CX, and is disposed on the radially inner surface of the cylindrical portion 12. The rotor core 141 is made of a magnetic material, and in this embodiment is, for example, a laminate of electromagnetic steel sheets stacked in the axial direction. An end portion of the rotor core 141 on one axial direction Da1 side is connected to the radially inner surface of the first cylindrical portion 121. An end portion of the rotor core 141 on the other axial direction Da2 side is connected to the radially inner surface of the second cylindrical portion 122. The first cylindrical portion 121 is connected to the second cylindrical portion 122 via the rotor core 141, with a gap in the axial direction. Since the volume of the cylindrical portion 12 can be reduced, this can contribute to reducing the weight of the motor 100 (particularly the rotor 1).

[0028] The rotor core 141 has a plurality of protruding portions 1411 arranged in the circumferential direction. The protruding portions 1411 protrude radially outward from the radially outer surface of the rotor core 141 and extend axially. An end of each of the protruding portions 1411 on one axial direction Da1 fits into a recessed portion 1211 of the first cylindrical portion 121. An end of each of the protruding portions 1411 on the other axial direction Da2 fits into a recessed portion 1221 of the second cylindrical portion 122. This fitting structure reliably prevents rotation of the rotor core 141 and the magnet 142 in the circumferential direction relative to the cylindrical portion 12. Furthermore, when assembling the rotor 1, the circumferential position of the portion of the rotor 1 on the other axial direction Da2, including the second cylindrical portion 122 and the second plate portion 132, can be easily determined relative to the portion of the rotor 1 on one axial direction Da1, including the first cylindrical portion 121 and the first plate portion 131.

[0029] The magnet 142 is disposed on the radially inner surface of the rotor core 141 and faces the stator 2 in the radial direction. In the magnet 142, different magnetic poles (i.e., north poles and south poles) are arranged alternately in the circumferential direction. The magnet 142 may be an annular member surrounding the central axis CX, or may be composed of a plurality of magnetic pole pieces arranged in the circumferential direction.

[0030] <1-1-7. Hole 15> The holes 15 penetrate at least one of the tubular portion 12, the first plate portion 131, and the second plate portion 132. As described above, the rotor 1 has the holes 15. By having the holes 15 in the rotor 1, when the rotor 1 rotates, the holes 15 function as air intakes or exhaust ports, and an air flow can be generated between the rotor 1 and the stator 2. This improves the heat dissipation performance of the stator 2, particularly its coil portion 22. This improves the heat dissipation performance of the motor 100.

[0031] Preferably, the hole portion 15 includes at least one rotor hole portion 150 of a first rotor hole portion 151 and a second rotor hole portion 152. The first rotor hole portion 151 axially penetrates the first plate portion 131. The second rotor hole portion 152 axially penetrates the second plate portion 132. In this embodiment, the hole portion 15 includes the first rotor hole portion 151 and the second rotor hole portion 152.

[0032] By arranging the first rotor hole 151 in the first plate portion 131, when the rotor 1 rotates, air can flow from outside the rotor 1 into the first space 101 between the first plate portion 131 and the end of the stator 2 on one axial side Da1. Alternatively, air circulating in the first space 101 can be discharged to the outside of the rotor 1. This allows heat to be dissipated from the end of the stator 2 on one axial side Da1, particularly the coil head 221 on the one axial side Da1, thereby suppressing temperature increases. The coil head 221 is a portion of the coil portion 22 of the stator 2 that is axially outward of the stator core 21, and includes, for example, a portion of the coil portion 22 on one axial side Da1 and a portion on the other axial side Da2 of the stator core 21.

[0033] Furthermore, by arranging the second rotor hole 152 in the second plate portion 132, when the rotor 1 rotates, air can flow from outside the rotor 1 into the second space 102 between the second plate portion 132 and the end portion of the stator 2 on the other axial direction Da2 side. Alternatively, air circulating in the second space 102 can be discharged to the outside of the rotor 1. Therefore, heat can be dissipated from the end portion of the stator 2 on the other axial direction Da2 side, particularly the coil head 221 on the other axial direction Da2 side, and a temperature rise therein can be suppressed.

[0034] More preferably, as shown in FIG. 1 , the hole 15 includes both a first rotor hole 151 and a second rotor hole 152. This allows one of the holes to function as an intake port and the other as an exhaust port. These functions change depending on the rotation direction of the rotor 1. For example, when the rotor 1 rotates in the circumferential direction, the first rotor hole 151 serves as an intake port and the second rotor hole 152 serves as an exhaust port. On the other hand, when the rotor 1 rotates in the opposite circumferential direction, the first rotor hole 151 serves as an exhaust port and the second rotor hole 152 serves as an intake port. Therefore, regardless of the rotation direction of the rotor 1, the motor 100 can reliably perform both intake and exhaust of air to the outside of the rotor 1, thereby improving ventilation efficiency between the rotor 1 and the stator 2.

[0035] Preferably, at least one of the rotor holes 150 overlaps with the coil portion 22 when viewed from the axial direction. For example, in FIG. 1 , when viewed from the axial direction, at least a portion of the first rotor hole 151 overlaps with the coil head 221 on one axial side Da1 of the coil portion 22. When viewed from the axial direction, at least a portion of the second rotor hole 152 overlaps with the coil head 221 on the other axial side Da2 of the coil portion 22. This allows the motor 100 to directly direct air flowing in from outside the rotor 1 onto the coil portion 22. Furthermore, the motor 100 can efficiently exhaust air near the coil portion 22 to the outside of the rotor 1. This improves the heat dissipation efficiency of the coil portion 22. However, this example does not exclude a configuration in which the first rotor hole 151 and the second rotor hole 152 do not overlap with the coil portion 22 when viewed from the axial direction.

[0036] 1 and 2, the cylindrical portion 12 does not have the hole 15. However, the present invention is not limited to the examples shown in FIGS. 1 and 2, and the hole 15 may be arranged in the cylindrical portion 12. FIG. 4A is a cross-sectional view showing an example of the arrangement of the hole 15 on one axial side Da1 of the rotor 1. FIG. 4B is a cross-sectional view showing an example of the arrangement of the hole 15 on the other axial side Da2 of the rotor 1. For example, as shown in FIGS. 4A and 4B, the hole 15 may further include a side hole 153 that penetrates the cylindrical portion 12 in the radial direction. In other words, the rotor 1 may have the side hole 153 that penetrates the cylindrical portion 12 in the radial direction. In FIG. 4A, the side hole 153 includes a first side hole 1531 that penetrates the first cylindrical portion 121 in the radial direction. In addition, in FIG. 4B, the side hole 153 includes a second side hole 1532 that penetrates the second cylindrical portion 122 in the radial direction. The side hole portion 153 may include both the first side hole portion 1531 and the second side hole portion 1532, or may include only one of the first side hole portion 1531 and the second side hole portion 1532. In this case, preferably, at least one of the rotor holes 150 is disposed radially inward from the cylindrical portion 12.

[0037] In this way, the motor 100 can draw air from outside the rotor 1 through the first rotor hole 151 and / or the second rotor hole 152 as the rotor 1 rotates, and can efficiently exhaust air that has radiated heat from the stator 2 through the side hole 153. Because air flows smoothly from the first rotor hole 151 and / or the second rotor hole 152 to the side hole 153, the motor 100 can efficiently ventilate the space between the rotor 1 and the stator 2. Furthermore, exhausting air from the side hole 153 can prevent water or dust from entering the interior of the rotor 1 through the side hole 153. However, the examples in FIGS. 4A and 4B do not exclude a configuration in which, when the hole 15 includes the side hole 153, at least one of the rotor holes 150 is not positioned radially inward of the tubular portion 12.

[0038] Preferably, at least a portion of the side hole 153 is disposed axially closer to at least one of the rotor holes 150 than the stator 2. In this way, the motor 100 can ventilate the space between the rotor 1 and the stator 2 more efficiently.

[0039] 4A , at least a portion of the first side hole 1531 is disposed in a portion of the first cylindrical portion 121 closer to one axial direction Da1 than the stator 2. More preferably, all of the first side hole 1531 is disposed in a portion of the first cylindrical portion 121 closer to one axial direction Da1 than the stator 2. This allows air to flow smoothly from the first rotor hole 151 toward the first side hole 1531.

[0040] 4B , when the second rotor hole portion 152 is disposed in the second plate portion 132, at least a portion of the second side hole portion 1532 is preferably disposed in a portion of the second cylindrical portion 122 that is closer to the other axial direction Da2 than the stator 2. More preferably, all of the second side hole portion 1532 is disposed in a portion of the second cylindrical portion 122 that is closer to the other axial direction Da2 than the stator 2. This allows air to flow smoothly from the second rotor hole portion 152 toward the second side hole portion 1532.

[0041] 1 to 4B do not exclude a configuration in which the hole portion 15 does not include the rotor hole portion 150, nor do they exclude a configuration in which the hole portion 15 does not include the side hole portion 153. In other words, it is sufficient for the hole portion 15 to include at least one of the first rotor hole portion 151, the second rotor hole portion 152, and the side hole portion 153.

[0042] <1-1-8. First Groove 161 and Second Groove 162> Next, the first groove portion 161 and the second groove portion 162 will be described with reference to Figures 5A and 5B. Figure 5A is a perspective view showing an example of the configuration of the first groove portion 161. Figure 5B is a perspective view showing an example of the configuration of the second groove portion 162. Figure 5A shows the first cylindrical portion 121 and the first plate portion 131 viewed from the other axial direction Da2 toward the one axial direction Da1. On the other hand, Figure 5B shows the second cylindrical portion 122 and the second plate portion 132 viewed from the one axial direction Da1 toward the other axial direction Da2. Therefore, the one axial direction Da1 and the other axial direction Da2 and the one circumferential direction Dr1 and the other circumferential direction Dr2 in Figure 5B are reversed from those in Figure 5A.

[0043] The rotor 1 has a plurality of first grooves 161 arranged in the circumferential direction and a plurality of second grooves 162 arranged in the circumferential direction. However, this is not limiting, and at least one of the number of first grooves 161 and the number of second grooves 162 may be singular. The first grooves 161 are disposed on the end face of the first plate portion 131 on the other axial direction Da2 side and are recessed toward the one axial direction Da1 side. The first grooves 161 extend at least radially inward and are connected to the first rotor hole 151. The second grooves 162 are disposed on the end face of the second plate portion 132 on the one axial direction Da1 side and are recessed toward the other axial direction Da2 side. The second grooves 162 extend at least radially inward and are connected to the second rotor hole 152.

[0044] In this embodiment, the first groove portion 161 and the second groove portion 162 extend spirally from the radially outer side toward the radially inner side. The first groove portion 161 and the second groove portion 162 spiral in opposite directions. For example, as shown in FIG. 5A , the first groove portion 161 extends further toward one circumferential direction Dr1 and extends radially inward as it moves toward the one circumferential direction Dr1. The radially inner end of the first groove portion 161 on the one circumferential direction Dr1 side is connected to the first rotor groove portion 171. As shown in FIG. 5B , the second groove portion 162 extends further toward the other circumferential direction Dr2 and extends radially inward as it moves toward the other circumferential direction Dr2. The radially inner end of the second groove portion 162 on the other circumferential direction Dr2 side is connected to the second rotor groove portion 172. 5A and 5B, the first groove portion 161 and the second groove portion 162 may have a spiral shape that spirals in the same direction. Furthermore, at least one of the first groove portion 161 and the second groove portion 162 does not have to have the spiral shape described above, and may, for example, extend radially from the radially outer side toward the radially inner rotor hole portion 150.

[0045] <1-1-8-1. Configuration of first groove portion 161> The first groove portion 161 has a first wall surface 1610 facing in the circumferential direction. The first wall surface 1610 is disposed at an end portion on the other axial direction Da2 side of the first plate portion 131 and extends at least in the radial direction. The first wall surface 1610 is connected to the first rotor hole portion 151 and inclined toward one circumferential direction Dr1 as it extends radially inward.

[0046] The first wall surface 1610 has an outer wall surface 1611 and an inner wall surface 1612. The outer wall surface 1611 and the inner wall surface 1612 face each other in the circumferential direction, and in this embodiment, also face each other in the radial direction. The outer wall surface 1611 and the inner wall surface 1612 extend at least in the axial direction and the radial direction. The outer wall surface 1611 faces at least toward the other circumferential direction Dr2, and in this embodiment, faces further radially inward. The inner wall surface 1612 is disposed closer to the other circumferential direction Dr2 than the outer wall surface 1611, and in this embodiment, is disposed further radially inward than the outer wall surface 1611. The inner wall surface 1612 faces at least toward one circumferential direction Dr1, and in this embodiment, faces further radially outward.

[0047] The first groove portion 161 further has a bottom surface 1613 facing the other axial direction Da2. The bottom surface 1613 is disposed between the outer wall surface 1611 and the inner wall surface 1612 when viewed from the axial direction, and extends at least in the radial direction.

[0048] In this embodiment, the outer wall surface 1611, the inner wall surface 1612, and the bottom surface 1613 further extend in the circumferential direction and extend radially inward toward one circumferential direction Dr1. An end portion of the outer wall surface 1611 on the radially inner side and on one circumferential direction Dr1 side is connected to a radially outer end portion of the first rotor hole 151. An end portion of the inner wall surface 1612 on the radially inner side and on one circumferential direction Dr1 side is connected to a radially inner end portion of the first rotor hole 151. An end portion of the bottom surface 1613 on the radially inner side and on one circumferential direction Dr1 side is connected to an end portion of the first rotor hole 151 on the other circumferential direction Dr2 side.

[0049] Preferably, the bottom surface 1613 extends from its end on the other circumferential side Dr2 toward the first rotor hole 151 toward the one axial side Da1. More preferably, the end of the bottom surface 1613 on the one circumferential side Dr1 and on the radially inner side is connected to the end of the first rotor hole 151 on the one axial side Da1. This allows the air flowing in from the first rotor hole 151 to flow smoothly along the bottom surface 1613. Alternatively, the bottom surface 1613 allows the air flowing near the bottom surface 1613 to flow smoothly toward the first rotor hole 151 and flow out of the first rotor hole 151. Therefore, the generation of turbulence in the first rotor hole 151 and the first groove 161 can be suppressed.

[0050] <1-1-8-2. Configuration of second groove portion 162> The second groove portion 162 has a second wall surface 1620 facing in the circumferential direction. The second wall surface 1620 is disposed at the end of the second plate portion 132 on one axial side Da1 and extends at least in the radial direction. The second wall surface 1620 is connected to the second rotor hole portion 152 and inclined toward the other circumferential side Dr2 as it extends radially inward.

[0051] The second wall surface 1620 has an outer wall surface 1621 and an inner wall surface 1622. The outer wall surface 1621 and the inner wall surface 1622 face each other in the circumferential direction and, in this embodiment, also face each other in the radial direction. The outer wall surface 1621 and the inner wall surface 1622 extend at least in the axial and radial directions. The outer wall surface 1621 faces at least one circumferential direction Dr1 and, in this embodiment, faces further radially inward. The inner wall surface 1622 is disposed on the one circumferential direction Dr1 side of the outer wall surface 1621 and, in this embodiment, is disposed further radially inward than the outer wall surface 1621. The inner wall surface 1622 faces at least the other circumferential direction Dr2 and, in this embodiment, faces further radially outward.

[0052] The second groove portion 162 further has a bottom surface 1623 facing one axial direction Da1. The bottom surface 1623 is disposed between the outer wall surface 1621 and the inner wall surface 1622 when viewed from the axial direction, and extends at least in the radial direction.

[0053] In this embodiment, the outer wall surface 1621, the inner wall surface 1622, and the bottom surface 1623 further extend in the circumferential direction and extend radially inward toward the other circumferential direction Dr2. An end portion of the outer wall surface 1621 on the radially inner side and on the other circumferential direction Dr2 side is connected to a radially outer end portion of the second rotor hole 152. An end portion of the inner wall surface 1622 on the radially inner side and on the other circumferential direction Dr2 side is connected to a radially inner end portion of the second rotor hole 152. An end portion of the bottom surface 1623 on the radially inner side and on the other circumferential direction Dr2 side is connected to an end portion of the second rotor hole 152 on one circumferential direction Dr1 side.

[0054] Preferably, the bottom surface 1623 extends from its end on one circumferential direction Dr1 side toward the second axial direction Da2 side as it moves toward the second rotor hole 152. More preferably, an end of the bottom surface 1623 on the other circumferential direction Dr2 side and radially inward is connected to an end of the second rotor hole 152 on the other axial direction Da2 side. This allows air flowing in from the second rotor hole 152 to flow smoothly along the bottom surface 1623. Alternatively, air flowing near the bottom surface 1623 can flow smoothly along the bottom surface 1623 toward the second rotor hole 152 and flow out of the second rotor hole 152. Therefore, the generation of turbulence in the second rotor hole 152 and the second groove 162 can be suppressed.

[0055] <1-1-8-3. Summary of the structure> In the present embodiment, the rotor 1 has both the first groove portion 161 and the second groove portion 162. However, without being limited to this example, the rotor 1 may have only either the first groove portion 161 or the second groove portion 162. Furthermore, the rotor 1 may be formed with a pair of first ribs having first wall surfaces 1610 instead of at least some of the first groove portions 161. In this case, the pair of first ribs are arranged spirally or radially, similar to the first groove portions 161, when viewed from the axial direction, and protrude in the other axial direction Da2 from the end face of the first plate portion 131 on the other axial direction Da2 side. Furthermore, in place of at least some of the second groove portions 162, a pair of second ribs having second wall surfaces 1620 may be formed. In this case, the pair of second ribs are arranged spirally or radially, similar to the second groove portions 162, and protrude in the one axial direction Da1 from the end face of the second plate portion 132 on the one axial direction Da1 side.

[0056] That is, the rotor 1 only needs to have at least one of the wall surfaces 160, the first wall surface 1610 and the second wall surface 1620. In other words, at least one of the plate portions 13, the first plate portion 131 and the second plate portion 132, only needs to have the wall surface 160 facing the circumferential direction. Note that the "wall surface 160" is a general term for the first wall surface 1610 and the second wall surface 1620. The wall surface 160 is disposed at the end of at least one of the plate portions 13 on the stator 2 side in the axial direction, extends at least in the radial direction, and is connected to at least one of the rotor holes 150. This allows air between the plate portion 13 and the stator 2 to flow along the wall surface 160. Therefore, air flowing in from the rotor hole 150, which functions as an intake port, can flow smoothly along the wall surface 160, thereby suppressing or preventing turbulence between the plate portion 13 and the stator 2. Alternatively, the air flowing along the wall surface 160 can be smoothly discharged from the rotor hole portion 150 which functions as an exhaust port.

[0057] More preferably, the rotor 1 has both the first wall surface 1610 and the second wall surface 1620. In other words, the wall surface 160 includes the first wall surface 1610 and the second wall surface 1620. By including both the first wall surface 1610 and the second wall surface 1620, the wall surface 160 can smoothly introduce air from outside the rotor 1 through one of the first wall surface 1610 and the second wall surface 1620, and can smoothly discharge air to outside the rotor 1 through the other. Therefore, the motor 100 can suppress or prevent the occurrence of turbulence between the first plate portion 131 and the second plate portion 132 and the stator 2, regardless of the rotation direction of the rotor 1, and can smoothly discharge air flowing along the wall surface 160 from the rotor hole 150, which functions as an exhaust port.

[0058] The wall surface 160 is inclined in the circumferential direction as it extends radially outward. This allows the wall surface 160 to have a shape that expands spirally about the central axis CX when viewed in the axial direction. This allows air to flow smoothly along the wall surface 160 in the circumferential direction relative to the rotor hole 150.

[0059] Furthermore, at least one of the plate portions 13 of the rotor 1 may have at least one of the bottom surfaces 1613 and 1623. The bottom surface is disposed at the end of at least one of the plate portions 13 on the stator 2 side in the axial direction, spreads out in the circumferential direction from the wall surface 160, and is connected to at least one of the rotor holes 150. The bottom surface inclines axially away from the stator 2 as it approaches at least one of the rotor holes 150 in the radial direction. For example, the bottom surface 1613 connected to the first rotor hole 151 spreads out in the circumferential direction from the end on one axial direction Da1 side of the first wall surface 1610 of the first plate portion 131, and inclines toward one axial direction Da1 as it approaches the first rotor hole 151 in the radial direction. Furthermore, the bottom surface 1623 connected to the second rotor hole 152 spreads in the circumferential direction from the end portion on the other axial direction Da2 side of the second wall surface 1620 of the second plate portion 132, and inclines toward the other axial direction Da2 as it approaches the second rotor hole 152 in the radial direction. This allows the air between at least one of the plate portions 13 and the stator 2 to flow smoothly toward at least one of the rotor holes 150. Alternatively, the air flowing in from at least one of the rotor holes 150 can flow smoothly between at least one of the plate portions 13 and the stator 2, thereby suppressing or preventing the occurrence of turbulence.

[0060] <1-2. Stator 2> Next, the stator 2 will be described with reference to Fig. 1 and Fig. 2. The stator 2 rotates the rotor 1 in response to power supply. The stator 2 has an annular stator core 21 that surrounds the central axis CX. As described above, the motor 100 includes the stator 2. In this embodiment, the stator core 21 is a laminated body made of stacked electromagnetic steel sheets.

[0061] The stator 2 further includes a coil portion 22 in which a conductor is disposed on the stator core 21. More specifically, the stator 2 further includes an insulator 23 having electrical insulation properties. The conductor of the coil portion 22 is wound around the stator core 21 via the insulator 23.

[0062] <1-3. Stator holder 3> Next, the stator holder 3 will be described with reference to Fig. 1 and Fig. 2. The stator holder 3 holds the stator 2. As described above, the motor 100 includes the stator holder 3. The stator holder 3 is cylindrical and extends axially around the central axis CX, and rotatably supports the shaft 10 via a bearing 30. The bearing 30 is a ball bearing in Fig. 1, but is not limited to this example and may be another type of bearing, such as a slide bearing.

[0063] The stator holder 3 has a holder base 31 and a holder tubular portion 32. The holder base 31 and the holder tubular portion 32 extend in the axial direction around the central axis CX. The holder base 31 holds the stator core 21. A portion of the stator core 21 on the other axial direction Da2 side is fixed to the radially outer end of the holder base 31. The holder tubular portion 32 is disposed radially inward of the stator core 21 and extends from the end of the holder base 31 on the one axial direction Da1 side toward the one axial direction Da1 side. The holder tubular portion 32 faces the stator 2 in the radial direction with a gap therebetween. The gap between the stator 2 and the holder tubular portion 32 allows the exposed area of ​​the stator 2 to be increased. This improves the heat dissipation efficiency of the stator 2.

[0064] <1-4. Base part 4> Next, the base portion 4 will be described with reference to FIGS. 1 and 2. The base portion 4 supports the stator holder 3. As described above, the motor 100 includes the base portion 4. The base portion 4 extends in a direction perpendicular to the axial direction and is connected to the end of the stator holder 3 on the other axial direction Da2 side. Note that in FIG. 1, the base portion 4 is connected by screws. However, this is not limiting, and other means such as adhesion or welding may be used as the means for connecting the base portion 4.

[0065] The base portion 4 has a base portion recess 41. The base portion recess 41 is arranged on the end face of the base portion 4 on one axial direction Da1 side and is recessed toward the other axial direction Da2. The base portion recess 41 is connected to the space inside the stator holder 3. The end of the shaft 10 on the other axial direction Da2 side is inserted into the base portion recess 41.

[0066] The base portion 4 also has a holder opening 42. The holder opening 42 axially penetrates the base portion 4. The holder opening 42 is disposed radially outward of the base portion recess 41. The holder opening 42 axially faces a gap between a radially inner end of the second plate portion 132 and a radially outer end of the holder base portion 31.

[0067] <1-5. Modification of the first embodiment> Next, a modified example of the first embodiment will be described with reference to Figs. 6 to 8. Fig. 6 is a cross-sectional view showing an example of the configuration of a motor 100 according to a modified example of the first embodiment. Fig. 7 is a perspective view showing the appearance of the motor 100 according to a modified example of the first embodiment. Fig. 8 is a cross-sectional view showing an example of the configuration of a stator holder 3 as viewed from the axial direction. Note that here, configurations different from the first embodiment described above will be described. Also, components similar to those in the first embodiment described above will be assigned the same reference numerals, and their description may be omitted.

[0068] <1-5-1. Rotor 1> In this modification of the first embodiment, the rotor 1 further has side holes 153 that penetrate the cylindrical portion 12 in the radial direction. That is, the holes 15 of the rotor 1 include the side holes 153. By arranging the side holes 153 in the cylindrical portion 12, air that radiates heat from the stator 2 as the rotor 1 rotates can be exhausted to the outside of the rotor 1. This allows efficient ventilation of the air between the rotor 1 and the stator 2, improving the cooling efficiency of the stator 2. Furthermore, exhausting air from the side holes 153 prevents water or dust from entering the rotor 1 through the side holes 153.

[0069] 6 and 7, the rotor 1 does not have the first rotor hole 151, the second rotor hole 152, the first groove 161, or the second groove 162. However, the rotor 1 is not limited to this example, and may have at least some of these.

[0070] The side hole portion 153 includes at least one of a first side hole portion 1531 and a second side hole portion 1532. For example, in FIGS. 6 and 7, the side hole portion 153 includes both the first side hole portion 1531 and the second side hole portion 1532. The first side hole portion 1531 penetrates the first cylindrical portion 121 in the radial direction and extends in the circumferential direction. The second side hole portion 1532 penetrates the second cylindrical portion 122 in the radial direction. In FIGS. 6 to 8, the second side hole portion 1532 is a part of the recess 1221 of the second cylindrical portion 122 and is an opening disposed between a bottom surface of the recess 1221 facing one axial direction Da1 side and an end portion of the protrusion 1411 of the rotor core 141 on the other axial direction Da2 side. In addition, in FIGS. 6 and 7, the first side hole portion 1531 and the second side hole portion 1532 are each plural and arranged in the circumferential direction. However, the present invention is not limited to this example, and at least one of the first side hole portion 1531 and the second side hole portion 1532 may be singular.

[0071] Preferably, at least a portion of the first side hole portion 1531 is located closer to the one axial direction Da1 than the stator core 21. Furthermore, at least a portion of the second side hole portion 1532 is located closer to the other axial direction Da2 than the stator core 21. More preferably, all of the first side hole portion 1531 is located closer to the one axial direction Da1 than the stator core 21. Furthermore, all of the second side hole portion 1532 is located closer to the other axial direction Da2 than the stator core 21. This allows the motor 100 to efficiently ventilate the first space 101 and / or the second space 102. For example, the motor 100 can exhaust air between the first plate portion 131 and the stator 2 to the outside of the rotor 1 through the first side hole portion 1531 due to rotation of the rotor 1. Therefore, the motor 100 can improve the heat dissipation efficiency of the portion of the stator 2 on the one axial direction Da1 side (particularly the coil head 221). Furthermore, in the motor 100, rotation of the rotor 1 allows air between the second plate portion 132 and the stator 2 to be discharged to the outside of the rotor 1 through the second side hole portion 1532. Therefore, the motor 100 can improve the heat dissipation efficiency of the portion of the stator 2 on the other axial side Da2 side (particularly the coil head 221).

[0072] The rotor 1 further has an inclined surface 111 that inclines radially outward toward one axial direction Da1. The inclined surface 111 is disposed at the end of the rotor hub 11 on the other axial direction Da2 side, and extends in the circumferential direction.

[0073] In addition, the rotor 1 further includes a rotor cover 17. The rotor cover 17 is disposed on one axial side Da1 of the first plate portion 131 and on the radially outer side, and extends radially outward from the radially outer end of the rotor hub 11.

[0074] <1-5-2. Stator holder 3> Next, the stator holder 3 further has a protrusion 33 and a holder through-hole .

[0075] The protrusion 33 extends from the end of the holder base 31 on the one axial direction Da1 side toward the one axial direction Da1 side, and protrudes radially outward from the radially outer end of the holder cylindrical portion 32. In FIG. 8, three protrusions 33 are arranged in the circumferential direction. However, without being limited to the example shown in FIG. 8, the number of protrusions 33 may be one or a plurality other than three. A portion of the stator core 21 on the one axial direction Da1 side is fixed to the radially outer end of the protrusion 33.

[0076] The holder through-hole 34 is disposed radially inward of the stator 2 and penetrates the stator holder 3 in the axial direction. As described above, the stator holder 3 has the holder through-hole 34. Specifically, the holder through-hole 34 penetrates the holder base portion 31 and the protrusion portion 33 in the axial direction. This allows the first space 101, which is located on one axial side (Da1) of the stator 2, to be connected to the second space 102, which is located on the other axial side (Da2) of the stator 2, via the holder through-hole 34. As described above, the first space 101 is the space between the stator 2 and the first plate portion 131 in the axial direction. The second space 102 is the space between the stator 2 and the second plate portion 132 in the axial direction. Increasing the number of airflow paths can further activate air circulation between the rotor 1 and the stator 2. Furthermore, since the air paths extending axially can be disposed radially inward of the stator 2, heat can be dissipated from the radially inner end of the stator 2. Therefore, the heat dissipation efficiency of the stator 2 can be improved.

[0077] An end portion on the other axial direction Da2 side of at least one holder through-hole 34 is disposed near the holder opening 42. Preferably, an end portion on the other axial direction Da2 side of at least one holder through-hole 34 overlaps with the holder opening 42 in the axial direction. However, this example does not exclude a configuration in which the end portions on the other axial direction Da2 side of all holder through-holes 34 do not overlap with the holder opening 42 in the axial direction.

[0078] Preferably, the minimum diameter of the holder through-hole 34 is smaller than the minimum diameter of the holder opening 42. By narrowing the flow path cross-sectional area of ​​the holder through-hole 34, the air flow velocity within the holder through-hole 34 can be increased. Therefore, the holder through-hole 34 can be ventilated more quickly, thereby improving the heat dissipation efficiency of the radially inner end of the stator 2. However, this example does not exclude a configuration in which the minimum diameter of the holder through-hole 34 is equal to or larger than the minimum diameter of the holder opening 42.

[0079] Furthermore, the sum of the opening areas of the ends of the holder through-holes 34 on the other axial side Da2 may be larger than the cross-sectional area occupied by the outer diameter of the holder cylindrical portion 32 as viewed in the axial direction. This allows the flow path cross-sectional area of ​​the holder through-holes 34 to be wider, thereby further activating the movement of air within the motor 100 and further improving the heat dissipation efficiency of the stator 2. However, this example does not exclude a configuration in which the above sum is equal to or smaller than the cross-sectional area occupied by the outer diameter of the holder cylindrical portion 32 as viewed in the axial direction.

[0080] Preferably, the end of the holder through-hole 34 on the one axial direction Da1 side is positioned closer to the one axial direction Da1 side than the end of the stator core 21 on the one axial direction Da1 side. This allows the end of the holder through-hole 34 on the one axial direction Da1 side to be closer to the first space 101 between the first plate portion 131 and the stator 2. Therefore, air flowing through the holder through-hole 34 can efficiently flow into the first space 101. However, this example does not exclude a configuration in which the end of the holder through-hole 34 on the one axial direction Da1 side is not positioned closer to the one axial direction Da1 side than the end of the stator core 21 on the one axial direction Da1 side.

[0081] Preferably, the end of the holder through-hole 34 on the one axial direction Da1 side faces the inclined surface 111 in the axial direction. More preferably, the entire end of the holder through-hole 34 on the one axial direction Da1 side overlaps the inclined surface 111 in the axial direction. In this way, air flowing out of the holder through-hole 34 in the axial direction flows along the inclined surface 111, and is smoothly sent to the first space 101 between the first plate portion 131 and the stator 2. Since air can easily flow from the end of the holder through-hole 34 on the one axial direction Da1 side toward the first space 101, the heat dissipation efficiency of the stator 2 can be improved. However, this example does not exclude a configuration in which the end of the holder through-hole 34 on the one axial direction Da1 side does not face the inclined surface 111 in the axial direction, and does not exclude a configuration in which, for example, the rotor 1 does not have an inclined surface 111.

[0082] Preferably, the end of the holder through-hole 34 on the other axial direction Da2 side is located closer to the other axial direction Da2 than the end of the stator core 21 on the other axial direction Da2 side. This makes it easier for air that has flowed in the other axial direction Da2 side of the stator core 21 to flow into the holder through-hole 34. However, this example does not exclude a configuration in which the end of the holder through-hole 34 on the other axial direction Da2 side is not located closer to the other axial direction Da2 side than the end of the stator core 21 on the other axial direction Da2 side.

[0083] 2. Second Embodiment Next, a second embodiment will be described with reference to FIGS. 9 to 13. FIG. 9 is a cross-sectional view showing an example of the configuration of a motor 100 according to the second embodiment. FIG. 10 is a perspective view showing the appearance of the motor 100 according to the second embodiment. FIG. 11 is a perspective view showing the end of the motor 100 according to the second embodiment on the other axial direction Da2 side. FIG. 12 is a cross-sectional view showing an example of the configuration of a motor 100 according to a modification of the second embodiment. FIG. 13 is a perspective view showing the appearance of a motor 100 according to a modification of the second embodiment. Note that, here, configurations of the second embodiment and its modifications that differ from the first embodiment and its modifications described above will be described. Furthermore, components similar to those of the first embodiment and its modifications described above will be designated by the same reference numerals, and their description may be omitted.

[0084] As shown in FIGS. 9 to 13, a motor 100 according to the second embodiment includes a rotor 1, a stator 2, and a stator holder 3.

[0085] <2-1. Rotor 1> The first plate portion 131 of the rotor 1 has a disk portion 1311 and rotary ribs 1312. The disk portion 1311 is disposed closer to one axial direction Da1 than the stator 2 and extends radially outward from the rotor hub 11. The radially outer end of the first plate portion 131 is connected to the first cylindrical portion 121. The rotary ribs 1312 extend radially outward from the radially outer end of the rotor hub 11. The radially outer end of the rotary ribs 1312 is connected to the first cylindrical portion 121. The end face on the one axial direction Da1 side of the rotary ribs 1312 is located closer to one axial direction Da1 than the end face on the one axial direction Da1 side of the disk portion 1311.

[0086] The rotor core 141 of the rotor 1 has a plurality of core pieces 1410. The core pieces 1410 are magnetic and are laminated bodies of electromagnetic steel sheets stacked in the axial direction. Each core piece 1410 is disposed on the radially inner surface of the cylindrical portion 12 and extends in the axial and circumferential directions. The plurality of core pieces 1410 are aligned in the circumferential direction and surround the central axis CX.

[0087] The hole portion 15 of the rotor 1 includes a side hole portion 153. The side hole portion 153 includes a first side hole portion 1531 and a second side hole portion 1532. The first side hole portion 1531 is a recess that is recessed from the end portion on one axial direction Da1 side of the first cylindrical portion 121 toward the other axial direction Da2 side, and penetrates the first cylindrical portion 121 in the radial direction and extends in the circumferential direction. The second side hole portion 1532 penetrates the second cylindrical portion 122 in the radial direction. The configuration of the second side hole portion 1532 in the second embodiment is similar to that of the second side hole portion 1532 in the modified example of the first embodiment (see FIGS. 6 to 8). In FIGS. 9 to 11, there are multiple first side hole portions 1531 and multiple second side hole portions 1532, and they are arranged in the circumferential direction. However, the present invention is not limited to this example, and at least one of the first side hole portion 1531 and the second side hole portion 1532 may be singular.

[0088] 9 to 11, the rotor 1 does not have the first rotor hole 151 and the second rotor hole 152 (see FIG. 1) and the first groove 161 and the second groove 162 (see FIGS. 4A and 4B). However, without being limited to the examples shown in FIGS. 9 to 11, the rotor 1 may have at least some of these. For example, as shown in FIGS. 12 and 13, the rotor 1 may have a first rotor hole 151 that axially penetrates the disk portion 1311.

[0089] <2-2. Stator holder 3> The stator holder 3 has a holder base 31, a holder tubular portion 32, and a holder through-hole 34. The holder base 31 and the holder tubular portion 32 are cylindrical and extend in the axial direction, surrounding the central axis CX. The holder base 31 holds the stator core 21. A portion of the stator core 21 on the other axial direction Da2 side is fixed to the radially outer end of the holder base 31. Further, on the other axial direction Da2 side of the stator 2, the radially outer end of the holder base 31 faces the radially inner end of the second plate portion 132 with a gap therebetween. In other words, the radially inner end of the second plate portion 132 faces the stator holder 3 with a gap therebetween. The holder tubular portion 32 is disposed radially inward of the stator core 21. The holder tubular portion 32 extends from the end of the holder base 31 on the one axial direction Da1 side to the one axial direction Da1 side. A portion of the holder cylindrical portion 32 on one axial side Da1 of the holder base portion 31 faces the stator 2 in the radial direction with a gap therebetween. The holder through-hole 34 is disposed radially inward of the stator 2 and penetrates the stator holder 3 in the axial direction.

[0090] The holder base 31 includes an inner cylindrical portion 311, an outer cylindrical portion 312, and a plurality of connecting portions 313. The inner cylindrical portion 311 and the outer cylindrical portion 312 are cylindrical and extend in the axial direction around the central axis CX. They are concentrically arranged on the other axial direction Da2 side of the holder cylindrical portion 32. An end of the inner cylindrical portion 311 on the one axial direction Da1 side is connected to the holder cylindrical portion 32. The outer cylindrical portion 312 is arranged radially outward of the inner cylindrical portion 311. A portion of the stator core 21 on the other axial direction Da2 side is fixed to a radially outer surface of the outer cylindrical portion 312. The plurality of connecting portions 313 are arranged between the inner cylindrical portion 311 and the outer cylindrical portion 312 and are aligned in the circumferential direction. The connecting portions 313 extend radially outward from the inner cylindrical portion 311. A radially outer end of the connecting portion 313 is connected to the outer cylindrical portion 312.

[0091] In this embodiment, the holder through-hole 34 is an opening surrounded by the inner cylindrical portion 311, the outer cylindrical portion 312, and the connecting portions 313 adjacent to each other in the circumferential direction, and penetrates the holder base portion 31 in the axial direction. Preferably, as shown in FIG. 11 , the sum of the opening areas of the ends of the holder through-hole 34 on the other axial direction Da2 side is larger than the cross-sectional area occupied by the outer diameter of the holder cylindrical portion 32 as viewed in the axial direction. This increases the flow path cross-sectional area of ​​the holder through-hole 34 at the end on the other axial direction Da2 side, thereby further activating air circulation within the motor 100 and further improving the heat dissipation efficiency of the stator 2. However, this example does not exclude a configuration in which the above sum is equal to or smaller than the cross-sectional area occupied by the outer diameter of the holder cylindrical portion 32 as viewed in the axial direction.

[0092] <3.Other> The embodiments of the present invention have been described above. However, the scope of the present invention is not limited to the above-described embodiments. The present invention can be implemented by adding various modifications to the above-described embodiments without departing from the spirit of the invention. Furthermore, the matters described in the above-described embodiments can be combined in any appropriate manner as long as no contradiction occurs. [Industrial Applicability]

[0093] The present invention is useful, for example, in an apparatus in which the stator generates heat in response to the rotation of the rotor. [Explanation of symbols]

[0094] 100 motor, 101 first space, 102 second space, 1 rotor, 10 shaft, 11 rotor hub, 111 inclined surface, 12 cylindrical portion, 121 first cylindrical portion, 1211 recess, 122 second cylindrical portion, 1221 recess, 13 plate portion, 131 first plate portion, 1311 disk portion, 1312 rotor rib, 132 second plate portion , 141... rotor core, 1410... core piece, 1411... convex portion, 142... magnet, 15... hole portion, 150... rotor hole portion, 151... first rotor hole portion, 152... second rotor hole portion, 153... side hole portion, 1531... first side hole portion, 1532... second side hole portion, 160... wall surface, 161... first groove portion, 162... second groove portion, 1610... first wall surface, 1 620... second wall surface, 1611, 1621... outer wall surface, 1612, 1622... inner wall surface, 1613, 1623... bottom surface, 17... rotor cover, 2... stator, 21... stator core, 22... coil portion, 221... coil head, 23... insulator, 3... stator holder 3, 30... bearing, 31... holder base portion, 311... inner cylinder portion, 312....Outer cylinder portion, 313....Connection portion, 32....Holder cylinder portion, 33....Protrusion portion, 34....Holder through hole, 4....Base portion, 41....Base portion recess, 42....Holder opening portion, 500....Aircraft, 501....Battery, 502....Propeller, CX...Central axis, Da1....One axial direction, Da2....Other axial direction, Dr1....One circumferential direction, Dr2....Other circumferential direction

Claims

1. a rotor rotatable about a central axis extending in the axial direction; a stator having an annular stator core surrounding the central axis; Equipped with The rotor is a cylindrical portion disposed radially outward of the stator and extending in an axial direction; a first plate portion that is disposed on one axial side of the stator and extends radially inward from one axial end of the cylindrical portion; a second plate portion disposed on the other axial side of the stator and extending radially inward from the other axial end of the cylindrical portion; a hole portion penetrating at least one of the cylindrical portion, the first plate portion, and the second plate portion; and the hole portion includes at least one of a first rotor hole portion that penetrates the first plate portion in the axial direction and a second rotor hole portion that penetrates the second plate portion in the axial direction, At least one of the first plate portion and the second plate portion has a groove portion and a wall surface facing in a circumferential direction, the groove portion and the wall surface are disposed at an end portion of at least one of the plate portions on the stator side in the axial direction, extend at least in the radial direction, and are connected to at least one of the rotor hole portions; The wall surface is an inner surface of the groove portion.

2. the stator further includes a coil portion in which a conductor is disposed in the stator core, The motor according to claim 1 , wherein at least one of the rotor hole portions overlaps with the coil portion when viewed in the axial direction.

3. At least one of the rotor holes is disposed radially inward of the cylindrical portion, The motor according to claim 1 or 2, wherein the hole further includes a side hole that penetrates the cylindrical portion in a radial direction.

4. The motor according to claim 3 , wherein at least a portion of the side hole portion is disposed axially closer to the at least one of the rotor holes than the stator.

5. a rotor rotatable about a central axis extending in the axial direction; a stator having an annular stator core surrounding the central axis; a stator holder that holds the stator; Equipped with The rotor is a cylindrical portion disposed radially outward of the stator and extending in an axial direction; a first plate portion that is disposed on one axial side of the stator and extends radially inward from one axial end of the cylindrical portion; a second plate portion disposed on the other axial side of the stator and extending radially inward from the other axial end of the cylindrical portion; a hole portion penetrating at least one of the cylindrical portion, the first plate portion, and the second plate portion; and The stator holder includes: a holder base portion for holding the stator core; a holder cylindrical portion extending from the holder base portion to one side in the axial direction; a holder through-hole that is disposed radially inward of the stator and radially outward of the holder cylindrical portion and that penetrates the stator holder in the axial direction; A motor having

6. The motor according to claim 5 , wherein a total opening area of ​​the other axial end of the holder through-hole is larger than a cross-sectional area occupied by an outer diameter of the holder cylindrical portion as viewed in the axial direction.

7. the hole portion includes at least one of a first rotor hole portion that penetrates the first plate portion in the axial direction and a second rotor hole portion that penetrates the second plate portion in the axial direction, At least one of the first plate portion and the second plate portion has a wall surface facing in a circumferential direction, 7. The motor according to claim 5, wherein the wall surface is disposed at an axial end of at least one of the plate portions on the stator side, extends at least in the radial direction, and is connected to at least one of the rotor hole portions.

8. The motor according to claim 1 , wherein the wall surface is inclined in the circumferential direction as it extends radially outward.

9. At least one of the plate portions has a bottom surface facing the axial direction, 5. The motor according to claim 1, wherein the bottom surface is positioned at an end of at least one of the plate portions on the stator side in the axial direction, extends circumferentially from the wall surface, connects to at least one of the rotor hole portions, and inclines axially toward the opposite side from the stator as it approaches at least one of the rotor hole portions in the radial direction, and forms the groove portion together with the wall surface.

10. the holes include the first rotor hole and the second rotor hole, The wall surface is a first wall surface disposed at the other axial end of the first plate portion, extending at least in the radial direction, connected to the first rotor hole portion, and inclined toward one circumferential side as it extends radially inward; a second wall surface disposed at one axial end of the second plate portion, extending at least in the radial direction, connected to the second rotor hole portion, and inclined toward the other circumferential side as it extends radially inward; 10. The motor according to any one of claims 1 to 4 and claims 8 to 9, comprising:

11. a rotor rotatable about a central axis extending in the axial direction; a stator having an annular stator core surrounding the central axis; Equipped with The rotor is a cylindrical portion disposed radially outward of the stator and extending in an axial direction; a first plate portion that is disposed on one axial side of the stator and extends radially inward from one axial end of the cylindrical portion; a second plate portion disposed on the other axial side of the stator and extending radially inward from the other axial end of the cylindrical portion; a hole portion penetrating at least one of the cylindrical portion, the first plate portion, and the second plate portion; and the hole portion includes a first rotor hole portion that penetrates the first plate portion in the axial direction and a second rotor hole portion that penetrates the second plate portion in the axial direction, The first plate portion and the second plate portion have wall surfaces facing in a circumferential direction, The wall surface is a first wall surface disposed at the other axial end of the first plate portion, extending at least in the radial direction, connected to the first rotor hole portion, and inclined toward one circumferential side as it extends radially inward; a second wall surface disposed at one axial end of the second plate portion, extending at least in the radial direction, connected to the second rotor hole portion, and inclined toward the other circumferential side as it extends radially inward; Including, a motor.

12. An aircraft comprising a motor according to any one of claims 1 to 11.

Images