Motor

Abstract

To provide a motor in which a heat dissipation member can be replaced according to an output.SOLUTION: A motor 1 includes a stator 39 having a magnetic body 37 having a plurality of magnetic pole portions 46 and a plurality of coils 38 wound around the magnetic body 37, a rotor 26, and a heat dissipation member 47 that is in direct contact with one end 38a (38b) of the coil 38 in a rotation axis direction of the rotor 26 or in contact with the one end via an another member (54). The heat dissipation member 47 is disposed so as to be attachable to and detachable from the stator 39.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] In a motor, when a current is supplied to a coil, the coil generates heat. Patent Document 1 discloses a motor having a heat sink for dissipating the heat generated by the coil. The heat sink is sandwiched and fixed between the yoke and the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-143205 A Summary of the Invention [Problem to be solved by the invention]

[0004] The current value supplied to the coil is determined according to the motor's output. When the output is large, the amount of heat generated also increases. There is a demand for the size of the heat sink to be able to be changed according to the increase or decrease in the output or amount of heat generated.

[0005] Therefore, an object of the present invention is to provide a motor in which the heat dissipation member can be replaced according to the output. [Means for solving the problem]

[0006] A motor according to one embodiment of the present invention comprises a stator having a magnetic body having a plurality of magnetic pole portions and a plurality of coils wound around the magnetic body, a rotor, and a heat dissipation member that contacts one end of the coil in the direction of the rotational axis of the rotor directly or via another member, and the heat dissipation member is arranged so as to be detachable from the stator. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view showing a schematic structure of a motor 1 according to an embodiment of the present invention. [Diagram 2] 2 is a vertical cross-sectional view of the motor 1 taken along line 2-2 of FIG. [Diagram 3] 1 is a perspective view of the motor 1 from above with the upper cover 14 removed. [Figure 4] FIG. 4 is a perspective cross-sectional view taken along line 4-4 in FIG. [Diagram 5] FIG. 4 is an exploded perspective view of the motor 1 of FIG. [Figure 6] 6 is a cross-sectional view of the motor 1 taken along line 6-6 in FIG. 4. [Figure 7] 13 is a perspective view of the motor 1, illustrating a schematic structure of a heat dissipation member 47 according to one modified example. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An embodiment of the present invention will be described below with reference to the accompanying drawings. Fig. 1 and Fig. 2 are perspective views that show a schematic structure of a motor 1 according to an embodiment of the present invention. Fig. 1 is a perspective view of the motor 1 as seen from one side, that is, the upper side, in a direction (hereinafter referred to as the "rotation axis direction") along a rotation axis (hereinafter referred to as the "axis line") x that constitutes the rotation axis of the motor 1. Fig. 2 is a cross-sectional view of the motor 1 taken along line 2-2 in Fig. 1. This cross-sectional view is a vertical cross-sectional view taken along an imaginary plane including the axis x.

[0009] In the following description of this embodiment, the upper and lower sides defined in the direction of the rotation axis do not necessarily correspond to the upper and lower relationship in the direction of gravity. In addition, the radial direction of the motor 1 is defined in a direction perpendicular to the axis x. In this radial direction, the side away from the axis x is defined as the outer circumferential side, while the direction approaching the axis x is defined as the inner circumferential side. Furthermore, the circumferential direction of the motor 1 is defined around the axis x. In this circumferential direction, clockwise and counterclockwise directions are defined around the axis x when the motor 1 is viewed from above.

[0010] 1 and 2, the motor 1 includes, for example, a cylindrical shaft 10 with an axis x as its central axis. In this example, the upper and lower ends of the shaft 10 along the axis x are open. Two bearings 11, 12 are attached to the outer circumferential surface of the shaft 10 along the direction of the rotation axis. The bearings 11, 12 are, for example, ball bearings. The bearings 11, 12 are attached to the shaft 10 by, for example, press fitting, clearance fit, or the like. The motor 1 includes a housing 13 supported by the bearings 11, 12 for rotation around the axis x. The housing 13 includes an upper cover 14 supported by the upper bearing 11 and a lower cover 15 supported by the lower bearing 12.

[0011] The upper cover 14 has an inner cylindrical portion (hereinafter referred to as the "inner portion") 16, a portion (hereinafter referred to as the "annular portion") 17 extending in an annular shape from the inner portion 16 to the outer peripheral side, and an outer cylindrical portion (hereinafter referred to as the "outer portion") 18 extending downward from the outer peripheral end of the annular portion 17. The annular portion 17 extends in a flat plate shape along an imaginary plane perpendicular to the axis x, for example. The inner portion 16 protrudes cylindrically upward from the annular portion 17. The upper end of the inner portion 16 is closed.

[0012] The lower cover 15 has an inner cylindrical portion (hereinafter referred to as the "inner portion") 20, a portion (hereinafter referred to as the "annular portion") 21 extending from the inner portion 20 to the outer peripheral side in an annular shape, and an outer cylindrical portion (hereinafter referred to as the "outer portion") 22 extending upward from the outer peripheral end of the annular portion 21. The inner portion 20 has a circular opening 23 formed around the axis x. The shaft 10 described above passes through the opening 23 of the inner portion 20 and protrudes downward from the lower cover 15 along the axis x. The annular portion 21 extends in a flat plate shape along a virtual plane perpendicular to the axis x, for example. The upper cover 14 and the lower cover 15 are formed of, for example, a resin material or a metal material.

[0013] A cylindrical yoke 24 is sandwiched and fixed between the outer periphery 18 of the upper cover 14 and the outer periphery 22 of the lower cover 15. The yoke 24 is formed, for example, from a magnetic material. A cylindrical magnet 25 is fixed to the inner periphery of the yoke 24. The magnet 25 is attached to the inner periphery of the yoke 24 by, for example, an adhesive or the like. The magnet 25 is formed, for example, from a permanent magnet. The yoke 24 and the magnet 25 form a rotor 26 in the motor 1. In other words, the motor 1 is an outer rotor type motor. The magnet 25 may be a single cylindrical permanent magnet, or may be formed into a cylindrical shape by connecting multiple permanent magnets in the circumferential direction.

[0014] A plurality of protrusions 27 and a plurality of protrusions 28 protruding outward are formed on the outer peripheral surfaces of the outer peripheral portion 18 and the outer peripheral portion 22, respectively. In this example, for example, six protrusions 27 and six protrusions 28 are arranged at equal intervals in the circumferential direction. The positions of the protrusions 27 and the protrusions 28 about the axis x are defined to be the same. A through hole 29 is formed in each of the protrusions 27 along the axis x, while a screw hole 30 is formed in each of the protrusions 28 along the axis x. A fastening part, i.e., a screw 31 is screwed into the screw hole 30 through the through hole 29, thereby joining the upper cover 14 and the lower cover 15 to each other. In this manner, the interior space of the motor 1 is sealed by the housing 13 and the yoke 24.

[0015] A base 32 is fixed to the lower end of the shaft 10 below the lower bearing 12 in the direction of the rotation axis. The base 32 has a cylindrical portion (hereinafter referred to as the "support portion") 33 supported by the outer circumferential surface of the shaft 10, and a portion (hereinafter referred to as the "flange portion") 34 extending in an annular shape from the lower end of the support portion 33 to the outer circumferential side. The support portion 33 and the flange portion 34 are formed by integral molding of a resin material, for example. The flange portion 34 has a plurality of screw holes 35 formed, for example, parallel to the axis x. Fastening parts such as screws for attaching the motor 1 to an unmanned aerial vehicle such as a drone are screwed into the screw holes 35.

[0016] FIG. 3 is a perspective view of the motor 1 from above with the upper cover 14 removed. FIG. 4 is a perspective cross-sectional view taken along line 4-4 in FIG. 1. The cross-section of this perspective cross-sectional view is a horizontal cross-section taken along a virtual plane perpendicular to the axis x. Referring to FIGS. 2 to 4 together, the motor 1 includes a holder 36 attached to the shaft 10 between the two bearings 11 and 12, a magnetic body, i.e., a stator core 37, attached to the outer circumferential surface of the holder 36, and a plurality of coils 38 wound around the stator core 37. The holder 36, the stator core 37, and the coils 38 form a stator 39 of the motor 1.

[0017] The holder 36 has an annular portion (hereinafter referred to as the "mounting portion") 40 attached to the outer circumferential surface of the shaft 10, an annular portion (hereinafter referred to as the "supporting portion") 41 arranged on the outer circumferential side of the mounting portion 40 and supporting the stator core 37, and a plurality of (e.g., eight) connection portions 42 connecting the mounting portion 40 and the support portion 41 to each other. The mounting portion 40 is, for example, press-fitted into the outer circumferential surface of the holder 36. Each connection portion 42 extends in the radial direction. In this example, the connection portions 42 are arranged at equal intervals in the circumferential direction. The stator core 37 is attached to the outer circumferential surface of the support portion 41. The holder 36 is formed from, for example, a metal material such as aluminum or a resin material.

[0018] The stator core 37 is formed of a laminate of magnetic materials such as silicon steel plates. The stator core 37 functions as a yoke for a stator 39. As is clear from FIG. 4, the stator core 37 has a cylindrical portion (hereinafter referred to as a "cylindrical portion") 43 and a plurality of (e.g., 24) teeth 44 extending from the outer circumferential surface of the cylindrical portion 43 to the outer circumferential side. Each tooth 44 has a spoke 45 connected at its inner circumferential end to the outer circumferential surface of the cylindrical portion 43, and a magnetic pole portion 46 continuing to the outer circumferential end of the spoke 45. The outer circumferential surface of the magnetic pole portion 46 faces the inner circumferential surface of the magnet 25 with a predetermined magnetic gap.

[0019] A coil 38 is wound around each spoke 45. The winding axis of the coil 38 is in the radial direction. An insulator (not shown) is disposed between the spoke 45 and the coil 38. The insulator insulates the stator core 37 from the coil 38. In this example, the magnet 25 has an S-pole region 25a magnetized to an S pole and an N-pole region 25b magnetized to an N pole. The S-pole region 25a and the N-pole region 25b are alternately arranged in the circumferential direction. In this way, a region where the magnetic pole changes is defined between the S-pole region 25a and the N-pole region 25b. When a current is supplied to the coil 38, the rotor 26 and the housing 13 rotate around the axis x, for example, clockwise or counterclockwise, due to interaction with the magnetic field generated by the magnet 25.

[0020] FIG. 5 is an exploded perspective view of the motor 1 of FIG. 3. Referring to FIGS. 2, 3 and 5 together, the motor 1 includes at least one heat dissipation member 47 that contacts one of the ends 38a, 38b of the coil 38 in the rotation axis direction. The ends 38a and 38b correspond to the upper and lower surfaces of the coil 38. In this example, the heat dissipation member 47 contacts both ends 38a, 38b of the coil 38, respectively. Each heat dissipation member 47 has an annular main body 48 and one or more (for example, four) protruding pieces 49 that protrude from the inner peripheral end of the main body 48 to the inner peripheral side. The protruding pieces 49 are arranged at equal intervals in the circumferential direction. Each protruding piece 49 has a through hole 50 that penetrates the protruding piece 49 in a direction parallel to the axis x.

[0021] One or more portions (hereinafter referred to as "mounting portions") 51 extending parallel to the axis x are formed on the inner peripheral surface of the support portion 41 of the holder 36. In this example, four mounting portions 51 are formed at positions corresponding to the protrusions 49 of the heat dissipation member 47. Each mounting portion 51 has a through hole 52 extending parallel to the axis x. A thread groove (not shown) is cut on the inner peripheral surface of the through hole 52. As shown in Figures 2 and 5, a fastening part, i.e., a screw 53 is screwed into the through hole 52 through the through hole 50 of the protrusion 49, whereby the heat dissipation member 47 is attached to the holder 36.

[0022] In this example, the lower surface of the main body 48 of the upper heat dissipation member 47 is in contact with or faces the end 38a of the coil 38, while the upper surface of the main body 48 of the lower heat dissipation member 47 is in contact with or faces the end 38b of the coil 38. As is clear from FIG. 2, the upper surface of the main body 48 of the upper heat dissipation member 47 faces the inner surface of the annular portion 17 of the upper cover 14 with a predetermined gap therebetween. On the other hand, the lower surface of the main body 48 of the lower heat dissipation member 47 faces the inner surface of the annular portion 21 of the lower cover 15 with a predetermined gap therebetween. The outer peripheral end of each main body 48 faces the outer peripheral side, that is, faces the inner peripheral surface of the outer peripheral portion 18 of the upper cover 14 and the inner peripheral surface of the outer peripheral portion 22 of the lower cover 15, respectively. The two heat dissipation members 47, 47 have the same shape and are arranged in the motor 1 so as to be plane symmetrical with respect to a virtual plane perpendicular to the axis x.

[0023] Between the heat dissipation member 47 and the ends 38a, 38b of the coil 38, another member, i.e., heat dissipation resin 54, is sandwiched. The heat dissipation resin 54 is, for example, clay-like or grease-like, and is a thermally conductive material that has fluidity and can retain its shape by itself. The heat dissipation resin 54 is formed from a resin material such as EPDM or silicone. The heat dissipation resin 54 can change its shape according to the outer shapes of the coil 38 and the heat dissipation member 47. As a result, the heat dissipation resin 54 can contact the coil 38 and the heat dissipation member 47 without any gaps. In this example, the heat dissipation resin 54 is arranged in a ring shape continuously in the circumferential direction between the coil 38 and the heat dissipation member 47.

[0024] FIG. 6 is a cross-sectional view of the motor 1 taken along line 6-6 in FIG. 4. This cross-sectional view is a vertical cross-sectional view taken along a virtual plane parallel to the axis x. As shown in FIGS. 3, 5, and 6, one or more recesses, i.e., grooves 55, are formed on the upper surface of the main body 48 of the heat dissipation member 47 in the direction of the rotation axis. Each groove 55 extends in the radial direction. Since the main body 48 is formed in a flat plate shape, the grooves 55 on the upper surface of the main body 48 form protrusions 56, which are convex portions, i.e., thin protruding portions, on the lower surface of the main body 48 in correspondence with the grooves 55. Each protrusion 56 extends in the radial direction. In this example, the heat dissipation member 47 is formed by pressing a metal material such as aluminum, iron, or copper. That is, the grooves 55 and the protrusions 56 are simultaneously formed in the main body 48 by pressing.

[0025] As is clear from FIG. 6, in a plan view, the positions of the grooves 55 and the ridges 56 in the circumferential direction correspond to the positions of the boundary positions 57 between the coils 38, 38 adjacent to each other in the circumferential direction. The boundary positions 57 are, for example, boundary surfaces between the coils 38, 38 defined along an imaginary plane including the axis x. Since the coils 38 are wound around the spokes 45, radially extending grooves 58 are formed on the upper and lower sides between the coils 38, 38 in the cross section shown in FIG. 6. Each groove 55 of the heat dissipation member 47 is disposed along this groove 58. In this example, as shown in FIG. 2, the outer peripheral end of the main body 48 of the heat dissipation member 47 extends in the radial direction to approximately the same position as the outer peripheral end of the coil 38.

[0026] When assembling the motor 1, before the heat dissipation member 47 is attached to the holder 36, the heat dissipation resin 54 is applied to the ends 38a, 38b of the coil 38. Then, the heat dissipation member 47 is attached to the holder 36 using the screws 53. At this time, the main body 48 of the heat dissipation member 47 is pressed against the ends 38a, 38b of the coil 38. As a result, the heat dissipation resin 54 can change its shape between the main body 48 and the coil 38 due to its own fluidity. Specifically, as shown in FIG. 6, the protrusions 56 of the heat dissipation member 47 can bite into the upper surface of the heat dissipation resin 54. In this way, the heat dissipation resin 54 can be reliably attached to the main body 48 and the coil 38 according to the shapes of the main body 48 and the coil 38.

[0027] In the motor 1 as described above, when a current is supplied to the coil 38, the coil 38 generates heat. The heat of the coil 38 is transferred to the heat dissipation member 47 through the heat dissipation resin 54. The transferred heat is released from the main body 48 of the heat dissipation member 47 into the space within the housing 13. This makes it possible to prevent the coil 38 from excessively increasing in temperature. The heat dissipation member 47 is detachably attached to the holder 36 with the screws 53. Therefore, for example, when the magnitude of the current supplied to the coil 38 is changed in accordance with the output of the motor 1, the heat dissipation member 47 can be replaced with one having a different size, i.e., a different surface area, in accordance with the change. As a result, the heat dissipation member 47 having the minimum necessary surface area can be used, thereby making it possible to reduce the weight of the motor 1.

[0028] Moreover, the main body 48 of the heat dissipation member 47 has grooves 55 and ridges 56 extending in the radial direction, for example. The surface area of ​​the main body 48 is increased by forming these grooves 55 and ridges 56. Therefore, the heat dissipation performance of the heat dissipation member 47 can be improved. The positions of the grooves 55 and ridges 56 in the circumferential direction coincide with the positions of the grooves 58 at the boundary positions 57 between the adjacent coils 38, 38. With this configuration, the main body 48 can be in contact with the coils 38 with sufficient tightness, and the heat dissipation member 47 can dissipate the heat of the coils 38 more efficiently. Furthermore, the heat is also transferred to the holder 36 via the protrusions 49 of the heat dissipation member 47 and the stator core 37. The transferred heat is released from the holder 36 to the space in the housing 13, and the heat dissipation performance can be further improved.

[0029] FIG. 7 corresponds to FIG. 3 and is a perspective view of the motor 1, which shows a schematic structure of a heat dissipation member 47 according to one modification. As shown in FIG. 7, in the heat dissipation member 47 according to one modification, the main body 48 may have flat upper and lower surfaces. That is, the grooves 55 and the protrusions 56 are not formed in the main body 48. In other words, the heat dissipation member 47 contacts the heat dissipation resin 54 at its flat lower surface. Since the shape of the heat dissipation member 47 is simpler than that of the heat dissipation member 47 having the grooves 55 and the protrusions 56, the heat dissipation member 47 can be manufactured more easily and at a reduced manufacturing cost.

[0030] In the motor 1 as described above, the incorporation of the heat dissipating resin 54 may be omitted. That is, the heat dissipating member 47 may be in direct contact with the ends 38a, 38b of the coil 38, not via the heat dissipating resin 54. In this case, the body 48 of the heat dissipating member 47 may have a shape that conforms to the shape of the ends 38a, 38b of the coil 38. Also, a gap is formed between the upper surface of the upper heat dissipating member 47 and the lower surface of the lower heat dissipating member 47 and the inner surfaces of the upper cover 14 and the lower cover 15 of the housing 13. Therefore, for example, a convex portion can be further formed on the upper surface of the upper heat dissipating member 47 and the lower surface of the lower heat dissipating member 47. The surface area of ​​the heat dissipating member 47 can be further increased by the convex portion.

[0031] Although the present invention has been described above through the above embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications or improvements can be made to the above embodiments. It is clear from the claims that such modifications or improvements can also be included in the technical scope of the present invention.

[0032] The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The components of the above-described embodiments, as well as their arrangements, materials, conditions, shapes, sizes, etc., are not limited to those illustrated, and can be modified as appropriate. Furthermore, components shown in different embodiments can be partially substituted or combined with each other within the scope of technical inconsistency. [Explanation of symbols]

[0033] 1 motor, 10 shaft, 11 bearing, 12 bearing, 13 housing, 14 upper cover, 15 lower cover, 16 portion (inner circumference), 17 portion (annular portion), 18 portion (outer circumference), 20 portion (inner circumference), 21 portion (annular portion), 22 portion (outer circumference), 23 opening, 24 yoke, 25 magnet, 25a south pole area, 25b north pole area, 26 rotor, 27 protrusion, 28 protrusion, 29 through hole, 30 screw hole, 31 screw (fastening part), 32 base, 33 portion (support portion), 34 portion (flange portion), 35 screw hole, 36 holder, 37 stator core (magnetic material), 38 coil, 38a end, 38b end, 39 stator, 40 portion (mounting portion), 41 part (support part), 42 connection part, 43 part (cylindrical part), 44 teeth, 45 spokes, 46 magnetic pole part, 47 heat dissipation member, 48 main body part, 49 protrusion, 50 through hole, 51 part (mounting part), 52 through hole, 53 screw (fastening part), 54 heat dissipation resin, 55 groove (recess), 56 protrusion (protrusion), 57 boundary position, 58 groove, x rotation axis (axis)

Claims

1. a stator including a magnetic body having a plurality of magnetic pole portions and a plurality of coils wound around the magnetic body; A rotor, a heat dissipation member that is in contact with one end of the coil in the rotation axis direction of the rotor directly or via another member, The heat dissipation member is disposed detachably relative to the stator.

2. The motor according to claim 1 , wherein the heat dissipation member contacts both ends of the coil in the rotation axis direction directly or via another member.

3. The rotor includes a housing that defines a space for accommodating the stator. The motor according to claim 1 , wherein the heat dissipation member faces an inner surface of the housing in a direction along the rotation axis of the rotor.

4. 4. The motor according to claim 1, wherein a winding axis of the coil is aligned in a radial direction of the rotor.

5. The motor according to claim 1 , wherein an outer circumferential end of the heat dissipation member faces an outer circumferential side in a radial direction of the rotor.

6. The motor according to claim 1 , wherein the other member is a heat dissipating resin.

7. The motor according to claim 1 , wherein a concave or convex portion is formed on a surface of the heat dissipation member in the axial direction of the rotor.

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