JP7275429B2 - motor - Google Patents

Description

The present invention relates to motors.

Conventionally, an outer rotor type motor is known. An outer rotor type motor has a rotating part having a magnet and a stationary part having a stator core. The magnet is arranged radially outside the stator core. For example, in the motor of Patent Document 1, the rotor yoke surrounds the stator and is rotatably supported by a bearing device.

JP-A-2000-189893

When a motor is used in an external environment, iron sand and dust contained in sand may enter the equipment. In Patent Literature 1, by providing a cover that covers the rotor, iron sand is prevented from being attracted to magnets, and dust enters gaps that cause malfunctions. However, providing the cover increases the size and weight of the motor.

Also, if the housing, which is a part of the bearing device, is a conductor, the lead wire of the coil may come into contact with the housing and short-circuit. As an alternative technique, contact between the lead wire and the housing can be suppressed by using a tangling pin for connection between the lead wire and the substrate. However, the use of tie pins increases the size and weight of the motor.

In view of the above points, it is an object of the present invention to provide a motor capable of preventing iron sand and dust from entering equipment without increasing the size of the motor.

Another object of the present invention is to provide a motor capable of preventing the lead wires of the coils from coming into contact with the housing by an easy assembly method without increasing the size of the motor.

An exemplary motor of the present invention has a rotating portion, a stationary portion, and a bearing. The rotating part has a shaft extending axially around a central axis extending vertically. The stationary part is arranged inside the rotating part and has a stator. A bearing supports the shaft. The rotating part has a rotor yoke and a magnet. The rotor yoke is magnetic and has a cylindrical shape. The magnet is fixed to the inner peripheral surface of the rotor yoke and faces the stator in the radial direction. The rotor yoke has a wall and a tip. The wall portion extends radially inward from the inner peripheral surface of the rotor yoke and faces the magnet in the axial direction. The tip extends axially below the wall.

An exemplary motor of the present invention has a rotating portion, a stationary portion, and a bearing. The rotating part has a shaft extending axially around a central axis extending vertically. The stationary part is arranged inside the rotating part and has a stator. A bearing supports the shaft. The rotating part has a rotor yoke and a magnet. The tubular rotor yoke is a magnetic material. The magnet is fixed to the inner peripheral surface of the rotor yoke and faces the stator in the radial direction. The stationary portion has a bracket, a bearing housing and a base plate. The bracket is positioned axially below the stator and extends radially. A bearing housing is disposed radially inward of the stator and extends axially. The substrate is arranged axially between the stator and the bracket. The stator has a plurality of coils with lead wires electrically connected to the substrate. The bearing housing has an insulating member radially opposed to the lead wire and arranged along the outer peripheral portion of the bearing housing.

According to the exemplary motor of the present invention, it is possible to prevent iron sand and dust from entering the equipment without increasing the size of the motor.

According to the exemplary motor of the present invention, it is possible to prevent the lead wire of the coil from coming into contact with the bearing housing by a simple assembly method without increasing the size of the motor.

FIG. 1 is a longitudinal sectional view of a motor according to a first embodiment of the invention. FIG. 2 is a partial cross-sectional view showing an enlarged part of the motor according to the first embodiment of the present invention. FIG. 3 is a partial cross-sectional view showing an enlarged part of the motor according to the second embodiment of the invention. FIG. 4 is a longitudinal sectional view of a motor according to a third embodiment of the invention. FIG. 5 is a partial cross-sectional view showing an enlarged part of a motor according to a third embodiment of the invention. FIG. 6 is a partial cross-sectional view showing an enlarged part of a motor according to a fourth embodiment of the invention. FIG. 7 is a plan view showing a substrate and a bracket according to the fifth embodiment of the invention. FIG. 8 is a partial cross-sectional view showing an enlarged part of a motor according to a fifth embodiment of the invention. FIG. 9 is a partial cross-sectional view showing an enlarged part of the motor according to the sixth embodiment of the present invention. FIG. 10 is a schematic perspective view showing the appearance of the unmanned airplane main body of the present invention.

Exemplary embodiments of the invention are described in detail below with reference to the drawings. In this manual, the direction in which the central axis of the motor extends is simply referred to as the "axial direction," and the direction perpendicular to the central axis of the motor as the center is simply referred to as the "radial direction." is simply referred to as the "circumferential direction". Further, in this document, for convenience of explanation, the axial direction is defined as the vertical direction, and the vertical direction in FIG. 1 is defined as the vertical direction of the motor. It should be noted that this definition of the vertical direction does not limit the orientation and positional relationship of the motor when it is in use.

FIG. 1 is a longitudinal sectional view of a motor 1 according to a first embodiment of the invention. The motor 1 is an outer rotor type motor, and is mounted on, for example, a small unmanned airplane shown in FIG. 10 to rotate the rotor blades. Note that the motor 1 may be used for applications other than the unmanned airplane. For example, the motor 1 may be mounted on transport machines such as automobiles and railways, OA equipment, medical equipment, tools, large-scale industrial equipment, and the like to generate various driving forces.

The motor 1 has a rotating portion 2 , a stationary portion 3 and bearings 4 . The stationary part 3 is arranged inside the rotating part 2 . The rotating part 2 rotates around a vertically extending central axis C and has a shaft 5 extending in the axial direction. Bearing 4 supports shaft 5 . The bearings 4 are arranged as a pair vertically in the axial direction. In this embodiment, the bearing 4 is configured by a ball bearing, but may be configured by a sleeve bearing or the like.

The rotating portion 2 has a shaft 5 , a rotor yoke 6 , a lid portion 7 and magnets 8 . The rotor yoke 6 is made of a magnetic material and is a cylindrical body extending in the axial direction. A detailed configuration of the rotor yoke 6 will be described later.

The magnet 8 is fixed to the inner peripheral surface 61 of the rotor yoke 6 and faces the stator 9 in the radial direction. That is, the magnet 8 is arranged radially outside the stator 9 . The magnet 8 is fixed to the inner peripheral surface 61 with an adhesive, for example. In this embodiment, the magnet 8 is formed of a plurality of plate-like magnets 8 . In the plurality of magnets 8, magnetic pole faces of N poles and magnetic pole faces of S poles are arranged alternately. The plurality of magnets 8 are arranged at regular intervals in the circumferential direction. A single ring-shaped magnet may be used instead of the plurality of magnets 8 . In this case, the inner peripheral surface of the magnet may be alternately magnetized with N poles and S poles in the circumferential direction.

The lid portion 7 is connected to the upper end of the rotor yoke 6 and covers the upper end of the rotor yoke 6 . The lid portion 7 has a radially extending top surface portion 71 , a plurality of ribs 72 extending downward from the radially outer end portion of the top surface portion 71 , and a through hole 73 penetrating through the center of the top surface portion 71 . . Magnets 8 are arranged between adjacent ribs 72 . In this embodiment, the upper portion of the shaft 5 is fitted into the through hole 73 and fixed. For example, a rotor blade of an unmanned aerial vehicle is fixed to a mounting portion 51 of the shaft 5 extending axially upward from the lid portion 7 .

The stationary part 3 has a stator 9 , a bracket 10 , a bearing housing 11 and a substrate 12 . The motor 1 is fixed to a chassis of an unmanned airplane or the like via a bracket 10 .

The stator 9 is arranged radially inside the magnet 8 . The stator 9 is fixed to the outer peripheral portion of the bearing housing 11 . The stator 9 has a stator core 91 and multiple coils 92 . The stator core 91 is made of laminated steel plates in which electromagnetic steel plates are laminated in the axial direction, and has a core back 911 and a plurality of teeth 912 .

The core back 911 is formed in an annular shape extending in the axial direction. A plurality of teeth 912 radially extend radially outward from the outer peripheral surface of core back 911 toward magnet 8 . Thereby, a plurality of teeth 912 are arranged in the circumferential direction. The coil 92 is formed by winding a conductive wire around each tooth 912 .

The bracket 10 is arranged axially below the stator 9 and extends radially. Bracket 10 has a central portion 101 and edge portions 102 . The central portion 101 faces the stator 9 in the axial direction. The edge portion 102 is arranged radially outside the central portion 101 . The upper end of the central portion 101 is located axially above the upper end of the edge portion 102 . That is, the bracket 10 is stepped radially outward.

The bearing housing 11 is arranged radially inside the stator 9 . The bearing housing 11 has a tubular shape extending in the axial direction. The bearing 4 is held inside a bearing housing 11 . Furthermore, the shaft 5 is supported by bearings 4 . In this embodiment, the bracket 10 and the bearing housing 11 are integrally formed. Note that the bracket 10 and the bearing housing 11 may be formed separately.

The substrate 12 is arranged axially below the stator 9 . That is, the substrate 12 is arranged axially between the stator 9 and the bracket 10 . A lead wire 13 of the coil 92 is electrically connected to the substrate 12 . An electronic circuit (not shown) for supplying drive current to the coil 92 is mounted on the substrate 12 . When a drive current is supplied to coil 92 , magnetic flux is generated in teeth 912 . Circumferential torque is generated by the action of the magnetic flux between the teeth 912 and the magnet 8 . As a result, the rotating part 2 rotates about the central axis C with respect to the stationary part 3, and the rotating operation of the motor 1 is started.

Coil 92 has lead wire 13 electrically connected to substrate 12 . The lead wire 13 radially faces a portion of the bearing housing 11 . The lead wire 13 is, for example, a copper wire.

The bracket 10 has a bracket mounting portion 104 and a board insertion hole 105 . The bracket 10 has at least two bracket attachment portions 104 . The bracket mounting portion 104 axially faces at least a portion of the stator 9 and axially penetrates the bracket 10 . Bracket mounting portion 104 is, for example, a hole into which a screw can be inserted. The motor 1 is fixed to the main body of the unmanned airplane by screwing it with a bracket mounting portion 104 . The substrate insertion hole 105 axially penetrates the bracket 10 on the radially outer side. The board insertion hole 105 is a hole through which a part of the board 12 passes.

A portion of the bearing housing 11 radially faces the lead wire 13 . The bearing housing 11 is a conductor. For example, the bearing housing 11 is a metal material such as aluminum alloy or stainless steel. The bearing housing 11 also has an insulating member 14 . The insulating member 14 is arranged along the outer periphery of the bearing housing 11 . For example, the insulating member 14 is arranged radially between the bearing housing 11 and the lead wire 13 . The insulating member 14 may or may not be in radial contact with the bearing housing 11 .

The substrate 12 has solder portions 121 to which the lead wires 13 are electrically connected. At least part of the solder portion 121 axially faces the stator 9 and is arranged radially outside the substrate 12 . Solder portion 121 electrically connects lead wire 13 drawn from coil 92 and substrate 12 . A flexible substrate, for example, is used for the substrate 12 . Note that the substrate 12 may be a printed substrate.

The substrate 12 has an external connection portion 124 extending radially outward from the bracket 10 . The external connection portion 124 is the same member as the substrate 12 . For example, a connector or the like is attached to the radially outer end of the external connection portion 124 . Note that the external connection portion 124 may be a lead wire. The lead wires are connected to the substrate 12 and drawn out of the motor 1 .

When the lead wire 13 is pulled out from the coil 92 and soldered to the substrate 12, the lead wire 13 and the bearing housing 11 may come into contact with each other. Also, if the lead wire 13 is soldered with a large amount of deflection so that the lead wire 13 is not broken, the bearing housing 11 and the lead wire 13 may come into contact with each other. In the present embodiment, if the bearing housing 11 is a conductor and the bearing housing 11 and the lead wire 13 come into contact with each other, a short circuit may occur.

According to the motor 1 of this embodiment shown in FIG. 1 , the bearing housing 11 faces the lead wire 13 in the radial direction, and the insulating member 14 is arranged along the outer peripheral portion of the bearing housing 11 . By arranging the insulating member 14 in the bearing housing 11, the lead wire 13 and the bearing housing 11 do not come into direct contact with each other, and short circuits can be suppressed. It is preferable that the insulating member 14 be cylindrical. If the insulating member 14 is cylindrical, it can cover the entire circumference of the bearing housing 11 . As a result, even if the lead wire 13 and the bearing housing 11 come into contact with each other at any place, it is possible to suppress a short circuit. The insulating member 14 may or may not contact the bearing housing 11 .

In this embodiment, the insulating member 14 is a heat-shrinkable tube. After being inserted into the bearing housing 11, the heat-shrinkable tube is crimped to the bearing housing 11 by applying heat. That is, the insulating member 14 contacts the bearing housing 11 . The contact of the insulating member 14 with the bearing housing 11 fixes the insulating member 14 to the bearing housing 11 , thereby suppressing movement of the insulating member 14 . Further, the weight of the motor 1 can be reduced by directly connecting the lead wires 13 of the coils 92 to the substrate 12 using a heat-shrinkable tube rather than using a tie pin to connect to the substrate. The heat-shrinkable tube is fixed to the bearing housing 11 by being shrunk by heat. In other words, the heat-shrinkable tube only needs to have a shape surrounding the bearing housing 11 , and it is not necessary to align the direction of the heat-shrinkable tube with respect to the bearing housing 11 . Therefore, it is not necessary to provide the bearing housing 11 with a positioning portion or the like for aligning the directions of the bearing housing 11 and the heat-shrinkable tube, and the assembly can be easily performed.

In this embodiment, the external connection portion 124 of the substrate 12 extends radially outward through the substrate insertion hole 105 . The external connection portion 124 of the substrate 12 is bent downward in the axial direction along the substrate insertion hole 105, and further bent upward in the radial direction from the bent portion. That is, the external connection portion 124 is radially sandwiched between the substrate insertion holes 105 . Moreover, since the external connecting portion 124 is bent twice, it is fixed to the bracket 10 in the axial direction and the radial direction, and the substrate 12 can be firmly fixed to the bracket 10 .

In this embodiment, at least a portion of the insulating member 14 contacts the radially inner upper surface of the substrate 12 . The external connection portion 124 of the substrate 12 extends radially outward through the substrate insertion hole 105 . In other words, the external connection portion 124 of the substrate 12 is bent downward in the axial direction to pass through the substrate insertion hole 105 penetrating in the axial direction. Therefore, the portion radially inward of the bent portion of the substrate 12 may float upward in the axial direction. Therefore, at least a part of the insulating member 14 is in contact with the radially inner upper surface of the substrate 12, so that the substrate 12 can be prevented from floating upward in the axial direction.

The substrate 12 passes axially downward through the substrate insertion hole 105 and is then pulled out radially outward. At that time, the board insertion hole 105 holds and fixes the board 12 in the axial direction and the radial direction. In other words, the substrate 12 can be prevented from rising from the bracket 10 by being fixed by the substrate insertion hole 105 and the insulating member 14 .

In this embodiment, at least a portion of the insulating member 14 contacts the radially inner lower surface of the stator 9 . That is, the upper end of the insulating member 14 and the radially inner lower surface of the stator 9 are in contact with each other, and the lower end of the insulating member 14 and the upper surface of the substrate 12 are in contact with each other. As a result, the substrate 12 can be further prevented from floating upward in the axial direction.

It is preferable to use a flexible substrate for the substrate 12 . By using a flexible substrate as the substrate 12, the substrate 12 becomes thin in the axial direction and becomes a soft material. As a result, when the insulating member 14 and the substrate 12 come into contact with each other in the axial direction, it is possible to prevent the substrate 12 from floating even if the contact is made with a weak force. Further, since the substrate 12 is made of a soft material, it is possible to easily open a hole or the like through which a screw is passed. Also, in order to reduce the size of the motor 1, it is preferable to use a flexible substrate that is thin and light in the axial direction.

Stator 9 is fixed to bearing housing 11 . That is, the inner surface of the stator 9 and the outer surface of the bearing housing 11 are fixed by press fitting or adhesion. Therefore, the joint between the stator 9 and the bearing housing 11 suppresses the axial movement of the stator 9 , thereby suppressing the axial movement of the insulating member 14 . As a result, the stator 9, the insulating member 14, and the substrate 12 are in contact with each other in the axial direction, so that the floating of the substrate 12 can be suppressed.

FIG. 2 is a partial cross-sectional view showing an enlarged part of the motor 1 according to the first embodiment of the invention. The rotor yoke 6 has a wall portion 62 and a tip portion 63 . The wall portion 62 extends radially inward from the inner peripheral surface 61 of the rotor yoke 6 and faces the magnet 8 in the axial direction. The tip portion 63 extends axially below the wall portion 62 .

Since the rotor yoke 6 is made of a magnetic material, magnetic flux leaks from the magnet 8 toward the rotor yoke 6 . The rotor yoke 6 is magnetized by the leaked magnetic flux. When the motor 1 is used in an external environment, iron sand and dust contained in sand may adhere to the outer peripheral surface of the rotor yoke 6 exposed to the outside and enter the motor 1 .

According to the motor 1 of the present embodiment, the magnetic flux that has leaked to the rotor yoke 6 travels radially inward through the wall portion 62 . That is, the magnetic flux leaking to the lower end through the tip portion 63 of the rotor yoke 6 can be reduced. By magnetizing the wall portion 62 arranged radially inward of the rotor yoke 6, the magnetic flux that contributes to the generation of torque increases. Therefore, the efficiency of the motor 1 is improved. Further, the magnetic flux leaking to the tip portion 63 can be reduced, and iron sand or the like outside the motor 1 can be prevented from adhering to the tip portion 63 and entering the motor 1 .

In the present embodiment, the radial thickness R1 of the rotor yoke 6 is greater than the radial length R2 of the wall portion 62 . By increasing the radial thickness R1 of the rotor yoke 6, the leaked magnetic flux can be reduced. Therefore, adsorption of iron sand or the like to the rotor yoke 6 is further suppressed.

In this embodiment, the wall portion 62 axially faces the magnet 8 via an adhesive or the first gap F. As shown in FIG. When fixing the magnet 8 to the rotor yoke 6, the position of the magnet 8 moves up and down, the radial outer side surface of the magnet 8 contacts the radial inner side surface of the wall portion 62, and the magnet 8 floats radially inward. There is a risk that it will be placed In such a case, for example, it is necessary for the worker to push the floating magnet 8 radially outward, which is poor workability. According to the motor 1 of the present embodiment, since the first gap F is arranged between the wall portion 62 and the magnet 8, the magnet 8 remains within the first gap F even if the position of the magnet 8 moves up and down. placed in As a result, the magnet 8 can be prevented from floating radially inward, and workability is facilitated.

In this embodiment, the axial length L1 of the tip portion 63 is greater than the axial length L2 of the wall portion 62 . As a result, the distance between the tip portion 63 and the magnet 8 can be increased, and the tip portion 63 is less likely to be magnetized by the leaked magnetic flux. Therefore, adsorption of iron sand or the like to the rotor yoke 6 is further suppressed.

In this embodiment, the wall portion 62 is annularly arranged along the inner peripheral surface 61 of the rotor yoke 6 . That is, the radial thickness of the rotor yoke 6 is increased at the portion where the wall portion 62 is provided. Thereby, the rigidity of the rotor yoke 6 is increased. Therefore, vibration and noise caused by the action of the magnetic flux between the teeth 912 and the magnet 8 can be reduced when the motor 1 is driven. However, the present invention is not limited to this. The wall portions 62 may be provided at a plurality of locations at intervals in the circumferential direction.

In the present embodiment, the radially inner end of the wall portion 62 is located radially outside the radially inner end of the magnet 8 . When fixing the magnet 8 to the cylindrical rotor yoke 6 , the magnet 8 is inserted from the axial end of the rotor yoke 6 . For example, when inserting the magnet 8 from below the rotor yoke 6 on the side opposite to the lid portion 7 , the magnet 8 is inserted above the wall portion 62 in the axial direction. According to the motor 1 of the present embodiment, the radially inner end of the wall portion 62 is located radially outside the radially inner end of the magnet 8 , so the magnet 8 is passed through the wall portion 62 radially outwardly. It can be moved axially upward for easy insertion.

In this embodiment, the distal end portion 63 faces the bracket 10 in the axial direction with the second gap G interposed therebetween. As a result, air flows in from the outside of the motor 1 through the second gap G. As shown in FIG. Therefore, the heat generated by the stator 9 can be cooled.

In this embodiment, the edge portion 102 of the bracket 10 axially faces the tip portion 63 on the radially outer side of the central portion 101 . Since the upper end of central portion 101 is located axially above the upper end of edge portion 102 , tip portion 63 radially faces the radially outer side surface of central portion 101 . That is, the second gap G communicates at the radially inner end with the gap extending axially between the radially outer side surface of the central portion 101 and the radially inner side surface of the tip portion 63 . Therefore, it is difficult for water, dust, iron sand, etc. to enter the motor 1 through the second gap G below the rotor yoke 6 .

In this embodiment, the substrate 12 is placed on the upper surface of the central portion 101 . Further, the substrate 12 radially faces the tip portion 63 . As a result, the substrate 12 is arranged at a position away from the second gap G. As shown in FIG. Therefore, adhesion of water, dust, iron sand, etc. to the substrate 12 is suppressed.

FIG. 3 is a partial cross-sectional view showing an enlarged part of the motor according to the second embodiment of the invention. The rotor yoke 6a has a wall portion 62a and a tip portion 63a. The stator 9a has a stator core 91a and a plurality of coils 92a. The stator core 91a is made of laminated steel plates in which magnetic steel plates are laminated in the axial direction. The bracket 10a is arranged axially below the stator 9a and extends radially. The substrate 12a is arranged axially below the stator 9a.

In the second embodiment shown in FIG. 3, the radially inner end of the wall portion 62a is located at the same position as the radially inner end of the magnet 8a. Thereby, the magnetic flux of the wall portion 62a arranged radially inward of the rotor yoke 6a can be further increased. In addition, since the wall portion 62a approaches the stator core 91a, the magnetic flux that contributes to the generation of torque increases, further improving the efficiency of the motor 1a. Magnetic flux leaking to the tip portion 63a can be reduced, and iron sand or the like outside the motor 1a can be prevented from adhering to the tip portion 63a and entering the inside of the motor 1a.

FIG. 4 is a cross-sectional view of a motor according to a third embodiment of the invention. FIG. 5 is a partial cross-sectional view showing an enlarged part of a motor according to a third embodiment of the invention. The rotor yoke 6c has a wall portion 62c and a tip portion 63c. The tip portion 63c has a tip surface 64c axially facing the edge portion 102c. The tip surface 64c is inclined with respect to a plane orthogonal to the central axis C. As shown in FIG. The bracket 10c has a central portion 101c and edge portions 102c. The edge portion 102c has an edge surface 103c axially facing the tip portion 63c. The edge surface 103c is inclined with respect to a plane perpendicular to the central axis C. As shown in FIG.

In the third embodiment shown in FIG. 5, the tip surface 64c and the edge surface 103c are provided parallel to each other. At the radially inner end, the second gap G communicates with the axially extending gap between the radially outer side surface of the central portion 101c and the radially inner side surface of the tip portion 63c. Therefore, it is difficult for water, dust, iron sand, and the like to enter the motor 1 through the second gap G. Since the tip surface 64c and the edge surface 103c are provided parallel to each other, entry of water, dust, iron sand, etc. into the second gap G can be suppressed. Furthermore, since the edge surface 103c is inclined with respect to the plane perpendicular to the central axis, water, dust, iron sand, and the like are easily discharged to the outside of the motor 1. FIG. As a result, the air that has flowed in from the second gap G can cool the heat generated by the stator 9 without containing water, dust, iron sand, or the like.

FIG. 6 is a partial cross-sectional view showing an enlarged part of a motor according to a fourth embodiment of the invention. Bracket 10b has a central portion 101b and edge portions 102b. The rotor yoke 6b has a wall portion 62b and a tip portion 63b. The tip portion 63b has a tip surface 64b axially facing the edge portion 102b. The tip surface 64b is inclined with respect to a plane perpendicular to the central axis C. As shown in FIG. More specifically, the tip surface 64b is inclined downward in the axial direction from the radially inner side to the radially outer side of the tip portion 63b. That is, the position of the radially inner end of the tip surface 64b is located axially above the position of the radially outer end. Note that the tip surface 64b may be formed in a straight line from the radially inner end toward the radially outer end, or may be formed in a curved shape.

In the fourth embodiment shown in FIG. 6, the tip surface 64b is inclined downward in the axial direction as it goes radially outward. As a result, water, dust, iron sand, etc. adhering to the tip end surface 64b are easily discharged to the outside of the motor 1 because the tip end surface 64b is inclined with respect to the plane perpendicular to the central axis.

In the embodiments shown in Figures 4, 5 and 6, the axial thickness of the central portion 101b (101c) is further lengthened in the axial direction. As a result, the axial length of the distal end portion 63b (63c) facing the radially outer side of the central portion 101b (101c) can be further increased, so that the inclination angles of the distal end surface 64b (64c) and the edge surface 103c are further increased. be able to. Therefore, water, dust, iron sand, etc. are more likely to be discharged to the outside of the motor 1, and water, dust, iron sand, etc. are more difficult to enter.

FIG. 7 is a plan view showing a substrate 12d and a bracket 10d according to the fifth embodiment of the invention. FIG. 8 is a partial cross-sectional view showing an enlarged part of a motor according to a fifth embodiment of the invention. The substrate 12d has a substrate recess 123d that is recessed radially inward from the outer edge of the substrate 12d. The substrate recess 123d is an edge portion of the substrate 12d that is recessed radially inward from the outer edge of the substrate 12d. At least part of the substrate recess 123d faces the stator in the axial direction. The bracket attachment portion 104d is arranged radially outside the substrate recess 123d. For example, the board recess 123d may radially face a screw inserted into the bracket mounting portion 104d.

In the embodiment shown in FIGS. 7 and 8, the bracket mounting portion 104d and the substrate recess 123d axially overlap. The substrate recess 123d opens radially with respect to the substrate 12d. A substrate recess 123d is provided in an extra portion of the substrate 12d where there is no pattern or the like. That is, the extra space of the substrate 12d can be effectively utilized as the substrate recess 123d. Thereby, the surface area of the bracket 10d can be reduced, and the motor 1d can be miniaturized.

In this embodiment, at least a portion of the solder portion 121d is arranged between adjacent bracket mounting portions 104d in the circumferential direction. As a result, the bracket attachment portion 104d and the solder portion 121d do not overlap in the radial direction, so it is possible to suppress an increase in the surface area of the bracket 10d. Therefore, the motor 1d can be miniaturized.

In connection between the substrate 12d and the lead wire, it is preferable to use solder alone rather than using a tie pin. The use of tie pins requires an axial distance for the tie pins to penetrate the substrate 12d. Furthermore, it is necessary to provide a hole through which the tie pin penetrates also in the bracket 10d. However, if only soldering is performed to connect the substrate 12d and the lead wires, there is no need to make extra holes in the axial direction. Therefore, the bracket 10d can be dustproof and waterproof.

In this embodiment, at least part of the solder portion 121d is arranged radially inward of the outer peripheral end of the stator. This makes it possible to effectively utilize the axial space between the coil and the substrate 12d. It is preferable to arrange the solder portion 121d as close to the central axis as possible. Thereby, the size of the substrate 12d can be reduced, and the motor 1d can be reduced in size.

In this embodiment, the board insertion hole 105d is arranged between the corners connecting each of the adjacent bracket mounting portions 104d and the central axis. As a result, the bracket attachment portion 104d and the board insertion hole 105d are not aligned in the radial direction. Therefore, an increase in the surface area of the bracket 10d can be suppressed, and the size of the motor 1d can be reduced. The external connection portion 124d axially penetrates the board insertion hole 105d and extends radially outward.

FIG. 9 is a partial cross-sectional view showing an enlarged part of the motor 1e according to the sixth embodiment of the present invention. The substrate 12e axially faces at least a portion of the stator and has a substrate through hole 122e that penetrates in the axial direction. The substrate through hole 122e is arranged radially outward of the substrate 12e. The board through hole 122e may radially surround the outer peripheral surface of the screw.

In this embodiment, the bracket attachment portion 104e and the board through hole 122e overlap in the axial direction. A substrate through-hole 122e is provided in an extra portion where there is no pattern or the like on the surface of the substrate 12e. That is, the extra space of the substrate 12e can be effectively utilized as the substrate through-hole 122e. As a result, the size of the substrate 12e can be reduced, the surface area of the bracket 10e can be reduced, and the motor 1e can be reduced in size.

FIG. 10 is a schematic perspective view showing the appearance of the unmanned airplane main body 1A according to the first embodiment. The unmanned airplane main body 1A includes a main body portion 100, a first motor 101A, a second motor 101B, a third motor 101C and a fourth motor 101D, a first propeller 102A, a second propeller 102B, a third propeller 102C and a third propeller 102C. 4 propellers 102D.

The body portion 100 has a shape branched in four directions from the center and has arms 100A to 100D. A first motor 101A, a second motor 101B, a third motor 101C, and a fourth motor 101D are supported at the tip of each of the arms 100A to 100D. A first propeller 102A to a fourth propeller 102D are fixed to each rotor of the first motor 101A to the fourth motor 101D. That is, in an unmanned airplane, four propellers are rotated by four motors. It should be noted that the number of motors and propellers is not limited to four, and may be at least two.

In this embodiment, an unmanned airplane 1A has a plurality of motors 1. FIG. Accordingly, in the unmanned airplane 1A, the motor 1 can be made smaller and lighter. Therefore, it is possible to reduce the size and weight of the unmanned airplane 1A.

Although the embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the gist of the invention. In addition, the above-described embodiment and its modification can be appropriately combined arbitrarily.

The present invention can be used, for example, in motors.

DESCRIPTION OF SYMBOLS 1... Motor, 2... Rotating part, 3... Stationary part, 4... Bearing, 5... Shaft, 51... Mounting part, 6... Rotor yoke, 61... Inside Peripheral surface 62 Wall portion 63 Tip portion 7 Lid portion 71 Top surface portion 72 Rib 73 Through hole 8 Magnet 9... Stator, 91... Stator core, 911... Core back, 912... Teeth, 92... Coil, 10... Bracket, 101... Center part, 102... Edge part , 11... bearing housing, 12... substrate, C... center shaft, F... first gap, G... second gap, 13... lead wire, 14... insulating member , 104 Bracket mounting portion 122 Substrate through hole 123 Substrate concave portion 121 Solder portion 105 Substrate insertion hole 124 External connection portion Unmanned airplane・・1A

Claims (9)

a rotating part having a shaft extending axially around a vertically extending central axis;
a stationary portion disposed inside the rotating portion and having a stator;
a bearing that supports the shaft;
has
The rotating part is
a tubular rotor yoke made of a magnetic material;
a magnet fixed to the inner peripheral surface of the rotor yoke and radially facing the stator;
has
The stationary part is
a radially extending bracket disposed axially below the stator;
an axially extending bearing housing disposed radially inward of the stator;
a substrate arranged axially between the stator and the bracket;
has
The stator has a plurality of coils having lead wires electrically connected to the substrate,
The bearing housing has an insulating member that faces the lead wire in a radial direction and is arranged along an outer peripheral portion of the bearing housing,
A motor for an unmanned aircraft , wherein the insulating member is a heat-shrinkable tube . a rotating part having a shaft extending axially around a vertically extending central axis;
a stationary portion disposed inside the rotating portion and having a stator;
a bearing that supports the shaft;
has
The rotating part is
a tubular rotor yoke made of a magnetic material;
a magnet fixed to the inner peripheral surface of the rotor yoke and radially facing the stator;
has
The stationary part is
a radially extending bracket disposed axially below the stator;
an axially extending bearing housing disposed radially inward of the stator;
a substrate arranged axially between the stator and the bracket;
has
The stator has a plurality of coils having lead wires electrically connected to the substrate,
The bearing housing has an insulating member that faces the lead wire in a radial direction and is arranged along an outer peripheral portion of the bearing housing,
The bracket has a substrate insertion hole that penetrates in the axial direction,
The motor for an unmanned airplane , wherein the external connection portion of the board extends radially outward through the board insertion hole . 3. The motor for an unmanned airplane according to claim 2 , wherein said board insertion hole is arranged between angles formed by connecting each of said adjacent bracket mounting portions and a central axis. a rotating part having a shaft extending axially around a vertically extending central axis;
a stationary portion disposed inside the rotating portion and having a stator;
a bearing that supports the shaft;
has
The rotating part is
a tubular rotor yoke made of a magnetic material;
a magnet fixed to the inner peripheral surface of the rotor yoke and radially facing the stator;
has
The stationary part is
a radially extending bracket disposed axially below the stator;
an axially extending bearing housing disposed radially inward of the stator;
a substrate arranged axially between the stator and the bracket;
has
The stator has a plurality of coils having lead wires electrically connected to the substrate,
The bearing housing has an insulating member that faces the lead wire in a radial direction and is arranged along an outer peripheral portion of the bearing housing,
The substrate has a solder portion to which the lead wire is electrically connected,
The bracket has a bracket mounting portion that penetrates in the axial direction,
at least part of the solder portion is arranged between the adjacent bracket mounting portions in the circumferential direction;
the bracket has at least two bracket mounting portions penetrating in the axial direction;
The motor for an unmanned airplane, wherein the substrate has a substrate recess that is recessed radially inward from an outer edge of the substrate, and the bracket mounting portion and the substrate recess overlap in an axial direction. The motor for an unmanned aircraft according to any one of claims 1 to 4 , wherein at least a portion of the insulating member is in contact with a radially inner upper surface of the substrate. The motor for an unmanned aircraft according to any one of claims 1 to 5, wherein at least part of the insulating member contacts a radially inner lower surface of the stator. The substrate has a solder portion to which the lead wire is electrically connected,
The bracket has a bracket mounting portion that penetrates in the axial direction,
The motor for an unmanned airplane according to any one of claims 1 to 6 , wherein at least part of the solder portion is arranged between adjacent bracket mounting portions in the circumferential direction. 8. The motor for an unmanned airplane according to claim 7 , wherein at least part of said solder portion is arranged radially inward of an outer peripheral edge of said stator. An unmanned airplane comprising a plurality of the unmanned airplane motors according to any one of claims 1 to 8 .

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