KR20220148360A - Stator and BLDC Motor for Propeller Driving Apparatus Using the Same - Google Patents

Abstract

The present invention relates to a stator, which has excellent heat radiation effects by forming an insulator (or a bobbin) insulating between a stator core and a coil with insulative heat radiation complex materials having heat radiation performance and insulation performance at the same time, and a BLDC motor for a propeller driving apparatus using the same. According to the present invention, the stator comprises: a stator core having a ring-shaped back yoke having a certain width to form a magnetic circuit, and a plurality of teeth reaching from the back yoke toward the center; an insulator formed to surround the outer circumferential surface on which a coil will be wound in each of the plurality of teeth; and a stator coil wound on the outer circumferential surface of the insulator from each of the plurality of teeth. The insulator is formed by using insulative heat radiation composite materials having heat radiation performance and insulation performance at the same time.

Description

Stator and BLDC Motor for Propeller Driving Apparatus Using the Same

The present invention relates to a stator and a BLDC motor for a propeller driving device using the same, and more specifically, an insulator (or bobbin) that insulates between a stator core and a coil is formed of an insulating heat dissipation composite material having both heat dissipation performance and insulation performance. It relates to a stator with excellent heat dissipation effect and a BLDC motor for a propeller driving device using the same.

A brushless electric motor typically used in an aircraft includes a stator to which a battery is connected, a rotor, and a case in which a propeller is mounted.

In this case, in the case of an electric motor for an aircraft, since the case acts as a rotor, the case itself rotates to rotate the propeller to generate the thrust of the aircraft.

In addition, in the case of an electric motor for aircraft, it is characterized by having a high torque because the case itself rotates. Also, a large propeller can be turned directly without a reducer, and the electric motor can be lightened because it does not require accessories such as a reducer.

However, in the case of an electric motor, since the case itself rotates as a rotor, a lot of heat is generated from the stator disposed inside the case. In the case of helicopters, which are mainly used, there is little air flow and the electric motor overheats, so it is necessary to cool the electric motor.

For this purpose, in the case of an electric motor used in an aircraft, the upper plate of the case is usually provided with a plurality of cooling holes formed by being perforated or cut in a predetermined area. Therefore, when the electric motor is driven, air is introduced into the cooling hole of the case through the air flow due to the rotation of the propeller, thereby cooling the electric motor.

However, when the electric motor is driven and the case rotates at a constant speed, there is no risk of rain, moisture, or other foreign substances entering by the rotational force of the case. Alternatively, foreign substances such as dust may be introduced.

Foreign substances such as rainwater, moisture, or dust introduced in this way may act as a cause of an electrical short or fire due to a short circuit.

Therefore, in order to solve this problem, conventional measures such as covering the electric motor with a tarpaulin such as vinyl have been taken, but these measures are temporary and cumbersome, and thus cannot be a solution to the fundamental problem.

Korean Patent Application Laid-Open No. 10-2017-0090037 (Patent Document 1) introduces an opening/closing control means that can open and close the cooling hole of the case formed to cool the electric motor. In addition to automatically closing the cooling hole to prevent moisture or foreign substances from entering the inside of the electric motor, the opening/closing control means adjusts the opening degree of the cooling hole of the case according to the rotational force of the case during aircraft operation, thereby improving the cooling function of the electric motor. Disclosed is a power transmission device for an aircraft having functions of preventing moisture penetration and preventing overheating that can be effectively implemented.

In general, electric motors generate more heat from the stator to which the motor driving current is applied to the coil than the rotor. have.

The electric motor of Patent Document 1 has a structure in which a stator (stator) is located in the center of the outer rotor method. In Patent Document 1, the front and rear surfaces of the cylindrical case serving as a rotor are provided with cooling holes through which air for air cooling is introduced and discharged.

Patent Document 1 introduces an opening/closing control means that can open and close the cooling hole of the case formed to cool the electric motor. Discloses a technology to block the inflow into

On the other hand, unmanned aerial vehicles (UAVs), i.e., drones, are used in logistics for delivering parcels, as well as monitoring/reconnaissance/search, quarantine/control/spreading, broadcasting/performance, environmental surveying, lifesaving, etc. is being applied in various ways.

Motors for propeller driving devices, especially BLDC motors, which are used in two-person light airplanes or large drones carrying heavy loads, require a driving motor of several tens of kilowatts. The outer rotor type motor (Patent Document 1) has a limit in effectively cooling a lot of heat generated from the stator.

Heat generated from the stator and not radiated to the outside and accumulated therein may shorten the operating life and reduce operating efficiency. In order to prevent this, a heat dissipating member or a heat dissipating device such as a heat sink or a heat exchanger is used together with a device that generates heat.

Accordingly, recently, a heat dissipation member manufactured using injection molding or extrudable polymer resin has been proposed, and many studies have been conducted due to advantages such as light weight and low unit price due to the material properties of the polymer resin itself.

However, a heat dissipation member manufactured using a polymer resin exhibits heat dissipation through a heat conductive filler, but a heat conductive filler with excellent heat dissipation performance has electrical conductivity as well. There is a problem that is very inappropriate for use in avionics electronic devices that require insulation.

In particular, in the case of an aviation motor, it is required to have insulation performance to avoid lightning.

In addition, in the case of an AC motor, it is not suitable as an aviation motor because it has a larger volume and weight than a BLDC motor.

: Korea Patent Publication No. 10-2017-0090037

The present inventor provides a plurality of through holes between the plurality of bridges connecting the stator, which generates more heat than the rotor, on the outside, and external air cooling through the natural side casing during flight, the upper and lower covers, and the rotor body and the rotating shaft. Formed to realize inner air cooling at the same time, and the problem of electric short due to moisture or foreign substances flowing into the motor due to inner air cooling was found to be able to prevent the occurrence of

Accordingly, the present invention has been proposed to solve the problems of the prior art, and its purpose is to form an insulator (or bobbin) that insulates between the stator core and the coil with an insulating heat dissipation composite having both heat dissipation performance and insulation performance. An object of the present invention is to provide a stator with excellent heat dissipation effect and a BLDC motor for a propeller driving device using the same.

Another object of the present invention is to enclose the coil wound on the insulator (or bobbin) of the stator while insert molding it with an insulating heat dissipation composite material having heat dissipation performance and insulation performance to insulate between the coil and the coil. Accordingly, an object of the present invention is to provide a stator and a BLDC motor for a propeller driving device using the stator, which can solve the problem that moisture or foreign substances are introduced into the motor to cause an electric short.

Another object of the present invention is to insulate the coil and the coil while surrounding the coil wound on the first insulating heat dissipation composite and the insulator (or bobbin) used to form the insulator (or bobbin) that insulates between the stator core and the coil. An object of the present invention is to provide a stator that maximizes heat dissipation performance by varying the composition of the second insulating heat dissipation composite coated with an insert molding method, and a BLDC motor for a propeller driving device using the stator.

Another object of the present invention is to provide a water jacket having a refrigerant circulation circuit capable of circulating refrigerant between the outer periphery of the stator core and the casing, thereby effectively dissipating heat in a water-cooled manner, and a BLDC motor for a propeller driving device using the same is to provide

Another object of the present invention is to provide a stator that can be effectively cooled by external air cooling and internal air cooling to the rotor and stator using the BLDC motor of the inner rotor-outer stator type, and a BLDC motor for a propeller driving device using the same. have.

Another object of the present invention is to form a plurality of through-holes in the upper and lower covers and at the same time connect them through a plurality of bridges between the rotor body and the rotating shaft to form a plurality of through-holes so that effective cooling can be achieved by inner air cooling. It is to provide a BLDC motor for a stator and a propeller driving device using the same.

Another object of the present invention is to form a plurality of through-holes by connecting through a plurality of bridges between the rotor body and the rotating shaft, so that inner air cooling can be achieved with the plurality of through-holes formed in the upper and lower covers BLDC for a propeller driving device. to provide a motor.

In order to achieve the above object, the stator for a BLDC motor according to an embodiment of the present invention includes an annular back yoke having a predetermined width to form a magnetic circuit and a plurality of teeth extending from the back yoke in the central direction. core; an insulator formed to surround an outer circumferential surface on which a coil is to be wound in each of the plurality of teeth; and a stator coil wound around the outer circumferential surface of the insulator at each of the plurality of teeth, wherein the insulator is formed of an insulating heat dissipation composite material having both heat dissipation performance and insulating performance.

The insulator includes upper and lower insulators enclosing an outer circumferential surface on which a coil is to be wound by 1/2 at each of the teeth, wherein the upper and lower insulators include an annular base frame each having a predetermined width; and a plurality of tooth accommodating parts protruding from the base frame and accommodating 1/2 of the winding area of the teeth from the upper part and the lower part.

The insulator includes upper and lower insulators enclosing an outer circumferential surface on which a coil is to be wound by 1/2 at each of the teeth, wherein the upper and lower insulators include an annular base frame each having a predetermined width; and a plurality of tooth accommodating parts protruding from the base frame and accommodating 1/2 of the winding area of the teeth from the upper part and the lower part.

The insulator may be pre-fabricated as upper and lower insulators in advance, and then assembled to a stator core, or may be integrally formed by insert molding with an insulating heat dissipation composite material having heat dissipation performance and insulating performance.

The stator according to an embodiment of the present invention further includes a stator support having heat dissipation characteristics while enclosing the stator coil wound on the insulator and insulating between adjacent coils and coils, wherein the stator support has heat dissipation performance and insulation performance. It may be integrally formed by insert molding with an insulating heat dissipation composite material.

In this case, the radially outer surface of the stator support for heat dissipation is in contact with a water jacket installed on the outside of the stator, and the water jacket may be cooled by a water cooling method.

In addition, the insulating heat dissipation composite material has a continuous use temperature of 150 ℃ or more and a polymer matrix serving as a binder; an insulating heat dissipation filler made of ceramic that is added and dispersed in a polymer matrix to improve thermal conductivity; and reinforcing fibers added to the polymer matrix to enhance strength.

The insulating heat dissipation composite material may have an insulating performance of at least 10Kv or more and a thermal conductivity of 3W/mK or more.

A BLDC motor for a propeller driving device according to another embodiment of the present invention includes: a housing in which an upper cover and a lower cover are respectively coupled to the upper and lower portions of a cylindrical case; a stator disposed inside the case of the housing and generating a rotating magnetic field; a rotor rotated by the rotating magnetic field of the stator; and a rotating shaft coupled to the center of the rotor and coupled to the front end of the propeller.

In addition, the BLDC motor according to an embodiment of the present invention includes a plurality of through holes provided in the upper cover from the outside, a plurality of spaces formed between a plurality of bridges connecting the rotation shaft and the rotor, and a plurality of through holes provided in the lower cover. An air flow passage through the hole is provided, and inner air cooling can be achieved using the air flow passage.

As described above, in the present invention, the insulator (or bobbin) that insulates between the stator core and the coil is formed of an insulating heat dissipation composite material having both heat dissipation performance and insulation performance, so that there is an excellent heat dissipation effect, thereby improving motor efficiency. . Furthermore, by forming an insulator (or bobbin) with an insulating heat dissipation composite material, it is possible to provide an aviation motor with guaranteed mechanical strength such as tensile strength and flexural modulus capable of supporting external forces as well as heat dissipation performance and insulating performance.

In addition, in the present invention, by insert molding with an insulating heat dissipation composite material having both heat dissipation performance and insulation performance to insulate between the coil and the coil while surrounding the coil wound on the insulator (or bobbin) of the stator, heat dissipation effect and inner air cooling It can solve the problem of electric short caused by moisture or foreign substances flowing into the motor at the same time. When insert-molded with the insulating heat dissipation composite, the stator is formed to cover all parts exposed to the outside except for the shoe part of the stator core facing the magnet of the rotor.

Furthermore, in the present invention, insert molding to insulate between the coil and the coil while enclosing the coil wound on the first insulating heat dissipation composite and the insulator (or bobbin) used to form the insulator (or bobbin) that insulates between the stator core and the coil Heat dissipation performance can be maximized by varying the composition of the second insulating heat dissipation composite material coated in this manner.

In the propeller driving apparatus of the present invention, an inner rotor-outer stator type BLDC motor is used, and effective cooling can be achieved by external air cooling and internal air cooling of the rotor and stator.

In addition, in the present invention, a plurality of through holes are formed in the upper and lower covers, and at the same time, a plurality of through holes are formed by connecting through a plurality of bridges between the rotor body and the rotating shaft, so that effective cooling can be achieved by inner air cooling. .

Furthermore, in the present invention, effective heat dissipation can be achieved in a water cooling manner by providing a water jacket having a refrigerant circulation circuit capable of circulating refrigerant between the outer periphery of the stator core and the casing.

1a to 1c are respectively a perspective view showing a propeller light aircraft to which a propeller driving device according to the present invention is applied, a photograph in which the propeller driving device is installed in a control box, and an enlarged side view showing that the propeller is coupled to the propeller driving device.
2A and 2B are a plan view showing a propeller driving device according to the present invention, respectively, and a cross-sectional view taken along line AA of FIG. 2A.
3 is a partially cut-away perspective view of a propeller driving device according to the present invention.
4 is an exploded perspective view of a propeller driving device according to the present invention.
5 is an exploded perspective view of the rotor of the propeller driving device according to the present invention.
6 is an exploded perspective view of the stator of the propeller driving device according to the present invention.
7 is a graph showing the temperature for each phase of an embodiment in which an insulator (or bobbin) is formed of an insulating heat dissipation composite material according to the present invention and a comparative example in which a heat dissipation plastic is not applied.

Hereinafter, preferred embodiments according to the present invention will be described with reference to the accompanying drawings.

In this process, the size or shape of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms specifically defined in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user or operator. Definitions of these terms should be made based on the content throughout this specification.

The propeller driving device according to the present invention can be applied to, for example, a two-person light aircraft or a large drone carrying a heavy load.

When a large amount of heat is generated from the stator in a large BLDC driving motor of several tens of kilowatts employed in the propeller driving device, if proper cooling and heat dissipation are not achieved, the efficiency of the motor may decrease and malfunction may occur.

In the present invention, an inner rotor-outer stator type BLDC motor in which a stator generating a lot of heat is disposed on the outside of the rotor is employed, and it will be described as an example applied to the propeller driving of a light aircraft.

In the description of the above embodiment, the rotation shaft of the propeller driving device may be applied to a case in which it is disposed in a horizontal direction or a case where it is disposed in a vertical direction. In this case, a reducer may be coupled to the output of the motor to increase the torque.

1A to 1C are respectively a perspective view showing a propeller light aircraft to which a propeller driving device according to the present invention is applied, a photograph in which the propeller driving device is installed in a control box, and an enlarged side view showing that the propeller is coupled to the propeller driving device. In addition, FIGS. 2A and 2B are a plan view showing a propeller driving device according to the present invention, respectively, and a cross-sectional view taken along line A-A of FIG. 2A .

1a to 1c, the propeller driving device 10 according to the present invention is installed at intervals on the front of the control box 220 disposed at the front end of the fuselage 210 of the light aircraft 200, the rotation shaft of The propeller 70 is coupled to the distal end to rotationally drive the propeller 70 , and the rotating shaft of the propeller driving device 10 is disposed in the horizontal direction.

The control box 220 may include a controller for controlling various electronic devices for controlling the operation of the light aircraft 200 and a motor driving device for driving the BLDC motor 100 provided in the propeller driving device 10 . .

In this case, the propeller driving device 10 according to the present invention is not limited to the light aircraft 200 and may be applied to a drone driving a single propeller as well as a multicopter-type drone driving a plurality of propellers, respectively.

2A to 3 , the propeller driving device 10 according to the present invention is a single rotor-single stator type motor 100 and a propeller 70 on the rotation shaft 50 of the motor 100. Includes a propeller mounting bracket (20) for.

The propeller mounting bracket 20 is largely ring-shaped, and a central through hole 21 having a large diameter is formed in the central portion. Further, a plurality of large-diameter peripheral through-holes 23 and a plurality of small-diameter peripheral through-holes 24 are arranged on the same circumference around the central through-hole 21 . The plurality of large-diameter peripheral through-holes 23 and a plurality of small-diameter peripheral through-holes 24 are arranged for weight loss to reduce weight.

The rotating shaft 50 of the motor 100 also has a central portion 50a in a hollow shape for weight reduction, and its outer diameter is set to a size corresponding to the central through hole 21 of the propeller installation bracket 20 .

In the central through hole 21 of the propeller installation bracket 20 , an annular protrusion 25 is disposed on the lower side for coupling with the rotation shaft 50 of the motor 100 . In addition, a plurality of screw-fastening through-holes for fastening and fixing a plurality of fixing screws 22 to the rotating shaft 50 of the motor 100 are formed in the annular protrusion 25 .

The upper end 50b of the rotation shaft 50 and the bottom surface of the annular protrusion 25 that receive and are surface-coupled thereto are coupled in a stepped structure. The step structure coupling between the upper end 50b of the rotating shaft 50 and the bottom surface of the protrusion 25 is to catch the torsion generated when the propeller 70 rotates.

The single rotor-single stator type motor 100 includes a cylindrical case 12 , and an upper cover 16 and a lower cover 18 coupled to upper and lower portions of the cylindrical case 12 , respectively. As a result, the cylindrical case 12 , the upper cover 16 , and the lower cover 18 serve as a housing of the motor 100 .

A water jacket 46 , a stator 40 , a rotor 30 , and a rotating shaft 50 are sequentially disposed inside the cylindrical case 12 to cool the motor 100 in a water-cooling manner. The rotating shaft 50 is rotatably supported by an upper bearing 51 and a lower bearing 52 installed in upper and lower bearing housings 16c and 18c located in the center of the upper cover 16 and the lower cover 18, respectively. has been

In this case, the upper bearing 51 is used, for example, a double-row angular ball bearing capable of supporting a radial load and one large axial load at the same time, and the lower bearing 52 is a single row angular ball bearing. can be used

As shown in FIG. 6 , the water jacket 46 has a helical protrusion 46a formed on the outer periphery of the cylindrical body to form a helical passage, and the helical protrusion 46a is in contact with the inner surface of the cylindrical case 12 . this is done As a result, a spiral passage 46b through which a refrigerant for cooling the motor 100 in a water cooling manner is circulated may be formed between the spiral protrusions 46a. In this case, the refrigerant may be water or aircraft cooling oil.

In addition, as shown in Figure 2b, the upper and lower portions of the cylindrical case 12, respectively, the inlet or outlet (47a, 47b) connected to the spiral passage (46b) is formed, the inlet or outlet (47a, 47b) is connected to a pump for circulating the refrigerant.

O-rings 48a and 48b for sealing are respectively inserted between the upper and lower portions of the water jacket 46 with the cylindrical case 12, thereby preventing leakage of the spiral passage 46b.

Between the cylindrical case 12 and the upper cover 16 and the lower cover 18, there is provided a protrusion in which a plurality of through holes 19 are formed in the upper cover 16 and the lower cover 18 for mutual coupling. , by fastening the fixing screws (19a) to the plurality of through holes (19).

A plurality of through-holes 16e and 18e serving as air-cooling air flow passages are formed in the upper cover 16 and the lower cover 18 . To this end, the upper cover 16 and the lower cover 18 have a space between the upper and lower bearing housings 16c and 18c, which are located inside and serve as a hub, and the outer rings 16a and 18a disposed on the outside. A plurality of bridges (16d, 16d; 18d) extends radially. Accordingly, a plurality of through holes 16e and 18e are formed between the upper and lower bearing housings 16c and 18c, the intermediate rings 16b and 18b, the outer rings 16a and 18a and the plurality of bridges 16d and 18d. has been

The intermediate rings 16b and 18b may be omitted or added as necessary for strength reinforcement, and a network for forming a plurality of through holes 16e and 18e formed in the upper cover 16 and the lower cover 18 . The structure may be changed differently.

The plurality of through-holes 16e and 18e introduces relatively low-temperature external air into the motor 100 from the outside, and then heat-exchanges with the heat generated from the stator 40, followed by air-cooling air discharged to the outside of the motor. form a flow path.

The motor 100 according to the present invention has an inner rotor structure in which the rotor 30 is disposed inside the stator 40 . In addition, the motor 100 constitutes a radial gap type electric motor in which the rotor 30 is concentrically disposed inside the stator 40 .

As shown in FIGS. 2A to 5 , in the rotor 30 , a plurality of bridges 34 extend radially from a hollow rotation shaft 50 disposed in the central portion, and distal ends of the plurality of bridges 34 . is connected to the annular rim (rim) (33). In addition, an annular hub 35 is reinforced for strength reinforcement in the connection portion between the plurality of bridges 34 and the rotation shaft 50 .

The rotating shaft 50 and the annular rim 33 connected through the plurality of bridges 34 are integrally formed, and a metal material capable of providing strength while being lightweight, for example, an aluminum alloy or duralumin, etc. can be made with

A back yoke 31 serving as a magnetic circuit is coupled to the outer periphery of the annular rim 33 in a sliding manner. To this end, a plurality of engaging grooves 33a are formed on the outer periphery of the rim 33 , and a plurality of engaging projections 31b coupled to the plurality of engaging grooves 33a protrude on the inner periphery of the back yoke 31 . has been

The back yoke 31 may be made of an electrical steel sheet (silicon steel sheet) to form a magnetic circuit together with a plurality of magnets 32 attached to the outer surface, and a plurality of magnets 32 attached to the outer surface. of the coupling protrusion 31a protrudes.

The plurality of coupling protrusions 31a of the back yoke 31 support while receiving the magnet 32 between two adjacent coupling protrusions 31a in a sliding coupling manner. In this case, the shape of the magnet 32 is formed in a trapezoidal shape, and the space formed between the two coupling protrusions 31a has a longer inner width so that the trapezoidal magnet 32 is coupled. Accordingly, the coupling protrusion 31a may prevent the magnet 32 coupled between the coupling protrusions 31a from scattering or leaving.

The plurality of magnets 32 are made of permanent magnets, and a plurality of N-pole and S-pole magnets are alternately arranged.

After the plurality of magnets 32 are attached to the outer surface of the back yoke 31 of the rotor 30 , the rotor support 36 is coupled thereto.

The rotor support 36 has an annular upper plate 36a and a lower plate 36b that cover the upper and lower portions of the magnet 32, and the magnet 32 and the magnet 32 are disposed between the two ends while the upper plate ( 36a) and a plurality of connecting portions 36c connected to the lower plate 36b. Accordingly, the rotor support 36 covers the outer surface except for the outer surface of each magnet 32 facing the shoe portion of the stator core.

A plurality of blades 37a and 37b protrude from the upper plate 36a and the lower plate 36b, respectively, to generate wind when the rotor 30 rotates to cool the stator 40 by air cooling. In this case, the shape of the plurality of blades 37a and 37b may be a linear shape, a round shape, or the like.

As described above, the wind generated by the plurality of blades 37a and 37b according to the rotation of the rotor 30 follows the circumferential direction, and the circumferential wind blows through the plurality of through holes 16e of the upper cover 16, the plurality of A vortex is generated by colliding with an air-cooling air stream passing through a plurality of spaces 33c formed between the bridges 34 and a plurality of through-holes 18e formed in the lower cover 18 . The vortex generated in this way reaches the inner corners of the motor 100 so that heat exchange with the stator 40 that generates the greatest heat can be effectively performed.

In addition, the upper plate 36a and the lower plate 36b are provided with protrusions having a plurality of through holes 36d formed therein for coupling with the back yoke 31, and a plurality of coupling holes ( 33b) is formed so that it can be fastened with a set screw or the like.

The rotor 30 is connected between the rotation shaft 50 and an annular rim 33 through a plurality of bridges 34 . As a result, the plurality of spaces 33c formed between the plurality of bridges 34 move from the outside of the motor to the inside through the plurality of through holes 16e and 18e provided in the upper cover 16 and the lower cover 18 . The introduced relatively low temperature outside air forms a flow path for the air discharged to the outside of the motor.

The stator 40 has an annular back yoke 41a having a predetermined width to form a magnetic circuit and a plurality of teeth 41b from the back yoke 41a, as shown in FIGS. 2A to 4 and 6 . ) of the stator core 41 extending radially inward, and the insulator (or bobbin) 42a and 42b of an insulating material integrally formed to surround the outer circumferential surface around which each coil of the teeth 41b is to be wound, and the A stator coil 43 wound around the outer peripheral surface of the insulators 42a and 42b of each of the plurality of teeth 41b is included.

Each of the plurality of teeth 41b is formed in a "T" shape, and a coil 43 is wound between a shoe portion opposite to the magnet 32 of the rotor 30 and an annular back yoke 41a. It has a winding area.

The insulators (or bobbins) 42a and 42b are pre-fabricated as upper and lower insulators 42a and 42b, and then assembled to the stator core 41 or integrally formed by insert molding with insulating plastic (resin). can

In this case, the upper and lower insulators 42a and 42b are provided on an annular base frame 420 each having a predetermined width, with the exception of a shoe portion facing the magnet 32 of the rotor 30 and teeth 41b. ), a plurality of tooth accommodating portions 422 accommodating the winding region by 1/2 at the upper and lower portions protrude at intervals.

The upper and lower insulators 42a and 42b may be preferably formed of an insulating heat dissipation composite material having both heat dissipation performance and insulation performance. When the motor 100 is employed in an aircraft, it is required to have insulation performance of at least 10Kv or more so as to be safe from lightning strikes, and thermal conductivity is preferably 3W/mK or more in consideration of heat dissipation characteristics.

In consideration of the above points, the insulating heat dissipation composite material used in the present invention has a continuous use temperature of 150° C. or higher, and an insulating heat dissipation filler composed of a polymer matrix acting as a binder, a ceramic added and dispersed to improve thermal conductivity, and strength reinforcement. It contains added reinforcing fibers.

The polymer matrix is polyamide, polyester, polyketone, liquid crystal polymer, polyolefin, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyphenylene oxide (PPO), polyether sulfone (PES), poly It may include one kind of compound selected from the group consisting of etherimide (PEI) and polyimide, or a mixture or copolymer of two or more kinds.

In this case, the polymer matrix preferably has a continuous use temperature of 150° C. or higher, and for example, polyphenylene sulfide (PPS) may be used.

In addition, the insulating heat dissipation filler may be provided in an amount of 75 to 100 parts by weight based on 100 parts by weight of the polymer matrix.

In addition, the insulating heat dissipation filler is selected from the group consisting of magnesium oxide, talc, titanium dioxide, aluminum nitride, silicon nitride, boron nitride, aluminum oxide, silica, zinc oxide, barium titanate, strontium titanate, beryllium oxide, silicon carbide and manganese oxide. It may include one or more species.

The insulating heat dissipation filler may have an average particle diameter of 10 nm to 600 μm.

Furthermore, the reinforcing fiber may be provided in an amount of about 30 parts by weight based on 100 parts by weight of the polymer matrix, for example, glass fiber or the like may be used.

In addition, the insulating composite may further include at least one additive selected from the group consisting of a dispersant, an antioxidant, a work improving agent, a coupling agent, a stabilizer, a flame retardant, a pigment, and an impact modifier.

The inner rotor-outer stator type BLDC motor 100 applied to the propeller driving device 10 of the present invention includes a single rotor 30 and a single stator 40 . In the stator 40, a three-phase (U, V, W) coil 43 is wound on the teeth 41b of the stator core 41, and the three-phase (U, V, W) It is connected through a cable 45 to apply a driving signal to the coil 43 .

<Heat dissipation characteristic test>

According to the present invention, whether an insulating heat dissipation composite is applied as a heat dissipating plastic for the insulator (or bobbin) of the stator according to the present invention and whether a blade for generating air cooling wind is applied to the rotor support of the rotor is combined as shown in Table 1 below to obtain four experimental sample samples. Prepared and measured the temperature of each phase according to the experimental sample sample is described in Table 1.

Whether heat dissipation plastic is applied Whether to apply air-cooled blades U-phase temperature
[℃] V-phase temperature
[℃] W-phase temperature
[℃] Experimental Example 1 × × 129.2 127.8 120.4 Experimental Example 2 × ○ 195.4 103.3 94.3 Experimental Example 3 ○ × 192.2 96.9 88.4 Experimental Example 4 ○ ○ 90.6 88.8 82.8

Experimental Example 1 is a motor composed of a combination of a stator and a rotor in which a blade for generating air-cooling wind is not formed on the rotor support of the rotor without applying an insulating heat-dissipating composite material as a heat-dissipating plastic to the insulator of the stator, Experimental Example 2 is the insulator of the stator It is a motor composed of a combination of a stator and a rotor in which a blade for generating air-cooling wind is formed on the rotor support of the rotor without applying an insulating heat-dissipating composite material as a heat-dissipating plastic to the rotor, and Experimental Example 3 is an insulator of the stator. and a motor composed of a combination of a stator and a rotor in which a blade for generating air-cooled wind is not formed on the rotor support of the rotor, Experimental Example 4 applies an insulating heat-dissipating composite material to the insulator of the stator as a heat-dissipating plastic, and air cooling on the rotor support of the rotor It is a motor composed of a combination of a stator and a rotor with blades for generating wind.

The above-mentioned test example sample motor is, for example, a 65 kV class, 16 kg large BLDC drive motor, the test conditions are 3,000 RPM, load conditions 30 kW, 100 Nm, 130 A, coolant temperature 50 ° C, coolant circulation flow 5 lpm to be.

In the case of not applying an insulating heat dissipation composite material as a heat dissipating plastic to the insulator of the stator, PEEK (polyether ether ketone), an injection compound having high heat resistance and chemical resistance, is applied, and insulating heat dissipation applied as a heat dissipation plastic applied to the insulator of the stator For the composite material, 40 wt% of polyphenylene sulfide (PPS) as a polymer matrix, 30 wt% of talc as a heat dissipation filler, and 30 wt% of glass fiber as a reinforcing fiber were used.

For temperature measurement, the temperature was calculated using the resistance measurement value as a result of the saturation temperature test for each phase of U, V, and W, and the temperature was calculated and described in Table 1 and shown as a graph in FIG. 7 .

As shown in Table 1, as shown in Table 1, the saturation temperature test results for each phase of U, V, and W, Experimental Example 4 to which both the heat dissipation plastic and the blade for generating air-cooled wind were applied, compared with Experimental Example 1 to which neither the heat-dissipating plastic nor the blade for generating the air-cooled wind were applied. When it was detected as having a temperature as low as 38.6°C for U phase, 39°C for V phase, and 37.6°C for W phase, it was found that an excellent heat dissipation effect was obtained.

In addition, as for the heat dissipation effect, it was found that a greater heat dissipation effect was obtained when a blade for generating air-cooled wind was applied when a heat dissipation plastic was applied.

Moreover, even when only heat-dissipating plastic was applied as in Experimental Example 3, it was detected to have a lower temperature as low as 27°C for U phase, 31°C for V phase, and 32°C for W phase compared to the case where heat-dissipating plastic was not applied as in Experimental Example 1. It was found that an excellent heat dissipation effect of more than % was obtained.

7 is a graph showing the temperature of each phase according to whether an insulating heat dissipation composite is applied as a heat dissipating plastic for the insulator (or bobbin) of the stator according to the present invention and whether a blade for generating air cooling wind is applied to the rotor support of the rotor.

Moreover, in the insulating heat dissipation composite of the present invention, while maintaining the content of the polymer matrix and reinforcing fibers, the case of containing 30% by weight of talc alone as a heat dissipation filler (20% by weight of talc + 10% by weight of boron nitride) in combination The tensile strength and flexural strength were higher, and the flexural modulus was, on the contrary, higher when 30 wt% of talc was contained alone.

In addition, when the content of the polymer matrix is reduced to 35 wt% while the content of the reinforcing fiber is maintained at 30 wt%, and the heat dissipation filler is increased to 35 wt%, 40 wt% of the polymer matrix, 30 wt% of the heat dissipation filler, 30 wt% of the reinforcing fiber The thermal conductivity properties were higher than that of the heat dissipation plastic composed of weight %.

However, when the content of the polymer matrix is reduced to 35% by weight and the heat dissipation filler is increased to 35% by weight, mold release defects occur due to the lowering of the impact strength. It was confirmed that when applied to a stator support for heat dissipation manufactured by insert molding method, desirable heat dissipation characteristics can be exhibited.

In the present invention, by forming an insulator (or bobbin) with an insulating heat dissipation composite material, it is possible to provide an aviation motor in which mechanical strength such as tensile strength and flexural modulus capable of supporting external forces as well as heat dissipation performance and insulating performance is guaranteed.

In addition, in the present invention, an insulating heat dissipation composite material having both heat dissipation performance and insulation performance to insulate the adjacent coil and coil while surrounding the coil 43 wound on the insulator (or bobbin) 42a, 42b of the stator 40. It includes an insert-molded stator support 44 for heat dissipation.

In this case, the stator support 44, which is insert-molded with the insulating heat dissipation composite, includes all parts exposed to the outside except for the shoe part of the stator core 41 facing the magnet 32 of the rotor 30. formed to cover.

The radially outer surface of the heat dissipation stator support 44 is in contact with the water jacket 46 . Therefore, when heat is generated from the coil 43 of the stator 40, the heat is conducted to the stator support 44 for heat dissipation, and then heat exchange is made with the water jacket 46 which is cooled by a water cooling method. Heat dissipation can be achieved.

In this case, in the present invention, the first insulating heat dissipation composite material used to form the insulator (or bobbin) 42a, 42b that insulates between the stator core and the coil and the insulator (or bobbin) 42a, 42b is wound around the stator coil. The heat dissipation performance can be maximized by varying the composition of the second insulating heat dissipation composite material used for the formation of the stator support 44 that surrounds the coil and insulates between the coil and the coil and radiates heat generated from the coil to the outside.

That is, the upper and lower insulators (or bobbins) 42a and 42b formed of the first insulating heat dissipation composite collect the generated heat into the stator core, and the upper and lower insulators 42a and 42b are separately manufactured by injection molding. It is then assembled to the stator core (41). Therefore, it is difficult to form the upper and lower insulators (or bobbins) 42a and 42b into a thin film structure to exhibit the minimum impact strength characteristics, and it is required to have excellent moldability, so that the thermal conductivity characteristics are relatively deteriorated.

That is, if the content of the heat dissipation filler is increased so that the first insulating heat dissipation composite material exhibits higher heat dissipation performance (ie, thermal conductivity), problems in impact strength characteristics and formability may be deteriorated.

In contrast, the stator support 44 formed of the second insulating heat dissipation composite material surrounds the stator coil 43 wound on the insulator (or bobbin) 42a, 42b and insulates between the coil and the coil by insert molding method. it is possible

Therefore, since the stator support 44 is formed and integrated to cover the coil and the coil while enclosing the stator coil 43 by an insert molding method instead of the injection molding method, the second insulating heat dissipation composite composition used for this is the first It is also possible to have lower impact strength characteristics and moldability than the insulating heat dissipation composite composition, so it is possible to increase the content of the heat dissipation filler to exhibit higher heat dissipation performance (ie, thermal conductivity).

As described above, in the propeller driving device 10 of the present invention, the inner rotor-outer stator type BLDC motor 100 is used to effectively cool the rotor 30 and the stator 40 by external air cooling and internal air cooling. can be done

For the inner air cooling, in the present invention, a plurality of cooling through-holes 16e and 18e are formed in the upper and lower covers 16 and 18, and an annular rim 33 and a rotating shaft supporting the body of the rotor at the same time By connecting through the plurality of bridges 34 between the 50 , an air flow passage passing through the inside of the motor is formed by forming a plurality of spaces 33c between the plurality of bridges 34 .

That is, when the aircraft to which the propeller driving device 10 of the present invention is applied flies, external air introduced from the outside into the inside through the plurality of through holes 16e provided in the upper cover 16 of the motor 100). After passing through the plurality of spaces 33c formed between the plurality of bridges 34 , it is discharged to the outside of the motor through the plurality of through holes 18e provided in the lower cover 18 .

As a result, after external air having a relatively low temperature is introduced into the motor and heat exchanged with the heat generated in the stator 40, the internal air cooling of the motor may be performed by the flow of air discharged to the outside of the motor.

Furthermore, in the present invention, effective heat dissipation can be achieved in a water cooling manner by providing a water jacket 46 having a refrigerant circulation circuit through which refrigerant circulation can be made between the outer periphery of the stator core 41 and the casing 12 .

In addition, in the present invention, the insulator (or bobbin) 42a, 42b that insulates between the stator core 41 and the coil 43 is formed of an insulating heat dissipation composite material having both heat dissipation performance and insulation performance, so that there is an excellent heat dissipation effect. Motor efficiency can be improved. In this case, by forming the insulator (or bobbin) 42a, 42b with an insulating heat dissipation composite material, it is possible to provide an aviation motor with guaranteed mechanical strength such as tensile strength and flexural modulus that can support external forces as well as heat dissipation and insulation performance. can

In the present invention, an insulating heat dissipation composite material having both heat dissipation performance and insulation performance to insulate the adjacent coils and coils while surrounding the coil 43 wound on the insulator (or bobbin) 42a, 42b of the stator for insert molding and heat dissipation A stator support body 44 is provided.

The heat dissipation stator support 44 covers all parts exposed to the outside except for the shoe part of the stator core 41 facing the magnet 32 of the rotor 30 . That is, waterproof molding is performed except for the magnet 32 of the rotor and the shoe portion of the stator core 41 that forms the magnetic circuit path.

As a result, even if moisture or foreign matter flows into the motor along the air flow path passing through the motor, an electric short does not occur.

In addition, as the radially outer surface of the stator support 44 for heat dissipation comes into contact with the water jacket 46 which is being cooled by a water cooling method, heat exchange with the water jacket 46 may be made and heat dissipation may be made.

In the above embodiment description, the present invention exemplifies that the propeller driving device rotates and drives the propeller of the light aircraft, but a single propeller driving device is installed in the drone body or a plurality of propeller driving devices are installed on a plurality of arms extending from the drone body It can be applied to installed multicopter type drones.

Moreover, in the description of the embodiment, the rotational shaft of the motor exemplifies rotation of the propeller of the light aircraft exposed to the outside, but it can be changed to a drone having a fan structure in which a propeller or a blade is built in a cylindrical casing.

In addition, the present invention provides a variety of logistics fields, monitoring/reconnaissance/search, quarantine/control/spreading, broadcasting/performance, environmental surveying, structure, etc., in which a distribution box for delivering parcels is detachably provided on the lower part of the drone body. It can be changed in various ways for the purpose.

In the above, the present invention has been illustrated and described with examples of specific preferred embodiments, but the present invention is not limited to the above-described embodiments, and within the scope of not departing from the spirit of the present invention, common knowledge in the technical field to which the present invention belongs Various changes and modifications will be possible by those who have

The present invention is an insulator (or bobbin) that insulates between a stator core and a coil, with internal air cooling using an air flow passage formed inside the motor, water cooling using a water jacket having a refrigerant circulation circuit, and heat dissipation performance and insulation performance. It relates to a propeller driving device having a heat dissipation structure formed of an insulating heat dissipation composite material having at the same time, and may be applied to a light aircraft or a drone.

10: propeller drive 12: casing
16: upper cover 16e, 18e: through hole
18: lower cover 20: propeller mounting bracket
30: rotor 31: back yoke
32: magnet 33: rim
34: bridge 35: hub
36: rotor support 37a, 37b: blade
40: stator 41: stator core
42a, 42b: insulator 43: stator coil
44: stator support 45: cable
46: water jacket 50: rotation shaft
51,52: bearing 100: motor
200: light aircraft 210: fuselage
220: control box

Claims (10)

an annular back yoke having a predetermined width to form a magnetic circuit and a stator core having a plurality of teeth extending from the back yoke in a central direction;
an insulator formed to surround an outer circumferential surface on which a coil is to be wound in each of the plurality of teeth; and
and a stator coil wound around the outer circumferential surface of the insulator in each of the plurality of teeth.
The insulator is a stator for a BLDC motor formed of an insulating heat dissipation composite material having both heat dissipation performance and insulation performance. According to claim 1,
The insulator includes upper and lower insulators that surround the outer circumferential surface on which the coil is to be wound by 1/2 in each of the teeth,
The upper and lower insulators are each
An annular base frame made of a predetermined width; and
A stator for a BLDC motor comprising a; a plurality of tooth accommodating parts protruding from the base frame and accommodating 1/2 of the winding area of the teeth from the upper part and the lower part. According to claim 1,
The insulator is a stator for a BLDC motor that is pre-fabricated as upper and lower insulators and then assembled to a stator core. According to claim 1,
Further comprising a stator support having heat dissipation properties while surrounding the stator coil wound on the insulator and insulating between the adjacent coil and the coil,
The stator support is a stator for a BLDC motor that is integrally formed by insert molding an insulating heat dissipation composite material having heat dissipation performance and insulating performance. 5. The method of claim 4,
A stator for a BLDC motor in which the radial outer surface of the stator support for heat dissipation is in contact with a water jacket installed outside the stator, and the water jacket is cooled by a water cooling method. 5. The method of claim 4,
The stator support for the heat dissipation is a stator for a BLDC motor that exposes only the shoe portion of the stator core facing the magnet of the rotor. According to claim 1,
The insulating heat dissipation composite is
a polymer matrix having a continuous use temperature of 150° C. or higher and serving as a binder;
an insulating heat dissipation filler made of ceramic that is added and dispersed in a polymer matrix to improve thermal conductivity; and
A stator for a BLDC motor comprising a; reinforcing fibers added to a polymer matrix for strength reinforcement. 8. The method of claim 7,
The insulating heat-dissipating composite material is a stator for a BLDC motor having an insulating performance of at least 10Kv and a thermal conductivity of 3W/mK or more. a housing in which an upper cover and a lower cover are respectively coupled to the upper and lower portions of the cylindrical case;
a stator disposed inside the case of the housing and generating a rotating magnetic field;
a rotor rotated by the rotating magnetic field of the stator; and
It includes a; rotation shaft coupled to the center of the rotor and to which a propeller is coupled to the front end;
The said stator is a BLDC motor for a propeller drive which is the stator in any one of Claims 1-8. 10. The method of claim 9,
The motor includes a plurality of through holes provided in the upper cover from the outside, a plurality of spaces formed between a plurality of bridges connecting the rotary shaft and the rotor, and an air flow passage through the plurality of through holes provided in the lower cover, ,
A BLDC motor for a propeller driving device in which internal air cooling is performed using the air flow passage.

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