US-12620841-B2 - Stator having bus bar structure, propeller driving motor using same, and method for manufacturing stator

US12620841B2US 12620841 B2US12620841 B2US 12620841B2US-12620841-B2

Abstract

A stator having a bus bar structure that enhances assembly productivity and durability by adopting the bus bar structure comprises: a division type stator core in which a plurality of split cores are assembled in an annular shape; upper and lower insulators surrounding the outer circumference of teeth of the split cores; a stator coil composed of a plurality of core groups continuously wound onto three teeth for each phase; a plurality of bus bar brackets coupled to the insulators so as to bind two split cores; U-phase, W-phase, and V-phase bus bars on which a connection terminal to which a start terminal of each core group is connected is protruded; a common electrode bus bar on which a connection terminal to which an end terminal of each core group is connected is protruded; and a stator support that insulates between coils so as to integrate the plurality of split cores.

Inventors

Jeong Hoon Lee
Chang Seob Song

Assignees

AMOTECH CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20220721
Priority Date: 20210809

Claims (13)

1 . A stator having a bus bar structure, the stator comprising: a split type state core in which a plurality of split cores, each tooth extending in a center direction from a back yoke part forming a magnetic circuit, are annularly assembled; an upper insulator and a lower insulator which are combined to surround an outer peripheral surface of the teeth of the split cores from above and below; a three-phase driving type stator coil which is wound around an outer circumference of each of the upper insulator and the lower insulator and includes a plurality of core groups which are continuously wound around three teeth adjacent for each phase, wherein the core groups on each phase are connected in parallel and are alternately arranged for each phase; a plurality of bus bar brackets coupled to one of the upper insulator and the lower insulator so as to bind two adjacent split cores, respectively, and each having four guide channels; U-phase, W-phase, and V-phase bus bars, each inserted and fixed to one of the four guide channels, in which a plurality of connection terminals to which start terminals of each core group are connected, protrude at intervals; a common electrode bus bar inserted into one of the four guide channels to be fixed, in which a plurality of connection terminals to which end terminals of each core group are connected, protrude at intervals; and a stator support which surrounds the stator coil wound on the insulators so as to integrate the plurality of split cores, and insulates between adjacent coils, wherein the plurality of bus bar brackets are positioned to bind a front end insulator coupled to a rear end split core of a front core group among adjacent core groups and a rear end insulator coupled to a front end split core of a rear end core group, and wherein each of the bus bar brackets has first and second coupling holes coupled to coupling protrusions of the insulators, respectively, a first coupling protrusion of the front insulator and a second coupling protrusion of the rear insulator are coupled to the first and second coupling holes, respectively, and an insulator not coupled to the bus bar bracket is arranged before and after the front insulator and the rear insulator coupled to the bus bar bracket.
2 . The stator having a bus bar structure of claim 1 , wherein the upper insulator and the lower insulator include a pair of flanges protruding inward and outward, and a coil winding region formed between the pair of flanges having a hollow part surrounding a teeth therein, and a coupling protrusion required to couple and fix the bus bar bracket protrudes from an outer flange of the lower insulator.
3 . The stator having a bus bar structure of claim 1 , wherein each of the bus bar brackets comprises: a rectangular base part; inner and outer side walls protruding from an inner circumference and an outer circumference of the base part, respectively; three-row guide protrusions protruding to form four guide channels to which U-phase, V-phase, and W-phase bus bars and a common electrode bus bar are coupled and fixed between the inner side wall and the outer side wall; and first and second protrusion parts protruding from both ends of the outer side wall and having first and second coupling holes respectively coupled to the coupling protrusions of the lower insulator.
4 . The stator having a bus bar structure of claim 1 , wherein the U-phase, V-phase, and W-phase bus bars each have a plurality of connection terminals protruding in which an output terminal to which one end of a cable is connected and start terminals of a plurality of core groups allocated on the U-phase, V-phase, and W-phase, are connected, the common electrode bus bar has a plurality of connection terminals to which a plurality of end terminals of the plurality of core groups are connected and an output terminal for a common electrode to which one end of the cable is connected, in which the plurality of connection terminals and the output terminal for a common electrode protrude, and the output terminals of the U-phase, V-phase, and W-phase bus bars, the plurality of connection terminals to which the start terminals of each core group are connected, the plurality of connection terminals of the common electrode bus bars, and the output terminal for the common electrode have intervals which are set to be located in the guide channels of the bus bar brackets.
5 . The stator having a bus bar structure of claim 4 , wherein one of the plurality of connection terminals of U-phase, W-phase, and V-phase bus bars, to which a start terminal of the core group for each U-phase, each V-phase, and each W-phase is connected, and one of the plurality of connection terminals of a common electrode bus bar to which an end terminal of each of the plurality of core groups is connected are arranged in each of the plurality of bus bar brackets, and the connection terminal is arranged at a position close to the start terminal and the end terminal of each core group arranged in an annular shape to minimize a coil length.
6 . The stator having a bus bar structure of claim 1 , wherein six successive teeth included in the core groups of two adjacent phases generate magnetic flux in opposite directions to rotate the magnet of the rotor arranged opposite to each other in the same direction.
7 . The stator having a bus bar structure of claim 1 , wherein: the stator coil includes 12 core groups; the core groups in each phase are connected in parallel by four; two adjacent core groups are activated for each conduction mode; one deactivated core group is arranged between the two activated adjacent core groups; and the activated eight core groups and the deactivated four core groups arranged therebetween are symmetrically arranged around a rotating shaft.
8 . A propeller driving motor comprising: a housing in which an upper cover and a lower cover are respectively coupled to an upper portion and a lower portion of a cylindrical case; a stator according to claim 1 and arranged inside the cylindrical case of the housing and generating a rotating magnetic field; and a rotor rotated by the rotating magnetic field generated from the stator; and a rotary shaft coupled to the center of the rotor and having a propeller coupled to a front end thereof.
9 . The propeller driving motor of claim 8 , wherein the driving motor comprises 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 rotating shaft and the rotor, and a plurality of through holes provided in the lower cover.
10 . The propeller driving motor of claim 8 , wherein the rotor comprises upper and lower blade support plates installed at a top and a bottom thereof, and each of the upper and lower blade support plates comprises a plurality of blades that generate a circumferential wind when the rotor rotates, and the circumferential wind collides with the air cooling air flow penetrating the motor to generate a vortex.
11 . The propeller driving motor of claim 8 , further comprising a water jacket having a spiral refrigerant circulation circuit placed between the cylindrical case and the stator and capable of refrigerant circulation between the case and the water jacket, wherein the stator support has heat dissipation through the water jacket installed on the outside.
12 . The propeller driving motor of claim 8 , wherein the insulator and the stator support of the stator comprise an insulating heat dissipation composite material having heat dissipation performance and insulation performance at the same time, and the insulating heat dissipation composite material has an insulation performance of at least 10 kV and a thermal conductivity of 3 W/mK or more.
13 . A stator having a bus bar structure, the stator comprising: a split type state core in which a plurality of split cores, each tooth extending in a center direction from a back yoke part forming a magnetic circuit, are annularly assembled; an upper insulator and a lower insulator which are combined to surround an outer peripheral surface of the teeth of the split cores from above and below; a three-phase driving type stator coil which is wound around an outer circumference of each of the upper insulator and the lower insulator and includes a plurality of core groups which are continuously wound around three teeth adjacent for each phase, wherein the core groups on each phase are connected in parallel and are alternately arranged for each phase; a plurality of bus bar brackets coupled to one of the upper insulator and the lower insulator so as to bind two adjacent split cores, respectively, and each having four guide channels; U-phase, W-phase, and V-phase bus bars, each inserted and fixed to one of the four guide channels, in which a plurality of connection terminals to which start terminals of each core group are connected, protrude at intervals; a common electrode bus bar inserted into one of the four guide channels to be fixed, in which a plurality of connection terminals to which end terminals of each core group are connected, protrude at intervals; and a stator support which surrounds the stator coil wound on the insulators so as to integrate the plurality of split cores, and insulates between adjacent coils, wherein: the stator coil includes 12 core groups; the core groups in each phase are connected in parallel by four; two adjacent core groups are activated for each conduction mode; one deactivated core group is arranged between the two activated adjacent core groups; and the activated eight core groups and the deactivated four core groups arranged therebetween are symmetrically arranged around a rotating shaft.

Description

TECHNICAL FIELD The present invention relates to a stator having a bus bar structure and a propeller driving motor using same and, more specifically, to a stator having a bus bar structure with improved assembly productivity and durability by adopting a bus bar structure, and a propeller driving motor using same and a method for manufacturing the stator. BACKGROUND ART Typically, a brushless electric motor used for an aircraft includes: a stator to which a battery is connected; a rotor; and a case wherein a propeller is mounted. In this case, since the case serves as a rotor in the case of the electric motor for an aircraft, the case itself rotates to rotate the propeller, thereby generating the propulsion force of the aircraft. In addition, since the case itself rotates in the case of the electric motor for an aircraft, thereby generating high torque. In addition, a large propeller can be directly turned without a reducer, and the electric motor can be lightened since an accessory such as a reducer is not required. However, in the case of the electric motor, since the case itself rotates as a rotor, a lot of heat is generated from the stator placed inside the case. In this case, if the aircraft is fast, the electric motor is cooled by the flow of air, but in the case of helicopters that mainly fly at rest, the electric motor is overheated due to little air flow, and thus is required to be cooled. To this end, in the case of the electric motor used for an aircraft, an upper plate of the case is typically perforated, or a plurality of cooling holes formed by being cut in a predetermined area are provided. Therefore, when the electric motor is driven, air flows into the cooling holes of the case through the air flow caused by 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, rain, moisture, and other foreign substances are not likely to enter the case by the rotational force of the case, but if the aircraft is stopped and located outside, foreign substances such as rainwater, moisture, or dust may enter the case through the cooling hole of the case. Foreign substances such as rainwater, moisture, or dust introduced in this way may cause electrical short circuits or fires due to short circuits. Therefore, in order to solve this problem, measures such as covering the electric motor with a tarp such as vinyl were previously taken, but these measures are temporary and cumbersome, so they are not a fundamental solution to the problem. Korean Patent Application Publication No. 10-2017-0090037 (Patent Document 1) discloses a power transmission device for an aircraft having a function of preventing moisture penetration and preventing overheating, which is capable of effectively implementing a cooling function of an electric motor, by introducing an opening and closing control means that can open and close the cooling hole of the case formed to cool the electric motor, thereby preventing moisture or foreign substances from entering the electric motor by automatically closing the cooling hole of the case when the aircraft is stopped, as well as enabling the opening and closing control means to adjust the opening amount of the cooling hole of the case according to the rotational force of the case when the aircraft operates, to thus effectively implement the cooling function of the electric motor. In general, the electric motor generates more heat in a stator in which a motor driving current is applied to the coil than a rotor, and when the heat generated in this way is not discharged to the outside of the electric motor, the heat may act as a factor of lowering the efficiency and lifespan of the motor. The electric motor of Patent Document 1 has a structure in which a stator is located in a central portion in an outer rotor scheme. Patent Document 1 includes a cooling hole through which air for air cooling is introduced into and discharged from a front surface and a rear surface of a cylindrical case serving as a rotor. The electric motor of Patent Document 1 has a structure in which a stator is located in a central portion in an outer rotor scheme. Patent Document 1 includes a cooling hole through which air for air cooling is introduced into and discharged from a front surface and a rear surface of a cylindrical case serving as a rotor. Meanwhile, an unmanned aerial vehicle (UAV), that is, a drone, is variously applied to various purposes such as surveillance/reconnaissance/search, disinfection/control/spray, broadcast/performance, environmental measurement, lifesaving, and flying cars, in addition to a logistics field for delivering parcel items. Propeller-driven motors, especially brushless direct-current (BLDC) motors, which are used in light airplanes for two people, fling cars, and large drones carrying high-weight loads, require several tens of kV driving motors, and in this case, an outer rotor-type motor (Paten