KR101215971B1 - Double rotor and single stator type bldc motor - Google Patents

Abstract

A double rotor and single stator type BLDC motor is disclosed.
Double rotor and single stator type BLDC motor according to an embodiment of the present invention, the motor casing is rotated around the motor shaft, is formed in the rear of the motor casing, the inner rotor with an inner magnet and an outer magnet A casing body integrally formed with an outer rotor, a casing cover coupled to the casing body at the front of the motor casing, and an inner magnet arranged on the inner rotor and an outer magnet arranged on the outer rotor; And a stator disposed to maintain a clearance therein and covering the upper portion of the winding part installed in the stator frame part with a cap part, and wherein the stator frame part is coupled to the motor shaft.

Description

DOUBLE ROTOR AND SINGLE STATOR TYPE BLDC MOTOR

The present invention relates to a brushless DC (BLDC) motor, and more particularly, to a double rotor and a single stator type BLDC motor capable of assembling a stator core with a stator frame portion and a cap portion.

In general, BLDC motors are used in various fields including high speed and precision machinery because of their high efficiency and ease of control.

BLDC motors perform electrical rectification using switch elements instead of mechanical rectification through commutators.

For example, a BLDC motor includes a control unit having a power supply device such as a switching mode power supply (SMPS), a switching device driver, and a switching device.

Here, the power supply device converts an AC voltage, which is a commercial power input from the outside, into a DC voltage. The switching device driver generates a switching control signal by receiving the DC voltage converted from the power supply.

The switching element converts the DC voltage applied from the power supply device into a three-phase voltage according to the switching control signal and applies it to the winding of the stator core of the stator for the BLDC motor. In this case, the winding of the stator core generates a magnetic field by rotating the rotor of the motor by the three-phase voltage.

However, the BLDC motor according to the related art has a disadvantage in that the core installation work is complicated and the work time is relatively long as the fixed stator core is simply fixed and installed along the ring-shaped stator core support plate.

In addition, the BLDC motor according to the prior art has a disadvantage in that the heat dissipation characteristics are inferior because the surface area of the heat dissipation is relatively narrow since the capping member is simply fixed to the stator core support plate and no cap member is used.

In addition, the BLDC motor according to the prior art has only a single stator core support plate, which is relatively difficult to compensate for magnetic loss.

Embodiment of the present invention relates to a double rotor and a single stator type BLDC motor which facilitates the assembly work of the stator core by the stator frame portion and the cap portion, and induces a heat dissipation effect by the cap portion as well as the stator frame portion.

In addition, an embodiment of the present invention relates to a BLDC motor capable of compensating the stator magnetic loss by a pair of stator frame portion and the cap portion.

According to an aspect of the present invention, in a BLDC motor in which a motor casing rotates around a motor shaft, an inner rotor formed inside the motor casing and having an inner magnet and an outer rotor having an outer magnet are provided. Maintains a clearance between the casing body formed integrally with the casing cover, the casing cover coupled to the casing body in front of the motor casing, and the inner magnet arranged on the inner rotor and the outer magnet arranged on the outer rotor. A double rotor and a single stator type BLDC motor are provided to cover the upper part of the winding part installed in the stator frame part, and the stator is coupled to the motor shaft. Can be.

The controller may further include a control unit installed in the stator to control the motor.

The stator includes a boss for being fixed to the motor shaft, a plurality of supports formed on the outside of the boss, the stator frame portion having an outer ring portion connected to be supported by the support, and a size corresponding to the outer diameter of the outer ring portion. And a cap portion having a ring shape, and the winding portion in which a plurality of stator cores are arranged to maintain a predetermined distance along the circumferential direction between the stator frame portion and the cap portion.

The stator frame portion of the stator may further include a circular first outer wall portion and a first inner wall portion formed in the outer ring portion of the stator frame portion, and an upper portion of the first outer wall portion so as to secure a height for a spaced space from the outer ring portion. Or it may include a seating groove formed in each of the upper portion of the first inner wall portion, and chamfers formed at an angle corresponding to the side inclination angle of the outer head or the inner head of the stator core on both sides of each of the seating groove.

The cap portion of the stator may further include a cap ring portion having a circular ring plate shape that covers an upper portion of the winding portion, a second outer wall portion and a second inner wall portion formed at an outer circumference portion and an inner circumference portion of the cap plane portion. A seating groove formed at a lower portion of the second outer wall portion or a lower portion of the second inner wall portion to secure a depth for the spaced apart from the cap plane portion, and an outer head of the stator core at both sides of each of the seating recesses; It may include a second chamfer formed at an angle corresponding to the side inclination angle of the inner head.

Embodiment of the present invention has the advantage that can facilitate the assembly process of the stator core by a pair of stator frame portion and the cap portion.

In addition, the embodiment of the present invention may be made of a pair of stator frame portion and the cap portion of the aluminum alloy material, the heat dissipation characteristics are very high as it is mounted in the mounting groove of the stator frame portion and the cap portion in direct contact with the stator core There is an advantage to implement a good, lightweight structure.

In addition, the embodiment of the present invention, as the stator core is disposed between the pair of stator frame portion and the cap portion, there is an advantage that can compensate for the stator magnetic losses.

1 is a perspective view of a double rotor and a single stator type BLDC motor according to an embodiment of the present invention.
Figure 2 is an exploded perspective view of the casing cover shown in FIG.
3 is a perspective view of a casing body in which the inner rotor and the outer rotor shown in FIG. 1 are integrally formed.
4 is a perspective view of a stator to be installed inside the double rotor and single stator type BLDC motor shown in FIG. 1.
5 is an exploded perspective view of the stator frame portion and the stator and cap portion.
FIG. 6 is a cross-sectional view illustrating an assembling state and a method of operating the double rotor and single stator type BLDC motor shown in FIG. 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a perspective view of a double rotor and a single stator type BLDC motor according to an embodiment of the present invention.

Referring to FIG. 1, the present embodiment is a hub type driving motor for driving a place of use (eg, an electric vehicle, an electric motorcycle, and an electric bicycle), and is fixed to a motor coupling position that is an installation position of the place of use. It may be a double rotor and a single stator type BLDC motor in which a motor casing rotates around the motor shaft 120.

Here, the double rotor may refer to the inner rotor and the outer rotor, and the single stator may refer to a single stator between the inner rotor and the outer rotor.

In addition, the motor casing may include a casing body 100 formed at the rear of the motor casing, and a casing cover 110 disposed at the front of the motor casing and coupled to the casing body 100.

This embodiment is a double rotor and single stator type BLDC motor that can operate by applying a voltage in the form of pulse width modulation (PWM) waveform, and when the duty ratio is large, the driving force of the motor is increased, and when the duty ratio is small, It may include a control unit 300 (see FIG. 4) having a motor driving circuit configured to weaken the driving force.

Here, the control unit 300 may be installed inside the casing body 100, and may be configured to adjust the rotational speed of the double rotor and single stator type BLDC motor by adjusting the duty ratio of PWM.

That is, the control unit 300 may be composed of a general double rotor and a single stator type BLDC motor control circuit element. In addition, the control unit 300 may be configured to alternately apply a voltage, that is, a positive voltage and a negative voltage, to the windings of the stator core when the isostatic period of the counter electromotive force.

In addition, the present embodiment is to block the open body of the casing body 100 and the casing body 100 for the double rotor and single stator type BLDC motor integrally formed by integrating the body rear portion and the inner rotor and the outer rotor. Casing cover 110 may be assembled.

According to the operation control of the controller 300, the entire casing body 100 and the casing cover 110, that is, the motor casing according to the present embodiment rotates around the motor shaft 120 installed along the virtual center line CL. It is possible to (R).

The power line for applying power to the control unit 300 may be electrically connected to the power input terminal of the control unit 300 through an inlet hole formed in the rear side of the motor shaft 120.

Structural portions of the casing body 100 (eg, body back portion, outer wall, inner wall, outer ring protrusion) and the casing cover 110 are each manufactured by die casting using aluminum alloy material, or powder metallurgy using tungsten material. It may be molded into.

The casing body 100 coupled with the casing cover 110 is integrally formed by integrating the body rear portion, the inner rotor and the outer rotor, and as a hub for driving an electric vehicle, an electric motorcycle, and an electric bicycle. It can exert structural stiffness that can withstand shock, vibration, dynamic and static loads.

Figure 2 is an exploded perspective view of the casing cover shown in FIG.

Referring to FIG. 2, the casing cover 110 is configured to be disassembled and assembled with the casing body 100 shown in FIG. 1.

The casing cover 110 may be disassembled for insertion and assembly of the internal components of the casing body 100 and maintenance.

To this end, the casing cover 110 is formed of a circular disk-shaped cover body 111 that can cover the open portion of the casing body 100, protruded to the outer edge of the cover body 111 and spaced apart along the circumferential direction A plurality of bolted fastening portions 112 formed to maintain the spacing, respectively formed with fastening holes, a bearing seat portion 113 formed at the center of the cover body 111, and a bearing 114 of the bearing seat portion 113. ) May include a ring plate 115 that is attachably attachable while covering the bearing seat 113.

In order to couple between the ring plate 115 and the bearing seat 113, a plurality of fastening holes are formed around the center through-hole of the ring plate 115 and around the bearing seat 113 to be fastened. They can be joined or separated from each other via bolts.

3 is a perspective view of a casing body in which the inner rotor and the outer rotor are integrally formed;

Referring to FIG. 3, the casing body 100 has a body rear portion 101 formed at the rear of the casing body 100 and a thickness direction of the body rear portion 101 at the outer side of the body rear portion 101 (eg, a motor shaft). The outer rotor 130 is formed based on the outer wall (103) protruding integrally along the (axial direction of) and the bearing seating portion 102 of the outer wall body 103 and the body rear portion 101 of the body back portion 101 It may include an inner rotor 150 formed based on the inner wall 105 integrally protruded to be parallel to the outer wall 103 in a position between.

In this case, the bearing seat 102 may be provided with a bearing 104 engaged with the motor shaft.

The outer circumferential surface of the outer wall body 103 may have a plurality of outer ring protrusions 107 and 108 extending along the circumferential direction of the outer wall body 103 and protruding in the radial direction of the outer wall body 103.

Here, the outer ring protrusions (107, 108) may extend the surface area of the casing body 100 and perform a role such as a cooling fin or a heatsink (heatsink) that is responsible for cooling efficiency, and, together with the hub drive motor ( When used as a hub type driving motor, it simultaneously plays the same role as a mounting table that can be mounted to a place of use (eg, an electric vehicle, an electric motorcycle, or an electric bicycle) through the installation holes 109 of the outer ring protrusions 107 and 108. can do.

In addition, a fastening seating part 106 corresponding to the bolt fastening part 112 of the casing cover 110 described above with reference to FIG. 2 may be formed in front of the front outer ring protrusion 107.

Each fastening seating part 106 is provided with a fastening hole corresponding to the fastening hole of the bolt fastening part 112 of the casing cover 110, and through the fastening bolt (not shown), the casing body 100 and the casing cover 110. ) Can be fastened so that it can be mounted.

An outer back yoke 131 may be formed on an inner circumferential surface of the outer wall 103.

The outer yoke 131 may have a plurality of outer magnets 132 arranged along the inner circumferential surface of the outer yoke 131 while maintaining a predetermined interval or magnet arrangement angle.

In addition, the sensing magnet 160 may be further installed on the outer wall 103.

An inner back yoke 151 may be formed on an outer circumferential surface of the inner wall 105.

The inner back yoke 151 may have a plurality of inner magnets 152 arranged along the outer circumferential surface of the inner back yoke 151 while maintaining a predetermined interval or magnet arrangement angle.

The casing body 100 integrates the body rear portion 101, the inner rotor 150, and the outer rotor 130 in one piece, thereby simplifying the assembly process of the double rotor and single stator type BLDC motor. You can do it.

The stator 200 of FIG. 4, which will be described in detail below, may be disposed while maintaining a clearance between the inner magnet 152 of the inner rotor 150 and the outer magnet 132 of the outer rotor 130. .

4 is a perspective view of a stator to be installed inside the double rotor and single stator type BLDC motor shown in FIG. 1.

Referring to FIG. 4, the stator 200 may be fixedly used to the motor shaft 120 of the double rotor and single stator type BLDC motor described above in FIG. 1.

The stator 200 includes a boss 211 for fixing to the motor shaft 120, a plurality of supports 212 formed on the outside of the boss 211, and an outer ring part 213 connected to be supported by the support 212. Along the circumferential direction between the stator frame portion 210 having a), the cap portion 220 having a ring shape as a size corresponding to the outer diameter of the outer ring portion 213, and the stator frame portion 210 and the cap portion 220. It may include a winding portion 230 having a plurality of stator cores 231 arranged to maintain a predetermined interval.

Here, the plurality of supports 212 are each formed in a bent shape has the advantage of ensuring a bearing mounting space.

The stator frame portion 210 and the cap portion 220 of the stator 200 may be manufactured by a die casting method using an aluminum alloy material, or may be molded by a powder metallurgy method using a tungsten material.

Receiving grooves 214 and 224 are formed at portions of the outer ring portion 213 and the cap portion 220 of the stator frame portion 210 facing each other to settle each stator core 231 of the winding portion 230. have.

The seating grooves 214 and 224 may be formed corresponding to the number and arrangement positions of the stator cores 231.

The stator core 231 seated in each of the seating grooves 214 and 224 and in direct contact with each other may allow heat to be transferred and distributed through the stator frame portion 210 and the cap 220 having the seating grooves 214 and 224. do.

The outer ring portion 213 and the cap portion 220 of the stator frame portion 210 are stacked in a sandwich structure with the winding portion 230 interposed therebetween, and the outer ring portion (between the winding portions 230 along the circumferential direction) is formed between the outer ring portion 213 and the cap portion 220. 213 and a plurality of fastening holes 225 formed through the cap 220 and fastening means (not shown) (eg, fastening bolts and nut assemblies or rivets).

Accordingly, the present embodiment has an advantage that the heat dissipation characteristics are very good and a light weight structure can be realized.

On the other hand, the sensor groove 215 for mounting the Hall IC 310 (Hall IC) of the control unit 300 may be formed on the basis of some of the stator core 231 among the stator frame portion 210.

For example, the hall IC 310 may be configured to sense the sensing magnet 160 shown in FIG. 3 and may be used to control the motor operation.

When the control unit 300 is installed on the outer surface of the stator frame unit 210, the plurality of Hall ICs 310 protruding on the PCB of the control unit 300 are electrically connected to the PCB of the control unit 300. The sensor grooves 215 of the frame part 210 may be fitted in a one-to-one correspondence and may be easily assembled.

Each of the windings 230 may include an insulator 240 (see FIG. 6) coupled to enclose an intermediate portion of each stator core 231, and a winding wire (not shown) wound on the insulator 240. .

On the other hand, the boss 211 of the stator 200, the shaft hole 216 for inserting the motor shaft 120 shown in Figure 6, and the stator shaft connecting portion of the circular plate shape protruding from the circumferential surface of the motor shaft 120 A plurality of bolt holes 217 formed to coincide with the coupling holes 122 of the 121 may be further formed.

The stator 200 may have a shape similar to that of a wheel for an automobile when the stator frame part 210, the winding part 230, and the cap part 220 are all combined.

5 is an exploded perspective view of the stator frame portion and the stator and cap portion.

Referring to FIG. 5, in this embodiment, the upper portion of the winding part 230 installed in the stator frame part 210 of the stator 200 may be covered with a cap part 220 to compensate for magnetic loss. Since the stator frame portion 210 is connected to the motor shaft, heat dissipation may be improved as heat is transferred to the outside.

A circular first outer wall portion 218 and a first inner wall portion 219 are formed in the outer ring portion 213 of the stator frame portion 210.

The first outer wall portion 218 and the first inner wall portion 219 are parallel to each other so as to maintain a spacing interval corresponding to the size of the stator core 231 for mounting the stator core 231 of the stator 200. While extending, they extend to form a ring shape along the outer or inner circumferential direction of the outer ring portion 213, respectively.

The seating grooves 214 and 214a of the stator frame portion 210 may have a height h for a spaced space from the outer ring portion 213 of the first outer wall portion 218 or the first inner wall portion 219. It is formed at the top, respectively.

By the height h of the stator frame 210, a clearance space may be secured inside the stator frame 210.

In this case, the first chamfer 214b may be formed at both sides of the seating grooves 214 and 214a at angles corresponding to the side inclination angles of the outer head or the inner head of the stator core 231, respectively.

Since the surface of the first chamfer 214b corresponds to an inclined surface having a relatively large surface area compared to a general plane, the first chamfer 214b may maintain a relatively excellent coupling state with excellent heat transfer efficiency. Here, the general plane may mean a rectangular cross section that is generated when a rectangular groove shape is generated in a direction perpendicular to the surface of the first outer wall portion 218 or the first inner wall portion 219.

Accordingly, the stator core 231 can be directly in contact with the stator frame portion 210 through the mounting grooves (214, 214a) even if there is no separate fixing projection or fixing means (not shown).

In this case, heat to be generated at the lower side of the stator core 231 is transferred directly to the stator frame portion 210, and thus can be transferred and dissipated through the stator frame portion 210.

Meanwhile, the cap portion 220 includes a cap ring portion 227 of a circular ring plate shape that covers the upper portion of the winding portion 230, and a cap plane portion 227 to secure the stator core 231. The second outer wall portion 228 and the second inner wall portion 229 are formed at the outer circumference portion and the inner circumference portion, respectively.

The seating grooves 224 and 224a of the cap portion 220 may have a second outer wall portion 228 or a second inner wall portion of the cap portion 220 so as to secure a depth d for a spaced space from the cap plane portion 227. It is formed in the lower part of 229, respectively.

By the depth d of the cap 220, a clearance space may be secured inside the cap 220.

At this time, the second chamfer 224b is formed at both sides of the seating grooves 224 and 224a of the cap 220 at an angle corresponding to the side inclination angle of the outer head or the inner head of the stator core 231, respectively. Can be.

Since the surface of the second chamfer 224b also corresponds to the inclined surface having a relatively large surface area compared to the general plane, the heat transfer efficiency is relatively excellent and a stable coupling state can be maintained.

Accordingly, the separate stator core 231 may be in direct contact with the cap portion 220 through the mounting grooves 224 and 224a even without the fixing coupling protrusion or the fixing means.

In this case, heat to be generated at the upper side of the stator core 231 is transferred directly to the cap portion 220, so that it can be transmitted and radiated through the cap portion 220.

In particular, when the winding part 230 is assembled to the cap part 220, a gap space may also be formed between the inner surface of the cap part 220 and the upper portion of the winding part 230, so that heat is transferred through the gap space. Cooling convection may be generated smoothly, and as a result, it may be possible to increase the heat dissipation effect of the stator 200.

In addition, each of the stator frame portion 210 and the cap portion 220 of the stator 200 is made of an aluminum alloy material, the heat transfer efficiency is relatively good compared to other iron plate material can improve the heat dissipation characteristics.

In addition, the stator 200 may also have an effect of compensating the magnetic loss of the stator 200 by covering the upper and lower portions of the winding part 230 by the stator frame part 210 and the cap part 220. .

Hereinafter, the assembly state and the operating method according to the present embodiment will be described.

FIG. 6 is a cross-sectional view illustrating an assembling state and a method of operating the double rotor and single stator type BLDC motor shown in FIG. 1.

Referring to FIG. 6, the motor shaft 120 has a hollow or solid (not shown) shaft shape, and the shaft front part 123 and the shaft for supporting the bearing 114 for the casing cover 110. A stator shaft connecting portion 121 having a circular plate shape protruding from the circumferential surface of the rear portion of the front portion 123 (for example, the middle portion of the motor shaft), and a rear portion of the stator shaft connecting portion 121 (for example, the rear portion of the motor shaft). In order to support the bearing 104 for the casing body 100 may include a shaft rear portion 124 having a circular block shape of a relatively large diameter compared to the shaft front portion 123.

Here, the inlet hole 125 for passing the power line 190 for applying power to the control unit to be in close contact with the stator 200 may be formed in the shaft rear portion 124.

Both ends of the motor shaft 120 is further provided with a bolt hole for fastening the mounting bolt, it can be mounted or coupled to the place of use.

The bearings 104 and 114 of the motor shaft 120 may play a role of rotatably supporting the casing body 100 or the casing cover 110, respectively.

In addition, the stator 200 may be coupled to the motor shaft 120 through the boss 211 and the stator shaft connecting portion 121.

The outer rotor 130 may be disposed on the outer ring side with the winding portion 230 of the stator 200 at the center thereof, and the inner rotor 150 may have a play on the inner ring side of the stator 200. Can be placed while maintaining.

That is, the stator 200 may be disposed while maintaining a clearance in the space between the outer rotor 130 and the inner rotor 150.

When the motor control operation of the control unit in this arrangement state, by the outer rotor 130 and the inner rotor 150 in response to the operation of the stator 200, the casing cover 110 and the casing body 100 is the motor shaft Rotation is possible based on bearings 104 and 114 of 120.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. For example, a person skilled in the art can change the material, size and the like of each constituent element depending on the application field or can combine or substitute the embodiments in a form not clearly disclosed in the embodiment of the present invention, Of the range. Therefore, it should be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive, and that such modified embodiments are included in the technical idea described in the claims of the present invention.

100: casing body 110: casing cover
120: motor shaft 130: external rotor
131: outer yoke 132: outer magnet
150: internal rotor 151: inner yoke
152: internal magnet 200: stator
210: stator frame portion 220: cap portion
230: windings 231: stator core

Claims (5)

A casing body integrally formed with an inner rotor having an inner magnet and an outer rotor having an outer magnet so as to form a rear portion of the motor casing so that the motor casing rotates around the motor shaft; A casing cover coupled to the casing body at the front of the motor casing; And a cap disposed between the inner magnets arranged on the inner rotor and the outer magnets arranged on the outer rotor to cover the upper portion of the winding part installed in the stator frame part with a cap part. In the BLDC motor including a stator coupled to the motor shaft,
A stator frame having a boss for fixing the stator to the motor shaft, a plurality of supports formed on the outside of the boss, an outer ring portion connected to be supported by the support, and a size corresponding to an outer diameter of the outer ring portion And a winding portion in which a plurality of stator cores are arranged to maintain a predetermined distance along the circumferential direction between the cap portion having a shape and the stator frame portion and the cap portion.
The first outer wall portion or the first inner wall portion of the first outer wall portion so as to secure a height for the spaced apart space from the outer ring portion and the circular first outer wall portion and the first inner wall portion formed in the outer ring portion of the stator frame portion. And a seating groove formed at an upper portion of the side wall portion, and a chamfer formed at an angle corresponding to a side inclination angle of an outer head or an inner head of the stator core at both sides of each of the seating grooves.
Double rotor and single stator type BLDC motors.
The method of claim 1,
A control unit installed on the stator to control a motor;
Double rotor and single stator type BLDC motors.
delete delete The method of claim 1,
The cap portion of the stator,
A cap plane portion having a circular ring plate shape covering an upper portion of the winding portion;
A second outer wall portion and a second inner wall portion formed at an outer circumference portion and an inner circumference portion of the cap plane portion;
A seating recess formed in each of a lower portion of the second outer wall portion or a lower portion of the second inner wall portion so as to secure a depth for the space spaced from the cap plane portion;
A second chamfer formed at both sides of each of the seating recesses at an angle corresponding to a side inclination angle of an outer head or an inner head of the stator core;
Double rotor and single stator type BLDC motors.

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