WO2024039067A1

WO2024039067A1 - Rotor core structure of motor and rotor of motor including the same

Info

Publication number: WO2024039067A1
Application number: PCT/KR2023/009493
Authority: WO
Inventors: Gyeong Jae Park; Jae Min Kim; Wonjung SUNG; Jeongmin Lee
Original assignee: Lg Electronics Inc.
Priority date: 2022-08-18
Filing date: 2023-07-05
Publication date: 2024-02-22
Also published as: KR20240025399A

Abstract

There is disclosed a rotor core structure of a motor including an annular base; a plurality of yokes disposed along a circumferential direction of the base; a plurality of core layers multilayered on each other, the plurality of core layers comprising a bridge portion connecting at least one pair of yokes facing each other among the plurality of yokes with the base, wherein each of the plurality of core layers are multilayered on each other by rotating adjacent ones by a preset angle.

Description

ROTOR CORE STRUCTURE OF MOTOR AND ROTOR OF MOTOR INCLUDING THE SAME

The present disclosure relates to a rotor core structure of a motor and a rotor of a motor including the same, more particularly, to a rotor core structure of a motor that may improve efficiency of the motor by changing a multilayer structure of a rotor core of a spoke motor and minimize leakage flux by partially removing a bridge portion of the rotor core, and a rotor of a motor including the same.

A motor is a mechanism configured to covert electrical energy into mechanical energy and is used as a driving source in various devices.

In general, such a motor includes a stator and a rotor. Specifically, the stator is provided with a casing defining an exterior thereof and a coil wound around an inner surface of the casing. The rotor is rotatably provided inside the stator with a predetermined air gap. The rotor may include a rotary shaft, a core coupled to the shaft, and a permanent magnet inserted in the core.

When power is applied to the stator, electromagnetic force is generated between the permanent magnet of the rotor and the coil of the stator to rotate the rotor.

Meanwhile, motors are divided into several types according to a method of generating rotational force. Among them, a spoke motor is a type in which permanent magnets are arranged side by side with respect to the rotor in a radial direction.

The spoke motor has a bridge portion for holding a pole piece at the center of the rotor core due to the spoke-shaped arrangement of permanent magnets. However, the spoke motor has a problem in that the output of the motor is decreased by leakage flux generated in the bridge portion holding the pole piece.

Accordingly, there is a need for a technical solution capable of minimizing leakage flux and improving motor efficiency by partially removing the bridge portion provided in the rotor core of the spoke motor.

There is KR 10-2016-0132512 (published on November 21, 2016) as the background art and it discloses a multilayer structure of a rotor core.

In the rotor core disposed in the background art, that is, the multilayer structure of the rotor core, a first core provided as a single sheet core and including a bridge portion and a second core layer provided as a single sheet core from which a base and a bridge portion are removed are alternately layered, to increase the output of the motor.

However, the conventional rotor core disclosed in the background art has a disadvantage in that the mold structure is complicated and the manufacturing cost is increased to realize the multilayer structure in the area from which the base and the bridge portion are removed. In addition, the conventional multilayer structure of the conventional rotor core has a disadvantage in that deformation or detects are highly likely to occur during the transportation and handling due to a weakened tangential direction supporting force.

Accordingly, one objective of the present disclosure is to provide a rotor core structure of a motor that may improve the output of a motor and reduce the weight thereof by partially removing a bridge portion and then leakage flux, and a rotor of a motor including the same.

Another objective of the present disclosure is to provide a rotor core structure of a motor multilayered by rotating a single sheet core including at least two bridge portions to a preset angle, unlike the conventional rotor core structure formed by alternately multilayering the single sheet core including the bridge portion and the single sheet core without the bridge portion in the rotor core, and a rotor of a motor including the same.

A further objective of the present disclosure is to provide a rotor core structure of a motor that may be transported and handled without deformation by maintaining a tangential direction supporting force due to uniformly distribution of a bridge portion connecting structure, and a rotor of a motor including the same.

A further objective of the present disclosure is to provide a rotor core structure of a motor that may be multilayered by changing only a punching angle using a single type rotor mold punch and then may significantly reducing the mold cost, compared to various punch methods.

Aspects according to the present disclosure are not limited to the above ones, and other aspects and advantages that are not mentioned above can be clearly understood from the following description and can be more clearly understood from the embodiments set forth herein. Additionally, the aspects and advantages in the present disclosure can be realized via means and combinations thereof that are described in the appended claims.

In an aspect of the present disclosure, a rotor core structure of a motor in which a single sheet core having at least two or more bridge portions is multilayered by rotating that single sheet core, unlike the conventional method of alternately multilayering the single sheet core having the bridge portion and the single core without the bridge portion in the rotor core.

A rotor core structure of a motor according to an embodiment of the present disclosure may include an annular base; a plurality of yokes disposed along a circumferential direction of the base; a plurality of core layers multilayered on each other, the plurality of core layers comprising a bridge portion connecting at least one pair of yokes facing each other among the plurality of yokes with the base. Each of the plurality of core layers may be multilayered on each other by rotating adjacent ones by a preset angle.

Here, the angle at which each of the core layers multilayered on each other is rotated may be one of 45°, 90° and 135°.

According to an embodiment of the present disclosure, the plurality of core layers may include a first bridge portion connecting a first yoke arranged at a first position of the base among the plurality of yokes with the base; and a second bridge portion connecting a second yoke facing the first yoke with the base, the second bridge portion disposed on the same line with the first bridge portion.

According to an embodiment of the present disclosure, the plurality of core layers may further include a second core layer disposed on the first core layer, and the second core layer may include a third bridge portion connecting a third yoke arranged at a second position rotated from the first yoke by 45° with the base; and a fourth bridge portion connecting a fourth yoke facing the third yoke with the base, the fourth bridge portion disposed on the same line with the third bridge.

According to an embodiment of the present disclosure, the plurality of core layers may further include a third core layer disposed on the second core layer, and the third core layer may include a fifth bridge portion connecting a fifth yoke arranged at a third position rotated from the first yoke by 90° with the base; and a sixth bridge connecting a sixth yoke facing the fifth yoke with the base, the sixth bridge portion disposed on the same line with the fifth bridge portion.

According to an embodiment of the present disclosure, the plurality of core layers may further include a fourth core layer disposed on the third core layer, and the fourth core layer may include a seventh bridge portion connecting a seventh yoke arranged at a fourth position rotated from the first yoke by 135°with the base; and an eighth bridge connecting a seventh yoke facing the seventh yoke with the base, the eighth bridge portion disposed on the same line with the seventh bridge portion.

Each of the plurality of core layers may further include a first magnet inserting portion formed between the plurality of yokes and inserting a first magnet therein in a radial direction of each of the plurality of yokes.

Each of the plurality of core layers may further include a second magnet provided inside each of the plurality of yokes and inserting a second magnet therein.

The second magnet inserting portion may be provided at an end of each of the plurality of yokes and may be a straight hole. The first magnet may have a first length and the second magnet may have a second length. The first length of the first magnet may be greater than the second length of the second magnet.

Each of the plurality of core layers may include a support protrusion supporting one end of the first magnet by protruding between the plurality of bridge portions toward the first magnet inserting portion by a preset length.

Each of the plurality of core layers may further include a shaft inserting hole provided at the center of the base, the shaft inserting hole through which a shaft inserted.

Each of the plurality of core layers may further include a fixing pin inserting hole formed inside each of the plurality of yokes, the fixing pin inserting hole through which a fixing pin is inserted.

At this time, the second magnet may be disposed at a position farther than the fixing pin inserting hole in a radial direction with respect to the center of the rotor core in each of the plurality of yokes.

At least one interlock portion may be formed inside each of the plurality of yokes.

In another aspect of the present disclosure, a rotor of a motor in which a single sheet core having at least two or more bridge portions is multilayered by rotating that single sheet core, unlike the conventional method of alternately multilayering the single sheet core having the bridge portion and the single core without the bridge portion in the rotor core.

According to an embodiment of the present disclosure, a rotor of a motor may include an annular base; a plurality of yokes disposed along a circumferential direction of the base; and a plurality of core comprising a plurality of bridge portions connecting at least one pair of yokes facing each other among the plurality of yokes with the base. Each of the plurality of core layers may include a rotor core multilayered on each other by rotating adjacent ones by a preset angle; and a first magnet inserted in a first magnet inserting portion provided between the plurality of yokes, the first magnet disposed in the rotor core.

In the rotor of the motor according to an embodiment of the present disclosure, the plurality of core layers may include a first bridge portion connecting a first yoke arranged at a first position of the base among the plurality of yokes with the base; and a second bridge portion connecting a second yoke facing the first yoke with the base, the second bridge portion disposed on the same line with the first bridge portion.

In the rotor of the motor according to an embodiment of the present disclosure, the plurality of core layers may further include a second core layer disposed on the first core layer, and the second core layer may include a third bridge portion connecting a third yoke arranged at a second position rotated from the first yoke by 45°with the base; and a fourth bridge portion connecting a fourth yoke facing the third yoke with the base, the fourth bridge portion disposed on the same line with the third bridge.

In the rotor of the motor according to an embodiment of the present disclosure, the plurality of core layers may further include a third core layer disposed on the second core layer, and the third core layer may include a fifth bridge portion connecting a fifth yoke arranged at a third position rotated from the first yoke by 90° with the base; and a sixth bridge connecting a sixth yoke facing the fifth yoke with the base, the sixth bridge portion disposed on the same line with the fifth bridge portion.

In the rotor of the motor according to an embodiment of the present disclosure, the plurality of core layers may further include a fourth core layer disposed on the third core layer, and the fourth core layer may include a seventh bridge portion connecting a seventh yoke arranged at a fourth position rotated from the first yoke by 135°with the base; and an eighth bridge connecting a seventh yoke facing the seventh yoke with the base, the eighth bridge portion disposed on the same line with the seventh bridge portion.

The rotor of the motor according to an embodiment of the present disclosure may further include a second magnet inserted into a second magnet inserting portion provided in each of the plurality of yokes.

The first magnet may be inserted in a first magnet inserting portion disposed between the plurality of yokes, and may be disposed in the rotor core in a radial direction. the first magnet refers to a main permanent magnet provided as a spoke type.

The second magnet may be inserted into a second magnet inserting portion provided in each of the plurality of yokes.

In the rotor of the motor according to an embodiment of the present disclosure, the second magnet may be disposed on the outside of the rotor core around a radial direction.

In the rotor of the motor according to an embodiment of the present disclosure, the second magnet inserting portion may be disposed at an end of each of the plurality of yokes, and may be a straight hole formed by crossing a radial direction of the rotor core. Together with a first magnet disposed in the rotor core in a spoke type, a second magnet disposed in a radial direction by utilizing an idle space of an outer end of the yoke may be applied to the rotor core at the same time. Accordingly, since the second magnet is added by utilizing the idle space inside the yoke as much as possible, while maintaining the basic structure of the spoke motor, the design change of the motor structure may be minimized and electromotive force of the motor may be improved, thereby reducing copper loss and improving motor efficiency. In addition, current application may be reduced, thereby improving the performance of a demagnetizer.

In the rotor of the motor according to an embodiment of the present disclosure, the first magnet may be disposed in the rotor core to have a first length along a radial direction. The second magnet may be disposed at one end of each yoke and disposed to have a second length by crossing a radial direction of the rotor core. At this time, the first length of the first magnet may be greater than the second length of the second magnet. While the first magnet is disposed in the spoke type along the radial direction of the rotor core, the second magnet shorter than the first magnet may be disposed at the end of the yoke in a direction crossing the radial direction of the rotor core. Accordingly, the second magnet may be further provided by utilizing the idle space inside the yoke even while minimizing design change by maintaining the basic structure of the spoke motor and the electromotive force of the motor may be improved. Accordingly, copper loss may be reduced and motor efficiency may be improved, and current application may be reduced, thereby improving the performance of the demagnetizer.

A second magnet inserting portion and the fixing pin inserting hole may be spaced apart a preset distance from each other. Accordingly, rigidity deterioration of the rotor core, in particular, the yoke may be prevented, thereby securing structural stability.

In the rotor of the motor according to an embodiment of the present disclosure, at least one interlock portion may be formed inside each of the plurality of yokes. The interlock portion may be disposed at a position of each yoke closer to a radial direction than the fixing pin inserting hole with respect to the center of the rotor core. The second magnet may be disposed on the outside of the yoke and the interlock portion may be disposed on the inside of the yoke. Accordingly, the idle space of the yoke may be utilized as much as possible, and the multilayered state of the rotor core may be maintained by the interlock portion. In addition, since the second magnet is added, the electromotive force of the motor may be improved, thereby reducing the copper loss and improving the motor efficiency. Also, the interlock portion may be disposed on the same line with the bridge portion in the radial direction, and may have a straight shape with a predetermined length. Accordingly, the multilayered state of the rotor core may be maintained, and deformation of the rotor core and scattering of the first and second magnet may be prevented.

The rotor of the motor according to an embodiment of the present disclosure may include may include a first end plate coupled to one end of the rotor core; and a second end plate coupled to the other end of the rotor core.

According to present disclosure, the bridge portion disposed at the center of the rotor core may be partially removed to reduce leakage flux, thereby having an effect of improving the output of the motor and reducing the weight of the motor. For example, leakage flux may be prevented in the portion where the bridge portion is removed, thereby improving the put of the motor by 9% or more compared with the conventional spoke motor.

In addition, unlike the conventional method of alternately multilayering the single sheet core having the bridge portion and the single core without the bridge portion in the rotor core, the single sheet core having at least two or more bridge portions may be multilayered in the rotor core by rotating that single sheet core.

In addition, the structure of connecting the bridge portions may be uniformly distributed enough to maintain the tangential direction supporting force, thereby advantageously preventing deformation and defects during transportation and handling processes.

In addition, according to the embodiments of the present disclosure, the multilayer structure may be facilitated by changing only the punching angle using one type rotor mold punch, thereby having an effect of significantly reducing the mold cost has an effect of compared with the variable punch methods. For example, the multilayered structure may be facilitated by changing only the punch angle by 45° using one type rotor mold punch. Due to this structure, the embodiments of the present disclosure may have the advantage of reducing the mold cost by 5% or more compared with the conventional variable punch method. In addition, since the design margin for the target efficiency may be increased, the magnet grade may be lowered. Accordingly, the embodiments of the present disclosure may have the advantage of reducing the material cost by amount 3% or more.

Specific effects are described along with the above-described effects in the section of Detailed Description.

FIG. 1 is a perspective view schematically showing a rotor of a motor according to an embodiment of the present disclosure;

FIG. 2 is a perspective view schematically showing a rotor of a motor according to an embodiment of the present disclosure;

FIG. 3 is a perspective view schematically showing a shape of a rotor of a motor according to an embodiment of the present disclosure that is coupled to a shaft;

FIG. 4 is a plane view showing a bridge portion of a first core layer constituting a rotor core structure of a motor according to an embodiment of the present disclosure;

FIG. 5 is a plane view showing a bridge portion of a second core layer constituting a rotor core structure of a motor according to an embodiment of the present disclosure;

FIG. 6 is a plane view showing a bridge portion of a third core layer constituting a rotor core structure of a motor according to an embodiment of the present disclosure;

FIG. 7 is a plane view showing a bridge portion of a third core layer constituting a rotor core structure of a motor according to an embodiment of the present disclosure; and

FIG. 8 is a plane view showing another modified example of a rotor core structure of a motor according to an embodiment of the present disclosure.

The above-described aspects, features and advantages are specifically described hereunder with reference to the accompanying drawings such that one having ordinary skill in the art to which the present disclosure pertains can easily implement the technical spirit of the disclosure. Aspects according to the present disclosure are not limited to the above ones, and other aspects and advantages that are not mentioned above can be clearly understood from the following description and can be more clearly understood from the embodiments set forth herein.

In the disclosure , detailed descriptions of known technologies in relation to the disclosure are omitted if they are deemed to make the gist of the disclosure unnecessarily vague . Below, preferred embodiments according to the disclosure are specifically described with reference to the accompanying drawings. In the drawings, identical reference numerals can denote identical or similar components. The above-described aspects, features and advantages are specifically described hereunder with reference to the accompanying drawings such that one having ordinary skill in the art to which the present disclosure pertains can easily implement the technical spirit of the disclosure. In the disclosure , detailed descriptions of known technologies in relation to the disclosure are omitted if they are deemed to make the gist of the disclosure unnecessarily vague .

It will be understood that although the terms first, second, A, B (a), (b), etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another. It will be understood that when an element is referred to as being "connected with" or "coupled to" another element, the element can be directly connected with the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly connected with" another element, there are no intervening elements present.

In implementing the present disclosure, for the convenience of explanation, components may be subdivided and described. However, the components may be realized within a single device or module, or a single component may be divided and implemented across multiple devices or modules.

Hereinafter, referring to the accompanying drawings, a rotor 10 of a motor according to an embodiment of the present disclosure will be described in detail.

FIG. 1 is a perspective view schematically showing a rotor of a motor according to an embodiment of the present disclosure. FIG. 2 is a perspective view schematically showing a rotor of a motor according to an embodiment of the present disclosure. FIG. 3 is a perspective view schematically showing that first and second endplates and a shaft are coupled to a rotor of a motor.

As shown in the drawings, the rotor 10 of the motor may include a rotor core 100, a first magnet 200 and a second magnet 300.

The rotor core 100 may include a base 110, a plurality of yokes 120 and a plurality of bridge portions 140.

The base 110 may be an annular body disposed at the center of the rotor core 100.

A shaft inserting hole 170 with a predetermined diameter may be provided at the center of the base 110.

A shaft 500 (see FIG. 3) may be inserted through the shaft inserting hole 170 and coupled to the base 110.

The plurality of yokes 120 may be connected as one body in a fan shape having a constant arc size along a circumferential direction of the base 110.

The plurality of bridge portions 140 may connect between the base 110 and the plurality of yokes 120.

More specifically, the plurality of

bridge portions

1401 and 1402 may be provided to connect at least one pair of

yokes

1201 and 120, which face each other among the plurality of yokes 120, with the base 110 (see FIG. 4).

The base 110, the plurality of yokes 120 and the plurality of bridge portions 140 may be integrally connected as one body to constitute the rotor core 100.

The first magnet 200 may be a main magnet basically disposed in the motor, that is, a spoke motor. In other words, the first magnet 200 may be a magnet with the length corresponding to the radial length of the rotor core 10, and a plurality of first magnets 200 may be coupled to the rotor core 10 in the form of a plurality of spokes.

The first magnet 200 may be inserted in a first magnet inserting portion 130 disposed between the plurality of yokes 120 to be disposed on the rotor core 100 in a radial direction.

The rotor 10 of the motor according to an embodiment of the present disclosure may further include a second magnet 300 in addition to the first magnet 200 by utilizing a partial space of the yoke 120, that is, an idle space. Accordingly, it is possible to reduce copper loss and improve motor efficiency by improving the counter electromotive force of the motor, and it is also possible to reduce the application of current, thereby improving the performance of a demagnetizer.

The second magnet 300 may be inserted in a second magnet inserting portion 160 disposed in each of the yokes 120.

For example, a plurality of second magnets 300 may be disposed around the outside of the rotor core 100 along a circumferential direction. To this end, the second magnet inserting portion 160 may be disposed at an end of each yoke 120, and may have a straight hole shape crossing the radial direction of the rotor core 100.

The first magnet 200 may have a first length along a radial direction of the rotor core 100. The first length of the first magnet 200 may have the same length as the radius of the rotor core 100.

The second magnet 300 may be provided an end of each yoke 120, and may have a second length crossing the radial direction of the core 100.

For example, the first length of the first magnet 200 may be greater than the second length of the second magnet 300.

Accordingly, while minimizing the structure change by maintaining the basic structure of the spoke motor, the first and second magnets may be simultaneously provided and thus the effects of improving counter electromotive force of the motor, reducing copper loss and improving motor efficiency may be expected. In addition, current application may be reduced and performance of the demagnetizer may be improved.

The rotor core 100 may further include a shaft inserting hole 170 and a fixing pin inserting hole 180.

The shaft inserting hole 170 may be provided in a hollow formed inside the annular base 110, and a shaft 500 (see FIG. 3) may be insertedly coupled to the shaft inserting hole 170.

The fixing pin inserting hole 180 may be formed inside each yoke 120 and it means a hole through which a fixing pin (not shown) is inserted.

At this time, the second magnet inserting portion 160 may be disposed at a position that is farther along a radial direction with respect to the center of the rotor core 100. Accordingly, a decrease in rigidity of the yoke 120 may be prevented.

Meanwhile, the rotor core 100 of the motor according to an embodiment of the present disclosure may include a support protrusion 141. The support protrusion 141. The support protrusion 141 may be a protrusion protruding toward the first magnet inserting portion 130 from the base 110 in the radial direction.

The support protrusion 141 may contact and support one end of the first magnet 200 inserted into the first magnet inserting portion 130 to prevent the first magnet 200 from scattering, and may be stably disposed at a preset position.

Meanwhile, a magnet fixing portion 150 may be further provided at each of both circumferential-direction ends of the yoke 120 to fix the first magnet 200 by locking the other end of the first magnet 200.

The magnet fixing portion 150 may include a first fixing protrusion 151 protruding from one circumferential-direction end of the yoke 120, and a second fixing protrusion 152 protruding from the other circumferential-direction end of the yoke 120, to lock the other end of the first magnet 200 in both sides.

Referring to FIG. 3, the first end plate 410 and the second end plate 420 may be coupled to one end and the other end of the rotor core 100, respectively. The first end plate 410 and the second end plate 420 may maintain the multilayered state of the rotor core 100 and prevent the scattering of the first and

second magnets

200 and 300.

Hereinafter, a plurality of

core layers

100a, 100b, 100c and 100d (see FIGS. 4 to 7) constituting the rotor core 100 according to embodiments of the present disclosure will be described.

The rotor core 100 according to the embodiments of the present disclosure may have a structure in which a single sheet core having at least two or more bridge portions are layered on the rotor core 100 by rotating the single sheet cores at a set angle, for example, 0°, 45°, 90° and 135°. Accordingly, the overall rotor core 100 may have the structure in which a plurality of core layers, for example, first, second, third and

fourth core layers

100a, 100b, 100c and 100d (see FIGS. 4 to 7) are multilayered vertically.

FIG. 4 is a plane view showing a bridge portion of a first core layer 100a constituting a rotor core structure of a motor according to an embodiment of the present disclosure.

Referring to FIG. 4, the first core layer 100a has a multilayer structure with respect to 0° at which it is not rotated at a set angle.

For example, the first core layer 100a may include a first bridge 140 connecting a first yoke 1201 disposed at a first position of the base 110 (i.e., a 12 o'clock direction) with the base 110.

In addition, the first core layer 100a may include a second bridge 1402 connecting a second yoke 1202 facing the first yoke 1201 with the base 110.

As described above, the first bridge 1401 and the second bridge 1402 may be positioned on the same line. In other words, when the first bridge 1401 is positioned in the 12 o'clock direction of the base 110, the second bridge 1402 may be positioned in a 6 o'clock direction of the base to be disposed on the same line together.

FIG. 5 is a plane view showing a bridge portion of a second core layer 100b constituting a rotor core structure of a motor according to an embodiment of the present disclosure.

The second core layer 100b may be layered on the first core layer 100a of FIG. 4 to form the overall rotor core 100.

Referring to FIG. 5, the second core layer 100b may have a multilayered structure rotated by 45°.

For example, the second core layer 100b may include a third bridge 1403 connecting a third yoke 1203 arranged at a second position of the base 110 with the base 110. Here, the second position refers to a position rotated in a counterclockwise direction by 45° from the first yoke 1201 (see FIG. 4).

In addition, the second core layer 100b may include a fourth bridge 1404 connecting a fourth yoke 1204 facing the third yoke 1203 with the base 110.

As described above, the third bridge 1403 and the fourth bridge 1404 may be positioned on the same line. In other words, the third bridge 1403 may be formed at a position where the first bridge 1401 (see FIG. 4) is rotated in a counterclockwise direction by 45°, and the fourth bridge 1404 may be formed at a position where the second bridge 1402 (see FIG. 4) is rotated in the counterclockwise direction by 45°. The third bridge 1403 and the fourth bridge 1404 may be disposed to face each other on the same line.

FIG. 6 is a plane view showing a bridge portion of a third core layer 100c constituting a rotor core structure of a motor according to an embodiment of the present disclosure.

The third core layer 100c may form the overall rotor core 100 by being multilayered on the second core layer 100b of FIG. 5.

Referring to FIG. 6, the third core layer 100c may have a multilayer structure rotated by 90°.

For example, the third core layer 100c may include a fifth bridge 1405 connecting a fifth yoke 1205 arranged at a third position of the base 110 with the base 110. Here, the third position refers to a position rotated in a counterclockwise direction by 90° from the first yoke 1202 (see FIG. 4).

In addition, the third core layer 100c may include a sixth bridge 1406 connecting a sixth yoke 1206 facing the fifth yoke 1205 with the base 110.

As described above, the fifth bridge 1405and the sixth bridge 1406 may be positioned on the same line. In other words, the fifth bridge 1405 may be formed at a position where the first bridge 1401 (see FIG. 4) is rotated in the counterclockwise direction by 90°, and the sixth bridge 1406 may be formed at a position where the second bridge 1402 (see FIG. 4) is rotated in the counterclockwise direction by 90°. The fifth bridge 1405and the sixth bridge 1406 may be disposed on the same line, while facing each other.

FIG. 7 is a plane view showing a bridge portion of a third core layer 100d constituting a rotor core structure of a motor according to an embodiment of the present disclosure.

The fourth core layer 100d may be layered on the third core layer 100c of FIG. 6 to form the overall rotor core 100.

Referring to FIG. 7, the fourth core layer 100d may have a multilayer structure rotated by 135°.

For example, the fourth core layer 100d may include a seventh bridge 1407 connecting a seventh yoke 1207 arranged at a fourth position of the base 110 with the base 110. Here, the fourth position refers to a position rotated in the counterclockwise direction by 135° from the first yoke 1201 (see FIG. 4).

In addition, the fourth core layer 100d may include an eighth bridge 1408 connecting an eighth yoke 1208 facing the seventh yoke 1207 with the base 110.

As described above, the seventh bridge 1407 and the eighth bridge 1408 may be positioned on the same line. In other words, the seventh bridge 1407 may be formed at a position where the first bridge 1401 (see FIG. 4) is rotated in the counterclockwise direction by 135°. The seventh bridge 1407 and the eighth bridge 1408 may be disposed on the same line, while facing each other.

The first magnet inserting portion 130 (see FIG. 2) and the second magnet inserting portion 160 (see FIG. 2) may be provided on each of the plurality of

core layers

100a, 100b, 100c and 100d. The first magnet inserting portion 130 may be configured to insert the first magnet 200 therein in the radial direction of the plurality of yokes 120. The second magnet inserting portion 160 may be configured to insert the second magnet 300 into the inside of each of the plurality of yokes 120 (see FIG. 1).

Meanwhile an interlock portion may be further provided in an idle space of the plurality of yokes 120. For example, the second magnet 300 may be disposed at one end of the yoke 120 and a separate interlock portion (not shown) may be formed inside the yoke 120. The interlock portion 190 may prevent deformation of the rotor core 100 to improve an effect of maintaining the multilayered state and provide a function of preventing scattering of the first and

second magnet

200 and 300.

Referring to FIG. 8, the core layer 100e shown in the drawing may have a structure in which

fourth yokes

1201, 1202, 1205 and 1206 are facing each other are connected in a cross shape by four

bridge portions

1401, 1402, 1405 and 1406. As described above, at least two or more bridge portions connecting the plurality of yokes with the annular base disposed at the center may be appropriately changed and used.

The rotor core 100 according to the embodiments of the present disclosure may reduce the number of the bridge portions 140, thereby reducing leakage flux. This technical feature is characterized in that the core layer, in which only bridge portion partially remains, is multilayered vertically while rotating the core layer by a preset angle, unlike the conventional rotor core according to the prior art, that is, the structure in which the portion with the bridge and the other portion without the bridge are alternately multilayered.

As described above, according to the configuration and operation of the present disclosure, the bridge portion disposed at the center of the rotor core may be partially removed to reduce leakage flux, thereby having an effect of improving the output of the motor and reducing the weight of the motor. For example, leakage flux may be prevented in the portion where the bridge portion is removed, thereby improving the put of the motor by 9% or more compared with the conventional spoke motor.

The embodiments are described above with reference to a number of illustrative embodiments thereof. However, the present disclosure is not intended to limit the embodiments and drawings set forth herein, and numerous other modifications and embodiments can be devised by one skilled in the art. Further, the effects and predictable effects based on the configurations in the disclosure are to be included within the range of the disclosure though not explicitly described in the description of the embodiments.

Claims

A rotor core structure of a motor comprising:

an annular base;

a plurality of yokes disposed along a circumferential direction of the base;

a plurality of core layers multilayered on each other, the plurality of core layers comprising a bridge portion connecting at least one pair of yokes facing each other among the plurality of yokes with the base,

wherein each of the plurality of core layers are multilayered on each other by rotating adjacent ones by a preset angle.
The rotor core structure of the motor of claim 1, wherein the plurality of core layers comprises,

a first bridge portion connecting a first yoke arranged at a first position of the base among the plurality of yokes with the base; and

a second bridge portion connecting a second yoke facing the first yoke with the base, the second bridge portion disposed on the same line with the first bridge portion.
The rotor core structure of the motor of claim 2, wherein the plurality of core layers further comprises,

a second core layer disposed on the first core layer, and

the second core layer comprises,

a third bridge portion connecting a third yoke arranged at a second position rotated from the first yoke by 45°with the base; and

a fourth bridge portion connecting a fourth yoke facing the third yoke with the base, the fourth bridge portion disposed on the same line with the third bridge.
The rotor core structure of the motor of claim 3, wherein the plurality of core layers further comprises,

a third core layer disposed on the second core layer, and

the third core layer comprises,

a fifth bridge portion connecting a fifth yoke arranged at a third position rotated from the first yoke by 90°with the base; and

a sixth bridge connecting a sixth yoke facing the fifth yoke with the base, the sixth bridge portion disposed on the same line with the fifth bridge portion.
The rotor core structure of the motor of claim 3, wherein the plurality of core layers further comprises,

a fourth core layer disposed on the third core layer, and

the fourth core layer comprises,

a seventh bridge portion connecting a seventh yoke arranged at a fourth position rotated from the first yoke by 135°with the base; and

an eighth bridge connecting a seventh yoke facing the seventh yoke with the base, the eighth bridge portion disposed on the same line with the seventh bridge portion.
The rotor core structure of the motor of claim 1, wherein each of the plurality of core layers further comprises,

a first magnet inserting portion formed between the plurality of yokes and inserting a first magnet therein in a radial direction of each of the plurality of yokes.
The rotor core structure of the motor of claim 6, wherein each of the plurality of core layers further comprises,

a second magnet provided inside each of the plurality of yokes and inserting a second magnet therein.
The rotor core structure of the motor of claim 1, wherein each of the plurality of core layers comprises,

a support protrusion supporting one end of the first magnet by protruding between the plurality of bridge portions toward the first magnet inserting portion by a preset length.
The rotor core structure of the motor of claim 1, wherein each of the plurality of core layers further comprises,

a shaft inserting hole provided at the center of the base, the shaft inserting hole through which a shaft inserted.
The rotor core structure of the motor of claim 1, wherein each of the plurality of core layers further comprises,

a fixing pin inserting hole formed inside each of the plurality of yokes, the fixing pin inserting hole through which a fixing pin is inserted.
The rotor core structure of the motor of claim 1, wherein at least one interlock portion is formed inside each of the plurality of yokes.
A rotor of a motor comprising:

an annular base;

a plurality of yokes disposed along a circumferential direction of the base; and

a plurality of core comprising a plurality of bridge portions connecting at least one pair of yokes facing each other among the plurality of yokes with the base,

wherein each of the plurality of core layers comprises,

a rotor core multilayered on each other by rotating adjacent ones by a preset angle; and

a first magnet inserted in a first magnet inserting portion provided between the plurality of yokes, the first magnet disposed in the rotor core.
The rotor of the motor of claim 12, wherein the plurality of core layers comprises,

a first bridge portion connecting a first yoke arranged at a first position of the base among the plurality of yokes with the base; and

a second bridge portion connecting a second yoke facing the first yoke with the base, the second bridge portion disposed on the same line with the first bridge portion.
The rotor of the motor of claim 13, wherein the plurality of core layers further comprises,

a second core layer disposed on the first core layer, and

the second core layer comprises,

a third bridge portion connecting a third yoke arranged at a second position rotated from the first yoke by 45°with the base; and

a fourth bridge portion connecting a fourth yoke facing the third yoke with the base, the fourth bridge portion disposed on the same line with the third bridge.
The rotor of the motor of claim 14, wherein the plurality of core layers further comprises,

a third core layer disposed on the second core layer, and

the third core layer comprises,

a fifth bridge portion connecting a fifth yoke arranged at a third position rotated from the first yoke by 90°with the base; and

a sixth bridge connecting a sixth yoke facing the fifth yoke with the base, the sixth bridge portion disposed on the same line with the fifth bridge portion.
The rotor of the motor of claim 15, wherein the plurality of core layers further comprises,

a fourth core layer disposed on the third core layer, and

the fourth core layer comprises,

a seventh bridge portion connecting a seventh yoke arranged at a fourth position rotated from the first yoke by 135°with the base; and

an eighth bridge connecting a seventh yoke facing the seventh yoke with the base, the eighth bridge portion disposed on the same line with the seventh bridge portion.
The rotor of the motor of claim 12, further comprising:

a second magnet inserted into a second magnet inserting portion provided in each of the plurality of yokes.
The rotor of the motor of claim 12, further comprising:

a first end plate coupled to one end of the rotor core; and

a second end plate coupled to the other end of the rotor core.