KR102625594B1 - Rotor and motor having the same - Google Patents

Abstract

The embodiment includes a first rotor part and a second rotor part arranged in an axial direction, wherein the first rotor part includes a first rotor core; A plurality of first magnets disposed on the outer peripheral surface of the first rotor core; It includes a first holder for fixing the plurality of first magnets, wherein the first holder includes a cylindrical first body; a first plate disposed on one side of the first body and covering the plurality of first magnets; and a rotor including a plurality of first coupling protrusions that protrude from the inner peripheral surface of the first body and couple to the first rotor core, and a motor including the same.

Description

Rotor and motor including the same {Rotor and motor having the same}

The embodiment relates to a rotor and a motor including the same.

The motor generates power while rotating through electromagnetic interaction between the rotor's magnet and the stator's coil.

The motor includes a housing, stator, rotor, and rotating shaft. The rotor includes a plurality of magnets. Rotors can be divided into an IPM type in which a magnet is inserted inside the rotor core, and an SPM (Surface Permanent Magnet) type in which a magnet is attached to the surface of the rotor core.

The SPM type rotor attaches multiple magnets to the surface of the rotor core and uses a SUS-based cover to protect the magnets. In the magnet attachment process, adhesive is applied to the outer surface of the rotor core, a magnet is attached, and the adhesive is cured. Afterwards, in the cover assembly process, adhesive is applied, the cover is placed, and the adhesive is cured again. However, this process is very complicated and the use of adhesives and covers increases material costs.

Japanese Patent Publication No. 2012-222835 (2012.11.12.)

The embodiment provides a rotor that facilitates magnet assembly and a motor including the same.

Additionally, the embodiment provides a rotor and motor capable of fixing a magnet without adhesive.

The problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned here will be clearly understood by those skilled in the art from the description below.

A rotor according to an embodiment of the present invention includes a first rotor part and a second rotor part arranged in the axial direction, wherein the first rotor part includes a first rotor core; A plurality of first magnets disposed on the outer peripheral surface of the first rotor core; It includes a first holder for fixing the plurality of first magnets, wherein the first holder includes a cylindrical first body; a first plate disposed on one side of the first body and covering the plurality of first magnets; and a plurality of first coupling protrusions protruding from the inner peripheral surface of the first body and coupled to the first rotor core.

The inner peripheral surface of the first body, the outer peripheral surface of the first rotor core, a pair of adjacent first coupling protrusions, and the first plate form pockets into which the plurality of first magnets are inserted.

It includes a first protrusion protruding from the bottom surface of the first coupling protrusion toward the second rotor part.

The first plate includes at least one insertion protrusion coupled to the first rotor core, and the insertion protrusion may be inserted into a coupling hole formed in the first rotor core.

The distance between the inner and outer peripheral surfaces of the first body may become thinner toward the midpoint of the adjacent first coupling protrusions.

The first coupling protrusion may include a through hole formed in the axial direction.

The first coupling protrusion may include a coupling portion coupled to the outer peripheral surface of the first rotor core and an extension portion connecting the coupling portion and the first body and fixing the side surface of the first magnet.

The first coupling protrusion may include a through hole formed in the axial direction on the bottom surface of the extension portion.

The first coupling protrusion may include a first protrusion protruding from the bottom surface of the extension portion toward the second rotor portion.

The thickness of the extension portion may become thinner as it moves from the inner peripheral surface of the body to the coupling portion.

The first magnet includes one surface facing the outer peripheral surface of the first rotor core, another surface facing the one surface, and a plurality of side surfaces connecting the one surface and the other surface, and the plurality of side surfaces are parallel to the axial direction. It includes a first side, a second side, and a third side and a fourth side perpendicular to the axial direction, and the pocket covers one side, the other side, the first side, the second side, and the third side of the first magnet. You can.

The first side or the second side may have a curvature in the direction from the one side to the other side.

The virtual circle extending from one side of the magnet may be larger than the virtual circle extending from the other side.

The second rotor unit includes a second rotor core; A plurality of second magnets disposed on the outer peripheral surface of the second rotor core; It includes a second holder for fixing the plurality of magnets, wherein the second holder includes a second body having a cylindrical shape; a second plate disposed on the other side of the second body and covering the plurality of second magnets; It may include a plurality of second coupling protrusions protruding from the inner peripheral surface of the second body.

The inner peripheral surface of the second body, the outer peripheral surface of the second rotor core, a pair of adjacent second coupling protrusions, and the second plate may form a pocket into which the plurality of second magnets are inserted.

The first holder may include a plurality of first protrusions protruding toward the second rotor, and the second holder may include a plurality of second protrusions protruding toward the first rotor.

The first protrusion may support the second magnet, and the second protrusion may support the first magnet.

The first holder and the second holder may include cured resin.

A motor according to an embodiment of the present invention may include any one of the above-described rotor characteristics.

According to the embodiment, the assembly process of the rotor can be simplified.

Additionally, costs can be reduced as adhesive or SUS material covers can be omitted.

The various and beneficial advantages and effects of the present invention are not limited to the above-described content, and may be more easily understood through description of specific embodiments of the present invention.

1 is a conceptual diagram of a motor according to an embodiment of the present invention,
Figure 2 is an exploded perspective view of a rotor according to an embodiment of the present invention;
Figure 3 is a diagram showing a state in which a rotor and a rotating shaft are combined according to an embodiment of the present invention;
Figure 4 is a cross-sectional view taken along the AA direction of Figure 3;
Figure 5 is a cross-sectional view in the BB direction of Figure 3,
Figure 6 is a diagram for explaining the gap between the first rotor and the second rotor;
Figure 7 is a diagram showing the state in which the magnet is inserted into the rotor,
Figure 8 is a plan view of Figure 7,
Figure 9 is an enlarged view of part C of Figure 8,
Figure 10 is a diagram showing a modified example of the holder.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated and described in the drawings. However, this is not intended to limit the embodiments of the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the embodiments.

Terms containing ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a second component may be named a first component without departing from the scope of the embodiment, and similarly, the first component may also be named a second component. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the embodiments of the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that it does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

In the description of the embodiment, when an element is described as being formed “on or under” another element, or under) includes both elements that are in direct contact with each other or one or more other elements that are formed (indirectly) between the two elements. Additionally, when expressed as "on or under," it can include not only the upward direction but also the downward direction based on one element.

Hereinafter, embodiments will be described in detail with reference to the attached drawings, but identical or corresponding components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted.

1 is a conceptual diagram of a motor according to an embodiment of the present invention.

Referring to FIG. 1, a motor according to an embodiment of the present invention includes a housing 10, a stator 30 disposed in the housing 10, a rotor 20, and a rotation shaft 70.

The housing 10 can accommodate the stator 30 and the rotor 20. The housing 10 may further include a cooling structure (not shown) to easily discharge internal heat. The cooling structure may be air-cooled or water-cooled, but is not limited thereto.

The stator 30 is inserted into the internal space of the housing 10. The stator 30 includes a stator core 31 and a coil 32 wound around the stator core 31.

The stator 30 can be manufactured by winding the coil 32 around the stator core 31, which is manufactured as one piece, but the cylindrical stator 30 can also be manufactured by winding the coils on each of a plurality of split cores and then assembling them. there is.

The bus bar 40 may be electrically connected to each of the coils 32 wound on the stator 30 and may include a plurality of terminals connecting the U, V, and W phases. The power terminal of the bus bar 40 may be exposed to the outside and electrically connected to an external power source or inverter.

The rotor 20 is rotatably disposed with respect to the stator 30. The rotor 20 may be placed inside the stator 30. The rotor 20 may include a first rotor unit 21 and a second rotor unit 22 arranged in the axial direction (longitudinal direction of the rotation axis). The first rotor unit 21 and the second rotor unit 22 may include a rotor core, a magnet, and a holder, respectively.

A rotating shaft 70 is coupled to the center of the rotor 20. Therefore, the rotor 20 and the rotation shaft 70 can rotate together. The rotation shaft 70 may be supported by a first bearing 61 disposed on one side and a second bearing 62 disposed on the other side.

A sensing plate 50 may be placed on the upper side of the rotor 20 to obtain position information of the rotor core, or a rotor position detection means similar to this may be installed.

The motor according to the embodiment may be an EPS motor used in an electric power steering device. Specifically, the electric power steering (EPS) can control the inverter to drive the motor according to the driving conditions detected by the electronic control unit (ECU) from the vehicle speed sensor, torque angle sensor, and torque sensor. The motor according to the embodiment can be driven by three-phase power supplied from an inverter. However, the configuration of the motor according to the embodiment is not necessarily limited to this.

FIG. 2 is an exploded perspective view of a rotor according to an embodiment of the present invention, FIG. 3 is a view showing a state in which a rotor and a rotating shaft are coupled according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view in the direction A-A of FIG. 3. , FIG. 5 is a cross-sectional view taken in the B-B direction of FIG. 3, and FIG. 6 is a view for explaining the gap between the first rotor section and the second rotor section.

Referring to FIG. 2, the rotor 20 of the embodiment includes a first rotor portion 21 and a second rotor portion 22 disposed in the axial direction. The first rotor unit 21 and the second rotor unit 22 include a rotor core 220, 250, a plurality of magnets 230, 260, and holders 210, 240 for fixing the magnets 230, 260, respectively. Includes. The first rotor unit 21 and the second rotor unit 22 may be manufactured from the same components and arranged to face each other.

The first rotor unit 21 fixes the first rotor core 220, a plurality of first magnets 230 disposed on the outer peripheral surface of the first rotor core 220, and a plurality of first magnets 230. Includes a first holder 210.

The first rotor core 220 has a cylindrical shape and may have a plurality of slits 221 formed in the axial direction. The area 223 between the plurality of slits 221 is an area where the first magnet 230 is fixed. The first rotor core 220 can be manufactured by stacking a plurality of plates in the axial direction. The first rotor core 220 may have a central hole 224 and a coupling hole 222 formed in the axial direction.

The first holder 210 includes a first body 211 having a hollow cylindrical shape, a first plate 212 having an annular shape connected to the first body, and protruding from the inner peripheral surface of the first body 211. It includes a plurality of first coupling protrusions 213 coupled to the first rotor core 220, and a first protrusion 214 protruding in the axial direction from the bottom surface of the first coupling protrusion 213. The first protrusion 214 can be defined as an area that protrudes further in the axial direction than the end of the first body 211. An insertion protrusion 212a may be formed on the inner surface of the first plate 212 to be inserted into the coupling hole 222 of the first rotor core 220. The first plate 212 covers the upper surface of the first magnet 230 exposed in the axial direction.

The second rotor unit 22 fixes the second rotor core 250, a plurality of second magnets 260 disposed on the outer peripheral surface of the second rotor core 250, and a plurality of second magnets 260. Includes a second holder (240). The second holder 240 includes a second body 241 having an empty cylindrical shape, a second plate 242 having an annular shape connected to the second body, and protruding from the inner peripheral surface of the second body 241. It includes a plurality of second coupling protrusions 243 coupled to the second rotor core 250, and a second protrusion 244 protruding in the axial direction from the bottom surface of the second coupling protrusion 243.

Since the first rotor unit 21 and the second rotor unit 22 are made of the same parts and are arranged to face each other, the configuration of the second rotor unit 22 is the same as that of the first rotor unit 21.

Referring to FIG. 3, the first rotor unit 21 and the second rotor unit 22 may be pressurized and fixed to the rotation shaft 70. At this time, the second rotor unit 22 may be coupled to the first rotor unit 21 by rotating it at a predetermined angle in the circumferential direction. The skew angle is not particularly limited. As a result, the first protrusion 214 and the second protrusion 244 are arranged to be staggered, thereby fixing the gap between the first rotor portion 21 and the second rotor portion 22.

Referring to FIG. 4, the first protrusion 214 of the first holder 210 protrudes toward the second rotor part 22, and with reference to FIG. 5, the second protrusion 244 is the first protrusion 214. protrudes toward. Accordingly, a gap 23 may be formed between the first rotor core 220 and the second rotor core 250 and between the first magnet 230 and the second magnet 260. According to this configuration, an air gap is formed between the first magnet 230 and the second magnet 260, so magnetic properties can be improved. In addition, the thickness of the rotor core can be reduced by an amount corresponding to the gap 23, thereby reducing costs.

The first protrusion 214 of the first holder 210 contacts the upper end of the second magnet 260, and the second protrusion 244 contacts the lower end of the first magnet 230. Accordingly, axial separation of the first magnet 230 and the second magnet 260 can be prevented.

Referring to FIG. 6, the gap 23 between the first rotor unit 21 and the second rotor unit 22 is the distance (W1) between the first and second magnets 230 and 260 and the inner peripheral surface of the stator 30. ) may be equal to or greater than. When the distance (W1) between the first and second magnets (230, 260) and the inner peripheral surface of the stator (30) is 0.7 mm, the gap (23) between the first rotor unit (21) and the second rotor unit (22) is It may be 0.7mm to 1.5mm.

If the gap 23 is less than 0.7 mm, there is a problem of magnetic leakage due to the distance between the outer diameters of the first and second magnets 230 and 260 and the stator 30, and if the gap 23 exceeds 1.5 mm. In this case, the total height W2 of the first and second magnets 230 and 260 may become higher than the height of the stator, resulting in loss of magnetic force lines.

FIG. 7 is a diagram showing a state in which a magnet is inserted into a rotor, FIG. 8 is a plan view of FIG. 7, and FIG. 9 is an enlarged view of portion C of FIG. 8. Hereinafter, the description will be made based on the first rotor part, but it is obvious that the same can be applied to the second rotor part.

Referring to FIG. 7, the cylindrical first holder 210 may be combined with the first rotor core 220 to form a pocket P into which the first magnet 230 is inserted. Conventionally, magnets were attached to the outer circumferential surface of the rotor core using an adhesive and then covered with a cover made of SUS using an adhesive. However, this structure has the problem of high processing and manufacturing costs.

According to the embodiment, the first magnets 230 are respectively inserted and fixed into the pockets P formed by combining the first holder 210 and the first rotor core 220, so that the first magnets 230 are fixed. adhesive can be omitted.

In addition, since the first holder 210 is manufactured by injection molding resin, the cost is reduced, and the first coupling protrusion 213 of the first holder 210 is coupled to the slit 221 of the first rotor core 220. Therefore, separate adhesive can be omitted.

The first magnet 230 has one side 231 facing the outer peripheral surface of the first rotor core 220, the other side 232 facing the one side 231, and a plurality of surfaces connecting the one side 231 and the other side 232. Includes sides 233, 234, 235, 236. The plurality of side surfaces (233, 234, 235, 236) include a first side (235) and a second side (236) horizontal to the axial direction, and a third side (233) and fourth side (234) perpendicular to the axial direction. ) includes. One side 231 and the other side 232 may have different curvatures. Accordingly, the virtual circle extending from one side 231 may be larger than the virtual circle extending from the other side 232.

Since all surfaces of the first magnet 230 except the third side 233 are accommodated in the pocket (P), the first magnet 230 can be firmly inserted into the pocket (P) without adhesive. Additionally, the corrosion prevention effect can also be improved. For fixation, it may be designed so that there is no gap between the first magnet 230 and the pocket (P).

Referring to FIG. 8, the first body 211 of the first holder 210 has a plurality of first coupling protrusions 213 protruding from the inner peripheral surface (F1) toward the center (C1), and the first body 211 The distance between the inner peripheral surface (F1) and the outer peripheral surface (F2) may become thinner toward the midpoint (211a) of the neighboring first coupling protrusion (213). The thickness of the middle point 211a may be about 0.1 mm to 0.5 mm or 0.3 mm.

Referring to FIG. 9, the first coupling protrusion 213 includes a coupling portion 213a coupled to the outer peripheral surface of the first rotor core 220 and an extension portion connecting the coupling portion 213a and the first body 211 ( 213b). The thickness of the extension portion 213b may become thinner as it moves from the inner peripheral surface F1 of the first body 211 to the coupling portion 213a.

The first coupling protrusion 213 may include a through hole 215 penetrating in the axial direction from the bottom surface. During the process of inserting the first magnet 230 into the pocket, excessive stress may be applied to the first magnet and/or the pocket. The through hole 215 may absorb stress applied to the first magnet 230 and/or the pocket. The shape of the through hole 215 may be deformed in the process of absorbing stress. The first protrusion 214 may be disposed adjacent to the through hole 215.

The side surface 235a of the first magnet 230 may have a concave curvature from one side 231 to the other side 232. Accordingly, the side surface 235a of the first magnet may have a non-contact section with the extension portion 213b. According to this configuration, the stress applied when inserting the first magnet 230 can be further relieved.

The structure of the first protrusion and the through hole 215 may be modified in various ways. Referring to FIG. 10, the through hole 215a is formed on the bottom surface of the first coupling protrusion 213, and the first coupling protrusion 213 itself may protrude in the axial direction and serve as a first protrusion. .

Referring to FIGS. 2, 4, and 7, the rotor manufacturing method according to the embodiment first manufactures the first holder 210 by injection molding resin, and then attaches the first rotor core 220 to the first holder 210. ) is installed to form a plurality of pockets (P). Thereafter, the first magnet 230 is inserted into the plurality of pockets (P) to assemble the first rotor unit 21. The second rotor unit 22 can also be assembled in the same way. Afterwards, the first rotor unit 21 and the second rotor unit 22 are inserted and fixed into the rotation shaft 70. At this time, as described above, a gap 23 is formed between the first rotor part 21 and the second rotor part 22 by the first protrusion 214 and the second protrusion 244.

10: Housing
20: rotor
21: First rotor section
22: Second rotor section
23: spacing
210: first holder
213: First combining protrusion
214: first protrusion
220: 1st rotor core
230: 1st magnet
240: Second holder
244: Second protrusion

Claims (19)

It includes a first rotor part and a second rotor part arranged in the axial direction,
The first rotor part,
1st rotor core;
A plurality of first magnets disposed on the outer peripheral surface of the first rotor core;
Includes a first holder for fixing the plurality of first magnets,
The first holder is,
A cylindrical first body;
a first plate disposed on one side of the first body and covering the plurality of first magnets; and
It includes a plurality of first coupling protrusions that protrude from the inner peripheral surface of the first body and engage the first rotor core,
The cylindrical first body entirely covers the outer peripheral surface of the plurality of first magnets,
The first coupling protrusion is a coupling portion coupled to the outer peripheral surface of the first rotor core, and
It includes an extension part that connects the coupling part and the first body and fixes a side of the first magnet,
A rotor in which the thickness of the extension portion becomes thinner as it moves from the inner peripheral surface of the first body to the coupling portion.
According to paragraph 1,
The inner peripheral surface of the first body, the outer peripheral surface of the first rotor core, a pair of adjacent first coupling protrusions, and the first plate form a pocket into which the plurality of first magnets are inserted,
The first holder is a rotor including a first protrusion protruding from the bottom surface of the first coupling protrusion toward the second rotor unit.
According to paragraph 1,
The first plate includes at least one insertion protrusion coupled to the first rotor core, and the insertion protrusion is inserted into a coupling hole formed in the first rotor core,
A rotor in which the distance between the inner and outer peripheral surfaces of the first body becomes thinner toward the midpoint of the adjacent first coupling protrusions.
According to paragraph 1,
The first coupling protrusion includes a through hole formed in the axial direction on the bottom surface of the extension portion.
According to paragraph 1,
The first holder is a rotor including a first protrusion protruding from the bottom surface of the extension portion toward the second rotor portion.
delete According to paragraph 2,
The first magnet includes one surface facing the outer peripheral surface of the first rotor core, another surface facing the one surface, and a plurality of side surfaces connecting the one surface and the other surface,
The plurality of side surfaces include a first side and a second side horizontal to the axial direction and a third side and a fourth side perpendicular to the axial direction,
The pocket covers one side, the other side, the first side, the second side, and the third side of the first magnet.
In clause 7,
The first side or the second side has a curvature in the direction from the one side to the other side,
The first magnet is a rotor in which the virtual circle extending from the one side is larger than the virtual circle extending from the other side.
According to paragraph 1,
The second rotor part
2nd rotor core;
A plurality of second magnets disposed on the outer peripheral surface of the second rotor core;
Includes a second holder for fixing the plurality of magnets,
The second holder,
A second body in a cylindrical shape;
a second plate disposed on the other side of the second body and covering the plurality of second magnets;
A rotor including a plurality of second coupling protrusions that protrude from the inner peripheral surface of the second body and couple to the second rotor core.
According to clause 9,
The inner peripheral surface of the second body, the outer peripheral surface of the second rotor core, a pair of adjacent second coupling protrusions, and the second plate form a pocket into which the plurality of second magnets are inserted.
According to clause 9,
The first holder includes a plurality of first protrusions protruding toward the second rotor, and the second holder includes a plurality of second protrusions protruding toward the first rotor.
According to clause 11,
The first protrusion supports the second magnet, and the second protrusion supports the first magnet.
housing;
A stator disposed in the housing;
A rotor according to any one of claims 1 to 5 and 7 to 12; and
A motor including a rotating shaft penetrating the rotor.


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