KR20170102747A - Rotor and motor having the same - Google Patents

Abstract

Disclosed are a rotor and a motor including the same. According to an embodiment, the rotor comprises a first rotor part and a second rotor part disposed in an axial direction, wherein the first rotor part includes: a first rotor core; a plurality of first magnets disposed on an outer circumferential surface of the first rotor core; and a first holder configured to fix the plurality of first magnets. The first holder includes: a first body in a cylindrical shape; a first plate disposed on one side of the first body and configured to cover the plurality of first magnets; and a plurality of first coupling protrusions protruding from an inner peripheral surface of the first body and coupled to the first rotor core. Accordingly, the rotor can be easily assembled with the magnets.

Description

Rotor and motor having the same [0002]

Embodiments relate to a rotor and a motor including the same.

The motor generates power by rotating by the electromagnetic interaction between the magnet of the rotor and the coil of the stator.

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

In the SPM type rotor, a plurality of magnets are attached to the surface of the rotor core, and a SUS-type cover is used to protect the magnets. In the magnet attaching process, the adhesive is applied to the outer surface of the rotor core, the magnet is attached, and the adhesive is cured. Thereafter, the cover assembly process applies the adhesive, covers the cover, and then cures the adhesive again. However, such a process is very complicated and the material cost is increased due to the use of adhesives and covers.

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

The embodiment also provides a rotor and a motor that can fix the magnet without an adhesive.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned here can be understood by those skilled in the art from the following description.

A rotor according to an embodiment of the present invention includes a first rotor portion and a second rotor portion disposed in an axial direction, and the first rotor portion includes a first rotor core; A plurality of first magnets disposed on an outer circumferential surface of the first rotor core; And a first holder for fixing the plurality of first magnets, wherein the first holder comprises: 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 engaging protrusions protruding from an inner circumferential surface of the first body and engaged with the first rotor core.

An inner circumferential surface of the first body, an outer circumferential surface of the first rotor core, a pair of first engaging projections adjacent to each other, and the first plate form a pocket into which the plurality of first magnets are inserted.

And a first protrusion protruding from the bottom surface of the first engaging projection toward the second rotor portion.

The first plate may include at least one insertion protrusion that engages with 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 circumferential surface and the outer circumferential surface of the first body may become thinner toward an intermediate point of the adjacent first coupling protrusions.

The first engaging projection may include a through hole formed in the axial direction.

The first coupling protrusion may include a coupling portion coupled to the outer circumferential 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 engaging projection may include a through hole formed axially in a bottom surface of the extended portion.

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

The extension may be thinned from the inner circumferential surface of the body toward the coupling portion.

Wherein the first magnet includes a first surface facing the outer circumferential surface of the first rotor core, a second surface opposite to the first surface, and a plurality of side surfaces connecting the first surface and the second surface, A first side and a second side, and a third side and a fourth side perpendicular to the axial direction, wherein the pocket covers one side of the first magnet, the first side, the second side and the third side .

The first side surface or the second side surface may have a curvature in the other surface direction on the one surface.

The magnet may have an imaginary circle extending from one side thereof to an imaginary circle extending from the other side thereof.

The second rotor portion includes a second rotor core; A plurality of second magnets disposed on an outer circumferential surface of the second rotor core; And a second holder for fixing the plurality of magnets, wherein the second holder comprises: a cylindrical second body; A second plate disposed on the other side of the second body and covering the plurality of second magnets; And a plurality of second coupling protrusions protruding from an inner circumferential surface of the second body.

The inner circumferential surface of the second body, the outer circumferential surface of the second rotor core, the pair of second engaging projections adjacent to each other, 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 comprise a hardened resin.

The motor according to one embodiment of the present invention may include any one of the features of the rotor described above.

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

In addition, it is possible to omit the adhesive or the cover made of the SUS material, thereby reducing the cost.

The various and advantageous advantages and effects of the present invention are not limited to the above description, and can be more easily understood in the course of describing a specific embodiment of the present invention.

1 is a conceptual diagram of a motor according to an embodiment of the present invention,
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 where a rotor and a rotating shaft are combined according to an embodiment of the present invention, and FIG.
Fig. 4 is a sectional view in the AA direction of Fig. 3,
5 is a cross-sectional view taken along line BB in Fig. 3,
6 is a view for explaining the interval between the first rotor and the second rotor,
7 is a view showing a state where a magnet is inserted into a rotor,
Fig. 8 is a plan view of Fig. 7,
Fig. 9 is an enlarged view of a portion C in Fig. 8,
10 is a view showing a modification of the holder.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the embodiments of the present invention are not intended to be limited to the specific embodiments but include all modifications, equivalents, and alternatives falling within the spirit and scope of the embodiments.

Terms including ordinals, such as first, second, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the embodiments, the second component may be referred to as a first component, and similarly, the first component may also be referred to as a second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

In the description of the embodiments, in the case where one element is described as being formed "on or under" another element, the upper (upper) or lower (lower) or under are all such that two elements are in direct contact with each other or one or more other elements are indirectly formed between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description 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 rotating 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) so as to easily discharge the internal heat. The cooling structure may be, but not limited to, an air-cooling or water-cooling structure.

The stator 30 is inserted into the inner 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 may be manufactured by winding the coils 32 on the stator core 31 manufactured in one piece, but it is also possible to manufacture the cylindrical stator 30 by winding the coils on a plurality of divided cores, have.

The bus bar 40 may be electrically connected to 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 an inverter.

The rotor 20 is rotatably disposed with respect to the stator 30. The rotor 20 may be disposed inside the stator 30. The rotor 20 may include a first rotor portion 21 and a second rotor portion 22 disposed in the axial direction (the longitudinal direction of the rotating shaft). The first rotor portion 21 and the second rotor portion 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 rotary shaft 70 can rotate together. The rotary 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 for acquiring positional information of the rotor core may be disposed above the rotor 20, or similar rotor position sensing means may be provided.

The motor according to the embodiment may be an EPS motor used in an electric power steering system. Specifically, an electric power steering apparatus (EPS) can control the inverter to drive the motor in accordance with driving conditions sensed by an electronic control unit (ECU), such as a vehicle speed sensor, a torque angle sensor, and a torque sensor. The motor according to the embodiment can be driven by a three-phase power source applied from an inverter. However, the configuration of the motor according to the embodiment is not limited thereto.

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 where a rotor and a rotary shaft are combined according to an embodiment of the present invention, FIG. 4 is a cross- FIG. 5 is a cross-sectional view taken along line BB of FIG. 3, and FIG. 6 is a view for explaining an interval between the first rotor portion and the second rotor portion.

Referring to Fig. 2, the rotor 20 of the embodiment includes a first rotor portion 21 and a second rotor portion 22 which are arranged in the axial direction. The first rotor unit 21 and the second rotor unit 22 are rotatably supported by holders 210 and 240 for fixing the rotor cores 220 and 250, the plurality of magnets 230 and 260, and the magnets 230 and 260, . The first rotor portion 21 and the second rotor portion 22 may be made of the same components and arranged to face each other.

The first rotor unit 21 includes a first rotor core 220, a plurality of first magnets 230 disposed on the outer circumferential surface of the first rotor core 220, And includes a first holder 210.

The first rotor core 220 may have a cylindrical shape and a plurality of slits 221 may be formed in the axial direction. The region 223 between the plurality of slits 221 is an area where the 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 be formed with a center hole 224 and a coupling hole 222 in the axial direction.

The first holder 210 includes a first body 211 having an empty cylindrical shape, a first plate 212 having an annular shape connected to the first body, and a second plate 212 protruding from the inner peripheral surface of the first body 211 A plurality of first engaging projections 213 engaging with the first rotor core 220 and a first protrusion 214 projecting axially from the bottom surface of the first engaging projection 213. The first protrusion 214 may be defined as an area protruding further in the axial direction than the end of the first body 211. An insertion protrusion 212a to be inserted into the coupling hole 222 of the first rotor core 220 may be formed on the inner surface of the first plate 212. [ The first plate 212 covers the upper surface of the first magnet 230 exposed in the axial direction.

The second rotor unit 22 includes a second rotor core 250 and a plurality of second magnets 260 disposed on the outer circumferential surface of the second rotor core 250 and a plurality of second magnets 260 And a second holder (240). The second holder 240 protrudes from an inner circumferential surface of the second body 241 and a second body 241 having an inner hollow shape, a second plate 242 having a ring shape connected to the second body, A plurality of second engaging protrusions 243 engaging with the second rotor core 250 and a second protrusion 244 protruding axially from the bottom surface of the second engaging protrusion 243.

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

Referring to FIG. 3, the first rotor portion 21 and the second rotor portion 22 can be pressed and fixed to the rotary shaft 70. At this time, the second rotor portion 22 may be rotated by a predetermined angle in the circumferential direction with reference to the first rotor portion 21. The skew angle is not particularly limited. As a result, the first projecting portion 214 and the second projecting portion 244 are staggered to fix the gap between the first rotor portion 21 and the second rotor portion 22.

4, the first protrusion 214 of the first holder 210 protrudes toward the second rotor portion 22, and the second protrusion 244 protrudes from the first protrusion 214, As shown in Fig. 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 such a configuration, an air gap is formed between the first magnet 230 and the second magnet 260 to improve the magnetic characteristics. Further, the thickness of the rotor core corresponding to the interval 23 can be reduced, and the cost can be reduced.

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, it is possible to prevent the first magnet 230 and the second magnet 260 from deviating in the axial direction.

6, the gap 23 between the first rotor portion 21 and the second rotor portion 22 is equal to the distance W1 between the first and second magnets 230 and 260 and the inner circumferential surface of the stator 30 ) Or greater. When the distance W1 between the first and second magnets 230 and 260 and the inner peripheral surface of the stator 30 is 0.7 mm, the gap 23 between the first rotor portion 21 and the second rotor portion 22 0.7 mm to 1.5 mm.

When the distance 23 is less than 0.7 mm, the distance between the outer diameters of the first and second magnets 230 and 260 is closer to the distance between the stator 30 and the magnetic field leakage occurs. If the gap 23 exceeds 1.5 mm , The total height W2 of the first and second magnets 230 and 260 becomes higher than the height of the stator, so that magnetic line loss may occur.

FIG. 7 is a view showing a state where a magnet is inserted into a rotor, FIG. 8 is a plan view of FIG. 7, and FIG. 9 is an enlarged view of a portion C of FIG. Hereinafter, the first rotor unit will be described with reference to the second rotor unit, but it is obvious that the same can be applied to the second rotor unit.

Referring to FIG. 7, the cylindrical first holder 210 may be coupled with the first rotor core 220 to form a pocket P into which the first magnet 230 is inserted. Conventionally, a magnet is attached to the outer circumferential surface of the rotor core by using an adhesive, and the cover is covered with an SUS material using an adhesive. However, such a structure has a problem of high process and manufacturing cost.

According to the embodiment, the first magnet 230 is inserted into the pocket P formed by the first holder 210 and the first rotor core 220, Can be omitted.

The first holder 210 of the first holder 210 is coupled to the slit 221 of the first rotor core 220 by the injection molding of the resin, So that a separate adhesive can be omitted.

The first magnet 230 has a first surface 231 facing the outer circumferential surface of the first rotor core 220, a second surface 232 facing the first surface 231, a plurality of second surfaces 231 connecting the first surface 231 and the second surface 232 Side surfaces 233, 234, 235, and 236, respectively. The plurality of side surfaces 233, 234, 235 and 236 includes a first side surface 235 and a second side surface 236 which are parallel to the axial direction and a third side surface 233 and a fourth side surface 234 ). The first surface 231 and the second surface 232 may have different curvatures from each other. Therefore, the imaginary circle extending from the one surface 231 may be larger than the imaginary circle extending from the other surface 232.

The first magnet 230 can be firmly inserted into the pocket P without the adhesive since the entire surface of the first magnet 230 is accommodated in the pocket P except for the third side surface 233. [ In addition, the corrosion prevention effect can also be improved. So that there is no clearance between the first magnet 230 and the pocket P for fixation.

8, the first body 211 of the first holder 210 has a plurality of first coupling protrusions 213 protruding from the inner circumferential surface F1 toward the center C1, The distance between the inner circumferential surface F1 and the outer circumferential surface F2 of the first coupling protrusion 213 may become thinner toward the intermediate point 211a of the adjacent first coupling protrusion 213. [ The thickness of the intermediate point 211a may be about 0.1 mm to 0.5 mm or 0.3 mm.

9, the first coupling protrusion 213 includes a coupling portion 213a coupled to the outer circumferential surface of the first rotor core 220 and an extension portion 213a connecting the coupling portion 213a and the first body 211 213b. The extension 213b may be thinned from the inner circumferential surface F1 of the first body 211 to the engagement portion 213a.

The first coupling protrusion 213 may include a through hole 215 penetrating axially from the bottom surface. Excessive stress may be applied to the first magnet and / or the pocket during the insertion of the first magnet 230 into the pocket. The through hole 215 can absorb the stress applied to the first magnet 230 and / or the pocket. The shape of the through hole 215 can be deformed in the process of absorbing the 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 in the direction of the other surface 232 from the one surface 231. [ Therefore, the side surface 235a of the first magnet can have a non-contact section with the extended portion 213b. According to this configuration, the stress applied when inserting the first magnet 230 can be further relaxed.

The structure of the first protrusion and the through hole 215 can be variously modified. 10, the through hole 215a is formed in the bottom surface of the first coupling protrusion 213, and the first coupling protrusion 213 itself protrudes in the axial direction to serve as a first protrusion .

Referring to FIGS. 2, 4 and 7, in the rotor manufacturing method according to the embodiment, the first holder 210 is manufactured by injection molding resin, and then the first rotor core 220 To form a plurality of pockets P. As shown in Fig. Thereafter, the first magnet part 230 is inserted into the plurality of pockets P to assemble the first rotor part 21. The second rotor portion 22 can also be assembled in the same manner. Thereafter, the first rotor portion 21 and the second rotor portion 22 are inserted and fixed to the rotary shaft 70. At this time, the gap 23 is formed between the first rotor portion 21 and the second rotor portion 22 by the first projecting portion 214 and the second projecting portion 244 as described above.

10: Housing
20: Rotor
21: First rotor
22: Second rotor
23: Interval
210: first holder
213: first engaging projection
214: first protrusion
220: first rotor core
230: 1st magnet
240: second holder
244: second protrusion

Claims (19)

A first rotor portion and a second rotor portion disposed in the axial direction,
The first rotor unit includes:
A first rotor core;
A plurality of first magnets disposed on an outer circumferential surface of the first rotor core;
And a first holder for fixing the plurality of first magnets,
Wherein the first holder comprises:
A cylindrical first body;
A first plate disposed on one side of the first body and covering the plurality of first magnets; And
And a plurality of first engaging projections projecting from an inner peripheral surface of the first body and engaging with the first rotor core.
The method according to claim 1,
Wherein the inner plate of the first body, the outer periphery of the first rotor core, the pair of first engaging projections adjacent to each other, and the first plate form a pocket into which the plurality of first magnets are inserted.
The method according to claim 1,
Wherein the first holder includes a first protrusion protruding from a bottom surface of the first engaging projection toward the second rotor portion.
The method according to claim 1,
Wherein the first plate includes at least one insertion protrusion that engages with the first rotor core, and the insertion protrusion is inserted into a coupling hole formed in the first rotor core.
The method according to claim 1,
The distance between the inner circumferential surface and the outer circumferential surface of the first body becomes thinner toward the middle point of the adjacent first coupling protrusions.
The method according to claim 1,
And the first engaging projection includes a through hole formed in the axial direction.
The method according to claim 1,
Wherein the first engaging projection has an engaging portion engaging with an 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.
8. The method of claim 7,
And the first engaging projection includes a through hole formed axially in a bottom surface of the extending portion.
8. The method of claim 7,
Wherein the first holder includes a first protrusion protruding from the bottom surface of the extension toward the second rotor portion.
8. The method of claim 7,
Wherein the extended portion is thinned from the inner circumferential surface of the body to the engaging portion.
3. The method of claim 2,
Wherein the first magnet includes one surface facing the outer circumferential surface of the first rotor core, another surface facing the one surface, and a plurality of surfaces connecting the one surface and the other surface,
Wherein the plurality of side surfaces include a first side surface and a second side surface that are parallel to the axial direction, and a third side surface and a fourth side surface that are perpendicular to the axial direction,
Wherein the pocket covers one side of the first magnet, the first side, the second side and the third side.
12. The method of claim 11,
Wherein the first side surface or the second side surface has a curvature in the other surface direction on the one surface.
12. The method of claim 11,
Wherein the first magnet is larger than the imaginary circle extending from the other surface.
The method according to claim 1,
The second rotor portion
A second rotor core;
A plurality of second magnets disposed on an outer circumferential surface of the second rotor core;
And a second holder for fixing the plurality of magnets,
Wherein the second holder comprises:
A cylindrical second body;
A second plate disposed on the other side of the second body and covering the plurality of second magnets;
And a plurality of second coupling protrusions protruding from an inner circumferential surface of the second body and engaged with the second rotor core.
15. The method of claim 14,
A pair of second engaging projections adjacent to each other, and a second plate having a pocket into which the plurality of second magnets are inserted, the inner plate of the second body, the outer periphery of the second rotor core, and the pair of adjacent second engaging projections.
15. The method of claim 14,
Wherein 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.
17. The method of claim 16,
Wherein the first protrusion supports the second magnet and the second protrusion supports the first magnet.
14. The method of claim 13,
Wherein the first holder and the second holder comprise a cured resin.
housing;
A stator disposed in the housing;
18. A rotor according to any one of the preceding claims, And
And a rotating shaft passing through the rotor.

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