KR20210138934A - Motor - Google Patents

Abstract

The present invention may provide a motor compriseing a rotor and a stator disposed to correspond to the rotor. The rotor comprises a rotor core and a magnet disposed at the rotor core. The rotor core comprises a first rotor core and a second rotor core disposed in an axial direction. The magnet comprises a first magnet disposed at the first rotor core and a second magnet disposed at the second rotor core and spaced apart from the first magnet. A side of the first magnet has a first inclination inclined with respect to the axial direction. A side of the second magnet has a second inclination inclined with respect to the axial direction.

Description

motor {Motor}

The embodiment relates to a motor.

The electric power steering system (EPS) is a device that enables the driver to safely drive by ensuring the turning stability of the vehicle and providing a quick recovery force. Such an electric steering system controls the driving of a steering shaft of a vehicle by driving a motor through an electronic control unit (ECU) according to driving conditions detected by a vehicle speed sensor, a torque angle sensor, and a torque sensor.

The motor includes a stator and a rotor. The rotor may include a rotor core and a magnet disposed on the rotor core. In the process of rotating the rotor, cogging torque may occur due to a difference in permeability between the stator made of metal and the air in the slot open, which is an empty space. In order to reduce the cogging torque, the rotor core and the magnet are composed of a plurality of pucks, and each puck is combined to implement a skew.

However, even if the puck is arranged to implement the skew, the offset effect of the cogging torque is limited, and there is a problem that the cogging torque remains. In addition, there is a problem in that it is difficult to manage the skew angle.

Accordingly, the embodiment is intended to solve the above problems, and an object thereof is to provide a motor capable of greatly reducing the cogging torque.

The problems to be solved by the embodiment are 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 following description.

In order to solve the above problems, a rotor and a stator disposed to correspond to the rotor are included, wherein the rotor includes a rotor core and a magnet disposed on the rotor core, and the rotor core is disposed in an axial direction. A first rotor core and a second rotor core are included, and the magnet includes a first magnet disposed on the first rotor core, and a second magnet disposed on the second rotor core and spaced apart from the first magnet, The side of the first magnet may have a first inclination with respect to the axial direction, and the side of the second magnet may have a second inclination with respect to the axial direction.

Preferably, the first magnet includes a first unit magnet and a second unit magnet spaced apart from the first unit magnet, and the second magnet includes a third unit magnet and a fourth unit magnet spaced apart from the third unit magnet. A unit magnet may be included, wherein the first unit magnet and the third unit magnet may have the same polarity, and the first unit magnet and the second unit magnet may have different polarities.

Preferably, the first slope and the second slope may be the same as each other.

Preferably, the first slope and the second slope may be different from each other.

Preferably, the side surface of the first magnet and the side surface of the second magnet may be disposed on the same plane.

Preferably, the side surface of the first magnet and the side surface of the second magnet may be disposed on the same plane.

Preferably, the side surface of the first magnet and the side surface of the second magnet may not be disposed on the same plane.

In order to solve the above problems, a rotor and a stator disposed to correspond to the rotor are included, wherein the rotor includes a rotor core and a magnet disposed on the rotor core, and the rotor core is disposed in an axial direction. a first rotor core and a second rotor core, wherein the magnet includes a first magnet disposed on the first rotor core and a second magnet disposed on the second rotor core, wherein the first magnet is disposed in an axial direction a first unit magnet and a second unit magnet having a side inclined at a first inclination with respect to the second magnet, wherein the second magnet has a third unit magnet and a fourth unit magnet having a side inclined at a second inclination with respect to the axial direction Including, the first unit magnet and the second unit magnet may be spaced apart from each other.

Preferably, the first rotor core may include a first protrusion, and the second rotor core may include a second protrusion disposed offset from the first protrusion at a predetermined angle.

Preferably, the first rotor core may have a first protrusion and the second rotor core may have a second protrusion, and the first protrusion and the second protrusion may be positioned on the same inclined line.

In order to solve the above problems, a rotor and a stator disposed to correspond to the rotor are included, wherein the rotor includes a rotor core and a plurality of magnets disposed on the rotor core, and the rotor core includes the plurality of magnets. A protrusion disposed between two magnets adjacent to each other in a middle circumferential direction may be included, and the protrusion may be disposed to be inclined with respect to the axial direction.

Preferably, the rotor core includes a first rotor core and a second rotor core, and the protrusions have a first protrusion protruding from the first rotor core to have a first inclination and a second inclination from the second rotor core. It may include a second protrusion protruding so as to have it.

Preferably, the first protrusion and the second protrusion may be arranged to be offset from each other at a predetermined angle.

Preferably, the first protrusion and the second protrusion may be positioned on the same inclined line.

Preferably, the first slope and the second slope may be the same as each other.

Preferably, the first slope and the second slope may be different from each other.

Preferably, the first slope and the second slope are tanθ values, respectively, and θ in tanθ may be calculated through Equation 1 below.

<Equation 1>

θ=((360°/A)/3)±5°

Here, A is the number of poles of the magnet.

Preferably, the offset may be calculated through Equation 2 below.

<Equation 2>

Offset=±(360°/A)/6

Here, A is the number of poles of the magnet.

According to the embodiment, there is provided an advantageous effect of greatly reducing the cogging torque.

According to the embodiment, there is an advantage in that it is easy to manage the skew angle of the rotor.

1 is a view showing a motor according to an embodiment;
2 is a perspective view showing a rotor;
3 is a view showing the rotor core shown in FIG. 2;
4 is a perspective view showing a magnet;
5 is a view looking at the magnet in the radial direction of the rotor;
6 is a side view of the rotor core;
7 is a perspective view of another type of rotor having an offset;
Figure 8 is a view showing the magnet shown in Figure 7,
9 is a view looking at the magnet in the radial direction of the rotor;
10 is a perspective view of the rotor core shown in FIG. 7;
11 is a side view of the rotor shown in FIG. 10 .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the technical spirit of the present invention is not limited to some embodiments described, but may be implemented in various different forms, and within the scope of the technical spirit of the present invention, one or more of the components may be selected among the embodiments. It can be combined and substituted for use.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be generally understood by those of ordinary skill in the art to which the present invention pertains, unless specifically defined and described explicitly. It may be interpreted as a meaning, and generally used terms such as terms defined in advance may be interpreted in consideration of the contextual meaning of the related art.

In addition, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention.

In this specification, the singular form may also include the plural form unless otherwise specified in the phrase, and when it is described as “at least one (or more than one) of A and (and) B, C”, it is combined with A, B, and C It may include one or more of all possible combinations.

In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used.

These terms are only used to distinguish the component from other components, and are not limited to the essence, order, or order of the component by the term.

And, when it is described that a component is 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected, coupled or connected to the other component, but also with the component It may also include a case of 'connected', 'coupled' or 'connected' due to another element between the other elements.

In addition, when it is described as being formed or disposed on “above (above) or under (below)” of each component, the top (above) or bottom (below) is one as well as when two components are in direct contact with each other. Also includes a case in which another component as described above is formed or disposed between two components. In addition, when expressed as “upper (upper) or lower (lower)”, the meaning of not only an upward direction but also a downward direction based on one component may be included.

1 is a diagram illustrating a motor according to an embodiment.

1 , the motor according to the embodiment includes a shaft 100 , a rotor 200 , a stator 300 , an insulator 400 , a housing 500 , a bus bar 600 , a sensing unit 700 , and a substrate. (800). Hereinafter, "inside" indicates a direction from the housing 500 to the shaft 100, which is the center of the motor, and "outside" indicates a direction opposite to the inside, which is a direction from the shaft 100 to the direction of the housing 500. . Also, below. The circumferential or radial direction is based on the axial center, respectively.

The shaft 100 may be coupled to the rotor 200 . When electromagnetic interaction occurs between the rotor 200 and the stator 300 through the supply of current, the rotor 200 rotates and the shaft 100 rotates in conjunction therewith. The shaft 100 is rotatably supported by a bearing 10 . The shaft 100 may be connected to a steering device of a vehicle to transmit power.

The rotor 200 rotates through electrical interaction with the stator 300 . The rotor 200 may be disposed inside the stator 300 . The rotor 200 may include a rotor core 210 and a magnet 220 disposed on the rotor core 210 . In this case, the rotor 200 may be of the SPM type in which the magnet 220 is disposed on the outer peripheral surface of the rotor core 210 .

The stator 300 is disposed outside the rotor 200 . The stator 300 may include a stator core 300A, a coil 300B, and an insulator 400 mounted on the stator core 300A. The coil 300B may be wound around the insulator 400 . The insulator 400 is disposed between the coil 300B and the stator core 300A, and serves to electrically insulate the stator core 300A and the coil 300B from each other. The coil 300B causes an electrical interaction with the magnet of the rotor 200 .

The stator 300 and the rotor 200 are disposed inside the housing 500 .

The bus bar 600 is disposed above the stator 300 . The bus bar 600 includes a bus bar holder (not shown) made of an insulating material and a plurality of terminals (not shown) coupled to the bus bar holder. At this time, the bus bar holder is formed of an insulating material to prevent a plurality of terminals from being connected to each other. In addition, the plurality of terminals connect the coils 300B wound around the stator core 300A to each other to apply a current to each coil.

The sensing unit 700 may be coupled to the shaft 100 . The sensing unit 700 includes a sensing plate 700A and a sensing magnet 700B disposed on the sensing plate. A sensor for sensing the magnetic force of the sensing magnet 700B may be disposed on the substrate 800 . In this case, the sensor may be a Hall IC, and serves to sense the magnetic flux of the sensing magnet of the sensing unit 700 coupled to the shaft 100 . The sensing unit 700 and the substrate 800 perform a function for detecting the position of the rotor 200 by sensing the magnetic flux changing according to the rotation.

FIG. 2 is a perspective view of the rotor, and FIG. 3 is a view showing the rotor core shown in FIG. 2 .

1 to 3 , the rotor 200 may include a rotor core 210 and a magnet 220 .

The rotor core 210 may include a first rotor core 210A and a second rotor core 210B. The magnet 220 may be disposed on the outer peripheral surfaces of the first rotor core 210A and the second rotor core 210B, respectively. The first rotor core 210A and the second rotor core 210B may be stacked in an axial direction. For example, two first rotor cores 210A and one second rotor core 210B are disposed, and in the axial direction, the second rotor core 210B is disposed between the two first rotor cores 210A. can be

The rotor core 210 may include a plurality of protrusions 211 protruding from the outer circumferential surface. The plurality of protrusions 211 may be disposed at regular intervals along the circumferential direction of the rotor core 210 . These protrusions 211 are for guiding the magnet 220 and fixing it to the rotor core 210 . Hereinafter, the protrusion 211 disposed on the first rotor core 210 will be referred to as a first protrusion 211A, and the protrusion 211 disposed on the second rotor core 210 will be referred to as a second protrusion 211B.

The magnet 220 is disposed on the outer peripheral surface of the rotor core 210 . Hereinafter, the magnet 220 disposed on the first rotor core 210 will be referred to as a first magnet 220A, and the magnet 220 disposed on the second rotor core 210 will be referred to as a second magnet 220B. The first magnet 220A and the second magnet 220B may be disposed to be spaced apart from each other.

4 is a perspective view illustrating the magnet 220, and FIG. 5 is a view of the magnet 220 in the radial direction of the rotor.

4 and 5 , the magnet 220 may have a hexahedral shape including both sides. The first magnet 220A may include a first unit magnet 220Aa and a second unit magnet 220Ab. The first unit magnet 220Aa and the second unit magnet 220Ab are disposed to be spaced apart from each other, and disposed adjacent to each other in the circumferential direction of the rotor 200 . The second magnet 220B may include a third unit magnet 220Ba and a fourth unit magnet 220Bb. The third unit magnet 220Ba and the fourth unit magnet 220Bb are disposed to be spaced apart from each other, and disposed adjacent to each other in the circumferential direction of the rotor 200 .

The polarity of the first unit magnet 220Aa and the polarity of the third unit magnet 220Ba may be the same, and the polarity of the first unit magnet 220Aa and the second unit magnet 220Ab may be different from each other. For example, if the first unit magnet 220Aa has an N pole, the second unit magnet 220Ab may have an S pole, and the third unit magnet 220Ba may have an N pole.

In order to increase the offsetting effect of the cogging torque, the magnet 220 is formed with an inclined side surface. Specifically, the side surface 221A of the first magnet 220A has a first inclination inclined with respect to the axial direction. Here, the first inclination is the degree of inclination of the side surface 221A of the first magnet 220A with respect to the reference line L, and when the first magnet 220A is viewed in the radial direction of the rotor 200, the first It may correspond to a ratio of the first distance L1 to the height h1.

Here, the reference line L is an imaginary line parallel to the axial direction, and the first height h1 is a linear distance between the upper surface and the lower surface of the first magnet 220A in the axial direction, and the first distance L1 may correspond to the distance from the intersection P1 with the lower surface of the first magnet 220A to the end of the lower surface of the first magnet 220A. The side surface 221A of the first unit magnet 220Aa of the first magnet 220A and the side surface 221A of the second unit magnet 220Ab may be formed to have a first inclination, respectively.

In addition, the second inclination is the degree of inclination of the side surface 221B of the second magnet 220B with respect to the reference line L, and when the second magnet 220B is viewed in the radial direction of the rotor 200 , the second It may correspond to a ratio of the second distance L2 to the height h2.

Here, the reference line (L) is an imaginary line parallel to the axial direction, and the second height (h2) is a straight line distance between the upper surface 223A and the lower surface 222A of the second magnet 220B with respect to the axial direction, The second distance L2 may correspond to a distance from the intersection P2 with the lower surface 222A of the second magnet 220B to the end of the lower surface 222A of the second magnet 220B. The side surface 221A of the third unit magnet 220Ba of the second magnet 220B and the side surface 221A of the fourth unit magnet 220Bb may each be formed to have a second inclination.

The first magnet 220A and the second magnet 220B may be formed to be the same as the first inclination and the second inclination in the drawing. However, the present invention is not limited thereto, and the first magnet 220A and the second magnet 220B may be respectively formed so that the first inclination and the second inclination are different from each other.

On the other hand, the positions of the first magnet 220A and the second magnet 220B may be determined such that the side surface 221A of the first magnet 220A and the side surface 221A of the second magnet 220B are disposed on the same plane. can

Since the side 221A of the magnet 220 is inclined to the reference line L, the magnet 220 not only secures a skew angle between the first rotor core 210A and the second rotor core 210B. Since the skew angle can be linearly secured in the first rotor core 210A itself or the second rotor core 210B itself, there is an advantage in that the cogging torque can be very effectively offset.

6 is a side view 221A of the rotor core 210 .

3 and 6 , 222A, the first rotor core 210A may include a first protrusion 211A. The first protrusion 211A protrudes from the outer circumferential surface of the first rotor core 210A. In addition, the first protrusion 211A may be long in the axial direction.

The first protrusion 211A may be inclined to correspond to the inclined side surface 221A of the first magnet 220A. Specifically, the first protrusion 211A has a third inclination inclined with respect to the axial direction.

The third inclination is the degree of inclination of the first protrusion 211A with respect to the reference line L, and when the first protrusion 211A is viewed in the radial direction of the rotor 200, the third height h3 is It may correspond to a ratio of the distance L3.

Here, the reference line (L) is an imaginary line parallel to the axial direction, and the third height (h3) is a linear distance between the upper end and the lower end of the first protrusion (211A) in the axial direction, and the third distance (L3) may correspond to the separation distance between the lower end of the first protrusion 211A and the reference line L.

The second rotor core 210B may include a second protrusion 211B. The second protrusion 211B protrudes from the outer peripheral surface of the second rotor core 210B. Also, the second protrusion 211B may be elongated in the axial direction.

The second protrusion 211B may be inclined to correspond to the inclined side surface 221B of the second magnet 220B. Specifically, the second protrusion 211B has a fourth inclination inclined with respect to the axial direction.

The fourth inclination is the degree of inclination of the second protrusion 211B with respect to the reference line L. When the second protrusion 211B is viewed in the radial direction of the rotor 200, the fourth inclination is the fourth height h4 with respect to the fourth height h4. It may correspond to the ratio of the distance L4.

Here, the reference line (L) is an imaginary line parallel to the axial direction, the fourth height (h4) is a straight distance between the upper end and the lower end of the third protrusion 211 in the axial direction, and the fourth distance (L4) may correspond to the separation distance between the lower end of the fourth protrusion 211 and the reference line L.

The third slope and the fourth slope may be the same. In addition, the first protrusion 211A and the second protrusion 211B may be positioned on the same inclined line M. As shown in FIG.

Meanwhile, the first slope, the second slope, the third slope, and the fourth slope are tanθ values, respectively, and θ in tanθ may be calculated through Equation 1 below.

“A” is the number of poles of the magnet 220 .

For example, when the number of poles of the magnet 220 is 8, the range of θ is 10° to 20°, and the first slope, the second slope, the third slope, and the fourth slope may be within 0.65 to 2.24, respectively.

7 is a perspective view of another type of rotor having an offset, FIG. 8 is a view showing the magnet 220 shown in FIG. 7, and FIG. 9 is a view looking at the magnet 220 in the radial direction of the rotor.

7 to 9 , as another type of rotor 200 , the first magnet 220A and the second magnet 220B are offset O1 at a predetermined angle with respect to the circumferential direction of the rotor 200 . It is twisted and arranged so as to have The side surface 221A of the first magnet 220A is formed to have a first inclination, the second magnet 220B is formed to have a second inclination, and the side surface 221A and the second magnet of the first magnet 220A are formed to have a second inclination. The side surfaces 221B of 220B are not coplanar. At this time, the offset O1 is based on the center of the rotor 200 .

And the offset O1 is a reference line T1 passing the lower end of the side surface 211A of the first magnet 200A in a direction parallel to the axial direction and the upper end of the side surface 211B of the second magnet 200B in the axial direction and It may be represented by an angle corresponding to between the reference lines T2 passing in a parallel direction.

The side surface 221A of the first magnet 220A is spaced apart from the side surface 221A of the second magnet 220B by an offset O1. This is to further secure a skew angle for increasing the offsetting effect of the cogging torque within the range of the first inclination and the second inclination.

10 is a perspective view of the rotor core 210 shown in FIG. 7 , and FIG. 11 is a side view 221A of the rotor shown in FIG. 10 .

10 and 11 , the first protrusion 211A and the second protrusion 211B are. Doedoe arranged to have a third inclination and a fourth inclination, respectively, corresponding to the positions of the first magnet 220A and the second magnet 220B, an offset O2 that is a predetermined angle with respect to the circumferential direction of the rotor 200 . It is twisted and arranged so as to have

The offset O2 is between a reference line T3 passing the lower end of the first protrusion 211A in a direction parallel to the axial direction and a reference line T4 passing the lower end of the second protrusion 211B in a direction parallel to the axial direction and It can be expressed as a corresponding angle.

Meanwhile, the offsets O1 and O2 may be calculated through Equation 2 below.

“A” is the number of poles of the magnet 220 .

For example, when the number of poles of the magnet 220 is 8, the offsets O1 and O2 may be ±7.5° with respect to the circumferential direction.

As described above, the motor according to a preferred embodiment of the present invention has been described in detail with reference to the accompanying drawings.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions are possible within the range that does not depart from the essential characteristics of the present invention by those of ordinary skill in the art to which the present invention pertains. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are for explaining, not limiting, the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments and the accompanying drawings. . The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: shaft
200: rotor
210: rotor core
210A: first rotor core
210B: second rotor core
211: turn
211A: first projection
211B: second projection
220: magnet
220A: first magnet
200Aa: first unit magnet
200Ab: second unit magnet
220B: second magnet
220Ba: 3rd unit magnet
220Bb: 4th unit magnet
300: stator

Claims (18)

rotor; and
and a stator disposed to correspond to the rotor,
The rotor includes a rotor core and a magnet disposed on the rotor core,
The rotor core includes a first rotor core and a second rotor core disposed in an axial direction,
The magnet includes a first magnet disposed on the first rotor core;
and a second magnet disposed on the second rotor core and spaced apart from the first magnet,
The side of the first magnet has a first inclination inclined with respect to the axial direction,
A side surface of the second magnet has a second inclination inclined with respect to the axial direction. According to claim 1,
The first magnet includes a first unit magnet and a second unit magnet spaced apart from the first unit magnet,
The second magnet includes a third unit magnet and a fourth unit magnet spaced apart from the third unit magnet,
The first unit magnet and the third unit magnet have the same polarity,
The first unit magnet and the second unit magnet have different polarities from each other. According to claim 1,
The first slope and the second slope are the same motor. According to claim 1,
The first slope and the second slope are different from each other. According to claim 1,
A side surface of the first magnet and a side surface of the second magnet are disposed on the same plane According to claim 1,
A side surface of the first magnet and a side surface of the second magnet are disposed on the same plane According to claim 1,
A side surface of the first magnet and a side surface of the second magnet are not disposed on the same plane rotor; and
It includes a stator disposed to correspond to the rotor,
The rotor includes a rotor core and a magnet disposed on the rotor core,
The rotor core includes a first rotor core and a second rotor core disposed in an axial direction,
The magnet includes a first magnet disposed on the first rotor core and a second magnet disposed on the second rotor core,
The first magnet includes a first unit magnet and a second unit magnet having a side inclined at a first inclination with respect to the axial direction,
The second magnet includes a third unit magnet and a fourth unit magnet having sides inclined at a second inclination with respect to the axial direction,
The first unit magnet and the second unit magnet are spaced apart from each other in the motor. 9. The method of claim 8,
The first rotor core includes a first protrusion, and the second rotor core includes a second protrusion that is offset from the first protrusion at a predetermined angle. According to claim 1,
The first rotor core includes a first protrusion, and the second rotor core includes a second protrusion,
The first protrusion and the second protrusion are positioned on the same inclined line. rotor; and
and a stator disposed to correspond to the rotor,
The rotor includes a rotor core and a plurality of magnets disposed on the rotor core,
The rotor core includes a protrusion disposed between two magnets adjacent to each other in a circumferential direction among the plurality of magnets,
The protrusion is disposed to be inclined with respect to the axial direction. 12. The method of claim 11,
The rotor core includes a first rotor core and a second rotor core,
The protrusion includes a first protrusion protruding from the first rotor core to have a first inclination and a second protrusion protruding from the second rotor core to have a second inclination. 12. The method of claim 11,
The first protrusion and the second protrusion are arranged to be offset from each other at a predetermined angle. 12. The method of claim 11,
The first protrusion and the second protrusion are positioned on the same inclined line. 12. The method of claim 11,
The first slope and the second slope are the same motor. 12. The method of claim 11,
The first slope and the second slope are different from each other. According to claim 1,
The first slope and the second slope are tanθ values, respectively, and θ in tanθ is calculated through Equation 1 below.
<Equation 1>
θ=((360°/A)/3)±5°
Here, A is the number of poles of the magnet. 14. The method according to claim 9 or 13,
The offset is a motor calculated through Equation 2 below.
<Equation 2>
Offset=±(360°/A)/6
Here, A is the number of poles of the magnet.

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