KR20200064530A - Motor - Google Patents

Abstract

An embodiment relates to a motor that includes: a shaft; a rotor coupled to the shaft; and a stator disposed outside the rotor. The stator includes a stator core and a coil wound around the stator core. The stator core includes a yoke, a tooth protruding radially from the yoke, a shoe disposed at an end of the tooth, and one groove formed radially concave in the center of an inner surface of the shoe. A width (W2) of the groove is 0.15 to 0.47 times a width (W1) of the tooth. Accordingly, the 10-pole 12-slot motor reduces noise vibration by providing the width and depth of the groove formed in the shoe against the radial width of the stator′s tooth by a response surface methodology (RSM) technique.

Description

Motor {MOTOR}

The embodiment relates to a motor.

A motor is a device that converts electrical energy into mechanical energy to obtain rotational force, and is widely used in vehicles, home electronics, and industrial equipment.

Particularly, the electronic power steering system (hereinafter referred to as EPS) in which the motor is used drives the motor in an electronic control unit according to the operating conditions to ensure turning stability and provides quick resilience. do. Accordingly, the driver of the vehicle can drive safely.

The motor includes a stator and a rotor. The stator may include teeth forming a plurality of slots, and the rotor may include a plurality of magnets disposed to face the teeth. Adjacent teeth of the teeth may be disposed apart from each other to form a slot open (slot open).

Since 10 of these motors are provided with 10 magnets and have 12 teeth, the 10-pole 12-slot motor is a very unfavorable combination for noise vibration, so it is necessary to improve noise vibration (NVH, Noise, Vibration, Harshness).

In particular, the performance and quality of the motor may vary depending on the shape of the groove formed in the tooth. Accordingly, a design criterion for width and depth of the groove can be suggested through correlation between torque representing the performance of the motor and torque ripple representing the quality of the motor, cogging torque, and total harmonic distortion (THD). Motors are in demand.

The embodiment provides a 10-pole 12-slot motor with reduced noise vibration by proposing the width and depth of the groove formed in the shoe relative to the width of the stator's tooth by the response surface methodology (RSM) method, which is a response surface analysis method. .

The problems to be solved by the embodiments are not limited to the problems mentioned above, and other problems not mentioned herein will be clearly understood by those skilled in the art from the following description.

The subject is, according to the embodiment, the shaft; A rotor to which the shaft is coupled; And a stator disposed outside the rotor, the stator including a stator core and a coil wound around the stator core, wherein the stator core is a yoke, a tooth protruding radially from the yoke, an end of the tooth. It includes a shoe disposed in the center of the inner surface of the shoe and the inner surface of the shoe, the width of the groove (W2) is achieved by a motor that is 0.15 to 0.47 times the width (W1) of the tooth .

Here, the depth D of the groove may be 0.015 to 0.24 times the width W1 of the tooth.

And, the width (W2) and the depth (D) of the groove can be obtained by RSM (RSM) technique.

And, each of the average torque value, torque ripple, cogging torque, and excitation force THD (Total Harmonic Distortion) formed in the shoe forms a contour plot by the above technique, and the width of the groove (W2) And depth D may be selected from the selection region S formed by the combination of the contour plots.

Further, the excitation force THD may include a radial THD and a tangential THD.

Meanwhile, the inner surface may be parallel to an imaginary line disposed perpendicular to the radial direction on a horizontal surface.

In addition, the rotor includes a rotor core and a plurality of magnets disposed on an outer circumferential surface of the rotor core, 10 magnets are provided, and 12 teeth of the stator may be provided.

The subject is, according to the embodiment, the shaft; A rotor to which the shaft is coupled; And a stator disposed outside the rotor, the stator including a stator core and a coil wound around the stator core, wherein the stator core is a yoke, a tooth protruding radially from the yoke, an end of the tooth. It includes a shoe disposed in the center of the inner surface of the shoe and the inner surface of the shoe, the torque average value, torque ripple, cogging torque and the excitation force formed in the shoe THD (Total Harmonic Distortion) each SM A contour plot is formed by the (RSM) technique, and the width (W2) and depth (D) of the groove relative to the width (W1) of the tooth is a selection region (S) formed by a combination of the contour plots. ) Is achieved by the motor selected.

The 10-pole 12-slot motor according to the embodiment having the above-described configuration is configured to determine the width and depth of the groove formed in the shoe against the width of the tangential direction of the teeth of the stator by the response surface methodology (RSM) technique. By proposing, noise vibration can be reduced.

That is, the motor can reduce the noise vibration by defining the width and depth of the groove formed in the shoe in relation to the width of the tooth through the RS technique. Accordingly, the quality of the motor can be improved.

Various and beneficial advantages and effects of the embodiments are not limited to the above, and may be more easily understood in the process of describing specific embodiments of the embodiments.

1 is a view showing a motor according to an embodiment,
2 is a cross-sectional view showing a motor according to an embodiment,
3 is a view showing a stator core of a motor according to an embodiment,
4 is a view showing the contour plot of the average torque (Average Torque) of the motor according to the embodiment,
5 is a view showing the contour plot of the torque ripple of the motor according to the embodiment,
6 is a view showing the contour plot of the cogging torque of the motor according to the embodiment,
7 is a view showing the contour plot of the radial THD of the motor according to the embodiment,
8 is a view showing the contour plot of the tangential direction THD of the motor according to the embodiment,
9 is a view showing a selection area according to a combination of contour plots of torque average values, torque ripples, cogging torques, and excitation forces formed by the shoe according to an embodiment,
10 is a table showing the width of the tooth, the width and the depth of the groove by the selection region of the motor according to the embodiment,
11 is a table showing the constraints applied to the motor according to the embodiment,
12 is a view showing a point selected from the selection region of FIG. 9 by applying a constraint.

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 technical spirit scope of the present invention, one or more of its components between embodiments may be selectively selected. It can be used by bonding and substitution.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention, unless specifically defined and described, can be generally understood by those skilled in the art to which the present invention pertains. It can be interpreted as meaning, and commonly used terms, such as predefined terms, may interpret the meaning in consideration of the contextual meaning of the related technology.

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 the present specification, a singular form may also include a plural form unless specifically stated in the phrase, and is combined with A, B, and C when described as "at least one (or more than one) of A and B, C". It can contain one or more of all possible combinations.

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

These terms are only for distinguishing the component from other components, and the term is not limited to the nature, order, or order of the component.

And, when a component is described as being'connected','coupled' or'connected' to another component, the component is not only directly connected to, coupled to, or connected to the other component, but also to the component It may also include the case of'connected','coupled' or'connected' due to another component between the other components.

Further, when described as being formed or disposed in the "top (top) or bottom (bottom)" of each component, the top (top) or bottom (bottom) is one as well as when the two components are in direct contact with each other It also includes a case in which another component is formed or disposed between two components. In addition, when expressed as "up (up) or down (down)", it may include the meaning of the downward direction as well as the upward direction based on one component.

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

1 is a view showing a motor according to an embodiment, FIG. 2 is a cross-sectional view showing a motor according to the embodiment, and FIG. 3 is a view showing a stator core of the motor according to the embodiment. Here, FIG. 2 is a cross-sectional view showing line A-A in FIG. 1. In addition, in FIG. 1, the y-direction refers to the axial direction, and the x-direction refers to the radial direction. And, the axial direction and the radial direction are perpendicular to each other. In addition, in FIG. 2, a t direction, which is a direction perpendicular to the x direction on a horizontal plane, may mean a tangential direction.

1 to 3, the motor 1 according to the embodiment includes a housing 100 having an opening formed on one side, a cover 200 disposed on the top of the housing 100, and an interior of the housing 100 The stator 300, the rotor 400 disposed on the inside of the stator 300, and the shaft 500 rotating together with the rotor 400, the bus bar 600 disposed on the upper side of the stator 300, and the shaft ( 500) may include a sensor unit 700 for sensing rotation. Here, the inner side means a direction arranged toward the center C based on the radial direction, and the outer side means a direction opposite to the inner side.

The housing 100 and the cover 200 may form the outer shape of the motor 1. Here, the housing 100 may be formed in a cylindrical shape with an opening on the top.

The cover 200 may be arranged to cover the open top of the housing 100.

Therefore, an accommodation space may be formed inside by combining the housing 100 and the cover 200. In addition, as shown in FIG. 1, the stator 300, the rotor 400, the shaft 500, the bus bar 600 and the sensor unit 700 may be disposed in the accommodation space.

The housing 100 may be formed in a cylindrical shape. A pocket portion accommodating the bearing 10 supporting the lower portion of the shaft 500 may be provided under the housing 100. In addition, a pocket portion accommodating the bearing 10 supporting the upper portion of the shaft 500 may also be provided on the cover 200 disposed on the upper portion of the housing 100.

The stator 300 may be supported by the inner circumferential surface of the housing 100. And, the stator 300 is disposed outside the rotor 400. That is, the rotor 400 may be disposed inside the stator 300.

1 to 3, the stator 300 includes a stator core 310, a coil 320 wound around the stator core 310, and an insulator 330 disposed between the stator core 310 and the coil 320. It may include.

A coil 320 forming a rotating magnetic field may be wound on the stator core 310. Here, the stator core 310 may be formed of one core or a plurality of divided cores may be combined.

In addition, the stator core 310 may be formed in a form in which a plurality of plates in the form of thin steel plates are stacked with each other, but is not limited thereto. For example, the stator core 310 may be formed as a single unit.

The stator core 310 is radially concave in the center of the yoke 311, the plurality of teeth 312, the shoe 313 formed at the inner end of the tooth 312, and the inner surface 313a of the shoe 313 It may include a groove 314 formed. Here, the inner surface 313a may be formed parallel to the tangential direction. For example, the inner surface 313a may be parallel to an imaginary line disposed perpendicular to the radial direction in the plane.

The yoke 311 may be formed in a cylindrical shape. Accordingly, the yoke 311 may include a planar ring-shaped cross section.

The coil 320 is wound around the tooth 312.

The tooth 312 may be disposed to protrude from the yoke 311 toward the radial direction (x direction) with respect to the center (C). In addition, the plurality of teeth 312 may be arranged to be spaced apart from each other on the inner circumferential surface of the yoke 311 along the circumferential direction. Accordingly, a slot, which is a space in which the coil 320 can be wound, may be formed between each of the teeth 312.

The tooth 312 may be formed to have a predetermined width W1 in the tangential direction.

Here, the tooth 312 may be provided in 12 pieces, but is not limited thereto.

The shoe 313 may extend to protrude inward from the inner end of the tooth 312. Here, the width of the shoe 313 may be greater than the width W1 of the tooth 312.

The shoe 313 may be disposed to face the magnet 420 of the rotor 400. At this time, the inner surface 313a of the shoe 313 based on the radial direction may be disposed to be spaced apart at a predetermined distance from the outer circumferential surface of the magnet 420.

2 and 3, as the shoes 313 are spaced apart from each other in the circumferential direction, an opening may be formed inside the slot. Here, the opening may be referred to as a distance between the slot opening or the shoe 313. In addition, the slot open may indicate between one end of the shoe 313 and the other end of the other shoe 313 adjacent thereto.

On the other hand, with respect to the noise vibration characteristics of the motor, the excitation force by the electromagnetic force formed by the rotation of the rotor 400 may be formed in the shoe 313. Accordingly, a tremor is formed in the shoe 313 and noise vibration may occur in the motor 1. At this time, the excitation force may be formed as a sine wave, and the tremor may be represented as a total harmonic distortion (THD). Here, the excitation THD may include a radial THD and a tangential THD.

Therefore, through one groove 314, the motor 1 can reduce noise and vibration.

Referring to FIG. 3, the groove 314 may be formed concave in the radial direction at the center of the inner surface 313a of the shoe 313. Here, the groove 314 may be formed such that one has a rectangular cross-section in the shoe 313, and the center C1 of the shoe 313 and the center C of the motor 1 are radially It can be placed on a virtual line. Accordingly, the center of the groove 314 may be disposed on the virtual line.

On the other hand, the groove 314 may be formed to have a predetermined width (W2) and depth (D). In addition, the width W2 and the depth D of the groove 314 may be optimized by an RSM technique. Here, the RSM (RSM) technique may be called a response surface analysis method.

4 is a view showing the contour plot of the torque average value (Average Torque) of the motor according to the embodiment, Figure 5 is a view showing the contour plot of the torque ripple of the motor according to the embodiment, Figure 6 is a motor according to the embodiment Is a view showing the contour plot of the cogging torque of, FIG. 7 is a view showing the contour plot of the radial THD of the motor according to the embodiment, and FIG. 8 is a view showing a contour plot of the tangential direction of the motor according to the embodiment. , FIG. 9 is a view showing a selection area according to a combination of a torque average value of a motor, a torque ripple, a cogging torque, and a contour plot of each excitation force formed by the shoe.

4 to 8, each of the torque average value of the motor 1, torque ripple, cogging torque and excitation force formed on the shoe 313 (THD, Total Harmonic Distortion), respectively, is the SM technique A contour plot can be formed by (RSM) technique. Here, the excitation THD may be divided into a radial THD and a tangential THD by a direction.

Then, as illustrated in FIG. 9, a selection region S may be formed by a combination of the contour plots. In addition, the width W2 and the depth D of the groove 314 may be selected in the selection area S.

The width W2 and the depth D of the groove 314 selected in the selection area S may be optimally designed based on the width W1 of the tooth 312.

10 is a table showing the width of the tooth, the width and the depth of the groove by the selection area of the motor according to the embodiment.

Referring to FIG. 10, when the width W1 of the tooth 312 is 6.4 mm, the width W2 of the groove 314 is 1 to 3 mm and the depth D of the groove 314 is 0.1 to 1.5 mm. Can be designed.

That is, when the width W1 of the tooth 312 is presented as a design criterion, the width W2 of the groove 314 in consideration of the selection region S is 0.15 to 0.47 compared to the width W1 of the tooth body. It can be formed by pears. In addition, the depth D of the groove 314 may be formed to be 0.015 to 0.24 times the width W1 of the tooth body. In detail, in consideration of the selection region S, the depth D of the groove 314 may be formed to be 0.015 to 0.20 times the width W1 of the tooth body.

On the other hand, the width (W2) and depth (D) of the groove 314 may be limited by constraints presented in the design of the motor (1).

11 is a table showing constraints applied to a motor according to an embodiment, and FIG. 12 is a diagram showing one point selected in the selection region of FIG. 9 by applying constraints.

Referring to FIG. 11, the motor 1 may select a section of the selection area S in consideration of constraints presented during design.

Referring to FIG. 12, one point P indicating the width W2 and the depth D of the groove 314 may be selected in the selection region S derived by applying the constraint. Accordingly, the motor 1 optimally designs the width W2 and the depth D of the groove 314 selected in the selection area S based on the width W1 of the tooth 312, so that the The tooth 312 and the groove 314 of the motor 1 can be manufactured.

Accordingly, the motor 1 in which the width W2 and the depth D of the groove 314 are optimally designed can reduce the noise of about 47% compared to the motor in which the groove 314 is removed.

The insulator 330 insulates the stator core 310 and the coil 320. Accordingly, the insulator 330 may be disposed between the stator core 310 and the coil 320.

Accordingly, the coil 320 may be wound on the tooth 312 of the stator core 310 on which the insulator 330 is disposed.

The rotor 400 is disposed inside the stator 300. In addition, the rotor 400 may include a hole into which the shaft 500 is inserted in the center. Accordingly, the shaft 500 may be coupled to the groove of the rotor 400.

Referring to FIG. 2, the rotor 400 may include a rotor core 410 and a magnet 420 disposed on an outer circumferential surface of the rotor core 410.

The rotor 400 may be divided into the following forms according to the coupling method of the rotor core 410 and the magnet 420.

As illustrated in FIG. 2, the rotor 400 may be implemented as a type in which the magnet 420 is coupled to the outer circumferential surface of the rotor core 410. In the rotor 400 of this type, a separate can member (not shown) may be coupled to the rotor core 410 in order to prevent the magnet 420 from coming off and increase the bonding force. Alternatively, the magnet 420 and the rotor core 410 may be integrally formed by double injection.

Meanwhile, the rotor 400 may be implemented as a type in which the magnet 420 is coupled to the interior of the rotor core 410. The rotor 400 of this type may be provided with a pocket into which the magnet 420 is inserted into the rotor core 410.

The rotor core 410 may be formed by stacking a plurality of plates in the form of thin steel plates. Of course, the rotor core 410 may be manufactured in the form of a single core composed of a single cylinder.

Further, the rotor core 410 may be formed in a form in which a plurality of pucks (unit cores) forming a skew angle are stacked.

Meanwhile, the rotor core 410 may include a hole formed in the center to insert the shaft 500.

The magnet 420 may be provided in ten, as shown in FIG. 2, but is not limited thereto.

The shaft 500 may be coupled to the rotor 400. When electromagnetic interaction occurs between the rotor 400 and the stator 300 through the current supply, the rotor 400 rotates and the shaft 500 rotates in cooperation with the rotor 400. At this time, the shaft 500 may be supported by the bearing 10.

The shaft 500 may be connected to the steering shaft of the vehicle. Accordingly, the steering shaft may receive power by rotation of the shaft 500.

The bus bar 600 may be disposed above the stator 300.

In addition, the bus bar 600 may be electrically connected to the coil 320 of the stator 300.

The bus bar 600 may include a bus bar body and a plurality of terminals disposed inside the bus bar body. Here, the bus bar body may be a molded product formed through injection molding. In addition, each of the terminals may be electrically connected to the coil 320 of the stator 300.

The sensor unit 700 detects the magnetic force of the sensing magnet installed so as to be interlocked with the rotor 400 and detects the current position of the rotor 400 to detect the rotation of the shaft 500.

The sensor unit 700 may include a sensing magnet assembly 710 and a printed circuit board (PCB, 720).

The sensing magnet assembly 710 is coupled to the shaft 500 to interlock with the rotation of the rotor 400 to detect the position of the rotor 400. At this time, the sensing magnet assembly 710 may include a sensing magnet and a sensing plate. The sensing magnet and the sensing plate may be coupled to have a coaxial.

The sensing magnet may include a main magnet disposed in a circumferential direction adjacent to a hole forming an inner circumferential surface and a sub magnet formed at an edge.

The main magnet may be arranged in the same manner as the magnet 420 of the rotor 400 of the motor.

The sub-magnet may be subdivided from the main magnet, and may be formed of many poles. Therefore, it is possible to measure the rotational angle of the rotor 400 through the sub-magnet in more detail, and accordingly, it is possible to smoothly drive the motor 1.

The sensing plate may be formed of a disc-shaped metal material. A sensing magnet may be coupled to the upper surface of the sensing plate. And the sensing plate may be coupled to the shaft 500. Here, a hole through which the shaft 500 passes is formed in the sensing plate.

A sensor detecting the magnetic force of the sensing magnet may be disposed on the printed circuit board 720. In this case, the sensor may be provided as a Hall IC. In addition, the sensor may generate a sensing signal by sensing changes in the N and S poles of the sensing magnet.

Although described above with reference to embodiments of the present invention, those skilled in the art can variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that you can change it. And, it should be interpreted that the differences related to the modifications and changes are included in the scope of the present invention defined in the appended claims.

1: motor 10: bearing
100: housing
200: cover
300: stator
310: stator core 311: yoke
312: Tooth 313: Shu
314: home
320: coil
400: rotor 410: rotor core
420: magnet
500: shaft
600: bus bar
700: sensor unit

Claims (8)

shaft;
A rotor to which the shaft is coupled; And
It includes a stator disposed on the outside of the rotor,
The stator includes a stator core and a coil wound around the stator core,
The stator core includes a yoke, a tooth protruding radially from the yoke, a shoe disposed at an end of the tooth, and a groove formed radially concave in the center of the inner surface of the shoe,
The width of the groove (W2) is 0.15 to 0.47 times the motor width (W1) of the tooth. According to claim 1,
The depth (D) of the groove is 0.015 to 0.24 times the motor width (W1) of the tooth. According to claim 2,
The width (W2) and depth (D) of the groove is a motor obtained by RSM (RSM) technique. According to claim 3,
Each of the average torque value, torque ripple, cogging torque, and total harmonic distortion (THD) formed in the shoe forms a contour plot by the above technique,
The width (W2) and the depth (D) of the groove are selected from a selection area (S) formed by a combination of the contour flats. The method of claim 4,
The excitation force THD is a motor including a radial THD and a tangential THD. According to claim 1,
The inner surface is a motor parallel to an imaginary line disposed perpendicular to the radial direction on a horizontal surface. According to claim 1,
The rotor includes a rotor core and a plurality of magnets disposed on an outer peripheral surface of the rotor core,
The magnet is provided with 10, and the tooth of the stator is provided with 12 motors. shaft;
A rotor to which the shaft is coupled; And
It includes a stator disposed on the outside of the rotor,
The stator includes a stator core and a coil wound around the stator core,
The stator core includes a yoke, a tooth protruding radially from the yoke, a shoe disposed at an end of the tooth, and a groove formed radially concave in the center of the inner surface of the shoe,
Each of the torque average value, torque ripple, cogging torque and excitation force THD (Total Harmonic Distortion) formed in the shoe forms a contour plot by RSM technique,
The width W2 and the depth D of the grooves compared to the width W1 of the tooth are selected in a selection region S formed by a combination of the contour flats.

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