KR20210053856A - Motor and electronic power steering system having the same - Google Patents

Abstract

The present invention relates to a rotor location detection device, a motor including the same, and an electronic power steering device. The rotor location detection device comprises: a substrate; a Hall signal magnetic element mounted on the substrate; and a first ground pattern disposed on one side of the substrate and electrically connected to the Hall signal magnetic element. Accordingly, the possibility of defects due to electromagnetic waves or static electricity can be reduced.

Description

Motor and electric steering system including the same {MOTOR AND ELECTRONIC POWER STEERING SYSTEM HAVING THE SAME}

The present invention relates to a motor and an electric steering apparatus including the same.

In general, the rotor rotates by an electromagnetic interaction between the rotor and the stator. At this time, the rotation shaft inserted in the rotor also rotates to generate rotational driving force.

As a rotor position sensing device, a sensor including a magnetic element is disposed inside the motor. The sensor detects the magnetic force of the sensing magnet installed so as to be rotationally interlocked with the rotor to determine the current position of the rotor.

The sensor may be made of a plurality of magnetic elements. At this time, in addition to the three magnetic elements for feeding back information on the U, V, and W phases, two magnetic elements are additionally installed in order to grasp the rotation direction and more precise rotation angle of the motor. The two magnetic elements are arranged at regular intervals along the circumferential direction of the sensing magnet. Accordingly, the sensing signals detected by the two magnetic elements have a phase difference, and through this, the rotation direction and rotation angle of the motor can be accurately grasped. Related inventions include Japanese Unexamined Patent Application Publication No. 2003-143812 (2003.05.16), Japanese Unexamined Patent Application Publication No. 2007-252096 (2007.09.27.) and Unexamined Patent Publication No. 14.).

The magnetic elements may be mounted on a printed circuit board and disposed inside a housing of a motor, and have a structure that is vulnerable to electromagnetic waves (EMI), and thus there is a high possibility of electromagnetic wave defects during an EMI test.

Accordingly, there is a problem in that the possibility of failure of the magnetic device increases during an electrostatic (ESD) test.

The technical problem to be achieved by the present invention is to solve the above problems, and to provide a motor that reduces the possibility of defects due to electromagnetic waves or static electricity by forming a ground pattern corresponding to a Hall IC on a substrate, and an electric steering device including the same. have.

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 object is, according to an embodiment of the present invention, a housing having an accommodation space therein and an opening formed at one side thereof; A bracket disposed to cover the opening of the housing; A stator disposed in the receiving space; A rotor disposed inside the stator; A shaft coupled to the rotor; A sensing magnet assembly disposed on the rotor; And a rotor position sensing device for sensing a change in magnetic flux of the sensing magnet assembly, wherein the rotor position sensing device includes: a substrate; A Hall signal magnetic device mounted on the substrate; An encoder signal magnetic device mounted on the substrate; And a first ground pattern formed on the substrate, wherein the first ground pattern is achieved by a motor electrically connected to the Hall signal magnetic element.

The first ground pattern may be disposed inside the substrate.

Further, the second ground pattern may be electrically connected to the encoder signal magnetic device and formed on an outer edge of the substrate.

Here, the bracket, the bracket body; A coupling hole formed in the center of the bracket body and in which the shaft is disposed; A seating portion formed concave toward the rotor around the coupling hole; And a coupling portion protruding from a lower surface of the bracket body.

In addition, the second ground pattern may be fixed to be in contact with one side of the coupling portion by a fixing member.

In addition, as the second ground pattern contacts the coupling portion by the fixing member, the first ground pattern may contact one side of the seating portion.

According to an embodiment of the present invention, the subject is a steering shaft; And a motor connected to the steering shaft, and the motor is achieved by an electric steering device provided with the above-described motor.

The rotor position sensing apparatus according to an embodiment of the present invention having the above configuration can reduce the possibility of an electromagnetic wave (EMI) defect of the motor due to the Hall IC.

In addition, it is possible to reduce the possibility of defects due to static electricity of the motor.

1 and 2 are perspective and exploded perspective views showing a motor according to an embodiment of the present invention,
3 is a view showing a cross section of a motor according to an embodiment of the present invention taken along the line AA of FIG. 1,
4 and 5 are a perspective view and a bottom perspective view showing a bracket of a motor according to an embodiment of the present invention,
6 is a view showing a sensing magnet assembly of a motor according to an embodiment of the present invention,
7 is a view showing a rotor position sensing device of a motor according to an embodiment of the present invention,
8 is a diagram showing improvement of EMI of a motor according to an embodiment of the present invention through comparison with a reference example,
9 is a view showing an electric steering apparatus according to an embodiment of the present invention.

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

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

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention are generally understood by those of ordinary skill in the art, unless explicitly defined and described. It can be interpreted as a meaning, and terms generally used, such as terms defined in a dictionary, may be interpreted in consideration of the meaning in the context of the related technology.

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

Terms including ordinal numbers such as second and first may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, the second element may be referred to as the first element, and similarly, the first element may be referred to as the second element. The term and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

And, when a component is described as being'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 the case of being'connected','coupled' or'connected' due to another element between the other elements.

In addition, when it is described as being formed or disposed on 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 the case where the above other component is formed or disposed between the 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.

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

The motor according to an embodiment of the present invention may reduce the possibility of defects due to electromagnetic waves or static electricity by forming a ground pattern corresponding to the Hall IC on the substrate.

1 to 9, the motor 1 according to an embodiment of the present invention includes a housing 100, a bracket 200, a stator 300 disposed inside the housing 100, and a stator 300. ) Rotatably disposed in the rotor 400, a shaft 500 that is inserted through the rotor 400 and rotates interlockingly, a bearing 600, a sensing magnet assembly 700, a rotor position sensing device 800, and a bus bar (900) may be included. Here, the stator 300 may be disposed to correspond to the rotor 400.

In addition, the motor 1 further includes a lower bearing 610 disposed to support the rotation of the shaft 500, a coupler 620 disposed at one end of the shaft 500, a bus bar power line 910, and the like. Can include.

The housing 100 is formed in a cylindrical shape to provide an accommodation space S in which the stator 300, the rotor 400, and the bus bar 900 can be mounted.

As shown in FIG. 1, the housing 100 may be formed in a cylindrical shape, and may include an opening formed at one side and an accommodation space S formed to communicate with the opening. In this case, the shape or material of the housing 100 may be variously modified, but a metal material capable of withstanding high temperatures may be selected.

The housing 100 is coupled with a bracket 200 disposed to cover the opening to shield the stator 300 and the rotor 400 from the outside. In addition, a cooling structure (not shown) may be further included so that internal heat can be easily discharged. Air cooling or water cooling may be selected as such a cooling structure, and the shape of the housing 100 may be appropriately deformed according to the cooling structure.

4 and 5, the bracket 200 has a plate-shaped bracket body 210, a coupling hole 220 formed in the center of the bracket body 210, and a concave shape around the coupling hole 220. It may include a formed seating portion 230 and a coupling portion 240.

As shown in FIG. 4, the seating part 230 may be formed in a groove shape concave in the center toward the rotor 400 with respect to the upper surface 211 of the bracket body 210. In addition, a coupling hole 220 may be formed in the center of the seating portion 230 so that the shaft 500 is disposed.

Accordingly, the bearing 600 may be disposed on the seating surface 231 of the seating portion 230 so as to rotatably support the shaft 500.

The coupling part 240 may be formed to protrude from the lower surface 212 of the bracket body 210. In addition, one side of the rotor position sensing device 800 may be fixed to contact with the coupling part 240 by a fixing member 10 such as a bolt or a screw. In more detail, the second ground pattern 850 of the rotor position sensing device 800 may be fixed to be in contact with the contact surface 241 of the coupling portion 240 by the fixing member 10.

The stator 300 is inserted into the receiving space S of the housing 100. The stator 300 may include a stator core 310 and a coil 320 wound around the stator core 310. The stator core 310 may be an integral core formed in a ring shape or may be a core in which a plurality of divided cores are combined.

The stator 300 may be appropriately deformed according to the type of motor. For example, in the case of a DC motor, a coil may be wound around the integral stator core, and in the case of a three-phase control motor, the U, V, and W phases may be respectively input to a plurality of coils.

A busbar 900 may be disposed above the stator 300, and the coil 320 of the stator 300 may be connected to the busbar 900. In this case, a plurality of metal members (terminals) electrically connected to the coil 320 may be fixedly disposed on the bus bar 900 while being insulated by an insulator.

The rotor 400 is disposed rotatably with the stator 300. A magnet is disposed on the rotor 400, and the rotor 400 may rotate by an electromagnetic interaction with the stator 300.

The shaft 500 is coupled to the central portion of the rotor 400. Therefore, when the rotor 400 rotates, the shaft 500 also rotates. In this case, the shaft 500 may be rotatably supported by the bearing 600.

The shaft 500 is coupled with an external mechanism to provide power. For example, when the motor 1 is used as an EPS motor, the shaft 500 may be connected to a steering shaft of a vehicle to provide power to assist steering.

The rotor position sensing apparatus 800 according to an embodiment of the present invention detects a rotation position of the rotor 400 by detecting a change in magnetic flux of the sensing magnet assembly 700 rotating in conjunction with the shaft 500.

Referring to FIG. 6, the sensing magnet assembly 700 may include a sensing plate 710 and a sensing magnet 720 mounted on the sensing plate 710. The sensing plate 710 may rotate by being coupled to the shaft 500.

The sensing magnet 720 is formed in a disk shape, and may include a main magnet 711 disposed at a center thereof and a sub magnet 712 disposed at an edge thereof. The main magnet 711 includes a plurality of split magnets formed in a split ring shape. The number of divided magnets (number of poles) of the main magnet 711 is arranged equal to the number (number of poles) of the rotor magnets, so that the rotation of the rotor can be detected.

The sub-magnet 712 is disposed at the edge of the original plate and includes a larger number (number of poles) of divided magnets than the main magnet 711. Accordingly, one pole (divided magnet) of the main magnet 711 is further subdivided and disassembled. Therefore, it is possible to measure the detection of the rotation amount more precisely. Here, in the sub-magnet 712, the divided magnet of the N pole and the divided magnet of the S pole may be alternately disposed along the circumferential direction.

Referring to FIG. 7, the rotor position sensing device 800 includes a substrate 810, a plurality of Hall signal magnetic elements 820 spaced apart from each other at a predetermined interval, and a predetermined substrate 810. A plurality of encoder signal magnetic elements 830 spaced apart from each other, a first ground pattern 840 electrically connected to the Hall signal magnetic element 820, and a second ground electrically connected to the encoder signal magnetic element 830 A pattern 850, a first ground terminal electrically connected to the first ground pattern 840, a second ground terminal electrically connected to the second ground pattern 850, and a fixing hole 860 may be included. have. Here, the plurality of Hall signal magnetic elements 820 may be referred to as a first magnetic element unit, and the plurality of encoder signal magnetic elements 830 may be referred to as a second magnetic element unit. Accordingly, the Hall signal magnetic element 820 may be referred to as a first magnetic element, and the encoder signal magnetic element 830 may be referred to as a second magnetic element. In addition, the first magnetic element may correspond to the main magnet 711 based on the axial direction of the shaft 500, and the second magnetic element corresponds to the sub magnet 712 based on the axial direction of the shaft 500. Can be. In this case, as shown in FIG. 7, the first ground pattern 840 and the second ground pattern 850 may be separated. In addition, the first magnetic device part and the second magnetic device part may be electrically separated. Accordingly, the first ground pattern 840 may be disposed on one side of the substrate 810, and the second ground pattern 850 may be disposed on the other side of the substrate 810.

The magnetic elements 820 and 830 disposed on the substrate 810 are disposed to be spaced apart from the sensing magnet assembly 700 to detect a change in the pole of the magnet, thereby calculating a rotation angle according to a change in magnetic flux. Here, the magnetic elements 820 and 830 may be Hall ICs, and as shown in FIG. 7, each of the magnetic elements 820 and 830 is formed in a structure in which Vcc and ground (GND) are separated. I can.

Referring to FIG. 7, the substrate 810 may be formed as an arc-shaped plate. In addition, the Hall signal magnetic device 820 and the first ground pattern 840 may be disposed inside the virtual line C shown in the center of the substrate 810 along the circumferential direction of the substrate 810. . As shown in FIG. 7, the first ground pattern 840 may be disposed adjacent to an inner circumferential surface that is inner than an outer circumferential surface of the substrate 810.

Here, the term'outside' means the outer side with respect to the imaginary line (C) in the radial direction from the center of rotation of the shaft 500, and'inside' refers to the radial direction from the center of rotation of the shaft 500 It means the inside based on the virtual line (C).

The plurality of Hall signal magnetic elements 820 may be disposed on a first arc having a first radius based on a rotation center of the shaft 500. Accordingly, the first ground pattern 840 may be formed in an arc shape and may be disposed on an inner edge of the substrate 810. In addition, the first ground pattern 840 may be electrically connected to the ground GND of the Hall signal magnetic device 820.

In addition, the first ground pattern 840 may be disposed to be in close contact with one side of the bracket 200. For example, the first ground pattern 840 may be disposed to be in close contact with the contact surface 232 positioned on the opposite side of the mounting surface 231 of the bracket 200.

Accordingly, the area of the ground (GND) of the Hall signal magnetic element 820 is relatively increased, and accordingly, the possibility of an electromagnetic wave (EMI) failure of the motor 1 due to the Hall signal magnetic element 820 or a failure of static electricity. The likelihood can be reduced.

Meanwhile, an encoder signal magnetic element 830 and a second ground pattern 850 may be disposed outside the virtual line C shown along the circumferential direction of the substrate 810. The second ground pattern 850 may be disposed adjacent to the outer circumferential surface of the substrate 810 rather than the inner circumferential surface.

The plurality of encoder signal magnetic elements 830 may be disposed on a second arc having a second radius different from the first radius based on the rotation center of the shaft 500. Accordingly, the second ground pattern 850 may be formed in an arc shape and may be disposed on an outer edge of the substrate 810. In addition, the second ground pattern 850 may be electrically connected to the ground GND of the encoder signal magnetic element 830.

In addition, the second ground pattern 850 may be disposed to be in close contact with the coupling portion 240 of the bracket 200. That is, the second ground pattern 850 may be fixed while being disposed in close contact with the coupling part 240 by the fixing member 10 disposed through the fixing hole 860. Here, the fixing hole 860 may be disposed adjacent to an outer circumferential surface of the substrate 810 than an inner circumferential surface of the substrate 810. Accordingly, the first ground pattern 840 may be closer to the inner circumferential surface than the outer circumferential surface, and the second ground pattern 850 may be closer to the outer circumferential surface than the inner circumferential surface. In addition, the fixing hole 860 may be disposed to be spaced apart from the first ground pattern 840. Here, the fixing hole 860 may be referred to as a fixing hole.

In addition, as the end of the fixing member 10 is coupled to the coupling portion 240, the first ground pattern 840 may also be disposed in close contact with the contact surface 232.

8 is a diagram showing improvement of EMI of a motor according to an embodiment of the present invention. That is, (a) of FIG. 8 is a diagram showing a case in which the first ground pattern 840 is not present (reference example) in the rotor position sensing device 800, and (b) of FIG. 8 is a reference example and the motor ( This is a graph comparing the improvement of EMI in 1).

As shown in (b) of FIG. 8, it can be seen that the first ground pattern 840 improves the motor 1 by about 160% EMI compared to the reference example.

Hereinafter, an operation of detecting the position of the rotor 400 using the rotor position sensing device 800 and the sensing magnet assembly 700 will be described.

The rotor position sensing device 800 may include a plurality of magnetic elements 820 and 830 that sense the position of the rotor 400 by sensing a change in magnetic flux according to the rotation of the sensing magnet assembly 700.

Since the main magnet 711 of the sensing magnet assembly 700 is provided to correspond to the magnet of the rotor 400, in order to detect the position of the rotor 400, a change in the magnetic flux of the main magnet 711 must be sensed.

The rotor position sensing device 800 may detect a pole change, which is a change in magnetic flux of the main magnet 711 through the Hall signal magnetic element 820, and detect three sensing signals. In addition, two sensing signals may be sensed by detecting a pole change, which is a change in magnetic flux of the sub-magnet 712 through the encoder signal magnetic element 830. Here, the rotation direction and detailed rotation angle of the motor can be calculated through the two sensing signals. Accordingly, the plurality of first magnetic elements may be disposed to correspond to the main magnet 711, and the plurality of second magnetic elements may be disposed to correspond to the sub magnet 712.

On the other hand, the electric steering apparatus (EPS, 2) according to an embodiment of the present invention may include the motor (1).

Referring to FIG. 9, the electric steering device 2 includes the motor 1, the steering wheel 3, the steering shaft 4, the steering angle sensor 5, and the electronic control device (ECU, 6). I can.

The steering wheel 3 is generally referred to as a steering wheel, and is rotated by the driver to change the direction of the vehicle. The steering wheel 3 may be arranged to be connected to the steering shaft 4, and when the driver rotates the steering wheel 3, the steering shaft 4 moves in the same direction in association with the rotation of the steering wheel 3 Rotate.

The motor 1 is a motor that assists the driver with a torque that manipulates the steering wheel 3 in order to steer, and assists the driver to perform the steering operation of the vehicle more easily.

A speed reducer and a torque sensor (not shown) may be coupled to one end of the motor 1. The torque sensor generates an electrical signal that senses the relative rotational displacement of the input shaft and the output shaft according to the rotation of the steering wheel 3 and then transmits the signal to the electronic control device 6.

The steering angle sensor 5 is installed near the steering wheel 3 and transmits a signal obtained by directly measuring the rotation angle of the steering wheel 3 rotating by the driver's operation to the electronic control device 6.

The electronic control device 6 may electronically control various driving sources of the electric steering device including the motor 1 based on information of a vehicle speed detection sensor, not shown, and the torque and steering angle sensor 5.

Here, the motor 1 may be connected to a steering shaft of the electric steering device 2.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. You will understand that you can do it.

1: motor 2: electric steering device
3: steering wheel 4: steering shaft
5: steering angle sensor 6: electronic control device
100: housing 200: bracket
300: stator 400: rotor
500: shaft 600: bearing
700: sensing magnet assembly 800: rotor position detection device
820: Hall signal magnetic element 830: Encoder signal magnetic element
860: fixed hole 900: bus bar

Claims (14)

shaft;
A sensing magnet coupled to the shaft; And
Including a position sensing device including a substrate disposed to face the sensing magnet,
The sensing magnet includes a main magnet disposed radially inside from the shaft and a sub magnet disposed outside,
The position sensing device includes a first magnetic element overlapping the main magnet in an axial direction and a second magnetic element overlapping the sub magnet in an axial direction,
The first magnetic element is electrically connected to a first ground terminal,
The second magnetic element is electrically connected to a second ground terminal,
The first ground terminal and the second ground terminal are spaced apart from each other and disposed on the substrate. shaft;
A sensing magnet coupled to the shaft; And
And a position sensing device corresponding to the sensing magnet and including a substrate on which a plurality of first magnetic elements and a plurality of second magnetic elements are disposed,
The sensing magnet includes a main magnet disposed along a first circumference and a sub magnet disposed along a second circumference,
The first magnetic element, the second magnetic element, the main magnet, and the sub-magnet are disposed on each concentric circle centered on the shaft,
The first magnetic element is electrically connected to the first ground pattern,
The second magnetic element is electrically connected to a second ground pattern,
Electrically connected to the first ground pattern and the second ground pattern,
The first ground pattern and the second ground pattern are spaced apart from each other and disposed on the substrate. shaft;
A sensing magnet coupled to the shaft and arranged in a ring shape; And
A position sensing device including a substrate disposed to correspond to the sensing magnet, a magnetic element disposed on the substrate, and a ground pattern,
The magnetic element includes a first magnetic element disposed along a first circumference and a second magnetic element disposed along a second circumference on the arc-shaped substrate,
The substrate is overlapped with the sensing magnet in the axial direction,
The ground pattern includes a first ground pattern disposed on one side of the substrate and a second ground pattern disposed on the other side of the substrate,
The first ground pattern and the second ground pattern are spaced apart from each other. The method according to at least any one of claims 1 to 3,
The substrate is a motor comprising an outer circumferential surface, an inner circumferential surface, and a side surface connecting the outer circumferential surface and the inner circumferential surface. The method of claim 4,
The side surface of the motor includes a convex portion. The method according to at least any one of claims 1 to 3,
A first power terminal electrically connected to the first magnetic element, and a second power terminal electrically connected to the second magnetic element,
The first power terminal and the second power terminal are spaced apart from each other. The method according to claim 2 or 3,
The first ground pattern includes a first arcuate portion having a first radius of curvature disposed adjacent to the inner side,
The second ground pattern includes a second arcuate portion having a second radius of curvature disposed adjacent to the outside. The method according to at least any one of claims 1 to 3,
The plurality of first magnetic elements form a first magnetic element portion,
The plurality of second magnetic elements form a second magnetic element portion,
The first magnetic device part and the second magnetic device part are electrically separated from each other. The method of claim 8,
A plurality of the first magnetic elements are disposed on a first arc having a first radius,
The plurality of second magnetic elements are disposed on a second arc having a second radius,
The first radius and the second radius are motors having different lengths. The method according to claim 2 or 3,
Including a bracket disposed on the substrate,
The motor includes a hole for fixing the substrate to the bracket. The method of claim 10,
The hole is a motor spaced apart from the first ground pattern. The method of claim 10,
The hole is disposed adjacent to the outer circumferential surface of the substrate than the inner circumferential surface of the substrate. The method according to claim 2 or 3,
The first ground pattern includes a first arcuate portion having a first radius of curvature disposed adjacent to the inner side,
The second ground pattern includes a second arcuate portion having a second radius of curvature disposed adjacent to the outside. The method of claim 1,
The plurality of first magnetic elements detect a pole change of the main magnet,
The plurality of second magnetic elements are motors for detecting a pole change of the sub magnet.

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