Motor

Abstract

A motor includes: a housing; a stator disposed inside the housing; a rotor disposed inside the stator; a shaft coupled with the center of the rotor; and a sensor magnet disposed outside the shaft, in which a groove in which the sensor magnet is disposed is formed on one surface of the rotor.

Description

Technical Field

[0001] This embodiment relates to a motor. Background Art

[0002] A motor is a device that converts electrical energy into rotational energy by utilizing the force exerted on a conductor in a magnetic field. Recently, as the uses of motors have expanded, the role of motors has become more important. In particular, as the electrification of automobiles has rapidly advanced, the demand for motors used in steering systems, braking systems, and design systems has increased significantly.

[0003] The motor has a housing, a stator arranged inside the housing, and a rotor arranged inside the stator, and is a device that generates rotational motion through electromagnetic interaction between the stator and the rotor. Specifically, a coil is wound on the stator, and a magnet facing the coil is arranged on the rotor, so that the rotor can rotate through the action of the coil and the magnet.

[0004] In addition, the motor includes a sensor magnet and a sensor for detecting the rotational position of the rotor or the rotating shaft. For example, the sensor magnet is arranged on one surface of the rotor, and the sensor is arranged in the housing facing the sensor magnet and the sensor detects the magnetic field of the sensor magnet to detect the position of the rotor or the position of the shaft.

[0005] However, according to the related art, there is a problem that the overall size of the motor increases due to the structure in which the rotor, the sensor magnet, and the sensor are arranged in the axial direction. Summary of the invention

[0006] Technical Topics

[0007] The present embodiment intends to provide a motor that can be miniaturized by improving the structure.

[0008] Technical Solutions

[0009] According to the present embodiment, the motor includes: a housing; a stator arranged inside the housing; a rotor arranged inside the stator; a shaft connected to the center of the rotor; and a sensor magnet arranged outside the shaft, wherein a groove is formed on one surface of the rotor and the sensor magnet is arranged in the groove.

[0010] The motor may include a bearing arranged to face one surface of the rotor and to support rotation of the shaft.

[0011] The rotor includes a rotor core and a magnet arranged on an outer surface of the rotor core, wherein the groove may be formed on one surface of the rotor core facing the bearing.

[0012] In terms of the axial direction, a length between the sensor magnet and the bearing may be longer than a length between the rotor core and the bearing.

[0013] In terms of the radial direction, at least a portion of the rotor core may be arranged to overlap the sensor magnet.

[0014] In terms of the axial direction, the length of the groove may be 1 / 2 of the length of the rotor core or less than the length of the rotor core.

[0015] The sensor magnet includes one surface facing the bearing and another surface facing the one surface, wherein the other surface of the magnet may be in contact with a bottom surface of the groove.

[0016] The motor includes a sensor plate in which a shaft is coupled to a center of the sensor plate and a sensor magnet is arranged on one surface facing the bearing, wherein the sensor plate may be arranged inside the groove.

[0017] The sensor plate includes: a first region arranged outside the shaft; and a second region extending radially outward from one end of the first region and perpendicular to the first region, wherein the sensor magnet may be arranged on a surface of the second region.

[0018] A surface of the second region facing the bearing and a surface of the sensor magnet may form the same plane.

[0019] Beneficial effects

[0020] According to the present embodiment, since the arrangement area of ​​the sensor magnet is formed by the groove penetrating the rotor core, the length of the motor in the axial direction can be reduced, there is an advantage that the motor can be miniaturized.

[0021] In addition, since the length of the shaft is reduced compared with the prior art, and since the volume is reduced due to the formation of the groove, there are advantages of reduced material cost and reduced weight compared with the prior art.

[0022] In addition, since the motor has a structure in which the sensor plate is supported by contacting with the bottom surface of the groove, there is an advantage that the assemblability is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a perspective view illustrating the appearance of a motor according to an embodiment of the present invention.

[0024] Figure 2 is a cross-sectional view of a motor according to an embodiment of the present invention.

[0025] Figure 3 is an exploded perspective view of a motor according to an embodiment of the present invention.

[0026] Figure 4 is a perspective view of a rotor according to an embodiment of the present invention.

[0027] Figure 5 is an exploded perspective view of a rotor according to an embodiment of the present invention.

[0028] Figure 6 is a cross-sectional view of a rotor according to an embodiment of the present invention.

[0029] Figures 7 to 9 1 and 2 are diagrams illustrating modified embodiments of the rotor and the sensor magnet according to the embodiment of the present invention. DETAILED DESCRIPTION

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0031] However, the technical concept of the present invention is not limited to some embodiments to be described, but can be implemented in various forms, and within the scope of the technical concept of the present invention, one or more of the constituent elements can be selectively combined or replaced between the various embodiments.

[0032] In addition, unless explicitly defined and described, the terms (including technical terms and scientific terms) used in the embodiments of the present invention may be interpreted as meanings that are generally understood by those skilled in the art, and common terms, such as terms defined in dictionaries, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0033] In addition, the terms used in this specification are used to describe the embodiments and are not intended to limit the present invention. In this specification, unless otherwise specified in a phrase, a singular form may include a plural form, and when described as "at least one (or more than one) of A and B and C", one or more combinations of all combinations that can be combined with A, B and C may be included.

[0034] In addition, when describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b) may be used.

[0035] These terms are only intended to distinguish a component from other components, and these terms do not limit the nature, order, or sequence of the components.

[0036] Furthermore, when a component is described as being “connected,” “coupled” or “interconnected” to another component, the component is not only directly connected, coupled or interconnected to the other component, but may also include a case where the component is “connected,” “coupled” or “interconnected” due to another component between the other components.

[0037] In addition, when described as being formed or arranged "on" or "below" each component, "on" or "below" means not only including the case where the two components are in direct contact, but also including the case where one or more other components are formed or arranged between the two components. In addition, when expressed as "on" or "below", it can include not only the meaning based on the upward direction of one component, but also the meaning based on the downward direction of one component.

[0038] The “axial direction” used hereinafter may be the length direction of the shaft.

[0039] A “radial direction” used hereinafter may be a direction perpendicular to an “axial direction”.

[0040] Figure 1 is a perspective view illustrating the appearance of a motor according to an embodiment of the present invention; Figure 2 is a cross-sectional view of a motor according to an embodiment of the present invention; Figure 3 is an exploded perspective view of a motor according to an embodiment of the present invention; Figure 4 is a perspective view of a rotor according to an embodiment of the present invention; Figure 5 is an exploded perspective view of a rotor according to an embodiment of the present invention; Figure 6 is a cross-sectional view of a rotor according to an embodiment of the present invention; and Figures 7 to 9 1 and 2 are diagrams illustrating modified embodiments of the rotor and the sensor magnet according to the embodiment of the present invention.

[0041] Reference Figures 1 to 6 , a motor 10 according to an embodiment of the present invention may include a housing 100 , a stator 200 , a rotor 300 , a shaft 340 , and a bearing 400 .

[0042] The housing 100 may form an outer shape of the motor 10. The housing 100 may have a cylindrical shape with an open upper surface. A space 110 for accommodating the stator 200, the rotor 300, and the shaft 340 may be formed inside the housing 100. The upper surface of the space 110 may be opened upward.

[0043] A cover (not shown) may be coupled to the upper surface of the housing 100. The space 110 may be closed by the coupling of the cover.

[0044] A connector terminal 190 may be formed on a side surface of the housing 100. The connector terminal 190 may have a shape protruding outward from another area of ​​the outer surface of the housing 100. A space connected to an external terminal (not shown) may be formed in the connector terminal 190. A pin 192 electrically connected to the external terminal may be arranged inside the connector terminal 190. Power may be provided to the motor 10 through the electrical connection between the external terminal and the pin 192, or an electrical signal related to the driving of the motor 10 may be transmitted or received.

[0045] The stator 200 may be disposed inside the housing 10 . The stator 200 may include a stator core 210 , an insulator 220 , and a coil 230 .

[0046] The stator core 210 may include a circular body and a plurality of teeth protruding inward from an inner surface of the body. The plurality of teeth may be arranged to be spaced apart from each other in a circumferential direction.

[0047] The insulator 220 may be coupled to the outer surface of the stator core 210. The insulator 220 may be arranged to surround the outer surface of the stator core 210.

[0048] The coil 230 may be wound around an outer surface of the insulator 220 .

[0049] A bus bar 240 may be disposed on one surface of the stator core 210. The coil 230 may be coupled to the bus bar 240. A plurality of bus bars 240 may be provided to correspond to polarities of the coil 230, and may be arranged to be spaced apart from each other in a circumferential direction.

[0050] The rotor 300 may be disposed inside the stator 200. The rotor 300 may include a rotor core 310, a magnet 320, and a cover plate 330.

[0051] The rotor core 310 may have a circular cross-sectional shape. A hole 316 coupled to the shaft 340 may be formed in the central portion of the rotor core 310. A magnet coupling component 315 coupled to the magnet 320 may be formed on the outer surface of the rotor core 310. The magnet coupling component 315 may have a groove shape that is recessed inwardly than other areas. A plurality of magnet coupling components 315 may be provided and may be arranged to be spaced apart from each other in the circumferential direction. Therefore, the area between two magnet coupling components 315 arranged adjacent to each other may have a shape that protrudes outwardly.

[0052] The magnet 320 may be coupled to the outer surface of the rotor core 310. The magnet 320 may be arranged to face the coil 230. The magnet 320 may be mounted on the outer circumferential surface of the rotor core 310. The magnet 320 may be coupled to the magnet coupling component 315. The magnet 320 may be coupled to the rotor core 310 by an adhesive. In this case, the adhesive may be arranged between the inner surface of the magnet 320 and the bottom surface of the magnet coupling component 315. A plurality of magnets 320 may be provided and arranged to be spaced apart from each other along the circumferential direction of the rotor core 310. In terms of the radial direction, the outer surface of the magnet 320 may protrude outward from the outer surface of the rotor core 310.

[0053] The cover plate 330 may be arranged outside the rotor core 310. The cover plate 330 may have a cross-sectional shape of an annular shape. The cover plate 330 may be arranged to cover the outer surface of the magnet 320 and the outer surface of the rotor core 310. An adhesive may be arranged between the inner surface of the cover plate 330 and the outer surface of the magnet 320 and between the inner surface of the cover plate 330 and the outer surface of the rotor core 310.

[0054] The length of the cover plate 330 may correspond to the length of the magnet 320 or the length of the rotor core 310 in terms of the axial direction.

[0055] The shaft 340 may be coupled to the center of the rotor 300. The shaft 340 may be disposed to penetrate the hole 316 formed at the central portion of the rotor core 310. Therefore, the shaft 340 may rotate together with the rotor 300 by electromagnetic interaction between the magnet 320 and the coil 230.

[0056] The rotor 300 may include a plurality of regions having different cross-sectional areas. For example, a bearing coupling member 342 may be disposed at one end of the rotor 300 and formed to have a smaller cross-sectional area than other regions.

[0057] The bearing 400 may be arranged in a region spaced apart from the rotor 300 by a predetermined distance in the axial direction. The bearing 400 may support the rotation of the rotor 300 and the rotation of the shaft 340. The bearing 400 may be arranged in a space inside the housing 100. The bearing 400 may be a ball bearing having a ball arranged between an inner wheel and an outer wheel. A hole 410 coupled to the shaft 340 may be formed at a central portion of the bearing 400. The bearing coupling member 342 of the shaft 340 may be coupled to the hole 410. Therefore, the rotation of the shaft 340 may be supported by the bearing 400.

[0058] The bearing 400 and the rotor 300 may be arranged to be spaced apart from each other by a predetermined distance in the axial direction. For example, the interval between the bearing 400 and the rotor core 310 may be 1 mm or more and 3 mm or less in terms of the axial direction.

[0059] Meanwhile, in order to detect the position of the rotor 300 and the position of the shaft 340 , the motor 10 may include a sensor magnet 360 and a sensor (not shown).

[0060] In detail, a groove 312 that is more recessed than another area may be formed on one surface of the rotor core 310 facing the bearing 400. When the groove 312 is formed on the lower surface of the rotor core 310, the bottom surface of the groove 312 may be arranged to be stepped upward from the lower surface of the rotor core 310. The groove 312 may have a circular cross-sectional shape. The cross-sectional area of ​​the groove 312 may be formed to be smaller than the cross-sectional area of ​​the rotor core 310. In terms of the axial direction, the length of the groove 312 may be equal to 1 / 2 of the length of the rotor core 310 or less than 1 / 2 of the length of the rotor core 310.

[0061] The sensor magnet 360 may be disposed in the recess 312 .

[0062] The sensor magnet 360 may be coupled to the shaft 340 and the rotor core 320 through the sensor plate 370. The sensor plate 370 may include a first region 377 disposed to surround the outer surface of the shaft 340 and a second region 375 bent and extended radially outward from one end of the first region 377. The first region 377 and the second region 375 may be disposed perpendicular to each other.

[0063] A hole 372 through which the shaft 340 penetrates may be formed at a central portion of the first region 377. The shaft 340 may be press-fitted into the hole 372, and thus, the shaft 340 may be arranged to penetrate the sensor plate 370. One end of the first region 377 may contact the bottom surface of the groove 312.

[0064] The second region 375 may be formed to extend radially outward from the lower end of the first region 377. The second region 375 may be arranged perpendicular to the shaft 340. The second region 375 may include an opening 371 that penetrates from one surface to another surface. The opening 371 may be arranged outside the hole 372. A plurality of openings 371 may be provided and may be arranged to be spaced apart from each other along the circumferential direction of the second region 375. For example, three openings 371 may be provided, and the three openings 371 may be arranged to form an equal interval of 120 degrees. During the assembly of the motor 10, the coupling force between the sensor magnet 360 and the sensor plate 370 may be confirmed through the opening 371.

[0065] A sensor magnet coupling part 378 having a more concave shape than another area may be formed on one surface of the second area 375 facing the bearing 400. The sensor magnet coupling part 378 may have a groove shape. The bottom surface of the sensor magnet coupling part 378 may be arranged to be stepped upward more than the bottom surface of the second area 375.

[0066] The sensor magnet 360 may be arranged on the sensor magnet coupling part 378. The sensor magnet 360 may have a cross-sectional shape of an annular shape. One surface of the sensor magnet 360 may form a coplanar surface with one surface of the second region 375. The bottom surface of the sensor magnet 360 may form a coplanar surface with the bottom surface of the second region 375. The sensor magnet 360 may be coupled to the sensor plate 370 by an adhesive. The sensor magnet 360 may be spaced apart from the bottom surface of the groove 312 by a predetermined distance.

[0067] The sensor magnet 360 may rotate along with the sensor plate 370 along with the shaft 340 .

[0068] The sensor (not shown) may be arranged in the housing 100 and spaced apart from the sensor magnet 360. For example, the sensor may be arranged at a lower portion of the housing 100 spaced apart from the sensor magnet 360 in the axial direction. The sensor may be arranged on a surface of a printed circuit board (not shown), and may detect the position of the rotor 300 and the position of the shaft 340 by detecting a magnetic field that changes according to the rotation of the sensor magnet 360.

[0069] In the motor 10 according to the present embodiment, the sensor plate 370 and the sensor magnet 360 may be arranged inside the groove 312 of the rotor core 310. Therefore, in terms of the axial direction, the length between the sensor plate 370 and the bearing 400 may be formed to be longer. The length between the sensor magnet 360 and the bearing 400 may be formed to be longer than the length between the rotor core 310 and the bearing 400. The lower surface of the sensor plate 370 or the lower surface of the sensor magnet 360 may be arranged to be stepped upward more than the lower surface of the rotor core 310. The sensor plate 370 and the sensor magnet 360 may be arranged to overlap with the magnet 320 in the radial direction. The sensor plate 370 and the sensor magnet 360 may be arranged to overlap with the rotor core 310 in the radial direction.

[0070] According to the above structure, by forming the arrangement area of ​​the sensor magnet 360 through the groove 312 of the rotor core 310, the length of the motor 10 in the axial direction can be reduced, so that there is an advantage that the motor 10 can be miniaturized.

[0071] In addition, since the length of the shaft 340 is also reduced compared to the prior art, and the volume reduction of the rotor core 310 is achieved due to the formation of the groove 312, there are advantages of reduced material cost and reduced weight compared to the prior art.

[0072] In addition, since the motor is supported by the sensor plate 370 being in contact with the bottom surface of the groove 312, there is an advantage that the assemblability is improved.

[0073] At the same time, refer to Figures 7 to 9 , the sensor plate 370 may be omitted from the motor 10 . In this case, the sensor magnet 360 may be disposed only in the groove 312 of the rotor core 310 .

[0074] In the present modified embodiment, the axial length of the groove 312 can be formed shorter than that of the above-described embodiment by omitting the sensor plate 370. In addition, in the present modified embodiment, the upper surface of the sensor magnet 360 can be in contact with the bottom surface of the groove 312. In this case, the upper surface of the sensor magnet 360 can be coupled to the bottom surface of the groove 312 using an adhesive.

[0075] In the above description, it is described that all parts constituting the embodiments of the present invention are combined or operated as one, but the present invention is not necessarily limited to these embodiments. In other words, within the scope of the present invention, all parts in these parts can be combined with one or more parts and selectively operate. In addition, unless otherwise specifically stated, the above-mentioned terms "include", "comprise" or "have" refer to that the corresponding parts can be inherent, and therefore should be interpreted as not excluding other parts, but also including other parts. Unless otherwise defined, all terms including technical terms and scientific terms have the same meaning as those of ordinary skill in the art are generally understood. Commonly used terms, such as terms defined in dictionaries, should be interpreted as consistent with the contextual meaning of the relevant field, and unless clearly defined in the present invention, should not be interpreted in an ideal or overly formal sense.

[0076] The above description is only an explanation of the technical concept of the present invention, and those skilled in the art to which the present invention belongs can make various modifications and changes without departing from the essential features of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical concept of the present invention, but to describe the present invention, and the scope of the technical concept of the present invention is not limited to these embodiments. The protection scope of the present invention should be interpreted by the attached claims, and all technical concepts within the equivalent scope should be interpreted as included in the scope of the present invention.

Claims

1. A motor, comprising: case; a stator, the stator being arranged inside the housing; a rotor, the rotor being arranged inside the stator; a shaft coupled to a center of the rotor; as well as a sensor magnet, the sensor magnet being arranged outside the shaft, A groove is formed on one surface of the rotor, and the sensor magnet is arranged in the groove.

2. The motor according to claim 1, comprising: A bearing is arranged to face one surface of the rotor and supports the rotation of the shaft.

3. The motor according to claim 2, in, The rotor includes a rotor core and a magnet arranged on an outer surface of the rotor core. The groove is formed on a surface of the rotor core facing the bearing.

4. The motor according to claim 3, in, In terms of the axial direction, a length between the sensor magnet and the bearing is longer than a length between the rotor core and the bearing.

5. The motor according to claim 3, in, At least a portion of the rotor core is arranged to overlap the sensor magnet in terms of a radial direction.

6. The motor according to claim 3, in, In terms of the axial direction, the length of the groove is 1 / 2 of or less than the length of the rotor core.

7. The motor according to claim 2, in, The sensor magnet includes one surface facing the bearing and another surface facing the one surface, and The other surface of the magnet is in contact with the bottom surface of the groove.

8. The motor according to claim 2, comprising: a sensor plate in which the shaft is coupled to the center of the sensor plate and the sensor magnet is arranged on one surface facing the bearing, Wherein, the sensor plate is arranged inside the groove.

9. The motor according to claim 8, in, The sensor plate includes a first region arranged outside the shaft and a second region extending outwardly from one end of the first region in a radial direction and perpendicularly to the first region, Therein, the sensor magnet is arranged on a surface of the second region.

10. The motor according to claim 9, in, A surface of the second region facing the bearing and a surface of the sensor magnet form the same plane.

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