Motor

Abstract

This motor comprises: a housing; a stator, which is disposed in the housing and has a hole formed therein; a rotor disposed in the stator; a shaft coupled to the center of the rotor; a bearing for supporting the rotation of the shaft; and a bearing guide in which the bearing is coupled, wherein the bearing guide includes a first coupling part in which the bearing is coupled, and a second coupling part disposed at one side of the first coupling part, the second coupling part being coupled to the hole of the stator and the diameter of the second coupling part being larger than the diameter of the first coupling part.

Description

motor

[0001] This embodiment relates to a motor.

[0002]

[0003] A motor is a device that converts electrical energy into rotational energy by utilizing the force exerted on a conductor within a magnetic field. Recently, as the applications of motors have expanded, their role has become increasingly important. In particular, with the rapid electrification of automobiles, the demand for motors applied to steering systems, braking systems, and assembly systems has increased significantly.

[0004] A motor is a device comprising a housing, a stator disposed within the housing, and a rotor disposed within the stator, which generates rotational motion through the electromagnetic interaction between the stator and the rotor. Specifically, a coil is wound on the stator, and a magnet is disposed on the rotor to face the coil, so that the rotor can rotate through the action of the coil and the magnet. A shaft is disposed in the center of the rotor, and the shaft can rotate together with the rotation of the rotor. A bearing supporting the rotation of the shaft is disposed within the housing. To minimize the wobble of the shaft relative to the shaft system, multiple bearings may be provided and connected to one end and the other end of the shaft, respectively.

[0005] In the motor according to the above-described structure, the center of the shaft and the bearing must be accurately aligned with respect to the axial direction to minimize shaft wobble; however, there is a problem in that the alignment between the shaft and the bearing becomes misaligned due to factors such as tolerances and thermal deformation.

[0006]

[0007] The present invention provides a motor in which axial alignment between the stator, rotor, shaft, and bearing can be precisely achieved by improving the structure.

[0008]

[0009] A motor according to the present embodiment comprises: a housing; a stator disposed within the housing and having a hole formed on its inner side; a rotor disposed within the stator; a shaft coupled to the center of the rotor; a bearing supporting the rotation of the shaft; and a bearing guide to which the bearing is coupled on its inner side, wherein the bearing guide comprises a first coupling portion to which the bearing is coupled on its inner side and a second coupling portion disposed on one side of the first coupling portion, wherein the second coupling portion is coupled to a hole of the stator and the diameter of the second coupling portion is greater than the diameter of the first coupling portion.

[0010] The first coupling portion includes a first top plate and a first side plate extending downward from the edge of the first top plate, and the second coupling portion includes a second top plate extending outward from the bottom of the first side plate and a second side plate extending downward from the edge of the second top plate, wherein the outer surface of the second side plate contacts the inner surface of the stator, the inner surface of the first side plate contacts the side of the bearing, and one surface of the first top plate contacts one surface of the bearing.

[0011] The first coupling member is positioned to overlap at least a portion of the bearing in a direction perpendicular to the axial direction, and the second coupling member may overlap at least a portion of the stator in a direction perpendicular to the axial direction.

[0012] The above stator includes a stator core and a coil wound on the stator core, and the rotor includes a rotor core and a magnet coupled to the rotor core, and with respect to the axial direction, the length of the stator core is longer than the length of the rotor core, and the bearing guide can be coupled to the inner side of the stator core that protrudes axially from the top of the rotor core.

[0013] The second upper plate and the upper surface of the rotor core may be spaced apart in the axial direction.

[0014] The axial length (H2) of the stator core may be 2 mm or more and 5 mm or less larger than the axial length (H1) of the rotor core (410).

[0015] The axial length of the bearing guide coupled within the hole of the stator may be 1 mm or more and 4 mm or less.

[0016] It may include a lower bearing positioned at the bottom of the rotor and supporting the rotation of the shaft.

[0017] The first plate includes a through hole through which the shaft passes, and the bearing includes an outer ring and an inner ring disposed on the inner side of the outer ring, the lower surface of the first plate is in contact with the upper surface of the outer ring, and the inner ring of the bearing can be exposed upward through the through hole.

[0018] The stator core includes a head and a tooth protruding from the head, and the second side plate of the second coupling part can be coupled to the end surface of the tooth.

[0019]

[0020] Through this embodiment, since the bearing guide is press-fitted into the stator core, the center of the bearing guide and the center of the stator core can be aligned, thereby providing the advantage that the axial systems between the bearing and shaft, the shaft and the stator, and the stator and the rotor placed within the bearing guide can be aligned together.

[0021]

[0022] FIG. 1 is a perspective view illustrating the external appearance of a motor according to an embodiment of the present invention.

[0023] FIG. 2 is a cross-sectional view of a motor according to an embodiment of the present invention.

[0024] FIG. 3 is an exploded perspective view of a bearing guide, rotor, and stator according to an embodiment of the present invention.

[0025] FIG. 4 is a drawing illustrating the coupled state of a bearing guide on a stator according to an embodiment of the present invention.

[0026] FIG. 5 is an enlarged view of the combined structure of the bearing guide and stator in FIG. 2.

[0027] FIG. 6 is a plan view of a stator core according to an embodiment of the present invention.

[0028]

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0030] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0031] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0032] Additionally, 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 include the plural form unless specifically stated otherwise in the text, and when described as “at least one of A and B and C (or more than one),” it may include one or more of all combinations that can be combined with A, B, and C.

[0033] In addition, terms such as first, second, A, B, (a), (b), etc. may be used when describing the components of the embodiments of the present invention.

[0034] These terms are intended merely to distinguish a component from other components and are not limited by the nature, order, sequence, etc., of the said component.

[0035] And, where it is stated that a component is 'connected', 'combined', or 'joined' to another component, this may include not only cases where the component is directly connected, combined, or joined to the other component, but also cases where it is 'connected', 'combined', or 'joined' due to another component located between the component and the other component.

[0036] Furthermore, when described as being formed or placed "above or below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0037] The “axial direction” described below may be the longitudinal direction of the shaft.

[0038] FIG. 1 is a perspective view showing the exterior of a motor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a motor according to an embodiment of the present invention, FIG. 3 is an exploded perspective view of a bearing guide, a rotor, and a stator according to an embodiment of the present invention, FIG. 4 is a drawing showing the coupled state of a bearing guide on a stator according to an embodiment of the present invention, FIG. 5 is a drawing showing an enlarged view of the coupled structure of the bearing guide and the stator in FIG. 2, and FIG. 6 is a plan view of a stator core according to an embodiment of the present invention.

[0039] Referring to FIGS. 1 to 5, a motor (10) according to an embodiment of the present invention may include a housing (100), a controller housing (200), a stator (300), a rotor (400), a shaft (500), a bearing guide (600), and bearings (710, 720).

[0040] The motor (10) may include a housing (100). The housing (100) may form the exterior of the motor (10). The housing (100) is formed in a cylindrical shape, and a space may be formed inside in which a stator (300), a rotor (400), a shaft (500), a bearing guide (600), and bearings (710, 720) are disposed.

[0041] The housing (100) may include regions with different cross-sectional areas. Here, the cross-sectional area may refer to the cross-sectional area of ​​the space within the housing (100) together with the outer surface of the housing (100). For example, the housing (100) may include a first region (101) having a first cross-sectional area, a second region (102) having a second cross-sectional area smaller than the first cross-sectional area, a third region (120) having a third cross-sectional area smaller than the second cross-sectional area, and a fourth region (103) having a fourth cross-sectional area smaller than the third cross-sectional area. The first to fourth regions (101, 102, 120, 104) may be arranged sequentially along the axial direction. A bearing guide (600) and a router (350) may be placed in the first region (101). A stator (300) and a rotor (400) may be placed in the second region (102). A lower bearing (720) may be placed in the third area (120).

[0042] Based on FIG. 2, a hole through which a shaft (500) passes may be formed on the lower surface of the housing (100). The lower end of the shaft (500) may pass through the hole of the housing (100) and be connected to a configuration for transmitting rotational driving force.

[0043] The upper part of the housing (100) that is coupled with the controller housing (200) has a flange shape that extends in a direction perpendicular to the axial direction, and a coupling part (190) for coupling with the controller housing (200) may be disposed therein.

[0044] The controller housing (200) can be coupled to the housing (100). The controller housing (200) can be coupled to the first region (101). A connector lead portion (290) is disposed on the side of the controller housing (200), and a connector pin may be disposed on the inside of the connector lead portion (290). Through the coupling of the external terminal and the connector lead portion (290), power can be supplied to the motor (10), or an electrical signal for driving the motor (10) can be transmitted and received.

[0045] A printed circuit board (250) may be disposed within the controller housing (200). The printed circuit board (250) may be disposed facing the stator (300), rotor (400), and shaft (500) in the axial direction. At least one electronic component for driving the motor (10) may be disposed on the printed circuit board (250). For example, a sensor (260) is disposed on the lower surface of the printed circuit board (250) facing the shaft (500), and the sensor (260) can detect the position of the shaft (500) through magnetic field detection of the sensor magnet (510) to be described later. The printed circuit board (250) may be connected to a connector pin.

[0046] A heat dissipation fin (210) with a shape protruding upward can be disposed on the controller housing (200). By increasing the surface area of ​​the controller housing (200) through the heat dissipation fin (210), the heat dissipation efficiency can be improved.

[0047]

[0048] *33 The motor (10) may include a stator (300). The stator (300) may be placed within a housing (100). The stator (300) may be placed in a first region (101) and a second region (102) within the housing (100). The stator (300) may include a stator core (310), an insulator (340), and a coil (330).

[0049] For example, the stator core (310) may include a ring-shaped head and a plurality of teeth protruding from the inner side of the head. An insulator (340) is coupled to the outer surface of the stator core (310), and the outer surface may form a winding area of ​​the coil (330). The coil (330) may be wound on the outer surface of the insulator (340). The end of the coil (330) may extend in a direction toward the controller housing (200) with respect to the axial direction and may be electrically connected to the substrate (250) through a busbar and a terminal. A router (350) may be disposed on the stator core (310) for aligning the coil (330) and aligning the busbar and terminal coupled to the coil (330). A plurality of terminals may be provided to correspond to the number of power supplies of the coil (330), extend toward the controller housing (200), and the upper end may be coupled to the substrate (250). Accordingly, power for driving the coil (330) can be provided.

[0050] A hole (380, see FIG. 3) to which a second coupling part (620) of a rotor (400) and a bearing guide (600) to be described later is coupled may be disposed on the inner side of the stator (300). The hole (380) may be disposed at the center of the stator (300).

[0051] The motor (10) may include a rotor (400). The rotor (400) may include a rotor core (410) and a magnet (430). The rotor core (410) may be formed in a ring shape with a hole formed in the center. A magnet coupling portion to which the magnet (430) is coupled may be disposed on the outer surface of the rotor core (410). The magnet coupling portion may have a concave groove shape extending inward from the outer surface of the rotor core (410). The magnet (430) may be the magnet coupling portion of the rotor core (410). In the embodiment, the rotor (400) may be of the SPM (Surface Permanent Magnet) type, but there are no restrictions on the mounting method of the magnet (430) within the rotor (400).

[0052] Accordingly, the rotor (400) can rotate together with the shaft (500) by means of electromagnetic interaction between the coil (330) and the magnet (430) of the stator (300).

[0053] The motor (10) may include a shaft (500). The shaft (500) may be coupled to the center of the rotor core (410). Both ends of the shaft (500) may protrude upward and downward from the upper and lower surfaces of the rotor core (410), respectively. The shaft (500) may be coupled to the rotor core (410) by press-fitting. Accordingly, the shaft (500) may also rotate together with the rotation of the rotor core (410).

[0054] A sensor magnet (510) may be disposed at the end of the shaft (500) facing the printed circuit board (250). For example, a groove with a shape more concave than other areas may be disposed on the end surface of the shaft (500), and at least a portion of the sensor magnet (510) may be embedded within the groove. The sensor magnet (510) may be disposed facing the sensor (260) of the printed circuit board (510) in the axial direction. Accordingly, the position of the shaft (500) and the rotor (400) can be detected by detecting the change in the magnetic field of the sensor magnet (510) that occurs according to the rotation of the shaft (500).

[0055] The motor (10) may include bearings (710, 720). The bearings (710, 720) may support the rotation of the shaft (500). The bearings (710, 720) may each be ball bearings in which an inner ring, an outer ring, and balls are disposed between the inner ring and the outer ring. The bearings (710, 720) may be provided in multiple numbers and spaced apart along the axial direction of the shaft (500). The bearings (710, 720) may include an upper bearing (710) positioned close to one end of the shaft (500) and a lower bearing (720) positioned close to the other end of the shaft (500). Accordingly, the rotational support structure of the shaft (500) through the plurality of bearings (710, 720) can minimize the misalignment of the shaft (500)'s rotational center. The upper bearing (710) and the lower bearing (720) can be named the first bearing and the second bearing, respectively.

[0056] The lower bearing (720) may be placed in a third region (120) within the housing (100). The cross-sectional area of ​​the third region (120) may correspond to the cross-sectional area of ​​the outer ring of the lower bearing (720). Accordingly, the lower bearing (720) is joined to the third region (120) by press-fitting, and thus the connection of the lower bearing (720) within the third region (120) can be maintained firmly.

[0057] The upper bearing (710) may be placed on the rotor (400). The upper bearing (710) may be placed between the rotor (400) and the substrate (250). The upper bearing (710) may be placed such that at least a portion overlaps the rotor core (410) in the axial direction.

[0058] For convenience of explanation, the upper bearing (710) will be referred to as the bearing (710) in the following description.

[0059] The motor (10) may include a bearing guide (600) for supporting a bearing (710) within a housing (100). The bearing guide (600) can align the position of the bearing (710) relative to the stator (300). Through the bearing guide (600), an axial system between the stator (300), the shaft (500), and the bearing (710) can be aligned. Through the bearing guide (600), the position of the shaft (500) relative to the center of the stator (300) and the position of the bearing (710) relative to the center of the stator (300) can be aligned.

[0060] The bearing guide (600) may be made of plastic. Accordingly, production is easy, and wear caused by press-fitting with the stator core (310), which will be described later, can be minimized.

[0061] In detail, the bearing guide (600) may include a first coupling part (610) and a second coupling part (620). The first coupling part (610) and the second coupling part (620) may be arranged along the axial direction. The first coupling part (610) may be arranged closer to the printed circuit board (250) than the second coupling part (620). The second coupling part (620) may be arranged closer to the rotor (400) than the first coupling part (610). The diameter of the second coupling part (620) may be larger than the diameter of the first coupling part (610). The cross-sectional area of ​​the second coupling part (620) may be larger than the cross-sectional area of ​​the first coupling part (610).

[0062] The first coupling portion (610) may be positioned to overlap at least a portion of the bearing (710) in a direction perpendicular to the axial direction. A bearing coupling portion (611) to which the bearing (710) is coupled may be positioned on the inner side of the first coupling portion (610). The cross-sectional area of ​​the bearing coupling portion (611) is formed to correspond to the cross-sectional area of ​​the outer ring of the bearing (710), and the bearing (710) may be coupled by press-fitting into the bearing coupling portion (611). The first coupling portion (610) may include a first top plate (612) and a first side plate (614) extending downward from the edge of the first top plate (612). The bearing coupling portion (611) may be formed by the lower surface of the first top plate (612) and the inner surface of the first side plate (614). One surface of the first top plate (612) may be in contact with one surface of the bearing (710). Based on FIG. 2, the lower surface of the first top plate (612) may come into contact with at least a portion of the upper surface of the bearing (710). The inner surface of the first side plate (614) may come into contact with the side surface of the bearing (710). The axial length of the first side plate (614) may correspond to the axial length of the bearing (710). A through hole (619) through which a shaft (500) passes may be formed in the first top plate (612).

[0063] The width of the first top plate (612) in a direction perpendicular to the axial direction may be shorter than the width of the bearing (710). Accordingly, the upper surface of the outer ring of the bearing (710) is supported by the lower surface of the first top plate (612), and at least a portion of the inner ring of the bearing (710) may be exposed upward through the through hole (619).

[0064] The second coupling portion (620) may be positioned to overlap at least a portion of the stator (300) in a direction perpendicular to the axial direction. The second coupling portion (620) may be positioned not to overlap the bearing (700) in a direction perpendicular to the axial direction.

[0065] The second coupling portion (620) may include a second top plate (622) and a second side plate (624). The second top plate (622) may have a shape extending outwardly perpendicular to the axial direction from the bottom of the first side plate (614). The second side plate (624) may have a shape extending downward from the outer surface of the second top plate (622). The cross-sectional area of ​​the second coupling portion (620), defined by the outer surface of the second side plate (624), may be the same as the cross-sectional area of ​​the hole (380) of the stator (300). The second side plate (624) may be coupled to the hole (380). The outer surface of the second side plate (624) may come into contact with the inner surface of the stator core (310). The second side plate (624) may be coupled by press-fitting into the hole (380). Accordingly, the second side plate (624) can be positioned so that at least a portion overlaps the stator (300) in a direction perpendicular to the axial direction.

[0066] As illustrated in FIG. 6, the stator core (310) can be formed by combining a plurality of unit stators. The unit stator includes a head (312) and a tooth (314) protruding from the head (312), and a coil (330) can be wound on the tooth (314). In this case, the outer surface of the second side plate (624) can be coupled to the end surface (316) of the tooth (314), and the end surface (316) of the tooth (314) has a predetermined curvature corresponding to the curvature of the outer surface of the second side plate (624), so that the coupling of the second side plate (624) can be easily guided.

[0067] As illustrated in FIG. 2, the top of the stator (300) may be positioned closer to the printed circuit board (250) than the top of the rotor (400). The top of the stator (300) may be positioned higher than the top of the rotor (400). The axial length (H2) of the stator core (310) may be longer than the axial length (H1) of the rotor core (410). The upper surface of the stator core (310) may be positioned with a step above the upper surface of the rotor core (410). Accordingly, when the formation area of ​​the hole (380) positioned at the center of the stator core (310) is divided into an upper region and a lower region, the rotor (400) may be positioned in the lower region, and the second coupling part (620) of the bearing guide (600) may be positioned in the upper region. To prevent contact due to rotation of the rotor (400), the upper surface of the rotor core (410) may be spaced apart in the axial direction from the lower surface of the second coupling part (620).

[0068] The axial length (H2) of the stator core (310) may be 2 mm or more and 5 mm or less larger than the axial length (H1) of the rotor core (410). If the difference between the axial length (H2) of the stator core (310) and the axial length (H1) of the rotor core (410) is less than 2 mm, the press-fit length of the bearing guide (600) is insufficient, and the coupling force between the stator core (310) and the second coupling part (620) of the bearing guide (600) may decrease. If the difference between the axial length (H2) of the stator core (310) and the axial length (H1) of the rotor core (410) exceeds 5 mm, the size of the motor (10) may increase more than necessary due to the increase in the axial length of the stator (300), and the opposing area between the coil (330) and the magnet (430) may be reduced.

[0069] Due to the difference between the axial length (H2) of the aforementioned stator core (310) and the axial length (H1) of the stator core (410), the axial press-fit length of the bearing guide (600), that is, the axial length of the second side plate (624) that overlaps with the stator core (310) in a direction perpendicular to the axial direction, may be 1 mm or more and 4 mm or less.

[0070] According to the above structure, since the bearing guide (600) is pressed into the hole (380) of the stator core (310), the center of the bearing guide (600) and the center of the stator core (310) can be aligned, thus providing an advantage that the shaft system between the bearing (710) and the shaft (500), the shaft (500) and the stator (300), and the stator (300) and the rotor (400) placed within the bearing guide (600) can be aligned together. That is, the center of the rotor (400), along with the center of the shaft (500) and the center of the bearing (710), can all be aligned with the center of the stator core (310).

[0071] Meanwhile, the router (350) coupled to the stator core (310) includes a hole through which a bearing guide (600) passes in the center, and at least a portion of the bearing guide (600) may be positioned to pass through the hole of the router (350).

[0072] In the foregoing, although all components constituting an embodiment of the present invention have been described as being combined or operating in combination, the present invention is not necessarily limited to such embodiments. That is, within the scope of the purpose of the present invention, all components may be selectively combined in one or more ways. Furthermore, terms such as "include," "constitute," or "have" described above, unless specifically stated otherwise, mean that the relevant component may be inherent; thus, they should be interpreted as allowing for the inclusion of additional components rather than excluding other components. All terms, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains, unless otherwise defined. Terms commonly used, such as those defined in advance, should be interpreted in accordance with their meaning in the context of the relevant technology and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the present invention.

[0073] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

Claims

1. Housing; A stator disposed within the above housing and having a hole formed on the inside; A rotor disposed within the above-mentioned stator; A shaft coupled to the center of the above rotor; A bearing that supports the rotation of the above shaft; and It includes a bearing guide to which the bearing is coupled on the inner side, and The above bearing guide includes a first coupling portion to which the bearing is coupled on the inside, and a second coupling portion disposed on one side of the first coupling portion. The above second coupling part is coupled to the hole of the stator, and A motor in which the diameter of the second coupling part is larger than the diameter of the first coupling part.

2. In Paragraph 1, The first coupling portion includes a first top plate and a first side plate extending downward from the edge of the first top plate, and The second coupling portion includes a second top plate extending outwardly from the bottom of the first side plate and a second side plate extending downward from the edge of the second top plate. The outer surface of the second side plate contacts the inner surface of the stator, and The inner surface of the first side plate contacts the side of the bearing, and One surface of the first plate above is a motor that contacts one surface of the bearing above.

3. In Paragraph 1, The first coupling portion is arranged to overlap at least a portion of the bearing in a direction perpendicular to the axial direction, and The second coupling portion is a motor that overlaps at least a part of the stator in a direction perpendicular to the axial direction.

4. In Paragraph 1, The above stator includes a stator core and a coil wound on the stator core, and The above rotor includes a rotor core and a magnet coupled to the rotor core, and With respect to the axial direction, the length of the stator core is longer than the length of the rotor core, and The above bearing guide is a motor coupled to the inner side of the stator core, which protrudes axially from the top of the rotor core.

5. In Paragraph 2, The upper surface of the second upper plate and the upper surface of the rotor core are spaced apart in the axial direction in a motor.

6. In Paragraph 4, The axial length (H2) of the stator core is 2mm or more and 5mm or less larger than the axial length (H1) of the rotor core (410).

7. In Paragraph 6, A motor in which the axial length of the bearing guide coupled within the hole of the stator is 1 mm or more and 4 mm or less.

8. In Paragraph 1, A motor comprising a lower bearing positioned at the lower part of the rotor and supporting the rotation of the shaft.

9. In Paragraph 2, The first plate above includes a through hole through which the shaft passes, and The above bearing includes an outer ring and an inner ring disposed on the inner side of the outer ring, and The lower surface of the first plate is in contact with the upper surface of the outer ring, and The inner ring of the above bearing is a motor exposed upward through the above through hole.

10. In Paragraph 4, The above stator core includes a head and a tooth protruding from the head, and The second side plate of the second coupling part is a motor coupled to the end surface of the tooth.

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