Motor

Abstract

The present invention can provide a motor comprising: a shaft; a magnet disposed on the outer surface of the shaft; a stator disposed corresponding to the magnet; and a magnet holder disposed on the outer side of the shaft and in contact with the magnet, wherein the shaft includes a groove disposed on the outer surface of the shaft, and the magnet holder includes a first holder disposed on the side of the shaft and a second holder extending axially from the first holder, wherein the first holder includes a projection, and the projection is disposed in the groove, so that the magnet holder is fixed to the shaft.

Description

Technology Field

[0001] The example relates to a motor. Background Technology

[0002] A motor includes a shaft and a stator. The shaft may be hollow. Magnets may be attached to the outer surface of the shaft. However, in the case of a hollow shaft, there is a problem with the difficulty of aligning the position of the magnets. This is because, considering the manufacturing process of a hollow shaft, it is difficult to form guides for aligning the magnets. If there are no guides on the shaft to align the magnets, the magnets may become misaligned during overmolding. Alternatively, when wrapping the magnets with a can or adhesive material, there is a risk that the magnets may shift. The problem to be solved

[0003] Accordingly, the embodiment aims to solve the above-mentioned problem by providing a motor capable of aligning and fixing a magnet disposed on the outer surface of a hollow shaft. means of solving the problem

[0004] An embodiment for achieving the above objective may provide a motor comprising a shaft, a magnet disposed on the outer surface of the shaft, a stator disposed corresponding to the magnet, and a magnet holder disposed on the outer side of the shaft and in contact with the magnet, wherein the shaft includes a groove disposed on the outer surface of the shaft, and the magnet holder includes a first holder disposed on the side of the shaft and a second holder extending axially from the first holder, wherein the first holder includes a projection, and the projection is disposed in the groove so as to provide a motor in which the magnet holder is fixed to the shaft. Effects of the invention

[0005] According to an embodiment, an advantageous effect is provided for easily aligning magnets disposed on the outer surface of a hollow shaft.

[0006] According to the embodiment, there is an advantage of preventing the magnet from becoming twisted during assembly.

[0007] According to the embodiment, there is an advantage in that the magnet can be fixed to the shaft without using adhesive.

[0008] According to the embodiment, by using a plastic magnet holder to prevent magnetic flux leakage, there is an advantage of increased motor performance.

[0009] According to the embodiment, the groove placed on the shaft and the protrusion of the magnet holder are combined, so there is an advantage that the assembly of the magnet holder is easy.

[0010] According to the embodiment, the contact surface between the groove placed on the shaft and the magnet holder is configured as a flat plane, which has the advantage of preventing not only vertical movement of the magnet holder but also horizontal movement.

[0011] According to the embodiment, the contact surface between the groove placed on the shaft and the magnet holder is configured as a flat surface, thereby providing an advantage in that a seating standard for the magnet holder on the shaft is established. Brief explanation of the drawing

[0012] FIG. 1 is a drawing illustrating a motor according to an embodiment, FIG. 2 is a perspective view showing a shaft and a magnet with a magnet holder arranged thereon according to an embodiment of a motor. FIG. 3 is an exploded view of the magnet holder and shaft illustrated in FIG. 2, FIG. 4 is a drawing showing a shaft, FIG. 5 is a side cross-sectional view of a shaft based on AA of FIG. 4, FIG. 6 is a drawing illustrating a first magnet holder, FIG. 7 is a plan view of the first magnet holder shown in FIG. 6, FIG. 8 is a drawing illustrating a second magnet holder, FIG. 9 is a plan view of the second magnet holder illustrated in FIG. 8, FIG. 10 is a side view of the second magnet holder illustrated in FIG. 8, FIG. 11 is a cross-sectional view based on AA of FIG. 2, FIG. 12 is a cross-sectional view based on BB of FIG. 2, Figure 13 is a drawing illustrating the process of assembling a magnet onto a shaft using a magnet holder. Specific details for implementing the invention

[0013] The direction parallel to the length direction (up-down direction) of the shaft is called the axial direction, the direction perpendicular to the axial direction with respect to the shaft is called the radial direction, and the direction following a circle with a radius in the radial direction with respect to the shaft is called the circumferential direction.

[0014] FIG. 1 is a drawing illustrating a motor according to an embodiment.

[0015] Referring to FIG. 1, the motor according to the embodiment may include a shaft (100), a magnet (200), a stator (300), a magnet holder (400), a housing (500), a bus bar (600), a bearing housing (700), and a terminal (800). Hereinafter, "inner side" refers to a direction arranged toward the shaft (100) with respect to the radial direction of the motor, and "outer side" refers to a direction opposite to the inner side.

[0016] The shaft (100) may be a hollow member with one side open. In the axial direction, both ends of the shaft (100) may be rotatably supported by bearings (10). The shaft (100) may have parts with different outer diameters arranged along the axial direction.

[0017] The magnet (200) contacts the outer surface of the shaft (100). The magnet (200) rotates in conjunction with the rotation of the shaft (100). There may be multiple magnets (200).

[0018] The stator (300) is positioned on the outside of the shaft (100) and the magnet (200). The stator (300) may include a stator core (310), an insulator (320) mounted on the stator core (310), and a coil (330) wound on the insulator (320). The coil (330) forms a magnetic field. The stator core (310) may be a single component or a combination of multiple divided cores. Additionally, the stator core (310) may be formed by stacking multiple plates in the form of thin steel plates, but is not necessarily limited thereto. For example, the stator core (310) may be formed as a single piece.

[0019] The magnet holder (400 in FIG. 2) secures the magnet (200) to the shaft (100). With the magnet holder (400) securing the magnet (200), the magnet holder (400) and the magnet (200) may be overmolded or a separate can or contact member may surround the magnet holder (400) and the magnet (200).

[0020] The housing (500) may be positioned outside the stator (300). The housing (500) may be a cylindrical member with an open top. The housing (500) accommodates the shaft (100), the magnet (200), the stator (300), and the magnet holder (400) inside. The housing (500) may also accommodate a bearing that supports the shaft (100).

[0021] The busbar (600) is positioned on the upper side of the stator (300). The busbar (600) connects the coils (330) wound around the core of the stator (300).

[0022] The bearing housing (700) accommodates the bearing (10). The bearing housing (700) can be coupled to the housing (500).

[0023] The terminal (800) is connected to the busbar (600) and can be connected to an external power source.

[0024] FIG. 2 is a perspective view showing a shaft and a magnet with a magnet holder arranged thereon according to an embodiment of a motor, and FIG. 3 is an exploded view of the magnet holder and shaft shown in FIG. 2.

[0025] Referring to FIGS. 2 and 3, the magnet holder (400) secures the magnet (200) to the shaft (100). The magnet holder (400) is secured to the shaft (100) first, and the magnet (200) can be secured to the shaft (100) along the magnet holder (400). The shaft (100) and the magnet holder (400) are made of different materials.

[0026] The magnet holder (400) may include a first holder (410) and a second holder (420). The first holder (410) may be positioned on the side of the shaft (100). The second holder (420) may extend axially from the first holder (410). Multiple second holders (420) may be positioned.

[0027] The first holder (410) may be an annular member. The inner surface of the first holder (410) may come into contact with the outer surface of the shaft (100). The shaft (100) may be divided axially and may include a region and another region with different outer diameters, and the first holder (410) may be placed on the outer surface of the region with a relatively smaller outer diameter.

[0028] Multiple second holders (420) may be arranged at regular intervals along the circumferential direction of the first holder (410). Meanwhile, the magnet (200) may be composed of multiple unit magnets (200A, 200B). The number of second holders (420) may be equal to the number of unit magnets (200). The axial length of the second holder (420) is formed to be shorter than the axial length of the magnet (200).

[0029] Such a magnet holder (400) may include a first magnet holder (400A) and a second magnet holder (400B). In the axial direction, the first magnet holder (400A) may be positioned on one side of the shaft (100), and the second magnet holder (400B) may be positioned on the other side of the shaft (100).

[0030] FIG. 4 is a drawing showing a shaft (100), and FIG. 5 is a side cross-sectional view of the shaft (100) based on AA of FIG. 4.

[0031] Referring to FIG. 4, the shaft (100) may include a groove (110) disposed on the outer surface. The groove (110) may be divided into a first groove (111) and a second groove (112). The first groove (111) and the second groove (112) may be spaced apart from each other in the axial direction. The first groove (111) and the second groove (112) may be aligned in the circumferential direction. The first groove (111) and the second groove (112) may each be formed by cutting a portion of the outer surface of the shaft (100) along the circumferential direction.

[0032] The first groove (111) and the second groove (112) may have different shapes or the first groove (111) and the second groove (112) may have different sizes.

[0033] FIG. 6 is a drawing showing a first magnet holder (400A), and FIG. 7 is a plan view of the first magnet holder (400A) shown in FIG. 6.

[0034] Referring to FIGS. 6 and 7, the first magnet holder (400A) may include a first holder (410A) and a second holder (420A). The second holder (420A) is positioned on a part of the side of the magnet (200). For example, based on the circumferential direction, the second holder (420A) may be positioned between the first unit magnet (200A) and the second unit magnet (200B).

[0035] A first coupling part (421A) may be disposed at the end of the second holder (420A). The first coupling part (421A) may be a hook-shaped projection that protrudes outward. This first coupling part (421A) is intended for coupling with the second magnet holder (400B).

[0036] The first holder (410A) may include one or more first protrusions (411A). The first protrusion (411A) protrudes inward from the inner circumference of the first holder (410A). The first protrusion (411A) is coupled to the first groove (111) of the shaft (100). Meanwhile, a plurality of first protrusions (411A) may be arranged facing each other.

[0037] The surface of the first projection (411A) that contacts the first groove (111) may be flat. If the surface (411Aa) that contacts the first groove (111) is flat, it is possible to effectively prevent flow that may occur between the first magnet holder (400A) and the shaft (100) in the circumferential direction as well as in the axial direction. The size and shape of the first projection (411A) correspond to the first groove (111) of the shaft (100).

[0038] FIG. 8 is a drawing showing a second magnet holder (400B), FIG. 9 is a plan view of the second magnet holder (400B) shown in FIG. 8, and FIG. 10 is a side view of the second magnet holder (400B) shown in FIG. 8.

[0039] Referring to FIGS. 8 through 10, the second magnet holder (400B) may include a first holder (410B) and a second holder (420B). The second holder (420B) is positioned on a different part of the side of the magnet (200). For example, based on the circumferential direction, the second holder (420B) may be positioned between the first unit magnet (200A) and the second unit magnet (200B).

[0040] A second coupling part (421B) may be disposed at the end of the second holder (420B). The second coupling part (421B) may be a hook-shaped projection that protrudes inward. This second coupling part (421B) is intended for coupling with the first magnet holder (400A).

[0041] The first holder (410B) may include one or more second protrusions (411B). The second protrusions (411B) protrude inward from the inner circumference of the first holder (410A). The second protrusions (411B) are coupled to the second groove (112) of the shaft (100). Meanwhile, a plurality of second protrusions (411B) may be arranged facing each other.

[0042] The second projection (411B) may have a flat surface (411Ba) that contacts the second groove (112). If the surface that contacts the second groove (112) is flat, it can effectively prevent flow that may occur between the second magnet holder (400B) and the shaft (100) in the circumferential direction as well as in the axial direction. The size and shape of the second projection (411B) correspond to the second groove (112) of the shaft (100).

[0043] The second projection (411B) may protrude axially from the inner surface of the first holder (410B) as well as from one side of the first holder (410B). The shape of this second projection (411B) corresponds to the shape of the second groove (112) positioned at the rounded corner of the axial end of the shaft (100). Accordingly, axially, the second projection (411B) may be larger than the first projection (411A).

[0044] FIG. 11 is a cross-sectional view based on AA of FIG. 2.

[0045] Referring to FIG. 11, a first magnet holder (400A) is positioned on one side of the magnet (200) in the axial direction. A second magnet holder (400B) is positioned on the other side of the magnet (200) in the axial direction. The first magnet holder (400A) can be fixed to the shaft (100) by the first projection (411A) being coupled to the first groove (111) of the shaft (100). The second magnet holder (400B) can be fixed to the shaft (100) by the second projection (411B) being coupled to the second groove (112) of the shaft (100).

[0046] The first groove (111) may include a first surface (S1), a second surface (S2), and a third surface (S3). When the first projection (411A) is coupled to the first groove (111), the first surface (S1) may come into contact with the inner surface of the first projection (411A). The second surface (S2) may come into contact with one axial surface of the first projection (411A). The third surface (S3) may come into contact with the other axial surface of the first projection (411A). At this time, the first surface (S1), the second surface (S2), and the third surface (S3) may all be flat. Since the first surface (S1), the second surface (S2), and the third surface (S3) are all flat, the seating area of ​​the first magnet holder (400A) on the shaft (100) is easily secured, and not only vertical movement but also circumferential movement can be effectively prevented.

[0047] The second groove (112) may include a fourth surface (S4) and a fifth surface (S5). When the second projection (411B) is coupled to the second groove (112), the fourth surface (S4) may come into contact with the inner surface of the second projection (411B). The fifth surface (S5) may come into contact with one axial surface of the second projection (411B). The other axial surface of the second projection (411B) does not come into contact with the second groove (112). At this time, both the fourth surface (S4) and the fifth surface (S5) may be flat. Since the fourth surface (S4) and the fifth surface (S5) are flat, the seating area of ​​the second magnet holder (400B) on the shaft (100) is easily secured, and not only vertical movement but also circumferential movement can be effectively prevented.

[0048] FIG. 12 is a cross-sectional view based on BB of FIG. 2.

[0049] Referring to FIG. 12, unlike the first magnet holder (400A), the second magnet holder (400B) is not constrained downward in the drawing due to the coupling relationship between the second groove (112) and the second projection (411B). Therefore, the second magnet holder (400B) may detach axially from the shaft (100). To prevent this, the second magnet holder (400B) is mechanically fastened to the second magnet holder (400B). Specifically, when the second magnet holder (400B) is mounted on the shaft (100), the second coupling part (421B) engages with the first coupling part (421A), thereby fixing the second magnet holder (400B) to the first magnet holder (400A) so that it does not detach axially from the shaft (100).

[0050] Since the first coupling part (421A) protrudes outward in a hook shape and the second coupling part (421B) protrudes inward in a hook shape, when the second magnet holder (400B) is inserted axially into the shaft (100), the second coupling part (421B) is naturally fastened to the first coupling part (421A). In this way, because the first coupling part (421A) and the second coupling part (421B) interlock with each other in a hook shape, there is an advantage of high axial restraint force and high stability.

[0051] FIG. 13 is a drawing illustrating the process of assembling a magnet (200) to a shaft (100) using a magnet (200) holder.

[0052] In a state as shown in (a) of FIGS. 11 to 13, as shown in (b) of FIG. 13, the first magnet holder (400A) is inserted into the shaft (100) from the lower side of the shaft (100) where the bearing is installed in the drawing. When the first projection (411A) is coupled to the first groove (111), the first magnet holder (400A) is fixed to the shaft (100). There is no separate process of applying adhesive or curing adhesive.

[0053] Next, as shown in (c) of FIG. 13, the second magnet holder (400B) is inserted into the shaft (100) from the lower side of the shaft (100) where the bearing is installed in the drawing. The axial position of the second magnet holder (400B) is determined as the second projection (411B) engages with the second groove (112). At this time, the second magnet holder (400B) is fixed to the shaft (100) as the second coupling part (421B) engages with the first coupling part (421A).

[0054] Next, as shown in FIG. 13 (d), a magnet (200) is placed between the first magnet holder (400A) and the second magnet holder (400B). An adhesive may be applied between the magnet (200) and the outer surface of the shaft (100). Since the first magnet holder (400A) and the second magnet holder (400B) are fixed to the shaft (100), the seating position of the magnet (200) is also accurately set. In addition, since the first magnet holder (400A) and the second magnet holder (400B) both contact and support one side and the side of the magnet (200), the position of the magnet (200) can be prevented from shifting during the process of covering with a can or wrapping with an adhesive sheet in the future. Here, the adhesive sheet may be a member in a radius state.

[0055] The present invention can be used in various devices, such as vehicles or home appliances. Explanation of the symbols

[0056] 100: Shaft 110: Home 111: Home 1 112: 2nd Home 200: Magnet 300: Status 400: Magnet Holder 400A: 1st magnet holder 400B: Second magnet holder 410: First holder 411: Protrusion 411A: 1st projection 411B: Second projection 420: Second holder 500: Housing 600: Busbar

Claims

Claim 1 A motor comprising: a shaft; a magnet disposed on the outer surface of the shaft; a stator disposed corresponding to the magnet; and a magnet holder disposed on the outer side of the shaft and in contact with the magnet, wherein the shaft includes a concave groove facing inward from the outer surface of the shaft, the magnet holder includes an annular first holder and a second holder extending axially from the first holder, the first holder includes a projection protruding inward from the inner circumference of the first holder, and the projection is disposed in the groove so that the magnet holder is fixed to the shaft. Claim 2 In claim 1, the second holder is a motor positioned on the side of the magnet. Claim 3 In claim 1, the magnet comprises a first unit magnet and a second unit magnet, and the second holder is a motor disposed between the first unit magnet and the second unit magnet. Claim 4 In claim 1, the motor in which the axial length of the second holder is shorter than the axial length of the magnet. Claim 5 In claim 1, the magnet holder comprises a first magnet holder and a second magnet holder, and the first magnet holder and the second magnet holder are connected to each other, such that the first magnet holder contacts one side of the magnet in an axial direction and the second magnet holder contacts the other side of the magnet in an axial direction. Claim 6 In claim 5, the groove comprises a first groove and a second groove spaced apart from each other in the axial direction, and the projection comprises a first projection disposed in the first groove and a second projection disposed in the second groove, wherein the first projection is disposed in the first magnet holder and the second projection is disposed in the second magnet holder. Claim 7 In claim 6, the first groove comprises a first surface in contact with the inner surface of the first projection, a second surface in contact with one axial surface of the first projection, and a third surface in contact with the other axial surface of the first projection, wherein the first surface, the second surface, and the third surface are flat. Claim 8 In claim 6, the second groove comprises a fourth surface in contact with the inner surface of the second projection and a fifth surface in contact with one axial surface of the second projection, wherein the fourth surface and the fifth surface are flat and the other axial surface of the second projection does not contact the second groove. Claim 9 In claim 5, each of the first magnet holder and the second magnet holder comprises the first holder and the second holder, the first magnet holder further comprises a first coupling portion disposed at the end of the second holder of the first magnet holder, and the second magnet holder further comprises a second coupling portion disposed at the end of the second holder of the second magnet holder, and the first coupling portion and the second coupling portion are fastened to each other so as to be constrained in the axial direction. Claim 10 In claim 9, the motor, wherein the first coupling part includes a hook-shaped projection protruding outwardly and the second coupling part includes a hook-shaped projection protruding inwardly.

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