Motor

Abstract

The present invention may provide a motor including: a shaft; a magnet coupled to the shaft; a stator provided to correspond to the magnet; and a magnet holder provided on the outside of the magnet, the magnet holder includes a first surface disposed to face an outer surface of the magnet, a second surface bent from the first surface, a third surface bent from the first surface and disposed to be spaced apart from the magnet in an axial direction, a fourth surface disposed to face another surface of the magnet, and a fifth surface connecting the third surface and the fourth surface, and a sixth surface bent from the fourth surface, the magnet including an inner surface in contact with the shaft and an outer surface disposed to face the inner surface, the fourth surface being in contact with the other surface of the magnet, the second surface being disposed to overlap a portion of the outer surface of the magnet, and the sixth surface being in contact with the outer surface of the shaft.

Description

Technical Field

[0001] The present invention relates to motors. Background Art

[0002] The motor includes a shaft and a stator. The shaft may be a hollow shaft. The magnet may be attached to the outer peripheral surface of the shaft. In this case, the hollow shaft has a problem that it is difficult to arrange the position of the magnet.

[0003] This is because it is difficult to form a guide for arranging the magnet in consideration of hollow shaft processing. When there is no guide for arranging the magnet at the shaft, the magnet may be distorted when the magnet is overmolded. In addition, the magnet can be fixed to the shaft by gluing a magnet holder formed of a composite material, but there is a high risk that the magnet holder may be separated from the shaft under high temperature conditions. Summary of the invention

[0004] Technical issues

[0005] The present invention is intended to solve the above-mentioned problems and to provide a motor in which a coupling force between a shaft and a magnet holder can be ensured under high temperature conditions.

[0006] Objectives to be achieved by the present invention are not limited to the above objectives, and other objectives not described above may be clearly understood by those skilled in the art through the following description.

[0007] Technical Solutions

[0008] In order to achieve the above-mentioned objectives, the present invention provides a motor, which includes: a shaft; a magnet connected to the shaft; a stator, which is arranged to correspond to the magnet; and a magnet holder, which is arranged on the outside of the magnet, wherein the magnet holder includes a first surface arranged to face the outer surface of the magnet, a second surface bent from the first surface, a third surface bent from the first surface and arranged to be spaced apart from the magnet in the axial direction, a fourth surface arranged to face the other surface of the magnet, a fifth surface connecting the third surface with the fourth surface, and a sixth surface bent from the fourth surface, the magnet includes an inner surface contacting the shaft and an outer surface arranged to face the inner surface, the fourth surface contacts the other surface of the magnet, the second surface is arranged to overlap with a portion of the outer surface of the magnet, and the sixth surface contacts the outer surface of the shaft.

[0009] The axial length of the sixth surface may be in the range of 5% to 15% of the axial length of the magnet.

[0010] The second surface may be disposed to be spaced apart from the shaft in a radial direction.

[0011] The second surface may be in contact with a surface of the magnet.

[0012] The shaft may include: a first region having a first inner diameter; a second region connected to one side of the first region in an axial direction and having a second inner diameter larger than the first inner diameter; and a third region connected to the other side of the first region and having a third inner diameter smaller than the first inner diameter, wherein the magnet may contact an outer surface of the first region.

[0013] The sixth surface may be disposed closer to the third region than to the second region in the axial direction.

[0014] An end portion of the sixth surface may be disposed closer to the third region in the axial direction than the third surface.

[0015] An axial length of the sixth surface may be smaller than a distance from an end of the sixth surface to an end of the first region in the axial direction.

[0016] A distance from an end of the sixth surface to an end of the first region in the axial direction may be smaller than an axial length of the magnet.

[0017] The radial length of the second surface may be smaller than the radial length of the third surface.

[0018] The third surface may be spaced apart from the magnet in the axial direction to form a space portion between the magnet holder and the magnet.

[0019] The magnet holder may include a third surface, a fifth surface, and a protrusion protruding from a lower end portion of the magnet holder in the axial direction, and the protrusion may have an annular shape.

[0020] Beneficial Effects

[0021] According to one embodiment of the present invention, since the magnet holder includes the region into which the shaft is press-fitted, there is an advantage in that a coupling force between the shaft and the magnet holder is ensured under high temperature conditions.

[0022] According to one embodiment of the present invention, since a magnet holder formed as a pot-shaped member is used, there is an advantage in that assembly and structure are simplified.

[0023] According to one embodiment of the present invention, since the fifth surface of the magnet holder is press-fitted onto the shaft and the fourth surface connected to the fifth surface contacts the other end portion of the magnet, there is an advantage in that the fixing force for the magnet is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a view illustrating a motor according to an embodiment.

[0025] Figure 2 is a perspective view illustrating a shaft, a magnet, and a magnet holder.

[0026] Figure 3 is a view illustrating the magnet holder before the magnet holder is assembled to the shaft.

[0027] Figure 4 is a side cross-sectional view illustrating a shaft.

[0028] Figure 5 is a top perspective view illustrating a magnet holder.

[0029] Figure 6 is a bottom perspective view illustrating a magnet holder.

[0030] Figure 7 is a side cross-sectional view illustrating a magnet holder.

[0031] Figure 8 is a side cross-sectional view illustrating a magnet with a magnet holder mounted thereon.

[0032] Fig. 9 is a side cross-sectional view illustrating a shaft with magnets and a magnet holder disposed thereon.

[0033] Fig.10 is a plan view illustrating a shaft on which a magnet and a magnet holder are disposed. DETAILED DESCRIPTION

[0034] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0035] However, the technical spirit of the present invention is not limited to some embodiments to be described and can be implemented in various different forms, and at least one or more components of the embodiments can be selectively combined, replaced, and used within the scope of the technical spirit of the present invention.

[0036] In addition, unless otherwise clearly and specifically defined by the context, all terms used herein (including technical and scientific terms) may be interpreted as having the meaning commonly understood by those skilled in the art, and the meaning of commonly used terms, such as those defined in commonly used dictionaries, will be interpreted in consideration of the contextual meaning of the relevant technology.

[0037] In addition, the terms used in the embodiments of the present invention are considered in a descriptive sense only and are not intended to limit the present invention.

[0038] In this specification, unless the context clearly indicates otherwise, the singular form includes its plural form, and in the case of describing "at least one (or one or more) of A, B and C", this may include at least one combination of all possible combinations of A, B and C.

[0039] In addition, in the description of the components of the present invention, terms such as "first", "second", "A", "B", "(a)", and "(b)" may be used.

[0040] These terms are used only to distinguish one component from another component, and the nature, order, etc. of the components are not limited by these terms.

[0041] In addition, it will be understood that when a first component is referred to as being “connected,” “coupled” or “linked” to a second component, such description may include the case where the first component is directly connected, coupled or linked to the second component and the case where the first component is connected, coupled or linked to the second component via a third component disposed between the first and second components.

[0042] In addition, when a first element is described as being formed or disposed “on” or “under” a second element, such description includes the case where the two elements are formed or disposed in direct contact with each other and the case where one or more other elements are interposed between the two elements. In addition, when a first element is described as being formed “on or under” a second element, such description may include the case where the first element is formed on the upper side or the lower side relative to the second element.

[0043] Figure 1 is a view illustrating a motor according to an embodiment.

[0044] Reference Figure 1 , a motor according to an embodiment may include a shaft 100 , a magnet 200 , a stator 300 , and a magnet holder 400 .

[0045] Hereinafter, the term “inward” is a direction toward the shaft 100 in a radial direction of the motor, and the term “outward” is a direction opposite to “inward.” In addition, the circumferential direction and the radial direction are defined based on the axial center of the motor.

[0046] The shaft 100 may be a hollow member with one side open. Both ends of the shaft 100 may be rotatably supported in the axial direction by bearings thereof. Portions of the shaft 100 having different outer diameters may be divided and arranged in the axial direction.

[0047] The magnet 200 contacts the outer peripheral surface of the shaft 100. The magnet 200 rotates together with the rotation of the shaft 100. The magnet 200 may be provided as a plurality of magnets 200.

[0048] The stator 300 is disposed outside 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 around the insulator 320. The coil 330 forms a magnetic field. The stator core 310 may be formed as one core or by combining a plurality of separate cores. In addition, the stator core 310 may be formed by stacking a plurality of thin steel plates on each other, but is not necessarily limited thereto. For example, the stator core 310 may be formed as a single component.

[0049] The magnet holder 400 is used to fix the magnet 200 to the shaft 100. The magnet holder 400 may be a cylindrical member formed of a metal material. The magnet holder 400 is fixed to the shaft 100 and is disposed at the outside of the magnet 200 at the same time, so as to fix the magnet 200 to the shaft 100 so that the magnet 200 will not be separated from the shaft 100.

[0050] Figure 2 is a perspective view illustrating the shaft 100, the magnet 200 and the magnet holder 400, and Figure 3 is a view illustrating the magnet holder 400 before the magnet holder 400 is assembled to the shaft 100 .

[0051] Reference Figure 2 and Figure 3 , a plurality of magnets 200 may be fixed along the outer surface of the shaft 100. An adhesive may be applied between the magnets 200 and the outer surface of the shaft 100. A plurality of magnets 200 may be arranged along the circumference of the shaft 100. In the drawings, the magnet holder 400 may be inserted and assembled from below the shaft 100.

[0052] Figure 4 is a side cross-sectional view illustrating the shaft 100 .

[0053] Reference Figure 4 The shaft 100 is a hollow member and can be divided into a first region 110 , a second region 120 , and a third region 130 .

[0054] The first region 110 has a first inner diameter D1. The second region 120 is connected to one side of the first region 110 and has a second inner diameter D2 greater than the first inner diameter D1. The third region 130 is connected to the other side of the first region 110 and has a third inner diameter D3 less than the first inner diameter D1. A shaft of an external device may be inserted into the shaft 100 and coupled to the shaft 100.

[0055] Meanwhile, the magnet 200 and the magnet holder 400 are disposed on the outer surface of the first region 110 .

[0056] Figure 5 is a top perspective view illustrating the magnet holder 400, and Figure 6is a bottom perspective view illustrating the magnet holder 400 . Figure 7 is a side cross-sectional view illustrating the magnet holder 400, and Figure 8 is a side cross-sectional view illustrating the magnet 200 with the magnet holder 400 mounted thereon.

[0057] Reference Figures 5 to 8 , the magnet holder 400 is a single component and is coupled to the shaft 100 to surround the entire magnet 200. In particular, since the magnet holder 400 is press-fitted onto the shaft 100, there is an advantage that the coupling force between the shaft 100 and the magnet holder 400 is mechanically high.

[0058] The magnet holder 400 has a cylindrical shape as a whole. The magnet holder 400 may include a first surface S1, a second surface S2, a third surface S3, a fourth surface S4, a fifth surface S5, and a sixth surface S6.

[0059] The first surface S1 is disposed to face the outer surface of the magnet 200 .

[0060] The second surface S2 is formed to be bent inward from one end portion of the first surface S1. The second surface S2 is disposed to face one surface of the magnet 200 in the axial direction.

[0061] The third surface S3 is formed to be bent inward from the other end portion of the first surface S1. The third surface S3 is disposed to face the other surface of the magnet 200 in the axial direction. In addition, the third surface S3 is disposed to be separated from the magnet 200 in the axial direction.

[0062] The fourth surface S4 is disposed to face the other surface of the magnet 200 in the axial direction. In addition, the fourth surface S4 is in contact with the other surface of the magnet 200 in the axial direction.

[0063] The fifth surface S5 is bent from the fourth surface S4 in the axial direction and connected to the third surface S3 .

[0064] The sixth surface S6 is bent from the fourth surface S4 , and is disposed to face the outer surface of the shaft 100 , and the sixth surface S6 is in contact with the outer surface of the shaft 100 .

[0065] When the magnet holder 400 is assembled to the shaft 100, the sixth surface S6 is press-fitted along the outer surface of the shaft 100. The sixth surface S6 may be press-fitted until the fourth surface S4 contacts the other surface of the magnet 200. Since the fourth surface S4 supporting the other surface of the magnet 200 is directly connected to the sixth surface S6 press-fitted onto the shaft 100, it is possible to effectively prevent the magnet 200 from moving not only in the radial direction but also in the axial direction.

[0066] The axial length L1 of the sixth surface S6 may be in the range of 5% to 15% of the axial length L2 of the magnet 200. When the axial length L1 of the sixth surface S6 is less than 5% of the axial length L2 of the magnet 200, there is a possibility that the magnet 200 is separated because the fixing force of the magnet holder 400 is small relative to the size of the magnet 200. On the contrary, when the axial length L1 of the sixth surface S6 is greater than 15% of the axial length L2 of the magnet 200, it is difficult to press-fit the magnet holder 400 to the shaft 100, and there is a possibility that the magnet holder 400 is deformed.

[0067] At the same time, the axial length L1 of the sixth surface S6 may also be smaller than the distance K1 from the end of the sixth surface S6 to the end of the first region in the axial direction (refer to Fig. 9 ).

[0068] Meanwhile, since the third surface S3 is disposed to be spaced apart from the magnet 200 in the axial direction, a space portion SP is formed between the magnet 200 and the third surface S3. Due to the space portion SP, an annular protrusion PT may be formed on the lower end portion of the magnet holder 400.

[0069] Fig. 9 is a side cross-sectional view illustrating the shaft 100 with the magnet 200 and the magnet holder 400 disposed thereon.

[0070] Reference Fig. 9 , the sixth surface S6 is disposed closer to the third region 130 of the shaft 100 in the axial direction than to the second region 120. In addition, the end of the sixth surface S6 is disposed closer to the third region 130 in the axial direction than the third surface S3. Since the magnet holder 400 is assembled to the other end portion of the shaft 100 on which the third region 130 is formed, the sixth surface S6 is positioned closer to the third region 130 of the shaft 100 in the axial direction. When the sixth surface S6 is positioned away from the third region 130 of the shaft 100 in the axial direction, since the length passing along the outer surface of the shaft 100 for press fitting increases, the sixth surface S6 should be positioned closer to the third region 130 in the axial direction.

[0071] Fig.10 1 is a plan view illustrating the shaft 100 on which the magnet 200 and the magnet holder 400 are provided.

[0072] Reference Figure 8 and Fig.10, the second surface S2 of the magnet holder 400 is formed to cover one surface of the magnet 200. The second surface S2 is bent inwardly from the first surface S1 in the radial direction and contacts one surface of the magnet 200. The second surface S2 and the magnet 200 are arranged to partially overlap in the axial direction. The second surface S2 prevents the magnet 200 from being separated in the axial direction.

[0073] The second surface S2 may be formed by bending after the magnet holder 400 is assembled to cover the magnet 200. Therefore, the second surface S2 is disposed to be spaced apart from the shaft 100 in the radial direction.

[0074] In addition, since the sixth surface S6 is bent when press-fitted onto the shaft 100 for forming the second surface S2 , the radial length L4 of the second surface S2 should be minimized to prevent the sixth surface S6 from being deformed.

[0075] Therefore, the magnet 200 may include an inner surface in contact with the shaft 100 and an outer surface disposed opposite to the inner surface, and the second surface S2 may be disposed to overlap only a portion of the outer surface of the magnet 200 in the axial direction. In this case, the radial length L4 of the second surface S2 may be smaller than the radial length L5 of the third surface S3.

[0076] Meanwhile, if possible, the length of the sixth surface S6 passing along the outer surface of the shaft 100 for press fitting should not be too long. For example, the distance K1 from the end of the sixth surface S6 to the end of the first region 110 in the axial direction may be less than the axial length L2 of the magnet 200.

[0077] The motor according to the exemplary embodiments of the embodiment motor has been described above in detail with reference to the accompanying drawings.

[0078] The above embodiments should be considered as descriptive meanings only, not for the purpose of limitation, and the scope of the present invention is not limited by the detailed description but by the appended claims. In addition, it should be explained that the scope of the present invention covers all modifications and variations derived from the meaning and scope of the appended claims and equivalent schemes.

Claims

1. The motor according to claim 1, wherein: An axial length of the sixth surface is in a range of 5% to 15% of an axial length of the magnet.

2. The motor according to claim 1, wherein: An axial length of the sixth surface is in a range of 5% to 15% of an axial length of the magnet.

3. The motor according to claim 1, wherein: The second surface is disposed to be spaced apart from the shaft in a radial direction.

4. The motor according to claim 1, wherein: The second surface is in contact with one surface of the magnet.

5. The motor according to claim 1, wherein: The shaft comprises: a first region having a first inner diameter; a second region connected to one side of the first region in the axial direction and having a second inner diameter larger than the first inner diameter; and a third region connected to the other side of the first region and having a third inner diameter smaller than the first inner diameter, Wherein, the magnet is in contact with the outer surface of the first region.

6. The motor according to claim 5, wherein: The sixth surface is disposed closer to the third region than to the second region in the axial direction.

7. The motor according to claim 5, wherein: An end portion of the sixth surface is disposed closer to the third region in the axial direction than the third surface.

8. The motor according to claim 5, wherein: The axial length of the sixth surface is smaller than the distance from the end of the sixth surface to the end of the first region in the axial direction.

9. The motor according to claim 5, wherein: A distance from an end of the sixth surface to an end of the first region in the axial direction is smaller than an axial length of the magnet.

10. The motor according to claim 1, wherein The radial length of the second surface is smaller than the radial length of the third surface.

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