Motor

Abstract

The present invention may provide a motor comprising: a shaft; a rotor coupled to the shaft; a stator positioned to correspond to the rotor; and a housing located on the outer side of the stator, wherein a plurality of protrusions protruding toward the stator are formed on the inner surface of the housing, the stator comprises a stator core and a coil wound around the stator core, and a first groove formed on the outer surface of the stator core into which the protrusions are fitted.

Description

Technology Field

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

[0002] Generally, in a motor, the rotor rotates due to the electromagnetic interaction between the rotor and the stator. At this time, the shaft connected to the rotor also rotates to generate rotational driving force.

[0003] The stator may include a stator core, an insulator mounted on the stator core, and a coil wound around the insulator. The stator core can be press-fitted into a housing. For example, if the housing is heated to expand its inner diameter, the stator is positioned inside the housing, and then cooled to room temperature, the stator is secured to the housing by the housing's contraction force. However, securing the stator to the housing in this manner causes a problem of slippage between the stator and the housing. In particular, if the housing's contraction force is small, the probability of slippage occurring is very high. The problem to be solved

[0004] Accordingly, the embodiment aims to solve the above-mentioned problems and to provide a motor capable of preventing slip between the housing and the stator.

[0005] The problems that the embodiments aim to solve are not limited to those mentioned above, and other problems not mentioned herein will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0006] An embodiment for achieving the above objective may provide a motor comprising a shaft, a rotor coupled to the shaft, a stator positioned corresponding to the rotor, and a housing located on the outside of the stator, wherein a plurality of protrusions protruding toward the stator are formed on the inner surface of the housing, the stator comprises a stator core and a coil wound around the stator core, and a first groove formed on the outer circumference of the stator core into which the protrusions are fitted. The housing may include a step on its inner surface, and the protrusions may be formed by caulking the step. The step may include a second groove, and the second groove may be formed by caulking the step. With respect to the circumferential direction, the protrusions and the step may be positioned in alignment. A part of the protrusion may be located in the first groove, and another part of the protrusion may be in contact with the top of the stator core. The step may be positioned higher than the top of the stator core so that a tool for caulking first contacts the step. The circumferential width of the second groove is the first groove It may be larger than the circumferential width. Both circumferential sides of the above-mentioned projection may each come into contact with both circumferential sides of the above-mentioned first groove. Radially, a gap may be formed between the above-mentioned projection and the above-mentioned first groove. In the axial direction, the uppermost part of the above-mentioned projection may be formed higher than the upper surface of the stator core of the above-mentioned stator. Effects of the invention

[0007] According to the embodiment, there is an advantage of preventing circumferential slip between the housing and the stator. There is also an advantage of preventing axial slip between the housing and the stator.

[0008] According to the embodiment, since additional bonding strength between the housing and the stator core is secured through the protrusion, there is an advantage in that there is no need to forcibly increase the interference deviation. Brief explanation of the drawing

[0009] FIG. 1 is a side cross-sectional view of a motor according to an embodiment, FIG. 2 is a drawing illustrating a stator core, FIG. 3 is a plan view of the housing and the stator, FIG. 4 is a side cross-sectional view of the housing, FIG. 5 is a drawing illustrating a step of the housing, a second groove, a first groove of the stator core, and a projection disposed in the first groove. FIG. 6 is a drawing showing the position of the top of the stator core and the step of the housing. FIG. 7 is a drawing showing the width of a projection placed in the second groove, FIG. 8 is a drawing showing a projection covering the second groove, FIGS. 9 and FIGS. 10 are drawings illustrating the process of forming a protrusion by caulking the shoulder of a housing. Specific details for implementing the invention

[0010] 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.

[0011] FIG. 1 is a side cross-sectional view of a motor according to an embodiment.

[0012] Referring to FIG. 1, the motor according to the embodiment may include a shaft (100), a rotor (200), a stator (300), and a housing (400).

[0013] Hereinafter, "inner side" refers to the direction from the housing (400) toward the shaft (100), which is the center of the motor, and "outer side" refers to the opposite direction of the inner side, which is the direction from the shaft (100) toward the housing (400).

[0014] The shaft (100) can be coupled with the rotor (200). When an electromagnetic interaction occurs between the rotor (200) and the stator (300) through the supply of current, the rotor (200) rotates and the shaft (100) rotates in conjunction with it. The shaft (100) can be made of a hollow member.

[0015] The rotor (200) rotates through electrical interaction with the stator (300). The rotor (200) may be positioned corresponding to the stator (300) and may be positioned inside. The rotor (200) may include a rotor core (210) and a plurality of magnets (220) coupled to the rotor core (210).

[0016] The stator (300) is positioned on the outside of the rotor (200). The stator (300) may include a stator core (310), an insulator (320), and a coil (330). The insulator (320) is seated on the stator core (310). The coil (330) is mounted on the insulator (320). The coil (330) causes electrical interaction with the magnet of the rotor (200).

[0017] The housing (400) may be positioned on the outside of the stator (300). The housing (400) may be a cylindrical member with one side open.

[0018] Figure 2 is a drawing illustrating a stator core.

[0019] Referring to FIG. 2, the stator core (310) may be formed by assembling a plurality of segmented cores consisting of teeth (311) and a yoke (312). The yoke (312) contacts the housing (400). The teeth (311) are positioned protruding from the inner side of the yoke (312). A first groove (313) may be positioned on the outer surface of the yoke (312). The first groove (313) may be positioned extending from one side of the yoke (312) to the other side. Although not shown in the drawing, the first groove (313) may be formed only on the upper part and the lower part of the outer surface of the stator core (310). The first groove (313) may be positioned at the center of the circumferential width of the yoke (312). Although the drawing shows that one first groove (313) is arranged in one stator core (310), the present invention is not limited thereto and may be arranged in the first groove (313) on each side of the yoke (312), and may have one first groove (313) arranged at the circumferential width center of the yoke (312) and additional first grooves (313) arranged on each side of the yoke (312).

[0020] FIG. 3 is a plan view of the housing (400) and the stator.

[0021] Referring to FIG. 3, the motor according to the embodiment may include a projection (410) that prevents slip from occurring between the housing (400) and the stator (300). Hereinafter, the projection (410) may be formed by caulking a part of the housing (400). Such a projection (410) may protrude inward from the inner surface of the housing (400). And a plurality of projections (410) may be arranged at regular intervals along the circumferential direction of the housing (400). A plurality of projections (410) may be arranged rotationally symmetrically with respect to the axis center (C).

[0022] FIG. 4 is a side cross-sectional view of the housing (400).

[0023] Referring to FIG. 4, the housing (400) may include a first region (400A) and a second region (400B) arranged continuously along the axial direction. The first region (400A) has a first radius (R1), and the second region (400B) has a second radius (R2) smaller than the first radius (R1). Thus, a step (420) is formed between the first region (400A) and the second region (400B) in the axial direction. The step (420) may be formed along the circumferential direction and arranged in an annular shape. The upper surface of the step (420) may be formed to be placed on the same plane as a plane perpendicular to the axial direction. The step (420) is a place where a tool entering the housing (400) along the axial direction for caulking comes into contact, and it is preferable that the step (420) be formed horizontally to increase the contact between the tool and the step (420).

[0024] The stator (300) core (310) contacts the second region (400B) but does not contact the first region (400A). The second region (400B) may be positioned longer in the axial direction than the first region (400A). The radial thickness of the second region (400B) is formed to be greater than the radial thickness of the first region (400A) to ensure the strength of the housing (400) that fixes the stator (300) core (310).

[0025] FIG. 5 is a drawing illustrating a step (420) and a second groove of a housing (400), a first groove (313) of a stator (300) core (310), and a projection (410) disposed in the first groove (313).

[0026] Referring to FIG. 5, the step (420) of the housing (400) may include a second groove (430). The second groove (430) may be formed concavely in the step (420). The second groove (430) may be arranged in alignment with the projection (410) and the first groove (313). These second groove (430) and the projection (410) may be formed by caulking the step (420) of the housing (400). Multiple second grooves (430) may be arranged. Multiple second grooves (430) may be arranged at regular intervals with respect to the circumferential direction.

[0027] FIG. 6 is a drawing showing the position of the top of the stator core (310) and the step (420) of the housing (400).

[0028] Referring to FIG. 6, the step (420) of the housing (400) is positioned higher than the top of the stator core (310). Thus, the step (420) and the top of the stator core (310) can be positioned with a height (h1) in the axial direction of the shaft (100). This is to guide the protrusion (410) formed in the caulking to be inserted into the first groove (313) of the stator core (310) and simultaneously cover the upper surface of the stator core (310). Additionally, this configuration is intended to ensure that a tool entering the inside of the housing (400) for caulking comes into contact with the step (420) before the upper surface of the stator core (310). The step height (h1) between the top of the stator core (310) and the step (420) of the housing (400) must be appropriately set so that a tool entering the inside of the housing (400) for caulking does not come into contact with the top of the stator core (310).

[0029] FIG. 7 is a drawing showing the width of the projection (410) placed in the second groove (430).

[0030] Referring to FIG. 7, the circumferential width (W1) of the second groove (430) may be larger than the circumferential width (W2) of the projection (410). This is to ensure that a sufficient area is placed in the second groove (430) to form the projection (410) by being deformed by caulking at the step (420). For example, the circumferential sides of the projection (410) may be formed to each abut against the circumferential sides of the first groove (313). Additionally, the area near the corner formed by the first groove (313) and the outer surface of the stator core (310) is pressed by the projection (410), thereby increasing the bonding strength between the housing (400) and the stator core (310). When the circumferential sides of the protrusion (410) are engaged with the circumferential sides of the first groove (313) in this way, circumferential movement between the housing (400) and the stator core (310) can be prevented. However, a gap (G) may be formed radially with respect to the axis center of the shaft (100) between the protrusion (410) and the first groove (313).

[0031] FIG. 8 is a drawing showing a projection (410) covering the second groove (430).

[0032] Referring to FIG. 8, as a projection (410) according to a modified example, a portion of the projection (410) may form an overlap area (O) with the stator core (310) based on the axial direction. That is, a portion of the projection (410) may cover the top of the stator core (310) around the second groove (430). For example, a portion of the projection (410) may be formed to cover the area near the corner formed by the outer surface of the stator core (310) and both sides of the second groove (430). Such a projection (410) can prevent slip from occurring between the housing (400) and the stator core (310), not only in the circumferential direction but also in the axial direction.

[0033] FIGS. 9 and FIGS. 10 are drawings illustrating the process of forming a projection (410) by caulking the step (420) of the housing.

[0034] First, a stator (300) can be placed inside the housing (400). The method of pressing the stator (300) into the housing (400) can be cold press-fit or hot press-fit. In the case of hot press-fit, the difference between the inner diameter of the housing (400) and the outer diameter of the stator (300) (also known as the interference deviation) can be significantly reduced before hot press-fit. Since additional bonding strength between the housing (400) and the stator core (310) is secured through the protrusion (410), there is no need to force a large interference deviation.

[0035] Referring to FIG. 9, when a stator (300) is positioned inside the housing (400) and a tool that has entered the inside of the housing (400) presses the step (420) in the axial direction, a portion of the step (420) is deformed and a projection (410) is formed to protrude toward the stator core (310).

[0036] As illustrated in FIG. 10, when the caulking is completed, a portion of the step (420) is pushed into the first groove (313), and at the same time, another portion of the step (420) can be positioned to cover the upper surface of the stator core (310). Thus, the uppermost portion of the axial projection (410) can be formed to be higher than the upper surface of the stator core (310) by a certain height (h2).

[0037] The aforementioned embodiment may also be applied to a motor in which the stator core (310) is formed as a single annular member. The aforementioned embodiment may be used in various devices, such as vehicles or home appliances. Explanation of the symbols

[0038] 100: Shaft 200: Rotor 210: Rotor Core 220: Magnet 300: Stator 310: Stator Core 313: First Groove 320: Insulator 330: Coil 400: Housing 410: Protrusion 420: Step 430: Second Groove

Claims

Claim 1 A motor comprising: a shaft; a rotor coupled to the shaft; a stator positioned to correspond to the rotor; and a housing located on the outer side of the stator, wherein a plurality of protrusions protruding toward the stator are formed on the inner surface of the housing, the stator comprises a stator core and a coil wound around the stator core, and a first groove formed on the outer surface of the stator core into which the protrusions are fitted. Claim 2 A motor according to claim 1, wherein the housing includes a step on its inner surface, and the projection is formed by caulking the step. Claim 3 In claim 2, the step comprises a second groove, and the second groove is formed by caulking the step. Claim 4 In claim 3, the motor in which the projection and the step are aligned with respect to the circumferential direction. Claim 5 In claim 2, a motor in which part of the projection is located in the first groove and another part of the projection contacts the top of the stator core. Claim 6 In claim 2, the step is positioned higher than the top of the stator core so that a tool for caulking first comes into contact with the step. Claim 7 In claim 3, the motor in which the circumferential width of the second groove is larger than the circumferential width of the first groove. Claim 8 In claim 7, the circumferential sides of the projection are each in contact with the circumferential sides of the first groove. Claim 9 In claim 2, a motor that forms a gap between the projection and the first groove in the radial direction. Claim 10 A motor according to claim 1, wherein the uppermost part of the projection in the axial direction is formed higher than the upper surface of the stator core of the stator.

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