Motor

Abstract

The present invention can provide a motor including a shaft, a rotor connected to the shaft, and a stator arranged to correspond to the rotor, wherein the rotor includes a rotor core, a plurality of magnets connected to the rotor core, and a magnet holder arranged outside the magnets, the rotor core including a protrusion arranged between adjacent magnets, the magnet holder including a first part arranged on a side of the magnet and a second part connected to the first part and arranged on one side of the magnet, the second part including a hole through which the protrusion and a portion of the magnet are exposed.

Description

[Technical Field]

[0001] The embodiment 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, generating a rotational driving force.

[0003] The rotor may include a rotor core and a magnet disposed on the outer surface of the rotor core. The rotor may also include a magnet holder that surrounds the rotor core and the magnet. The magnet holder may be a cylindrical can member made of a metal material.

[0004] The rotor core may include protrusions, and multiple magnets may be disposed between the protrusions. However, in order to insert the magnets, the circumferential width between the protrusions is designed to be wider than the circumferential width of the magnets, so there are gaps between the magnets and the protrusions in the circumferential direction. Because these gaps can change the spacing between the magnets in the circumferential direction, all magnets are pushed clockwise or counterclockwise to set the spacing between the magnets in the circumferential direction to a constant value.

[0005] To push all the magnets clockwise or counterclockwise, after attaching the magnet holder, the magnet holder is pushed clockwise or counterclockwise to align the magnets. However, there is a problem that the magnet holder often spins freely without pushing the magnets.

[0006] Also, once the magnet holder is installed, it is difficult to check whether the magnets are properly aligned because the magnets cannot be seen from the outside.

[0007] On the other hand, when the rotor rotates at high speed, slippage may occur between the rotor cores, which may cause unstable rotor operation and reduce motor performance.

[0008] Therefore, the present embodiment is intended to solve the above-mentioned problems, and aims to provide a motor that can align magnets and check the alignment of magnets while the magnet holder is attached, and that increases the slip torque between the contact surfaces of the rotor core to prevent the rotor core from slipping, thereby providing a motor with stable rotor operation.

[0009] The problems to be solved by the embodiments are not limited to those mentioned above, and other problems not mentioned here will be clearly understood by those skilled in the art from the following description. Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, the present embodiment is intended to solve the above-mentioned problems, and aims to provide a motor that can align magnets and check the alignment of magnets while the magnet holder is attached, and that increases the slip torque between the contact surfaces of the rotor core to prevent the rotor core from slipping, thereby providing a motor with stable rotor operation.

[0011] The problems to be solved by the embodiments are not limited to those mentioned above, and other problems not mentioned here will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0012] An embodiment for achieving the above object includes a shaft, a rotor coupled to the shaft, and a stator arranged to correspond to the rotor, wherein the rotor includes a rotor core, a plurality of magnets coupled to the rotor core, and a magnet holder arranged outside the magnets, the rotor core includes a protrusion arranged between adjacent magnets, and the magnet holder includes a first part arranged on a side of the magnet and a second part connected to the first part and arranged on one side of the magnet, and the second part includes a hole, and the hole can expose the protrusion and a portion of the magnet.

[0013] The holes may be arranged at regular intervals in the circumferential direction, and the holes may be arranged corresponding to each of the protrusions.

[0014] The aforementioned hole The maximum circumferential width of the projection may be greater than the maximum circumferential width of the projection.

[0015] The maximum radial length of the hole may be greater than the maximum radial length of the protrusion.

[0016] The holes may expose a first magnet disposed on one side of the protrusion and a second magnet disposed on the other side of the protrusion in a circumferential direction.

[0017] The hole may expose one surface and a side surface of the magnet.

[0018] A first distance, which is the circumferential distance between the side of the hole and the exposed side of the first magnet, and a second distance, which is the circumferential distance between the side of the hole and the exposed side of the second magnet, may be different from each other.

[0019] A third distance, which is the circumferential distance between a reference line passing through the circumferential width center of the hole and the axial center of the shaft and the exposed side surface of the first magnet, and a fourth distance, which is the circumferential distance between the reference line and the exposed side surface of the second magnet, may be different from each other.

[0020] The second part includes a second A part and a second B part connected to the second A part, and the second A part is bent at the first part and positioned axially apart from the protrusion and the magnet, and the second B part can be bent at the second A part and contact the rotor core.

[0021] Some of the holes may be located in the second A part, and other parts of the holes may be located in the second B part.

[0022] An embodiment can provide a motor including a shaft; a rotor coupled to the shaft; and a stator arranged to correspond to the rotor, wherein the rotor includes a rotor core and a plurality of magnets coupled to the rotor core and a magnet holder arranged outside the magnets, wherein the magnets include a first magnet and a second magnet circumferentially spaced from the first magnet, the rotor core includes a protrusion arranged between the first magnet and the second magnet, the protrusion including a first surface facing the first magnet, a second surface facing the second magnet, and a first region arranged between the first surface and the second surface, the first region including a first portion, a second portion arranged between the first portion and the first surface, and a third portion arranged between the first portion and the second surface, wherein the radial length of the first portion is smaller than the radial length of the second portion or the third portion, and the magnet holder includes a hole axially overlapping with the protrusion.

[0023] Preferably, the protrusion may include a groove disposed between the second portion and the third portion.

[0024] Preferably, the holes are arranged at regular intervals in the circumferential direction, and the holes may be arranged corresponding to each of the protrusions.

[0025] Preferably, the first magnet includes a first side surface facing the second magnet, the second magnet includes a second side surface facing the first side surface, and the first side surface and the second side surface may overlap with the hole in the axial direction.

[0026] Preferably, the protrusion, the first side surface and the second side surface form a first space, and the first space may overlap the hole in the axial direction.

[0027] Preferably, the magnet holder includes a first part disposed on a side of the magnet and a second part connected to the first part and disposed on one side of the magnet, and the second part may include the hole.

[0028] Preferably, the rotor core includes a plurality of rotor plates stacked in the axial direction, the rotor plates including a first rotor plate and a second rotor plate, and the first rotor plate may be positioned closer to the second part than the second rotor plate.

[0029] Preferably, the first rotor plate includes a plurality of first protrusions protruding circumferentially from its outer peripheral surface, and the second rotor plate includes a plurality of second protrusions protruding circumferentially from its outer peripheral surface, and the first protrusions and the second protrusions may have different shapes.

[0030] Preferably, the first protrusion includes a first A surface facing the first side surface, a second A surface facing the second side surface, and a first A region disposed between the first A surface and the second A surface, and a first groove may be formed in the first A region.

[0031] Preferably, the second protrusion includes a 1B surface facing the first side surface, a 2B surface facing the second side surface, and a 1B region disposed between the 1B surface and the 2B surface, and the minimum radial length of the 1B region may be greater than the minimum radial length of the 1A region.

[0032] An embodiment can provide a motor including a shaft, a rotor coupled to the shaft, and a stator arranged to correspond to the rotor, the rotor including a rotor core and a plurality of magnets coupled to the rotor core, the rotor core including a first rotor core and a second rotor core arranged axially with the first rotor core, the first rotor core having a first surface in contact with the first rotor core and including a protrusion arranged on the first surface, the second rotor core having a second surface in contact with the first surface, including a first groove arranged on the second surface and a second groove arranged circumferentially with the first groove, and the protrusion arranged in the second groove.

[0033] A first arrangement angle formed by a first imaginary line passing from the axial center of the first rotor core through the width center of the magnet and a second imaginary line passing from the axial center of the first rotor core through the width center of the protrusion may be different from a second arrangement angle formed by a third imaginary line passing from the axial center of the second rotor core through the width center of the magnet and a fourth imaginary line passing from the axial center of the second rotor core through the width center of the second groove.

[0034] The first rotor core includes a plurality of first protrusions arranged circumferentially on its outer peripheral surface, and the second imaginary line can overlap with a fifth imaginary line passing from the axial center of the first rotor core to the width center of the first protrusions.

[0035] The second rotor core may include a first hole and a second hole circumferentially spaced apart from the first hole, and the first groove and the second groove may be disposed between the first hole and the second hole based on the circumferential direction.

[0036] The first rotor core includes a plurality of first rotor plates stacked in the axial direction, and the first rotor plates include a first A surface and a second A surface, and include a first A protrusion and a second A protrusion arranged on the first A surface, and a first A groove and a second A groove arranged on the second A surface.

[0037] The first A groove may be formed by the first A protrusion protruding therefrom, and the second A groove may be formed by the second A protrusion protruding therefrom.

[0038] The second rotor core includes a plurality of second rotor plates stacked in the axial direction, and the second rotor plates include a 1B surface and a 2B surface, and include a 1B protrusion and a 2B protrusion arranged on the 1B surface, and a 1B groove and a 2B groove arranged on the 2B surface.

[0039] The first B groove may be formed by the first B protrusion protruding therefrom, and the second B groove may be formed by the second B protrusion protruding therefrom.

[0040] The first A protrusion may be axially overlapped with the second B groove of the second rotor core.

[0041] The first rotor core may include a third rotor plate disposed between the first rotor plate and the second rotor plate.

[0042] The third rotor plate may include a first C surface arranged toward the second B surface and a second C surface arranged toward the first A surface, a first C protrusion arranged on the first C surface, and a first C hole penetrating the first C surface and the second C surface.

[0043] The first B protrusion may be disposed in the first C hole, and the first C protrusion may be disposed in the second B groove and overlap with the second B protrusion in the axial direction.

[0044] The projection may have a radial length greater than a circumferential width.

[0045] The radial length of the protrusions may be smaller than the radial length of the rotor core, and the ratio of the radial length of the protrusions to the radial length of the rotor core may be 0.25 to 0.4. [Effects of the Invention]

[0046] According to the embodiment, there is provided an advantageous effect that the magnets can be aligned with the magnet holder attached.

[0047] According to the embodiment, an advantageous effect is provided in that the alignment of the magnets can be confirmed with the magnet holder attached.

[0048] According to the embodiment, it is possible to provide an advantageous effect that the state of the magnet and the state of the adhesive can be checked after the magnet holder is attached.

[0049] According to the embodiment, the fixing force of the magnets is improved, and the phenomenon of the cogging torque of the motor being deteriorated due to the misalignment of the magnets can be prevented.

[0050] According to the embodiment, the slip torque between the rotor cores is increased to prevent the slip phenomenon, thereby stabilizing the driving of the rotor.

[0051] In addition, the skew angle can be adjusted while stacking the plates, which increases work efficiency, and the bonding strength between the rotor plates increases because the protrusions are inserted into the grooves or holes when stacking. [Brief explanation of the drawings]

[0052] [Figure 1] 1 is a side cross-sectional view of a motor according to an embodiment. [Figure 2] FIG. [Figure 3] 3 is a partial cross-sectional side view of the rotor shown in FIG. 2. [Figure 4] 1 is a diagram illustrating a rotor core and a magnet. [Figure 5]FIG. [Figure 6] 1 is a diagram illustrating a magnet holder. [Figure 7] FIG. 7 is a plan view of the magnet holder shown in FIG. 6. [Figure 8] 10 is a diagram illustrating a protrusion and a magnet exposed through a hole. [Figure 9] 10 is a diagram illustrating a protrusion and a magnet exposed through a hole. [Figure 10] 10 is a diagram illustrating a protrusion and a magnet exposed through a hole. [Figure 11] 10 is a view illustrating another embodiment of a hole. [Figure 12] FIG. 7 is a side cross-sectional view of the magnet holder shown in FIG. 6. [Figure 13] 10 is a view illustrating a state in which pins of an external device are aligned with holes of a magnet holder. [Figure 14] 10 is a view illustrating a state in which a pin of an external device is inserted into a hole. [Figure 15] 10 is a diagram illustrating a process in which magnets are aligned by pins. [Figure 16] FIG. 10 is a perspective view illustrating a rotor of a motor according to another embodiment. [Figure 17] FIG. 2 is an exploded perspective view illustrating a rotor. [Figure 18] FIG. [Figure 19] FIG. [Figure 20] 20 is an enlarged view of region A in FIG. 19. [Figure 21] 20 is an enlarged view of region A in FIG. 19. [Figure 22] 20 is an enlarged view of region A in FIG. 19. [Figure 23] FIG. 2 is an exploded perspective view illustrating a rotor core. [Figure 24] FIG. 2 is a plan view illustrating a first rotor plate. [Figure 25]FIG. 4 is a plan view illustrating a second rotor plate. [Figure 26] 10 is a view illustrating a modified example of the first protrusion. [Figure 27] 10 is a view illustrating a state before a primary protrusion is deformed. [Figure 28] 10 is a view illustrating a state in which a first protrusion is deformed. [Figure 29] 10 is a view showing a state in which a shaft is coupled to a rotor core of a motor according to another embodiment; [Figure 30] 1 is a view illustrating a state in which a first rotor core and a second rotor core are stacked; [Figure 31] FIG. 2 is a plan view of a first rotor core. [Figure 32] FIG. 4 is a bottom view of the second rotor core. [Figure 33] FIG. 2 is an exploded perspective view of a first rotor core. [Figure 34] FIG. 2 is a plan view of the first rotor plate and the second rotor plate. [Figure 35] FIG. 2 is a plan view of the first rotor plate and the second rotor plate. [Figure 36] FIG. 2 is a bottom view of the first rotor plate and the second rotor plate. [Figure 37] FIG. 2 is a bottom view of the first rotor plate and the second rotor plate. [Figure 38] FIG. 10 is a plan view of a third rotor plate. [Figure 39] FIG. 10 is a plan view of a third rotor plate. [Figure 40] 1 is a view illustrating a state in which a plurality of first rotor plates and third rotor plates are stacked; [Figure 41] 1 is a diagram illustrating a state in which a plurality of first rotor plates, a plurality of second rotor plates, and a third rotor plate are stacked. DETAILED DESCRIPTION OF THE INVENTION

[0053] The direction parallel to the length of the shaft (vertical direction) is the axial direction, the direction perpendicular to the axial direction around the shaft is the radial direction, and the direction along a circle with a radius in the radial direction around the shaft is the circumferential direction.

[0054] FIG. 1 is a side cross-sectional view of a motor according to an embodiment.

[0055] 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 .

[0056] Hereinafter, "inside" refers to the direction from the housing 400 toward the shaft 100, which is the center of the motor, and "outside" refers to the opposite direction from the inside, which is the direction from the shaft 100 toward the housing 400.

[0057] The shaft 100 may be coupled to 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, which in turn rotates the shaft 100. The shaft 100 may be a hollow member.

[0058] The rotor 200 rotates through electrical interaction with the stator 300. The rotor 200 may be disposed corresponding to or inside the stator 300. The rotor 200 may include a rotor core 210, a plurality of magnets 220 coupled to the rotor core 210, and a magnet holder 230 disposed outside the magnets 220. The magnet holder 230 may be a can member made of a metal material.

[0059] The stator 300 is disposed outside the rotor 200. The stator 300 may include a stator core 310, an insulator 320, and a coil 330. The insulator 320 is attached to the stator core 310. The coil 330 is attached to the insulator 320. The coil 330 induces electrical interaction with the magnet of the rotor 200.

[0060] The housing 400 may be disposed outside the stator 300. The housing 400 may be a cylindrical member with one side open.

[0061] FIG. 2 is an exploded view illustrating the rotor, and FIG. 3 is a partial cross-sectional side view of the rotor illustrated in FIG.

[0062] 2 and 3, the rotor 200 may include a rotor core 210, a plurality of magnets 220 disposed on the outside of the rotor core 210, and a magnet holder 230 covering the rotor core 210 and the magnets 220. The rotor core 210 may include a first rotor core 210A and a second rotor core 210B. The first rotor core 210A and the second rotor core 210B may be stacked in the axial direction. The magnet holder 230 may include a first magnet holder 230A and a second magnet holder 230B. The first magnet holder 230A may be inserted into the rotor core 210 from one side of the rotor core 210 in the axial direction, and the second magnet holder 230B may be inserted into the rotor core 210 from the other side of the rotor core 210 in the axial direction.

[0063] In the drawings, the magnet holder 230 is illustrated as consisting of a first magnet holder 230A and a second magnet holder 230B, but the present invention is not limited to this and the magnet holder 230 may be a single member that completely covers the rotor core 210 and the magnet 220.

[0064] FIG. 4 is a diagram illustrating the rotor core 210 and the magnet 220, and FIG. 5 is a perspective view illustrating the magnet 220. As shown in FIG.

[0065] 4, rotor core 210 may include a plurality of protrusions 211 protruding radially from its outer surface. The plurality of protrusions 211 are arranged at regular intervals along the circumferential direction. Each of the protrusions 211 may be arranged on the outer surface of rotor core 210 and extend along the axial direction.

[0066] The protrusions 211 align the positions of the magnets 220 in the circumferential direction and serve to guide the insertion of the magnets 220. The magnets 220 are inserted in the axial direction between the protrusions 211 in the circumferential direction. Hereinafter, the magnets 220 adjacent to each other in the circumferential direction, arranged with the protrusion 211 in between, the magnet 220 arranged on one side of the protrusion 211 will be referred to as a first magnet 220A, and the magnet 220 arranged on the other side of the protrusion 211 will be referred to as a second magnet 220B.

[0067] 5, the magnet 220 may include an outer surface 221 that contacts the magnet holder 230, an inner surface 222 that contacts the rotor core 210, and two side surfaces 223 that connect the outer surface 221 and the inner surface 222. The magnet 220 may also include one surface 224 that forms both ends of the magnet 220 in the axial direction.

[0068] For smooth insertion of the magnet 220, the circumferential width between the protrusions 211 is wider than the circumferential width of the magnet 220, so a gap may occur between the protrusions 211 and the side of the magnet 220. This gap causes an error in aligning the magnet 220 in the circumferential direction. For this reason, the magnet 220 must be aligned by pushing it clockwise or counterclockwise.

[0069] 6 is a view illustrating the magnet holder 230, FIG. 7 is a plan view of the magnet holder 230 illustrated in FIG. 6, and FIG. 12 is a side cross-sectional view of the magnet holder 230 illustrated in FIG.

[0070] 6, 7, and 12, magnet holder 230 includes hole 233. This hole 233 is where pin P of an external device is inserted to push magnet 220 in one direction after magnet holder 230 is attached. Hole 233 is also where the state of magnet 220 and the state of the adhesive applied to magnet 220 can be observed with the naked eye.

[0071] The magnet holder 230 may be divided into a first part 231 and a second part 232. The first part 231 is a cylindrical member. The second part 232 may be formed by bending an end of the first part 231. A hole 233 may be disposed in the second part 232. The second part 232 may be divided into a second A part 232a and a second B part 232b. The second A part 232a is bent inward from the first part 231. The second B part 232b may be bent at the second A part 232a and disposed to have a step with the second A part 232a.

[0072] The holes 233 may be arranged at regular intervals along the circumferential direction. The positions of the holes 233 in the circumferential direction correspond to the protrusions 211. Therefore, the number of the holes 233 may correspond to the number of the protrusions 211.

[0073] Such a hole 233 may be located in the 2A part 232a.

[0074] 8 to 10 are views illustrating the protrusion 211 and the magnet 220 exposed through the hole 233. FIG.

[0075] 8, after magnets 220 are attached to rotor core 210, magnet holder 230 is attached to rotor core 210 so that holes 233 and protrusions 211 are aligned. When magnet holder 230 is attached to rotor core 210, protrusions 211 and portions of magnets 220 are exposed through holes 233. Protrusions 211 and one surface and side surface of first magnet 220A, and one surface and side surface of second magnet 220B are exposed through holes 233.

[0076] The hole 233 may include an outer surface 233a, an inner surface 233b facing the outer surface 233a, and both side surfaces 233c connecting the outer surface 233a and the inner surface 233b. The space formed by the outer surface 233a, the side surface of the first magnet 220A, the side surface of the second magnet 220B, and the protrusion 211 is a space into which a pin P of an external device can be inserted. The outer surface 233a may be curved to maximize the space into which the pin P can be inserted.

[0077] When the magnets 220 are mounted between the protrusions 211, a gap G is generated between the magnets 220 and the protrusions 211. Because of this gap G, the distance between the magnets 220 in the circumferential direction may vary for each magnet 220, so it is necessary to insert a pin P into the hole 233 and press the magnets 220 to align them.

[0078] Meanwhile, the maximum circumferential width W1 of the hole 233 may be set to be larger than the maximum circumferential width W2 of the protrusion 211 so that the side surfaces of the first magnet 220A and the second magnet 220B as well as the protrusion 211 can be exposed through the hole 233. Also, the maximum radial length R1 of the hole 233 may be larger than the maximum radial length R2 of the protrusion 211.

[0079] 9, the first distance L1 and the second distance L2 may be different from each other. The first distance L1 is the circumferential distance between the side surface 233c of the hole 233 and the exposed side surface of the first magnet 220A, and the second distance L2 is the circumferential distance between the side surface 233c of the hole 233 and the exposed side surface of the second magnet 220B. In this case, the first distance L1 and the second distance L2 may be the distance on the circumference of an imaginary circle O that passes through the center of the side surface 233c of the hole 233.

[0080] 10, the third distance L3 and the fourth distance L4 may be different. The third distance L3 may be the circumferential distance between a reference line T passing through the circumferential width center P1 of the hole 233 and the axial center C of the shaft 100, and the exposed side surface of the first magnet 220A. The fourth distance L4 may be the circumferential distance between the reference line T and the exposed side surface of the second magnet 220B. In this case, the third distance L3 and the fourth distance L4 may be the distance on the circumference of an imaginary circle O passing through the center of the side surface 233c of the hole 233.

[0081] The hole 233 may be formed so that the circumferential center P2 of the protrusion 211 passes through the reference line T.

[0082] FIG. 11 is a view illustrating another embodiment of the hole 233. In FIG.

[0083] Referring to FIG. 11, the hole 233 has an outer surface 233a formed with a groove 233a recessed outward. a The groove 233a may be disposed a The groove 233a may be disposed in a region of the outer surface 233a of the hole 233 that does not overlap with the magnet 220. a This is to prevent the outer surface of the magnet 220 from being exposed due to the groove 233a. a This has the advantage of expanding the space formed by the outer surface 233a of the hole 233, the side surface of the magnet 220, and the protrusion 211, thereby securing a large space into which the pin P of the external device can be inserted.

[0084] 13 is a view showing a state in which the pin P of the external device is aligned with the hole 233 of the magnet holder 230, and FIG. 14 is a view showing a state in which the pin P of the external device is inserted into the hole 233. As shown in FIG.

[0085] 13, a pin P of an external device is aligned to be inserted into the radially outer region of the protrusion 211. Although one pin P is shown in the drawing, multiple pins P may be aligned with each hole 233. Referring to FIG. 14, a pin P is inserted into the radially outer region of the protrusion 211. Pins P may be inserted into all of the holes 233 of the magnet holder 230.

[0086] FIG. 15 is a diagram illustrating the process of aligning the magnets 220 by the pins P. As shown in FIG.

[0087] 15, when pins P are inserted into holes 233 and rotated clockwise or counterclockwise, they push and move magnet 220 clockwise or counterclockwise. One of the pins P inserted into adjacent holes 233 pushes the side of first magnet 220A, moving first magnet 220A until first magnet 220A contacts protrusion 211. The other pin P pushes the side of second magnet 220B in the other hole 233, moving second magnet 220B until it contacts protrusion 211.

[0088] In this way, by pushing and moving all the magnets 220 in a clockwise or counterclockwise direction, the magnets 220 can be aligned so as to be positioned at regular intervals in the circumferential direction even after the magnet holder 230 is attached.

[0089] FIG. 16 is a perspective view illustrating a rotor according to another embodiment, and FIG. 17 is an exploded perspective view illustrating the rotor.

[0090] Referring to FIG. 16, a rotor 1200 may include a rotor core 1210, a plurality of magnets 1220 disposed on the outside of the rotor core 1210, and a magnet holder 1230 that covers the rotor core 1210 and the magnets 1220.

[0091] 17, the rotor core 1210 may include a first rotor core 1210A and a second rotor core 1210B. The first rotor core 1210A and the second rotor core 1210B may be arranged axially. The magnet holder 1230 may include a first magnet holder 1230A and a second magnet holder 1230B. The first magnet holder 1230A may cover the first rotor core 1210A. The second magnet holder 1230B may cover the second rotor core 1210B. However, this is not limited thereto, and the magnet holder may be a single member. One magnet holder may cover the first rotor core 1210A and the second rotor core 1210B.

[0092] FIG. 18 is a perspective view illustrating the magnet.

[0093] 18, the magnet 1220 may include an outer surface 1221 that contacts the magnet holder 1230, an inner surface 1222 that contacts the rotor core 1210, and two side surfaces 1223 that connect the outer surface 1221 and the inner surface 1222. The magnet 1220 may also include one surface 1224 that forms both ends of the magnet 1220 in the axial direction.

[0094] 17 again, the magnet holder 1230 may include a first part 1231 and a second part 1232. The first part 1231 is a cylindrical member. The first part 1231 may contact an outer surface 1221 of the magnet 1220. The first part 1231 may cover the outer peripheral surface of the rotor core 1210. The second part 1232 may be formed by bending an end of the first part 1231. At this time, it may extend toward the axial center of the rotor core 1210. The second part 1232 may contact one surface 1224 of the magnet 1220. The second part 1232 may cover one surface of the rotor core 1210 arranged in the axial direction.

[0095] The rotor core 1210 includes a plurality of protrusions 1211. The protrusions 1211 protrude radially from the outer circumferential surface of the rotor core 1210. The protrusions 1211 are arranged at regular intervals along the circumferential direction. Each protrusion 1211 may be arranged along the axial direction on the outer surface of the rotor core 1210. The protrusions 1211 align the circumferential positions of the magnets 1220 and serve to guide the insertion of the magnets 1220. The magnets 1220 are inserted axially between the protrusions 1211 in the circumferential direction. Hereinafter, the magnets 1220 adjacent to each other in the circumferential direction, arranged with the protrusion 1211 in between, and arranged on one side of the protrusion 1211 will be referred to as a first magnet 1220A, and the magnet 1220 arranged on the other side of the protrusion 1211 will be referred to as a second magnet 1220B.

[0096] FIG. 19 is a plan view illustrating the rotor.

[0097] 19, the magnet holder 1230 includes holes 1230H. At this time, the alignment of the magnets 1220 can be confirmed through the holes 1230H. An external jig for aligning the magnets 1220 can be inserted into the holes 1230H. There may be a plurality of holes 1230H. The holes 1230H may be spaced apart in the circumferential direction. The holes 1230H may overlap with the protrusions 1211 in the axial direction. That is, when the rotor 1200 is viewed from the axial direction, the protrusions 1211 may be exposed through the holes 1230H. Accordingly, an operator can visually check the alignment of the magnets 1220 through the holes 1230H.

[0098] The first magnet 1220A may include a first side surface 1223A. The first side surface 1223A may be disposed opposite the second magnet 1220B. The second magnet 1220B may include a second side surface 1223B. The second side surface 1223B may be disposed opposite the first side surface 1223A. The first side surface 1223A and the second side surface 1223B may overlap with the hole 1230H in the axial direction. Accordingly, an operator can check the positions of the first side surface 1223A and the second side surface 1223B through the hole 1230H.

[0099] 20 to 22 are enlarged views of region A in FIG.

[0100] Referring to FIG. 20, the protrusion 1211 has a first surface 2111 and a second surface 2112. 1 12 and a first region 2113. The first surface 2111 can be in contact with the first side surface 1223A. 1 12 can contact the second side surface 1223B. The first region 2113 is connected to the first surface 2111 and the second surface 2112. 1 12. At this time, a groove 2113G may be formed on the outer circumferential surface of the first region 2113.

[0101] On the other hand, a gap G is formed between the outer peripheral surface of the protrusion 1211 and the first and second side surfaces 1223A and 1223B. 1 At this time, the gap may overlap with the hole 1230H in the axial direction. When the rotor 1200 is viewed from the axial direction, the gap G1 may be exposed through the hole 1230H. At this time, the gap G 1 A jig may be placed on the

[0102] 21, the first region 2113 may include a first portion S1, a second portion S2, and a third portion S3. In the first region 2113, the first portion S1 may have the smallest radial length. The second portion S2 may be disposed between the first portion S1 and the first surface 2111. And, the third portion S3 may be disposed between the first portion S1 and the second surface 2112. The radial length of the first region 2113 may gradually increase from the first portion S1 to the second portion S2 or the third portion S3.

[0103] Referring to FIG. 22, the first region 2113 has a maximum length L max and minimum length L min At this time, the maximum length L max can be the radial length of the second section S2 or the third section S3. And the minimum length L min may be the radial length of the first section S1. According to an embodiment, the first region 2113 has a maximum length L max Minimum length L for min The ratio may be between 0.3 and 0.8.

[0104] FIG. 23 is an exploded perspective view illustrating the rotor core.

[0105] 23, the rotor core 1210 may include a rotor plate 1210P. There may be a plurality of rotor plates 1210P. The rotor core 1210 may be formed by stacking the rotor plates 1210P in the axial direction.

[0106] The rotor plate 1210P can include a first rotor plate 1211P and a second rotor plate 1212P.

[0107] There may be a plurality of first rotor plates 1211P. There may be five first rotor plates 1211P. The plurality of first rotor plates 1211P may be stacked one on top of the other. The first rotor plates 1211P may be disposed adjacent to the second part 1232.

[0108] There may be a plurality of second rotor plates 1212P. The plurality of second rotor plates 1212P may be stacked consecutively. The stacked plurality of second rotor plates 1212P may be axially arranged with the stacked plurality of first rotor plates 1211P. The second rotor plate 1212P may be spaced apart from the second part 1232. In this case, the first rotor plate 1211P may be arranged between the second rotor plate 1212P and the second part 1232.

[0109] FIG. 24 is a plan view illustrating the first rotor plate, and FIG. 25 is a plan view illustrating the second rotor plate.

[0110] Referring to FIGS. 24 and 25, first rotor plate 1211P and second rotor plate 1212P may have different shapes.

[0111] The first rotor plate 1211P includes a first protrusion P1. The first protrusion P1 protrudes from the outer peripheral surface of the first rotor plate 1211P. The first protrusion P1 includes a first A surface A1 and a second A surface A2. The first A surface A1 and the second A surface A2 are arranged in the circumferential direction. A first A area SA is arranged between the first A surface A1 and the second A surface A2. A first groove G11 may be formed in the first A area SA.

[0112] The second rotor plate 1212P includes a second protrusion P2. The second protrusion P2 protrudes from the outer peripheral surface of the second rotor plate 1212P. The second protrusion P2 includes a first B surface B1 and a second B surface B2. The first B surface B1 and the second B surface B2 are arranged in the circumferential direction. 1BThe first B region SB is disposed between the surface B1 and the second B region B2. The minimum radial length L12 of the first B region SB may be greater than the minimum radial length L11 of the first A region SA. No grooves are formed in the first B region SB. In this case, the first rotor plate 1211P and the second rotor plate 1212P may have the same structure except for the presence or absence of grooves formed in the first A region SA and the first B region SB.

[0113] FIG. 26 is a diagram illustrating a modified example of the primary projection.

[0114] 26, the first groove G11 of the first protrusion P1 may have a first width W1 in the circumferential direction and a first depth D1 in the radial direction. The first width W1 and first depth D1 of the first groove G11 of the first protrusion P1 may vary. As the first width W1 and first depth D1 increase, deformation using a jig becomes easier, but the rigidity of the first protrusion P1 may decrease. On the other hand, as the first width W1 and first depth D1 decrease, the rigidity of the first protrusion P1 increases, but a greater pressure force from the jig is required to deform the first protrusion P1. Accordingly, the first width W1 and first depth D1 can be adjusted depending on the rigidity of the material of the first protrusion P1.

[0115] FIG. 27 is a view illustrating the state before the primary protrusion is deformed.

[0116] 27, the first protrusion P1 may be exposed through the hole 1230H. The first A-side A1 may be at least partially separated from the first side surface 1223A. The second A-side A2 may be at least partially separated from the second side surface 1223B. Although the first A-side A1 and the second A-side A2 are shown not to contact the first side surface 1223A and the second side surface 1223B in the drawings, only a portion of the first A-side A1 and the second A-side A2 may be separated from the first side surface 1223A and the second side surface 1223B. Therefore, an air gap AG may be formed between the first A-side A1 and the first side surface 1223A or between the second A-side A2 and the second side surface 1223B.

[0117] FIG. 28 is a view illustrating a state in which the primary protrusion is deformed.

[0118] Referring to FIG. 28, a jig J can be inserted into the gap. The jig J can pass through the hole 1230H. The jig J can come into contact with the first protrusion P1. The jig J can be inserted by the axial thickness of the stacked first rotor plates 1211P. The inserted jig J can press the first A region SA toward the axial center of the rotor core 1210. At this time, the circumferential width of the first groove can be expanded. The first A surface A1 and the second A surface A2 can be closely attached to the first side surface 1223A and the second side surface 1223B, respectively. At this time, the air gap AG shown in FIG. 27 can be reduced or eliminated. In the motor according to the present invention, the alignment of the magnets can be checked with the magnet holder installed, making it easy to align the magnets.

[0119] FIG. 29 is a view showing a state in which a shaft of a motor according to another embodiment is coupled.

[0120] Referring to Figure 29, the rotor 320 according to the present invention is formed by stacking multiple rotor cores 321, 322, and 323. In this embodiment, three rotor cores are shown stacked, but the number of rotor cores can be appropriately adjusted depending on the design. Each of the rotor cores 321, 322, and 323 is formed by stacking multiple rotor plates. The rotor plates are formed in the shape of thin disks. The multiple rotor plates can be stacked in the axial direction.

[0121] The rotor core may include a first rotor core 321 and a second rotor core 322. The first rotor core 321 may be axially disposed with respect to the second rotor core 322. The first rotor core 321 and the second rotor core 322 are rotated at a predetermined angle while coupled to a shaft 337. When the first rotor core 321 and the second rotor core 322 are stacked with an angular deviation, the cogging torque of the motor may be reduced. According to an embodiment, the first rotor core 321 may be disposed at one end of the second rotor core 322, and the first rotor core 321 may be stacked at a predetermined angle in a clockwise direction relative to the second rotor core 322. Another first rotor core 323 may be disposed at one end of the second rotor core 322. The another first rotor core 323 may be stacked at a predetermined angle in a clockwise direction relative to the second rotor core 322. Hereinafter, the angle at which the rotor core is rotated and stacked in a clockwise or counterclockwise direction is defined as a skew angle.

[0122] FIG. 30 is a diagram illustrating a state in which the first rotor core and the second rotor core are stacked.

[0123] 30, the second rotor core 322 is disposed on one surface of the first rotor core 321. The second rotor core 322 has a predetermined skew angle with respect to the first rotor core 321. The second rotor core 322 may be fixed to one surface of the first rotor core 321. To this end, the first rotor core 321 may include protrusions, and the second rotor core 322 may include grooves in which the protrusions are disposed.

[0124] The first rotor core 321 has a first surface 321A that contacts the second rotor core 322. The second rotor core 322 has a second surface 322B that contacts the first surface 321A. In this case, the first rotor core 321 may include a plurality of protrusions 321P arranged on the first surface 321A. The number of protrusions 321P may be the same as the number of poles (the number of magnets) of the motor. The plurality of protrusions 321P may be arranged spaced apart in the circumferential direction. The plurality of protrusions 321P may be spaced apart at equal intervals in the circumferential direction.

[0125] The second rotor core 322 may include a plurality of first grooves 322G1 arranged on the second surface 322B. The number of the first grooves 322G1 may be the same as the number of the protrusions 321P. The plurality of first grooves 322G1 may be arranged spaced apart along the circumferential direction. The plurality of first grooves 322G1 may be spaced apart at equal intervals in the circumferential direction. The second rotor core 322 may also include a plurality of second grooves 322G2 arranged on the second surface 322B. 2 The number of grooves 322G2 may be the same as the number of first grooves 322G1. The second grooves 322G2 may be disposed between the first grooves 322G1 that are spaced apart from each other. In this case, the second grooves 322G2 may be farther away from the first grooves 322G1 disposed on one side than the first grooves 322G1 disposed on the other side.

[0126] FIG. 31 is a plan view of the first rotor core.

[0127] Referring to FIG. 31 , a plurality of protrusions 321P are disposed on the first surface 321A. The radial length of the protrusions 321P may be greater than the circumferential width. The radial length of the protrusions 321P may be smaller than the radial length of the rotor cores 321, 322, and 323. According to an embodiment, the ratio of the radial length of the protrusions 321P to the radial lengths of the rotor cores 321, 322, and 323 may be 0.25 to 0.4. The first rotor core 321 may have a plurality of protrusions 321S disposed on its outer circumferential surface. The protrusions 321S may be spaced apart in the circumferential direction. The number of the protrusions 321S may be the same as the number of the magnets 324. The magnets 324 are attached to the outer circumferential surface of the first rotor core 321 defined by the protrusions 321S.

[0128] When a virtual line extending from the axial center C of the first rotor core 321 to pass through the width center of the magnet 324 is defined as a first virtual line L31, and a virtual line extending from the axial center C of the first rotor core 321 to pass through the width center of the protrusion 321P is defined as a second virtual line L32, the first virtual line L31 and the second virtual line L32 can be disposed at a first arrangement angle θ1. In this case, the first virtual line L31 can be disposed between two different second virtual lines L32. Furthermore, when a virtual line extending from the axial center C of the first rotor core 321 to pass through the width center of the protrusion 321S is defined as a fifth virtual line L35, the second virtual line L32 and the fifth virtual line L35 can overlap.

[0129] FIG. 32 is a bottom view of the second rotor core.

[0130] Referring to FIG. 32, the second surface 322B has a plurality of first grooves 322G1 and a plurality of second grooves. 322 G2 is arranged. The second groove 322G2 may be arranged between two different first grooves 322G1. The first groove 322G1 and the second groove 322G2 may be arranged on the same circumferential line. The second rotor core 322 may have a plurality of protrusions 322S arranged on the outer peripheral surface. The protrusions 322S of the second rotor core 322 may have the same shape as the protrusions 321S of the first rotor core 321 shown in FIG. 31, except that they are arranged rotated with a predetermined angular deviation from each other.

[0131] When a virtual line extending from the axial center C of the second rotor core 322 to pass through the width center of the magnet 324 is defined as the third virtual line L33, a virtual line extending from the axial center C of the second rotor core 322 to pass through the width center of the second groove 322G2 is defined as the fourth virtual line L34, and a virtual line extending from the axial center C of the second rotor core 322 to pass through the width center of the first groove 322G1 is defined as the sixth virtual line L36, the fourth virtual line L34 can be positioned between the third virtual line L33 and the sixth virtual line L36.

[0132] The fourth virtual line L34 may be disposed between two different third virtual lines L33. The fourth virtual line L34 is disposed at a third disposition angle (θ 3 ), and may be arranged to have a third arrangement angle (θ3) with another third virtual line L33. The second arrangement angle (θ2) may be different from the first arrangement angle (θ1) shown in FIG. 31. Also, the fourth virtual line L34 may be arranged to have a fourth arrangement angle (θ4) with the sixth virtual line L36. In this case, the difference between the first arrangement angle (θ1) and the second arrangement angle (θ2) may be equal to the fourth arrangement angle (θ4). The fourth arrangement angle (θ4) may be equal to the skew angle between the first rotor core 321 and the second rotor core 322.

[0133] FIG. 33 is an exploded perspective view of the first rotor core.

[0134] 33, the first rotor core 321 may include a plurality of first rotor plates 3237 and a third rotor plate 3230. The plurality of first rotor plates 3237 may be stacked consecutively, and the third rotor plate 3230 may be disposed on one side of the stacked first rotor plates 3237. The second rotor core 321 may be disposed on one side of the third rotor plate 3230. 322 There may be at least one third rotor plate 3230.

[0135] 34 and 35 are plan views of the first rotor plate and the second rotor plate.

[0136] Referring to FIG. 34, the first rotor plate 3237 and the second rotor plate 3220 are identical members having the same shape except that they are rotated with an angular deviation from each other.

[0137] The first rotor plate 3237 may have a first A-surface A31 and a second A-surface A32. The first A-surface A31 of any one of the first rotor plates 3237 may contact the second A-surface A32 of another first rotor plate 3237. AThe surface A31 may include a first A protrusion 3211 and a second A protrusion 3212. There may be a plurality of first A protrusions 3211 and a plurality of second A protrusions 3212. The plurality of first A protrusions 3211 may be spaced apart at equal intervals in the circumferential direction. The second A protrusions 3212 may be located between two spaced apart first A protrusions 3211. The plurality of second A protrusions 3212 may be spaced apart at equal intervals in the circumferential direction.

[0138] Similarly, the second rotor plate 3220 may have a first B surface B1 and a second B surface B2. The first B surface B1 of any one second rotor plate 3220 may contact the second surface B2 of another second rotor plate 3220. The second rotor plate 3220 may include a first B protrusion 3221 and a second B protrusion 3222 disposed on the first B surface B1.

[0139] The first rotor plate 3237 and the second rotor plate 3220 may each have a plurality of holes formed therein. The holes may be spaced apart in the circumferential direction. The holes may include a first hole H1 and a second hole H2 arranged in the circumferential direction. In this case, the first A protrusion 3211 and the second A protrusion 3212 may be arranged between the first hole H1 and the second hole H2 of the first rotor plate 3237, and the first B protrusion 3221 and the second B protrusion 3222 may be arranged between the first hole H1 and the second hole H2 of the second rotor plate 3220.

[0140] Hereinafter, a description will be given of the arrangement angle of an imaginary line extending from the axial center C of the first rotor plate 3237 to the width center of the magnet 324, the first A protrusion 3211, and the second A protrusion 3212. This description will be given based on the first rotor plate 3237, but can be equally applied to the second rotor plate 3220.

[0141] 35, when an imaginary line extending from the axial center C of the first rotor plate 3237 to pass through the width center of the magnet 324 is defined as a first A imaginary line LA1, an imaginary line extending from the axial center C of the first rotor plate 3237 to pass through the width center of the first A protrusion 3211 is defined as a second A imaginary line LA2, and an imaginary line extending from the axial center C of the first rotor plate 3237 to pass through the width center of the second A protrusion 3212 is defined as a third A imaginary line LA3, the third A imaginary line LA3 may be located between the first A imaginary line LA1 and the second A imaginary line LA2. The third A imaginary line LA3 may be located closer to the second A imaginary line LA2 than the first A imaginary line LA1.

[0142] 36 and 37 are bottom views of the first and second rotor plates.

[0143] 36, the first rotor plate 3237 may include a first A groove 3213 and a second A groove 3214 disposed on the second A surface A32. There may be a plurality of first A grooves 3213 and a plurality of second A grooves 3214. The plurality of first A grooves 3213 may be spaced apart at equal intervals in the circumferential direction. The second A groove 3214 may be disposed between two spaced-apart first A grooves 3213. The plurality of second A grooves 3214 may be spaced apart at equal intervals in the circumferential direction. In this case, the first A groove 3213 and the first A protrusion 3211 may be simultaneously formed by punching, and the second A groove 3214 and the second A protrusion 3212 may be simultaneously formed by punching.

[0144] Similarly, the second rotor plate 3220 may include a first B groove 3223 and a second B groove 3224 disposed on the second B surface B2. The first B groove 3223 and the second B groove 3224 have configurations corresponding to the first A groove 3213 and the second A groove 3214, and therefore will not be described again.

[0145] The following description will be made regarding the arrangement angle of an imaginary line extending from the axial center C of the first rotor plate 3237 to the width center of the magnet 324, the first A groove 3213, and the second A groove 3214. This description will be made based on the first rotor plate 3237, but can be equally applied to the second rotor plate 3220.

[0146] 37, when an imaginary line extending from the axial center C of first rotor plate 3237 to pass through the width center of magnet 324 is defined as a first B imaginary line LB1, an imaginary line extending from the axial center C of first rotor plate 3237 to pass through the width center of first A groove 3213 is defined as a second B imaginary line LB2, and an imaginary line extending from the axial center C of first rotor plate 3237 to pass through the width center of second A groove 3214 is defined as a third B imaginary line LB3, the third B imaginary line LB3 may be located between the first B imaginary line LB1 and the second B imaginary line LB2. The third B imaginary line LB3 may be located closer to the second B imaginary line LB2 than the first B imaginary line LB1.

[0147] 38 and 39 are plan views of the third rotor plate.

[0148] 38, the third rotor plate 3230 may have a first C-face C1 and a second C-face. The first C-face C1 may contact the second B-face B2 of the second rotor plate 3220. The second C-face is the opposite surface of the first C-face and may contact the first A-face A31 of the first rotor plate 3237. The third rotor plate 3230 may include a first C-protrusion 3231 disposed on the first C-face C1. The third rotor plate 3230 may also include a first C-hole 3232 penetrating the first C-face C1 and the second C-face C2.

[0149] Referring to FIG. 39, the third rotor plate 3230 The imaginary line extending from the axial center C of the third rotor plate to pass through the width center of the magnet 324 is defined as the first imaginary line LC1. 3230 The imaginary line extending from the shaft center C to pass through the width center of the first C protrusion 3231 is defined as the second C imaginary line LC2, and the third rotor plate 3230When a virtual line extending from the axial center C to pass through the width center of the first C hole 3232 is defined as a third C virtual line LC3, the third C virtual line LC3 may be located between the first C virtual line LC1 and the second C virtual line LC2. The third C virtual line LC3 may be located closer to the second C virtual line LC2 than the first C virtual line LC1.

[0150] FIG. 40 is a diagram illustrating a state in which a plurality of first rotor plates and third rotor plates are stacked.

[0151] Referring to FIG. 40, the first rotor core 321 may be formed by stacking a plurality of first rotor plates 3237 and one third rotor plate 3230. The plurality of first rotor plates 3237 may be stacked continuously. The third rotor plate 3230 may be disposed on one side of the stacked plurality of first rotor plates 3237. In this case, the third protrusion 3230S formed on the outer circumferential surface of the third rotor plate 3230 may be disposed on the same line in the axial direction as the first protrusion 237S formed on the outer circumferential surface of the first rotor plate 3237. The first A protrusion 3211 may overlap the first C protrusion 3231 in the axial direction. The second A protrusion 3212 may be disposed in the first C hole 3232. In this case, the axial protrusion length of the second A protrusion 3212 may be equal to or greater than the third protrusion 3230S. rotor plate 3230 Therefore, one end of the second A protrusion 3212 may be smaller than the thickness in the axial direction of the third A protrusion 3212. rotor plate 3230 It can be positioned lower than one side of the

[0152] FIG. 41 is a diagram illustrating a state in which a plurality of first rotor plates, a plurality of second rotor plates, and a third rotor plate are stacked.

[0153] 41, a second rotor core 3322 may be stacked on one side of a third rotor plate 3230. In this case, the second rotor core 3322 may be formed by stacking a plurality of second rotor plates 3220. Although not shown in the drawing, the second rotor core 3322 may include a fourth rotor plate (not shown). The fourth rotor plate (not shown) may be disposed on one side of the plurality of second rotor plates. The fourth rotor plate may have the same shape as the third rotor plate. Another first rotor core may be disposed on one side of the fourth rotor plate.

[0154] The second rotor plate 3220 is disposed to be rotated with respect to the third rotor plate 3230 with an angular deviation therebetween. The second protrusion 220S protruding from the outer peripheral surface of the second rotor plate 3220 is disposed to be offset by a predetermined angle from the third protrusion 3230S. The first C protrusion 3231 is disposed in the second B groove and may overlap with the second B protrusion 3222 in the axial direction. The first rotor core 321 and the second rotor core 322 can be fixed by the engagement of the first C protrusion 3231 and the second B groove.

[0155] This structure increases work efficiency by adjusting the skew angle while stacking the first to third rotor plates, and increases the bonding force between the rotor plates because the protrusions are inserted into the grooves or holes when stacking. It also increases the slip torque between the contact surfaces of the rotor core, preventing the rotor core from slipping and stabilizing the rotor's drive.

[0156] The above-described embodiment can be used in various devices such as vehicles and home appliances.

Claims

1. shaft, a rotor coupled to the shaft; and a stator disposed to correspond to the rotor; The rotor includes a rotor core, a plurality of magnets coupled to the rotor core, and a magnet holder disposed outside the magnets, the rotor core includes protrusions disposed between adjacent magnets, the magnet holder includes a hole; The hole exposes the protrusion and a portion of the magnet, The maximum radial length of the hole is greater than the maximum radial length of the protrusion.

2. 2. The motor according to claim 1, wherein the plurality of holes are arranged at regular intervals in the circumferential direction, and the holes are arranged corresponding to the respective protrusions.

3. The motor according to claim 1 , wherein the maximum width of the hole in the circumferential direction is greater than the maximum width of the protrusion in the circumferential direction.

4. The magnet holder includes a first part arranged on a side surface of the magnet, and a second part connected to the first part and arranged on one surface of the magnet; The motor of claim 1 , wherein the second part includes the hole.

5. shaft, a rotor coupled to the shaft; and a stator disposed to correspond to the rotor; the rotor includes a rotor core, a plurality of magnets coupled to the rotor core, and a magnet holder disposed outside the magnets; The magnet includes a first magnet and a second magnet spaced apart from the first magnet in a circumferential direction, the rotor core includes a protrusion disposed between the first magnet and the second magnet, the protrusion includes a first surface facing the first magnet, a second surface facing the second magnet, and a first region disposed between the first surface and the second surface; the first region includes a first portion, a second portion disposed between the first portion and the first surface, and a third portion disposed between the first portion and the second surface; a radial length of the first portion is smaller than a radial length of the second portion or the third portion; The magnet holder includes a hole that overlaps with the protrusion in the axial direction.

6. The motor of claim 5 , wherein the protrusion includes a groove disposed between the second portion and the third portion.

7. 6. The motor according to claim 5, wherein the plurality of holes are arranged at regular intervals in the circumferential direction, and the holes are arranged corresponding to the respective protrusions.

8. shaft, a rotor coupled to the shaft; and a stator disposed to correspond to the rotor; the rotor includes a rotor core and a plurality of magnets coupled to the rotor core; the rotor core includes a first rotor core and a second rotor core arranged in the axial direction with respect to the first rotor core, the first rotor core has a first surface that contacts the second rotor core and includes a protrusion disposed on the first surface; the second rotor core has a second surface in contact with the first surface and includes a second groove disposed in the second surface; the protrusion is disposed in the second groove; the rotor core includes a protrusion formed on an outer circumferential surface, The motor, wherein the protrusion is aligned with the convex portion in the radial direction, and the second groove is not aligned with the convex portion in the radial direction.

9. A first arrangement angle formed by a first imaginary line extending from the axial center of the first rotor core through the width center of the magnet and a second imaginary line extending from the axial center of the first rotor core through the width center of the protrusion is:

9. The motor according to claim 8, wherein the angle is different from a second arrangement angle formed by a third imaginary line extending from the axial center of the second rotor core through the width center of the magnet and a fourth imaginary line extending from the axial center of the second rotor core through the width center of the second groove.

10. the first rotor core includes a plurality of first protrusions arranged in a circumferential direction on an outer peripheral surface thereof, The motor according to claim 9 , wherein the second imaginary line overlaps with a fifth imaginary line that passes from the axial center of the first rotor core to the width center of the first protrusion.

Images