Motor and pump comprising same

Abstract

An electric machine includes: a housing; the stator is arranged in the shell; and a rotor provided inside the stator. The rotor includes: a rotor core including a body portion, a flange portion extending radially from a bottom portion of the body portion, and a protruding portion protruding from an upper surface of the flange portion; and a magnet disposed on an outer surface of the body portion, with the protruding portion disposed between the flange portion and the magnet.

Description

Technical Field

[0001] The present embodiment relates to a motor and a pump including the motor. Background Art

[0002] The pump includes a motor section that generates a rotational driving force and a pump section that generates a hydraulic pressure. Therefore, since the motor section and the pump section inside the pump are independent of each other, there is a problem of increasing the number of parts and the overall size of the product.

[0003] Generally, an EOP may include a housing, a stator disposed inside the housing, and an outer gear and an inner gear disposed inside the stator, wherein the arrangement area of ​​the outer gear is set by a can disposed between the stators, and the arrangement area of ​​the inner gear is set by a cover coupled to the housing.

[0004] Since the EOP according to the prior art does not have a means for supporting the load applied to the external gear, there is a problem that, as the working pressure inside the pump increases, the rotation stability of the external gear or the internal gear deteriorates due to the force applied at the pump outlet. In particular, when high pressure occurs inside the pump, as the driving torque of the external gear increases, irregular friction occurs due to rotation, which becomes a factor that degrades pump performance. Summary of the invention

[0005] Technical issues

[0006] The present embodiment aims to provide a motor and a pump including the motor, which can ensure the rotation stability of the rotor, thereby minimizing the torque loss due to friction and improving the performance of the pump.

[0007] Technical Solution

[0008] The motor according to this embodiment includes: a shell; a stator arranged inside the shell; and a rotor arranged inside the stator, wherein the rotor includes: a rotor core, the rotor core including a body part, a flange part radially extending from the lower end of the body part and a protrusion protruding from the upper surface of the flange part; and a magnet arranged on the outer surface of the body part, wherein the protrusion part is arranged between the flange part and the magnet.

[0009] The flange portion and the magnet may be spaced apart from each other with respect to the axial direction.

[0010] With respect to the axial direction, the length of the flange portion may be within 15% to 40% of the length of the body portion.

[0011] The protruding portion may be in contact with the magnet.

[0012] Relative to the radial direction, the rotor and the stator may be spaced apart by 0.08 mm to 0.16 mm.

[0013] The upper surface of the magnet may be exposed above the body portion.

[0014] A guide portion protruding from an outer surface of the body portion and facing a side surface of the magnet may be included.

[0015] The guide portion may have a pentagonal cross-sectional shape.

[0016] The guide portion may include a first side surface contacting a side surface of the magnet, a second side surface disposed on an outer side of the first side surface and spaced apart from the side surface of the magnet, and an outer surface disposed on an outer side of the second side surface.

[0017] The pump according to this embodiment includes: a housing; a stator located inside the housing; an external gear arranged on the inner side of the stator; and an internal gear arranged inside the external gear, wherein the external gear includes: a core including a main body part, a flange part extending radially from the lower end of the main body part and a protrusion protruding from the upper surface of the flange part; and a magnet arranged on the outer surface of the main body part, wherein the protrusion is arranged between the flange part and the magnet.

[0018] Beneficial Effects

[0019] According to this embodiment, there is an advantage in that a section having a function of a dynamic pressure bearing is formed inside the rotor by the flange portion, thereby ensuring the rotation stability of the rotor.

[0020] Furthermore, due to the magnet floating structure through the protruding portion, the magnetic force of the magnet can be easily guided to the stator, thereby having an advantage of improving the performance of the motor and the pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a perspective view showing the appearance of a pump according to an embodiment of the present invention.

[0022] Figure 2 is an exploded perspective view of a pump according to an embodiment of the present invention.

[0023] Figure 3 is an exploded perspective view of an external gear, an internal gear, and a cover according to an embodiment of the present invention.

[0024] Figure 4 is a cross-sectional view of a pump according to an embodiment of the present invention.

[0025] Figure 5 is a perspective view of a rotor according to an embodiment of the present invention.

[0026] Figure 6 is an exploded perspective view of a rotor according to an embodiment of the present invention.

[0027] Figure 7 is a cross-sectional view of a rotor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0029] However, the technical idea of ​​the present invention is not limited to some embodiments to be described, but can be implemented in various forms, and within the scope of the technical idea of ​​the present invention, one or more of the constituent elements can be selectively combined or replaced between the embodiments.

[0030] In addition, unless explicitly defined and described, the terms (including technical terms and scientific terms) used in the embodiments of the present invention may be interpreted as meanings that are generally understood by those skilled in the art, and commonly used terms (such as terms defined in dictionaries) may be interpreted in consideration of the contextual meaning of the relevant technology.

[0031] In addition, the terms used in this specification are for describing the embodiments rather than for limiting the present invention. In this specification, unless otherwise specified in a phrase, a singular form may include a plural form, and when described as "at least one (or more than one) of A, B, and C", it may include one or more of all combinations that can be combined with A, B, and C.

[0032] Furthermore, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used.

[0033] These terms are only intended to distinguish a component from other components, and these terms do not limit the nature, sequence, or order of the components.

[0034] Furthermore, when a component is described as being “connected,” “coupled,” or “interconnected” with another component, the component is not only directly connected, coupled, or interconnected with the other components, but may also include a case where the component is “connected,” “coupled,” or “interconnected” due to the presence of another component between the other components.

[0035] Furthermore, when described as being formed or disposed “on” or “below” each component, “on” or “below” means that it includes not only a case where two components are in direct contact, but also a case where one or more other components are formed or disposed between the two components. Furthermore, when expressed as “on” or “below”, an upward direction as well as a downward direction based on one component may be included.

[0036] The "axial direction" used hereinafter is defined as the direction forming the rotation center of the internal gear, the external gear and the rotor. The "axial direction" may be Figure 2 The direction in which disassembled parts are connected. The "axial direction" can be defined as the up-down direction.

[0037] The “radial direction” used hereinafter is defined as a direction perpendicular to the above-mentioned “axial direction.” The “radial direction” may be defined as a direction in which a first lobe protrudes from an inner surface of an external gear, and a direction in which a second lobe protrudes from an inner surface of an internal gear.

[0038] The "circumferential direction" used hereinafter may be defined as the circumferential direction of any one of the stator, rotor, external gear and internal gear, or the circumferential direction of an area forming an imaginary concentric circle with the circumferential direction of any one of the stator, rotor, external gear and internal gear.

[0039] Figure 1 is a perspective view showing the appearance of a pump according to an embodiment of the present invention; Figure 2 is an exploded perspective view of a pump according to an embodiment of the present invention; Figure 3 is an exploded perspective view of an outer gear, an inner gear and a cover according to an embodiment of the present invention; Figure 4 is a cross-sectional view of a pump according to an embodiment of the present invention; Figure 5 is a perspective view of a rotor according to an embodiment of the present invention; Figure 6 is an exploded perspective view of a rotor according to an embodiment of the present invention; and Figure 7 is a cross-sectional view of a rotor according to an embodiment of the present invention.

[0040] Reference Figures 1 to 7 , the outer shape of the pump 10 according to the embodiment of the present invention can be formed by coupling the housing 100 and the cover 200. The cover 200 can be coupled to the lower surface of the housing 100. The housing 100 and the cover 200 can be threadedly coupled by the screw 290. The housing 100 and the cover 200 can each include a first coupling portion 112 and a second coupling portion 230 coupled to the screw 290. The first coupling portion 112 and the second coupling portion 230 can be disposed to face each other in the up-down direction, and can each include a hole coupled to the screw 290.

[0041] The cover 200 may include an opening. Specifically, a first opening and a second opening may be formed on one surface of the cover 200, the fluid is sucked through the first opening, and the circulating fluid is discharged through the second opening. A third opening 212 connected to the first opening and a fourth opening 214 connected to the second opening may be formed on the other surface of the cover 200. The first opening and the second opening may be formed on the lower surface of the cover 200, and the third opening 212 and the fourth opening 214 may be formed on the upper surface of the cover 200 coupled to the housing 100.

[0042] A mounting portion 210 may be provided on the upper surface of the cover 200, the mounting portion protruding upward and coupled to the space inside the can 470 described later. Therefore, the cover 200 may be understood to include a cover body and the mounting portion 210 protruding from the upper surface of the cover body. The cross section of the mounting portion 210 may be circular.

[0043] The mounting portion 210 may be coupled to the space inside the tank 470. The cross-sectional shape of the mounting portion 210 may correspond to the cross-sectional shape of the space inside the tank 470. An annular sealing member 220 for sealing may be provided between the outer surface of the mounting portion 210 and the inner surface of the space inside the tank 470. The sealing member 220 may be formed of a rubber material to prevent fluid from leaking between the outer surface of the mounting portion 210 and the inner surface of the space inside the tank 470. A groove may be formed on the outer surface of the mounting portion 210, the groove being more recessed than other areas, and the sealing member 220 is coupled to the groove.

[0044] The third opening 212 and the fourth opening 214 can be formed on the upper surface of the cover 200, and the fluid is sucked through the third opening, and the sucked fluid is discharged through the fourth opening. The fluid can be oil. The third opening 212 and the fourth opening 214 can both be formed in an arc shape, and can be arranged so that the gap between them gradually narrows as it moves from one side to the other side. More specifically, the side with a wider gap between the third openings 212 can be arranged to face the side with a wider gap between the fourth openings 214, and the side with a narrower gap between the third openings 212 can be arranged to face the side with a narrower gap between the fourth openings 214.

[0045] The third opening 212 and the fourth opening 214 may be formed on an upper surface of the mounting portion 210 .

[0046] The housing 100 may be formed of metal or plastic material, but is not limited thereto.

[0047] The pump 10 may include a motor. The motor may include a housing 100, a stator 300, and a rotor 410. The rotor 410 is a component inside the pump 10, and may also be referred to as an external gear 410.

[0048] The housing 100 may include an upper region 120 and a lower region 110. The upper region 120 may have a rectangular cross section. The lower region 110 is disposed at a lower portion of the upper region 120 and may be formed to have a circular cross section.

[0049] A second space 122 may be formed inside the upper region 120. The second space 122 may be in a groove shape. A plurality of electronic components for driving may be disposed in the second space 122. For example, a printed circuit board (not shown) and a terminal 395 may be disposed in the second space 122. A plurality of components may be mounted on the printed circuit board.

[0050] The housing 100 may include a first partition wall 101 (see FIG. 1 ) that divides an upper region 120 and a lower region 110. Figure 2 A hole to which a first protrusion portion 478 of a can 470 described later is coupled may be formed at the center of the first partition wall 101 .

[0051] A separate cover (not shown) may be coupled to the upper surface of the housing 100 to cover the second space 122. In this case, the separate cover is referred to as a second cover, and the cover 200 may be referred to as a first cover 200.

[0052] The stator 300 and the rotor 410 may be disposed in the housing 100. The rotor 410 may be disposed on the cover 200.

[0053] The stator 300 may be disposed inside the housing 100 .

[0054] When the material of the housing 100 is plastic, the stator 300 can be formed integrally with the housing 100 by double injection molding. The stator 300 and the housing 100 can be formed integrally by insert injection molding. The stator 300 can be molded inside the housing 100. A stator accommodation space for the stator 300 to be arranged therein can be formed inside the housing 100. The stator accommodation space can be arranged outside the first space 114. The outer surface of the stator 300 can be surrounded by the housing 100.

[0055] The stator 300 may include a stator core 320 and a coil 310 wound around the stator core 320. The stator 300 may include an insulator (not shown) disposed around an outer surface of the core. The coil 310 may be wound around the outer surface of the insulator.

[0056] A router 390 may be provided on an upper surface of the stator core 320 , and the coils 310 protruding upward from the stator core 320 may be aligned by the router 390 .

[0057] A bus bar 340 may be disposed on an upper surface of the router 390 , and ends of the coil 310 protruding upward from the stator core 320 may be fused to the bus bar 340 .

[0058] A terminal 395 may be provided on an upper surface of the router 390, and may have a shape protruding upward from the router 390. A printed circuit board may be electrically connected to the terminal 395.

[0059] The first space 114 may be formed at the center of the housing 100. The first space 114 may be formed at the inner side of the lower area 110. The first space 114 may be in the shape of a groove, in which a portion of the lower surface of the housing 100 is recessed upward. The arrangement area of ​​the first space 114 and the stator 300 may be separated by a second partition wall (not shown). The inner surface of the second partition wall may form the inner surface of the first space 114. In other words, the second partition wall may be provided between the stator 300 and the outer gear 410 described later. The second partition wall may be formed to have a thickness of 0.2 mm to 1 mm.

[0060] The second space 122 and the first space 114 may be partitioned in the upper and lower directions by the first partition wall 101. The lower surface of the first partition wall 101 may form the upper surface of the first space 114. The first space 114 and the second space 122 may be partitioned into different areas by the first partition wall 101. Therefore, the fluid inside the first space 114 may be prevented from flowing into the second space 122.

[0061] The rotor 410 may be disposed inside the stator 300. As described above, the rotor 410 may be referred to as an outer gear 410 as a component of the motor or a component of the pump 10. As a component of the pump 10, the gear may include an outer gear 410 and an inner gear 450. The outer gear 410 and the inner gear 450 may be disposed in the first space 114.

[0062] The rotor 410 may be disposed inside the stator 300. A second partition wall may be disposed between the rotor 410 and the stator 300. The rotor 410 includes a magnet 440, and when current is applied to the coil 310 of the stator 300, the rotor 410 may rotate by electromagnetic interaction between the stator 300 and the rotor 410.

[0063] A first hole 413 may be formed at the center of the rotor 410, and the inner gear 450 is disposed in the first hole. A plurality of peaks 412 protruding inward from the inner surface and a plurality of grooves disposed between the plurality of peaks 412 may be formed on the inner surface of the first hole 413 (see FIG. Figure 5 ). That is, a first gear in which a plurality of peaks and grooves are alternately provided on the inner circumferential surface of the first hole 413 may be formed.

[0064] The inner gear 450 may be disposed inside the rotor 410. The inner gear 450 may be disposed in the first hole 413. The rotor 410 may be referred to as an outer rotor, and the inner gear 450 may be referred to as an inner rotor.

[0065] The inner gear 450 may include a plurality of peaks 454 protruding outward from the outer surface and grooves disposed between the plurality of peaks 454 on its outer circumferential surface. A second gear may be formed on the outer surface of the inner gear 450 in which the plurality of peaks 454 and the plurality of grooves are alternately disposed.

[0066] In other words, the inner gear 450 may have a second cam having N gear teeth arranged radially outward in the circumferential direction based on the rotation center. The rotor 410 may have N+1 first cams arranged radially inward. The first cam may be arranged to be caught by the second cam. When the rotor 410 rotates, the inner gear 450 may rotate by the first cam and the second cam. Depending on the rotation of the inner gear 450, the fluid may be introduced into the space inside the tank 470 described later, or the fluid in the space inside the tank 470 may be discharged to the outside.

[0067] The rotor 410 and the internal gear 450 can rotate eccentrically. Due to the eccentricity of the rotor 410 and the internal gear 450, a volume capable of conveying fluid fuel is generated between the rotor 410 and the internal gear 450, and the increased volume portion sucks in the surrounding fluid due to reduced pressure, while the reduced volume portion discharges the fluid due to increased pressure.

[0068] The internal gear 450 and the rotor 410 may be arranged so that their centers do not coincide with each other. The rotation centers of the internal gear 450 and the rotor 410 may be different.

[0069] A hole 452 may be formed at the center of the internal gear 450 , and a shaft 250 described later may be coupled in the hole.

[0070] The pump 10 may include a tank 470. The tank 470 may be disposed in the first space 114. The tank 470 may be formed of a metal material. The tank 470 may be formed integrally with the housing 100 by double injection molding. However, this is exemplary, and the tank 470 may also be formed of a plastic material.

[0071] The can 470 may include a body portion 472 , a lower end portion 474 protruding outward from a lower end of the body portion 472 , and a first protrusion portion 478 protruding upward from an upper surface of the body portion 472 .

[0072] A space may be formed inside the body portion 472. The internal gear 450 and the rotor 410 may be disposed in the space. The cross-sectional shape of the body portion 472 may be formed to correspond to the cross-sectional shape of the first space 114. For example, the cross-sectional shape of the body portion 472 may be circular.

[0073] The lower end portion 474 may be formed to extend outward by being bent from the lower end of the body portion 472. The lower end portion 474 may be disposed between a lower surface of the housing 100 and an upper surface of the cover 200.

[0074] The first protrusion 478 may be coupled to the hole in the first partition wall 101. The cross-sectional shape of the first protrusion 478 may be formed to correspond to the cross-sectional shape of the hole. The upper end of the first protrusion 478 may protrude upward from the upper surface of the first partition wall 101.

[0075] A bearing space for accommodating a bearing 490 described later may be formed inside the first protrusion portion 478. The first protrusion portion 478 may be formed to have a smaller cross-sectional area than the body portion 472.

[0076] The tank 470 may prevent the fluid in the first space 114 from flowing into the second space 122 .

[0077] The motor may include a bearing 436. The bearing 490 may be disposed on the rotor 410. The bearing 490 may be a ball bearing. Therefore, the bearing 490 may include a ball disposed between an outer ring and an inner ring. A hole may be formed in the center of the bearing 490. The shaft 250 may be coupled to the hole. The shaft 250 may be press-fitted into the hole. The shaft 250 may be coupled to the inner ring. The outer surface of the shaft 250 may contact the inner surface of the inner ring. Therefore, when the rotor 410 rotates, the bearing 490 may support the rotation of the rotor 410. In some cases, the motor may include a support (not shown) rotatably coupled to the rotor 410, and the bearing 490 may rotate with the rotation. In this case, the bearing 490 may rotate relative to the shaft 250 by the rotation of the rotor 410.

[0078] The pump 10 may include a shaft 250. The shaft 250 may support the rotation of the rotor 410 or the internal gear 450. The shaft 250 may have a shape protruding upward from the upper surface of the cover 200. The shaft 250 may have a shape protruding upward from the upper surface of the mounting portion 210. The shaft 250 may be formed integrally with the cover 200.

[0079] The shaft 250 may include a first region 252 coupled to the inner gear 450 and a second region 254 coupled to the bearing 490. The first region 252 may be coupled to the hole 452 of the inner gear 450, and the second region 254 may be coupled to the hole of the bearing 490.

[0080] The first region 252 and the second region 254 may each have a circular cross section. The first region 252 and the second region 254 may have different centers. The center O1 of the first region 252 may be different from the center O2 of the second region 254. The first region 252 and the second region 254 may be eccentrically disposed.

[0081] The center of the first region 252 may correspond to the rotation center of the internal gear 450. The center of the second region 254 may correspond to the rotation center of the rotor 410. Therefore, the rotation of the rotor 410 and the bearing 490 may be supported with the second region 254 as the center, and the rotation of the internal gear 450 may be supported with the first region 252 as the center.

[0082] Hereinafter, the rotor 410 will be described.

[0083] The rotor 410 may be disposed inside the stator 300. The rotor 410 may be spaced 0.08 mm to 0.16 mm from the inner surface of the can 470 relative to the radial direction. When the can 470 is omitted, the rotor 410 may be spaced 0.08 mm to 0.16 mm from the stator 300 relative to the radial direction.

[0084] like Figures 5 to 7 As shown, the rotor 410 may include a rotor core including a body portion 411, a flange portion 420, a protrusion 423, and a guide portion 436. In addition, the rotor 410 may include a magnet 440 disposed on an outer surface of the body portion 411. The body portion 411, the flange portion 420, the guide portion 436, and the protrusion 423 may be formed of a metal material and formed integrally. The body portion 411, the flange portion 420, the guide portion 436, and the protrusion 423 may be formed as one body. Different from this, the material of the body portion 411, the flange portion 420, and the protrusion 423 may also be plastic.

[0085] The rotor core may be referred to as a core.

[0086] The body portion 411 may form an outer shape of the rotor 410. The body portion 411 may be formed in a ring shape, with its upper and lower surfaces opened. A first hole 413 may be formed at the center of the body portion 411, the first hole extending in the axial direction and coupled to the internal gear 450. As described above, a plurality of peaks 412 and grooves may be alternately provided on the inner circumferential surface of the first hole 413 along the circumferential direction.

[0087] A first groove 416 may be formed on the outer circumferential surface of the body portion 411, and the magnet 440 may be coupled to the first groove. The first groove 416 may have a shape that is inwardly concave from the outer surface of the body portion 411 compared to other areas. The first groove 416 may be provided in plurality and may be arranged to be spaced apart from each other along the circumferential direction of the body portion 411. The magnet 440 may be coupled to the first groove 416.

[0088] A second groove 417 may be formed on the bottom surface of the first groove 416, the second groove being formed to be more concave inward than other regions. An adhesive may be applied to the second groove 417. By the adhesive applied to the second groove 417, the inner surface of the magnet 440 may be coupled to the bottom surface of the first groove 416. At the same time, an adhesive may also be applied to the bottom surface of the first groove 416.

[0089] A guide portion 430 may be provided between the plurality of first grooves 416. The guide portion 430 may have a shape protruding outward from the outer surface of the body portion 411. The guide portion 430 may be provided between two adjacent magnets 440. When the magnet 440 is coupled to the body portion 411, an inner surface 444 of the magnet 440 may be provided to face the bottom surface of the first groove 416 in a radial direction, and a side surface of the magnet 440 may be provided to face the side surface of the guide portion 430 in a circumferential direction.

[0090] The guide portion 430 may have a polygonal cross-sectional shape. For example, the cross-sectional shape of the guide portion 430 may be a pentagon. The guide portion 430 may include a first side surface 432 , a second side surface 434 , and an outer surface 436 .

[0091] For a single guide portion 430, a first side surface 432 may be provided in plurality and arranged to face each other. The first side surface 432 may form an acute angle with the outer surface of the body portion 411. The first side surface 432 may contact the side surface 446 of the magnet 440. The first side surface 432 may form the inner surface of the first groove 416. With respect to the radial direction of the body portion 411, the first side surface 432 may be an inclined surface, the shape of which is such that the circumferential length of the first groove 416 decreases as it goes outward. With respect to the radial direction of the body portion 411, the first side surface 432 may be an inclined surface, the shape of which is such that the circumferential length of the first side surface 432 of the adjacent guide portion 430 decreases as it goes outward.

[0092] With respect to the single guide portion 430, the second side surface 434 may be provided in plurality and arranged to face each other. The second side surface 434 may be arranged outside the first side surface 432. The second side surface 434 may be spaced apart from the side surface 446 of the magnet 440. The second side surface 434 may form an inner surface of the first groove 416. With respect to the radial direction of the body portion 411, the second side surface 434 may be an inclined surface shaped such that the circumferential length of the first groove 416 increases as it goes outward.

[0093] The outer surface 436 of the guide portion 430 may be arranged to connect the plurality of second side surfaces 434. The outer surface 436 of the guide portion 430 may be a flat surface, but may be a curved surface having a predetermined curvature, as opposed to this. When the outer surface 436 of the guide portion 430 is a curved surface, the curvature of the outer surface 436 may correspond to the curvature of the bottom surface of the first groove 416, or may correspond to the curvature of the flange portion 420 described later. The outer surface 436 may be arranged to form the same plane as the outer surface of the flange portion 420. The radial length from the center of the body portion 411 to the outer surface 436 of the guide portion 430 may correspond to the radial length from the center of the body portion 411 to the outer surface 442 of the magnet 440. The radial length from the center of the body portion 411 to the outer surface 436 of the guide portion 430 may correspond to the radial length from the center of the body portion 411 to the outer surface of the flange portion 420.

[0094] The magnet 440 may be disposed in the first groove 416 between the plurality of guide portions 430. The magnet 440 may be provided in plurality and may be provided spaced apart from each other along the circumferential direction of the body portion 411. The magnet 440 may include an outer surface 442, an inner surface 444, and a side surface 446 connecting the outer surface 442 and the inner surface 444.

[0095] The side surface 446 of the magnet 440 may be disposed to face the first side surface 432 of the guide portion 430. The side surface 446 of the magnet 440 may contact the first side surface 432 of the guide portion 430. The side surface 446 of the magnet 440 and the first side surface 432 of the guide portion 430 may be inclined surfaces having shapes corresponding to each other.

[0096] An outer surface 442 of the magnet 440 may be spaced apart from the outer surface 436 of the guide portion 430 in a circumferential direction. An inner surface 446 of the magnet 440 may be coupled to a bottom surface of the first groove 416, that is, an outer circumferential surface of the body portion 411.

[0097] The rotor 410 may include a flange portion 420. The flange portion 420 may have a shape protruding radially from one end of the body portion 411. Through the flange portion 420, the rotor 410 may include a plurality of regions having different radial lengths relative to the center. The upper surface of the flange portion 420 may be arranged to face the lower surface of the magnet 440. The upper surface of the flange portion 420 may be spaced apart from the lower surface of the magnet 440. A gap G may be formed between the upper surface of the flange portion 420 and the lower surface of the magnet 440.

[0098] like Figure 7As shown, the axial length L1 of the body portion 411 may be equal to the sum of the axial length L2 of the magnet 440 , the axial length L3 of the flange portion 420 , and the axial length of the gap G.

[0099] The radial length from the center of the body portion 411 to the outer surface 436 of the guide portion 430 may correspond to the radial length from the center of the body portion 411 to the outer surface of the flange portion 420. The radial length from the center of the body portion 411 to the outer surface 442 of the magnet 440 may correspond to the radial length from the center of the body portion 411 to the outer surface of the flange portion 420. With respect to the axial direction, the length of the flange portion 420 may be shorter than the length of the guide portion 430. With respect to the axial direction, the length of the flange portion 420 may be within 15% to 40% of the length of the body portion 411 or the rotor 410.

[0100] The first groove 416 may have an inner surface defined by the side surface of the guide portion 430 and the upper surface of the flange portion 420. The magnet 440 may have both side surfaces 446 and a lower surface respectively covered by the side surface of the guide portion 430 and the upper surface of the flange portion 420, and the upper surface may be opened upward.

[0101] The rotor 410 may include a protrusion 423. The protrusion 423 may be formed to protrude from one surface of the flange portion 420 facing the magnet 440 in the axial direction. The protrusion 423 may be disposed to overlap with the magnet 440 in the axial direction. The protrusion 423 may be formed to protrude upward from the upper surface of the flange portion 420. Through the protrusion 423, the lower surface of the magnet 440 may be spaced apart from the upper surface of the flange portion 420 in the axial direction. The upper surface of the protrusion 423 may contact the lower surface of the magnet 440. With respect to the single first groove 416, the protrusion 423 may be disposed at the center of the circumference of the flange portion 420. With respect to the single first groove 416, the protrusions 423 may be disposed one by one, but differently from this, the protrusions 423 may also be disposed in a plurality of forms and spaced apart from each other.

[0102] The length of the protrusion portion 423 may be formed to be smaller than the length of the flange portion 420 with respect to the axial direction.

[0103] The area of ​​a region where the protrusion portion 423 and the magnet 440 are in contact may be smaller than the area of ​​an upper surface of the flange portion 420 facing the magnet 440 .

[0104] According to the above structure, there is an advantage in that a section having a function of a dynamic pressure bearing is formed inside the rotor by the flange portion, thereby ensuring the rotation stability of the rotor.

[0105] Furthermore, due to the magnet floating structure through the protruding portion, the magnetic force of the magnet can be easily guided to the stator, thereby having an advantage of improving the performance of the motor and the pump.

[0106] Meanwhile, in the present embodiment, the flange portion 420 is disposed at the lower end of the body portion 411 facing the cover 200, but is not limited thereto, and the flange portion 420 may be disposed at the upper end of the body portion 411 facing the bearing 490. In this case, the protrusion 423 may be formed to protrude downward from the lower surface of the flange portion 420 facing the magnet 440.

[0107] In the above description, it is described that all parts constituting the embodiment of the present invention are combined or operated as a whole, but the present invention is not necessarily limited to these embodiments. In other words, within the scope of the present invention, all parts can be selectively operated in combination with one or more parts. In addition, the terms "including", "comprising" or "having" described above mean that unless otherwise specifically stated, the corresponding parts can be inherent, and therefore should be interpreted as not excluding other parts, but also including other parts. Unless otherwise defined, all terms (including technical and scientific terms) have the same meaning as those of ordinary skill in the art are generally understood. Commonly used terms (such as terms defined in dictionaries) should be interpreted as consistent with the contextual meaning of the relevant technology, and unless clearly defined in the present invention, should not be interpreted in an ideal or overly formal sense.

[0108] The above description is only used to illustrate the technical idea of ​​the present invention, and those skilled in the art to which the present invention belongs can make various modifications and changes without departing from the essential features of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention, but to describe the present invention, and the scope of the technical idea of ​​the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent range should be interpreted as included in the scope of the present invention.

Claims

1. A motor, comprising: case; A stator is arranged inside the housing; as well as A rotor is arranged inside the stator, The rotor comprises: a rotor core including a body portion, a flange portion extending radially from a lower end of the body portion, and a protrusion portion protruding from an upper surface of the flange portion; as well as a magnet disposed on an outer surface of the body portion, and The protruding portion is disposed between the flange portion and the magnet. 2 . The motor according to claim 1 , wherein the flange portion and the magnet are spaced apart from each other with respect to an axial direction. 3 . The motor according to claim 1 , wherein a length of the flange portion is within 15% to 40% of a length of the body portion with respect to an axial direction. The motor according to claim 1 , wherein the protruding portion is in contact with the magnet. 5 . The motor according to claim 1 , wherein the rotor and the stator are spaced apart by 0.08 mm to 0.16 mm with respect to a radial direction. The motor according to claim 1 , wherein an upper surface of the magnet is exposed above the body portion. 7 . The motor according to claim 1 , comprising a guide portion protruding from an outer surface of the body portion and facing a side surface of the magnet. 8 . The motor of claim 7 , wherein the guide portion has a pentagonal cross-sectional shape.

9. The motor according to claim 7, wherein the guide portion comprises: a first side surface in contact with a side surface of the magnet; a second side surface disposed on an outer side of the first side surface and spaced apart from a side surface of the magnet; and an outer surface disposed on an outer side of the second side surface.

10. A pump comprising: case; A stator, located inside the housing; An external gear, arranged inside the stator; as well as an internal gear, arranged inside the external gear, The external gear comprises: a core including a body portion, a flange portion extending radially from a lower end of the body portion, and a protrusion portion protruding from an upper surface of the flange portion; and a magnet disposed on an outer surface of the body portion, and The protruding portion is disposed between the flange portion and the magnet.

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