Motor and pump including the motor

Abstract

The motor includes a housing, a stator disposed within the housing, and a rotor disposed inside the stator, the rotor including a rotor core including a main body portion, a flange portion extending radially from the lower end of the main body portion, and a protrusion portion protruding from the upper surface of the flange portion; and a magnet disposed on the outer surface of the main body portion, the protrusion portion being 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 technology]

[0002] The pump includes a motor area that generates rotational driving force and a pump area that generates hydraulic pressure. Therefore, since the motor area and the pump area in the pump are separated from each other, there is a problem that the number of parts increases and the overall size of the product becomes larger.

[0003] Generally, an EOP includes a housing, a stator disposed in the housing, an outer gear disposed in the stator, and an inner gear. The outer gear has a mounting area defined by a can disposed between the outer gear and the stator, and the inner gear has a mounting area defined by a cover coupled to the housing.

[0004] The conventional EOP has a problem that, since there is no means for supporting the load applied to the outer gear, as the working pressure inside the pump increases, the rotational stability of the outer gear or inner gear decreases due to the force applied to the pump outlet. In particular, as the driving torque of the outer gear increases when high pressure is generated inside the pump, irregular friction occurs due to rotation, which becomes a factor that hinders the performance of the pump. Summary of the Invention [Problem to be solved by the invention]

[0005] The present embodiment provides a motor and a pump including the motor, which can ensure the rotational stability of the rotor, minimize torque loss due to friction, and improve the performance of the pump. [Means for solving the problem]

[0006] The motor of this embodiment includes a housing, a stator disposed within the housing, and a rotor disposed inside the stator, the rotor including a rotor core including a main body portion, a flange portion extending radially from the lower end of the main body portion, and a protrusion portion protruding from the upper surface of the flange portion, and a magnet disposed on the outer surface of the main body portion, the protrusion portion being disposed between the flange portion and the magnet.

[0007] The flange portion and the magnet may be spaced apart from each other with respect to the axial direction.

[0008] The length of the flange portion may be within 15% to 40% of the length of the main body portion in the axial direction.

[0009] The protrusion may be in contact with the magnet.

[0010] The rotor and the stator may be spaced apart from each other by 0.08 mm to 0.16 mm in the radial direction.

[0011] An upper surface of the magnet may be exposed above the main body.

[0012] The magnet may include a guide portion that protrudes from an outer surface of the main body and faces a side surface of the magnet.

[0013] The guide portion may have a pentagonal cross section.

[0014] The guide portion may include a first side surface that contacts a side surface of the magnet, a second side surface that is disposed outside the first side surface and spaced apart from the side surface of the magnet, and an outer surface that is disposed outside the second side surface.

[0015] The pump of this embodiment includes a housing, a stator arranged in the housing, an outer gear arranged in the stator, and an inner gear arranged in the outer gear, and the outer gear includes a core including a main body portion, a flange portion extending radially from the lower end of the main body portion, and a protrusion portion protruding from the upper surface of the flange portion, and a magnet arranged on the outer surface of the main body portion, and the protrusion portion is arranged between the flange portion and the magnet. [Effects of the Invention]

[0016] This embodiment has the advantage that a section having the effect of a dynamic pressure bearing within the rotor is formed via the flange portion, thereby ensuring the rotational stability of the rotor.

[0017] Furthermore, the magnetic floating structure via the protrusions allows the magnetic force of the magnet to be easily guided to the stator, which has the advantage of improving the performance of the motor and pump. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view illustrating the appearance of a pump according to an embodiment of the present invention. [Figure 2] 1 is an exploded perspective view of a pump according to an embodiment of the present invention. [Figure 3] FIG. 2 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] 1 is a cross-sectional view of a pump according to an embodiment of the present invention. [Figure 5] 1 is a perspective view of a rotor according to an embodiment of the present invention. [Figure 6] FIG. 2 is an exploded perspective view of a rotor according to an embodiment of the present invention. [Figure 7] 1 is a cross-sectional view of a rotor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] However, the technical concept of the present invention is not limited to the described embodiments and can be realized in various different forms, and one or more of the components between the embodiments can be arbitrarily combined or substituted within the scope of the technical concept of the present invention.

[0021] Furthermore, unless otherwise clearly defined and described, terms (including technical and scientific terms) used in the embodiments of the present invention can be interpreted as meanings that are commonly understood by a person having ordinary knowledge in the technical field to which the present invention belongs, and commonly used terms, such as predefined terms, can be interpreted in light of the contextual meaning of the relevant technology.

[0022] Furthermore, the terms used in the examples of the present invention are intended to describe the examples and are not intended to limit the present invention. In this specification, the singular can include the plural unless otherwise specified in the context, and when it is stated as "A and at least one (or more) of B and C," it can include one or more of all possible combinations of A, B, and C.

[0023] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe elements of embodiments of the present invention.

[0024] Such terms are used to distinguish a component from other components, and are not intended to limit the nature, order, or sequence of the components.

[0025] It should be noted that when a component is described as being "coupled," "coupled," or "connected" to another component, it can include not only the case where the component is directly "coupled," "coupled," or "connected" to the other component, but also the case where the component is "coupled," "coupled," or "connected" by another component between the component and the other component.

[0026] Furthermore, when described as being formed or disposed "above" or "below" each component, "above" or "below" includes not only the case where two components are in direct contact with each other, but also the case where one or more other components are formed or disposed between the two components. Furthermore, when described as "above" or "below," it can include not only the meaning of the upward direction but also the meaning of the downward direction based on one component.

[0027] The "axial direction" used below is defined as the direction forming the center of rotation of the rotor, inner gear, and outer gear. The "axial direction" may also be the direction in which the exploded structure shown in FIG. 2 is joined. The "axial direction" may also be defined as the up-down direction.

[0028] The "radial direction" used below is defined as a direction perpendicular to the "axial direction" described above. The "radial direction" may also be defined as the direction in which the first lobe protrudes from the inner surface of the outer gear, and the direction in which the second lobe protrudes from the inner surface of the inner gear.

[0029] The "circumferential direction" used below may be defined as the circumferential direction of either the stator, rotor, outer gear, or inner gear, or as the circumferential direction of an area that forms an imaginary concentric circle with the circumferential direction of either the stator, rotor, outer gear, or inner gear.

[0030] Figure 1 is a perspective view illustrating 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.

[0031] 1 to 7, the pump 10 according to the embodiment of the present invention may have an outer shape formed by combining a housing 100 and a cover 200. The cover 200 may be combined with a lower surface of the housing 100. The housing 100 and the cover 200 may be threadedly combined with each other using a screw 290. The housing 100 and the cover 200 may each include a first coupling portion 112 and a second coupling portion 230 to which the screw 290 is combined. The first coupling portion 112 and the second coupling portion 230 are disposed facing each other in the vertical direction and each include a hole to which the screw 290 is combined.

[0032] The cover 200 may include openings. Specifically, one side of the cover 200 may be formed with a first opening through which fluid is drawn in and a second opening through which circulated fluid is discharged. The other side of the cover 200 may be formed with a third opening 212 connected to the first opening and a fourth opening 214 connected to the second opening. The first and second openings may be formed on a lower surface of the cover 200, and the third and fourth openings 212 and 214 may be formed on an upper surface of the cover 200 that is coupled to the housing 100.

[0033] A mounting portion 210 may be disposed on the upper surface of the cover 200, protruding upward and coupled to the space within the can 470, which will be described later. Accordingly, it will be understood that the cover 200 includes 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.

[0034] The mounting part 210 may be coupled to the space within the can 470. A cross-sectional shape of the mounting part 210 may correspond to the cross-sectional shape of the space within the can 470. A ring-shaped sealing member 220 for sealing may be disposed between the outer circumferential surface of the mounting part 210 and the inner surface of the space within the can 470. The sealing member 220 may be made of a rubber material and may prevent fluid from leaking between the outer circumferential surface of the mounting part 210 and the inner surface of the space within the can 470. The outer surface of the mounting part 210 may be recessed compared to other areas, and a groove into which the sealing member 220 is coupled may be formed.

[0035] The cover 200 may have a third opening 212 through which a fluid is drawn and a fourth opening 214 through which the drawn fluid is discharged formed on the upper surface thereof. The fluid may be oil. The third opening 212 and the fourth opening 214 may each be formed in an arc shape, and the distance between them may gradually narrow from one side to the other. More specifically, the wide-spaced side of the third opening 212 may face the wide-spaced side of the fourth opening 214, and the narrow-spaced side of the third opening 212 may face the narrow-spaced side of the fourth opening 214.

[0036] The third opening 212 and the fourth opening 214 may be formed on the upper surface of the mounting part 210 .

[0037] The housing 100 may be made of, but is not limited to, metal or plastic material.

[0038] 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 within the pump 10 and may also be referred to as an outer gear 410.

[0039] The housing 100 may include an upper area 120 and a lower area 110. The upper area 120 may have a rectangular cross section. The lower area 110 may be disposed below the upper area 120 and may have a circular cross section.

[0040] A second space 122 may be formed inside the upper area 120. The second space 122 may have a groove shape. A number of electronic components for driving may be disposed in the second space 122. For example, a printed circuit board (not shown) and terminals 395 may be disposed in the second space 122. A number of elements may be mounted on the printed circuit board.

[0041] The housing 100 may include a first partition 101 (see FIG. 2) that separates the upper area 120 and the lower area 110. A hole may be formed in the center of the first partition 101 to which a first protrusion 478 of a can 470 (described later) is coupled.

[0042] 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 may be referred to as a second cover, and the cover 200 may be referred to as a first cover 200.

[0043] A stator (300) and a rotor (410) may be disposed in the housing (100). The rotor (410) may be disposed on the cover (200).

[0044] The stator 300 may be disposed within the housing 100 .

[0045] When the housing 100 is made of plastic, the stator 300 may be integrally formed with the housing 100 by double injection. The stator 300 and the housing 100 may be integrally formed by insert injection. The stator 300 may be molded within the housing 100. A stator accommodating space in which the stator 300 is disposed may be formed within the housing 100. The stator accommodating space may be disposed outside the first space 114. The outer surface of the stator 300 may be surrounded by the housing 100.

[0046] 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) arranged to cover an outer surface of the core. The coil 310 may be wound around the outer surface of the insulator.

[0047] A router 390 may be disposed on the upper surface of the stator core 320, and the coils 310 protruding above the stator core 320 may be aligned by the router 390.

[0048] A bus bar 340 may be disposed on an upper surface of the router 390, and the ends of the coils 310 protruding above the stator core 320 may be fused to the bus bar 340.

[0049] Terminals 395 may be disposed on the upper surface of the router 390, and the terminals 395 may have a shape that protrudes upward from the router 390. The printed circuit board may be electrically connected to the terminals 395.

[0050] The first space 114 may be formed in the center of the housing 100. The first space 114 may be formed inside the lower area 110. The first space 114 may be a groove-like shape in which a portion of the lower surface of the housing 100 is recessed upward. An arrangement area of ​​the stator 300 and the first space 114 may be partitioned 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 disposed between the stator 300 and an outer gear 410 (described later). The second partition wall may be formed to a thickness of 0.2 mm to 1 mm.

[0051] The second space 122 and the first space 114 may be partitioned upward and downward by a first partition wall 101. A lower surface of the first partition wall 101 may form an 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. This prevents the fluid in the first space 114 from flowing into the second space 122.

[0052] 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 as a component of the pump 10. As a component of the pump 10, gears 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.

[0053] The rotor 410 may be disposed inside the stator 300. The second bulkhead may be disposed between the rotor 410 and the stator 300. The rotor 410 includes a magnet 440, and when a current is applied to the coil 310 of the stator 300, the rotor 410 can rotate due to electromagnetic interaction between the stator 300 and the rotor 410.

[0054] A first hole 413 in which the inner gear 450 is disposed may be formed in the center of the rotor 410. The inner circumferential surface of the first hole 413 (see FIG. 5) may be formed with a plurality of peaks 412 protruding inward from the inner circumferential surface and a plurality of valleys disposed between the peaks 412. That is, the inner circumferential surface of the first hole 413 may be formed with a first gear in which a large number of peaks and valleys are alternately disposed.

[0055] 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.

[0056] The outer circumferential surface of the inner gear 450 may include a plurality of ridges 454 protruding outward from the outer circumferential surface and a plurality of valleys disposed between the ridges 454. The outer circumferential surface of the inner gear 450 may be formed with a second gear in which a plurality of ridges 454 and a plurality of valleys are alternately disposed.

[0057] In other words, the inner gear 450 may have second lobes having N gears arranged radially outward from the center of rotation in the circumferential direction. The rotor 410 may have N+1 first lobes arranged radially inward. The first lobes may be arranged to overlap the second lobes. When the rotor 410 rotates, the inner gear 450 may be rotated by the first lobe and the second lobe. The rotation of the inner gear 450 may cause fluid to flow into a space within a can 470 (described later) or cause fluid in the space within the can 470 to be discharged to the outside.

[0058] The rotor 410 and the inner gear 450 can rotate eccentrically. Due to the eccentricity between the rotor 410 and the inner gear 450, a volume capable of transporting fluid fuel is generated between the rotor 410 and the inner gear 450. The increased volume portion draws in surrounding fluid due to a pressure drop, and the decreased volume portion discharges fluid due to an increase in pressure.

[0059] The inner gear 450 and the rotor 410 may be arranged so that their centers do not coincide with each other, and the rotor 410 and the inner gear 450 may have different rotation centers.

[0060] The inner gear 450 may have a hole 452 formed at the center thereof to which the shaft 250 (described later) is coupled.

[0061] The pump 10 may include a can 470. The can 470 may be disposed in the first space 114. The can 470 may be made of a metal material. The can 470 may be integrally formed with the housing 100 by double injection molding. However, this is merely an example, and the can 470 may also be made of a plastic material.

[0062] The can 470 may include a main body 472 , a lower end 474 protruding outward from the lower end of the main body 472 , and a first protrusion 478 protruding upward from the upper surface of the main body 472 .

[0063] A space may be formed inside the main body portion 472. The inner gear 450 and the rotor 410 may be disposed in the space. The cross-sectional shape of the main body portion 472 may be formed to correspond to the cross-sectional shape of the first space 114. As an example, the cross-sectional shape of the main body portion 472 may be circular.

[0064] The lower end portion 474 may be formed to be bent outward and extend from the lower end of the main body portion 472. The lower end portion 474 may be disposed between the lower surface of the housing 100 and the upper surface of the cover 200.

[0065] The first protrusion 478 may be coupled to a 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. An upper end of the first protrusion 478 may protrude above an upper surface of the first partition wall 101.

[0066] A bearing space for accommodating a bearing 490 (described later) may be formed inside the first protrusion 478. The first protrusion 478 may be formed to have a smaller cross-sectional area than the main body 472.

[0067] The can 470 can prevent the fluid in the first space 114 from flowing into the second space 122 .

[0068] 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. Accordingly, the bearing 490 may include balls 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 rotating the bearing 490 together with the rotor 410. In this case, the bearing 490 may rotate relative to the shaft 250 as the rotor 410 rotates.

[0069] The pump 10 may include a shaft 250. The shaft 250 may support the rotation of the inner gear 450 or the rotor 410. The shaft 250 may have a shape that protrudes upward from an upper surface of the cover 200. The shaft 250 may have a shape that protrudes upward from an upper surface of the mounting portion 210. The shaft 250 may be formed integrally with the cover 200.

[0070] The shaft 250 may include a first area 252 that is coupled to the inner gear 450 and a second area 254 that is coupled to the bearing 490. The first area 252 may be coupled to a hole 452 of the inner gear 450, and the second area 254 may be coupled to a hole of the bearing 490.

[0071] The first area 252 and the second area 254 may each have a circular cross section. The first area 252 and the second area 254 may have centers that are different from each other. The center O1 of the first area 252 may be different from the center O2 of the second area 254. The first area 252 and the second area 254 may be disposed eccentrically.

[0072] The center of the first area 252 may correspond to the rotation center of the inner gear 450. The center of the second area 254 may correspond to the rotation center of the rotor 410. Accordingly, the rotation of the bearing 490 and the rotor 410 may be supported around the second area 254, and the rotation of the inner gear 450 may be supported around the first area 252.

[0073] The rotor 410 will now be described.

[0074] The rotor 410 may be disposed inside the stator 300. The rotor 410 may be spaced apart from the inner surface of the can 470 by 0.08 mm to 0.16 mm in the radial direction. If the can 470 is omitted, the rotor 410 may be spaced apart from the stator 300 by 0.08 mm to 0.16 mm in the radial direction.

[0075] 5 to 7, the rotor 410 may include a rotor core including a main body 411, a flange 420, a protrusion 423, and a guide 436. In addition, the rotor 410 may include a magnet 440 disposed on the outer surface of the main body 411. The main body 411, the flange 420, the guide 436, and the protrusion 423 may be integrally formed using a metal material. The main body 411, the flange 420, the guide 436, and the protrusion 423 may be integrally formed using a metal material. Alternatively, the main body 411, the flange 420, and the protrusion 423 may be made of plastic.

[0076] The rotor core may be referred to as a core.

[0077] The main body 411 may form the outer shape of the rotor 410. The main body 411 may be formed in a ring shape with open top and bottom surfaces. A first hole 413 extending in the axial direction and coupled with the inner gear 450 may be formed in the center of the main body 411. As described above, a plurality of peaks 412 and valleys may be alternately arranged along the circumferential direction on the inner circumferential surface of the first hole 413.

[0078] A first groove 416 to which the magnet 440 is coupled may be formed on the outer circumferential surface of the main body 411. The first groove 416 may have a shape that is recessed inward from the outer surface of the main body 411 more than other areas. A plurality of the first grooves 416 may be provided and arranged to be spaced apart from each other along the circumferential direction of the main body 411. The magnet 440 can be coupled to the first groove 416.

[0079] A second groove 417 may be formed in the bottom surface of the first groove 416 so as to be recessed inward more than other areas. An adhesive may be applied to the second groove 417. The inner surface of the magnet 440 may be bonded to the bottom surface of the first groove 416 via the adhesive applied to the second groove 417. Meanwhile, the adhesive may also be applied to the bottom surface of the first groove 416.

[0080] A guide portion 430 may be disposed between the plurality of first grooves 416. The guide portion 430 may have a shape that protrudes outward from an outer surface of the main body portion 411. The guide portion 430 may be disposed between two adjacent magnets 440. When the magnets 440 are coupled to the main body portion 411, an inner surface 444 of the magnets 440 may be disposed to face a bottom surface of the first grooves 416 in the radial direction, and a side surface of the magnet 440 may be disposed to face a side surface of the guide portion 430 in the circumferential direction.

[0081] 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 the first side surface 432, the second side surface 434, and an outer surface 436.

[0082] The first side surfaces 432 may be provided in plurality and arranged to face each other with respect to a single guide portion 430. The first side surfaces 432 may form an acute angle with the outer surface of the main body portion 411. The first side surfaces 432 may contact the side surfaces 446 of the magnets 440. The first side surfaces 432 may form the inner surfaces of the first grooves 416. The first side surfaces 432 may be inclined surfaces such that the circumferential length of the first grooves 416 decreases toward the outside with respect to the radial direction of the main body portion 411. The first side surfaces 432 may be inclined surfaces such that the circumferential length to the first side surfaces 432 of adjacent guide portions 430 decreases toward the outside with respect to the radial direction of the main body portion 411.

[0083] The second side surfaces 434 may be provided in plurality and arranged to face each other with respect to a single guide portion 430. The second side surfaces 434 may be arranged outside the first side surfaces 432. The second side surfaces 434 may be spaced apart from a side surface 446 of the magnet 440. The second side surfaces 434 may form the inner surface of the first groove 416. The second side surfaces 434 may be inclined surfaces shaped such that the circumferential length of the first groove 416 increases outwardly with respect to the radial direction of the main body portion 411.

[0084] The outer surface 436 of the guide portion 430 may be disposed to connect the plurality of second side surfaces 434. The outer surface 436 of the guide portion 430 may be flat, or alternatively, may be a curved surface having a predetermined curvature. If the outer surface 436 of the guide portion 430 is curved, the curvature of the outer surface 436 may correspond to the curvature of the bottom surface of the first groove 416 or the curvature of the flange portion 420 (described below). The outer surface 436 may be disposed to form the same plane as the outer surface of the flange portion 420. The radial length from the center of the main body portion 411 to the outer surface 436 of the guide portion 430 may correspond to the radial length from the center of the main body portion 411 to the outer surface 442 of the magnet 440. The radial length from the center of the main body portion 411 to the outer surface 436 of the guide portion 430 may correspond to the radial length from the center of the main body portion 411 to the outer surface of the flange portion 420.

[0085] The magnet 440 may be disposed in the first groove 416 disposed between the plurality of guide portions 430. A plurality of the magnets 440 may be provided and may be spaced apart from each other along the circumferential direction of the main 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.

[0086] A side surface 446 of the magnet 440 may be disposed to face the first side surface 432 of the guide part 430. The side surface 446 of the magnet 440 may be in contact with the first side surface 432 of the guide part 430. The side surface 446 of the magnet 440 and the first side surface 432 of the guide part 430 may be inclined surfaces having shapes corresponding to each other.

[0087] An outer surface 442 of the magnet 440 may be spaced apart from an outer surface 436 of the guide part 430 in the circumferential direction. An inner surface 446 of the magnet 440 may be coupled to a bottom surface of the first groove 416, i.e., an outer peripheral surface of the body part 411.

[0088] The rotor 410 may include a flange portion 420. The flange portion 420 may have a shape that protrudes in the radial direction from one end of the body portion 411. In the flange portion 420, the rotor 410 may include a plurality of areas having different radial lengths based on the center. An upper surface of the flange portion 420 may be disposed to face a 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.

[0089] As in Figure 7, the axial length L1 of the main body portion 411 may be the same as 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.

[0090] The radial length from the center of the main body 411 to the outer surface 436 of the guide unit 430 may correspond to the radial length from the center of the main body 411 to the outer surface of the flange unit 420. The radial length from the center of the main body 411 to the outer surface 442 of the magnet 440 may correspond to the radial length from the center of the main body 411 to the outer surface of the flange unit 420. The length of the flange unit 420 may be shorter than the length of the guide unit 430 in the axial direction. The length of the flange unit 420 may be within 15% to 40% of the length of the rotor 410 or the main body 411 in the axial direction.

[0091] 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 covered by the side surface of the guide portion 430 and the upper surface of the flange portion 420, respectively, and an upper surface open upward.

[0092] The rotor 410 may include a protrusion 423. The protrusion 423 may be formed to protrude from one surface of the flange portion 420 that faces the magnet 440 in the axial direction. The protrusion 423 may be disposed to overlap 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. The lower surface of the magnet 440 may be spaced axially apart from the upper surface of the flange portion 420 via the protrusion 423. The upper surface of the protrusion 423 may contact the lower surface of the magnet 440. The protrusion 423 may be disposed at the circumferential center of the flange portion 420 with respect to a single first groove 416. Although one protrusion 423 may be disposed with respect to a single first groove 416, a plurality of protrusions 423 may be provided and spaced apart from each other.

[0093] The length of the protrusion 423 may be shorter than the length of the flange 420 in the axial direction.

[0094] The area where the protrusion 423 and the magnet 440 contact each other may be smaller than the area of ​​the upper surface of the flange 420 facing the magnet 440 .

[0095] The above-described structure has the advantage that a section having the effect of a dynamic pressure bearing within the rotor is formed via the flange portion, thereby ensuring the rotational stability of the rotor.

[0096] Furthermore, the magnetic floating structure via the protrusions allows the magnetic force of the magnet to be easily guided to the stator, which has the advantage of improving the performance of the motor and pump.

[0097] Meanwhile, in this embodiment, the flange portion 420 is disposed at the lower end of the body portion 411 facing the cover 200, but this is not limiting, 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.

[0098] Although all components constituting the embodiments of the present invention have been described above as being combined or operating in combination, the present invention is not necessarily limited to such embodiments. That is, all components may be selectively combined and operate in combination with one another within the scope of the present invention. Furthermore, unless otherwise specified, the terms "comprise," "comprise," "have," and the like used above mean that the component in question may be inherently present, and should be interpreted as including other components rather than excluding other components. All terms, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention belongs, unless otherwise defined. Commonly used terms, along with predefined terms, should be interpreted in a manner consistent with the context of the relevant art and should not be interpreted as idealized or overly formal unless expressly defined in the present invention.

[0099] The above description merely exemplifies the technical concept of the present invention, and various modifications and changes may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed herein are for illustrative purposes only and are not intended to limit the technical concept of the present invention. The scope of the present invention should be interpreted by the following claims, and all technical concepts within the scope of the claims should be interpreted as being within the scope of the present invention.

Claims

1. Housing and A stator is disposed within the housing, The rotor is disposed inside the stator, The rotor is A rotor core including a main body, a flange extending radially from the lower end of the main body, and a projection protruding from the upper surface of the flange, Includes a magnet disposed on the outer surface of the main body, A motor in which the projection is positioned between the flange 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 the axial direction.

3. The motor according to claim 1, wherein the length of the flange portion is within 15% to 40% of the length of the main body portion, with respect to the axial direction.

4. The motor according to claim 1, wherein the projection contacts the magnet.

5. The motor according to claim 1, wherein the rotor and the stator are separated by approximately 0.08 mm to 0.16 mm with respect to the radial direction.

6. The motor according to claim 1, wherein the upper surface of the magnet is exposed above the main body.

7. The motor according to claim 1, further comprising a guide portion that protrudes from the outer surface of the main body and faces the side surface of the magnet.

8. The motor according to claim 7, wherein the guide portion has a pentagonal cross-sectional shape.

9. The motor according to claim 7, wherein the guide portion includes a first side surface that contacts the side surface of the magnet, a second side surface that is located outside the first side surface and is separated from the side surface of the magnet, and an outer surface located outside the second side surface.

10. Housing and A stator is disposed within the housing, The outer gear, which is located within the stator, Includes an inner gear disposed within the outer gear, The outer gear is, A core including a main body, a flange extending radially from the lower end of the main body, and a projection protruding from the upper surface of the flange, Includes a magnet disposed on the outer surface of the main body, A pump in which the projection is positioned between the flange and the magnet.

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