Motor and pump including the motor

Abstract

The present invention may provide a motor including: a shaft; a rotor coupled to the shaft; a stator disposed to correspond to the rotor; a plate coupled to the rotor; the first bearing and the second bearing are used for supporting the plate; the rotor comprises a rotor core and a magnet arranged on the rotor core, the shaft comprises a hole, and the plate comprises a main body arranged at one side of the rotor; a first post protruding from the body toward one side thereof in the axial direction so as to be disposed in the hole; and a second post protruding toward the other side thereof in the axial direction, the first bearing being in contact with the first post and an inner wall of the hole, and the second bearing being in contact with the second post and an inner wall of the can body.

Description

Technical Field

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

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

[0003] A pump including a motor may include an external gear and an internal gear as a rotor in a housing. A shaft is disposed inside the internal gear. The internal gear is rotatably coupled to the shaft. Magnets may be disposed on an outer surface of the external gear. The magnets are disposed to face the stator, with the housing interposed between the magnets and the stator.

[0004] The housing and the external gear rotate about the shaft through electrical interaction between the magnets and the stator, and the internal gear rotates about the shaft together with the external gear.

[0005] Bearings are disposed between the external gear and the shaft. The external gear is rotatably supported by the bearings. However, since the bearings are only disposed at one side of the external gear in the axial direction, the external gear may be inclined due to tolerances of the bearings in the axial direction.

[0006] When the external gear is inclined in the axial direction due to tolerances of the bearings, an outer circumferential portion of the magnet or an outer surface of the external gear contacts an inner wall of the housing to increase frictional resistance, and thus there is a problem in that rotational stability of the external gear or the internal gear is reduced.

[0007] The housing and the external gear rotate about the shaft through electrical interaction between the magnets and the stator, and the internal gear rotates about the shaft together with the external gear.

[0008] Due to magnetic force and hydraulic pressure, loads are applied to the external gear and the internal gear in the radial direction. When the load at the pump increases, the load is concentrated in a partial region at one side of the plate where the rotor is located, and the external gear is inclined in the axial direction. When the shaft system is inclined as described above, an outer circumferential portion of the magnet or an outer surface of the external gear contacts an inner wall of the housing to increase frictional force, and thus there is a problem in that rotational stability of the external gear or the internal gear is reduced.

[0009] The external gear may be coupled to a plate, and the plate may be rotatably supported by the shaft through bearings. However, since the bearings are only disposed at one side of the external gear in the axial direction, there is a problem in that the shaft system is inclined when high hydraulic pressure is generated in the housing.

[0010] When the shaft system is inclined, the external gear is inclined in the axial direction, an outer circumferential portion of the magnet or an outer surface of the external gear contacts an inner wall of the housing to increase frictional resistance, and thus there are problems in that rotational stability of the external gear or the internal gear is reduced and efficiency of the pump rapidly decreases.

[0011] Technical problem

[0012] The present invention aims to solve the above problems and aims to provide a motor and a pump including the motor that can reduce the resistance between the external gear and the internal gear and prevent the external gear and the internal gear from tilting to ensure rotational stability.

[0013] The object of the present invention is not limited to the above object, and those skilled in the art will clearly understand other objects described above through the following description.

[0014] Technical solution

[0015] One aspect of the present invention provides a motor including: a shaft; a rotor coupled to the shaft; a stator arranged to correspond to the rotor; a plate coupled to the rotor; a first bearing and a second bearing for supporting the plate; and a can for accommodating the rotor, wherein the rotor includes a rotor core and magnets provided on the rotor core, the shaft includes a hole, the plate includes a main body provided on one side of the rotor, a first post protruding from the main body in the axial direction and arranged in the hole, and a second post protruding in the axial direction toward the other side, the first bearing contacts the first post and the inner wall of the hole, and the second bearing contacts the second post and the inner wall of the can.

[0016] Another aspect of the present invention provides a pump including: a can; a stator provided outside the can; an external gear provided in the can; an internal gear provided inside the external gear; a shaft provided inside the internal gear; a plate coupled to the shaft; and a first bearing and a second bearing for supporting the plate, wherein the shaft includes a hole, and the plate includes a main body provided on one side of the external gear, a first post protruding from the main body in the axial direction and arranged in the hole, and a second post protruding in the axial direction toward the other side, the first bearing contacts the first post and the inner wall of the hole, and the second bearing contacts the second post and the inner wall of the can.

[0017] Advantageous effects

[0018] According to an embodiment, since the motor includes the first bearing and the second bearing that respectively support the first post and the second post provided on the plate, the external gear and the internal gear are prevented from tilting with respect to the reference axial direction, and thus there are advantages of improving the rotational stability of the rotor and reducing the torque loss caused by friction with the can.

[0019] According to an embodiment, since an elastic member provided between the can and the second bearing is used to pre-compress the second bearing in the axial direction, the external gear is prevented from tilting due to the tolerance of the second bearing, and thus there is an advantage of more effectively improving the rotational stability of the rotor.

[0020] According to an embodiment, since the first bearing is installed inside the hole using the hole of the shaft, both the one side and the outer side of the rotor can be rotatably supported in a limited space, and thus there is an advantage of further improving the rotational stability of the rotor.

[0021] According to an embodiment, since the plate and the tank body are directly fixed to the shaft using a fastening member, tilting of the plate is prevented, and thus there is an advantage of preventing tilting of the shaft system.

[0022] According to an embodiment, since the vibration of the plate is minimized, there is an advantage of being able to precisely manage the tolerance between the rotor and the plate.

[0023] According to an embodiment, since the plate is directly fixed using a fastening member, rotation of the plate can be prevented.

[0024] According to an embodiment, since the bearing is installed in the first shaft and the bearing is formed to rotatably support both ends of the second shaft connected to the plate, tilting of the shaft system is prevented, and thus there is an advantage of reducing frictional resistance to improve efficiency.

[0025] According to an embodiment, since the bearing is formed to support both the one side and the other side of the second shaft in the axial direction based on the center of the rotor, there is an advantage of effectively preventing tilting of the shaft system.

[0026] According to an embodiment, since the bearing (which supports both ends of the second shaft at both ends and is arranged to be spaced apart from the inner circumferential surface of the first shaft) is easily assembled in the first shaft and the central portion of the bearing is spaced apart from the second shaft, the contact property at both ends of the second shaft is improved to more effectively prevent tilting of the shaft system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a cross-sectional view showing a pump according to an embodiment.

[0028] Figure 2 is a view showing Figure 1 the exploded view of the pump shown in

[0029] Figure 3 is a view showing Figure 1 the external gear, internal gear and cover shown in

[0030] Figure 4 is a plan view showing the cover and the shaft.

[0031] Figure 5 is an exploded view showing the external gear and the magnet.

[0032] Figure 6 is a perspective view showing the external gear and the magnet.

[0033] Figure 7is a perspective view showing an external gear including a first surface and a second surface.

[0034] Figure 8 is a cross-sectional view showing the external gear along Figure 7 line A-A.

[0035] Figure 9 is a perspective view showing a plate.

[0036] Figure 10 is a cross-sectional view showing the plate along Figure 9 line B-B.

[0037] Figures 11 to 13 is an enlarged cross-sectional view showing a pump.

[0038] Figure 14 is a cross-sectional view showing a pump according to an embodiment.

[0039] Figure 15 is a perspective view showing Figure 14 the exploded view of the pump shown in

[0040] Figure 16 is a perspective view showing Figure 14 the external gear, internal gear, and cover shown in

[0041] Figure 17 is a plan view showing the cover and the shaft.

[0042] Figure 18 is an exploded view showing the external gear and the magnet.

[0043] Figure 19 is a perspective view showing the external gear and the magnet.

[0044] Figure 20 is a perspective view showing a plate.

[0045] Figure 21 is a bottom view showing the plate.

[0046] Figure 22 is a cross-sectional view showing the shaft.

[0047] Figure 23 is a perspective view showing the tank body and the fastening member.

[0048] Figure 24 is a cross-sectional view showing the pump.

[0049] Figure 25 is a cross-sectional view showing a pump according to an embodiment.

[0050] Figure 26 is an exploded view showing the pump shown in FIG. 265.

[0051] Figure 27 is a view showing Figure 26 the external gear, internal gear and cover shown in

[0052] Figure 28 is a plan view showing the cover and the shaft.

[0053] Figure 29 is an exploded view showing the external gear and the magnet.

[0054] Figure 30 is a perspective view showing the external gear and the magnet.

[0055] Figure 31 is a perspective view showing the external gear including a first surface and a second surface.

[0056] Figure 32 is a cross-sectional view showing the external gear along Figure 31 line A-A of

[0057] Figure 33 is a perspective view showing the plate.

[0058] Figure 34 is a cross-sectional view showing the plate along Figure 33 line B-B of

[0059] Figure 35 is a cross-sectional view showing the first shaft.

[0060] Figure 36 is a view showing the second shaft and the snap ring.

[0061] Figure 37 is a cross-sectional view showing the bearing.

[0062] Figure 38 is a cross-sectional view showing the rotor. DETAILED DESCRIPTION

[0063] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0064] However, the technical spirit of the present invention is not limited to some embodiments to be described, but can be implemented in various different forms, and one or more components of the embodiments can be selectively combined, replaced and used within the scope of the technical spirit of the present invention.

[0065] In addition, unless clearly and specifically defined otherwise by the context, all terms (including technical terms and scientific terms) used herein can be interpreted as having the meanings commonly understood by those skilled in the art, and the meanings of commonly used terms such as those defined in a common dictionary will be interpreted in consideration of the context meanings of the related technology.

[0066] In addition, the terms used in the embodiments of the present invention are considered only in a descriptive sense and do not limit the present invention.

[0067] In this specification, unless the context clearly indicates otherwise, the singular forms include the plural forms, and in the case of describing "at least one (or one or more) of A, B, and C", this may include at least one combination among all possible combinations of A, B, and C.

[0068] In addition, in the description of the components of the present invention, terms such as "first", "second", "A", "B", "(a)", and "(b)" may be used.

[0069] These terms are only used to distinguish one component from another component, and the nature, order, etc. of the components are not limited by the terms.

[0070] In addition, it should be understood that when the first component is referred to as "connected", "coupled", or "linked" to the second component, such description may include both the case where the first component is directly connected, coupled, or linked to the second component and the case where the first component is connected, coupled, or linked to the second component through a third component interposed between the first component and the second component.

[0071] In addition, when the first component is described as being formed or disposed "on (above)" or "under (below)" the second component, such description includes both the case where the two components are formed or disposed in direct contact with each other and the case where one or more other components are interposed between the two components. In addition, when the first component is described as being formed "on (above) or under (below)" the second component, such description may include the case where the first component is formed on the upper side or the lower side with respect to the second component.

[0072] The "axial direction" used below is defined as the direction forming the rotation center of the rotor, the internal gear, and the external gear. The "axial direction" may be Figure 2 the direction in which the disassembled components are coupled. The "axial direction" may be defined as the vertical direction.

[0073] The "radial direction" used below is defined as the direction perpendicular to the "axial direction". The "radial direction" may be defined as the protruding direction of the convex angle from the inner surface of the external gear and the protruding direction of the convex angle from the inner surface of the internal gear.

[0074] The "circumferential direction" used below may be defined as the circumferential direction of any one of the stator, the rotor, the external gear, and the internal gear, or the circumferential direction of a region formed concentrically in the circumferential direction of any one of the stator, the rotor, the external gear, and the internal gear.

[0075] Figure 1is a cross-sectional view showing a pump according to an embodiment, Figure 2 shows Figure 1 an exploded view of the pump shown in Figure 3 and shows Figure 1 views of the external gear, internal gear, and cover shown in

[0076] Referring to Figures 1 to 3 , the housing 20 is coupled to the cover 10. The motor is disposed in an internal space formed by the cover 10 and the housing 20. The cover 10 and the housing 20 may be coupled by separate fastening members.

[0077] The cover 10 may include an inlet 11 and an outlet 12 formed in a surface facing the external gear 210 and the internal gear 220 in an axial direction. Fluid is introduced into the rotor 200 through the inlet 11, and the fluid in the rotor 200 is discharged through the outlet 12.

[0078] The shaft 100 may include a hole 110. The hole 110 is provided to extend in an axial direction. The hole 110 is a hole into which the first post 420 of the plate 400 is inserted.

[0079] The motor includes a rotor 200 and a stator 300. The stator 300 may be disposed outside the can 700, and the rotor 200 may be disposed inside the can 700. The can 700 may be a cylindrical member open on one side. The can 700 is coupled to the cover 10. An internal portion of the can 700 is a space in which fluid flows and is sealed. The inlet 11 and the outlet 12 of the cover 10 and the shaft 100 are disposed in the can 700.

[0080] The rotor 200 may include a rotor core 200A and magnets 200B. The magnets 200B may be disposed on an outer surface of the rotor core 200A. A plurality of magnets 200B may be disposed along a circumference of the rotor core 200A. In this case, the rotor core 200A may be divided into an external gear 210 and an internal gear 220. The internal gear 220 is rotatably coupled to the shaft 100. The external gear 210 is disposed outside the internal gear 220.

[0081] The stator 300 is disposed outside the can 700. Additionally, the stator 300 is fixed to the housing 20. The stator 300 may include a stator core 310, an insulator 320 mounted on the stator core 310, and a coil 330. The coil 330 may be wound around the insulator 320. The insulator 320 is disposed between the coil 330 and the stator core 310 and is used to electrically insulate the stator core 310 from the coil 330. The coil 330 causes an electrical interaction with the magnets 200B of the rotor 200.

[0082] A bus bar B may be disposed at one side of the stator 300. The bus bar B is connected to the coil 330.

[0083] The plate 400 is disposed in the tank body 700 and at one side of the rotor 200. The plate 400 is coupled to the external gear 210. Additionally, the plate 400 is rotatably coupled to the shaft 100. As the plate 400 rotates, the external gear 210 also rotates along with this rotation.

[0084] The first bearing 500 is disposed on the shaft 100 and rotatably supports the first column 420 of the plate 400.

[0085] The second bearing 600 is disposed at one side of the rotor 200. The second bearing 600 is disposed between the tank body 700 and the second column 430 of the plate 400 in the radial direction and rotatably supports the plate 400.

[0086] When the internal gear 220 rotates, the internal gear 220 has a certain eccentric structure relative to the external gear 210, and due to such eccentricity, a space for transmitting fluid is formed between the external gear 210 and the internal gear 220. That is, when the external gear 210 rotates, the pressure of the part with an increasing volume decreases, causing this part to absorb the fluid around it, and the pressure of the part with a decreasing volume increases, causing this part to discharge the fluid.

[0087] Figure 4 is a plan view showing the cover 10 and the shaft 100.

[0088] Referring to Figure 4 , the shaft 100 includes a hole 110 therein. The hole 110 is eccentrically disposed at the center C of the shaft 100. This is to generate a space between the external gear 210 and the internal gear 220 through which fluid can be transmitted.

[0089] Figure 5 is an exploded view showing the external gear 210 and the magnet 200B. Figure 6 is a perspective view showing the external gear 210 and the magnet 200B.

[0090] Referring to Figure 5 and Figure 6 , in the external gear 210, N external convex angles facing inward in the radial direction can be formed in the circumferential direction. Additionally, the external gear 210 may include a groove 213 for accommodating the magnet 200B in the outer surface. A plurality of grooves 213 are provided along the circumference of the outer surface of the external gear 210. The guide 211 is disposed between the grooves 213 in the circumferential direction. The guide 211 can be formed to protrude from the outer surface of the external gear 210 in the radial direction and can extend in the axial direction.

[0091] The side surface 211a of the guide member 211 faces the side surface of the magnet 200B disposed in the groove 213. The cross-sectional shape of the guide member 211 may be a polygonal shape. The outer surface 211b of the guide member 211 may be a flat or curved surface. When the outer surface 211b of the guide member 211 is a curved surface, the curvature of the outer surface of the guide member 211 may be the same as the curvature of the outer surface 211b of the outer gear 210. Additionally, the outer surface 211b of the guide member 211 may be formed to be connected to the outer surface of the outer gear 210 without a step. The outer gear 210 may include a protrusion 214 that contacts one surface of the magnet 200B in the axial direction. The protrusion 214 may be disposed on the inner wall of the groove 213.

[0092] Figure 7 is a perspective view showing the outer gear 210 including a first surface S1 and a second surface S2, and Figure 8 is a cross-sectional view showing the outer gear along Figure 7 line A-A.

[0093] Referring to Figure 7 and Figure 8 , the outer surface of the outer gear may include a first surface S1 and a second surface S2. The first surface S1 corresponds to the outer surface of the outer gear 210 that contacts the magnet 200B. The second surface S2 corresponds to the outer surface of the outer gear 210 that is spaced apart from the magnet 200B. The second surface S2 is disposed near the end of the outer gear 210. The first surface S1 and the second surface S2 are provided in a stepped shape.

[0094] In the outer gear 210, the outer diameter of the region where the second surface S2 is formed may be smaller than the outer diameter of the region where the first surface S1 is formed.

[0095] The second surface S2 is the surface that contacts the plate 400, that is, the surface into which the side portion 431 of the plate 400 is press-fitted.

[0096] Figure 9 is a perspective view showing the plate 400, and Figure 10 is a cross-sectional view showing the plate 400 along Figure 9 line B-B.

[0097] Referring to Figure 9 and Figure 10 , the plate 400 may include a main body 410, a first post 420, and a second post 430.

[0098] The main body 410 is disposed at one side of the rotor 200. The main body 410 may be a disk-shaped member. The main body 410 may include a side portion 431. The side portion 431 may be formed to bend vertically from the edge of the main body 410 in the axial direction. The side portion 431 may be disposed along the circumference of the main body 410. The side portion 431 is the portion that contacts the second surface S2 of the external gear 210.

[0099] The first column 420 protrudes from one side of the main body 410 in the axial direction. The first column 420 may be disposed on the central portion of the main body 410. The first column 420 is a cylindrical member. The first column 420 is disposed in the hole 110 and serves as the rotation axis of the external gear 210. The first column 420 is rotatably supported by the first bearing 500.

[0100] The second column 430 protrudes from the other side of the main body 410 in the axial direction. The second column 430 may also be disposed on the central portion of the main body 410. The second column 430 is a cylindrical member. The second column 430 is disposed outside the hole 110. The second column 430 is rotatably supported by the second bearing 600.

[0101] Meanwhile, the other surface 430a of the main body 410 may include a mounting surface 430b on which the second bearing 600 is mounted. The mounting surface 430b may be disposed close to the second column 430 and may protrude more than the other surface 430a of the main body 410.

[0102] In addition, the outer diameter D3 of the first column 420 may be smaller than the outer diameter D4 of the second column 430. The outer diameter D3 of the first column 420 disposed in the shaft 100 is smaller than the outer diameter D3 of the second column 430 disposed outside the shaft 100. In addition, the length H1 of the second column 430 in the axial direction may be smaller than the length H2 of the first column 420 in the axial direction.

[0103] Figures 11 to 13 It is an enlarged cross-sectional view showing the pump.

[0104] Referring to Figure 11 , the hole 110 is disposed in the shaft 100, and the first column 420 is disposed in the hole 110. The first bearing 500 is disposed in the hole 110 and rotatably supports the first column 420.

[0105] The second bearing 600 is coupled to the second column 430. The inner ring 620 of the second bearing 600 contacts the second column 430, and the outer ring 610 of the second bearing 600 contacts the inner wall of the tank body 700.

[0106] The first bearing 500 may include a region that does not overlap with the external gear 210 and the internal gear 220 in the radial direction. That is, the first bearing 500 may be disposed to protrude more than the external gear 210 and the internal gear 220 in the axial direction.

[0107] As described above, the first bearing 500 and the second bearing 600 rotatably support the first column 420 and the second column 430 that are the shafts of the outer gear 210, respectively. That is, since the first bearing 500 and the second bearing 600 support the two end portions of the shaft of the outer gear 210, the outer gear 210 can be prevented from tilting in the axial direction due to the tolerances of the first bearing 500 and the second bearing 600. In the case of the pump according to the present embodiment, since the outer gear 210 does not tilt in the axial direction, there are advantages that the rotational stability of the rotor 200 is improved and torque loss caused by contact between the outer gear 210 and the tank 700 does not occur.

[0108] Meanwhile, an elastic member 800, such as a washer, is disposed between the tank 700 and the second bearing 600 in the axial direction. The elastic member 800 contacts the outer ring 610 of the second bearing 600 to squeeze the second bearing 600 in the axial direction. Since the second bearing 600 is pre-squeezed in the axial direction, the tolerance of the second bearing 600 in the axial direction can be removed. Since the pressure is pre-applied to the second bearing 600 through the elastic member 800, the outer gear 210 is prevented from tilting due to the tolerance of the second bearing 600 in the axial direction.

[0109] Refer to Figure 12 , the length L1 in the axial direction between the first bearing 500 and the second bearing 600 can be greater than the length L3 of the rotor 200 core in the axial direction, and less than or equal to the sum of the following two: the length L2 of the rotor core 200A in the axial direction; and half of the sum of the length L4 of the first bearing 500 in the axial direction and the length L5 of the second bearing 600 in the axial direction.

[0110] Meanwhile, the inner surface of the side portion 431 contacts the second surface S2. The outer surface of the side portion 431 can contact the inner surface of the magnet 200B. When the side portion 431 is coupled to the outer gear 210, the plate 400 and the outer gear 210 rotate together. The side portion 431 is arranged to overlap the magnet 200B and the outer gear 210 in the radial direction.

[0111] Meanwhile, the length L6 of the side portion 431 in the axial direction (see Figure 10 ) can be less than the length L1 of the magnet 200B in the axial direction.

[0112] The length L7 of the hole 110 in the axial direction is greater than the length L2 of the outer gear 210 in the axial direction and the length L2 of the inner gear 220 in the axial direction. This is to ensure the installation space of the first bearing 500 and the sufficient length of the first column 420 to support the outer gear 210 from the outside of the outer gear 210 in the axial direction. In addition, asFigure 13 As shown in Figure 13 , the inner diameter D5 of the hole 110 may be smaller than the outer diameter D6 of the second bearing 600.

[0113] As described above, since the hole 110 of the shaft 100 is used and the first bearing 500 can be installed inside the hole 110, both one side and the other side of the rotor 200 can be rotatably supported within a limited space, and thus the rotational stability of the rotor 200 can be further improved.

[0114] Figure 14 is a cross-sectional view showing a pump according to an embodiment, Figure 15 is showing Figure 14 an exploded view of the pump shown in Figure 14 , and Figure 16 is showing Figure 14 a view of the external gear, internal gear, and cover shown in Figure 14 .

[0115] Referring to Figures 14 to 16 , the housing 1120 is coupled to the cover 1110. The motor is disposed in the internal space formed by the cover 1110 and the housing 1120. The cover 1110 and the housing 1120 may be coupled by separate fastening members. Figures 14 to 16 The cover 1110 may include an inlet 11 (see Figure 17 ) and an outlet 12 (see Figure 17 ) formed in the surfaces facing the external gear 1210 and the internal gear 1220 in the axial direction. Fluid is introduced into the rotor 200 through the inlet 1111, and the fluid in the rotor 1200 is discharged through the outlet 1112.

[0116] The cover 1110 may include an inlet 11 (see Figure 17 ) and an outlet 12 (see Figure 17 ) formed in the surfaces facing the external gear 1210 and the internal gear 1220 in the axial direction. Fluid is introduced into the rotor 200 through the inlet 1111, and the fluid in the rotor 1200 is discharged through the outlet 1112. Figure 17 ) and an outlet 12 (see Figure 17 ). Fluid is introduced into the rotor 200 through the inlet 1111, and the fluid in the rotor 1200 is discharged through the outlet 1112.

[0117] The shaft 1100 is disposed on the cover 1110. The shaft 1100 may be integrated with the cover 1110.

[0118] The motor includes a rotor 1200 and a stator 1300. The stator 1300 may be disposed outside the canister 1500, and the rotor 1200 may be disposed inside the canister 1500. The canister 1500 may be a cylindrical member with one side open. The canister 1500 is coupled to the cover 1110. The internal portion of the canister 1500 is a space where fluid flows and is sealed. The inlet 1111 and the outlet 1112 of the cover 1110 and the shaft 1100 are disposed in the canister 1500.

[0119] The rotor 1200 may include a rotor core 1200A and magnets 1200B. The magnets 1200B may be disposed on the outer surface of the rotor core 1200A. A plurality of magnets 1200B may be disposed along the circumference of the rotor core 1200A. In this case, the rotor core 1200A may be divided into an external gear 1210 and an internal gear 1220. The internal gear 1220 is rotatably coupled to the shaft 1100. The external gear 1210 is disposed outside the internal gear 1220.

[0120] The stator 1300 is disposed outside the tank body 1500. Additionally, the stator 1300 is fixed to the housing 1120. The stator 1300 may include a stator core 1310, an insulator 1320 mounted on the stator core 1310, and a coil 1330. The coil 1330 may be wound around the insulator 1320. The insulator 1320 is disposed between the coil 1330 and the stator core 1310 and is used to electrically insulate the stator core 1310 from the coil 1330. The coil 1330 causes an electrical interaction with the magnet 1200B of the rotor 1200.

[0121] The bus bar B may be disposed at one side of the stator 1300. The bus bar B is connected to the coil 1330.

[0122] The plate 1400 is disposed in the tank body 1500 and is disposed at one side of the rotor 1200. The plate 1400 is coupled to the shaft 1100.

[0123] When the internal gear 1220 rotates, the internal gear 1220 has a certain eccentric structure relative to the external gear 1210, and due to such eccentricity, a space for transmitting fluid is formed between the external gear 1210 and the internal gear 1220. That is, when the external gear 1210 rotates, the pressure in the part where the volume increases decreases, causing this part to absorb the fluid around it, and the pressure in the part where the volume decreases increases, causing this part to discharge the fluid.

[0124] Figure 17 is a plan view showing the cover 1110 and the shaft 1100.

[0125] Refer to Figure 17 , the hole 1110 is included in the shaft 1100. The hole 1110 is disposed at the center C1 of the shaft 1100. The inlet 1111 and the outlet 1112 are disposed around the shaft 1100.

[0126] Figure 18 is an exploded view showing the external gear 1210 and the magnet 1200B, and Figure 19 is a perspective view showing the external gear 1210 and the magnet 1200B.

[0127] Refer to Figure 18 and Figure 19, in the external gear 1210, N external convex corners facing inward in the radial direction can be formed in the circumferential direction. Additionally, the external gear 1210 can include a groove 1212 on its outer surface for accommodating the magnet 1200B. A plurality of grooves 1212 are arranged along the circumference of the outer surface of the external gear 1210. The guide 1211 is arranged between the grooves 1212 in the circumferential direction. The guide 1211 can be formed to protrude from the outer surface of the external gear 1210 in the radial direction and can extend in the axial direction.

[0128] The side surface 1211a of the guide 1211 faces the side surface of the magnet 1200B arranged in the groove 1212. The cross-sectional shape of the guide 1211 can be a polygonal shape. The outer surface 1211b of the guide 1211 can be a flat or curved surface.

[0129] Refer to Figure 19 , in the external gear 1210, N external convex corners facing inward in the radial direction can be formed in the circumferential direction. Additionally, the external gear 1210 forms a space 1210a in which the internal gear 1220 is located.

[0130] Figure 20 is a perspective view showing the plate 1400, and Figure 21 is a bottom view showing the plate 1400.

[0131] Refer to Figure 20 and Figure 21 , the plate 1400 is coupled to the shaft 1100 and covers the rotor 1200 in the axial direction. The first hole H11 is provided at a position eccentric with respect to the center of the plate 1400.

[0132] The plate 1400 can include a first flow path 1401 and a second flow path 1402 that are recessed and formed in the surface facing the external gear 1210 and the internal gear 1220 in the axial direction. The first flow path 1401 is arranged to correspond to the inlet 1111. The second flow path 1402 is arranged to correspond to the outlet 1112.

[0133] Figure 22 is a cross-sectional view showing the shaft 1100.

[0134] Refer to Figure 22 , the shaft 1100 can include a first part 1100A and a second part 1100B. The first part 1100A has a first outer diameter D11, and the second part 1100B extends from the first part 1100A and has a second outer diameter D21 that is smaller than the first outer diameter D11.

[0135] The stepped surface ST1 is provided at the boundary between the first part 1100A and the second part 1100B. Another surface of the plate 1400 is disposed on the stepped surface ST1. Additionally, the second part 1100B is located in the first hole of the plate 1400.

[0136] Meanwhile, the shaft 1100 includes a second hole H21 to which the fastening member 1600 is fastened. The second hole H21 is provided from the first part 1100A to the second part 1100B. Threads may be formed on the inner circumferential surface of the second hole H21 such that the fastening member 1600 can be fastened to the second hole H21 when rotated.

[0137] Figure 23 is a view showing the tank body 1500 and the fastening member 1600.

[0138] Refer to Figure 23 , the tank body 1500 includes a third hole H31 at the center. The third hole H31 is formed to pass through one surface and the other surface of the tank body 1500. Additionally, the tank body 1500 may include an inner part 1510 and an outer part 1520. The inner part 1510 is provided along the circumference of the third hole H31. The outer part 1520 may be provided outside the inner part 1510 in the radial direction. The inner part 1510 and the outer part 1520 are provided in a stepped shape.

[0139] The fastening member 1600 may be a rotary fastening member 1600, such as a bolt. The fastening member 1600 is inserted into the third hole H31 such that the head 1610 of the fastening member 1600 contacts the inner part 1510. An annular sealing member 1700 may be provided between the fastening member 1600 and the inner part 1510. During the process of fastening the fastening member 1600 to the sealing member 1700, the sealing member 1700 is compressed by the head 1610 of the fastening member 1600 to prevent hydraulic oil from leaking through the third hole H31 or foreign matters from being introduced into the tank body 1500.

[0140] Figure 24 is a cross-sectional view showing the pump.

[0141] Refer to Figure 24 , the fastening member 1600 fixes both the inner part 1510 of the tank body 1500 and the plate 1400 to the shaft 1100.

[0142] In this case, as shown in part O of Figure 24 , the head 1610 of the fastening member 1600 is provided to overlap the tank body 1500 and the plate 1400 in the axial direction.

[0143] The second part 1100B of the shaft 1100 is disposed in the first hole H11 of the plate 1400. Thus, the second part 1100B is disposed to overlap the plate 1400 in the radial direction.

[0144] The plate 1400 is placed on the stepped surface ST1 of the shaft 1100. The fastening member 1600 presses the plate 1400 while being fastened to the second hole H21, and since the plate 1400 is placed on the stepped surface ST1, the plate 1400 can be supported against the pressing force of the fastening member 1600.

[0145] The inner part 1510 of the tank 1500 contacts the plate 1400. In addition, the outer part 1520 of the tank 1500 is disposed to be spaced apart from the plate 1400 in the axial direction.

[0146] The plate 1400 may include a first surface S11 and a second surface S21. The first surface S11 is the surface that contacts the tank 1500, and the second surface S21 is the surface that is spaced apart from the tank 1500 in the axial direction.

[0147] The inner part 1510 of the tank 1500 contacts the upper part of the plate 1400, the sealing member 1700 contacts the upper part of the inner part 1510 of the tank 1500, and the head 1610 of the fastening member 1600 contacts the upper part of the sealing member 1700. In this state, when the fastening member 1600 is fastened to the second hole H21, the plate 1400 and the tank 1500 are pressed by the head 1610 of the fastening member 1600 and directly fixed to the shaft 1100.

[0148] In this case, the length L11 of the second part 1100B in the axial direction may be less than the length L21 of the plate 1400 in the axial direction, so that the second part 1100B can be formed not to contact the tank 1500.

[0149] In the state where the fastening member 1600 is fastened to the shaft 1100, the fastening member 1600 may be disposed to overlap the tank 1500, the plate 1400, and the rotor 1200 in the radial direction.

[0150] As described above, since the plate 1400 and the tank 1500 are directly fixed to the shaft 1100 using the fastening member 1600 to prevent the plate 1400 from tilting, shaft misalignment can be prevented. In addition, since the fastening member 1600 directly fixes the plate 1400, vibration or rotation of the plate 1400 is prevented, and thus there is an advantage that the tolerance between the rotor and the plate 1400 can be precisely managed.

[0151] Figure 25 is a cross-sectional view showing a pump according to an embodiment, Figure 26is an exploded view showing the pump shown in FIG. 265, and Figure 27 is a view showing Figure 26 the external gear, internal gear, and cover shown in

[0152] Referring to Figures 25 to 27 , the housing 2220 is coupled to the cover 10. The motor is disposed in the internal space formed by the cover 2210 and the housing 2220. The cover 2210 and the housing 2220 may be coupled by separate fastening members.

[0153] The cover 2210 may include an inlet 2211 (see Figure 28 ) and an outlet 2212 (see Figure 28 ) formed in the surfaces facing the external gear 2210 and the internal gear 2220 in the axial direction. Fluid is introduced into the rotor 200 through the inlet 2211, and the fluid in the rotor 200 is discharged through the outlet 2212.

[0154] The shaft 2100 is disposed on the cover 2210. The shaft 2100 may be integrated with the cover 2210.

[0155] The motor includes a rotor 2200 and a stator 2300. The stator 2300 may be disposed outside the can 2500, and the rotor 2200 may be disposed inside the can 2500. The can 1500 may be a cylindrical member with one side open. The can 2500 is coupled to the cover 2210. The internal portion of the can 2500 is a space where fluid flows and is sealed. The inlet 2211 and outlet 2212 of the cover 2210 and the shaft 2100 are disposed in the can 2500.

[0156] The rotor 2200 may include a rotor core 2200A and magnets 2200B. The magnets 2200B may be disposed on the outer surface of the rotor core 2200A. A plurality of magnets 2200B may be disposed along the circumference of the rotor core 2200A. In this case, the rotor core 2200A may be divided into an external gear 2210 and an internal gear 2220. The internal gear 2220 is rotatably coupled to the shaft 2100. The external gear 2210 is disposed outside the internal gear 2220.

[0157] The stator 2300 is disposed outside the can 2500. Additionally, the stator 2300 is fixed to the housing 2220. The stator 2300 may include a stator core 2310, an insulator 2320 mounted on the stator core 2310, and a coil 2330. The coil 2330 may be wound around the insulator 2320. The insulator 2320 is disposed between the coil 2330 and the stator core 2310 and is used to electrically insulate the stator core 2310 from the coil 2330. The coil 2330 causes an electrical interaction with the magnets 2200B of the rotor 2200.

[0158] The bus bar B2 can be disposed at one side of the stator 2300. The bus bar B2 is connected to the coil 2330.

[0159] The plate 2400 is disposed in the tank 2500 and at one side of the rotor 2200. The plate 2400 is coupled to the external gear 2210. Additionally, the plate 2400 is rotatably coupled to the shaft 2100. As the plate 2400 rotates, the external gear 2210 rotates along with the rotation.

[0160] The second shaft 2600 is coupled to the center of the plate 2400. Additionally, the second shaft 2600 can be disposed in the first shaft 2100.

[0161] The bearing 2700 is disposed on the first shaft 2100. The bearing 2700 rotatably supports the second shaft 2600.

[0162] When the internal gear 2220 rotates, the internal gear 2220 has a certain eccentric structure relative to the external gear 2210, and due to such eccentricity, a space for transmitting fluid is formed between the external gear 2210 and the internal gear 2200. That is, when the external gear 2210 rotates, the pressure of the part with an increasing volume decreases, so that this part absorbs the fluid around it, while the pressure of the part with a decreasing volume increases, so that this part discharges the fluid.

[0163] Figure 28 is a plan view showing the cover 2210 and the shaft 2100.

[0164] Refer to Figure 28 , the first hole 2110 is included in the shaft 2100. The first hole 2110 is eccentrically disposed at the center C2 of the shaft 2100. This is to generate a space through which fluid can be transmitted between the external gear 2210 and the internal gear 2220.

[0165] Figure 29 is an exploded view showing the external gear 2210 and the magnet 2200B, and Figure 30 is a perspective view showing the external gear 2210 and the magnet 2200B.

[0166] Refer to Figure 29 and Figure 30 , in the external gear 2210, N convex corners 2210b facing the inside in the radial direction can be formed in the circumferential direction. Additionally, the space 210a in which the internal gear 2220 is located is formed in the external gear 2210.

[0167] The external gear 2210 may include a groove 2212 that houses the magnet 2200B in its outer surface. A plurality of grooves 2212 are provided along the circumference of the outer surface of the external gear 2210. The guide 2211 is provided between the grooves 2213 in the circumferential direction. The guide 2211 may be formed to protrude from the outer surface of the external gear 2210 in the radial direction and may extend in the axial direction.

[0168] The side surface 2211a of the guide 2211 faces the side surface of the magnet 2200B disposed in the groove 2213. The cross-sectional shape of the guide 2211 may be a polygonal shape. The outer surface 2211b of the guide 2211 may be a flat or curved surface. When the outer surface 2211b of the guide 2211 is a curved surface, the curvature of the outer surface of the guide 2211 may be the same as the curvature of the outer surface 2211b of the external gear 2210. Additionally, the outer surface 2211b of the guide 2211 may be formed to be connected to the outer surface of the external gear 2210 without a step.

[0169] Figure 31 is a perspective view showing the external gear 2210 including the first surface S12 and the second surface S22, and Figure 32 is a cross-sectional view showing the external gear 2210 along Figure 31 line A-A.

[0170] Referring to Figure 31 and Figure 32 , the outer surface of the external gear may include a first surface S12 and a second surface S22. The first surface S12 corresponds to the outer surface of the external gear 2210 that contacts the magnet 2200B. The second surface S22 corresponds to the outer surface of the external gear 2210 that is disposed to be spaced apart from the magnet 2200B. The second surface S22 is provided near the end of the external gear 2210. The first surface S12 and the second surface S22 are provided in a stepped manner.

[0171] In the external gear 2210, the outer diameter of the region forming the second surface S22 may be smaller than the outer diameter of the region forming the first surface S12.

[0172] The second surface S22 is the surface that contacts the plate 2400, that is, the surface into which the side portion 2431 of the plate 2400 is press-fitted.

[0173] Figure 33 is a perspective view showing the plate 2400, and Figure 34 is a cross-sectional view showing the plate 2400 along Figure 33 line B-B.

[0174] Referring to Figure 33 and Figure 34, the plate 2400 may include a main body 2410, side portions 2420, and columns 2430.

[0175] The main body 2410 is disposed at one side of the rotor 2200. The main body 2410 may be a disk-shaped member. The main body 2410 may include the side portions 2420. The side portions 2420 may be formed to vertically bend from the edge of the main body 2410 in the axial direction. The side portions 2420 may be disposed along the circumference of the main body 2410. The side portions 2420 are the portions that contact the second surface S22 of the external gear 2210.

[0176] The columns 2430 protrude from one side of the main body 2410 in the axial direction. The columns 2430 may be disposed on the central portion of the main body 2410. A second hole H22 through which the second shaft 2600 passes may be disposed in the columns 2430. The columns 2430 may be used to ensure a sufficient length of the second hole H22 that can support the end of the second shaft 2600.

[0177] Figure 35 is a cross-sectional view showing the first shaft 2100.

[0178] Referring to Figure 35 , the first hole H12 of the first shaft 2100 may include a third region A32 and a fourth region A42. A step surface ST2 is disposed at the boundary in the axial direction between the third region A32 and the fourth region A42. A snap ring 2800 is placed on the step surface ST2.

[0179] Figure 36 is a view showing the second shaft 2600 and the snap ring 2800.

[0180] Referring to Figure 36 , the second shaft 2600 may have a cylindrical shape. The second shaft 2600 may include a groove 2610 provided in the outer surface. The groove 2610 is disposed along the circumference of the second shaft 2600. The snap ring 2800 is inserted into the groove 2610 of the second shaft 2600. The snap ring 2800 is placed on the step surface ST2 of the first hole H12 and is used to restrict the second shaft 2600 to prevent the second shaft 2600 from retracting in the axial direction.

[0181] Figure 37 is a cross-sectional view showing the bearing 2700.

[0182] Referring to Figure 37, the bearing 2700 can be a bearing 2700 in which the bearing surface and the journal contact each other's surfaces. The bearing 2700 can be divided into a first region A12 and a second region A22. The first region A12 is defined as the region in which its inner surface contacts the outer surface of the second shaft 2600 and its outer surface is spaced apart from the inner surface of the first shaft 2100. Additionally, the second region A22 is defined as the region in which its inner surface is spaced apart from the outer surface of the second shaft 2600 and its outer surface contacts the inner surface of the first shaft 2100.

[0183] The second region A22 can be provided in the central portion of the bearing 2700 in the axial direction. The first region A12 can be provided on each of one side and the other side of the second region A22 in the axial direction. The outer diameter of the second region A22 is larger than the outer diameter of the first region A12. The first region A12 is for rotatably supporting the second shaft 2600, and the second region A22 is for fixing the bearing 2700 to the first shaft 2100.

[0184] The length L12 of the first region A12 in the axial direction can be less than the length L22 of the second region A22 in the axial direction.

[0185] Figure 38 is a cross-sectional view showing the rotor 2200.

[0186] Referring to Figure 35 and Figure 38 , the fourth region A42 of the first hole H12 of the first shaft 2100 can be provided on the other side of the rotor 2200 in the axial direction so as not to overlap the rotor 2200 in the radial direction. Additionally, the snap ring 2800 can also be provided on the other side of the rotor 2200 in the axial direction so as not to overlap the rotor 2200 in the radial direction.

[0187] Meanwhile, the inner surface of the side portion 2431 contacts the second surface S22. The outer surface of the side portion 2431 can contact the inner surface of the magnet 2200B. The first surface S12 of the external gear 2210 contacts the inner surface of the magnet 2200B. When the side portion 2431 is coupled to the external gear 2210, the plate 2400 and the external gear 2210 rotate together. The side portion 2431 is provided to overlap the magnet 2200B and the external gear 2210 in the radial direction.

[0188] Referring to Figure 38, with the bearing 2700 disposed in the first shaft 2100, the second region A22 of the bearing 2700 is press-fitted into the inner circumferential surface of the first shaft 2100. The outer surface of the first region A12 is spaced apart from the inner circumferential surface of the first shaft 2100. Since the first region A12 is provided at both ends of the bearing 2700, when the bearing 2700 is press-fitted into the first shaft 2100, the entrance space for the bearing 2700 to enter the first shaft 2100 is ensured, and thus the bearing 2700 can be more easily press-fitted into the first shaft 2100.

[0189] One of the two first regions A12 is provided on one side in the axial direction of the center of the rotor 2200, and the other first region of the two first regions A12 is provided on the other side in the axial direction of the center of the rotor 2200. Therefore, in a state where the second region A22 provided at the center portion of the bearing 2700 is spaced apart from the outer surface of the second shaft 2600, as Figure 38 shown in the portion K1 of, the first region A12 only supports one end of the second shaft 2600, and as Figure 38 shown in the portion k2 of, the second region A22 only supports the other end of the second shaft 2600. Thus, the contact at both ends of the second shaft 2600 is improved, and therefore the second shaft 2600 can be effectively supported in the shaft system without tilting.

[0190] As described above, when the bearing 2700 directly supports the second shaft 2600 to prevent the second shaft 2600 from tilting, the tilting of the shaft system that may occur due to the hydraulic pressure in the tank can be effectively prevented. In addition, the friction generated by the contact between the outer gear and the cover can be prevented, thereby improving the efficiency of the pump.

[0191] Although all the components constituting the embodiments of the present invention have been described as being combined into one unit or operating in a combined manner, the present invention is not necessarily limited thereto. That is, one or more components can be selectively combined and operated within the scope of the present invention. In addition, since the above-described terms "comprising", "including", "having", etc. mean the presence of corresponding components unless otherwise clearly described, they should be interpreted as not excluding other components and can additionally include other components. Unless otherwise defined, all terms including technical terms and scientific terms have the same meaning as commonly understood by those skilled in the art. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless clearly defined in the present invention.

[0192] The above description is only an illustrative description of the technical spirit of the present invention, and those skilled in the art can make various changes and modifications without departing from the basic features of the present invention. Therefore, the embodiments disclosed in the present invention are only used for description rather than for limiting the spirit of the present invention, and the spirit scope of the present invention is not limited by the embodiments. The scope of the present invention should be interpreted according to the appended claims and be construed to cover all modifications and equivalents falling within the scope of the appended claims.

[0193] The embodiments can be used in various devices for transportation means, household appliances, etc.

Claims

1. A motor, comprising: a shaft; a rotor coupled to the shaft; a stator arranged to correspond to the rotor; a plate coupled to the rotor; a first bearing and a second bearing supporting the plate; and a can accommodating the rotor, wherein the rotor includes a rotor core and magnets provided on the rotor core, the shaft includes a hole, the plate includes a main body provided at one side of the rotor, a first post protruding axially from the main body toward one side and disposed in the hole, and a second post protruding toward the other side in the axial direction, the first bearing contacts the first post and the inner wall of the hole, and the second bearing contacts the second post and the inner wall of the can.

2. The motor according to claim 1, wherein: the main body includes a side portion extending toward the rotor core; and the side portion contacts the rotor.

3. The motor according to claim 2, wherein: the rotor includes the rotor core and the magnets provided on the rotor core; and the length between the first bearing and the second bearing in the axial direction is greater than the length of the rotor core of the rotor in the axial direction and less than or equal to the sum of the following two: the length of the rotor core in the axial direction; and half of the sum of the length of the first bearing in the axial direction and the length of the second bearing in the axial direction.

4. A motor, comprising: a can; a stator provided outside the can; an external gear provided in the can; an internal gear provided inside the external gear; a shaft provided inside the internal gear; a plate coupled to the shaft; and a first bearing and a second bearing supporting the plate, wherein the shaft includes a hole, the plate includes a main body provided at one side of the external gear, a first post protruding axially from the main body toward one side and disposed in the hole, and a second post protruding toward the other side in the axial direction, the first bearing contacts the first post and the inner wall of the hole, and the second bearing contacts the second post and the inner wall of the can.

5. A motor, comprising: a shaft; a rotor coupled to the shaft; a stator arranged to correspond to the rotor; a plate coupled to the shaft; a can accommodating the rotor; and a fastening member passing through the can and fastened to the shaft, wherein the head of the fastening member is arranged to: overlap the can and the plate in the axial direction and fix both the can and the plate to the shaft.

6. The motor according to claim 5, wherein: the shaft includes a first hole; the shaft includes a first portion having a first outer diameter and a second portion extending from the first portion and smaller than the first outer diameter; and the second portion is disposed in the first hole.

7. A pump, comprising: a can; a stator provided outside the can; an external gear provided in the can; an internal gear provided inside the external gear; a first shaft provided inside the internal gear; a second shaft provided inside the first shaft; a plate coupled to the second shaft; and A fastening member that passes through the tank body and is fastened to the shaft, wherein the head of the fastening member is arranged to overlap the tank body and the plate in the axial direction and fix both the tank body and the plate to the shaft.

8. A motor, comprising: A first shaft; A rotor coupled to the first shaft; A stator arranged to correspond to the rotor; A second shaft disposed in a first hole of the first shaft; A plate coupled to the second shaft; A bearing disposed in the first hole and coupled to the second shaft; And A tank body that houses the rotor, wherein the bearing includes a first region and a second region, an inner surface of the first region contacts an outer surface of the second shaft, and an outer surface of the first region is arranged to be spaced apart from an inner surface of the first shaft, an inner surface of the second region is arranged to be spaced apart from the outer surface of the second shaft, and an outer surface of the second region contacts the inner surface of the first shaft, and The first region is disposed at each of one side and the other side of the second region in the axial direction.

9. The motor according to claim 8, wherein: The second shaft includes a groove provided in the outer surface, and further includes a snap ring provided in the first shaft; and The snap ring is disposed in the groove.

10. A pump, comprising: A tank body; A stator disposed outside the tank body; An external gear disposed in the tank body; An internal gear disposed inside the external gear; A first shaft disposed inside the internal gear; A second shaft disposed inside the first shaft; A plate coupled to the second shaft; And A bearing disposed in the first shaft and coupled to the second shaft, wherein the bearing includes a first region and a second region, an inner surface of the first region contacts an outer surface of the second shaft, and an outer surface of the first region is arranged to be spaced apart from an inner surface of the first shaft, an inner surface of the second region is arranged to be spaced apart from the outer surface of the second shaft, and an outer surface of the second region contacts the inner surface of the first shaft, and The first region is disposed at each of one side and the other side of the second region in the axial direction.

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