electric motor

Abstract

The motor is provided, which includes: a base member; a stator coupled to the outer side of the base member; a rotor including a rotating shaft, a rotor frame coupled to the rotating shaft in an axially constrained manner, and a permanent magnet arranged on the rotor frame, the rotor being coupled to the stator in a manner capable of rotating relative to the stator; a first bearing and a second bearing respectively having an outer ring, a ball and an inner ring, the first bearing and the second bearing being arranged axially spaced apart from each other between the base member and the rotating shaft; a preload washer including an axial section having a rotating shaft hole for accommodating the rotating shaft and having a preset fixed length in the axial direction, and an elastic deformation section extending from one end of the axial section in an elastically deformable manner, the preload washer applying a preset size of preload to the inner ring of the first bearing or the inner ring of the second bearing; a fastening member threadedly coupled to the end of the rotating shaft in a manner capable of relative movement in the axial direction, so that the preload washer is elastically deformed in the axial direction.

Description

Technical Field

[0001] The present invention relates to an electric motor, and more particularly, to an electric motor capable of applying pre-load to a bearing in an axial direction. Background Art

[0002] As we all know, an electric motor (or motor) is a device that converts electrical energy into mechanical energy.

[0003] Such a motor generally includes a stator and a rotating shaft, and includes a rotor spaced apart from the stator by a predetermined air gap (AIRGAP) and rotating about the rotating shaft.

[0004] The rotating shaft is generally rotatably supported by a plurality of bearings.

[0005] The plurality of bearings are implemented by an outer ring, an inner ring concentrically arranged inside the outer ring, and a ball bearing including balls provided between the outer ring and the inner ring.

[0006] Some of the electric motors are configured to provide a fan, blades, or rotary blades (hereinafter referred to as "rotary blades") on the rotary shaft to drive the rotary blades to rotate.

[0007] However, in this prior art electric motor including rotating blades, when the rotating blades are driven, thrust acts on the bearing in the axial direction, and the gap (play) between the outer ring, balls and inner ring becomes smaller, so that the friction between the metals increases, thereby causing the life of the bearing to be significantly shortened.

[0008] In view of this problem, some electric motors, such as drone motors, use a method of assembling a thrust screw using a torque meter to apply a preload to the bearing that acts opposite to the thrust.

[0009] However, in this prior art drone motor, in the bearings spaced apart in the axial direction, preload is applied in the form of the inner ring of the upper bearing being pressed downward and the inner ring of the lower bearing being pressed upward. Therefore, during operation, if the rotating blades rotate, the preload acting on the inner ring of the upper bearing is released due to the generation of thrust, so that the clearance between the inner ring of the upper bearing and the ball is reduced, and thus there is a problem of significantly increased wear.

[0010] In addition, in this prior art drone motor, since the pre-stress of different subtle deformation energy is stored in the thread cross-section and length changes of the thrust screw, even if the tightening length of the thrust screw changes slightly, the preset pre-stress will exceed or fall short of the appropriate range, so there is a problem of difficulty in applying appropriate pre-stress (pre-pressure).

[0011] On the other hand, in consideration of such a problem, some electric motors use washers that apply an elastic force (preload) to the bearing in a direction opposite to the thrust applied when the rotary blades rotate.

[0012] However, in this prior art electric motor including a washer for applying preload, in order to apply preload to the outer ring of the bearing, a structure is provided in which the outer ring and the bearing receiving portion of the housing can slide, and a structure is provided in which the inner ring and the rotating shaft can also slide. However, during operation, the slip increases due to the relative speed difference, so that the center of the shaft system of the motor is offset, resulting in a problem of rapidly shortening the life.

[0013] In another conventional electric motor including a washer for applying preload, a flange portion is formed on a general wave washer, and the amount of preload is adjusted by changing the fastening length.

[0014] However, in such a motor including a wave washer provided with a flange portion, since a screw structure fastened to the flange portion must be formed, there are problems in that the number of parts increases and the structure becomes complicated.

[0015] Patent Document 1: KR20-0488662Y1

[0016] Patent Document 2: KR10-2019-0124667A Summary of the Invention

[0017] Therefore, an object of the present invention is to provide a motor that can suppress excessive preload from being applied to a bearing and stably maintain a predetermined preload when thrust is applied.

[0018] Another object of the present invention is to provide a motor capable of suppressing an excessive increase in the number of components and / or steps for applying preload.

[0019] Still another object of the present invention is to provide a motor capable of reducing the manufacturing cost of components for applying preload.

[0020] In order to solve the above problems, the electric motor according to the present invention is characterized in that it includes a preload washer, which is configured to elastically deform within a preset range in the axial direction and contact the inner ring of the bearing that rotatably supports the rotating shaft to apply a preset size of preload to the inner ring.

[0021] More specifically, the preload washer includes: an axial interval portion, which is provided with a rotating axial hole inside, has a fixed length in the axial direction, and one end is in contact with the inner ring of the bearing; an elastic deformation portion, which extends from the other end of the axial interval portion in the radial and axial directions respectively and has a free length, and elastically deforms in the axial direction, so as to be able to apply a preset preload to the inner ring of the bearing.

[0022] A plurality of rotating blades are provided at one end of the rotating shaft.

[0023] Here, the plurality of rotating blades are configured to generate lift when rotating, and when the lift is generated, thrust acts on the rotating shaft in the axial direction.

[0024] A fastening member is provided at the other end portion of the rotating shaft. The fastening member moves relative to the rotating shaft in the axial direction to elastically deform the preload washer in the axial direction.

[0025] Here, the free length and the fixed length of the preload washer are configured to be significantly larger than the displacement in the axial direction caused by the thrust generated by the plurality of rotating blades.

[0026] Therefore, even if thrust due to the rotation of the plurality of rotating blades acts on the inner ring, the inner ring is still pressed in the axial direction by the preload washer, so that the outer ring, balls and inner ring of the bearing can stably maintain a preset clearance suitable for rotation.

[0027] According to this structure, when the plurality of rotating blades rotate, the outer ring, ball and inner ring of the bearing can respectively maintain a preset clearance suitable for rotation, thereby suppressing the occurrence of forced wear of the outer ring, ball and inner ring caused by the change (reduction) of the clearance.

[0028] Therefore, the service life of the bearing can be extended.

[0029] Since the preload washer undergoes elastic deformation within the fixed length and the free length, it is possible to eliminate the need for tools such as a torque meter (torque measuring instrument) or a torque wrench used to apply a predetermined amount of preload.

[0030] The fastening member can be fastened quickly and easily using common tools that do not have a torque measuring function.

[0031] In one embodiment of the present invention, the electric motor includes: a base member; a stator coupled to the outer side of the base member; a rotor including a rotating shaft, a rotor frame coupled to the rotating shaft in an axially constrained manner, and a permanent magnet arranged on the rotor frame, the rotor being coupled to the stator in a manner capable of rotating relative to the stator; a first bearing and a second bearing, each having an outer ring, a ball, and an inner ring, the first bearing and the second bearing being arranged axially spaced apart from each other between the base member and the rotating shaft; a preload washer including an axial section having a rotating shaft hole for accommodating the rotating shaft and having a preset fixed length in the axial direction, and an elastic deformation section extending from one end of the axial section in an elastically deformable manner, the preload washer applying a preset size of preload to the inner rings of the first bearing and the inner rings of the second bearing; and a fastening member threadedly coupled to the end of the rotating shaft in a manner capable of relative movement in the axial direction, causing the preload washer to elastically deform in the axial direction.

[0032] The base member is formed in an annular (ring-shaped) shape.

[0033] A stator is coupled to an outer side of the base member.

[0034] The rotor is rotatably arranged outside the stator with an air gap therebetween.

[0035] The stator includes a stator core and a stator coil wound around the stator core.

[0036] The rotor includes: a rotating shaft; a rotor frame coupled to the rotating shaft in a manner constrained in an axial direction; and a permanent magnet provided on the rotor frame.

[0037] The permanent magnet is arranged concentrically with the stator core and forms the air gap.

[0038] The rotating shaft has a long length to protrude toward both sides of the rotor frame.

[0039] A plurality of rotating blades are provided at one end of the rotating shaft.

[0040] A fastening member screwed together is provided at the other end of the rotating shaft, and the fastening member moves relative to the rotating shaft in the axial direction.

[0041] The fastening member includes a screw and a washer interposed between the screw and the rotating shaft.

[0042] The rotating shaft is coupled to the base member in such a manner as to pass through the center of the base member.

[0043] A bearing supporting the rotating shaft is provided between the rotating shaft and the base member.

[0044] The bearing includes a first bearing and a second bearing spaced apart in the axial direction.

[0045] Here, the first bearing is arranged adjacent to the rotor frame, and the second bearing is arranged farther from the rotor frame than the first bearing.

[0046] Here, since the first bearing is arranged adjacent to the rotor frame, the first bearing may be referred to as a rotor frame side bearing, and since the second bearing is arranged adjacent to the end of the rotating shaft, the second bearing may be referred to as a rotating shaft end side bearing.

[0047] The first bearing and the second bearing are implemented by ball bearings including an outer ring, an inner ring concentrically disposed inside the outer ring, and a plurality of balls disposed between the outer ring and the inner ring.

[0048] Here, a bearing accommodation portion is provided inside the base member, and the bearings (the first bearing and the second bearing) are accommodated in the bearing accommodation portion.

[0049] The bearing accommodation portion includes a first bearing accommodation portion and a second bearing accommodation portion spaced apart in the axial direction.

[0050] The bearing can be pressed into the interior of the bearing receptacle.

[0051] More specifically, the outer ring of the first bearing may be pressed into the interior of the first bearing accommodation portion.

[0052] The outer ring of the second bearing can be pressed into the interior of the second bearing receptacle.

[0053] The base member is provided with an outer ring support portion that supports the outer ring of the bearing in the axial direction.

[0054] The outer ring support portion includes a first bearing outer ring support portion supporting the outer ring of the first bearing.

[0055] The outer ring support portion includes a second bearing outer ring support portion supporting the outer ring of the second bearing.

[0056] The preload washer is configured to have a preset fixed length and a free length, and is elastically deformable in the axial direction within the fixed length and the free length.

[0057] Therefore, the use of a separate tool capable of measuring torque for elastically deforming the prestressing washer in the axial direction can be eliminated.

[0058] Therefore, the preload washer can be elastically deformed in the axial direction using a common tool without a torque measuring function.

[0059] The preload washer is configured to be able to contact the inner ring of the first bearing or the inner ring of the second bearing in the axial direction.

[0060] The preload washer may be coupled to the rotating shaft to contact the first bearing or the second bearing.

[0061] In one embodiment of the present invention, the rotor frame is disposed on an upper side of the first bearing in the axial direction.

[0062] A plurality of rotating blades are provided at the upper end of the rotating shaft, and the fastening member is provided at the lower end of the rotating shaft.

[0063] When the plurality of rotary blades rotate, thrust is generated in the axially upward direction.

[0064] The preload washer is configured to include a first preload washer inserted between the rotor frame and the inner ring of the first bearing.

[0065] The first preload washer is constructed to include: an axial interval portion having the fixed length in the axial direction, one end of which is capable of contacting the inner ring of the first bearing, and the other end of which is capable of contacting the rotor frame; and an elastic deformation portion, which is formed to extend from the end of the axial interval portion in the radial and axial directions respectively and has a free length, and contacts the rotor frame.

[0066] Here, in an initial stage of tightening of the tightening member, the elastic deformation portion is in contact with the rotor frame within the free length.

[0067] When the fastening member is completely fastened, the elastic deformation portion is elastically deformed in the axial direction to be aligned with the fixed length, and the other end portion of the shaft section contacts the rotor frame.

[0068] Therefore, the reaction force of the fastening member is greatly increased, and the operator can clearly and easily recognize (perceive) this and terminate the fastening of the fastening member.

[0069] Here, the shaft section portion has a cylindrical shape in which the rotation shaft hole is formed.

[0070] Contact portions protruding in the radial direction and extending in the circumferential direction are respectively formed at both axial ends of the shaft section.

[0071] Here, any one of the contact portions formed at both ends of the shaft section portion increases a reaction force when the fastening member is fastened to restrict the fastening of the fastening member, and thus the contact portion may be referred to as a stopper.

[0072] In one embodiment of the present invention, the elastic deformation portion is composed of a plurality of elastic deformation portions spaced apart from each other along the circumferential direction of the rotor.

[0073] Therefore, by adjusting the size (width and length) and number of the elastic deformation parts, the magnitude of the elastic deformation force (preload) can be easily adjusted.

[0074] The preload washer includes an annular portion connecting end portions (outer end portions) of a plurality of the elastic deformation portions.

[0075] A groove is formed between the elastic deformation portions adjacent to each other in the circumferential direction.

[0076] In one embodiment of the present invention, the first preload washer includes a rotor frame contact portion, the rotor frame contact portion is connected to ends of the plurality of elastic deformation portions and has a circular ring shape, and the rotor frame contact portion is in contact with the rotor frame.

[0077] Therefore, the preload acting between the rotor frame and the inner ring of the bearing can be uniformly applied to the inner ring.

[0078] In one embodiment of the present invention, the rotor frame is disposed on a lower side of the second bearing.

[0079] Here, a plurality of rotating blades are provided at the lower end of the rotating shaft, and the fastening member is provided at the upper end of the rotating shaft.

[0080] When the plurality of rotary blades rotate, thrust is generated in the axially upward direction.

[0081] The preload washer is configured to include a second preload washer inserted between the fastening member and the inner ring of the second bearing.

[0082] In one embodiment of the present invention, the second preload washer includes: an axial interval portion having the fixed length in the axial direction, one end of which is capable of contacting the inner ring of the second bearing, and the other end of which is capable of contacting the fastening member; and an elastic deformation portion, which is formed to extend from the end of the axial interval portion in the radial and axial directions respectively and has a free length, and contacts the fastening member.

[0083] Here, the second preload washer includes an inner ring contact portion that protrudes radially from the shaft interval portion and contacts the inner ring of the second bearing.

[0084] In one embodiment of the present invention, the rotor frame is disposed on an upper side of the first bearing in the axial direction.

[0085] A plurality of rotating blades are provided at the upper end of the rotating shaft, and the fastening member is provided at the lower end of the rotating shaft.

[0086] Here, when the plurality of rotary blades rotate, thrust is generated in the axially upward direction.

[0087] The preload washer is configured to include a third preload washer inserted between the inner ring of the second bearing and the fastening member.

[0088] In one embodiment of the present invention, the third preload washer includes: an axial interval portion, which has the fixed length in the axial direction, one end of which can contact the fastening member, and the other end of which can contact the end of the rotating shaft; and an elastic deformation portion, which is formed to extend from the axial interval portion in the radial and axial directions respectively and has a free length, and contacts the inner ring of the second bearing.

[0089] In one embodiment of the present invention, the elastic deformation part is composed of a plurality of parts spaced apart along the circumference of the rotor, and the third preload washer includes an inner ring contact part, which connects the ends of the plurality of elastic deformation parts and contacts the inner ring of the second bearing.

[0090] In one embodiment of the present invention, the third preload washer includes a skirt portion, and the skirt portion extends axially from the inner ring contact portion.

[0091] In one embodiment of the present invention, the pre-compression washer includes a first partial pre-compression washer and a second partial pre-compression washer coupled to each other in the axial direction.

[0092] Therefore, the configuration of the apparatus for manufacturing the preload washer can be simplified.

[0093] In one embodiment of the present invention, it includes: a first partial shaft interval portion, which forms a part of the fixed length along the axial direction and is coupled to the rotating shaft; and an elastic deformation portion, which is formed to extend radially and axially from the first partial shaft interval portion and has a free length, and is capable of elastic deformation in the axial direction.

[0094] The second partial preload washer includes: a second partial shaft section coupled to the rotating shaft in a manner of cooperating with the first partial shaft section in the axial direction to form the fixed length; and a contact portion extending radially from the second partial shaft section.

[0095] In one embodiment of the present invention, an engaging portion is provided in the first partial shaft section and the second partial shaft section, and the engaging portion enables the first partial shaft section and the second partial shaft section to engage in a manner of overlapping in the axial direction and constraining in the circumferential direction.

[0096] The engaging portion is constructed to include: a protrusion that protrudes axially from any one of the surfaces of the first partial shaft interval portion and the second partial shaft interval portion that contact each other; and a protrusion accommodating portion that is formed to be able to accommodate the protrusion in the other one of the surfaces of the first partial shaft interval portion and the second partial shaft interval portion that contact each other.

[0097] Here, the first partial pre-compression washer and the second partial pre-compression washer may be made of different materials.

[0098] Specifically, the first partial preload washer including the elastic deformation portion is made of a material having a larger elastic modulus than that of the second partial preload washer.

[0099] As an example, the first portion of the preload washer is made of spring steel, and the second portion of the preload washer can be made of ordinary steel.

[0100] Therefore, the amount of material having a relatively large elastic modulus used can be reduced.

[0101] Therefore, compared with making the entire preload washer from a material with a large elastic modulus, the number of steps for manufacturing the material with a large elastic modulus can be reduced, thereby facilitating manufacturing.

[0102] In addition, the overall manufacturing cost of the preload washer can be reduced.

[0103] In one embodiment of the present invention, the second partial preload washer is provided with a first partial shaft section accommodating portion, and the first partial shaft section accommodating portion can accommodate the first partial shaft section of the first partial preload washer in the axial direction.

[0104] Therefore, deformation of the first partial shaft section portion can be suppressed.

[0105] In one embodiment of the present invention, an end portion of the first partial shaft section accommodating portion contacts the elastic deformation portion in the axial direction so as to support the elastic deformation portion when the elastic deformation portion is elastically deformed.

[0106] Here, the first partial preload washer including the elastic deformation portion is made of a material having a larger elastic coefficient than that of the second partial preload washer. Specifically, the first partial preload washer is made of spring steel, and the second partial preload washer is made of ordinary steel.

[0107] Therefore, the amount of material having a relatively large elastic modulus used can be reduced.

[0108] Therefore, compared with manufacturing the entire preload washer from a material having a large elastic modulus, the number of steps for manufacturing the material having a large elastic modulus can be reduced, thereby facilitating manufacturing.

[0109] In addition, the overall manufacturing cost of the preload washer can be reduced.

[0110] As described above, according to one embodiment of the present invention, a preload washer is provided, which has a preset fixed length and a free length in the axial direction and is capable of elastically deforming within the free length and the fixed length, thereby eliminating the need for a device and / or tool with a torque adjustment function during tightening.

[0111] Furthermore, even when thrust is applied in the axial direction, the outer ring, balls, and inner ring of the bearing can each maintain a predetermined clearance, thereby reducing forced wear of the bearing caused by changes in the clearance and thereby extending the service life of the bearing.

[0112] Furthermore, the rotor frame is axially positioned above the first bearing, and the preload washer comprises a first preload washer inserted between the rotor frame and the inner ring of the first bearing. This allows the inner ring of the first bearing to be axially compressed even under the thrust generated by the rotation of the rotor frame, thereby suppressing changes in the preset clearance between the outer ring, balls, and inner ring of the first bearing. Consequently, the service life of the first bearing can be extended.

[0113] Furthermore, the rotor frame is axially positioned below the second bearing, and the preload washer includes a second preload washer inserted between the fastening member and the inner ring of the second bearing. This allows the inner ring of the second bearing to be axially compressed even under the thrust generated by rotation of the rotor frame, thereby suppressing changes in the preset clearance between the outer ring, balls, and inner ring of the second bearing. Consequently, the service life of the second bearing can be extended.

[0114] Furthermore, the rotor frame is axially positioned above the first bearing, and the preload washer includes a third preload washer inserted between the inner ring of the second bearing and the fastening member. This allows the inner ring of the second bearing to be axially compressed even under the thrust generated by rotation of the rotor frame, thereby suppressing changes in the preset clearance between the outer ring, balls, and inner ring of the second bearing. Consequently, the service life of the second bearing can be extended.

[0115] Furthermore, the preload washer includes a first preload washer portion and a second preload washer portion that are coupled to each other in the axial direction, thereby enabling the preload washer to be manufactured in a partially separated manner. This simplifies the structure of the equipment used to manufacture the preload washer and facilitates manufacturing.

[0116] In addition, the first partial preload washer is configured to include an elastic deformation portion, and the second partial preload washer is made of a material having a smaller elastic coefficient than that of the first partial preload washer, thereby reducing the amount of material with a large elastic coefficient used.

[0117] Therefore, the material cost of the material having a large elastic modulus can be reduced.

[0118] In addition, the number of manufacturing steps for materials with a large elastic modulus can be reduced, thereby facilitating manufacturing.

[0119] Furthermore, an engaging portion may be provided to engage the first and second partial preload washers so as to overlap in the axial direction and constrain them in the circumferential direction, thereby suppressing play between the first and second partial preload washers in the axial and circumferential directions.

[0120] In addition, the second partial preload washer may include a first partial shaft section receiving portion for receiving the first partial shaft section portion of the first partial preload washer, thereby stably supporting the first partial preload washer.

[0121] In addition, the end portion of the first partial shaft section accommodating portion may be in contact with the elastic deformation portion in the axial direction, thereby suppressing unnecessary deformation of the elastic deformation portion when the elastic deformation portion is elastically deformed. BRIEF DESCRIPTION OF THE DRAWINGS

[0122] Figure 1 This is a cross-sectional view of a motor according to an embodiment of the present invention.

[0123] Figure 2 yes Figure 1 Magnified view of the first preload washer area.

[0124] Figure 3 yes Figure 1 Plan view of the preload washer.

[0125] Figure 4 yes Figure 3 Partial cross-sectional view of the preload washer.

[0126] Figure 5 yes Figure 4 An enlarged cross-sectional view of the preload washer.

[0127] Figure 6 It shows Figure 2 Diagram of the initial bonded free length of a preloaded washer.

[0128] Figure 7 It shows Figure 2 Figure 2 shows the thrust acting on the preload washer.

[0129] Figure 8 (a) to (h) are views each showing a preload washer for a motor according to another embodiment of the present invention.

[0130] Figure 9 is a cross-sectional view of a motor according to another embodiment of the present invention.

[0131] Figure 10 yes Figure 9 Magnified view of the second preload washer area.

[0132] Figure 11 It shows Figure 9 Diagram of the free length of the second preload washer at the initial stage of tightening.

[0133] Figure 12 It shows Figure 9 Figure 2 shows the second preload washer after the thrust is applied.

[0134] Figure 13 is a cross-sectional view of a motor according to another embodiment of the present invention.

[0135] Figure 14 yes Figure 13 Magnified view of the third preload washer area.

[0136] Figure 15 yes Figure 13 A perspective view of the third preload washer.

[0137] Figure 16 yes Figure 15 Partial cross-sectional view of the third preload washer.

[0138] Figure 17 yes Figure 16 An enlarged cross-sectional view of the third preload washer.

[0139] Figure 18 It shows Figure 16 Diagram of the free length of the third preload washer at the initial stage of tightening.

[0140] Figure 19 It shows Figure 16 Diagram of the thrust effect of the third preload washer.

[0141] Figure 20 is a cross-sectional view of a motor according to another embodiment of the present invention.

[0142] Figure 21 yes Figure 20 Magnified view of the preload washer area.

[0143] Figure 22 yes Figure 21 A partial cross-sectional view of a first partial preload washer and a second partial preload washer before being combined.

[0144] Figure 23 yes Figure 22 An enlarged cross-sectional view of the first portion of the preload washer and the second portion of the preload washer when combined.

[0145] Figure 24 is a cross-sectional view of a motor according to another embodiment of the present invention.

[0146] Figure 25 yes Figure 24 Magnified view of the preload washer area.

[0147] Figure 26 yes Figure 25 A partial cross-sectional view of a first partial preload washer and a second partial preload washer before being combined.

[0148] Figure 27 yes Figure 26 An enlarged cross-sectional view of the first portion of the preload washer and the second portion of the preload washer when combined.

[0149] Figure 28 It shows Figure 26 Diagram of the initial combined free lengths of the first and second preloaded washers.

[0150] Figure 29 It shows Figure 26 Diagram of the thrust action of the first and second preload washers. DETAILED DESCRIPTION

[0151] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. In this specification, even in different embodiments, the same or similar configurations are given the same reference marks, and the description is replaced by the first description. In addition, unless the context clearly stipulates otherwise, expressions in the singular include expressions in the plural. When describing the embodiments disclosed in this specification, when it is judged that the specific description of the relevant known technology may make the gist of the embodiments disclosed in this specification unclear, its detailed description will be omitted. In addition, it should be noted that the drawings are provided to facilitate the understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited to the drawings.

[0152] Figure 1 is a cross-sectional view of a motor according to an embodiment of the present invention, Figure 2 yes Figure 1 A magnified view of the first preload washer area. Figure 1 As shown, the motor of this embodiment includes a stator 150 , a rotor 200 , a rotating shaft 210 , a bearing 300 , and a preload washer 400 .

[0153] The motor of this embodiment is implemented as a so-called outer rotor type motor in which the rotor 200 is rotatably provided outside the stator 150 .

[0154] The stator 150 is formed in a cylindrical shape.

[0155] A base member 110 is provided inside the stator 150 .

[0156] The base member 110 is formed in a cylindrical shape.

[0157] The stator 150 may be supported by the base member 110 .

[0158] The stator 150 includes, for example, a stator core 160 and a stator coil 170 wound around the stator core 160 .

[0159] The stator core 160 includes a plurality of teeth 165 spaced apart in the circumferential direction.

[0160] The stator core 160 includes a plurality of slots 167 formed between the plurality of teeth 165 .

[0161] The plurality of teeth 165 and grooves 167 are alternately formed along the circumferential direction.

[0162] A base member receiving portion 163 is formed through the stator core 160 so that the base member 110 can be inserted into the base member receiving portion 163 in the axial direction.

[0163] The rotor 200 includes, for example, a rotation shaft 210 and a rotor frame 220 that rotates about the rotation shaft 210 .

[0164] The rotor 200 includes permanent magnets 240 disposed on the rotor frame 220 .

[0165] The permanent magnet 240 may be formed, for example, as a plurality of permanent magnets 240 spaced apart from each other along the circumference of the rotor frame 220 .

[0166] In this embodiment, the case where the permanent magnet 240 is formed as a plurality of permanent magnets 240 spaced apart in the circumferential direction is taken as an example, but this is only an example and is not limited thereto.

[0167] The permanent magnet 240 may be formed in a cylindrical shape, and may be formed so that different magnetic poles (N pole, S pole) are alternately arranged in a circumferential direction.

[0168] The rotor frame 220 includes a permanent magnet support portion 245 that supports the permanent magnet 240 .

[0169] The permanent magnet support portion 245 may be formed in a cylindrical shape, for example.

[0170] The permanent magnet support portion 245 can be made of, for example, magnetic material to form a magnetic circuit.

[0171] The permanent magnet support portion 245 may be formed by, for example, laminating a plurality of annular electrical steel plates 247 in an insulated manner.

[0172] On the inner surface of the permanent magnet support portion 245 , for example, a plurality of permanent magnets 240 may be arranged at predetermined intervals.

[0173] A protruding end portion 245 a protruding toward one side of the permanent magnet 240 in the axial direction is provided at one end portion of the permanent magnet support portion 245 .

[0174] The rotor frame 220 may include, for example, a rotating shaft coupling portion 222 for accommodating and coupling the rotating shaft 210 , and a disk portion 230 extending radially around an outer periphery of the rotating shaft coupling portion 222 .

[0175] The rotation shaft coupling portion 222 is formed to protrude from the disk portion 230 in the axial direction toward one side (the lower side in the drawing).

[0176] A rotating shaft receiving hole 224 is provided inside the rotating shaft coupling portion 222 . The rotating shaft receiving hole 224 passes through the rotating shaft coupling portion 222 in the axial direction to receive the rotating shaft 210 .

[0177] The disk portion 230 , for example, includes a radial section 231 extending radially from the rotation shaft coupling portion 222 and an axial section 235 protruding axially from the radial section 231 .

[0178] A plurality of through holes 233 are provided in the disk portion 230 (the radial section 231 ), and the plurality of through holes 233 axially penetrate the disk portion 230 . Therefore, the inside and outside of the rotor frame 220 can communicate with each other.

[0179] A cutout portion 237 cut out in the radial direction is provided in the axial section 235 , so that the permanent magnet support portion 245 can be coupled to the cutout portion 237 .

[0180] The protruding end portion 245 a of the permanent magnet supporting portion 245 is coupled to the cutout portion 237 to be fixed and supported.

[0181] On the other hand, the rotating shaft 210 and the rotor frame 220 are coupled to each other in an axial direction in a constrained manner.

[0182] In a region where the rotating shaft 210 and the rotor frame 220 contact each other, a radially projecting protrusion 215 is formed on the rotating shaft 210 side, and a receiving portion 226 for receiving the protrusion 215 is formed on the rotor frame 220 side.

[0183] In this embodiment, the protrusion 215 may be formed, for example, to protrude radially outward from the outer surface of the rotating shaft 210 and extend circumferentially.

[0184] The accommodation portion 226 may be communicated with the rotation shaft accommodation hole 224 inside the rotation shaft coupling portion 222 , and may be formed in a cylindrical shape that expands radially outward and extends circumferentially.

[0185] The accommodation portion 226 is formed to be open outward in the axial direction.

[0186] Therefore, the protrusion 215 can be accommodated in the accommodation portion 226 in the axial direction and constrained in one axial direction (insertion direction).

[0187] The rotating shaft 210 is configured to protrude toward both sides of the rotor frame 220 .

[0188] A plurality of rotary blades 140 are provided at one end portion (an upper end portion in the drawing) of the rotary shaft 210 .

[0189] The plurality of rotating blades 140 protrude radially from the outer circumference of the hub 141 .

[0190] The hub 141 is provided with a coupling portion 143 to couple with the rotating shaft 210. Although not specifically shown in the figures, coupling means that can couple in the axial direction and be constrained in the circumferential direction may be provided in the coupling portion 143 and the rotating shaft 210.

[0191] A fastening member 260 is provided at the other end portion (the lower end portion in the drawing) of the rotating shaft 210 . The fastening member 260 is screwed together so as to be movable relative to the rotating shaft 210 in the axial direction.

[0192] The fastening member 260 includes, for example, a screw 270 having an external thread and a washer 262 interposed between the screw 270 and the rotating shaft 210 .

[0193] The screw 270 is configured to include, for example, a body 272 having the external thread 274 provided on an outer surface thereof, and a head 276 extending from an end of the body 272 .

[0194] The head portion 276 is provided with a tool coupling portion 277 to enable coupling of a tool.

[0195] The tool engaging portion 277 is configured to be recessed in the axial direction to allow a screwdriver or a wrench to be inserted into the tool engaging portion 277. The tool engaging portion 277 may be formed as a groove having a "+" shape, a "-" shape, or a hexagonal shape in the axial direction.

[0196] The rotating shaft 210 may be formed in the shape of a hollow body (tube) having a through hole 212 extending therethrough in the axial direction.

[0197] An internal thread portion 214 that can be threadedly engaged with the screw 270 is provided inside the rotating shaft 210 .

[0198] The rotating shaft 210 may be rotatably supported by a bearing 300 , for example.

[0199] The bearing 300 may be composed of a plurality of bearings 300 spaced apart in the axial direction, for example.

[0200] The bearing 300 may include a first bearing 300 a and a second bearing 300 b spaced apart in the axial direction.

[0201] The bearing 300 includes, for example, an outer ring 301 , an inner ring 302 concentrically disposed inside the outer ring 301 , and a plurality of balls 303 disposed between the outer ring 301 and the inner ring 302 . That is, the bearing 300 is constituted by a ball bearing.

[0202] Each bearing 300 may be configured to include, for example, a blocking member 304 (shielding member or sealing member) that axially blocks the narrow gap between the outer ring 301 and the inner ring 302. Lubricant (grease) may be injected into the outer ring 301, the inner ring 302, and the blocking member 304.

[0203] Here, each of the bearings 300 (the first bearing 300a and the second bearing 300b) can be constructed so that the outer ring 301, the balls 303, and the inner ring 302 have axial clearance (hereinafter referred to as "post-assembly clearance") after assembly.

[0204] Each of the bearings 300 (the first bearing 300 a and the second bearing 300 b ) may have a clearance (hereinafter referred to as “post-tightening clearance”) in which a preload of a predetermined magnitude is applied after the preload washer 400 is tightened.

[0205] More specifically, for example, the post-assembly clearance may be configured such that the outer ring 301 , the balls 303 , and the inner ring 302 are pressed in the axial direction and have a relatively small clearance.

[0206] The post-fastening clearance may be configured to have a larger clearance than the post-assembly clearance, so that the outer ring 301 , the balls 303 , and the inner ring 302 can rotate smoothly after the preload is applied.

[0207] Therefore, the outer ring 301, ball 303 and inner ring 302 of the bearing 300 have a clearance suitable for rotation (the clearance after tightening), thereby suppressing the increase in forced wear of the outer ring 301, ball 303 and inner ring 302 caused by the change (reduction) of the clearance of the bearing 300.

[0208] On the other hand, a bearing accommodation portion 120 is provided inside the base member 110 , and the bearing 300 is accommodated in the bearing accommodation portion 120 .

[0209] The bearing accommodating portion 120 includes a first bearing accommodating portion 121 , and the first bearing 300 a is accommodated in the first bearing accommodating portion 121 .

[0210] The bearing accommodating portion 120 includes a second bearing accommodating portion 122 , and the second bearing 300 b is accommodated in the second bearing accommodating portion 122 .

[0211] In this embodiment, the bearing 300 may be press-fitted into the bearing accommodation portion 120 .

[0212] Therefore, the outer ring 301 of the bearing 300 can be tightly fixed to the inner surface of the bearing accommodation portion 120 .

[0213] A bearing outer ring support portion 130 is provided inside the base member 110 , and the bearing outer ring support portion 130 supports the outer ring 301 of the bearing 300 in the axial direction.

[0214] In this embodiment, the bearing outer ring support portion 130 is axially disposed between the first bearing 300 a and the second bearing 300 b .

[0215] The bearing outer ring support portion 130 is configured to prevent the outer ring 301 of the first bearing 300 a and the outer ring 301 of the second bearing 300 b from approaching each other in the axial direction.

[0216] The bearing outer ring support portion 130 , for example, includes a first bearing outer ring support portion 131 that supports the outer ring 301 of the first bearing 300 a .

[0217] The bearing outer ring support portion 130 includes, for example, a second bearing outer ring support portion 133 that supports the outer ring 301 of the second bearing 300 b .

[0218] The first bearing outer ring support portion 131 is, for example, axially disposed on one side (the lower side in the drawing) of the outer ring 301 of the first bearing 300 a .

[0219] Therefore, the outer ring 301 of the first bearing 300 a can be suppressed from moving downward in the axial direction.

[0220] The second bearing outer ring support portion 133 is, for example, provided on the other side (upper side in the drawing) of the outer ring 301 of the second bearing 300 b in the axial direction.

[0221] Therefore, the outer ring 301 of the second bearing 300 b can be suppressed from moving upward in the axial direction.

[0222] On the other hand, the preload washer 400 includes: an axial section portion 410 having a rotating shaft hole 412 for accommodating the rotating shaft 210 and having a preset fixed length L1 along the axial direction; and an elastic deformation portion 430 extending from one end of the axial section portion 410 in an elastically deformable form.

[0223] The preload washer 400 is configured to apply a predetermined amount of preload to the inner ring 302 of the first bearing 300 a or the inner ring 302 of the second bearing 300 b .

[0224] Here, the elastic deformation portion 430 of the pre-compression washer 400 may be configured to have a free length Lf before pre-compression is applied.

[0225] The elastic deformation portion 430 may be configured to extend from one end of the shaft interval portion 410 in the axial direction.

[0226] More specifically, the elastic deformation portion 430 may be configured such that a total length Lt along the axial direction of the preload washer 400 is increased compared to the fixed length L1 .

[0227] In addition, the elastic deformation portion 430 may be configured to overlap with the fixed length of the axial section portion 410 of the preload washer 400. In this case, the total length of the preload washer 400 in the axial direction is configured to be the same as the fixed length.

[0228] More specifically, the preload washer 400 can be configured to contact the inner ring 302 of the first bearing 300a or the inner ring 302 of the second bearing 300b so that a preset size of preload can be applied axially to the inner ring 302 of the first bearing 300a or the inner ring 302 of the second bearing 300b.

[0229] According to this configuration, when the pre-compression washer 400 is coupled and the fastening member 260 is fastened, the pre-compression process of the pre-compression washer 400 is as follows.

[0230] The rotor frame 220 and the rotating shaft 210 are constrained in the axial direction when coupled, and a fastening member 260 is screwed to an end portion (a lower end portion in the drawing) of the rotating shaft 210 .

[0231] The first bearing 300a and the second bearing 300b are arranged between the rotor frame 220 and the fastening member 260 in a manner spaced apart from each other in the axial direction, and the preload washer 400 contacts the inner ring 302 of the first bearing 300a or the inner ring 302 of the second bearing 300b to which preload is applied.

[0232] The fastening member 260 is screwed to an end portion (a lower end portion in the drawing) of the rotating shaft 210 and is rotatable in a direction in which the fastening member 260 and the rotor frame 220 approach each other.

[0233] When the fastening member 260 rotates relative to the rotation shaft 210 , the gap between the rotor frame 220 and the fastening member 260 decreases, and the preload washer 400 contracts in the axial direction, thereby storing elastic energy.

[0234] The preload washer 400 applies pressure to the inner ring 302 of the first bearing 300 a or the inner ring 302 of the second bearing 300 b in contact with the preload washer 400 using stored elastic energy, thereby applying a preset preload.

[0235] Here, under the thrust generated by the rotation of the plurality of rotating blades 140, the elastically deformable portion 430 of the preload washer 400 undergoes axial displacement significantly greater than the axial displacement of the rotor frame 220. Therefore, even if the rotor frame 220 undergoes axial displacement due to the thrust of the plurality of rotating blades 140, the preload washer 400 can maintain its elastic deformation. This configuration allows a predetermined preload to be continuously applied to the inner ring 302 of the bearing in contact with the preload washer 400.

[0236] The preload washer 400 provides preload for the bearing 300, ensuring that the outer ring 301, balls 303, and inner ring 302 maintain a predetermined clearance, preventing the clearance from decreasing. This prevents the outer ring 301, balls 303, and inner ring 302 from experiencing forced wear due to the clearance reduction. Consequently, the bearing 300's service life can be extended.

[0237] In this embodiment, the preload washer 400 may be configured as a first preload washer 400 disposed between the rotor frame 220 and the inner ring 302 of the first bearing 300a to apply a predetermined amount of preload to the inner ring 302 of the first bearing 300a. Since the first preload washer 400 and the preload washer 400 have substantially the same structure, they are assigned the same reference numerals for ease of description.

[0238] like Figure 2 As shown, after the fastening member 260 is fastened, one end portion (the lower end portion in the drawing) of the first preload washer 400 contacts the inner ring 302 of the first bearing 300 a in the axial direction, while the other end portion (the upper end portion in the drawing) contacts the lower end of the rotor frame 220 .

[0239] Figure 3 yes Figure 1 Plan view of the preload washer, Figure 4 yes Figure 3 Partial cross-sectional view of the preload washer, Figure 5 yes Figure 4 An enlarged cross-sectional view of the preload washer. Figures 3 to 5 As shown, the first preload washer 400 includes: an axial interval portion 410, which has the fixed length in the axial direction, one end of which can contact the inner ring 302 of the first bearing 300a, and the other end of which can contact the rotor frame 220; an elastic deformation portion 430, which extends from the end of the axial interval portion 410 in the radial and axial directions respectively and has a free length (axial length), and contacts the rotor frame 220.

[0240] Specifically, if Figure 3 As shown, the shaft interval portion 410 includes a rotating shaft hole 412 passing through in the axial direction, and the rotating shaft hole 412 can accommodate the rotating shaft 210 .

[0241] like Figure 4 As shown, the shaft section portion 410 is provided with contact portions 415 and 416 protruding in the radial direction and extending in the circumferential direction at both ends in the axial direction.

[0242] Here, the contact portion 416 provided at one end (the lower end in the drawing) of the axial section portion 410 contacts the inner ring 302 of the first bearing 300 a , and thus may be referred to as the inner ring contact portion 416 .

[0243] The contact portion 415 provided at the other end portion (the upper end portion in the drawing) of the shaft interval portion 410 contacts the rotor frame 220 (actually the rotating shaft coupling portion 222 ) after the fastening member 260 is fastened to limit the fastening of the fastening member 260 (screw 270 ), and can therefore be called a stopper 415 .

[0244] The contact portion 415 provided at the upper end of the shaft section portion 410 includes an elastic deformation portion 430 extending outward in the radial direction and the axial direction and being elastically deformable in the axial direction.

[0245] In this embodiment, the fixed length may refer to the axial length from one end (the inner ring contact portion 416 ) of the shaft interval portion 410 to the other end (the stop portion 415 ) along the axial direction.

[0246] The free length may refer to the length (free length) along the axial direction from one end of the shaft interval portion 410 (the inner ring contact portion 416 ) to the end (free end) of the elastic deformation portion 430 before the first preload washer 400 is elastically deformed.

[0247] Also refer to Figure 2 and Figure 3 The elastic deformation parts 430 may be formed in a plurality of numbers spaced apart from each other along the circumferential direction of the rotor 200. In this embodiment, the elastic deformation parts 430 are formed in six numbers, but this is only an example and is not limited thereto.

[0248] The grooves 433 may be formed to pass through the elastic deformation parts 430 adjacent to each other in the circumferential direction. In this embodiment, the number of the grooves 433 may be the same as the number of the elastic deformation parts 430.

[0249] The first preload washer 400 includes an annular portion 435 . The annular portion 435 has a circular or ring shape and connects ends of the plurality of elastic deformation portions 430 .

[0250] Here, the ring-shaped portion 435 of this embodiment contacts the rotor frame 220 , and thus may be referred to as a rotor frame contact portion 435 .

[0251] Figure 6 It shows Figure 2 Diagram of the initial free length of the preloaded washer, Figure 7 It shows Figure 2 The figure shows the thrust of the preload washer. Figure 6 As shown, the first preload washer 400 is inserted into and coupled between the first bearing 300 a and the rotor frame 220 in the axial direction.

[0252] More specifically, the stator 150 is coupled to the base member 110 , and the first bearing 300 a and the second bearing 300 b may be accommodated and coupled inside the base member 110 .

[0253] The rotor frame 220 may be combined with the rotating shaft 210 and may be combined with the first preload washer 400 .

[0254] At this time, when the first pre-load washer 400 is coupled, the elastic deformation portion 430 can contact the rotating shaft coupling portion 222 of the rotor frame 220 .

[0255] Then, the rotating shaft 210 may be inserted into the inner ring 302 of the first bearing 300 a and the inner ring 302 of the second bearing 300 b to be coupled.

[0256] When the rotation shaft 210 is completely coupled, the fastening member 260 is coupled to the end of the rotation shaft 210 .

[0257] In the fastening member 260 , the washer 262 is first coupled, and then the screw 270 is screwed into the internal thread portion 214 of the rotation shaft 210 .

[0258] On the other hand, in the initial stage of the connection of the fastening member 260, that is, before the elastic deformation portion 430 is elastically deformed, one end (the lower end in the drawing) of the first preload washer 400 contacts the inner ring 302 of the first bearing 300a, and the other end (the upper end in the drawing) only contacts the lower end of the rotating shaft connection portion 222 of the rotor frame 220.

[0259] At this time, if the fastening member 260 is rotated in a direction in which the rotor frame 220 and the fastening member 260 approach each other, the screw 270 moves relatively toward the inside of the rotating shaft 210 .

[0260] As a result, the axial interval (distance) between the fastening member 260 and the protruding portion 215 of the rotating shaft 210 is shortened, and the elastic deformation portion 430 of the first preload washer 400 contacting the lower end of the rotor frame 220 (rotating shaft coupling portion 222) is elastically deformed while being compressed in the axial direction, thereby storing elastic energy.

[0261] If the screw 270 is continued to be rotated, Figure 2 As shown, the elastic deformation portion 430 of the first pre-compression washer 400 is elastically deformed into a nearly horizontal state, and the stopper portion of the first pre-compression washer 400 is in contact with the rotating shaft coupling portion 222 .

[0262] Therefore, the rotation of the screw 270 in the axial direction is suppressed, and the fastening of the fastening member 260 is completed.

[0263] On the other hand, when the operation starts and power is applied to the stator coil 170 , the rotor 200 rotates about the rotation axis 210 due to the interaction between the magnetic field formed by the stator coil 170 and the magnetic field of the permanent magnet 240 .

[0264] When the plurality of rotating blades 140 rotate together with the rotating shaft 210 , a lift force is generated, and a thrust force in an axial direction toward one side (upper side in the drawing) acts on the rotor frame 220 and the rotating shaft 210 .

[0265] As a result, the rotor frame 220 moves axially in the thrust direction (upward direction in the drawing), and as Figure 7 As shown, the first preload washer 400 is elastically in contact with the rotor frame 220 and is axially extended upward by a small displacement (ΔL) corresponding to the displacement of the rotor frame 220 .

[0266] At this time, the first preload washer 400 maintains an elastically deformed state and can use the stored elastic energy to apply elastic pressure to the inner ring 302 of the first bearing 300 a , thereby applying a preload of a preset magnitude.

[0267] Thus, the outer ring 301 , the balls 303 and the inner ring 302 of the first bearing 300 a can maintain an initial alignment state, and the outer ring 301 , the balls 303 and the inner ring 302 can maintain an initial clearance.

[0268] Therefore, it is possible to suppress the occurrence of forced wear of the outer ring 301 , the balls 303 , and the inner ring 302 due to a decrease in the clearance between the outer ring 301 , the balls 303 , and the inner ring 302 .

[0269] Therefore, the service life of the bearing 300 can be extended.

[0270] Figure 8 Figures (a) through (h) illustrate a preload washer for a motor according to another embodiment of the present invention. As described above, the preload washer 4001 of the motor according to this embodiment includes a rotating shaft hole 4121, in which the rotating shaft 210 is received, a shaft section 4101 having a predetermined fixed length in the axial direction, and an elastically deformable portion 4301 elastically extending from one end of the shaft section 4101.

[0271] The preload washer 4001 is configured to apply a preload of a predetermined magnitude to the inner ring 302 of the first bearing 300 a or the inner ring 302 of the second bearing 300 b in the axial direction.

[0272] In the axial direction, a contact portion 4151 and a contact portion 4161 are respectively provided at the upper end and the lower end of the shaft interval portion 4101 .

[0273] The elastic deformation portion 4301 of the pre-load washer 4001 is formed, for example, as Figure 8 As shown, a plurality of them are formed spaced apart in the circumferential direction.

[0274] like Figure 8 As shown in (a), the plurality of elastic deformation parts 4301 can be formed into three, for example.

[0275] In addition, if Figure 8 As shown in (b), the plurality of elastic deformation parts 4301 can be formed into eight, or as shown in FIG. Figure 8 As shown in (c) to (f), six are formed.

[0276] Here, the preload washer 4001 may be configured to include a ring-shaped portion 4351 circumferentially connecting ends (outer ends) of a plurality of elastic deformation portions 4301 and having a circular ring shape (annular shape).

[0277] In the preload washer 4001 , a groove 4331 may be formed between two elastic deformation portions 4301 adjacent to each other in the circumferential direction.

[0278] Here, the plurality of elastic deformation parts 4301 and the grooves 4331 are alternately formed along the circumferential direction, and the number of the grooves 4331 may be the same as the number of the plurality of elastic deformation parts 4301 .

[0279] The plurality of elastic deformation parts 4301 may be configured to have different widths (circumferential width w), radial lengths Lr, and different numbers according to the magnitude of the preload to be applied.

[0280] In addition, the plurality of elastic deformation portions 4301 may be formed to have different free lengths (axial lengths) in consideration of the magnitude of the preload to be applied.

[0281] like Figure 8 As shown in (g), the plurality of elastic deformation parts 4301 can be formed to have a first free length Lf1, for example.

[0282] like Figure 8 As shown in (h), the plurality of elastic deformation portions 4301 may be formed to have a second free length Lf2 that is extended in the axial direction compared to the first free length Lf1, for example.

[0283] According to one embodiment of the present invention, the manufacturing of the preload washer 4001 can be facilitated by appropriately changing and adjusting the number, circumferential width and axial length of the elastic deformation portion 430 to correspond to the size of the preload to be applied to the inner ring 302 of the bearing.

[0284] Figure 9 is a sectional view of a motor according to another embodiment of the present invention, Figure 10 yes Figure 9 A magnified view of the second preload washer area, Figure 11 It shows Figure 9 Diagram of the free length of the second preload washer at the initial stage of tightening, Figure 12 It shows Figure 9 The figure shows the thrust of the second preload washer. Figure 9 and Figure 10 As shown, the motor 100 a of this embodiment includes a stator 150 , a rotor 200 , a rotating shaft 210 , a bearing 300 , and a second preload washer 400 a .

[0285] The stator 150 includes, for example, a stator core 160 and a stator coil 170 wound around the stator core 160. A base member 110 is provided inside the stator 150. Therefore, the stator 150 may be supported by the base member 110.

[0286] For example, the rotor 200 includes a rotating shaft 210, a rotor frame 220 coupled to the rotating shaft 210, and permanent magnets 240 disposed on the rotor frame 220. The rotating shaft 210 is configured to protrude toward both sides of the rotor 200.

[0287] A plurality of rotary blades 140 are provided at one end portion (lower end portion in the drawing) of the rotary shaft 210. The plurality of rotary blades 140 are formed so as to generate lift in one axial direction (upper side in the drawing) when rotating, for example.

[0288] The rotor frame 220 is provided with a rotating shaft coupling portion 222, into which the rotating shaft 210 can be received and coupled. A rotating shaft receiving hole 224 is formed axially through the interior of the rotating shaft coupling portion 222. When the rotating shaft 210 and the rotor frame 220 are coupled, they are axially constrained.

[0289] More specifically, a protrusion 215 protruding in the radial direction is provided in the rotating shaft 210. A receiving portion 226 is provided in the rotor frame 220, and the protrusion 215 is received in the receiving portion 226 to be engaged in the axial direction.

[0290] A fastening member 260 is provided at the other end (the upper end in the drawing) of the rotating shaft 210. For example, the fastening member 260 includes a washer 262 and a screw 270 that is threadedly engaged with the rotating shaft 210. An internal thread portion 214 is provided inside the rotating shaft 210, and the screw 270 can be threadedly engaged with the internal thread portion 214.

[0291] The rotating shaft 210 is rotatably supported by a first bearing 300a and a second bearing 300b spaced apart in the axial direction. The first bearing 300a is disposed, for example, adjacent to the rotor frame 220. The second bearing 300b is disposed, for example, spaced apart from the rotor frame 220.

[0292] The first bearing 300 a is axially disposed on one side of the rotating shaft coupling portion 222 , and the second bearing 300 b is disposed on one side of the first bearing 300 a and spaced apart therefrom.

[0293] Each of the first bearing 300a and the second bearing 300b includes an outer ring 301, an inner ring 302 concentrically disposed within the outer ring 301, and a plurality of balls 303 disposed between the outer ring 301 and the inner ring 302. The first bearing 300a and the second bearing 300b may be configured such that, for example, blocking members 304 (shielding members or sealing members) may be provided on both axial sides.

[0294] The first and second bearings 300a, 300b may be press-fitted into the bearing receiving portion 120. The outer rings 301 of the first and second bearings 300a, 300b may be axially supported by the first and second bearing outer ring support portions 131, 133 of the base member 110, respectively.

[0295] Here, the rotating shaft coupling portion 222 is coupled to the inner ring 302 of the first bearing 300 a in contact with the inner ring 302 .

[0296] On the other hand, a second preload washer 400 a is provided between the fastening member 260 and the second bearing 300 b , and the second preload washer 400 a can apply a predetermined amount of preload to the inner ring 302 of the second bearing 300 b .

[0297] The second pre-compression washer 400a is configured, for example, as Figure 11 As shown, it includes: an axial interval portion 410a, which has the fixed length in the axial direction, and one end can contact the inner ring 302 of the second bearing 300b, and the other end can contact the fastening member 260; an elastic deformation portion 430a, which extends from the end of the axial interval portion 410a in the radial and axial directions respectively and has a free length, and contacts the fastening member 260.

[0298] The shaft section 410a of the second preload washer 400a is configured to have a fixed length in the axial direction. A contact portion 415a and a contact portion 416a are respectively provided at both ends of the shaft section 410a. The contact portions 415a and 416a protrude in the radial direction and extend in the circumferential direction.

[0299] A contact portion 415a formed at one end (upper end in the drawing) of the shaft section portion 410a contacts the fastening member 260 to restrict fastening of the fastening member 260 , and thus the contact portion 415a may be referred to as a stopper 415a .

[0300] The contact portion 416a formed at the other end (the lower end in the drawing) of the shaft section 410a contacts the inner ring 302 of the first bearing 300a, and thus the contact portion 416a may be referred to as an inner ring contact portion 416a.

[0301] The rotating shaft hole 412 a is provided to pass through the interior of the shaft section portion 410 a in the axial direction, so that the rotating shaft 210 can be accommodated in the rotating shaft hole 412 a and coupled thereto.

[0302] The elastic deformation portion 430 a of the second preload washer 400 a may be formed in plural numbers to be spaced apart from each other along the circumferential direction of the rotor 200 .

[0303] The second preload washer 400a includes a ring-shaped portion 435a that connects the ends of the plurality of elastic deformation portions 430a and has a ring shape. Here, the ring-shaped portion 435a contacts the fastening member 260 and can be referred to as a fastening member contact portion 435a.

[0304] A groove 433 a may be formed between two elastic deformation portions 430 a adjacent to each other along the circumferential direction of the second preload washer 400 a .

[0305] According to this configuration, the stator 150 can be coupled to the outside of the base member 110, and the rotor frame 220 can be coupled to the rotating shaft 210. The first bearing 300a and the second bearing 300b can be respectively accommodated and coupled inside the base member 110. The rotating shaft 210 can be respectively inserted into and coupled to the inner rings 302 of the first bearing 300a and the inner rings 302 of the second bearing 300b.

[0306] On the other hand, the second preload washer 400 a may be coupled to an end portion (an upper end portion in the drawing) of the rotating shaft 210 that passes through the inner ring 302 of the second bearing 300 b .

[0307] Here, when the second preload washer 400 a is coupled, the inner ring contact portion 416 a of the shaft section portion 410 a may contact the inner ring 302 of the second bearing 300 b .

[0308] Then, when the second pre-compression washer 400 a is completely coupled, the fastening member 260 (the washer 260 and the screw 270 ) may be coupled.

[0309] When the screw 270 is rotated in a direction in which the rotor frame 220 and the fastening member 260 approach each other, the fastening member 260 may be inserted into the rotating shaft 210 , and the rotor frame 220 may relatively move toward the fastening member 260 .

[0310] As a result, the inner ring 302 of the first bearing 300a is axially compressed toward one side (the upper side in the drawing), while the inner ring 302 of the second bearing 300b is axially compressed toward the other side (the lower side in the drawing). Consequently, the elastically deformable portion 430a of the second preload washer 400a is axially compressed, storing elastic energy.

[0311] If the screw 270 is allowed to continue rotating, Figure 10 As shown, the elastic deformation portion 430a is in a nearly horizontal state, and the stopper portion 415a of the shaft section portion 410a contacts the washer 262. Thus, the rotation of the screw 270 stops, and the fastening of the fastening member 260 is terminated.

[0312] On the other hand, when the operation starts and power is applied to the stator coil 170, the rotor 200 rotates about the rotation shaft 210. When the rotation shaft 210 and the plurality of rotating blades 140 start rotating, thrust acts on the rotation shaft 210 in the axial direction toward one side (upper side in the drawing).

[0313] Under the action of the thrust, the fastening member 260 (washer 262) is slightly displaced axially to one side (upper side in the drawing), and as shown in FIG. Figure 12 As shown, the elastic deformation portion 430a of the second preload washer 400a slightly extends axially upward. However, due to the elastic energy stored in the elastic deformation portion 430a, the inner ring 302 of the second bearing 300b is axially compressed. Therefore, even under the thrust of the rotating shaft 210, the outer ring 301, balls 303, and inner ring 302 of the second bearing 300b can maintain a predetermined axial clearance.

[0314] According to this configuration, occurrence of forced wear of the outer ring 301, balls 303 and inner ring 302 of the second bearing 300b due to change (reduction) in clearance between the outer ring 301, balls 303 and inner ring 302 of the second bearing 300b can be suppressed.

[0315] Figure 13 is a sectional view of a motor according to another embodiment of the present invention, Figure 14 yes Figure 13 An enlarged view of the third preload washer area. Figure 13 and Figure 14As shown, the motor 100 b of this embodiment includes a stator 150 , a rotor 200 , a rotating shaft 210 , a bearing 300 , and a third preload washer 400 b .

[0316] The stator 150 includes a stator core 160 and a stator coil 170 wound around the stator core 160. A base member 110 is provided inside the stator 150. A first bearing 300a and a second bearing 300b are accommodated and coupled inside the base member 110 in a manner spaced apart in the axial direction.

[0317] Each of the first bearing 300 a and the second bearing 300 b includes an outer ring 301 , an inner ring 302 concentrically disposed inside the outer ring 301 , and a plurality of balls 303 disposed between the outer ring 301 and the inner ring 302 .

[0318] The base member 110 includes a bearing receiving portion 120, into which the bearing is received and coupled. The base member 110 includes a first bearing outer ring support portion 131, which axially supports the outer ring 301 of the first bearing 300a. The base member 110 includes a second bearing outer ring support portion 133, which axially supports the outer ring 301 of the second bearing 300b.

[0319] The rotor 200 is configured to include, for example, a rotating shaft 210, a rotor frame 220 coupled to the rotating shaft 210, and permanent magnets 240 disposed on the rotor frame 220. The rotor frame 220 includes a rotating shaft coupling portion 222, into which the rotating shaft 210 is received and coupled. A rotating shaft receiving hole 224 is provided within the rotating shaft coupling portion 222. The rotating shaft receiving hole 224 axially extends through the interior of the rotating shaft coupling portion 222 to accommodate the rotating shaft 210.

[0320] The rotating shaft 210 and the rotor frame 220 are axially constrained when coupled. The rotating shaft coupling portion 222 axially contacts and engages with the inner ring 302 of the first bearing 300a. A radially projecting protrusion 215 is provided on the rotating shaft 210. The rotor frame 220 is provided with a receiving portion 226, into which the protrusion 215 is received, thereby constraining the protrusion 215 in the axial direction.

[0321] The rotating shaft 210 may be formed to have a longer length so as to protrude toward both sides of the rotor frame 220. A plurality of rotating blades 140 are axially disposed at one end of the rotating shaft 210 (the upper end in the drawings). For example, the plurality of rotating blades 140 are configured to generate lift when rotating. When the plurality of rotating blades 140 rotate, thrust is applied to the rotating shaft 210 axially toward one side (the upper end in the drawings).

[0322] A fastening member 260 is provided at the other axial end portion (the lower end portion in the drawing) of the rotating shaft 210. For example, the fastening member 260 is configured to include a washer 262 and a screw 270 that is threadedly engaged with the rotating shaft 210. The rotating shaft 210 is provided with an internal thread portion 214 so that the screw 270 can be threadedly engaged with the internal thread portion 214.

[0323] On the other hand, a third preload washer 400 b is provided between the fastening member 260 and the inner ring 302 of the second bearing 300 b in the axial direction.

[0324] The third preload washer 400b is constructed to include, for example: an axial interval portion 410b, which has the fixed length in the axial direction, and one end can contact the fastening member 260, and the other end can contact the end of the rotating shaft 210; an elastic deformation portion 430b, which extends radially and axially from the axial interval portion 410b and has a free length, and contacts the inner ring 302 of the second bearing 300b.

[0325] Figure 15 yes Figure 13 A perspective view of the third preload washer, Figure 16 yes Figure 15 A partial cross-sectional view of the third preload washer, Figure 17 yes Figure 16 An enlarged cross-sectional view of the third preload washer, Figure 18 It shows Figure 16 Diagram of the free length of the third preload washer at the initial stage of tightening, Figure 19 It shows Figure 16 The thrust effect of the third preload washer is shown in Figure 1. Figure 15 As shown, a rotation shaft hole 412 b is provided inside the shaft section portion 410 b of the third preload washer 400 b , and the rotation shaft 210 can be accommodated in the rotation shaft hole 412 b .

[0326] A contact portion 415 b and a contact portion 416 b are formed at both axial ends of the shaft section portion 410 b , respectively. The contact portions 415 b and 416 b protrude in the radial direction and extend in the circumferential direction.

[0327] In this embodiment, the contact portion 415b formed at one end (the upper end in the drawing) of the shaft interval portion 410b contacts the rotating shaft 210 when the screw 270 is tightened, thereby limiting the tightening of the screw 270, and therefore the contact portion 415b can be called a stop portion 415b.

[0328] Also refer to Figure 14 and Figure 16 The contact portion 416b formed at the other end portion (the lower end portion in the drawing) of the shaft interval portion 410b contacts the fastening member 260 (washer 262), so the contact portion 416b can be referred to as a fastening member contact portion 416b.

[0329] In this embodiment, after the fastening member 260 is fastened, that is, after the elastic deformation portion 430 b is elastically deformed, the stopper 415 b may come into contact with the end portion of the rotation shaft 210 .

[0330] On the other hand, in this embodiment, Figure 17 As shown, the elastic deformation portion 430b of the third preload washer 400b may be configured to extend from the lower contact portion 416b (the fastening member contact portion) of the shaft interval portion 410b in the radial and axial directions.

[0331] Here, the free length Lf of the elastic deformation portion 430b is configured to be smaller than the fixed length L1.

[0332] According to this configuration, since the free length Lf of the elastic deformation portion 430b overlaps with the fixed length L1 in the axial direction, the total axial length Lt of the third preload washer 400b may be the same as the fixed length L1.

[0333] The elastic deformation portion 430 b of the third preload washer 400 b may be formed in a plurality and spaced apart from each other in the circumferential direction.

[0334] The third preload washer 400 b includes a ring-shaped portion 435 b that connects the ends of the plurality of elastic deformation portions 430 b and has a circular ring shape.

[0335] The third preload washer 400 b includes a skirt portion 437 extending axially downward from the annular portion 435 b .

[0336] Here, the annular portion 435 b contacts the inner ring 302 of the second bearing 300 b , and thus the annular portion 435 b may be referred to as an inner ring contact portion 435 b .

[0337] In this embodiment, the second bearing 300b may be formed to protrude axially from the end portion (the lower end portion in the drawing) of the rotating shaft 210 (see FIG. Figure 14 ).

[0338] The lower end portion of the rotating shaft 210 may be spaced apart upward from the lower end portion of the inner ring 302 of the second bearing 300 b by a predetermined distance.

[0339] This is so that when tightening the fastening member 260, the two end portions (stop portion 415b, fastening member contact portion 416b) of the third preload washer 400b first contact the fastening member 260 and the inner ring 302 of the second bearing 300b before contacting the third preload washer 400b and the end portion of the rotating shaft 210, so that the elastic deformation portion 430b of the third preload washer 400b is elastically deformed, thereby enabling a preset size of preload to be applied to the inner ring 302 of the second bearing 300b.

[0340] According to this structure, the stator 150 is coupled to the outer side of the base member 110 , and the rotor frame 220 is coupled to the rotating shaft 210 .

[0341] The first and second bearings 300 a and 300 b are respectively accommodated and coupled to the base member 110 , and ends (lower ends) of the rotating shaft 210 passing through the rotor frame 220 may be coupled to the first and second bearings 300 a and 300 b , respectively.

[0342] The third preload washer 400 b may be coupled to an end portion (lower end portion) of the rotation shaft 210 passing through the inner ring 302 of the second bearing 300 b .

[0343] In the third preload washer 400 b , the end of the rotating shaft 210 can be inserted into the shaft section portion 410 b with the elastic deformation portion 430 b facing upward.

[0344] When the third preload washer 400 b is coupled, the washer 262 is coupled to the end of the rotating shaft 210 , and the screw 270 is passed through the washer 262 and screwed into the internal thread portion 214 of the rotating shaft 210 .

[0345] When the screw 270 is rotated in a direction in which the rotor frame 220 and the fastening member 260 approach each other, the screw 270 is inserted into the interior of the rotating shaft 210 and moves in the axial direction.

[0346] If the screw 270 continues to rotate in the same direction, Figure 18 As shown, the end portion (the upper end portion in the drawing) of the elastic deformation portion 430b of the third preload washer 400b contacts the inner ring 302 of the second bearing 300b.

[0347] If the screw 270 continues to be rotated, the elastic deformation portion 430b is compressed in the axial direction and elastic energy is stored at the same time. The elastic deformation portion 430b can apply a preset size of pre-load to the inner ring 302 of the second bearing 300b by applying pressure to the inner ring 302 of the second bearing 300b in the axial direction.

[0348] If the screw 270 continues to rotate, the end of the shaft section 410b (stopper 415b) contacts the end of the rotating shaft 210, and the rotational reaction force of the screw 270 increases significantly. As a result, the tightening of the screw 270 can be terminated.

[0349] On the other hand, when the operation starts and the rotor 200 rotates, the thrust generated by the rotation of the plurality of rotating blades 140 acts on one side (the upper side in the drawing) of the rotating shaft 210 in the axial direction.

[0350] Therefore, if Figure 19 As shown, the preload washer 400b extends axially upward by a small amount (ΔL) to correspond to the displacement caused by the thrust. Since the axial displacement caused by the thrust is very small compared to the total axial displacement of the elastically deformable portion 430b, the preload washer 400b remains elastically deformed. Consequently, the preload washer 400b utilizes stored elastic energy to apply pressure to the inner ring 302 of the second bearing 300b, thereby continuously applying a predetermined preload.

[0351] According to this structure, the outer ring 301, balls 303 and inner ring 302 of the second bearing 300b can stably maintain a clearance suitable for rotation, thereby suppressing forced wear of the outer ring 301, balls 303 and inner ring 302 of the second bearing 300b due to reduced clearance.

[0352] Therefore, the service life of the second bearing 300b of the motor 100b of this embodiment can be greatly extended.

[0353] Figure 20 is a sectional view of a motor according to another embodiment of the present invention, Figure 21 yes Figure 20 Magnified view of the preload washer area, Figure 22 yes Figure 21 A partial cross-sectional view of the first portion of the preload washer and the second portion of the preload washer before being combined, Figure 23 yes Figure 22 An enlarged cross-sectional view of the first and second preload washers when combined. Figure 20 and Figure 21As shown, the motor 100 c of this embodiment includes a base member 110 , a rotor 200 , a rotating shaft 210 , a bearing 300 , and a preload washer 400 c .

[0354] The stator 150 includes a stator core 160 and a stator coil 170 wound around the stator core 160 .

[0355] A base member 110 is provided inside the stator 150 .

[0356] The first bearing 300 a and the second bearing 300 b are received and coupled to the base member 110 and are spaced apart in the axial direction.

[0357] The first bearing 300 a is configured to include an outer ring 301 , an inner ring 302 concentrically arranged inside the outer ring 301 , and a plurality of balls 303 disposed between the outer ring 301 and the inner ring 302 .

[0358] The second bearing 300 b includes an outer ring 301 , an inner ring 302 concentrically disposed inside the outer ring 301 , and a plurality of balls 303 disposed between the outer ring 301 and the inner ring 302 .

[0359] The base member 110 includes a bearing receiving portion 120 , and the bearing 300 is received and coupled to the bearing receiving portion 120 .

[0360] The base member 110 includes a first bearing outer ring support portion 131 , which supports the outer ring 301 of the first bearing 300 a in the axial direction.

[0361] The base member 110 includes a second bearing outer ring support portion 133 , which supports the outer ring 301 of the second bearing 300 b in the axial direction.

[0362] The rotor 200 is configured to include, for example, a rotating shaft 210 , a rotor frame 220 coupled to the rotating shaft 210 , and permanent magnets 240 disposed on the rotor frame 220 .

[0363] The rotor frame 220 includes a rotation shaft coupling portion 222 , and the rotation shaft 210 is received and coupled to the rotation shaft coupling portion 222 .

[0364] The rotating shaft receiving hole 224 is provided through the rotating shaft coupling portion 222 in the axial direction so as to receive the rotating shaft 210 .

[0365] The rotating shaft 210 and the rotor frame 220 are constrained in the axial direction when combined.

[0366] A protrusion 215 protruding in the radial direction is provided in the rotating shaft 210 .

[0367] The rotor frame 220 is provided with an accommodation portion 226 , and the protrusion 215 is accommodated in the accommodation portion 226 , so that the protrusion 215 is constrained in the axial direction.

[0368] The rotating shaft 210 may have a long length to protrude toward both sides of the rotor frame 220 .

[0369] The plurality of rotary blades 140 are axially disposed at one end portion (the upper end portion in the drawing) of the rotary shaft 210 .

[0370] The plurality of rotating blades 140 are configured to generate lift when rotating, for example.

[0371] When the plurality of rotating blades 140 rotate, thrust acts on one side (the upper side in the drawing) of the rotating shaft 210 in the axial direction.

[0372] A fastening member 260 is provided at the other end portion (the lower end portion in the drawing) in the axial direction of the rotating shaft 210 .

[0373] The fastening member 260 is configured to include, for example, a washer 262 and a screw 270 threadedly coupled to the rotating shaft 210 .

[0374] An internal thread portion 214 is provided in the rotation shaft 210 so that the screw 270 can be screwed into the internal thread portion 214 .

[0375] On the other hand, a preload washer 400 c is provided between the fastening member 260 and the inner ring 302 of the second bearing 300 b in the axial direction.

[0376] The preload washer 400 c is configured to include, for example, a first preload washer portion 400 c 1 and a second preload washer portion 400 c 2 coupled to each other in the axial direction.

[0377] like Figure 22 and Figure 23 As shown, the first part of the preload washer 400c1 includes, for example: a first part shaft interval portion 410c1, which forms a part of the fixed length in the axial direction and is combined with the rotating shaft 210; an elastic deformation portion 430c, which extends radially and axially from the first part shaft interval portion 410c1 and has a free length and can be elastically deformed in the axial direction.

[0378] The second partial preload washer 400c2 includes: a second partial shaft interval portion 410c2, which is coupled to the rotating shaft 210 to cooperate with the first partial shaft interval portion 410c1 in the axial direction to form the fixed length; and a contact portion 416c, which protrudes radially from the second partial shaft interval portion 410c2 and extends circumferentially.

[0379] The contact portion 416 c of the second partial preload washer 400 c 2 contacts the inner ring 302 of the first bearing 300 a , and thus the contact portion 416 c may be referred to as an inner ring contact portion 416 c .

[0380] A contact portion 415c is provided at one end portion (the upper end portion in the drawing) of the first partial shaft section 410c1 of the first partial preload washer 400c1. The contact portion 415c protrudes radially from the first partial shaft section 410c1 and extends circumferentially.

[0381] Here, when the fastening member 260 is fastened, the contact portion 415 c contacts the rotor frame 220 (rotation shaft coupling portion 222 ) to restrict the fastening of the fastening member 260 , and thus the contact portion 415 c may be referred to as a stopper 415 c .

[0382] The first partial preload washer 400c1 is provided with a plurality of elastic deformation portions 430c spaced apart along the circumferential direction.

[0383] A groove 433 c is formed between two adjacent elastic deformation parts 430 c among the plurality of elastic deformation parts 430 c.

[0384] The first partial preload washer 400c1 includes, for example, a ring-shaped portion 435c connecting outer ends of the plurality of elastic deformation portions 430c and having a ring shape. The ring-shaped portion 435c contacts the rotor frame 220 and is therefore referred to as a rotor frame contact portion 435c.

[0385] Here, the elastic deformation portion 430 c of the first partial preload washer 400 c 1 is configured to increase the total length of the preload washer 400 c in the axial direction.

[0386] A rotation shaft hole 412c1 and a rotation shaft hole 412c2 are respectively provided in the first partial shaft section 410c1 and the second partial shaft section 410c2 of the preload washer 400c so as to accommodate the rotation shaft 210 therein and couple the preloaded washer 400c with the rotation shaft 210 .

[0387] On the other hand, the elastic deformation portion 430c of the first partial preload washer 400c1 includes an engaging portion 450 that is overlapped in the axial direction of the preload washer 400c and is constrained in the circumferential direction.

[0388] The engaging portion 450, for example, includes: a protrusion 451, which protrudes axially from any one of the surfaces of the first partial shaft interval portion 410c1 and the second partial shaft interval portion 410c2 that contact each other; and a protrusion accommodating portion 453, which is formed on the other one of the surfaces of the first partial shaft interval portion 410c1 and the second partial shaft interval portion 410c2 that contact each other and is capable of accommodating the protrusion 451.

[0389] In this embodiment, the protrusion 451 is formed in the first partial shaft section 410c1 and the protrusion accommodating portion 453 is formed in the second partial shaft section 410c2 as an example, but this is only an example and is not limited thereto.

[0390] More specifically, for example, the protrusion 451 protrudes axially from the end of the first partial shaft section 410c1, and the protrusion receiving portion 453 is recessed axially at the end of the second partial shaft section 410c2.

[0391] Here, the first portion pre-compression washer 400c1 and the second portion pre-compression washer 400c2 may be made of different materials.

[0392] Specifically, the first partial preload washer 400c1 where the elastic deformation portion 430c is provided may be made of a material having a larger elastic coefficient than that of the second partial preload washer 400c2.

[0393] As an example, the first portion of the preload washer 400c1 may be made of spring steel, and the second portion of the preload washer 400c2 may be made of a material having a smaller elastic modulus than that of the spring steel (eg, ordinary steel).

[0394] Therefore, the amount of material (spring steel) with a relatively large spring constant used can be reduced.

[0395] Therefore, compared with making the entire preload washer 400c from a material with a large elastic modulus (spring steel), the man-hour for producing the material with a large elastic modulus can be reduced, thereby making the manufacturing quick and easy.

[0396] In addition, the usage of relatively expensive materials with large elastic coefficients (spring steel) can be reduced, thereby correspondingly reducing the overall manufacturing cost of the preload washer 400 c.

[0397] According to this structure, the stator 150 may be coupled to the outside of the base member 110 , and the first and second bearings 300 a and 300 b may be coupled to the inside of the base member 110 .

[0398] The rotor frame 220 may be coupled to the rotating shaft 210 , and the first and second preload washers 400c1 and 400c2 may be coupled axially. The first and second preload washers 400c1 and 400c2 may engage with each other axially.

[0399] When the coupling of the first partial preload washer 400c1 and the second partial preload washer 400c2 is completed, the rotation shaft 210 may be coupled to the inner ring 302 of the first bearing 300a and the inner ring 302 of the second bearing 300b.

[0400] The washer 262 and the screw 270 may be respectively coupled to ends of the rotation shaft 210 passing through the inner ring 302 of the second bearing 300 b .

[0401] When the screw 270 is rotated in a direction to shorten the distance between the rotor frame 220 and the fastening member (the screw 270 ), the washer 262 contacts the inner ring 302 of the second bearing 300 b , and the rotor frame 220 can relatively move in the axial direction.

[0402] Therefore, the elastic deformation portion 430 c of the preload washer 400 c is compressed in the axial direction and stores elastic energy.

[0403] If the screw 270 continues to be rotated, the elastically deformable portion 430c elastically deforms and assumes a substantially horizontal position, and the upper contact portion 415c (the stopper 415c) of the first partial shaft section 410c1 contacts the rotor frame 220. Therefore, the reaction force against the rotation of the screw 270 significantly increases, and tightening of the screw 270 can be terminated.

[0404] On the other hand, when the operation is started and lift is generated by the rotation of the plurality of rotating blades 140 , thrust acts on the rotating shaft 210 in the axial direction toward the upper side of the drawing.

[0405] When thrust is applied to the rotating shaft 210, the rotor frame 220 slightly displaces upward in the drawing, causing the elastically deformable portion 430c of the preload washer 400c to axially extend by a corresponding distance. Even with this slight displacement in the extension direction caused by the thrust, the preload washer 400c remains elastically deformed, thereby continuously applying a predetermined preload to the inner ring 302 of the first bearing 300a.

[0406] Therefore, the outer ring 301, balls 303 and inner ring 302 of the first bearing 300a stably maintain the initial clearance without reducing the preset clearance, thereby suppressing the outer ring 301, balls 303 and inner ring 302 from forced wear due to clearance reduction.

[0407] Therefore, the service life of the first bearing 300a can be extended.

[0408] Figure 24 is a sectional view of a motor according to another embodiment of the present invention, Figure 25 yes Figure 24 Magnified view of the preload washer area. Figure 24 and Figure 25 As shown, the motor 100d of this embodiment includes a stator 150, a rotor 200, a rotating shaft 210, a bearing 300, and a preload washer 400d.

[0409] The stator 150 includes a stator core 160 and a stator coil 170 wound around the stator core 160 .

[0410] A base member 110 is provided inside the stator 150 .

[0411] The first bearing 300 a and the second bearing 300 b are accommodated and coupled to the base member 110 in a manner of being spaced apart in the axial direction.

[0412] The first bearing 300 a is configured to include an outer ring 301 , an inner ring 302 concentrically arranged inside the outer ring 301 , and a plurality of balls 303 disposed between the outer ring 301 and the inner ring 302 .

[0413] The second bearing 300 b includes an outer ring 301 , an inner ring 302 concentrically disposed inside the outer ring 301 , and a plurality of balls 303 disposed between the outer ring 301 and the inner ring 302 .

[0414] The base member 110 includes a bearing receiving portion 120 , and the bearing is received and coupled to the bearing receiving portion 120 .

[0415] The base member 110 includes a first bearing outer ring support portion 131 that supports the outer ring 301 of the first bearing 300 a in the axial direction.

[0416] The base member 110 includes a second bearing outer ring support portion 133 that supports the outer ring 301 of the second bearing 300 b in the axial direction.

[0417] The rotor 200 is configured to include, for example, a rotating shaft 210 , a rotor frame 220 coupled to the rotating shaft 210 , and permanent magnets 240 disposed on the rotor frame 220 .

[0418] The rotor frame 220 includes a rotation shaft coupling portion 222 , and the rotation shaft 210 is received and coupled to the rotation shaft coupling portion 222 .

[0419] The rotating shaft receiving hole 224 is provided through the rotating shaft coupling portion 222 in the axial direction so that the rotating shaft 210 can be received in the rotating shaft receiving hole 224 .

[0420] The rotating shaft 210 and the rotor frame 220 are constrained in the axial direction when combined.

[0421] The rotating shaft 210 is provided with a protrusion 215 protruding in the radial direction.

[0422] An accommodation portion is provided in the rotor frame 220 to accommodate and constrain the protrusion 215 in the axial direction.

[0423] The rotating shaft 210 may be formed to have a longer length to protrude toward both sides of the rotor frame 220 .

[0424] The plurality of rotary blades 140 are provided at one end portion (an upper end portion in the drawing) in the axial direction of the rotary shaft 210 .

[0425] The plurality of rotating blades 140 are configured to generate lift, for example, when rotating.

[0426] When the plurality of rotating blades 140 rotate, thrust is applied to one axial side (upper side in the drawing) of the rotating shaft 210 .

[0427] A fastening member 260 is provided at the other end portion (the lower end portion in the drawing) in the axial direction of the rotating shaft 210 .

[0428] The fastening member 260 is configured to include, for example, a washer 262 and a screw 270 threadedly coupled to the rotating shaft 210 .

[0429] The rotating shaft 210 is provided with an internal thread portion 214 so that the screw 270 can be screwed into the internal thread portion 214 .

[0430] On the other hand, a preload washer 400d is provided between the fastening member 260 and the inner ring 302 of the second bearing 300b in the axial direction.

[0431] The preload washer 400d is configured to include, for example, a first preload washer portion 400d1 and a second preload washer portion 400d2 coupled to each other in the axial direction.

[0432] Figure 26 yes Figure 25 A partial cross-sectional view of the first portion of the preload washer and the second portion of the preload washer before being combined, Figure 27 yes Figure 26 An enlarged cross-sectional view of the first part of the preload washer and the second part of the preload washer when combined, Figure 28 It shows Figure 26 Diagram of the initial combined free length of the first and second preload washers, Figure 29 It shows Figure 26 Diagram of the thrust action of the first and second preload washers.

[0433] like Figure 26 and Figure 27 As shown, the first part preload washer 400d1 is constructed to include: a first part shaft interval portion 410d1, which forms a part of the fixed length in the axial direction and is combined with the rotating shaft 210; an elastic deformation portion 430d, which extends radially and axially from the first part shaft interval portion 410d1 to form a free length and can be elastically deformed in the axial direction.

[0434] The second partial preload washer 400d2 is configured to include: a second partial shaft section 410d2 coupled to the rotating shaft 210 to form the fixed length in cooperation with the first partial shaft section 410d1 in the axial direction; and a contact portion 416d extending radially from the second partial shaft section 410d2.

[0435] Here, a rotation shaft hole 412d1 and a rotation hole 412d2 are formed inside the first partial shaft section 410d1 and the second partial shaft section 410d2, respectively, so that the rotation shaft 210 can be accommodated in the rotation shaft hole 412d1 and the rotation hole 412d2 for coupling.

[0436] In this embodiment, the contact portion 416d of the second partial preload washer 400d2 contacts the inner ring 302 of the first bearing 300a, so the contact portion 416d can be referred to as an inner ring contact portion 416d.

[0437] A contact portion 415d is provided at one end (the upper end in the drawing) of the first partial shaft section 410d1 of the first partial preload washer 400d1. When the fastening member 260 is tightened, the contact portion 415d of the first partial shaft section 410d1 contacts the rotor frame 220 (rotating shaft coupling portion 222) to limit the tightening of the fastening member 260. Therefore, the contact portion 415d can be referred to as a stopper 415d.

[0438] The first partial preload washer 400d1 is provided with a plurality of elastic deformation portions 430d spaced apart along the circumferential direction.

[0439] Each of the plurality of elastic deformation portions 430 d is formed to extend in the radial direction and the axial direction from the upper end portion (stopper portion 415 d ) of the first partial shaft section 410 d 1 , for example.

[0440] A groove 433d is formed between two adjacent elastic deformation parts 430d among the plurality of elastic deformation parts 430d.

[0441] The first partial preload washer 400d1 includes, for example, a ring-shaped portion 435d1 that connects the outer ends of the plurality of elastically deformable portions 430d and has a ring shape. The ring-shaped portion 435d1 contacts the rotor frame 220 (rotating shaft coupling portion 222) and can therefore be referred to as a rotor frame contact portion 435d1.

[0442] Here, the elastic deformation portion 430d of the first partial preload washer 400d1 is configured to increase the total length of the preload washer in the axial direction.

[0443] On the other hand, a first partial shaft section accommodating portion 417 is provided in the second partial preload washer 400d2 so that the first partial shaft section 410d1 of the first partial preload washer 400d1 can be axially accommodated in the first partial shaft section accommodating portion 417 .

[0444] The first partial shaft section accommodating portion 417 may be formed to protrude from the second partial shaft section 410 d 2 in the radial direction and be bent in the axial direction, for example.

[0445] A space into which the first partial shaft section 410 d 1 can be inserted is formed between the inner surface of the first partial shaft section accommodating portion 417 and the outer surface of the rotating shaft 210 .

[0446] like Figure 27 As shown, the end portion (the upper end portion in the drawing) of the first partial shaft section accommodating portion 417 is configured to contact the elastic deformation portion 430d in the axial direction.

[0447] Therefore, when the elastic deformation portion 430d is elastically deformed, the elastic deformation portion 430d can be stably supported.

[0448] Here, the first portion pre-compression washer 400d1 and the second portion pre-compression washer 400d2 may be made of different materials.

[0449] Specifically, the first partial preload washer 400d1 having the elastic deformation portion 430d is made of a material having a larger elastic coefficient than that of the second partial preload washer 400d2.

[0450] As an example, the first portion of the preload washer 400d1 may be made of spring steel, and the second portion of the preload washer 400d2 may be made of a material having a smaller elastic modulus than that of the spring steel (eg, ordinary steel).

[0451] Therefore, the amount of material (spring steel) with a relatively large spring constant used can be reduced.

[0452] Therefore, compared with forming the entire preload washer from a material with a large elastic modulus (spring steel), the man-hour for producing the material with a large elastic modulus can be reduced, thereby making the manufacturing quick and easy.

[0453] In addition, the usage of relatively expensive spring steel can be reduced, thereby reducing the overall manufacturing cost of the preload washer 400d.

[0454] In addition, since relatively small pressure is required when forming the protrusion 451 and the first partial shaft section receiving portion 417 , the second partial pre-load washer 400 d 2 can be manufactured relatively easily.

[0455] According to this structure, the stator 150 can be coupled to the outside of the base member 110, and the first bearing 300a and the second bearing 300b can be coupled to the inside of the base member 110.

[0456] The rotor frame 220 may be coupled to the rotating shaft 210 , and the first and second preload washers 400d1 and 400d2 may be coupled to each other in the axial direction.

[0457] The first partial shaft section portion 410d1 of the first partial preload washer 400d1 may be axially inserted into the first partial shaft section accommodating portion 417 of the second partial preload washer 400d2.

[0458] If the first partial preload washer 400d1 and the second partial preload washer 400d2 are completely coupled, the rotation shaft 210 may be coupled to the inner ring 302 of the first bearing 300a and the inner ring 302 of the second bearing 300b.

[0459] The washer 262 and the screw 270 may be respectively coupled to ends of the rotation shaft 210 passing through the inner ring 302 of the second bearing 300 b .

[0460] When the screw 270 is rotated in a direction in which the distance between the rotor frame 220 and the screw 270 is shortened, the washer 262 may contact the inner ring 302 of the second bearing 300 b , and the rotor frame 220 may relatively move in the axial direction.

[0461] Therefore, the elastic deformation portion 430d of the preload washer 400d is compressed in the axial direction and stores elastic energy.

[0462] If the screw 270 is further rotated, the elastically deformable portion 430d elastically deforms and assumes a substantially horizontal position, and the end of the first partial shaft section 410d1 contacts the rotor frame 220, thereby significantly increasing the reaction force against the rotation of the screw 270. Therefore, the tightening operation of the screw 270 can be easily terminated.

[0463] On the other hand, when the operation is started and lift is generated by the rotation of the plurality of rotating blades 140 , thrust acts on the rotating shaft 210 in the axial direction toward the upper side of the drawing.

[0464] When thrust is applied to the rotating shaft 210, the rotor frame 220 is slightly displaced upward in the drawing, and the elastically deformable portion 430d of the preload washer 400d is axially extended by a corresponding distance. Even with this slight displacement in the extension direction caused by the thrust, the preload washer 400d remains elastically deformed, thereby continuously applying a predetermined preload to the inner ring 302 of the first bearing 300a.

[0465] Therefore, the outer ring 301, the balls 303 and the inner ring 302 of the first bearing 300a stably maintain a preset clearance, thereby suppressing forced wear of the outer ring 301, the balls 303 and the inner ring 302 due to reduced clearance.

[0466] Therefore, the service life of the first bearing 300a can be extended.

[0467] The specific embodiments of the present invention have been shown and described above. However, the present invention can be implemented in various forms without departing from the spirit or essential characteristics thereof, and therefore the above embodiments should not be limited by the detailed description provided herein.

[0468] Furthermore, even if the embodiments are not listed in detail in the above detailed description, they should be broadly interpreted within the scope of the technical concept defined in the appended claims. Moreover, all modifications and variations that fall within the scope of the claims and their equivalents are intended to be covered by the appended claims.

Claims

1. An electric motor, characterized in that: include: base member; a stator coupled to an outer side of the base member; a rotor including a rotating shaft, a rotor frame coupled to the rotating shaft in an axially constrained manner, and a permanent magnet provided on the rotor frame, the rotor being coupled to the stator in a rotatable manner relative to the stator; a first bearing and a second bearing, each having an outer ring, a ball, and an inner ring, the first bearing and the second bearing being arranged spaced apart from each other in the axial direction between the base member and the rotating shaft; a preload washer comprising a shaft section having a rotating shaft hole for accommodating the rotating shaft and having a preset fixed length in the axial direction, and an elastically deformable portion extending from one end of the shaft section in an elastically deformable manner, the preload washer applying a preset amount of preload to the inner ring of the first bearing or the inner ring of the second bearing; and a fastening member threadedly coupled to the end of the rotating shaft in a manner capable of relative movement in the axial direction, so as to elastically deform the preload washer in the axial direction; The rotor frame is axially arranged on the upper side of the first bearing. The pre-load washer includes a first pre-load washer, and the first pre-load washer is inserted between the rotor frame and the inner ring of the first bearing; The first pre-load washer comprises: A shaft section having a rotating shaft hole for accommodating the rotating shaft, having the fixed length in the axial direction, one end of which can contact the inner ring of the first bearing, and the other end of which can contact the rotor frame; and The elastic deformation portion is formed to extend from an end portion of the shaft section portion in radial and axial directions to have a free length and to be in contact with the rotor frame.

2. The electric motor according to claim 1, wherein The elastic deformation portion is composed of a plurality of elastic deformation portions spaced apart from each other along the circumferential direction of the rotor.

3. The electric motor according to claim 2, characterized in that The first preload washer includes a rotor frame contact portion, the rotor frame contact portion connecting ends of the plurality of elastic deformation portions and having a circular ring shape, and the rotor frame contact portion contacts the rotor frame.

4. An electric motor, characterized in that: include: base member; a stator coupled to an outer side of the base member; a rotor including a rotating shaft, a rotor frame coupled to the rotating shaft in an axially constrained manner, and a permanent magnet provided on the rotor frame, the rotor being coupled to the stator in a rotatable manner relative to the stator; a first bearing and a second bearing, each having an outer ring, a ball, and an inner ring, the first bearing and the second bearing being arranged spaced apart from each other in the axial direction between the base member and the rotating shaft; a preload washer comprising a shaft section having a rotating shaft hole for accommodating the rotating shaft and having a preset fixed length in the axial direction, and an elastically deformable portion extending from one end of the shaft section in an elastically deformable manner, the preload washer applying a preset amount of preload to the inner ring of the first bearing or the inner ring of the second bearing; and A fastening member is screwed to the end of the rotating shaft in a manner that allows relative movement in the axial direction, so that the preload washer is elastically deformed in the axial direction; the rotor frame is axially arranged on the lower side of the second bearing, The preload washer includes a second preload washer, the second preload washer being inserted between the fastening member and the inner ring of the second bearing; The second pre-load washer comprises: The shaft interval portion has the fixed length in the axial direction, one end of which is capable of contacting the inner ring of the second bearing and the other end of which is capable of contacting the fastening member; as well as The elastic deformation portion is formed to extend from the end of the shaft section portion in the radial direction and the axial direction respectively to have a free length and to be in contact with the fastening member.

5. An electric motor, characterized in that: include: base member; a stator coupled to an outer side of the base member; a rotor including a rotating shaft, a rotor frame coupled to the rotating shaft in an axially constrained manner, and a permanent magnet provided on the rotor frame, the rotor being coupled to the stator in a rotatable manner relative to the stator; a first bearing and a second bearing, each having an outer ring, a ball, and an inner ring, the first bearing and the second bearing being arranged spaced apart from each other in the axial direction between the base member and the rotating shaft; a preload washer comprising a shaft section having a preset fixed length in the axial direction and an elastically deformable portion extending from one end of the shaft section in an elastically deformable manner, the preload washer applying a preset preload to the inner ring of the first bearing or the inner ring of the second bearing; and a fastening member threadedly coupled to the end of the rotating shaft in a manner capable of relative movement in the axial direction, so as to elastically deform the preload washer in the axial direction; The rotor frame is axially arranged on the upper side of the first bearing. The preload washer includes a third preload washer, and the third preload washer is inserted between the inner ring of the second bearing and the fastening member; The third pre-load washer comprises: an axis interval portion having the fixed length in the axial direction, one end of which is capable of contacting the fastening member and the other end of which is capable of contacting the end of the rotating shaft; as well as The elastic deformation portion is formed to extend from the shaft section portion in the radial direction and the axial direction to have a free length and to contact the inner ring of the second bearing.

6. The electric motor according to claim 5, characterized in that The elastic deformation portion is composed of a plurality of elastic deformation portions spaced apart along the circumferential direction of the rotor. The third preload washer includes an inner ring contact portion that connects ends of the plurality of elastic deformation portions and contacts the inner ring of the second bearing.

7. The electric motor according to claim 6, characterized in that The third preload washer includes a skirt portion extending axially from the inner ring contact portion.

8. The electric motor according to any one of claims 1 to 7, characterized in that The fastening member comprises: a screw threadably coupled to the rotating shaft; and A washer is sandwiched between the rotating shaft and the screw.

9. The electric motor according to any one of claims 1 to 7, characterized in that A bearing accommodation portion is provided in the base member, and the bearing accommodation portion accommodates the first bearing and the second bearing.

10. The electric motor according to any one of claims 1 to 7, characterized in that The base member comprises: a first bearing outer ring support portion, supporting the outer ring of the first bearing in the axial direction; and The second bearing outer ring support portion supports the outer ring of the second bearing in the axial direction.

11. The electric motor according to claim 1, wherein The preload washer includes a first portion preload washer and a second portion preload washer coupled to each other in the axial direction.

12. The electric motor according to claim 11, characterized in that The first part of the preload washer includes: A first partial shaft section, forming a portion of the fixed length along the axial direction and coupled to the rotating shaft; and The elastic deformation portion is formed to extend from the first partial shaft section in the radial direction and the axial direction to have a free length and is elastically deformable in the axial direction. The second part of the preload washer includes: a second partial shaft section coupled to the rotating shaft in such a manner as to cooperate with the first partial shaft section in the axial direction to form the fixed length; and The contact portion extends radially from the second partial shaft interval portion.

13. The electric motor according to claim 12, characterized in that The first partial shaft section portion and the second partial shaft section portion are provided with an engaging portion that engages the first partial shaft section portion and the second partial shaft section portion so as to overlap in the axial direction and be constrained in the circumferential direction.

14. The electric motor according to claim 12, wherein The second partial preload washer is provided with a first partial shaft section accommodating portion, and the first partial shaft section accommodating portion can accommodate the first partial shaft section of the first partial preload washer in the axial direction.

15. The electric motor according to claim 14, characterized in that An end portion of the first partial shaft section accommodating portion contacts the elastic deformation portion in the axial direction so as to support the elastic deformation portion when the elastic deformation portion is elastically deformed.

16. The electric motor according to any one of claims 12 to 15, characterized in that The second portion of the preload washer is made of a material having a smaller elastic modulus than that of the first portion of the preload washer.

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