WO2022270397A1 - モータ、およびモータの製造方法 - Google Patents

モータ、およびモータの製造方法 Download PDF

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Publication number
WO2022270397A1
WO2022270397A1 PCT/JP2022/024094 JP2022024094W WO2022270397A1 WO 2022270397 A1 WO2022270397 A1 WO 2022270397A1 JP 2022024094 W JP2022024094 W JP 2022024094W WO 2022270397 A1 WO2022270397 A1 WO 2022270397A1
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WO
WIPO (PCT)
Prior art keywords
stator
shaft
rotor
motor
bearing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2022/024094
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English (en)
French (fr)
Japanese (ja)
Inventor
勇太 榎園
大地 東
達哉 齋藤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Electric Sintered Alloy Ltd
Sumitomo Electric Industries Ltd
Original Assignee
Sumitomo Electric Sintered Alloy Ltd
Sumitomo Electric Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Electric Sintered Alloy Ltd, Sumitomo Electric Industries Ltd filed Critical Sumitomo Electric Sintered Alloy Ltd
Priority to JP2023530397A priority Critical patent/JP7840944B2/ja
Publication of WO2022270397A1 publication Critical patent/WO2022270397A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/12—Stationary parts of the magnetic circuit
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
    • H02K21/12—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
    • H02K21/24—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets axially facing the armatures, e.g. hub-type cycle dynamos

Definitions

  • the present disclosure relates to motors and methods of manufacturing motors.
  • This application claims priority based on Japanese Patent Application No. 2021-102188 filed in Japan on June 21, 2021, and incorporates all the contents described in the Japanese application.
  • the axial gap type rotary electric machine of Patent Document 1 includes a case, a stator, a rotor, a shaft, and a bearing.
  • the case includes a cylindrical peripheral wall portion and a pair of disk-shaped plates. A pair of plates are attached to both ends of the peripheral wall. A through hole is formed in the center of the pair of plates. A shaft is provided in the through hole.
  • the stator and rotor are arranged to face each other in the axial direction of the shaft within the case.
  • the stator is arranged on the plate.
  • the rotor is provided with a gap from the stator.
  • the shaft is the axis of rotation of the rotor.
  • the bearing rotatably supports the shaft.
  • the motor of the present disclosure includes a shaft, a bearing rotatably supporting the shaft, a rotor fixed integrally with the shaft, and a gap of a design length in the axial direction of the shaft with respect to the rotor. and a stator arranged with a gap, the stator having a stator core made of a compacted body, the stator core having a first surface facing the gap and the first surface in the axial direction. and a second surface provided on the opposite side of the second surface, and at least one of the first surface and the second surface has grinding marks.
  • a method of manufacturing a motor according to the present disclosure includes a step of adjusting the height of a stator in an axial gap type motor, and a step of assembling parts of the motor. and a bearing that rotatably supports the shaft, the stator has a stator core made of a compacted body, and the step of adjusting the height of the stator includes: obtaining a design height of the stator core in consideration of the actual dimensions of the shaft and the bearing; wherein the design height is a height where the length of the gap between the rotor and the stator is the design length, and the first surface faces the gap and the second surface is a surface provided on the opposite side of the first surface in the axial direction of the shaft.
  • FIG. 1 is a schematic cross-sectional view showing an outline of a motor according to Embodiment 1.
  • FIG. 2 is a schematic cross-sectional view showing an enlarged area A of FIG.
  • FIG. 3 is a cross-sectional schematic diagram showing another example of the region A in FIG. 1 in an enlarged manner.
  • 4 is a schematic perspective view of a stator core provided in the motor according to Embodiment 1.
  • FIG. 5 is a cross-sectional view taken along the line VV of FIG. 4.
  • FIG. FIG. 6 is a schematic cross-sectional view showing an enlarged region B of FIG.
  • FIG. 7 is a graph showing the relationship between the load on the inner race of the first bearing and the amount of displacement of the inner race with respect to the outer race of the first bearing.
  • FIG. 8 is a diagram for explaining an example of grinding in the motor manufacturing method according to the first embodiment.
  • FIG. 9 is a diagram illustrating another example of grinding in the motor manufacturing method according to the first embodiment.
  • FIG. 10 is a schematic cross-sectional view showing the outline of the motor according to the second embodiment.
  • One of the purposes of the present disclosure is to provide a motor with excellent assembly accuracy.
  • Another object of the present disclosure is to provide a method of manufacturing a motor that is excellent in manufacturability of the motor.
  • the motor of the present disclosure has excellent assembly accuracy.
  • the manufacturing method of the motor of the present disclosure is excellent in manufacturability of the motor of the present disclosure.
  • Axial gap type motors are manufactured, for example, through two assembling steps of temporary assembly and final assembly of motor parts.
  • the reason for temporarily assembling the parts is that it is difficult to make the length of the gap between the stator and the rotor the design length if the parts are assembled only once.
  • the design gap length is a target value of the design gap length determined based on the motor specifications. Therefore, the length of the gap of the motor that is temporarily assembled is measured. A difference between the measured length of the gap obtained by measurement and the design length of the gap is obtained. After obtaining the measured length of the gap, disassemble the motor.
  • the parts are assembled.
  • a shim is placed between the bearing and the plate.
  • the placement of the shim moves the bearing away from the plate by the thickness of the shim.
  • the shaft supported by the bearings is displaced in the axial direction of the shaft.
  • Misalignment of the shaft separates the rotor from the stator.
  • the separation of the rotor causes the length of the gap to be longer than the measured length. That is, the length of the gap is longer than the measured length by the thickness of the shim. Since the thickness of the shim is the same as the above difference, the length of the gap can be the designed length.
  • the parts are assembled twice, so the manufacturing work becomes complicated. Moreover, in the manufacturing method described above, the number of parts increases by the number of shims. Also, the use of shims may increase mechanical losses due to increased bearing preload.
  • the inventors diligently studied a method of manufacturing a motor that does not use shims. As a result, the inventors have developed a manufacturing method that enables the length of the gap between the stator and rotor to be substantially the same as the design length in a single assembly of the parts.
  • the embodiments of the present disclosure are listed and described.
  • a motor includes a shaft, a bearing rotatably supporting the shaft, a rotor fixed integrally with the shaft, and an axial direction of the shaft with respect to the rotor. and a stator arranged with a gap of a design length, the stator has a stator core made of a powder compact, the stator core has a first surface facing the gap, and the and a second surface provided on the opposite side of the first surface in the axial direction, and at least one of the first surface and the second surface has grinding marks.
  • the above motor has excellent assembly accuracy. Grinding marks are formed by grinding during the manufacturing process.
  • the stator core is made of a powder compact with lower dimensional accuracy than the electromagnetic steel sheet, the stator core can be made to have a height that allows the gap length to be the designed length by grinding.
  • the above motor does not have shims, it is possible to suppress an increase in the number of parts. Moreover, since the motor can suppress an increase in preload of the bearings, an increase in mechanical loss can be suppressed.
  • the stator core has an annular plate-shaped yoke and a plurality of columnar teeth arranged at intervals in the circumferential direction of the yoke
  • the yoke has an outer peripheral surface, an inner peripheral surface, a planar upper surface and a planar lower surface connecting the outer peripheral surface and the inner peripheral surface
  • each of the plurality of teeth is connected to the upper surface of the yoke and an end surface connected to an end of the side surface opposite to the side connected to the upper surface, the lower surface being the second surface, and the end surface being the first surface.
  • a difference between a maximum value and a minimum value of the height between the lower surface of the yoke and the end surface of each of the plurality of teeth may be 0.02 mm or less.
  • the above motor is easy to reduce noise and vibration. This is because torque ripple is easily reduced when the difference is 0.02 mm or less.
  • the relative density of the compact may be 90% or more.
  • a powder compact with a relative density of 90% or more can easily improve magnetic properties such as saturation magnetic flux density.
  • a compacted body having a relative density of 90% or more tends to improve mechanical properties such as strength.
  • the powder compact includes a plurality of coated particles, and each of the plurality of coated particles is made of a soft magnetic material. It has metal particles and an insulating coating covering the metal particles, the metal particles being composed of pure iron or an iron-based alloy, and the iron-based alloy being an Fe—Si alloy or an Fe—Al alloy. , or an Fe—Si—Al alloy.
  • the saturation magnetic flux density of pure iron is higher than that of iron-based alloys. Therefore, if the metal particles of the powder compact are made of pure iron, the saturation magnetic flux density of the compact is likely to increase. Also, the formability of pure iron is superior to iron-based alloys. Therefore, if the metal particles of the powder compact are made of pure iron, the relative density of the powder compact tends to increase.
  • Iron loss such as eddy current loss in iron-based alloys is easier to reduce than in pure iron. Therefore, if the metal particles of the powder compact are composed of an iron-based alloy, the loss of the powder compact can be easily reduced.
  • the above motor is excellent in assembly accuracy because the fastening member can suppress the deviation between the stator and the first plane.
  • the number of stators and the number of rotors may be one each.
  • the above motor is of the single-stator/single-rotor type.
  • the above motor has excellent assembly accuracy.
  • the number of stators may be two and the number of rotors may be one.
  • the above motor is a double stator/single rotor type.
  • the above motor has excellent assembly accuracy.
  • a method for manufacturing a motor includes the steps of adjusting the height of a stator in an axial gap type motor, and assembling parts of the motor, wherein the parts include a rotor and , the stator, a shaft that is a rotation axis of the rotor, and a bearing that rotatably supports the shaft, the stator having a stator core made of a compacted body, and the height of the stator
  • the step of adjusting the height includes: obtaining a design height of the stator core in consideration of the actual dimensions of each of the shaft and the bearing; and grinding at least one of the second surface, wherein the design height is a height at which the length of the gap between the rotor and the stator is the design length, and the first The surface is a surface facing the gap, and the second surface is a surface provided on the opposite side of the first surface in the axial direction of the shaft.
  • the above motor manufacturing method includes a step of determining the design height and a step of grinding a predetermined surface of the stator core so as to achieve the determined design height, thereby making it possible to manufacture a stator core with the design height.
  • the design height is the height of the stator core where the length of the gap is the design length.
  • the rotor has an annular plate-shaped rotor body and at least one magnet fixed to the rotor body, and the rotor body has , the magnet has a first surface facing the magnet, the magnet has a first end surface facing the stator, and the step of determining the design height is performed on the rotor to which the rotor body and the magnet are fixed.
  • the design height may be obtained by considering the actual length between the first surface of the rotor body and the first end surface of the magnet.
  • the above motor manufacturing method can obtain an accurate design height, so it is possible to manufacture a motor with excellent assembly accuracy.
  • the step of assembling the parts is repeated, and the step of determining the design height includes a number of the shafts that is less than the number of the motors to be manufactured; and the average value of the actual dimensions of each of the bearings to determine the design height.
  • the above motor manufacturing method can obtain an accurate design height, so it is possible to manufacture a motor with excellent assembly accuracy.
  • the grinding process may be surface grinding.
  • the above motor manufacturing method makes it easy to manufacture a stator core with a designed height.
  • the part includes a case having a first plane on which the stator is mounted, and the step of grinding includes: The second surface may be ground while the stator and the case are combined.
  • the above motor manufacturing method can manufacture a motor with excellent assembly accuracy.
  • the part includes a case having a first plane on which the stator is mounted, and the step of grinding includes: At least one of the first surface and the second surface of the stator core may be ground while the stator and the case are not combined.
  • the stator core can be easily ground, so the above motor manufacturing method can manufacture a motor with excellent assembly accuracy. In addition, it is easy to remove the grinding dust of the stator core.
  • FIG. 1 is a sectional view of the motor 1 taken along a plane parallel to the axial direction of the shaft 4.
  • FIG. 1 exemplifies a single-stator/single-rotor axial gap motor as the motor 1 .
  • a single-stator/single-rotor motor is a motor in which the number of stators 2 and the number of rotors 3 are one each.
  • An axial gap motor is a motor in which a stator 2 and a rotor 3 face each other with a gap in the axial direction of a shaft 4 .
  • FIG. 4 is a perspective view showing only the stator core 21 of the motor 1 for convenience of explanation.
  • the motor 1 of this embodiment includes a stator 2 , a rotor 3 , a shaft 4 and a first bearing 51 .
  • the motor 1 has a stator 2, a rotor 3 and a shaft 4 housed in a case 7 which will be described later.
  • the stator 2 and the rotor 3 in the case 7 face each other with a gap in the axial direction of the shaft 4 .
  • the length of this gap along the axial direction satisfies the design length G1.
  • the design length G1 is a target value of the designed gap length determined based on the specifications of the motor 1 .
  • the design length G1 has a certain allowable width.
  • One of the features of the motor 1 of this embodiment is that the stator 2 has a specific stator core 21 .
  • the stator 2 is arranged on the first plane 71f of the case 7, as shown in FIG.
  • the stator 2 includes a stator core 21 and a plurality of coils 25, as shown in FIG.
  • the stator core 21 includes an annular plate-shaped yoke 22 and a plurality of columnar teeth 23 .
  • the yoke 22 magnetically couples adjacent teeth 23 among the teeth 23 arranged in the circumferential direction of the yoke 22 .
  • the yoke 22 has a planar upper surface 22a, a planar lower surface 22b, an outer peripheral surface, and an inner peripheral surface.
  • the upper surface 22a and the lower surface 22b are surfaces connecting the outer peripheral surface and the inner peripheral surface.
  • the upper surface 22a is a surface connected to the side surfaces 23b of the teeth 23.
  • the lower surface 22b is a surface in contact with the first plane 71f.
  • the lower surface 22 b is the second surface 21 s of the stator core 21 .
  • the second surface 21s is a surface arranged on the opposite side of the shaft 4 in the axial direction from the first surface 21f in the stator core 21 .
  • a first surface 21f of the stator core 21 faces the gap.
  • the up and down referred to here does not necessarily coincide with the up and down of the motor 1 .
  • the teeth 23 are provided with coils 25 as shown in FIG.
  • the number of teeth 23 is plural.
  • Each tooth 23 is arranged at predetermined intervals in the circumferential direction of the yoke 22 .
  • Each tooth 23 protrudes perpendicularly to the upper surface 22a of the yoke 22 shown in FIG.
  • Each of the teeth 23 and the yoke 22 of the present embodiment are configured as an integrated compacted body. The powder compact will be described later.
  • Each tooth 23 has the same shape and size.
  • the shape of each tooth 23 is prismatic or cylindrical.
  • Each tooth 23 has a side surface 23b and an end surface 23a.
  • the side surface 23 b is a surface connected to the upper surface 22 a of the yoke 22 .
  • the end surface 23a is a surface connected to the side surface 23b.
  • the end surface 23a is the first surface 21f.
  • the end surface 23a faces magnets 35 of the rotor 3, which will be described later.
  • ⁇ Grinding marks> At least one of the lower surface 22b, which is the second surface 21s, and the end surface 23a, which is the first surface 21f, has grinding marks. Grinding marks are formed by grinding during the manufacturing process. In FIG. 4, for convenience of explanation, the grinding mark 231 is exaggeratedly shown on one end surface 23a. FIG. 4 omits the grinding marks provided on the other end face 23a. Grinding traces 231 are streak-like irregularities generated during grinding. The lines of the grinding marks 231 are formed along the direction of relative movement between the end surface 23a and a grinder 1000, which will be described later with reference to FIGS. 8 and 9, during grinding.
  • Grinding marks refer to streak-like unevenness that satisfies, for example, an arithmetic mean roughness Ra of 0.1 ⁇ m or more and 50 ⁇ m or less.
  • Arithmetic mean roughness Ra is a value measured according to JIS B 0601 (2013).
  • the arithmetic mean roughness Ra may further satisfy 0.1 ⁇ m or more and 10 ⁇ m or less, particularly 0.1 ⁇ m or more and 5 ⁇ m or less.
  • Each side surface 23b is not ground, unlike each end surface 23a. If the second surface 21s is ground during the manufacturing process, grinding marks similar to the grinding marks 231 shown in FIG. 4 are also provided on the second surface 21s, although not shown.
  • the stator core 21 has a hole as shown in FIG. A fastening member 91 is provided in this hole.
  • the fastening member 91 fixes the stator core 21 to the first plane 71f.
  • the fastening member 91 suppresses misalignment between the stator 2 and the first plane 71f.
  • An example of the fastening member 91 is a screw or bolt.
  • the hole is formed halfway through the tooth 23 from the second surface 21s.
  • the number of holes may be less than the number of teeth 23 or may be the same as the number of teeth 23 .
  • the height of the stator core 21 satisfies the design height H1 as shown in FIGS.
  • the design height H1 is the height of the stator core 21 at which the length of the gap is the design length G1.
  • the design height H1 has a certain allowable width.
  • the above difference is the difference between the maximum value and the minimum value of the length between each end surface 23a and the lower surface 22b.
  • a micrometer is used to measure the length between each end surface 23a and the lower surface 22b.
  • a plurality of measurement points are selected on each end surface 23a.
  • the measurement point is set on a straight line drawn so as to pass through the center of gravity of the end surface 23 a and the center of the yoke 22 in a plan view of the stator core 21 , for example. Three or more measurement points are selected on the straight line.
  • the measurement points include the center of gravity of the end face 23a, the edge of the end face 23a near the center of the yoke 22, and the edge of the end face 23a far from the center of the yoke 22 on the straight line.
  • the length between each end surface 23a and the lower surface 22b is the average value of the lengths of the straight lines that connect the lower surface 22b and each measurement point among the straight lines perpendicular to the lower surface 22b.
  • the difference may be 0.02 mm or less. If the difference is 0.02 mm or less, the torque ripple of the motor 1 is small. Therefore, noise and vibration of the motor 1 are small. The smaller the difference, the easier it is to reduce the torque ripple. Said difference may be 0.01 mm or less, even 0.008 mm or less, in particular 0.005 mm or less.
  • the parallelism between the lower surface 22b and each end surface 23a may be 0.02 mm or less. If the parallelism is 0.02 mm or less, the torque ripple of the motor 1 is small. Therefore, noise and vibration of the motor 1 are small. The smaller the degree of parallelism, the easier it is to reduce the torque ripple.
  • the parallelism may be 0.01 mm or less, further 0.008 mm or less, especially 0.005 mm or less.
  • the above parallelism is obtained as follows.
  • a height gauge with a grade 0 platen is used.
  • the stator core 21 is placed on the surface plate so that the end surface 23a faces upward.
  • a plurality of measurement points are selected on each end surface 23a.
  • a measurement point is set on a straight line drawn so as to pass through the center of gravity of the end surface 23 a and the center of the yoke 22 in a plan view of the stator core 21 .
  • Three or more measurement points are selected on the straight line.
  • the measurement points on the straight line include the center of gravity of the end face 23a, the edge of the end face 23a near the center of the yoke 22, and the edge far from the center of the yoke 22 of the end face 23a.
  • the parallelism between the lower surface 22b and each end surface 23a is the average value of the lengths of the straight lines that connect the surface plate and each measurement point among the straight lines perpendicular to the surface plate.
  • a compacted body that constitutes the stator core 21 is composed of an aggregate of a plurality of coated particles 24 shown in FIG. Coated particles 24 have metal particles 241 and insulating coatings 242 .
  • the metal particles 241 are made of a soft magnetic material.
  • Soft magnetic materials are pure iron or iron-based alloys.
  • Pure iron is iron with a purity of 99% or more. That is, pure iron has an iron (Fe) content of 99% by mass or more.
  • the saturation magnetic flux density of pure iron is higher than that of iron-based alloys. Therefore, if the metal particles 241 of the powder compact are made of pure iron, the saturation magnetic flux density of the compact is likely to be improved. Also, the formability of pure iron is superior to iron-based alloys. Therefore, if the metal particles 241 of the compacted body are made of pure iron, the relative density of the compacted body tends to increase.
  • An iron-based alloy is one that contains additional elements, with the balance being Fe and unavoidable impurities. Iron-based alloys contain the most Fe.
  • the iron-based alloy is, for example, at least selected from the group consisting of Fe—Si (silicon) alloys, Fe—Al (aluminum) alloys, Fe—Si—Al alloys, and Fe—Ni (nickel) alloys. It is one kind.
  • Fe—Si based alloys is silicon steel.
  • An example of the Fe--Si--Al alloy is sendust.
  • An example of the Fe—Ni alloy is permalloy.
  • the electrical resistance of iron-based alloys is greater than that of pure iron.
  • the iron-based alloy easily reduces iron loss such as eddy current loss. Therefore, if the metal particles 241 of the powder compact are made of an iron-based alloy, the loss of the powder compact can be easily reduced.
  • the powder compact may contain both metal particles composed of pure iron and metal particles composed of an iron-based alloy.
  • the insulating coating 242 covers the metal particles 241 .
  • the insulating coating 242 can reduce iron loss such as eddy current loss.
  • a powder compact provided with the insulating coating 242 tends to reduce loss.
  • the material of the insulating coating 242 is, for example, oxide. Examples of oxides are phosphates, silica, magnesium oxide or aluminum oxide. Phosphate has excellent adhesion to the metal particles 241 and also has excellent deformability. Therefore, if the insulating coating 242 is made of phosphate, the insulating coating 242 is likely to deform following the deformation of the metal particles 241 in the process of producing the compact. Therefore, the insulating coating 242 is less likely to be damaged. Since the insulating coating 242 is less likely to be damaged, the loss of the powder compact can be easily reduced.
  • the relative density of the compact may be 90% or more.
  • a green compact having a relative density of 90% or more can easily improve the saturation magnetic flux density.
  • a green compact having a relative density of 90% or more is likely to improve mechanical properties such as strength.
  • the relative density may be 93% or higher, or even 95% or higher.
  • the relative density may be 99% or less.
  • “Relative density of the compact” refers to the ratio (%) of the actual density of the compact to the true density of the compact. That is, the relative density of the compact is obtained by [(actual density of compact/true density of compact) ⁇ 100].
  • the actual density of the green compact is obtained by immersing the green compact in oil and impregnating the green compact with oil, [oil-impregnated density x (mass of green compact before oil impregnation / pressure after oil impregnation (Mass of powder compact)].
  • the oil-impregnated density is (mass of compacted product after impregnated with oil/volume of compacted product after impregnated with oil).
  • the actual density of the green compact can be determined by (mass of green compact before oil impregnation/volume of green compact after oil impregnation).
  • the volume of the compacted body after impregnation with oil can typically be measured by a liquid displacement method.
  • the true density of the powder compact is the theoretical density when voids are not included inside.
  • Each coil 25 has a tubular portion.
  • the cylindrical portion is configured by spirally winding a wire.
  • the coil 25 of this embodiment is an edgewise wound coil.
  • a covered rectangular wire is used for the winding of the coil 25 .
  • Each coil 25 is arranged on the outer circumference of the side surface 23 b of the tooth 23 .
  • the cross-sectional shape of the cylindrical portion of each coil 25 is, for example, a shape corresponding to the cross-sectional shape of the teeth 23 .
  • the axial length of the cylindrical portion is slightly shorter than the length of the teeth 23 .
  • FIG. 1 only the cylindrical portion is shown, and the illustration of both end portions of the winding is omitted.
  • the rotor 3 is provided with a gap from the stator 2 .
  • the rotor 3 is integrally fixed to the shaft 4 . This fixation allows the rotor 3 to rotate integrally with the shaft 4 around the rotation axis of the shaft 4 .
  • the rotor 3 comprises a rotor body 31 and at least one magnet 35 .
  • the rotor body 31 is rotatably supported by the shaft 4 with respect to the case 7 .
  • the rotor body 31 is an annular member.
  • the rotor body 31 is provided with a through hole in the center.
  • a third shaft portion 43 of the shaft 4, which will be described later, is provided in this through hole.
  • the rotor main body 31 and the shaft 4 are combined by press-fitting the shaft 4 into the through hole. The press-fitting tends to reduce the deflection of the rotor 3 .
  • the position of the rotor body 31 along the axial direction of the shaft 4 is determined by the rotor body 31 coming into contact with a second end surface 42s of the second shaft portion 42, which will be described later.
  • the rotor body 31 has a first surface 31f, a second surface 31s, an inner peripheral surface and an outer peripheral surface.
  • the first surface 31f and the second surface 31s connect the inner peripheral surface and the outer peripheral surface.
  • the first surface 31f is a surface facing the stator 2 .
  • the second surface 31s is a surface facing the second bearing 55 shown in FIG. The second bearing 55 will be described later.
  • a concave portion 32 is provided on the first surface 31f of the present embodiment.
  • the recess 32 opens toward the stator 2 .
  • a magnet 35 is fixed to the bottom surface 32 a of the recess 32 .
  • the inner peripheral surface of the rotor body 31 is in contact with the third shaft portion 43 of the shaft 4 .
  • the outer peripheral surface of the rotor body 31 is not in contact with the inner peripheral surface of the peripheral wall portion 73 of the case 7, as shown in FIG. A space is provided between the outer peripheral surface of the rotor body 31 and the inner peripheral surface of the peripheral wall portion 73 of the case 7 .
  • the number of magnets 35 may be one or plural. If the number of magnets 35 is one, compared with the case where the number of magnets 35 is plural, the number of parts is small and the rotor 3 is easy to manufacture. Therefore, it is easy to improve the manufacturability of the motor 1 . Moreover, it is easy to manufacture the motor 1 with excellent assembly accuracy.
  • the shape of the magnets 35 is annular.
  • One sheet of magnet 35 has S poles and N poles alternately arranged in the circumferential direction.
  • the specific number of magnets 35 is the same as the number of teeth 23 .
  • the plurality of magnets 35 are arranged at regular intervals in the circumferential direction of the rotor body 31 .
  • the shape of each magnet 35 is, for example, a flat plate shape.
  • the planar shape of each magnet 35 is the same as the planar shape of the end face 23a of the tooth 23, for example.
  • Each magnet 35 is magnetized in the axial direction of the rotating shaft of the rotor 3 .
  • the magnetization directions of the magnets 35 adjacent to each other in the circumferential direction of the rotor body 31 are opposite to each other.
  • the magnet 35 repeats attraction and repulsion with respect to each tooth 23 by the rotating magnetic field generated by the stator 2 , thereby rotating the rotor 3 .
  • the magnet 35 is a permanent magnet.
  • permanent magnets are ferrite magnets, neodymium magnets, samarium-cobalt magnets, or bonded magnets.
  • neodymium magnets and samarium-cobalt magnets have strong magnetic forces.
  • a shaft 4 is a rotating shaft of the rotor 3 .
  • the shaft 4 is composed of a solid round bar-shaped body.
  • the shaft 4 has a plurality of shaft portions with different outer diameters, as shown in FIG.
  • the plurality of shaft portions are configured integrally.
  • the shaft 4 of the present embodiment has a first shaft portion 41, a second shaft portion 42, a third shaft portion 43, and a fourth shaft portion in order from the first plate portion 71 of the case 7 toward the second plate portion 72. 44 and a fifth shaft portion 45 .
  • the first shaft portion 41 is provided inside the first bearing 51 as shown in FIG.
  • the outer peripheral surface of the first shaft portion 41 is in contact with the inner peripheral surface of the inner race 52 of the first bearing 51, as shown in FIG.
  • the second shaft portion 42 has a diameter larger than that of the first shaft portion 41, as shown in FIG.
  • the second shaft portion 42 as shown in FIG. 2, has a first end surface 42f and a second end surface 42s.
  • the first end surface 42 f contacts the first end surface 52 f of the inner race 52 .
  • the first end face 42f is not in contact with the outer race 53 of the first bearing 51.
  • the second end surface 42 s is in contact with the first surface 31 f of the rotor body 31 .
  • the third shaft portion 43 is provided in the through hole of the rotor body 31, as shown in FIG.
  • the outer peripheral surface of the third shaft portion 43 is in contact with the inner peripheral surface of the rotor body 31 as shown in FIG.
  • the third shaft portion 43 has a diameter smaller than that of the second shaft portion 42, as shown in FIG.
  • the third shaft portion 43 has an end face 43a, as shown in FIG.
  • the end face 43 a contacts the first end face of the inner race 56 of the second bearing 55 .
  • the fourth shaft portion 44 is provided inside the second bearing 55 as shown in FIG.
  • the outer peripheral surface of the fourth shaft portion 44 is in contact with the inner peripheral surface of the inner race 56 of the second bearing 55 .
  • the fourth shaft portion 44 has a smaller diameter than the diameter of the third shaft portion 43 .
  • the fifth shaft portion 45 is provided in the through hole 72h of the second plate portion 72 of the case 7.
  • the outer peripheral surface of the fifth shaft portion 45 is not in contact with the inner peripheral surface of the second plate portion 72 .
  • the fifth shaft portion 45 has a smaller diameter than the diameter of the fourth shaft portion 44 .
  • the first bearing 51 and the second bearing 55 support the shaft 4 rotatably around the rotation axis.
  • the first bearing 51 is attached to the first shaft portion 41 of the shaft 4 .
  • the second bearing 55 is attached to the fourth shaft portion 44 of the shaft 4 .
  • the configurations of the first bearing 51 and the second bearing 55 may be the same configuration as each other, or may be different configurations.
  • the first bearing 51 is a radial bearing or an angular bearing.
  • the first bearing 51 has an inner race 52 and an outer race 53, as shown in FIGS.
  • the first bearing 51 of this embodiment is a ball bearing in which balls 54 are arranged between an inner race 52 and an outer race 53 .
  • the inner peripheral surface of the inner race 52 is in contact with the outer peripheral surface of the first shaft portion 41 of the shaft 4 .
  • the outer peripheral surface of the outer race 53 is in contact with a projecting portion 71a, which will be described later.
  • the inner race 52 has a first end face 52f and a second end face 52s.
  • the outer race 53 has a first end face 53f and a second end face 53s.
  • the first end surface 52f is in contact with the first end surface 42f.
  • the first end surface 53f is not in contact with the shaft 4.
  • the second end face 52s is not in contact with the case 7.
  • the second end face 52s is in contact with a fixing member (not shown).
  • This fixing member mechanically fixes the first bearing 51 and the first shaft portion 41 .
  • An example of this fixing member is a retaining ring or a shaft nut. When a shaft nut is used as the fixing member, it is preferable to form a threaded portion on the outer peripheral surface of the first shaft portion 41 .
  • This fixing member may not be used.
  • the inner race 52 and the first shaft portion 41 are fixed by being fitted together.
  • the second end face 53s is in contact with the first plane 71f.
  • FIG. 2 shows an example in which the first end face 52f and the first end face 53f are not shifted along the axial direction of the first bearing 51.
  • FIG. 3 shows an example in which the first end face 52f and the first end face 53f are shifted along the axial direction of the first bearing 51.
  • the first end surface 52f and the first end surface 53f may be displaced along the axial direction of the first bearing 51 .
  • the second bearing 55 is a radial bearing or an angular bearing.
  • the configuration of the second bearing 55 is the same as that of the first bearing 51 . That is, the second bearing 55 has an inner race 56 and an outer race 57, as shown in FIGS.
  • the second bearing 55 is a ball bearing in which balls 58 are arranged between an inner race 56 and an outer race 57, as shown in FIG.
  • the inner peripheral surface of the inner race 56 is in contact with the outer peripheral surface of the third shaft portion 43 .
  • the outer peripheral surface of the outer race 57 is in contact with the inner peripheral surface of the recess 72a.
  • the recess 72 a is provided in the second plate portion 72 of the case 7 .
  • Each of inner race 56 and outer race 57 has a first end surface and a second end surface.
  • a first end surface of the inner race 56 is in contact with the end surface 43a.
  • a second end face of the inner race 56 is not in contact with the elastic member 8 and the case 7, which will be described later.
  • the second end face of the inner race 56 may be in contact with a fixed member similar to the first bearing 51, or may not be in contact with the fixed member. This is because the outer race 57 is pressed in the direction toward the rotor 3 by the elastic member 8 .
  • a first end face of the outer race 57 is not in contact with the rotor 3 and the shaft 4 .
  • a second end face of the outer race 57 is in contact with the elastic member 8 shown in FIG.
  • the elastic member 8 presses the second bearing 55 toward the rotor 3 .
  • the elastic member 8 is arranged between the outer race 57 and the bottom of the recess 72a.
  • An example of the elastic member 8 is a spring washer, a disc spring washer, a corrugated washer, or a rubber O-ring.
  • the case 7 accommodates the stator 2, the rotor 3, a portion of the shaft 4, the first bearing 51, the second bearing 55, and the like.
  • the case 7 includes a first plate portion 71 , a second plate portion 72 and a peripheral wall portion 73 .
  • the peripheral wall portion 73 and the second plate portion 72 of this embodiment are integrally formed.
  • the peripheral wall portion 73 and the first plate portion 71 of the present embodiment are configured separately.
  • the peripheral wall portion 73 and the first plate portion 71 may be configured integrally, and the peripheral wall portion 73 and the second plate portion 72 may be configured separately.
  • the peripheral wall portion 73, the first plate portion 71, and the second plate portion 72 may be configured separately.
  • the peripheral wall portion 73 and the first plate portion 71 of this embodiment are fixed to each other by a fastening member 92 .
  • An example of the fastening member 92 is, like the fastening member 91, a screw or bolt.
  • the peripheral wall portion 73 surrounds the outer peripheries of the stator 2 and the rotor 3 .
  • a hole is provided in the end surface of the peripheral wall portion 73 .
  • a fastening member 92 is provided in this hole.
  • the first plate portion 71 has a first flat surface 71f, a projecting portion 71a, a first through hole, a second through hole, and a third through hole.
  • the stator 2 is arranged on the first plane 71f.
  • the projecting portion 71 a is provided between the stator 2 and the first bearing 51 .
  • the projecting portion 71a is connected to the first plane 71f.
  • the shape of the projecting portion 71a is, for example, cylindrical.
  • the inner peripheral surface of the projecting portion 71 a is in contact with the outer peripheral surface of the outer race 53 .
  • the projecting portion 71 a can be used for positioning the first bearing 51 .
  • the outer peripheral surface of the projecting portion 71a may or may not be in contact with the inner peripheral surface of the yoke 22 .
  • a portion of the first shaft portion 41 is provided in the first through hole.
  • a fastening member 91 is provided in the second through hole.
  • the second through hole is provided at a portion of the stator core 21 corresponding to the hole portion.
  • a fastening member 92 is provided in the third through hole.
  • the third through hole is provided at a portion of the peripheral wall portion 73 corresponding to the hole portion.
  • the second plate portion 72 has a recess 72a in the center.
  • a through hole 72h is provided at the bottom of the recess 72a.
  • a fifth shaft portion 45 is provided in the through hole 72h.
  • the inner diameter of the through hole 72 h is larger than the outer diameter of the fifth shaft portion 45 . Therefore, the shaft 4 rotates without contacting the inner peripheral surface of the through hole 72h and the fourth shaft portion 44 .
  • the motor 1 of this embodiment has excellent assembly accuracy.
  • the stator core 21 is made of a powder compact with lower dimensional accuracy than the electromagnetic steel sheet, the stator core 21 can be made to have a height where the gap length is the design length H1 by grinding in the manufacturing process. is. Since the motor 1 does not have shims, it is possible to suppress an increase in the number of parts. Moreover, since the motor 1 can suppress an increase in preload of the bearings, an increase in mechanical loss can be suppressed.
  • FIG. 1 A method of manufacturing the motor of the first embodiment will be described with reference to FIGS. 2, 3, and 7 to 9.
  • FIG. The manufacturing method of the motor according to the present embodiment includes a process A and a process B. As shown in FIG. Process A adjusts the height of the stator. Process B assembles the parts of the motor.
  • Process A includes process A1 and process A2.
  • Step A1 obtains the design height H1 of the stator core 21 .
  • step A2 at least one of the lower surface 22b, which is the second surface 21s, and the end surface 23a, which is the first end surface 21f, of the stator core 21 is ground. By this grinding process, the height of the stator core 21 is set to the design height H1.
  • the parts assembled in step B are the parts of the motor 1 described above with reference to FIGS. In this embodiment, the parts include stator 2 , rotor 3 , shaft 4 , first bearing 51 , second bearing 55 , case 7 , elastic member 8 , fastening member 91 and fastening member 92 .
  • the stator core 21 is produced by pressure-molding raw material powder.
  • the raw material powder contains a plurality of coated particles.
  • the coated particles have metal particles and an insulating coating.
  • the material of the metal particles and the material of the insulating coating are as described above.
  • the raw material powder may contain a binder and a lubricant in addition to the coated particles. A lubricant may be applied to the inner peripheral surface of the die, which will be described later.
  • a press molding machine or the like can be used for pressure molding of the raw material powder.
  • a press molding machine includes a die, a core rod, an upper punch and a lower punch.
  • the die and core rod form a cavity that is filled with raw powder.
  • the upper punch and the lower punch pressure-mold the raw material powder filled in the cavity.
  • the pressure during pressure molding is, for example, 500 MPa or more and 2000 MPa or less. If the pressure during pressure molding is 500 MPa or more, a powder compact with a high relative density can be produced. If the pressure during pressure molding is 2000 MPa or less, the insulating coating on the coated particles is less likely to be damaged.
  • the pressure during pressure molding may be 700 MPa or more and 1800 MPa or less, and particularly 800 MPa or more and 1500 MPa or less.
  • step A1 the design height H1 of the stator core 21 manufactured as described above is obtained.
  • the design height H1 is obtained by considering the actual dimensions of each of the shaft 4 and the first bearing 51 .
  • the actual dimensions of the shaft 4 are dimensions of the shaft 4 actually measured before assembly.
  • the concept of actual dimensions is the same for the actual dimensions of the first bearing 51 .
  • Consideration of the actual dimensions includes consideration of the actual dimensions themselves and consideration of calculated values obtained from the actual dimensions.
  • the calculated value obtained from the actual dimensions of the shafts 4 is the average value of the actual dimensions of the shafts 4 obtained from the plurality of shafts 4 .
  • the concept of the calculated value is the same for the calculated value of the first bearing 51 as well.
  • the design height H1 takes into account the actual dimensions of each of the shaft 4 and the first bearing 51, as described above. It is required by doing.
  • the number of measurements for obtaining the average value may be less than the number of motors 1 manufactured. For example, assume that 1000 motors 1 are manufactured. If one part in one motor 1 is used, the number of measurements for finding the average value of the actual dimensions of the part should be less than 1000. Even if two parts are used, the number of measurements for obtaining the average value of the actual dimensions of the part should be less than 1000. More specifically, the average value is obtained from the actual dimensions of 50 or less parts. An average value may be obtained for each lot of a certain part.
  • the design height H1 is obtained by "length L1+length L2+length L3-(length L4+design length G1)".
  • the design height H1 is obtained by “length L1+length L2 ⁇ design length G1”.
  • Length L1 is the height of first bearing 51 .
  • the length L2 is the length of the second shaft portion 42 . That is, the length L2 is the length between the first end surface 42f and the second end surface 42s.
  • Length L3 is the depth of recess 32 . That is, the length L3 is the length between the first surface 31f and the bottom surface 32a.
  • Length L4 is the thickness Tm of magnet 35 . When the magnet 35 and the rotor body 31 are fixed with the adhesive 38, the length L4 is the sum of the thickness Tm of the magnet 35 and the thickness Ta of the adhesive 38. All of these lengths are lengths along the axial direction of the shaft 4 .
  • the actual size of the length L1 may be either the actual height of the inner race 52 or the actual height of the outer race 53.
  • the actual height of the outer race 53 is easier to measure than the actual height of the inner race 52 .
  • the actual height of the inner race 52 or the actual height of the outer race 53 is the average value of heights at a plurality of measurement points. Measurement points are taken at equal intervals in the circumferential direction of the inner race 52 or the outer race 53 .
  • the number of measurement points shall be 3 or more.
  • the actual dimension of length L2 is the average value of lengths at multiple measurement points.
  • the measurement points are taken at regular intervals in the circumferential direction of the second shaft portion 42 .
  • the number of measurement points shall be 3 or more.
  • the actual dimension of length L3 is the average value of depths at multiple measurement points. Measurement points are taken at equal intervals on the circumference of three concentric circles.
  • the three circumferences refer to the circumference of the inner peripheral edge of the recess 32, the circumference of the outer peripheral edge of the recess 32, and the middle point between the inner peripheral edge and the outer peripheral edge of the recess 32 when viewed from above. Circumferential.
  • the number of measurement points on each circumference shall be 3 or more.
  • a measurement point on the circumference of the inner peripheral edge, a measurement point on the circumference of the outer circumference, and a measurement point on the circumference of the intermediate point are located on a straight line along the radial direction of the rotor 3. .
  • the actual dimension of the length L4 is the average value of the thicknesses Tm of the plurality of magnets 35 when the number of magnets 35 is plural.
  • Each thickness Tm may be the thickness at one measurement point, or may be the average value of the thicknesses Tm at a plurality of measurement points.
  • One measurement point is the center of gravity of the first end face 35f when the magnet 35 is viewed from above.
  • a plurality of measurement points are set on a straight line drawn so as to pass through the center of gravity of the first end surface 35 f and the center of the rotor 3 in plan view of the magnet 35 . Three or more measurement points are taken on the straight line.
  • the plurality of measurement points on the straight line are the center of gravity of the first end face 35f, the edge of the first end face 35f near the center of the rotor 3, and the edge far from the center of the rotor 3 of the first end face 35f. including the part and
  • the actual dimension of the length L4 is the average value of the thicknesses Tm at a plurality of measurement points.
  • Measurement points are taken at equal intervals on the circumference of three concentric circles.
  • the three circumferences are the circumference of the inner circumference of the first end face 35f, the circumference of the outer circumference of the first end face 35f, and the inner circumference and the outer circumference of the first end face 35f. It shall be on the circumference of the midpoint to the rim.
  • the number of measurement points on each circumference shall be 3 or more.
  • a measurement point on the circumference of the inner peripheral edge, a measurement point on the circumference of the outer circumference, and a measurement point on the circumference of the intermediate point are located on a straight line along the radial direction of the rotor 3. .
  • the thickness at each measurement point is the length along the axial direction of the rotor 3 at each measurement point.
  • the actual dimension of the length L4 is the actual dimension when the rotor body 31 and the magnet 35 are fixed when the adhesive 38 is provided. That is, the actual dimension of the length L4 is the average length along the axial direction of the rotor 3 between the measurement point of the thickness Tm of the magnet 35 and the bottom surface 32a of the recess 32 described above.
  • the shift amount g is the length along the axial direction of the first bearing 51 between the first end surface 53f and the first end surface 52f.
  • the amount of deviation g is determined by considering the load acting on the inner race 52 due to the weight of the shaft 4 and the rotor 3 and the load acting on the inner race 52 due to the attraction of the magnet 35 to the stator 2 . Further, the amount of deviation g acts on the inner race 52 due to the load acting on the inner race 52 due to the weight of the second bearing 55 and the pressing force of the elastic member 8 pressing the second bearing 55 toward the first bearing 51 . It is obtained by considering at least one of the load.
  • a load due to the weight of the shaft 4 and the rotor 3 and a load due to the attraction of the magnet 35 to the stator 2 are mainly applied to the inner race 52 .
  • At least one of a load due to the weight of the second bearing 55 and a load due to the pressing force of the elastic member 8 pressing the second bearing 55 toward the first bearing 51 acts on the inner race 52 .
  • the first end surface 52f may be displaced from the first end surface 53f.
  • the displacement of the first end surface 52f is greatly affected by the attractive force of the magnet 35. As shown in FIG. That is, the stronger the magnetic force of the magnet 35, the more the first end surface 52f is displaced.
  • the length of the gap is shorter than the design length G1 by the amount of deviation g. Therefore, the shift amount g is taken into consideration.
  • the amount of deviation g can be obtained from a graph such as that shown in FIG.
  • the load (N) on the vertical axis in FIG. 7 indicates the load on the inner race 52 of the first bearing 51 .
  • the shift amount (mm) on the horizontal axis in FIG. 7 indicates the shift amount g of the first end surface 52f of the inner race 52 from the first end surface 53f of the outer race 53 of the first bearing 51.
  • the graph in FIG. 7 should be prepared in advance. Specifically, the graph of FIG. 7 can be obtained by applying the load in the axial direction of the first bearing 51 to the inner race 52 while displacing it.
  • the design height H1 is obtained by "(length L1-shift amount g)+length L2+length L3-(length L4+design length G1)".
  • the first surface 31f and the first end surface 35f are flush with each other, and the first end surface 52f and the first end surface 53f are displaced along the axial direction of the first bearing 51.
  • the design height H1 is obtained by "(length L1-shift amount g)+length L2-design length G1".
  • Step A2 grinding is performed by the difference between the design height H1 obtained in step A1 and the actual height of the stator core 21.
  • FIG. When both the lower surface 22b, which is the second surface 21s, and the end surface 23a, which is the first surface 21f, are ground, the total grinding length is the actual dimension of the design height H1 obtained in step A1 and the height of the stator core 21. be the difference between
  • the actual height of the stator core 21 is determined by the actual length between the lower surface 22b and the end surface 23a.
  • the actual length between the lower surface 22b and the end surface 23a is obtained by the same measuring method as the method for measuring the length between each end surface 23a and the lower surface 22b described above.
  • the timing for performing step A2 is before step B, which will be described later, or between steps B2 and B3.
  • FIG. 8 shows an example of performing grinding before step B.
  • FIG. 9 shows an example of performing grinding between steps B2 and B3.
  • the stator core 21 is ground while the stator core 21 and the first plate portion 71 are not combined. In this case, at least one of the lower surface 22b and the end surface 23a of the stator core 21 can be ground.
  • the stator core 21 is ground while the stator core 21 and the first plate portion 71 are combined. In this case, only the end surface 23a can be ground.
  • a grinder 1000 can be used for grinding in both FIGS.
  • the grinding process may be surface grinding. Surface grinding easily aligns the positions of the end faces 23a in the height direction of the stator core 21 .
  • the end surface 23a When grinding the end surface 23a, the end surface 23a may be ground while fixing the end of the side surface 23b of each tooth 23 as shown in FIG. 8 or FIG.
  • a plate member 1100 as shown in FIG. 8 may be used to fix the ends.
  • the plate member 1100 has a plurality of through holes 1110 .
  • the through holes 1110 are holes into which the ends of the teeth 23 can be inserted.
  • the number of through holes 1110 corresponds to the number of teeth 23 .
  • the inner peripheral shape of through hole 1110 is similar to the outer peripheral shape of teeth 23 .
  • the size of the through hole 1110 is such that the end can be inserted, and the gap between the side surface 23b and the inner peripheral surface of the through hole 1110 is minute when the end is inserted.
  • the inner peripheral shape and size of each through hole 1110 are the same.
  • Each tooth 23 is inserted into each through hole 1110 as shown in FIG. 8 or FIG.
  • the inner peripheral surface of the through hole 1110 holds the side surface 23b.
  • the end surface 23a is ground in the held state. 8 and 9 show exaggerated areas of the teeth 23 exposed from the plate member 1100 for convenience of explanation.
  • the plate-like member 1100 may also be ground together.
  • the grinding marks 231 described with reference to FIG. 4 are formed on the ground end surface 23a.
  • grinding marks similar to the grinding marks 231 are also formed on the lower surface 22b, though not shown.
  • step B of assembling the parts each member is fixed at a predetermined position. Through the process B, the motor 1 as shown in FIG. 1 is manufactured. As an example of the order of assembling the parts, the following steps B1 to B6 are performed in order.
  • step B1 the stator 2 and the first bearing 51 are arranged on the first flat surface 71f of the first plate portion 71.
  • step B2 the fastening member 91 fixes the first plate portion 71 and the stator 2 .
  • the fastening member 91 is provided in the second through hole of the first plate portion 71 and the hole portion of the stator 2 .
  • step B3 the first shaft portion 41 of the shaft 4 is placed inside the first bearing 51.
  • a rotor assembly in which the rotor 3 and the shaft 4 are combined is prepared in advance.
  • step B3 the first shaft portion 41 of the rotor assembly is placed inside the first bearing 51 .
  • step B4 is performed without step B31.
  • the step B31 is performed before the step B4.
  • step B31 the rotor 3 is fitted to the shaft 4 with the first shaft portion 41 arranged in the first bearing 51 .
  • step B4 the second bearing 55 is fitted to the fourth shaft portion 44 of the shaft 4.
  • step B5 the elastic member 8 is placed on the second bearing 55.
  • step B6 the fifth shaft portion 45 of the shaft 4 is fitted into the through hole 72h of the second plate portion 72, and the end surface of the peripheral wall portion 73 and the first plate portion 71 are butted against each other. Then, the first plate portion 71 and the peripheral wall portion 73 are fixed by the fastening member 92 .
  • the fastening member 92 is provided in the third through hole of the first plate portion 71 and the hole portion of the peripheral wall portion 73 .
  • the motor manufacturing method of the present embodiment may further include a step C of heat-treating the stator core 21 .
  • Process C is performed before Process A or between Process A and Process B.
  • the heat treatment temperature is, for example, 350°C or higher and 800°C or lower.
  • the heat treatment temperature may further be 400° C. or higher and 750° C. or lower, and particularly 450° C. or higher and 700° C. or lower.
  • the holding time of the heat treatment is, for example, 5 minutes or more and 60 minutes or less.
  • the holding time of the heat treatment may be 10 minutes or more and 45 minutes or less, and particularly 15 minutes or more and 30 minutes or less.
  • the atmosphere in the heat treatment is, for example, an oxidizing atmosphere.
  • the oxygen concentration in the oxidizing atmosphere is, for example, 500 ppm or more and 20000 ppm or less.
  • the oxygen concentration here is a volume ratio.
  • the oxygen concentration in the oxygen atmosphere may be 700 ppm or more and 10000 ppm or less, 1000 ppm or more and 7500 ppm or less, or particularly 2000 ppm or more and 5000 ppm or less.
  • step C is performed before step A, oxides are formed between the coated particles near the surface of the stator core 21 .
  • the formed oxide suppresses the plastic flow of the metal particles 241 that accompanies the grinding process. Therefore, even if the insulating coating 242 is damaged by grinding, it is possible to prevent the adjacent metal particles 241 from connecting to each other.
  • step C is performed between steps A and B, the ground surface is oxidized. That is, even if the insulating coating 242 is damaged by grinding and the adjacent metal particles 241 are connected to each other, the connecting portions are oxidized. Therefore, the metal particles 241 adjacent to each other are insulated by the oxide film. Therefore, by performing the process C, the eddy current loss is reduced, which in turn reduces the loss.
  • the design height H1 of the stator core 21 corresponding to the design length G1 can be obtained before assembling the parts.
  • the height of the stator core 21 can be brought to the design height H1 by grinding before or during the assembly of the parts. Therefore, in the motor manufacturing method of the present embodiment, the length of the gap can be set to the design length G1 by assembling the parts only once. Therefore, the motor manufacturing method of the present embodiment is excellent in productivity of the motor 1 with excellent assembly accuracy without using shims.
  • the inner race 52 may be displaced with respect to the outer race 53 of the first bearing 51. Even in this case, the motor manufacturing method of the present embodiment can determine the design height H1 in consideration of the deviation amount g described above. Therefore, even if the inner race 52 is misaligned, the motor manufacturing method of the present embodiment is excellent in the productivity of the motor 1 with excellent assembly accuracy.
  • the motor manufacturing method of the present embodiment is excellent in manufacturability of a plurality of motors 1 with excellent assembly accuracy even when the process of assembling parts is repeated. Therefore, the motor manufacturing method of the present embodiment can manufacture a plurality of motors 1 with small variations in performance.
  • the design height H1 is obtained by considering the average value of the actual dimensions of a part that is less than the number of manufactured parts
  • the design height H1 is obtained by considering the actual dimensions of the same number of parts as the number of manufactured parts. As compared with , it is easy to improve the manufacturability of the motor 1 .
  • the motor 1 of Embodiment 2 will be described with reference to FIG.
  • the motor 1 of the second embodiment differs from the motor 1 of the first embodiment mainly in that it is a double-stator/single-rotor axial gap motor.
  • the double-stator/single-rotor type motor 1 has two stators 2 and one rotor 3 .
  • two stators 2 are assembled so that one rotor 3 is sandwiched between the shafts 4 in the axial direction.
  • At least one of the two stators 2 is the stator 2 described in the first embodiment.
  • Both of the two stators 2 may be the stator 2 described in the first embodiment.
  • the following description will focus on the differences from the first embodiment. Descriptions of configurations similar to those of the first embodiment may be omitted.
  • the rotor body 31 is an annular flat plate member.
  • the rotor body 31 has a first through hole and at least one second through hole.
  • a first through hole is provided in the center.
  • a third shaft portion 43 of the shaft 4 is provided in the first through hole.
  • the second through hole is provided on the outer periphery of the first through hole.
  • a magnet 35 is provided in the second through hole.
  • the number of second through holes is the same as the number of magnets 35 .
  • the thickness of the rotor body 31 and the thickness of the magnets 35 in this embodiment are the same. That is, the first surface of the rotor body 31 and the first end surface of the magnet 35 are flush with each other. Also, the second surface of the rotor body 31 and the second end surface of the magnet 35 are flush with each other. The first surface of the rotor body 31 and the first end surface of the magnet 35 are surfaces closer to the first stator 2 . The second surface of the rotor body 31 and the second end surface of the magnet 35 are surfaces closer to the second stator 2 .
  • the stator 2 shown on the lower side of FIG. 10 is the first stator 2 .
  • the stator 2 shown on the upper side of FIG. 10 is the second stator 2 .
  • the rotor body 31 and the magnets 35 do not have to have the same thickness.
  • the case 7 of this embodiment includes a pair of first plate portions 71 and a peripheral wall portion 73 .
  • the pair of first plate portion 71 and peripheral wall portion 73 are configured separately.
  • the first first plate portion 71 and the peripheral wall portion 73 are fixed by a fastening member 92 .
  • the second first plate portion 71 and the peripheral wall portion 73 are fixed by a fastening member 92 .
  • the design height of the first stator core 21 is obtained by considering the actual dimensions of each of the shaft 4 and the first bearing 51 shown on the bottom side of FIG.
  • the design height of the first stator core 21 is obtained by "the actual height of the first bearing 51 + the actual length of the second shaft portion 42 - the design length G1".
  • the design height of the second stator core 21 is obtained by considering the actual dimensions of each of the rotor 3, shaft 4, and first bearing 51 shown on the upper side of FIG.
  • the design height of the second stator core 21 is obtained by "the actual height of the first bearing 51 + the actual length of the third shaft portion 43 - (the thickness of the magnet 35 + the design length G1)". be done.
  • the actual length of the third shaft portion 43 is the actual length between the end surface 43a and the second end surface 42s.
  • the actual length of the third shaft portion 43 is the average value of lengths at a plurality of measurement points.
  • the measurement points are taken at regular intervals in the circumferential direction of the third shaft portion 43 .
  • the number of measurement points shall be 3 or more.
  • the length of each measurement point is the length along the axial direction of the third shaft portion 43 at each measurement point.
  • the motor 1 of this embodiment has excellent assembly accuracy, as in the first embodiment.
  • the motor manufacturing method of the present embodiment is excellent in manufacturability of the motor 1 with excellent assembly accuracy without using shims.
  • the yoke may be composed of a plurality of fan plate-shaped yoke pieces.
  • the number of teeth connected to each yoke piece may be one or plural.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)
PCT/JP2022/024094 2021-06-21 2022-06-16 モータ、およびモータの製造方法 Ceased WO2022270397A1 (ja)

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JP2023530397A JP7840944B2 (ja) 2021-06-21 2022-06-16 モータ、およびモータの製造方法

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JP2021102188 2021-06-21
JP2021-102188 2021-06-21

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