WO2021106637A1 - Outer rotor-type electric motor and method for manufacturing rotor yoke of outer rotor-type electric motor - Google Patents

Outer rotor-type electric motor and method for manufacturing rotor yoke of outer rotor-type electric motor Download PDF

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Publication number
WO2021106637A1
WO2021106637A1 PCT/JP2020/042481 JP2020042481W WO2021106637A1 WO 2021106637 A1 WO2021106637 A1 WO 2021106637A1 JP 2020042481 W JP2020042481 W JP 2020042481W WO 2021106637 A1 WO2021106637 A1 WO 2021106637A1
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Prior art keywords
rotor yoke
wall portion
region
peripheral wall
magnetic flux
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PCT/JP2020/042481
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French (fr)
Japanese (ja)
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雄二郎 杉山
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マーレエレクトリックドライブズジャパン株式会社
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Publication of WO2021106637A1 publication Critical patent/WO2021106637A1/en

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    • 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
    • H02K1/22—Rotating parts of the magnetic circuit
    • 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
    • H02K1/22—Rotating parts of the magnetic circuit
    • H02K1/27—Rotor cores with permanent magnets

Definitions

  • the present invention relates to an electric motor, and particularly relates to an outer rotor type motor and a method for manufacturing a rotor yoke of the outer rotor type motor.
  • the outer rotor type motor has a stator arranged inside a cup-shaped rotor yoke, and has a feature that the driving torque can be increased.
  • Such an outer rotor type motor is shown in, for example, Japanese Patent Application Laid-Open No. 2010-7208 (Patent Document 1).
  • the outer rotor type motor described in Patent Document 1 includes a rotor in which a plurality of permanent magnets are arranged on an inner peripheral wall surface of a rotor yoke, and a stator having a plurality of electromagnetic coils wound in slots formed in a stator core. It has. Further, the stator is inserted into the inner surface of the rotor through a slight gap, and the rotor is rotatably supported by a rotary support shaft fixed to the rotor being pivotally supported by a bearing provided on the stator. Has been done.
  • the rotors are arranged on the inner peripheral wall surface of the rotor yoke at equal angular intervals in the circumferential direction so that a plurality of plate-shaped permanent magnets alternate between north and south poles.
  • This rotor yoke has a thin cylindrical shape whose axial width is shorter than the radius.
  • the stator includes a stator core having a ring-shaped core center portion and a plurality of electromagnetic coils, and the electromagnetic coils are each wound around the corresponding teeth in a concentrated winding manner.
  • the teeth are formed in a substantially T shape, and are radially outwardly projected on the stator core at equal angular intervals.
  • FIG. 4 shows an enlarged view of a part of the rotor yoke and the stator core.
  • teeth 51 are formed on the stator core 50 at equal angular intervals, and the teeth 51 are formed in a shape extending radially outward from the center of the stator core 50.
  • An electromagnetic coil 52 is wound around the teeth 51, and a magnetic field is generated when the teeth 51 are energized.
  • plate-shaped permanent magnets 54 are arranged on the inner circumference of the rotor yoke 53 at equal intervals by an adhesive such as synthetic resin. Further, on the inner peripheral side of the rotor yoke 53, a positioning protrusion 55 projecting inward for positioning is formed between the permanent magnets 54.
  • the rotor yoke 53 has a function as a magnetic path through which magnetic flux passes.
  • the rotor yoke 53 is formed by pressing a circular steel plate into a cup shape, or by rolling a flat steel plate into a cup shape.
  • the plate thickness (tr) of the rotor yoke 53 is a plate thickness (tr) at which the magnetic flux is not saturated and is formed to have an equal thickness over the entire circumference, that is, a so-called equal thickness.
  • a low magnetic flux region (LMG) having a small magnetic flux density is formed near the center of the permanent magnet 54 in the circumferential direction, and conversely, a high magnetic flux density is large near the center between the adjacent permanent magnets 54. It becomes the magnetic flux region (HMg).
  • the magnetic flux density is not defined by a clear boundary between the low magnetic flux density region (LMG) and the high magnetic flux density region (HMg), but the magnetic flux density changes with an inclination, which is well known. It is a matter that is.
  • the plate thickness (tr) around the entire circumference of the rotor yoke 53 is determined to be a uniform plate thickness with reference to the above-mentioned high magnetic flux region (HMg) in order not to saturate the magnetic flux. .. Therefore, the weight of the rotor yoke 53 becomes heavy, which hinders the weight reduction as an electric motor. Further, since the rotor yoke 53 is heavy, the inertia becomes large, which also causes a performance problem that the start-up of rotation of the electric motor is delayed.
  • the plate thickness (tr) of the rotor yoke 53 may be uniformly thinned, but if the plate thickness (tr) is uniformly thinned, the magnetic flux is generated in the high magnetic flux region (HMg). The density will be saturated and the performance of the motor will be reduced.
  • a positioning protrusion 55 for positioning the plate-shaped permanent magnet 54 is formed, and in order to form the positioning protrusion 55, both sides of the positioning protrusion 55 are cut with a cutting tool. This creates an extra manufacturing process, wastes materials, and raises the manufacturing unit price.
  • An object of the present invention is to provide a novel outer rotor type motor capable of reducing the weight of the rotor yoke and suppressing the saturation of the magnetic flux density associated therewith, and a method for manufacturing the rotor yoke of the outer rotor type motor. ..
  • the first feature of the present invention is a rotor yoke provided with a side peripheral wall portion that covers the radial outer peripheral side of the stator core, and a permanent magnet attached to the inner peripheral surface of the side peripheral wall portion of the rotor yoke at predetermined angular intervals in the circumferential direction.
  • the thickness of the side peripheral wall of the rotor yoke is formed thin in the region where the magnetic flux density is small according to the magnetic flux density of the magnetic flux generated on the side peripheral wall of the rotor yoke.
  • the region where the density is high is where the thickness of the side peripheral wall portion of the rotor yoke is formed to be thick.
  • the second feature of the present invention is a rotor yoke provided with a side peripheral wall portion that covers the radial outer peripheral side of the stator core, and a permanent magnet mounted on the inner peripheral surface of the side peripheral wall portion of the rotor yoke at predetermined angular intervals in the circumferential direction.
  • It is an outer rotor type motor equipped with a magnet, and the thickness of the side peripheral wall of the rotor yoke near the center in the circumferential direction of the permanent magnets arranged on the inner peripheral wall surface of the rotor yoke is formed thinly, and the permanent magnets adjacent to each other are formed.
  • the thickness of the side peripheral wall of the rotor yoke between them is thickly formed.
  • the third feature of the present invention is that the inner peripheral side press jig in which the positioning region between the permanent magnet arrangement regions where adjacent permanent magnets are arranged is open is brought into close contact with the inner peripheral side of the side peripheral wall portion of the rotor yoke.
  • a press jig on the outer peripheral side in which the deformation region near the center in the circumferential direction of the permanent magnet placement region is open is placed in close contact with the outer peripheral side of the side peripheral wall portion of the rotor yoke, and the deformation press treatment is performed in this state.
  • the tool is pressed against the deformed region to deform the metal material of the rotor yoke in the deformed region to form a thin wall, and the excess metal material due to this thinning bulges inward from the positioning region of the inner peripheral side press jig. It is there to form the positioning part of the permanent magnet.
  • the plate thickness is formed thin in the region where the magnetic flux density is low and the plate thickness is formed thick in the region where the magnetic flux density is high according to the magnetic flux density generated in the rotor yoke. It can be reduced and the saturation of the magnetic flux density accompanying this can be suppressed.
  • the plate thickness of the side peripheral wall portion of the rotor yoke near the center in the circumferential direction of the permanent magnet is formed to be thin, and the plate thickness of the side peripheral surface wall portion of the rotor yoke between adjacent permanent magnets is formed to be thick. Therefore, the weight of the rotor yoke can be reduced and the saturation of the magnetic flux density associated therewith can be suppressed.
  • the deformed press jig is pressed against the deformed region of the outer peripheral side press jig to deform the metal material of the rotor yoke in the deformed region to form a thin wall, and the extra metal material due to this thinning is formed. Is bulged inward from the positioning area of the inner press jig to form the positioning part of the permanent magnet, so it is not necessary to cut both sides of the positioning part with a cutting tool, and an extra manufacturing process can be omitted. Moreover, the material is not wasted due to cutting, and it is possible to suppress an increase in the manufacturing unit price.
  • FIG. 1 It is sectional drawing which shows the cross section in the axial direction of the outer rotor type motor to which this invention is applied. It is a partially enlarged sectional view of the rotor and the stator which cross-sectioned in the plane orthogonal to the axial direction of the rotation support shaft of the rotor in embodiment of this invention. It is explanatory drawing explaining the manufacturing method of the rotor yoke shown in FIG. It is a partially enlarged cross-sectional view of a rotor and a stator which are cross-sectioned in the plane orthogonal to the axial direction of the rotation support shaft of a rotor in a conventional motor.
  • FIG. 1 shows a cross section of a brushless outer rotor type motor, and the motor 10 has, for example, an 8-pole / 12-slot, 3-phase drive type configuration.
  • the stator 11 is composed of a stator core 12 and an electromagnetic coil 13.
  • the stator core 12 of the stator 11 is provided with a tubular portion 14 near the central portion thereof, and the tubular portion 14 is formed with 12 teeth 15 extending outward in the radial direction.
  • Each tooth 15 is provided with an electromagnetic coil 13 wound around a bobbin 16 made of synthetic resin.
  • a shaft 17 as a rotation support shaft is rotatably supported on the cylinder portion 14 via a ball bearing 17B as a bearing.
  • a rotor yoke 19 constituting the rotor 18 is attached to one end of the shaft 17 by a fixing method such as press fitting so as to rotate integrally with the shaft 17.
  • the rotor yoke 19 is formed in a cup shape including an upper surface wall portion 19U and a side peripheral wall portion 19S perpendicularly intersecting the upper surface wall portion 19U, and is formed in a shape that covers the stator core 12.
  • the rotor yoke 19 has an open side on one end side (lower side in FIG. 1) of the shaft 17.
  • a plurality of plate-shaped permanent magnets 20 are attached to the inner peripheral wall surface of the side peripheral wall portion 19S of the rotor yoke 19 at predetermined angular intervals in the circumferential direction.
  • the number of permanent magnets 20 is eight.
  • Each permanent magnet 20 is magnetized so that the magnetic poles change in the plate thickness direction, and the magnetic poles of adjacent permanent magnets 20 are arranged so as to be different.
  • the permanent magnets 20 are all formed to have the same shape and size. As shown in FIG. 2, the permanent magnet 20 has a plate shape, and the permanent magnet 20 is arranged so that the length direction of the permanent magnet 20 corresponds to the axial direction of the shaft 17 and the thickness direction of the permanent magnet 20 corresponds to the radial direction. It is attached to the inner peripheral wall side of the side peripheral wall portion 19S of the rotor yoke 19. Further, the circumferential direction of the permanent magnet 20 means the same direction as the circumferential direction of the rotor yoke 19.
  • the permanent magnet 20 is formed so that the central portion in the circumferential direction is thicker than both ends in the circumferential direction.
  • the outer surface 20A which is the side surface attached to the side peripheral wall portion 19S of the rotor yoke 19, has a curved surface that is convex outward in the radial direction
  • the inner surface 20B which is the surface facing the teeth 15, is formed. It is formed so as to have a curved surface that is convex inward in the radial direction.
  • a printed circuit board (not shown) is attached to the side facing the rotor yoke 19, and the printed circuit board detects the magnetic force corresponding to the convex portion (not shown) provided on the permanent magnet 20.
  • a Hall IC as a sensor of the above is attached. The Hall IC is arranged at a position facing the end surface of the opening of the rotor yoke 19.
  • FIG. 2 is a partially enlarged cross-sectional view of the rotor yoke 19S and the stator core 12 cross-sectionald in a plane orthogonal to the axial direction of the shaft 17 which is a rotation support shaft.
  • a thick-walled region portion 21 and a thin-walled region portion 22 are formed along the circumferential direction with reference to the magnetic flux density generated in the side peripheral wall portion 19S of the rotor yoke 19.
  • the thick-walled region portion 21 roughly corresponds to the high magnetic flux density region (HMg)
  • the thin-walled region portion 22 also roughly corresponds to the low magnetic flux density region (LMG).
  • the thick region portion 21 has a uniform plate thickness and an annular cross section as in the conventional case.
  • the thin-walled region portion 22 is formed in a groove shape as a recess 22R on the outer peripheral side of the side peripheral wall portion 19S.
  • the thin-walled region portion 22 is provided with a length corresponding to the permanent magnet 20 in the axial direction.
  • the plate thickness (Tr1) is set to a thickness that does not saturate the magnetic flux density.
  • the plate thickness (Tr2) is also set to a thickness so that the magnetic flux density is not saturated. Therefore, the magnetic flux density does not saturate even if the plate thickness (Tr2) of the thin-walled region portion 22 is formed to be thin.
  • the relationship between the plate thickness (Tr1) of the thick region portion 21 and the plate thickness (Tr2) of the thin region portion 22 is determined as the relationship of "Tr2 ⁇ TR1". Since the thin-walled region portion 22 is formed in a low magnetic flux density region (LMG) having a small magnetic flux density, it is possible to suppress saturation of the magnetic flux density. Further, the weight of the rotor yoke 19 can be reduced by forming the thin-walled region portion 22, and as a result, the weight of the motor 10 can be reduced.
  • LMG low magnetic flux density region
  • the cross-sectional shape of the recess 22R of the thin-walled region portion 22 is formed in the shape of an arc in the present embodiment, but it can also be formed in the shape of a linearly inclined groove that forms the apex angle of a triangle. Can also be formed into a rectangular groove shape.
  • the side peripheral wall portion 19S of the rotor yoke 19 of the present embodiment is a region between the thin-walled region portion 22 corresponding to the vicinity of the center of each permanent magnet 20 in the circumferential direction, that is, the vicinity of the magnetic pole center, and the adjacent permanent magnets 20. It can be said that the thick-walled region portion 21 corresponding to (so-called crossover region) is provided.
  • the number of the thin-walled region portion 22 and the thick-walled region portion 21 is the same as the number of permanent magnets 20, and the thin-walled region portion 22 and the thick-walled region portion 21 are thick from the portion where the thin-walled region portion 21 should be formed by metal stamping. It is formed by plastically flowing a metal material to a portion where the meat region portion 21 should be formed. Therefore, the total weight of the rotor yoke can be made lighter than the total weight of the conventional rotor yoke.
  • the side peripheral wall portion 19S of the rotor yoke 19 is formed with positioning portions 23 for arranging the permanent magnets 20 at predetermined intervals. Therefore, the magnetizing step can be performed immediately after applying the adhesive and attaching the permanent magnet 20 to the side peripheral wall portion 19S of the rotor yoke. Since the permanent magnet 20 is magnetically attracted to the side peripheral wall portion 19S of the rotor yoke 19 by magnetism, the permanent magnet 20 is held in a predetermined position unless an excessive vibration impact is applied, so that an adhesive jig can be eliminated. .. The method of forming the thin-walled region portion 22 and the positioning portion 23 will be described later.
  • the portion where the adjacent permanent magnets 20 face each other is formed thick.
  • the region between the adjacent permanent magnets 20 is a region where the magnetic flux density becomes large. Therefore, since the region where the magnetic flux density is large is the thick-walled region portion 21, it has the effect of alleviating the magnetic saturation and reducing the magnetic resistance.
  • the vicinity of the center of the permanent magnet 20 in the circumferential direction is formed to be thin. Since the vicinity of the center of the permanent magnet 20 is a region where the magnetic flux density is small, thinning the permanent magnet 20 does not cause any problem in the magnetic circuit, and the weight of the rotor yoke can be reduced.
  • the permanent magnet 20 is formed in a shape in which the vicinity of the center in the circumferential direction is thicker than both ends in the circumferential direction. Therefore, the permanent magnet 20 is thick in the thin-walled region portion 22 where the side peripheral wall portion 19S of the rotor yoke 19 is thin, and thin in the thick-walled region portion 21 where the side peripheral wall portion 19S of the rotor yoke 19 is thick. The thickness is changing. Therefore, the weight of the rotor yoke 19 as a whole becomes almost uniform in the circumferential direction, so that the rotation of the rotor 18 can be made less likely to fluctuate.
  • FIG. 3 shows a method of manufacturing the rotor yoke of the present embodiment, in which the side peripheral wall portion 19S of the rotor yoke 19 is restrained by the inner peripheral side press jig 30 and the outer peripheral side press jig 32, and the side peripheral surface wall.
  • the thin-walled region portion 22 is formed from the outer peripheral side of the portion 19S by the deformation press jig 34, and at the same time, the positioning portion 23 is formed at the same time.
  • the inner peripheral side press jig 30 has a shape that is in close contact with the inner peripheral wall surface of the side peripheral surface wall portion 19S of the rotor yoke 19, and the positioning region 31 between the permanent magnet arrangement regions in which the adjacent permanent magnets are arranged is open. Has been done.
  • the positioning region 31 is an opening for forming the positioning portion 23, and is formed along the axis of the rotor yoke 19.
  • the outer peripheral side press jig 32 has a shape that is in close contact with the outer peripheral wall surface of the side peripheral wall portion 19S of the rotor yoke 19, and is a deformation region 33 near the center in the circumferential direction of the permanent magnet arrangement region in which the permanent magnet is arranged. Is open.
  • the deformed region 33 is an opening for forming the thin-walled region portion 22, and is formed along the axis of the rotor yoke 19.
  • the inner peripheral side press jig 30 is brought into close contact with the inner peripheral wall surface of the side peripheral surface wall portion 19S of the rotor yoke 19
  • the outer peripheral side press jig 32 is brought into close contact with the outer peripheral wall surface of the side peripheral surface wall portion 19S of the rotor yoke 19.
  • the deformation press jig 34 is pushed into the deformation region 33 to form the thin-walled region portion 22.
  • the deformed press jig 34A shows the state before being pushed into the deformed region 33
  • the deformed press jig 34B shows the state before being pushed into the deformed region 33.
  • the thin-walled region portion 22 and the positioning portion 23 are formed at the same time by press working. Therefore, it is not necessary to cut both sides of the positioning portion with a cutting tool as in the conventional case, an extra manufacturing process can be omitted, and the material is not wasted due to cutting, and it is possible to suppress an increase in the manufacturing unit price.
  • the plate thickness is formed thin in the region where the magnetic flux density is low and the plate thickness is formed thick in the region where the magnetic flux density is high in accordance with the magnetic flux density generated in the rotor yoke. It is possible to reduce the weight of the magnetic flux density and suppress the saturation of the magnetic flux density associated therewith.
  • the thickness of the side peripheral wall portion of the rotor yoke near the center in the circumferential direction of the permanent magnet is formed thin, and the plate thickness of the side peripheral wall portion of the rotor yoke between adjacent permanent magnets is formed thick. Since the structure is configured, the weight of the rotor yoke can be reduced, and the resulting saturation of the magnetic flux density can be suppressed.
  • the deformed press jig is pressed against the deformed region of the outer peripheral side press jig to deform the metal material of the rotor yoke in the deformed region to form a thin wall, and the extra metal material due to this thinning is formed. Since the permanent magnet positioning portion is formed by bulging inward from the positioning region of the inner press jig, it is not necessary to cut both sides of the positioning portion with a cutting tool, and an extra manufacturing process can be omitted. It is possible to prevent the material from being wasted due to cutting and to suppress the increase in the manufacturing unit price.
  • the present invention is not limited to the above-described embodiment, and includes various modifications.
  • the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations.
  • it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment and it is also possible to add the configuration of another embodiment to the configuration of one embodiment.
  • 10 outer rotor type motor, 11 ... stator, 12 ... stator core, 13 ... electromagnetic coil, 14 ... cylinder, 15 ... teeth, 17 ... shaft, 18 ... rotor, 19 ... rotor yoke, 19U ... top wall, 19S ... Side peripheral wall portion, 20 ... Permanent magnet, 21 ... Thick wall region portion, 22 ... Thin wall region portion, 23 ... Positioning portion, HMg ... High magnetic flux density region, LMg ... Low magnetic flux density region.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Permanent Field Magnets Of Synchronous Machinery (AREA)
  • Manufacture Of Motors, Generators (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)

Abstract

Provided are: a novel outer rotor-type electric motor capable of reducing the weight of a rotor yoke and suppressing the saturation of the magnetic flux density associated therewith; and a method for manufacturing a rotor yoke of an outer rotor-type electric motor.　In accordance with the magnetic flux density of the magnetic flux generated in a side peripheral wall portion 19S of a rotor yoke 19, a side peripheral wall portion 19S of the rotor yoke 19 is formed to have a thin plate thickness in a region (LMg) where the magnetic flux density is small, and the side peripheral wall portion 19S of the rotor yoke 19 is formed to have a thick plate thickness in a region (HMg) where the magnetic flux density is large. Since the plate thickness of the annular rotor yoke is configured in accordance with the generated magnetic flux density such that the plate thickness is small in the region where the magnetic flux density is small and the plate thickness is great in the region where the magnetic flux density is large, it is possible to reduce the weight of a rotor yoke and suppress the saturation of the magnetic flux density associated therewith.

Description

アウターロータ形電動機、及びアウターロータ形電動機のロータヨークの製造方法Manufacturing method of outer rotor type motor and rotor yoke of outer rotor type motor
　本発明は電動機に係り、特にアウターロータ形電動機、及びこのアウターロータ形電動機のロータヨークの製造方法に関するものである。 The present invention relates to an electric motor, and particularly relates to an outer rotor type motor and a method for manufacturing a rotor yoke of the outer rotor type motor.
　一般的な産業機械分野においては、電動機によって機械系要素を駆動することが行われている。そして、このような電動機においては、インナーロータ方式とアウターロータ方式の電動機が知られている。アウターロータ方式の電動機は、カップ状のロータヨークの内部にステータを配置したもので、駆動トルクを大きくできるという特徴を有している。このようなアウターロータ方式の電動機は、例えば特開２０１０ー７２０８号公報(特許文献１)に示されている。 In the general industrial machinery field, mechanical elements are driven by electric motors. As such electric motors, inner rotor type motors and outer rotor type motors are known. The outer rotor type motor has a stator arranged inside a cup-shaped rotor yoke, and has a feature that the driving torque can be increased. Such an outer rotor type motor is shown in, for example, Japanese Patent Application Laid-Open No. 2010-7208 (Patent Document 1).
　特許文献１に記載のアウターロータ方式の電動機は、ロータヨークの内周壁面に複数の永久磁石を配設したロータと、ステータコアに形成されたスロットに巻回された複数の電磁コイルを備えたステータとを備えている。また、ステータは、ロータの内面に対して、僅かなギャップを介して内挿されており、ロータは、ロータに固定された回転支持軸がステータに設けた軸受に軸支され、回転可能に支持されている。 The outer rotor type motor described in Patent Document 1 includes a rotor in which a plurality of permanent magnets are arranged on an inner peripheral wall surface of a rotor yoke, and a stator having a plurality of electromagnetic coils wound in slots formed in a stator core. It has. Further, the stator is inserted into the inner surface of the rotor through a slight gap, and the rotor is rotatably supported by a rotary support shaft fixed to the rotor being pivotally supported by a bearing provided on the stator. Has been done.
　また、ロータは、複数の板状の永久磁石がＮ極とＳ極とが交互になるように、ロータヨークの内周壁面に、周方向で等角度間隔に配列されている。このロータヨークは、半径よりも軸方向幅が短い薄型の円筒形状である。ステータは、リング状のコア中心部を有するステータコアと複数の電磁コイルとを備え、電磁コイルは対応するティースに集中巻で各々巻回されている。尚、ティースは、略Ｔ字状に形成され、ステータコアに放射状に外側に向けて等角度間隔に凸設されている。 Further, the rotors are arranged on the inner peripheral wall surface of the rotor yoke at equal angular intervals in the circumferential direction so that a plurality of plate-shaped permanent magnets alternate between north and south poles. This rotor yoke has a thin cylindrical shape whose axial width is shorter than the radius. The stator includes a stator core having a ring-shaped core center portion and a plurality of electromagnetic coils, and the electromagnetic coils are each wound around the corresponding teeth in a concentrated winding manner. The teeth are formed in a substantially T shape, and are radially outwardly projected on the stator core at equal angular intervals.
特開２０１０ー７２０８号公報Japanese Unexamined Patent Publication No. 2010-7208
　ところで、特許文献１にあるような電動機のロータヨークとステータコアにおいては、回転支持軸が延びる方向である軸線方向に直交する面で断面した形状は、図４に示すような形状とされている。尚、図４は、ロータヨークとステータコアの一部を拡大して示している。 By the way, in the rotor yoke and the stator core of the electric motor as described in Patent Document 1, the cross-sectional shape of the rotor yoke and the stator core in a plane orthogonal to the axial direction, which is the direction in which the rotation support shaft extends, is as shown in FIG. Note that FIG. 4 shows an enlarged view of a part of the rotor yoke and the stator core.
　図４において、ステータコア５０には等角度間隔にティース５１が形成されており、このティース５１は、ステータコア５０の中心から外側に向けて放射状に延びる形状に形成されている。ティース５１には電磁コイル５２が巻回されており、通電されることによって磁界を発生する。 In FIG. 4, teeth 51 are formed on the stator core 50 at equal angular intervals, and the teeth 51 are formed in a shape extending radially outward from the center of the stator core 50. An electromagnetic coil 52 is wound around the teeth 51, and a magnetic field is generated when the teeth 51 are energized.
　一方、ロータヨーク５３の内周には板状の永久磁石５４が合成樹脂等の接着剤によって、これも等角度間隔で配設されている。また、ロータヨーク５３の内周側で永久磁石５４の間には位置決め用の内側に向かって突出する位置決め突起５５が形成されている。ロータヨーク５３は磁束が通過する磁路としての機能を備えている。 On the other hand, plate-shaped permanent magnets 54 are arranged on the inner circumference of the rotor yoke 53 at equal intervals by an adhesive such as synthetic resin. Further, on the inner peripheral side of the rotor yoke 53, a positioning protrusion 55 projecting inward for positioning is formed between the permanent magnets 54. The rotor yoke 53 has a function as a magnetic path through which magnetic flux passes.
　ここで、ロータヨーク５３は、円形の鋼板をカップ状にプレス加工して形成されるか、或いは平角板の鋼板を丸めてカップ状に加工して形成されている。そして、ロータヨーク５３の板厚(ｔｒ)は、磁束が飽和しない板厚(ｔｒ)で全周に亘って等しい厚さ、いわゆる等肉に形成されている。 Here, the rotor yoke 53 is formed by pressing a circular steel plate into a cup shape, or by rolling a flat steel plate into a cup shape. The plate thickness (tr) of the rotor yoke 53 is a plate thickness (tr) at which the magnetic flux is not saturated and is formed to have an equal thickness over the entire circumference, that is, a so-called equal thickness.
　ロータヨーク５３を通る磁束についてみると、永久磁石５４の周方向の中央付近で、磁束密度が小さい低磁束領域(ＬＭｇ)となり、逆に隣り合う永久磁石５４の間の付近で、磁束密度が大きい高磁束領域(ＨＭｇ)となる。尚、磁束密度は、低磁束密度領域(ＬＭｇ)と高磁束密度領域(ＨＭｇ)とが明確に境界をもって規定されるものではなく、磁束密度が傾きをもって変化するものであり、これは良く知られている事項である。 Looking at the magnetic flux passing through the rotor yoke 53, a low magnetic flux region (LMG) having a small magnetic flux density is formed near the center of the permanent magnet 54 in the circumferential direction, and conversely, a high magnetic flux density is large near the center between the adjacent permanent magnets 54. It becomes the magnetic flux region (HMg). The magnetic flux density is not defined by a clear boundary between the low magnetic flux density region (LMG) and the high magnetic flux density region (HMg), but the magnetic flux density changes with an inclination, which is well known. It is a matter that is.
　そして、図４に示すロータヨーク５３では、磁束を飽和させないために上述した高磁束領域(ＨＭｇ)を基準にして、ロータヨーク５３の全周の板厚(ｔｒ)を一様な板厚に決めている。このため、ロータヨーク５３の重量が重くなり、電動機としての軽量化を阻害している。更にロータヨーク５３の重量が重いので慣性が大きくなり、電動機の回転の立ち上がりが遅くなるという性能上の課題も併せ生じる。 Then, in the rotor yoke 53 shown in FIG. 4, the plate thickness (tr) around the entire circumference of the rotor yoke 53 is determined to be a uniform plate thickness with reference to the above-mentioned high magnetic flux region (HMg) in order not to saturate the magnetic flux. .. Therefore, the weight of the rotor yoke 53 becomes heavy, which hinders the weight reduction as an electric motor. Further, since the rotor yoke 53 is heavy, the inertia becomes large, which also causes a performance problem that the start-up of rotation of the electric motor is delayed.
　そして、このような課題を解決するには、ロータヨーク５３の板厚(ｔｒ)を一様に薄くすれば良いが、板厚(ｔｒ)を一様に薄くすると、高磁束領域(ＨＭｇ)で磁束密度が飽和して電動機の性能を低下させることになる。 Then, in order to solve such a problem, the plate thickness (tr) of the rotor yoke 53 may be uniformly thinned, but if the plate thickness (tr) is uniformly thinned, the magnetic flux is generated in the high magnetic flux region (HMg). The density will be saturated and the performance of the motor will be reduced.
　更に、これは副次的であるが、板状の永久磁石５４を位置決めする位置決め突起５５を形成しているが、この位置決め突起５５を形成するために、位置決め突起５５の両側を切削工具で切削することが必要となり、余分な製造工程が生じ、しかも材料の無駄が発生して製造単価を押し上げるという課題も生じる。 Further, although this is secondary, a positioning protrusion 55 for positioning the plate-shaped permanent magnet 54 is formed, and in order to form the positioning protrusion 55, both sides of the positioning protrusion 55 are cut with a cutting tool. This creates an extra manufacturing process, wastes materials, and raises the manufacturing unit price.
　本発明の目的は、ロータヨークの重量を軽減すると共に、これに伴う磁束密度の飽和を抑制することができる新規なアウターロータ形電動機、及びアウターロータ形電動機のロータヨークの製造方法を提供することにある。 An object of the present invention is to provide a novel outer rotor type motor capable of reducing the weight of the rotor yoke and suppressing the saturation of the magnetic flux density associated therewith, and a method for manufacturing the rotor yoke of the outer rotor type motor. ..
　本発明の第１の特徴は、ステータコアの径方向の外周側を覆う側周面壁部を備えたロータヨークと、ロータヨークの側周面壁部の内周面で周方向に所定角度間隔で取り付けられた永久磁石を備えたアウターロータ形電動機であって、ロータヨークの側周面壁部に発生する磁束の磁束密度に合せて、磁束密度が小さい領域はロータヨークの側周面壁部の板厚が薄く形成され、磁束密度が大きい領域はロータヨークの側周面壁部の板厚が厚く形成されている、ところにある。 The first feature of the present invention is a rotor yoke provided with a side peripheral wall portion that covers the radial outer peripheral side of the stator core, and a permanent magnet attached to the inner peripheral surface of the side peripheral wall portion of the rotor yoke at predetermined angular intervals in the circumferential direction. In an outer rotor type electric motor equipped with a magnet, the thickness of the side peripheral wall of the rotor yoke is formed thin in the region where the magnetic flux density is small according to the magnetic flux density of the magnetic flux generated on the side peripheral wall of the rotor yoke. The region where the density is high is where the thickness of the side peripheral wall portion of the rotor yoke is formed to be thick.
　本発明の第２の特徴は、ステータコアの径方向の外周側を覆う側周面壁部を備えたロータヨークと、ロータヨークの側周面壁部の内周面で周方向に所定角度間隔で取り付けられた永久磁石を備えたアウターロータ形電動機であって、ロータヨークの内周壁面に配設された永久磁石の周方向の中央付近のロータヨークの側周面壁部の板厚が薄く形成され、隣り合う永久磁石の間のロータヨークの側周面壁部の板厚が厚く形成されている、ところにある。 The second feature of the present invention is a rotor yoke provided with a side peripheral wall portion that covers the radial outer peripheral side of the stator core, and a permanent magnet mounted on the inner peripheral surface of the side peripheral wall portion of the rotor yoke at predetermined angular intervals in the circumferential direction. It is an outer rotor type motor equipped with a magnet, and the thickness of the side peripheral wall of the rotor yoke near the center in the circumferential direction of the permanent magnets arranged on the inner peripheral wall surface of the rotor yoke is formed thinly, and the permanent magnets adjacent to each other are formed. The thickness of the side peripheral wall of the rotor yoke between them is thickly formed.
　本発明の第３の特徴は、隣り合う永久磁石が配置される永久磁石配置領域の間の位置決め領域が開放された内周側プレス治具をロータヨークの側周面壁部の内周側に密着して配置する共に、永久磁石配置領域の周方向の中央付近の変形領域が開放された外周側プレス治具をロータヨークの側周面壁部の外周側に密着して配置し、この状態で変形プレス治具を変形領域に押し当て、変形領域のロータヨークの金属材料を変形させて薄肉に形成すると共に、この薄肉化による余分な金属材料を内周側プレス治具の位置決め領域から内側に向けて膨出させて永久磁石の位置決め部を形成する、ところにある。 The third feature of the present invention is that the inner peripheral side press jig in which the positioning region between the permanent magnet arrangement regions where adjacent permanent magnets are arranged is open is brought into close contact with the inner peripheral side of the side peripheral wall portion of the rotor yoke. A press jig on the outer peripheral side in which the deformation region near the center in the circumferential direction of the permanent magnet placement region is open is placed in close contact with the outer peripheral side of the side peripheral wall portion of the rotor yoke, and the deformation press treatment is performed in this state. The tool is pressed against the deformed region to deform the metal material of the rotor yoke in the deformed region to form a thin wall, and the excess metal material due to this thinning bulges inward from the positioning region of the inner peripheral side press jig. It is there to form the positioning part of the permanent magnet.
　本発明によれば、ロータヨークに発生する磁束密度に合せて、磁束密度が小さい領域は板厚を薄く形成し、磁束密度が大きい領域は板厚を厚く形成する構成としたので、ロータヨークの重量を軽減すると共に、これに伴う磁束密度の飽和を抑制することができる。 According to the present invention, the plate thickness is formed thin in the region where the magnetic flux density is low and the plate thickness is formed thick in the region where the magnetic flux density is high according to the magnetic flux density generated in the rotor yoke. It can be reduced and the saturation of the magnetic flux density accompanying this can be suppressed.
　また、本発明によれば、永久磁石の周方向の中央付近のロータヨークの側周面壁部の板厚を薄く形成し、隣り合う永久磁石の間のロータヨークの側周面壁部の板厚を厚く形成する構成としたので、ロータヨークの重量を軽減すると共に、これに伴う磁束密度の飽和を抑制することができる。 Further, according to the present invention, the plate thickness of the side peripheral wall portion of the rotor yoke near the center in the circumferential direction of the permanent magnet is formed to be thin, and the plate thickness of the side peripheral surface wall portion of the rotor yoke between adjacent permanent magnets is formed to be thick. Therefore, the weight of the rotor yoke can be reduced and the saturation of the magnetic flux density associated therewith can be suppressed.
　更に、本発明によれば、外周側プレス治具の変形領域に変形プレス治具を押し当て、変形領域のロータヨークの金属材料を変形させて薄肉に形成すると共に、この薄肉化による余分な金属材料を内側プレス治具の位置決め領域から内側に向けて膨出させて永久磁石の位置決め部を形成するので、位置決め部の両側を切削工具で切削することが必要なくなって余分な製造工程を省略でき、しかも切削による材料の無駄が発生せず製造単価を押し上げることを抑制できる。 Further, according to the present invention, the deformed press jig is pressed against the deformed region of the outer peripheral side press jig to deform the metal material of the rotor yoke in the deformed region to form a thin wall, and the extra metal material due to this thinning is formed. Is bulged inward from the positioning area of the inner press jig to form the positioning part of the permanent magnet, so it is not necessary to cut both sides of the positioning part with a cutting tool, and an extra manufacturing process can be omitted. Moreover, the material is not wasted due to cutting, and it is possible to suppress an increase in the manufacturing unit price.
本発明が適用される、アウターロータ方式の電動機の軸線方向の断面を示す断面図である。It is sectional drawing which shows the cross section in the axial direction of the outer rotor type motor to which this invention is applied. 本発明の実施形態におけるロータの回転支持軸の軸線方向に直交する面で断面したロータとステータの一部拡大断面図である。It is a partially enlarged sectional view of the rotor and the stator which cross-sectioned in the plane orthogonal to the axial direction of the rotation support shaft of the rotor in embodiment of this invention. 図２に示すロータヨークの製造方法を説明する説明図である。It is explanatory drawing explaining the manufacturing method of the rotor yoke shown in FIG. 従来の電動機におけるロータの回転支持軸の軸線方向に直交する面で断面したロータとステータの一部拡大断面図である。It is a partially enlarged cross-sectional view of a rotor and a stator which are cross-sectioned in the plane orthogonal to the axial direction of the rotation support shaft of a rotor in a conventional motor.
　以下、本発明の実施形態について図面を用いて詳細に説明するが、本発明は以下の実施形態に限定されることなく、本発明の技術的な概念の中で種々の変形例や応用例をもその範囲に含むものである。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following embodiments, and various modifications and applications are included in the technical concept of the present invention. Is also included in that range.
　本発明の実施形態を説明する前に、本発明が実施されるアウターロータ方式の電動機の構成を、図１を用いて簡単に説明する。 Before explaining the embodiment of the present invention, the configuration of the outer rotor type motor in which the present invention is carried out will be briefly described with reference to FIG.
　図１においては、ブラシレスのアウターロータ方式の電動機の断面を示しており、電動機１０は、例えば８極／１２スロットで３相駆動式の構成になっている。 FIG. 1 shows a cross section of a brushless outer rotor type motor, and the motor 10 has, for example, an 8-pole / 12-slot, 3-phase drive type configuration.
　ステータ１１は、ステータコア１２と電磁コイル１３から構成されている。ステータ１１のステータコア１２はその中央部付近に筒部１４を備えており、筒部１４には径方向で外側に延びる１２個のティース１５が形成されている。各ティース１５には合成樹脂製のボビン１６に巻回された電磁コイル１３が設けられている。 The stator 11 is composed of a stator core 12 and an electromagnetic coil 13. The stator core 12 of the stator 11 is provided with a tubular portion 14 near the central portion thereof, and the tubular portion 14 is formed with 12 teeth 15 extending outward in the radial direction. Each tooth 15 is provided with an electromagnetic coil 13 wound around a bobbin 16 made of synthetic resin.
　筒部１４には、回転支持軸としてのシャフト１７が、軸受としてのボールベアリング１７Ｂを介して回転可能に支持されている。シャフト１７の一端には、ロータ１８を構成するロータヨーク１９がシャフト１７と一体で回転するように圧入等の固定方法で取り付けられている。 A shaft 17 as a rotation support shaft is rotatably supported on the cylinder portion 14 via a ball bearing 17B as a bearing. A rotor yoke 19 constituting the rotor 18 is attached to one end of the shaft 17 by a fixing method such as press fitting so as to rotate integrally with the shaft 17.
　ロータヨーク１９は、上面壁部１９Ｕと、これに垂直に交わる側周面壁部１９Ｓからなるカップ状に形成されており、ステータコア１２を覆うような形状に形成されている。尚、ロータヨーク１９は、シャフト１７の一端側(図１の下側)が開放側になっている。 The rotor yoke 19 is formed in a cup shape including an upper surface wall portion 19U and a side peripheral wall portion 19S perpendicularly intersecting the upper surface wall portion 19U, and is formed in a shape that covers the stator core 12. The rotor yoke 19 has an open side on one end side (lower side in FIG. 1) of the shaft 17.
　ロータヨーク１９の側周面壁部１９Ｓの内周壁面には、複数個の板状の永久磁石２０が周方向に所定角度間隔で取り付けられている。この実施形態では永久磁石２０は８個である。各永久磁石２０は板厚方向に磁極が変化するように着磁され、隣り合う永久磁石２０の磁極が異なるように配置されている。 A plurality of plate-shaped permanent magnets 20 are attached to the inner peripheral wall surface of the side peripheral wall portion 19S of the rotor yoke 19 at predetermined angular intervals in the circumferential direction. In this embodiment, the number of permanent magnets 20 is eight. Each permanent magnet 20 is magnetized so that the magnetic poles change in the plate thickness direction, and the magnetic poles of adjacent permanent magnets 20 are arranged so as to be different.
　永久磁石２０は、いずれも同一の形状及び大きさに形成されている。図２に示すように永久磁石２０は板状であり、永久磁石２０の長さ方向がシャフト１７の軸線方向に、また永久磁石２０の厚み方向が径方向に対応するように、永久磁石２０はロータヨーク１９の側周面壁部１９Ｓの内周壁側に取り付けられている。また、永久磁石２０の周方向とは、ロータヨーク１９の周方向と同方向を意味する。 The permanent magnets 20 are all formed to have the same shape and size. As shown in FIG. 2, the permanent magnet 20 has a plate shape, and the permanent magnet 20 is arranged so that the length direction of the permanent magnet 20 corresponds to the axial direction of the shaft 17 and the thickness direction of the permanent magnet 20 corresponds to the radial direction. It is attached to the inner peripheral wall side of the side peripheral wall portion 19S of the rotor yoke 19. Further, the circumferential direction of the permanent magnet 20 means the same direction as the circumferential direction of the rotor yoke 19.
　永久磁石２０は、図２にあるように周方向の中央部が、周方向両端部より厚く形成されている。永久磁石２０は、ロータヨーク１９の側周面壁部１９Ｓに取り付けられる側の面である外側面２０Ａが径方向で外側に凸な曲面になり、ティース１５に対向する側の面である内側面２０Ｂが径方向内側に凸な曲面になるように形成されている。 As shown in FIG. 2, the permanent magnet 20 is formed so that the central portion in the circumferential direction is thicker than both ends in the circumferential direction. In the permanent magnet 20, the outer surface 20A, which is the side surface attached to the side peripheral wall portion 19S of the rotor yoke 19, has a curved surface that is convex outward in the radial direction, and the inner surface 20B, which is the surface facing the teeth 15, is formed. It is formed so as to have a curved surface that is convex inward in the radial direction.
　尚、一般的にロータヨーク１９と対向する側にプリント基板(図示せず)が取付けられており、プリント基板には永久磁石２０に設けた凸部(図示せず)に対応する磁力を検出するためのセンサとしてのホールＩＣが取り付けられている。ホールＩＣはロータヨーク１９の開口部の端面に対向する位置に配置されている。 Generally, a printed circuit board (not shown) is attached to the side facing the rotor yoke 19, and the printed circuit board detects the magnetic force corresponding to the convex portion (not shown) provided on the permanent magnet 20. A Hall IC as a sensor of the above is attached. The Hall IC is arranged at a position facing the end surface of the opening of the rotor yoke 19.
　以上のアウターロータ方式の電動機１０は良く知られているので、これ以上の詳細な説明は省略する。 Since the above outer rotor type motor 10 is well known, further detailed description will be omitted.
　次に本発明の実施形態について図２に基づき説明する。図２は、回転支持軸であるシャフト１７の軸線方向に直交する面で断面したロータヨーク１９Ｓとステータコア１２の一部拡大断面図である。 Next, an embodiment of the present invention will be described with reference to FIG. FIG. 2 is a partially enlarged cross-sectional view of the rotor yoke 19S and the stator core 12 cross-sectionald in a plane orthogonal to the axial direction of the shaft 17 which is a rotation support shaft.
　ロータヨーク１９の側周面壁部１９Ｓには、周方向に沿って厚肉領域部２１と薄肉領域部２２が、ロータヨーク１９の側周面壁部１９Ｓに発生する磁束密度を基準にして形成されている。厚肉領域部２１は、おおまかに高磁束密度領域(ＨＭｇ)に対応し、薄肉領域部２２もおおまかに低磁束密度領域(ＬＭｇ)に対応している。(図４参照)
　そして、厚肉領域部２１は、従来と同様に板厚が一様で、断面が円環状に形成されている。一方、薄肉領域部２２は側周面壁部１９Ｓの外周側に凹部２２Ｒとして溝状に形成されている。この薄肉領域部２２は、軸線方向で永久磁石２０に対応した長さに設けられている。 On the side peripheral wall portion 19S of the rotor yoke 19, a thick-walled region portion 21 and a thin-walled region portion 22 are formed along the circumferential direction with reference to the magnetic flux density generated in the side peripheral wall portion 19S of the rotor yoke 19. The thick-walled region portion 21 roughly corresponds to the high magnetic flux density region (HMg), and the thin-walled region portion 22 also roughly corresponds to the low magnetic flux density region (LMG). (See Fig. 4)
The thick region portion 21 has a uniform plate thickness and an annular cross section as in the conventional case. On the other hand, the thin-walled region portion 22 is formed in a groove shape as a recess 22R on the outer peripheral side of the side peripheral wall portion 19S. The thin-walled region portion 22 is provided with a length corresponding to the permanent magnet 20 in the axial direction.
　そして、厚肉領域部２１は高磁束密度領域(ＨＭｇ)に対応しているので、磁束密度が飽和しないような厚さに設定された板厚(Ｔｒ１)に決められている。また、薄肉領域部２２は低磁束密度領域(ＬＭｇ)に対応しているので、これも磁束密度が飽和しないような厚さに設定された板厚(Ｔｒ２)に決められている。このため、薄肉領域部２２の板厚(Ｔｒ２)は薄く形成しても磁束密度が飽和することはない。 Since the thick region portion 21 corresponds to the high magnetic flux density region (HMg), the plate thickness (Tr1) is set to a thickness that does not saturate the magnetic flux density. Further, since the thin-walled region portion 22 corresponds to the low magnetic flux density region (LMG), the plate thickness (Tr2) is also set to a thickness so that the magnetic flux density is not saturated. Therefore, the magnetic flux density does not saturate even if the plate thickness (Tr2) of the thin-walled region portion 22 is formed to be thin.
　このように、厚肉領域部２１の板厚(Ｔｒ１)と薄肉領域部２２の板厚（Ｔｒ２）の関係は、「Ｔｒ２＜ＴＲ１」の関係に決められている。そして、薄肉領域部２２は磁束密度が小さい低磁束密度領域(ＬＭｇ)に形成されているので、磁束密度が飽和することを抑制することができる。また、薄肉領域部２２の形成によってロータヨーク１９の重量を軽減することができ、結果的に電動機１０の軽量化を図ることができる。 As described above, the relationship between the plate thickness (Tr1) of the thick region portion 21 and the plate thickness (Tr2) of the thin region portion 22 is determined as the relationship of "Tr2 <TR1". Since the thin-walled region portion 22 is formed in a low magnetic flux density region (LMG) having a small magnetic flux density, it is possible to suppress saturation of the magnetic flux density. Further, the weight of the rotor yoke 19 can be reduced by forming the thin-walled region portion 22, and as a result, the weight of the motor 10 can be reduced.
　薄肉領域部２２の凹部２２Ｒの断面形状は、本実施形態では円弧の形状に形成されているが、三角形の頂角を形成するような直線状に傾斜した溝形状に形成することもでき、更には矩形の溝形状に形成することもできる。 The cross-sectional shape of the recess 22R of the thin-walled region portion 22 is formed in the shape of an arc in the present embodiment, but it can also be formed in the shape of a linearly inclined groove that forms the apex angle of a triangle. Can also be formed into a rectangular groove shape.
　また、本実施形態のロータヨーク１９の側周面壁部１９Ｓは、夫々の永久磁石２０の周方向の中央付近、即ち磁極中心付近に対応する薄肉領域部２２と、隣り合う永久磁石２０の間の領域(いわゆる、渡り領域)に対応する厚肉領域部２１とを備えている、ということができる。 Further, the side peripheral wall portion 19S of the rotor yoke 19 of the present embodiment is a region between the thin-walled region portion 22 corresponding to the vicinity of the center of each permanent magnet 20 in the circumferential direction, that is, the vicinity of the magnetic pole center, and the adjacent permanent magnets 20. It can be said that the thick-walled region portion 21 corresponding to (so-called crossover region) is provided.
　薄肉領域部２２、及び厚肉領域部２１は永久磁石２０の数と同数であり、薄肉領域部２２、及び厚肉領域部２１は、金属プレス加工によって薄肉領域部２１を形成すべき箇所から厚肉領域部２１を形成すべき箇所へ金属材料を塑性流動させることにより形成されている。このため、ロータヨークの全体重量は、従来のロータヨークの全体重量より軽量化できる。 The number of the thin-walled region portion 22 and the thick-walled region portion 21 is the same as the number of permanent magnets 20, and the thin-walled region portion 22 and the thick-walled region portion 21 are thick from the portion where the thin-walled region portion 21 should be formed by metal stamping. It is formed by plastically flowing a metal material to a portion where the meat region portion 21 should be formed. Therefore, the total weight of the rotor yoke can be made lighter than the total weight of the conventional rotor yoke.
　また、ロータヨーク１９の側周面壁部１９Ｓには、永久磁石２０を所定の間隔に配置する位置決め部２３が形成されている。このため、接着剤を塗布して永久磁石２０をロータヨークの側周面壁部１９Ｓに取付けた直後に着磁工程を行うこともできる。着磁により永久磁石２０はロータヨーク１９の側周面壁部１９Ｓに磁力で吸着されるので、過度な振動衝撃を与えない限り永久磁石２０は所定位置に保持されるため、接着治具を不要にできる。尚、薄肉領域部２２と位置決め部２３の形成方法は後述する。 Further, the side peripheral wall portion 19S of the rotor yoke 19 is formed with positioning portions 23 for arranging the permanent magnets 20 at predetermined intervals. Therefore, the magnetizing step can be performed immediately after applying the adhesive and attaching the permanent magnet 20 to the side peripheral wall portion 19S of the rotor yoke. Since the permanent magnet 20 is magnetically attracted to the side peripheral wall portion 19S of the rotor yoke 19 by magnetism, the permanent magnet 20 is held in a predetermined position unless an excessive vibration impact is applied, so that an adhesive jig can be eliminated. .. The method of forming the thin-walled region portion 22 and the positioning portion 23 will be described later.
　このように、ロータヨーク１９の側周面壁部１９Ｓは、隣り合う永久磁石２０が対向する部分が厚肉に形成されている。ロータヨーク１９の側周面壁部１９Ｓにおいて、隣り合う永久磁石２０間の領域は、磁束密度が大きくなる領域である。したがって、磁束密度が大きくなる領域が厚肉領域部２１であることにより、磁気飽和を緩和し、磁気抵抗を低減する効果を有する。 As described above, in the side peripheral wall portion 19S of the rotor yoke 19, the portion where the adjacent permanent magnets 20 face each other is formed thick. In the side peripheral wall portion 19S of the rotor yoke 19, the region between the adjacent permanent magnets 20 is a region where the magnetic flux density becomes large. Therefore, since the region where the magnetic flux density is large is the thick-walled region portion 21, it has the effect of alleviating the magnetic saturation and reducing the magnetic resistance.
　一方、ロータヨーク１９の側周面壁部１９Ｓにおいて、周方向の永久磁石２０の中央付近は薄肉に形成されている。この永久磁石２０の中央付近は磁束密度が小さい領域であるため、薄肉とすることは磁気回路上、問題なく、ロータヨークの重量を軽減することができる。 On the other hand, in the side peripheral wall portion 19S of the rotor yoke 19, the vicinity of the center of the permanent magnet 20 in the circumferential direction is formed to be thin. Since the vicinity of the center of the permanent magnet 20 is a region where the magnetic flux density is small, thinning the permanent magnet 20 does not cause any problem in the magnetic circuit, and the weight of the rotor yoke can be reduced.
　また、図２に示すように永久磁石２０は、周方向の中央付近が周方向の両端より厚い形状に形成されている。したがって、永久磁石２０は、ロータヨーク１９の側周面壁部１９Ｓが薄い薄肉領域部２２のところでは厚く、ロータヨーク１９の側周面壁部１９Ｓが厚い厚肉領域部２１のところでは薄くなるように周方向に厚さが変化している。このため、ロータヨーク１９の全体として重量が周方向に均一に近くなるので、ロータ１８の回転をぶれ難くすることができる。 Further, as shown in FIG. 2, the permanent magnet 20 is formed in a shape in which the vicinity of the center in the circumferential direction is thicker than both ends in the circumferential direction. Therefore, the permanent magnet 20 is thick in the thin-walled region portion 22 where the side peripheral wall portion 19S of the rotor yoke 19 is thin, and thin in the thick-walled region portion 21 where the side peripheral wall portion 19S of the rotor yoke 19 is thick. The thickness is changing. Therefore, the weight of the rotor yoke 19 as a whole becomes almost uniform in the circumferential direction, so that the rotation of the rotor 18 can be made less likely to fluctuate.
　次に、薄肉領域部２２と位置決め部２３の形成方法を図３に基づき説明する。図３には、本実施形態のロータヨークの製造方法を示しており、内周側プレス治具３０と外周側プレス治具３２によってロータヨーク１９の側周面壁部１９Ｓを拘束しておき、側周面壁部１９Ｓの外周側から変形プレス治具３４によって薄肉領域部２２を形成すると同時に位置決め部２３を同時に形成する、ことを特徴としている。 Next, a method of forming the thin-walled region portion 22 and the positioning portion 23 will be described with reference to FIG. FIG. 3 shows a method of manufacturing the rotor yoke of the present embodiment, in which the side peripheral wall portion 19S of the rotor yoke 19 is restrained by the inner peripheral side press jig 30 and the outer peripheral side press jig 32, and the side peripheral surface wall. The thin-walled region portion 22 is formed from the outer peripheral side of the portion 19S by the deformation press jig 34, and at the same time, the positioning portion 23 is formed at the same time.
　内周側プレス治具３０は、ロータヨーク１９の側周面壁部１９Ｓの内周壁面に密着する形状を備えており、隣り合う永久磁石が配置される永久磁石配置領域の間の位置決め領域３１が開放されている。この位置決め領域３１は位置決め部２３を形成するための開口であり、ロータヨーク１９の軸線に沿って形成されている。 The inner peripheral side press jig 30 has a shape that is in close contact with the inner peripheral wall surface of the side peripheral surface wall portion 19S of the rotor yoke 19, and the positioning region 31 between the permanent magnet arrangement regions in which the adjacent permanent magnets are arranged is open. Has been done. The positioning region 31 is an opening for forming the positioning portion 23, and is formed along the axis of the rotor yoke 19.
　また、外周側プレス治具３２は、ロータヨーク１９の側周面壁部１９Ｓの外周壁面に密着する形状を備えており、永久磁石が配置される永久磁石配置領域の周方向で中央付近の変形領域３３が開放されている。この変形領域３３は薄肉領域部２２を形成するための開口であり、ロータヨーク１９の軸線に沿って形成されている。 Further, the outer peripheral side press jig 32 has a shape that is in close contact with the outer peripheral wall surface of the side peripheral wall portion 19S of the rotor yoke 19, and is a deformation region 33 near the center in the circumferential direction of the permanent magnet arrangement region in which the permanent magnet is arranged. Is open. The deformed region 33 is an opening for forming the thin-walled region portion 22, and is formed along the axis of the rotor yoke 19.
　そして、内周側プレス治具３０をロータヨーク１９の側周面壁部１９Ｓの内周壁面に密着させ、外周側プレス治具３２をロータヨーク１９の側周面壁部１９Ｓの外周壁面に密着させて、ロータヨーク１９の側周面壁部１９Ｓを拘束した状態で、変形プレス治具３４を変形領域３３に押し込んで薄肉領域部２２を形成する。 Then, the inner peripheral side press jig 30 is brought into close contact with the inner peripheral wall surface of the side peripheral surface wall portion 19S of the rotor yoke 19, and the outer peripheral side press jig 32 is brought into close contact with the outer peripheral wall surface of the side peripheral surface wall portion 19S of the rotor yoke 19. With the side peripheral wall portion 19S of 19 restrained, the deformation press jig 34 is pushed into the deformation region 33 to form the thin-walled region portion 22.
　図３で変形プレス治具３４Ａは変形領域３３に押し込まれる前の状態を示し、変形プレス治具３４Ｂは変形領域３３に押し込まれた状態を示している。この図からわかるように、変形プレス治具３４が押し込まれることによって、この部分の金属材料は塑性流動して薄肉領域部２２を形成することになる。一方、この変形プレス治具３４が押し込まれることによって、位置決め領域３１では金属材料が膨出して位置決め部２３が形成されることになる。 In FIG. 3, the deformed press jig 34A shows the state before being pushed into the deformed region 33, and the deformed press jig 34B shows the state before being pushed into the deformed region 33. As can be seen from this figure, when the deformation press jig 34 is pushed in, the metal material in this portion plastically flows to form the thin-walled region portion 22. On the other hand, when the deformation press jig 34 is pushed in, the metal material bulges out in the positioning region 31 to form the positioning portion 23.
　このように、プレス加工によって、薄肉領域部２２と位置決め部２３が同時に形成されることになる。したがって、従来のように位置決め部の両側を切削工具で切削することが必要なくなって余分な製造工程を省略でき、しかも切削による材料の無駄が発生せず製造単価を押し上げることを抑制できる。 In this way, the thin-walled region portion 22 and the positioning portion 23 are formed at the same time by press working. Therefore, it is not necessary to cut both sides of the positioning portion with a cutting tool as in the conventional case, an extra manufacturing process can be omitted, and the material is not wasted due to cutting, and it is possible to suppress an increase in the manufacturing unit price.
　以上述べた通り本発明においては、ロータヨークに発生する磁束密度に合せて、磁束密度が小さい領域は板厚を薄く形成し、磁束密度が大きい領域は板厚を厚く形成する構成としたので、ロータヨークの重量を軽減すると共に、これに伴う磁束密度の飽和を抑制することができる。 As described above, in the present invention, the plate thickness is formed thin in the region where the magnetic flux density is low and the plate thickness is formed thick in the region where the magnetic flux density is high in accordance with the magnetic flux density generated in the rotor yoke. It is possible to reduce the weight of the magnetic flux density and suppress the saturation of the magnetic flux density associated therewith.
　また、本発明においては、永久磁石の周方向の中央付近のロータヨークの側周面壁部の板厚を薄く形成し、隣り合う永久磁石の間のロータヨークの側周面壁部の板厚を厚く形成する構成としたので、ロータヨークの重量を軽減すると共に、これに伴う磁束密度の飽和を抑制することができる。 Further, in the present invention, the thickness of the side peripheral wall portion of the rotor yoke near the center in the circumferential direction of the permanent magnet is formed thin, and the plate thickness of the side peripheral wall portion of the rotor yoke between adjacent permanent magnets is formed thick. Since the structure is configured, the weight of the rotor yoke can be reduced, and the resulting saturation of the magnetic flux density can be suppressed.
　更に、本発明においては、外周側プレス治具の変形領域に変形プレス治具を押し当て、変形領域のロータヨークの金属材料を変形させて薄肉に形成すると共に、この薄肉化による余分な金属材料を内側プレス治具の位置決め領域から内側に向けて膨出させて永久磁石の位置決め部を形成するので、位置決め部の両側を切削工具で切削することが必要なくなって余分な製造工程を省略でき、しかも切削による材料の無駄が発生せず製造単価を押し上げることを抑制できる。 Further, in the present invention, the deformed press jig is pressed against the deformed region of the outer peripheral side press jig to deform the metal material of the rotor yoke in the deformed region to form a thin wall, and the extra metal material due to this thinning is formed. Since the permanent magnet positioning portion is formed by bulging inward from the positioning region of the inner press jig, it is not necessary to cut both sides of the positioning portion with a cutting tool, and an extra manufacturing process can be omitted. It is possible to prevent the material from being wasted due to cutting and to suppress the increase in the manufacturing unit price.
　尚、本発明は上記した実施例に限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施例は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、ある実施例の構成の一部を他の実施例の構成に置き換えることが可能であり、また、ある実施例の構成に他の実施例の構成を加えることも可能である。また、各実施例の構成の一部について、他の構成の追加・削除・置換をすることが可能である。 The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.
　１０…アウターロータ方式の電動機、１１…ステータ、１２…ステータコア、１３…電磁コイル、１４…筒部、１５…ティース、１７…シャフト、１８…ロータ、１９…ロータヨーク、１９Ｕ…上面壁部、１９Ｓ…側周面壁部、２０…永久磁石、２１…厚肉領域部、２２…薄肉領域部、２３…位置決め部、ＨＭｇ…高磁束密度領域、ＬＭｇ…低磁束密度領域。 10 ... outer rotor type motor, 11 ... stator, 12 ... stator core, 13 ... electromagnetic coil, 14 ... cylinder, 15 ... teeth, 17 ... shaft, 18 ... rotor, 19 ... rotor yoke, 19U ... top wall, 19S ... Side peripheral wall portion, 20 ... Permanent magnet, 21 ... Thick wall region portion, 22 ... Thin wall region portion, 23 ... Positioning portion, HMg ... High magnetic flux density region, LMg ... Low magnetic flux density region.

Claims (6)

  1. 　電磁コイルが巻回されたステータコアと、前記ステータコアの中心部に設けられた軸受と、前記軸受に軸支された回転支持軸と、前記回転支持軸に固定されると共に、前記ステータコアの径方向の外周側を覆う側周面壁部を有するロータヨークとを備え、前記ロータヨークの前記側周面壁部の内周面には複数個の永久磁石が設けられ、前記永久磁石は、前記ステータコアの径方向の外周側に対向し、周方向に極性が変化する状態で周方向に所定角度間隔で取り付けられたアウターロータ形電動機であって、
    　前記ロータヨークの前記側周面壁部に発生する磁束の磁束密度に合せて、前記磁束密度が小さい領域は前記ロータヨークの前記側周面壁部の板厚が薄く形成され、前記磁束密度が大きい領域は前記ロータヨークの前記側周面壁部の板厚が厚く形成されている
    ことを特徴とするアウターロータ形電動機。     A stator core around which an electromagnetic coil is wound, a bearing provided at the center of the stator core, a rotary support shaft pivotally supported by the bearing, and a rotary support shaft fixed to the rotary support shaft in the radial direction of the stator core. A rotor yoke having a side peripheral wall portion that covers the outer peripheral side is provided, and a plurality of permanent magnets are provided on the inner peripheral surface of the side peripheral wall portion of the rotor yoke. An outer rotor type motor that faces the side and is mounted at predetermined angular intervals in the circumferential direction with the polarity changing in the circumferential direction.
    In accordance with the magnetic flux density of the magnetic flux generated on the side peripheral wall portion of the rotor yoke, the region where the magnetic flux density is small is formed so that the plate thickness of the side peripheral wall portion of the rotor yoke is thin, and the region where the magnetic flux density is large is the region. An outer rotor type electric motor characterized in that the thickness of the side peripheral wall portion of the rotor yoke is formed to be thick.
  2. 　電磁コイルが巻回されたステータコアと、前記ステータコアの中心部に設けられた軸受と、前記軸受に軸支された回転支持軸と、前記回転支持軸に固定されると共に、前記ステータコアの径方向の外周側を覆う側周面壁部を有するロータヨークとを備え、前記ロータヨークの前記側周面壁部の内周面には複数個の永久磁石が設けられ、前記永久磁石は、前記ステータコアの径方向の外周側に対向し、周方向に極性が変化する状態で周方向に所定角度間隔で取り付けられたアウターロータ形電動機であって、
    　前記前記永久磁石の周方向の中央付近の前記ロータヨークの前記側周面壁部の板厚が薄く形成され、隣り合う前記永久磁石の間の前記ロータヨークの前記側周面壁部の板厚が厚く形成されている
    ことを特徴とするアウターロータ形電動機。     A stator core around which an electromagnetic coil is wound, a bearing provided at the center of the stator core, a rotary support shaft pivotally supported by the bearing, and a rotary support shaft fixed to the rotary support shaft in the radial direction of the stator core. A rotor yoke having a side peripheral wall portion that covers the outer peripheral side is provided, and a plurality of permanent magnets are provided on the inner peripheral surface of the side peripheral wall portion of the rotor yoke. An outer rotor type motor that faces the side and is mounted at predetermined angular intervals in the circumferential direction with the polarity changing in the circumferential direction.
    The thickness of the side peripheral wall portion of the rotor yoke near the center in the circumferential direction of the permanent magnet is formed to be thin, and the plate thickness of the side peripheral surface wall portion of the rotor yoke between adjacent permanent magnets is formed to be thick. An outer rotor type motor that is characterized by being
  3. 　請求項１又は請求項２に記載のアウターロータ形電動機であって、
    　前記側周面壁部の板厚が薄く形成された薄肉領域部は、前記ロータヨークの前記側周面壁部の外周側で、しかも前記回転支持軸の方向に沿って形成されている
    ことを特徴とするアウターロータ形電動機。     The outer rotor type motor according to claim 1 or 2.
    The thin-walled region portion formed with a thin plate thickness of the side peripheral surface wall portion is characterized in that it is formed on the outer peripheral side of the side peripheral surface wall portion of the rotor yoke and along the direction of the rotation support shaft. Outer rotor type motor.
  4. 　請求項３に記載のアウターロータ形電動機であって、
    　前記薄肉領域部は、前記ロータヨークの前記側周面壁部の外周側で、しかも前記回転支持軸の方向に沿って形成された溝である
    ことを特徴とするアウターロータ形電動機。     The outer rotor type motor according to claim 3.
    The outer rotor type motor is characterized in that the thin-walled region portion is a groove formed on the outer peripheral side of the side peripheral wall portion of the rotor yoke and along the direction of the rotation support shaft.
  5. 　請求項４に記載のアウターロータ形電動機であって、
    　前記薄肉領域部である前記溝は、断面が円弧状に形成された溝である
    ことを特徴とするアウターロータ形電動機。     The outer rotor type motor according to claim 4.
    The outer rotor type motor, wherein the groove, which is the thin-walled region portion, is a groove formed in an arc shape in cross section.
  6. 　電磁コイルが巻回されたステータコアと、前記ステータコアの中心部に設けられた軸受と、前記軸受に軸支された回転支持軸と、前記回転支持軸に固定されると共に、前記ステータコアの径方向の外周側を覆う側周面壁部を有するロータヨークとを備え、前記ロータヨークの前記側周面壁部の内周面には複数個の永久磁石が設けられ、前記永久磁石は、前記ステータコアの径方向の外周側に対向し、周方向に極性が変化する状態で周方向に所定角度間隔で取り付けられたアウターロータ形電動機のロータヨークの製造方法であって、
    　隣り合う前記永久磁石が配置される永久磁石配置領域の間の位置決め領域が開放された内周側プレス治具を前記ロータヨークの内周側に密着して配置する共に、前記永久磁石配置領域の周方向の中央付近の変形領域が開放された外周側プレス治具を前記ロータヨークの外周側に密着して配置し、
    　この状態で変形プレス治具を前記変形領域に押し当て、前記変形領域の前記ロータヨークの前記側周面壁部の金属材料を変形させて薄肉に形成すると共に、この薄肉化による余分な金属材料を前記位置決め領域から内側に向けて膨出させて前記永久磁石の位置決め部を形成する
    ことを特徴とするアウターロータ形電動機のロータヨークの製造方法。     A stator core around which an electromagnetic coil is wound, a bearing provided at the center of the stator core, a rotary support shaft pivotally supported by the bearing, and a rotary support shaft fixed to the rotary support shaft in the radial direction of the stator core. A rotor yoke having a side peripheral wall portion that covers the outer peripheral side is provided, and a plurality of permanent magnets are provided on the inner peripheral surface of the side peripheral wall portion of the rotor yoke. It is a method of manufacturing a rotor yoke of an outer rotor type motor that faces the side and is mounted at predetermined angular intervals in the circumferential direction in a state where the polarity changes in the circumferential direction.
    The inner peripheral side press jig in which the positioning region between the permanent magnet arrangement regions where the adjacent permanent magnets are arranged is open is arranged in close contact with the inner peripheral side of the rotor yoke, and the circumference of the permanent magnet arrangement region An outer peripheral side press jig having an open deformation region near the center of the direction is placed in close contact with the outer peripheral side of the rotor yoke.
    In this state, the deformation press jig is pressed against the deformation region to deform the metal material of the side peripheral wall portion of the rotor yoke in the deformation region to form a thin wall, and the excess metal material due to this thinning is described. A method for manufacturing a rotor yoke of an outer rotor type motor, which comprises bulging inward from a positioning region to form a positioning portion of the permanent magnet.
PCT/JP2020/042481 2019-11-25 2020-11-13 Outer rotor-type electric motor and method for manufacturing rotor yoke of outer rotor-type electric motor WO2021106637A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000184643A (en) * 1998-12-14 2000-06-30 Toyota Motor Corp Outer rotor for wheel-in motor
JP2004064891A (en) * 2002-07-29 2004-02-26 Asmo Co Ltd Brushless motor and its rotor yoke
JP2004357470A (en) * 2003-05-30 2004-12-16 Matsushita Electric Ind Co Ltd Permanent magnet synchronous motor
JP2004360499A (en) * 2003-06-02 2004-12-24 Toyota Industries Corp Electric compressor
JP2008061436A (en) * 2006-09-01 2008-03-13 Matsushita Electric Ind Co Ltd Motor
US20190193849A1 (en) * 2016-08-03 2019-06-27 Lg Innotek Co., Ltd. Motor for drone and drone including same

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000184643A (en) * 1998-12-14 2000-06-30 Toyota Motor Corp Outer rotor for wheel-in motor
JP2004064891A (en) * 2002-07-29 2004-02-26 Asmo Co Ltd Brushless motor and its rotor yoke
JP2004357470A (en) * 2003-05-30 2004-12-16 Matsushita Electric Ind Co Ltd Permanent magnet synchronous motor
JP2004360499A (en) * 2003-06-02 2004-12-24 Toyota Industries Corp Electric compressor
JP2008061436A (en) * 2006-09-01 2008-03-13 Matsushita Electric Ind Co Ltd Motor
US20190193849A1 (en) * 2016-08-03 2019-06-27 Lg Innotek Co., Ltd. Motor for drone and drone including same

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