US20030098628A1 - Electric motor - Google Patents

Electric motor Download PDF

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Publication number
US20030098628A1
US20030098628A1 US10/083,644 US8364402A US2003098628A1 US 20030098628 A1 US20030098628 A1 US 20030098628A1 US 8364402 A US8364402 A US 8364402A US 2003098628 A1 US2003098628 A1 US 2003098628A1
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US
United States
Prior art keywords
core
connection
connection housing
stator
magnetic pole
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.)
Abandoned
Application number
US10/083,644
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English (en)
Inventor
Yuuji Enomoto
Yasuaki Motegi
Masashi Kitamura
Yuji Takagai
Toshimi Abukawa
Takashi Ando
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.)
Hitachi Ltd
Nidec Advanced Motor Corp
Original Assignee
Individual
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 Individual filed Critical Individual
Assigned to JAPAN SERVO CO., LTD., HITACHI, LTD. reassignment JAPAN SERVO CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MOTEGI, YASUAKI, ABUKAWA, TOSHIMI, ANDO, TAKASHI, TAKAGAI, YUJI, KITAMURA, MASASHI, ENOMOTO, YUUJI
Publication of US20030098628A1 publication Critical patent/US20030098628A1/en
Priority to US10/679,409 priority Critical patent/US6794786B2/en
Abandoned legal-status Critical Current

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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
    • H02K1/12—Stationary parts of the magnetic circuit
    • H02K1/18—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
    • H02K15/02—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies
    • H02K15/022—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies with salient poles or claw-shaped poles
    • 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
    • H02K1/18—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
    • H02K1/187—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures to inner stators

Definitions

  • the present invention relates to compact and high-torque electric motors, particularly to the stator cores of externally rotating type of compact-size high-torque motors such as data-processing equipment driving motors, fan motors, or disk driving motors.
  • the predominant conventional method of improving the coil space ratio of the motor has been by, after splitting the core into segments according to the particular number of poles, laser-welding the outer surfaces of the core segments for the fastening thereof or press-fitting or shrinkage-fitting their inner surfaces into a cylindrical housing.
  • stator of the internally rotating type of motor it is difficult to fasten the core segments from the outer surface portion of the stator since the stator is constructed in such a manner that its magnetic poles are arranged radially in the direction of the outer surface of the stator from the inner surface thereof and that a magnetic gap with respect to the magnet rotor of the motor is formed on the outer surface of the stator. Besides, a member such as a housing cannot be shrinkage-fit or press-fit from the outer surface portion. For these reasons, for the stator of the internally rotating type of motor, the rotor of a coil-type direct-current motor, or the like, it has been difficult to adopt a split-core method in which the core is to be split and assembled.
  • the stator has such structure that the yoke section and tooth section of the stator core are split, that both sections are provided with dovetail-shaped recess and protrusion, and that these dovetailed portions are combined.
  • both methods there occur the problems that since the yoke and tooth sections are fastened only by press-fitting, the mechanical strength of the corresponding product is not sufficient, and that in view of the motor undergoing the repulsion of a torque at the end of the tooth section, the corresponding method cannot be applied to a motor of a large torque.
  • connection pins is described as the fastening method, other methods such as welding are also available.
  • the yoke section of the split core is connected by shrinkage-fitting its protruding portion and recessed portion, then punched into the recessed portion, and flared outward by plastic deformation. Consequently, the gap between the protruding portion and recessed portion is removed to form a strong and rigid connection.
  • the split core structure of the externally rotating type of motor is established for a low-torque motor
  • the externally rotating type of motor that has split core structure is not such that the motor can be employed in an actual product in terms of mechanical strength or long-term reliability associated with high-torque rotation.
  • the housing is likely to be located at the inner surface portion of the core and then stressed in the direction thereof.
  • the housing is cold-shrinkage-fit, in which case, the housing to which a minus temperature difference from normal temperature has been given using liquid nitrogen or the like, is located at the inner surface portion of the core, then expands by returning to normal temperature, and stressed towards the core.
  • shrinkage-fitting of a very thin, non-magnetized housing into the outer surface portion of the core means the spreading of a magnetic gap and deteriorates motor performance significantly.
  • the present invention supplies the electric motors that have a stator core formed by split core blocks in order to solve the problems described above; the fixed core having the sufficient capability to withstand the repulsion of the motor torque and not deteriorating the performance of the motor significantly.
  • a motor having a metallic connection housing which connects a plurality of split core blocks in dovetailed form to create one connected core section, wherein the motor is characterized in that the dovetailed connections at the above-mentioned connection housing are plastically deformed to remove the connection gap existing at each dovetailed connection.
  • the present invention creates the structure in which the rotor core of an internally rotating type motor is split into a plurality of segments in a circumferential direction, provides each core segment with a dovetailed recess and a dovetailed protrusion at the inner surface side of the core, and further provides the housing located at the inner surface portion of the core, with the protrusion and recess that can be fit into the recess and protrusion provided at the core side.
  • the housing can be easily assembled by fitting it into a clearance, and this fitting portion has sufficient dimensions to provide the clearance required for the housing to be assembled in the fitting portion.
  • the gap volume of the assembling clearance is given as (Assembling clearance ⁇ Circumferential length of the fitting portion ⁇ Laminating thickness of the core).
  • the laminating direction of the core can also be fixed at the same time according to the particular manner of giving plastic deformation, in other words, the shape of the dieing tool, such as punch, that is to be inserted. That is to say, the laminating direction of the core can be fixed by giving a stepped shape to the punch to be inserted into the fitting portion and spreading the edge of the housing.
  • FIG. 1 shows one of the embodiments pertaining to the present invention and consists of a front view showing the stator core of an externally rotating type motor, and a partly enlarged view of this front view.
  • FIG. 2 shows another embodiment of the present invention and consists of an assembly diagram showing the insertion of a connection housing into a stator core, and a view that shows related punching.
  • FIG. 3 shows yet another embodiment of the present invention and is a diagram showing a series of processes from the punching of a stator core to assembly and coil winding.
  • FIG. 4 shows a further embodiment of the present invention and is a view showing the adjustment of the roundness of a stator core using a collet holder and a collet chuck.
  • FIG. 5 shows a further embodiment of the present invention and is a view showing the fastening of a dovetailed connection by insertion with a punch.
  • FIG. 6 shows a further embodiment of the present invention and consists of the views that show connection housings of various shapes.
  • FIG. 7 consists of the views that show punches of various shapes and also show fastening by insertion with each punch.
  • FIG. 8 shows a further embodiment of the present invention and is a view showing a motor of the internally rotating type.
  • FIG. 9 shows a further embodiment of the present invention and is a view showing another motor of the internally rotating type.
  • FIG. 10 shows a further embodiment of the present invention and is a total view showing an externally rotating type motor based on the present invention.
  • FIG. 1 shows the stator core structure of an externally rotating type motor, wherein (a) is a front view of the stator core. Likewise, (b) is an enlarged view of (a), showing the status existing before plastic deformation using a punch takes place, and (c) is another enlarged view of (a), showing the status existing after plastic deformation using a punch has taken place.
  • the core section of the rotor core is formed by combining a plurality of split core blocks 2 (magnetic pole tooth sections or teeth) into a single unit.
  • Each magnetic pole tooth section 2 further comprises a coil winding drum portion, an outer-surface magnetic pole portion provided at the outer-surface front end of the coil winding drum and spread in a circumferential direction, and a support portion provided at the inner-surface front end of the coil winding drum.
  • split magnetic pole tooth sections 2 are arranged in such a manner that the respective outer-surface magnetic pole portions are positioned at the outer-surface side and that the coil winding drum is radially positioned.
  • the above-mentioned magnetic pole tooth sections that have thus been arranged are connected into a single unit so that they are connected to connection housing 1 positioned at the inner-surface side of the support portion mentioned above.
  • the stator core is formed by the core section which is further formed by radially arranged magnetic pole tooth sections 2 , and connection housing 1 by which the magnetic pole tooth sections 2 forming the core section are connected into a single unit.
  • Connection housing 1 uses a metallic material softer than the metal of the core section.
  • Magnetic pole tooth sections 2 and connection housing 1 are connected in dovetail form.
  • An engagement recess 2 a for dovetailed connection is provided on the inner surface of the support portion of each magnetic pole tooth section 2
  • an engagement protrusion 1 a for dovetailed connection is provided on the outer surface of connection housing 1 so as to protrude to the outer surface side thereof.
  • connection housing 1 and at magnetic pole tooth section 2 can also be provided in connection housing 1 and at magnetic pole tooth section 2 , respectively.
  • description is continued below in accordance with the structure of the embodiments shown in the drawings.
  • connection housing 1 When engagement protrusion 1 a provided on the outer surface of connection housing 1 is inserted into engagement recess 2 a provided on the inner surface of the support portion of each magnetic pole tooth section 2 , the magnetic pole tooth section will be connected to the connection housing and individual magnetic pole tooth sections 2 will be connected into unity via connection housing 1 .
  • engagement protrusion 1 a is so constructed as to loosely fit into engagement recess 2 a.
  • the creation of the loose fit permits easy insertion of engagement protrusion 1 a into engagement recess 2 a , and hence, very easy assembly, and improves assembly efficiency. These can be achieved by making the width and height of engagement protrusion 1 a smaller than those of engagement recess 2 a.
  • connection gap exists between engagement protrusion 1 a and engagement recess 2 a , as shown in FIG. 1( b ).
  • a machining hole 11 for plastic deforming is formed at engagement protrusion 1 a by inserting a dieing tool such as a punch, engagement protrusion 1 a will be pushed outward and the connection gap will be consequently filled in and removed.
  • connection housing 1 If an engagement recess is provided in connection housing 1 and an engagement protrusion is provided at each magnetic pole tooth section 2 , fastening can be accomplished by inserting a dieing tool or punch into the outer vicinity of the engagement recess. With either method, the dovetailed connection at the connection housing side can be fastened by plastically deforming this connection.
  • FIG. 2 is an oblique view showing the assembly process.
  • connection housing 1 is inserted along the laminating thickness of the core section, that is, in the lateral laminating direction thereof. Since engagement recesses and engagement protrusions are already formed in that direction, connection housing 1 can be easily assembled along the inner edge of the core section.
  • the magnetic pole teeth 2 split core blocks
  • connection housing 1 that has been extruded by the punch flows into the connection clearance (connection gap) that has existed at up to that time, and the material that has been extruded more strongly creates a residual stress inside the connection housing to implement fastening between magnetic pole teeth 2 (split core blocks) and between magnetic pole teeth 2 and the connection housing. Consequently, rigid and looseness-free dovetailed connection is established.
  • connection housing is made of a soft metallic material (aluminum). It is desirable that the connection housing material be relatively small in tensile strength and in yield strength, and for example, an aluminum alloy, a zinc alloy, a copper alloy, magnesium, or the like is likely to be suitable, but other materials are also usable. It suffices just to use a material softer than the material forming the magnetic pole teeth.
  • a core is formed by, as shown in FIG. 3( a ), punching out magnetic pole teeth 2 from an unprocessed motor core material such as a silica steel plate, and the magnetic pole teeth are laminated as shown in FIG. 3( b ). These magnetic pole teeth are then fixed so that they do not disperse.
  • the plate members of the magnetic pole teeth laminated are so fixed using a staking member 2 b as to be connected to each other.
  • the magnetic pole teeth may be fixed by welding the outer-surface and/or inner-surface edges of magnetic pole teeth 2 by means of a laser or the like.
  • split punching of individual magnetic pole teeth 2 can be implemented at a higher yield ratio than the punching of an integrated magnetic pole tooth section, for the quantity of residual material wasted will be smaller and the punching yield ratio will improve.
  • the punching yield obtained from punching an integrated magnetic pole tooth section is about 30%, whereas the punching yield obtained from punching split magnetic pole teeth is about 60%, which is about twice the above value.
  • an insulating bobbin of the shape shown in FIG. 3( c ) is installed to ensure the adequate insulation between magnetic pole tooth section 2 and the coils to be wound.
  • This bobbin is usually made of a resin material such as nylon, PBT, PET, PPS, or LCP. Instead, it is also possible to wind tape-like electrical insulating paper or to cut similar paper into small pieces and attach them.
  • insulation can likewise be implemented by using an insert molding made up of resin and a core or coating the core with epoxy resin or the like. Since magnetic pole tooth section 2 is created in split form, outside is provided with coiling and any of the methods described above can be freely selected for processing.
  • Insulated magnetic pole tooth section 2 is then set in a coil winding machine as shown in FIG. 3( d ), and coils are wound around the coil winding drum of magnetic pole tooth section 2 .
  • each magnetic pole tooth section 2 is supported by setting the engagement recess of the support portion of the magnetic pole tooth section at the core holding portion 6 of the coil winding machine.
  • Magnetic pole teeth 2 is set in cross form and then aligned coiling is provided so that a wide working space can be created at the flyer arm 5 of the coil winding machine.
  • FIG. 3( e ) the process for setting coiled magnetic pole tooth section 2 on an assembly jig is shown in FIG. 3( e ).
  • four coils are wound for one phase.
  • Magnetic pole teeth 2 on which these coils ( 4 u 1 , 4 u 2 , 4 u 3 , 4 u 4 , 4 v 1 , 4 w 1 ) have been mounted are set on assembly jig 7 so that the teeth are arranged according to the particular number of poles of the motor.
  • FIG. 3( e ) applies to a 10-pole motor, this arrangement can also be applied to other motors such as an 8-pole motor, depending on the way the magnetic pole teeth are to be arranged.
  • the engagement recesses of magnetic pole teeth 2 are also supported in a similar way to that of supporting on the coil winding machine.
  • the status that the magnetic pole tooth section 2 provided with three phases of coiling is supported using assembly jig 7 is shown in FIG. 3( f ).
  • connection housing 1 is inserted and on completion of the insertion, the assembly jig is removed. This state is shown in FIG. 3( g ). After removal of the jig, assembly is started.
  • connection housing 1 At the phase of FIG. 3 showing the status that coiled magnetic pole tooth section 2 has been moved from assembly jig 7 to connection housing 1 for the purpose of its insertion, the stator core is not sufficient in terms of roundness and position accuracy.
  • a connection gap exists between engagement recess 2 a and engagement protrusion 1 a , and adjacent gaps also exist between the support portions of adjacent magnetic pole teeth, with the result that the position of magnetic pole tooth section 2 is not fixed and the stator core is not sufficient in terms of roundness and position accuracy.
  • connection housing After the connection housing has been inserted as shown in FIGS. 4 ( a ) and ( b ), the outer surface portion of the stator core is restrained using a tapered collet chuck 9 .
  • a collect chuck holder 8 whose inner surface portion has a taper of the same angle as that of the taper of the collet chuck 9 , is applied over the outside of the collet chuck.
  • collet chuck holder 8 is inserted as shown in FIG. 4( a ), and as a result, the stator core is restrained in its radial direction, that is to say, pressed towards the center, by collet chuck 9 at the same time the stator core is contracted.
  • stator core with the inserted connection housing has been described above, roundness can likewise be adjusted using the collet chuck holder before the connection housing is inserted.
  • connection gap existing at the dovetailed connection between engagement recess 2 a and engagement protrusion 1 a has a width of W1 in the case of connection gap “g1” or a width of W2 in the case of connection gap “g2”. Adjacent gaps “gk” are present between adjoining support portions. This state exists before the stator core is pressed by the collet chuck holder.
  • connection gap “g2” Under the adjusted status of roundness, connection gap “g2” still exists. Although connection gap “g1” is narrowed, its size has been increased beforehand for a portion of the gap to remain. Thus, the assembly procedure for inserting the connection housing can be taken after the roundness of the stator core has been accurately adjusted using the collet chuck holder.
  • connection gaps “g1” and “g2” fills in connection gaps “g1” and “g2” to clear both to zero (“g1” and “g2”, respectively).
  • FIG. 5( c ) shows the shape existing before punching.
  • FIG. 5( d ) shows the shape existing after punching.
  • connection gaps “g1” and “g2” [0067] The total space volume of the above-mentioned connection gaps “g1” and “g2” can be expressed as follows:
  • connection gaps “g1” and “g2” are greater than the space volume required for connection gaps “g1” and “g2” to be filled in.
  • stator core can be assembled into highly accurate roundness, both adjacent gaps “gk” are cleared to zero (“gk1”, “gk2”) and both ends of each adjacent support portion are connected. Since this connection spans over the entire length in a radial direction, magnetic characteristics similar to those of a stator core which is formed into a single unit are maintained and the motor does not decrease in characteristics.
  • the laminating thickness (laminating direction) of the stator core can also be fixed by generating plastic deformation in the laminating direction. That is to say, as shown in the figure, the lower end is supported by the stepped section of the connection housing and the upper end is held by the plastically deformed section, with the result that the magnetic pole teeth constituting the stator core are held vertically in sandwiched form.
  • FIG. 6 is an explanatory view showing the shapes that the connection housing can take.
  • connection housing can take is a housing shape having the same cross section in the direction of lamination (axial direction), as shown, in FIG. 6( a ). Since this shape has the same cross section, the housing, if made of aluminum, copper, or the like, can be manufactured using a method such as cold forging, cold-draw molding, hot drawing, extruding, or die-casting. Also, a connection housing, such as that shown in FIG. 6( b ), that has the structure consisting of a combination of a cylinder and a cross-sectional shape having the portion fitting into the stator core, or a connection housing, such as that shown in FIG. 6( c ), that has a different diameter at its inside diameter section as well, is applied to an actual motor. These housings can be manufactured by cold forging.
  • FIG. 7 shows the shapes of dovetailed connections.
  • FIG. 8 shows the shapes of plastic deforming punches.
  • FIG. 7( a ) shows the shape of a connection housing provided with a semi-circular notch, in which case, a plastic deforming punch 10 having a tapered end is inserted into the notch and thus elliptical plastic deformation is generated to fasten the stator core.
  • Another shape can be created by, as shown in FIG. 7( b ), providing the stator core beforehand with a notch of a semi-circular shape or the like and then inserting a punch whose end is tapered and whose cross-sectional shape is circular.
  • fastening can likewise be achieved by providing the connection housing with a positioning mark such as a punched hole and then providing cylindrical hole plastic machining by use of a punch having a spherical end.
  • FIG. 8 shows an example in which the fastening of the plastically deformed stator cores pertaining to the present invention is to be applied to motors of the internally rotating type.
  • connection housing 41 inserted along the outer surface of a stator core 41 .
  • the connection housing 41 is made of a steel plate softer than an aluminum or silica steel plate.
  • connection housing 41 Assembly can be simplified by giving to connection housing 41 an inside diameter slightly greater than the outside diameter of the stator coil 41 . After assembly, the sections of connection housing 41 that are close to the notches 42 provided along the outer surface of stator core 41 are provided with holes 43 by punching, as shown in FIG. 8( c ). Hereby, the forming material of connection housing 41 plastically deforms and fits into notches 42 , and consequently, connection housing 41 is securely fixed to the outer surface of stator core 41 .
  • stator core 41 is equipped with a rotor yoke 44 and a rotor magnet 45 .
  • connection housing 41 inserted along the outer surface of the stator core which has been formed by combining a plurality of split magnetic pole teeth 46 .
  • the connection housing 41 is made of a steel plate softer than an aluminum or silica steel plate.
  • connection housing 41 Assembly can be simplified by giving to connection housing 41 an inside diameter slightly greater than the outside diameter of the stator coil 41 . After assembly, the sections of connection housing 41 that are close to the notches 47 provided along the outer surface of magnetic pole teeth 46 are provided with holes 43 by punching, as shown in FIG. 8( d ). Hereby, the forming material of connection housing 41 plastically deforms and fits into notches 47 , and consequently, connection housing 41 and magnetic pole teeth 46 are securely fixed and the plurality of magnetic pole teeth 46 are rigidly connected into a single unit.
  • FIG. 9 shows another method of fastening an internally rotating type motor by plastic deforming.
  • connection housing 41 of the internally rotating type motor has an open outer surface. Connection housing 41 is inserted along the outer surface of stator core 50 as shown in FIG. 9( a ).
  • Connection housing 41 is made of a steel plate softer than an aluminum or silica steel plate.
  • connection housing 41 an inside diameter slightly greater than the outside diameter of the stator coil 50 .
  • connection housing 41 After assembly, when a plastic deforming die such as a punch is inserted directly from the outer surface of connection housing 41 in the direction of its inner surface, the plastic deformation will allow the forming material of connection housing 41 to flow into the groove of the stator core 50 and the clearance between stator core 50 and connection housing 41 , with the result that the fastening of the split stator core segments 50 and the fastening of the stator core and the connection housing will be implemented.
  • the holes 51 that have been created by the plastic deformation will be formed on the surface of connection housing 41 .
  • FIG. 10 shows the total structure of an externally rotating type motor.
  • Stator core 60 is equipped with a connection housing 61 on its inner surface. Stator core 60 is fastened by the plastic deformation of the connection housing 61 .
  • the inner surface of the connection housing 61 is equipped with bearings 62 and a collar 63 .
  • a rotating shaft 64 is supported on bearings 62 so as to be freely rotatable, and a rotor core 65 is supported at one end of the rotating shaft 64 .
  • Rotor core 65 has the shape of a cup, and magnets 66 are provided at the inner surface portions of the rotor core that face the outer surface portions of the stator core. Magnets 66 are installed using an adhesive or the like.
  • Connection housing 61 is fixed to the base portion 67 of the motor.
  • a control circuit board 68 is equipped between base portion 67 and stator core 60 . The base portion 67 of the motor and the connection housing 61 are fixedly connected by press-fitting, screwing, shrinkage fitting, welding, or the like.
  • the magnetic pole tooth section formed by each of said split core blocks is characterized in that this tooth section comprises a coil winding drum portion, an outer-surface magnetic pole portion provided at the outer-surface front end of said coil winding drum and spread in a circumferential direction, and a support portion provided at the inner-surface front end of the coil winding drum,
  • said magnetic pole tooth section whose outer-surface magnetic pole portion is positioned at the outer-surface side and whose coil winding drum is radially positioned is connected in dovetailed form to said connection housing positioned at the inner-surface side of said support portion
  • an engagement protrusion or engagement recess for dovetailed connection is provided on the inner surface of the support portion and an engagement protrusion or engagement recess for dovetailed connection is provided on the outer surface of the connection housing so as to fit into the engagement protrusion or engagement recess on the inner surface of the support portion, and
  • connection protrusion or engagement recess for dovetailed connection provided in the connection housing, is plastically deformed to remove the connection gap existing between the engagement protrusion and engagement recess that fit one another.
  • the engagement protrusion and the engagement recess can be easily fit into one another since a connection gas is present between both. Accordingly, the magnetic pole tooth section formed by each split core block can be easily assembled into the connection housing.
  • connection gap is plastically deformed to fill in the gap so that it is removed, the corresponding dovetailed connection is rigidly fastened and a rigid stator core is formed.
  • stator core forming the magnetic pole teeth is the plastically deformed portion of the connection housing, and the lower end is held by the stepped portion of the connection housing.
  • the entire stator core is therefore supported in sandwiched form in its laminating direction by the connection housing, and for this reason, the fastening of the stator core in its laminating direction is improved.
  • the sandwiched supporting force in the laminating direction of the stator core can be enhanced by bestowing a stepped shape on the punch to be used for plastic deforming.
  • stator core forming the magnetic pole teeth can be assembled into highly accurate roundness, adjacent gaps are removed and both ends of each support portion of adjacent magnetic pole teeth are connected. Since this connection spans over the entire length in a radial direction, magnetic characteristics similar to those of a stator core which is formed into a single unit are maintained and the motor does not decrease in characteristics.
  • Coils can be wound directly around split magnetic pole teeth. Therefore, these magnetic pole teeth, unlike the magnetic pole teeth formed on an integrated type of stator core, can have their shape designed according to the particular specifications of the motor.
  • stator core that has been split into segments enables coil winding without coil conductors being inserted from the narrow grooves between adjacent outer-surface magnetic pole teeth, the slots in the magnetic pole teeth can be coiled at a high space ratio. Also, since the slots can be coiled so as to be filled in, the thermal conductivity between coil conductors improves and increases in temperature can be suppressed.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)
  • Windings For Motors And Generators (AREA)
  • Motor Or Generator Frames (AREA)
  • Manufacture Of Motors, Generators (AREA)
  • Permanent Magnet Type Synchronous Machine (AREA)
US10/083,644 2001-11-29 2002-02-27 Electric motor Abandoned US20030098628A1 (en)

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Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030030345A1 (en) * 2001-08-07 2003-02-13 Hitachi, Ltd Core, rotating machine using the core and production method thereof
US20030175542A1 (en) * 2002-03-13 2003-09-18 Edscha Cabrio-Dachsysteme Gmbh Bent extruded profile
WO2005004311A1 (en) * 2003-07-07 2005-01-13 Ats Automation Tooling Systems Inc. Apparatus and method for winding stator teeth
US20060113859A1 (en) * 2004-12-01 2006-06-01 Chun-Hsien Lu Electric motor
US20070096586A1 (en) * 2005-10-31 2007-05-03 Jerome Cros Multi-phase electrical motor for use in a wheel
US20070196615A1 (en) * 2004-05-17 2007-08-23 Grundfos A/S Laminated core for electromagnetic applications
US20080157610A1 (en) * 2006-12-28 2008-07-03 Ichinomiya Denki Co., Ltd. Stator for inner rotor type mold brushless motor
US20090015093A1 (en) * 2007-07-13 2009-01-15 Kornelius Reutter Miniature electrical drive and magnetic return path element, and method for its production
US20100192357A1 (en) * 2004-09-09 2010-08-05 Mitsui High-Tec, Inc. Method of manufacturing laminated core
EP2669531A1 (en) * 2012-06-01 2013-12-04 Siemens Aktiengesellschaft Fixing of stator segment elements
US20150076955A1 (en) * 2013-09-16 2015-03-19 Nidec Motor Corporation Dual-out stator lamination for outer rotor motor
CN104704712A (zh) * 2012-10-10 2015-06-10 三菱电机株式会社 旋转电机及其制造方法
US20150214791A1 (en) * 2014-01-27 2015-07-30 Samsung Electro-Mechanics Co., Ltd. Stator core and spindle motor including the same
US20160094094A1 (en) * 2014-09-26 2016-03-31 Alstom Renewable Technologies Electrical machines
EP1976094A4 (en) * 2006-01-16 2017-03-08 Toyota Jidosha Kabushiki Kaisha Rotary motor core, and rotary motor
EP3352332A1 (en) * 2017-01-20 2018-07-25 GE Renewable Technologies Salient pole machine
EP3477821A4 (en) * 2016-06-17 2019-05-01 Yamaha Motor Electronics Kabushiki Kaisha STATOR FOR DYNAMOELECTRIC MACHINE
WO2019233739A1 (fr) * 2018-06-07 2019-12-12 Moteurs Leroy-Somer Stator de machine electrique tournante
US10734854B2 (en) * 2016-05-02 2020-08-04 Mitsuba Corporation Rotor and motor
CN112134377A (zh) * 2019-06-24 2020-12-25 信浓绢糸株式会社 定子、定子的制造方法和外转子型马达
US20210159741A1 (en) * 2018-04-17 2021-05-27 Rolls-Royce Deutschland Ltd & Co Kg Stator, electric machine, aircraft comprising an electric machine, and method for producing a stator
US11223246B2 (en) * 2019-08-19 2022-01-11 Wittenstein Se Stator
US11374443B2 (en) * 2018-09-27 2022-06-28 Denso Corporation Rotary electric machine
EP4060867A3 (de) * 2021-03-16 2022-10-05 ebm-papst Mulfingen GmbH & Co. KG Elektromotor mit verbesserter motorausnutzung
EP3930150A4 (en) * 2019-02-20 2022-11-16 Nidec Corporation STATOR CORE, ROTOR CORE AND MOTOR
US11677286B2 (en) 2017-03-03 2023-06-13 Ge Renewable Technologies Salient pole machine with rotor having rotor rim with pole-rim interface and fixation points

Families Citing this family (54)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3521824B2 (ja) * 1999-12-17 2004-04-26 国産電機株式会社 フライホイールマグネト用ステータ
JP2004104986A (ja) * 2002-07-16 2004-04-02 Japan Servo Co Ltd 永久磁石形回転電機
US7211920B2 (en) * 2003-09-05 2007-05-01 Black & Decker Inc. Field assemblies having pole pieces with axial lengths less than an axial length of a back iron portion and methods of making same
US7205696B2 (en) * 2003-09-05 2007-04-17 Black & Decker Inc. Field assemblies having pole pieces with ends that decrease in width, and methods of making same
KR100564090B1 (ko) * 2003-12-10 2006-03-24 뉴모텍(주) 모터의 고정자 코어
JP4523779B2 (ja) * 2004-01-19 2010-08-11 株式会社三井ハイテック 分割積層固定子鉄心
JP2006027355A (ja) * 2004-07-13 2006-02-02 Nsk Ltd 電動パワーステアリング装置
US7247967B2 (en) * 2004-08-09 2007-07-24 A. O. Smith Corporation Electric motor having a stator
US7737598B2 (en) * 2004-08-09 2010-06-15 A. O. Smith Corporation Electric motor having a stator
KR100673442B1 (ko) * 2004-08-25 2007-01-24 엘지전자 주식회사 모터의 스테이터
JP4657661B2 (ja) * 2004-09-09 2011-03-23 株式会社三井ハイテック 積層固定子鉄心の製造方法
US20060066171A1 (en) * 2004-09-28 2006-03-30 Toyo Denso Kabusiki Kaisha Stator core for rotating electric machine
EP2562912A1 (en) 2005-03-07 2013-02-27 Black & Decker Inc. Power Tools with Motor Having a Multi-Piece Stator
US7200046B2 (en) * 2005-06-14 2007-04-03 Micron Technology, Inc. Low power NROM memory devices
KR100647835B1 (ko) * 2005-07-21 2006-11-23 삼성전기주식회사 브러쉬리스 직류모터용 스테이터 코어
JP2007043845A (ja) * 2005-08-04 2007-02-15 Toyota Motor Corp ステータ構造およびステータの製造方法
US7348706B2 (en) * 2005-10-31 2008-03-25 A. O. Smith Corporation Stator assembly for an electric machine and method of manufacturing the same
DE102006016249A1 (de) * 2006-03-31 2007-10-04 Robert Bosch Gmbh Stator für eine Elektromaschine und Verfahren zur Herstellung
CN101461119B (zh) * 2006-06-05 2011-11-16 三菱电机株式会社 分割型定子铁心及其制造方法、定子铁心
KR101275210B1 (ko) * 2006-06-16 2013-06-18 엘지전자 주식회사 와인딩 타입 스테이터 코어를 갖는 스테이터 및 이를포함한 세탁장치
TW200822488A (en) * 2006-09-08 2008-05-16 Sanyo Electric Co Motor
KR100856032B1 (ko) * 2007-01-16 2008-09-02 주식회사 포스코아 코아몸체, 코아날개 및 이를 구비한 조립식 적층 코아
US7928029B2 (en) * 2007-02-20 2011-04-19 Corning Incorporated Refractory ceramic composite and method of making
US7704905B2 (en) * 2007-05-07 2010-04-27 Corning Incorporated Reduced strain refractory ceramic composite and method of making
US20080317616A1 (en) * 2007-06-22 2008-12-25 Air Cool Industrial Co., Ltd. Positioning device for a detecting device of a motor of a ceiling fan
US8986597B2 (en) * 2007-10-31 2015-03-24 Corning Incorporated Low creep refractory ceramic and method of making
JP5171224B2 (ja) * 2007-11-22 2013-03-27 三菱電機株式会社 回転電機
KR101011861B1 (ko) * 2010-04-13 2011-01-31 주식회사 강림정공 스테이터
EP2385609B1 (en) * 2010-05-05 2018-11-28 Siemens Aktiengesellschaft Generator with a segmented stator
US8749108B2 (en) * 2011-03-15 2014-06-10 Electric Torque Machines, Inc. Transverse and/or commutated flux systems having laminated and powdered metal portions
KR101886154B1 (ko) 2011-10-06 2018-08-08 삼성전자 주식회사 모터의 로터 및 로터용 연결 핀
JP5741410B2 (ja) * 2011-11-29 2015-07-01 トヨタ自動車株式会社 回転電機用ロータ
CN102832724A (zh) * 2012-09-03 2012-12-19 重庆乾威科技有限公司 一种大功率盘式永磁电机定子
CN102820716A (zh) * 2012-09-05 2012-12-12 慈溪市顺达实业有限公司 一种定子铁芯
CN103872814A (zh) * 2012-12-17 2014-06-18 泰豪沈阳电机有限公司 扇形片转子的鸽尾筋结构
DE102013204759A1 (de) * 2013-03-19 2014-09-25 Robert Bosch Gmbh Zahnsegment zum Zusammenbau eines Stators oder Rotors einer elektrischen Maschine und Verfahren für die Herstellung einer solchen
US10056793B2 (en) 2013-07-19 2018-08-21 Honda Motor Co., Ltd. Stator including integrated cores and holder
DE102013222329A1 (de) * 2013-11-04 2015-05-07 Robert Bosch Gmbh Maschinenkomponente für eine Elektromaschine und Verfahren zur Herstellung einer solchen Maschinenkomponente
JP6435722B2 (ja) * 2013-11-25 2018-12-12 株式会社デンソー 回転電機
DE102014216743B4 (de) * 2014-08-22 2021-03-18 Robert Bosch Gmbh Elektrische Maschine
TW201640791A (zh) * 2015-05-05 2016-11-16 Jun Fu Clean Energy Co Ltd 發電機
US9422187B1 (en) 2015-08-21 2016-08-23 Corning Incorporated Laser sintering system and method for forming high purity, low roughness silica glass
US10848029B2 (en) * 2016-03-02 2020-11-24 Hitachi Industrial Equipment Systems Co., Ltd. Axial gap type rotating electric machine and rotating electric machine stator bobbin
WO2017170298A1 (ja) * 2016-03-31 2017-10-05 日本電産株式会社 電動モータ用ステータの製造方法、電動モータの製造方法、電動モータ用ステータ、および電動モータ
US11248671B2 (en) 2016-12-22 2022-02-15 Research Institute Of Industrial Science & Technology Brake disc and manufacturing method therefor
JP6787257B2 (ja) * 2017-06-06 2020-11-18 株式会社デンソー 回転電機
CN109286295A (zh) * 2018-10-16 2019-01-29 华北电力大学（保定） 一种具有聚磁效应的永磁同步电机
TWI738152B (zh) * 2018-12-17 2021-09-01 日商日本製鐵股份有限公司 積層鐵芯及旋轉電機
JP7211883B2 (ja) * 2019-04-17 2023-01-24 ダイキン工業株式会社 ステータおよびモータ
CN110365132B (zh) * 2019-07-02 2021-10-29 武汉研道科技有限公司 一种电动汽车用变支路模块化永磁内置式外转子轮毂电机
TWI723493B (zh) * 2019-08-14 2021-04-01 財團法人工業技術研究院 組合式馬達定子
KR102391686B1 (ko) * 2019-09-04 2022-04-28 엘지전자 주식회사 스테이터
CN113178965B (zh) * 2021-05-12 2023-07-21 安徽乐普电机有限公司 一种直流无刷电机内定子及其生产方法
DE102022126462A1 (de) 2022-10-12 2024-04-18 Schaeffler Technologies AG & Co. KG Stator für eine elektrische Maschine

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6515396B1 (en) * 2001-11-27 2003-02-04 General Electric Company Stator flux ring having fastenable pole pieces and method of making same

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3914859A (en) * 1974-01-17 1975-10-28 Ray T Pierson Method of fabricating closed slot stator construction particularly adapted for stepper motors
US5223761A (en) * 1991-08-14 1993-06-29 General Electric Company Electromotor with laminated stator and method of manufacturing the same
JP3320174B2 (ja) * 1993-10-29 2002-09-03 花王株式会社 ジ長鎖型第３級アミン酸塩の製造方法
JPH07203644A (ja) 1993-12-29 1995-08-04 Tokai Rubber Ind Ltd 回動装置
JPH08126231A (ja) * 1994-10-26 1996-05-17 Asmo Co Ltd 電動機の固定子
DE19538483A1 (de) * 1995-10-17 1997-04-24 Bosch Gmbh Robert Verfahren zum Herstellen einer Fügeverbindung, insbesondere zwischen Erregerpolen und Polgehäuse einer Elektromaschine und nach dem Verfahren hergestellte Maschine
JPH1094230A (ja) 1996-09-12 1998-04-10 Hitachi Ltd 外転型集中巻回転電機とそれを用いた電動車両
JP3568364B2 (ja) * 1996-09-30 2004-09-22 松下電器産業株式会社 回転電機のコア
JP4078706B2 (ja) 1998-03-05 2008-04-23 神鋼電機株式会社 分割コイル
JP3655474B2 (ja) 1998-11-12 2005-06-02 株式会社三協精機製作所 多極コア及びそれを用いたインナー型電機子、並びにその製造方法
JP2000184636A (ja) 1998-12-18 2000-06-30 Calsonic Kansei Corp モータ
CN1301075A (zh) * 2000-09-29 2001-06-27 许俊甫 组合式的马达定子结构

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6515396B1 (en) * 2001-11-27 2003-02-04 General Electric Company Stator flux ring having fastenable pole pieces and method of making same

Cited By (42)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030030345A1 (en) * 2001-08-07 2003-02-13 Hitachi, Ltd Core, rotating machine using the core and production method thereof
US6806615B2 (en) * 2001-08-07 2004-10-19 Hitachi, Ltd. Core, rotating machine using the core and production method thereof
US20030175542A1 (en) * 2002-03-13 2003-09-18 Edscha Cabrio-Dachsysteme Gmbh Bent extruded profile
US6821640B2 (en) * 2002-03-13 2004-11-23 Edscha Cabrio-Dachsysteme Gmbh Bent extruded profile
WO2005004311A1 (en) * 2003-07-07 2005-01-13 Ats Automation Tooling Systems Inc. Apparatus and method for winding stator teeth
US20050051661A1 (en) * 2003-07-07 2005-03-10 Ats Automation Tooling Systems, Inc. Apparatus and method for winding stator teeth
US20070196615A1 (en) * 2004-05-17 2007-08-23 Grundfos A/S Laminated core for electromagnetic applications
US9000650B2 (en) * 2004-05-17 2015-04-07 Grundfos A/S Laminated core for electromagnetic applications
US20100192357A1 (en) * 2004-09-09 2010-08-05 Mitsui High-Tec, Inc. Method of manufacturing laminated core
US8205322B2 (en) 2004-09-09 2012-06-26 Mitsui High-Tec, Inc. Method of manufacturing laminated core
US20060113859A1 (en) * 2004-12-01 2006-06-01 Chun-Hsien Lu Electric motor
US20090179517A1 (en) * 2004-12-01 2009-07-16 Chun-Hsien Lu Electric motor
US7583001B2 (en) * 2004-12-01 2009-09-01 Industrial Technology Research Institute Electric motor design for in hub motors
US20070096586A1 (en) * 2005-10-31 2007-05-03 Jerome Cros Multi-phase electrical motor for use in a wheel
US7579738B2 (en) 2005-10-31 2009-08-25 Greenee Energy Inc. Multi-phase electrical motor for use in a wheel
EP1976094A4 (en) * 2006-01-16 2017-03-08 Toyota Jidosha Kabushiki Kaisha Rotary motor core, and rotary motor
US7626303B2 (en) * 2006-12-28 2009-12-01 Ichinomiya Denki Co., Ltd. Stator for inner rotor type mold brushless motor
US20080157610A1 (en) * 2006-12-28 2008-07-03 Ichinomiya Denki Co., Ltd. Stator for inner rotor type mold brushless motor
US8143760B2 (en) 2007-07-13 2012-03-27 Dr. Fritz Faulhaber Gmbh & Co. Kg Miniature electrical drive and magnetic return path element, and method for its production
EP2017944A1 (de) 2007-07-13 2009-01-21 Dr. Fritz Faulhaber GmbH & Co. KG Elektrischer Kleinstantrieb sowie Rückschlusselement und Verfahren zu dessen Herstellung
US20090015093A1 (en) * 2007-07-13 2009-01-15 Kornelius Reutter Miniature electrical drive and magnetic return path element, and method for its production
EP2669531A1 (en) * 2012-06-01 2013-12-04 Siemens Aktiengesellschaft Fixing of stator segment elements
CN104704712A (zh) * 2012-10-10 2015-06-10 三菱电机株式会社 旋转电机及其制造方法
US20150076955A1 (en) * 2013-09-16 2015-03-19 Nidec Motor Corporation Dual-out stator lamination for outer rotor motor
US20150214791A1 (en) * 2014-01-27 2015-07-30 Samsung Electro-Mechanics Co., Ltd. Stator core and spindle motor including the same
US20160094094A1 (en) * 2014-09-26 2016-03-31 Alstom Renewable Technologies Electrical machines
US10193402B2 (en) * 2014-09-26 2019-01-29 Ge Renewable Technologies Wind B.V. Fastening system for coupling electrical machine components
US10734854B2 (en) * 2016-05-02 2020-08-04 Mitsuba Corporation Rotor and motor
EP3477821A4 (en) * 2016-06-17 2019-05-01 Yamaha Motor Electronics Kabushiki Kaisha STATOR FOR DYNAMOELECTRIC MACHINE
EP3352332A1 (en) * 2017-01-20 2018-07-25 GE Renewable Technologies Salient pole machine
US11677286B2 (en) 2017-03-03 2023-06-13 Ge Renewable Technologies Salient pole machine with rotor having rotor rim with pole-rim interface and fixation points
US20210159741A1 (en) * 2018-04-17 2021-05-27 Rolls-Royce Deutschland Ltd & Co Kg Stator, electric machine, aircraft comprising an electric machine, and method for producing a stator
FR3082376A1 (fr) * 2018-06-07 2019-12-13 Moteurs Leroy-Somer Stator de machine electrique tournante
CN112243557A (zh) * 2018-06-07 2021-01-19 利莱森玛电机公司 用于旋转电机的定子
US20210203197A1 (en) * 2018-06-07 2021-07-01 Moteurs Leroy-Somer Stator for a rotating electrical machine
WO2019233739A1 (fr) * 2018-06-07 2019-12-12 Moteurs Leroy-Somer Stator de machine electrique tournante
US11374443B2 (en) * 2018-09-27 2022-06-28 Denso Corporation Rotary electric machine
EP3930150A4 (en) * 2019-02-20 2022-11-16 Nidec Corporation STATOR CORE, ROTOR CORE AND MOTOR
CN112134377A (zh) * 2019-06-24 2020-12-25 信浓绢糸株式会社 定子、定子的制造方法和外转子型马达
US11316388B2 (en) * 2019-06-24 2022-04-26 Shinano Kenshi Kabushiki Kaisha Stator, method of manufacturing stator, and outer rotor type motor
US11223246B2 (en) * 2019-08-19 2022-01-11 Wittenstein Se Stator
EP4060867A3 (de) * 2021-03-16 2022-10-05 ebm-papst Mulfingen GmbH & Co. KG Elektromotor mit verbesserter motorausnutzung

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CN1421980A (zh) 2003-06-04
KR20030044747A (ko) 2003-06-09
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CN1319247C (zh) 2007-05-30
TW552761B (en) 2003-09-11
US6794786B2 (en) 2004-09-21

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