JP2007295740A - Stator core and its manufacturing method, and motor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stator core which enables the security of connection strength between split cores and the reduction of a heat loss, and to provide its manufacturing method, and a motor and its manufacturing method. <P>SOLUTION: The stator core 10 is composed of a first core body where a plurality of split cores 1, 1, and 1 divided in its circumferential direction are assembled, and an envelope 4 which envelops the first core. This envelope 4 is composed of an electromagnetic steel wire 41 wound in its circumferential direction, and a hardening body of a prepreg sheet 42 where a fibrous fabric is impregnated with a thermosetting resin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a stator core composed of a plurality of divided cores and a method for manufacturing the same, and an electric motor including the stator core and a method for manufacturing the same, and in particular, a stator core capable of ensuring connection strength between divided cores and reducing heat loss. The present invention also relates to a manufacturing method thereof, an electric motor including the stator core, and a manufacturing method thereof.

  A stator core constituting an electric motor is manufactured by punching a magnetic steel sheet or the like in a shape having a plurality of teeth protruding radially inward from an annular yoke, and laminating such steel sheets to a predetermined height. Is common. In the case of such a manufacturing method, a substantially annular steel plate portion defined by the tips of a plurality of teeth is used for rotor manufacture without discarding the steel plate after being punched into a substantially annular shape.

  By the way, since the fluctuation of the magnetic flux density in the rotor is extremely small compared to the stator, the material steel plate used for rotor manufacture does not necessarily have to have the magnetic characteristics required for the material steel plate used for stator manufacture. Absent. However, according to the stator core manufacturing method described above, from the viewpoint of reducing the amount of material disposal, it is necessary to use a relatively expensive material such as an electromagnetic steel plate similar to the stator, and as a result, Manufacturing costs were unnecessarily increased.

  As a technology to reduce the amount of steel sheet disposal and efficiently manufacture the stator and rotor from different steel sheets, manufacturing a stator core by joining a plurality of divided stators in the circumferential direction as a technology to reduce the amount of steel sheet disposal. Technology has been developed and is generally known. According to this manufacturing method, for example, a split piece for a split stator can be punched out as much as possible from an electromagnetic steel plate, so that the steel plate portion remaining after punching is used for the rotor in order to avoid disposal of the steel plate. There is no need to do it. That is, a relatively expensive steel plate such as an electromagnetic steel plate is applied for stator production, and a steel plate made of a soft magnetic material that is cheaper than the electromagnetic steel plate can be used as a steel plate for rotor production.

  Another advantage of manufacturing the stator from the split core is an improvement in the yield of the entire stator manufacturing including the coil forming. This is because the divided core pieces are laminated to produce the divided core, and the stator is produced by connecting the divided cores in the circumferential direction after forming the coil around the teeth of each divided core. It is possible to save manufacturing time when the coil is formed on the manufactured stator core, and to greatly improve the manufacturing time.

  By the way, in the method of forming the stator core from the split cores, it is essential to firmly connect the split cores. In order to connect or constrain the divided cores, conventionally, a stator is manufactured by shrink fitting a stator core assembled in an annular shape inside a cylindrical member made of steel (for example, Patent Document 1).

  In the case of the manufacturing method based on the shrink fitting process to the cylindrical member described above, it is necessary to manufacture the cylindrical member separately from the stator core, and the number of parts increases. The problem that becomes large becomes a new issue. In addition, since the cylindrical member is a planar member, an eddy current is generated by the magnetic flux leaking from the yoke to the cylindrical member, and the motor performance is such that the rotational performance and torque performance of the motor are reduced by heat loss due to this eddy current. There is also a problem with.

  As a technique for solving such a problem, an invention relating to a stator disclosed in Patent Document 2 has been proposed. In this stator, a split core that is fastened to other devices such as a housing for an electric motor and has an engaging convex portion on a side portion, and an engaging concave portion that engages with the engaging convex portion on a side portion. The stator core is formed by connecting the separate split cores included in the above in the circumferential direction. By providing the fastening portion between the engaging portion and the housing in the split core, the split cores can be connected to each other without using the cylindrical member described above.

JP 11-299138 A JP 2005-57886 A

  According to the stator disclosed in Patent Document 2, a cylindrical member for connecting or constraining the divided cores is not required, and thus it is possible to prevent an increase in the number of parts. However, a simple engagement connection between the split cores makes it difficult to ensure sufficient strength of the connection part, and when the engagement part is detached due to repeated use of the electric motor, the flow of magnetic flux cannot be ensured. This leads to motor malfunction. In addition, in the case where the engagement concave portion and the engagement convex portion are fitted to each other, the uniform flow of the magnetic flux in the yoke is likely to be hindered, and an air gap can be generated at least in the engagement portion. The flow of magnetic flux is obstructed.

  The present invention has been made in view of the above-described problems, and by effectively reducing heat loss while sufficiently securing the connection or restraint between the split cores, the rotational performance and torque performance of the motor can be improved. It is an object of the present invention to provide a stator core capable of preventing the reduction and a manufacturing method thereof, an electric motor including the stator core, and a manufacturing method thereof.

  In order to achieve the above object, a stator core according to the present invention is a stator core of an electric motor having an annular shape in a plan view, and the stator core is formed by assembling a plurality of first divided cores divided in the circumferential direction. A core body and a surrounding body surrounding the first core body. The surrounding body is composed of an electromagnetic steel wire wound in the circumferential direction and a cured body of a thermosetting resin. It is characterized by being.

  The stator core of the present invention has a ring-shaped core body (first core body) in plan view by assembling a plurality of (for example, 12) divided cores (first divided cores) in the circumferential direction. The present invention relates to a stator core that is formed and whose outer peripheral portion is surrounded by a separate enclosure from the conventional steel cylindrical member.

  Each divided core is formed of, for example, an electromagnetic steel plate, a steel plate made of a powder magnetic core, a steel plate made of a soft magnetic material, and the like, and is arranged with an arc-shaped yoke and the yoke projecting from the yoke toward the center of the arc and spaced apart It is comprised by laminating | stacking the division | segmentation piece which consists of several teeth or a single tooth to predetermined height.

  On the other hand, the surrounding body is formed in a cylindrical shape that can accommodate the outer side surfaces of a plurality of divided cores assembled in the circumferential direction, and its constituent members are made of a cured body of an electromagnetic steel wire and a thermosetting resin. It is.

  Here, the electromagnetic steel wire is a conductive steel wire, and the material is a material that can easily pass magnetic lines of force such as iron, cobalt, and nickel, and a material that contains silicon (the same material as the electromagnetic steel plate). ) And the like. Moreover, it is preferable that the steel wire diameter is as small as possible from the viewpoint of making it difficult to generate an eddy current with respect to the leakage magnetic flux from the yoke.

  Moreover, as a thermosetting resin, appropriate thermosetting synthetic resins including urea resin, melamine resin, and phenol resin can be used.

  For example, the above-described electromagnetic steel wire is wound around the outer side surface of the split core assembled in the circumferential direction, and a thermosetting resin is applied to the outside or filled in a mold and heated to form a cured body. Thus, by surrounding the split core with the winding of the electromagnetic steel wire and the cured body of the thermosetting resin, the leakage magnetic flux from the yoke can be passed in the circumferential direction by the electromagnetic steel wire, and the electromagnetic steel wire is planar. Since it is not a member, eddy currents are less likely to occur, and further, the split cores are firmly connected by the cured resin body. In addition, the resin cured body which is a planar member is insulative, and therefore, no eddy current is generated in the resin cured body.

  Further, another embodiment of the stator core according to the present invention is a stator core of an electric motor having an annular shape in plan view, and the stator core is a first assembly in which a plurality of first divided cores divided in the circumferential direction are assembled. And a surrounding body surrounding the first core body, the surrounding body comprising an electromagnetic steel wire wound in the circumferential direction and a fiber woven fabric impregnated with a thermosetting resin. And a cured body of the prepreg sheet.

  In the stator core of the present invention, the surrounding body that surrounds the plurality of divided cores is composed of the wound electromagnetic steel wire and the cured body of the prepreg sheet described above.

  Here, the prepreg sheet is a sheet obtained by impregnating a woven fabric in which a fiber material such as glass fiber or carbon fiber is impregnated with an appropriate thermosetting resin, and is easily wound around the side surface of the split core. The film can be shrink-cured by heating after winding.

  By applying the prepreg sheet, in addition to the effects described above, the production yield of the stator core can be significantly improved.

  In another embodiment of the stator core according to the present invention, the stator core includes a second divided core having a thickness different from that of the first divided core, and a hole projecting radially outward of the second divided core. A second core body formed by assembling a third split core having a protrusion in the circumferential direction has holes in the perforated protrusions disposed at coaxial positions at both ends of the first core body. A hollow rod body fixed in a posture and having a through hole for communicating the opposed holes is attached between the opposed perforated protrusions.

  The stator core of this invention is related with the stator core which comprises the connection structure for connecting this stator core and the housing for motors which accommodates this.

  In this stator core, a separate core body (second core body) having a different thickness (relatively small thickness) from the first core body is fixed to both ends of the first core body described above. The The second core body is also formed by assembling a plurality of divided cores (second divided core and third divided core) in the circumferential direction.

  Both the second divided core and the third divided core are formed from a steel plate such as an electromagnetic steel plate, a steel plate made of a dust core, a steel plate made of a soft magnetic material, and the like in the same manner as the first divided core. Divided pieces made up of a plurality of teeth projecting from the yoke in the direction of the center of the arc and spaced apart are stacked at a predetermined height.

  Here, the third split core is provided with a plurality of (for example, three) perforated protrusions protruding outward from the yoke. When the second core body is fixed to both ends of the first core body, the holes of the corresponding perforated protrusions of the respective core bodies are arranged at the coaxial positions. By inserting the hole of the perforated projection part and the hollow part of the hollow rod body formed of an appropriate material in communication between the opposing pair of perforated projection parts, for example, a shaft such as a bolt Allow it to penetrate the clasp.

  In the stator core of the present invention, a mechanism for connecting the housing constituting the electric motor and the stator core is provided, and the pressing force at the time of tightening when the bolt is fastened to the housing by the perforated protrusion and the hollow rod body of the stator core. It is effectively prevented from acting on other parts.

  The electric motor according to the present invention is characterized in that the stator core and a housing surrounding the stator core are fixed via a hole of the perforated protrusion of the stator core and a bolt passing through the through hole.

  The target electric motor is an inner rotor type arbitrary electric motor, and includes general electric motors such as a synchronous reluctance motor, an induction motor, a brushless motor, and an IPM motor.

  The electric motor including the stator core according to the present invention can effectively reduce eddy currents that can be generated by leakage magnetic flux from the yoke because the surrounding body constituting the stator core is not a conventional steel cylindrical member. , Its rotational performance and torque performance are excellent. In addition, the stator core is composed of split cores to improve manufacturing yield, reduce the amount of steel plate material discarded and reduce manufacturing costs, and the enclosure provides sufficient connection strength between split cores. The improvement of durability resulting from being ensured can be realized.

  Further, the stator core manufacturing method according to the present invention manufactures a first divided body by laminating a first divided steel plate obtained by dividing a planar steel plate in the circumferential direction, and a plurality of first divided steel plates are manufactured. The first core body is manufactured by assembling the bodies in the circumferential direction, and the second divided body is manufactured by laminating the first divided steel sheets, and has the same shape and the same dimensions as the first divided steel sheets. A second steel plate having a perforated protrusion protruding outward in the radial direction is laminated to produce a third divided body, and the second divided body and the third divided body are arranged in the circumferential direction. A first step of assembling and manufacturing a second core body and fixing the holes of the perforated protrusions of the two second core bodies coaxially to both ends of the first core body; The second step of winding the electromagnetic steel wire around the outer peripheral side surface of the first core body, and molding the thermosetting resin on the outside of the wound electromagnetic steel wire A third step of, is characterized in that consist.

  In another embodiment of the method for manufacturing a stator core according to the present invention, a first divided body is manufactured by laminating a first divided steel sheet obtained by dividing an annular steel sheet in plan view in the circumferential direction, A first core body is manufactured by assembling a plurality of first divided bodies in the circumferential direction, and a second divided body is manufactured by laminating the first divided steel plates. A steel plate having the same shape and dimensions as the steel plate, a second steel plate having a perforated protrusion protruding outward in the radial direction is laminated to produce a third divided body, and the second divided body and the third The second core body is manufactured by assembling the divided bodies in the circumferential direction, and fixed to both ends of the first core body in a posture in which the holes of the perforated protrusions of the two second core bodies are arranged coaxially. A first step, a second step of winding the electromagnetic steel wire around the outer peripheral side surface of the first core body, and a fiber on the outside of the wound electromagnetic steel wire. The prepreg sheets formed by impregnating a thermosetting resin is wound around the object and is characterized a third step of heating and curing the said prepreg sheet, in that it consists of.

  Furthermore, in another embodiment of the method for manufacturing a stator core according to the present invention, a first divided body is manufactured by laminating a first divided steel sheet obtained by dividing an annular steel sheet in plan view in the circumferential direction, A first core body is manufactured by assembling a plurality of first divided bodies in the circumferential direction, and a second divided body is manufactured by laminating the first divided steel plates. A steel plate having the same shape and dimensions as the steel plate, a second steel plate having a perforated protrusion protruding outward in the radial direction is laminated to produce a third divided body, and the second divided body and the third The second core body is manufactured by assembling the divided bodies in the circumferential direction, and fixed to both ends of the first core body in a posture in which the holes of the perforated protrusions of the two second core bodies are arranged coaxially. And a second step of winding a sheet material made of an electromagnetic steel wire and a thermosetting resin around the outer peripheral side surface of the first core body. A third step of curing the heat to a thermosetting resin the sheet material and is characterized in that it consists of.

  An electric motor can be manufactured by bolting the above-described stator core manufactured by the above-described stator core manufacturing method of the present invention and a housing surrounding the stator core. In addition, when forming a coil by a concentrated winding system, it is preferable to form a coil around teeth before assembling each division | segmentation core to the circumferential direction.

  Of the stator core manufacturing methods of the present invention described above, in particular, when a prepreg sheet is applied, the manufacturing yield of the stator core can be improved, so that the manufacturing cost of the electric motor can be reduced.

  As can be understood from the above description, according to the stator core of the present invention, the manufacturing method thereof, the electric motor and the manufacturing method thereof, a plurality of divided cores are assembled in the circumferential direction, and an electromagnetic steel wire and a thermosetting resin (or By forming an enclosure made of a prepreg sheet), it is possible to reduce the manufacturing cost, ensure the durability of the electric motor, and improve the rotational performance / torque performance.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view showing the stator core of the present invention, FIG. 2 is a view taken along the line II-II in FIG. 1, FIG. 3 is a view taken along the line III-III in FIG. 1, and FIG. FIG. 5 is a perspective view showing an embodiment of the seat, and FIG. 5 is a perspective view showing the electric motor of the present invention. Illustration of coils formed around the teeth of the stator core and a rotor disposed inside the stator core is omitted.

  FIG. 1 is a perspective view showing an embodiment of a stator core. This stator core 10 has divided cores 2, 2,..., And divided cores 3, 3,. A core body made up of the electromagnetic steel wire 41 and the prepreg sheet 42 wound on the outer peripheral surface of the core body made up of the divided cores 1, 1,. Formed.

  The divided cores 1, 2 and 3 are each formed by laminating electromagnetic steel plates composed of yokes 1b, 2b and 3b and teeth 1a, 2a and 3a protruding from the yoke. For example, as shown in FIG. 2, the split core 1 is manufactured by stacking electromagnetic steel plates 1 ′ punched into split pieces having teeth 1 a ′ and yokes 1 b ′ and integrating them by caulking, welding, or the like. The split core 3 further includes a perforated protrusion 3c protruding outward from the yoke 3b (having a hole 3c1). In addition to the electromagnetic steel plate, the split core may be a steel plate made of a dust core, a steel plate made of a soft magnetic material, or the like.

  Further, as shown in FIG. 3, the split cores 3 and 3 disposed at both ends of the stator core 10 are arranged so that the holes 3c1 and 3c1 provided in the perforated protrusions 3c and 3c are in the coaxial direction. In the illustrated embodiment, three combinations of the split cores 3 and 3 are provided. A hollow rod body 5 having a hollow portion 5a is installed between the opposed perforated protrusions 3c and 3c, and a bolt for connecting and fixing a housing for an electric motor, which will be described later, and the stator core 10 Is to be penetrated.

  The electromagnetic steel wire 41 to be wound is also made of the same material as that of the electromagnetic steel plate, and is, for example, a thin wire having a diameter of about 0.1 mm.

  The prepreg sheet 42 is a sheet formed by impregnating an appropriate thermosetting synthetic resin such as a urea resin, a melamine resin, or a phenol resin into a fabric in which a fiber material such as glass fiber or carbon fiber is woven.

  The stator core 10 is manufactured by first manufacturing the divided cores 1, 2, 3, and assembling the divided cores 2, 1, 2 or 3, 3, 3 corresponding to the height direction of the stator core 10, A coil is formed by winding a copper wire (not shown) around the teeth.

  Thereafter, each divided core having a coil formed in the circumferential direction is assembled, and the electromagnetic steel wire 41 is wound around the outer periphery thereof. Next, a prepreg sheet 42 is wound around the outer side of the electromagnetic steel wire 41, and heat treatment is performed to thermally cure the resin.

  Finally, the stator core 10 is completed by installing the hollow rods 5, 5, and 5 at predetermined positions. In addition, the coil formation timing may be that the prepreg sheet is thermally processed and then wound around each tooth from the center portion of the stator core, or a coil wound around a coil bobbin (not shown) is installed together with the coil bobbin. Good.

  FIG. 4 shows another embodiment of the prepreg sheet. The prepreg sheet 42 a is a sheet in which an electromagnetic steel wire 41 is embedded in a fiber fabric impregnated with a thermosetting resin 43. By using this prepreg sheet 42a, the electromagnetic steel wire constituting the enclosure and the fiber fabric impregnated with the thermosetting resin can be wound around the outer periphery of the split core at once, so that the production yield is further improved. Is possible.

  FIG. 5 shows an electric motor 100 formed by connecting a housing 6 including a cylindrical body 61 surrounding the stator core 10 shown in FIG. 1 and end plates 62 and 62 installed at both ends thereof to the stator core 10. It is a thing.

  The abutting portions between the end plates 62 and 62 and the cylindrical body 61 are bonded and fixed, and the bolts 71 penetrating the hollow rod body 5 penetrate the both end plates 62 and 62, and the projecting portions are connected to the nuts 72 and 72. As a result, the connection between the stator core 10 and the housing 6 is completed.

  Note that a rotor (not shown) in which, for example, a permanent magnet is embedded is disposed inside the stator core 10, and a shaft 8 that is axially attached to the rotor projects from the housing 6.

  In the electric motor having the stator core described above, each of the split cores is firmly restrained by the electromagnetic steel wire and the prepreg sheet, and the electromagnetic steel wire forms a flow path of the leakage magnetic flux from the yoke, and the prepreg sheet Since it is comprised with the insulating material, possibility that the eddy current resulting from a leakage magnetic flux will be excited can be reduced. Therefore, it is possible to improve the rotational performance / torque performance of the electric motor by reducing the heat loss based on the eddy current. In addition, the production yield can be improved by applying the prepreg sheet, and the production cost of the electric motor can be reduced.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

The perspective view which showed the stator core of this invention. II-II arrow line view of FIG. III-III arrow line view of FIG. The perspective view which showed embodiment of the prepreg sheet. The perspective view which showed the electric motor of this invention.

Explanation of symbols

  1, 2, 3 ... split core, 1 '... electromagnetic steel plate, 1a, 2a, 3a, 1a', 2a ', 3a' ... teeth, 1b, 2b, 3b, 1b ', 2b', 3b '... yoke, 3c ... perforated protrusions, 3c1 ... holes, 4 ... enclosure, 41 ... electromagnetic steel wire, 42, 42a ... prepreg sheet, 43 ... thermosetting resin, 5 ... hollow rod, 5a ... hollow part, 6 ... housing, 61 ... cylindrical body, 62 ... end plate, 71 ... bolt, 8 ... shaft, 10 ... stator core, 100 ... electric motor

Claims (8)

A stator core of an electric motor having a ring shape in plan view,
The stator core includes a first core body formed by assembling a plurality of first divided cores divided in the circumferential direction, and an enclosure body that surrounds the first core body. A stator core comprising an electromagnetic steel wire wound in the circumferential direction and a cured body of a thermosetting resin. A stator core of an electric motor having a ring shape in plan view,
The stator core includes a first core body formed by assembling a plurality of first divided cores divided in the circumferential direction, and an enclosure body that surrounds the first core body. A stator core comprising an electromagnetic steel wire wound in the circumferential direction and a cured body of a prepreg sheet obtained by impregnating a fiber fabric with a thermosetting resin. The stator core according to claim 1 or 2,
Assembling in a circumferential direction a second divided core having a thickness different from that of the first divided core, and a third divided core having a perforated protrusion protruding outward in the radial direction of the second divided core The second core body is fixed in a posture in which the holes of the perforated protrusions are disposed at the coaxial positions at both ends of the first core body, and the through-holes communicating the opposed holes with each other A stator core formed by attaching a hollow rod body having a hole between opposed hole projections.   An electric motor in which a stator core and a housing surrounding the stator core are fixed through a hole of the perforated protrusion of the stator core according to claim 3 and a bolt penetrating the through hole. A first divided steel sheet is manufactured by laminating a first divided steel sheet obtained by dividing an annular steel sheet in plan view in the circumferential direction, and a plurality of first divided bodies are assembled in the circumferential direction. And the second divided body is manufactured by laminating the first divided steel plates, and the steel plate has the same shape and the same dimensions as the first divided steel plate, and protrudes radially outward. A second steel sheet having a perforated protrusion is laminated to produce a third divided body, and the second divided body and the third divided body are assembled in the circumferential direction to produce a second core body. A first step of fixing the holes of the perforated protrusions of the two second core bodies to both ends of the first core body in a posture in which the holes are coaxially disposed;
A second step of winding the electromagnetic steel wire around the outer peripheral side surface of the first core body;
And a third step of molding a thermosetting resin on the outside of the wound electromagnetic steel wire. A first divided steel sheet is manufactured by laminating a first divided steel sheet obtained by dividing an annular steel sheet in plan view in the circumferential direction, and a plurality of first divided bodies are assembled in the circumferential direction. And the second divided body is manufactured by laminating the first divided steel plates, and the steel plate has the same shape and the same dimensions as the first divided steel plate, and protrudes radially outward. A second steel sheet having a perforated protrusion is laminated to produce a third divided body, and the second divided body and the third divided body are assembled in the circumferential direction to produce a second core body. A first step of fixing the holes of the perforated protrusions of the two second core bodies to both ends of the first core body in a posture in which the holes are coaxially disposed;
A second step of winding the electromagnetic steel wire around the outer peripheral side surface of the first core body;
A third step of winding a prepreg sheet formed by impregnating a fiber woven fabric with a thermosetting resin on the outside of the wound electromagnetic steel wire, and heating and curing the prepreg sheet. A method for manufacturing a stator core. A first divided steel sheet is manufactured by laminating a first divided steel sheet obtained by dividing an annular steel sheet in plan view in the circumferential direction, and a plurality of first divided bodies are assembled in the circumferential direction. And the second divided body is manufactured by laminating the first divided steel plates, and the steel plate has the same shape and the same dimensions as the first divided steel plate, and protrudes radially outward. A second steel sheet having a perforated protrusion is laminated to produce a third divided body, and the second divided body and the third divided body are assembled in the circumferential direction to produce a second core body. A first step of fixing the holes of the perforated protrusions of the two second core bodies to both ends of the first core body in a posture in which the holes are coaxially disposed;
A second step of winding a sheet material made of an electromagnetic steel wire and a thermosetting resin on the outer peripheral side surface of the first core body;
And a third step of curing the thermosetting resin by heating the sheet material.   A rod member having a through-hole that communicates the holes of the opposed perforated protrusions with respect to the stator core manufactured by the method for manufacturing a stator core according to claim 5. A method of manufacturing an electric motor, wherein a bolt is passed through the hole and the through hole, and both ends of the bolt are fixed to a housing surrounding the stator core.

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