JP4722276B2 - Electric motor stator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stator for an electric motor used in industrial equipment, office equipment, and home appliances.
[0002]
[Prior art]
A conventional embodiment will be described with reference to FIG. FIG. 7 shows a three-phase four-pole stator. The stator core 1 of the electric motor is formed of a laminated body in which a large number of thin electromagnetic steel plates are laminated in the axial direction. As a method of integrally fixing the laminated body, the outer peripheral portion of the laminated body is fixed by welding, or by forming a concave / convex portion on each thin steel plate with a press or the like, and then fitting the convex / concave portions together. The stator core 1 is formed by a well-known auto-clamp method or the like that is fixed.
[0003]
A slot 5 is formed in the stator core 1, and a winding is directly wound around the stator teeth S 1, S 2, S 3, S 4, S 5, S 6 via the slot insulation 4 by a concentrated winding method. The tooth portion S1 is wound with a U1 phase winding 3, and similarly, the tooth portion S2 has a V1 phase, the tooth portion S3 has a W1 phase, the tooth portion S4 has a U2 phase, and the tooth portion S5 has a V2 phase. The W3 phase winding 3 is wound around the tooth portion S6. The U1 phase and the U2 phase, the V1 phase and the V2 phase, the W1 phase and the W2 phase are connected by a connecting wire that connects the respective phases, and one end of each phase is connected to form a neutral point. Is connected to the lead wire to form a three-phase Y-connection (in series).
[0004]
As another connection method, the U1 phase and the U2 phase are arranged in parallel, and one end of the U1 phase, one end of the U2 phase, the other end of the U1 phase, and the other end of the U2 phase Connect each one, connect one end of the U1 phase and U2 phase to the neutral point, and connect the other end of the U1 phase and U2 phase to the lead wire. In the other phases, the V1 phase and the V2 phase, and the W1 phase and the W2 phase are connected in the same manner to form a three-phase 2Y connection (parallel).
[0005]
In recent years, in such electric motors, the demand for small and high-performance motors has become very strong, and in response to this demand, the number of permanent magnet motors having high-performance permanent magnets has increased. Normally, when magnetizing a rotor having a permanent magnet of this permanent magnet type electric motor, set it in a magnetizing device having a magnetized winding before assembling it to a motor housing or the like. The rotor is made permanent magnet by applying a direct current to the rotor.
[0006]
However, in the process until the rotor with the magnetic field is assembled in the motor housing or the like, iron powder or the like adheres to the permanent magnetized rotor, causing rotation failure during motor operation, There has been a problem that it is difficult to handle by being attracted to a magnetic jig.
[0007]
In order to solve the above problem, after the stator and the rotor are assembled in the motor housing, the stator winding is used as a magnetizing winding, thereby magnetizing the rotor arranged opposite to the stator. A so-called built-in magnetization method is employed. FIG. 8 shows the magnetization connection when the built-in magnetization is performed by the stator of the electric motor. Since the built-in magnetization can be performed in the same manner in the above-described series-connected three-phase Y connection and parallel-connected three-phase 2Y connection, only the three-phase Y connection connected in series will be described here.
[0008]
When the lead wire side of the U1 phase of the stator winding is connected to the plus side of the magnetizing power source E, the V1 phase and the W1 phase are connected to the minus side, and a large DC current flows through this stator winding. This makes it possible to magnetize the rotor disposed opposite to the stator. Further, the connection is a method in which all three phase windings of the stator are used for built-in magnetization, and after the first magnetization is performed using specific two phases of the stator windings, a predetermined angle is used. Magnetization can also be performed by a magnetization method in which the second magnetization is performed by changing the partial magnetization position.
[0009]
[Problems to be solved by the invention]
In such a conventional concentrated-winding motor, the ratio of the windings concentrated in the stator slot is not so high, so that the insulation space distance between adjacent phases in the stator slot can be maintained. However, as described above, with the demand for smaller size and higher performance, the percentage of windings concentrated in the stator slot is very high, and insulation of each phase in the stator slot can be maintained. It is gone.
[0010]
In particular, when a motor is started, a large current flows through the adjacent phase windings in the slot, so that the windings of each phase vibrate and damage the coating of the windings, causing a dielectric breakdown due to the potential difference between the phases, resulting in a serious market failure. Yes. As a result, the reliability is significantly impaired.
[0011]
Recently, an electric motor mounted on a compressor serving as a driving source for an air conditioner and a refrigerator has come to employ a concentrated winding type electric motor in which windings are directly wound around the teeth of a stator. In order to improve the size and performance of such an electric motor, a permanent magnet type electric motor having a permanent magnet in a rotor has been used.
[0012]
In a compressor using such a permanent magnet type electric motor, if the rotor having the permanent magnet before being incorporated into the compressor is magnetized as described above, iron powder or the like is likely to adhere to the rotor, and it remains as it is. Incorporating a stator and a rotor into the compressor housing is problematic because it may cause operational problems when incorporated in a compressor, and the rotor may be attracted to a magnetic jig and difficult to assemble into the compressor housing. Thereafter, the stator winding is used as a magnetizing winding, and the rotor arranged opposite to the stator is magnetized.
[0013]
Electric motors used in compressors for air conditioners and refrigerators have a very high ratio of windings concentrated in the stator slots in response to demands for smaller size and higher performance. When used, a very large magnetizing current flows in the windings of adjacent phases in the stator slot, causing the windings of each phase to collide violently, damaging the coating of the windings, and causing dielectric breakdown due to the potential difference between the phases. Is causing.
[0014]
[Means for Solving the Problems]
In a concentrated winding type motor in which windings are wound directly around the teeth of the stator, an insulating member in which the cross-sectional shape of the interphase insulating resin inserted between adjacent windings in each slot of the stator is formed in a V shape And the opening of the insulating member in which the cross-sectional shape of the interphase insulating resin is formed in a V shape is inserted facing each slot opening on the inner diameter side of the stator,
A bent portion is formed at the end of the opening of the insulating member having a V-shaped cross-sectional shape of the interphase insulating resin, and the bent portion is wound around the teeth of the stator. The stator of the motor is interposed between the wound winding and the iron core side on the stator inner diameter side in the stator slot.
[0015]
Further, the stator of the electric motor has 3n slots (n is a natural number) and 2n poles (n is a natural number).
[0016]
Moreover, it is set as the electric motor which comprises the rotor provided with the permanent magnet.
[0017]
The material of the insulating member of the interphase insulating resin inserted between adjacent windings in each slot of the stator is engineering plastic (engineering plastic) or super engineering plastic (super engineering plastic). The stator of the motor.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an enlarged view of a slot of a stator of an electric motor in the present embodiment. A slot insulation 4 is inserted into a slot 5 of the stator core 1. The slot insulation 4 may be formed integrally with resin or formed with a thin insulating film. After the slot insulation 4 is applied to the stator core 1, the winding 3 is wound by a concentrated winding method in which the winding is wound directly around the tooth portion 2 sandwiched between the slots. Since a large current flows in the windings 3 of adjacent phases in the slot 5 when the motor is started, the windings 3 of each phase vibrate and the windings 3 rub against each other and damage the coating. After that, due to the potential difference between the phases, dielectric breakdown occurs in the damaged and thin part.
[0019]
The present invention has been made in view of this, and the winding 3 in the slot 5 of the stator core 1 has an interphase insulating resin 7 (hereinafter referred to as a V-shaped interphase insulating resin 7) having a V-shaped cross section. In this case, adjacent phases can be surely separated from each other, and the windings 3 are prevented from vibrating and rubbing, so that dielectric breakdown does not occur even if a large potential difference occurs. The stator core 1 is inserted so as to face each slot opening 6 side and the opening side of the insulating member of the V-shaped interphase insulating resin 7 faces the slot opening 6 side. Also, the V-shaped interphase insulating resin 7 is curved in the slot 5 by inserting the end portion on the opening side of the V-shaped interphase insulating resin 7 so as to abut against the iron core side on the stator inner diameter side in the slot 5. In addition, each winding 3 has an effect of pressing into the slot 5. However, it is possible to simultaneously prevent the winding 3 from jumping out to the inner diameter of the stator, which has been a problem.
[0020]
Therefore, when the V-shaped interphase insulating resin 7 is interposed between the narrow windings, the spring effect of the V-shaped interphase insulating resin 7 can be obtained, and the winding 3 is prevented from popping out from the stator core 1. Moreover, since the V-shaped interphase insulating resin 7 does not fall off from the stator core 1, the adjacent windings 3 in the slot 5 can be reliably separated from each other, and the windings 3 vibrate and rub. It is possible to prevent dielectric breakdown even if a large potential difference occurs. FIG. 2 is a perspective view of the V-shaped interphase insulating resin 7 of this embodiment. Further, the opening angle of the opening of the V-shaped interphase insulating resin 7 is appropriately determined by the amount of use of the winding 3, and may be set to an extent that does not impair the spring effect.
[0021]
Another embodiment will be described with reference to FIG. FIG. 3 is an enlarged view of the slot of the stator. As in FIG. 1, the slot insulation 4 is inserted into the slot 5 of the stator core 1. The slot insulation 4 is made of resin or formed of a thin insulating film. After the slot insulation 4 is applied to the stator core 1, the slot insulation 4 is directly wound around the teeth 2 sandwiched between the slots. The winding 3 is wound by a concentrated winding method in which a wire is wound. As shown in FIG. 3, the present embodiment can be applied when the proportion of the windings 3 in the slots 5 is small, whereby a very good effect can be obtained.
[0022]
Interphase insulating resin 8 (hereinafter referred to as V) of an insulating member having a V-shaped cross-section formed between the winding 3 wound directly around the teeth of the stator core 1 and the slot insulation 4 mounted in the slot 5. A bent portion is formed at the V-shaped end portion of the V-shaped interphase insulating resin 8) opposite to the slot opening 6 side, and this bent portion is formed between the winding 3 and the stator core 1. By sandwiching, the V-shaped interphase insulating resin 8 can be more reliably fixed between the phases in the slot 5. In this case, the bent portion of the V-shaped end portion may be sandwiched between the stator core 1 and the slot insulation 4, or may be sandwiched between the winding 3 and the slot insulation 4. Further, the bending angle of the V-shaped end is preferably set to an angle that does not impair the spring effect of the V-shaped interphase insulating resin 8.
[0023]
Accordingly, even when the ratio of the windings 3 in the slots 5 is small, the adjacent windings 3 in the slots 5 can be reliably separated from each other, and the V-shaped interphase insulating resin 8 is used as the stator. Since it can be reliably fixed without falling off from the iron core 1, it is possible to prevent the windings 3 from vibrating and rubbing, and even if a large potential difference occurs, the coating of the winding 3 is not broken and insulation failure does not occur. FIG. 4 is a perspective view of the V-shaped interphase insulating resin 8 provided with a bent portion at the V-shaped end of the present embodiment.
[0024]
Further, the winding 3 is wound by the concentrated winding method in which the winding is directly wound around the tooth portion 2 sandwiched between the slot of the stator core 1 and the windings 3 of adjacent phases in the slot 5 vibrate. An electric motor that rubs and breaks the coating of the winding 3 to cause insulation failure, or an electric motor that generates a large potential difference between phases, that is, the number of stator slots is 3n (n is a natural number), and the number of poles is 2n (n is In an electric motor that is a natural number), adjacent windings can be reliably separated by inserting the V-shaped interphase insulating resins 7 and 8 in the winding 3 in the slot 5, so that the windings 3 vibrate and rub against each other. Therefore, even if a large potential difference occurs, dielectric breakdown that destroys the coating of the winding 3 is not caused.
[0025]
5 and FIG. 6, the slot 5 of the stator core 1 is integrally molded with resin or slot insulation 4 formed of a thin insulating film is applied, and then the slot and the slot are used. The winding 3 is wound by a concentrated winding method in which the winding is wound directly around the sandwiched tooth portion 2, and the rotors 9 and 10 including the permanent magnet 11 are disposed on the inner diameter of the stator.
[0026]
When such an electric motor having a rotor having a permanent magnet is employed in a compressor which is a driving source of an air conditioner and a refrigerator, if the rotors 9 and 10 are magnetized before being incorporated in the compressor, the motor rotates. Iron powder or the like easily adheres to the cores 9 and 10, and if incorporated in the compressor as it is, the compressor operation is disturbed, and the magnetized rotors 9 and 10 are attracted to the magnetic jig and compressed. There is a problem that it is difficult to install in the machine housing. For this reason, after incorporating the stator and the rotors 9 and 10 into the compressor housing, the rotors 9 and 10 are magnetized using the stator winding 3 as a magnetizing winding.
[0027]
In this case, a very large magnetizing current flows in the windings 3 of adjacent phases concentrated in one slot of the stator and the windings 3 of each phase collide violently and damage the coating of the windings 3 between the phases. Dielectric breakdown is caused by the potential difference. However, by interposing the V-shaped interphase insulating resins 7 and 8 in order to prevent such dielectric breakdown, the windings 3 of adjacent phases in the slot can be reliably separated, so that no insulation failure occurs. Therefore, after a concentrated winding type electric motor in which a winding is directly wound around the teeth of the stator is incorporated in the casing, the rotor having a permanent magnet can be magnetized without any problem using the stator winding of the electric motor. it can.
[0028]
The structure of the rotor is a surface-mounted permanent magnet in which a permanent magnet is embedded in the rotor core as shown in FIG. 5 and the permanent magnet shown in FIG. 6 is mounted on the rotor surface. It may be a magnet rotor.
[0029]
Further, the materials of the V-shaped interphase insulating resins 7 and 8 inserted between adjacent phases in each slot 5 of the stator are made of engineering plastic when the operating environment of the motor is 100 ° C. or more, and the operating environment of the motor is 150 ° C. In such a case, by using a super engineering plastic, it is possible to reduce insulation failure caused by deterioration of the insulating material due to the temperature rise of the electric motor. As a result, the windings 3 of adjacent phases in the stator slot 5 do not vibrate to destroy the insulating material, and even if a large potential difference occurs, the coating of the winding 3 is not destroyed and insulation failure does not occur. . In addition, material costs can be saved by appropriately selecting engineering plastics or super engineering plastics according to the specifications of the motor.
[0030]
When the space factor of the windings in the slot is very high, the V-shaped interphase insulating resins 7 and 8 inserted between the windings in the slot are made into engineering plastic or super engineering plastic film shape. Even when the gap is small, it can be reliably inserted, so that the coating of the winding 3 is not broken and insulation failure does not occur. The V-shaped interphase insulating resins 7 and 8 are formed into a film shape, thereby reducing the amount of insulating material used and improving the workability, and further improving the ease of insertion into the stator slot and facilitating handling. it can.
[0031]
Examples of engineering plastics include polyamide (PA), polyacetal (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and syndiotactic polystyrene (SPS). Examples of super engineering plastics include polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), liquid crystal polymer resin (LCP), fluororesin, and polyetheretherketone (PEEK).
[0032]
In addition, the refrigerant used for air conditioners and refrigerators has conventionally been CFC12, CFC22, etc. and the refrigeration oil has been naphthenic, paraffinic mineral oil or alkylbenzene oil, especially due to environmental problems, etc. When using refrigerants such as HFC410a and HFC407c and mixed oils such as polyalkylene glycol oils, polyester oils, or ether oils that are refrigeration oils, the materials for the V-shaped interphase insulating resins 7 and 8 should be super engineering plastics. Thus, hydrolysis of the insulator due to the amount of water contained in the refrigerator oil can be minimized. Needless to say, hydrolysis of the slot insulation 4 can be minimized by using super engineering plastic as the material of the slot insulation 4.
[0033]
【The invention's effect】
In the concentrated winding type motor in which the winding is directly wound around the teeth of the stator of the motor, the present invention is ensured by inserting a V-shaped interphase insulating resin between the windings of adjacent phases in one slot. Adjacent phases can be separated, the windings are prevented from rubbing by vibration, and the coating of the windings is not broken even if a large potential difference occurs.
[0034]
In addition, the opening side of the V-shaped interphase insulating resin faces the opening side of the slot on the inner diameter side of the stator core, and the end of the opening of the V-shaped interphase insulating resin is opposite to the slot opening. Forming a bent portion that is bent into a slot, and inserting the bent portion between the winding wound around the teeth of the stator and the iron core side on the stator inner diameter side in the stator slot. Inner V-shaped interphase insulating resin can be securely fixed without falling off. In addition, since the spring effect of the V-shaped interphase insulating resin allows the winding to be pushed into the slot, the winding of the winding to the stator inner diameter has also become a problem. It is preventing.
[0035]
In particular, even when the proportion of the windings in the slot is small, the adjacent windings in the slot can be reliably separated from each other, and the V-shaped interphase insulating resin does not fall off from the stator core. Can be securely fixed. [0036]
Further, by applying the present invention to a stator having 3n slots (n is a natural number) and 2n poles (n is a natural number), the stator of the motor is surely adjacent to one slot. The phase windings can be insulated.
[0037]
Further, by applying the present invention to a permanent magnet type motor having a permanent magnet in the rotor of the motor, even when the stator winding is magnetized as a magnetized winding after being incorporated in the housing. In addition, it is possible to eliminate the dielectric breakdown of the winding caused by the magnetizing current.
[0038]
Further, the material of the V-shaped interphase insulating resin inserted between adjacent windings in each slot of the stator is an engineering plastic or a super engineering plastic so that it can be used as a driving source for an air conditioner or a refrigerator. Can be specified.
[0039]
For these reasons, the V-shaped interphase insulating resin can reliably perform insulation between adjacent phases, and can eliminate the insulation failure of the winding due to the potential difference, thereby improving the quality and reliability.
[Brief description of the drawings]
FIG. 1 is a partial sectional view of a stator showing an embodiment of the present invention.
2 is a perspective view of the V-shaped interphase insulating resin in FIG. 1. FIG.
FIG. 3 is a partial sectional view of a stator showing an embodiment of the present invention.
4 is a perspective view of the V-shaped interphase insulating resin in FIG. 3. FIG.
FIG. 5 is a cross-sectional view of an electric motor having a permanent magnet on a rotor according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view of an electric motor having a permanent magnet on a rotor according to an embodiment of the present invention.
FIG. 7 is a cross-sectional view of a stator showing a conventional example.
FIG. 8 is a connection diagram when the stator winding of the motor of the present invention is used as a magnetized winding.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Stator core, 2, S1-S6 ... Tooth part, 3 ... Winding, 4 ... Slot insulation, 5 ... Slot, 6 ... Slot opening, 7, 8 ... V-shaped interphase insulation resin, 9, 10 ... Rotation Child, 11 ... permanent magnet, U1, V1, W1, U2, V2, W2 ... phase, E ... magnetized power source.

Claims (4)

In a concentrated winding type motor in which windings are directly wound around the teeth of the stator, an insulating member in which the cross-sectional shape of the interphase insulating resin inserted between adjacent windings in each slot of the stator is formed in a V shape a is, the phase between the openings of the insulating member cross section is formed in a V-shaped insulating resin, and interposed facing each slot opening of the stator inner diameter side,
A bent portion is formed at the end portion of the opening portion of the insulating member having a V-shaped cross-sectional shape of the interphase insulating resin, and the bent portion is wound around the teeth of the stator. A stator for an electric motor, wherein the stator is interposed between the wound winding and an iron core side on the inner diameter side of the stator in the stator slot. The stator of an electric motor according to claim 1, wherein the number of slots of the stator of the electric motor is 3n (n is a natural number) and the number of poles is 2n (n is a natural number). The electric motor according to claim 2 , wherein the electric motor includes a rotor having a permanent magnet. A material of an insulating member of an interphase insulating resin inserted between adjacent windings in each slot of the stator is engineering plastic (engineering plastic) or super engineering plastic (super engineering plastic). The stator of the electric motor according to claim 1 or 2 .

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