JP5754424B2 - Rotating electric machine stator - Google Patents

Description

  The present invention provides a rotation including a stator core in which a plurality of teeth projecting toward a rotor are arranged at intervals and a slot is formed between the teeth, and a coil wound around the tooth through the slot. The present invention relates to an electric stator.

  In the rotating electrical machine disclosed in Patent Document 1 described below, the tip portion of the coil that is close to the rotor is a split-section winding portion, thereby reducing eddy currents that are generated due to fluctuations in magnetic flux interlinking with the coil.

JP2012-110114A JP 2011-188721 A

  When the magnetic flux acts between the stator and the rotor, if the magnetic flux flowing in the stator teeth saturates, the magnetic flux leaks from the teeth and flows out through the coil located between adjacent teeth (in the slot). become. When the leakage magnetic flux flowing through the coil between the teeth fluctuates, an eddy current is generated in the coil.

  In Patent Document 1, an eddy current is reduced by using a winding having a divided cross-sectional shape in which a coil is divided into a plurality of regions. However, when the leakage magnetic flux flowing through the coil between the teeth fluctuates, a circulating current circulating in the coil is generated by the eddy current generated in each divided region, and a loss due to this circulating current occurs.

  The stator of the rotating electrical machine according to the present invention aims to suppress the generation of a circulating current in the coil due to the fluctuation of the leakage magnetic flux flowing through the coil between the teeth, and to suppress the loss due to the circulating current.

  The stator of the rotating electrical machine according to the present invention employs the following means in order to achieve the above-described object.

In the stator of the rotating electrical machine according to the present invention, a plurality of teeth protruding toward the rotor are arranged at intervals from each other, and a stator core having slots formed between the teeth, and the teeth are wound around the slots. A coil having a collective conductor in which a plurality of strands are assembled in a slot, and the collective conductor is overlapped in the teeth projecting direction in the slot and wound around the tooth. Among the assembly conductors on the teeth tip side and the teeth root side of the assembly conductors stacked in the teeth projecting direction, only the assembly conductor on the teeth tip side is twisted by 180 ° to dispose a plurality of strands. The phase inversion of 180 ° is repeated within the slot, and the aggregate conductor on the tip end side of the teeth has the same arrangement of a plurality of strands at one end and the other end of the slot. In addition, the gist of the invention is that the phase inversion portions of a plurality of strands are odd-numbered between one end and the other end of the slot.

  According to the present invention, even if an eddy current is generated in the collective conductor due to the fluctuation of the leakage magnetic flux between the teeth, the eddy currents flowing through the wires in the entire slot cancel each other. As a result, generation of a circulating current in the collective conductor can be suppressed, and loss due to the circulating current can be suppressed.

It is sectional drawing which shows schematic structure of the stator and rotor which were seen from the direction parallel to a rotor rotating shaft. It is sectional drawing which shows schematic structure of the stator and rotor seen from the direction orthogonal to a rotor rotating shaft. In the stator which concerns on embodiment of this invention, it is sectional drawing which shows the structure of the coil inserted in the slot. In the stator which concerns on embodiment of this invention, it is a figure which shows the dislocation state of the some strand inserted in the slot.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  1-4 is a figure which shows schematic structure of a rotary electric machine provided with the stator which concerns on embodiment of this invention. FIG. 1 is a schematic configuration diagram of the stator 12 and the rotor 14 as seen from the direction of the stator shaft or the rotor rotation axis (hereinafter simply referred to as the rotation axis), and FIG. 2 is a view of the stator 12 and the rotor 14 as seen from the direction orthogonal to the rotation axis. 3 is a schematic configuration diagram of the stator 12 as viewed from the direction of the rotation axis, and FIG. 4 is a schematic configuration diagram of the stator 12 as viewed from the direction orthogonal to the rotation axis. The rotating electrical machine according to the present embodiment includes a stator 12 whose rotation is fixed and a rotor 14 that can rotate relative to the stator 12. In the example shown in FIGS. 1 and 2, the stator 12 and the rotor 14 are arranged to face each other with a predetermined minute gap in the radial direction orthogonal to the rotation axis, and the rotor 14 is arranged on the inner peripheral side of the stator 12.

  The rotor 14 includes a rotor core 31 and a plurality of permanent magnets 32 disposed on the rotor core 31 along the circumferential direction thereof. The stator 12 includes a stator core 21 and a plurality of (for example, three-phase) coils 22 disposed on the stator core 21. A plurality of teeth 23 protruding radially inward toward the rotor 14 are arranged on the stator core 21 at intervals (equal intervals) in the circumferential direction around the rotation axis, and the teeth 23 adjacent in the circumferential direction are arranged. Between them, a slot 24 is formed extending along the rotation axis direction. In the example shown in FIGS. 1 and 2, the protruding direction of each tooth 23 coincides with the radial direction, the arrangement direction of the plurality of teeth 23 coincides with the circumferential direction, and the extending direction of the slot 24 coincides with the rotation axis direction. When the coil 22 is wound around the tooth 23 through a slot 24 between the teeth 23 by a winding method such as distributed winding, a magnetic pole is formed on the stator 12.

  As shown in FIGS. 3 and 4, the coil 22 has an assembly conductor 42 in which a plurality of strands (thin wires) 44 are assembled and joined in a slot 24, and the assembly extends in the slot 24 along the rotation axis direction. A plurality of conductors 42 are stacked in the radial direction (tooth protruding direction) and wound around the teeth 23. In FIG. 3, the tooth 23 and the coil 22 are partially illustrated in the circumferential direction, but the configuration of the portion not illustrated can be realized by the same configuration as the illustrated portion. Each element wire 44 includes a conductor wire and an insulator layer that covers the outer periphery of the conductor wire, and is electrically insulated from each other by the insulator layer in the slot 24 and electrically connected outside the slot 24. Is done. In this way, coil turns are formed that are arranged in the slots 24 with the aggregated conductors 42 in which the strands 44 are aggregated (divided by thick section lines) as a unit. Each coil turn (collective conductor 42) is composed of parts, and the coil turns are joined by welding or the like, for example. In the example shown in FIGS. 3 and 4, the assembly conductors 42 are arranged in four rows in a line along the radial direction in the slot 24. In the example shown in FIGS. 3 and 4, the four-layer aggregate conductors 42 are arranged in the radial direction, but the number of the aggregate conductors 42 arranged in the radial direction can be arbitrarily set. In the example shown in FIGS. 3 and 4, the number of the strands 44 constituting the assembly conductor 42 is (4 in the circumferential direction) × (4 in the radial direction), which is 16 in total. The number of the strands 44 constituting 42 can be arbitrarily set. Further, outside the slot 24, the coil 22 does not necessarily have to be constituted by the collective conductor 42.

  In the present embodiment, as shown in FIG. 4, the assembly conductor 42 is twisted (twisted) around its central axis as it goes from one end 24 a to the other end 24 e of the slot 24. The arrangement of the strands 44 is dislocated. Further, in the collective conductor 42 extending between the one end 24 a and the other end 24 e of the slot 24 in the rotation axis direction, the arrangement of the plurality of strands 44 is phase-inverted an odd number of times in the slot 24. In this case, the phase inversion of the strands 44 refers to a state in which the strands 44 have moved to a 180 ° point symmetric position with respect to the central axis of the assembly conductor 42. As shown in FIG. 4, in the collective conductor 42, the arrangement of the plurality of strands 44 is the same (in phase) at one end 24 a and the other end 24 e of the slot 24. Then, if the distance in the rotational axis direction between the one end 24a and the other end 24e of the slot 24 is L, the slot position 24b from the one end 24a of the slot 24 to the rotational axis direction distance L / 4 is compared with the one end 24a of the slot 24. The assembly conductor 42 is twisted 180 °, so that the arrangement of the plurality of strands 44 is 180 ° phase-inverted. Then, at the slot position (center position) 24c at the rotational axis direction distance L / 2 from the one end 24a of the slot 24, the assembly conductor 42 is twisted by 180 ° compared to the slot position 24b. The arrangement of the line 44 is 180 ° out of phase. Further, at the slot position 24d having a distance of 3 × L / 4 in the rotational axis direction from the one end 24a of the slot 24, the assembly conductor 42 is twisted by 180 ° compared to the slot position 24c, so that the plurality of strands 44 Is 180 ° out of phase. Further, the collective conductor 42 is twisted 180 ° from the slot position 24 d to the other end 24 e of the slot 24. In FIG. 4, the configuration of the strand 44 is illustrated only for the collective conductor 42 that is radially innermost (closest to the rotor 14), but the configuration of the strand 44 in another collective conductor 42 that is not illustrated. This can also be realized with the same configuration as the illustrated part.

  As described above, the assembly conductor 42 is twisted in the slot 24, and the arrangement of the strands 44 is shifted to a different position in the slot 24. Furthermore, the collective conductor 42 has odd-numbered locations (three locations of slot positions 24b, 24c, and 24d in the example shown in FIG. 4) in the slot 24 in the phase inversion locations of the plurality of strands 44. However, the arrangement of the strands 44 is shifted (phase inversion) within the same coil turn (collection conductor 42), and the arrangement of the strands 44 is not shifted (phase inversion) between different coil turns (collection conductor 42). Further, the arrangement of the strands 44 is shifted only within the slot 24, and the arrangement of the strands 44 is not displaced outside the slot 24. Furthermore, in the collective conductor 42, it is preferable that the distance between the phase inversion portions of the plurality of strands 44 (the distance between the slot positions 24b, 24c, and 24d) is equal. In the example shown in FIG. 4, the number of phase inversions in the slot 24 of the arrangement of each strand 44 constituting the assembly conductor 42 is three, but the arrangement of each strand 44 constituting the assembly conductor 42 is The number of phase inversions in the slot 24 can be arbitrarily set within a range satisfying an odd number of times, for example, once or five times.

  In the rotating electrical machine, each tooth 23 is sequentially magnetized by passing an alternating current through a plurality of (three-phase) coils 22, and a rotating magnetic field that rotates in the circumferential direction is formed in the stator 12. The rotor 14 is rotated by applying torque (magnet torque) to the rotor 14 by electromagnetic interaction (attraction and repulsion) between the rotating magnetic field generated in the stator 12 and the field magnetic flux generated in the permanent magnet 32 of the rotor 14. Can be driven. In this manner, the rotating electrical machine can be caused to function as an electric motor that generates power in the rotor 14 using the power supplied to the coil 22. On the other hand, the rotating electrical machine can also function as a generator that generates power in the coil 22 using the power of the rotor 14. The rotor 14 is not limited to the configuration in which the permanent magnet 32 is provided. For example, the rotor 14 may have a configuration in which a coil is provided or a configuration in which reluctance torque is used by a change in magnetic resistance.

  When torque is applied between the stator 12 and the rotor 14, a magnetic flux acts between the stator 12 and the rotor 14, and the magnetic flux flows in the teeth 23 in the radial direction. However, when the magnetic flux flowing through the teeth 23 is saturated, the magnetic flux leaks from the teeth 23 and flows between adjacent teeth 23 (in the slots 24) in the circumferential direction. In particular, when the torque of the rotor 14 is large, the magnetic flux flowing through the teeth 23 is likely to be saturated, and the magnetic flux easily flows between the teeth 23 in the circumferential direction. The leakage magnetic flux between the teeth 23 flows in the circumferential direction in the collective conductor 42 (each strand 44). When the leakage magnetic flux flowing through the collective conductor 42 between the teeth 23 fluctuates, an eddy current is generated in each wire 44, thereby generating a circulating current in the collective conductor 42, thereby causing a loss due to the circulating current. .

  On the other hand, in this embodiment, the assembly conductor 42 is twisted in the slot 24, and the arrangement of the strands 44 is shifted to a different position in the slot 24. As a result, the direction of the eddy current generated in each wire 44 changes simultaneously due to the fluctuation of the leakage magnetic flux between the teeth 23, and the eddy currents are mutually considered in the entire slot 24 (between the one end 24a and the other end 24e of the slot 24). Negate each other. For example, as shown in FIG. 4, the direction of the eddy current 46a flowing in the wire a between the one end 24a of the slot 24 and the slot position 24b, and the direction of the eddy current 46b flowing in the wire a between the slot position 24b and the slot position 24c. Reverse and cancel each other. The direction of the eddy current 46c flowing in the wire a between the slot position 24c and the slot position 24d and the direction of the eddy current 46d flowing in the wire a between the slot position 24d and the other end 24e of the slot 24 are reversed. Counteract each other. In this way, the direction of the eddy current flowing through the strands is reversed before and after the slot positions 24b, 24c, and 24d (phase inversion locations), and the eddy currents flowing through the strand a in the entire slot 24 cancel each other. Then, eddy currents cancel out each other when considering the other wires in the entire slot 24. As a result, generation of a circulating current in the collective conductor 42 can be suppressed, and loss due to the circulating current can be suppressed. Furthermore, since the closed loop of the current circulating in the strand 44 becomes small, even if the distance between the phase inversion portions of the plurality of strands 44 (distance between the slot positions 24b, 24c, 24d) is not uniform, Loss due to circulating current can be reduced.

  In the above embodiment, it is not necessary to reverse the phase of the arrangement of the strands 44 in the slot 24 for all of the collective conductors 42 arranged in the radial direction. For example, only for the collective conductor 42 on the radially inner side (tooth tip side) that is close to the rotor 14, the arrangement of the strands 44 is phase-inverted an odd number of times in the slot 24, and the radially outer side (tooth base) away from the rotor 14. As for the collective conductor 42 on the side, it is possible not to reverse the phase of the arrangement of the strands 44 in the slot 24.

  In the above embodiment, the case where the coil 22 is wound around the tooth 23 by distributed winding has been described. However, the coil 22 can be wound around the tooth 23 by a winding method other than distributed winding, for example, concentrated winding. .

  In the above embodiment, the case where the present invention is applied to a radial type rotating electric machine has been described. However, the present invention can also be applied to an axial type rotating electric machine.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

  12 stators, 14 rotors, 21 stator cores, 22 coils, 23 teeth, 24 slots, 31 rotor cores, 32 permanent magnets, 42 collective conductors, 44 strands.

Claims (1)

A plurality of teeth protruding toward the rotor are arranged at intervals, and a stator core having slots formed between the teeth;
A coil wound around the teeth through the slot;
A stator of a rotating electric machine comprising:
The coil has an assembly conductor in which a plurality of strands are assembled in a slot, and the assembly conductor is overlapped in the teeth protruding direction in the slot and wound around the teeth.
Of the collective conductors on the tooth tip side and the root side of the collective conductors stacked in the teeth protruding direction, only the collective conductor on the tooth tip side is twisted by 180 ° so that the arrangement of the plurality of strands is shifted by 180 °. Phase inversion is repeated in the slot,
The assembly conductor on the tip end side of the teeth has the same arrangement of a plurality of strands at one end and the other end of the slot, and has the odd number of the phase inversion portions of the plurality of strands between the one end and the other end of the slot. Stator.

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