JP2016111751A - Rotary electric machine - Google Patents

Abstract

A rotating electrical machine having a flux switching motor structure with less copper loss and capable of being miniaturized. A rotating electrical machine including: a stator having a plurality of magnetic poles arranged to extend toward a rotating shaft; and a rotor having a plurality of salient poles arranged to extend toward the magnetic pole. In the stator, the armature windings 125 and the field windings 126 concentratedly wound on the magnetic poles are alternately arranged, and the rotor includes a plurality of non-magnetic salient poles and the salient poles. And a rotor core 115 made of a magnetic material held by the rotor. The rotor core has an outer peripheral surface 111a having a width corresponding to at least two adjacent magnetic poles. [Selection] Figure 1

Description

  The present invention relates to a rotating electrical machine that functions as a flux switching motor.

  A surface magnet type synchronous motor (SPMSM: Surface Permanent Magnet Synchronous Motor) with a permanent magnet on the surface of the rotor is known, but the permanent magnet of this surface magnet type synchronous motor is arranged on the stator side and only the iron core Flux switching motors with improved robustness have been proposed.

  Furthermore, a winding field type flux switching motor has been proposed in which the permanent magnet of the flux switching motor is replaced with an electromagnet so that field adjustment is possible. This winding field type flux switching motor uses a field winding which is supplied with a direct current and is excited by direct current excitation, and an armature winding which is supplied with an alternating current and is excited by alternating current as a salient pole of the stator. By arranging and supplying electric power to each, the rotor is driven to rotate (see, for example, Patent Document 1).

JP 2013-2018869 A

  However, in the rotary electric machine as described in Patent Document 1, since the distributed winding structure in which the armature winding is wound so as to straddle a plurality of salient poles is adopted, the coil length becomes long. There was an inconvenience that copper loss increased.

  Further, in such a distributed winding structure of winding coils, coil ends wound around both end surfaces of the core material in the direction of the rotation axis overlap and become higher (thickness in the direction of the rotation axis), which hinders downsizing. Inconvenience occurred.

  Accordingly, an object of the present invention is to provide a rotating electrical machine having a flux switching motor structure that has a small copper loss and can be miniaturized.

  An aspect of the invention of a rotating electrical machine that solves the above problems includes a stator having a plurality of magnetic poles arranged to extend toward the rotating shaft, and a rotor having a plurality of salient poles arranged to extend toward the magnetic pole. The armature winding and the field winding concentratedly wound on the magnetic poles are alternately arranged on the stator, and the rotor includes the plurality of salient poles made of a non-magnetic material. And a rotor core made of a magnetic material held between the salient poles.

  As described above, according to one aspect of the present invention, the armature winding and the field winding on the stator side are concentrated and the rotor core is held between the salient poles of the nonmagnetic material on the rotor side. Therefore, the coil end can be shortened and the coil end can be reduced.

  Therefore, it is possible to provide a rotating electrical machine having a flux switching motor structure that has a small copper loss and can be miniaturized.

FIG. 1 is a view showing a rotating electrical machine according to an embodiment of the present invention, and is a cross-sectional view perpendicular to a rotating shaft showing the overall configuration. FIG. 2 is a circuit diagram of a power supply for supplying power to the armature winding and the field winding. FIG. 3 is a partially enlarged conceptual model diagram showing a magnetic circuit formed between the rotor and the stator. FIG. 4 is a partially enlarged conceptual model diagram showing a magnetic circuit formed when the rotor and the stator are relatively rotated from the state of FIG. FIG. 5 is a magnetic flux diagram showing a magnetic flux density distribution formed by the magnetic flux transferred between the rotor and the stator. FIG. 6 is a graph for explaining the torque generated when power is supplied to the armature winding and the field winding. FIG. 7 is a view showing a rotating electrical machine of a comparative example compared with the rotating electrical machine of the present embodiment, and is a cross-sectional view orthogonal to the rotating shaft showing the overall configuration. FIG. 8 is a partially enlarged conceptual model diagram showing a magnetic circuit formed between the rotor and the stator of the rotating electrical machine of FIG. 7 corresponding to FIG. FIG. 9 is a partially enlarged conceptual model diagram showing a magnetic circuit formed when the rotor and the stator of the rotating electrical machine of FIG. 7 relatively rotate from the state of FIG. 8 corresponding to FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1-6 is a figure which shows the rotary electric machine which concerns on one Embodiment of this invention.

  In FIG. 1, a rotating electrical machine 100 includes a cylindrical rotor 110 that rotates integrally around a rotation shaft 101, and a substantially cylindrical stator 120 that rotatably accommodates the rotor 110. The rotating electrical machine 100 is suitably mounted as a drive source in, for example, a hybrid vehicle and an electric vehicle that are required to have high output as well as cost reduction and downsizing.

  The rotating electrical machine 100 supplies an electric power to the armature winding 125 and the field winding 126 arranged on the stator 120 side to form a magnetic circuit passing through the rotor 110 side in the same manner as a so-called flux switching motor. Torque is generated and driven to rotate.

  Here, since the flux switching motor is excited at twice the frequency for driving the motor, it cannot be synchronized with reluctance torque, that is, so-called d-axis inductance or q-axis inductance. Therefore, the flux switching motor is not driven by reluctance torque, but is driven by electromagnet (magnet) torque using a DC magnetic field (static magnetic field) excited from the stator side. That is, the flux switching motor has an equivalent structure as compared with an SPM (surface magnet type) motor as a structure for driving as a permanent magnet motor.

  The rotor 110 includes a hub 119 that fixes the rotating shaft 101, and a plurality of salient poles 111 that are formed on the same member together with the hub 119 and extend away from the axis of the rotating shaft 101. And a plurality of rotor cores 115 fitted and held between the poles 111.

  The rotor 110 is manufactured in the form of 10 poles in which the salient poles 111 and the rotor core 115 are evenly arranged at 10 locations around the hub 119 centered on the rotation shaft 101, and the outer peripheral surfaces of the salient poles 111 and the rotor core 115. The outer shape is formed in a cylindrical shape that smoothly continues on the side, and rotates integrally with the rotary shaft 101.

  The rotor core 115 is produced, for example, by laminating magnetic electromagnetic steel plates made of a magnetic material in the extending direction of the rotating shaft 101. The salient poles 111 and the hub 119 are made in one piece, for example, by cutting or molding a non-magnetic aluminum material, or by laminating aluminum plates in the extending direction of the rotating shaft 101.

  The stator 120 includes a plurality of magnetic poles 121 that are extended in a salient pole shape toward the cylindrical outer peripheral surface of the rotor 110 and in which an armature winding 125 and a field winding 126 are arranged. The stator 120 is produced by, for example, laminating magnetic electromagnetic steel plates in the extending direction of the rotating shaft 101 in the same manner as the rotor core 115.

  The magnetic pole 121 is formed on the same member as the yoke 129 on the outer peripheral surface side of the cylindrical shape. The magnetic pole 121 is formed so that the end surface 121a on the inner peripheral surface side faces the salient pole 111 of the rotor 110 and the outer peripheral surfaces 111a and 115a of the rotor core 115 via a minute gap G. It is formed in parallel and formed in a salient pole shape extending toward the outer peripheral surface side of the rotor 110.

  The magnetic poles 121 are evenly arranged at 24 locations on the inner peripheral surface side of the yoke 129, and the rotor core 115 constitutes 10 poles around the rotating shaft 101, whereas the armature winding 125 and the field winding Twenty-four slots 122 are formed between the magnetic poles 121 to be used when winding the winding coil functioning as 126.

  The armature winding 125 and the field winding 126 are installed by winding the winding coil so as to be concentrated winding so that each of the armature winding 125 and the field winding 126 is located on every other magnetic pole 121, and the rotor 110 rotates relatively. It is constructed so as to alternately face the rotor core 115.

  The armature winding 125 supplies three-phase AC power to be excited by AC, and the field winding 126 supplies DC current to be DC excited. Therefore, in the stator 120, the U-phase armature winding 125u, the V-phase armature winding 125v, and the W-phase armature winding 125w are sequentially arranged on every other magnetic pole 121. The field winding 126 is disposed on the magnetic pole 121 between them.

  On the other hand, in the rotor 110, the outer peripheral surface 111 a side of the salient pole 111 and the hub 119 side are formed to have the same width in the cross-sectional shape orthogonal to the rotation shaft 101, and the hub 119 on the side surface 111 b of the salient pole 111. By projecting a portion that is close to the side, a protruding shape portion 112 that narrows the space between the side surfaces 111b that are close to the hub 119 side is formed.

  The rotor core 115 is formed in a shape that coincides with the space between the salient poles 111, and a recess-shaped receiving shape part 116 into which the projecting shape part 112 of the side surface 111 b of the salient pole 111 can be fitted is formed.

  As a result, the rotor core 115 is formed in a shape in which the thickness in the rotation direction gradually decreases as the width between the side surfaces 111b of the salient pole 111 decreases from the outer peripheral surface 115a toward the rotation shaft 101. A wedge portion 117 that functions as a wedge is provided by forming the receiving shape portion 116 so as to gradually increase in thickness from the position beyond the deepest portion 116a of the receiving shape portion 116 to the hub 119 side.

  With this structure, the rotor 110 is inserted into the space between the salient poles 111 from one end side in the extending direction of the rotating shaft 101 and is slid into the cylindrical shape so that the outer peripheral surfaces 111a and 115a are smoothly continuous. can do. Further, even if the rotor 110 is subjected to centrifugal force to be separated from between the salient poles 111 during the rotation, the wedge part 117 of the rotor core 115 reaches the top part 112 a of the projecting shape part 112 of the salient pole 111. It is formed so as to abut against the inclined surface 112b.

  In addition, the rotor core 115 has a width (thickness) that allows an outer peripheral surface 115 a that coincides with the opening width between the salient poles 111 that open toward the stator 120 to simultaneously face two adjacent magnetic poles 121 of the stator 120. It is formed as follows. The rotor core 115 has an outer periphery that is closer to the outer periphery than the rotary shaft 101 side so that the distance between the outer edges of the outer peripheral surface 115a matches the distance between the outer edges of the end surfaces 121a of the two magnetic poles 121 facing the outer peripheral surface 115a. The surface 115a side is formed thick.

  Here, as a power source for supplying power to the armature winding 125 and the field winding 126, for example, in the case of the rotating electrical machine 100 mounted on a vehicle, as shown in FIG. The inverter 302 and the converter 303 are connected in parallel so as to be able to supply power to each.

  Specifically, the U-phase armature winding 125u, the V-phase armature winding 125v, and the W-phase armature winding 125w are connected to the inverter 302 in series for each phase. Thus, the direct current power stored in the direct current battery 301 is supplied as alternating current power obtained by direct current (DC) / alternating current (AC) conversion, and each is subjected to alternating current excitation. Further, the field winding 126 is connected in series to the converter 303 so that the direct current power of the direct current battery 301 is supplied after direct current (DC) / direct current (DC) conversion and voltage adjustment, and direct current excitation is performed. It is supposed to be.

  With this structure, the rotating electrical machine 100 supplies the AC power to the armature winding 125 of the stator 120 to rotate and supply the DC power to the field winding 126 at a timing that assists the rotational driving. The rotor 110 can be rotated similarly to a so-called flux switching motor.

  At this time, as shown in FIG. 3, the magnetic flux generated by supplying power to the armature winding 125 and the field winding 126 (the DC magnetic flux φdc generated by DC excitation is shown in the figure) is one. After interlinking from the magnetic pole 121 from the end side of the outer peripheral surface 115a of the rotor core 115, the magnetic circuit bypasses the yoke 129 side of the stator 120 by interlinking with the adjacent magnetic pole 121 from the opposite end side of the outer peripheral surface 115a. Can be formed.

  Therefore, even in the rotating electrical machine 100 that supplies power by alternately concentrating the armature winding 125 and the field winding 126 for each magnetic pole 121, the rotor 110 is relative to the stator 120 as shown in FIG. Even in the case of rotation, a magnetic path through which magnetic flux passes can be formed in the adjacent magnetic pole 121 to maintain the magnetic circuit.

  Therefore, as shown in the magnetic flux diagram of FIG. 5, the rotating electrical machine 100 produces a difference in the magnetic flux line density where the magnetic flux lines FL are concentrated in the rotor core 115 at the portion illustrated as the torque generation surface T as the rotational force. A functioning electromagnet torque can be generated, and as shown in the graph of FIG. 6, the electromagnet torque functioning as the rotational force can be generated without interruption. The torque waveform shown in FIG. 6 can be output with smooth and continuous high quality characteristics by adjusting the timing of power supply to the armature winding 125 and the field winding 126.

(Comparative example)
On the other hand, in the rotating electrical machine 200 as shown in FIG. 7, the rotor 210 and the stator 220 are each formed by laminating magnetic electromagnetic steel plates in the extending direction of the rotating shaft 201. A plurality of magnetic poles 221 forming 24 slots 222 are formed in the stator 220. The rotor 210 includes a salient pole 211 that extends integrally with a hub 219 that fixes the rotating shaft 201 and is separated from the axis, and the salient pole 211 functions as 10 poles that are evenly arranged. Has been built.

  The salient pole 211 of the rotor 210 has the same width (thickness) from the outer peripheral surface 211a side to the hub 219 side in the cross-sectional shape orthogonal to the rotating shaft 201 without forming the protruding shape portion 112 unlike the rotary electric machine 100. Is formed. The salient pole 211 is formed so that the outer peripheral surface 211 a faces with a width that matches the end surface 221 a of the magnetic pole 221 of the stator 220.

  For this reason, the rotor 210 is formed in a shape in which the outer peripheral surfaces 211a of the two adjacent salient poles 211 cannot simultaneously face the end surfaces 221a of the two adjacent magnetic poles 221 of the stator 220.

  Therefore, the stator 220 of the rotating electrical machine 200 is disposed by performing distributed winding in which the armature winding 225 and the field winding 226 wind the winding coil around the two magnetic poles 221 sandwiching one slot 222. ing. That is, the armature winding 225 and the field winding 226 are arranged so as to be alternately positioned in the circumferential direction in a distributed winding that is shifted by one magnetic pole 221 and overlapped.

  For this reason, the stator 220 is formed so that every other magnetic pole 221, in other words, two magnetic poles 221 on both sides sandwiching one magnetic pole 221 are simultaneously facing the salient poles 211 adjacent to the rotor 210. The rotor 210 is constructed so as to form a magnetic circuit by interlinking magnetic flux between every other magnetic pole 221 via two salient poles 211 and a hub 219.

  Here, in the rotating electrical machine 200 as well, as with the rotating electrical machine 100, three-phase AC power is supplied to the armature winding 225 for AC excitation, and a DC current is supplied to the field winding 226 for DC excitation. It is like that.

  For this reason, in the stator 220, the U-phase armature winding 225u, the V-phase armature winding 225v, and the W-phase armature winding 225w are wound by using every other slot 222 in common. The wire coils are arranged so as to be successively continuous in the circumferential direction as distributed windings wound around two adjacent magnetic poles 221. Further, the field winding 226 is disposed so as to be continuous in the circumferential direction as a distributed winding in which a winding coil is wound around two adjacent magnetic poles 221 using the vacant slot 222.

  In this structure, as shown in FIG. 8, the magnetic flux generated by supplying power to the armature winding 225 and the field winding 226 (the DC magnetic flux φdc generated by DC excitation is shown in the figure) is 1 After interlinking from one magnetic pole 221 to the salient pole 211 of the rotor 210, the hub 219 is detoured as a yoke and is interlinked with the magnetic pole 221 that is skipped from the adjacent salient pole 211 to detour the yoke 229 side of the stator 220. A magnetic circuit can be formed.

  Therefore, even in the rotating electrical machine 200 that distributes the armature windings 225 and the field windings 226 to supply electric power, even when the rotor 210 rotates relative to the stator 220 as shown in FIG. A magnetic path through which magnetic flux passes can be formed in the alternate magnetic pole 221 to maintain the magnetic circuit, and an electromagnet torque that functions as a rotational force can be generated.

(Comparison result)
As described above, the rotating electrical machine 100 and the rotating electrical machine 200 rotate similarly by supplying AC power and DC power to the armature windings 125 and 225 and the field windings 126 and 226, respectively, as flux switching motors. It can be driven.

  However, in the rotating electric machine 200, the winding coil is formed by distributed winding so that both the armature winding 225 and the field winding 226 straddle two adjacent magnetic poles 221. On the other hand, in the rotating electrical machine 100, the armature winding 125 and the field winding 126 are formed by concentrating winding coils for each magnetic pole 121.

  For this reason, the rotary electric machine 100 can shorten the coil length to be used compared with the rotary electric machine 200, and can suppress that a copper loss becomes large. In addition, since the rotating electrical machine 100 does not need to overlap winding coils for concentrated winding for each magnetic pole 121, the presence of overlapping winding coils as in the distributed winding of the rotating electrical machine 200 causes rotation of the stator 220. It can be avoided that the coil ends exposed on the end faces on both ends of the shaft 201 are high (thick in the direction of the rotation axis), and the size is prevented from being reduced.

  For this reason, the rotary electric machine 100 can shorten the coil length to be used compared with the rotary electric machine 200, and can suppress that a copper loss becomes large. In addition, since the rotating electrical machine 100 does not need to overlap winding coils because concentrated winding is performed for each magnetic pole 121, the rotating shaft 201 of the stator 220 is present due to the presence of overlapping winding coils such as distributed winding of the rotating electrical machine 200. It can be avoided that the coil ends exposed to the end faces on both ends of the metal plate are high (thick in the direction of the rotation axis) and prevent the size from being reduced.

  Further, in the rotating electrical machine 200, a magnetic circuit is formed by a magnetic path that passes through the salient pole 211 of the rotor 210 and the hub 129. On the other hand, in the rotating electrical machine 100, a magnetic circuit is formed by forming a magnetic path in the rotor core 115 held by the salient pole 111 of the rotor 110.

  For this reason, the rotating electrical machine 100 can link the magnetic flux transferred to and from the magnetic pole 121 of the stator 120 via the magnetic path in one rotor core 115 on the rotor 110 side. As a result, in the rotating electrical machine 100, the magnetic flux that is linked to and enters one salient pole 211 of the rotor 210 as in the rotating electrical machine 200 is dispersed to the plurality of salient poles 211 via the hub 219. Therefore, the magnetic flux can be effectively concentrated on the torque generation surface T (FIG. 5) of the rotor core 115, and the electromagnet torque can be generated efficiently.

  In addition, the rotor core 115 can be manufactured by punching a magnetic steel sheet or the like as a separate member from the hub 119 or the salient pole 111, and can be punched in parallel so as to minimize the wasted area. It can be produced at a low material cost.

  That is, in the present embodiment, the armature winding 125 and the field winding 126 are alternately arranged in a concentrated manner for each magnetic pole 121 of the stator 120 and are held on the non-magnetic salient pole 111 of the rotor 110. The rotor core 115 to be made is opposed to two adjacent magnetic poles 121 of the stator 120. For this reason, the rotating electrical machine 100 can operate efficiently as in the flux switching motor by forming a magnetic circuit for each magnetic pole 121 by the armature winding 125 and the field winding 126 with less copper loss. It can be manufactured with an inexpensive structure that does not hinder downsizing.

  Here, as another aspect of the present embodiment, the present invention is not limited to the radial gap structure, but can be applied to a flux switching motor having an axial gap structure to obtain the same function and effect.

  In addition, the rotor core 115 and the stator 120 are not only made of a laminated structure of electromagnetic steel plates, but also, for example, a soft magnetic composite material (Soft Magnetic Composites) in which the surface of magnetic particles such as iron powder is subjected to insulation coating is further provided. A powder magnetic core produced by iron powder compression molding and heat treatment, a so-called SMC core may be employed. This SMC core is suitable for an axial gap structure because it is easy to mold. Moreover, even if the rotor 110 and the stator 120 are manufactured using an aluminum conductor, the same function can be achieved.

  The rotating electrical machine 100 is not limited to being mounted on a vehicle, and can be suitably employed as a drive source for wind power generation, machine tools, and the like.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

DESCRIPTION OF SYMBOLS 100 Rotating electrical machine 101 Rotating shaft 110 Rotor 111 Salient pole 111a Outer peripheral surface 112 Projection shape part 115 Rotor core 116 Reception shape part 117 Wedge part 120 Stator 121 Magnetic pole 121a End face 125 Armature winding 126 Field winding

Claims (2)

A stator having a plurality of magnetic poles arranged extending on the rotating shaft side;
A rotating electric machine comprising: a rotor having a plurality of salient poles arranged extending on the magnetic pole side;
In the stator, armature windings and field windings concentrated on the magnetic poles are alternately arranged,
The rotor is a rotating electrical machine having the plurality of salient poles made of a non-magnetic material and a rotor core made of a magnetic material held between the salient poles. The rotating electrical machine according to claim 1, wherein the rotor core has an outer peripheral surface having a width that faces at least two adjacent magnetic poles.

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