JP2007202333A - Rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide rotating electric machine capable of acquiring the maximum torque by efficiently utilizing the area of a rotor. <P>SOLUTION: The rotating electric machine has a rotor 10 mounted with permanent magnets 13, teeth 14 each projected oppositely to the rotor 10, and two stators 11, 12 arranged so that the teeth 14 thereof are shifted by a predetermined approximately mechanical angle θm. The permanent magnets 13 are each formed into embedded magnets and arranged in a V-shape or arcuately so that a portion opposing one of the stators forms a concave shape, the teeth 14 of the other stator are arranged so as to be shifted by an approximate mechanical angle θm (θm=(π/4-β)/p[rad](0<β<β<SB>max</SB>, β: current phase angle, p: paired numbers of poles)) in the circumferential direction of the stator for the teeth 14 of the one stator, and a gap (a) is provided on the rotor 10 so that the other stator has a salient pole ratio. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine, and more particularly to a rotating electrical machine using a permanent magnet for a rotor.

Conventionally, a “permanent magnet motor” (see Patent Document 1), which is a rotating electrical machine using a permanent magnet as a rotor, is known.
7A and 7B show a configuration of a conventional permanent magnet motor, where FIG. 7A is a cross-sectional view, and FIG. 7B is a schematic diagram showing a part of the rotor of FIG. As shown in FIG. 7A, a rotor (rotor) 2 is rotatably supported on an axial center portion of a stator (stator) 1. The rotor 2 is composed of a rotor core in which four permanent magnets 3 formed in an arc shape are embedded. In this case, the four permanent magnets 3 are arranged so that the convex side formed in an arc shape is directed to the center side of the rotor 2 and the N poles and S poles are alternately arranged in the circumferential direction. Yes. Further, the salient pole core 5 is formed on the radially outer side which is the concave side of the permanent magnet 3. These constitute a four-pole motor.

  That is, the permanent magnet motor shown in FIG. 7A includes a salient pole rotor 2 having a four-pole salient pole iron core 5 and a stator 1 having six stator teeth 6. A magnetic pole piece 8a protruding in the rotation direction (Dr) side and a magnetic pole piece 8b protruding in the counter rotation direction side are provided at the tip of the stator tooth 6. When these magnetic pole pieces 8a and 8b are compared, the thickness of the magnetic pole piece 8b is larger than the thickness of the magnetic pole piece 8a when viewed in the radial direction.

In such a rotating electrical machine having the rotor 2 using the permanent magnet 3 and the stator 1 having the teeth on both sides of the rotor 2, the magnet arrangement of the rotor 2 on the side facing the stator 1 is concave on the stator 1 side. When the rotor 2 rotates from the position facing the permanent magnet 3 and the magnetic resistance (d-axis magnetic resistance) by the magnetic circuit when the teeth face the permanent magnet 3 by arranging in a V shape. The ratio of the magnetic resistance (q-axis magnetic resistance) is increased, and there is an advantage that reluctance torque can be used in addition to torque by the permanent magnet 3.
Japanese Patent Laid-Open No. 11-098721

However, the side opposite to the side facing the teeth of the conventional rotor 2 described above is used only for short-circuiting the magnetic flux (see FIG. 7B, short-circuit portion s), and the volume of the rotor 2 is It was not available effectively.
An object of the present invention is to provide a rotating electrical machine capable of obtaining a maximum torque by effectively utilizing the volume of a rotor.

  In order to achieve the above object, a rotating electrical machine according to the present invention includes a rotor on which a permanent magnet is mounted, and teeth projecting from the rotor, and the phases of the teeth are set to a predetermined approximate amount. And two stators arranged so as to be shifted by the mechanical angle.

  According to the present invention, the rotating electrical machine includes a rotor on which a permanent magnet is mounted, and two stators each having teeth protruding so as to face the rotor. The phases of the teeth are shifted by a predetermined substantially mechanical angle. For this reason, the maximum torque can be obtained by effectively using the volume of the rotor.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a partially developed explanatory view of a rotor and a stator schematically shown in a cross section along the rotor rotation axis direction of a rotating electrical machine according to an embodiment of the present invention. As shown in FIG. 1, in this rotating electrical machine, one rotor (rotor) 10 and two stators (stators) 11 and 12 are arranged in the axial direction so as to sandwich the rotor 10 from both sides. For example, an AC synchronous motor disposed opposite to the motor.

  The rotor 10 includes a rotor core 10a formed in a disk shape, and a plurality of permanent magnets 13 arranged in parallel with each other at a substantially equal interval along the circumferential direction, embedded in the rotor core 10a. These are arranged in a V shape (see FIG. 1) or an arc shape so that the side facing the one stator 11 (the rotor 10A side) is a recess. Adjacent permanent magnets 13 have opposite polarities (see the arrow in FIG. 1), and each permanent magnet 13 has a convex portion side, that is, a side facing the other stator 12 of the rotor 10 (rotor 10B side). Is provided with a gap a so as to have a salient pole ratio on the rotor 10B side.

The respective stators 11 (12) are juxtaposed at a substantially equal interval along the circumferential direction of the stator core 11a (12a) formed in a disc shape and the stator core 11a (12a), and project toward the rotor 10. A plurality of teeth 14 are provided. Each tooth 14 is wound with an armature winding to form U-phase, V-phase, and W-phase coils 15. The coil 15 generates a magnetic flux in each tooth 14.
Further, the two stators 11 and 12 are arranged such that the phases are shifted by a predetermined mechanical angle θm (see FIG. 1). Here, θm = (π / 4−β) / p [rad] (0 <β <β _max , β: current phase angle, p: number of pole pairs). Then, in-phase currents are supplied to the teeth 11 of the stator 11 and the stator 12 that face each other with a shift of about the mechanical angle θm on the rotor 10A side and the rotor 10B side.

  2 shows a state of magnetic flux generation in the rotor and stator of FIG. 1, (a) is a partially developed explanatory view similar to FIG. 1 in which one stator is in the d-axis state, and (b) is one stator in the q-axis state. FIG. 2 is a partially developed explanatory view similar to FIG. 1. As shown in FIG. 2, when the V phase of each tooth 14 of the stator 12 facing the convex air gap side (rotor 10B side) surface of each permanent magnet 13 arranged in a V shape is seen, the stator 12 is In the d-axis state (see (a)), since the magnetic flux crosses the permanent magnet 13, the magnetic resistance is the highest. When the stator 12 is in the q-axis state (see (b)), the magnetic flux does not cross the permanent magnet 13. The magnetic resistance is in the lowest state.

For this reason, when the stator 12 is in the d-axis state (see (a)) and the q-axis state (see (b)), there is a difference in inductance, and reluctance torque is generated from the difference in the stored magnetic energy. When the reluctance torque is generated, the rotor 10 is rotationally driven. The reluctance torque becomes maximum when the electrical angle θ is advanced by π / 4 [rad] with respect to the phase angle of the current that generates the maximum magnet torque.
Further, when the rotor 10 is seen on the side facing the concave air gap (the rotor 10A side) of the permanent magnet 13, it is a normal interior magnet (IPM) type motor, and has a certain current phase angle. Maximum torque can be obtained when energized at β.

3A is an explanatory diagram showing the relationship between the electrical phase angle for each current and the maximum torque in a graph when the stator side of the rotor is an embedded magnet type, and FIG. 3B is a diagram of a rotor similar to FIG. It is a partial expansion explanatory view of a rotor and a stator shown in a section along a rotation axis direction. As shown in FIG. 3, in the case of an embedded magnet type motor, since the coils 15 of the teeth 14 facing each other on both sides of the rotor 10 (the rotor 10A side and the rotor 10B side) are shared, the stator 11 on the rotor 10A side By shifting the teeth 14 by the mechanical angle θm, the maximum torque can be obtained on the rotor 10B side when the current I having the current phase angle β is supplied. Here, [theta] m = ([pi] / 4- [beta]) / p [rad] (0 <[beta] <[beta] _max , [beta]: current phase angle, p: number of pole pairs), and in particular, when increasing the maximum torque, [beta] = Β _max .

  4 is a schematic explanatory diagram of a rotation mechanism provided in the stator of FIG. As shown in FIG. 4, the two stators 11 and 12 are each fixed to a case (not shown). The rotor 10 arranged with an air gap between the stators 11 and 12 passes through one stator (for example, the stator 12) and is supported by a rotating shaft (shaft) 16 via a bearing (not shown). Therefore, it is mounted so that it can rotate freely. A permanent magnet (not shown) is embedded in the rotor 10.

  The other stator (for example, the stator 11) is provided with a rotation operation unit 18 at the center of the stator plane via a mechanical rotation mechanism 17 such as a ball screw that can rotate the stator along the circumferential direction. Yes. The other stator can be mechanically rotated by rotating the lever 18 a of the rotation operation unit 18. For example, the stator 11 can be mechanically angled θm = (π according to the current phase angle β of the stator 12, for example. It is possible to operate while maintaining the maximum reluctance torque by mechanically rotating only -4-β) / p [rad].

  When the current phase angle β is changed by mechanically rotating the stator by the rotation operation unit 18, the current phase angle β corresponding to the frequently used current value I is the relationship between the electrical phase angle for each current and the maximum torque ( Therefore, the mechanical angle θm is adjusted to the current phase angle β corresponding to the current value I to be energized and fixed by the stopper means.

  FIG. 5 is a partial development explanatory view of a rotor and a stator, shown in a cross section along the rotor rotation axis direction of a rotating electrical machine according to another embodiment of the present invention. As shown in FIG. 5, in this example, each permanent magnet 13 is not V-shaped or arc-shaped, but is exposed to the rotor plane (rotor 10 </ b> A) facing the stator 11 and is flat so as to cover the entire region. Are arranged side by side without any gaps. Further, the air gap a provided on the convex portion side of each permanent magnet 13 is formed as a concave portion having a rectangular cross section exposed to the rotor plane (rotor 10 </ b> B) facing the stator 12. The mechanical angle θm, which is a phase shift between the two stators 11 and 12, is θm = (π / 4) / p [rad] (p: number of pole pairs). Other configurations and operations are the same as those shown in FIG.

  With such a configuration, that is, since the rotor 10 has a surface permanent magnet (SPM) type structure, the rotor 10B side has no salient pole ratio, so the current phase angle β that gives the maximum torque is 0 [rad]. The maximum torque can be obtained even on the rotor 10A side by shifting the teeth 14 of the stator 11 on the rotor 10A side by the mechanical angle θm. In addition, since the magnetic flux branches off on the back surface of the permanent magnet 13, there is a portion with a low magnetic flux density. By providing a gap a in that portion, the reluctance torque on the rotor 10 </ b> A side is obtained without reducing the magnetic resistance on the rotor 10 </ b> B side. be able to.

  That is, in the case of the embedded magnet (IPM) type shown in FIG. 1, a difference in inductance is generated on the rotor back surface (rotor 10B) side, so that the reluctance torque can be obtained only by arranging the stator on the rotor back surface side. On the other hand, in the case of a surface magnet (SPM) type, since the reluctance torque cannot be obtained if the rotor back side is smooth without a step, a concave air gap a is provided on the rotor back side and the rotor surface is stepped (see FIG. 5). ), Reluctance torque can be obtained.

  FIG. 6 is an explanatory view showing another example of the stator in a cross section along the rotor rotation axis direction. As shown in FIG. 6, in this example, the stator 19 is composed of a plurality of stator constituent bodies 20 arranged on the outer periphery of the rotor 10 at substantially equal intervals, and the stator constituent body 20 is the outer peripheral side of the rotor 10. Are formed so as to have a laterally U-shaped cross section continuously covering substantially the entire front and back surfaces of the rotor.

Each stator component 20 is formed of a magnetic material such as a laminated core or a dust material, and armature windings are wound around the inner and outer circumferences of the bent portion 20a around the bent portion 20a. 21 is formed. Both side surface portions 20b and 20b sandwiching the rotor 10 on both sides of the bent portion 20a of each stator structure 20 are arranged so as to be shifted from each other by the mechanical angle θm.
That is, each stator structure 20 is provided with an armature coil 21 that generates magnetic flux in the stator teeth located on both sides of the rotor, in one place, so that from the coil winding portion to the stator teeth located on the rotor both sides. A magnetic path is formed.

As a result, the stator 19 can use the coil in common, and it is not necessary to divide the armature coil 21 into each of the stator teeth arranged opposite to each other, so that the coil current can be shared. Reduction of copper loss and cost of copper wire can be reduced.
Moreover, the rotating shaft 22 which penetrates the front and back of the rotor 10 is rotatably supported by the opening part end surface of each stator structure 20 via the bearing. A permanent magnet (not shown) is embedded in the rotor 10.

As described above, according to the present invention, the rotating electrical machine includes a rotor on which a permanent magnet is mounted, and two stators each having teeth protruding so as to face the rotor. Since the stators are arranged with the phases of their teeth shifted by a predetermined substantially mechanical angle, the maximum torque can be obtained by effectively using the volume of the rotor.
In the above embodiment, the rotating electrical machine has been described with respect to the axial gap type in which the rotor and the stator are arranged opposite to each other in the axial direction. However, the rotating electric machine is not limited to the axial gap type. The present invention can also be applied to a radial gap type that is arranged in parallel to the central axis direction of the.

It is a partial expansion explanatory view of a rotor and a stator typically shown in a section along a rotor rotation axis direction of a rotating electrical machine according to an embodiment of the present invention. 1 shows a state of magnetic flux generation in the rotor and stator of FIG. 1, (a) is a partially developed explanatory view similar to FIG. 1 in which one stator is in the d-axis state, and (b) is FIG. 1 in which one stator is in the q-axis state. It is the same partial expansion explanatory drawing. When the stator side of the rotor is an embedded magnet type, (a) is an explanatory diagram showing the relationship between the electrical phase angle for each current and the maximum torque in a graph, and (b) is in the same direction as the rotor axis of rotation of FIG. It is partial expansion explanatory drawing of the rotor and stator which are shown in the cross section which follows. It is a schematic explanatory drawing of the rotation mechanism provided in the stator of FIG. It is a partial expansion explanatory drawing of a rotor and a stator shown in a section which meets a rotor rotating shaft direction of a rotary electric machine concerning other embodiments of this invention. It is explanatory drawing which shows the other example of a stator in the cross section along a rotor rotating shaft direction. The structure of the conventional permanent magnet motor is shown, (a) is sectional drawing, (b) is a schematic diagram which shows a part of rotor of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rotor 10a Rotor core 11, 12, 19 Stator 11a, 12a Stator core 13 Permanent magnet 14 Teeth 15 Coil 16, 22 Rotating shaft 17 Mechanical rotation mechanism 18 Rotation operation part 18a Lever 20 Stator structure 20a Bending part 20b Side part 21 Armature Coil a Air gap I Current value θm Mechanical angle β Current phase angle

Claims (6)

A rotor fitted with a permanent magnet;
A rotating electrical machine comprising: two stators each having teeth protruding so as to face the rotor, and having phases shifted from each other by a predetermined substantially mechanical angle. The permanent magnet is arranged in an embedded magnet type and in a V shape or arc shape in which a portion facing the one stator is a recess,
The teeth of the other stator are set to a mechanical angle θm (θm = (π / 4-β) / p [rad] (0 <β <β _max ) in the circumferential direction of the stator with respect to the teeth of the one stator. , Β: current phase angle, p: pole pair number))
The rotating electrical machine according to claim 1, wherein a gap is provided in the rotor so as to have a salient pole ratio on the other stator side. The permanent magnet is arranged in a surface magnet type and over the entire area facing the one stator,
The teeth of the other stator are shifted from the teeth of the one stator by a mechanical angle θm (θm = (π / 4) / p [rad] (p: number of pole pairs)) in the circumferential direction of the stator. And place
The rotating electrical machine according to claim 1, wherein a gap is provided in the rotor so as to have a salient pole ratio on the other stator side.   The rotating electrical machine according to claim 2, wherein a mechanism capable of rotating along the circumferential direction of the stator with respect to the other is provided on one of the two stators.   The stator is formed of a magnetic material, and an armature coil that generates magnetic flux between both teeth arranged opposite to each other is installed at one position of the stator, and the magnet is wound from the wound portion of the armature coil to both the teeth. The rotating electrical machine according to any one of claims 1 to 3, wherein a path is formed. 6. The rotating electrical machine according to claim 1, wherein the rotating electric machine is an axial gap type AC synchronous motor in which one rotor and two stators are arranged to face each other in the axial direction.

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