JP2013106462A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine capable of smoothly rotating a rotor by suppressing an influence of pulsation torque on rotation of the rotor.SOLUTION: The rotary electric machine comprises: a rotor having a plurality of permanent magnets so disposed as to be concentric with a revolving shaft, be in parallel with the revolving shaft in an equal interval, and alternate their magnetization directions, and a magnetic material, disposed between the permanent magnets while sandwiching a nonmagnetic material; a stator core so disposed as to connect a front end part and a rear end part of the permanent magnets via a gap, respectively; and a coil wound around the stator core.

Description

  The present invention relates to a rotating electrical machine, and more particularly to a rotating electrical machine with reduced pulsating torque.

  In a conventional rotating electrical machine, for example, a generator, energy such as hydraulic power or thermal power is converted into rotational energy, and the generator is driven by the converted rotational energy to generate electric power. Generally used generators include a rotor in which a permanent magnet having N poles and S poles is attached to a rotating shaft, an armature core having magnetic poles corresponding to the number of magnetic poles formed by the permanent magnets, and the armature core The generator coil is wound around and the rotor is driven to rotate, thereby generating an AC magnetic field in the armature core and generating an AC voltage in the generator coil by the generated AC magnetic field.

  By the way, an armature core constituting a rotating electric machine such as a generator or an electric motor may be disposed close to a magnet attached to the rotor to supply a sufficient magnetic field to a coil wound around the armature core. desired. When the permanent magnet and the armature core are arranged close to each other, an attractive force acts between the permanent magnet and the iron core. This attractive force is particularly large when a strong permanent magnet is used to improve the output of the rotating electrical machine.

  Further, this suction force varies depending on the rotation angle of the rotor, and affects the rotation torque of the rotor. When this torque, that is, torque based on the magnetic attractive force between the armature and the rotor (pulsation torque) increases, the rotational angular speed of the rotor varies, and the generator has abnormal vibration or noise. Problems occur. For example, in a generator used for wind power generation or the like, the starting torque at which the rotor blades start to move increases. Moreover, the resistance for continuously rotating the rotor blades also increases. Therefore, it is difficult to generate power in a breeze.

  Patent Document 1 is known as a technique for suppressing such a problem caused by pulsating torque. According to Patent Document 1, a magnet in which an even number of magnetic poles are arranged in the rotation direction of a rotating shaft, and a yoke in which an iron piece corresponding to the even number of magnetic poles of the magnet is disposed close to the magnetic pole and coaxial with the rotating shaft, 3 or more of the power generation means including the power generation means are coupled by the rotating shaft, and the magnets and yokes of one power generation means and the magnets and yokes of the other power generation means are relatively rotated, respectively. The force attracted by the iron pieces and the force attracted by the magnet pieces of the other power generation means and the iron pieces of the yoke are offset. Patent Document 2 discloses a rotating plate in which a plurality of rectangular magnets whose longitudinal direction intersects the rotating direction of the rotating plate are arranged and the polarities of adjacent magnets are alternately different from each other, and the rotating plate A rotating electrical machine including an armature in which a plurality of armature cores provided at positions where the magnet of the specific magnetic pole is sandwiched from above and below the rotating plate are disposed, and a common winding is wound between the plurality of armature cores It is shown.

JP 2009-240159 A JP 2011-101535 A

  According to the prior art, in order to suppress the pulsating torque, the power generation means has a structure in which a plurality of electromotive means are connected to one rotating shaft.

  Here, the electromotive means includes a permanent magnet in which magnetic poles are arranged radially and alternately along the circumferential direction with respect to a rotating shaft to which a rotational force is supplied from the outside, and a bobbin is provided on the outer periphery of the rotating shaft. A coil wound around, a yoke for inducing magnetic flux generated from the permanent magnet to interlink with the coil, and a radial and circumferential direction with respect to the rotating shaft, and magnetized by the permanent magnet. And an attraction means having a plurality of attracted pieces. The attraction means is means for reducing pulsation torque, which is attraction applied to the rotating shaft, by canceling out to some extent the attraction acting between the pole of the permanent magnet and the attracted piece.

  For this reason, according to the said prior art, the structure of an electric power generation means becomes complicated. In addition, it is difficult to reduce the size of the power generation means.

  The present invention has been made in view of these problems, and provides a rotating electrical machine capable of suppressing the influence of pulsating torque on the rotation of a rotor.

  In order to solve the above problems, the present invention employs the following means.

  A plurality of permanent magnets arranged concentrically with the rotation axis and in parallel with the rotation axis at an equal interval and having alternate magnetization directions; and a magnetic body arranged with a non-magnetic material sandwiched between the permanent magnets And a stator core disposed so as to connect the front end portion and the back end portion of the permanent magnet via gaps, respectively, and a coil wound around the stator core.

  Since this invention is provided with the above structure, the influence which it has on the rotation of the rotor of a pulsation torque can be suppressed, and a rotor can be rotated smoothly.

It is a perspective view explaining the rotary electric machine of this invention. It is a figure explaining a rotor. It is a figure explaining the torque which acts on a rotor. It is a figure explaining the torque which acts on a rotor. It is a figure explaining the torque which acts on a rotor. It is a figure explaining the torque which acts on a rotor. It is a figure explaining the suppression operation of pulsation torque by pulse current. It is a figure explaining the suppression operation of pulsation torque by pulse current. It is a figure explaining the rotary electric machine provided with the 2nd stator iron core.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First embodiment)
1 is a perspective view for explaining a generator (24 poles) according to the first embodiment, FIG. 2 is a view for explaining a rotor shown in FIG. 1, FIG. 2a is a 12 pole, FIG. 2b. Indicates the case of 6 poles.

  In these drawings, 10 is a rotating electrical machine, 11 is a rotating shaft, 12 is a rotor, 12M (12M-1, 12M-2...) Is a permanent magnet, concentric with the rotating shaft 11 and the rotating shaft 11. In parallel, the plurality of magnets are arranged at equal intervals so that the magnetization directions alternate. Reference numeral 13 (13-1, 13-2,...) Denotes a C-shaped stator iron core. The stator iron core is accommodated in a housing (not shown).

  A rotating shaft 11 passes through the rotor 12, and the rotating shaft 11 is supported by the housing via a bearing (not shown).

  The magnetic plates 12F and 12R are arranged before and after the rotation direction W of the permanent magnet 12M. In addition, a non-magnetic plate 12C is disposed between adjacent permanent magnets 12M via magnetic plates 12F and 12R. A stainless steel plate, a bakelite plate or the like is used as the nonmagnetic plate 12C, and an electromagnetic steel plate is used as the magnetic plates 12F and 12R. The angle θ that the permanent magnet 12M, the laminate of the magnetic plates 12F and 12R, and the nonmagnetic plate 12C occupy in the circumferential direction is set equal (θ1 = θ2, θ3 = θ4).

  The C-shaped stator cores 13 (13-1, 13-2,...) Are front end portions of the plurality of permanent magnets 12M (12M-1, 12M-2,. ) And the rear end (the lower side of the figure) are arranged so as to be connected via a gap. Moreover, the coil 14 is each wound around a C-shaped stator iron core, and these coils are connected in series, for example.

  Thereby, for example, when the rotating shaft 11 is driven from the outside, the magnetic flux passing through the permanent magnet → the stator iron core → the permanent magnet is intermittent, and an AC output can be obtained from the coil 14.

  In FIG. 1, the coil 14 is wound around each of the straight portions (14a, 14b, 14c, 14d, and 14e) of the C-shaped stator core, but may be wound only around 14a and 14e, for example.

  3, 4, 5, and 6 are diagrams illustrating torque acting on the rotor, and FIG. 3 is a diagram in which the front surface of the permanent magnet 12 </ b> M arranged on the rotor is opposed to the front surface of the stator iron core in its entirety. Is in a position facing the entire back surface of the stator core. 3, 4, 5, and 6 show a plurality of permanent magnets, magnetic plates, nonmagnetic plates, and portions of the C-shaped stator core that constitute the rotor 12 that face the permanent magnets. It is a figure developed and shown along the surface.

  FIG. 4 shows a state in which the rotor 12 has rotated and the permanent magnet has moved to the left by half of the magnet width. The latter half of the permanent magnet movement direction (the right half of the permanent magnet) and the magnetic plate 12R Opposite the front and back of the stator core.

  FIG. 5 further shows a state in which the rotor has rotated and the permanent magnet has moved 1/2 of the magnet width in the left direction, and the permanent magnet does not face either the front surface or the back surface of the stator core.

  FIG. 6 further shows a state in which the rotor has rotated and the permanent magnet has moved 1/2 of the magnet width to the left, and the front half and the magnetic plate 12F in the rotational direction of the permanent magnet are the front and back surfaces of the stator core. Opposite to.

  By the way, “reluctance torque” and “magnet torque” act on the rotating electrical machine. The reluctance torque is a torque based on the force with which the magnet attracts a magnetic body such as an iron core, and the magnet torque is a torque based on the force with which the magnetic poles repel or attract each other.

  When the permanent magnet is at the position shown in FIG. 3, for example, the magnetic flux φm generated by the permanent magnet 12M-2 passes through the permanent magnet 12M-2 → the front surface of the stator core 13 → the back surface of the stator core 13 → the permanent magnet 12M-2. Interlinking with the power generation coil 14 wound around the stator core. An electromotive force e is induced in the power generation coil 14 with the linkage.

  When an electromotive force is generated in the power generation coil and a load current i flows, a load magnetic flux 2φc is generated. The load magnetic flux 2φc mainly passes through the magnetic plates 12F and 12R arranged before and after the rotation direction of the permanent magnet (relative permeability μs = 1 of the permanent magnet = 1, μs = 6000 of the magnetic material. Therefore, the magnetic flux. Most of it passes through the magnetic plate).

  When the permanent magnet is at the position shown in FIG. 4, a part αφm of the magnetic flux φm by the permanent magnet 12M-2 passes through the permanent magnet → the front surface of the stator core → the back surface of the stator core → the permanent magnet. At this time, the reluctance torque which tries to rotate the rotor in the right direction is acting on the permanent magnet. This reluctance torque causes pulsation torque. The magnetic flux αφm is linked to the power generation coil.

  A part βφm of the magnetic flux φm passes through the magnetic plates 12F and 12R and returns to the permanent magnet.

  Along with the linkage, an electromotive force e is induced in the power generation coil wound around the stator core, a load current ic flows through the power generation coil, and a load magnetic flux 2φc (φc1 + φc2) is generated.

  The load magnetic flux 2φc mainly passes through the magnetic plates 12F and 12R arranged before and after the rotation direction of the permanent magnet. That is, a part φc1 of 2φc passes through the magnetic plate 12R, and a part φc2 of 2φc passes through the magnetic plate 12F.

  In this way, the magnetic fluxes φc1 + βφm and the magnetic flux φc2-βφm pass through the magnetic plates 12F and 12R of the rotor, respectively. This magnetic flux generates torque that drives the rotor in the left direction.

  The torque for driving the rotor in the left direction is opposite to the reluctance torque acting between the permanent magnet and the stator core. For this reason, the pulsation torque based on the reluctance torque acting between the permanent magnet and the stator iron core can be suppressed.

  When the permanent magnet 12M-2 is in the position of FIG. 5, the magnetic flux flowing from the permanent magnet into the stator core cancels out in the coil. For this reason, no voltage is induced in the power generation coil.

  Further, when the permanent magnet is at the position shown in FIG. 6, a part αφm of the magnetic flux φm by the permanent magnet passes through the permanent magnet → the front surface of the stator core → the back surface of the stator core → the permanent magnet. At this time, a reluctance torque that tries to rotate the rotor in the left direction acts on the permanent magnet. This reluctance torque causes pulsation torque. The magnetic flux αφm is linked to the power generation coil. Further, a part βφm of the magnetic flux φm passes through the magnetic plates 12F and 12R and returns to the permanent magnet.

  Along with the linkage, an electromotive force e is induced in the power generation coil wound around the back stator core, a load current ic flows through the power generation coil, and a load magnetic flux 2φc is generated.

  The load magnetic flux 2φc mainly passes through the magnetic plates 12F and 12R arranged before and after the rotation direction of the permanent magnet. That is, a part φc1 of φc passes through the magnetic plate 12F, and a part φc2 of φc passes through the magnetic plate 12R.

  That is, the magnetic flux φc1 + βφm and the magnetic flux φC2-βφm pass through the rotor magnetic plates 12F and 12R, respectively. The magnetic flux generates torque that drives the rotor in the right direction.

  The torque for driving the rotor in the right direction is opposite to the reluctance torque acting between the permanent magnet and the stator core. For this reason, the pulsation torque based on the reluctance torque acting between the permanent magnet and the stator iron core can be suppressed. The shape of the stator iron core is a C-shaped stator iron core 13 (13-1, 13-2...). The front end (lower side) of the permanent magnet 12M and the rear end (upper side of the figure). ) As long as it can be connected via a gap.

  As described above, according to the first embodiment of the present invention, the pulsation torque based on the reluctance torque can be suppressed.

(Second Embodiment)
In the first embodiment, stator iron cores (first stator iron cores) are arranged at intervals in the rotational direction. For this reason, for example, when the rotor is at the position shown in FIG. 5, the magnetic flux emitted from the permanent magnet is not effectively used. According to the present embodiment, second stator cores (13-1 ′, 13-2 ′...) Having the same shape as the first stator core are prepared, and the second stator cores are prepared as shown in FIG. 1 between the stator cores (13-1, 13-2...). For this reason, the permanent magnet of the rotor is placed at a position that affects any of the stator cores, and the output of the rotating electrical machine can be increased.

  In the above example, the repulsive torque generated by the magnetic flux φc1 + βφm and the magnetic flux φc2-βφm passing through the magnetic plates 12F and 12R of the rotor is used to suppress the pulsation torque based on the reluctance torque. The torque can be generated by exciting a coil wound around the stator core.

  FIGS. 7A and 7B are diagrams for explaining a pulsating torque suppression operation by a pulse current, in which a rotor and an armature portion of a generator including the first and second stator cores are arranged in a circumferential direction. FIG. In addition, (1)-(10) in FIGS. 7-1 and 7-2 has shown the movement position of the rotor for every time.

  As shown in FIGS. 7-1 (2) to (3) and FIGS. 7-2 (6) to (7), for example, among the sides of the stator core facing the permanent magnet 12M-1, the rotation direction (example in the figure) In this case, the facing area between the side a of the stator iron core 13-1 preceding (in the left direction) and the permanent magnet 12M-1 is such that the side b of the stator iron core 13-1 ′ following in the rotation direction faces the permanent magnet. When the area is smaller, that is, the reluctance torque acting between the side a of the stator iron core 13-1 preceding in the rotation direction and the permanent magnet is the side b of the stator iron core 13-1 ′ following in the rotation direction. When the reluctance torque acting between the permanent magnet and the permanent magnet is smaller (in this case, the rotor of the rotating electrical machine is located between the side b of the stator iron core 13-1 'following in the rotation direction and the permanent magnet). Reluctance torque acting on the rotation direction Is driven in the opposite direction), and a pulse current is generated so that a magnetic pole is generated in a direction in which the permanent magnet is attracted to a coil (pulsation suppressing coil) wound around the stator core 13-1 preceding the rotation direction. Supply. Alternatively, a pulse current is supplied to a coil (pulsation suppressing coil) wound around the stator core 13-1 'so that a magnetic pole is generated in a direction in which the permanent magnet is repelled. The pulsation suppression coil can be shared with the power generation coil.

  Here, in FIGS. 7A and 7B, the magnetic poles at the positions indicated by “N” and “S” on the stator core are pulse currents supplied to the coil (pulsation suppressing coil) wound around the magnetic poles. The magnetic pole formed by is shown. By generating the magnetic poles in this way, for example, the reluctance torque acting between the permanent magnet 12M-1 and the side b of the stator iron core 13-1 ′ following in the rotation direction is suppressed, and based on the reluctance torque. Pulsating torque can be suppressed. The pulsation suppressing coil may be wound around one place (for example, the stator core 13-1), but the pulse current is supplied to a circuit in which the second stator core is wound around and connected in series. Also good. The supply timing of the pulse current supplied to the pulsation suppression coil can be obtained from a position sensor or the like that detects the rotational position of the rotor.

  As described above, the pulsation torque can be suppressed by supplying the pulse current so that the magnetic pole is generated in the direction of attracting or repelling the permanent magnet and driving the rotor.

  As described above, when the rotation direction of the rotor by the attractive force acting between the stator iron core and the permanent magnet is different from the rotation direction (drive direction) of the rotor (for example, as shown in FIG. 4, the center of the permanent magnet). Is shifted forward in the rotational direction from the center of the stator core, and torque is generated in the rotor in the direction opposite to the rotational direction), the pulsation suppressing coil wound around the first or second stator core is Since a pulse current is supplied in a direction that attracts or repels the magnet, it is possible to suppress the pulsating torque by generating a torque that opposes the pulsating torque.

  As mentioned above, although embodiment of this invention was described taking the generator as an example, it is applicable similarly to an electric motor.

DESCRIPTION OF SYMBOLS 10 Rotating electrical machine 11 Rotating shaft 12 Rotor 12M Permanent magnet 12F, 12R Magnetic body plate 12C Nonmagnetic body plate 13 Stator iron core 14 Coil

Claims (4)

A plurality of permanent magnets arranged concentrically with the rotation axis and in parallel with the rotation axis at an equal interval and having alternate magnetization directions; and a magnetic body arranged with a non-magnetic material sandwiched between the permanent magnets Rotor and
A stator core disposed so as to connect the front end portion and the back end portion of the permanent magnet via a gap;
A rotating electrical machine comprising a coil wound around the stator core. The rotating electrical machine according to claim 1, wherein
A rotating electric machine characterized in that a circumferential width of the permanent magnet is equal to a circumferential width of a magnetic body disposed with a non-magnetic body interposed between the permanent magnets. The rotating electrical machine according to claim 1, wherein
The rotating electric machine according to claim 1, wherein the stator core is disposed corresponding to each permanent magnet. A plurality of permanent magnets arranged concentrically with the rotation axis and in parallel with the rotation axis at an equal interval and having alternate magnetization directions; and a magnetic body arranged with a non-magnetic material sandwiched between the permanent magnets A disc-shaped rotor,
Stator cores arranged so as to connect the respective front end portions and back end portions of the respective permanent magnets via gaps,
An armature coil wound around each of the stator cores;
A rotating electrical machine comprising a pulsation suppressing coil wound around at least one of the stator cores, and supplying a pulse current to the coil to suppress a pulsating torque acting on a rotor.