JP4621661B2 - Rotating machine - Google Patents

Description

The present invention relates to a rotary machine that can be used in the generator and the motor using permanent magnets, to be rotating machine efficiency that can be configured more compact.

For example, as shown in Japanese Patent Application Laid-Open No. 2002-191155, which is a patent document, a rotating machine in which a rotor having a plurality of permanent magnets is arranged inside a stator having an iron core wound with a coil is known, For example, it is used in automobiles and other industrial equipment. In this rotating machine, the generator is used to generate an induced electromotive force in the stator coil by rotating the rotor, and an alternating current controlled according to the rotation angle of the rotor is passed through the stator coil. Thus, the use as an electric motor for generating rotational power in a rotor is known.
However, in a conventional rotating machine, the stator iron core has a plurality of magnetic pole portions (12 in the patent document) facing the inner rotor, and the stator iron core is an electromagnetic steel plate (usually a silicon steel plate). In general, non-oriented electrical steel sheets (usually non-oriented silicon steel sheets) are used. Furthermore, the iron core to which the winding is applied has a yoke part in the middle part, and an alternating magnetic field is generated in this yoke part, so the overall magnetic path length through which the magnetic flux passes is long, which results in a large iron loss. There was a problem.

On the other hand, in order to improve the output of the rotating machine, it is necessary to increase the amount of magnetic flux passing through the iron core. In this case, since the iron core is a non-oriented electrical steel sheet as described above, the maximum magnetic flux density is considerably low, Eventually, in order to pass a predetermined magnetic flux, it is necessary to increase the amount of iron core (referred to as the volume of the iron core). If the amount of iron core is increased, the amount of winding also increases, which is an obstacle to miniaturization and higher efficiency. It was.
The present invention has been made in view of such circumstances, and a first object of the present invention is to provide a rotating machine that can be reduced in size by reducing the amount of iron core with respect to the same output. It is a second object of the present invention to provide a rotating machine that can increase the magnetic flux density and can be further miniaturized with higher efficiency by using a directional electrical steel sheet having a high maximum magnetic flux density for each of the iron cores.

In the rotating machine according to the first aspect of the present invention, the magnetic poles (N, S) that are equally provided in the circumferential direction of the rotating shaft are arranged opposite to each other with a certain distance in the radial direction. rotor and, in the space of the annular formed between the opposing magnetic poles, comprising a plurality of cores arranged side by side with a between the opposing magnetic pole and gap in the circumferential direction, yet each of said iron core a rotating machine that have a radial of the stator first and second windings, respectively inner and at the outer is applied,
Each of the magnetic poles of the rotor is formed by a pair of permanent magnets arranged at a certain distance in the radial direction, and the pair of permanent magnets are magnetically connected by a yoke and have opposite polarities. And the permanent magnets adjacent in the circumferential direction have opposite polarities,
A casing of the rotor and the stator is connected to the rotating shaft via a first bearing, and a first fixing frame that fixes the plurality of iron cores side by side in the circumferential direction, and the first fixing And a cup-shaped second fixed frame attached to the rotary shaft via a second bearing and covering the periphery of the rotor, and the iron core includes the first and second cores. It is fixed to the first fixed frame by an attachment member provided between the windings.
Here, the plurality of iron cores arranged in the circumferential direction are preferably arranged evenly in the circumferential direction, but may be unequal.
As a result, the iron core of the stator becomes substantially linear, and the effective length of the iron core can be reduced, thereby reducing the volume of the iron core through which the magnetic flux passes, resulting in a reduction in iron loss. be able to. Iron loss than reducing the amount of heat generated from the rotary machine by reducing the can to reduce the size of the rotating machine. In the present invention, when the winding does not rotate, a slip ring or the like is not required, and the overall structure is simplified.

  In the rotating machine according to the first invention, each of the magnetic poles of the rotor is formed by a strong permanent magnet arranged at a certain distance in the radial direction, and the pair of permanent magnets is magnetically Are connected by the yoke, the amount of magnetic flux passing through the stator core can be increased. The magnetic flux passing through the yoke pulsates but is not an alternating magnetic field, so there is little iron loss or eddy current loss.
  In the rotating machine according to the first invention, the casing of the rotor and the stator is connected to the rotating shaft via a first bearing, and the plurality of iron cores are arranged side by side in the circumferential direction and fixed. A first fixed frame; and a cup-shaped second fixed frame that is attached to the rotary shaft via a second bearing and covers the periphery of the rotor in pairs with the first fixed frame. Therefore, the assembly and disassembly of the stator are simplified.

  A rotating machine according to a second invention is the rotating machine according to the first invention, wherein the iron cores are provided radially with respect to the rotating shaft, and each of the iron cores has a directionality having a high magnetic permeability in a radial direction. It consists of a laminate of electromagnetic steel sheets. Thereby, the magnetic flux density of the iron core on which the winding is applied can be increased, and the volume of the iron core can be reduced. When the volume of the iron core (that is, the iron core through which the magnetic flux passes) is reduced, the iron loss is reduced, and when the cross-sectional area of the iron core is further reduced, the amount of winding is reduced, so that the copper loss is also reduced.

Further, the rotating machine according to the third invention is the rotating machine according to the first and second inventions, wherein a sensor for detecting the rotation angle of the rotor is provided in the stator, and by a power source provided separately, Based on a signal from the sensor, a predetermined AC power that matches a rotational phase of the rotor is sent to the first and second windings of the stator, and in particular, rotational power from the rotating shaft is transmitted. Use as a motor to obtain. As the sensor, for example, it is preferable to employ a Hall element sensor that detects magnetic strength .

It is the sectional side view which abbreviate | omitted the lower half of the rotary machine which concerns on one Example of this invention. It is the front sectional view which omitted the lower half of the rotation machine. It is a graph which shows the relationship between the magnetic flux density of an electromagnetic steel plate, and an iron loss.

  As shown in FIG. 1, a rotating machine 10 according to an embodiment of the present invention includes a first fixed frame 11 and a second fixed frame 12 constituting a casing, and a fixed attached to the first fixed frame 11. It has the child 13, and the rotor 15 which gives a moving magnetic field to the some iron core 14 which is the component of the stator 13, and was arrange | positioned along the circumference. These will be described in detail below.

  The first and second fixed frames 11 and 12 are made of a magnetic metal such as iron or casting, or other nonmagnetic metal, and in some cases, a nonmetallic material, and each has a leg portion (not shown) at the bottom. In FIG. 1, a flange 16 is provided at the right end of the first fixed frame 11 and a flange 17 is provided at the left end of the second fixed frame 12, and the flanges 16 and 17 are firmly connected by a plurality of screws 18. . A stepped hole 20 through which the rotation shaft 19 is inserted is provided at the center of the first fixed frame 11. The large-diameter hole 21 inside the stepped hole 20 is provided with a rotary roller bearing 22 which is an example of a first bearing, and rotatably supports the rotary shaft 19.

  An inner portion of the first fixed frame 11 has an iron core mounting portion 23, and as shown in FIG. 2, a plurality (12 in this embodiment) of iron cores 14 are fixed radially around the axis m. ing. Each iron core 14 is fixed by a mounting member 24 made of metal (nonmagnetic metal is preferred) or hard plastic. The attachment member 24 may be a band or a screw that penetrates the iron core 14. When the attachment member 24 is made of metal, it is preferable to use a high-resistance material (for example, austenitic stainless steel) in order to suppress the generation of eddy currents.

  The iron core 14 is composed of a laminate of thin grain-oriented electrical steel sheets cut into strips (that is, a rectangular shape), and is arranged radially with the same radius around the rotating shaft 19 as shown in FIG. Yes. Windings 25 and 26 are provided on both sides of each iron core 14, and the windings 25 and 26 wound around each iron core 14 pass through a predetermined connection (for example, a single-phase connection, a delta connection, or a star connection). It is connected to two or three external conductors (not shown). The iron cores 14 arranged radially and provided with the windings 25 and 26 constitute the stator 13 described above.

When the rotating machine 10 is used as a generator, the windings 25 and 26 become coils that generate an induced electromotive force. When the rotating machine 10 is used as an electric motor, for example, the rotation of a rotor is externally applied. By sending AC power in accordance with the phase, an attractive force or a repulsive force is generated between the magnetic poles of the stator 13 and the rotor 15.

  The second fixed frame 12 facing the first fixed frame 11 is provided with a stepped hole 39 through which the rotary shaft 19 is inserted at the center, and the cup 17 is provided with the flange 17 described above at one end. The other end is rotatably mounted on the rotary shaft 19 via a rotary roller bearing 28 which is an example of a second bearing mounted in the large-diameter hole 27 inside the stepped hole 39. In this embodiment, since the first and second fixed frames 11 and 12 are fixed with legs, the rotary roller bearings 22 and 28 are attached to the casing formed of the first and second fixed frames 11 and 12. Thus, the rotary shaft 19 is attached so as to be freely rotatable.

  As described above, since the plurality of iron cores 14 are radially attached to the first fixed frame 11 in a cantilever structure, between the rotary shaft 19 and the radially inner end of the iron core 14, and the second Between the inner wall of the fixed frame 12 and the radially outer end of the iron core 14, annular space portions 29 and 30 are formed, respectively. A space portion 31 communicating with the space portions 29 and 30 is also formed between the open end (that is, the axial direction) end of the cantilevered stator 13 and the second fixed frame 12, and this space portion 31 is formed. The rotor 15 excluding the rotating shaft 19 is disposed in the space portions 29 to 31.

  The rotor 15 includes a rotating shaft 19, a yoke 32 fixed to the rotating shaft 19, and permanent magnets 33 and 34 attached to both ends of the yoke 32. The yoke 32 is preferably made of a material having high magnetic permeability, but in some cases, it may be normal iron or iron casting, and the magnetic flux passing through the inside fluctuates but does not alternate. In addition, the generation of eddy current is small and not only the laminated iron core but also a normal massive magnetic body can be applied. The permanent magnets 33 and 34 are preferably, for example, neodymium / iron / boron strong magnets, but the present invention is not necessarily limited to the type of magnets as long as they are strong magnets. In FIG. 2, a two-dot chain line indicates a flow of alternating magnetic flux.

  Permanent magnets 33 and 34 facing each other with a certain distance in the radial direction centered on one iron core 14 must always face the south and north poles. And it is preferable that the permanent magnets 33, 33 and 34, 34 adjacent to each other in the circumferential direction have an S pole and an N pole, respectively. As a result, the magnetic resistance of the magnetic flux generated from the permanent magnets 33 and 34 is reduced, and the rotating machine 10 becomes more efficient. In this embodiment, the permanent magnet 33 is radially or partially embedded in a portion located radially outside the boss 35 attached to the rotary shaft 19. Further, the permanent magnet 34 is fixed by burying a part or all of it inside a cylindrical body 38 connected to the boss 35 via a disk-shaped member 37. Here, the boss 35, the disk-shaped member 37, and the cylindrical body 38 are constituent elements of the yoke 32, and are configured by a magnetic body (for example, iron). Therefore, the permanent magnets 33 and 34 are magnetically connected by the yoke 32.

By configuring the stator 13 and the rotor 15 as described above, the magnetic flux passing through the iron core 14 of the stator 13 becomes linear in the radial direction, and as a result, the magnetic flux generated by the permanent magnets 33 and 34 is more efficient. (Ie, with a lower reluctance). Further, by using the grain-oriented electrical steel sheet for the iron core 14, the magnetic flux passing through the iron core 14 is further increased and the iron loss is reduced, whereby the efficiency of the rotating machine 10 is improved. The reason for this will be described below. For example, the output Po in the case of a generator having a general cylindrical stator and a rotor rotating inside thereof (the same applies to an electric motor) is expressed as follows.
That is, Po∝ (Bg) ・ (ac) ・ (D2 ・ L) ・ (N)
Here, (Bg) is the average magnetic flux density (magnetic loading) of the gap between the stator and the rotor, (ac) is the ampere conductor (electric loading), (D2 · L) is the equipment size, and in detail, D is The inner diameter of the stator core, L is the thickness of the core layer, and (N) is the rotational speed. Therefore, when the magnetic permeability of the iron core increases, the magnetic resistance decreases and the magnetic load (Bg) increases. In addition, the cross-sectional area of the iron core is reduced, the internal resistance of the winding wound around this is also reduced, the internal resistance is reduced, the copper loss is reduced, and the output of the rotating machine is increased.

  In addition, when a grain-oriented electrical steel sheet is used for the iron core 14, it can be used with an increased magnetic flux density as shown in FIG. 3, and there is less iron loss than a non-oriented electrical steel sheet (for example, 1/2 This reduces heat generation, thereby improving efficiency and reducing the size of the device. In FIG. 3, k1 represents the magnetic flux density of the grain-oriented electrical steel sheet, k2 represents the magnetic flux density of the non-oriented electrical steel sheet, w1 represents the iron loss of the directional magnetic steel sheet, and w2 represents the iron loss of the non-oriented electrical steel sheet. Show.

  In this embodiment, the permanent magnets 33 and 34 are provided by providing a small gap at both ends in the length direction of the iron core 14, and the windings 25 and 26 are provided on the iron core 14 at two locations inside and outside in the radial direction. Is provided. If the windings 25 and 26 for the same iron core 14 have the same number of turns, the same and in-phase electromotive forces are generated. Therefore, the windings 25 and 26 are connected in parallel or in series. The impedance of 25 and 26 can be changed, whereby the voltage and current can be changed. In addition, it is possible to change the circuit impedance by providing one or more intermediate taps in the windings of each iron core 14 and changing the connection method (for example, directly, in parallel or in combination thereof).

  When the rotating machine 10 is used as a generator, a rotational power of a windmill, an engine, a water turbine or the like is connected to a rotating shaft, and when the rotating machine 10 is used as an electric motor, a sensor (for example, a rotation angle of the rotor 15 is detected. , A Hall sensor) is provided in the stator 13, and a magnetic pole having a reverse polarity is generated on the phase advance side in the rotation direction with respect to the magnetic pole of the rotor 15 based on a signal from the sensor, and is delayed from the magnetic pole of the rotor 15 A current is supplied by a power source provided separately in the windings 25 and 26 of the stator 13 so that magnetic poles of the same polarity can be formed on the phase side.

  Furthermore, the present invention is not limited to the above-described embodiments, and the number of rotor and stator magnetic poles is changed, or the rotor and stator, and the casing shape and dimensions are changed in accordance with these. The present invention also applies to cases.

The rotating machine according to the present invention can reduce the iron loss by minimizing the iron core on which the windings are made straight, thereby reducing the size and efficiency of the rotating machine. Can be provided. In particular, when the iron core is a grain-oriented electrical steel sheet, the permeability of each iron core can be dramatically increased, thereby reducing the cross-sectional area of the iron core for the same power, and further, the cross-sectional area of the iron core. Since the amount of windings is reduced as the number of turns decreases, a smaller and more efficient rotating machine can be provided.
Therefore, when used as an electric motor, it is optimal for transportation such as electric bicycles, automobiles, ships, airplanes, trains and the like that need to be small and light. In addition, when it is used as a generator, it is small, light and highly efficient, so it can be used not only for wind power generation but also as a generator for ordinary power plants.

Claims (4)

Different magnetic poles that are equally provided in the circumferential direction of the rotating shaft are arranged in an annular space formed between the rotor arranged opposite to each other with a certain distance in the radial direction and the opposing magnetic poles. the a between the opposing magnetic pole and gap comprising a plurality of cores arranged side by side in the circumferential direction, moreover the first and second windings respectively at the radially inner and outer respectively the iron core facilities a rotating machine that have a and are stator,
Each of the magnetic poles of the rotor is formed by a pair of permanent magnets arranged at a certain distance in the radial direction, and the pair of permanent magnets are magnetically connected by a yoke and have opposite polarities. And the permanent magnets adjacent in the circumferential direction have opposite polarities,
A casing of the rotor and the stator is connected to the rotating shaft via a first bearing, and a first fixing frame that fixes the plurality of iron cores side by side in the circumferential direction, and the first fixing And a cup-shaped second fixed frame attached to the rotary shaft via a second bearing and covering the periphery of the rotor, and the iron core includes the first and second cores. The rotating machine is fixed to the first fixed frame by an attachment member provided between the windings . The rotating machine according to claim 1, wherein the plurality of iron cores are arranged uniformly in a circumferential direction. 3. The rotating machine according to claim 1, wherein the iron cores are provided radially with respect to the rotating shaft, and each of the iron cores is formed of a laminated body of directional electrical steel sheets having a high magnetic permeability in a radial direction. Rotating machine. The rotating machine according to any one of claims 1 to 4 , wherein a sensor for detecting a rotation angle of the rotor is provided in the stator, and a power source provided separately is based on a signal from the sensor, The first and second windings of the stator are used as an electric motor that sends a predetermined AC power in accordance with the rotational phase of the rotor, and in particular, obtains rotational power from the rotating shaft. Rotating machine.

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