JP2016116368A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain higher efficiency and higher torque of a rotary electric machine by an inexpensive and highly reliable technique.SOLUTION: In an axial gap type rotary electric machine, a rotor comprises a plurality of salient pole iron core parts 2 distributed and arranged in a peripheral direction while a winding axis of a winding 14 for rotor is formed in parallel with a rotary shaft direction, and the salient pole iron core parts 2 for winding each comprises a plurality of concentric arcuate teeth projecting in an axial direction and also formed concentrically and arcuately. A stator comprises a magnetic pole part of a magnetic body having a plurality of concentric arcuate tooth groove parts formed concentrically and arcuately to correspond to the plurality of teeth, and the plurality of magnetic pole parts are provided in a peripheral direction, and distributed and arranged while magnetized alternately to the different polarities by a permanent magnet, and the concentric arcuate teeth enter and face the concentric arcuate tooth groove parts rotatably to engage with what is called a three-dimensional gap. The winding of the rotor is provided with a commutator 12 or a slip ring, and the stator is provided with a brush 15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an axial gap type rotating electrical machine used as an electric motor or a generator.

In recent years, rotating electric machines such as electric motors and generators have been increasingly demanded for energy saving and high efficiency as a countermeasure against global warming. In addition, there is a strong demand for lighter, thinner and smaller devices than the market. Furthermore, low vibration, low noise, and low cost are also strongly required. Among them, it is known that an axial gap type rotating electrical machine having an air gap in the direction of the rotation axis has a flat and thin structure that is advantageous. In general, the output of a rotating electrical machine is proportional to D ² L. D is the diameter of the rotating electrical machine, and L is the axial thickness of the rotating electrical machine. Since the axial gap type rotating electrical machine is flat and thin, D ² L can be increased, and the rotating electrical machine is suitable for higher output, and has been attracting attention in recent years. However, compared to a radial gap type rotating electrical machine, it is difficult to reduce the air gap, and because it is difficult to produce a laminated iron core using a silicon steel plate, etc. The penetration rate is extremely low compared to radial gap type rotating electrical machines.

JP 2013-150543 A

  On the other hand, as a prior art disclosing a related axial gap type rotating electrical machine, there is the above-mentioned patent document in which the authors invent and propose a high torque by increasing the facing area of the air gap.

  Rotating electric machines are roughly classified into radial gap type and axial gap type. Brushless DC motors (hereinafter referred to as BLDC motors) and synchronous generators that use permanent magnets for the rotors of conventional general radial gap type rotating electrical machines are pressed with a silicon steel plate in the direction of the axis of rotation. A rotary electric machine is formed by stacking after punching.

  However, in the axial gap type rotating electrical machine having an air gap in the one axial direction, the magnetic flux magnetic path is formed in the axial direction. Therefore, when the silicon steel plates are laminated in the axial direction, the magnetic flux passes in the lamination direction. . In addition, it is technically very difficult to construct a winding salient pole in the axial direction by laminating silicon steel plates, and even if it can be constructed, the product cost becomes expensive due to an increase in mold cost.

  On the other hand, regardless of the lamination of silicon steel plates, if a powdered iron core coated with an appropriate insulating resin binder and heat-treated after compression is adopted, the degree of freedom of the iron core shape is increased and the axial gap is increased. The rotary electric machine of the type can be high performance and inexpensive. The technology of the axial gap type rotating electrical machine that employs this dust core is disclosed in Patent Document 1 that has been developed and proposed by the present inventors. Patent Document 1 discloses a technique for increasing the torque by configuring the air gap of an axial gap type rotating electrical machine so as to mesh in an uneven shape.

  However, the configuration has a winding only on the stator side assuming a brushless DC motor and a switched reluctance motor, a so-called SR motor, and it can be said that the rotating electric machine is a technology biased to a rotating field type. Had the disadvantages. When a brushless DC motor or SR motor is driven to rotate, it is not driven even if the winding end is directly connected to a DC power source or the like. In order to drive, a so-called driver for a dedicated drive circuit is required. It is not uncommon for the cost of this driver to be higher than that of a motor, which is a frequent problem. Also, the driver is generally closed-loop driving that feeds back the rotor position information. For example, in the case of a general three-phase star connection type brushless motor, there are three lead wires for motor winding at the time of driving. In addition, since the sensor lead wires have to be wired with a total of eight lead wires, there is a disadvantage that the work is troublesome. A rotating electric machine has an armature side having windings and a field side that generates a field magnetic flux such as a permanent magnet. When one is a rotor, the other is a stator. A case where the armature is a rotor is called a rotary armature type, and a DC motor with a brush is a typical example. A case where the field side rotates is called a rotating field type, and a brushless DC motor or SR motor is a typical example. Since the production quantity ratio between the rotary armature type and the rotating field type rotary electric machine is approximately 2: 1, the rotary armature type uses a brush, but its product life is shorter than that of a brushless motor. Depending on the application, it can be said that it is an inexpensive and easy to use rotating electrical machine.

  The present invention compensates for the shortcomings of Patent Document 1 described above, expands the scope of the technology, increases the utilization, and constitutes an axial three-dimensional gap type rotary armature type rotary electric machine, thereby increasing the height of the axial gap type rotary electric machine. The goal is to contribute to performance and lower product prices.

  The rotating electrical machine according to the present invention is an axial gap type rotating electrical machine including a stator and a rotor that is rotatably disposed in an axial direction with respect to the stator via an air gap. The winding axis of the rotor winding is formed in parallel with the rotation axis direction and includes a plurality of winding salient cores distributed in the circumferential direction. A plurality of concentric arc-shaped teeth projecting in the axial direction and formed concentrically in an arc, and the stator includes a plurality of concentric arc-shaped tooth grooves formed concentrically so as to correspond to the plurality of teeth. The magnetic pole portion is provided with an even number of magnetic pole portions in the circumferential direction, and magnetized alternately with different polarity by a permanent magnet and distributed, the concentric arc teeth enter the concentric arc tooth groove portion, So-called three-dimensional air gap Rotatably opposite will be as mutually seen, the windings of the rotor, the commutator or slip ring is provided, wherein the stator is characterized in that the brush is provided.

  In the rotating electrical machine according to the present invention, it is preferable that the commutator or the slip ring and the brush face each other in the rotation axis direction.

  In the rotating electrical machine according to the present invention, it is preferable that the brush position of the brush can be varied in the circumferential direction.

  In the rotating electrical machine according to the present invention, it is preferable that the rotor can be variably controlled by making the position variable in the direction of the rotation axis with respect to the stator.

  In the rotating electrical machine according to the present invention, it is preferable that a pair of the rotors are disposed on both sides of the stator.

  In the rotating electrical machine according to the present invention, it is preferable that a pair of the stators is disposed on both sides of the rotor.

  In the rotating electrical machine according to the present invention, the rotor includes a disk-shaped rotor yoke made of a silicon steel plate laminate or a dust core, and the disk-shaped rotor yoke has a plurality of holes or recesses. In addition, it is preferable that the winding salient pole core is combined and coupled to the hole or recess.

  Since the rotary electric machine according to the present invention is an axial solid gap type rotary armature type rotary electric machine, if it is a brushed DC motor, it becomes an inexpensive high-performance motor that can be directly driven by a DC power source without a drive circuit.

  In the rotating electrical machine according to the present invention, since the air gap facing portion between the stator teeth and the rotor teeth is meshingly facing, the facing area increases, and a highly efficient rotating electrical machine with a large air gap permeance is realized.

  In addition, the rotating electrical machine according to the present invention is an axial gap type rotating electrical machine, and the teeth of the stator and the rotor mesh with each other in a concentric arc shape. Therefore, the rotor can be easily inserted into the bearing of the stator. Since it can be assembled, an inexpensive and highly efficient rotating electrical machine is realized.

  Further, the rotating electrical machine according to the present invention can control the advance angle during high-speed rotation if the brush position is set to be variable in the circumferential direction, and further efficient driving is possible.

  Further, the rotating electric machine according to the present invention can be driven at higher efficiency by using a variable air gap so that the air gap is reduced to be a strong field at low speeds and the air gap is increased to be a weak field at high speeds. Is possible.

  In addition, the rotating electrical machine according to the present invention is small in size and further increases in torque if the stator is disposed on both sides of the rotor, or vice versa, if the rotor is disposed on both sides of the stator. It becomes a rotating electrical machine.

  In the rotating electrical machine according to the present invention, the rotor includes a disk-shaped rotor yoke made of a silicon steel plate laminate or a dust core, and the disk-shaped rotor yoke has a plurality of holes or recesses. If the winding salient core is combined with the hole or recess, the winding occupancy rate is improved, and the eddy current loss is close to zero by the dust core, especially at high speeds. A high-efficiency rotating electrical machine with low iron loss.

Sectional drawing including the axis | shaft of the rotary electric machine of an example of this invention Schematic view from the axial direction of FIG. Three-dimensional view of the rotor yoke of FIG. Three-dimensional view of salient pole core of the present invention 3D view of the stator of the present invention 3D view of another stator of the present invention Diagram of the commutator of the present invention The figure for demonstrating the speed-torque characteristic of the DC motor of this invention Connection diagram of two-pole seven-slot DC motor and commutator of one example of the present invention Figure of prior art radial gap type 2-pole 7-slot DC motor

  This will be described below with reference to the drawings.

  FIG. 1 shows an example of the configuration of the present invention, and shows an axial three-dimensional gap type rotary armature type rotary electric machine. The rotor yoke 1 is made of a magnetic material and has a disk shape. The rotor yoke 1 may be constituted by a laminated type of silicon steel plates or a dust core. A yoke center boss 1-1 is formed at the center of the rotor yoke 1, and the rotating shaft 8 is fixed thereto. As shown in FIG. 3, the rotor yoke 1 is provided with a plurality of holes or recesses, and as shown in FIG. 1, the rotor yoke 1 is composed of a dust core having a winding 14 wound in parallel with the rotation axis direction. A salient pole core 2 as a winding salient pole core is combined and formed. The external appearance of the salient pole iron core 2 is shown as a three-dimensional view in FIG. A compacted iron core is an iron core that is coated with an appropriate insulating resin binder, heat-treated after compression, and the shape of the iron core is embossed to increase the degree of freedom of the shape. Therefore, the eddy current loss is close to zero, the iron loss is reduced, and the efficiency especially at high speed rotation can be improved.

  In the configuration of FIG. 1, the so-called rotor yoke 1 and salient pole core 2 are wound in a split core state, so that the winding occupancy rate is improved and the eddy current loss is close to zero by the dust core. A high-efficiency rotating electrical machine with low iron loss at high speed. As shown in FIG. 4, the salient pole iron core 2 is formed with concentric arc-shaped teeth provided with concentric concavities and convexities. The stator magnetic pole part 3 as a magnetic pole part having the magnetic pole part is rotatably arranged opposite to the stator magnetic pole part 3. The stator magnetic pole 3 is in close contact with the permanent magnet 4 on the non-air gap side and magnetized, and the permanent magnet 4 is in close contact with a stator yoke as a back yoke to form a stator.

  This will be described below with reference to FIGS. FIG. 2 is a schematic view seen from the direction of the rotation axis on the side of the stator yoke 5 in FIG. The outer periphery of the bush 10 is closely fixed to the stator yoke 5, but two portions of the outer periphery are recessed in a concave shape, and a pair of claws protruding in the axial direction of the cylindrical brush holder 11 are in the circumferential direction. It is built in to be partially rotatable. Referring to FIG. 1, the right end of the brush holder 11 is provided with two holes formed in the axial direction, and the brush 15 is connected to the commutator or commutator 12 by a conductor spring 16 in the axial direction in each hole. Pressed and in contact. The commutator 12 is fixed to the yoke center boss 1-1 of the rotor yoke 1. The detailed configuration of the commutator 12 is shown in FIG. 7, but it is a disk body in which seven conductor segments are held and fixed to an insulator disk in an insulated state. Each segment conductor is conductively coupled to the winding end 13 of the winding 14. When the rotor rotates, the segment conductor of the commutator 12 slides and rotates with the stationary brush 15. As shown in FIG. 2, the position center line 23 is the position center line of the plurality of salient pole cores 2 described above, and in this case, seven salient pole cores are provided. The windings wound around the seven salient pole iron cores are conductively coupled to the segment conductors of the commutator 12 described above as shown in FIG. Instead of the commutator, AC power can be taken out using a slip ring as a generator.

  FIG. 3 is a three-dimensional view of the rotor yoke 1. The yoke central boss 1-1 described above is provided at the center of the rotor yoke 1, and seven holes or recesses are provided at an equal pitch around the yoke boss 1-1. The rotor yoke 1 may be formed by stacking silicon steel plates in the axial direction, but may be integrally formed with a dust core. The neck portion of the salient pole iron core 2 shown in FIG. 4 has a winding 14 and is fixedly united with the seven holes or recesses of the rotor yoke 1 shown in FIG. The fixing method may be appropriately selected from adhesion, welding, caulking, resin molding, and the like. Concentric arc-shaped teeth and grooves are alternately provided on the upper portion of the salient pole iron core 2 disclosed in FIG. Therefore, the axial cross-sectional area of the neck at the bottom of the salient pole iron core only needs to be the same as the total area of the upper concentric arc-shaped teeth, so the neck and the groove are always smaller than the projected area when viewed from the axial direction. Can be formed. And if it winds around a neck part, the amount of winding copper can be ensured large and it will become a structure advantageous for high torque.

  FIG. 5 is an example of a three-dimensional external view of the stator. Since the rotating electrical machine of this embodiment is a 2-pole 7-slot axial solid gap type rotating electrical machine, a diagram of a 2-pole stator is shown. The stator magnetic pole 3 is provided with a plurality of concavities and convexities to form a concentric arc-shaped groove. As described above, the stator magnetic pole 3 is in close contact with the permanent magnet 4 magnetized in the axial direction, and the two stator magnetic poles 3 are different in polarity from each other. The concentric arc-shaped groove portions are concentrically provided by being magnetized by the permanent magnet 4. The back sides of the two permanent magnets are fixedly connected to each other by a stator yoke 5 which is a disk-like magnetic body having a back yoke function to form a stator. Then, an axial gap type rotating electrical machine having the function of an electric motor or a generator is formed by facing the rotor in which seven salient cores shown in FIG. To do. FIG. 6 shows a stator having the same function as that shown in FIG. 5, but its configuration is slightly different. That is, the stator shown in FIG. 5 requires the stator yoke 5 because the permanent magnet is magnetized in the axial direction. However, in the case of the stator shown in FIG. With the so-called spoke magnet arrangement in which the body is magnetized in the plate thickness direction, the stator yoke 5 in the case of FIG. 5 becomes unnecessary. As in the case of FIG. 5, the two stator magnetic poles 6 are concentrically provided with concavities and convexities to form concentric arc-shaped grooves, and are magnetized by two permanent magnets 7 into two poles having different polarities. Yes. Similar to FIG. 5, the stator of FIG. 6 is also used in the present invention.

  FIG. 1 further illustrates the configuration and functions of the present invention. The rotor shaft 8 fixed to the rotor yoke 1 is rotatably supported by two bearings 20 such as ball bearings, the right bearing 20 has its outer ring held by the housing 9, and the left bearing 20 is supported by the bush 10. The outer ring is held. The gear 17 for taking out the output torque is a pinion although the structure of the speed reducer is omitted.

  The rotating electrical machine according to the present embodiment forms a three-dimensional air gap by making the air gap opposed between the stator and the rotor part uneven, and when used as a motor, it has high torque and high efficiency as a generator. When used, the greatest feature is that the rotating electrical machine has high efficiency. For example, in the case of high torque, if the unevenness is deepened and meshed, the facing area can be increased to 2 to 3 times the plane air gap, and the permeance is proportional to the facing area ratio. The value more than double is obtained.

  In addition, the present embodiment has the following features by functions. The first additional function is to provide an advance angle control function. As described above, the pair of claws protruding in the axial direction of the cylindrical brush holder 11 are incorporated so as to be partially rotatable in the circumferential direction. However, by changing the claw protruding in the circumferential direction, the magnetic field is reduced during low-speed rotation. Drive the phase angle of the armature magnetic flux axis with respect to the magnetic flux axis with an advance angle of about 90 ° in electrical angle, and improve the high-speed rotation characteristics by making the phase angle greater than 90 ° during high-speed rotation. Can do. During high-speed rotation, the reactance ωL, which is the product of the winding inductance L and the rotor angular velocity ω, becomes large and a current delay occurs, so that advance angle control is performed as compensation means for preventing the phase angle from being 90 °.

  Furthermore, the second additional function is provided with means for changing the air gap to enable field control. In contrast to an axial gap type rotating electrical machine with a plain air gap where the stator and rotor do not mesh with the irregularities, the three-dimensional air gap type with the stator and rotor meshing with the irregularities allows for a large and variable air gap. The characteristic is that the characteristic can be changed more linearly with respect to the quantity.

  The specific means is as follows. As shown in FIG. 1, two steel balls 21 are arranged on the left and right of the rotating shaft 8. Since the rotating electrical machine according to the present embodiment is an axial solid gap type, the size of the air gap can be changed by changing the position of the rotor in the axial direction.

Consider a case where the rotating electrical machine according to the present embodiment is applied to an EV application that is a small electric vehicle. Air gap length in FIG. 1 is a slow speed in this case are illustrated as L _g, the high-speed rotation, the rotor shaft 8 in the right direction with the axis 18, it is increased further L ₀ minutes, which is illustrated The air gap length is increased and varied from L _g to L _g + L ₀ . In this case, the speed torque characteristics of the motor can be changed as shown in FIG. In FIG. 8, the vertical axis N represents the rotation speed, and the horizontal axis T represents the torque. The alternate long and short dash line 26 is a characteristic when the air gap is L _g , while the solid line 25 is a characteristic when the air gap is expanded to L _g + L ₀ and corresponds to field weakening control. That is, in the application to the EV car, the EV car is driven with the characteristics indicated by the alternate long and short dash line 26 at the start or at low speed, and when the speed is accelerated and becomes high speed, the characteristics indicated by the alternate long and short dash line 26 are insufficient. In this case, the field weakening control drive can be performed by switching to the characteristic indicated by the solid line 25. Generally, when the speed increases, the internal counter electromotive force increases in proportion to the speed, so that the inflow current from the power source decreases, and the torque has a so-called drooping characteristic that decreases as the speed increases. The internal counter electromotive force is proportional to ωΦ. ω is the rotor angular velocity, Φ is the field magnetic flux, and is approximately inversely proportional to the air gap. Further, since the torque T is proportional to Φ, it can be easily understood that if the air gap is increased, the torque decreases and the speed increases. In this variable control of the air gap, the air gap can be increased by pushing the rotating shaft 8 through the steel ball 21 in the right direction with the shaft 18, and when the air gap is reduced, the pressure applied to the shaft 18 is weakened. At the same time, since it is during deceleration and torque is required, a current flows into the winding from the external power source via the lead wire 29 and the suction force increases, and a spring provided on the right side of the rotary shaft 8 The rotor position is displaced through the plate 19 and the steel ball 21 with the force return force of 22. This is because when the rotational speed is reduced, the internal counter electromotive force is reduced and the inflow current is automatically increased even if the power supply voltage is constant. Even if the rotor position is displaced, the brush is crimped to the commutator with a conductor spring, and the commutator and the brush face each other in the axial direction if they are designed to maintain a pressurized body even when the position of L ₀ changes. So there is no problem.

  FIG. 9 is a diagram in which the two-pole seven-slot DC motor and the commutator of the rotating electric machine according to the present embodiment are linearly developed. The commutator segment conductor 24 has two coils in each of the seven winding pole grooves, and is a diagram of a lap winding of a DC motor. This connection is the same as in the prior art of a radial air gap. Various combinations of the number of poles and slots and the winding method can be used. What is necessary is just to select suitably also including selection of winding methods, such as concentrated winding.

  1 is a so-called shaft rotation type that is fixed to the rotor and the rotation shaft 8 rotates to extract the output from the rotation shaft. However, the rotation shaft 8 is fixed and the rotor is guided to the rotation shaft 8. Thus, it is possible to make a so-called fixed shaft type in which the output is taken out from the outer peripheral portion or the side portion of the rotor. Although not shown in the figure, the bearing 20 is removed from the state of FIG. 1, and it is provided between the outer periphery of the rotating shaft 8 inside the yoke central boss 1-1, and the rotor yoke 1, the salient pole core 2 and the winding. A rotor portion such as a wire 14 is rotatable with respect to the rotation shaft 8, and the bush 10 is fixed to the rotation shaft 8. If the housing 9 is removed and tires are mounted on the outer periphery of the rotor yoke 1, an in-wheel electric vehicle of a fixed shaft type is obtained. If the fixed shaft type is easier to use as an in-wheel electric vehicle, this may be done.

  FIG. 10 is a diagram of a conventional radial gap two-pole seven-slot, which includes a rotor core 27 and a stator segment magnet 28. In order to make a three-dimensional air gap with a radial gap type rotating electrical machine, the stator magnet portion cannot be assembled unless it is divided into three parts in the circumferential direction. On the other hand, according to the present invention, a three-dimensional air gap rotating electrical machine can be easily obtained by combining the stator and the rotor in the axial direction.

  The axial gap type rotating electrical machine according to the present invention can be used for an electric motor or a generator, and is extremely practical, inexpensive, robust, light and thin, suitable for high torque and high efficiency. Therefore, it is expected to make a significant industrial contribution.

1 Rotor yoke 1-1 Yoke central boss 2 Salient pole iron cores 3, 6 Stator magnetic poles 4, 7 Permanent magnet 5 Stator yoke 8 Rotating shaft 9 Housing 10 Bush 11 Brush holder 12 Commutator 13 Winding end 14 Winding 15 Brush 16 conductor spring 17 gear 18 shaft 19 plate 20 bearing 21 steel ball 22 spring 23 salient pole core position center line 24 segment conductor 25 speed-torque curve 26 when the air gap is large speed-torque curve 27 when the air gap is small rotor core 28 Stator segment magnet 29 Lead wire

Claims (7)

In an axial gap type rotating electrical machine comprising a stator and a rotor arranged to be rotatable in an axial direction with respect to the stator via an air gap,
The rotor includes a plurality of salient pole cores for windings that are formed so that the winding axis of the winding for the rotor is parallel to the rotation axis direction and distributed in the circumferential direction,
The winding salient pole core portion includes a plurality of concentric arc-shaped teeth protruding in the axial direction and formed concentrically in an arc shape,
The stator includes magnetic pole portions of a magnetic body having a plurality of concentric arc-shaped tooth grooves formed concentrically so as to correspond to the plurality of teeth, and the magnetic pole portions are provided in an even number in the circumferential direction, It is magnetized with different polarity by permanent magnets and distributed.
The concentric arcuate teeth enter the concentric arcuate tooth space, and are rotatably opposed so as to engage with a so-called three-dimensional air gap,
The winding of the rotor is provided with a commutator or a slip ring,
A rotating electric machine, wherein the stator is provided with a brush. In the rotating electrical machine according to claim 1,
The rotating electrical machine characterized in that the commutator or slip ring and the brush face each other in the direction of the rotation axis. In the rotating electrical machine according to claim 1 or 2,
The rotating electrical machine characterized in that the brush position of the brush can be varied in the circumferential direction. The rotating electrical machine according to any one of claims 1 to 3,
The rotating electric machine is characterized in that the air gap can be variably controlled by making the position of the rotor variable in the direction of the rotation axis with respect to the stator. In the rotary electric machine according to any one of claims 1 to 4,
A rotating electric machine, wherein a pair of the rotors are arranged on both sides of the stator. In the rotary electric machine according to any one of claims 1 to 4,
A rotating electric machine, wherein a pair of the stators are arranged on both sides of the rotor. The rotating electrical machine according to any one of claims 1 to 6,
The rotor includes a disk-shaped rotor yoke made of a silicon steel plate laminate or a dust core,
The disk-shaped rotor yoke has a plurality of holes or recesses, and the winding salient core is combined with the holes or recesses.

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