JP4604565B2 - Rotor and rotating electric machine equipped with the same - Google Patents

Description

  The present invention relates to a rotor in which a field magnet is installed, and a rotating electrical machine including the rotor.

In a rotating electric machine having a rotor on which a conventional field magnet is installed, the field magnet is generally fixed to the rotor. Since the induced voltage of such a rotating electrical machine is proportional to the field magnetic flux and the rotational speed of the rotor, the relationship of the induced voltage with respect to the rotational speed has characteristics as shown by the straight line ab in FIG. Therefore, if an electric motor whose power supply voltage is limited by the voltage c is taken as an example, the maximum rotational speed of the electric motor is a narrow operating range limited by the rotational speed d.
Therefore, an electric motor that changes the field magnetic flux in accordance with the rotational speed of the rotor has been proposed. (For example, refer to Patent Document 1).
JP-A-10-155262 (page 8, FIG. 1)

FIG. 8 is shown in FIG.
In FIG. 8, the first field magnet 31 and the second field magnet 32 installed on the rotor 2 are magnetic poles having the same polarity as shown in FIG. When the rotation speed is high, the magnetic poles having the same polarity are displaced as shown in FIG.
According to this technique, when the rotational speed of the rotor is high, the magnetic flux of the field magnet cancels out, so that the induced voltage can be lowered and the high-speed operation range can be expanded accordingly.

However, in the electric motor that changes the conventional field magnetic flux shown in Patent Document 1 in accordance with the rotational speed of the rotor, the interlinkage magnetic flux in the stator winding is canceled without reducing the magnetic flux of the field magnet. Therefore, it is possible to widen the high-speed operation range, but in particular, iron loss generated in the stator has not been reduced. Therefore, the higher the rotor speed, the lower the efficiency due to an increase in iron loss, the higher the motor temperature, and the lower the rated output.
The present invention has been made in view of such a problem. The field magnetic flux is changed according to the number of rotations of the rotor, and the magnetic flux of the field magnet is reduced to achieve high efficiency even in a high rotation operation region. It aims at providing the rotary electric machine which operate | moves.

In order to solve the above problem, the present invention is configured as follows.
According to a first aspect of the present invention , there is provided a rotary electric machine comprising: a hollow stator having windings; and a rotor disposed in a hollow portion of the stator and provided with a field magnet. Comprises a first field magnet movable part and a second field magnet movable part in which magnetic poles of different polarities are sequentially arranged in the rotation direction, and a magnetic path inside the field magnet, A stationary rotor core yoke, and the field magnet movable portion automatically changes the position of the rotation direction with respect to the yoke portion in accordance with the number of rotations of the rotor. A mechanism is provided inside the field magnet movable part, and the first field magnet movable part and the second field magnet movable part are respectively connected to the yoke part according to the number of rotations of the rotor. by changing the position in the rotational direction for a feature in that magnetic flux field interlinked to the stator windings is changed To have.
According to a second aspect of the present invention, in the rotating electric machine according to the first aspect , a centrifugal weight is provided on the rotor, and a radial force of a centrifugal force acting on the centrifugal weight as the number of rotations of the rotor increases or decreases. Are provided on the first field magnet movable portion and the second field magnet movable portion to convert the field magnet into a rotational force that changes the position of the field magnet with respect to the yoke portion. It is a feature.
According to a third aspect of the present invention, in the rotating electrical machine according to the first or second aspect , the yoke portion has a shape with a different thickness in a rotational direction constituting a magnetic path inside the field magnet, When the rotational speed of the rotor is low, the thick portion of the yoke portion is located between adjacent field magnets so that magnetic flux can easily pass therethrough, and when the rotational speed of the rotor is high, The first field magnet movable part and the second field magnet movable part change their positions in the rotational direction opposite to the yoke part, and the first field magnet movable part and the second field magnet are aligned. The magnetic field flux interlinked with the windings is reduced by shifting the magnetic poles of the movable part for the magnet and making it difficult to pass the magnetic flux at the same time .

According to the rotor according to claim 1, the field magnet movable part interlinks with the winding of the stator by changing the relative position in the rotation direction with respect to the rotor core according to the number of rotations of the rotor. The field magnetic flux easily changes, and a rotor that operates with high efficiency even in a high rotation operation region can be obtained.
According to the invention of the rotating electric machine according to claim 2, since the two field magnets change the position in the rotational direction with respect to the yoke portion of the rotor, a wide range of relative operating angles can be easily obtained. The field magnetic flux interlinking with the windings can be controlled from 0 to 100%, and in the electric motor, the rotor can be driven to a high speed without being limited by the voltage of the power source. In the generator, the induced voltage can be adjusted to a desired value regardless of the number of rotations of the rotor.
According to the invention described in claim 3, since the position of the centrifugal weight is regulated by the two inclined surfaces of the first and second field magnet moving parts, it is necessary to provide a separate mechanism for supporting the centrifugal weight. In addition, the structure is simple and the centrifugal force acting on the centrifugal weight can be converted into a rotational force that changes the position of the field magnet with respect to the yoke part, and the mass of the centrifugal weight is designed to the minimum. can do.
According to a fourth aspect of the present invention, when the rotational speed of the rotor is high, a thin portion of the yoke portion is located between adjacent field magnets so that the magnetic flux is difficult to pass. Therefore, it is possible to provide a rotating electrical machine that can reduce iron loss and operate with high efficiency even in a high rotation operation region.
According to a fifth aspect of the present invention, when the rotational speed of the rotor is high, the first and second field magnet movable parts change their positions in the rotational direction opposite to the yoke part and are aligned. In order to reduce the field magnetic flux interlinked with the windings by shifting the magnetic poles of the first and second field magnet moving parts, and simultaneously making the magnetic flux according to claim 3 difficult to pass, Therefore, the rotor can be driven with high efficiency up to high rotation without being limited by the voltage. In addition, in the generator, the induced voltage can be adjusted to a desired value with high efficiency regardless of the rotational speed of the rotor.
According to the sixth aspect of the present invention, since it is not necessary to provide the mechanism outside the rotor, the conventional field magnet is kept at the same size as the rotating electrical machine fixed to the rotor, and the rotation speed can be increased. A rotating electrical machine that operates at high efficiency can be provided.
According to the seventh aspect of the invention, the field magnet movable portion changes the relative position in the rotational direction with respect to the rotor core in accordance with the rotational speed of the rotor, and when the rotational speed of the rotor is low, The thicker part of the iron part is located between adjacent field magnets, making it easier for the magnetic flux to pass, whereas when the rotor rotation speed is high, the yoke is between the adjacent field magnets. Since the thin part is located and the magnetic flux does not easily pass, the field magnetic flux interlinked with the stator winding can be easily changed, and the operation can be performed with high efficiency even in the high rotation operation region.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an external view of a rotor of a rotating electrical machine according to the present invention.
In the figure, a first field magnet movable portion 1 and a second field magnet movable portion 2 are rotatably attached to a yoke portion 3 a of a rotor core fixed to a shaft 4. Yes. Since FIG. 1 shows the state when the rotational speed of the rotor is low, the field magnets of the first field magnet moving part and the second field magnet moving part have magnetic poles of the same polarity. It shows the state of being lined up. Moreover, the thick part of the yoke part 3a of the rotor core is located between adjacent field magnets, so that the magnetic flux can easily pass therethrough.
A centrifugal weight (not shown) is attracted to the inner periphery by a load of a return spring 6 through a pin 5 of the centrifugal weight.
FIG. 2 is a radial cross-sectional view at a portion where the centrifugal weight of the rotating electrical machine of the present invention is present. FIG. 3 is an axial sectional view of the electric motor of the present invention. FIG. 4 is a component configuration diagram of the rotor shown in FIG.
In FIG. 4, the first field magnet movable part 1 and the second field magnet movable part 2 include a rivet 9, a plate 10, a ring plate 11, a laminated iron core 12, and a laminated iron core 12 shown in FIGS. 3 is fixed to the shaft 4 shown in FIG. 3 only in the axial direction.
The plate 10 is provided with a slope that converts a radial force such as a centrifugal force acting on the centrifugal weight 7 into a rotational force that changes the position of the field magnet with respect to the yoke portion. The position of the centrifugal weight is regulated by the two slopes of the first and second field magnet moving parts.
As shown in FIG. 3, the rivets constituting the first and second field magnet moving parts are used to fix a laminated iron core in which field magnets are embedded via a ring plate to the plate.
The yoke portion 3a of the rotor core has a shape with a different thickness in the rotation direction constituting the magnetic path inside the field magnet, and when the rotation speed of the rotor is low, the thickness of the yoke portion is reduced. The thick part is located between adjacent field magnets, so that the magnetic flux easily passes.
When the number of rotations of the rotor is high, the first field magnet moving part and the second field magnet moving part change the position in the rotation direction, and a thin portion of the yoke part is located between adjacent field magnets. It becomes difficult to pass magnetic flux. The sliding resistance such as the inner circumference of the laminated core 12 and the outer circumference of the stator core 3 of the field magnet movable part is reduced by using a lubricating film material or the like.
The centrifugal weight pin 5 shown in FIGS. 2 and 3 passes through the centrifugal weight 7 and has return springs 6 attached to both ends of the shaft. The pin of the centrifugal weight is fixed only in the rotational direction by the groove 3b of the stator core shown in FIG. 4, and is determined by the centrifugal force acting on the centrifugal weight and the load of the return spring in the radial direction. By adjusting the load characteristics of the spring, the angle of the slope, etc., the timing at which the centrifugal weight moves outward can be adjusted for each rotational speed. Accordingly, in FIG. 7, the characteristic of the straight line be can be realized not only by changing the inclination of the straight line be and the rotation speed d of the centrifugal weight, but also by a desired curvilinear characteristic.

FIG. 5 is an explanatory diagram of the operation of the field magnet movable portion.
In the figure, (a) and (c) show the initial state when the rotational speed of the rotor is low, and (b) and (d) show an example of the state when the rotational speed is high. is there. (A) and (b) show the positional relationship of the first and second field magnet movable parts with respect to the diameter iron part of the stator core, and (c) and (d) are the field magnets. The increase / decrease of the magnetic flux by the positional relationship with the yoke part of the inner periphery of a magnet is shown.
In contrast to (a) and (c), in the states of (b) and (d), the first and second field magnet moving parts change their positions in the rotational direction opposite to the yoke part and are aligned. By shifting the magnetic poles of the first and second field magnet moving parts that have been used and making the magnetic flux difficult to pass at the same time, the field magnetic flux linked to the windings is reduced. Therefore, the induced voltage of the electric motor can be lowered and the iron loss can be reduced, so that the rotor can be driven with high efficiency up to high rotation.
In this embodiment, the first field magnet movable part and the second field magnet movable part having the same structure are juxtaposed back to back, but the present invention is not limited to this. Instead, for example, the first field magnet movable part and the second field magnet movable part having the same structure may be arranged to face each other face to face, or the first field magnet movable part and the second field magnet movable part The field magnet movable part may be provided with slopes in different directions, and both may be juxtaposed in the same direction.

As a measure for reducing the cogging torque, there is a case where the first and second field magnet movable parts are shifted by an appropriate amount from the initial state in (a) showing the initial state when the rotational speed is low. This also has the effect that the magnetic repulsive force acting on the first and second field magnet movable parts can be used as an auxiliary to the centrifugal force acting on the centrifugal weight.
In the figure, the angle of the inclined surface 10a is larger toward the outer side in the radial direction, but this is against the centrifugal force of the centrifugal weight that is proportional to the square of the rotational speed. This is because there is no balance point between the force and the load of the return spring, and the two field magnet movable parts operate at a certain speed at a certain rotational speed.
FIG. 6 shows an example of the state of the field magnet movable part during high rotation. In this example, the relative movement of the field magnet with respect to the stator core is performed at an angle corresponding to the magnetic pole pitch, so that the magnetic flux does not easily pass through and the field magnetic flux interlinked with the winding is completely cancelled. According to this embodiment, the field magnetic flux interlinking with the stator winding can be controlled from 0 to 100%. Therefore, in the electric motor, the rotor can be driven to a high speed without being restricted by the voltage of the power source.
In the generator, the induced voltage can be adjusted to a desired value regardless of the number of rotations of the rotor.

The difference between the present invention and the invention described in Patent Document 1 is that the first field magnet movable part and the second field magnet movable part are repositioned in the rotational direction opposite to the yoke part of the rotor core. Since the induced voltage can be lowered and the iron loss can be reduced, the rotor can be driven with high efficiency up to high rotation.
By using the present invention for an industrial servomotor, it becomes possible to drive with higher efficiency up to a higher rotation than the conventional one while maintaining the same size as the conventional one, thereby improving workability. Moreover, a transmission mechanism becomes unnecessary by utilizing that the torque constant can be controlled five times or more as an electric motor for a vehicle.
In addition, by using the present invention as a wind power generator or a vehicle generator, it is possible to always generate a desired constant voltage regardless of the number of revolutions, so that a step-up / step-down device is not required for line voltage and battery voltage. It becomes.

It is a perspective view of the rotor of the rotary electric machine which shows 1st Example of this invention. It is sectional drawing cut | disconnected by the surface orthogonal to the axis | shaft of the rotary electric machine which shows 1st Example of this invention. It is sectional drawing cut | disconnected by the vertical surface which passes along the axis | shaft of the rotary electric machine which shows 1st Example of this invention. It is a disassembled perspective view of the rotor which concerns on this invention. It is a figure explaining operation | movement of the field magnet movable part which concerns on this invention. It is a figure which shows the example of a state of the field magnet movable part which concerns on this invention at the time of high rotation. It is a rotation speed characteristic diagram of an induced voltage. FIG. 2 is a citation diagram of FIG. 1 in Patent Document 1.

Explanation of symbols

A Rotor B Stator C Rotating electrical machine 1 First field magnet moving part 2 Second field magnet moving part 3 Rotor core 3a Rotor core yoke part 3b Rotor core groove 4 Shaft 5 Centrifugal weight pin 6 Return spring 7 Centrifugal weight 8 Field magnet 9 Rivet 10 Plate 10a Slope 11 Ring plate 12 Multilayer iron core

Claims (3)

In a rotating electrical machine comprising: a hollow stator having windings; and a rotor disposed in a hollow portion of the stator and provided with a field magnet.
The rotor constitutes a first field magnet movable portion and a second field magnet movable portion in which magnetic poles of different polarities are sequentially arranged in the rotation direction, and a magnetic path inside the field magnet. A rotor core yoke fixed to the shaft, and
A centrifugal mechanism that automatically changes the position of the rotation direction in accordance with the number of rotations of the rotor with respect to the yoke portion is provided inside the field magnet movable portion with respect to the yoke portion .
The first field magnet moving part and the second field magnet moving part change the position in the rotation direction with respect to the yoke part according to the number of rotations of the rotor. A rotating electric machine characterized in that a field magnetic flux linked to a wire changes . A centrifugal weight is provided on the rotor, and a radial force of the centrifugal force acting on the centrifugal weight as the number of rotations of the rotor increases or decreases, the field magnet is positioned relative to the yoke portion. 2. The rotating electrical machine according to claim 1 , wherein slopes for converting the force in the rotating direction to be changed are provided in the first field magnet movable portion and the second field magnet movable portion . The yoke part has a shape with a different thickness in the rotation direction constituting the magnetic path inside the field magnet, and when the number of rotations of the rotor is low, the thick part of the yoke part is It is located between adjacent field magnets, making it easier for magnetic flux to pass through .
When the number of rotations of the rotor is high, the first field magnet movable part and the second field magnet movable part change positions in the opposite direction of rotation with respect to the yoke part and are aligned. shifting the poles of the field magnet movable portion and the second field magnet movable portion, at the same time by hardly passes the magnetic flux, claim 1, characterized in that to reduce the magnetic flux field interlinked in windings or 2. The rotating electrical machine according to 2.

Images