JP2005057941A - Rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary electric machine capable of regulating the voltage between terminals in correspondence with the moving amount in the radial direction by moving the stator divided into a plurality of sections in the radial direction during operation of the rotary electric machine depending on it rotational speed. <P>SOLUTION: In the rotary electric machine, the stator is divided into a plurality of sections in the axial direction facing the rotor wherein each divided stator is further divided into a plurality of sections in the circumferential direction. The stator is movable in the radial direction and provided with a coil. Voltage between terminals of the rotary electric machine can be regulated by moving the plurality of stators in the radial direction during operation of the rotary electric machine depending on its rotational speed thereby generating a voltage corresponding to the moving amount in the radial direction between the coil terminals of the plurality of stators. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rotating electrical machine such as an electric motor or a generator used to supply rotational power and voltage of various devices such as an elevator, an air conditioner, and an on-vehicle device, and particularly uses a frequency variable device such as an inverter. This relates to a rotating electrical machine that performs variable speed operation.

Conventionally, many techniques have been shown to achieve high efficiency in electric motors and generators operated over a wide range from low speed rotation to high speed rotation. Among these, it has been shown that the gap between the rotor and the stator is changed in accordance with the rotational speed (the number of rotations) for the purpose of improving the efficiency at high speed rotation (for example, Patent Documents 1 and 2).
In addition, a plurality of rotors are configured, and at least one of the plurality of rotors is shifted in the rotational direction with respect to the magnetic poles of the other rotors according to changes in the rotational speed, thereby increasing or decreasing the facing area with the stator magnetic poles. Thus, it has been shown that high-speed rotation is possible (for example, Patent Document 3).

JP 2002-247822 (FIG. 1, 0015 column) Japanese Utility Model Publication No. 6-24383 (FIG. 1, 0004 column) JP 2000-20461 A (FIG. 1, 0009 column)

However, the one disclosed in Patent Document 1 relates to a power storage flywheel device having an axial gap. When applied to a general motor or the like, for example, when the output is different with the same frame number. Is a technology that needs to be changed in diameter and lacks versatility in terms of manufacturing cost, mass productivity, and the like. Further, the one disclosed in Patent Document 2 has a complicated structure in which the opposing surfaces of the rotor and the stator are conical, and has a problem that the mass productivity is poor and the manufacturing cost is high. Yes.
Further, in Patent Document 3, the rotor is relatively rotated during rotation, and moving an object during high-speed rotation requires not only high technology but also rotation balance. There is a problem that it is difficult to remove and causes vibration and noise.

  In addition to the above problems, problems related to the voltage and loss of general-purpose rotating electrical machines will be described below.

  The amount of magnetic flux linked to one turn of a coil of a certain phase provided in the stator is expressed as the following formula 1.

  Since the amount of magnetic flux changes with time, the following voltage is generated in the coil. The voltage is shown as Equation 2 below.

  Here, the maximum voltage is expressed as Vm = n · Φm · ω, and it can be seen that the voltage is proportional to the rotational speed. This voltage is a voltage of one coil of a certain phase, and the terminal voltage of the rotating electrical machine varies depending on the connection, but is not proportional to the rotational speed. The output is expressed as the following Equation 3 using the voltage between terminals and the current.

In the case of a motor, what is often used in relation to rotational speed and output is constant output. From Equation 3, if the efficiency and power factor are constant, the current is inversely proportional to the voltage. That is, the current is inversely proportional to the rotation speed.
The main losses in the motor are primary copper loss and iron loss, which are simply expressed as the following Equation 4.

From these results, it can be seen that the voltage is proportional to the rotational speed, the current is inversely proportional to the rotational speed, the primary copper loss is inversely proportional to the square of the rotational speed, and the iron loss is proportional to the square of the rotational speed. A conceptual diagram showing these relationships is shown in FIG. In FIG. 1, V is voltage, I is current, Loss is loss, Φ is magnetic flux, Wc1 is primary copper loss, and Wi is iron loss. Many problems can be seen from FIG.
(1) The maximum rated voltage for use is determined for inverter devices for variable speed operation, etc., and exceeding this will cause failure. For this reason, the upper limit of the speed (number of rotations) of the rotating electrical machine is defined by the maximum voltage.
(2) The maximum temperature rise limit of a rotating electrical machine is limited by coil insulation or the like, and exceeding this will cause insulation failure. For this reason, the upper limit of speed (rotation speed) is prescribed | regulated by the said loss.
(3) If the rotation speed range is to be set wide, a motor drive power source rated for the lowest speed current (maximum current) and the highest speed voltage (maximum voltage) is required. This shows that the power supply is larger than a motor operated at a constant speed.

  The present invention was made to solve the above-described problems, and during operation of the rotating electrical machine, by moving the stator divided into a plurality according to the rotational speed in the radial direction, An object of the present invention is to provide a rotating electrical machine in which the voltage between terminals can be adjusted in accordance with the amount of radial movement.

  In the rotating electrical machine according to the present invention, the stator is divided into a plurality of parts in the axial direction facing the rotor, and each of the divided stators is divided into a plurality of parts in the circumferential direction and moves in the radial direction. Each stator is provided with a coil, and a plurality of stators are moved in the radial direction according to the rotational speed during operation of the rotating electrical machine. A voltage corresponding to the radial movement amount is generated between the coil terminals of the individual stators, whereby the voltage between the terminals of the rotating electrical machine can be adjusted.

  In the rotating electrical machine according to the second aspect of the present invention, the stator is divided into a plurality of parts in the axial direction facing the rotor, and is configured to be movable in the circumferential direction. The teeth are provided with a mechanism that is movable in the radial direction, and a coil is provided, and during operation of the rotating electrical machine, a plurality of teeth move in the radial direction according to the rotational speed. By changing the gap between the rotor and the rotor, a voltage corresponding to the gap is generated between the coil terminals of each stator, so that the voltage between the terminals of the rotating electrical machine can be adjusted.

  In the rotating electrical machine according to the third aspect of the invention, the stator is divided into a plurality in the circumferential direction and has a configuration movable in the radial direction, and the stator is provided with a coil. During operation of the rotating electrical machine, by moving the stator in the radial direction according to the rotational speed, a voltage corresponding to the radial movement amount is generated between the coil terminals of the stator, so that the voltage between the terminals of the rotating electrical machine is increased. Can be adjusted.

  In the rotating electrical machine according to the fourth aspect of the invention, the stator is provided with a plurality of teeth and a mechanism that is movable in the radial direction, and is provided with a coil. A plurality of teeth move in the radial direction in accordance with the rotational speed to change the gap with the rotor, and a voltage corresponding to the gap is generated between the coil terminals of the stator. Can be adjusted.

  In the rotating electrical machine according to the present invention, the gap between the rotor and the stator is changed by moving the plurality of stators in the radial direction according to the rotational speed, so that the voltage between the terminals is substantially constant, and the current and the loss are substantially constant accordingly. As a result, the efficiency during high-speed rotation is improved and the power source capacity is reduced.

  In addition, the stator is divided into a plurality of pieces, and a plurality of teeth are provided, and the teeth are moved in the radial direction according to the rotational speed.

  Further, since the stator is moved in the radial direction according to the rotational speed, the same effect is obtained.

  Further, since the teeth are moved in the radial direction according to the rotation speed, the same effect is obtained.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
In FIG. 2, the rotating electrical machine 100 includes a first stator 21 and a second stator 22 that are opposed to the shaft 3 and divided into two in the axial direction. As shown in FIGS. 3 and 4, the first and second stators 21 and 22 are each provided with a coil 4, and a coil end 4 a exists outside in the axial direction. The coils 4 of the stators 21 and 22 are connected in series or in parallel.
Side views of the stators 21 and 22 are shown in FIGS. 3 (a) and 3 (b) and FIGS. 4 (a) and 4 (b).
In FIG. 3 (a), the first and second stators 21 and 22 are divided into two parts having split surfaces 21b and 22b, and the radial direction (vertical direction) is determined according to the rotational speed by a mechanism not shown. It has a movable configuration. FIG. 3B shows a state in which the first and second stators 21 and 22 have moved according to the rotational speed.
FIG. 4A shows a configuration in which the first and second stators 21 and 22 are divided into four parts having dividing surfaces 21b and 22b, and can be moved in the radial direction according to the rotational speed by a mechanism not shown. It has become. FIG. 4B shows a state in which the first and second stators 21 and 22 have moved.
As described above, in the first embodiment, the first and second stators 21 and 22 move in the radial direction according to the rotation speed, so that the gap between the rotor and the stator changes, and the rotation speed becomes high. If the gap length is increased correspondingly, the magnetic resistance is increased and the amount of magnetic flux is reduced, so that the voltage V = dΦ / dt is lowered and the increase in voltage can be suppressed.
When such a stator configuration is adopted, when the stators 21 and 22 are moved so that the air gap is increased substantially in proportion to the rotation speed, the voltage becomes constant, the current associated therewith is substantially constant, and the loss is also constant. Is improved and the power supply capacity is further reduced. Also, by setting the radial movement amounts of the plurality of stators to a predetermined movement amount determined by the rotational speed, the voltage between the terminals of the rotating electrical machine can be set to a predetermined value, and the same efficiency is achieved. A schematic diagram of the above relation is shown in FIG.

  Further, in the conventional technique, for example, when the motor is operated at a variable speed, a power capacity that satisfies the maximum voltage value at the maximum speed and the maximum current value at the minimum speed in the variable speed range has been provided. However, the actual output is much smaller than its power supply capacity. As described in the first embodiment, as described above, the maximum voltage can be suppressed by dividing the stator into two parts in the axial direction and also in the circumferential direction. This also leads to current reduction. Therefore, the power capacity is reduced.

Embodiment 2. FIG.
When the rotary electric machine 100 having a plurality of stators is configured, the coil end 4 a of the coil 4 provided in each stator is interposed between the stators 21 and 22, thereby preventing the rotary electric machine 100 from being downsized. The axial length of the coil end 4a is preferably as short as possible. Therefore, the coil 4 uses the toroidal or concentrated winding stators 21 and 22 to shorten the axial length of the coil end 4a, thereby reducing the size of the rotating electrical machine.

In addition, as shown in FIG. 6, the rotor protrusions 21 a and 22 a that protrude in the axial direction of the rotor 3 are provided on the rotor 3 side of the coil ends 4 a on the opposite sides of the stators 21 and 22. Thus, the magnetic flux 3 can be used effectively. Further, as shown in FIG. 7, the stators 21 and 22 may be configured by a flexible common coil 4 c to enable movement in the radial direction.
The stators 21 and 22 may have the same axial length (stacked length) or may have different axial lengths. In addition, although the stator showed the example of 2 division | segmentation and 4 division | segmentation, it cannot be overemphasized that other plurality may be sufficient.

Embodiment 3 FIG.
In the rotary electric machine provided with the stator divided into a plurality of parts in the first embodiment described above, the present invention may be applied to a permanent magnet type motor having a permanent magnet in the rotor.
In the case of a normal permanent magnet type motor, an induced voltage is generated only by rotation by the permanent magnet of the rotor without energizing the stator. By applying the stator configuration of the first embodiment, the induced voltage can be reduced. As a result, even if the permanent magnet motor rotates due to some cause when the power is stopped and an induced voltage is generated, the induced voltage is reduced, so that it is possible to easily prevent the failure of the power supply.

Embodiment 4 FIG.
The rotary electric machine according to the first embodiment described above includes the stator divided in the axial direction and the outer and inner peripheral sides. However, the stator of the rotary electric machine according to the fourth embodiment is divided in the axial direction. The outer peripheral side stator 11a is divided into an outer peripheral side and an inner peripheral side, and an inner peripheral side stator 11b is provided. In this case, you may apply to the permanent magnet type motor which provided the permanent magnet in the rotor.
The side view of the stator of this Embodiment 4 is shown to Fig.8 (a) (b). The conceptual diagram corresponding to FIG. 2 described in the first embodiment is not shown in the fourth embodiment.
In FIG. 8, the stator 11 is divided into an outer peripheral side stator 11a and an inner peripheral side stator 11b, and the inner peripheral side stator 11b has a mechanism (not shown) that can move in the circumferential direction with respect to the outer peripheral side stator 11a. It is configured. FIG. 8B shows a view in which the inner circumferential side stator 11b moves in the circumferential direction relative to the outer circumferential side stator 11a, relative to FIG. 8A.
A coil 4 is provided on the inner peripheral side stator 11b. As shown in FIG. 8, the inner peripheral side stator 11b is composed of a plurality of teeth (teeth) 11e, and the plurality of teeth 11e are integrated with a connection ring (not shown) to the outer side stator 11a. It can move in the circumferential direction. The outer peripheral side stator 11a corresponds to a yoke, and is provided with a convex part 11c and a concave part 11d that are in close contact with the teeth of the inner peripheral side stator 11b so as to be movable. The coil 4 is connected in series or in parallel.

Here, the reason for adopting the fourth embodiment will be described.
The maximum voltage Vm is indicated by n, Φm, and ω as described above. Here, the magnetic flux amount Φ is inversely proportional to the magnetic resistance Rm. Rm is represented by 1 / μ · l / S. Therefore, the magnetic flux amount Φ is proportional to μ, inversely proportional to the magnetic circuit length l, and proportional to the magnetic circuit cross-sectional area S. When the inner circumferential side stator 11b moves in the circumferential direction with respect to the outer circumferential side stator 11a as shown in FIG. 8 (b) from the state of FIG. 8 (a) described above, μ becomes smaller and Φ becomes smaller. Less.

As described above, in the fourth embodiment, the stator is not divided in the axial direction, and the circumferential stator 11b is moved in the circumferential direction with respect to the outer stator 11a according to the rotational speed. Therefore, the increase in the maximum voltage Vm can be suppressed. In the case of a permanent magnet type rotating electrical machine having a permanent magnet in the rotor, an induced voltage is generated only by the rotation of the rotor. By applying the stator configuration of the fourth embodiment, the induced voltage can be reduced. As a result, even if the permanent magnet motor rotates due to some cause when the power is stopped and an induced voltage is generated, the induced voltage is reduced, so that it is possible to easily prevent the failure of the power supply.
Further, even when the power is stopped (rotated) due to some unexpected cause when the power is stopped, an induced voltage is not generated, and damage to related equipment caused by the induced voltage can be prevented.

Embodiment 5 FIG.
Next, details of the stator 11 according to the fifth embodiment will be described with reference to FIG. In FIG. 9, a plurality of teeth 51 (teeth) are provided on a yoke 52 that couples them to face the rotor 3. The teeth 51 can be moved in the radial direction with respect to the rotor 3 by a moving mechanism (not shown). That is, the gap between the rotor 3 and the teeth 51 is variable. Each of the teeth 51 is provided with a coil 4. FIG. 9A shows a state where the tooth 51 is moved and installed with respect to the rotor 3 so as to be a small gap G1, and FIG. 9B shows a state where the tooth 51 is moved into the large gap G2. If a toroidal winding or a distributed winding is employed for the coil 4, the coil end is shortened and the overall length of the rotating electrical machine can be shortened. The radial movement of the teeth 51 is performed by a moving mechanism (not shown) according to the rotational speed of the rotating electrical machine 100.

As described above, in the fifth embodiment, the tooth 51 provided in the stator 11 moves in the radial direction according to the rotation speed, so that the gap between the rotor 3 and the stator 11 changes, and the rotation speed becomes high. If the gap length is increased correspondingly, the magnetic resistance is increased and the amount of magnetic flux is reduced, so that the voltage V = dΦ / dt is lowered and the increase in voltage can be suppressed.
By adopting such a stator configuration, when the tooth 51 is moved so that the air gap becomes larger in proportion to the rotation speed, the voltage becomes constant, the current is constant and the loss is constant, and the efficiency is improved. Furthermore, the power capacity is reduced. In addition, by setting the radial movement amount of the plurality of teeth 51 to a predetermined movement amount determined by the rotational speed, the voltage between the terminals of the rotating electrical machine can be set to a predetermined value, and the same efficiency is achieved. A schematic diagram of the above relation is shown in FIG.
Moreover, the permanent magnet type rotary electric machine provided with the permanent magnet in the rotor may be sufficient. The rotor 3 can be braked by moving the teeth 51 in contact with the rotor 3 and fixing the rotor 3 with the teeth 51 when the permanent magnet rotating machine is powered off. Alternatively, the gogging torque can be reduced by increasing the gap when the power is turned off, and unintended rotation can be prevented.

Embodiment 6 FIG.
When performing variable speed operation of the motor, a variable frequency power supply device such as an inverter is used. In this variable frequency power supply device, the optimum operation is performed using the circuit constants of the motor. However, when the stator is moved in the radial direction and the air gap is changed as shown in the fourth embodiment, the optimum circuit of the motor is obtained. The constant changes. For this reason, optimal operation cannot be achieved if the motor circuit constants are fixed. Therefore, by changing the motor constant according to the radial movement amount of the plurality of stators, the optimum operation using the variable frequency power supply device can be performed.

Embodiment 7 FIG.
When a plurality of teeth as shown in the fifth embodiment are moved in the radial direction to change the gap, the optimum circuit constant of the motor changes. For this reason, optimal operation cannot be achieved if the motor circuit constants are fixed. Therefore, by changing the motor constant according to the radial movement amount of the plurality of teeth, it is possible to perform an optimum operation using the variable frequency power supply device.

  As described above, when the first to seventh embodiments of the present invention are applied to a device that requires variable speed operation, such as a generator for an automobile (alternator), a motor for a train, and a spindle motor for a machine tool, There is an effect that efficiency is improved.

It is a conceptual diagram which shows the relationship between the rotational speed of a rotary electric machine, a voltage, and loss. It is a conceptual diagram which shows the rotary electric machine of Embodiment 1 of this invention. It is a side view which shows the stator of Embodiment 1 of this invention. It is a side view which shows the other stator of Embodiment 1 of this invention. It is a conceptual diagram which shows the relationship between the rotational speed, voltage, and loss of Embodiment 1,4,5 of this invention. It is a conceptual diagram which shows the rotary electric machine of Embodiment 2 of this invention. It is a conceptual diagram which shows the other rotary electric machine by Embodiment 2 of this invention. It is a side view which shows the stator of Embodiment 4 of this invention. It is a side view which shows the stator of Embodiment 5 of this invention.

Explanation of symbols

3 rotor, 4, 4c coil, 4a coil end, 11 stator,
11a outer peripheral side stator, 11b inner peripheral side stator, 11e, 51 teeth,
21 First stator, 22 Second stator.

Claims (15)

A rotating electrical machine including a stator and a rotor, wherein the stator is divided into a plurality of parts in an axial direction facing the rotor, and each of the divided stators is divided into a plurality of parts in a circumferential direction. Each of the stators is provided with a coil, and during operation of the rotating electric machine, the plurality of the plurality of stators are arranged in accordance with the rotational speed. By moving the stator in the radial direction, a voltage corresponding to the amount of radial movement is generated between the coil terminals of the plurality of stators, so that the voltage between the terminals of the rotating electrical machine can be adjusted. A rotating electric machine that is characterized. A rotating electrical machine including a stator and a rotor, wherein the stator is divided into a plurality of parts in an axial direction facing the rotor, and has a configuration movable in a circumferential direction. The stator is provided with a plurality of teeth and a mechanism that is movable in the radial direction, and is provided with a coil. The teeth of the rotor move in the radial direction to change the gap with the rotor, so that a voltage corresponding to the gap is generated between the coil terminals of each stator, thereby adjusting the voltage between the terminals of the rotating electrical machine. A rotating electric machine characterized by being made possible. A rotating electrical machine including a stator and a rotor, wherein the stator is divided into a plurality of parts in a circumferential direction, has a configuration that can move in a radial direction, and the stator is provided with a coil. During operation of the rotating electrical machine, a voltage corresponding to the radial movement amount is generated between the coil terminals of the stator by moving the stator in the radial direction according to the rotation speed. The rotating electric machine is characterized in that the voltage across the terminals of the rotating electric machine can be adjusted. A rotating electrical machine including a stator and a rotor, wherein the stator includes a plurality of teeth and a mechanism that is movable in a radial direction, and is provided with a coil. During the operation, the plurality of teeth move in the radial direction according to the rotation speed to change the gap with the rotor, so that a voltage corresponding to the gap is generated between the coil terminals of the stator. The rotating electric machine is characterized in that the voltage between the terminals of the rotating electric machine can be adjusted. 4. The rotating electrical machine according to claim 1, wherein when the rotational speed is increased, the stator is moved so that a radial movement amount of the stator is increased. 5. 2. The terminal voltage of the rotating electrical machine is set to a predetermined value by setting a radial movement amount of the plurality of stators to a predetermined movement amount determined by the rotation speed. The rotating electrical machine according to claim 3. 5. The rotating electrical machine according to claim 2, wherein when the rotation speed increases, the teeth are moved so that the gap also increases. 5. The terminal voltage of the rotating electrical machine is set to a predetermined value by setting the amount of radial movement of the teeth to a predetermined amount of movement determined by the rotational speed. The rotating electrical machine according to any one of the above. The rotating electrical machine according to any one of claims 1 to 4, wherein the coil of the stator is provided with a toroidal winding. The rotating electrical machine according to any one of claims 1 to 4, wherein concentrated winding is applied to the coil of the stator. The rotating electrical machine according to claim 1, wherein the rotating electrical machine has a rotor of a permanent magnet type. The plurality of teeth of the stator move so that the gap becomes zero when the rotating electric machine is stopped, and the teeth hold the rotor so as not to rotate the rotor. Or the rotary electric machine of any one of Claim 4. 5. The rotating electrical machine is provided with a driving inverter device, and a circuit constant of the driving inverter device changes according to a rotational speed of the rotating electrical machine. The rotating electrical machine according to any one of the above. 4. The rotary electric machine is provided with a drive inverter device, and a circuit constant of the drive inverter device changes according to a radial movement amount of the stator. The rotating electrical machine according to any one of the above. 5. The rotary electric machine is provided with a drive inverter device, and a circuit constant of the drive inverter device changes in accordance with a radial movement amount of the teeth. The rotating electrical machine according to any one of the above.

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