JP2000050584A - Electric motor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a hybrid engine, when a rotor of an electric motor directly connected to a wheel shaft rotates, iron loss occurs in a stator of the electric motor due to a permanent magnet provided in the rotor, and output of the motor is reduced. The temperature will drop or the motor will generate heat. SOLUTION: The present invention relates to a rotor in which a first rotating body portion 2 provided with a permanent magnet 6 and a second rotating body portion 3 provided with a magnetic flux shielding groove 11 so as to have saliency are connected in a rotation axis direction. And a stator 21 that generates a magnetic field for driving the rotor by supplying a current, and a rotating shaft of the rotor is rotated by external rotation driving means. Reduce the amount of permanent magnets by using a motor,
It is possible to provide a high-output, high-efficiency motor in which the generation of induced voltage is suppressed and iron loss is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronous motor.

[0002]

2. Description of the Related Art Conventionally, an internal combustion engine has been generally used as a motor of a vehicle. Recently, air pollution, global warming, and the like have become problems, and from the viewpoint of coexistence with the global environment, research on hybrid vehicles combining a gasoline / diesel engine and an electric motor as prime movers has been advanced. Such a hybrid vehicle, when the load fluctuates greatly, such as at the time of startup, acceleration and deceleration,
Assist the engine with the motor. Alternatively, the load on the engine is reduced by driving only the motor. In a running state in which the load of the engine is steady, the drive of the motor is stopped, and the fuel efficient driving can be performed by using the engine efficiently. Also, the exhaust gas becomes clean.

[0003]

However, it is suitable to use a small-sized, high-output, and high-efficiency permanent-magnet embedded motor as such a hybrid engine, but the rotor of the electric motor directly connected to the drive shaft is required. When the rotor rotates, an induced voltage is generated by a permanent magnet provided on the rotor. The induced voltage, that is, the magnetic flux linked to the stator, causes iron loss in the stator of the electric motor. In particular, even if the motor is not energized, iron loss occurs, so the engine output decreases,
There is a problem that the rated heat output is reduced because the motor generates heat.

[0004] In particular, when the gasoline engine is running at a constant load with good efficiency, the power supply to the electric motor is turned off and the electric motor is rotated only by the gasoline engine. Rotate. In such an operation, the induced voltage is large, and the iron loss of the stator of the electric motor is increased.

In view of only suppressing the induced voltage, when the electric motor is not driven by using a clutch or the like, the drive shaft is separated from the rotor of the electric motor, and the wheels rotate. Although it is conceivable that the rotor of the electric motor is in a stopped state, the mechanism and its control are complicated, and a space for providing such a mechanism is required. In contrast to reducing the size and weight of the electric vehicle itself, the electric vehicle has a contradictory problem of increasing the indoor space of the electric vehicle, and it is difficult to increase the size of the driving device including the electric motor.

The present invention solves such a problem, and suppresses an induced voltage generated in an electric motor when a rotating shaft is rotated by an external force, thereby reducing iron loss and achieving a small, high-output, and high-efficiency. An object is to provide a motor.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a rotating device in which a first rotating member provided with a permanent magnet and a second rotating member provided with a magnetic flux blocking portion having saliency are connected in the direction of the rotation axis. And a stator that generates a magnetic field that drives the rotor by supplying current, and a rotating shaft of the rotor may be rotated by an external rotation driving unit. By using a reluctance motor for a part of the child, the amount of permanent magnets can be reduced, and the generation of induced voltage can be suppressed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electric motor according to the present invention is a motor in which a first rotor having a permanent magnet and a second rotor having a magnetic flux cut-off portion having saliency are connected in a rotation axis direction. And a stator for generating a field for rotationally driving the rotor by supplying an electric current, and a rotation shaft of the rotor is rotated by an external rotation driving unit. That is,
Even if the rotating shaft is rotated by an external force, a part of the rotor is formed as a reluctance motor to reduce the amount of permanent magnets, suppress generation of induced voltage, and reduce iron loss.
Further, even when the electric motor forms a rotating magnetic field by the current supplied to the stator and the rotor is driven to rotate, the motor is provided with the permanent magnets, so that the electric motor can have high output and high efficiency. The magnetic flux cut-off portion is a magnetic flux resistance of a non-magnetic material, a low-magnetic material for canceling an ineffective magnetic flux due to an armature reaction.

Further, the rotating shaft of the rotor is rotated by the rotation driving means in a state where no current flows through the stator, so that the rotor fixed to the rotation shaft rotates according to the rotation driving means.

Further, the first rotating body has saliency by embedding a permanent magnet, and the first rotating body can utilize reluctance torque in addition to magnet torque.

Further, by using a hybrid engine having an electric motor and an internal combustion engine as a rotary drive means, it is possible to provide an engine with good fuel efficiency by selectively using the advantages of the electric motor and the internal combustion engine.

Further, the first rotating body and the second rotating body are connected in the direction of the rotation axis, and a non-magnetic body is interposed between the first rotating body and the second rotating body. Thus, since the first rotator and the second rotator have independent magnetic properties, the rotor can be easily designed.

[0013] Further, the first rotating body portion may include a first rotating body portion.
The magnetic and mechanical balance is improved by interposing the rotating member.

Further, a high torque can be obtained by combining the first rotator with the phase where the maximum torque is generated and the phase with which the second rotator generates the maximum torque. .

Furthermore, since the magnetic resistance layer is narrower on the outer diameter side of the rotor than on the rotation axis side, the permanent magnet of the first rotating body portion is transferred from the permanent magnet of the first rotating body portion to the outer periphery of the second rotating body portion along the magnetic flux cutoff portion. By flowing the magnetic flux, the distribution of the magnetic flux output to the outer periphery of the second rotating body portion becomes sinusoidal, the torque fluctuation is reduced, and controllability can be improved.

Further, the rotor includes a rotor provided with a magnetic flux interrupting portion so as to have saliency, and a stator that supplies a current to generate a field for driving the rotor. In a state in which the rotor is not supplied, the rotating shaft of the rotor is rotated by the internal combustion engine. Since the rotor has no permanent magnet, it is possible to provide a hybrid motor that does not generate an induced voltage when the motor is not energized and that does not generate iron loss when the motor is not energized. The magnetic flux cut-off portion is a magnetic flux resistance of a non-magnetic material, a low-magnetic material for canceling an ineffective magnetic flux due to an armature reaction.

Further, by directly connecting the rotor of the electric motor to the drive shaft of the wheel, it is possible to provide a small-sized and high-output electric vehicle hybrid engine without increasing the number of parts.

[0018]

Embodiment 1 Embodiment 1 shows a hybrid engine in which a gasoline engine used in an electric vehicle and an electric motor are combined. An electric vehicle having such a hybrid engine switches to an electric motor or an electric motor and a gasoline engine at the time of startup or acceleration / deceleration, and switches to a gasoline engine for stable running at a constant load, and uses the advantages of the gasoline engine and the electric motor. To provide fuel-efficient electric vehicles.

First, in the electric motor, a first rotor 2 having saliency by a permanent magnet and a second rotor 3 having saliency by a plurality of slits are connected in the direction of the rotation axis. The present invention has a rotor, has a small iron loss in the stator, and can reduce the size of the electric motor.

As shown in FIG. 1, a first rotating body 2 and two second rotating bodies 3 are fixed to the same rotating shaft 4, and the second rotating body 3 is a first rotating body 3. The rotating body 2 is sandwiched therebetween. In addition, a non-magnetic body 5 is interposed between the first rotating body 2 and the second rotating body so that the first rotating body 2 and the second rotating body 3 are magnetically independent. It is connected to.

As shown in FIG. 2, the first rotating body 2 is formed by laminating electromagnetic steel sheets, has a convex shape toward the rotating shaft 4, and has a slit having an end close to the outer periphery of the rotating body 2. The permanent magnet 6 is embedded in the slit portion. This permanent magnet 6 is not the same size as the slit,
A gap 7 is formed between the end and the slit end. At this time, a resin or the like may be embedded in the gap 7. First
Of the rotor 2 has saliency due to the permanent magnets 6 and the gaps 7, and the first rotor 2 is synchronized with the magnetic field generated by the stator, so that the first rotor 2 has a reluctance torque and a magnet torque (magnet torque> reluctance torque). ). A through-hole is provided between the rotating shaft 4 and the slit portion, and a plurality of electromagnetic steel plates are fixed to the through-hole by a fastening means such as a rivet pin 8 or a bolt.

As shown in FIG. 3, the second rotating body 3 is formed by laminating electromagnetic steel sheets, and has a convex shape toward the rotating shaft 4.
A plurality of slits 11 each having an end serving as a magnetic flux shielding groove close to the outer periphery of the second rotating body portion 3 are provided, and the second rotating body portion 3 is configured to have saliency. In addition, slit 1
Reference numeral 1 denotes a gap penetrating in the direction of the rotation axis. A magnetic flux resistor such as a resin or a low-magnetic material may be embedded in the slit. The second rotating body 3 has saliency due to the slits 11 and is driven to rotate only by reluctance torque in synchronization with a magnetic field generated by the stator. Since the second rotating body 3 does not include a permanent magnet that is a magnetic body, no magnet torque is generated.

In the rotor of the present embodiment, the second rotating body 3 is connected to both end faces of the first rotating body 2 via the non-magnetic body 5. The second rotating body 3 is fixed to the same rotating shaft, and the first rotating body 2 and the second rotating body 3 rotate integrally.

A stator 21 around which a winding 22 is wound is disposed outside the rotor, and a current is applied to the winding 22 to generate a magnetic field for rotationally driving the rotor.

The electric motor having such a configuration drives the rotor to rotate by passing a current through the stator. The first rotator 2 and the second rotator 3 are connected so that the maximum torque phase of the first rotator 2 and the maximum torque phase of the second rotator 3 coincide. This further increases the torque at the same current. As shown in FIG. 4, the phase of the first rotator has a maximum torque at an electrical angle of 20 ° (a), and the phase of the second rotator has a maximum torque at an electrical angle of 45 ° (b). However, the rotor in which the second rotating body portion was shifted by 15 ° to obtain the maximum torque at 30 ° was designated as (c). With such a configuration, the output torque of the electric motor can be increased. (D) shows the case where the slits of the first rotating body and the second rotating body are combined at the same position, that is, the first rotating body and the second rotating body are connected in a state where the maximum phases do not match. It can be seen from FIG. 4 that (c) has an increased maximum torque compared to (d).

FIG. 5 shows the configuration of a drive device for an electric vehicle using a hybrid engine. In a hybrid engine in which an electric motor 21 and a gasoline engine 22 as an internal combustion engine are connected, a drive shaft 23 and a rotation shaft of the electric motor 21 are directly connected, and the drive shaft 23 is connected to the gasoline engine 22 by a clutch 24 or the like. I have. Drive shaft 23
When the wheel rotates, the wheel 26 rotates via the differential 25. Such a drive device can connect and rotate the electric motor 21 and the gasoline engine 22, or can cut off the gasoline engine 22. But,
Even if the drive shaft 23 is rotated by the gasoline engine, the drive shaft 23 and the rotary shaft 4 of the electric motor are the same, so that when the gasoline engine 22 is driven to rotate, electricity may flow through the stator of the electric motor 21. Regardless, the rotor of the electric motor rotates.

When the hybrid gasoline engine runs at a constant load with good fuel efficiency, the hybrid gasoline engine is driven to rotate only by the gasoline engine. At this time, the electric motor is not energized. However, since the rotor 1 of the electric motor is fixed to the rotating shaft 4 which is the same as the drive shaft, when driven only by the gasoline engine, the rotor 1 of the electric motor rotates according to the rotation of the gasoline engine.

Since the electric motor of this embodiment is driven not only by magnets but also by using reluctance torque, the amount of the permanent magnet 6 is small in spite of the magnitude of the output torque. That is, since the induced voltage generated when the rotor rotates is small, the iron loss generated in the stator 21 is also small. This is because the induced voltage is generated by the change of the magnetic flux induced by the movement of the permanent magnet provided in the rotor. However, the electric motor of the present embodiment employs a conventional magnet in which a permanent magnet is attached to the surface of the rotor. It has a feature that it has less magnetic flux compared to a permanent magnet synchronous motor that is driven to rotate only by torque. However, the reluctance torque obtained by the salient pole ratio provided by the second rotating body portion 3 and the salient pole ratio provided by the first rotating body portion 2 even though the magnetic flux is reduced is lower than that of the conventional electric motor. An equivalent rotational drive torque can be obtained.

From the standpoint of suppressing the generation of the induced voltage only, the rotor of the electric motor may be a rotor provided with a non-magnetic portion so as to have saliency, and may be rotationally driven only by the reluctance torque. It is suitable. That is, when the motor is not energized, even if the rotating shaft is rotated by the gasoline engine, no induced voltage is generated because the rotor has no permanent magnet. However, with such a configuration, an attempt to obtain the same output torque as a permanent magnet synchronous motor that is driven to rotate using a conventional magnet torque increases the size of the electric motor.

In the current automobile, it is desired that the size of the automobile itself is small and the interior space of the automobile is widened, and the size of the electric motor becomes too large.
It is not preferable that the interior space is cut. Therefore,
The size of the electric motor is increased by using a rotor in which a first rotating body portion 2 having a permanent magnet and a second rotating body portion 3 having a magnetic flux interrupting portion so as to have saliency are connected in a rotation axis direction. And the occurrence of induced voltage can be reduced.

In this embodiment, the second rotating body 3 is
If the motor is a reluctance motor, an axial lamination motor may be used as the synchronous motor. Further, in the first embodiment, the first rotator is sandwiched between the two second rotators, but one first rotator and one second rotator are connected. It may be in a state.

Further, even if the rotating shaft is rotated by the gasoline engine, there is a problem that iron loss is generated. As a cause of rotating the rotating shaft, even if the wheel rotates on a downhill, the iron loss is generated by the present application. Can be suppressed. Further, the internal combustion engine is not limited to a gasoline engine, and the same applies to a diesel engine and a natural gas engine.

FIG. 6 shows another shape of the first rotating body portion. As shown in FIG. 6A, a surface permanent magnet may be attached. FIG. 7 shows another embodiment of the combination of the first rotator and the second rotator.

(Embodiment 2) In the electric motor of Embodiment 2, the thickness of the non-magnetic body 31 becomes narrower as the non-magnetic body 31 extends from the rotation axis to the outside of the rotor, and the axial width of the first rotating body portion becomes larger than the rotation axis. The difference from the first embodiment is that the width becomes wider toward the outer diameter side of the rotor, and the other configuration is the same as that of the first embodiment.

FIG. 8 is a partially enlarged cross-sectional view of a connection portion between the first rotating body portion 32 and the second rotating body portion 33. The first rotator 32 has a permanent magnet 34 embedded in the first rotator 32. At this time, the permanent magnet 34 is embedded in a shape protruding from the rotating shaft 35, and the first rotating body 32 has saliency. The second rotating body portion 33 is provided with a plurality of arc-shaped slits 36 having a shape protruding from the rotating shaft 35 so as to have saliency. The non-magnetic body 31 interposed between the first rotator 32 and the second rotator 33 is wider on the rotation shaft side, and becomes smaller toward the outside of the rotor. The outermost magnetic flux passage 37a is directly connected to the first rotator 32, and the magnetic flux of the first rotator 32 flows through the magnetic flux passage 37a.

In this embodiment, by changing the thickness of the non-magnetic member 31, the amount of magnetic flux is changed from the permanent magnet 34 to the respective magnetic flux paths of the second rotating member 33. Since the first non-magnetic body is designed to independently design the first rotating body and the second rotating body, the magnetic flux generated from the permanent magnet of the first rotating body is generated by the second rotating body. The non-magnetic material is thickened so that it does not flow into the non-magnetic material.
In order to positively use the magnetic flux of the permanent magnet generated in step 4, the thickness of the non-magnetic material of the first embodiment is small.

The magnetic flux generated from the permanent magnet 34 is transmitted to the second rotating body 33 by magnetic flux paths 37a, 37b, 37c, 37.
The amount of magnetic flux flowing through d, 37e, and 37f is inversely proportional to the thickness of the non-magnetic material 31, and is equal to the size of the arrow as shown in FIG. The amount of magnetic flux flowing in the magnetic flux path outside the rotor is large. That is, the thickness of the non-magnetic member 31 is large on the rotating shaft side, and the thickness of the non-magnetic member 31 serves as a magnetic flux resistance. On the other hand, the thickness of the non-magnetic body 31 is small outside the rotor, and the amount of magnetic flux flowing through the magnetic flux passage 37 outside the rotor is large. That is, as shown in FIG. 9, when the magnetic flux generated from the permanent magnet 34 flows through the magnetic flux passage 37 of the second rotating body portion, the magnetic flux is large at the center 37a of the magnetic pole and small at 37f. That is, the distribution of the magnetic flux in the gap generated from the second rotating body portion has a sine wave shape.

When magnet torque is generated in the second rotating body, the magnetic flux distribution from the second rotating body is sinusoidal, so that torque fluctuation is small, controllability is improved, and stable rotational driving is achieved. It can be carried out.

[0039]

According to the first, second and third aspects of the present invention, it is possible to provide a small-sized motor in which the generation of induced voltage is suppressed and the occurrence of iron loss is suppressed.

According to the fourth aspect of the invention, when the engine is driven, the generation of the induced voltage of the non-energized motor can be suppressed, so that the fuel loss can be reduced by suppressing the iron loss.

According to the fifth and sixth aspects of the present invention, the first rotor and the second rotor can be easily designed.

According to the seventh aspect of the present invention, the output torque of the electric motor can be further increased. In the invention according to claim 8, the magnetic flux generated from the second rotating body is a sine wave,
Torque fluctuation is small, controllability is improved, and stable rotational driving can be performed.

According to the ninth aspect of the present invention, it is possible to provide a hybrid engine in which no induced voltage is generated.

According to the tenth and eleventh aspects of the present invention, an electric vehicle with low fuel consumption can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electric motor according to a first embodiment.

FIG. 2 is a diagram showing a first rotating body part.

FIG. 3 is a diagram showing a second rotating body portion.

FIG. 4 is a torque characteristic diagram of the electric motor.

FIG. 5 is a diagram showing a configuration of a drive device of the electric vehicle.

FIG. 6 is a view showing a first rotating body of another embodiment.

FIG. 7 is a sectional view of a rotor according to another embodiment.

FIG. 8 is a sectional view of a rotor according to a second embodiment.

FIG. 9 is a view showing a magnetic flux distribution of the second rotating body.

[Explanation of symbols]

 2 1st rotating body part 3 2nd rotating body part 6 Permanent magnet 11 Magnetic flux shielding groove 21 Stator

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasufumi Kazumi 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 5H111 AA01 BB02 BB06 CC01 CC13 DD05 DD08 DD12 FF05 JJ04

Claims (11)

[Claims] An electric current is supplied to a rotor in which a first rotating body portion provided with a permanent magnet and a second rotating body portion provided with a magnetic flux blocking portion having saliency are connected in a rotation axis direction. And a stator for generating a field for rotationally driving the rotor, wherein a rotation shaft of the rotor is rotated by a rotation driving means. 2. An electric motor in which a rotating shaft of a rotor is rotated by a rotation driving means in a state where no current flows through the stator. 3. The electric motor according to claim 1, wherein the first rotating body has saliency. 4. A hybrid engine comprising: the electric motor according to claim 1; and an internal combustion engine as rotation driving means. 5. The first rotating body and the second rotating body are connected in the direction of the rotation axis, and a non-magnetic body is interposed between the first rotating body and the second rotating body. The electric motor according to claim 1. 6. The electric motor according to claim 1, wherein a first rotating body is interposed between the plurality of second rotating bodies. 7. The electric motor according to claim 1, wherein the phase at which the maximum torque of the first rotator is generated is the same as the phase at which the maximum torque of the second rotator is generated. 8. The first rotating body and the second rotating body are connected in the direction of the rotating shaft, and a rotor is provided between the first rotating body and the second rotating body from the rotating shaft side. 2. The electric motor according to claim 1, wherein a magnetic resistance layer whose outside becomes narrower is interposed. 9. A rotor provided with a magnetic flux cut-off portion having saliency and a stator for generating a magnetic field for driving the rotor by supplying a current, wherein a current is supplied to the stator. A hybrid engine in which the rotating shaft of the rotor is rotated by an internal combustion engine in a state where the rotor is not supplied. 10. An electric vehicle equipped with the hybrid engine according to claim 4. 11. The electric vehicle according to claim 10, wherein a rotor of an electric motor is fixed to a drive shaft of a wheel.