Patent Application
20230352994
The present disclosure relates to a magnetic geared rotary electric machine.
Priority is claimed on Japanese Patent Application No. 2020-009938, filed Jan. 24, 2020, the content of which is incorporated herein by reference.
Patent Document 1 (cited below) discloses a magnetic geared rotary electric machine in which a low-speed rotor (first rotor), a high-speed rotor (second rotor), and a stator are coaxially rotatable relative to each other.
When the magnetic geared rotary electric machine is used as, for example, a motor, the low-speed rotor which is an output shaft rotates at a predetermined reduction ratio due to a harmonic magnetic flux by rotating the high-speed rotor by an electromotive force of a coil provided in the stator.
In the magnetic geared rotary electric machine, a magnetic force of a specific frequency is generated based on the number of poles N1 of the low-speed rotor, the number of pole pairs Nh, of the high-speed rotor, and the number of pole pairs Ns of the stator. Among these, a low-frequency magnetic force of N1-Ns contributes to driving the high-speed rotor. On the other hand, a high-frequency magnetic force of N1+Ns does not contribute to driving the high-speed rotor, but rather causes vibration of the stator. The vibration of the stator may lead to noise and fatigue failure. Here, there is an increasing demand for a technique capable of suppressing the vibration of the stator.
The present disclosure has been made to solve the above-described problems and an object thereof is to provide a magnetic geared rotary electric machine that suppresses a vibration.
In order to solve the above-described problems, a magnetic geared rotary electric machine according to the present disclosure includes: a stator which includes a stator core formed in an annular shape centered on an axis, a coil installed inside a slot of the stator core, and a plurality of stator magnets installed inside the stator core at intervals in a circumferential direction about the axis; a first rotor which includes a plurality of pole pieces provided inside the stator at intervals in the circumferential direction of the axis; and a second rotor which includes a rotor core provided inside the first rotor and a plurality of rotor magnets provided in the rotor core at intervals in the circumferential direction, wherein the stator further includes an anti-vibration member that is made of fiber-reinforced plastic and is installed on an inner surface of the stator core.
According to the present disclosure, it is possible to provide a magnetic geared rotary electric machine that suppresses a vibration.
Hereinafter, a magnetic geared rotary electric machine 100 according to a first embodiment of the present disclosure will be described with reference to
The casing 4 is formed in annular shape centered on the axis Ac. A space is formed inside the casing 4. The stator 1 is provided on a surface (casing inner peripheral surface 5A) facing the inside of the radial direction with respect to the axis Ac in the inner surface of the casing 4.
As shown in
The plurality of coils C are attached to a plurality of tooth bodies 72. Each of the coil C is formed by winding a copper wire or the like around the tooth body 72. An area which is surrounded by the back yoke 71, the pair of adjacent tooth bodies 72, and the tooth top end portion 73 is a slot S for accommodating the coil C.
The plurality of stator magnets 1B are arranged on the inner peripheral surface of the stator core 1A, that is, the radially inner surface of the tooth top end portion 73 to be adjacent to each other in the circumferential direction. The stator magnet 1B is a permanent magnet such as a ferrite magnet or a neodymium magnet. The poles of the stator magnets 1B adjacent to each other are different. That is, the stator magnets 1B with different poles are arranged alternately in the circumferential direction. An inner peripheral surface defined by these stator magnets 1B is a cylindrical inner peripheral surface 1S as part of the inner surface of the stator core 1A.
The anti-vibration member 90 is attached to this cylindrical inner peripheral surface 1S. The anti-vibration member 90 is provided to attenuate the vibration generated in the stator core 1A. Specifically, as the anti-vibration member 90, a relatively flexible fiber-reinforced plastic containing an aramid resin or a vector resin is used. In addition, a glass fiber reinforced resin or a carbon fiber reinforced resin can be used as the anti-vibration member 90. Accordingly, the anti-vibration member 90 itself can absorb and attenuate the vibration of the stator core 1A. The anti-vibration member 90 has a cylindrical shape continuing along the cylindrical inner peripheral surface 1S.
As shown in
As shown in
Next, an operation of the magnetic geared rotary electric machine 100 will be described. When the magnetic geared rotary electric machine 100 is used as an electric motor, electric power is first supplied to the coil C from the outside. Accordingly, the coil C is excited. Due to the magnetic force of the coil C, the second rotor 3 rotates around the axis Ac. Further, when the second rotor 3 rotates, the first rotor 2 rotates. The rotation speed of the first rotor 2 is decelerated under a reduction ratio based on the number of poles N1 of the first rotor 2 and the number of pole pairs Nh of the second rotor 3. Specifically, the reduction ratio G is G=N1/Nh.
On the other hand, when the magnetic geared rotary electric machine 100 is used as a generator, a rotational force (torque) around the axis Ac is applied to the rotating shaft 6. Accordingly, the first rotor 2 and the second rotor 3 rotate by the rotation of the rotating shaft 6. As the first rotor 2 and the second rotor 3 rotate, an induced electromotive force is generated in the coil C. By taking out this electric power to the outside, the magnetic geared rotary electric machine 100 can be used as a generator.
Incidentally, in the magnetic geared rotary electric machine 100, a magnetic force of a specific vibration is generated based on the number of poles N1 of the first rotor 2, the number of pole pairs Nh of the second rotor 3, and the number of pole pairs Ns of the stator 1. Among them, a low-frequency magnetic force of N1-Ns contributes to driving of the second rotor 3. On the other hand, a high-frequency magnetic force of N1-Ns does not contribute to driving the second rotor 3, but rather causes vibration of the stator 1. The vibration of the stator 1 may lead to noise and fatigue failure.
Here, in this embodiment, the anti-vibration member 90 is provided on the inner surface (cylindrical inner peripheral surface 1S) of the stator 1. According to this configuration, the anti-vibration member 90 can absorb and attenuate the vibration even when the stator 1 is vibrated. Particularly, since fiber-reinforced plastic is used as the anti-vibration member 90, it is possible to ensure durability as compared with other resin materials not containing fibers. Further, since the anti-vibration member 90 is made of fiber-reinforced plastic, it is also possible to suppress eddy current and heat generation unlike the case of using other metal materials. As a result, it is possible to more stably operate the magnetic geared rotary electric machine 100.
Further, according to the above-described configuration, the anti-vibration member 90 is provided on the cylindrical inner peripheral surface 1S defined by the stator magnet 1B. That is, the anti-vibration member 90 is provided on the entire circumferential area on the inner peripheral side of the stator 1. Accordingly, it is possible to stably absorb and attenuate the vibration of the stator 1 over the entire circumferential area.
The first embodiment of the present disclosure has been described above. Additionally, various changes and modifications can be made to the above configuration as long as it does not deviate from the gist of this disclosure. For example, as shown in
According to this configuration, it is possible to reduce the possibility that heat stays in the stator 1 through the hole portion h. As a result, it is possible to more stably operate the magnetic geared rotary electric machine 100.
Further, as shown in
In this configuration, a gap is formed between the anti-vibration pieces P. Through this gap, the possibility that heat stays in the stator 1 can be reduced. As a result, it is possible to more stably operate the magnetic geared rotary electric machine 100.
Next, a second embodiment of the present disclosure will be described with reference to
At least the bottom surface 8A is provided with a thin plate-shaped anti-vibration member 91. In this embodiment, the anti-vibration member 91 is also provided on the side surface 8B in addition to the bottom surface 8A. That is, the stator magnet 1B is surrounded by these anti-vibration members 91.
According to the above-described configuration, the anti-vibration member 91 can absorb and attenuate the vibration generated in the stator 1. Further, it is possible to ensure a large clearance between the stator 1 and the first rotor 2 as compared with a case in which the anti-vibration member is provided between the stator 1 and the first rotor 2. As a result, it is possible to more stably operate the magnetic geared rotary electric machine 100.
The second embodiment of the present disclosure has been described above. Additionally, various changes and modifications can be made to the above configuration as long as it does not deviate from the gist of this disclosure. For example, the anti-vibration member 91 described in the second embodiment and the anti-vibration member 90 described in the first embodiment can be used in combination.
Next, a third embodiment of the present disclosure will be described with reference to
According to the above-described configuration, since the wall surface 2S of the slot S is provided with the anti-vibration member 92, it is possible to absorb and attenuate the vibration generated in the stator 1. Further, since the anti-vibration member 92 is firmly pressed against the wall surface 2S by the coil C, it is possible to reduce the possibility that the anti-vibration member 92 may fall off.
The third embodiment of the present disclosure has been described above. Additionally, various changes and modifications can be made to the above configuration as long as it does not deviate from the gist of this disclosure. For example, at least one of the anti-vibration member 92 described in the third embodiment, the anti-vibration member 91 described in the second embodiment, and the anti-vibration member 90 described in the first embodiment can be used in combination.
The magnetic geared rotary electric machine 100 described in each embodiment can be summarized as follows, for example.
(1) The magnetic geared rotary electric machine 100 according to a first aspect includes: the stator 1 which includes the stator core 1A formed in an annular shape centered on the axis Ac, the coil C installed inside the slot S of the stator core 1A, and the plurality of stator magnets 1B installed inside the stator core 1A at intervals in the circumferential direction about the axis; the first rotor 2 which includes the plurality of pole pieces 2P provided inside the stator 1 at intervals in the circumferential direction of the axis Ac; and the second rotor 3 which includes the rotor core 3A provided inside the first rotor 2 and the plurality of rotor magnets 3B provided in the rotor core 3A at intervals in the circumferential direction, wherein the stator 1 further includes the anti-vibration member 90 that is made of fiber-reinforced plastic and is installed on the inner surface of the stator core 1A.
According to the above-described configuration, the anti-vibration member 90 can absorb and attenuate the vibration even when the stator 1 is vibrated. Particularly, since fiber-reinforced plastic is used as the anti-vibration member 90, it is possible to ensure durability as compared with other resin materials not containing fibers. Further, since the anti-vibration member 90 is made of fiber-reinforced plastic, it is also possible to suppress eddy current and heat generation.
(2) In the magnetic geared rotary electric machine 100 according to a second aspect, the stator core 1A includes the cylindrical inner peripheral surface 1S which is defined by the plurality of stator magnets 1B as the inner surface of the stator core, and the anti-vibration member 90 is placed on the cylindrical inner peripheral surface 1S.
According to the above-described configuration, the anti-vibration member 90 is provided on the cylindrical inner peripheral surface 1S defined by the stator magnet 1B. That is, the anti-vibration member 90 is provided in the entire circumferential area on the inner peripheral side of the stator 1. Accordingly, it is possible to stably absorb and attenuate the vibration of the stator 1 over the entire circumferential area.
(3) In the magnetic geared rotary electric machine 100 according to a third aspect, the anti-vibration member 90b is provided with the plurality of hole portions h penetrating the anti-vibration member 90b in the radial direction with respect to the axis.
According to the above-described configuration, the anti-vibration member 90b is provided with the plurality of hole portions h. Through this hole portion h, the possibility that heat stays in the stator 1 can be reduced. As a result, it is possible to more stably operate the magnetic geared rotary electric machine 100.
(4) In the magnetic geared rotary electric machine 100 according to a fourth aspect, the anti-vibration member 90c includes the plurality of anti-vibration pieces P arranged at intervals in the direction of the axis Ac.
According to the above-described configuration, the anti-vibration member 90c is composed of the plurality of anti-vibration pieces P. A gap is formed between the anti-vibration pieces P. Through this gap, the possibility that heat stays in the stator 1 can be reduced. As a result, it is possible to more stably operate the magnetic geared rotary electric machine 100.
(5) In the magnetic geared rotary electric machine 100 according to a fifth aspect, the stator core 1A is provided with the plurality of cavities 8 which accommodate the stator magnet 1B, are arranged at intervals in the circumferential direction, and include the bottom surface 8A facing the radial inside as the inner surface of the stator core, and the anti-vibration member 91 is installed at least on the bottom surface 8A.
According to the above-described configuration, it is possible to absorb and attenuate the vibration generated in the stator 1 by the anti-vibration member 91. Further, it is possible to ensure a large clearance between the stator 1 and the first rotor 2 as compared with a case in which the anti-vibration member is provided between the stator 1 and the first rotor 2. As a result, it is possible to more stably operate the magnetic geared rotary electric machine 100.
(6) In the magnetic geared rotary electric machine 100 according to a sixth aspect, the anti-vibration member 92 is provided between the wall surface 2S of the slot S as the inner surface of the stator core and the coil.
According to the above-described configuration, since the anti-vibration member 92 is provided on the wall surface 2S of the slot S, it is possible to absorb and attenuate the vibration generated by the stator 1. Further, since the anti-vibration member 92 is firmly pressed against the wall surface 2S by the coil C, it is possible to reduce the possibility that the anti-vibration member 92 may fall off.
According to the present disclosure, it is possible to provide a magnetic geared rotary electric machine that suppresses a vibration.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-009938 | Jan 2020 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/001771 | 1/20/2021 | WO |
