JPH07163111A - Permanent magnet generator - Google Patents

Abstract

PURPOSE:To provide a permanent magnet generator for producing strong magnetic force by dispersing the flux density on the inside of a permanent magnet. CONSTITUTION:A magnetic path ring 4 is press fitted between a rotor 2 and a permanent magnet 9 with the truncated cone type magnetic path part 7, provided at the end of the magnetic path ring 4, projecting from the end lace 21 of the permanent magnet 9. An annular air gap is provided between the permanent magnet 9 and the magnetic path part 7 by a notch 8 made in the magnetic path part 7. Magnetic force of the permanent magnet 9 flows to the magnetic path part 7 and the peripheral flux density is dispersed. Consequently, the magnetic force is enhanced at the outer peripheral part thus realizing a powerful generator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet generator having a permanent magnet as a rotor.

[0002]

2. Description of the Related Art Conventionally, a generator or an electric motor using a permanent magnet as a rotor has a high magnetic flux density of the permanent magnet, so that the output can be extremely effectively increased, and the structure is simple. , Became widely used in industrial equipment. However, since the mechanical strength of the permanent magnet is not high, there is a problem that the permanent magnet is damaged as the rotation of the rotor increases. Therefore, it is necessary to reinforce the outer circumference of the permanent magnet in order to reinforce the mechanical strength of the permanent magnet.
In particular, when the rotor is divided and the permanent magnets are used as its poles, the permanent magnets cannot function as the rotor unless they are sequentially arranged in the circumferential direction and assembled together.

Conventionally, a rotating electric machine disclosed in Japanese Utility Model Laid-Open No. 60-162977 has a centrifugal governor which can change the magnetic flux density of a magnetic circuit formed by a permanent magnet on a rotatable support shaft according to the number of revolutions. It has a magnetic flux density variable mechanism provided, and the permanent magnets are joined in a state of being surrounded by a reinforcing plate.

Further, the AC generator disclosed in Japanese Patent Laid-Open No. 3-251067 discloses a boss portion provided on the outer periphery of a shaft, a pair of protrusions extending from the both ends of the boss portion in the outer peripheral direction, and the protrusion. A rotor having a plurality of claw-shaped magnetic pole portions extending in the axial direction from the outer periphery of the rotor, a stator having a stator winding arranged on the outer periphery of the rotor, a field winding wound on the outer periphery of the boss portion, The permanent magnet is provided so as to abut the projecting portion so that the magnetic flux flows in the same direction as the direction of the magnetic flux flowing in the projecting portion when a current is applied to the field winding.

Further, in Japanese Patent Laid-Open No. 62-272850, a permanent magnet is arranged in the rotor, and a magnetic pole piece is formed to guide the movable magnetic body in the radial direction by the rotation of the rotor in which the movable magnetic body is enclosed. A permanent magnet type rotating machine in which a container for use is provided in a rotor is disclosed.

Further, Japanese Patent Laid-Open No. 3-265451 discloses a power generator. The power generator includes a field winding,
Rotor with a magnetic flux that is generated in the field winding by passing a permanent magnet and current and a magnetic pole that allows the magnetic flux of the permanent magnet to flow, and is placed in opposition to the rotor. A stator having an armature winding that generates a magnetic field and a suppressing unit that controls the output generated in the armature winding of the stator by the magnetic flux of the permanent magnet of the rotor.

[0007]

By the way, the permanent magnet generator uses a permanent magnet as a rotor. The rotor is formed as a multi-pole rotor by forming permanent magnets in an arcuate shape in cross section, and by sequentially arranging and combining these permanent magnets in the circumferential direction with a non-magnetic material interposed, a permanent magnet is formed in a ring shape. ing. However, in the sequentially arranged arc-shaped permanent magnets, the area of the outer peripheral portion is larger than the area of the inner peripheral portion. In particular, the smaller the rotor attached to the rotating shaft having the smaller diameter, the smaller the area of the inner peripheral portion of the permanent magnet compared to the area of the outer peripheral portion. When the rotor is configured using such permanent magnets, the magnetic flux density is limited to the amount passing through the inner peripheral portion, and there is a problem that the power generation efficiency is reduced.

Therefore, an object of the present invention is to solve the above-mentioned problems. When the rotor is composed of a plurality of permanent magnets having an arcuate cross section, the area of the inner peripheral portion of the permanent magnet is smaller than that of the outer peripheral portion. Even if the area is smaller than the area, a ring-shaped magnetic path body press-fitted into the inner peripheral surface of the permanent magnet is provided with a truncated cone-shaped magnetic path portion protruding from the permanent magnet, and the magnetic flux passage is formed by the truncated cone-shaped magnetic path portion. By providing the magnetic force of the permanent magnet to the frustoconical magnetic path portion, the permanent magnet generator capable of securing a strong power generation amount even in a small size is provided.

[0009]

In order to achieve the above object, the present invention is configured as follows. That is,
The present invention relates to a rotor provided with a rotating shaft rotatably supported by a housing, a rotor provided with a permanent magnet having an arc-shaped cross section and spaced in the circumferential direction by a low magnetic permeability member fixed to the rotating shaft, and a rotor of the rotor. A permanent magnet power generator having a stator having an outer periphery fixed to the housing and having a winding wound therein, a ring-shaped magnetic path body press-fitted between the rotor and the rotating shaft, and A permanent magnet type characterized in that it has a frustoconical magnetic path portion formed integrally with the end portion of the ring-shaped magnetic path body and having an outer peripheral portion protruding from the permanent magnet and contacting the end surface of the permanent magnet. Regarding the generator.

Further, in this permanent magnet generator, slits are formed in the frustoconical magnetic path portion so as to be spaced apart in the circumferential direction and extend in the radial direction, and the slits separate the permanent magnets from each other. The fan-shaped end surface of the frustoconical magnetic path portion and the end surface of the permanent magnet are aligned so as to face the low-permeability magnetic body, and the facing surface between the permanent magnet and the frustoconical magnetic path portion is A notch that forms a ring-shaped void is formed.

In this permanent magnet generator, a non-magnetic band is arranged in a groove formed on the outer peripheral surface of the permanent magnet, and the permanent magnets are arranged in a ring shape with the low magnetic permeability material interposed therebetween. It is fixed.

Further, in this permanent magnet type generator, the ring-shaped magnetic path body is composed of a pair of ring-shaped magnetic path portions, and the ring-shaped magnetic path portions are press-fitted from both sides of the permanent magnet, respectively, and are centered in the central portion. A gap is formed between the end faces of the ring-shaped magnetic path portion located.

[0013]

The permanent magnet generator according to the present invention is constructed as described above and operates as follows. That is, this permanent magnet power generator includes a ring-shaped magnetic path body press-fitted between a rotor and the rotary shaft, and a truncated cone integrally formed at an end of the ring-shaped magnetic path body. The magnetic flux path portion is projected from the end face of the permanent magnet, and a ring-shaped air gap is formed between the permanent magnet and the truncated cone magnetic path portion by the notch formed in the truncated cone magnetic path portion. The magnetic force of the permanent magnets flows in the frustoconical magnetic path portion, the magnetic flux density of the circumference is reduced and dispersed, and the magnetic force of the outer peripheral portion is strengthened to construct a strong electric motor or generator. Further, a slit extending in the radial direction is formed at a distance from the frustoconical magnetic path portion to divide the frustoconical magnetic path portion, and a notch formed in the frustoconical magnetic path portion. Since a ring-shaped air gap is formed between the permanent magnet and the frustoconical magnetic path portion by the portion, the magnetic flux of the inner peripheral portion flows through each of the frustoconical magnetic path portions, and the magnetic force is short-circuited. There is no.

Further, in this permanent magnet type generator, since the magnetic flux of the permanent magnet is unlikely to leak to the outside, it does not adversely affect the sensor or the like using magnetic force.

[0015]

Embodiments of the permanent magnet type generator according to the present invention will be described below with reference to the drawings. 1 is a sectional view showing an embodiment of a permanent magnet generator according to the present invention, FIG. 2 is an end view showing a rotor in the permanent magnet generator of FIG. 1, and FIG. 3 shows a ring-shaped magnetic path body. It is a perspective view.

The permanent magnet generator according to the present invention is mainly composed of a rotary shaft 2 rotatably supported by a housing 1 via a pair of bearings 16, a rotary shaft 2 fixed to the rotary shaft 2, and a low magnetic permeability body 10 surrounding the rotary shaft 2. A rotor 3 having permanent magnets 9 spaced apart in the direction, and a stator fixed to the housing 1 and having a coil or winding 6 wound around it with a clearance 29 formed around the rotor 3. 5 is included. Further, the rotary shaft 2 is rotatably supported by the casings 15 and 24 of the transmission 14 via bearings 17. The casing 15 is provided with a pulley 22 directly connected to the engine. The transmission 14 functions as a speed increasing gear composed of a planetary gear mechanism, and has a ring gear 12 fixed to the casing 18 and a sun gear 1 fixed to the rotating shaft 2.
3, and the planetary gear 11 that meshes with the sun gear 13 and the ring gear 12. The casing 24 functions as a carrier for the planetary gear 11, and is attached to, for example, the housing 1 or another rotating body, and the shaft 25 that rotatably supports the planetary gear 11 is fixed. Therefore, the rotation of the pulley 22 rotated by the rotational force from the engine is transmitted to the rotary shaft 2 after being accelerated through the ring gear 12, the planetary gear 11 and the sun gear 13 of the transmission 14.

In this permanent magnet type generator, the rotor 3
Is a pair of ring-shaped magnetic path bodies 4 axially fixed to the rotating shaft 1 by nuts 23, and a plurality (six in the figure) of low magnetic permeability bodies 10 fixed to the outer periphery of the ring-shaped magnetic path body 4. , And a plurality of (six in the figure) permanent magnets 9 each having a fan-shaped cross section, which are circumferentially spaced by a low magnetic permeability member 10. Further, in the rotor 3, since the permanent magnets 9 are fixed between the low magnetic permeability bodies 10, a plurality of (four in the figure) are circumferentially spaced on the outer peripheral surface of the permanent magnet 9 in the longitudinal direction. Grooves 19 are formed, and non-magnetic bands 20 are inserted into these grooves 19 and arranged therein. Fixed to each other.

In particular, this permanent magnet generator has an outer peripheral portion which is integrally formed at the end of the ring-shaped magnetic path body 4 and which projects from the end face 21 of the permanent magnet 9 and contacts the end face 21 of the permanent magnet 9. It is characterized in that it has a truncated cone-shaped magnetic path portion 7 that has. The frusto-conical magnetic path portion 7 is formed with a number of slits 26 that are spaced apart in the circumferential direction and extend in the radial direction, the number of which corresponds to the low magnetic permeability body 10. The slits 26 separate the permanent magnets 9 having a fan-shaped cross section. The fan-shaped end face of the truncated cone-shaped magnetic path portion 7 and the end face of the permanent magnet 9 are aligned so as to face the low magnetic permeability member 10 to be placed. Further, a notch 8 that forms a ring-shaped void is formed on the facing surface between the permanent magnet 9 and the truncated cone-shaped magnetic path portion 7.

The ring-shaped magnetic path body 4 is composed of a pair of ring-shaped magnetic path portions 27. The ring-shaped magnetic path portions 27 are press-fitted from both sides of the permanent magnet 9, respectively, and the ring-shaped magnetic path portions 27 are located in the central portion. A gap 28 is formed between the end faces of the road portion 27. In other words, the pair of ring-shaped magnetic path portions 27 are fixed to the permanent magnet 9 on the rotary shaft 2 in a state of being press-fitted from both sides of the permanent magnet 9.

Since this permanent magnet generator is constructed as described above, it is operated as follows. When the engine is started and the pulley 22 rotates, the rotary shaft 2 rotates at an increased speed through the transmission 14. When the rotating shaft 2 rotates, the magnetic flux generated by the permanent magnet 9 flows through the ring-shaped magnetic path body 4 and the truncated cone-shaped magnetic path portion 7 to the stator 5,
A current is generated in the coil winding 6 to generate electricity.

Since this permanent magnet generator is constructed as described above, the magnetic force of the permanent magnet 9 flows in the conical magnetic path, so that the magnetic flux density in the circumference becomes small and the truncated conical magnetic path portion. It is dispersed through 7, the magnetic force of the outer circumference becomes strong, and a powerful generator is obtained. In particular, since the magnetic flux flows from the inner peripheral portion to the outer peripheral portion through the frustoconical magnetic path portion 7, it is possible to obtain a strong power generation amount even with a small generator. Furthermore, since the notch 8 is formed in the corner of the truncated cone-shaped magnetic path portion 7 and the slit 26 is formed, the magnetic force on the inside is not short-circuited. Further, in this permanent magnet generator, even if the rotor 3 rotates at high speed and a large centrifugal force is generated in the permanent magnet 9, the permanent magnet 9 is fastened by the non-magnetic band 8, so that the permanent magnet 9 is The rotor 9 rotates well without being damaged, and the output is improved with high efficiency.

This permanent magnet type generator is, as described above,
Even if the rotor composed of permanent magnets rotates at high speed, there is no risk of damage to the permanent magnets. For example, a cogeneration engine that converts rotational energy into electrical energy, a turbocharger in an automobile engine, energy It is extremely preferable when applied as a generator such as a recovery device. In that case, the output shaft of an engine such as a cogeneration engine can be incorporated by directly connecting an input shaft such as a pulley of a permanent magnet generator to the output shaft.

[0023]

The permanent magnet generator according to the present invention is constructed as described above and has the following effects.
That is, in this permanent magnet generator, a rotor provided with a permanent magnet having an arcuate cross section is fixed to a rotation shaft rotatably supported by a housing, and a winding is wound around the outer circumference of the rotor. A stator is arranged, a ring-shaped magnetic path body is press-fitted and arranged between the rotor and the rotary shaft, and a truncated cone-shaped magnetic path portion is integrally formed at an end portion of the ring-shaped magnetic path body. , The truncated cone-shaped magnetic path portion is projected from the permanent magnet, and the outer peripheral portion of the truncated cone-shaped magnetic path portion is brought into contact with the end surface of the permanent magnet. It becomes the magnetic path of the inner peripheral part. Therefore, the magnetic flux density is dispersed by the frustoconical magnetic path portion, and the magnetic force of the outer peripheral portion of the permanent magnet becomes strong,
Even small power generators will be able to secure strong power output.

Further, slits extending in the radial direction are formed in the frustoconical magnetic path portion so as to be spaced apart from each other in the circumferential direction, and the slits face the low magnetic permeability bodies that respectively separate the permanent magnets. A fan-shaped end surface of the truncated cone-shaped magnetic path portion and an end surface of the permanent magnet are aligned with each other, and a notch that forms a ring-shaped void is formed on a surface facing the permanent magnet and the truncated cone-shaped magnetic path portion. Since the portion is formed, the inner magnetic force does not short-circuit.

A non-magnetic band is arranged in a groove formed on the outer peripheral surface of the permanent magnet, and the permanent magnets are fixed to each other in a ring shape with the low magnetic permeability material interposed therebetween. The permanent magnet will not be broken even if it rotates at a high speed and a large centrifugal force is generated.

The ring-shaped magnetic path body comprises a pair of ring-shaped magnetic path portions, and the ring-shaped magnetic path portions are press-fitted from both sides of the permanent magnet, respectively, and the ring-shaped magnetic path portion is incorporated into the permanent magnet. Is easy.

This permanent magnet type generator is, as described above,
Since even a small generator can secure a strong amount of power generation, it is extremely preferable to be applied to, for example, a cogeneration engine that converts rotational energy into electric energy. In that case, the cogeneration engine can be incorporated by directly connecting the output shaft of the cogeneration engine to a pulley of a generator / motor having a permanent magnet as a rotor.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a permanent magnet generator according to the present invention.

FIG. 2 is a sectional view showing the rotor taken along the line AA in FIG.

FIG. 3 is a perspective view showing a ring-shaped magnetic path body in the permanent magnet generator of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Rotating shaft 3 Rotor 4 Ring-shaped magnetic path body 5 Stator 6 Winding 7 Frustum-shaped magnetic path part 8 Notch 9 Permanent magnet 10 Low magnetic permeability 16, 17 Bearing 19 Groove 20 Non-magnetic band 21 Permanent magnet End face of

Claims (4)

[Claims] 1. A rotor provided with a rotary shaft rotatably supported by a housing, permanent magnets having an arcuate cross section, which are circumferentially separated by a low magnetic permeability member fixed to the rotary shaft, and the rotor. A permanent magnet generator having a stator fixed to the housing on the outer periphery of and having a winding wound around it, and a ring-shaped magnetic path body press-fitted between the rotor and the rotating shaft, And a frustoconical magnetic path portion that is integrally formed so as to connect the end portion of the ring-shaped magnetic path body and the outer end portion of the permanent magnet and is divided for each of the permanent magnets. A characteristic permanent magnet generator. 2. The frustoconical magnetic path portion is formed with slits that are spaced apart in the circumferential direction and extend in the radial direction, and the slits face the low magnetic permeability bodies that respectively separate the permanent magnets. The fan-shaped end surface of the frustoconical magnetic path portion and the end surface of the permanent magnet are aligned with each other, and a cutout portion forming a ring-shaped void is formed on the opposing surface of the permanent magnet and the frustoconical magnetic path portion. The permanent magnet type generator according to claim 1, wherein the permanent magnet type generator is provided. 3. A non-magnetic band is disposed in a groove formed on the outer peripheral surface of the permanent magnet, and the permanent magnets are fixed to each other in a ring shape with the low magnetic permeability material interposed therebetween. The permanent magnet generator according to claim 1. 4. The ring-shaped magnetic path body comprises a pair of ring-shaped magnetic path portions, the ring-shaped magnetic path portions being press-fitted from both sides of the permanent magnet, respectively, and the ring-shaped magnetic path portion located in the central portion. The permanent magnet generator according to claim 1, wherein a gap is formed between the end faces of the.