CN104067483B - Synchronous motor - Google Patents

Abstract

The present invention provides the rotor of a kind of synchronous motor, and including the permanent magnet (1) of high magnetic force, it is configured at rotor surface in the form of a ring, and outer peripheral face is opposite with stator core (4)；And permanent magnet (2), it is in the form of a ring, magnetic force is relatively low compared with permanent magnet (1) and is orientated for polar anisotropic, and it being embedded with permanent magnet (1) in the way of its outer peripheral face two ends on the rotary shaft direction surrounding permanent magnet (1) and inner peripheral surface side, the length on its rotary shaft direction is longer than stator core (4).

Description

Synchronous motor

Technical field

The present invention relates to a kind of synchronous motor.

Background technology

In the case of the rotor of synchronous motor uses high magnetic force Magnet, owing to rare earth element magnet is price The highest material, so in order to suppress its usage amount and relatively thin with wall thickness the most as far as possible Shape is used.Additionally, in the case of the motor for aerator purposes, owing to blade is straight Connect and be arranged in the rotary shaft of motor use, if so the torque of motor output produces pulsation, then The reason producing noise is become, therefore with the magnetic easily producing torque pulsation based on reluctance torque by blade Ferrum embedded (IPM:Interior Permanent Magnet) structure is compared, and uses Magnet more It is configured at the structure of rotor surface (SPM:Surface Permanent Magnet).In this case Rotor, general use following structure: make the soft magnetic materials such as ferrum as back yoke, configure at rotor surface The tile-type Magnet (such as patent documentation 1,2) of relatively thin ringshaped magnet or arc-shaped.

Additionally, in the case of the external diameter of motor is more than the motor that axial dimension becomes flat, turning When the axial length value of son is bigger than the laminated thickness of stator core, rotor not opposite with stator core The amount that interlinks in stator of the magnetic flux of part motor characteristic is affected greatly, so in most cases The axial dimension value making the permanent magnet of rotor is bigger than the laminated thickness of stator core.

But, in the case of the axial dimension making permanent magnet is more than stator core, not with stator core There is more non magnetic space (air) at magnet surface in opposite part, the pcrmeability of Magnet declines, The magnetic force causing Magnet to produce declines.In the case of the rotor using rare earth element magnet, owing to using relatively Thin permanent magnet, declines bigger so above-mentioned because pcrmeability declines the magnetic force caused.Therefore, even if Increase the axial length of rotor of permanent magnet relative to the laminated thickness of stator, its effect is relative to material The increase of material cost also reduces.

There is the situation being made up of rotor in the axial direction multiple different structures or ferromagnetic material, and have use The rare-earth sintered magnet of high magnetic force and the rotor (such as patent documentation 3,4) of ferrite sintered magnet. The many employings of manufacture method of rare-earth sintered magnet are cut to rule after sintering out bigger magnet piece The method of shaped, therefore to the manufacturing cost of suppression Magnet, adds with writing board shape as a rule To utilize.Therefore, in the case of utilizing in the rotor of synchronous motor, use at soft magnetism iron core more Middle IPM mode magnet insertion holes being set and configuring permanent magnet at internal rotor.Additionally, ferrite Sintered magnet is in the more high purposes of speed, in order to prevent centrifugal force from causing Magnet to disperse, too The structures using IPM mode more.

But, in the case of the rotor of IPM structure, owing to existing as iron core between adjacent magnetic pole Soft magnetic material, so there is a large amount of magnetic flux short-circuit with adjacent magnetic pole through this part.At ferrum oxygen In the case of body sintered magnet, owing to its magnetic force is relatively low compared with rare-earth sintered magnet, so between magnetic pole Magnetic flux short circuit impact bigger than rare earth element magnet.It is being configured at not opposite with stator core turning In the case of two ends on sub-direction of principal axis, owing to the outside of rotor surface is air, so magnetic resistance increases, Pcrmeability declines, and the magnetic flux produced from Magnet declines.Magnetic flux in the magnetic intereelectrode short-circuit of internal rotor will not Because being a greater impact with or without stator core, therefore the magnetic flux change of short circuit is less, as its result, Magnetic flux in internal rotor short circuit increases relative to the ratio of the magnetic flux produced by Magnet, it is difficult to effectively Utilize the magnetic force of Magnet.

In order to improve the performance of rotor, have use the higher rare earth element magnet of magnetic force situation, but due to The price of material is higher, so existing, rare earth element magnet is encased in the rotor that is made up of low magnetic force Magnet Method (such as patent documentation 5,6) in a part.

But, in the case of the structure described in patent documentation 5, owing to needing to prevent the back yoke of stator Magnetic saturation is produced so that flux leakage is to the outside of motor because of the permanent magnet of high magnetic force, so nothing Method obtains the highest magnetic force.Additionally, in the case of using the structure described in patent documentation 6, by A part of magnetic force in circumference strengthens because of high magnetic force Magnet, so cause the magnetic flux density of rotor surface Distribution waveform greatly distortion, easily produces torque pulsation when motor operation, become generation vibration and The reason of noise.

In patent documentation 7, record and realize high property by the low magnetic force Magnet of combination and high magnetic force Magnet The rotor of energyization.Use the relatively low Magnet of magnetic force in the inner side of this rotor, but to have polarity each for this Magnet Anisotropy is orientated, by flux concentrating effect near pole center, even the Magnet that magnetic force is relatively low, It also is able to obtain higher magnetic force.The magnetic of high magnetic force is had in the periphery of this Magnet i.e. surface configuration of rotor Ferrum.The Magnet of high magnetic force as such in rare earth element magnet, owing to material price is higher, so in order to suppress Usage amount, generally uses the high magnetic force Magnet that thickness is thin, but in the case of this rotor, due to magnetic The inner side of ferrum is the ferromagnetic material that magnetic force is relatively low, so the pcrmeability of the Magnet of high magnetic force can reduce, it is impossible to Obtain enough magnetic force.In the case of this rotor, by the magnetic at inner side configuration polar anisotropic Ferrum, it is possible to supplement the amount that the magnetic force of high magnetic force Magnet declines, it is thus achieved that the highest magnetic force.

But, as it has been described above, relatively thin high magnetic force Magnet is when pcrmeability is relatively low, it is difficult to obtain Sufficiently magnetic force, is therefore being arranged in situation (rotor axial of not opposite with stator part Size is more than the situation of stator) under, typically can not obtain and increase the raising of corresponding magnetic force, sexual valence with size Than declining.

Patent documentation 1: Japanese Unexamined Patent Publication 2005-312166 publication

Patent documentation 2: Japanese Unexamined Patent Publication 2009-142144 publication

Patent documentation 3: Japanese Unexamined Patent Publication 2005-304204 publication

Patent documentation 4: Japanese Unexamined Patent Publication 2010-68600 publication

Patent documentation 5: Japanese Patent Publication 7-3278 publication

Patent documentation 6: Japanese Unexamined Patent Publication 9-205746 publication

Patent documentation 7: Japanese Unexamined Patent Publication 2011-87393 publication

Summary of the invention

The present invention completes in view of the foregoing, even if its object is to provide a kind of high magnetic reducing high price The usage amount of power Magnet also is able to obtain the synchronous motor of enough magnetic flux.

In order to solve the problems referred to above, realize goal of the invention, the synchronous motor that the present invention relates to, its feature It is, including: rotor, described rotor includes: the 1st permanent magnet, and it is configured at and turns in the form of a ring Sub-surface；With the 2nd permanent magnet, its in the form of a ring, magnetic characteristic is relatively low compared with described 1st permanent magnet, And at its outer peripheral face to surround the two ends on the rotary shaft direction of described 1st permanent magnet and inner peripheral surface side Mode be configured with described 1st permanent magnet；And stator, described stator includes: stator core, institute State stator core opposite with the outer peripheral face of described 1st permanent magnet, the described rotation of described stator core Length on direction of principal axis is longer than the length on the described rotary shaft direction of described 1st permanent magnet, and compares institute State the length on the described rotary shaft direction of the 2nd permanent magnet short, described 2nd permanent magnet be formed as with The polar anisotropic orientation that multiple pole pairs of described rotor are answered.

According to the present invention, even if the usage amount playing the 1st permanent magnet of the high magnetic force reducing high price also can Enough obtain the effect of enough magnetic flux.

Additionally, for the 2nd permanent magnet, flux concentrating can be made in pole center by making it be orientated to Polar anisotropic, although magnetic force is relatively low is but obtained in that more magnetic flux.Additionally, by increasing the The thickness of 2 permanent magnets, though distant away from stator, it is also possible to the decline of suppression magnetic flux density, More effectively obtain magnetic flux.

Accompanying drawing explanation

Fig. 1 is the longitudinal section of the structure of the synchronous motor representing the rotor using embodiment 1 to relate to Figure.

Fig. 2 is the A-A cross-sectional view of the rotor in Fig. 1.

Fig. 3 is the B-B cross-sectional view of the rotor in Fig. 1.

Fig. 4 is the rotor that the induced voltage of the rotor 6 relating to embodiment 1 relates to existing structure The figure that induced voltage compares.

Fig. 5 is the figure of the manufacture method of the rotor representing that embodiment 2 relates to.

Fig. 6 is the figure of the manufacture method of the rotor representing that embodiment 3 relates to.

Fig. 7 is the figure of the manufacture method of the rotor representing that embodiment 4 relates to.

Symbol description

1,1a, 2,2a～2f permanent magnet

3 stators

4 stator cores

5 windings

6 rotors

7 rotary shafts

Detailed description of the invention

Below, based on accompanying drawing, the embodiment of the synchronous motor that the present invention relates to is carried out specifically Bright.Additionally, the present invention is not limited to implementation below.

Embodiment 1

The rotor of synchronous motor of the present embodiment is illustrated.Fig. 1 is to represent this reality of use The longitudinal section of the structure of the synchronous motor of the rotor that the mode of executing relates to.Fig. 2 is the rotor in Fig. 1 A-A cross-sectional view.Fig. 3 is the B-B cross-sectional view of the rotor in Fig. 1.A-A cross section and B-B are horizontal Cross section is the cross section vertical with the rotary shaft direction of rotor.Synchronous motor bag of the present embodiment Including: stator 3, it is circular；And rotor 6, it is can be arranged in this stator in the way of rotating The inner side of 3, and heart portion is provided with rotary shaft 7 wherein.

Stator 3 includes: stator core 4, and it is formed by laminated electromagnetic steel plate in the form of a ring；And Winding 5, it is wound in this stator core 4.In the inside of stator core 4, in the way of can rotating It is configured with rotor 6.At stator core 4, within it week side is circumferentially provided with multiple teeth portion (not along whole Diagram), it is the core portion of overshooting shape, rolls up in the groove portion (not shown) as the space between teeth portion It is wound with the winding 5 for applying electric current from outside.Winding 5 is concentrated and is wound in each teeth portion.

Rotor 6 includes 2 kinds of permanent magnets 1,2 that magnetic characteristic is different.Here, permanent magnet 1 ( 1 permanent magnet) represent high magnetic force permanent magnet, e.g. mischmetal class Magnet forms with resin Binding magnet, rare earth element magnet uses the material such as NdFeB or SmFeN.Additionally, resin material uses The materials such as nylon, PPS (Polyphenylene sulfide, polyphenylene sulfide) or epoxy resin.Forever Magnet 2 (the 2nd permanent magnet) represents the permanent magnet of low magnetic force, such as use ferrite magnet and The binding magnet of mixed with resin.The resin material wherein used is identical with above-mentioned resin material.Turn The axial length (length in the axial direction of rotary shaft 7) of son 6 is more than the laminated thickness (stator of stator 3 The axial length of iron core 4).

With reference to Fig. 1～Fig. 3, the configuration structure of permanent magnet 1,2 is illustrated.Permanent magnet 1 Being ring-type, its outer peripheral face is opposite with stator core 4.The axial length of permanent magnet 1 compares stator The axial length of iron core 4 is short.The axial both ends of the surface of permanent magnet 1 and inner peripheral surface are by permanent magnet 2 Surround.That is, near the axially central authorities of the outer peripheral face of permanent magnet 2, it is formed along whole circumference For loading the groove of permanent magnet 1, permanent magnet 1 is configured in this groove, becomes and is embedded forever The form of the outer peripheral face of Magnet 2.Additionally, permanent magnet 1 configures coaxially with permanent magnet 2. So, following structure is formed: join near the outer circumferential side and axial central authorities of ring-type permanent magnet 2 It is equipped with permanent magnet 1, is configured with permanent magnet at the axial both ends of permanent magnet 1 and inner peripheral surface side 2.Additionally, permanent magnet 1,2 forms the same cylindric outer peripheral face of rotor 6, outside rotor 6 Side face is in the axial direction by the outer peripheral face of permanent magnet 1 and clips the permanent magnetic of this outer peripheral face in the axial direction The outer peripheral face of ferrum 2 is constituted.

As in figure 2 it is shown, the magnetic pole that permanent magnet 1 such as has with rotor 6 makes Magnet accordingly Thickness change, shape in uneven thickness.That is, make near the center P of magnetic pole (radially ) thickness increase improves magnetic force, and make the lower thickness of interpolar Q, thus uniform with thickness Ringshaped magnet compare and be obtained in that more magnetic flux.Additionally, inside the Magnet of permanent magnet 1 Orientation such as become close to polar anisotropic be orientated.The periphery of permanent magnet 2 is with forever The shape that the inner circumferential shape of Magnet 1 is corresponding.

The polar anisotropic orientation that permanent magnet 2 is answered for example formed as the pole pair with rotor 6. Permanent magnet 1 is relatively thin Magnet compared with permanent magnet 2, owing to not using soft magnetism iron core As back yoke, so the pcrmeability of Magnet is relatively low, for permanent magnet 1 monomer, and there is the back of the body The situation of yoke is compared, and the magnetic flux produced at rotor surface is relatively low.But, due to permanent magnet 2 It is present in the inner side of permanent magnet 1, so reality is permanent magnet at the magnetic flux that rotor surface obtains 1 and the magnetic flux that produces respectively of permanent magnet 2 be added obtained by amount, it is possible to obtain and employ forever The performance that the structure of Magnet 1 monomer and back yoke is close for a long time.Additionally, due to permanent magnet 2 is formed as Polar anisotropic is orientated, so the effective thickness of the Magnet of magnetic poles is more than the thickness in size Degree (external diameter-internal diameter), even if distant away from stator core 4, the pcrmeability of Magnet also declines Must lack, although and distant away from stator core 4, but magnetic flux declines few.

If permanent magnet 1 is arranged in not opposite with stator core 4 position, then permanent magnetic The outside of ferrum 1 is surrounded by nonmagnetic substance and air, and therefore magnetic resistance increases, and pcrmeability declines, and And the magnetic flux occurring in surface declines to a great extent.Therefore, at the axial dimension expanding permanent magnet 1 In the case of, although adding size, but the increase of magnetic flux is less, cost performance is deteriorated.

Therefore, axial end portion at rotor 6 uses as shown in Figure 3 and is only made up of permanent magnet 2 Structure.Permanent magnet 2 such as uses ferritic binding magnet, and is formed as and the magnetic of rotor 6 Extremely corresponding polar anisotropic orientation.In figure 3, arrow polar anisotropic is shown Differently-oriented directivity.The Magnet of polar anisotropic, owing to the effective thickness of Magnet described above can take Higher value, so at the axial end portion of not opposite with stator core 4 rotor 6, it is also possible to Rotor surface produces bigger magnetic flux.

As it has been described above, in the present embodiment, in the structure of synchronous motor, at the magnetic of Magnet Conductance can obtain part opposite with stator core 4 near the axially central authorities of the rotor 6 of high value, The permanent magnet 1 of configuration high magnetic force, the axial end portion of the stator core 4 easily declined at pcrmeability is attached Closely, although but the relatively low permanent magnet 2 with polar anisotropic orientation of configuration magnetic force, thus can Even if the usage amount accessing the permanent magnet 1 reducing high price and high magnetic force also is able under rejection characteristic The synchronous motor of fall.

Then, the running to present embodiment illustrates.Fig. 4 is to of the present embodiment turn The figure that the induced voltage of the rotor that the induced voltage of son 6 relates to existing structure compares.Concrete and Speech, in the case of the laminated thickness (L3) making stator core 4 is 15mm, to by having by scheming The induced voltage that the synchronous motor of rotor 6 that the combination of the structure of 2 and Fig. 3 is constituted obtains with by tool The induced voltage having the existing synchronous motor of the rotor being only made up of the structure of Fig. 2 to obtain compares. That is, the rotor that existing structure relates to, it has the structure of Fig. 2 with axially vertical arbitrary cross section, and And the axial length that is configured to permanent magnet 1 is equal with the axial length of permanent magnet 2.

In the diagram, transverse axis represents the axial dimension of the structure division shown in Fig. 2, i.e. permanent magnet 1 Axial length.Here, it is shown that the entire axial length of rotor 6 is fixed (18mm), taken permanent magnet on transverse axis 1 axial length time curve (L1, L2).L1 represents the rotor 6 of present embodiment, and L2 represents existing knot The rotor that structure relates to.Additionally, due to the axial dimension of rotor is fixed, so deducting figure from this fixed dimension The axial dimension (i.e. the axial length of permanent magnet 1) of the structure division of 2 and the knot that size is Fig. 3 that obtains The size of structure part.Additionally, in the diagram, it is located at the laminated thickness (L3) of stator core and existing knot The faradism obtained in the situation (i.e. the intersection point of L2 Yu L3) that the axial length of the rotor that structure relates to is identical Pressure is 100%, if the longitudinal axis is induced voltage ratio.

As shown in Figure 4, in the rotor that existing structure relates to, at the axle of the permanent magnet 1 making terres rares When length and stator core 4 are all 15mm, induced voltage ratio is 100%, on the other hand, is using In the case of rotor 6 of the present embodiment, induced voltage ratio becomes 100% at terres rares The when of the axial length of permanent magnet 1 nearly 11mm, although the axial length of rotor 6 has grown 3mm, But the volume of permanent magnet 1 decreases about 30% compared with existing structure.Due to rare earth element magnet (forever For a long time Magnet 1) and the material unit price difference more than 10 times of ferrite magnet (permanent magnet 2), so root According to present embodiment, although the axial length of rotor 6 increases, the usage amount of ferrite magnet increases, but Being from the point of view of material holistic cost, cost reducing effect is sufficiently large.

As described above, in the present embodiment, at the table of the rotor 6 opposite with stator 3 Side, face configures the permanent magnet 1 (such as rare earth element magnet) of two kinds of different Magnet of magnetic characteristic, i.e. high magnetic force With the permanent magnet 2 (such as ferrite magnet) of low magnetic force, and use permanent magnet 1 is embedded in forever The form of the axially central authorities vicinity of the outer peripheral face of Magnet 2 for a long time so that at the axial two ends of permanent magnet 1 Outside and radially inner side be configured with permanent magnet 2, and then make permanent magnet 2 be oriented to polarity respectively to different Property.

According to present embodiment, it is possible to realize the rotor of such synchronous motor: reduce the high magnetic of high price The usage amount of the permanent magnet 1 (rare earth element magnet) of power, the material cost of suppression motor but can obtain Obtain magnetic flux enough.

Additionally, at permanent magnet 2, by carry out making flux concentrating in pole center polarity respectively to Opposite sex orientation, it is possible to obtain more magnetic flux from low magnetic force Magnet.Additionally, by making permanent magnet 2 Thickness increases, though distant away from stator 3, it is also possible to the decline of suppression magnetic flux density, more effectively Ground obtains the magnetic flux of permanent magnet 2.

Additionally, in the case of the synchronous motor of built-in drive circuit, if rotor exists conductivity Higher soft magnetic material, then via stator core, rotor, rotary shaft, drive circuit the height produced Frequently electric current (shaft current) readily flows to rolling bearing, easily becomes the reason of galvanic corrosion (electric discharge).This reality Execute the rotor 6 of mode, owing to rotor 6 need not use soft magnetic material, it is possible to reduce shaft current The reason of flowing.

Embodiment 2

Fig. 5 is the figure of the manufacture method representing rotor of the present embodiment.The rotor of present embodiment Structure identical with the rotor 6 of embodiment 1.That is, the rotor of present embodiment is by Fig. 2 and Fig. 3 Structure combination constitute rotor 6.About permanent magnet 1,2, as explained in Embodiment 1, Such as can be namely to binding magnet.

The permanent magnet 2 of the permanent magnet 2 and Fig. 3 of Fig. 2 can be identical material, Them can be made well to form as one, but permanent magnet 2 be have near axial central authorities for , therefore there is the part (concavity that external diameter diminishes in the structure in the concavity space of configuration permanent magnet 1 Point).In this case, owing to cannot take out from mould, so permanent magnet 2 is difficult to Carry out the molding making entirety be integrally forming.Additionally, if it is intended to after formerly making permanent magnet 1 molding, Make permanent magnet 2 one-body molded by insert molding (insert molding), the most relatively thin forever Magnet 1 is subject to the probability crushed from the briquetting pressure of internal side diameter higher when molding for a long time.

Therefore, in the present embodiment, shape and Fig. 3 of Fig. 2 of rotor 6 are carried out respectively The molding of shape.Details is as described below.First, such as made forever by injection mo(u)lding Magnet 1 and configuration annular permanent magnnet 2a one-body molded (Fig. 5 (a)) within it for a long time.Forever Magnet 2a is made up of the material identical with permanent magnet 2, has identical magnetic characteristic.Permanent magnet 2a be equivalent to permanent magnet 2 is positioned at the inner peripheral surface side of permanent magnet 1 and axially on allocation position The part overlapping with permanent magnet 1.

Additionally, such as make annular permanent magnnet 2b, 2c separately molding (figure by injection mo(u)lding 5(a)).Permanent magnet 2b, 2c are made up of the material identical with permanent magnet 2, have identical Magnetic characteristic.Permanent magnet 2b, 2c are identical cross sectional shape, and its internal diameter is with permanent magnet 2a's Internal diameter is equal, and its external diameter is equal with the external diameter of permanent magnet 1.Permanent magnet 2b is equivalent to permanent magnetic Ferrum 2 is configured at the part in the outside of one end of permanent magnet 1, permanent magnet 2c phase in the axial direction Part when the outside of the other end being configured at permanent magnet 1 in permanent magnet 2 in the axial direction.

Then, by permanent magnet 2b (the 2nd magnet component) and permanent magnet 2c (the 3rd magnet part Part) will permanent magnet 2a (1st magnet component) integrated with permanent magnet 1 from axial both sides Be clipped in the middle, make they in the axial direction superposition and be bonded with each other, it is possible to manufacture its structure and reality Execute the rotor (Fig. 5 (b)) that the rotor 6 of mode 1 is identical.In this case, by by 3 Permanent magnet 2a～2c engages in the axial direction and constitutes permanent magnet 2.

According to present embodiment, permanent magnet 2 is divided into permanent magnet 2a, permanent magnet 2b With permanent magnet 2c, and make permanent magnet 1 and permanent magnet 2a, permanent magnet 2b, Yi Jiyong Magnet 2c separately molding for a long time manufactures, and it is possible to manufacture the rotor 6 of embodiment 1.

Additionally, due to permanent magnet 2a～2c separately molding can be made, so also being able to point Shi Jia not be suitable for the polar anisotropic orientation of each permanent magnet, the alignment magnetic field of mould It also is able to be adjusted accordingly with each permanent magnet.

Embodiment 3

Fig. 6 is the figure of the manufacture method representing rotor of the present embodiment.The rotor of present embodiment Structure identical with the rotor 6 of embodiment 1.That is, the rotor of present embodiment is by Fig. 2 and Fig. 3 Structure combination constitute rotor 6.About permanent magnet 1,2, as explained in Embodiment 1, Such as can be namely to binding magnet.

Detailed methods of fabrication is as described below.First, such as permanent magnet 2d mono-is made by injection mo(u)lding Body formed (Fig. 6 (a)), permanent magnet 2d is equivalent to make the permanent magnet of explanation in embodiment 2 The parts that 2a and permanent magnet 2c is one-body molded and obtains.Permanent magnet 2d by with permanent magnet 2 Identical material is constituted, and has identical magnetic characteristic.That is, permanent magnet 2d is to pass through following manner The parts obtained: make to be positioned in the permanent magnet 2 of embodiment 1 inner peripheral surface side of permanent magnet 1 And allocation position on the axially part (part 1) overlapping with permanent magnet 1 and in the axial direction The part (part 2) being arranged in the outside of one end of permanent magnet 1 is one-body molded.

Then, make permanent magnet 1 one-body molded with permanent magnet 2d by insert molding, to be formed The form (Fig. 6 (b)) that permanent magnet 1 is embedded in the part 1 of permanent magnet 2d.Additionally, Such as make ring-type permanent magnet 2e with monomer molding (Fig. 6 (b)) additionally by injection mo(u)lding.Forever Magnet 2e is made up of the material identical with permanent magnet 2 for a long time, has identical magnetic characteristic.Permanent magnetic The internal diameter of ferrum 2e is equal with the internal diameter of permanent magnet 2d, outside its external diameter is with the maximum of permanent magnet 1 Footpath is equal.

Then, in the way of permanent magnet 1 is configured at joint face, will be with permanent magnet 1 one The permanent magnet 2d (the 1st magnet component) of molding and permanent magnet 2e (the 2nd magnet component) exists Axially go up superposition and be bonded with each other, it is possible to rotor 6 phase manufacturing its structure with embodiment 1 Same rotor (Fig. 6 (b)).In this case, it is possible to by integrated with permanent magnet 1 Permanent magnet 2d and permanent magnet 2e both parts manufacture rotor 6.Permanent magnet 2 is by permanent magnetic Ferrum 2d and permanent magnet 2e is constituted.

According to present embodiment, owing to the parts constituting the permanent magnet 1,2 of rotor 6 can be subtracted It is 2 less, it is possible to reduce number of components, it is possible to cut down the processing cost manufactured.

Embodiment 4

Fig. 7 is the figure of the manufacture method representing rotor of the present embodiment.The rotor of present embodiment Structure identical with the rotor 6 of embodiment 1.That is, the rotor of present embodiment is by Fig. 2 and Fig. 3 Structure combination constitute rotor 6.About permanent magnet 1,2, as explained in Embodiment 1, Such as can be namely to binding magnet.

Detailed methods of fabrication is as described below.First, such as permanent magnet 2f mono-is made by injection mo(u)lding Body formed (Fig. 7), permanent magnet 2f is equivalent to the permanent magnet of explanation in embodiment 2 A wherein side and permanent magnet 2c after 2a has carried out decile segmentation in the axial direction are one-body molded and obtain The parts arrived.Permanent magnet 2f is made up of the material identical with permanent magnet 2, has identical magnetic Characteristic.That is, permanent magnet 2f is formed by following part merging: make the permanent magnet of embodiment 1 Be positioned in 2 permanent magnet 1 inner peripheral surface side and axially on allocation position overlapping with permanent magnet 1 Part be split into two halves in the axial direction after part and be arranged in the one of permanent magnet 1 in the axial direction The part in the outside of end.

Then, make permanent magnet 1a one-body molded with permanent magnet 2f by insert molding, with shape Becoming permanent magnet 1a to be embedded in the form in permanent magnet 2f, wherein, permanent magnet 1a is at axle Upwards permanent magnet 1 is carried out the side (Fig. 7) after decile segmentation.Prepare 2 so to obtain It is embedded with the permanent magnet 2f of permanent magnet 1a, they are become composition surface with permanent magnet 1a Mode superposition in the axial direction and be bonded with each other, it is possible to manufacture turning of its structure and embodiment 1 Son 6 identical rotors (Fig. 7).In this case, rotor 6 can be by two parts manufactures. Additionally, permanent magnet 2 is made up of 2 permanent magnet 2f, permanent magnet 1 is by 2 permanent magnets 1a is constituted.

According to present embodiment, owing to the parts constituting the permanent magnet 1,2 of rotor 6 can be subtracted It is 2 less, it is possible to cut down the processing cost manufactured.Additionally, due to make 2 same shapes Unit construction, so that the mould of this parts-moulding can be identical, it is possible to reduce mould kind, The expense of mould can be cut down.

As it has been described above, the present invention is useful as the rotor of synchronous motor.

Claims (6)

1. a synchronous motor, it is characterised in that including:

Rotor, described rotor includes: the 1st permanent magnet, and it is configured at rotor surface in the form of a ring；With the 2nd permanent magnet, its in the form of a ring, magnetic characteristic is relatively low compared with described 1st permanent magnet, and its outer peripheral face by surround described 1st permanent magnet rotary shaft direction on two ends and inner peripheral surface side in the way of be configured with described 1st permanent magnet；And

Stator, described stator includes: stator core, described stator core is opposite with the outer peripheral face of described 1st permanent magnet, length on the described rotary shaft direction of described stator core is longer than the length on the described rotary shaft direction of described 1st permanent magnet, and it is shorter than the length on the described rotary shaft direction of described 2nd permanent magnet

Described 2nd permanent magnet is formed as the polar anisotropic orientation that the multiple pole pairs with described rotor are answered.

Synchronous motor the most according to claim 1, it is characterised in that:

Described 1st permanent magnet is in the cross section vertical with described rotary shaft direction, and its thickness at the center of the plurality of magnetic pole of described rotor is more than its thickness between the center of the plurality of magnetic pole.

Synchronous motor the most according to claim 1, it is characterised in that:

Described 1st permanent magnet is rare earth element magnet,

Described 2nd permanent magnet is ferrite magnet.

Synchronous motor the most according to claim 1, it is characterised in that:

Described rotor is constituted by being clipped in the middle by the 1st magnet component by the 2nd magnet component and the 3rd magnet component on described rotary shaft direction and engaging, wherein,

Described 1st magnet component by by one-body molded to part overlapping with described 1st permanent magnet for the allocation position being positioned in described 2nd permanent magnet on the inner peripheral surface side of described 1st permanent magnet and described rotary shaft direction and described 1st permanent magnet and obtain,

Described 2nd magnet component is the part in the outside of the one end being arranged in described 1st permanent magnet on described rotary shaft direction in described 2nd permanent magnet, and obtains with described 1st magnet component molding dividually,

Described 3rd magnet component is the part in the outside of the other end being arranged in described 1st permanent magnet on described rotary shaft direction in described 2nd permanent magnet, and obtains with described 1st magnet component and described 2nd magnet component molding dividually.

Synchronous motor the most according to claim 1, it is characterised in that:

Described rotor is by engaging the 1st magnet component and the 2nd magnet component and constitute on described rotary shaft direction, wherein,

Described 1st magnet component be carried out insert molding by making described 1st permanent magnet be embedded into described part 1 in the parts part 1 in described 2nd permanent magnet and part 2 being made of one piece obtained by, wherein, described part 1 is the part that the allocation position being positioned on the inner peripheral surface side of described 1st permanent magnet and described rotary shaft direction in described 2nd permanent magnet is overlapping with described 1st permanent magnet, described part 2 is the part in the outside of the one end being arranged in described 1st permanent magnet on described rotary shaft direction in described 2nd permanent magnet,

Described 2nd magnet component is the part in the outside of the other end being arranged in described 1st permanent magnet on described rotary shaft direction in described 2nd permanent magnet, and obtains with described 1st magnet component molding dividually.

Synchronous motor the most according to claim 1, it is characterised in that:

Described rotor is by engaging the 1st magnet component and the 2nd magnet component and constitute on described rotary shaft direction, wherein,

Described 1st magnet component is by a part after part overlapping with described 1st permanent magnet for the allocation position being positioned in described 2nd permanent magnet on the inner peripheral surface side of described 1st permanent magnet and described rotary shaft direction being split into two halves on described rotary shaft direction, in the parts being made of one piece with the part in the outside of the one end being arranged in described 1st permanent magnet on described rotary shaft direction in described 2nd permanent magnet, obtained by making the side after being split into two halves by described 1st permanent magnet on described rotary shaft direction be embedded into one part and having carried out insert molding,

Described 2nd magnet component is in the parts being made of one piece by the part of another part after part overlapping with described 1st permanent magnet for the allocation position being positioned in described 2nd permanent magnet on the inner peripheral surface side of described 1st permanent magnet and described rotary shaft direction being split into two halves on described rotary shaft direction and the outside of the other end being arranged in described 1st permanent magnet on described rotary shaft direction in described 2nd permanent magnet, make the opposing party after being split into two halves by described 1st permanent magnet on described rotary shaft direction be embedded into another part described and obtained by having carried out insert molding.