CN102195378A - Interior magnet machine with reduced cogging - Google Patents

Abstract

An interior permanent magnet machine has non-contiguous, non-magnetic radial slots between the magnets and the cylindrical periphery and the magnets have non-magnetic radial end slots.

Description

Inner magnet machine with the slot effect that reduces

Technical field

The present invention relates generally to have the machine that is embedded in the permanent magnet in the rotor core, be particularly related to the slotted rotor that is used for the inner magnet machine, under Electronic Control, this machine produces with the torque of the slot effect (cogging) that reduces and raising under fixing or variable frequency and moves.

Background technology

Inner magnet (interior magnet) machine has following characteristic.

At first, compare many inner magnets and have lower power density with mounted on surface magnet machine.When being buried, the surface area of magnet reduces usually, needs bigger motor or generator to obtain same power output.The motor of large-size or generator can cause encapsulation or performance issue in final the application.

Secondly, trapezoidal gap flux distributes and is produced by the inner magnet rotor usually.At winding current is in the sine-shaped application, and trapezoidal Flux Distribution can cause significant torque ripple.Torque ripple is brought noise and the vibration in the final application.This can minimize by selecting correct groove and number of poles or winding, but these schemes are always practical.

The 3rd, the unexpected conversion during rotor flux distributes brings cogging torque (cogging torque).---for example skewed slot (skewing)---causes lower power density typically to be used to reduce the technology of cogging torque.

The 4th, to compare with the surface magnet machine, the inner magnet machine has higher average inductance.Higher inductance is in operation and has reduced the power factor of machine, has increased to producing the complex power (VA) that given torque needs from driver.If must use bigger power device, increase the driver volt-ampere and require to increase the driver cost.

The output torque of interior permanent-magnet machines and back electromotive force and winding current are proportional, when the two same phase time.Fixedly the winding current in the busbar voltage system is subjected to the restriction of back electromotive force and machine resistance and inductance.When allowing the number of turn to be adjusted to, the rotor geometry designs that causes higher back electromotive force or low inductance obtains the minimum current absorption.The reducing of electric current can allow to use the smaller power device, reduces system cost.

The solution that is used in the prior art to have more than or equal to the inner magnet machine of the power density of surface magnet machine comprises " V " magnet and spoke (spoke) magnet design.These designs may be difficult to magnetize and tend to have high cogging torque.

The solution that is used to reduce the influence that trapezoidal rotor flux distributes in the prior art comprises the machine with distributed winding.Because terminal winding, the stator with distributed winding tends to greater than the monodentate winding, and may not be installed in the encapsulation of some application need.Also can use the electrical degree of each groove to be not equal to 120 or 240 monodentate winding.The quantity of practical combinations is subjected to the restriction of machine dimensions.

The solution that is used to reduce cogging torque in the prior art comprises stator and rotor airgap surface and skewed slot is formalized that these solutions tend to reduce the power density of machine.

The solution that is used to reduce the average inductance of inner magnet machine in the prior art comprises to the rotor polar cap increases the crack.These cracks in most of the cases are placed as perpendicular to magnet surface.

Summary of the invention

The other objects and features of the invention will be by hereinafter understanding and partly pointing out.

Description of drawings

Fig. 1,2,3,6,9,10,14,15,16 is the sectional view of embodiments of the invention, and it comprises four inner magnets, has the angled groove of two of every magnetic poles separately;

Figure 1A is a chart, and it shows the back electromotive force of motor or generator, and this motor or generator have rotor, and this rotor has the lamination shown in Figure 1 that comprises angled groove 16;

Figure 1B is a chart, and it shows the back electromotive force of motor or generator, and this motor or generator have rotor, and rotor has the lamination shown in Figure 1 that does not comprise angled groove 16;

Fig. 2 A, 3A, 6A, 9A, 10A, 14A, 15A are chart, it shows the back electromotive force of motor or generator, this motor or generator have rotor, and this rotor has the lamination shown in Fig. 2,3,6,9,10,14,15 respectively that angled groove is arranged separately;

Fig. 4,5,7,8,11,12,13 is the sectional view of embodiments of the invention, and it comprises four inner magnets, and each magnet has the angled groove of four of every magnetic poles;

Fig. 4 A, 5A, 7A, 8A, 11A, 12A, 13A are chart, it shows the back electromotive force of motor or generator, this motor or generator comprise rotor, this rotor have have separately angled groove respectively at the lamination shown in Fig. 4,5,7,8,11,12,13;

Fig. 9 B is a chart, and it shows the cogging torque of motor or generator, and this motor or generator have rotor, and this rotor has the lamination shown in Figure 9 that comprises angled groove 172;

Figure 11 B is a chart, and it shows the cogging torque of motor or generator, and this motor or generator have rotor, and this rotor has the lamination shown in Figure 11 that comprises angled groove 202;

Figure 17,18 is the sectional view of embodiments of the invention, and it comprises six inner magnets, and each magnet has the angled groove of two of every magnetic poles;

Figure 19,20 is the sectional view of embodiments of the invention, and it comprises two inner magnets, and each magnet has the angled groove of two of every magnetic poles;

Figure 19 A is a chart, and it shows the Flux Distribution of motor or generator, and this motor or generator have rotor, and this rotor has the lamination shown in Figure 19 that comprises angled groove 364;

Figure 19 B is a chart, and its flux density that shows motor or generator distributes, and this motor or generator have rotor, and this rotor has the lamination shown in Figure 9 that comprises angled groove 364;

Figure 21 is the sectional view of embodiments of the invention, and it comprises 12 inner magnets, and magnet is arranged to and produces six magnetic poles, and each has two angled grooves;

Figure 22 is the rotor laminated sectional view of diadem shape (crown) of prior art, and it does not have according to any angled groove of the present invention, and extremely Biao Mian diadem shape causes uneven air gap;

Figure 22 A is a chart, and it shows the back electromotive force of non-homogeneous air gap motor or generator, and this motor or generator comprise rotor, and this rotor has according to as shown in figure 22 the lamination of prior art without any angled groove;

Figure 22 B is a chart, and it shows the cogging torque of non-homogeneous air gap motor or generator, and this motor or generator have rotor, and this rotor has according to as shown in figure 22 the lamination of prior art without any angled groove;

Figure 23 is the sectional view of one embodiment of the invention, and it has four inner magnets, and each magnet has the angled groove of two of every magnetic poles and has the nonmagnetic end trough of adjacency (contiguous);

Figure 23 A shows the embodiment of Figure 23, and it comprises axis peripheral and groove end;

Figure 24 A shows a kind of interior permanent magnet rotor in the appendix 1, and Figure 24 B shows its rotor airgap flux waveform;

Figure 25 A shows the another kind of interior permanent magnet rotor in the appendix 1, and Figure 25 B shows its rotor airgap flux waveform;

Figure 26,27 shows respectively that flux density in the appendix 2 distributes and the FFT of Flux Distribution.

Run through accompanying drawing, the corresponding reference label is represented corresponding components.

Embodiment

In one embodiment, the present invention comprises a kind of machine, the rotor that it has stator and engages with the stator magnet coupling, and wherein, rotor has the geometry designs of the angled groove between pole surface and rotor overall diameter.In another embodiment, the present invention comprises the rotor geometry designs that the groove between pole surface of being added on and the rotor overall diameter is arranged.Groove is placed in the position and the angle of the fundametal compoment that can increase the rotor flux distribution.Groove also can reduce cogging torque.Each magnetic pole adds minimum two grooves.Although the embodiment here shows any even number groove, those skilled in the art will envision that other configuration.

The interpolation of groove distributes rotor flux and changes into more sinusoidal distribution from trapezoidal.The fundametal compoment of more sinusoidal distribution can be greater than the fundametal compoment of trapezoidal profile, and the harmonic distortion of this distribution can reduce.Appendix 1 is that mathematics of the present invention constitutes.First demonstrates does not have even (trapezoidal) rotor flux of groove to distribute.The FFT fundametal compoment of Flux Distribution is 1.433 amplitude units.The total harmonic distortion that distributes is 11.805%.The ensuing part of appendix 1 shows the method for the position that is used to calculate groove.Shown method increases fundametal compoment and is 1.616 and THD is reduced to 4.263%.

Fig. 1-2 1 shows the possible realization of groove, the Mathematical Modeling above it satisfies.Appendix 2 and Figure 19 A, 19B show as having of predicting of limited meta analysis and do not have the rotor flux of the rotor among Figure 19 of groove to distribute.Under the situation that increases groove, the fundametal compoment of flux increases 5.6%.The FEA model also shows significantly the reducing of total harmonic distortion of Flux Distribution.Notice that Mathematical Modeling is not considered the leakage around the groove.

The comparison of Mathematical Modeling and FEA model can use rotor shown in Figure 17 to carry out.This rotor has the leakage paths that reduces.The FEA model prediction goes out in the first-harmonic flux 11.5% increase, and mathematical model prediction goes out 12.7% increase.

The FEA model shows the improvement on the shape, Flux Distribution fundametal compoment value of Flux Distribution, average inductance, back electromotive force fundametal compoment value, cogging torque value, average torque, the torque ripple.

The position of groove and angle also are not optimised this moment.Need further work, so that reduce to come these parameters of optimization for torque generation and cogging torque.

The advantage of introducing above also is applicable to line start (line start) permanent-magnet machines.The example of LSPM rotor is shown in Figure 19 and 20.Because the existence of cage (cage), the angle of groove and position may need to regulate.

The present invention has reduced cogging torque, keeps simultaneously or increased back electromotive force and average torque producing.This is very uncommon result.The most methods that is used to reduce cogging torque has also reduced back electromotive force and average torque.

Higher back electromotive force can utilize in two ways.At first, it can be used for increasing the power density of machine, by the torque that provides by fixing motor or generator size is provided, or the size of motor or generator by reducing to produce same torque.

Perhaps, the number of turn can be reduced, so that keep same back electromotive force.The inductance of machine and the number of turn square proportional is possible so the substance of inductance reduces.Compare with the rotor that does not have groove, use the motor of the rotor with groove shown in Figure 1 or generator to produce many 1.9% torque.Suppose that the torque and the number of turn are proportional, adopt groove to reduce the number of turn 1.9% to produce 3.61% reduce that same torque causes average inductance.

Fig. 1-2 1 shows a plurality of embodiment of the present invention.For the purpose of the facility, rotor of the present invention is shown to have the lamination of groove on the cross section.In use, piling up of lamination will cooperate with permanent magnet, and groove can open wide (being fills with air) or fill with nonmagnetic substance.For the purpose of the facility, each lamination is shown to include interior permanent magnet.

Therefore, Fig. 1 is the graphical representation of exemplary according to an embodiment of rotor of the present invention.Rotor comprises cylindrical skirt 18, and it has rotary middle spindle 10.The cross section of rotor as shown in Figure 1, is obtained and is comprised following content perpendicular to central shaft 10.A plurality of burying (for example built-in) permanent magnet 14 is placed in the groove of rotor, and each magnet 14 has size longitudinally, and it is greater than lateral dimension (for example the cross section is a rectangle).One in a plurality of non magnetic grooves 16 and the magnet 14 is associated, and each groove 16 has the longitudinal size greater than lateral dimension, and wherein, the axle of the longitudinal size of groove is not orthogonal to the axle of the longitudinal size of its associated inner magnet.Each groove 16 generally is placed between one of inner magnet 14 that periphery 18 and groove be associated.Be preferably, exist the even number at least two grooves 16 to be associated with each magnet.The axle of the longitudinal direction of each magnet 14 is arranged essentially parallel to the tangent line of the periphery 18 of cylinder blanket, and in one embodiment, groove 16 is in the angle that is not equal to 90 degree about the axis of the longitudinal size of its related inner magnet 14.

Fig. 1 is for along the sectional view of obtaining perpendicular to the rotary middle spindle 10 of the lamination 12 of rotor according to an embodiment of the invention.Each inner magnet 14 has the groove 16 of two associations between magnet 14 and the lamination periphery 18, and wherein, the longitudinal axis 20 of groove is in the angle of spending less than 90 about the longitudinal axis 22 of its related inner magnet 14.In this embodiment, each inner magnet 14 has according to circumstances optionally end trough 24.Groove 16 and/or end trough 24 available air or other nonmagnetic substance are filled.

In Fig. 2-16, show multiple lamination embodiment, each has four same quadrants (quadrant), as about shown in quadrant A, the B of Fig. 1, C, the D.For simplicity, only introduce and mark a quadrant with reference number.

Fig. 2 is similar to Fig. 1 along the sectional view of obtaining perpendicular to the rotary middle spindle 10 of the lamination 30 of rotor according to an embodiment of the invention.In this embodiment, compare with the angle of axis 20 shown in Figure 1, the longitudinal axis 32 of groove 34 is in bigger angle (but less than 90 degree) about the longitudinal axis 36 of its related inner magnet 38.In this embodiment, groove 32 is shorter than the groove 16 of Fig. 1 on length.

Fig. 3 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 50 of rotor according to an embodiment of the invention.In this embodiment, compare with the angle of the axis 20 of groove 16 shown in Figure 1, the longitudinal axis 52 of groove 54 is in less angle (but greater than 0 degree and less than 90 degree) about the longitudinal axis 56 of its related inner magnet 58.In this embodiment, groove 54 is longer than the groove 16 of Fig. 1 on length.

Fig. 4 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 72 of rotor according to an embodiment of the invention.Each inner magnet 74 has between magnet 74 and the lamination periphery 78 four related grooves 76 and 77, and wherein, the longitudinal axis 80 of groove and 81 longitudinal axiss 82 about its related inner magnet 74 are in the angle less than 90 degree.In this embodiment, each inner magnet 74 has optionally trough of belt end 84, its available air or other nonmagnetic substance filling according to circumstances.In this embodiment, compare with two inside grooves 77, two water jackets 76 constitute the less angle with axis 82, and two water jackets 76 are shorter than two inside grooves 77 on length.

Fig. 5 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 92 of rotor according to an embodiment of the invention.Each inner magnet 94 has the groove 96 and 97 of four associations between magnet 94 and the lamination periphery 98, and wherein, the longitudinal axis 100 of groove is in the angle of spending less than 90 with 101 longitudinal axiss 102 about its related inner magnet 94.In this embodiment, each inner magnet 94 has according to circumstances optionally trough of belt end 104, and its available air or other nonmagnetic substance are filled.In this embodiment, the angle that two water jackets 96 constitute with axis 102 and two inside grooves 97 are same, two water jackets 96 are shorter than two inside grooves 97 on length.

Fig. 6 is similar to Fig. 1 along the sectional view of obtaining perpendicular to rotor laminated according to an embodiment of the invention 110 rotating shaft 10.In this embodiment, compare with angle shown in Figure 1, the longitudinal axis 112 of groove 114 is in identical angle about the longitudinal axis 116 of its related inner magnet 118.In this embodiment, groove 114 has same length with the groove 16 of Fig. 1.In this embodiment, compare with the angle of the axis 20 of groove 16 shown in Figure 1, the longitudinal axis 113 of groove 115 is in less angle about the longitudinal axis 116 of its related inner magnet 118.In this embodiment, groove 115 is longer than the groove 16 of Fig. 1 on length.

Fig. 7 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 132 of rotor according to an embodiment of the invention.This embodiment is identical with Fig. 5, except groove 134 has about the vertical longitudinal axis 136 of the longitudinal axis 138 of its inner magnet that is associated 140.

Fig. 8 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 152 of rotor according to an embodiment of the invention.This embodiment is identical with Fig. 5, and except groove 154 had such longitudinal axis 156: compare with the angle of the axis 101 of the groove 97 of Fig. 5, longitudinal axis 156 was in less angle about the longitudinal axis 158 of its inner magnet that is associated 160.

Fig. 9 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 170 of rotor according to an embodiment of the invention.This embodiment is identical with Fig. 1, and except comparing with the groove 16 of Fig. 1, groove 172 is tear-drop shaped, has beyond the end of being wider than the other end.In addition, groove 172 has longitudinal axis 174, compares with the angle of the axis 20 of the groove 16 of Fig. 1, and longitudinal axis 174 is in less angle about the longitudinal axis 176 of its inner magnet that is associated 178.

Figure 10 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 180 of rotor according to an embodiment of the invention.This embodiment is identical with Fig. 1, except end trough 182 the end trough 24 that is narrower than Fig. 1 on the width.

Figure 11 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 200 of rotor according to an embodiment of the invention.This embodiment is identical with Fig. 4, and except comparing with the groove 76 of Fig. 4, groove 202 is that an end is wider than beyond the tear-drop shaped of the other end.In addition, groove 202 has axis 204 longitudinally, compares with the angle of the axis 80 of the groove 76 of Fig. 4, and its longitudinal axis 206 about its inner magnet that is associated 208 is in less angle.

Figure 12 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 220 of rotor according to an embodiment of the invention.This embodiment is identical with Figure 11, and except comparing with the groove 202 of Figure 11, groove 222 has beyond the narrower width.In addition, groove 222 has longitudinal axis 224, and than the angle of the axis 204 of the groove 202 of Figure 11, longitudinal axis 224 has bigger angle about the longitudinal axis 226 of its inner magnet that is associated 228.

Figure 13 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 240 of rotor according to an embodiment of the invention.This embodiment is identical with Figure 12, and except the angle than the axis 224 of the groove 222 of Figure 12, the longitudinal axis 246 that groove 242 has about its inner magnet that is associated 248 is in beyond the longitudinal axis 244 of smaller angle.

Figure 14 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 260 of rotor according to an embodiment of the invention.This embodiment is identical with Fig. 1, and---its two have same shape and position, one of two grooves 262---be groove 262B---is long and for beyond the tear-drop shaped except the groove 16 than Fig. 1.In addition, than the groove 16 of Fig. 1, tear-drop shaped groove 262B has the long length along axis 264B.In addition, than the angle of the axis 20 of the groove 16 of Fig. 1, groove 262B is in less angle about the longitudinal axis 266 of its inner magnet that is associated 268.

Figure 15 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 280 of rotor according to an embodiment of the invention.This embodiment is identical with Fig. 1, and except the groove 16 than Fig. 1---the two has same shape and position, two grooves 282 are beyond tear-drop shaped and groove 282B grow.In addition, than the groove 16 of Fig. 1, tear-drop shaped groove 282B has the long length along axis 284B.In addition, than the angle of the axis 20 of the groove 16 of Fig. 1, tear-drop shaped groove 282 all is in less angle about the longitudinal axis 286 of its inner magnet that is associated 288.

Figure 16 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 290 of rotor according to an embodiment of the invention.This embodiment is identical with Fig. 1, and except than Fig. 1, two grooves 292 are connected to beyond the groove 294 for the inner magnet 296 of association, and in Fig. 1, groove 16 is free of attachment to the groove for magnet 14.In addition, than the angle of the axis 20 of the groove 16 of Fig. 1, two grooves 292 are in less angle about the longitudinal axis 298 of its inner magnet that is associated 296.

Figure 17 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 300 of rotor according to an embodiment of the invention.Figure 17 is similar to Fig. 1, except four inner magnets 14 with six inner magnets 302 rather than Fig. 1.In addition, Figure 17 has the groove 16 of S shape groove 304 rather than Fig. 1, and the groove of Fig. 1 is generally the rectangular shape of fillet.

Figure 18 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 340 of rotor according to an embodiment of the invention.In Figure 18, show even isolated six inner magnets 342 around periphery.Each magnet has trapezoidal end trough at each end.Each inner magnet 342 has the groove 346 of two associations between the periphery 348 of magnet 342 and lamination 340, and wherein, the longitudinal axis 350 of groove 346 is in angle less than 90 degree about the longitudinal axis 352 of its inner magnet that is associated 342.In this embodiment, each inner magnet 342 is shown to have according to circumstances optionally end trough 344.Groove 346 and/or end trough 344 available air or other nonmagnetic substance are filled.In addition, as shown in figure 18, groove 346 is free of attachment in the end trough 344.In addition, in this embodiment, has the axis of aiming at the radius 356 of lamination 340 354 to small part in the end trough 344.

Figure 19 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 360 of rotor according to an embodiment of the invention.In Figure 19, show two parallel inner magnets 362 that in periphery, are evenly spaced apart.Each inner magnet 362 has the groove 364 of two associations between the startup cage groove (start cage slot) 366 of location around magnet 362 and the periphery 368 at lamination 360.The longitudinal axis 370 of groove 364 is in the angle of spending less than 90 about the longitudinal axis 372 of its inner magnet that is associated 362.Groove 364 and/or startup cage groove 366 available air or other nonmagnetic substance are filled.In addition, as shown in figure 19, groove 364 is connected to of starting in the cage groove 366 and integrated with it.

Figure 20 is for along the sectional view of obtaining perpendicular to the rotating shaft 10 of the lamination 380 of rotor according to an embodiment of the invention.Figure 20 is identical with Figure 19, except groove 382 is free of attachment to any startup cage groove 384.On the contrary, in Figure 20, groove 382 is independent of cage groove 384, and is positioned between cage groove 384 and the magnet 386.

Figure 21 is for along the sectional view of obtaining perpendicular to the rotary middle spindle 10 of the lamination 400 of rotor according to an embodiment of the invention.Among superincumbent Fig. 1-2 0, inner magnet is placed in parallel to the tangent line of rotor laminated periphery.On the contrary, in the lamination 400 of Figure 21, each inner magnet 402R, 402L are the right part of V-arrangement, are in an angle about the periphery tangent line separately.In addition, each magnet 402R, 402L have at least one related groove 404R, the 404L between magnet 402R, 402L and the lamination periphery 406.In this embodiment, longitudinal axis 408R, the 408L of groove 404R, 404L are in the angle of spending less than 90 about longitudinal axis 410R, the 410L of its inner magnet that is associated 402.

In the embodiment of Figure 21, longitudinal axis 408R, the 408L of each groove 404R, 404L do not aim at the radius 412 of lamination 400, still, can expect, axis 408R, 408L and radius 412 can be aimed at.Similarly, in Fig. 1-2 0, groove is not aimed at radius, and is parallel with the tangent line of rotor laminated periphery because inner magnet is placed as, and groove is paired, and each groove of a centering is towards this another right groove.Therefore, the angles less than 90 degree of groove formation and inner magnet.Can expect, groove can for away from each other towards, in this case, groove can be aimed at the radius of rotor, but groove can still be in inner magnet less than 90 the degree angles.

Figure 22 is the diagram according to diadem shape (crown) rotor of prior art without any groove.Each inner magnet 420 has end trough 422, as shown in the figure.The end trough of Fig. 1-18 has and end trough 422 slight different shapes.Especially, the distance same with end trough 422 that the end trough of Fig. 1-18 is positioned as periphery is to keep same flux leakage.Stator 430 is shown in broken lines, and stator is in the magnetic coupling of diadem shape rotor to be arranged.

Figure 23 and 23A are the sectional view of one embodiment of the invention, and it comprises four inner magnets, and each has the angled groove of two of each magnetic poles, and have the non magnetic end trough of adjacency.Shown rotor 500 comprises a plurality of laminations, and each has cylindrical skirt 502, and periphery has rotary middle spindle 504.Figure 23 and 23A show the perspective view in the cross section of obtaining perpendicular to rotary middle spindle 504.Rotor 500 comprises a plurality of inner magnets 506 with square-section, and this cross section has along the longitudinal axis of the string of cylindrical skirt 502, and it does not intersect with rotating shaft 504.Can expect also, but not illustrate that magnet 506 can have the trapezoid cross section, the trapezoid cross section can be adapted to by a plurality of non magnetic end troughs 508.Permanent magnet has two utmost point 510A, 510B in each, and has the longitudinal size 512 greater than lateral dimension 514.

In order to reduce slot effect, increase the first-harmonic back electromotive force and to reduce the back electromotive force harmonic component, rotor 500 comprises the several characteristic of combination.A plurality of non magnetic peripheral grooves 516,518,520 and 522, at least one non magnetic peripheral groove related with each utmost point 510 of inner magnet 506 is positioned between cylindrical skirt 502 and its inner magnet that is associated 506.In one embodiment, groove 516,518,520,522 changes on length, and has substantially the same width and/or at least two non magnetic peripheral grooves are associated with each utmost point of interior permanent magnet.

Interior permanent magnet 506 adjacency that each non magnetic peripheral groove 516,518,520,522 is not associated with it, each non magnetic peripheral groove has longitudinal size 516L, and it is greater than lateral dimension 516T.Groove 516,518,520,522 is oriented, and the axis of the longitudinal size 516L of each non magnetic peripheral groove is not orthogonal to the axis of the longitudinal size 512 of its contiguous, related interior permanent magnet 506.Described a plurality of non magnetic end trough 508 separately in abutting connection with and with each in each end of each utmost point of permanent magnet 506 integrated, aiming at along the string 524 that is essentially the center to small part of each non magnetic end trough 508, this string does not intersect (that is, string 524 is not the radius or the diameter of rotor) with rotary middle spindle 504.In one embodiment, end trough 508 has: string fragment 508C, and it has the central shaft of aiming at along the string of cylindrical skirt 502; Radius fragment 508R, it has the central shaft of the string that generally is parallel to rotor 500.The central shaft formation of string fragment 508C and the obtuse angle of the central shaft of radius fragment 508R.String fragment 508C has the trapezoid cross section, and its central shaft---being parallel to its parallel side---aims at the longitudinal axis 526 of rectangular magnet 506.Therefore, in one embodiment, each non magnetic end trough 508 have central shaft to small part (for example string fragment 508C), it is associated with it embedded in the longitudinal axis 526 of permanent magnet 506 aim at.

The radial segment 508R of non magnetic end trough 508 has the longitudinal size greater than lateral dimension.Radial segment 508R and its corresponding radial segment 508R ' have the trapezoid cross section separately.Fragment 508R, 508R ' aim at along the string 524 that is essentially the center, and this string is parallel to their parallel side.Shown in Figure 23 A, contiguous radial segment 508R, 508R ' have along the string 524 at the parallel center that is essentially of its longitudinal size, and/or opposing ends fragment 508R, 508R ' have along the central shaft of the aligning of its longitudinal size.In one embodiment, the longitudinal size 512 of magnet 506 is less than the length 528 of the non magnetic string groove that holds magnet 506, so that the trapezoidal non magnetic string fragment 508C on each end of formation magnet 506.Can expect that also the longitudinal size 512 of magnet 506 can equate with the length 528 of string groove, makes end trough can only comprise radial segment 508R, end trough can not comprise string fragment 508C.

In one embodiment, peripheral groove 516,518,520,522 and end trough 508 are placed as the distance D that equates apart from periphery 502.

Shown in Figure 23 A, rotor 500 is configured to, and the cross section is symmetrical around the string 530,532 perpendicular to interior permanent magnet, and intersects with rotary middle spindle 504.In one embodiment, string 516P, the 518P of the longitudinal size of non magnetic peripheral groove, 520P, 522P are not crossing with the centre chord 524 of rotation 504.

In one embodiment, rotor 500 comprises a plurality of laminations, and each has the cylindrical skirt 502 around the centre chord 524 of rotation 504, at least shown in Figure 23,23A.

In one embodiment, the present invention comprises machine, the rotor 500 that this machine comprises stator and engages with the stator magnet coupling.

Table 1 shows about the back electromotive force of Fig. 1,2,3,4,5,22 embodiment and the finite element modeling result of slot effect, the groove size shown in this embodiment has.Groove 1 refers to groove in the two grooves configurations and the water jacket in the configuration of four grooves.Groove 2 refers to the inside groove in the configuration of four grooves.

Table 2 shows about the back electromotive force of Fig. 6,7,8,9,10,11 embodiment and the finite element modeling result of slot effect, the groove size shown in this embodiment has.Groove 1 refers to groove in the two grooves configurations and the water jacket in the configuration of four grooves.Groove 2 refers to the inside groove in the configuration of four grooves.

Table 3 shows about the back electromotive force of Figure 12,13,14,15 embodiment and the finite element modeling result of slot effect, the groove size shown in this embodiment has.Groove 1 refers to groove in the two grooves configurations and the water jacket in the configuration of four grooves.Groove 2 refers to the inside groove in the configuration of four grooves.

Table 4 shows about the back electromotive force of the embodiment of Fig. 1,9,11,22 (diadem formula) and the finite element modeling result of slot effect, the groove size shown in this embodiment has.

Table 1: Fig. 1,2,3,4,5,22

Table 2: Fig. 6,7,8,9,10,11.

Table 3: Figure 12,13,14,15.

Table 4: Fig. 1,9,11,22

Described the present invention in detail, will be seen that, under the situation of the scope of the present invention that does not break away from the claims qualification, can modify and change.

When introducing the element of the present invention or its preferred embodiment, article " ", " one ", " being somebody's turn to do ", " described " are used to represent to exist one or more than this element of one.Term " comprises ", " comprising ", " having " comprising property, means the additional elements that may exist except that institute's column element.

By above introduction, it will be appreciated that, can realize several purpose of the present invention and obtain other favourable outcome.

Owing to can make multiple modification without departing from the scope of the invention in said structure, product and method, top place of matchmakers comprises and all the elements shown in the drawings are explained with illustrative rather than restrictive, sense.

Appendix 1---Mathematics structural

IPM flux concentration (flux concentration)

The torque that motor produces results from the interaction of stator and rotor field.Most of torque is produced by each fundametal compoment.For the interior permanent magnet rotor shown in Figure 24 A, the rotor airgap flux waveform shown in Figure 24 B is typical.Note, shown in Figure 24 A corresponding to the situation that does not have groove.

Shown in total flux under the waveform be:

φ _r＝A ₁p ₁ (1)

Wherein, A ₁Be the amplitude of gap flux, p1 is as pole span (pole pitch) width percentage, the flux waveform.The fundametal compoment of gap flux is provided by following formula:

$b_1=\frac{-2A_1}{\mathrm{\π}}\left\{\cos \right[\frac{\mathrm{\π}(1+p_1)}{2}]-\cos [\frac{(1-p_1)}{2}\left]\right\}---\left(2\right)$

The present invention has changed the shape of air gap waveform, so that increase fundametal compoment.The interpolation of one group of groove (Figure 25 B) becomes the rotor airgap Flux Distribution shown in Figure 25 B.Notice that Figure 25 A is corresponding to Figure 24 A that groove is arranged.

Because magnet width, length and service conditions do not change, total rotor airgap flux remains unchanged, perhaps:

φ _r＝A ₂p ₂+(A ₃-A ₂)p ₃ (3)

The fundametal compoment of this waveform is:

$b_1=\frac{-2A_1}{\mathrm{\π}}\left\{\cos \right[\frac{\mathrm{\π}(1-p_3)}{2}]-\cos [\frac{\mathrm{\π}(1-p_2)}{2}\left]\right\}-\frac{2A_3}{\mathrm{\π}}\left\{\cos \right[\frac{\mathrm{\π}(1-p_2)}{2}]-\cos [\frac{\mathrm{\π}(1-p_3)}{2}\left]\right\}$ $\left(4\right)$

$-\frac{2A_2}{\mathrm{\π}}\left\{\cos \right[\frac{\mathrm{\π}(1+p_2)}{2}]-\cos [\frac{\mathrm{\π}(1-p_3)}{2}\left]\right\}$

In table 1, provided the example that fundametal compoment increases owing to groove.In this example, be same from the flux of magnet to each waveform, because the area under the waveform is 1.0 in all cases.Fundametal compoment has increased by 12.8%.The increase of the fundametal compoment of gap flux has caused bigger back electromotive force and torque.The change that gap flux distributes, shown as the change of total harmonic distortion, also will change cogging torque.

?	The waveform of Fig. 2	The waveform of Fig. 4
			A1	1.149	-
p1	0.87	-
			A2	-	0.6
p2	-	0.87
			A3	-	1.596
p3	-	0.48
			Area under the waveform	1.0	1.0
First-harmonic	1.433	1.616
			Total harmonic distortion (%)	11.803	4.263

Table 1

Above analysis ignored that motor is non-linear, stator channelization effect (slotting effect) and flux leakage.These all will influence top analysis.In order to take into account these effects, be necessary to some modification of groove position.

Appendix 2 rotor fluxes distribute

The FFT that the gap flux that FEM (finite element) calculation obtains distributes

Carry out the Fourier transform of flux density to the waveform of angle.

From the file reading of data

no_slot：＝READPRN(“c:\projects\flux_focus\fea\s1r1\no_slot\flux_dist_no_slot.gs”)

slot：＝READPRN(“c:\projects\flux_focus\fea\s1r1\slot\flux_dist_slot.gs”)

Extract data from file

N：＝rows(no_slot) M：＝rows(slot)

n：＝0...N-1 m：＝0...M-1

${\mathrm{\θ}}_{{\mathrm{ns}}_n}:=\mathrm{no}\_\mathrm{slo}{t}_{n,0}{\mathrm{\θ}}_{s_m}:=\mathrm{slo}{t}_{m,0}$

Figure 26,27 shows the FFT of flux density distribution and Flux Distribution respectively.

$\frac{\left|B_{s\_m_1}\right|}{\left|B_{\mathrm{ns}\_m_1}\right|}=1.056$ THD_B _ns＝10.205％ THD_B _s＝2.505％

Claims (20)

1. rotor comprises:

Cylindrical skirt, it has rotary middle spindle;

Perpendicular to the cross section that rotary middle spindle is obtained, the described cross section of rotor comprises:

Permanent magnets in a plurality of, permanent magnet has two utmost points and has longitudinal size greater than lateral dimension in each;

A plurality of non magnetic peripheral grooves, at least one non magnetic peripheral groove is associated with each utmost point of interior permanent magnet, each non magnetic peripheral groove be positioned in cylindrical skirt with and the interior permanent magnet that is associated between, each non magnetic peripheral groove is not in abutting connection with its associated interior permanent magnet, wherein, each non magnetic peripheral groove has the longitudinal size greater than lateral dimension, and wherein, the axis of the longitudinal size of each non magnetic peripheral groove is not orthogonal to the axis of the longitudinal size of its associated interior permanent magnet; And

Each of each utmost point of a plurality of non magnetic end troughs, each non magnetic end permanent magnet in each is terminal and integrated with it, wherein, each non magnetic end trough have the central shaft of not aiming to small part with rotor radius.

2. according to the rotor of claim 1, wherein, have different length and same in fact width with the non magnetic peripheral groove that permanent magnet pole in each is associated.

3. according to the rotor of claim 1, wherein, at least two non magnetic peripheral grooves are associated with each utmost point of interior permanent magnet.

4. according to the rotor of claim 1, wherein, end trough has the longitudinal size greater than lateral dimension, and wherein, contiguous end trough has the parallel central shaft along its longitudinal size.

5. according to the rotor of claim 4, wherein, the opposing ends groove has along the central shaft of the aligning of its longitudinal size.

6. according to the rotor of claim 1, wherein, interior permanent magnet has the square-section of obtaining perpendicular to rotary middle spindle.

7. according to the rotor of claim 1, wherein, peripheral groove and end trough are positioned as apart from the same in fact distance of periphery.

8. according to the rotor of claim 1, wherein, the cross section is symmetry around the line that intersects perpendicular to interior permanent magnet and with rotary middle spindle.

9. according to the rotor of claim 1, wherein, the axis of the longitudinal size of non magnetic peripheral groove does not intersect with rotary middle spindle.

10. rotor comprises:

A plurality of laminations, each lamination has the cylindrical skirt that rotary middle spindle is arranged;

Perpendicular to the cross section that rotary middle spindle is obtained, the described cross section of each lamination comprises:

Permanent magnet trough in a plurality of, permanent magnet trough has the longitudinal size greater than lateral dimension in each;

A plurality of non magnetic peripheral grooves, at least one non magnetic peripheral groove is associated with permanent magnet trough in each, each non magnetic peripheral groove is positioned between cylindrical skirt and its associated interior permanent magnet trough, the interior permanent magnet trough adjacency that each non magnetic peripheral groove is not associated with it, wherein, each non magnetic peripheral groove has the longitudinal size greater than lateral dimension, and wherein, and the axle of the longitudinal size of each the non magnetic peripheral groove not axle with the longitudinal size of its associated interior permanent magnet trough is vertical; And

A plurality of non magnetic end troughs, each non magnetic end trough each of permanent magnet trough in each is terminal and integrated with it, wherein, each non magnetic end trough have the central shaft of not aiming to small part with rotor radius.

11. the rotor of claim 10 wherein, has different length and has identical in fact width with the non magnetic peripheral groove that permanent magnet pole in each is associated.

12. the rotor of claim 10, wherein, at least two non magnetic peripheral grooves are associated with each utmost point of interior permanent magnet.

13. the rotor of claim 10, wherein, end trough has the longitudinal size greater than lateral dimension, and wherein, contiguous end trough has the parallel central shaft along its longitudinal size, and wherein, the opposing ends groove has along the central shaft of the aligning of its longitudinal size.

14. according to the rotor of claim 10, wherein, at least one in following:

Interior permanent magnet has the square-section of obtaining perpendicular to rotary middle spindle;

Peripheral groove and end trough are positioned as apart from the same in fact distance of periphery;

The cross section is symmetry around the line that intersects perpendicular to interior permanent magnet and with rotary middle spindle; And

The axis of the longitudinal size of non magnetic peripheral groove does not intersect with rotary middle spindle.

15. a machine comprises:

Stator; And

Rotor engages with the stator magnet coupling, and described rotor comprises: the cylindrical skirt with rotary middle spindle;

Perpendicular to the cross section that rotary middle spindle is obtained, the described cross section of rotor comprises:

A plurality of interior permanent magnets that bury, each magnet have two utmost points and have longitudinal size greater than lateral dimension;

A plurality of non magnetic peripheral grooves, at least one non magnetic peripheral groove is associated with each utmost point of interior permanent magnet, each non magnetic peripheral groove is positioned between cylindrical skirt and its associated interior permanent magnet, the interior permanent magnet adjacency that each non magnetic peripheral groove is not associated with it, wherein, each non magnetic peripheral groove has the longitudinal size greater than lateral dimension, and wherein, and the axle of the longitudinal size of each the non magnetic peripheral groove not axle with the longitudinal size of its associated interior permanent magnet is vertical; And

Each of each utmost point of a plurality of non magnetic end troughs, each non magnetic end trough permanent magnet in each is terminal and integrated with it, wherein, each non magnetic end trough have the central shaft of not aiming to small part with rotor radius.

16. the rotor of claim 15 wherein, has different length and has identical in fact width with the non magnetic peripheral groove that permanent magnet pole in each is associated.

17. the rotor of claim 15, wherein, at least two non magnetic peripheral grooves are associated with each utmost point of interior permanent magnet.

18. the rotor of claim 15, wherein, end trough has the longitudinal size greater than lateral dimension, and wherein, contiguous end trough has the parallel central shaft along its longitudinal size, and wherein, the opposing ends groove has along the central shaft of the aligning of its longitudinal size.

19. according to the rotor of claim 15, wherein, at least one in following:

Interior permanent magnet has the square-section of obtaining perpendicular to rotary middle spindle;

Peripheral groove is positioned as apart from the identical in fact distance of periphery with end trough;

The cross section is symmetry around the line that intersects perpendicular to interior permanent magnet and with rotary middle spindle; And

The axis of the longitudinal size of non magnetic peripheral groove does not intersect with rotary middle spindle.

20. according to the rotor of claim 15, wherein, each non magnetic end trough have the central shaft that the longitudinal axis of permanent magnet in be associated with it embedded is aimed to small part.

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