DE102013219106A1 - Electric rotating machine with interior permanent magnet for, e.g. hybrid vehicle, has side regulation grooves formed near outer ends of permanent magnets that forms a magnetic pole, designed such that preset relationship is satisfied - Google Patents

Abstract

The machine (10) has stator (11), rotor (12), permanent magnets (16), and side regulation grooves (22) near outer ends of magnets that forms magnetic pole. Each groove is designed such that preset relationship comprising values of included angle between longitudinal axis and radial reference line that extends from rotor axis at reference point on longitudinal axis of farthest edge of groove and included angle between longitudinal axis and reference line which become reference point at corner of magnet facing outer circumference of rotor closest to extend from rotor axis is satisfied. The electric rotating machine (10) has a stator (11) for receiving stator windings, and a rotor (12) rotatably mounted on stator about a rotor axis and having an outer periphery (12a) and several pairs of permanent magnets (16). The permanent magnets are arranged in a V-shaped configuration that opens towards the outer circumference to form a magnetic pole and are received in apertures (17) in the rotor. The openings with a low permeability, replaces the portion located in a predetermined area of one of the permanent magnets that generate directed magnetic flux lines emanating from stator magnetic flux lines which are erased in the vicinity of longitudinal axis of one of the magnetic poles, when the magnet is located in predetermined area. The opening comprises an additional space formed in one of the openings because of a shortening of magnetic length of magnet received in the opening along the magnet bore. The opening of additional space to the rotor axis extends to the outer periphery, and a pair of side regulation grooves (22) are formed in a parallel relation to the rotor axis in the outer circumference of the magnetic pole. The pair of side regulation grooves is located near two outer ends of the permanent magnets of the pair that forms the magnetic pole. Each of the side regulation grooves of the pair is designed for the magnetic pole so that a predetermined relationship comprising the values of included angle between longitudinal axis and radial reference line that extends from rotor axis at a reference point on the longitudinal axis of farthest edge of side regulating groove and the included angle between longitudinal axis and radial reference line which become a reference point at a corner of one of the permanent magnets facing the outer circumference of rotor closest to extend from rotor axis, is satisfied.

Description

TECHNICAL AREA

The present invention relates to an inside permanent magnet (IPM) rotating electrical machine, and more particularly to an IPM rotary electric machine having a high efficiency operation in a driving mode.

GENERAL PRIOR ART

Electric lathes must meet various output performance characteristics to meet various requirements by devices to which they are attached. For example, in a hybrid electric vehicle (HEV: Hybrid Electric Vehicle) used as a power source in cooperation with an internal combustion engine or in an electric vehicle (EV) as a sole power source, a traction motor should perform the function of a traction motor operate in a drive mode at a variable speed over a wide speed range and provide a sufficiently high torque at low speeds.

In the vehicles of the above type, improvement in fuel efficiency requires an improvement in the energy conversion efficiency of each of the constituents including a rotary electric machine, and in the case of an on-vehicle rotary electric machine, particularly, an improvement in efficiency in a frequently used range. Further, the in-vehicle rotary electric machine has to have a more compact structure with a high energy density from the viewpoint of space limitations for its mounting and from the viewpoint of miniaturization.

Incidentally, a rotary electric machine in HEVs or EVs in a normal drive mode generally operates at low speeds under low load conditions. For this reason, since the magnetic moment contributes more to the generation of torque for the on-vehicle rotating electrical machine than the reluctance torque variable with the amplitude of the currents through the stator windings, the permanent magnet tends to use strong permanent magnets for high efficiency.

This tendency manifests itself in the increasing use of permanent magnet type synchronous motors comprising a high remanence neodymium magnet embedded in a magnetic core and referred to as IPM synchronous motors (permanent magnet synchronous motors). In such IPM rotary electric machines, it is proposed to embed a plurality of pairs of permanent magnets in a rotor in such a manner that the permanent magnets of each pair are arranged in a "V" -shaped configuration opening toward an outer periphery of the rotor Magnetic circuit capable of actively using both the reluctance torque and the magnetic moment (see, for example, Patent Literature Examples 1 and 2). Further, in IPM rotary electric machines, it is also proposed to form grooves or grooves in an outer circumference of a rotor in order to regulate the magnetic resistance between the rotor and a stator (see, for example, Patent Literature Examples 3 to 5).

STATE OF THE ART

• Patent Literature Example 1 JP-A 2006-254629
• Patent Literature Example 2: JP-A 2012-39775
• Patent Literature Example 3: JP-A 2004-328956
• Patent Literature Example 4: JP-A 2008-206308
• Patent Literature Example 5: JP-A 2008-312316

Incidentally, in recent electric lathes, permanent magnets containing rare earth elements such as Nd, Dy, and Tb are increasingly being used to increase magnetism and heat resistance, but rising prices caused by their rarity and instability of their distribution cause one Increasing demand for improving efficiency in reducing the use amount of these rare earth elements.

However, since a rotary electric machine works in HEVs and EVs in a normal drive mode at low speeds under low load conditions, there is a tendency to increase the use amount of high magnet permanent magnets even in IPM motors such as those described in Patent Literature Examples 1 to 5 to increase the magnetic moment that contributes to low speed operation under low load conditions in the drive mode. This approach is remote from the task of reducing the use amount of rare earth elements.

Further, in an IPM rotary electric machine, the torque ripple is not limited to a satisfactorily small extent even if grooves formed in the outer periphery of a rotor as described in Patent Literature Examples 3 to 5 for regulating the magnetic resistance are employed as it is.

SUMMARY

Therefore, an object of the present invention is to provide a low-cost high-density electric rotating machine which performs high-efficiency operation in a drive mode while reducing the use amount of the permanent magnets.

According to a first aspect of the invention, there is provided an internal permanent magnet (IPM) rotating lathe comprising:
a stator configured to receive stator windings;
a rotor rotatable about a rotor axis with respect to the stator, the rotor having an outer periphery;
a plurality of pairs of permanent magnets in the rotor, the permanent magnets of each pair being arranged in a "V" shaped configuration opening toward the outer periphery, forming a magnetic pole and accommodated in magnet openings in the rotor;
Low permeability openings, each of which replaces the predetermined area portion of one of the permanent magnets that would generate so-directed magnetic flux lines that magnetic flux lines emanating from the stator would be canceled in the vicinity of a longitudinal axis (direct axis) of one of the magnetic poles the permanent magnet would be in the predetermined range,
wherein the opening comprises an additional space formed in one of the magnet openings due to a shortening of the length of the permanent magnet received in the magnet opening along the magnet opening,
wherein the opening extends from the additional space to the rotor axis and to the outer periphery; and
a middle regulating groove (center regulating groove) and a pair of lateral regulating grooves formed per magnetic pole in a parallel relation to the rotor axis in the outer circumference of the rotor,
the median regulatory groove being on a longitudinal axis for the magnetic pole,
wherein the pair of lateral regulating grooves are located near both outer ends of the permanent magnets of the pair forming the magnetic pole,
wherein each of the lateral regulating grooves of the magnetic pole pair is configured to have a relationship of θ4 ≦ θ3 is fulfilled,
wherein θ4 is the angle of inclusion between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point on the edge of the lateral regulating groove farthest from the longitudinal axis, and θ3 is the angle of inclusion between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point at a corner of one of the permanent magnets which is closest to the outer circumference of the rotor.

According to a second aspect of the invention, each of the lateral regulating grooves satisfies a relationship of 0.945 ≦ θ5 / θ4 ≦ 0.98, where θ5 is the angle of inclusion between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point on the edge of the lateral regulating groove least distant from the longitudinal axis.

According to a third aspect of the invention, each of the lateral regulating grooves satisfies a relationship of 0.0 ≦ RG / AG ≦ 0.73, where AG is the width of an air gap between an inner periphery of the stator and an outer circumference of the rotor, and RG is the depth of the lateral regulating groove.

According to the above-mentioned first aspect of the present invention, since a port having a low permeability replaces the portion of one of the permanent magnets in a predetermined range which would generate so-directed magnetic flux lines, magnetic flux lines originating from the stator would be counteracted in the vicinity of a longitudinal axis of a magnetic pole (they would be extinguished), magnetic flux lines of the magnets in the vicinity of a longitudinal axis do not counteract (do not extinguish) magnetic flux lines of the stator windings, and the passage of the magnetic flux lines through the predetermined range is restricted. Therefore, both the magnetic moment and the reluctance torque are effectively used by eliminating magnetic flux lines of the magnets that would be useless near the longitudinal axis magnetic flux lines of the stator and the use amount of the permanent magnets is reduced while a torque is equal to or larger than before replacing the portion of each of the permanent magnets with an opening.

Moreover, replacement of the portion of each of the permanent magnets with the aperture improves the output at high speeds, since a reduction in the magnetic flux lines of the magnets causes a reduction in the induced voltage constant. In addition, weight saving causes a reduction in inertia.

A reduction in the magnetic flux lines of the magnets causes a reduction in the space-harmonic causing magnetic distortion (magnetostriction) due to a reduction in field weakening regions (a reduction in the extent of field weakening). This restricts the generation of heat by influencing the generation of eddy currents, and restricts the demagnetization caused by a temperature change of the permanent magnets, resulting in lower costs because the degree of heat resistance can be lowered.

In addition, by forming an additional space toward the longitudinal axis, this opening restricts it to have such a configuration as to expand toward the axis of the rotor, a bypass path of magnetic flux lines of the stator windings extending from the side of a lateral axis (quadrature axis). on one side of a magnetic pole inwardly penetrate into the rotor, to the outer peripheral side of the magnetic pole, thereby causing the magnetic flux lines of the stator windings to extend to the other transverse axis on the other side of the magnetic pole, resulting in saturation caused by connection with Avoid magnetic flux lines of the magnets, which extend to the outer peripheral side of the magnetic pole, avoided. Therefore, this increases the total torque since the reluctance torque obtained from the magnetic flux lines of the stator windings is effectively used.

Further, by thus forming the additional space toward the longitudinal axis, this opening enables it to have a configuration which widens toward the outer circumference of the rotor, making an appropriate adjustment of the direction of that part of the magnetic flux lines of the magnets which does not cancel of magnetic flux lines of the stator windings, but can not effectively cooperate with the magnetic flux lines of the stator windings, on the side of the longitudinal axis of the magnetic pole. Therefore, since the synthetic magnetic flux lines formed by the combined action of the magnetic flux lines of the stator windings and the magnetic flux lines of the magnets are made to pass over a flow flow path that contributes to an efficient generation of torque, it further increases the overall torque.

Further, in addition to a reduction in the magnetic flux in the vicinity of the longitudinal axis, thanks to the above-mentioned opening, the middle regulating grooves can regulate an increase in the reluctance between the rotor and the stator teeth in the vicinity of the longitudinal axis, an increase in the concatenation Magnet flux of the stator windings are limited. Therefore, it is possible to prevent a drop in drive efficiency caused by an increase in torque ripple and iron loss.

In addition, the lateral regulation grooves may limit harmonics superimposed on the concatenated magnetic flux waveform by controlling the magnetic reluctance in the vicinity of the two outer ends of the permanent magnets of each pair arranged in a "V" shape (θ4 ≦ θ3, where θ4 is the inclusion angle between each of the longitudinal axes and a radial reference line extending from the rotor axis to a reference point at the edge of one of the lateral control grooves farthest from the longitudinal axis, and θ3 is the inclusion angle between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point at a corner of the permanent magnet which is closest to the outer circumference of the rotor). Therefore, it is possible not only to restrict the cogging torque but also to prevent a drop in drive efficiency caused by an increase in torque ripple and iron loss.

Consequently, a cheap rotary electric machine is realized, which provides a high-quality operation with a high energy density in a drive mode.

According to the above-mentioned second aspect of the present invention, by the lateral regulating grooves each having a relationship of 0.945 ≦ θ5 / θ4 ≦ 0.98 fulfill,
where θ5 is the angle of inclusion between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point on the edge of the lateral regulating groove least distant from the longitudinal axis,
An increase in the cogging torque, the torque ripple and the iron loss are effectively limited.

According to the above-mentioned third aspect of the present invention, by the lateral regulating grooves each having a relationship of 0.0 ≦ RG / AG ≦ 0.73, fulfill,
wherein AG is the width of an air gap between an inner circumference of the stator and an outer circumference of the rotor, and RG is the depth of the lateral regulating groove, an increase in cogging torque, torque ripple and iron loss are effectively restricted.

BRIEF DESCRIPTION OF THE DRAWINGS

1 Figure 11 is a plan view of a rotor and stator of an IPM rotary electric machine embodying features of the invention.

2 FIG. 12 is a diagrammatic view of a rotor embodying features of the invention wherein the stator has windings energized with electric current, but wherein the permanent magnets are not included and the magnetic flux lines (ψ _r ) are generated only by the energized stator windings, not shown, during operation in a drive mode under low load conditions.

3 is a 2 similar view, wherein the stator has no current and the magnetic flux lines (ψ _m ) from the north poles (N) to the south poles (S) only by the permanent magnets, which are accommodated in magnet openings in the rotor, generated during operation in one Drive mode under low load conditions.

4 FIG. 13 is a graph showing torque characteristics with respect to various degrees of current phases for a V-type IPM motor including a conventional rotor made with an opening that is not large and located on the side of the longitudinal axis of each of FIGS Permanent magnets is located;

5A is a diagrammatic view of the conventional rotor, wherein the stator has no current and the magnetic flux lines (ψ _m ) are generated only by the permanent magnets, which are accommodated in magnet openings in the rotor.

5B FIG. 15 is an enlarged view of an area in the vicinity of each of the longitudinal axes of FIG 5A rotor shown that indicates a vector field (V _m), which is formed only by the magnetic flux lines generated by the permanent magnets.

6A is a 5A similar view, wherein the stator having current-energized stator windings, but wherein the permanent magnets are not included and the magnetic flux lines (ψ _r ) are generated only by the energized stator windings, during operation in a drive mode under maximum load.

6B FIG. 12 is an enlarged view of an area near each of the longitudinal axes of FIG 6A shown rotor, which indicates a vector field (V _r ), which is formed only by the magnetic flux lines, which are generated by the energized stator windings.

7 FIG. 12 is a diagram of a model showing a relationship of the vector distribution by the permanent magnets of each pair forming a magnetic pole with respect to the vector distribution by the energized stator windings in an area on the outer peripheral side of the magnetic pole of FIG 5A shows shown conventional rotor during operation in a drive mode under maximum load.

8th FIG. 13 is a graph showing the coincidence of the torque with the phase of the input current with respect to the V-type IPM motor corresponding to the one in FIG 5A contains shown rotor shows.

9 is a 5A and 6A similar view, wherein the magnetic flux lines (ψ _r ) are generated only by the energized stator windings, during operation in a drive mode under low load.

10 is a 5A . 6A and 9 similar view, but in addition to the synthetic magnetic flux lines (ψ _s ) which by the combined effect of magnetic flux lines (ψ _m ), which are generated by the permanent magnets and magnetic flux lines (ψ _r ), which are generated by the energized stator windings are formed Contains flow-flow paths defined by the flux-flow distribution of the synthetic magnetic flux lines (ψ _s ) in a low-load drive mode.

11 FIG. 12 is a graph showing the variation of the output torque and the rate of torque ripple reduction when each of the embedded permanent magnets in a rotor embodying features of the invention is shortened.

12 Fig. 12 is a diagram showing the variation of the 5th order space harmonics when each of the embedded permanent magnets in the rotor embodying the features of the invention is shortened.

13 is a graph that compares percentages of torques generated when the in 5A . 6A and 9 shown conventional rotor during operation in a drive mode under low loads, with percentages of torque when the rotor embodying the features of the invention is used during operation in a drive mode under low loads shows.

14 is a 13 similar graph, but a comparison of percentages of torques generated when the in 5A . 6A and 9 shown used during operation in a drive mode under a maximum load, with percentages of torque, when the rotor embodying the features of the invention is used during operation in a drive mode under a maximum load shown.

15 is a 2 similar view, wherein the stator having current-energized stator windings, but wherein the permanent magnets are not included and the magnetic flux lines (ψ _r ) are generated only by the not shown energized stator windings, during operation in a drive mode under a maximum load.

16 is a 2 and 15 Similar view, but containing synthetic magnetic flux lines (ψ _s ), which are formed by the combined effect of magnetic flux lines generated by the permanent magnets, and magnetic flux lines generated by the energized stator windings, during operation in a low-drive mode Charges.

17 is a 2 . 15 and 16 Similar view, but containing synthetic magnetic flux lines (ψ _s ), which are formed by the combined effect of magnetic flux lines generated by the permanent magnets, and magnetic flux lines generated by the energized stator windings, during operation in a drive mode under a maximum load.

18 FIG. 12 is a diagrammatic view of a comparison structure of a rotor for comparison with the structure of FIG 17 11, which includes synthetic magnetic flux lines (ψ _s ) formed by the combined action of magnetic flux lines generated by the permanent magnets and magnetic flux lines generated by the energized stator windings during operation in a drive mode under a maximum load ,

19 is an illustration of the instantaneous torque in the average torque with respect to the electrical angle represented by the structure A of FIG 17 shown embodiment, and that of the in 18 Comparative Example B shown.

20 is a graph that shows the percentage of each harmonic that the in 19 superimposed momentary torque waveform shown for each of the in 17 shown construction A of the present embodiment and the in 18 Comparative construction B shown shows.

21 is a graph showing the percentage of each content of the flux waveshape chained with a tooth for each of the in 17 shown construction A of the present embodiment and the in 18 Comparative construction B shown shows.

22 FIG. 13 is a plot of torque versus R2 / R1 as a parameter, where R2 is the radial distance of that end wall of each of the flux barriers 17c , which is closer to the rotor axis, is from the rotor axis, and R1 is the outer radius of the rotor.

23 FIG. 4 is a plot of torque versus R3 / R2 as a parameter, where R3 is the inner radius of the rotor, and R2 is the radial distance of the end wall of each of the flux barriers 17c , which is closer to the rotor axis, is from the rotor axis.

24 FIG. 12 is a diagrammatic view of a portion of a rotor embodying aspects of the invention near the corners of permanent magnets of each pair located near a longitudinal axis that includes a model having a relationship of vector distribution through the permanent magnets with respect to FIG Indicates vector distribution by energized windings during operation in a drive mode under a maximum load, wherein the rotor is designed with a large opening, which includes an additional space in a magnet opening, which is formed due to a shortening of the length of the associated permanent magnets along the magnet opening, wherein the large opening does not extend beyond the circumference of the permanent magnet to the outer periphery of the rotor.

25 is a 24 similar view, but comprising a rotor, which carries out aspects of the invention, wherein the rotor is designed with a large opening, which includes an additional space in a magnet opening, which is formed due to a shortening of the length of the associated permanent magnet along the magnet opening, wherein the large opening extends from the additional space beyond the circumference of the permanent magnet to the outer periphery of the rotor.

26 FIG. 12 is a diagram that is enlarged and includes parameters that are used to determine shape dimensions of that portion of the opening that extends from the additional space beyond the circumference of the associated permanent magnet to the outer periphery of the rotor.

27 is a diagram of examples of design models when an in 26 shown parameter DL _{d is} changed.

28 FIG. 13 _is a graph showing the variation of the torque and the variation of the harmonic torque components when a ratio of DL _d to an outer radius R1 of the rotor is changed as a parameter.

29 FIG. 12 is a diagram showing the variation of the torque ripple when the ratio of DL _d to the outer radius R1 is changed.

30 FIG. 15 is a graph showing the variation of the torque and the variation of the harmonic torque components when a ratio θ1 / θ2 is changed as a parameter.

31 FIG. 13 is a graph showing the variation of the torque ripple when the ratio θ1 / θ2 is changed.

32 FIG. 12 is a graph of the instantaneous torque in the average torque with respect to the electrical angle to compare the case of elongation of flux barriers in the form of openings with the case where the flux barriers are not elongated.

33 is a representation that represents the percentage of each harmonic torque component that is in 32 superimposed shown waveform of the instantaneous torque shows.

34A is a 5A similar view containing only by permanent magnets generated magnetic flux lines (ψ _m ), wherein the conventional rotor is designed with a non-large opening, which is located at each permanent magnet on the side of the longitudinal axis, but is not designed with center grooves.

34B is a vector field for the synthetic magnetic flux lines formed by the combined action of the magnetic flux lines generated by the permanent magnets and the magnetic flux lines generated by the energized stator windings, in the vicinity of a longitudinal axis when the V-type IPM motor is the conventional rotor includes, which is designed with the non-large opening, which is at the side of the longitudinal axis in each permanent magnet, operates in a drive mode under maximum load, the conventional rotor is not designed with center grooves.

35A Fig. 12 is a diagrammatic view showing magnetic flux lines generated only by the permanent magnets of a V-type IPM motor including a less preferable rotor having a large opening located at each side of the longitudinal axis of each permanent magnet is located, wherein the less preferred rotor is not designed with center grooves.

35B is a vector field for the synthetic magnetic flux lines formed by the combined action of the magnetic flux lines generated by the permanent magnets and the magnetic flux lines generated by the energized stator windings, near a longitudinal axis when the V-type IPM motor is the less preferred one Rotor, which is designed with the large opening, which is at the side of the longitudinal axis in each permanent magnet, operates in a drive mode under maximum load, the less preferred rotor is not designed with center grooves.

36 is a representation of the magnetic flux waveform concatenated with a tooth in relation to the electrical angle to the in 34A shown conventional rotor, which is designed with the non-large opening, which is located at each permanent magnet on the side of the longitudinal axis, wherein the conventional rotor is designed with no center grooves, with the in 35A shown less preferred rotor, which is designed with the large opening, which is located at each permanent magnet on the side of the longitudinal axis, the less preferred rotor is not designed with center grooves to compare.

37 FIG. 12 is a graph showing the percentage of the content of each of the space harmonics contained in a magnetic flux waveform concatenated with a stator tooth after a Fourier transform of the magnetic field in FIG 36 shows flow waveforms shown.

38 is a vector field for the synthetic magnetic flux lines formed by the combined action of the magnetic flux lines generated by the permanent magnets and the magnetic flux lines generated by the energized stator windings near a longitudinal axis when a V-type IPM motor including a rotor , which embodies aspects of the invention operates in a drive mode under maximum load, wherein the rotor is designed in addition to a large opening, which is located at each permanent magnet on the side of the longitudinal axis, with center grooves.

39 FIG. 14 is a graph of torque versus electrical angle to illustrate the present embodiment with the embodiment of FIG 35A to compare structure shown, wherein the less preferred rotor is not designed with center grooves.

40 FIG. 12 is a graph showing the degree of each harmonic torque component, which is the torque waveform that after a Fourier transform of the in 39 given waveforms is superimposed.

41 Figure 10 is an enlarged fragmentary view of a magnetic pole of the rotor showing parameters used to determine the shape dimensions of each of the center grooves.

42 FIG. 12 is a graph showing the variation of the torque ripple when the in 41 shown, used for the shape dimensions of the center groove ratio of R4 to the outer radius R1 is changed as a parameter.

43 FIG. 12 is a diagram showing phase voltage waveforms and a line voltage waveform when an outer arc angle θ _{a is used} as a parameter.

44 FIG. 14 is a graph of torque versus electrical angle to illustrate the present embodiment with the embodiment of FIG 35A to compare the construction shown, wherein the less preferred rotor is not designed with center grooves, wherein the torque waveforms are shown during operation in a drive mode under low loads.

45 FIG. 12 is a graph showing the degree of each harmonic torque component, which is the torque waveform that after a Fourier transform of the in 44 given waveforms is superimposed.

46 FIG. 12 is a diagram of a structure executed without any lateral grooves, showing a positional relationship of a magnetic pole to stator teeth. FIG.

47 FIG. 13 is an illustration of a gap magnetic flux waveform generated when the in 46 shown construction, which is executed without any lateral grooves, operates under a non-load condition.

48 FIG. 13 is an illustration of a gap magnetic flux waveform generated when the in 46 shown construction, which is executed without any lateral grooves, operates under a maximum load condition.

49 Fig. 10 is an enlarged fragmentary view of a magnetic pole of the rotor showing parameters used to determine the shape dimensions of each of the lateral grooves to be formed in the outer circumference of the rotor.

50 FIG. 12 is a graph showing the changes in the average torque, the harmonic torque components and the torque ripple when the ratio θ5 (inner trapped angle from the longitudinal axis) / θ4 (outer trapped angle from the longitudinal axis) at the in 49 shown shape dimensions for each of the lateral grooves as parameters during operation under a maximum load condition is changed.

51 FIG. 15 is a graph showing the changes in the average torque, the harmonic torque components and the torque ripple when the ratio θ5 (inner inclination angle of the longitudinal axis) / θ4 (outer inclination angle of the longitudinal axis) in the 49 shown shape dimensions for each of the lateral grooves as parameters during operation under low load conditions is changed.

52 FIG. 13 is a graph showing the changes of the average torque and the torque ripple when the ratio RG (groove depth) / AG (air gap width) in the in 49 shown shape dimensions for each of the lateral grooves as parameters during operation under a maximum load condition is changed.

53 FIG. 15 is a diagram showing slit magnetic flux waveforms, one of which is generated by the lateral groove configuration and the other of which is generated by the structure without lateral grooves, during operation under a no-load condition to compare the amplitudes of the overlying harmonics.

54 FIG. 12 is a graph showing torque waveforms, one of which is generated by the side groove structure and the other is generated by the structure without side grooves, during operation under a maximum load condition to compare the amplitudes of the torque ripples.

55 FIG. 13 is a graph showing torque waveforms, one generated by the side groove configuration and the other generated by the structure without side grooves, during low load condition operation to compare the amplitudes of the torque ripples. FIG.

56 FIG. 15 is a diagram showing cogging torque waveforms, one of which is generated by the side groove structure and the other is generated by the structure without side grooves, during operation under a no-load condition to check a reduction in cogging torque.

DETAILED DESCRIPTION

An embodiment (s) of the present invention will be described with reference to the accompanying drawings. 1 to 56 show an embodiment of an electrical IPM lathe according to the present invention. In the following description of the preferred embodiment, for illustrative purposes only, a rotor rotates in such a direction as to rotate in a counterclockwise (CCW) direction with respect to a stator, for example.

In 1 includes a rotating electrical machine or a motor 10 a stator 11 formed in the shape of a generally cylindrical shape and a rotor 12 that from this stator 11 is surrounded, is rotatable on a rotation axis or a rotor axis, and fixed to a drive shaft 13 , which is arranged coaxially with the axis of rotation is coupled. The electric lathe 10 provides a power adapted to specifications required for a power source of a hybrid vehicle (HEV) or an electric vehicle (EV), such as an internal combustion engine for a vehicle is required as a power source, or adapted to specifications for a built Power source in each of the drive wheels of a vehicle are required.

The stator 11 is with several stator teeth 15 designed to extend in such a manner in radial directions from the rotor axis that an inner circumference 15a of the stator 11 and an outer circumference 12a of the rotor 12 facing each other with a gap G therebetween. The stator 11 is wound with three-phase windings, each representing a distributed winding (not shown) for each phase, to form stator windings capable of generating a magnetic flux associated with the rotor 12 interacts to produce a rotor torque.

The rotor 12 is designed as a rotor of an IPM motor (motor with internal permanent magnets); and there are several sets of permanent magnets 12 embedded, with each set per pole a pair of permanent magnets 16 has, which are arranged in a "V" -shaped shape, which is to the outer periphery 12a opens. For the permanent magnets of each pair is the rotor 12 with a set of openings 17 executed, which are arranged in a "V" -shaped shape, which is to the outer periphery 12a opens to the permanent magnets 16 , each of which has the same rectangular cross-sectional profile along its length and extending in the axial direction along the rotor axis, to be firmly held by allowing their corners 16a in the set of openings 17 be used.

The openings 17 Each set arranged in a "V" shaped configuration includes magnet openings 17a that are designed to be the permanent magnets 16 of the corresponding pair and include and openings 17b and 17c passing over each of the permanent magnets 16 are disposed away from each other in the direction of its width and serve as flow barriers to prevent the magnetic flux around the permanent magnet 16 turns (hereafter referred to as "flux barriers" 17b and 17c ) designated. Every set of openings 17 , which are arranged in a "V" -shaped design, has a central bridge 20 on, extending between the openings 17c , which are between the permanent magnets 16 of each pair, extending in a radial direction from the rotor axis, to connect the inner and outer edges defining the opening to the permanent magnets against the centrifugal force generated when the rotor 12 rotating at a high speed, keeping in position.

In this electric lathe 10 form openings, each between two adjacent stator teeth 15 of the stator 11 there are slots 18 in which stator windings are inserted to coil groups around the stator teeth 15 to build. On the other hand, each of the eight sets of permanent magnets 16 at the rotor 12 to the corresponding six of the stator teeth 15 of the stator 11 directed. In short, this electric lathe 10 designed so that every pole through a pair of permanent magnets 16 on the rotor 12 is formed, to the adjacent six slots 18 of the stator 11 is directed. That means the electric lathe 10 is designed as a three-phase IPM motor in which the two mutually facing sides of a pair of magnets in each second magnetic pole have the north poles, while the two mutually facing sides of a pair of magnets in the adjacent magnetic pole have the south poles, and a 48- Slotted stator is wound in distributed windings to form coils, each under each phase has a coil spacing in electrical degrees of five stator teeth, whereby 8 magnetic poles (4 pairs of magnetic poles) are formed. In other words, the rotary electric machine 10 is constructed as an IPM type structure in which (slot number q per pole and phase) = {(slot number) / (pole number)} / (phase number) = 2.

This allows the rotor 12 working in a drive mode by moving the stator windings in the slots 18 of the stator 11 are energized to generate magnetic flux lines extending from the stator teeth 15 directed radially inward into the opposite rotor 12 extend. In this case, in the electric lathe 10 (Stator 11 and rotor 12 ) Reluctance torque, which seeks to shorten the Flußfließweg, with a magnetic moment, the attraction and repulsion forces between the permanent magnets 16 originates, combined to produce a composite torque. Therefore, electrical energy generated by a current that is fed into the stator windings, from a drive shaft, with respect to the stator 11 with the rotor 12 is rotatable, taken as mechanical energy.

Everyone from the stator 11 and the rotor 12 includes multiple layers arranged in a stacked relationship. Each of the layers is formed of an electric steel such as silicon steel. The layers are made by fasteners 19 axially stacked to a suitable axial thickness for a desired output torque.

The electric lathe 10 has a coil group for each phase, which is in slots 18 is housed in a distributed winding, so as in 2 illustrated for each set of stator teeth 15 leading to a pair of permanent magnets 16 , which form a magnetic pole, a flux flow path generated by the energized stator windings defines a flux flow path (from magnetic flux lines ψ _r generated only by the energized stator windings) between the slots 18 through the stator 11 extends radially inwardly after it is close to the outer circumference of the stator 11 ie, behind the set of stator teeth 15 has moved in a circumferential direction to enter the rotor 15 to penetrate and run through it. The permanent magnets 16 every pair are in the magnet openings 17a a set of apertures arranged in a "V" shaped configuration 17 Which are along the flow path of the flow lines of magnetic flux ψ _r, which are generated only by the energized stator windings, is formed, are formed in other words so that they ψ the construction of these magnetic flux lines _r not prevent was added.

The through the permanent magnets 16 produced flow flow paths (the magnetic flux lines ψ _m , which are generated only by the permanent magnets), by a as in 3 flow distribution defined are only perpendicular to the north poles (N poles) on one side of the permanent magnets 16 each pair forming a magnetic pole penetrates vertically into the south poles (S poles) on opposite sides of the permanent magnets 16 one. In particular, each of the river flow paths runs after entering the stator 11 from the corresponding stator teeth 15 near the outer periphery of the stator 11 in a circumferential direction.

In the IPM design, in which the permanent magnets 16 every pair in the rotor 12 are embedded and arranged in a "V" -shaped configuration, a direction of the flux lines formed by each of the magnetic poles becomes, ie, a central axis between the permanent magnets 16 each pair arranged in a "V" -shaped configuration is referred to as a longitudinal axis (d-axis), and a central axis, which shows electrical and magnetic orthogonality with respect to the longitudinal axis, between adjacent permanent magnets 16 between adjacent magnetic poles referred to as a transverse axis (q-axis). In the rotor 12 extend radially inner openings 17c located at the side of the longitudinal axis of each set of openings 17 located in a "V" -shaped configuration, are radially inward of the rotor axis, and are designed to function as flux barriers 17c perform. Suitable shape dimensions of the river barriers 17c every set of openings 17 which are arranged in a "V" shaped configuration will be described later.

In this electric lathe 10 this allows flux lines ψ _r generated by the stator windings to travel in radially inward directions from the stator teeth 15 in the rotor 12 penetrate further inwardly near the inner circumference (the rotor axis) in such a way that they do not enter the radially outward region of the openings 17 each set, which are arranged in a "V" -shaped shape, penetrate before going to the stator teeth 15 return, as in 2 is illustrated. In a word, the electric lathe is 10 designed as a V-type IPM motor, which has a rotor 12 comprises, which is carried out in the vicinity of the longitudinal axes with openings.

Further, the rotary electric machine includes 10 for preventing heavy superimposition of the 5th and 7th spatial harmonics on the flux lines ψ _r generated by the stator windings and stator teeth 15 corresponding to the longitudinal axes, in radially inward directions into the rotor 12 penetration, center grooves (middle regulation grooves or center control grooves) 21 located in the outer periphery of the rotor 12 are formed and each parallel to the inner circumference 15a one of the corresponding stator teeth 15 extend (in a direction along the rotor axis). Suitable shape dimensions for each of the center grooves 21 will be described later.

Further, the rotary electric machine includes 10 one pair of lateral grooves (lateral regulation grooves) per magnetic pole 22 at the locations near the radially outer ends of the permanent magnets of each pair forming a magnetic pole in the outer circumference 12a of the rotor 12 are formed to attenuate the pulsation of the engine torque over the entire operating range in a drive mode by the non-load cogging torque and the torque ripple are reduced under low load conditions and a maximum load, while minimizing a reduction of the torque. Matching shape dimensions for each of the side grooves 22 will be described later.

P_P

die Anzahl der Polpaare ist, ψ_m die Flusslinien von Magneten sind, die mit dem Stator (Statorzähnen 15) verketten,

i_d

der Strom der Längsachse ist, i_q der Strom der Querachse ist,

L_d

die Induktivität der Längsachse ist, und L_q die Induktivität der Querachse ist.

In the electric lathe 10 with the IPM construction, in which permanent magnets 16 in a "V" -shaped design in the rotor 12 are embedded, the torque T by the following equation (1) as T = P _p {ψ _m i _q + (L _d -L _q ) i _d i _q } (1) expressed, where

P _P

the number of pole pairs is, ψ _{m are} the flux lines of magnets connected to the stator (stator teeth 15 ),

i _d

the current of the longitudinal axis is, i _{q is} the current of the transverse axis,

L _d

the inductance of the longitudinal axis is, and L _{q is} the inductance of the transverse axis.

As in 4 is shown by a operation with the current phase in which the sum of the magnetic moment T _m and the reluctance torque T _{r reaches} the maximum value, a highly efficient operation with a high torque of the rotary electric machine 10 provided.

With reference to the 5A to 6B are in the case of a comparative rotor 12A according to the related technology, the river barriers 17c (please refer 1 to 3 ) in the form of openings located on the side of the longitudinal axis by flow barriers 17d replaced. The river barriers 17d are generally with flow barriers in terms of mold dimensions 17b located on the radially outer sides of the openings arranged in a "V" shaped configuration 17 each sentence are identical. With regard to the comparison rotor 12A are the river flow paths through the permanent magnets 16 through an in 5A illustrated flow distribution defined. The magnetic flux lines ψ _m , which are generated by the magnets, define vectors V _m , which as shown by a vector field in 5B have indicated directions. In addition, magnetic flux lines are ψ _r , which by energized stator windings, which in slots 18 are recorded, generated by an in 6A flow distribution specified and define vectors V _r , as shown by a vector field in 6B have indicated directions.

The electric lathe, which is the rotor 12A of the above-mentioned type is operated by advancing a phase angle of the current to produce a high torque with a high efficiency in the drive mode under a maximum load. Under this condition, the rotor becomes 12A operated according to the related technology in a state in which magnetic flux lines ψ _{m of} the magnets and magnetic flux lines ψr the stator windings in a small area A1 (see 6B ) extending from the set of apertures arranged in a "V" shaped configuration 17 radially outward and in the vicinity of the longitudinal axis, generate opposite fields, so that the reluctance torque T _r the magnetic moment T _m erases (compensates), as illustrated by the vector fields in 5B and 6B is shown. In short, this small area A1 is like in 7 For example, an interaction region in which magnetic flux lines ψ _{m of} the magnets and magnetic flux lines ψr of the stator windings act against each other at an induced angle equal to or greater than 90 degrees, so that the magnetic flux lines ψ _{r of} the stator windings are weakened because they are Magnetic flux lines ψ _{m of} the magnets counteract (they cancel) that of areas B in the vicinity of the longitudinal axis of the permanent magnets 16 each pair, which at the radially outward of the set of openings arranged in a "V" -shaped design 17 bordering small area A1, go out.

Because of this, it can be said that it is because of the fact that it is the areas B of the permanent magnets 16 , which are located near the longitudinal axis, failing to make any active contribution to the generation of torque T, is possible, the amount of use of the permanent magnets 16 in itself decrease by the volume of the areas B, near the longitudinal axis, of the permanent magnets 16 is reduced while maintaining a ratio of saliency ratio in the magnetic circuit as high as the previous ratio of saliency ratio.

Now, the torque T expressed by the aforementioned equation (1) becomes a reduction in the use amount of the permanent magnets 16 as high as the previous torque, before reducing the amount of use of the permanent magnets 16 was generated by increasing the reluctance torque T _r . This reluctance torque T _r is increased by increasing a difference between the inductance L _{d of} the longitudinal axis and the inductance L _{q of} the transverse axis, that is, by increasing a ratio of saliency ratio.

Therefore, the torque T according to the present embodiment of the rotor 12 as high as the previous torque held by each of the areas B, near the longitudinal axis, of the permanent magnets 16 is replaced by an opening having a small magnetic permeability (referred to as a "restricted area") to increase a ratio of saliency ratio, while the use amount of the permanent magnets 16 is reduced. Viewed from a different angle of view, the reluctance torque T _{r is} increased by wasteful of that portion of the magnetic flux lines ψ _{r of} the stator windings caused by the action against the magnetic flux lines ψ _m by the permanent magnets emanating from the areas B in the vicinity of the longitudinal axis was used effectively, so that the torque T despite the reduction in the amount of use of the permanent magnets 16 remains unchanged.

The torque T can also be expressed by the following equation (2). The ratio of the magnetic moment T _m is under low load conditions under which the amplitude of the current I _a is decreased, high. As in 8th As shown, the phase angle of the current β at which the torque is the maximum value approaches, the more zero the lower the amplitude of the current I _a . The illustrated waveforms i, ii, iii, iv and v in FIG 8th are characteristic curves, each representing the relationship between the torque and the phase angle of the current at one of different amplitudes of the current I _a (i), I _a (ii), I _a (iii), I _a (iv) and I _a ( v), where the amplitudes of the currents have the relationship of the following inequality equation: i <ii <iii <iv <v. Therefore, despite the fact that the ratio of (the dependence on) the magnetic moment T _m during operation under high load conditions is naturally high, it is desirable to produce a magnetic circuit that maximizes the effective use of this magnetic moment T _m . T = P _p {ψ _m I _a cosβ + ½ (L _d -L _q ) I _a ² sin 2β} (2) where β is the phase angle of the current and I _{a is} the amplitude of the phase current.

As in 9 As shown, the number of magnetic flux lines ψ _{r of} the stator windings in the rotor increases 12A according to the related technology at each of the transverse axes between the adjacent two magnetic poles (between the permanent magnets 16 the adjacent two different magnetic poles), because the phase angle of the current β due to the operation under low load conditions with a small amplitude of the current is close to zero. Therefore, it is ideal when a magnetic circuit over in 10 shown flow paths MP1 and MP2 as paths of the superimposed flux lines ψ _s , which are formed by the combined effect of the magnetic flux lines of the magnets ψ _m and the above-mentioned magnetic flux lines ψ _{r of} the stator windings extends. This will allow for active use of the reluctance torque T _r since the juxtaposed flux lines ψ _{s will increase} the inductance L _{q of} the transverse axis along each transverse axis by dispersing the transverse axis flux path (magnetic flux lines through the transverse axis) extending along the transverse axis (without any saturation to induce).

The flow path MP1 turns after penetration into the rotor 12A in the interpolar portion between the adjacent two magnetic poles across the air gap G of one of the stator teeth 15 in a chained relationship in one direction to the adjacent one of a pair of permanent magnets 16 which form a preceding one of the two magnetic poles with respect to the direction of rotation of the rotor (in 10 seen to the left side), and extends from the side thereof in the vicinity of the inner circumference of the rotor 12A through him. The Flußfließweg MP1 then traverses the outer peripheral portion A2 of the magnetic pole and returns via the air gap G again to another of the stator teeth 15 back.

The flow flow path MP2 turns into the rotor in the same manner as the flow flow path MP1 in the interpolar section 12A has penetrated, in a circumferential direction to the distal of the permanent magnets 16 which form, with respect to the direction of rotation of the rotor, the preceding of the two magnetic poles, and extends from its side in the vicinity of the inner circumference of the rotor 12A through him. The flux flow path MP2 then traverses the outer peripheral portion A2 of the magnetic pole and returns via the air gap G again to another of the stator teeth 15 back.

When permanent magnets 16 If each pair has been moved inwardly towards the rotor axis by removing portions that are inwardly from their farthest two ends (the radially outer ends of the pole), these flux flow paths MP1 and MP2 will not succeed, the entire outer circumference A2 of each Pols effectively to use because enlarged flux barriers, which adjoin the farthest ends of the permanent magnets of the pair, concentrate in the vicinity of the center of the pole and make it difficult for the Flußfließwege to extend in particular through the right half of the outer peripheral portion A2 ,

When the permanent magnets 16 On the other hand, by removing portions that are inward from their nearest ends (the radially inner ends of the magnetic pole) near the center axis of the permanent magnets, large flux barriers occur in the vicinity of the central axis of the permanent magnets causes the flow flow paths to be scattered to pass through both side portions of the magnetic pole, and therefore, the magnetic flux lines smoothly pass through the outer peripheral portion A2 of the magnetic pole by effectively using the entire outer peripheral portion A2 including its right half. In this structure, a flux flow path MP3 connects the adjacent magnetic poles from the north pole (N pole) of a permanent magnet 16 the subsequent one of the adjacent two magnetic poles to the south pole (S-pole) of the adjacent permanent magnet 16 the preceding of the adjacent two magnetic poles with respect to the direction of rotation of the rotor, after passing through the permanent magnet 16 of the subsequent magnetic pole - from the outside of which is near the outer periphery of the rotor to its inner side in the vicinity of the inner circumference of the rotor - run. In a manner similar to the flow flow path MP1, the flow path MP3 extends through the outer peripheral portion A2 of the preceding magnetic pole with respect to the rotational direction of the rotor, causing the effect of decentralizing the magnetic flux lines to become high.

For this reason it is favorable if a rotor 12 for the structure for embedding the permanent magnets 16 every pair that forms a magnetic pole that uses the design, in which the permanent magnets 16 of the pair are moved outwardly to their farthest ends (the radially outermost ends of the magnetic pole) while the "V" shaped configuration of the permanent magnets 16 is maintained in order not to affect the distribution of the magnetic flux lines ψ _r , which generate the reluctance torque T _r . Furthermore, it is favorable to use the design in which between the permanent magnets 16 of the pair (the radially inner ends of the magnetic pole) are flux barriers 17c are formed to restrict the short-circuit path of the magnetic flux lines. In addition, it is favorable to use the design, in which at each of the longitudinal axes of a center groove 21 in the outer peripheral surface of the rotor 12 is located to generate a saturation of the magnetic flux lines ψ _{r of} the stator windings, that of the stator teeth 15 of the stator 11 come to restrict or, in other words, to scatter the magnetic flux lines ψ _{r of} the stator windings. By employing these designs, the rotor can 12 actively use the reluctance torque T _r by scattering the transverse axis flux paths (magnetic flux lines) to increase the inductance L _{q of} the lateral axis.

The optimum value for a longitudinal length W _pm (width) of each of the permanent magnets in the accompanying drawings 16 is determined as a standard after comparison with the case where the longitudinal length W _{pm is} not extended.

Specifically, it is determined by changing a ratio δ given by calculating the following equation (3), where a pole number P is fixed, an outer radius R1 extending from the axis of the rotor 12 extends to the outer periphery, is fixed, and the length W _pm of each permanent magnet 16 a pair disposed at an outer end portion of a magnetic pole is made variable, that is, the position of each of the inner ends of the permanent magnets 16 of the couple is changed. As the determining factors of the ratio, the change of the value per unit of the torque T under the condition of the maximum load with respect to the ratio δ and the change in the rate of reduction of the fluctuation of this torque T, ie, the torque ripple, with respect to the ratio δ given after a magnetic field analysis and as in the representation of 11 shown graphically. For example, in the "per unit" system, 1.0 [per unit] means that the size of a base unit is the same. δ = (P × W _pm ) / R1 (3)

In 11 the ratio δ of 1.84 (δ = 1.84) represents the case in which each of the permanent magnets 16 has a shape dimension, wherein a length W _{pm of} the permanent magnet 16 is not shortened (ie, a reduction in the amount of the permanent magnet material is 0%). It can be seen that when the mold size satisfies the ratio of δ = 1.38 (ie, when the reduction in the amount of permanent magnet material is 24.7%), the generated torque T is equivalent to the torque produced by the rotor 12A the related technology with permanent magnets 16 whose length W _{pm is} not shortened is generated (ie, the torque T is 1.0 [per unit]). With the permanent magnets 16 For example, when the ratio δ is 1.38 (δ = 1.38), the same torque is generated during operation even at slow speeds under low load conditions that are commonly used.

In 11 becomes the rotor 12A the related technology used for comparison. In this comparison rotor 12A defines each set of openings arranged in a "V" shaped configuration 17 at its radially outer and inner ends, outer and inner flux barriers 17b and 17d of the same size. In contrast, the rotor divides and separates 12 According to the present embodiment, the magnetic flux lines ψ _{r of} the stator windings thanks to the provision of the flow barriers 17c and a means 21 per magnetic pole effective in two. This causes the rotor to effectively produce a reluctance torque T _r and limit the torque ripple, while the torque T at the ratio δ = 1.84, where the length W _pm of each of the permanent magnets 16 not shortened, ie, the permanent magnets 16 in length W _pm that of the rotor 12A are the same, is improved. In other words shows 11 Changes in torque and those of torque ripple at different values for the ratio δ when the length W _pm of each of the permanent magnets 16 in the structure of the rotor 16 is shortened according to the present embodiment. It is believed that over the range of the ratio δ of 1.84 to near 1.38, no appreciable change in torque T occurs, ie, the torque T remains substantially 1.0 [per unit] when the length W _pm of each of the permanent magnets 16 in the structure of the rotor 12A the related technology is shortened.

In rotary electric machines, rotation of a rotor due to magnetic distortion resulting from field weakening upon generation of an induced voltage (ie, a reverse voltage) whose amplitude is variable depending on the amount of use of the embedded permanent magnets results in a superposition of space harmonics. The space harmonics cause an increase in iron loss since the 5th, 7th, 11th, and 13th space harmonics cause the generation of torque ripple. The creation of the 5th space harmonic is like in 12 shown graphically per unit with respect to the ratio δ. Out 12 It can be seen that the smaller the ratio δ becomes from 1.75 (δ = 1.75) the more the generation of the 5th space harmonic is reduced. In this case, the use amount of the permanent magnets is reduced by 4.7 or more and the generation of heat is reduced by eddy currents thanks to an improvement in the efficiency resulting from a reduction in iron loss due to the reduction of the space harmonic caused by magnetic distortion in the permanent magnet 16 be limited.

It follows that it is the rotor 12 according to the present embodiment for reducing the amount of permanent magnet material used to make the permanent magnets 16 is used while the output of the torque as high as the rotor 12A favorably, the ratio δ is established by shortening the length W _pm of each of the permanent magnets to about 1.38, that is, δ = 1.38 (reducing the amount of the permanent magnet material by 24.7 %). This also reduces the torque ripple. In short, the shape dimensions of each of the permanent magnets 16 be chosen to suit a desired torque output T and torque ripple characteristic such that the ratio δ falls within a range of δ = 1.38 (a 24.7% reduction in the amount of permanent magnet material) to δ = 1.75 (a 4.7% reduction in the amount of permanent magnet material).

A magnetic analysis of two different IPM motors capable of producing the same torque, with the length W _{pm of} the permanent magnets 16 each pair arranged in a "V" -shaped configuration is shortened in a motor so as to leave openings near each longitudinal axis (d-axis) so as to provide shape dimensions in which the ratio δ = 1, 38 is while the permanent magnets 16 each pair, which is arranged in a "V" shaped configuration, are not shortened in the other motor, shows that as in the 13 and 14 shown the electric lathe 10 produces substantially the same torque T when the ratio of the reluctance torque T _r to the magnetic torque T _{m is} changed. The V-shaped IPM motor with openings near each longitudinal axis is designed to provide flux barriers L7C large apertures located near each longitudinal axis occupy, while the bare V-shaped IPM engine is designed to provide flux barriers L7D small openings, which are located near each longitudinal axis, occupy.

13 shows a relationship between the torque T _m and the torque T _r during low-load operation during operation 14 shows a relationship between the torque T _m and the torque T _r during operation in the maximum load range. As 13 and 14 In the case of the IPM engine of the V-shaped type with large openings near each longitudinal axis, the ratio of the reluctance torque T _r in both load ranges decreases with a reduction in the ratio of the magnetic moment T _m caused by a shortening of the length every permanent magnet 16 is caused, too. In a small area A1, which is like in the 6B and 7 shown near the outer periphery of each pole, are formed by forming the flux barriers 17c , which occupy large openings, instead of permanent magnets 16 near the longitudinal axis and also forming a center groove 21 the magnetic flux lines ψ _{m of} the magnets, which counteract the magnetic flux lines ψ _{r of} the stator windings, reduced. This leads to an increase in the inductance L _{q of} the transverse axis (q-axis), which causes a difference between the inductance L _{q of} the transverse axis (q-axis) and the inductance L _{d of} the longitudinal axis (or the ratio of saliency (Saliency Ratio) is greater than that (or the ratio of the saliency ratio) of the IPM motor of the V-shaped type with non-shortened permanent magnets, which allows the rotating electrical machine 10 by effectively utilizing the reluctance torque T _m generates an equivalent torque.

As by the river flow distribution in 15 As shown, this structure allows the rotary electric machine 10 some of the magnetic flux lines ψ _{r of} the stator windings concentrated in the small area A1 located radially outward from the permanent magnets of each pair forming a magnetic pole, effective from the flow path M _r 1 passing through the radially outward small area A1 runs, in the river flow path M _r 2 scatters (separates), which is located around the longitudinal axis located radially inwardly located side of the openings 17c a set of openings 17 which are arranged in a "V" -shaped design runs. As a result, the magnetic lathe decreases 10 the magnetic interaction between magnetic flux lines ψ _{m of} the magnets and magnetic flux lines ψ _{r of} the stator windings (d-axis, q-axis) to avoid local magnetic saturation on the preceding side with respect to the rotational direction of the radially outward small area A1 of the magnetic pole , whereby they can contribute effectively to the generation of torque T.

Therefore, as through the flow distribution in 16 The majority of the synthetic magnetic flux lines ψ _s , which are formed by the combined effect of the magnetic flux lines ψ _{m of} the magnets and the magnetic flux lines ψ _{r of} the stator windings, are illustrated by flow paths MPO extending through the permanent magnets 16 each pair extend when the rotary electric machine 10 in a drive mode under low loads, while the synthetic magnetic flux lines ψ _s as determined by the flow distribution of 17 Illustrates dividing into a flow flow path MP1 and a flow flow path MP2 when operating under a maximum load in the drive mode. As a result, the rotary electric machine realizes 10 avoiding local magnetic saturation together with a reduction of the magnetic interaction to effectively produce the same or a higher degree of torque T than the IPM motor of V-shaped type with non-shortened permanent magnets, while decreasing the amount of the permanent magnet material the permanent magnets 16 is achieved. During operation in a drive mode under low load conditions, the magnetic flux lines ψ _{m of} the magnets make up a high percentage compared to the magnetic flux lines ψ _{r of} the stator windings in the synthetic magnetic flux lines ψ _s .

When the permanent magnets 16 for example, have such shape dimensions that the ratio δ = 1.44 and the amount of the permanent magnet material is reduced by 23 and by flux barriers 17c is replaced with a low magnetic permeability (reducing the magnetic flux lines ψ _{m of} the magnets), it makes a reduction of the back EMF constant of about 13.4 that of a reduction the inertia is accompanied, for the electric lathe 10 possible that their output power increases at high rotational speeds. In addition, a reduction in the spatial harmonics that cause magnetic distortion reduces the heat and iron loss in the permanent magnets 16 due to eddy currents, and it limits the electromagnetic noise.

In other words, it is as easily apparent from the illustrated flow flow lines in FIG 18 is apparent, for example, if, for example, each of the flux barriers 17e not in a radially inward direction to the axis of the rotor 12 extends difficult, _s ψ to divide the synthetic magnetic flux to a sufficient degree into two streams to form a local magnetic saturation, which located at the outer circumferential side of each rotor pole small area A1 with respect to the direction of rotation of the rotor 12 (in 18 seen the left side), can not be avoided.

If the in 17 shown, with the river barriers 17c provided structure A according to the present embodiment, using the amount of output torque and its fluctuations (torque ripple) with the in 18 Comparative construction B shown, with the flow barriers 17e is compared is out 19 showing the output torque characteristics in the maximum load state, it can be seen that the structure A is superior to the structure B in that the output torque increases by about 6%, and the torque ripple falls, thereby providing high quality operation in the drive mode. In 19 are calculated by averaging the average torque using the in 18 structure B shown as base unit size, the instantaneous output torque of in 17 shown construction A and that of the in 18 Structure B shown in terms of the angle of rotation (the electrical angle) in terms of "per unit" expressed.

In order to compare the harmonic torque components superimposed on the output torque of the structure A with those on the output torque of the structure B, the in 19 shown waveforms processed by a Fourier series expansion, which as in 20 show results shown that, in particular, the 12th and 24th harmonic components of torque superimposed on the output torque are considerably smaller in structure A than in structure B. In the structure A according to the present embodiment, this suppresses the occurrence of jerking in the acceleration when ascending a slope, and considerably reduces the degree of electromagnetic noise, in particular, by considerably reducing the 12th harmonic torque component. In 20 are the percentages (%) of harmonic torque components included in output torques of assemblies A and B.

In order to compare the content of the 11th and the 13th space harmonics in Structure A with that in Composition B, the waveform of the magnetic flux becomes concatenated with one of the stator teeth 15 processed via the gap G by a Fourier series expansion, whereby as in 21 show results that show that the content of the 11th and 13th space harmonics is considerably lower in the case of structure A than in structure B. In 21 For example, the content of the space harmonic is expressed after normalizing a fundamental waveform component of the magnetic flux concatenated with a tooth in the construction A and that in the construction B as the base unit "per unit".

Incidentally, it can be seen that in the electric lathe 10 the torque ripple, in the case of three phases, through space harmonics which superimpose one flux waveform per phase per magnetic pole and time harmonics contained in phase currents into electrical degrees at the 6fth order component (where f is a natural number of 1, 2, 3, ... is) is generated.

When the reason for generating the torque ripple is described below, the three-phase output power (the electric power) P (t) and the torque τ _{t can be expressed} by the formulas (4) and (5) as P (t) = E _u (t) I _u (t) + E _v (t) I _v (t) + E _w (t) I _w (t) (4) τ (t) = P (t) / ω _m = [E _u (t) I _u (t) + E _v (t) I _v (t) + E _w I _w (t)] (5), be expressed
where ω _{m is} the angular velocity, E _u (t), E _v (t) and E _w (t) are the induced electromotive forces of phase U, phase V and phase W, respectively, and I _u (t), I _v (t) and I _w (t) is the current of phase U, phase V and phase W, respectively.

The three-phase torque is the sum of the torque of the phase U, the torque of the phase V and the torque of the phase W; and when the current I _u (t) of the phase U is expressed by the formula (6) in which "m" is the order of the harmonic component contained in the current, and "n" is the order of the harmonic component contained in the voltage is, the torque τ _u (t) of the phase U can be expressed by the following formula (7):

wobei 6f = n ± m (f ist eine natürliche Zahl) ist, s = nα_n + mβ_m ist, und t = nα_n – mβ_m ist.Both the phase current I (t) and the phase voltage E (t) are symmetrical waves, so it is necessary for m and n to be odd. With regard to the torques other than that of the phase U - the phase V torque and the phase W torque - the phase shift of the phase V torque is dependent on the induced voltage E _u (t) of the phase U and the current I _u ( t) of the phase U and the phase shift of the torque of the phase W of them + 2π / 3 (rad.) and -2π / 3 (rad.). The resulting torque is given by sweeping the members except for members having a coefficient of "6" and can be expressed by the following formula (8).

where 6f = n ± m (f is a natural number), s = nα _n + mβ _m , and t = nα _n -mβ _m .

In addition, since an induction voltage is a time derivative of a magnetic flux, harmonic components of the same order as those contained in an induction voltage in each phase also occur in one magnetic flux per pole per phase. It follows that in a three-phase motor, the 6f-th torque harmonic appears as a torque ripple when n, d. h., the number of the order of the space harmonic contained in the magnetic flux (the induction voltage), and m, d. that is, the number of the order of the time harmonics contained in the phase current is combined to give 6f.

As with this electric lathe 10 torque ripple occurs when the equation 6f = n ± m is satisfied, when one magnetic flux per pole per phase contains the nth space harmonic and a phase current contains the mth time harmonic arises, for example, in response to a combination of, for example , the overlapping 11th and 13th space harmonics (n = 11, 13) and the fundamental wave (m = 1) of a phase current, the 12th harmonic torque.

In this electric lathe 10 is the position of an end wall on the side near the rotor axis, each of the flux barriers 17c in the rotor 12 formed openings 17 each set disposed in a "V" shaped configuration increases in a radially inward direction, so determined that its increased size is optimized toward the rotor axis while the shape dimensions of each of the permanent magnets 16 be kept in such a manner that the condition in which the ratio δ is 1.44 (δ = 1.44) is satisfied.

Referring again to 1 becomes the structure of the rotor 12 by rating the in the 22 and 23 shown torque characteristics changing a radial distance R2 of the end wall of the flux barriers 17c located near the rotor axis, of the rotor axis in the ratios R2 / R1 and R3 / R2 used as parameters, where R1 is the outer radius to an outer circumference of the rotor, and R3 is the inner radius to its inner circumference, obtained. Because the permeability (the ease with which magnetic flux is generated) of stacked electrical steel plates depends on the von Mises stress resulting from the compressive stress caused by the interference fit to their connection to the drive shaft, with which the electrical steel plates are compressed , worsens, the shape dimensions of the rotor in the torque characteristics are determined taking into account the Von Mises stress. In 22 and 23 are quantities of torque that are in the State of maximum load is expressed in terms of "per unit" sizes, based on the 18 refer to reference example B as shown.

Out 22 It can be seen that a torque equal to or greater than the torque generated by the structure B is generated when the ratio R2 / R1 falls within a range A of 0.56 to 0.84. Preferably, the radial distance R2 of the end wall of the flow barrier 17c from the rotor axis from a range B of 0.565 near a turning point to 0.75 near another inflection point. In particular, it is selected from a range C of 0.59 to about 0.63, in which an increase in torque of about 5 is expected.

Next is out 23 that a torque equal to or greater than the torque generated by the structure B is generated when the ratio R3 / R2 falls within a range of 0.54 to 0.82. Preferably, the radial distance R2 of the end wall of the flow barrier 17c from the rotor axis from a range B of 0.60 near a turning point to 0.81 near another inflection point. In particular, it is selected from a range C of 0.72 to 0.77 in which an increase in torque of about 5 is expected.

This allows the size of the river barriers 17c is determined in such a way that a sufficient width for the in 17 is ensured without causing any magnetic saturation in the flow path MP2.

With reference to a in 24 shown rotor 12B are as mentioned above even if the length in a longitudinal direction (width) W _pm of each of the permanent magnets 16 optimally designed, near the corners 16a the permanent magnets 16 each pair of vectors V _r obtained close to the longitudinal axis of the electromagnetic flux ψ _r counteract the vectors V _m obtained from the magnetic flux ψ _m . In particular, stays near the corners 16a the permanent magnets 16 close to the longitudinal axis, there is a state of a relationship of opposite magnetic fields in which those of the magnetic flux lines ψ _{r of} the stator windings extending over a Flußfließweg extending with respect to the rotor axis all the way to the innermost of the radially outside of each magnetic pole located small area A1 , vectors V _{r obtained} vectors V _m of magnetic flux lines ψ _{m of} the magnets in the reverse direction with an induced angle of equal to or greater than 90 degrees counteract (counteract) and balance them (cancel). For this reason, in the structure of this rotor 12B the magnetic flux lines ψ _{r of} the stator windings, which are close to the corners located in the vicinity of the longitudinal axis 16a walk past, weakened, as they act against magnetic flux lines ψ _m through magnets (they extinguish).

It follows that in the electric lathe 10 (the rotor 12 ), the (in) 25 is shown near the longitudinal axis located river barriers 17c are formed in openings which also directed outwards to the outer periphery 12a of the rotor 12 extend. This will provide a structure that effectively uses magnetic flux lines ψ _{r of} the stator windings and magnetic flux lines ψ _{m of} the magnets by the flux flow path over which the magnetic flux lines ψ _{m of} the magnets near the corners 16a near the longitudinal axis, is allowed to pass in such a manner that vectors V _{r obtained} from magnetic flux lines ψ _{r of} the stator windings are near the corners 16a with an induced angle of equal to or less than 90 degrees with vectors V _m , which were obtained from magnetic flux lines ψ _{m of} the magnets interact.

Be more precise in this electric lathe 10 the shape dimensions 1 and 2 that section of each of the openings that the river barriers 17c the arranged in a "V" -shaped openings 17 each set facing outward to the outer circumference 12a of the rotor 12 extends, so determined that the section is optimized while the shape dimensions of each of the permanent magnets 16 are set so as to preserve the relationship of the ratio δ = 1.44.

As in 26 First, a separation distance DL _d from a point Y at which the longitudinal axis and an expansion plane of an outer peripheral end surface (a plane shape) of the flow barrier is shown 17cu intersect each other, to a point X where the longitudinal axis and the outer circumference 12a of the rotor 12 intersect each other, as a shape dimension 1 for the river barriers 17c of the rotor 1 selected. The optimal range for this separation distance DL _d is determined after a review of the average torque, the harmonic torque components and the torque ripple, which are obtained when a ratio of the distance DL _d to the outer radius R1, DL _d / R1, is used as a parameter , In other words, the distance (separation distance) becomes DL _d from the outer circumference 12a to a longitudinal axis side end of the outer peripheral end surface (the shape of a plane) 17cu as a shape dimension 1 for the river barrier 17c is determined so as to obtain optimum characteristics which prevent saturation of the magnetic flux defining the flux flow path MP1 crossing the outer peripheral portion A2 of each magnetic pole.

As in 27 As shown, the outer peripheral side end surfaces extend 17cu the river barriers 17c in a radially outward direction so toward the outer circumference 12a as if from the outer circumference 12a of the rotor 12 over a range of the designated DL _d / R1 = 0.194 shown initial position at which each of them the same plane with the associated extension of the planes of the wall surfaces (the outer surfaces of the permanent magnets 16 ) 17au located on the outer peripheral side of the magnet openings 17a the arranged in a "V" -shaped openings 17 of any sentence divides that would be drawn to the illustrated end position indicated by DL _d / R1 = 0.086. It can be seen that, if this is the case, the torque characteristics as in 28 and 29 change shown. 28 shows the average torque during operation in a drive mode under the maximum load condition per unit using the case of DL _d / R1 = 0.194 as the base unit. Additionally shows 28 as harmonic torque components, the superimposed sixth and twelfth component (electrical angle) in percent and the rate of change of torque as torque ripple.

With regard to the shape dimension 1 for the river barriers 17c of the rotor 12 can out 28 it can be seen that when DL _d / R1 falls within a range A of 0.098 to 0.194, the amount of generated torque becomes equal to or greater than that produced by the structure in which the outer peripheral side of the magnet openings 17a the arranged in a "V" -shaped openings 17 every set of wall surfaces 17au are only extended. With regard to this dimensional size 1 Further, when DL _d / R1 falls within a range B of about 0.11 to about 0.194, the 12th harmonic torque component is reduced, and in particular, the maximum torque is generated when DL _d / R1 falls within a range C of about 0.12 until about 0.14 drops. How out 29 As can be seen, the torque ripple reaches a minimum when DL _d / R for this shape dimension 1 to provide a best-point design BP1 is 0.139.

In addition, as in 26 shown an angle of inclination α of the outer peripheral side end surface 17cu the river barrier 17c to the associated wall surfaces 17au located on the outer peripheral side of the magnet openings 17a the arranged in a "V" -shaped openings 17 each sentence are located, as the shape dimension 2 for the river barriers 17c of the rotor 12 selected.

Using DL _d / R1 = 0.139 as the basis, this inclination angle α determines a ratio θ1 / θ2, where θ1 is the one through the longitudinal axis and the outer peripheral side end surface 17cu the river barrier 17c formed angle of incidence, and θ2 through the longitudinal axis and the associated wall surfaces 17au located on the outer peripheral side of the magnet openings 17a the arranged in a "V" -shaped openings 17 each sentence is formed, formed inclusion angle is. The optimum range for this ratio θ1 / θ2 is determined after evaluating the average torque, the harmonic torque components, and the torque ripple obtained when used as a parameter, as in FIG 30 and 31 is shown. In other words, the inclination angle α becomes the shape dimension 2 for the river barriers 17c determined so as to obtain optimum properties that will produce such a flow path that prevents the electromagnetic flux ψ _{r from} the magnetic flux ψ _m near that corner 16a each of the permanent magnets located close to the longitudinal axis of the peripheral side of each rotor pole of the rotor 12 located small area A1 is suppressed. 30 shows the average torque during operation in a drive mode under the maximum load condition per unit using the case of θ1 / θ2 = 1.7 as the base unit. Additionally shows 30 as harmonic torque components the superimposed 6th and 12th component in percent and shows 31 the rate of change of torque as torque ripple. Since the angle θ2 is often referred to as the magnetic opening angle, the angle θ1 is referred to as the flux barrier opening angle.

With regard to the shape dimension 2 for the river barriers 17c of the rotor 12 is out 30 It can be seen that the magnitude of the generated torque becomes large and the 12th harmonic torque component is decreased when θ1 / θ2 falls within a range D of about 1.2 to about 1.7. With regard to the shape dimension 2 is also out 31 It can be seen that the torque reaches a maximum and the torque ripple reaches a minimum when θ1 / θ2 is preferably 1.52 for providing a bestpoint design BP2.

If now both dimensional dimensions 1 and 2 for each of the river barriers 17c are considered, under the condition that the ratio DL _d / R1 falls within the range A from 0.098 to 0.194, the angle θ1 under this condition is given by its division by the angle θ2 shifts the angle θ1, and becomes suitable Torque characteristics provided when the ratio θ1 / θ2 is selected from a range of 1.0 to 2.13. In addition, under the condition that the ratio DL _d / R1 falls within the range B of 0.11 to 0.194, even more suitable torque characteristics are provided when the ratio θ1 / θ2 is selected from a range of 1.0 to 2.02.

Further, on the condition that - after taking into account the two shape dimensions 1 and 2 for each of the river barriers 17c - an optimization with DL _d = 0.139 and θ1 / θ2 = 1.5 is made, as in 32 shown the average torque compared with the in 24 illustrated comparative example increased by about 1.8 and suppresses the torque ripple. As in 33 shown reduce these shape dimensions 1 and 2 the 12th and 24th harmonic torque components compared to the in 24 illustrated comparative construction example considerably. This suppresses the occurrence of jerking in the acceleration when ascending a slope and considerably reduces the degree of electromagnetic noise, in particular, considerably reducing the 12th harmonic torque component.

Since now with reference to the in 34A shown rotor 12A the permanent magnets 16 Each pair that forms a magnetic pole, even in the vicinity of a longitudinal axis between them, will pass through the permanent magnets 16 generates many magnetic flux lines ψ _m in the radially outward region A2 of the magnetic pole. On the other hand, with regard to an in 35A shown rotor 12C who does not use a means 21 per magnetic pole, since it is close to a longitudinal axis between the permanent magnets of each pair of flux barriers 17c is executed, each having the shape of an opening, the property of the straight course of the permanent magnets 16 deteriorate generated magnetic flux lines ψ _m . In other words, the flux density of the magnetic flux lines ψ _m near the longitudinal axis is small. Since the magnetic resistance in the vicinity of the longitudinal axis is small, therefore, the inductance for a Flußfließweg ψ _q , which crosses the longitudinal axis, high. As a result, leads in the rotor 12C a superposition of harmonics on the outer circumference 12a As a result of increased torque ripple and increased iron loss, chained magnetic flux caused by the occurrence of a density difference in the magnetic flux causes a decrease in efficiency.

Referring to a in 34B shown flux vector field, which is formed during operation under maximum load, is the density of the interlinkage magnetic flux from the opposite stator tooth 15D , which corresponds to the flow path of the magnetic flux lines ψ _{m of} the magnets, in the vicinity of the longitudinal axis of the rotor 12A not high. On the other hand, with reference to the in 35B shown flow field formed during operation under maximum load, the density of the interlinkage magnetic flux in the vicinity of the longitudinal axis of the rotor 12C higher than that of the magnetic flux flowing in the stator tooth 15D remains, which causes an increased influx of magnetic flux.

This is from the illustrations in 36 that results from a comparison of the rotor 12C (Flux barriers 17c , no means 21 ) with the rotor 12A (Flux barriers 17d , no means 21 ) with respect to the waveform of the interlinkage magnetic flux from a stator tooth, that is, magnetic flux lines which define the air gap G from a stator tooth 15D Cross over, visible, with the rotor 12C less preferred than the rotor 12A is when the magnetic flux lines can more easily cross the air gap G at a point "P" where they are affected by the vicinity of the longitudinal axis, causing an increased tendency for harmonic interference. As well as from the in 37 shown results after processing of in 36 shown waveforms by a Fourier series expansion, containing by the rotor 12C Magnetic flux waveform generated considerably more at 5th and 7th room harmonics, as compared to the magnetic flux waveform generated by the rotor 12A is generated, which is the case.

Therefore, the rotor 12 at the electric lathe 12 on its outer circumference 12a with means 21 executed, each located on one of the longitudinal axes to the magnetic resistance at the common with the inner circumference of the stator tooth 15 to regulate the air gap G formed. As by a in 38 as shown, limits the flow vector field formed during operation under maximum load with such centerlines 21 executed rotor 12 an increase in the flux of magnetic flux from a stator tooth 15 which comes successively opposite the rotor in the vicinity of the longitudinal axis.

As from the illustrations in 39 that is made up of a comparison of this rotor 12 (with means 21 ) generated torque waveform with that by the rotor 12C (without means 21 ) using the rotor 12C As a basic unit - 1.0 (per unit) - revealed, the rotor decreases 12 with means 21 the amplitude of the torque waveform stronger to limit the torque ripple, as it is in the rotor 12C the case is. As from the in 40 shown results after processing of in 39 shown waveforms by a Fourier series expansion, are the 6th, 12th, 18th and 24th harmonic torque component of the rotor 12 with means 21 generated waveform significantly reduced. In 39 is the torque waveform of the instantaneous torque using the average torque generated by the rotor 12C is generated as base unit - 1.0 (base unit) - illustrated.

Thus, in the electric lathe 10 the appropriate shape dimensions of each of the center grooves 21 determined on the basis of torque characteristics such as the above-mentioned torque ripple.

With regard to the means 21 will determine the appropriate shape dimension after evaluating the in 42 shown torque ripple by changing an in 41 shown radial distance R4 of a groove bottom 21a the center 21 from the rotor axis in the ratio R4 / R1 used as a parameter, where R1 is the outer radius to the outer circumference of the rotor 12 is, certainly.

First, in terms of the depth of the center groove 21 using the molding size for the rotor without center grooves 21 as standard (R4 / R1 = 1.0) the depth is carried out with the following shape dimension, 0.98 ≦ R4 / R1 <1.0, to allow a reduction in the torque ripple generated under maximum load operation.

Then, in terms of the means 21 of the rotor 12 for their shape dimensions, a determination of their relative relationship to the stator teeth 15 of the stator 11 required, wherein a definition by an outer arc angle θa for the center groove 21 around the axis of the rotor 12 and an inner arc angle θb for the groove bottom 21a is possible.

With continued reference to the rotor 12 the phase voltages and the line voltage are as shown by their representations in 43 indicated at points indicated by peaks F and apex sections (vertex sections) W, when the outside angle θa for the center groove 21 is changed as a parameter.

Specifically, a period between G1 and G3 of the U-phase voltage waveform changes from the positional relationship between the stator 11 and the rotor 12 depending on the width of the outer arc angle θa for the center groove 21 , The voltage waveform of the U phase becomes a waveform in which the period between G1 and G3 is narrowed to be sharpened to an apex when the outer arc angle .theta.a is narrowed, and the waveform of the conductor voltage becomes a waveform that varies approximates a triangular waveform as the tips F approach the apex section W. On the other hand, the voltage waveform of the phase U becomes a waveform in which a portion in the period between G1 and G3 is flattened as the outer arc angle .theta.a is widened, and the waveform of the conductor voltage becomes a waveform approximating a trapezoidal waveform the tips F leave the apex section W, leading to the tendency of superposition by the 5th and 7th space harmonics.

With regard to the means 21 requires the gap G between the rotor 12 and the stator teeth 15 As mentioned above, a high magnetic resistance (or a low permeability), but since the tendency for a superposition by the 5th and the 7th space harmonic is increased if it is too much expanded, the outer arc angle θa must have a minimum required shape dimension ,

With reference to 41 SO should be the one to the rotor 12 directed open end measured width of each of the slots 18 Let TB be the face width of the inner circumference of each of the stator teeth 15 represent TW, the end section width of the stator tooth 15 represent at the remainder portion inwardly from the inner periphery of the stator tooth 15 is measured, and AG is the gap width across the gap G between the rotor 12 and the stator teeth 15 be. Then the rotor 12 and the stator 15 designed to fulfill the following relationships.

First, the media people have to 21 , each having a width, the front width TB of one of the stator teeth 15 is equal to or greater than this, meet the requirement of increased magnetic resistance across the gap G. It follows that the lower limit for the outer arc angle θa as 2 × tan ^-1 {(TB / 2) / (R1 + AG)} ≦ θa is expressed because the shape enclosed by the frontal width TB and the rotor axis equals an isosceles triangle (2 × a right triangle).

In addition, in view of automatic insertion of the stator windings and the required energy density, it is necessary that the opening width SO of each slot 18 greater than the gap width AG of the air gap width G, ie, SO> AG. According to this relationship, the magnetic resistance at the gap G is lower than that at the opening space of the slot 18 , which reduces the density of the rotor 12 interacting magnetic flux lines from a pointed corner portion K (see 38 ) of each of the stator teeth 15 required. Therefore, it is necessary that each of the middle people 21 is located on an arc in Bogengrad an arc between the adjacent two inner peripheral portions 15a on every second stator tooth 15 equal to or greater than this. It follows that the upper limit of the outer bow angle θa is equal to θa ≦ 2 × tan ^-1 [{SO + (TB / 2)} / (R1 + AG)}]. is expressed.

Next, the inner arc angle defines θb for the bottom of the center groove 21 an arc between the adjacent two inner peripheral portions 15a on every second stator tooth 15 As its upper limit, the upper limit is expressed similarly to the outer arc angle θa as θb ≦ 2 × tan ^-1 [{SO + (TB / 2)} / (R1 + AG)}].

On the other hand, since the arc for the lower limit of the outer arc angle θa is the end width TB of the stator tooth 15 is to regulate the reluctance at the gap G so as to increase, the center groove 21 on the ground 21a Therefore, the lower limit of the inner arc angle θb can be expressed as θ ° ≦ θb.

In addition, the front width TB and the end portion width TW of the stator tooth 15 TW ≦ TB, since the above conditions would not be met if the end portion of each of the stator teeth 15 would be pointed.

Similarly, the rotor decreases 12 with means 21 during operation in drive mode under low load conditions as shown in the figures in 44 that is made up of a comparison of this rotor 12 generated torque waveform with that through the rotor 12C without means 21 using the rotor 12C As the base unit - 1.0 (per unit) -, the amplitude of the torque waveform becomes more apparent, thereby limiting the torque ripple, as compared to the rotor 12C the case is. As from the in 45 shown results after processing of in 44 shown waveforms by a Fourier series expansion, is the 6th harmonic torque component of the torque waveform passing through the rotor 12 with means 21 produced is considerably reduced.

In addition, in the foregoing, the influence of the average people is mainly 21 described on the torque characteristics, but are the center grooves 21 useful as markers in manufacturing such as assembly. For example, it is twisting around the permanent magnets 16 possible to rotate in different positional relationships along the longitudinal direction, possible, the presence of twisting from that through the center grooves 21 to confirm generated straightness.

With reference to a in 46 shown less preferred rotor 12D without lateral grooves 22 is out 47 it can be seen that the magnetic flux density at the gap G during operation under no load assumes a waveform that approximates a trapezoidal wave deviated from the fundamental wave. At this gap G, the superposition of the gap magnetic flux waveform caused in accordance with the stator teeth 15 on the stator 11 , the permanent magnet 16 one in a "V" shaped configuration on the rotor 12D located pair and the river barriers 17b and 17c the arranged in a "V" -shaped magnet openings is determined by Raumharmonische increased torque ripple, increased electromagnetic noise and increased iron loss.

In the gap magnet waveform, the stator teeth correspond 15a to 15g for a magnetic pole of the rotor 12D each part A to G of the waveform, wherein each part has an electrical angle of 30 degrees, since a longitudinal axis at 90 degrees in the electrical angle is shown, a transverse axis at 0 degrees in the electrical angle is shown, and the other transverse axis at 180 degrees electrical angle is shown. This gap magnetic flux waveform is near the part A, the flux barriers 17c (Openings) on the side of the longitudinal axis corresponds, recessed. From a comparison with the basic waveform, it can be seen that the magnetic flux density is too high on the one hand during a range of C to B and on the other hand during a range of E to F. It follows that the superposition by the harmonics at the second and third stator teeth 15b and 15c from the longitudinal axis in a forward direction of rotation of the rotor 12D and at the second and third stator teeth 15e and 15f is considerable from the longitudinal axis in a reverse direction opposite to the forward direction.

That's why it's the rotor 12D beneficial, in two places on the outer circumference 12a that deviate within a range of ± 30 to 60 degrees from the longitudinal axis, a pair of lateral grooves 22 form, with one between the stator teeth 15b and 15c to the stator tooth 15 directed, and the other between the stator teeth 15e and 15f directed to the stator tooth to reduce the interlinkage magnetic flux density.

Incidentally, means for counteracting (reducing) a torque ripple component having a certain order of an IPM motor include rotating axially disposed portions of a rotor, a portion relative to the adjacent portion, or, in other words, performing twisting stages , For example, in the case of a three-phase motor, a 12th order torque ripple component can be counteracted (can be reduced) by exposing one rotor to a 15 degree electrical angle per stage.

In particular, the 12th harmonic chained to the magnetic flux is expressed as a function. She can as F (θ) = sin 12 θ be set.

Then, the shifted by 15 degrees in electrical angle waveform as F (θ + 15 °) = sin12 (θ + 15 °) = -sin12θ expressed.

Theoretically, the 12th harmonic counteracts and is thereby extinguished by the 11th and the 13th space harmonics. This leads to a reduction in the 12th torque ripple.

When the gap magnetic flux waveform to which harmonics are interlinked is inspected not only during non-load operation but also under a load condition, the in 48 caused waveforms caused. 48 shows two waveforms, one in the case without lateral grooves 22 and without twisting steps, and the other in the case without lateral grooves 22 and generating twist levels.

From these slit magnetic flux waveforms, it can be found that the provision of twist stages restricts the overlying space harmonics, but it can be seen from a comparison with the basic waveform that the twist magnetic flux density both during operation under load conditions and without load during a range of B to C and during a Range from E to F is too high.

Thus, in the electric lathe 10 appropriate shape dimensions for each of a plurality of pairs of lateral grooves 22 determined on the basis of the torque characteristics for the torque and the torque ripple.

As far as the lateral grooves 22 each pair are affected as determined in 49 shown (see also 26 ) induced angles θ2, θ3, θ4, θ5, where each of the lateral grooves 22 is to form
where θ2 is the induced angle between the longitudinal axis and a reference plane extending from a wall surface of one of the permanent magnets 16 every pair near the outer circumference 12a (= a wall surface 17au a magnet opening 17 for the permanent magnet 16 near the outer circumference 12a , please refer 26 ), the so-called "magnetic opening angle through which a magnet is separated from the longitudinal axis";
at θ3, the angle of confinement between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point at a corner 16b of the permanent magnet 16 that the outer circumference 12a of the rotor 12 is closest, extends the so-called "magnetic arc angle, by which the magnetic edge is rotated from the longitudinal axis about the rotor axis"acts;
at θ4, the external angle of confinement between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point at the edge farthest from the longitudinal axis 22o a lateral groove extends acts;
at θ5, the internal confinement angle between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point at the edge 22i the lateral groove 22 which is the least far from the longitudinal axis extends, acts.

If each of the lateral grooves 22 of a pair far beyond the magnetic edge angle θ3 or the magnetic opening angle θ2 far from the longitudinal axis, the lateral grooves become a range of C to D and a range of F to G in the slit magnetic flux waveform, respectively 47 are shown and therefore fall outside of places where a reduction of the magnetic flux is necessary. What the rotor 12 concerns, requires a footbridge 12c that is between the outer circumference 12a and the river barrier 17b due to the fact that it is exposed to a concentration of Von Mises stress due to the centrifugal force during a high speed rotation of the permanent magnets 16 comes, a certain thickness, so that its breaking is avoided. Therefore, the body needs the formation of each of the lateral grooves 22 through inequality θ5 (inner inclination angle) <θ4 (outer inclination angle) ≦ θ3 (magnetic edge angle) be determined.

The shape dimensions of each of the lateral grooves 22 a couple are based on the in the 50 and 51 The torque characteristics of the average torque, the harmonic torque components, and the torque ripple, which are obtained when a ratio θ5 (inner clipping angle) / θ4 (outer clipping angle) is used as a parameter, are determined.

First, the torque ripple can be effectively reduced while maintaining a certain degree of average torque when, after considering the in 50 shown torque characteristics during operation under a maximum load, wherein the rotor 12D (θ5 / θ4 = 1.0), without any lateral grooves 22 is executed, as the base unit (1.0 [per unit]) is used, each side groove 22 Has mold dimensions that have a relationship of 0.945 ≦ θ5 / θ4 ≦ 0.98 fulfill. In particular, the torque ripple can be kept to a minimum when the lateral grooves 22 satisfy the relationship of θ5 / θ4 0.97.

In addition, the torque can be effectively reduced while maintaining a certain degree of average torque when each lateral groove 22 considering the in 51 shown torque characteristics during operation under high loads form dimensions, which has a relationship of θ5 / θ4 ≦ 0.98 fulfill.

The shape dimensions of each of the lateral grooves 22 of a couple are based on the in 52 shown torque characteristics of the average torque and the torque ripple, which are obtained when a ratio RG (groove depth) / AG (air gap width) (see 49 ) is used as a parameter.

First, the torque ripple can be effectively reduced while maintaining a certain degree of average torque when, after considering the in 52 shown torque characteristics during operation under a maximum load, wherein the rotor 12D (RG / AG = 0.0), without any lateral grooves 22 is executed, as the base unit (1.0 [per unit]) is used, each side groove 22 Has mold dimensions that have a relationship of 0.0 ≦ RG / AG ≦ 0.73 fulfill. In particular, the torque ripple can be kept to a minimum when the lateral grooves 22 satisfy the relationship of 0.30 ≦ RG / AG ≦ 0.45.

This allows the electric lathe 10 , the magnetic flux density in a by the representation of the slit magnetic flux waveform in 53 in a range of B to C and in a range of E to F, if the lateral grooves 22 at appropriate locations in the outer circumference 12a of the rotor 12 are formed.

In addition, the electric lathe 10 reduce the torque ripple not only during operation under a maximum load but also during operation under a light load when the lateral grooves 22 at the appropriate places in the outer circumference 12a of the rotor 12 are formed as easily from the in 54 shown torque waveform during operation under a maximum load and the in 55 shown torque waveform during operation under a low load is visible.

Furthermore, the rotary electric machine 10 reduce the cogging torque by more than 50% when the lateral grooves 22 at appropriate locations in the outer circumference 12a of the rotor 12 are formed as by an in 56 shown illustration of the cogging torque waveform is shown.

Thus, according to the present invention, after eliminating that portion of each of the permanent magnets of each pair forming a magnetic pole located in a region B located on the side near a longitudinal axis between the permanent magnets and replacing the permanent magnet eliminated section through a considerable river barrier 17c the magnetic flux ψ _m is removed by the permanent magnets, which is output in such directions as to act against the magnetic flux ψ _{r of} the stator windings, preventing them from being counteracted (canceling each other out), and the magnetic flux ψ _{r also} passes restricted to area B.

This provides significant amounts of magnetic moment T _m and reluctance torque T _r while substantially reducing the amount of use of the permanent magnets 16 is provided, since the magnetic fluxes ψ _r and ψ _m of each of the permanent magnets 16 of the pair are used on sides of the longitudinal axis while the usage amount of the permanent magnets 16 is reduced. In addition, thanks to a reduction in the induced voltage constant, it increases the output at high speeds, and is lowered by lowering the degree of heat resistance resulting from limitation of demagnetization caused by temperature changes due to limitation of eddy current heat generation by the permanent magnets 16 also contributed to a reduction in costs.

In addition, a large torque T can be efficiently generated by the separation distance R2 to the axial center-side end of the flow barrier 17c is set so that the relationships (the size and the shape) to the outer radius R1 and the inner radius R2 of the rotor are 0.56 R2 / R1 ≦ 0.84 and 0.54 ≦ R3 / R2 ≦ 0.82.

In addition, the river barriers provide 17c a powerful generation of high torque when the separation distance DL _d from each of the flux barriers 17c to the outer periphery of the rotor 12 with respect to the outer radius R1 of the rotor, a relation of 0.098 ≦ DL _d / R1 <0.194 is satisfied. The river barriers 17c provide powerful generation of greater torque, preferably when the two relationships 0.12 ≦ DL _d / R1 ≦ 0.14 and 1.2 ≦ (flux barrier opening angle θ1) / (magnetic opening angle θ2) ≦ 1.7 are satisfied or even better the relationships DL _d / R1 = 0.139 and θ1 / θ2 = 1.52 are satisfied.

Additionally, by providing the in the rotor 12 educated media people 21 the torque ripple can be effectively reduced by suppressing harmonic torque components when the ratio of the radial distance R4 to the groove bottom 21a with respect to the outer radius R1 of the rotor 12 is made to fall in the range of 0.98 ≦ R4 / R1 <1.0. In addition, each of the middle people 21 further reduce torque ripple by suppressing more harmonic torque components when their shape dimensions are made to satisfy the following: 2 × tan ^-1 {(TB / 2) / (R1 + AG)} ≦ θ _a ≦ 2 × tan ^-1 [{SO + (TB / 2)} / (R1 + AG)}], 0 ° ≦ θ _b ≦ 2 × tan ^-1 [{SO + (TB / 2)} / (R1 + AG)}], and TW ≦ TB.

In addition, space harmonics that overlay the gap magnetic flux waveform may be restricted if each side groove 22 to the rotor having shape dimensions satisfying a relationship of θ4 (outer confinement angle) θ3 (magnetic edge arc angle) and a relationship of 0.945 ≦ θ5 / θ4 ≦ 0.98 and a relationship of 0.0 ≦ RG / AG 0.73, which is makes it possible to prevent a drop in the operating efficiency caused by increases in cogging torque, torque ripple and iron loss.

Consequently, a cheap rotary electric machine is realized, which provides a high-quality operation with a high energy density in a drive mode.

In the present embodiment, a rotary electric machine 10 with the shape of a motor having 8 poles and 48 slots as an example, it should be noted that the present invention is not limited to this embodiment but may be preferably applied to any structure in which a slot number q per pole per phase 2 is (q = 2). For example, the present invention may be applied without any modifications to 6-pole and 36-slot or 4-pole and 24-slot or 10-pole and 60-slot motor structures.

The present invention is not limited to the described and illustrated exemplifying embodiment, but includes all embodiments that provide effects equivalent to those to which the present invention is directed. Further, the present invention is not limited to combinations of features of the subject matters defined by the individual claims, but is defined by any desired combinations of particular ones disclosed throughout the claims.

In the foregoing, an embodiment of the present invention has been described, but the present invention is not limited to the above-mentioned embodiment but may be embodied in various forms within the technical ideas of the present invention.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2006-254629 A [0006]
• JP 2012-39775 A [0006]
• JP 2004-328956 A [0006]
• JP 2008-206308 A [0006]
• JP 2008-312316A [0006]

Claims (3)

An internal permanent magnet (IPM) rotary electric machine comprising: a stator configured to receive stator windings; a rotor rotatable about a rotor axis with respect to the stator, the rotor having an outer periphery; a plurality of pairs of permanent magnets in the rotor, the permanent magnets of each pair being arranged in a "V" shaped configuration opening toward the outer periphery, forming a magnetic pole and accommodated in magnet openings in the rotor; Low permeability openings, each of which replaces the predetermined area portion of one of the permanent magnets that would generate so directed magnetic flux lines that magnetic flux lines emanating from the stator near a longitudinal axis of one of the magnetic poles would be extinguished when the permanent magnet in the predetermined area, the opening comprising an additional space formed in one of the magnet openings due to shortening the length of the permanent magnet received in the magnet opening along the magnet opening, the opening being from the additional space to the rotor axis and to the rotor axis Extending the outer circumference; and a middle regulating groove and a pair of lateral regulating grooves formed per magnetic pole in parallel relation to the rotor axis in the outer circumference of the rotor, the center regulating groove being located on a longitudinal axis of the magnetic pole, the pair of lateral regulating grooves close to both outer Ends of the permanent magnets of the pair, which forms the magnetic pole, wherein each of the lateral regulating grooves of the pair for the magnetic pole is designed so that a relationship of θ4 ≦ θ3 is satisfied, where θ4 is the inclusion angle between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point at the edge of the lateral regulation groove farthest from the longitudinal axis, and θ3 is the inclusion angle between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point at a corner of one of the permanent magnets closest to the outer circumference of the rotor. The IPM rotary electric machine according to claim 1, wherein each of the lateral regulating grooves of the pair has a relationship of 0.945 ≦ θ5 / θ4 ≦ 0.98 where θ5 is the angle of inclusion between the longitudinal axis and a radial reference line extending from the rotor axis to a reference point on the edge of the lateral regulating groove least distant from the longitudinal axis. An IPM rotary electric machine according to claim 1 or 2, wherein each of the lateral regulating grooves of the pair has a relationship of 0.0 ≦ RG / AG ≦ 0.73 where AG is the width of an air gap between an inner circumference of the stator and an outer periphery of the rotor, and RG is the depth of the lateral regulating groove.

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