JP4862556B2 - Field element and rotating electric machine - Google Patents

Description

  The present invention relates to a field element and a rotating electric machine, and can be applied to, for example, an electric motor or a generator.

  For example, axial gap type field elements and armatures are used for electric motors and generators. According to the field element and the armature, the thickness in the direction along the axis that is the center of rotation can be reduced, and the torque density can be increased because the magnetic pole area is large.

  In an axial gap type field element, field magnets are annularly arranged in the circumferential direction around an axis, and a magnetic pole surface having a single polarity is directed to the armature side for each field magnet.

  For any one field magnet, the length in the radial direction around the axis is preferably greater near the center than the end in the circumferential direction of the one field magnet. This is because the waveform around the axis of the magnetic flux density generated in the field element can be approximated to a sine wave. The shape of such a field magnet is disclosed in Patent Document 1, for example.

JP 2005-94955 A

  However, when the shape of the field magnet becomes complicated, it becomes difficult to manufacture the field magnet.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to facilitate the manufacture of a field magnet while the waveform around the axis of the magnetic flux density generated in the field element is brought close to a sine wave. Is done.

  A field element according to a first aspect of the present invention comprises a plurality of field magnets (12) arranged in an annular shape along a circumferential direction (92) around an axis (91) along a predetermined direction (90). Each of the field magnets is single and has a first magnetic pole surface (12a) and a second magnetic pole surface (12b) having different polarities adjacent to each other in the circumferential direction on the predetermined direction side. The first magnetic pole surfaces and the second magnetic pole surfaces belonging to each of the field magnets adjacent in the circumferential direction and having the same polarity are adjacent to each other, and each position in the circumferential direction The length in the radial direction (93) about the axis is determined by the edge (123, 124) in the circumferential direction of the field magnet belonging to the same field magnet. Boundary between the first magnetic pole surface and the second magnetic pole surface (125 Greater than.

  A field element according to a second aspect of the present invention is the field element according to the first aspect, wherein the field magnet (12) viewed from the predetermined direction (90) has a trapezoidal shape, The upper side (121) of the trapezoidal shape is located on the inner peripheral side of the magnet and the lower side (122) of the trapezoidal shape is located on the outer peripheral side.

  A field element according to a third aspect of the present invention is the field element according to the first or second aspect, wherein the field magnet (12) has an edge (123, 124) in the circumferential direction (92). ) Belong to each of the field magnets (12) adjacent in the circumferential direction (92), and one of the edges adjacent to each other is along the other.

  A field element according to a fourth aspect of the present invention is the field element according to the third aspect, wherein the one of the edges (123, 124) and the other are in contact with each other.

  A field element according to a fifth aspect of the present invention is the field element according to any one of the first to fourth aspects, wherein the boundary is provided in a direction in which the boundary (125) extends. It is inclined with respect to the radial direction determined at a position in the circumferential direction.

  A field element according to a sixth aspect of the present invention is the field element according to any one of the first to fifth aspects, wherein the boundary (125) is the circumferential direction (92) of the boundary. The field magnet (12) extends along the radial direction (93) determined at a position about the shape of the field magnet (12) as viewed from the predetermined direction (90) and is symmetrical with respect to the boundary.

  A field element according to a seventh aspect of the present invention is the field element according to any one of the first to sixth aspects, wherein the field magnet (12) is the first magnetic pole surface. There is a non-magnetized portion along the boundary (125) between (12a) and the second magnetic pole surface (12b).

  A field element according to an eighth aspect of the present invention is the field element according to any one of the first to seventh aspects, wherein the field magnet is adjacent in the circumferential direction (92). ) And a single first magnetic plate (141) covering either one of the magnetic pole faces (12a; 12b) having the same polarity from the predetermined direction (90) side or the opposite side thereof. In addition, the first magnetic plates are magnetically shielded in a plane perpendicular to the predetermined direction.

  A field element according to a ninth aspect of the present invention is the field element according to any one of the first to eighth aspects, wherein the magnetic core (12) is provided on the outer peripheral side of the field magnet (12). 13), and the magnetic core is unevenly distributed in the circumferential direction (92).

  A field element according to a tenth aspect of the present invention is the field element according to the ninth aspect, wherein the magnetic core (13) is the field magnet (12) when viewed from the predetermined direction (90). Is located between a circle (Coo) circumscribing the outer peripheral edge (122) and the edge.

  A field element according to an eleventh aspect of the present invention is the field element according to the ninth or tenth aspect, wherein the position of the boundary (125) in the circumferential direction (92) and the magnetic core (13). ) In the circumferential direction is deviated by a predetermined angle (θ) around the axis (91).

  A field element according to a twelfth aspect of the present invention is the field element according to the eleventh aspect, wherein the predetermined angle (θ) is 90 ° divided by half the number of field magnets. It is.

  A field element according to claim 13 of the present invention is the field element according to claim 11 or claim 12, wherein the positions of the magnetic core (13) in the circumferential direction (92) are the same. It exists in the center vicinity of each position of the said edge (123,124) about the said circumferential direction of a magnet (12).

  A field element according to a fourteenth aspect of the present invention is the field element according to any one of the ninth to thirteenth aspects, wherein the field element side is a predetermined direction (90) side with respect to the magnetic core (13). Alternatively, a single second magnetic plate (142) covering from the opposite side is further provided, and the second magnetic plates are magnetically shielded in a plane perpendicular to the predetermined direction. .

  A field element according to a fifteenth aspect of the present invention is the field element according to any one of the first to fourteenth aspects, wherein the field element is viewed from a side opposite to the predetermined direction (90). It further comprises a single yoke (11) provided on the magnet (12).

  A field element according to a sixteenth aspect of the present invention is the field element according to the fifteenth aspect, wherein the field element is the same surface as the surface of the yoke (11) on which the field magnet (12) is provided. A magnetic core (13) provided on the outer peripheral side of the magnet is further provided.

  A rotating electric machine according to a seventeenth aspect of the present invention is the field element (1a; ...; 1d) according to the fifteenth or sixteenth aspect, and the field element from the predetermined direction (90) side. And an armature (100) provided to face each other.

  According to an eighteenth aspect of the present invention, there is provided a rotating electric machine from the field element (1a;..., 1d) according to any one of the first to fourteenth aspects and the predetermined direction (90) side. A first armature (100) provided to face the field element.

  A rotating electric machine according to a nineteenth aspect of the present invention is the rotating electric machine according to the eighteenth aspect, and is opposed to the field element (1a;..., 1d) from a side opposite to the predetermined direction (90). And a second armature (101) provided as a second armature.

  A rotating electric machine according to a twentieth aspect of the present invention is the rotating electric machine according to any one of the seventeenth to nineteenth aspects, wherein the armature (100; 101) has teeth (102, 104). The radius (Rco) of the circle (Cco) circumscribing the outer peripheral edge (1042) of the teeth is the radius of the circle (Coi) inscribed in the outer peripheral edge (122) of the field magnet (12). A radius (Rci) of a circle (Cci) larger than (Roi) and inscribed in the inner peripheral edge (1041) of the teeth is a circle (Cii) inscribed in the inner peripheral edge (121) of the field magnet. ) Radius (Rii) or more and less than or equal to the radius (Rio) of the circle (Cio) circumscribing the edge.

  A rotating electric machine according to a twenty-first aspect of the present invention is the rotating electric machine according to the twentieth aspect, wherein the radius of the circle (Cco) circumscribing the edge (1042) on the outer peripheral side of the teeth (102, 104). (Rco) is greater than or equal to the radius (Roo) of the circle (Coo) circumscribing the edge (122) on the outer peripheral side of the field magnet (12).

  According to the field element of the first aspect of the present invention, a magnetic pole surface having a single polarity is formed by two magnetic pole surfaces adjacent in the circumferential direction. In the magnetic pole surface, the length of the magnetic pole surface in the radial direction is large near the center in the circumferential direction. Therefore, the waveform in the circumferential direction of the magnetic flux density generated on the surface on the predetermined direction side of the field element approaches a sine wave, so that the harmonic component contained in the magnetic flux density can be reduced. In addition, the manufacturing is easier than in the case where the field magnet is formed for each of the first and second magnetic pole surfaces. Further, since both the first and second magnetic pole surfaces are provided in the same field magnet, the number of field magnets does not increase.

  According to the field element of claim 2 of the present invention, since the shape of the field magnet is trapezoidal, it is easy to form the field magnet.

  According to the field element of the third aspect of the present invention, the gap between the field magnets adjacent in the circumferential direction can be narrowed, so that the magnetic flux density generated in the field element can be increased.

  According to the field element according to claim 4 of the present invention, the magnetic flux density generated in the field element can be further increased.

  According to the field element of the fifth aspect of the present invention, the field element can be skewed by inclining the extending direction of the boundary with respect to the radial direction. Therefore, generation of cogging torque is suppressed in a rotating electric machine obtained by providing an armature on a field element.

  According to the field element of claim 6 of the present invention, a magnetic pole surface having a single polarity is formed by two magnetic pole surfaces adjacent in the circumferential direction. In the magnetic pole surface, the length in the radial direction of the magnetic pole surface is the maximum at the center position in the circumferential direction. Therefore, the waveform in the circumferential direction of the magnetic flux density generated on the surface on the predetermined direction side of the field element can be made closer to a sine wave, thereby further reducing the harmonic component contained in the magnetic flux density. it can.

  According to the field element of claim 7 of the present invention, the waveform in the circumferential direction of the magnetic flux density generated on the surface on the predetermined direction side of the field element approaches a sine wave, and is thus included in the magnetic flux density. Harmonic components can be reduced. Therefore, in the rotating electrical machine obtained by providing the armature on the field element, uneven rotation and vibration can be reduced.

  According to the field element of the eighth aspect of the present invention, the influence of the demagnetizing field on the field magnet can be reduced. Moreover, eddy currents generated in the field magnet can be reduced by reducing the change in the magnetic flux flowing in the field magnet. Furthermore, since the first magnetic plates are magnetically cut off, a short circuit of the magnetic flux in the field element is prevented.

  According to the field element of the ninth aspect of the present invention, the q-axis inductance can be increased by providing the magnetic core. Therefore, in a rotating electric machine obtained by providing an armature on the field element, the reluctance torque generated due to the difference between the q-axis inductance and the d-axis inductance increases, thereby increasing the torque and improving the efficiency of the device. improves.

  According to the field element of claim 10 of the present invention, in the rotating electrical machine obtained by providing the armature from the predetermined direction side or the opposite side to the field magnet, the armature is also provided to the magnetic core. opposite.

  According to the field element of the eleventh aspect of the present invention, in the rotating electric machine obtained by providing the field element with the armature, the reluctance torque and the magnet torque can be effectively used to increase the torque.

  According to the field element according to claim 12 or claim 13 of the present invention, in a rotating electric machine obtained by providing an armature on the field element, a current having a phase corresponding to a predetermined angle is passed, Is the maximum.

  According to the field element of the fourteenth aspect of the present invention, most of the magnetic flux flowing on the second magnetic plate side of the magnetic core can be led to the magnetic core. Moreover, since the second magnetic plates are magnetically interrupted, a short circuit of the magnetic flux in the field element is prevented.

  According to the field element of the fifteenth aspect of the present invention, since the yoke is single, the yoke acts as a back yoke, thereby reducing the magnetic resistance. Therefore, most of the magnetic flux can be flowed in the predetermined direction.

  According to the field element of the sixteenth aspect of the present invention, by providing the magnetic core, the q-axis inductance can be increased without reducing the amount of the field magnet. Therefore, in a rotating electrical machine obtained by providing an armature on the field element, the reluctance torque generated due to the difference between the q-axis inductance and the d-axis inductance increases, thereby increasing the torque and improving the efficiency of the device. To do.

  According to the rotating electrical machine of the seventeenth aspect of the present invention, the waveform in the circumferential direction of the magnetic flux density generated on the surface of the field element in the predetermined direction approaches a sine wave and is thus included in the magnetic flux density. Harmonic components can be reduced. Therefore, the cogging torque is reduced in the rotating electrical machine.

  According to the rotating electrical machine of the eighteenth aspect of the present invention, the waveform in the circumferential direction of the magnetic flux density generated on the surface on the predetermined direction side of the field element approaches a sine wave, and is thus included in the magnetic flux density. Harmonic components can be reduced. Therefore, the cogging torque is reduced in the rotating electrical machine.

  According to the rotating electrical machine of the nineteenth aspect of the present invention, the magnetic flux flowing into and out of the predetermined direction can be linked to the second armature, so that the output and efficiency of the rotating electrical machine are increased. . Moreover, the thrust force generated in the field element can be reduced, thereby reducing the bearing loss.

  According to the rotary electric machine according to claim 20 or claim 21 of the present invention, since the magnetic flux of the field magnet can be linked to the armature without leaking, the magnetic flux linked to the armature is also a sine wave. It can be changed with a waveform close to. Therefore, the cogging torque generated in the rotating electrical machine is reduced.

First embodiment.
FIG. 1 conceptually shows a field element 1a according to the present embodiment. The field element 1 a includes a plurality of field magnets 12.

  The field magnet 12 is annularly arranged along the circumferential direction 92 around the axis 91 along the predetermined direction 90. Each of the field magnets 12 is single, and has a first magnetic pole surface 12a and a second magnetic pole surface 12b having different polarities adjacent to each other in the circumferential direction 92 on the predetermined direction 90 side. For example, the first magnetic pole surface 12a exhibits an N pole, and the second magnetic pole surface 12b exhibits an S pole.

  For the field magnet 12, it is desirable to employ a material having a large saturation magnetic flux density and a large field, such as a Nd—Fe—B based sintered magnet. Although a material having a high density and a large energy product is difficult to process, according to the present invention, the field magnet 12 can be easily formed as will be described later, and such a material can be employed.

  It is desirable to employ a material having magnetic anisotropy for the field magnet 12. This is because by setting the easy magnetization axis along the axis 91, the magnetic flux density generated on the surface of the field element 1a in the predetermined direction 91 can be increased, and the magnetization is increased. However, the field magnet 12 may be made of a magnetically isotropic material. In this case, the components in the predetermined direction 90 of the magnetic flux appearing on the magnetic pole surfaces 12a and 12b can be varied by varying the magnetization direction. Details will be described later.

  The field magnet 12 is obtained, for example, by magnetization. The magnetization may be performed before or after the field magnet 12 is incorporated in the field element 1a.

  The first magnetic pole surfaces 12a and the second magnetic pole surfaces 12b belonging to each of the adjacent field magnets 12 in the circumferential direction 92 and having the same polarity are adjacent to each other.

  The field magnet 12 has an edge 121 on the inner peripheral side, an edge 122 on the outer peripheral side, and edges 123 and 124 in the circumferential direction 92. The length of the radial direction 93 centered on the shaft 91 is larger at the edges 123 and 124 than the boundary 125 between the first magnetic pole surface 12a and the second magnetic pole surface 12b belonging to the same field magnet 12. . In FIG. 1, the length of the edge 124 is represented by a symbol L1, and the length of the boundary 125 is represented by a symbol L2.

  Here, the radial direction 93 is determined for each position in the circumferential direction 92. Specifically, with respect to the edges 123 and 124, the direction from the position of the shaft 91 to the position in the circumferential direction of the edges 123 and 124 is adopted as the radial direction 93. Regarding the boundary 125, the direction from the position of the shaft 91 to the position in the circumferential direction 92 of the boundary 125 is adopted as the radial direction 93.

  Also shown in FIG. 1 is a single plate 11 that exhibits an annulus along a circumferential direction 92 about an axis 91. The plate 11 is provided on the field magnet 12 from the side opposite to the predetermined direction 90 and holds the field magnet 12.

  It is desirable to employ a soft magnetic material such as iron for the plate 11. This is because the soft magnetic material functions as a back yoke, and thus the magnetic resistance is reduced. Thereby, much magnetic flux can be sent to the predetermined direction 90 side. As the yoke, a dust core or a wound core may be employed, or a laminate of electromagnetic steel sheets in a predetermined direction 90 may be employed.

  The plate 12 may not be provided, and the field magnets 12 arranged in an annular shape along the circumferential direction 92 may be held by molding with a resin or the like, for example. Such an aspect is shown in FIG. 8 to be described later. In FIG. In this case, the magnetic pole surfaces 12a and 12b of the field magnet 12 may be exposed from the resin or may be covered with the resin. However, since the air gap length increases by the thickness of the resin covering the magnetic pole surfaces 12a and 12b, it is desirable that the thickness of the resin is small.

  According to the above-described field elements 1a and 1b, the two magnetic pole surfaces 12a (12b) adjacent in the circumferential direction 92 form a magnetic pole surface having a single polarity. In the magnetic pole surface, the length of the magnetic pole surface in the radial direction 93 is large near the center in the circumferential direction 92. Accordingly, the waveform of the magnetic flux density generated on the surface of the field elements 1a and 1b on the side in the predetermined direction 90 in the circumferential direction 92 approaches a sine wave, so that the harmonic component included in the magnetic flux density can be reduced.

  In addition, the manufacturing is easier than in the case where a field magnet is formed for each of the first and second magnetic pole faces 12a and 12b. When a field magnet is molded by fitting in a mold, the density of the field magnet increases. On the other hand, when a field magnet having a predetermined shape is obtained by forming a single magnet and then cutting it, the number of steps required for cutting is reduced.

  Further, since both the first and second magnetic pole surfaces 12a and 12b are provided in the same field magnet 12, the number of field magnets 12 does not increase. Specifically, the number of field magnets 12 may be half as compared with the case where a field magnet is formed for each of the first and second magnetic pole faces 12a and 12b.

  From the viewpoint of facilitating the molding of the field magnet 12, it is desirable that the field magnet 12 viewed from a predetermined direction 90 has a trapezoidal shape. In this case, the upper side of the trapezoid is directed to the inner peripheral side, and the bottom side is directed to the outer peripheral side. That is, the upper side of the trapezoidal shape is positioned on the inner peripheral side (edge 121) of the field magnet 12, and the bottom of the trapezoidal shape is positioned on the outer peripheral side (edge 122).

  In FIG. 1, one of the edges 123 and 124 that belong to each of the field magnets 12 adjacent in the circumferential direction 92 and are adjacent to each other is along the other. According to such a shape, the gap between the adjacent field magnets 12 in the circumferential direction 92 can be reduced, so that the magnetic flux density generated on the predetermined direction 90 side of the field element 1a can be increased. In particular, when one and the other of the edges 123 are in contact with each other, that is, when the field magnets 12 adjacent in the circumferential direction 92 are in contact with each other without a gap, the magnetic flux density can be further increased.

  In FIG. 1, the boundary 125 extends along a radial direction 93 determined at its own position in the circumferential direction 92. Moreover, the shape of the field magnet 12 viewed from the predetermined direction 90 is symmetric with respect to the boundary 125. According to this aspect, in the magnetic pole surface formed by the two magnetic pole surfaces 12a (12b) adjacent in the circumferential direction 92, the length of the magnetic pole surface in the radial direction 93 is the maximum at the center position in the circumferential direction 92. It becomes. Therefore, the waveform in the circumferential direction 92 of the magnetic flux density generated on the surface on the predetermined direction 90 side of the field element 1a can be made closer to a sine wave, thereby further reducing the harmonic component contained in the magnetic flux density. can do.

  FIG. 2 shows a different aspect of the boundary 125 from the field element 1a shown in FIG. The direction in which the boundary 125 extends with respect to the boundary 125 of the field element 1b shown in FIG.

  According to the field element 1b, a skew can be provided in the field element 1b. Therefore, in the rotating electric machine obtained by providing the armature on the field element 1b, the magnetic flux smoothly changes at the boundary between the magnetic poles, thereby suppressing the generation of cogging torque.

  In any of the above-described field elements 1a and 1b, for example, the field magnet 12 has a non-magnetized portion along the boundary 125 between the first magnetic pole surface 12a and the second magnetic pole surface 12b. May be. Also in such an aspect, the waveform of the magnetic flux density can be approximated to a sine wave, and thus harmonic components contained in the magnetic flux density can be reduced. Therefore, in the rotating electric machine obtained by providing the armatures on the field elements 1a and 1b, rotation unevenness and vibration can be reduced.

  For example, a material having magnetic anisotropy can be employed as the field magnet 12. In this case, it is desirable to use a material that is not easily magnetized near the boundary 125. This is because the magnetic flux density changes gradually in the vicinity of the boundary 125, and thus harmonic components contained in the magnetic flux density are reduced.

  A magnetically isotropic material may be used as the field magnet 12. In such a case, in the vicinity of the boundary 125, the magnetization direction changes from the predetermined direction 90 to the opposite direction as it goes from one of the first and second magnetic pole faces 12a, 12b to the other. Therefore, the magnetic flux density gradually changes in the vicinity of the boundary 125, and thus harmonic components included in the magnetic flux density can be reduced.

  The configuration of the field magnet 12 on the predetermined direction 90 side can be applied to the configuration of the field magnet 12 on the side opposite to the predetermined direction 90.

Second embodiment.
FIG. 3 conceptually shows the field element 1c according to the present embodiment. The field element 1c is the field elements 1a and 1b described in the first embodiment, and further includes a magnetic core 13. In FIG. 3, the field element 1a provided with the magnetic core 13 is shown as a field element 1c.

  The magnetic core 13 is provided on the outer peripheral side of the field magnet 12. In particular, FIG. 3 shows a case where the position of the magnetic core 13 in the circumferential direction 92 is near the center of the respective positions of the edges 123 and 124 of the same field magnet 12.

  For example, when the field magnet 12 is provided on the plate 11, the magnetic core 13 is provided on the outer peripheral side of the field magnet 12 on the same surface as the surface of the plate 11 on which the field magnet 12 is provided. As the magnetic core 13, for example, a dust core or a wound core can be used.

  A yoke can be adopted as the plate 11 as in the first embodiment. Even if the plate 11 is not provided, the field magnet 12 and the magnetic core 13 disposed on the outer peripheral side of the field magnet 12 can be fixed by molding with a resin or the like.

  The magnetic core 13 is desirably separated from the field magnet 12 by a predetermined distance. This is because it is possible to prevent the magnetic flux from being short-circuited in the field element 1c. In the rotating electrical machine obtained by providing the armature to the field element 1c described in the third embodiment, the distance between the magnetic core 13 and the field magnet 12 is the gap between the field element 1c and the armature. It is particularly desirable that the length is twice or more of the length. In this case, the magnetic resistance in the magnetic path directly going from one of the field magnet 12 and the magnetic core 13 to the other in the field element 1c goes from one of the field magnet 12 and the magnetic core 13 to the other via the armature. It becomes larger than the magnetic resistance in the magnetic path. Therefore, short-circuiting of the magnetic flux hardly occurs between the field magnet 12 and the magnetic core 13 in the field element 1c.

  By providing the magnetic core 13, since the magnetic core 13 is unevenly distributed in the circumferential direction 92, the q-axis inductance Lq can be increased. Therefore, in the rotating electrical machine obtained by providing the armature on the field element 1c, the reluctance torque generated due to the difference between the q-axis inductance Lq and the d-axis inductance Ld increases, and thus the torque increases. Efficiency is improved.

  The reluctance torque Tr1 is expressed by Expression (1). Here, the symbol Pn represents the number of pole pairs, and the symbol Ia represents the magnitude of the current vector flowing through the armature winding. Further, symbol β is a phase and represents an angle (0 ° or more and 90 ° or less) formed by the current vector with respect to the q axis. In the field element 1c, a magnetic pole surface having a single polarity is formed by the two magnetic pole surfaces 12a (12b) adjacent in the circumferential direction 92, as in the first embodiment. Therefore, the field element 1 c has the same number of poles as the number of magnets 12, so that the number of pole pairs is half the number of magnets 12.

  FIG. 4 conceptually shows the position where the magnetic core 13 is provided. When viewed from the predetermined direction 90, the magnetic core 13 is positioned between the edge 122 and the circle C 1 circumscribing the edge 122 on the outer peripheral side of the field magnet 12.

  According to the position of the magnetic core 13, by providing the armature so as to face the field magnet 12 from the predetermined direction 90 with respect to the field element 1c, the armature can be made to face the magnetic core 13. Therefore, the q-axis inductance tends to increase. The magnetic core 13 preferably has saliency in a range facing the armature. Further, it is desirable that the magnetic cores 13 are unevenly distributed at a pitch corresponding to the number of poles.

  5 and 6 conceptually show the positional relationship between the magnetic core 13 and the boundary 125. That is, the position of the magnetic core 13 in the circumferential direction 92 and the position of the boundary 125 in the circumferential direction 92 are shifted by a predetermined angle θ around the axis 91.

  In FIG. 5, the boundary 125 is shifted from the magnetic core 13 by a predetermined angle θ as compared with the field element 1 c shown in FIG. 3.

  In FIG. 6, with respect to the armature 1 c shown in FIG. 3, the magnetic core 13 is shifted from the boundary 125 by a predetermined angle θ. Specifically, the magnetic core 13 is shifted by a predetermined angle θ toward the opposite side of the circumferential direction 92 with respect to the boundary 125. In this case, the field element 1d is preferably rotated in the circumferential direction 93 (counterclockwise direction when viewed from the predetermined direction 90).

  According to this positional relationship, in the rotating electric machine obtained by providing the armature on the field element 1c, the reluctance torque and the magnet torque can be effectively used to increase the torque. Details will be described below.

  Torque T generated in the rotating electric machine obtained by providing the armature on the field element 1c is represented by the sum of the magnet torque Tm and the reluctance torque Tr2. The magnet torque Tm is expressed by equation (2), and the reluctance torque Tr2 is expressed by equation (3). Here, the symbol φa represents the magnetic flux interlinking with the armature when there is no load. The symbol θ1 represents an electrical angle obtained from the predetermined angle θ by the equation (4).

  In the field element 1c shown in FIG. 3, the magnetic core 13 and the boundary 125 are at the same position in the circumferential direction 92 (θ = 0 °), so the electrical angle θ1 is 0 °. And what substituted (theta) 1 = 0 degree to Formula (3) is represented as Formula (1).

  When the electrical angle θ1 is 0 °, the phase β at which the magnet torque Tm is maximized is different from the phase β at which the reluctance torque Tr is maximized. For example, at the phase β (= 0 °) at which the magnet torque Tm is maximum, the reluctance torque Tr is zero. In the phase β (= 45 °) at which the reluctance torque Tr is maximum, the magnet torque Tm is 1 / √2 times the maximum value Pn · φa · Ia.

  On the other hand, by adopting a value other than 0 ° for the electrical angle θ1, that is, an angle other than 0 ° for the predetermined angle θ, the value of the torque T can be made larger than when the electrical angle θ1 is 0 °.

  In particular, by adopting 90 ° / (2Pn) as the predetermined angle θ, the electrical angle θ1 becomes 45 °, the phase β (= 0 °) at which the magnet torque Tm becomes maximum, and the phase at which the reluctance torque Tr becomes maximum. β (= 0 °) can be matched. Therefore, the maximum torque T can be obtained in the rotating electrical machine. For example, in the armature 1d shown in FIG. 5, since the number of pole pairs is 3, by setting the predetermined angle θ to 15 °, the electric angle θ1 becomes 45 °.

Third embodiment.
7 and 8 conceptually show the rotating electrical machine according to the present embodiment. The rotating electric machine includes a field element 1 a and an armature 100. The armature 100 is provided to face the field element 1a from the predetermined direction 90 side. Instead of the field element 1a, any one of the field elements 1b to 1d may be employed.

  The field element 1a shown in FIG. 7 includes a plate 11, which is indicated by a broken line in FIG. A field element 1 a shown in FIG. 8 is formed by fixing a field magnet 12 by molding with a resin 15. 7 and 8, the field element 1a and the armature 100 are shown separated in a predetermined direction 90.

  FIG. 9 conceptually shows the armature 100. The armature 100 includes a yoke 101, a tooth 102, a winding 103 and a magnetic plate 104. In FIG. 9, the winding 103 and the magnetic plate 104 are shown separated along the shaft 91 with respect to the yoke 101 and the teeth 101.

  The teeth 102 are arranged on the surface of the yoke 101 opposite to the predetermined direction 91 in a ring shape along the circumferential direction 92 around the shaft 91. A winding 103 is wound around each of the teeth 102 in a concentrated manner. The winding 103 may be wound around the teeth 102 by distributed winding or wave winding, for example.

  When the winding 103 is wound around the teeth 102 in a concentrated manner, the number N of the teeth 102 can be 1.5 times the number of poles 2Pn of the field element 1a. 7 and 8, since the six field magnets 12 are provided, the number of poles is six, and the number of teeth 102 is nine. In the case of concentrated winding, the number of poles 2Pn of the field element 1a and the number N of teeth 102 are (2Pn, N) = (4,6), (8,12), (8,9) And values such as (10, 12) can be employed.

  On the other hand, in the case of distributed winding or wave winding, the number of poles 2Pn of the field element 1a and the number N of teeth 102 are (2Pn, N) = (4, 12), (4, 24), ( 4, 36), (6, 18) and (8, 24) can be adopted.

  A three-phase current flows through each of the windings 103. Specifically, each of the windings 103 through which the U-phase current, the V-phase current, and the W-phase current flow is repeatedly arranged in this order along the circumferential direction 92. For wiring of the winding 103, star connection, delta connection, or the like can be employed.

  The magnetic plate 104 is provided on the end surface 102 a of the tooth 102 opposite to the yoke 101. A surface 104a of the magnetic plate 104 opposite to the teeth 102 faces the field magnet 12 of the field element 1a. The area of the surface 104a is larger than the area of the end face 102a. By providing the magnetic body plate 104, much of the magnetic flux flowing from the field element 1 a can be linked to the winding 103. The magnetic plate 104 may not be provided.

  According to the rotating electric machine provided with the field elements 1a to 1d, as described in the first embodiment, the surface of the field elements 1a to 1d on the armature 100 side has a sine wave around the shaft 91. A magnetic flux density having a waveform close to. Therefore, the cogging torque is reduced in the rotating electrical machine, thereby increasing the efficiency of the rotating electrical machine.

  In particular, according to the rotating electrical machine provided with the field element 1b, since the field element 1b is provided with a skew, the cogging torque is further reduced in the rotating electrical machine.

  Further, according to the rotating electrical machine provided with the field elements 1c and 1d, as described in the second embodiment, the reluctance torque is generated in the rotating electrical machine, so that the output of the rotating electrical machine can be increased.

  FIG. 10 conceptually shows the relationship between the size of the field magnet 12 and the magnetic plate 104. In addition, in order to show the said relationship, in FIG. 10, the rotary electric machine shown in FIG. 8 is used.

  The radius Rco of the circle Cco circumscribing the outer edge 1042 of the magnetic plate 104 is larger than the radius Roi of the circle Coi inscribed to the outer edge 122 of the field magnet 12. Note that FIG. 10 shows a case where the edge 1042 presents an arc along the circle Cco.

  The radius Rci of the circle Cci inscribed in the inner peripheral edge 1041 of the magnetic plate 104 is equal to or larger than the radius Rii of the circle Cii inscribed in the inner peripheral edge 121 of the field magnet 12, and circumscribes the edge 121. The radius Cio is less than or equal to the radius Cio. FIG. 10 shows a case where the edge 1041 exhibits an arc along the circle Cci.

  If the magnetic plate 104 and the teeth 103 are grasped as one tooth, the edges 1041 and 1042 can be grasped as the inner peripheral edge and the outer peripheral edge of the teeth, respectively. Further, the armature 100 does not have to include the magnetic body plate 104, and in this case, the above relationship is applied between the field magnet 12 and the teeth 103.

  According to the relationship described above, since the armature 100 can be linked without leaking the magnetic flux of the field magnet 12, the magnetic flux linked to the armature 100 can also be changed in a waveform close to a sine wave. Can do. Therefore, the cogging torque generated in the rotating electrical machine is reduced. Moreover, the armature 100 is not increased in size by setting the radius Rci to be equal to or less than the radius Rio.

  From the viewpoint of interlinking with the armature 100 without leaking the magnetic flux of the field magnet 12, the radius Rco of the circle Cco is preferably greater than or equal to the radius Roo of the circle Coo circumscribing the edge 122.

  The relationship described above can also be applied to a rotating electrical machine including the field elements 1a to 1d. In the field elements 1c and 1d provided with the magnetic core 13, it is desirable to provide the magnetic core 13 inside the circle Cco when viewed from the predetermined direction 90.

  In any of the rotating electric machines described above, the armature 101 having the same configuration as the armature 100 may be provided from the side opposite to the predetermined direction 90 with respect to the field elements 1a to 1d. In this case, the surface 104 a of the magnetic plate 104 of the armature 101 faces the surface of the field magnet 12 opposite to the predetermined direction 90. However, it is desirable to employ field elements 1a to 1d (FIG. 8) molded with the resin or the like described in the first and second embodiments for the rotating electric machine. This is because the armature 101 can be brought close to the field magnet 12.

  According to such a rotating electrical machine, the magnetic flux flowing into and out of the field element 1b opposite to the predetermined direction can be linked to the armature 101, so that the output and efficiency of the rotating electrical machine are increased. In addition, the thrust force generated in the field elements 1a to 1d can be reduced, thereby reducing the bearing loss.

  Also, the relationship shown in FIG. 10 can be applied between the field elements 1 a to 1 d and the armature 101.

  Furthermore, the field elements 1a to 1d may be provided on both sides of the armature in the predetermined direction 90.

  FIG. 11 conceptually shows a field element 1c including magnetic plates 141 and 142. FIG. In FIG. 11, the plate 11 and the magnetic plates 141 and 142 are shown separated along the axis 91 with respect to the field magnet 12 and the magnetic core 13.

  The magnetic plate 141 is single, belongs to each of the adjacent field magnets 12 in the circumferential direction 92, and covers the magnetic pole surfaces 12a (12b) having the same polarity from the predetermined direction 90 side. In a plane perpendicular to the predetermined direction 90, the magnetic plates 141 are shielded magnetically. In FIG. 11, a gap extending from the inner peripheral side to the outer peripheral side is provided between the magnetic plates 141 adjacent in the circumferential direction 92.

  By providing the magnetic body plate 141, the influence of the demagnetizing field on the field magnet 12 can be reduced. In addition, the eddy current generated in the field magnet 12 can be reduced by reducing the change in the magnetic flux flowing in the field magnet 12. Furthermore, since the magnetic plates 141 are magnetically shielded from each other, a short circuit of the magnetic flux in the field element 1c is prevented.

  The magnetic plate 142 is single and covers the magnetic core 13 from the predetermined direction 90 side. In the plane perpendicular to the predetermined direction 90, the magnetic plates 142 are magnetically shielded from each other.

  By providing the magnetic plate 142, much of the magnetic flux flowing in the predetermined direction 90 side of the magnetic core 13 can be guided to the magnetic core 13. In addition, since the magnetic cores 13 are magnetically interrupted, a short circuit of the magnetic flux in the field element 1c is prevented.

  In FIG. 11, the magnetic plates 141 and 142 are provided in the field magnet 12 and the magnetic core 13, respectively. However, for example, only one of the magnetic plates 141 and 142 may be provided. Further, the magnetic elements 141 and 142 can be provided on the field elements 1a and 1b, and the magnetic elements 141 and 142 can be provided on the field element 1d in the same manner as described above.

  Moreover, it is desirable to employ a dust core for the magnetic plates 141 and 142. This is because the generation of eddy currents in the magnetic plates 141 and 142 can be suppressed.

  When the armature 101 is provided on the side opposite to the predetermined direction 90 of the field elements 1a to 1d, the magnetic plates 141 and 142 are respectively connected to the field magnet 12 and the magnetic element plates 141 and 142 from the side opposite to the predetermined direction 90. It is desirable to cover the magnetic core 13.

  The magnetic plates 141 and 142 are fixed to the field magnet 12 and the magnetic core 13 by, for example, an adhesive. For example, the magnetic plate 141 and the field magnet 12 and the magnetic plate 142 and the magnetic core 14 are molded with resin or the like, so that the magnetic plates 141 and 142 are fixed to the field magnet 12 and the magnetic core 13, respectively. You may do it.

  The magnetic plates 141 may be coupled to each other while being magnetically blocked (FIG. 11). For example, the inner peripheral side or outer peripheral side of the magnetic body plate 141 is connected. According to this aspect, the magnetic plate 141 can be formed integrally.

  The magnetic plates 142 may be coupled to each other while being magnetically blocked (FIG. 11). For example, the outer peripheral side of the magnetic material plate 142 is connected. According to this aspect, the magnetic plate 142 can be formed integrally.

  The magnetic plates 141 and 142 may be connected to each other. Also in this case, the magnetic plates 141 and 142 are magnetically shielded from each other. FIG. 11 shows such a mode.

  In addition, as shown in FIG. 12, the magnetic plate 142 and the magnetic core 13 may be integrally formed. The field magnet 12 can be fixed to the plate 11 by fixing the integrally molded product to the plate 11 and sandwiching the field magnet 12 between the plate 11 and the magnetic plate 142.

  In FIG. 12, grooves 61 and 62 into which the field magnet 12 and the magnetic core 13 are fitted are provided in the plate 11. By providing the grooves 61 and 62 in the plate 11, the field magnet 12 and the magnetic core 13 can be easily fixed to the plate 11.

It is a top view which shows notionally the field element 1a demonstrated by 1st Embodiment. It is a figure which shows the aspect of the boundary 125 notionally. It is a top view which shows notionally the field element 1c demonstrated by 2nd Embodiment. It is a figure which shows notionally the position which the magnetic core 13 provides. It is a figure which shows notionally the positional relationship of the magnetic core 13 and the boundary 125. FIG. It is a figure which shows notionally the positional relationship of the magnetic core 13 and the boundary 125. FIG. It is a perspective view which shows notionally the rotary electric machine demonstrated by 3rd Embodiment. It is a perspective view which shows notionally the rotary electric machine demonstrated by 3rd Embodiment. 1 is a perspective view conceptually showing an armature 100. FIG. 3 is a diagram conceptually showing the relationship between a field magnet 12 and a magnetic plate 104. FIG. It is a figure which shows notionally the field element 1c provided with the magnetic body plates 141 and 142. FIG. FIG. 2 is a diagram conceptually showing a magnetic plate 142 and a magnetic core 13 that are integrally formed.

Explanation of symbols

1a to 1d field element 11 plate (yoke)
DESCRIPTION OF SYMBOLS 12 Field magnet 12a 1st magnetic pole surface 12b 2nd magnetic pole surface 13 Magnetic core 90 Predetermined direction 91 Axis 92 Circumferential direction 93 Radial direction 100,101 Armature 102 Teeth 104 Magnetic body plate 121-124,1041,1042 Edge 125 Boundary 141, 142 Magnetic plate Coo, Coi, Cio, Cii, Cco, Cci circle θ Predetermined angle Roo, Roi, Rio, Rii, Rco, Rci Radius

Claims (21)

Comprising a plurality of field magnets (12) arranged annularly along a circumferential direction (92) around an axis (91) along a predetermined direction (90);
Each of the field magnets is single and has a first magnetic pole surface (12a) and a second magnetic pole surface (12b) having different polarities adjacent to each other in the circumferential direction on the predetermined direction side,
The first magnetic pole surfaces belonging to each of the field magnets adjacent in the circumferential direction and having the same polarity and the second magnetic pole surfaces are adjacent to each other,
The length in the radial direction (93) centered on the axis, which is determined for each position in the circumferential direction, is the same for the edges (123, 124) in the circumferential direction of the field magnet. Larger than a boundary (125) between the first magnetic pole surface and the second magnetic pole surface belonging to a field magnet,
Field element.   The field magnet (12) viewed from the predetermined direction (90) has a trapezoidal shape, the upper side (121) of the trapezoidal shape is located on the inner peripheral side of the field magnet, and the trapezoidal shape on the outer peripheral side. The field element according to claim 1, wherein the bottom side (122) is located.   The edges (123, 124) in the circumferential direction (92) of the field magnet (12) belong to each of the field magnets (12) adjacent in the circumferential direction (92) and are adjacent to each other. The field element according to claim 1, wherein one of the two is along the other.   4. A field element according to claim 3, wherein the one and the other of the edges (123, 124) are in contact with each other.   The field according to any one of claims 1 to 4, wherein a direction in which the boundary (125) extends is inclined with respect to the radial direction determined at a position in the circumferential direction in which the boundary is provided. Child. The boundary (125) extends along the radial direction (93) determined at a position of the boundary in the circumferential direction (92),
The shape of the field magnet (12) viewed from the predetermined direction (90) is symmetric with respect to the boundary,
The field element according to any one of claims 1 to 5.   The field magnet (12) has a non-magnetized portion along the boundary (125) between the first magnetic pole surface (12a) and the second magnetic pole surface (12b). The field element according to any one of claims 1 to 6. Each of the magnetic pole faces (12a; 12b) belonging to each of the field magnets (12) adjacent in the circumferential direction (92) and having the same polarity has a predetermined direction (90) side or the opposite side thereof A single first magnetic plate (141) covering from
In a plane perpendicular to the predetermined direction, the first magnetic plates are magnetically shielded from each other.
The field element according to claim 1. A magnetic core (13) provided on the outer peripheral side of the field magnet (12);
The magnetic core is unevenly distributed in the circumferential direction (92),
The field element according to any one of claims 1 to 8.   When viewed from the predetermined direction (90), the magnetic core (13) is located between a circle (Coo) circumscribing the outer edge (122) of the field magnet (12) and the edge. The field element according to claim 9.   The position of the boundary (125) in the circumferential direction (92) and the position of the magnetic core (13) in the circumferential direction are shifted by a predetermined angle (θ) around the axis (91). The field element according to claim 9 or 10.   12. The field element according to claim 11, wherein the predetermined angle ([theta]) is 90 [deg.] Divided by half the number of field magnets.   The position of the magnetic core (13) in the circumferential direction (92) is near the center of the respective position of the edge (123, 124) in the circumferential direction of the same field magnet (12). Item 11. The field element according to item 11 or claim 12. A single second magnetic plate (142) covering the magnetic core (13) from a predetermined direction (90) side or the opposite side thereof;
In a plane perpendicular to the predetermined direction, the second magnetic plates are magnetically shielded from each other.
The field element according to any one of claims 9 to 13. A single yoke (11) provided on the field magnet (12) from the side opposite to the predetermined direction (90)
The field element according to any one of claims 1 to 14, further comprising: A magnetic core (13) provided on the outer peripheral side of the field magnet on the same surface as the surface of the yoke (11) on which the field magnet (12) is provided.
The field element according to claim 15, further comprising: Field element (1a; ...; 1d) according to claim 15 or claim 16,
A rotating electric machine comprising: an armature (100) provided to face the field element from the predetermined direction (90) side. A field element (1a; ...; 1d) according to any one of claims 1 to 14,
A rotating electric machine comprising: a first armature (100) provided to face the field element from the predetermined direction (90) side. A second armature (101) provided to face the field element (1a; ...; 1d) from the opposite side to the predetermined direction (90).
The rotating electrical machine according to claim 18, further comprising: The armature (100; 101) has teeth (102, 104),
The radius (Rco) of the circle (Cco) circumscribing the outer peripheral edge (1042) of the teeth is the radius (Roi) of the circle (Coi) inscribed in the outer peripheral edge (122) of the field magnet (12). Bigger)
The radius (Rci) of the circle (Cci) inscribed in the inner peripheral edge (1041) of the teeth is the radius (Rii) of the circle (Cii) inscribed in the inner peripheral edge (121) of the field magnet. It is above, and is below the radius (Rio) of the circle (Cio) circumscribing the edge,
The rotating electrical machine according to any one of claims 17 to 19. The radius (Rco) of the circle (Cco) circumscribing the edge (1042) on the outer peripheral side of the teeth (102, 104) is circumscribed on the edge (122) on the outer peripheral side of the field magnet (12). 21. The rotating electrical machine according to claim 20, wherein the rotating electric machine is equal to or greater than a radius (Roo) of a circle (Coo).

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