JP6217319B2 - Rotor for rotating machine - Google Patents

Description

  The present invention relates to a rotor used in a rotating machine.

  There is an embedded magnet type synchronous rotating machine (hereinafter referred to as “IPM motor”) as a rotating machine that is small and can provide a large output. The rotor of this IPM motor has a structure in which a rectangular parallelepiped slot extending in the axial direction is formed in a rotor core in which electromagnetic steel plates are laminated, and a rectangular parallelepiped permanent magnet is inserted into the slot. According to the IPM motor provided with this rotor, it is possible to obtain a high synthetic torque obtained by adding the reluctance torque to the magnet torque.

  For example, Patent Document 1 describes an IPM motor including permanent magnets arranged at equal pitches at a plurality of locations in the circumferential direction of a rotor core. In this rotor core, salient poles are formed at equal pitches in the center between the permanent magnets. The salient pole is formed in an asymmetric shape with respect to a line connecting the center of the salient pole in the circumferential direction of the rotor core and the axis of the rotor core.

  Here, the direction of the magnetic flux generated by the permanent magnet, that is, the direction of the line connecting the center of the permanent magnet and the axis of the rotor core in the circumferential direction of the rotor core is defined as d-axis. The direction of the line connecting the center between the permanent magnets (center of salient poles) and the axis of the rotor core in the direction perpendicular to the d axis electrically and magnetically, that is, in the circumferential direction of the rotor core, is defined as the q axis. .

  The IPM motor described in Patent Document 1 includes a salient pole having an asymmetric shape, and includes a rotor core having a so-called windmill shape in plan view. For this reason, the d axis and the q axis can be equivalently shifted in the circumferential direction of the rotor core to bring the peak phase of the reluctance torque and the peak phase of the magnet torque closer to each other, and the combined torque can be increased.

  However, in the IPM motor described in Patent Document 1, the planar shape of the rotor core is a windmill shape and not a perfect circle. Therefore, if a foreign object is bitten between the rotor and the stator, the motor is easily locked due to being caught by a salient pole. There is. Further, in the case of an IPM motor in which oil is stored between the rotor and the stator, there is a problem that the stirring resistance of the rotor core increases and the motor efficiency decreases. In order to solve these problems, Patent Documents 2 and 3 describe an IPM motor having a gap between the outer periphery of a rotor core having a perfect circular shape and a permanent magnet.

JP 2004-32947 A JP 2012-23904 A JP 2009-219291 A

  When the permanent magnet grade (residual magnetic flux density, etc.) or electromagnetic steel sheet grade is changed due to the IPM motor design change, the magnitude of the magnet torque and reluctance torque changes. The shift amount of the d axis and the q axis also changes. However, in the IPM motors described in Patent Documents 2 and 3, since the shift amounts of the d-axis and the q-axis are determined by the shape of the gap provided in the rotor core, it is necessary to change the mold for manufacturing the rotor core. There is a problem that labor and cost increase.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a rotor for a rotating machine having a simple structure capable of increasing a combined torque of a magnet torque and a reluctance torque.

(Aspect 1) A rotor for a rotating machine according to the present invention includes a rotor core formed of a plurality of laminated ferromagnetic plates and having a slot formed in an axial direction, and a permanent magnet accommodated in the slot. The rotor core includes a core main body portion, a first outer peripheral magnetic body region positioned radially outside the slot, an outer peripheral edge of the core main body portion, and the first outer peripheral magnetic body region. And a bridge portion that is located radially outside the end of the slot, and the first outer peripheral magnetic region is bordered by the center in the peripheral direction of the first outer peripheral magnetic region. The magnetic permeability of the first reverse rotation side region, which is the region on the direction opposite to the rotation direction of the rotor core, is smaller than the magnetic permeability of the first positive rotation side region, which is the region on the rotation direction side of the rotor core. are formed on, the core body portion adjacent A second outer peripheral magnetic region sandwiched by the bridge portion is formed in the matching first outer peripheral magnetic region, and the second outer peripheral magnetic region is bordered by a circumferential center of the second outer peripheral magnetic region. Further, the magnetic permeability of the second positive rotation side region, which is the region on the rotation direction side of the rotor core, is smaller than the magnetic permeability of the second reverse rotation side region, which is the region opposite to the rotation direction of the rotor core. It is formed as follows.

  In this way, the d-axis can be equivalently shifted only by changing the magnetic permeability of the first outer peripheral magnetic region. Thereby, the peak phase of the magnet torque can be brought close to the peak phase of the reluctance torque, and the combined torque of the magnet torque and the reluctance torque can be increased. Therefore, even when the permanent magnet grade (magnitude of residual magnetic flux density, etc.) or the magnetic steel sheet grade is changed due to the design change of the IPM motor, etc., the change of the magnetic permeability is changed to shift the d axis. Since the amount can be optimized, labor and cost are not increased, and it is possible to easily cope with a design change of the IPM motor.

And if the magnetic permeability of a 2nd outer periphery magnetic body area | region is changed, a q axis | shaft can be shifted equivalently. Thereby, the peak phase of the reluctance torque can be brought close to the peak phase of the magnet torque, and the combined torque of the magnet torque and the reluctance torque can be further increased. Therefore, even when the permanent magnet grade (magnitude of residual magnetic flux density, etc.) or the electromagnetic steel sheet grade is changed due to a design change of the IPM motor or the like, the change in the permeability is changed to shift the q axis. Since the amount can be optimized, labor and cost are not increased, and it is possible to easily cope with a design change of the IPM motor.

(Claim 2 ) The first reverse rotation side region may be formed such that the magnetic permeability increases from the bridge portion toward the center in the circumferential direction of the first outer peripheral magnetic region. Thereby, the magnetic flux density in the circumferential direction in the first outer peripheral magnetic body region can be made substantially sinusoidal, and torque ripple can be reduced and generation of sound and vibration can be suppressed.

(Claim 3 ) The second positive rotation side region may be formed so that the magnetic permeability increases from the bridge portion toward the center in the circumferential direction of the second outer peripheral magnetic region. Thereby, the magnetic flux density in the circumferential direction in the second outer peripheral magnetic region can be made substantially sinusoidal, and the torque ripple can be reduced to further suppress the generation of sound and vibration.

(Claim 4 ) The first reverse rotation side region may be formed so as to have the same magnetic permeability from the bridge portion toward the center in the circumferential direction of the first outer peripheral magnetic body region. Thereby, the magnetic permeability of a 1st reverse rotation side area | region can be changed easily.
(Claim 5 ) The second positive rotation side region may be formed so as to have the same magnetic permeability from the bridge portion toward the center in the circumferential direction of the second outer peripheral magnetic region. Thereby, the magnetic permeability of the second positive rotation side region can be easily changed.

(Claim 6 ) A rotor for a rotating machine comprising a rotor core formed of a plurality of laminated ferromagnetic plates and having a slot formed in an axial direction, and a permanent magnet accommodated in the slot, The rotor core connects a core main body, a first outer peripheral magnetic body region located radially outside the slot, an outer peripheral edge of the core main body, and a circumferential end of the first outer peripheral magnetic region. A second outer peripheral magnetic region sandwiched between the first outer peripheral magnetic region adjacent to the core body portion via the bridge portion, and a bridge portion positioned radially outward of the end portion of the slot. The second outer peripheral magnetic body region has a magnetic permeability of a second positive rotation side region, which is a region on the rotation direction side of the rotor core, with the circumferential center of the second outer peripheral magnetic region as a boundary. The area on the opposite side of the rotor core rotation direction It is formed so as to be smaller than the magnetic permeability of the second reverse rotation side region which is a region.

  In this way, the q axis can be shifted equivalently only by changing the permeability of the second outer peripheral magnetic region, so that the peak phase of the reluctance torque can be brought close to the peak phase of the magnet torque, and the magnet torque In addition, the combined torque of the reluctance torque can be increased. Therefore, even when the permanent magnet grade (magnitude of residual magnetic flux density, etc.) or the electromagnetic steel sheet grade is changed due to a design change of the IPM motor or the like, the change in the permeability is changed to shift the q axis. Since the amount can be optimized, labor and cost are not increased, and it is possible to easily cope with a design change of the IPM motor.

( 7 ) The second positive rotation side region may be formed so that the magnetic permeability increases from the bridge portion toward the center in the circumferential direction of the second outer peripheral magnetic region. Thereby, the magnetic flux density in the circumferential direction in the second outer peripheral magnetic region can be made substantially sinusoidal, and the torque ripple can be reduced to further suppress the generation of sound and vibration.
(Claim 8 ) The second positive rotation side region may be formed to have the same magnetic permeability from the bridge portion toward the center in the circumferential direction of the second outer peripheral magnetic region. Thereby, the magnetic permeability of the second positive rotation side region can be easily changed.

(Claim 9 ) The first positive rotation side region may be formed so as to have the same magnetic permeability from the bridge portion toward the center in the circumferential direction of the first outer peripheral magnetic body region. Accordingly, it is not necessary to form a non-magnetized region in the first positive rotation side region, and the magnetic region can be left as it is.
(Claim 10 ) The second reverse rotation side region may be formed so that the magnetic permeability becomes the same from the bridge portion toward the center in the circumferential direction of the second outer peripheral magnetic region. Accordingly, it is not necessary to form a non-magnetized region in the second reverse rotation side region, and the magnetic region can be left as it is.

(Claim 11 ) The part that makes the magnetic permeability different from other parts is formed by melting by heating to form a keyhole and disposing an alloy element in a molten pool around the keyhole. You may make it.
A keyhole is formed by heating the part where the magnetic permeability differs from other parts, and the alloy element is supplied to the molten pool around the keyhole. As a result, the alloy element is convected in the molten pool, diffused in a portion where the magnetic permeability is different from other portions, and a process of changing the magnetic permeability is performed. In addition, the supply of the alloy element to the part where the magnetic permeability is different from other parts may be performed before, during or after the formation of the keyhole. That is, as a result, the alloy element should just be arrange | positioned in the molten pool.

(Claim 12 ) The part that makes the magnetic permeability different from that of another part is melted from the outer peripheral edge of the part that makes the magnetic permeability different from that of the other part to the inner peripheral part by heating to form a keyhole. It may be.
The alloy element convects in the molten pool, diffuses in the depth direction (radial direction) of the portion where the magnetic permeability differs from other portions, and reaches a predetermined depth. That is, in the melted part (including the part where the keyhole is formed) in the part where the magnetic permeability differs from other parts, the keyhole is formed from the outer peripheral edge toward the inner peripheral part. Since the alloy element surely diffuses from the outer periphery of the part to be made different from this part to a predetermined depth, it is possible to reliably change the magnetic permeability.

1 is a plan view of a rotor for a rotating machine. FIG. 3 is a partially enlarged perspective view of a bridge portion and first and second outer peripheral magnetic body regions in FIG. 1. It is a model perspective view for demonstrating the demagnetization method of a bridge | bridging part. It is a schematic cross section for demonstrating the demagnetization method of a bridge | bridging part. It is a figure for demonstrating the 1st formation method of the change part of the magnetic permeability in a 1st, 2nd outer periphery magnetic body area | region, (a) is a top view, (b) is a side view. It is a figure for demonstrating the 2nd formation method of the change part of the magnetic permeability in a 1st, 2nd outer periphery magnetic body area | region, (a) is a top view, (b) is a side view. It is a figure for demonstrating the 3rd formation method of the change part of the magnetic permeability in a 1st, 2nd outer periphery magnetic body area | region, (a) is a top view, (b) is a side view. It is a figure which shows the relationship between the electric angle of the rotor for rotary machines, and the torque which generate | occur | produces in the rotor for rotary machines. FIG. 3 is a partially enlarged perspective view of a bridge portion and first and second outer peripheral magnetic body regions of a rotor for a rotary machine according to a second embodiment of the present invention. FIG. 3 is a partially enlarged perspective view of a bridge portion and first and second outer peripheral magnetic body regions of a rotor for a rotary machine according to a third embodiment of the present invention. It is a figure for demonstrating the angle of the skew provided in the non-magnetization area | region of 3rd embodiment.

(1. Configuration of first embodiment of rotor for rotating machine)
The rotor of the IPM motor will be described with reference to FIG. 1 as the rotor used in the rotating machine of the first embodiment. In the following description, “radial direction” and “axial direction” refer to the radial direction and axial direction of the rotor (rotor core).

  As shown in FIG. 1, the rotor 1 includes a rotor core 2 and four permanent magnets 3. The rotor core 2 is configured by laminating a plurality of thin disc-shaped ferromagnetic plates 4 made of, for example, electromagnetic steel plates. The four permanent magnets 3 are each formed in a rectangular parallelepiped shape by, for example, neodymium magnets, and are arranged in a rectangular shape on the rotor core 2. That is, each permanent magnet 3 is accommodated in each of four slots 5 that are formed in the vicinity of the outer peripheral edge of the core body 20 at intervals of 90 degrees in the axial direction, and is fixedly held on the rotor core 2.

  The four slots 5 include a rectangular opening 51 and a trapezoidal opening 52 extending from both ends of the rectangular opening 51 toward the outer peripheral edge of the core body 20. The trapezoidal opening 52 is formed as an air gap for magnetism.

  As shown in FIG. 1 and FIG. 2, the rotor core 2 includes a core body 20, a first outer peripheral magnetic body region 21 located on the radially outer side of the slot 5, an outer periphery 2 a of the core body 20, and a first outer periphery. A bridge portion 23 is connected to the circumferential end of the magnetic region 21 and is located radially outside the slot 5. Specifically, the first outer peripheral magnetic body region 21 is located between the inner peripheral wall 51 a located on the radially outer side of the rectangular opening 51 of the slot 5 and the outer peripheral edge of the core body 20. The bridge portion 23 is located between the inner peripheral wall 52 a located on the radially outer side in the trapezoidal opening 52 of the slot 5 and the outer peripheral edge of the core main body portion 20. In addition, the core body 20 has a second outer peripheral magnetic region 22 sandwiched between adjacent first outer peripheral magnetic regions 21 via a bridge portion 23 (connection between ends of adjacent permanent magnets 3 in FIG. 1). A region radially outside of L0) is formed.

  The first outer peripheral magnetic region 21 has a magnetic permeability of the first reverse rotation region 21a on the opposite side to the rotation direction R of the rotor core 2 with the circumferential center L1 of the first outer peripheral magnetic region 21 as a boundary. Is formed so as to be smaller than the magnetic permeability of the first positive rotation region 21b on the rotation direction R side.

  That is, in the first reverse rotation region 21a, the first non-magnetization in which the magnetic permeability gradually increases from the bridge portion 23 on the first reverse rotation region 21a side toward the circumferential center L1 of the first outer peripheral magnetic region 21. A region 24 (a thick horizontal line portion in FIGS. 1 and 2) is formed. On the other hand, the non-magnetized region is not formed in the first positive rotation region 21b, and is a magnetic region as it is. The boundary line 24a (see FIG. 2) of the increased end portion in the first non-magnetized region 24 is such that the first non-magnetized region 24 has the same area from one end surface to the other end surface of the rotor core 2. 1 is formed to be parallel to the rotation axis CL.

  By forming the first non-magnetized region 24, as shown in FIG. 1, the d-axis is equivalently shifted to the dd-axis in the circumferential direction of the rotor core 2 (rotation direction R of the rotor core 2). As shown in FIG. 5, the phase of the magnet torque (indicated by the alternate long and short dash line in the figure) is shifted in the direction of the arrow a1 in the figure to bring the peak phase of the magnet torque closer to the peak phase of the reluctance torque (indicated by the two-dot chain line in the figure). The combined torque of the torque can be increased. The amount of shift of the d-axis can be arbitrarily set according to the radial depth, the circumferential width, the permeability change rate, and the like of the first non-magnetized region 24.

  In the second outer peripheral magnetic region 22, the permeability of the second positive rotation region 22 a on the rotation direction R side of the rotor core 2 with respect to the circumferential center L <b> 2 of the second outer peripheral magnetic region 22 is the rotation direction R of the rotor core 2. Is formed so as to be smaller than the magnetic permeability of the second reverse rotation region 22b on the reverse direction side.

  That is, in the second positive rotation region 22a, the second non-magnetization in which the permeability gradually increases from the bridge portion 23 on the second positive rotation region 22a side toward the circumferential center L2 of the second outer peripheral magnetic region 22. A region 25 (a finely shaded portion in FIGS. 1 and 2) is formed. On the other hand, the non-magnetized region is not formed in the second reverse rotation region 22b, and is a magnetic region as it is. The boundary line 25a of the increased end portion in the second non-magnetized region 25 is the rotational axis CL of the rotor 1 so that the second non-magnetized region 25 has the same area from one end surface to the other end surface of the rotor core 2. It is formed so that it may become parallel to.

  By forming the second non-magnetized region 25, as shown in FIG. 1, the q axis is equivalently shifted to the qq axis in the circumferential direction of the rotor core 2 (the direction opposite to the rotation direction R of the rotor core 2). 6, the phase of the reluctance torque (two-dot chain line in the figure) can be shifted in the direction of the arrow a2 in the figure to bring the peak phase of the reluctance torque closer to the peak phase of the magnet torque (one-dot chain line in the figure), as shown in FIG. The combined torque of magnet torque and reluctance torque can be increased. The shift amount of the q-axis can be arbitrarily set by the radial depth, the circumferential width, the permeability change rate, and the like of the second non-magnetized region 25.

The bridge portion 23 is entirely demagnetized in order to reduce the leakage magnetic flux (the rough shaded portion in FIGS. 1 and 2).
Here, demagnetization includes complete demagnetization in which the relative permeability is 1, and weak magnetism in which the relative permeability is lower than the relative permeability of the electrical steel sheet. The demagnetization is performed by a known technique, for example, heating to the first reverse rotation region 21a, the second forward rotation region 22a, and the bridge portion 23, application of a nonmagnetic paint, or the like. 21a, the second positive rotation region 22a and the bridge portion 23 are heated and melted to form a keyhole, and an alloying element is disposed around the keyhole.

  The demagnetization process by the keyhole of the bridge part 23 is demonstrated with reference to FIG. 3 and FIG. The demagnetization process includes a keyhole formation process and an element arrangement process. The keyhole forming step is a step of forming the keyhole H by irradiating the bridge portion 23 of the rotor core 2 with the laser L from the outer peripheral edge of the bridge portion 23 (the outer peripheral edge 2a of the core body 20). The keyhole H means a circular hole formed by irradiation of the laser L from the outer peripheral edge of the bridge portion 23 irradiated with the laser L toward the inner peripheral wall 52 a of the trapezoidal opening 52. When the keyhole H is formed, evaporated metal is generated, and a molten pool P is formed around the keyhole H. That is, the molten pool P is formed from the laser irradiation surface to the back surface in the bridge portion 23.

  The element arranging step is a step of arranging the alloy element A in the molten pool P around the keyhole H to form a solid solution alloy. A wire W formed of an alloy element A (manganese, nickel, chromium, or the like) is disposed around the laser L irradiation position on the outer peripheral edge of the bridge portion 23. And the laser L irradiation position with respect to the outer periphery of the bridge | bridging part 23 is relatively moved, and the wire W is also relatively moved according to the laser L irradiation position. When the laser L irradiation position is relatively moved, the keyhole H at the previous irradiation position is filled with the melted bridge portion 23.

  The wire W comes into contact with the molten pool P and melts, and the melted wire W (that is, the alloy element A) is mixed into the molten pool P and diffused. In the weld pool P, convection (see the arc-shaped arrow in FIG. 4) is likely to occur. In particular, convection is likely to occur behind the laser L irradiation position in the traveling direction. The alloy element A supplied to the molten pool P is diffused from the inner peripheral side of the bridge portion 23 to the outer peripheral side by the convection of the molten pool P, and supplied to the outer peripheral side. If it does so, the part of the molten pool P will be alloyed by presence of the alloy element A, and it will become non-magnetic from the laser irradiation surface in the bridge | bridging part 23 to a back surface. The alloy element A may be supplied to the bridge portion 23 before, during, or after the keyhole H is formed.

  The demagnetization process using the keyholes in the first reverse rotation region 21a and the second forward rotation region 22a is performed in the same manner as the demagnetization process using the keyholes in the bridge portion 23 described above. However, although the bridge part 23 made the whole bridge part 23 non-magnetic from the outer periphery of the bridge part 23 to the inner peripheral wall 52a of the trapezoidal opening 52, the first reverse rotation area 21a is the first reverse rotation area. The difference is that only the first demagnetized region 24 from the outer peripheral edge of 21a to the middle of the inner peripheral wall 51a of the slot 5 is demagnetized. Similarly, the second positive rotation region 22a demagnetizes only the second non-magnetization region 25 from the outer peripheral edge of the second positive rotation region 22a to the middle between the adjacent slots 5 (connection L0). Different.

  That is, in the first reverse rotation region 21a and the second forward rotation region 22a, the magnetic permeability increases from the bridge portion 23 toward the respective circumferential centers L1, L2 of the first reverse rotation region 21a and the second forward rotation region 22a. It is because it is necessary to form so that it may become. Since the method of forming the magnetic permeability change portion in the first reverse rotation region 21a and the second positive rotation region 22a is the same, the method of forming the magnetic permeability change portion in the first reverse rotation region 21a will be described below.

  As shown in FIG. 5A, the formation amount of the magnetic permeability change portion in the first reverse rotation region 21a is the same as the compounding amount of the alloy element, the circumferential width w and the axial length h are the same, A plurality of first non-magnetized regions 24a1 to 24a8 are formed as the depth in the radial direction gradually decreases from the bridge portion 23 toward the circumferential direction (d1> d2> d3> d4> d5> d6> d7> d8). .

  Further, as shown in FIG. 5B, the compounding amounts of the alloy elements are the same, the circumferential width w and the radial depth d of the first non-magnetized region 24 are the same, and the axial length is the bridge portion. A plurality of first demagnetized regions 24b1 to 24b8 that are intermittently changed so as to gradually become shorter from 23 in the circumferential direction are formed.

Further, as shown in FIG. 5C, the circumferential width w, the axial length h, and the radial depth d of the first non-magnetized region 24 are the same, and the compounding amount of the alloy element is from the bridge portion 23. A plurality of non-magnetized regions 24c1 to 24c8 that gradually decrease in the circumferential direction are formed.
In FIGS. 5A to 5C, the bridge portion 23 and the first non-magnetized regions 24a1 to 24a8, 24b1 to 24b8, and 24c1 to 24c8 are displayed at predetermined intervals. The first non-magnetized regions 24a1 to 24a8, 24b1 to 24b8, and 24c1 to 24c8 may be formed without leaving a predetermined interval. Further, the first and second demagnetized regions 24 and 25 may have any radial depth and circumference at any position within the ranges of the first reverse rotation region 21a and the second forward rotation region 22a. You may form by the width | variety of a direction and the change rate of a magnetic permeability.

  According to the rotor 2 of the first embodiment, only the first and second non-magnetized regions 24 and 25 are formed by nonmagnetic modification of the first reverse rotation region 21a and the second forward rotation region 22a. The d-axis and q-axis can be equivalently shifted to the dd-axis and qq-axis. As a result, as shown in FIG. 6, the phase of the magnet torque (indicated by the alternate long and short dash line) can be shifted in the direction of the arrow a1, and the peak phase of the magnet torque can be brought closer to the peak phase of the reluctance torque (indicated by the dashed double dotted line). At the same time, the phase of the reluctance torque (two-dot chain line in the figure) can be shifted in the direction of the arrow a2 to bring the peak phase of the reluctance torque closer to the peak phase of the magnet torque (one-dot chain line in the figure). That is, the peak phase of the magnet torque and the peak phase of the reluctance torque can be brought close to each other. Therefore, the combined torque of the magnet torque and the reluctance torque can be greatly increased from Tb to Ta.

  Even when the grade of the permanent magnet 3 (the magnitude of the residual magnetic flux density) or the grade of the electromagnetic steel sheet 4 is changed by a design change of the IPM motor, the first and second non-magnetized regions 24, It is possible to optimize the shift amount of the d-axis and the q-axis by changing the radial depth of 25, the width in the circumferential direction, the change rate of the magnetic permeability, and the like. Therefore, labor and cost are not increased, and it is possible to easily cope with a design change of the IPM motor. In addition, when the torque of the IPM motor before and after the shift of the d-axis and the q-axis is the same, the amount of magnet usage can be reduced, and further cost reduction can be achieved.

  Further, the non-magnetized region 24 in the first reverse rotation region 21 a is formed so that the magnetic permeability increases from the demagnetized bridge portion 23 toward the center in the circumferential direction of the first outer peripheral magnetic region 21. Therefore, the magnetic flux density distribution in the circumferential direction in the first outer peripheral magnetic body region 21 can be changed in an arbitrary shape. For example, by reducing the magnetic flux density on the bridge portion 23 side in the first reverse rotation region 21a and increasing the magnetic flux density in the central portion of the magnetic pole in the circumferential direction of the first outer peripheral magnetic region 21, the circumferential magnetic flux density distribution is increased. It can be made substantially sinusoidal.

  Thereby, since the inclusion of the fifth-order component and the seventh-order component is reduced in the magnetic flux density distribution, it is possible to reduce the sixth-order torque ripple and suppress the generation of sound and vibration. Since the non-magnetized region 25 in the second forward rotation region 22a is also formed in the same manner as the non-magnetized region 24 in the first reverse rotation region 21a, the torque ripple is reduced and the generation of sound and vibration is further suppressed. can do.

(2. Configuration of Second Embodiment of Rotor for Rotating Machine)
The rotor 6 used in the rotating machine of the second embodiment has the same basic configuration as the rotor 1 used in the rotating machine of the first embodiment shown in FIG. 1 and FIG. It has a different configuration.

  In the first reverse rotation region 21a of the rotor core 2 of the first embodiment, the permeability gradually increases from the bridge portion 23 on the first reverse rotation region 21a side toward the circumferential center L1 of the first outer peripheral magnetic material region 21. Although increasing non-magnetized regions 24 are formed, as shown in FIG. 7, the bridge portion 23 on the first reverse rotation region 21a side is provided in the first reverse rotation region 21a of the rotor core 7 of the second embodiment. A first non-magnetized region 26 having the same magnetic permeability is formed from the first outer peripheral magnetic region 21 toward the center in the circumferential direction.

  The boundary line 26a of the increased end portion in the first non-magnetized region 26 is the rotation axis CL of the rotor 6 so that the first non-magnetized region 26 has the same area from one end surface to the other end surface of the rotor core 7. It is formed so that it may become parallel to. Similarly, the second non-magnetization region 27 having the same magnetic permeability is formed in the second positive rotation region 22a. The first and second non-magnetized regions 26 and 27 have any radial depth and circumferential direction at any position within the range of the first reverse rotation region 21a and the second forward rotation region 22a. You may form with the width of.

  According to the rotor 6 of the second embodiment, similarly to the rotor 1 of the first embodiment, the d-axis and the q-axis are shifted to bring the peak phase of the reluctance torque and the peak phase of the magnet torque closer to each other. And the combined torque of the magnet torque and the reluctance torque can be greatly increased. In addition, since the first and second non-magnetized regions 26 and 27 have the same magnetic permeability, it is easier than the first and second non-magnetized regions 24 and 25 where the magnetic permeability gradually increases. Can be formed.

(3. Configuration of third embodiment of rotor for rotating machine)
The rotor 8 used in the rotating machine of the third embodiment has the same basic configuration as the rotor 1 used in the rotating machine of the first embodiment shown in FIG. 1 and FIG. It has a different configuration.

  In the first reverse rotation region 21a of the rotor core 2 of the first embodiment, a first non-magnetization region 24 is formed that has the same magnetic permeability from the upper end surface toward the lower end surface in the axial direction of the rotor core 2. However, as shown in FIG. 8, in the first reverse rotation region 21a of the rotor core 9 of the third embodiment, the magnetic permeability gradually increases in the axial direction of the rotor core 9 from the upper end surface toward the lower end surface. Increasing first non-magnetized regions 28 are formed. Similarly, in the second positive rotation region 22a, a second non-magnetized region 29 in which the magnetic permeability gradually increases is formed. Hereinafter, the first non-magnetized region 28 will be described.

  Specifically, the boundary line 24a of the increased end portion in the non-magnetized region 24 of the rotor core 2 of the first embodiment is provided so as to be parallel to the rotation axis CL of the rotor 1, while the third The first non-magnetized region 28 of the rotor core 9 according to the embodiment has the largest area at the upper end surface of the rotor core 9 and the increased end portion in the first demagnetized region 28 so that the area becomes zero at the lower end surface of the rotor core 9. The boundary line 28a is provided so as to be inclined at a predetermined angle α with respect to a straight line AL parallel to the rotation axis CL of the rotor 8 and passing through the boundary between the first demagnetized region 28 and the bridge portion 23.

  That is, the axial permeability change portion of the first non-magnetized region 28 in the first reverse rotation region 21 a is provided with a skew in the axial direction from the end face of the rotor core 9. The relationship between the skew angle φ and the predetermined angle α is expressed as shown in FIG. That is, when the intersection of the boundary line 28a of the increased end in the first demagnetized region 28 and the circumference of the upper end surface of the rotor 8 is S1, this intersection S1 and the center point (rotation axis CL) of the rotor 8 Let SC1 be the line connecting the two. Further, when the intersection of the straight line AL parallel to the rotation axis CL of the rotor 8 and the circumference of the upper end surface of the rotor 8 is S2, a line connecting the intersection S2 and the center point of the rotor 8 (rotation axis CL) SC2. The angle formed by the straight line SC1 and the straight line SC2 at this time is the skew angle φ.

  By providing this skew angle φ, the position of one magnetic pole and the position of the other magnetic pole adjacent to this magnetic pole can be shifted by approximately a half period of the cogging torque waveform, thereby reducing the basic order of the cogging torque. And the generation of sound and vibration can be further suppressed. Since the basic order of the cogging torque is the least common multiple of the number of poles and the number of slots of the motor, for example, in the case of an 8-pole 12-slot motor, the least common multiple is 24, so 24 waves are generated by one rotation of the motor. The wave period is 360 ° / 24 = 15 °. Therefore, the optimum skew angle φ for this motor is 15 °. By obtaining a predetermined angle α from the skew angle φ, the first non-magnetized region 28 can be formed.

  Since the non-magnetized region 29 in the second forward rotation region 22a is formed in the same manner as the non-magnetized region 28 in the first reverse rotation region 21a, the basic order of the cogging torque is lowered to generate sound and vibration. Can be further suppressed. The first and second non-magnetized regions 28 and 29 are in any radial depth and circumferential direction at any position as long as they are within the range of the first reverse rotation region 21a and the second forward rotation region 22a. You may form with the width of.

(4. Modifications)
In each of the above-described embodiments, the first and second non-magnetized regions 24, 26, 28, 25, 27, and 29 are formed to shift the d-axis and the q-axis. Only the magnetized region may be formed. The first and second non-magnetized regions 24, 26, 28, 25, 27, and 29 may be arbitrarily combined. In addition, the bridge portion 23 is preferably made nonmagnetic so that leakage flux is reduced. However, the bridge portion 23 can obtain a high torque without being made nonmagnetic.

  In each of the above-described embodiments, the wire W formed of the alloy element A is disposed around the laser L irradiation position on the outer peripheral surface of the bridge portion 23, the first reverse rotation region 21a, and the second forward rotation region 22a, and the key Although the alloy element A is supplied to the molten pool P formed around the hole H to be demagnetized, it may be demagnetized by the following method.

  That is, the pellet of the alloy element A is formed in the bridge portion 23, the first reverse rotation region 21a, and the second forward rotation region 22a at the first and second non-magnetization regions 24, 26, 28, 25, 27, and 29. And the pellets of the alloy element A are pressed into the bridge portion 23, the first and second non-magnetized regions 24, 26, 28, 25, 27, the first reverse rotation region 21a and the second forward rotation region 22a. Alternatively, the alloy element A may be demagnetized by irradiating the pellet of the alloy element A with a laser L.

  In addition, the powder of the alloy element A is formed at locations where the bridge portion 23, the first reverse rotation region 21a, and the second forward rotation region 22a are to be the first and second non-magnetization regions 24, 26, 28, 25, 27, 29. Alternatively, a coarse particle or a thin film may be disposed, and the alloy element A powder may be irradiated with the laser 2 to be demagnetized. The keyhole H may be formed by any means that can irradiate high-density energy. For example, an electron beam or the like may be used instead of the laser L.

  Further, in each of the above-described embodiments, a plurality of ferromagnetic plates 4 are laminated to form the rotor cores 2, 7, 9, and then the laser L is irradiated from the radial direction (outer peripheral edge side) of the rotor cores 2, 7, 9. Although it is configured to be magnetized, a single ferromagnetic plate 4 is demagnetized by irradiating it with laser L from the axial direction (front side) of the ferromagnetic plate 4, and a plurality of the ferromagnetic plates 4 are laminated. It is good also as a structure which shape | molds rotor core 2,7,9. In this case, since the ferromagnetic plate 4 is thin, the keyhole can be formed from the front surface to the back surface of the ferromagnetic plate 4, and the nonmagnetic region can be reliably formed with high accuracy. In particular, by demagnetizing the ferromagnetic plates 4 one by one, the first and second demagnetized regions 24 and 25 of the first embodiment in which the radial depth gradually changes, and the diameter The first and second demagnetized regions 28 and 29 of the third embodiment in which the direction depth and the axial length gradually change can be formed with high accuracy.

  Further, in the above-described embodiment, the planar shape of the rotor cores 2, 7, and 9 is circular, but it can also be applied to a so-called petal-shaped rotor core with the magnetic pole center portion protruding, and the magnetic flux density distribution is made sinusoidal. By approaching, generation | occurrence | production of a sound and a vibration can be suppressed further. Moreover, although the case where it applied to the IPM motor of an inner rotor was demonstrated in the above-mentioned embodiment, it is also possible to apply to the IPM motor of an outer rotor. Moreover, although the case where it applied to the IPM motor provided with the four permanent magnets 3 was demonstrated, it is also possible to apply to the IPM motor which has arrange | positioned arbitrary number of permanent magnets in arbitrary positions.

  1, 6, 8: Rotor, 2, 7, 9: Rotor core, 2a: Outer peripheral edge of rotor core, 3: Permanent magnet, 4: Ferromagnetic plate, 5: Slot, 20: Core main body, 21: First outer peripheral magnetism Body region, 21a: first reverse rotation region, 21b: first forward rotation region, 22: second outer peripheral magnetic region, 22a: second forward rotation region, 22b: second reverse rotation region, 23: bridge portion, 24 , 26, 28: first demagnetized region, 25, 27, 29: second demagnetized region, H: keyhole, L: laser, P: molten pool, A: alloy element

Claims (12)

A rotor core formed by a plurality of laminated ferromagnetic plates and having slots formed in the axial direction;
A permanent magnet housed in the slot;
A rotor for a rotating machine comprising:
The rotor core connects a core main body, a first outer peripheral magnetic body region located radially outside the slot, an outer peripheral edge of the core main body, and a circumferential end of the first outer peripheral magnetic region. A bridge portion positioned radially outward of the end of the slot,
The first outer peripheral magnetic region has a magnetic permeability of a first reverse rotation side region which is a region opposite to the rotation direction of the rotor core with respect to the center in the circumferential direction of the first outer peripheral magnetic region. It is formed to be smaller than the magnetic permeability of the first positive rotation side region that is the region on the rotation direction side of the rotor core ,
In the core body part, a second outer peripheral magnetic region sandwiched between the first outer peripheral magnetic regions adjacent to each other via the bridge portion is formed,
The second outer peripheral magnetic region has a magnetic permeability of a second positive rotation side region, which is a region on the rotation direction side of the rotor core, with respect to the center in the circumferential direction of the second outer peripheral magnetic region. A rotor for a rotating machine that is formed so as to be smaller than the magnetic permeability of the second reverse rotation side region that is a region on the opposite direction side . 2. The rotor for a rotating machine according to claim 1 , wherein the first reverse rotation side region is formed such that a magnetic permeability increases from the bridge portion toward a circumferential center of the first outer peripheral magnetic region. 2. The rotor for a rotating machine according to claim 1 , wherein the second positive rotation side region is formed so that a magnetic permeability increases from the bridge portion toward a circumferential center of the second outer peripheral magnetic region. 2. The rotor for a rotating machine according to claim 1 , wherein the first reverse rotation side region is formed to have the same magnetic permeability from the bridge portion toward a circumferential center of the first outer peripheral magnetic region. 2. The rotor for a rotating machine according to claim 1 , wherein the second positive rotation side region is formed to have the same magnetic permeability from the bridge portion toward a circumferential center of the second outer peripheral magnetic region. A rotor core formed by a plurality of laminated ferromagnetic plates and having slots formed in the axial direction;
A permanent magnet housed in the slot;
A rotor for a rotating machine comprising:
The rotor core connects a core main body, a first outer peripheral magnetic body region located radially outside the slot, an outer peripheral edge of the core main body, and a circumferential end of the first outer peripheral magnetic region. A bridge portion positioned radially outward of the end of the slot,
In the core body part, a second outer peripheral magnetic region sandwiched between the first outer peripheral magnetic regions adjacent to each other via the bridge portion is formed,
The second outer peripheral magnetic region has a magnetic permeability of a second positive rotation side region, which is a region on the rotation direction side of the rotor core, with respect to the center in the circumferential direction of the second outer peripheral magnetic region. A rotor for a rotating machine that is formed so as to be smaller than the magnetic permeability of the second reverse rotation side region that is a region on the opposite direction side. The rotor for a rotating machine according to claim 6 , wherein the second positive rotation side region is formed so that a magnetic permeability increases from the bridge portion toward a circumferential center of the second outer peripheral magnetic region. The rotor for a rotating machine according to claim 6 , wherein the second positive rotation side region is formed so as to have the same magnetic permeability from the bridge portion toward a circumferential center of the second outer peripheral magnetic region. The first forward rotation side area, permeability towards the circumferential center of the first outer magnetic body region from said bridge portion is formed to be the same, the rotor for a rotating machine according to claim 1 to 5 . The rotor for a rotating machine according to claim 1 , wherein the second reverse rotation side region is formed so as to have the same magnetic permeability from the bridge portion toward a circumferential center of the second outer peripheral magnetic body region. . The part that makes the magnetic permeability different from other parts is formed by melting by heating to form a keyhole and disposing an alloy element in a molten pool around the keyhole. The rotor for a rotating machine according to any one of 10 to 10 . The rotation according to claim 11 , wherein the part that makes the magnetic permeability different from the other part is melted from an outer peripheral edge of the part that makes the magnetic permeability different from the other part to the inner peripheral part by heating to form a keyhole. Rotor for machine.

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