Rotating electric machine and elevator traction machine

Abstract

In a rotating electric machine, three teeth arranged continuously in the circumferential direction of the stator constitute a tooth group. Coils of the same phase are wound around the three teeth constituting one tooth group. In the tooth group, a low magnetic permeability portion is provided at the end of each of the two teeth on the outer side, avoiding the central tooth, among the three teeth. The magnetic permeability of the low magnetic permeability portion is lower than the magnetic permeability of the stator core.

Description

Technical Field

[0001] The present invention relates to a rotating electric machine including a stator having teeth, and an elevator hoisting machine including the rotating electric machine. Background Art

[0002] Conventionally, there is known a rotating electric machine in which torque ripple is reduced by providing auxiliary grooves at the tip end portions of all teeth of a stator (for example, refer to Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-094901 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the conventional rotating electric machine disclosed in Patent Document 1, the auxiliary slots are provided at the tip ends of all teeth, thereby reducing the magnetic flux passing through all teeth. Therefore, in the conventional rotating electric machine, there is a concern that the torque output may be reduced.

[0008] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a rotating electrical machine and an elevator hoisting machine capable of achieving reduction in torque pulsation and suppressing reduction in torque output.

[0009] Means for solving problems

[0010] The rotary electric machine of the present invention comprises: a rotor which rotates about an axis line; and a stator which opposes the rotor with a gap in the radial direction of the rotor, the rotor having a rotor core and a plurality of magnetic poles, the plurality of magnetic poles being provided on the rotor core and arranged in the circumferential direction of the rotor, the stator having a stator core and a plurality of windings, the plurality of windings being provided on the stator core, the stator core having a back yoke and a plurality of teeth, the plurality of teeth protruding from the back yoke toward the rotor, the plurality of teeth being arranged at intervals from each other in the circumferential direction of the stator, each tooth having a terminal portion, the terminal portion being opposed to the rotor, the winding being wound around the tooth by concentrated winding, three teeth arranged continuously in the circumferential direction of the stator constituting a tooth group, the same-phase windings being wound around the three teeth constituting one tooth group, and low magnetic permeability portions being provided at the terminal portions of two teeth on the outer sides avoiding the central tooth among the three teeth in the tooth group, the magnetic permeability of the low magnetic permeability portions being lower than the magnetic permeability of the stator core.

[0011] Effects of the Invention

[0012] According to the rotating electrical machine and the elevator hoisting machine of the present invention, it is possible to reduce torque pulsation and suppress a reduction in torque output. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional view showing the rotating electrical machine according to the first embodiment.

[0014] Figure 2 It shows that Figure 1 An expanded view of the stator core including the U-phase tooth group after the part is expanded.

[0015] Figure 3 : is a cross-sectional view showing the rotating electrical machine of Comparative Example 1.

[0016] Figure 4 2 is a cross-sectional view showing a rotating electrical machine according to Comparative Example 2.

[0017] Figure 5 : This is a graph showing the magnitude of torque output of each of Comparative Example 1, Comparative Example 2, and Embodiment 1.

[0018] Figure 6 Graphs showing waveforms of torque outputs in Comparative Example 1, Comparative Example 2, and Embodiment 1, respectively.

[0019] Figure 7 : is a graph which shows the magnitude of the torque pulsation of each of Comparative Example 1, Comparative Example 2 and Embodiment 1.

[0020] Figure 8 This is a development view showing another example of the portion including the U-phase teeth group of the rotating electrical machine according to the first embodiment.

[0021] Fig. 9 This is a development view showing another example of the portion including the U-phase teeth group of the rotating electrical machine according to the first embodiment.

[0022] Fig.10 It is a cross-sectional view showing a rotating electrical machine according to the second embodiment.

[0023] Fig.11 : is a graph showing the magnitude of the torque output of the rotating electric machine of the comparative example 1, the rotating electric machine of the second embodiment during forward rotation, and the rotating electric machine of the second embodiment during reverse rotation.

[0024] Fig.12 Graphs showing waveforms of torque outputs of the rotating electric machine of Comparative Example 1, the rotating electric machine of Embodiment 2 during forward rotation, and the rotating electric machine of Embodiment 2 during reverse rotation.

[0025] Fig.13 1 is a graph showing the magnitude of torque pulsation of the rotating electric machine of Comparative Example 1, the rotating electric machine of Embodiment 2 during forward rotation, and the rotating electric machine of Embodiment 2 during reverse rotation.

[0026] Fig.14It is a cross-sectional view showing a rotating electrical machine according to a third embodiment.

[0027] Fig.15 It is a cross-sectional view showing a rotating electrical machine according to a fourth embodiment.

[0028] Fig.16 It is a cross-sectional view showing a rotating electrical machine according to a fifth embodiment.

[0029] Fig.17 It is an exploded perspective view showing a stator core of a rotating electrical machine according to a sixth embodiment.

[0030] Fig.18 This is an exploded perspective view showing another example of the stator core of the rotating electrical machine according to the sixth embodiment.

[0031] Fig.19 This is a longitudinal sectional view showing the hoisting machine of the elevator according to the seventh embodiment. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments will be described with reference to the drawings.

[0033] Implementation Method 1

[0034] Figure 1 1 is a cross-sectional view showing a rotating electrical machine according to Embodiment 1. The rotating electrical machine 1 includes a rotor 2 and a stator 6. The rotor 2 and the stator 6 have a common axis as a main axis. The rotor 2 is fixed to a rotating shaft 3, and the rotating shaft 3 is rotatably supported by a housing (not shown). The rotor 2 and the stator 6 are arranged coaxially with the rotating shaft 3. The rotor 2 rotates integrally with the rotating shaft 3 around the main axis. Here, the direction along the radius of the rotor 2 is referred to as the radial direction, and the direction along the rotation direction of the rotor 2 is referred to as the circumferential direction.

[0035] The stator 6 faces the rotor 2 with a gap in the radial direction of the rotor 2. The stator 6 surrounds the rotor 2. The inner peripheral portion of the stator 6 faces the outer peripheral portion of the rotor 2 with a gap. The rotor 2 and the stator 6 are accommodated in a housing.

[0036] The rotor 2 includes a rotor core 4 which is a magnetic body and is fixed to the rotating shaft 3 , and a plurality of magnetic poles 5 which are provided on the rotor core 4 .

[0037] The rotor core 4 is a cylindrical laminated body formed by stacking a plurality of thin plates in a direction along the main axis. As the plurality of thin plates constituting the rotor core 4, for example, electromagnetic steel plates are used. The rotor core 4 is provided with an axial through hole along the main axis. The rotating shaft 3 is inserted into the axial through hole of the rotor core 4.

[0038] A plurality of magnetic poles 5 are fixed to the outer peripheral surface of the rotor core 4. The plurality of magnetic poles 5 are arranged in the circumferential direction of the rotor core 4. The plurality of magnetic poles 5 are arranged at equal intervals in the circumferential direction of the rotor core 4. Each magnetic pole 5 is composed of a permanent magnet. The plurality of magnetic poles 5 are arranged on the outer peripheral surface of the rotor core 4 in such a manner that the polarities opposing the stator 6 are alternately different in the circumferential direction of the rotor 2. Therefore, the N pole of one of the two magnetic poles 5 adjacent to each other in the circumferential direction of the rotor 2 is opposed to the stator 6, and the S pole of the other magnetic pole 5 is opposed to the stator 6. In this example, the number of magnetic poles 5 in the rotor 2 is 10 poles.

[0039] The stator 6 includes a stator core 7 which is a magnetic body and a plurality of windings 10 which are provided on the stator core 7 .

[0040] The stator core 7 is a laminated body formed by laminating a plurality of thin plates in a direction along the main axis. As the plurality of thin plates constituting the stator core 7, for example, electromagnetic steel plates are used. In addition, the stator core 7 has: an annular back yoke 9; and a plurality of teeth 8, which protrude radially inward from the back yoke 9 toward the rotor 2.

[0041] The plurality of teeth 8 are arranged at intervals from each other in the circumferential direction of the stator 6. The plurality of teeth 8 are arranged at equal intervals in the circumferential direction of the stator 6. In this example, the stator core 7 includes nine teeth 8. Each tooth 8 has a terminal end 83, and the terminal end 83 faces the rotor 2 via a gap. In the stator core 7, the spaces formed between the plurality of teeth 8 are provided as slots.

[0042] The plurality of windings 10 are wound one by one on each tooth 8 by concentrated winding. Thus, a part of the winding 10 is accommodated in each slot. In this example, the stator 6 includes nine windings 10.

[0043] The plurality of windings 10 are connected to an AC power source via electric wires not shown. Thus, three-phase AC power is supplied to the plurality of windings 10. The three-phase AC power includes U-phase, V-phase, and W-phase electric power whose electrical phases differ from each other by 120°. In the stator 6, a rotating magnetic field is generated by supplying three-phase AC power to the plurality of windings 10. In the rotor 2, torque is generated by the magnetic interaction between the rotating magnetic field generated in the stator 6 and the plurality of magnetic poles 5. Thus, the rotor 2 rotates integrally with the rotating shaft 3 relative to the stator 6.

[0044] In the stator core 7, three teeth 8 continuous in the circumferential direction of the stator 6 constitute a tooth group 81. In this example, since the stator core 7 includes nine teeth 8, the U-phase tooth group 81, the V-phase tooth group 81, and the W-phase tooth group 81 exist in the stator core 7 as three tooth groups 81.

[0045] The same-phase power is supplied to each of the coils 10 wound around the three teeth 8 constituting one teeth group 81. That is, the same-phase power is supplied to each of the coils 10 wound around the three teeth 8 constituting one teeth group 81. In other words, the same-phase power is supplied to each of the coils 10 wound around the three teeth 8 constituting one teeth group 81.

[0046] Thus, the winding 10 wound around each tooth 8 of the tooth group 81 constituting the U phase among the three tooth groups 81 is a U phase winding supplied with the power of the U phase. The winding 10 wound around each tooth 8 of the tooth group 81 constituting the V phase is a V phase winding supplied with the power of the V phase. The winding 10 wound around each tooth 8 of the tooth group 81 constituting the W phase is a W phase winding supplied with the power of the W phase.

[0047] In each tooth group 81 , the winding direction of the winding 10 wound around the two outer teeth 8 is the forward direction, and the winding direction of the winding 10 wound around the center tooth 8 is the reverse direction.

[0048] In the present embodiment, in order to clearly distinguish the winding directions of the windings 10, the U-phase winding 10 is indicated as "U phase" when the winding direction is the positive direction, and is indicated as "Ui phase" when the winding direction is the reverse direction. Similarly, the V-phase winding 10 is indicated as "V phase" when the winding direction is the positive direction, and is indicated as "Vi phase" when the winding direction is the reverse direction. The W-phase winding 10 is indicated as "W phase" when the winding direction is the positive direction, and is indicated as "Wi phase" when the winding direction is the reverse direction.

[0049] The low magnetic permeability portion 82 is provided at the tip portion 83 of each of the two outer teeth 8 of the three teeth 8 constituting the tooth group 81. The low magnetic permeability portion 82 is not provided at the tip portion 83 of the central tooth 8 of the three teeth 8 constituting the tooth group 81. That is, in each tooth group 81, among the three teeth 8, the low magnetic permeability portion 82 is provided at the tip portion 83 of each of the two outer teeth 8 avoiding the central tooth 8. The magnetic permeability of the low magnetic permeability portion 82 is lower than the magnetic permeability of the stator core 7.

[0050] A groove 821 is provided at the tip end 83 of each of the two outer teeth 8 in each tooth group 81. The space formed by the groove 821 is a low magnetic permeability portion 82.

[0051] The slot 821 opens from the tip end 83 of the tooth 8 toward the rotor 2. The slot 821 is arranged in the direction along the main axis. The slot 821 is arranged over the entire range of the stator core 7 in the direction along the main axis. In each tooth group 81, one slot 821 is provided on each of the two outer teeth 8. In the cross section of the tooth 8 on a plane orthogonal to the main axis, the shape of the low magnetic permeability portion 82 formed by the slot 821 is rectangular.

[0052] Figure 2 It shows that Figure 1An expanded view of a stator core 7 including a U-phase tooth group 81 after partial expansion. The back yoke 9 has a plurality of back yoke components 91 arranged in a circular ring shape. In this example, the back yoke 9 includes 9 back yoke components 91. Each back yoke component 91 is arranged in such a manner that the width direction of the back yoke component 91 is along the circumferential direction of the stator 6.

[0053] One tooth 8 is provided on each of the plurality of back yoke members 91. The tooth 8 protrudes from a center portion of the back yoke member 91 in the width direction.

[0054] Abutment surfaces 50 are formed at both ends in the width direction of each back yoke component 91. In a circular state where a plurality of back yoke components 91 are arranged in a circular shape, the abutment surfaces 50 of two adjacent back yoke components 91 contact each other. The two adjacent back yoke components 91 are connected to each other via a connecting portion 60 at the corner on the side opposite to the tooth 8. By rotating each back yoke component 91 around the connecting portion 60, the state of the stator core 7 changes from a circular state to an expanded state. In the expanded state of the stator core 7, the abutment surfaces 50 are separated from each other, and the plurality of back yoke components 91 are arranged in a row.

[0055] Each tooth 8 has a center line along the radial direction of the stator 6. In the cross section of the stator core 7 on a plane orthogonal to the main axis, the straight line passing through the main axis and passing through the center position of the tooth 8 in the width direction is the center line of the tooth 8. When the state of the stator core 7 is the expanded state, in each tooth group 81, the center line CL of the central tooth 8, the center line CL1 of one outer tooth 8, and the center line CL2 of the other outer tooth 8 are parallel to each other. In addition, when the state of the stator core 7 is the expanded state, the distance between the center line CL of the central tooth 8 and the center line CL1 of one outer tooth 8, and the distance between the center line CL of the central tooth 8 and the center line CL2 of the other outer tooth 8 are equal to each other by a distance τ0.

[0056] Each low magnetic permeability portion 82 formed by the slot 821 has a center line parallel to the center lines CL1 and CL2 of the tooth 8 provided with the low magnetic permeability portion 82. Here, the center line of the low magnetic permeability portion 82 provided on the tooth 8 having the center line CL1 among the two low magnetic permeability portions 82 of each tooth group 81 is CL11, and the center line of the low magnetic permeability portion 82 provided on the tooth 8 having the center line CL2 is CL21. When the state of the stator core 7 is the expanded state, in each tooth group 81, the distance from the center line CL11 to the center line CL and the distance from the center line CL21 to the center line CL are equal to each other by a distance τ. In addition, when the state of the stator core 7 is the expanded state, the relationship of τ>τ0 holds.

[0057] Therefore, in each tooth group 81, the low magnetic permeability portion 82 provided on the tooth 8 having the center line CL1 is arranged at a position farther from the center line CL than the center line CL1. In addition, in each tooth group 81, the low magnetic permeability portion 82 provided on the tooth 8 having the center line CL2 is arranged at a position farther from the center line CL than the center line CL2. That is, the low magnetic permeability portion 82 is arranged at a position farther from the center line CL of the central tooth 8 in the circumferential direction of the stator 6 than the center lines CL1 and CL2 of the tooth 8 provided with the low magnetic permeability portion 82. In addition, the low magnetic permeability portions 82 of the two teeth 8 respectively provided on the outside are arranged at positions geometrically symmetrical with respect to the center line CL. The shapes of the low magnetic permeability portions 82 of the two teeth 8 provided on the outside are the same shape as each other.

[0058] Next, a description will be given of rotating electrical machines of Comparative Example 1 and Comparative Example 2 for comparison with the rotating electrical machine 1 of the first embodiment. Figure 3 2 is a cross-sectional view showing a rotary electric machine according to Comparative Example 1. In the rotary electric machine 200 according to Comparative Example 1, no groove 821 is provided in the tip end portion 83 of all teeth 8. The other structures of Comparative Example 1 are the same as those of the first embodiment.

[0059] Figure 4 2 is a cross-sectional view showing a rotary electric machine of Comparative Example 2. In the rotary electric machine 300 of Comparative Example 2, a low magnetic permeability portion 82 is provided at the tip portion 83 of all teeth 8 included in the stator core 7. In Comparative Example 2, a space portion formed by the same slot 821 as in Embodiment 1 is provided in each tooth 8 as the low magnetic permeability portion 82. In addition, in Comparative Example 2, two low magnetic permeability portions 82 are provided in each tooth 8. The other structures of Comparative Example 2 are the same as those of Comparative Example 1.

[0060] Figure 5 : is a graph showing the magnitude of torque output of each of Comparative Example 1, Comparative Example 2, and Embodiment 1. Figure 5 , the magnitude of the torque output of the rotating electrical machine when the rotor 2 is rotated at the same rotation speed in Comparative Example 1, Comparative Example 2, and Embodiment 1 is shown. Figure 5 In the example, the magnitude of the torque output of Comparative Example 1 is set as a reference value "100", and the magnitudes of the torque outputs of Comparative Example 2 and Embodiment 1 are standardized by the reference value of Comparative Example 1 that has been set.

[0061] Figure 6 : is a graph showing the waveforms of the torque outputs of Comparative Example 1, Comparative Example 2, and Embodiment 1. Figure 6 , the waveform of the torque output of the rotating electric machine when the plurality of windings 10 are excited by the same current magnitude in Comparative Example 1, Comparative Example 2, and Embodiment 1 is shown. Figure 6In FIG. 1 , the waveform of the torque output of Comparative Example 1 is shown by a solid line, the waveform of the torque output of Comparative Example 2 is shown by a dotted line, and the waveform of the torque output of Embodiment 1 is shown by a dashed line. The torque ripple is calculated by the difference between the maximum value and the minimum value of the torque output waveform.

[0062] Figure 7 : is a graph showing the magnitude of torque pulsation of Comparative Example 1, Comparative Example 2, and Embodiment 1. Figure 7 In the figure, it is shown that according to Figure 6 The torque pulsation component calculated from the waveform of the torque output is the sixth component relative to the electrical angle of 360°. Figure 7 In the example, the magnitude of the torque pulsation of Comparative Example 1 is set as a reference value "100", and the magnitudes of the torque pulsation of Comparative Example 2 and Embodiment 1 are normalized by the reference value of Comparative Example 1 that has been set.

[0063] according to Figure 5 It can be seen that the torque output of the rotating electric machine 1 of the first embodiment is greater than the torque output of the rotating electric machine 300 of the second comparative example. This is because the low magnetic permeability portion 82 is not provided in the central tooth 8 of each tooth group 81, thereby suppressing the increase of the magnetic resistance in the central tooth 8 and suppressing the decrease of the effective magnetic flux passing through each tooth 8. Figure 6 and Figure 7 It can be seen that the torque pulsation of the rotating electric machine 1 of the first embodiment is smaller than the torque pulsation of the rotating electric machine 200 of the first comparative example. This is considered to be due to the fact that the two outer teeth 8 in each tooth group 81 are provided with the low magnetic permeability portion 82. Figure 7 It can be seen that the magnitude of the torque pulsation in the rotating electrical machine 1 of Embodiment 1 is about the same as the magnitude of the torque pulsation in the rotating electrical machine 300 of Comparative Example 2. Therefore, it can be confirmed that the rotating electrical machine 1 of Embodiment 1 can reduce the torque pulsation and suppress the reduction of the torque output.

[0064] In the rotating electrical machine 1 of the first embodiment, in each tooth group 81, the low magnetic permeability portion 82 is provided at the tip 83 of each of the two outer teeth 8 avoiding the center tooth 8. Therefore, it is possible to reduce torque ripple and suppress reduction in torque output.

[0065] Furthermore, in each tooth group 81, in a cross section perpendicular to the main axis, the low magnetic permeability portions 82 of the two teeth 8 respectively provided on the outer sides are provided at positions geometrically symmetrical with respect to the center line CL of the central tooth 8. Therefore, regardless of whether the rotation direction of the rotor 2 is the clockwise direction or the counterclockwise direction, the waveform of the torque output of the rotating electrical machine 1 can be made the same. Therefore, it is possible to prevent the state in which the generation of noise and vibration of the rotating electrical machine 1 differs depending on the difference in the rotation direction of the rotor 2.

[0066] Furthermore, the low magnetic permeability portion 82 is disposed at a position farther from the center line CL of the central tooth 8 in the circumferential direction of the stator 6 than the center lines CL1 and CL2 of the teeth 8 provided with the low magnetic permeability portion 82. Therefore, the torque pulsation can be reduced and the reduction in torque output can be more reliably suppressed.

[0067] Furthermore, the low magnetic permeability portion 82 is a space portion formed by the groove 821 provided at the distal end portion 83 of the tooth 8. Therefore, the low magnetic permeability portion 82 can be easily provided at the distal end portion 83 of the tooth 8.

[0068] In addition, the cross-sectional shapes of the low magnetic permeability portions 82 are the same as each other. Therefore, it is possible to suppress the generation of the secondary component of the torque pulsation with respect to the electrical angle 360°. However, if the generation of the secondary component of the torque pulsation is within the allowable range, the cross-sectional shapes of the low magnetic permeability portions 82 may be different from each other.

[0069] Furthermore, the same-phase windings 10 are respectively wound around the three teeth 8 arranged continuously in the circumferential direction of the stator 6. Therefore, the same-phase windings 10 can be continuously wound around the three teeth 8. As a result, the time taken for the winding process of winding the windings 10 around each tooth 8 can be shortened, and the manufacturing time of the rotary electric machine 1 can be shortened.

[0070] In addition, in Embodiment 1, the low magnetic permeability portion 82 provided on the tooth 8 having the center lines CL1 and CL2, respectively, is arranged at a position farther from the center line CL of the central tooth 8 than the center lines CL1 and CL2 of the tooth 8 in the circumferential direction of the stator 6. However, the low magnetic permeability portion 82 provided on the tooth 8 having the center line CL1 may be arranged at the same position as the center line CL1, or may be arranged at a position closer to the center line CL than the center line CL1. In addition, the low magnetic permeability portion 82 provided on the tooth 8 having the center line CL2 may be arranged at the same position as the center line CL2, or may be arranged at a position closer to the center line CL than the center line CL2. That is, the relationship of τ=τ0 may be established, or the relationship of τ<τ0 may be established. In this way, the torque pulsation of the rotating electric machine 1 can be reduced, and the reduction in the torque output of the rotating electric machine 1 can be suppressed.

[0071] In the first embodiment, the cross-sectional shape of the low magnetic permeability portion 82 formed by the groove 821 is a rectangle. However, the cross-sectional shape of the low magnetic permeability portion 82 is not limited to a rectangle. Figure 8 As shown in FIG. 8 , the cross-sectional shape of the low magnetic permeability portion 82 formed by the groove 821 may also be set to a semicircular shape. Fig. 9 As shown, the cross-sectional shape of the low magnetic permeability portion 82 formed by the groove 821 may be set to a triangular shape.

[0072] Implementation Method 2

[0073] Fig.10 2 is a cross-sectional view of a rotary electric machine 1 according to Embodiment 2. In Embodiment 2, among the three teeth 8 constituting the tooth group 81, a low magnetic permeability portion 82 is provided at the tip end 83 of the other outer tooth 8, avoiding the center and one outer tooth 8. That is, in each tooth group 81, among the three teeth 8, the low magnetic permeability portion 82 is not provided at the center and one outer tooth 8, but the low magnetic permeability portion 82 is provided only at the tip end 83 of the other outer tooth 8. The low magnetic permeability portion 82 is a space portion formed by the same groove 821 as in Embodiment 1. The other structures of Embodiment 2 are the same as those of Embodiment 1.

[0074] exist Fig.10 In the embodiment, when the rotary electric machine 1 rotates forward, the rotation direction of the rotor 2 is counterclockwise, and when the rotary electric machine 1 rotates reversely, the rotation direction of the rotor 2 is clockwise. Therefore, in each tooth group 81, a low magnetic permeability portion 82 is provided on the tooth 8 located at the rear side in the rotation direction of the rotor 2 when the rotary electric machine 1 rotates forward among the three teeth 8.

[0075] Fig.11 It is shown Figure 3 Graph showing the magnitude of the torque output of the rotating electric machine of Comparative Example 1, the rotating electric machine of Embodiment 2 during forward rotation, and the rotating electric machine of Embodiment 2 during reverse rotation. Fig.11 , the magnitude of the torque output of each rotating electrical machine when the rotor 2 is rotated at the same rotation speed is shown. Fig.11 In the example, the magnitude of the torque output of Comparative Example 1 is set as a reference value "100", and the magnitudes of the torque outputs during forward rotation and reverse rotation of Implementation Example 2 are normalized by the reference value of Comparative Example 1 that has been set.

[0076] Fig.12 : is a graph showing waveforms of torque outputs of the rotating electric machine of Comparative Example 1, the rotating electric machine of Embodiment 2 during forward rotation, and the rotating electric machine of Embodiment 2 during reverse rotation. Fig.12 , the waveform of the torque output of the rotating electric machine when the plurality of windings 10 are excited with the same current magnitude in the forward rotation of Comparative Example 1 and Embodiment 2 and the reverse rotation of Embodiment 2 is shown. Fig.12 In FIG. 1 , the solid line shows the waveform of the torque output of Comparative Example 1, the dotted line shows the waveform of the torque output during forward rotation of Implementation Example 2, and the dashed line shows the waveform of the torque output during reverse rotation of Implementation Example 2. The torque pulsation is calculated by the difference between the maximum value and the minimum value of the torque output waveform.

[0077] Fig.13: is a graph showing the magnitude of torque pulsation of the rotating electric machine of Comparative Example 1, the rotating electric machine of Embodiment 2 during forward rotation, and the rotating electric machine of Embodiment 2 during reverse rotation. Fig.13 In the figure, it is shown that according to Fig.12 The torque pulsation component calculated from the waveform of the torque output is the sixth component relative to the electrical angle of 360°. Fig.13 In the example, the magnitude of the torque pulsation of Comparative Example 1 is set as a reference value "100", and the magnitudes of the torque pulsation during the forward rotation and the reverse rotation of the second embodiment are normalized by the reference value of Comparative Example 1 that has been set.

[0078] according to Fig.11 It can be seen that the magnitude of the torque output of the rotating electrical machine 1 of the second embodiment is the same whether in forward rotation or reverse rotation. In addition, the magnitude of the torque output of the rotating electrical machine 1 of the second embodiment is smaller than the magnitude of the torque output of the rotating electrical machine 200 of the first comparative example. Fig.11 and Figure 5 It can be seen that the torque output of the rotating electrical machine 1 of the second embodiment is greater than Figure 4 The magnitude of the torque output of the rotary electric machine 300 of the comparative example 2 shown is large. This is because, by providing the low magnetic permeability portion 82 on only one tooth 8 among the three teeth 8 of each tooth group 81, the reduction in the effective magnetic flux passing through each tooth 8 can be suppressed compared to the reduction in the effective magnetic flux in the rotary electric machine 300 of the comparative example 2.

[0079] according to Fig.12 and Fig.13 It can be seen that the torque pulsation of the rotating electrical machine 1 of the second embodiment during forward rotation and reverse rotation is smaller than the torque pulsation of the rotating electrical machine 200 of the first comparative example. In particular, the magnitude of the torque pulsation during forward rotation of the second embodiment is significantly smaller than the torque pulsation of the first comparative example. Fig.13 and Figure 7 , the magnitude of the torque pulsation during the reverse rotation of the embodiment 2 is larger than that of the comparative example 2. Therefore, by providing the low magnetic permeability portion 82 only on the tooth 8 located on the rear side in the rotation direction of the rotor 2 among the three teeth 8 constituting the tooth group 81, it is possible to effectively achieve the reduction of the torque pulsation and suppress the reduction of the torque output. Therefore, in the case where the rotation direction of the rotating electric machine 1 is restricted to a predetermined direction for use, it is effective to provide the low magnetic permeability portion 82 on the tooth 8 on the rear side in the rotation direction of the rotor 2.

[0080] As described above, in the rotary electric machine 1 of the second embodiment, the low magnetic permeability portion 82 is provided at the tip end 83 of the other outer teeth 8, avoiding the center and one outer teeth 8, of the three teeth 8 constituting each tooth group 81. Therefore, by limiting the rotation direction of the rotor 2 to a predetermined direction, it is possible to reduce the torque pulsation and suppress the reduction of the torque output. That is, by limiting the rotation direction of the rotor 2 to a predetermined direction, it is possible to provide the low magnetic permeability portion 82 only on the teeth 8 located on the rear side of the rotation direction of the rotor 2 among the three teeth 8 constituting the tooth group 81. Thus, it is possible to provide the low magnetic permeability portion 82 on the teeth 8 that effectively reduce the torque pulsation with respect to the rotation direction of the rotor 2 among the three teeth 8 constituting the tooth group 81. In addition, it is possible to further suppress the reduction of the effective magnetic flux that contributes to the torque output. Therefore, it is possible to reduce the torque pulsation and effectively suppress the reduction of the torque output.

[0081] In addition, the low magnetic permeability portion 82 may be arranged at the same position as the center line of the tooth 8 provided with the low magnetic permeability portion 82, or may be arranged at a position closer to the center line of the tooth 8 than the center line of the tooth 8. In this way, the torque pulsation of the rotating electric machine 1 can be reduced, and the reduction in the torque output of the rotating electric machine 1 can be suppressed.

[0082] Implementation 3

[0083] Fig.14 1 is a cross-sectional view showing a rotary electric machine 1 according to Embodiment 3. In each tooth group 81, among the three teeth 8, the tip end 83 of each of the two teeth 8 on the outer side avoiding the central tooth 8 is provided with a through hole 824 in the direction along the main axis. In each tooth group 81, the space formed by the through hole 824 is a low magnetic permeability portion 82. The low magnetic permeability portion 82 is not provided in the central tooth 8.

[0084] The cross-sectional shape of the through hole 824 is circular. The position of the through hole 824 in the circumferential direction of the stator 6 is the same as the position of the slot 821 in the first embodiment. Therefore, the low magnetic permeability portion 82 is arranged at a position farther from the center line CL of the central tooth 8 in the circumferential direction of the stator 6 than the center lines CL1 and CL2 of the tooth 8 provided with the low magnetic permeability portion 82. In addition, in each tooth group 81, the low magnetic permeability portions 82 of the two teeth 8 respectively provided on the outer side are provided at positions geometrically symmetrical with respect to the center line CL of the central tooth 8. The other structures of the fourth embodiment are the same as those of the first embodiment.

[0085] Thus, by providing the through hole 824 at the tip 83 of the tooth 8, the space formed by the through hole 824 can be provided as the low magnetic permeability portion 82 at the tip 83 of the tooth 8. Therefore, the low magnetic permeability portion 82 can be easily provided at the tip 83 of the tooth 8.

[0086] In addition, in Embodiment 3, the cross-sectional shape of the low magnetic permeability portion 82 formed by the through hole 824 is circular. However, the cross-sectional shape of the low magnetic permeability portion 82 formed by the through hole 824 is not limited to this. The cross-sectional shape of the low magnetic permeability portion 82 formed by the through hole 824 may also be rectangular, triangular, or other shapes.

[0087] Embodiment 4

[0088] Fig.15 FIG. is a cross-sectional view showing the rotating electric machine 1 of Embodiment 4. In each tooth group 81, among the three teeth 8, a space portion formed by the same groove 821 as in Embodiment 1 is provided at the end portion 83 of each of the two outer teeth 8 while avoiding the central tooth 8. A filling material 825 is filled in the space portion formed by the groove 821 as the low magnetic permeability portion 82. That is, the low magnetic permeability portion 82 is the filling material 825 filled in the space portion formed by the groove 821. As the filling material 825, a resin or the like as a non-magnetic body is used. The low magnetic permeability portion 82 is not provided in the central tooth 8. Other structures of Embodiment 4 are the same as those of Embodiment 1.

[0089] In the rotating electric machine 1 of Embodiment 4, the filling material 825 is filled in the space portion provided at the end portion 83 of the tooth 8 as the low magnetic permeability portion 82. Therefore, the space portion formed by the groove 821 can be filled with the filling material 825, and the filling materials 825 can be connected in the direction along the main axis. Thereby, the rigidity of the tooth 8 can be improved. Therefore, the resonance frequency of the rotating electric machine can be increased, and the generation of mechanical noise and vibration can be suppressed.

[0090] In addition, the filling material 825 is not limited to resin. For example, a metal having a magnetic permeability lower than that of the stator core 7 may be used as the filling material 825.

[0091] Furthermore, in Embodiment 4, the filling material 825 is filled in the space portion provided at the end portion 83 of the tooth 8 in Embodiment 1. However, the filling material 825 may also be filled in the space portion provided at the end portion 83 of the tooth 8 in Embodiment 2 and Embodiment 3.

[0092] Embodiment 5

[0093] Fig.16 FIG. is a cross-sectional view showing the rotating electric machine of Embodiment 5. In each tooth group 81, among the three teeth 8, a caulking portion (Japanese: かしめ部) 826 is provided at the end portion 83 of each of the two outer teeth 8 while avoiding the central tooth 8 as the low magnetic permeability portion 82. The caulking portion 826 is a portion that joins the plurality of thin plates laminated in the stator core 7. The caulking portion 826 provided at the end portion 83 of the tooth 8 is arranged parallel to the main axis.

[0094] The stator core 7 is manufactured by joining a plurality of stacked raw material plates to each other. The plurality of raw material plates are partially deformed by machining and thereby joined to each other. The portion of the raw material plate that is deformed by machining is formed on the stator core 7 as a rivet portion 826 for joining the plurality of raw material plates to each other. On the other hand, the portion of the raw material plate other than the rivet portion 826 becomes a part of the stator core 7 as a thin plate. The rivet portion 826 is magnetically inferior to the stator core 7 due to the deformation of the raw material plate caused by machining. Therefore, the magnetic permeability of the rivet portion 826 is lower than the magnetic permeability of the stator core 7.

[0095] The caulking portion 826 has a circular shape. The position of the caulking portion 826 is the same as that of the through hole 824 in the second embodiment. The other structures in the fifth embodiment are the same as those in the first embodiment.

[0096] In the rotary electric machine 1 of the fifth embodiment, the rivet portion 826 provided at the terminal portion 83 of the tooth 8 becomes the low magnetic permeability portion 82. Therefore, by only forming the rivet portion by machining the plurality of stacked raw material plates, the plurality of raw material plates can be joined to each other, and the low magnetic permeability portion 82 can be provided at the terminal portion 83 of the tooth 8. That is, the formation of the low magnetic permeability portion 82 and the joining of the plurality of raw material plates can be performed in one process. Thus, the manufacturing process of the stator core 7 can be simplified, and the manufacturing of the rotary electric machine can be facilitated. In addition, since no space portion is formed at the terminal portion 83 of the tooth 8, the increase in noise and vibration of the rotary electric machine 1 can also be suppressed.

[0097] Implementation 6

[0098] Fig.17 1 is an exploded perspective view showing a stator core 7 of a rotating electrical machine according to Embodiment 6. The stator core 7 includes at least one first core structure 70 and at least one second core structure 71 as a plurality of core structures.

[0099] The first core structure 70 is a core structure in which the low magnetic permeability portion 82 is not provided at the terminal portions 83 of all teeth 8. The second core structure 71 is a core structure in which the low magnetic permeability portion 82 is provided at the terminal portions 83 of the two outer teeth 8, excluding the central tooth 8, among the three teeth 8 of each tooth group 81.

[0100] The structure of the stator core 7 of the first embodiment is applied to the structure of the second core structure 71. Therefore, in the second core structure 71, the space formed by the slot 821 is the low magnetic permeability portion 82. The low magnetic permeability portion 82 is provided in the entire range of the second core structure 71 in the direction along the main axis. In addition, the low magnetic permeability portion 82 is provided parallel to the main axis.

[0101] In the stator core 7, the first core structure 70 and the second core structure 71 overlap alternately in the direction along the main axis. In this example, the stator core 7 includes two first core structures 70 and one second core structure 71 as three core structures. The first core structure 70 and the second core structure 71 on one side and the first core structure 70 on the other side overlap in sequence in the direction along the main axis. In addition, the sizes of the first core structures 70 and the second core structures 71 in the direction along the main axis are the same as each other.

[0102] In the stator core 7, in the direction along the main axis, the low magnetic permeability portion 82 does not exist in the range where the first core structure portion 70 is arranged, and the low magnetic permeability portion 82 exists in the range where the second core structure portion 71 is arranged. Therefore, in the tooth 8 provided with the low magnetic permeability portion 82, the low magnetic permeability portion 82 exists locally in the direction along the main axis. The other structures in the sixth embodiment are the same as those in the first embodiment.

[0103] In the rotary electric machine 1 of the sixth embodiment, the low magnetic permeability portion 82 exists locally in the direction along the main axis. Therefore, compared with the case where the low magnetic permeability portion 82 exists in the entire range of the stator core 7 in the direction along the main axis, it is possible to suppress the reduction of the effective magnetic flux that contributes to the torque output. As a result, it is possible to more reliably suppress the reduction of the torque output.

[0104] In the sixth embodiment, the stator core 7 includes two first core structures 70 and one second core structure 71. Fig.18 As shown, the stator core 7 may include one first core structure 70 and two second core structures 71. In this case, the second core structure 71 on one side, the first core structure 70, and the second core structure 71 on the other side overlap in sequence in the direction along the main axis. In this way, the low magnetic permeability portion 82 can also be locally present in the direction along the main axis, thereby being able to more reliably suppress the reduction in torque output.

[0105] In Embodiment 6, the number of core structures included in the stator core 7 is 3. However, the number of core structures included in the stator core 7 may be 2 or 4 or more. In this case, in the stator core 7, the first core structures 70 and the second core structures 71 overlap alternately in the direction along the main axis.

[0106] Implementation 7

[0107] Fig.19 1 is a longitudinal sectional view showing an elevator hoisting machine according to Embodiment 7. The elevator hoisting machine 100 includes a rotary electric machine 1 , a drive sheave 101 , a casing 102 , a frame 103 , a brake device 104 , and a main shaft 105 .

[0108] The rotating electric machine 1 is an electric motor that generates a driving force for rotating a driving sheave 101. The rotating electric machine 1 has a rotor 2 and a stator 6. The rotor 2 and the stator 6 have a common axis as a main axis. A main shaft 105 and a cylindrical housing 102 are fixed to a frame 103. The rotor 2, the stator 6, and the housing 102 are arranged coaxially with the main shaft 105.

[0109] The driving sheave 101 is rotatably supported by the main shaft 105 via a bearing 108. Thus, the driving sheave 101 is coaxially arranged with the main shaft 105. The rotor 2 is fixed to the driving sheave 101.

[0110] The rotor 2 has a cylindrical rotor core 4 and a plurality of magnetic poles 5, and the plurality of magnetic poles 5 are provided on the outer peripheral surface of the rotor core 4. The cylindrical rotor core 4 is formed integrally with the drive sheave 101. In this example, the material constituting the rotor core 4 and the drive sheave 101 is cast iron. The stator 6 is fixed to the inner peripheral surface of the housing 102. The other structures of the rotating electric machine 1 are the same as those of the rotating electric machine 1 of the first embodiment.

[0111] By supplying three-phase AC power to the plurality of windings 10, the drive sheave 101 and the rotor 2 rotate about the main axis relative to the main shaft 105 and the stator 6. When the drive sheave 101 and the rotor 2 rotate, the housing 102 receives a reaction force generated by the rotation of the drive sheave 101 and the rotor 2.

[0112] The driving sheave 101 is disposed at a position away from the range of the stator 6 in the direction along the main axis. A plurality of main rope grooves 107 are provided on the outer peripheral surface of the driving sheave 101 along the circumferential direction of the driving sheave 101. A plurality of main ropes for suspending a car and a counterweight (not shown) are hung around the driving sheave 101 along the main rope grooves 107. The car and the counterweight move in the up-and-down direction in the hoistway by the rotation of the driving sheave 101.

[0113] The brake device 104 is provided inside the cylindrical rotor core 4. The brake device 104 is a device for applying a braking force to the drive sheave 101 and the rotor 2. The brake device 104 has a brake shoe (not shown) which can be displaced in the radial direction of the rotor 2 relative to the rotor core 4. The brake device 104 applies a braking force to the drive sheave 101 and the rotor 2 by bringing the brake shoe into contact with the inner peripheral surface of the rotor core 4. In addition, the brake device 104 releases the braking force on the drive sheave 101 and the rotor 2 by making the brake shoe separate from the rotor core 4.

[0114] The elevator hoisting machine 100 of Embodiment 7 includes a rotary electric machine 1 having the same structure as that of Embodiment 1 as a motor. Therefore, as in Embodiment 1, it is possible to reduce the torque pulsation of the elevator hoisting machine 100 and suppress the reduction in the torque output of the elevator hoisting machine 100. As a result, the vibration of the car caused by the torque pulsation of the rotary electric machine 1 can be reduced, and the swing of the car during the operation of the elevator can be reduced.

[0115] In Embodiment 7, the rotor 2 rotates integrally with the drive sheave 101. However, a traction machine having a geared motor that integrates a reducer including a gear and a rotary electric machine 1 as an electric motor may be used as the elevator traction machine 100. In this case, the drive sheave 101 rotates by the rotational force output from the reducer of the geared motor.

[0116] Furthermore, instead of using the rotating electrical machine 1 of the first embodiment, the configurations of the rotating electrical machines 1 of the second to sixth embodiments may be used as the configuration of the electric motor of the hoisting machine 100 of the elevator.

[0117] In each of the above-described embodiments, a rotating electrical machine in which the number of magnetic poles 5 of the rotor 2 is 10 and the number of slots of the stator core 7 is 9, that is, a rotating electrical machine with 10 poles and 9 slots, is used as the rotating electrical machine 1. However, a rotating electrical machine in which the number of magnetic poles 5 of the rotor 2 is 8 and the number of slots of the stator core 7 is 9, that is, a rotating electrical machine with 8 poles and 9 slots, may be used as the rotating electrical machine 1.

[0118] In each of the above-mentioned embodiments, a combination of 10 poles and 9 slots may be used as one unit A, and an integer n times of one unit A, that is, a combination of 10n poles and 9n slots, may be used as a combination of the number of magnetic poles 5 of the rotor 2 and the number of slots of the stator core 7. In this case, the number of windings 10 is 9n. In addition, a combination of 8 poles and 9 slots may be used as one unit B, and an integer n times of one unit B, that is, a combination of 8n poles and 9n slots, may be used as a combination of the number of magnetic poles 5 of the rotor 2 and the number of slots of the stator core 7. In this case, the number of windings 10 is also 9n.

[0119] In each of the above embodiments, the number of low magnetic permeability portions 82 provided at the tip portion 83 of the tooth 8 is set to one low magnetic permeability portion 82 for one tooth 8. However, two or more low magnetic permeability portions 82 may be provided at the tip portion 83 of the tooth 8 for one tooth 8.

[0120] In each of the above-described embodiments, the back yoke 9 includes a plurality of back yoke members 91 arranged in an annular shape. However, the back yoke 9 may be an annular body that is not divided into a plurality of back yoke members but is integrally molded.

[0121] In each of the above-mentioned embodiments, a surface magnet type (SPM: Surface Permanent Magnet) rotating electric machine in which a plurality of magnetic poles 5 are arranged on the outer peripheral surface of the rotor core 4 is used as the rotating electric machine 1. However, an embedded magnet type (IPM: Interior Permanent Magnet) rotating electric machine in which a plurality of magnetic poles 5 are embedded inside the rotor core 4, or a commutation pole type rotating electric machine in which permanent magnets and magnetic salient poles are alternately arranged in the circumferential direction may be used as the rotating electric machine 1.

[0122] In each of the above embodiments, an inner rotor structure rotating machine in which the rotor 2 is arranged inside the annular stator 6 is used as the rotating machine 1. However, an outer rotor structure rotating machine in which the annular rotor 2 is arranged outside the stator 6 may be used as the rotating machine 1.

[0123] Description of symbols

[0124] 1: rotating electrical machine; 2: rotor; 4: rotor core; 5: magnetic pole; 6: stator; 7: stator core; 8: tooth; 9: back yoke; 10: winding; 81: tooth group; 82: low magnetic permeability portion; 821: slot; 824: through hole; 825: filling material; 826: riveted portion; 100: elevator traction machine.

Claims

1. A rotating electrical machine comprising: a rotor that rotates about an axis; and a stator which is opposed to the rotor with a gap therebetween in the radial direction of the rotor, The rotor comprises a rotor core and a plurality of magnetic poles, wherein the plurality of magnetic poles are arranged on the rotor core and arranged in a circumferential direction of the rotor. The stator comprises a stator core and a plurality of windings, wherein the plurality of windings are arranged on the stator core. The stator core has a back yoke and a plurality of teeth, the plurality of teeth protruding from the back yoke toward the rotor, The plurality of teeth are arranged at intervals from each other in the circumferential direction of the stator, Each of the teeth has a terminal end, and the terminal end is opposed to the rotor. The winding is wound around the teeth by concentrated winding, The three teeth continuously arranged in the circumferential direction of the stator constitute a tooth group, The windings of the same phase are respectively wound around the three teeth constituting one teeth group. In the tooth group, among the three teeth, the two teeth on the outer sides avoiding the central tooth are each provided with a low magnetic permeability portion at the tip end thereof, The low magnetic permeability portion has a magnetic permeability lower than a magnetic permeability of the stator core.

2. The rotating electrical machine according to claim 1, wherein: In the tooth group, in a cross section perpendicular to the axis, the low magnetic permeability portions of the two teeth respectively provided on the outer sides are provided at positions geometrically symmetrical with respect to a center line of the central tooth.

3. The rotating electrical machine according to claim 1, wherein: The low magnetic permeability portion is disposed at a position farther from the center line of the tooth at the center in the circumferential direction of the stator than the center line of the tooth at which the low magnetic permeability portion is provided.

4. The rotating electrical machine according to claim 2, wherein: The low magnetic permeability portion is disposed at a position farther from the center line of the tooth at the center in the circumferential direction of the stator than the center line of the tooth at which the low magnetic permeability portion is provided.

5. The rotating electrical machine according to any one of claims 1 to 4, wherein: The low magnetic permeability portion is a space portion formed by a groove provided at the tip end portion of the tooth.

6. The rotating electrical machine according to any one of claims 1 to 4, wherein: The low magnetic permeability portion is a space portion formed by a through hole provided at the tip end portion of the tooth.

7. The rotating electrical machine according to any one of claims 1 to 4, wherein: The low magnetic permeability portion is a filling material filled in a space portion provided at the tip end portion of the tooth.

8. The rotating electrical machine according to any one of claims 1 to 4, wherein: The low magnetic permeability portion is a rivet portion provided at the distal end portion of the tooth.

9. The rotating electrical machine according to any one of claims 1 to 4, wherein: In the tooth provided with the low magnetic permeability portion, the low magnetic permeability portion exists locally in the direction along the axis.

10. A rotating electrical machine comprising: a rotor that rotates about an axis; and a stator which is opposed to the rotor with a gap therebetween in the radial direction of the rotor, The rotor comprises a rotor core and a plurality of magnetic poles, wherein the plurality of magnetic poles are arranged on the rotor core and arranged in a circumferential direction of the rotor. The stator comprises a stator core and a plurality of windings, wherein the plurality of windings are arranged on the stator core. The stator core has a back yoke and a plurality of teeth, the plurality of teeth protruding from the back yoke toward the rotor, The plurality of teeth are arranged at intervals from each other in the circumferential direction of the stator, Each of the teeth has a terminal end, and the terminal end is opposed to the rotor. The winding is wound around the teeth by concentrated winding, The three teeth continuously arranged in the circumferential direction of the stator constitute a tooth group, The windings of the same phase are respectively wound around the three teeth constituting one teeth group. In the tooth group, among the three teeth, a low magnetic permeability portion is provided at the tip of the other outer tooth, avoiding the center and the outer teeth, respectively. The low magnetic permeability portion has a magnetic permeability lower than a magnetic permeability of the stator core.

11. The rotating electrical machine according to claim 10, wherein: The low magnetic permeability portion is disposed at a position farther from the center line of the tooth at the center in the circumferential direction of the stator than the center line of the tooth at which the low magnetic permeability portion is provided.

12. The rotating electrical machine according to claim 10 or 11, wherein: The low magnetic permeability portion is a space portion formed by a groove provided at the tip end portion of the tooth.

13. The rotating electrical machine according to claim 10 or 11, wherein: The low magnetic permeability portion is a space portion formed by a through hole provided at the tip end portion of the tooth.

14. The rotating electrical machine according to claim 10 or 11, wherein: The low magnetic permeability portion is a filling material filled in a space portion provided at the tip end portion of the tooth.

15. The rotating electrical machine according to claim 10 or 11, wherein: The low magnetic permeability portion is a rivet portion provided at the distal end portion of the tooth.

16. The rotating electrical machine according to claim 10 or 11, wherein: In the tooth provided with the low magnetic permeability portion, the low magnetic permeability portion exists locally in the direction along the axis.

17. A traction machine for an elevator, comprising the rotating electrical machine according to any one of claims 1 to 16.

Images