JP2020043695A - Rotary electric machine, and hoist system for elevator - Google Patents

Abstract

To provide a rotary electric machine which can suppress torque ripples and to which a cover for preventing scattering of debris of permanent magnets of a rotor can be installed without applying stress to the permanent magnets, and a hoist system for an elevator with the rotary electric machine.SOLUTION: A rotary electric machine of the present invention comprises: a rotor 1 with a rotor core 3, a plurality of permanent magnets 5 provided in a circumferential direction on a surface part of the rotor core 3, and a shaft 8; and stator 2 provided outside a radial direction of the rotor 1. The rotor 1 comprises a projecting part 10 projecting outside the radial direction between the permanent magnets 5 adjacent to each other in the circumferential direction on the surface of the rotor core 3. In the projecting part 10, an end surface 10a outside the radial direction is located outside the radial direction of an end surface 5a outside the radial direction of the permanent magnets 5, and a part of an end surface 10b in the circumferential direction contacts at least a part of an end surface 5b in the circumferential direction of the permanent magnets 5. The projecting part 10 does not comprise a part extending in the circumferential direction outside the radial direction of the end surface 5a outside the radial direction of the permanent magnets 5.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotating electric machine including a rotor and a stator, and an elevator hoisting system including the rotating electric machine.

  Conventionally, induction motors have been used as rotary electric machines for elevators.In recent years, however, permanent magnets have been reduced in price and the use of high-performance inverters has been reduced. Rotating electric machines have been adopted.

  Elevators are required to have good ride comfort because people board like cars and trains. One of the factors that deteriorate the ride comfort of an elevator is torque ripple (torque pulsation) generated from the rotating electric machine. In particular, in a high-speed and heavy-load elevator system, the rotating electric machine and the transmission gear are connected, but the torque ripple reduces the reliability of the transmission gear. In order to reduce torque ripple, the rotor has a surface magnet type structure in which permanent magnets are arranged on the surface of the rotor core. Further, when the rotor is provided with a D-shaped or tile-shaped permanent magnet having a curved surface near the gap between the rotor and the stator, torque ripple can be reduced.

  The surface magnet type rotor may be provided with a scattering prevention cover that covers the radially outermost portion of the rotor so that fragments of the permanent magnet do not scatter when the permanent magnet is damaged. With this cover, it is possible to prevent members of the rotating electric machine, such as the stator and the rotor, from being damaged due to the damage of the permanent magnet.

  As described above, the rotating electric machine for an elevator needs to be provided with a rotor of a surface magnet type, to reduce the torque ripple and to prevent scattering of the permanent magnet when it is damaged.

  For example, Patent Literature 1 describes an example of such a rotating electric machine (electric motor). In the electric motor described in Patent Document 1, the rotor includes a D-shaped permanent magnet, a substantially T-shaped protrusion between the permanent magnets, and a gap between the circumferential end face of the permanent magnet and the protrusion. It has a void. The substantially T-shaped protrusion is a covering portion extending toward both sides in the circumferential direction, and covers an end of the permanent magnet.

JP 2017-79570A

  In the electric motor described in Patent Document 1, the rotor has a structure in which a substantially T-shaped protrusion between the permanent magnets covers the permanent magnet, so that the magnetic flux from the permanent magnet does not flow into the gap, and the protrusion does not. Return to the magnet via. That is, the electric motor described in Patent Document 1 has a structure in which the rotor has a large amount of leakage magnetic flux. Since the torque ripple increases as the leakage flux of the magnet increases, it is difficult for a rotor having a structure with a large leakage flux to suppress the torque ripple. Further, in the electric motor described in Patent Document 1, the shape of the permanent magnet of the rotor is D-shaped, and there is a concern that the processing cost of the permanent magnet is high.

  As described above, the rotor is preferably provided with a cover for preventing the fragments of the permanent magnet from scattering. When providing the cover, it is necessary to prevent stress from being applied to the permanent magnet in order to prevent damage to the permanent magnet. The conventional rotating electric machine does not have a configuration that allows the cover to be installed without applying stress to the permanent magnet, and the permanent magnet may be damaged when the cover is installed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rotating electric machine capable of installing a cover that can suppress torque ripple and prevent fragments of permanent magnets of a rotor from being scattered without applying stress to a permanent magnet, and an elevator equipped with the rotating electric machine. A hoist system is provided.

  A rotating electric machine according to the present invention includes a rotor having a rotor core, a plurality of permanent magnets provided along a circumferential direction on a surface portion of the rotor core, and a shaft that is a rotating shaft extending in an axial direction. , A stator provided radially outside the rotor. The rotor includes a protrusion projecting radially outward between the permanent magnets adjacent to each other in a circumferential direction on a surface of the rotor core. The protrusion has a radially outer end face located radially outward from the radially outer end face of the permanent magnet, and a part of the circumferential end face is at least a part of the circumferential end face of the permanent magnet. Contact part. The protrusion does not include a portion extending in the circumferential direction on the radially outer side than the radially outer end face of the permanent magnet.

  ADVANTAGE OF THE INVENTION According to this invention, while the torque ripple can be suppressed, the rotating electric machine which can install the cover which prevents the fragment of the permanent magnet of a rotor from scattering without applying a stress to a permanent magnet, and the hoist for the elevator provided with this rotating electric machine Machine system can be provided.

FIG. 2 is a sectional view of the rotating electric machine according to the first embodiment of the present invention, which is perpendicular to the axial direction. It is sectional drawing which shows two poles of a rotor. It is an enlarged view of the protrusion of a rotor. It is an enlarged view of the protrusion provided with two parts from which the length of a circumferential direction differs mutually. It is an enlarged view of a projection provided with a portion where a circumferential end face contacts a permanent magnet and a tapered portion. FIG. 4 is a diagram illustrating a difference in magnetic flux density distribution due to a difference in shape of a permanent magnet. It is a front view of the rotor in Example 1 of the present invention. FIG. 7B is a cross-sectional view of the rotor taken along section line AA in FIG. 7A. It is a front view of the rotor which provided the projection part over all the parts of the axial direction. FIG. 8B is a cross-sectional view of the rotor taken along section line AA of FIG. 8A. 8 is a graph comparing torque and torque ripple of the rotor shown in FIGS. 8A and 8B and the rotor shown in FIGS. 7A and 7B. It is a front view of the rotor which minimized the installation number of the protrusion. FIG. 9 is a front view of a rotor 1 according to a second embodiment. FIG. 11B is a cross-sectional view of the rotor taken along section line AA in FIG. 11A. FIG. 13 is a front view of a rotor 1 according to a third embodiment. FIG. 12B is a cross-sectional view of the rotor taken along section line AA of FIG. 12A. FIG. 13 is a cross-sectional view of a rotary electric machine according to Embodiment 4 of the present invention along the axial direction. FIG. 13 is a cross-sectional view illustrating two poles of a rotor in a rotary electric machine according to Embodiment 5 of the present invention. FIG. 13 is a cross-sectional view illustrating two poles of a rotor in a rotary electric machine according to Embodiment 6 of the present invention. It is a figure which shows the hoist system for elevators by Example 7 of this invention. FIG. 14 is a view showing another elevator hoist system according to the seventh embodiment of the present invention.

  The rotating electric machine according to the present invention includes a protrusion for supporting a cover for preventing fragments of the permanent magnet from being scattered between permanent magnets provided along the circumferential direction of the rotor. Since the protrusion does not include a portion extending in the circumferential direction outside the permanent magnet in the radial direction, it is possible to reduce magnetic flux leakage from the permanent magnet and suppress torque ripple generated in the rotating electric machine. Since the cover is supported by the projection, it can be installed without applying stress to the permanent magnet.

  The protrusions provided between the permanent magnets of the rotor are necessary for installation of the cover, but if the volume is large, the torque ripple increases. The present invention has been obtained by focusing on the fact that the shape of the protrusion is extremely important in a rotating electric machine. The rotating electric machine according to the present invention includes the protrusion having a shape that does not increase the torque ripple, so that the torque ripple can be suppressed, the permanent magnet can be prevented from being damaged by the installation of the cover, and the reliability of the rotating electric machine can be secured. it can.

  Hereinafter, a rotating electric machine and an elevator hoist system according to an embodiment of the present invention will be described with reference to the drawings. In the drawings used in this specification, the same or corresponding components are denoted by the same reference characters, and a repeated description of these components may be omitted.

FIG. 1 is a sectional view of a rotating electric machine 100 according to a first embodiment of the present invention, which is perpendicular to the axial direction. FIG. 1 shows a quarter of the rotating electric machine 100 in the circumferential direction. The rotating electric machine 100 is a rotating electric machine (for example, an electric motor) having an output of several hundred kW and a rotation speed of several hundred min- ¹ and is provided mainly in a hoisting system for an elevator, particularly in a high-speed and large-load elevator. .

  In the rotating electric machine 100, the direction in which the rotating shaft extends is referred to as “axial direction”, the rotating direction of the rotating shaft is referred to as “circumferential direction”, and the radial direction of the rotating shaft is referred to as “radial direction”.

  The rotating electric machine 100 includes a rotor 1 and a stator 2. The rotor 1 includes a rotor core 3, a permanent magnet 5 provided on the rotor core 3, and a shaft 8, which is a rotating shaft extending in the axial direction. The stator 2 is provided radially outside the rotor 1 and includes a stator core 4 and a coil 6 provided on the stator core 4. A gap 7 is provided between the rotor 1 and the stator 2.

  FIG. 2 is a sectional view showing two poles of the rotor 1. The rotor 1 is a surface magnet type rotor in which a plurality of permanent magnets 5 are provided on the surface of the rotor core 3. The plurality of permanent magnets 5 are arranged on the surface portion (radial surface portion) of the rotor core 3 along the circumferential direction. The permanent magnet 5 has a rectangular parallelepiped shape, that is, a flat plate type configured by six planes.

  The rotor 1 includes a protrusion 10 that protrudes radially outward between the permanent magnets 5 adjacent to each other in the circumferential direction on the surface of the rotor core 3. The protrusion 10 may be provided on the rotor core 3 when the rotor core 3 is manufactured, or may be installed on the rotor core 3 after the rotor core 3 is manufactured. The protrusion 10 may be made of a magnetic material (for example, the same iron as the rotor core 3) or may be made of a non-magnetic material (for example, stainless steel). The protrusion 10 can have any shape, but is preferably, for example, prismatic.

  The protrusion 10 has a radially outer end face 10 a located radially outward of the radially outer end face 5 a of the permanent magnet 5. In the protrusion 10, a part of the circumferential end face 10 b contacts at least a part of the circumferential end face 5 b of the permanent magnet 5.

  The protruding portion 10 has a portion where the circumferential end face 10b is located radially inward of the radially outer end face 5a of the permanent magnet 5 (in FIG. 2, the permanent magnet 5 of the circumferential end face 10b of the protruding portion 10). (A portion in contact with the circumferential end face 5b of the permanent magnet 5), and a portion (in FIG. 2) of the circumferential end face 10b of the protrusion 10 in the circumferential direction from the radially outer end face 5a of the permanent magnet 5. (The portion not in contact with the end face 5b in the circumferential direction) linearly (planar) along the radial direction. That is, the protruding portion 10 does not include a portion extending along the circumferential direction outside the radially outer end surface 5a of the permanent magnet 5 so as not to cover the permanent magnet 5.

  Since the protrusion 10 is in contact with the circumferential end face 5b of the permanent magnet 5, the permanent magnet 5 is fixed so as not to shift in the circumferential direction. In addition, since the protruding portion 10 and the permanent magnet 5 are in surface contact, concentrated stress is less likely to be generated in the permanent magnet 5, and damage to the permanent magnet 5 can be prevented, so that the reliability of the permanent magnet 5 can be improved. .

  The protrusion 10 can include a cover 11 for preventing fragments of the permanent magnet 5 from scattering on a radially outer end surface 10a. The cover 11 is provided on the protrusion 10 at a position covering the permanent magnet 5. The protrusion 10 is a member that supports the cover 11. The cover 11 is a member that extends so as to cover the permanent magnet 5, and is, for example, a cylindrical shape that can be fitted over the rotor 1 and can be an existing one, and is made of metal or resin. . A gap 19 is formed between the cover 11 and the permanent magnet 5.

  Since the rotor 1 includes the protrusion 10 on which the cover 11 can be provided, the cover 11 can prevent fragments of the permanent magnet 5 from scattering into the gap 7 and improve the reliability of the rotating electric machine 100. it can. In addition, even when the rotor 1 includes the protrusions 10, the protrusions 10 do not extend in the circumferential direction and do not cover the permanent magnets 5, so that the rotor 1 has a shape different from that of the rotor including protrusions of other shapes. Leakage magnetic flux from the permanent magnet 5 can be reduced, and torque ripple can be suppressed.

  As a method of attaching the cover 11 to the rotor 1, for example, press fitting with a metal tube, shrink fitting, press fitting with a resin tube, and the like can be given. When the rotor 11 without the protrusion 10 is provided with the cover 11 by using such a method, a stress is directly applied to the permanent magnet 5. The permanent magnet 5 is often made of a hard and brittle rare earth magnet and is easily broken. For this reason, in the rotor 1 without the protrusion 10, the permanent magnet 5 is easily damaged by the stress generated when the cover 11 is attached to the rotor 1, and thus the productivity may be reduced and the reliability may be reduced. is there.

  In the rotating electric machine 100 according to the present embodiment, the rotor 1 includes the protrusion 10 that is a member that supports the cover 11, and the cover 11 can be provided on the protrusion 10, so that the permanent magnet 5 is not stressed. The cover 11 can be attached, and productivity and reliability can be improved.

  FIG. 3 is an enlarged view of the protrusion 10 of the rotor 1. FIG. 3 does not show the cover 11. The protrusion 10 has a curved outer end surface 10a in the radial direction. For example, the end surface 10a is a curved surface that curves convexly outward in the radial direction.

  If the end face 10a of the protrusion 10 is flat, the cover 11 comes into contact with the protrusion 10 at a corner where the end face 10a and the circumferential end face 10b intersect, so that stress concentration occurs and strength is reduced. If the end face 10a of the projection 10 is a curved surface, the cylindrical cover 11 easily contacts the end face 10a, so that stress concentration on the cover 11 can be reduced. If the radius of curvature of the inside of the cover 11 in the radial direction is equal to the curvature of the end face 10a of the protrusion 10, the cover 11 and the protrusion 10 are in contact with each other, so that the stress generated in the cover 11 can be minimized. In addition, a decrease in the strength of the cover 11 can be prevented.

  FIGS. 4 and 5 are enlarged views of the protrusion 10, and are diagrams illustrating the protrusion 10 having a shape different from that of FIG. 3. 4 and 5, the cover 11 is not shown. The protrusion 10 shown in FIG. 4 includes two portions 10c and 10d having different circumferential lengths. In the portion 10 c having a long circumferential length, the circumferential end face 10 b contacts a part of the circumferential end face 5 b of the permanent magnet 5. The portion 10 d having a short circumferential length does not contact the permanent magnet 5. The protruding portion 10 shown in FIG. 5 includes a portion 10e in which the circumferential end face 10b contacts a part of the circumferential end face 5b of the permanent magnet 5, and a tapered portion in which the circumferential length decreases radially outward. 10f. The tapered portion 10f does not contact the permanent magnet 5.

  If the protrusion 10 is made of a magnetic material (for example, iron), the protrusion 10 shown in FIGS. 4 and 5 is smaller in amount of the magnetic material forming the protrusion 10 than the protrusion 10 shown in FIG. (Volume) is small. For this reason, the rotor 1 having the protrusion 10 shown in FIGS. 4 and 5 can reduce the magnetic flux leakage from the permanent magnet 5 and reduce the torque ripple compared to the rotor 1 having the protrusion 10 shown in FIG. Can also be suppressed.

  FIG. 6 is a diagram illustrating a difference in distribution of magnetic flux density due to a difference in shape of the permanent magnet. FIG. 6 shows the shapes and magnetic flux densities of the flat permanent magnet 5, the D-shaped permanent magnet 12, and the tile-shaped permanent magnet 13 provided in the rotor 1 of the rotating electric machine 100 according to the present embodiment. The distribution is shown. The D-shaped permanent magnet 12 is a curved surface whose outer surface in the radial direction is curved outward in the radial direction, and whose inner surface in the radial direction is flat. The tile-shaped permanent magnet 13 is a curved surface in which a radially outer surface and a radially inner surface are curved radially outward.

  As shown in FIG. 6, the difference in the shape of the permanent magnet appears in the distribution of the magnetic flux density in the gap 7. In the plate type permanent magnet 5, the magnetic flux density shows a uniform distribution. With the D-shaped permanent magnet 12 and the tile-shaped permanent magnet 13, the magnetic flux density shows a distribution that is maximum at the center of the permanent magnets 12 and 13.

  A conventional surface magnet type rotor includes a D-shaped permanent magnet 12 and a tile-shaped permanent magnet 13 to suppress torque ripple. This is because torque ripple can be suppressed by making the shape of the distribution of the magnetic flux density in the gap 7 close to a sine wave. However, manufacturing the D-shaped permanent magnet 12 or the tile-shaped permanent magnet 13 requires more cost than manufacturing the flat permanent magnet 5. In particular, in a rotating electric machine having a large capacity (output), the amount of use of the permanent magnet increases, so that the cost is greatly increased, which is not preferable. For this reason, it is desired that the rotor be provided with the flat permanent magnet 5 and that the leakage flux of the permanent magnet 5 be reduced as much as possible to suppress the torque ripple.

  The protrusion 10 provided on the rotor 1 of the rotating electric machine 100 according to the present embodiment is characterized by its shape, but still generates leakage magnetic flux from the permanent magnet 5. In order to reduce the leakage magnetic flux from the permanent magnet 5 as much as possible, it is effective to reduce the position where the protrusion 10 is provided as much as possible. The purpose of providing the protrusion 10 is to support the cover 11 and to fix the circumferential position of the permanent magnet 5 as described above. Therefore, the rotor 1 does not need to include the protrusions 10 continuously over the entire axial direction, and achieves the above-described two points by providing a plurality of protrusions 10 intermittently along the axial direction. it can.

  FIG. 7A is a front view of the rotor 1, and is a diagram illustrating two pole portions of the rotor 1 as in FIG. 2. 7A, the cover 11 is not shown so that the position of the protrusion 10 can be seen.

  FIG. 7B is a cross-sectional view of the rotor 1 along a cutting line AA in FIG. 7A. FIG. 7B shows a portion radially outward from the shaft 8.

  In the rotor 1, as shown in FIG. 7A, it is assumed that a plurality of permanent magnets 5 are arranged in the axial direction. The plurality of permanent magnets 5 arranged in the axial direction are in contact with and connected to adjacent permanent magnets 5. The circumferential position of the permanent magnet 5 can be fixed by providing protrusions 10 at both ends in the axial direction of one permanent magnet 5. In the rotor shown in FIGS. 7A and 7B, the protrusions 10 are provided at the connection portions of the plurality of permanent magnets 5 (both ends in the axial direction of the permanent magnets 5). By providing the protrusions 10 at the connection portions of the plurality of permanent magnets 5 arranged in the axial direction, the amount (total volume) of the protrusions 10 provided in the rotor 1 can be reduced.

  8A and 8B are views showing the rotor 1 in which the protrusions 10 are provided over all portions in the axial direction. FIG. 8A is a front view of the rotor 1 corresponding to FIG. 7A. FIG. 8B is a sectional view of the rotor 1 corresponding to FIG. 7B and taken along a cutting line AA in FIG. 8A. In FIG. 8B, the permanent magnet 5 is hidden by the protrusion 10 and is not actually visible.

  In the following, regarding the rotor 1 (CASE-1) having the configuration shown in FIGS. 8A and 8B and the rotor 1 (CASE-2) having the configuration shown in FIGS. And the difference between torque ripple.

  FIG. 9 is a graph comparing torque obtained by numerical calculation and torque ripple for the rotor 1 of CASE-1 and the rotor 1 of CASE-2. In FIG. 9, the torque indicates the torque of CASE-1 normalized to 1.0, and the torque ripple indicates the ratio between the maximum amplitude of torque pulsation and the torque.

  As shown in FIG. 9, there is almost no difference in torque between CASE-1 and CASE-2. This is because the physique of the rotating electric machine 100 itself is reduced as much as possible, and the magnetic flux density in the rotating electric machine 100 is high (the magnetic flux is close to saturation). On the other hand, regarding torque ripple, CASE-2 is 1.0 point smaller than CASE-1. This decrease in torque ripple is caused by the difference in the volume of the protrusion 10. That is, in CASE-2, the amount of the protrusion 10 is smaller than in CASE-1, and the entire volume of the protrusion 10 is smaller. Therefore, leakage flux (magnetic flux flowing through the protrusion 10) is smaller than CASE-1, and torque ripple is reduced. Has been reduced. From this, it can be said that the protrusion 10 is closely related to the torque ripple.

  Therefore, the projections 10 are provided to support the cover 11, but it is necessary to provide the minimum required amount of the projections 10 to reduce torque ripple. That is, it is necessary to reduce the size (volume) of each projection 10 or the number of the projections 10 to reduce the overall volume.

  FIG. 10 is a front view of the rotor 1 corresponding to FIG. 7A, and is a diagram illustrating a portion corresponding to two poles of the rotor 1 as in FIG. 2. In FIG. 10, the cover 11 is not shown so that the position of the protrusion 10 can be seen. In the rotor shown in FIG. 10, three protrusions 10 are provided for one permanent magnet 5. That is, two protrusions 10 are provided on one end face in the circumferential direction of one permanent magnet 5, one protrusion 10 is provided on the other end face, and two protrusions 10 on one end face are provided. Is provided at a connection portion between the plurality of permanent magnets 5 arranged in the axial direction (both ends of the permanent magnet 5 in the axial direction), and one projection 10 on the other end face is provided at a central portion in the axial direction of this end face. It is provided in.

  By providing the protrusions 10 as shown in FIG. 10, the circumferential position of the permanent magnet 5 can be fixed, and the total number of protrusions 10 can be reduced by minimizing the number of protrusions 10 to be installed. Thus, torque ripple can be reduced.

  In the present embodiment, the permanent magnet 5 is of a flat plate type, and the graph shown in FIG. 9 also shows the result when the flat permanent magnet 5 is used. Conventionally, in order to suppress the torque ripple, a D-shaped permanent magnet 12 or a tile-shaped permanent magnet 13 is used rather than the flat permanent magnet 5. However, as can be seen from the graph shown in FIG. 9, when the amount of the protrusion 10 (the whole volume) is reduced, the torque ripple can be suppressed to 1% or less even when the flat permanent magnet 5 is used. is there.

  Another reason why torque ripple can be suppressed even when the flat permanent magnet 5 is used is the number of poles of the rotor 1. The rotor 1 in this embodiment has 56 poles. In a surface magnet type rotor, the larger the number of poles, the easier it is to suppress torque ripple even when a flat permanent magnet 5 is used. For example, when a flat permanent magnet 5 is used for a rotor having four or six poles, a change in magnetic flux density distribution increases when the rotor rotates, and torque ripple increases. Therefore, as described above, the D-shaped permanent magnet 12 and the tile-shaped permanent magnet 13 are used for the surface magnet type rotor. When the number of poles of the rotor is large, the change in the magnetic flux density distribution when the rotor rotates is small even with the use of the plate-shaped permanent magnet 5. For this reason, for example, in a rotor having a number of poles of several tens or more, which is used in a rotating electric machine having a large capacity (output), torque ripple is suppressed even if a flat permanent magnet 5 is used to suppress an increase in cost. be able to.

  In addition, as shown in FIGS. 7A, 7B, and 10, in the rotor 1 having the plurality of protrusions 10 intermittently along the axial direction, the rotor core 3 is manufactured by casting, and the protrusions are formed by casting. The part 10 may be provided on the rotor core 3. By manufacturing the rotor core 3 by casting, the number of assembling steps can be reduced as compared with the case where the rotor core 3 is manufactured by using an electromagnetic steel sheet, so that an effect of further cost reduction can be expected. Although the rotating electric machine 100 according to the present embodiment has 56 poles and 72 slots, the present embodiment can be applied to a rotating electric machine having a different number of poles and slots. The same effect as that of the embodiment can be obtained. Further, the coil 6 may be formed by concentrated winding or another winding method.

  11A and 11B are views showing the rotor 1 of the rotating electric machine 100 according to Embodiment 2 of the present invention. FIG. 11A is a front view of the rotor 1 as in FIG. 7A, and is a diagram illustrating a portion corresponding to two poles of the rotor 1 as in FIG. In FIG. 11A, the cover 11 is not shown so that the position of the protrusion 10 can be seen. FIG. 11B is a cross-sectional view of the rotor 1 along a cutting line AA in FIG. 11A, as in FIG. 7B. FIG. 11B shows a portion radially outward from the shaft 8.

  In the rotating electric machine 100 according to the present embodiment, the rotor 1 includes the T-shaped protrusion 10. The protrusion 10 has a T-shape including a portion protruding radially outward and a portion 10g extending in the axial direction. The portion 10g extending in the axial direction is located radially outward from the radially outer end surface 5a of the permanent magnet 5, and extends to both sides in the axial direction including the radially outer end surface 10a of the protrusion 10. It is.

  The protrusion 10 is provided between the permanent magnets 5 adjacent to each other in the circumferential direction. However, since the protrusion 10 does not include a portion extending in the circumferential direction, the protrusion 10 does not cover the permanent magnet 5 and the amount of leakage magnetic flux flowing through the protrusion 10 is reduced. Few. For this reason, the rotor 1 can reduce the magnetic flux leakage from the permanent magnet 5 and can also suppress the torque ripple.

  Further, since the protrusion 10 has a T-shape including a portion 10g extending in the axial direction, the protrusion 10 can contact the cover 11 at the portion 10g extending in the axial direction, and the contact area with the cover 11 increases. I do. For this reason, the cover 11 can be stably installed in close contact with the rotor 1, and the reliability of the rotor 1 can be improved.

  12A and 12B are views showing the rotor 1 of the rotary electric machine 100 according to Embodiment 3 of the present invention. FIG. 12A is a front view of the rotor 1 as in FIG. 7A, and is a diagram illustrating a portion corresponding to two poles of the rotor 1 as in FIG. 2. FIG. 12A does not show the cover 11 so that the position of the protrusion 10 can be seen. FIG. 12B is a cross-sectional view of the rotor 1 along a cutting line AA in FIG. 12A, as in FIG. 7B. FIG. 12B shows a portion radially outward from the shaft 8.

  In the rotating electric machine 100 according to the present embodiment, the protrusion 10 is configured by the screw 14 provided on the rotor core 3. The screw 14 may be formed of a magnetic material or a non-magnetic material. When the screw 14 is formed of a non-magnetic material such as stainless steel, the rotor 1 can eliminate the magnetic flux leakage from the permanent magnet 5 due to the screw 14 (projection 10), and further suppress the torque ripple. can do.

  FIG. 13 is a cross-sectional view of a rotating electric machine 100 according to Embodiment 4 of the present invention along the axial direction. FIG. 13 shows a portion above the shaft 8 that is the rotating shaft of the rotating electric machine 100.

  The rotating electric machine 100 includes a rotor 1, a stator 2, a frame 15, an end bracket 16, a bearing 17, and a fan 18. The frame 15 and the end bracket 16 are installed outside the rotor 1 and the stator 2. The rotor 1 includes a shaft 8, a rotor core 3, and a permanent magnet 5, and is supported by a bearing 17 and rotates. The stator 2 includes a stator core 4 and a coil 6 and is fastened to a frame 15. A gap 7 is provided between the rotor 1 and the stator 2. The fan 18 is a cooling fan that allows the coolant 20 to flow in the axial direction, and is provided on one end of the rotating electric machine 100 in the axial direction, that is, on one end bracket 16 in the axial direction.

  The rotor 1 includes a protrusion 10 that protrudes radially outward on the surface of the rotor core 3. The protrusion 10 includes a cover 11 that covers the permanent magnet 5 on a radially outer end surface 10a. A gap 19 is formed between the cover 11 and the permanent magnet 5 in the radial direction.

  The radial position of the fan 18 will be described. The portions that generate heat due to the loss of the rotating electric machine 100 are the stator core 4 and the coil 6 of the stator 2 and the permanent magnet 5 of the rotor 1. In the rotating electric machine 100 according to the present embodiment, since the air gap 19 is provided between the cover 11 and the permanent magnet 5, the radial position of the fan 18 is a position axially opposed to the air gap 19, that is, It is a position that is easy to flow. The radial position of the fan 18 is preferably a position where the air gap 19 exists within a range occupied by the fan 18 in the radial direction. If the position of the fan 18 in the radial direction is such a position, the coolant 20 can be positively flowed into the gap 19 by the fan 18, so that the temperature of the permanent magnet 5 can be effectively reduced.

  Since the rotating electric machine 100 according to the present embodiment can effectively lower the temperature of the permanent magnet 5, it is possible to suppress a decrease in the amount of magnetic flux of the permanent magnet 5 due to a rise in temperature, and to suppress a decrease in the torque of the rotating electric machine 100.

  In a rotating electric machine having no gap 19 between the cover 11 and the permanent magnet 5 (for example, a rotating electric machine in which the gap 19 is filled with a filling member), the cooling medium 20 does not flow through the permanent magnet 5 by the fan 18. The fan 18 may be installed at the radially outermost position so as to actively cool the stator 2.

  FIG. 14 is a cross-sectional view illustrating two poles of the rotor 1 of the rotary electric machine 100 according to Embodiment 5 of the present invention. The cover 11 is provided on a radially outer end face 10 a of the protrusion 10 at a position to cover the permanent magnet 5. In the rotating electric machine 100 according to the present embodiment, the cover 11 is further in contact with a radially outer end face 5 a of the permanent magnet 5. The cover 11 can restrict the radial movement of the permanent magnet 5 by contacting the permanent magnet 5, and can prevent the permanent magnet 5 from coming off the rotor core 3. Preferably, the cover 11 contacts the permanent magnet 5 at a position where stress is not applied to the permanent magnet 5 as much as possible.

  FIG. 15 is a cross-sectional view illustrating two poles of the rotor 1 of the rotary electric machine 100 according to Embodiment 6 of the present invention. The rotating electric machine 100 according to the present embodiment includes a filling member 21 between the cover 11 and the permanent magnet 5, and a gap 19 between the cover 11 and the permanent magnet 5 is filled with the filling member 21. The filling member 21 is made of a material softer than the permanent magnet 5, and is preferably made of, for example, a resin, rubber, or silicon member. The permanent magnet 5 is made of metal.

  By providing the filling member 21 between the cover 11 and the permanent magnet 5, the radial movement of the permanent magnet 5 can be restrained, and the permanent magnet 5 can be prevented from coming off the rotor core 3. Further, since the filling member 21 is softer than the permanent magnet 5, when a stress is generated between the permanent magnet 5 and the filling member 21, the filling member 21 is deformed or broken not in the permanent magnet 5 but in the permanent magnet 5. Can be prevented from being damaged.

  In a seventh embodiment of the present invention, an example is shown in which the rotating electric machine 100 according to the first to sixth embodiments of the present invention is applied to an elevator hoist system. In the elevator hoist system according to the present embodiment, the torque ripple of the rotating electric machine 100 can be suppressed, and the cover 11 for preventing the fragments of the permanent magnet 5 of the rotor 1 from scattering is applied without applying stress to the permanent magnet 5. 100 can be installed.

  FIG. 16 is a diagram showing an elevator hoist system according to a seventh embodiment of the present invention. The elevator hoist system according to the present embodiment includes a rotating electric machine 100, a hoist 22, and a coupling 23. The rotating electric machine 100 is the rotating electric machine 100 according to any one of the first to sixth embodiments. The hoist 22 includes a sheave. The rotating electric machine 100 is connected to a sheave of the hoist 22 via a coupling 23 and drives the hoist 22. In the rotating electric machine 100 shown in FIG. 16, the bearings 17 that support the shaft 8 are provided at both ends of the rotating electric machine 100 in the axial direction.

  FIG. 17 is a diagram showing another elevator hoist system according to the seventh embodiment of the present invention. The rotating electric machine 100 is connected to a sheave of the hoisting machine 22 via a coupling 23 to drive the hoisting machine 22, but the bearing 17 is provided only at one end in the axial direction. That is, the rotating electric machine 100 shown in FIG. 17 does not include the bearing 17 on the side closer to the hoist 22 in the axial direction, but includes only the bearing 17 on the side farther from the hoist 22. The elevator hoist system shown in FIG. 17 has a structure in which the hoist 22 supports one end of the rotating electric machine 100 in the axial direction. With such a structure, the size (length in the axial direction) of the elevator hoist system can be reduced. In addition, since the bearing 17 is not provided at one end in the axial direction, the effect of reducing the number of components of the rotating electric machine 100 can be obtained.

  It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible. For example, the above embodiments have been described in detail in order to explain the present invention in an easily understandable manner, and the present invention is not necessarily limited to an embodiment having all the configurations described above. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Further, it is possible to add the configuration of another embodiment to the configuration of one embodiment. Further, a part of the configuration of each embodiment can be deleted, or another configuration can be added or replaced.

  DESCRIPTION OF SYMBOLS 1 ... Rotor, 2 ... Stator, 3 ... Rotor iron core, 4 ... Stator iron core, 5 ... Permanent magnet, 5a ... Radially outer end face of permanent magnet, 5b ... Peripheral end face of permanent magnet, 6 ... Coil, 7: gap, 8: shaft, 10: protrusion, 10a: radial end face of the protrusion, 10b: circumferential end face of the protrusion, 10c: part of the protrusion having a long circumferential length, 10d: a portion in which the circumferential length of the protrusion is short; 10e: a portion in which the circumferential end face of the protrusion contacts the permanent magnet; 10f: a tapered portion of the protrusion; 10g: extending in the axial direction of the protrusion. Part, 11 ... cover, 12 ... D-shaped permanent magnet, 13 ... tile-shaped permanent magnet, 14 ... screw, 15 ... frame, 16 ... end bracket, 17 ... bearing, 18 ... fan, 19 ... void, 20 ... Refrigerant, 21 filling member, 22 hoisting machine, 23 coupling, 100 rotating electric machine

Claims (10)

A rotor comprising a rotor core, a plurality of permanent magnets provided along a circumferential direction on a surface portion of the rotor core, and a shaft which is a rotating shaft extending in an axial direction.
A stator provided radially outside the rotor,
With
The rotor includes a protrusion that protrudes radially outward between the permanent magnets that are adjacent to each other in a circumferential direction on a surface of the rotor core,
The protrusion has a radially outer end face located radially outward from a radially outer end face of the permanent magnet, and a part of a circumferential end face is at least a circumferential end face of the permanent magnet. Touching part,
The protrusion does not include a portion extending in the circumferential direction on a radially outer side than a radially outer end face of the permanent magnet,
A rotating electric machine characterized by the above-mentioned. The protrusion has a curved outer end surface in the radial direction,
The rotating electric machine according to claim 1. The permanent magnet has a rectangular parallelepiped shape,
The rotating electric machine according to claim 1. The rotor includes a plurality of the protrusions along an axial direction,
The rotating electric machine according to claim 1. The protrusion includes a portion extending in the axial direction on a radially outer side than an end surface on a radially outer side of the permanent magnet,
The rotating electric machine according to claim 4. The protrusion is configured by a screw provided on the rotor core,
The rotating electric machine according to claim 4. Equipped with a fan for flowing the refrigerant along the axial direction,
The protrusion includes a cover that covers the permanent magnet on a radially outer end surface,
In the fan, a radial position is a position axially opposed to a gap between the cover and the permanent magnet,
The rotating electric machine according to claim 1. The protrusion includes a cover that covers the permanent magnet on a radially outer end surface,
The cover is in contact with the permanent magnet;
The rotating electric machine according to claim 1. The protrusion includes a cover that covers the permanent magnet on a radially outer end surface,
A filling member is provided in a gap between the cover and the permanent magnet,
The rotating electric machine according to claim 1. A hoist equipped with a sheave,
A rotating electric machine connected to the sheave,
With
The rotating electric machine is the rotating electric machine according to any one of claims 1 to 9,
A hoist system for elevators, characterized in that:

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