JP2017112705A - Permanent magnet type rotating electrical machine and manufacturing method thereof - Google Patents

Abstract

[PROBLEMS] To provide a configuration in which two outermost magnet slots are communicated with an outer peripheral surface of a rotor core through a communication path, which achieves both reduction of leakage magnetic flux and improvement of anti-centrifugal force without causing a large amount of windage loss. An adopted permanent magnet type rotating electrical machine and a method for manufacturing the same are provided. In a permanent magnet type rotating electrical machine 1, a rotor core 21 includes a plurality of magnet slots 23 arranged side by side per one magnetic pole 22 and two outermost magnet slots 23 on the outer periphery of the rotor core 21. And two communication passages 27 communicating with the surface 21a. Protruding portions 29a and 29b that narrow the width of each communicating passage 27 are formed in each of the two communicating passages 27, and part or all of the protruding portions 29a and 29b are nonmagnetic portions. [Selection] Figure 2

Description

  The present invention relates to a permanent magnet type rotating electrical machine and a method for manufacturing the same.

Permanent magnet type rotating electrical machines are known to have higher torque and higher efficiency than induction machines, and their applications are expanding in recent years. Among permanent magnet type rotating electric machines, electric motors used as main machines of EVs (Electric Vehicles) and HEVs (Hybrid Electric Vehicles) are increasingly used in a high-speed rotation region in order to obtain a small size and a large output.
When a permanent magnet type rotating electrical machine is used in a high-speed rotation range of, for example, about 20000 rpm, the first problem is damage to the rotor.

  In the case of a surface magnet type rotating electrical machine, it is common to attach a permanent magnet to the rotor core with an adhesive. However, the adhesive alone cannot withstand centrifugal force, and the permanent magnet may peel off. High nature. In view of this, a reinforcing method of winding a bind around the outer periphery of the magnet has been considered. However, when the binding is wound around the outer periphery of the magnet, the magnetic circuit gap widens and the torque decreases.

  On the other hand, in the case of an embedded magnet type rotating electrical machine, the permanent magnet is disposed in a magnet slot formed inside the rotor core. Generally, a rotor core of an embedded magnet type rotating electrical machine has a plurality of magnet slots per pole, and a permanent magnet is disposed in each magnet slot. The rotor core includes an outer peripheral edge portion formed on the outer side of the magnet slot and a core portion formed on the inner side of the magnet slot. The outer peripheral edge and the core have one or more center bridges formed between adjacent magnet slots, and two side bridges formed at the edges of the two endmost magnet slots opposite to the center bridge And connected. For this reason, in a permanent magnet type rotating electrical machine, the permanent magnet disposed in the magnet slot is supported by the center bridge and the side bridge. It can be said that it is more suitable than a surface magnet type rotating electrical machine.

  Here, in order to withstand the strong centrifugal force generated in a rotating machine with a high speed and a large diameter, the centrifugal force is dispersed not only by the two side bridges per pole as described above but also by one or more center bridges. And it is necessary to make it the structure which can endure centrifugal force by making the width | variety of each bridge wide. If the number of bridges is increased or the width is increased in this way, the magnetic flux from the permanent magnet leaks through each bridge, and high torque cannot be easily achieved. That is, it is one of the problems of the high speed rotating embedded magnet type rotating electrical machine to achieve both reduction of magnetic flux leakage and improvement of anti-centrifugal force in each bridge.

  In order to solve this problem, Patent Document 1 adopts a configuration that eliminates the side bridge to solve the above-described problem. That is, the two endmost magnet slots communicate with the outer peripheral surface of the rotor core through the communication path, and the outer peripheral edge and the core are connected by only one center bridge. In this way, when the two endmost magnet slots are communicated with the outer peripheral surface of the rotor core through the communication passages, the portions of the communication passages become air and the relative permeability becomes 1, so that the magnetic flux leakage in the bridge is prevented. Can be reduced. In addition, when the two most end magnet slots are communicated with the outer peripheral surface of the rotor core through the communication path, the anti-centrifugal force can be improved. This means that the permanent magnet must be supported only by the center bridge, so it seems contradictory at first, but it can be explained as follows.

  Generally, the rotor core and the shaft are fixed by shrink fitting. When shrink fitting is performed, tensile stress is generated in the circumferential direction inside the rotor core. Since the centrifugal force generated during high-speed rotation is added to the tensile stress generated by shrink fitting, the sum of the centrifugal force and tensile stress generated by shrink fitting should be designed not to exceed the rotor core strength limit. There is a need. Moreover, if the shrink fit size is set large so that it can withstand high-speed rotation, the tensile stress increases accordingly. However, when the two outermost magnet slots are communicated with the outer peripheral surface of the rotor core through the communication passages, the outer peripheral edge formed on the outer side of the magnet slot has a part of the circumference around the rotation axis. Since it is cut, it can be deformed, and stress due to shrink fitting can be released. That is, since tensile stress due to shrink fitting hardly occurs outside the magnet slot, it is only necessary to withstand only the centrifugal force. For this reason, if the two endmost magnet slots are communicated with the outer peripheral surface of the rotor core through the communication path, the strength problem can be solved.

  As described above, the permanent magnet type rotating electrical machine of the embedded magnet type adopting the configuration in which the side bridge is eliminated and adopting the configuration in which the two endmost magnet slots are communicated with the outer peripheral surface of the rotor core through the communication path, respectively. It can be said that it is suitable for rotating applications.

International Publication No. 2014/122947

However, a configuration in which the side bridge is eliminated, such as the permanent magnet type rotating electrical machine shown in the conventional patent document 1, and the configuration in which the two endmost magnet slots are communicated with the outer peripheral surface of the rotor core through the communication path, respectively. The embedded magnet type permanent magnet type rotating electrical machine employed has the following problems.
That is, in an embedded magnet type permanent magnet type rotating electrical machine employing such a configuration, the width of each communication path needs to be relatively large in order to sufficiently reduce the leakage flux. This is because if the width of each communication path is narrow, the magnetic resistance of the air portion having a relative permeability of 1 in each communication path does not increase so much, and eventually the magnetic flux leaks.

  On the other hand, if the width of each communication path is large, there arises a problem that excessive windage loss occurs during high-speed rotation. Wind loss is a mechanical loss caused by air flow or friction generated between the stator and the rotor when the rotor rotates in the vicinity of the gap between the rotor and the stator. It increases in proportion to the fourth power. For this reason, wind loss hardly poses a problem in a general industrial low-speed rotary motor, whereas in many cases, for example, a high-speed rotary motor of about 20000 rpm cannot ignore the influence of wind loss. Further, if the gap between the rotor and the stator does not have a perfect circular double cylinder structure, turbulent flow occurs and windage loss further increases. When the windage loss increases, not only the efficiency decreases, but also overheating of the gap portion may cause a failure due to dielectric breakdown or demagnetization of the permanent magnet.

  Therefore, the present invention has been made to solve this conventional problem, and its purpose is to achieve both reduction of leakage flux and improvement of centrifugal resistance without generating a large amount of windage loss. It is an object of the present invention to provide a permanent magnet type rotating electrical machine that employs a configuration in which two end magnet slots communicate with the outer peripheral surface of a rotor core through a communication path, and a manufacturing method thereof.

  In order to achieve the above object, a permanent magnet type rotating electrical machine according to an aspect of the present invention includes a cylindrical stator core having an inner peripheral surface formed in a cylindrical shape and a plurality of teeth provided in the stator core. A stator having a plurality of windings wound around each of the stator core, and a rotor that is rotatably disposed opposite to the inner periphery of the stator core with a predetermined gap therebetween. The rotor is a rotor core having an outer peripheral surface formed in a cylindrical shape and rotatably disposed on the inner peripheral side of the stator core, and a plurality of magnet slots arranged side by side per magnetic pole, An outer peripheral edge portion formed on the outer side of the magnet slot, a core portion formed on the inner side of the plurality of magnet slots, and one formed between adjacent magnet slots and connecting the outer peripheral edge portion and the core portion. Or front multiple center bridges and two extreme magnet slots A rotor core having two communication passages communicating with the outer peripheral surface of the rotor core, a plurality of permanent magnets disposed in each of the plurality of magnet slots, and a shaft fixed to the rotor core And a projecting portion that narrows the width of each communicating passage is formed in each of the two communicating passages, and a part or all of the projecting portion is a non-magnetic portion.

  In addition, a method of manufacturing a permanent magnet type rotating electrical machine according to another aspect of the present invention includes a step of forming a cylindrical stator core having an inner peripheral surface formed in a cylindrical shape, and the stator core. A step of winding a plurality of windings around each of a plurality of teeth, a rotor core having an outer peripheral surface formed in a cylindrical shape, a plurality of magnet slots arranged side by side per magnetic pole, and a plurality of An outer peripheral edge formed on the outer side of the magnet slot; a core formed on the inner side of the plurality of magnet slots; and one or more formed between adjacent magnet slots and connecting the outer peripheral edge and the core. A plurality of center bridges, two communication paths for communicating the two endmost magnet slots with the outer peripheral surface of the rotor core, and the width of each communication path formed in each of the two communication paths is narrowed Forming a rotor core with protrusions A step of fixing the shaft to the rotor core and a step of rotatably disposing the rotor core on an inner peripheral side of the stator core, and the step of forming the rotor core includes a plurality of plate members A plate material preparing step for preparing the plurality of plate materials, and a circular outer peripheral surface for each of the plurality of plate materials, a hole into which the shaft is fitted, a hole in which the plurality of magnet slots are formed, and the two communication paths A plate material processing step for forming a hole for forming the protruding portion in each, and a plurality of non-magnetic portions are formed by demagnetizing part or all of the portion corresponding to the protruding portion of each of the plurality of plate materials A demagnetizing step, a hole into which the shaft is fitted, a hole in which the plurality of magnet slots are formed, and a hole that forms the protrusion in each of the two communication paths in the stacking direction. To align , And summarized in that comprising a plate laminating step of fixing by lamination.

  According to the permanent magnet type rotating electrical machine and the manufacturing method thereof according to the present invention, the two endmost magnet slots that rotate both the reduction of leakage flux and the improvement of the centrifugal force without causing a large amount of windage loss are rotated. It is possible to provide a permanent magnet type rotating electrical machine that employs a configuration in which the outer core of the child core is communicated with each other through a communication path, and a manufacturing method thereof.

It is sectional drawing which shows schematic structure of the permanent magnet type rotary electric machine which concerns on one Embodiment of this invention. It is sectional drawing of the part of one magnetic pole of the rotor in the permanent magnet type rotary electric machine shown in FIG. It is sectional drawing of the part of one magnetic pole of the rotor in the modification of the permanent magnet type rotary electric machine shown in FIG. It is sectional drawing of the part of one magnetic pole of the rotor in the permanent magnet type rotary electric machine which concerns on a 1st reference example. It is sectional drawing of the part of one magnetic pole of the rotor in the permanent magnet type rotary electric machine which concerns on a 2nd reference example.

Embodiments of the present invention will be described below with reference to the drawings.
A permanent magnet type rotating electrical machine according to an embodiment of the present invention is shown in FIG. 1, and the permanent magnet type rotating electrical machine 1 is an embedded magnet type synchronous motor having 4 poles and 24 slots. Note that the present invention is not limited by the number of magnetic poles, the number of slots, the dimensions of other parts, and the like.
As shown in FIG. 1, the permanent magnet type rotating electrical machine 1 includes a stator 10 and a rotor 20 that is rotatably disposed opposite to the inner peripheral side of the stator 10 with a predetermined gap G therebetween. I have.

  Here, the stator 10 includes a cylindrical frame 2 and a cylindrical stator core 11 in which an inner peripheral surface 11 a disposed on the inner peripheral side of the frame 2 is formed in a cylindrical shape. On the inner peripheral surface 11a side of the stator core 11, 24 slots 12 and 24 teeth 13 formed at equal intervals in the circumferential direction are formed. A winding 14 wound in the slot 12 is wound around each tooth 13.

Further, the rotor 20 is formed of a laminated core, and a cylindrical rotor core 21 having an outer peripheral surface 21a formed in a cylindrical shape, and four rotor cores 21 provided at equal intervals in the circumferential direction. And a magnetic pole 22. The rotor 20 is rotated by the shaft 3 that is fitted and fixed to the center of the rotor core 21.
As shown in FIG. 2, the rotor core 21 has two magnet slots 23, an outer peripheral edge 24 formed outside the two magnet slots 23, and an inner side of the two magnet slots 23. And a center bridge 26 formed between adjacent magnet slots 23 and connecting the outer peripheral edge 24 and the core 25. The two magnet slots 23 are two magnet slots 23 having a center C2 on the line L1 connecting the center C2 between the two magnet slots 23 and the center C1 of the rotor core 21 (core portion 25). Are arranged side by side so that the center line L2 in the width direction is vertical. Each magnet slot 23 is formed by a substantially rectangular through-hole penetrating to both ends of the rotor core 21 in the axial direction.

  A rectangular parallelepiped permanent magnet 28 is arranged and fixed in each magnet slot 23. Accordingly, two permanent magnets 28 are arranged side by side in the form of the two magnet slots 23 described above per one magnetic pole 22. The magnetic poles of the two permanent magnets 28 are arranged to be different from the magnetic poles of the permanent magnets 28 in the adjacent magnetic poles 22.

  Further, in the rotor core 21, two communication passages 27 are formed to communicate the two endmost magnet slots 23 (only two magnet slots in the present embodiment) with the outer peripheral surface 21 a of the rotor core 21. ing. That is, the communication path 27 that extends upward from the end opposite to the center bridge 26 of one magnet slot 23 (upper left in FIG. 2) and communicates with the outer peripheral surface 21a of the rotor core 21, and the other ( In FIG. 2, a communication passage 27 extending rightward from the end opposite to the center bridge 26 of the magnet slot 23 on the lower right side) and communicating with the outer peripheral surface 21 a of the rotor core 21 is formed. Each communication passage 27 penetrates to both ends of the rotor core 21 in the axial direction. Each communication passage 27 extends linearly from the end of each magnet slot 23 opposite to the center bridge 26 toward the outer peripheral surface 21a of the rotor core 21, and includes a pair of protrusions 29a and 29b described later. The width H when not formed is slightly smaller than the width H1 of each magnet slot 23.

  As shown in FIG. 2, each communication passage 27 is formed with a pair of protrusions 29 a and 29 b facing each other so as to narrow the width H of each communication passage 27 described above. The pair of projecting portions 29a and 29b project from both wall portions of the communication passage 27 and extend along the direction in which the communication passage 27 extends, and the width h between the pair of projecting portions 29a and 29b facing each other is a pair of projections. It is narrower than the width H of the communication passage 27 when the portions 29a and 29b are not formed. That is, the width h between the pair of protrusions 29a and 29b facing each other is significantly smaller than the width H1 of each magnet slot 23. Here, the pair of projecting portions 29 a and 29 b facing each other project in a rectangular shape as viewed from above from the wall surface of the rotor core 21 constituting both wall portions of the communication passage 27, and extend in a direction along the communication passage 27. The length is substantially the same as the length of the communication path 27. Each protrusion 29a, 29b extends to both ends of the rotor core 21 in the axial direction.

  Thus, by forming a pair of protrusions 29a and 29b facing each other so as to narrow the width H of each communication path 27 in each communication path 27, the width H of each communication path 27 is not reduced. Windage loss can be reduced. Further, by forming a pair of protrusions 29a and 29b facing each other so as to narrow the width H of each communication path 27 in each communication path 27, the outer peripheral surface 21a of the rotor core 21 is made to be a pair of protrusions 29a. , 29b can be made closer to a perfect circle than when not formed, and the gap G portion of the rotor core 21 and the stator core 11 can be brought closer to a double-cylindrical structure of perfect circles. Winding loss can be prevented from increasing as much as possible.

  A part or all of at least one of the pair of protrusions 29a and 29b is a non-magnetic part made non-magnetic. By forming a pair of projecting portions 29a and 29b facing each other so as to narrow the width H of each communication path 27 in each communication path 27, the width H of each communication path 27 becomes narrower, and the air in each communication path 27 Since the width of the portion having the relative magnetic permeability 1 becomes narrow, the leakage of magnetic flux from each permanent magnet 28 becomes larger than when the width H of each communication path 27 is not reduced. However, since part or all of at least one of the pair of protrusions 29a and 29b is a non-magnetic part, the amount of magnetic flux leaking from each permanent magnet 28 via the pair of protrusions 29a and 29b can be reduced. it can. For this reason, magnetic flux leakage can be reduced equivalent to the case where the width H of each communication path 27 is not reduced. From the viewpoint of avoiding magnetic flux leakage, it is preferable that both of the pair of protruding portions 29a and 29b are all non-magnetic portions.

Here, the meaning of “non-magnetic” that defines the non-magnetic portion includes all of paramagnetism, diamagnetism and antiferromagnetism, and also includes so-called weak magnetism.
Since each communication path 27 remains even if the width of each communication path 27 is narrowed, the outer peripheral edge 24 formed outside the two magnet slots 23 is centered on the center C1 of the rotor core 21. Since the outer peripheral surface 21a is partially cut, it can be deformed, and stress due to shrink fitting of the shaft 3 can be released. For this reason, the strength problem in the rotor core 21 can be solved.

Therefore, according to the permanent magnet type rotating electrical machine 1 according to the present embodiment, the two endmost magnet slots 23 that achieve both reduction of leakage magnetic flux and improvement of centrifugal resistance without generating a large amount of windage loss. It is possible to provide the permanent magnet type rotating electrical machine 1 adopting a configuration in which the outer circumferential surface 21a of the rotor core 21 is communicated with each other through the communication passage 27.
Next, a modification of the permanent magnet type rotating electrical machine according to an embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view of one magnetic pole portion of the rotor in a modification of the permanent magnet type rotating electrical machine shown in FIG. 3, the same members as those shown in FIG. 2 are denoted by the same reference numerals, and the description thereof may be omitted.

  In the modification of the permanent magnet type rotating electrical machine shown in FIG. 3, as in the permanent magnet type rotating electrical machine shown in FIG. 1, in the rotor core 21, the two outermost magnet slots 23 are arranged on the outer peripheral surface of the rotor core 21. Two communication passages 27 are formed to communicate with 21a. That is, the communication path 27 that extends upward from the end opposite to the center bridge 26 of one magnet slot 23 (upper left in FIG. 3) and communicates with the outer peripheral surface 21a of the rotor core 21, and the other ( In FIG. 3, a communication passage 27 extending rightward from the end opposite to the center bridge 26 of the magnet slot 23 (below right) in FIG. 3 and communicating with the outer peripheral surface 21 a of the rotor core 21 is formed. Each communication passage 27 penetrates to both ends of the rotor core 21 in the axial direction. Each communication passage 27 extends linearly from the end of each magnet slot 23 on the side opposite to the center bridge 26 toward the outer peripheral surface 21a of the rotor core 21, and does not form one protrusion 29a described later. The width H in the state is slightly smaller than the width H1 of each magnet slot 23.

  In addition, unlike each permanent magnet type rotating electrical machine 1 shown in FIG. 1, each communication passage 27 is formed with one protrusion 29 a that narrows the width H of each communication passage 27 described above, as shown in FIG. 3. . The protruding portion 29a protrudes from one wall portion of the communication passage 27 and extends along the direction in which the communication passage 27 extends, and the width h between the protruding portion 29a and the opposing wall portion of the communication passage 27 is one. It is narrower than the width H of the communication passage 27 when the protruding portion 29a is not formed. That is, the width h between the protruding portion 29 a and the wall portion of the communication path 27 is significantly smaller than the width H <b> 1 of each magnet slot 23. Here, the protrusion 29a protrudes in a rectangular shape when viewed from above from the wall surface of the rotor core 21 constituting one wall portion of the communication path 27, and the length in the direction along the communication path 27 is the communication path It is almost the same as the length of 27. Further, the protruding portion 29 a extends to both ends of the rotor core 21 in the axial direction. Note that the width h between the projecting portion 29a and the wall portion of the communication passage 27 in the present modification is substantially the same as the width h between the pair of projecting portions 29a and 29b facing each other shown in FIG.

  In this way, by forming the protruding portion 29a that narrows the width H of each communication path 27 in each communication path 27, the windage loss can be reduced as compared with the case where the width H of each communication path 27 is not narrowed. Further, by forming the protrusions 29a that narrow the width H of each communication passage 27 in each communication passage 27, the outer peripheral surface 21a of the rotor core 21 is made closer to a perfect circle than when the protrusion 29a is not formed. The gap G between the rotor core 21 and the stator core 11 can be brought close to a double-cylindrical structure of perfect circles, and generation of turbulence can be suppressed as much as possible to prevent an increase in windage loss. .

  And a part or all of the protrusion part 29a is a non-magnetic part made non-magnetic. By forming a protruding portion 29 a that narrows the width H of each communication passage 27 in each communication passage 27, the width H of each communication passage 27 is reduced, and the relative permeability 1 portion of the air portion of each communication passage 27 is reduced. Since the width becomes narrower, the leakage of magnetic flux from each permanent magnet 28 becomes larger than when the width H of each communication path 27 is not reduced. However, since some or all of the protrusions 29a are non-magnetic parts, the amount of magnetic flux leaking from each permanent magnet 28 through the protrusions 29a can be reduced. For this reason, magnetic flux leakage can be reduced equivalent to the case where the width H of each communication path 27 is not reduced. From the viewpoint of avoiding magnetic flux leakage, it is preferable that all of the protruding portions 29a are nonmagnetic portions.

  Since each communication path 27 remains even if the width of each communication path 27 is narrowed, the outer peripheral edge 24 formed outside the two magnet slots 23 is centered on the center C1 of the rotor core 21. Since the outer peripheral surface 21a is partially cut, it can be deformed, and stress due to shrink fitting of the shaft 3 can be released. For this reason, the strength problem in the rotor core 21 can be solved.

Therefore, according to the permanent magnet type rotating electrical machine according to the present modification, the two endmost magnet slots 23 that rotate both the reduction of leakage magnetic flux and the improvement of the centrifugal resistance without causing a large amount of windage loss are rotated. It is possible to provide the permanent magnet type rotating electrical machine 1 adopting a configuration in which the outer peripheral surface 21a of the child core 21 is communicated with each other through the communication passage 27.
Here, the permanent magnet type rotating electrical machine according to the first reference example will be described with reference to FIG.

  As shown in FIG. 4, the rotor core 21 in the permanent magnet type rotating electrical machine according to the first reference example has two magnet slots 23 and outer portions formed outside the two magnet slots 23, as shown in FIG. 4. A peripheral portion 24, a core portion 25 provided inside the two magnet slots 23, and a center bridge 26 formed between the adjacent magnet slots 23 and connecting the outer peripheral edge portion 24 and the core portion 25 are provided. The two magnet slots 23 are two magnet slots 23 having a center C2 on the line L1 connecting the center C2 between the two magnet slots 23 and the center C1 of the rotor core 21 (core portion 25). Are arranged side by side so that the center line L2 in the width direction is vertical. Each magnet slot 23 is formed by a substantially rectangular through-hole penetrating to both ends of the rotor core 21 in the axial direction.

  A rectangular parallelepiped permanent magnet 28 is arranged and fixed in each magnet slot 23. Accordingly, two permanent magnets 28 are arranged side by side in the form of the two magnet slots 23 described above per one magnetic pole 22. The magnetic poles of the two permanent magnets 28 are arranged to be different from the magnetic poles of the permanent magnets 28 in the adjacent magnetic poles 22.

  On the other hand, in the case of the permanent magnet type rotating electrical machine according to the first reference example, unlike the permanent magnet type rotating electrical machine of the present embodiment, the rotor core 21 has two magnet slots 23 (the first reference example of the first reference example). In this case, only two magnet slots) are not formed to communicate with the outer peripheral surface 21a of the rotor core 21, respectively, and the center bridge 26 of one magnet slot 23 (upper left in FIG. 4) is formed. A side bridge 30 that connects the outer peripheral edge portion 24 and the core portion 25 is provided at the opposite end to the center bridge 26 of the other (slightly lower right in FIG. 4) end opposite to the center bridge 26. The side bridge 30 which connects the outer periphery part 24 and the core part 25 is also provided in the part.

Thus, in the case of the permanent magnet type rotating electrical machine according to the first reference example, the permanent magnet 28 disposed in the magnet slot 23 is supported by the center bridge 26 and the side bridge 30, so that it rotates at high speed. In addition, it can withstand the strong centrifugal force generated by a large-diameter rotating electrical machine.
However, there is a problem that the magnetic flux from each permanent magnet 28 leaks through the side bridge 30.

On the other hand, in the case of the permanent magnet type rotating electrical machine according to the second reference example shown in FIG. 5, the problem that the magnetic flux from each permanent magnet 28 leaks through the side bridge portion can be solved.
That is, the rotor core 21 in the permanent magnet type rotating electrical machine according to the second reference example is formed on the outer side of the two magnet slots 23 and the two magnet slots 23 as shown in FIG. The outer peripheral edge 24, a core 25 provided inside the two magnet slots 23, and a center bridge 26 formed between the adjacent magnet slots 23 and connecting the outer peripheral edge 24 and the core 25. Yes. The two magnet slots 23 are two magnet slots 23 having a center C2 on the line L1 connecting the center C2 between the two magnet slots 23 and the center C1 of the rotor core 21 (core portion 25). Are arranged side by side so that the center line L2 in the width direction is vertical. Each magnet slot 23 is formed by a substantially rectangular through-hole penetrating to both ends of the rotor core 21 in the axial direction.

  A rectangular parallelepiped permanent magnet 28 is arranged and fixed in each magnet slot 23. Accordingly, two permanent magnets 28 are arranged side by side in the form of the two magnet slots 23 described above per one magnetic pole 22. The magnetic poles of the two permanent magnets 28 are arranged to be different from the magnetic poles of the permanent magnets 28 in the adjacent magnetic poles 22.

  Further, in the rotor core 21, two communication paths 27 are formed to communicate the two endmost magnet slots 23 (only two magnet slots in the second reference example) with the outer peripheral surface 21 a of the rotor core 21. Has been. That is, the communication path 27 that extends upward from the end opposite to the center bridge 26 of one magnet slot 23 (upper left in FIG. 5) and communicates with the outer peripheral surface 21a of the rotor core 21, and the other ( In FIG. 5, a communication passage 27 is formed extending rightward from the end opposite to the center bridge 26 of the magnet slot 23 (lower right in FIG. 5) and communicating with the outer peripheral surface 21 a of the rotor core 21. Each communication passage 27 penetrates to both ends of the rotor core 21 in the axial direction. Each communication path 27 extends linearly from the end of each magnet slot 23 opposite to the center bridge 26 toward the outer peripheral surface 21 a of the rotor core 21, and its width H is equal to the width of each magnet slot 23. It is slightly smaller than the width H1.

  As described above, in the case of the permanent magnet type rotating electrical machine according to the second reference example, in the rotor core 21, the two communication paths 27 that respectively connect the two endmost magnet slots 23 to the outer peripheral surface 21 a of the rotor core 21. Is formed. The width H of each communication passage 27 is formed to be slightly smaller than the width H1 of each magnet slot 23. For this reason, since the portion of each communication path 27 becomes air and the relative permeability becomes 1, magnetic flux leakage in the side bridge can be reduced.

  However, in the case of the permanent magnet type rotating electrical machine according to the second reference example, the width H of each communication passage 27 is large (as compared to the case of the present embodiment, the pair of protrusions 29a and 29b are not formed). As compared with the modified example, it is large because one projecting portion 29a is not formed), and there is a problem that excessive windage loss occurs during high-speed rotation. Further, since the gap portion between the rotor core 21 and the stator core does not have a perfect circular double cylindrical structure due to the presence of the communication path 27, there is a problem that turbulence occurs and windage loss further increases. .

  On the other hand, in the case of the permanent magnet type rotating electrical machine of this embodiment and the permanent magnet type rotating electrical machine of the modified example, a pair of projecting portions facing each other so as to narrow the width H of each communicating path 27 in each communicating path 27. By forming one protrusion 29a that narrows the width H of each communication path 27 in 29a and 29b or in each communication path 27, the wind loss can be reduced as compared with the case where H of each communication path 27 is not narrowed. Can do. Further, each communication passage 27 is provided with a pair of protrusions 29a and 29b facing each other so as to narrow the width H of each communication passage 27, or one protrusion that narrows the width H of each communication passage 27 in each communication passage 27. By forming the portion 29a, the outer peripheral surface 21a of the rotor core 21 can be made closer to a perfect circle than a pair of protrusions 29a and 29b or a case where one protrusion 29a is not formed. The portion of the gap G between 21 and the stator core 11 can be brought close to a double-cylindrical structure of perfect circles, and generation of turbulence can be suppressed as much as possible to prevent an increase in windage loss.

  Further, in the case of the permanent magnet type rotating electrical machine of the present embodiment, at least one part or all of the pair of projecting portions 29a and 29b is a non-magnetic portion, which is a modified permanent magnet type. In the case of a rotating electrical machine, a part or all of one projecting portion 29a is a non-magnetic portion made non-magnetic. For this reason, the amount of magnetic flux leaking from each permanent magnet 28 via the pair of protrusions 29a, 29b or one protrusion 29a can be reduced. Thereby, magnetic flux leakage can be reduced equivalent to the case where the width of each communication path 27 is not narrowed.

Next, a method for manufacturing the permanent magnet type rotating electrical machine 1 according to this embodiment shown in FIG. 1 will be described.
When manufacturing the permanent magnet type rotating electrical machine 1, first, the stator 10 is manufactured.
The manufacturing process of the stator 10 includes a process of forming a cylindrical stator core 11 in which the inner peripheral surface 11a is formed in a cylindrical shape (stator core forming process), and a plurality of teeth provided on the stator core 11. 13 includes a step of winding a plurality of windings 14 around each of them (winding winding step).

  Here, in the stator core forming step, a plate material made of a soft magnetic material is pressed into a predetermined two-dimensional shape having a portion for forming a plurality of teeth 13 and punched, and a necessary number of sheets are stacked and crimped. Fix in the stacking direction by welding. Thereby, the stator core 11 is formed. Examples of the plate material made of a soft magnetic material include a non-oriented electrical steel sheet. When forming the stator core 11, the soft magnetic ferrite material may be pressed into a predetermined three-dimensional shape and sintered.

In the winding winding step, a material having conductivity and having an insulated surface is prepared as a material for the winding 14. For example, a generally used magnet wire is suitable as the material of the winding 14. The winding method of the winding 14 is the distributed winding method in the case of 24 slots shown in FIG.
Then, after the winding winding step, the stator core 11 is fixed by the frame 2. Thus, the stator 10 is manufactured.

Next, the rotor 20 is manufactured.
The manufacturing process of the rotor 20 includes a process of forming the rotor core 21 (rotor core forming process) and a process of fixing the shaft 3 to the rotor core 21 (shaft fixing process).
The rotor core forming step is a rotor core 21 having an outer peripheral surface 21a formed in a cylindrical shape, and is arranged outside two magnet slots 23 and two magnet slots 23 arranged side by side per one magnetic pole 22. One center bridge formed between the outer peripheral edge 24 and the core 25, formed between the adjacent outer periphery 24 and the core 25 formed between the two magnet slots 23 and the adjacent magnet slot 23. The rotor core 21 is formed with the two communication paths 27 that communicate the outermost two magnet slots 23 with the outer peripheral surface 21 a of the rotor core 21.
And in this rotor core formation process, while making the outer peripheral surface circular with respect to each of the process (plate material preparation process) of preparing a plurality of plate materials (not shown) and the plurality of plate materials, the shaft 3 A step of forming a hole to be fitted, a hole in which two magnet slots 23 are formed, and a hole for forming a pair of projecting portions 29a and 29b in each of the two communication paths 27 (plate material processing step), and each of the plurality of plate materials Forming a plurality of nonmagnetic portions by demagnetizing at least one part or all of the portions corresponding to the pair of projecting portions 29a, 29b, and a plurality of plate members, A hole into which the shaft 3 is fitted, a hole in which a plurality of (two in the present embodiment) magnet slots 23 are formed, and a hole in which a pair of protrusions 29a and 29b are formed in each of the two communication paths 27 are laminated. Align in direction In so that, and a step (plate laminating step) for fixing stacked.

  Here, in the plate material preparation step, a plurality of plate materials made of martensitic stainless material that is a material of the rotor core 21 are prepared. As the plate material, a silicon steel plate can be used in addition to the martensitic stainless material. However, in the case of using a silicon steel plate, it is necessary to use a modifying substance when performing the demagnetization process. The plate thickness of the plate material is preferably reduced to about 0.35 mm to 0.65 mm from the viewpoint of reducing eddy current loss. The stainless steel material has an insulating layer on the surface, so that insulation between the plates can be obtained to some extent. However, in order to reliably reduce eddy current loss, the surface may be coated with an inorganic or organic insulating coating. Martensitic stainless steel has a relatively high soft magnetic property when used in an annealed state in which a carbide is dispersed in a ferrite phase, and can contribute to an increase in torque of a rotating electrical machine.

  Next, in the plate material processing step, for each of the plurality of plate materials, the outer peripheral surface to be the outer peripheral surface 21a of the rotor core 21 is made circular, and a hole into which the shaft 3 is fitted and two magnet slots 23 are formed. And a hole for forming a pair of projecting portions 29a and 29b is formed in each of the two communicating paths 27 described above. Examples of the processing of the plate material include wire cutting in addition to punching with a press. About the hole which forms a pair of protrusion part 29a, 29b in each of the two communicating paths 27, the space | interval between a pair of protrusion part 29a, 29b is made as narrow as possible so that it may not make a turbulent flow of air at the time of rotation. It is preferable to do. However, if it is too narrow, the pair of protrusions 29a and 29b may come into contact with each other due to slight deformation during the shrink fitting of the shaft 3 or the demagnetization process. The interval between 29b is ideally about 1-2 mm, for example. Further, the outer peripheral surface of each processed plate material may not be a perfect circle, but a perfect circle or a shape close to a perfect circle is preferable from the viewpoint of reducing windage loss as much as possible.

  Next, in the demagnetization step, at least one part or all of the portions corresponding to the pair of protrusions 29a and 29b of each of the plurality of plate members subjected to the above-described processing is demagnetized to obtain a plurality of A nonmagnetic part is formed. This non-magnetization method is most preferably laser irradiation from the viewpoint of simplicity and the like, but any method can be used as long as it can be locally heated and rapidly cooled. The case where laser irradiation is performed will be described below. Further, although the effect of the present invention can be obtained even with weak magnetism in which part of the magnetism remains after laser irradiation, it is preferable to perform demagnetization to sufficiently lose magnetism by adjusting the laser irradiation time.

  The portions to be demagnetized are part or all of at least one of the portions corresponding to the pair of protrusions 29a and 29b in each plate member. From the viewpoint of avoiding magnetic flux leakage, it is preferable that both of the portions corresponding to the pair of projecting portions 29a and 29b are nonmagnetic portions, but the magnetic resistance in each communication path 27 can be sufficiently increased. For example, in each plate member, only one or all of the portions corresponding to the pair of protrusions 29a and 29b may be demagnetized. Moreover, when irradiating a laser, it may irradiate to the part which demagnetizes at once, and you may scan a laser with a small spot. Further, the rapid cooling after the laser irradiation may be air cooling, but water cooling or oil cooling may be performed as necessary. Further, when a silicon steel plate is used as a material for the plate material of the rotor core 21, it is necessary to apply a modifying material such as Cr or C in order to stabilize the nonmagnetic austenite phase. Specifically, these substances may be applied to the surface of the plate material before laser irradiation. However, in this case, in order to allow the modifying substance to penetrate into the plate material during laser irradiation, it is preferable that at least the laser irradiation portion is not provided with an insulating coating.

  Next, in the plate material laminating step, a plurality of plate materials subjected to the demagnetization described above are paired into a hole into which the shaft 3 is fitted, a hole in which the two magnet slots 23 are formed, and the two communication paths 27. The holes forming the portions 29a and 29b are stacked and fixed so that the holes are aligned in the stacking direction. Bonding of the laminated plate materials can be performed by caulking or welding. Thereby, the rotor core 21 is manufactured.

  In the shaft fixing step performed thereafter, the shaft 3 is fixed to the hole of the rotor core 21 into which the shaft 3 is fitted. At this time, the shaft 3 is fixed to the rotor core 21 by shrink fitting. Moreover, after fixing the shaft 3 to the rotor core 21, the permanent magnet 28 is inserted in each magnet slot 23, and the permanent magnet 28 is fixed with an adhesive agent. Then, the permanent magnet 28 is magnetized. Thereby, the rotor 20 is manufactured.

Finally, when the rotor 20 is manufactured, the rotor core 21 is rotatably arranged inside the stator core 11 via a bearing (not shown) (rotor core arranging step). Thereby, the permanent magnet type rotary electric machine 1 is manufactured.
In the case of the permanent magnet type rotating electrical machine according to the modification shown in FIG. 3, in the plate material processing step, the outer peripheral surface to be the outer peripheral surface 21 a of the rotor core 21 is circular with respect to each of the plurality of plate materials. At the same time, a hole into which the shaft 3 is fitted, a hole in which the two magnet slots 23 are formed, and a hole for forming one protruding portion 29a are formed in each of the two communication paths 27 described above. In the demagnetization step, a part or all of the portions corresponding to the protruding portions 29a of the plurality of plate members are demagnetized to form a plurality of nonmagnetic portions. The other manufacturing steps are the same as the manufacturing method of the permanent magnet type rotating electrical machine 1 according to this embodiment shown in FIG.

  As described above, according to the permanent magnet type rotating electrical machine 1 according to the present embodiment, the permanent magnet type rotating electrical machine according to the modification, and the manufacturing method thereof, it is possible to reduce the leakage magnetic flux without generating a large amount of windage loss. A permanent magnet type rotating electrical machine 1 adopting a configuration in which the two endmost magnet slots 23 are communicated with the outer peripheral surface 21a of the rotor core 21 through the communication passages 27, which achieves both improved centrifugal resistance, and a manufacturing method thereof. Can be provided.

  Further, demagnetization performed on at least one part or all of the parts corresponding to the pair of protrusions 29a and 29b of each of the plurality of plate members and part of the part corresponding to the protrusions 29a of each of the plurality of plate members. Alternatively, the demagnetization performed on the entire surface is performed by locally heating the portion to be demagnetized by laser irradiation and rapidly cooling the portion. As a result, local demagnetization can be easily achieved by irradiating only the portion where demagnetization is desired. In general, there is a technique such as high-frequency heating for local demagnetization of the iron core, but a complicated structure in which the side bridge is separated, that is, the width of each communication path 27 is narrowed to each communication path 27. Where a pair of projecting portions 29a and 29b facing each other is formed or a structure in which each projecting passage 29 is formed with one projecting portion 29a that narrows the width of each communicating passage 27 is desired to be demagnetized. It is difficult to concentrate the current by high-frequency heating only.

  Further, a martensitic stainless material is used as each material of the plurality of plate members constituting the rotor core 21. Since martensitic stainless steel is austenitic by simply heating and quenching, the magnetism can be lost or weakened relatively easily. As described above, when a silicon steel plate or the like is used as a material for a plurality of plate members constituting the rotor core 21, a modifying material such as Cr or C is applied to achieve demagnetization. This is necessary and the demagnetization process becomes complicated. In addition, since martensitic stainless steel material contains a large amount of Cr, the electrical resistance is high, and when the plate thickness is equal, eddy current loss characteristics comparable to the electromagnetic steel plate are exhibited. Among them, it also has a characteristic required for a portion that is not demagnetized.

As mentioned above, although embodiment of this invention has been described, this invention is not limited to this, A various change and improvement can be performed.
For example, the projecting portion that narrows the width of each communication passage 27 is a pair of projecting portions 29a and 29b facing each other so as to narrow the width H of each communication passage 27 shown in FIG. 2 or the width of each communication passage 27 shown in FIG. The number is not limited as long as the width of each communication passage 27 is narrowed. And the one part or all part of the protrusion part which narrows the width | variety of each communicating path 27 should just be a nonmagnetic part.

In addition, although the rotor core 21 has two magnet slots 23 arranged side by side with respect to one magnetic pole 22, three or more magnet slots 23 may be arranged side by side. In this case, there are two or more center bridges 26 between adjacent magnet slots 23.
In addition, in the case described above, a part or all of one center bridge 26 may be a non-magnetic part. Thereby, the magnetic flux leakage from each permanent magnet 28 via the center bridge 26 can be suppressed, and the torque can be further increased.

  In the case where a part or all of one or a plurality of center bridges 26 are made nonmagnetic portions, in the above-described demagnetization step, each of the plurality of plate members corresponds to the pair of protrusions 29a and 29b. In addition to demagnetizing at least one part or all of the portions, if part or all of the portions corresponding to one or a plurality of center bridges 26 of each of the plurality of plate members are demagnetized. Good.

DESCRIPTION OF SYMBOLS 1 Permanent-magnet-type rotary electric machine 2 Frame 3 Shaft 10 Stator 11 Stator core 11a Inner peripheral surface 13 Teeth 14 Winding 20 Rotor 21 Rotor core 21a Outer peripheral surface 22 Magnetic pole 23 Magnet slot 24 Outer peripheral part 25 Core part 26 Center Bridge 27 Communication path 28 Permanent magnet 29a, 29b Protrusion G gap

Claims (8)

A stator having a cylindrical stator core having an inner peripheral surface formed in a cylindrical shape, a plurality of windings wound around each of a plurality of teeth provided on the stator core, and the stator core A rotor disposed on the inner peripheral side of the rotor so as to be opposed to and spaced apart from a predetermined gap,
The rotor is a rotor core having an outer peripheral surface formed in a cylindrical shape and rotatably disposed on the inner peripheral side of the stator core, and a plurality of magnet slots arranged side by side per magnetic pole; The outer peripheral edge formed on the outer side of the plurality of magnet slots, the core formed on the inner side of the plurality of magnet slots, and formed between adjacent magnet slots, and connects the outer peripheral edge and the core. In each of the plurality of magnet slots, one or a plurality of center bridges and two communication paths that respectively connect the two endmost magnet slots to the outer peripheral surface of the rotor core. A plurality of permanent magnets arranged, and a shaft fixed to the rotor core,
A permanent magnet type rotating electrical machine characterized in that each of the two communication paths is formed with a protrusion that narrows the width of each communication path, and a part or all of the protrusion is a non-magnetic part.   The protrusion is composed of a pair of protrusions facing each other so as to narrow the width of each communication path, and at least one part or all of the pair of protrusions is the non-magnetic part. The permanent magnet type rotating electrical machine according to claim 1, wherein   The permanent magnet type rotating electrical machine according to claim 1 or 2, wherein a part or all of the one or more center bridges are nonmagnetic portions. A step of forming a cylindrical stator core having an inner peripheral surface formed in a cylindrical shape, a step of winding a plurality of windings around each of a plurality of teeth provided on the stator core, and an outer peripheral surface A rotor core formed in a cylindrical shape, with a plurality of magnet slots arranged side by side per magnetic pole, an outer peripheral edge formed outside the plurality of magnet slots, and inside the plurality of magnet slots One or a plurality of center bridges that are formed between the formed core portion and adjacent magnet slots and connect the outer peripheral edge portion and the core portion, and two outermost magnet slots are arranged on the outer periphery of the rotor core. Forming a rotor core having two communication passages respectively communicating with the surface, and a projecting portion formed in each of the two communication passages to narrow the width of each communication passage; Fixing the shaft, and the rotor core And a step of rotatably disposed on the inner peripheral side of the stator core,
The step of forming the rotor core includes a plate material preparation step of preparing a plurality of plate materials, a circular outer peripheral surface for each of the plurality of plate materials, a hole into which the shaft is fitted, and the plurality of magnets A plate material processing step of forming a hole for forming a slot and a hole for forming the protruding portion in each of the two communication paths, and a part or all of a portion corresponding to the protruding portion of each of the plurality of plate materials A demagnetization step of forming a plurality of nonmagnetic portions by demagnetization, a plurality of plate members, a hole into which the shaft is fitted, a hole in which the plurality of magnet slots are formed, and the two communication paths A method of manufacturing a permanent magnet type rotating electrical machine, comprising: a plate material laminating step of laminating and fixing each of the holes forming the protruding portions so as to be aligned in the laminating direction.   The projecting portion is composed of a pair of projecting portions facing each other so as to narrow the width of each communication path. In the plate material processing step, each of the two communication paths is provided for each of the plurality of plate materials. In the demagnetization step, at least one part or all of the portions corresponding to the pair of projections of each of the plurality of plate members is demagnetized. The method of manufacturing a permanent magnet type rotating electrical machine according to claim 4, wherein:   6. The demagnetization step includes demagnetizing a part or all of a portion corresponding to the one or the plurality of center bridges of each of the plurality of plate members. Manufacturing method for permanent magnet type rotating electrical machines.   The permanent magnetizing according to any one of claims 4 to 6, wherein the demagnetization is performed by locally heating the portion to be demagnetized by laser irradiation and rapidly cooling the portion. A manufacturing method of a magnet type rotating electrical machine. The method for manufacturing a permanent magnet type rotating electrical machine according to any one of claims 4 to 7, wherein a martensitic stainless material is used as a material of each of the plurality of plate members.

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