JP2013115899A - Rotor of permanent magnet type motor, manufacturing method of the same, and permanent magnet type motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor of a permanent magnet type motor which effectively utilizes magnetic flux generated from permanent magnets without deteriorating the efficiency of the permanent magnet type motor thereby achieving further streamlining and improving the reliability of the mechanical strength during high-speed operation.SOLUTION: A rotor 100 has a first yoke part 1 formed by laminating multiple magnetic steel sheets and disposed at the center side of the rotor; multiple permanent magnets 2 disposed at the outer peripheral side of the first yoke part 1; a second yoke part 3 formed by laminating multiple magnetic steel sheets and disposed at the outer peripheral side of the permanent magnets 2; and a ring part 4 provided at the outer peripheral side of the second yoke part 3 and pressing the first yoke part 1, the permanent magnets 2, and the second yoke part 3 from the outer peripheral side of the second yoke part 3 to the rotor center side.

Description

  The present invention relates to a rotor of a permanent magnet type electric motor used for a compressor, a fan motor, and the like, a manufacturing method thereof, and a permanent magnet type electric motor.

  Permanent magnet type electric motors that have existed in recent years are efficiently constructed by laminating electromagnetic steel plates that are integrally punched by a press or the like to form a rotor core and embedding permanent magnets in the core. Are often adopted. Such an electric motor is generally called IPM. In addition, there is also a permanent magnet type electric motor configured by a surface arrangement type in which a permanent magnet is fixed to the outside of a laminated polygonal core by some method. Such an electric motor is generally called SPM.

  Particularly in recent years, there has been a demand for higher output of electric motors for the purpose of reducing the size and weight of on-board equipment as well as high efficiency. The output can be realized by adopting a high magnetic flux density magnet such as a rare earth magnet to cope with a high torque, or by dealing with a high rotational speed by expanding a variable speed range by a frequency converter.

  Various types of rotor cores have been proposed to deal with such a background (see, for example, Patent Document 1). In Patent Document 1, protrusions are projected radially from the apexes of a rotor core having a polygonal plane shape, permanent magnets having a substantially bowl-shaped cross section are arranged, and a nonmagnetic sleeve is fitted on the outer periphery of the permanent magnet. A permanent magnet type electric motor is disclosed. As the nonmagnetic sleeve, it is disclosed that a stainless steel tube of SUS304 is adopted as an example of a metal sleeve. Further, it is disclosed that a ferrite magnet is employed as the magnet.

  And it is disclosed that reluctance torque that cannot be expected with the conventional SPM type magnet arrangement can be generated by the radial projections from the rotor core, and the efficiency can be improved. In addition, when an SPM type metal sleeve is used, an eddy current loss occurs in the metal sleeve, and therefore it is disclosed that a boost chopper circuit or the like is used as a countermeasure.

  Further, in the case of a rotor core of an IPM type electric motor, leakage of magnetic flux generated by the magnet increases due to the presence of the iron core portion on the side surface of the magnet and the iron core portion on the outer periphery of the magnet, and the efficiency of the motor decreases. For this reason, it is disclosed that leakage of magnetic flux of the magnet can be reduced and reduction in efficiency can be avoided by keeping only the radial protrusions as the iron core on the side surface of the magnet.

Japanese Patent Laid-Open No. 11-299150 (2-4 pages, FIG. 1)

  In the permanent magnet electric motor described in Patent Document 1, when a metal sleeve is used as the non-magnetic sleeve, there is a restriction on the drive waveform side such as an expensive step-up chopper circuit to reduce eddy current loss in the sleeve. Must be turned on. Even if the harmonic component of the drive waveform can be reduced, it is impossible to eliminate the fundamental wave that motivates the rotation, and the eddy current due to the fundamental wave cannot be reduced.

  In particular, in order to achieve high-speed operation in the future, it is conceivable to increase the thickness in the radial direction in order to prevent scattering due to the centrifugal force of the permanent magnet, but by increasing the thickness, the eddy current increases. Become. Moreover, since the frequency of the fundamental wave also increases, there is a concern that eddy current loss will increase dramatically. Needless to say, the problem of eddy current loss also occurs in conventional SPM motors.

  Moreover, in the conventional IPM type motor rotor core, the rotor is formed by the laminated cores to reduce the eddy current. However, the centrifugal force of the permanent magnet or the core itself during high-speed operation can be reduced. In general, the iron core portion on the side surface of the magnet is thick. However, when the iron core on the side surface of the magnet is thickened, the leakage of magnetic flux generated by the magnet is increased. As a countermeasure, a shape that is easy to leak magnetic flux is selected for the minimum necessary thickness, that is, one corresponding to high speed, and the efficiency of the electric motor is reduced.

  In the case of an IPM type electric motor, since a magnet can be embedded inside, the rotor circuit can have a saliency and a reluctance torque can be used as the magnetic circuit as described above. However, in the electric motor described in Patent Document 1, the shape of the rotor core is a polygon, and protrusions are provided radially from each vertex of the rotor core, and magnetic flux passes through these protrusions to produce saliency. However, considering the leakage of magnetic flux of the magnet, the circumferential thickness of the protrusion can only be increased to a certain extent. For this reason, the electric motor described in Patent Document 1 cannot completely eliminate the problems of the IPM type electric motor.

  Moreover, when manufacturing the shape of the rotor core as described in Patent Document 1 by punching, the strip-shaped electromagnetic steel sheet is punched, but since there is a protruding portion, the rotation of the strip-shaped electromagnetic steel sheet Many unnecessary parts that do not become the child's iron core occur. Therefore, the shape of the rotor core as described in Patent Document 1 has room for improvement from the viewpoint of so-called yield deterioration. Yield deterioration is also a problem in terms of resource saving and cost reduction.

  The present invention has been made to solve the above-described problems, and leads to further increase in efficiency by effectively using magnetic flux generated from the permanent magnet without reducing the efficiency of the permanent magnet motor. An object of the present invention is to provide a rotor of a permanent magnet type electric motor and a permanent magnet type electric motor with improved reliability of mechanical strength at high speed operation. It is another object of the present invention to provide a method for manufacturing a rotor of a permanent magnet type electric motor having a high yield.

  A rotor of a permanent magnet electric motor according to the present invention is a first permanent magnet electric motor rotor that rotates in synchronization with a change in rotating magnetic flux of a stator, and is a first in which a plurality of electromagnetic steel plates are laminated on the center side of the rotor. A yoke portion, a plurality of permanent magnets arranged on the outer periphery of the first yoke portion, a second yoke portion in which a plurality of electromagnetic steel plates are laminated on the outer periphery of the permanent magnet, and the second yoke And a ring portion that presses the first yoke portion, the permanent magnet, and the second yoke portion from the outer periphery side to the center side of the second yoke portion.

  A method of manufacturing a rotor of a permanent magnet type electric motor according to the present invention is a method of manufacturing a rotor of the above permanent magnet type electric motor, the step of magnetizing the permanent magnet, and the magnetizing permanent magnet, A step of pasting the first yoke portion to the predetermined magnetic pole direction, a step of pasting the second yoke portion to the outer peripheral side of the permanent magnet, and an outer periphery formed by the second yoke portion. A step of selecting the ring portion having an inner diameter that becomes a predetermined tightening allowance after grasping the dimensions, and press-fitting the ring portion from the outer peripheral side of the second yoke portion.

  A permanent magnet type electric motor according to the present invention is a stator in which the rotor of the above permanent magnet type electric motor is disposed on the outer peripheral surface side of the rotor, and a multi-phase stator winding is mounted on the stator core. And.

  According to the rotor of the electric motor according to the present invention, the effective use of the reluctance torque, which is an advantage of the conventional rotor (particularly, the IPM type electric motor), can be realized by eliminating the leakage magnetic flux of the permanent magnet, which was a drawback. I have to. In addition, according to the rotor of the electric motor according to the present invention, the strength of the conventional rotor (especially the SPM type electric motor), which is an advantage of high-speed operation, is ensured, and the eddy current loss of the ring portion, which has been a drawback, is reduced. Occurrence can also be improved.

  According to the method of manufacturing a rotor of a permanent magnet type electric motor according to the present invention, since the attractive force of the magnetized permanent magnet can be used, the members are in close contact with each other, and the second yoke It becomes easy to grasp the outer peripheral dimensions made by the part. Further, according to the method for manufacturing a rotor of an electric motor according to the present invention, each member tries to be magnetically stable, so that positioning of each yoke portion and the permanent magnet can be performed with high accuracy.

  According to the permanent magnet type electric motor according to the present invention, since the rotor is provided, the same effect as that of the rotor is obtained.

It is the schematic for demonstrating the rotor of the electric motor which concerns on Embodiment 1 of this invention. It is a top view which shows roughly another example of the planar shape of the rotor of the electric motor which concerns on Embodiment 1 of this invention. It is explanatory drawing for demonstrating the magnetic flux of the conventional rotor. It is explanatory drawing for demonstrating the separation distance of the 1st yoke part of the rotor of the electric motor which concerns on Embodiment 1 of this invention, and a 2nd yoke part. It is the schematic which shows a part of manufacturing process of the rotor structure steel plate which comprises the rotor iron core of the rotor of the electric motor which concerns on Embodiment 1 of this invention. It is a side view which shows roughly an example of the side surface shape of the rotor of the electric motor which concerns on Embodiment 2 of this invention. It is a side view which shows roughly an example of the side surface shape of the rotor of the electric motor which concerns on Embodiment 3 of this invention. It is a top view which shows roughly an example of the planar shape of the rotor of the electric motor which concerns on Embodiment 4 of this invention. It is a top view which shows roughly an example of the planar shape of the rotor of the electric motor which concerns on Embodiment 5 of this invention. It is a schematic perspective view for demonstrating the manufacturing method of the rotor of the electric motor which concerns on Embodiment 6 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a schematic diagram for explaining a rotor 100 of an electric motor according to Embodiment 1 of the present invention. Based on FIG. 1, the structure of the rotor 100 of an electric motor is demonstrated. 1A is a top view schematically showing a planar shape of the rotor 100, and FIG. 1B is a longitudinal sectional view schematically showing a longitudinal section of the rotor 100. FIG. Moreover, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one. Further, in FIG. 1, the magnetic flux generated from the permanent magnet 2 is indicated by arrows (arrow A, arrow B).

  The rotor 100 is used as a part of a motor of a fan motor such as a compressor or a blower such as a refrigerator, a freezer, a vending machine, an air conditioner, a refrigeration apparatus, a water heater, or the like. The As shown in FIG. 1, the rotor 100 is disposed on a first yoke portion 1 formed by laminating electromagnetic steel plates in the axial direction on the rotation center side, and an outer shell (outer peripheral side) of the first yoke portion 1. A plurality of (four in FIG. 1A) permanent magnets 2 and the same number of second yoke parts as permanent magnets 2 formed by axially laminating electromagnetic steel plates on the outer peripheral side of each permanent magnet 2 3 and a ring portion 4 that is provided on the outer peripheral side of the second yoke portion 3 and includes the first yoke portion 1, the permanent magnet 2, and the second yoke portion 3.

  That is, the first yoke part 1 and the second yoke part 3 constituting the rotor core are not constituted by one electromagnetic steel sheet, but are separated by different electromagnetic steel sheets. is there. Further, a through hole 11 for inserting and fixing a rotation shaft (not shown) is formed at the center of the first yoke portion 1. Further, the first yoke portion 1 has a polygonal planar shape. The production of the first yoke part 1 will be described in detail with reference to FIG.

  The permanent magnet 2 is composed of a rare earth magnet or the like, and is magnetized in the direction indicated by the arrow B in FIG. As shown in FIG. 1 (a), in a state in which the permanent magnet 2 is viewed in plan, a side surface portion (hereinafter simply referred to as a side surface portion 2a) in the short direction of the permanent magnet 2 is the first yoke portion 1 and the second yoke portion. It is not in contact with any of the yoke parts 3. That is, the first yoke portion 1 and the second yoke portion 3 are in contact with the side surface portion in the longitudinal direction of the permanent magnet 2 in a state where the permanent magnet 2 is viewed in plan, but are in contact with the side surface portion 2a. Absent. A space surrounded by a part of the first yoke part 1, a part of the second yoke part 3, the side part 2 a of the permanent magnet, and the inner peripheral wall of the ring part 4 is referred to as an inter-electrode part 5.

  The ring portion 4 presses the first yoke portion 1, the permanent magnet 2, and the second yoke portion 3 from the outer peripheral side of the second yoke portion 3, and constitutes the outer periphery of the rotor 100. That is, the ring part 4 is a thin cylinder that generates an internal pressure that presses the first yoke part 1, the permanent magnet 2, and the second yoke part 3 against the center side of the rotor 100. The iron part 1, the permanent magnet 2 and the second yoke part 3 are configured to be press-fitted or shrink-fitted. By this ring part 4, the 1st yoke part 1, the permanent magnet 2, and the 2nd yoke part 3 are assembled in the state which each contact | adhered without gap.

  Here, the ring portion 4 is assumed to be made of a nonmagnetic material and a nonmetallic material. For example, the ring portion 4 may be composed of engineering plastic (PPS, PEEK, LCP, PBT, bakelite, etc.), carbon fiber, or a composite product thereof.

  The rotor 100 is rotatably arranged on the inner peripheral surface side of a stator (for example, the stator 50 shown in FIG. 4) to constitute an electric motor (permanent magnet type electric motor). That is, the electric motor of the present invention has a predetermined number of permanent magnets 2 in the rotor 100, and the rotor 100 rotates in synchronization with a change in the rotating magnetic flux of the stator. As the rotor 100 rotates, the rotating shaft fixed to the through hole 11 also rotates. 1 shows an example in which four permanent magnets 2 are provided, the number of permanent magnets 2 is not limited to four (described in FIG. 2).

  FIG. 2 is a top view schematically showing another example of the planar shape of rotor 100A of the electric motor according to Embodiment 1 of the present invention. The configuration of the rotor 100A will be described based on FIG. The basic configuration of the rotor 100A is the same as that of the rotor 100 described above, and the same parts are denoted by the same reference numerals and description thereof is omitted.

  The rotor 100A functions in the same manner as the rotor 100, but the number of permanent magnets 2 is different from the number of permanent magnets 2 of the rotor 100. Accordingly, the shapes of the first yoke portion 1 and the second yoke portion 3 also change, so that each member (the first yoke portion 1, the permanent magnet 2, the second yoke) is distinguished from the rotor 100. Part 3) shall be supplemented with the symbol “A”. Note that the ring portion 4 is not changed by the change in the number of the permanent magnets 2, and therefore remains as a “ring portion” and is not appended with “A”.

  Although the case where the rotor 100 is configured using four permanent magnets 2 has been described as an example in FIG. 1, the rotor 100 </ b> A may be configured using six permanent magnets 2 </ b> A as illustrated in FIG. 2. Good. Needless to say, even if the number of permanent magnets 2A is six as in the rotor 100A, the rotor 100A functions in the same manner as the rotor 100. In this case, the planar shapes of the first yoke portion 1A and the second yoke portion 3A are different from the planar shapes of the first yoke portion 1 and the second yoke portion 3 of the rotor 100 accordingly. . However, it is the same that the plane of the 1st yoke part 1A is polygonal. FIG. 2 shows an example in which six permanent magnets 2A are provided, but the number of permanent magnets 2A is not limited to six.

  The rotor 100 is formed of a first yoke part 1, a permanent magnet 2, a second yoke part 3, and a non-magnetic and non-metallic ring part 4. Therefore, as shown by the arrow A in FIG. 1A, the magnetic flux emitted from the magnetic pole surface of the permanent magnet 2 (for example, the N pole of the permanent magnet 2 shown on the upper side of the paper) is the second yoke part 3 (for example, on the upper side of the paper). The second yoke part 3) is passed through the second yoke part 3) and linked to the rotating magnetic field generated by energizing the stator to generate a desired rotational torque. Passes through the iron part 3), enters the magnetic pole face of the adjacent permanent magnet 2 (for example, the S pole of the permanent magnet 2 on the left side of the paper), passes through the first yoke part 1, and returns to its own magnetic pole face (S pole) again. .

  And since the magnetic body used as a magnetic circuit does not exist in the side part 2a of the permanent magnet 2, there is no leakage magnetic flux and the magnetic flux which generate | occur | produces from the permanent magnet 2 can be utilized almost completely. Therefore, a high torque electric motor can be obtained. Alternatively, an equivalent torque can be obtained with a small permanent magnet with a reduced leakage magnetic flux compared to a conventional permanent magnet of an IPM type rotor having a leakage magnetic flux. Therefore, with such a configuration, it is possible to realize resource saving and cost reduction of rare earth magnets, which have become a problem in recent years.

  Further, since the ring portion 4 is made of a non-metal, there is no generation of eddy current due to the magnetic flux generated by the stator. Therefore, the problems of the conventional SPM type motor and IPM type motor can be improved without imposing a burden on the frequency control device or the like.

  Furthermore, since the stress is generated in the ring portion 4 due to the centrifugal force of the permanent magnet 2 and the second yoke portion 3, and the stress is approximately proportional to the square of the rotational speed, it is particularly in an electric motor that is required to operate at high speed. Mechanical strength is required. In that respect, by using a material having high strength, for example, an engineering plastic as the ring portion 4, by increasing the thickness of the conventional SUS304 metal that is about 1/3 the tensile strength, The stress can be suppressed to an equivalent or lower stress.

  That is, when the ring portion 4 is formed of SUS304 and the thickness thereof is increased, the eddy current loss is increased. However, if an engineering plastic having high electrical insulation is used as the constituent material of the ring portion 4, the eddy current is increased. Since there is no loss, it is possible to cope with higher speed without increasing the loss. For example, if a PEEK material containing 30% glass is used as the constituent material of the ring portion 4, the thickness is about 0.6 mm and the strength is equivalent to 0.2 mm SUS304, and the thickness is within the air gap of a normal electric motor. Can be kept in adjustment.

  Further, if carbon fiber or a composite product thereof is used as a constituent material of the ring portion, it has a tensile strength 10 times or more that of conventional metals, and can sufficiently withstand a normally assumed high speed operation of about 300 rps. On the other hand, the volume resistivity is lowered, but the volume resistivity can be adjusted by, for example, coating the fiber product with insulation or reducing the contact surface between the fibers by devising the way of braiding.

  FIG. 3 is an explanatory diagram for explaining the magnetic flux of a conventional rotor. Based on FIG. 3, the magnetic flux of the rotor 100 is demonstrated, comparing with the conventional rotor. FIG. 3A shows a plan view of the rotor described in Patent Document 1, and FIG. 3B shows a plan view of another conventional rotor. Here, unless otherwise specified, the description will be made assuming that the rotor 100 includes the rotor 100A.

  As shown to Fig.3 (a) and FIG.3 (b), the rotor core is comprised with the electromagnetic steel plate. Therefore, the magnetic flux generated from the stator tends to pass through the rotor core. On the other hand, the magnetic flux generated from the stator is difficult to pass through the permanent magnet. The permanent magnet is equivalent to an air gap with respect to the magnetic flux generated from the stator. That is, the magnetic flux easily passes in the direction of the solid arrow shown in FIGS. 3A and 3B, but the magnetic flux hardly passes in the direction of the dotted arrow shown in FIGS. 3A and 3B.

  Since the reluctance torque is generated due to the difference in the ease of passing in the rotational phase, the second yoke portion 3 is also present in the rotor 100 according to the first embodiment, so that the difference can be given, and FIG. As in the conventional rotor shown in a) and FIG. 3B, high efficiency can be achieved. At that time, in the conventional rotor shown in FIGS. 3 (a) and 3 (b), even if the structure for obtaining the reluctance torque is adopted, the permanent magnet has a magnetic core portion and a protruding portion, and therefore the permanent magnet has a magnetic flux. Has caused a short circuit. On the other hand, in the rotor 100, since there is no iron core part and protrusion part which consist of electromagnetic steel plates, a short circuit of a magnetic flux is not caused to a permanent magnet.

  FIG. 4 is an explanatory diagram for explaining a separation distance between the first yoke part 1 and the second yoke part 3. Based on FIG. 4, the separation distance between the first yoke part 1 and the second yoke part 3 will be described. FIG. 4A is a top view schematically showing another example of the planar shape of the rotor 100, and FIG. 4B is a top view schematically showing still another example of the planar shape of the rotor 100. , Respectively. In FIG. 4, a part of the stator 50 is also illustrated on the outer peripheral side of the ring portion 4. In FIG. 4, each member is illustrated using the reference numerals shown in FIG.

  The stator 50 is disposed on the outer peripheral surface side of the rotor 100, and a plurality of phases of stator windings (not shown) are mounted on the stator core. The stator 50 and the rotor 100 constitute a permanent magnet type electric motor.

  As shown to Fig.4 (a), the distance of the outer peripheral side of the 2nd yoke part 3 and the inner peripheral side of the stator 50 acts as a magnetic air gap. This air gap is t1, and the shortest distance between the first yoke part 1 and the second yoke part 3 is t2. A magnet generated magnetic flux line (line A1 shown in FIG. 4) generated from the permanent magnet 2 passes through the second yoke portion 3 as described above, jumps over the air gap t1, and intersects with the rotating magnetic field generated by the stator 50. There is a need. However, if the air gap t1 is too far and the shortest distance t2 between the first yoke part 1 and the second yoke part 3 is short, the first yoke part 1 and the second yoke part 3 will be divided into two. Even if the rotor core is separated, leakage magnetic flux is generated.

  Therefore, the rotor 100 is formed so that the air gap t1 <the shortest distance t2 between the first yoke portion 1 and the second yoke portion 3 in order to reduce the leakage of magnetic flux generated from the permanent magnet 2 as much as possible. Has been. By doing in this way, in the rotor 100, the leakage magnetic flux from the permanent magnet 2 can be reduced as much as possible, and the permanent magnet 2 for generating the leakage magnetic flux becomes unnecessary, and resource saving is achieved compared to the conventional rotor. Can be achieved.

  In addition, the rotor 100 should just be formed so that it may become the shortest distance t2 of the 1st yoke part 1 and the 2nd yoke part 3 in the air gap t1 in the state which looked at the space | interval part 5 in the top view. The planar shape is not particularly limited. In consideration of the assembly process, the rotor 100 may be configured using the second yoke portion 3 having a planar shape as shown in FIG. You may form the 2nd yoke part 3 by the shape (shape which used the circular arc and the string as the side wall) as shown in FIG.4 (b). If it does in this way, the part exposed to the space | interval part 5 of the 2nd yoke part 3 will function as a positioning part with the permanent magnet 2. FIG. Further, if the four corners of the first yoke part 1 (the part exposed at the inter-electrode part 5 of the first yoke part 1) are chamfered as shown in FIGS. 4 (a) and 4 (b). The portion exposed to the inter-pole portion 5 of the first yoke portion 1 also functions as a positioning portion for the permanent magnet 2.

  In addition, although the positioning part with the permanent magnet 2 is not indispensable, if there is a positioning part with the permanent magnet 2, the positioning can be performed with high accuracy, and the effect that the mechanical rotation balance and the magnetic balance can be achieved. Can be obtained. As a result, a motor with low vibration and high efficiency can be obtained.

  Therefore, according to the rotor 100, the effective use of the reluctance torque, which is an advantage of the conventional rotor (especially the IPM type electric motor), can be realized by eliminating the leakage flux of the permanent magnet 2 which has been a drawback. Yes. The rotor 100 also improves the occurrence of eddy current loss in the ring portion 4, which is a drawback, while ensuring strength reliability for high-speed operation, which is an advantage of a conventional rotor (especially an SPM motor). be able to. In addition, although the case where the permanent magnet 2 was flat plate shape was demonstrated to the example in FIG. 1, the shape of the permanent magnet 2 is not specifically limited. For example, the same effect can be obtained even if the permanent magnet 2 is formed in an arc shape, a V shape combining a flat plate shape, or a bathtub shape.

  Here, manufacture of the iron core of a rotor is demonstrated. FIG. 5 schematically shows a part of a manufacturing process of a rotor-constituting steel plate (each electromagnetic steel plate constituting the first yoke part 1 (including the first yoke part 1A)) constituting the rotor core. FIG. FIG. 5A shows a part of the manufacturing process of the rotor constituting steel plate of the rotor 100, FIG. 5B shows a part of the manufacturing process of the rotor constituting steel plate of the rotor 100A, and FIG. Each part of the manufacturing process of the conventional rotor structure steel plate given in literature 1 is shown.

  The rotor core of the rotor 100 is configured by combining a plurality of first yoke portions 1 and second yoke portions 3 in which rotor-constituting steel plates are laminated to a predetermined number or stack thickness. Similarly, the rotor core of the rotor 100A is configured by combining a plurality of first yoke portions 1A and second yoke portions 3A in which rotor-constituting steel plates are laminated to a predetermined number or stack thickness. In FIG. 5, the width of the belt-shaped electromagnetic steel sheet 20 is shown as L, and the feed pitch of the rotor-constituting steel sheets is shown as P.

  As shown in FIG. 5A, since the planar shape of the rotor constituting steel plate of the rotor 100 is substantially square (substantially square), the rotor constituting steel plate is arranged along the longitudinal direction of the belt-like electromagnetic steel plate 20. Arrangement is made to produce a rotor constituting steel plate. By producing the rotor-constituting steel plate in this way, it is possible to minimize the unnecessary portion 21 of the belt-like electromagnetic steel plate 20.

  Further, as shown in FIG. 5B, since the planar shape of the rotor constituting steel plate of the rotor 100A is substantially hexagonal, the rotor constituting steel plate is arranged in a honeycomb shape with respect to the belt-like electromagnetic steel plate 20 and rotated. A child component steel plate is to be produced. By producing the rotor-constituting steel plate in this way, it is possible to minimize the unnecessary portion 21 of the belt-like electromagnetic steel plate 20. When the rotor-constituting steel plates are arranged in a honeycomb shape with respect to the strip-shaped electromagnetic steel plate 20, at least two rows of rotor-constituting steel plates are arranged on the strip-shaped electromagnetic steel plate 20.

  On the other hand, as shown in FIG. 5 (c), the conventional rotor-constituting steel plate has protrusions at the corners, so that the unnecessary portion 21 'of the strip-shaped electromagnetic steel plate 20' increases. In the rotor-constituting steel plate having such a shape, many unnecessary portions 21 ′ that do not become the rotor core are generated regardless of the arrangement of the rotor-constituting steel plate 20 ′.

  As described above, if the first yoke portion 1 of the rotor 100 and the first yoke portion 1A of the rotor 100A are shaped, the unnecessary portion 21 of the strip-shaped electrical steel sheet 20 can be reduced, so that the conventional one is used. In comparison with the above, the rotor-constituting steel plate can be produced with a high yield. In addition, since unnecessary portions 21 can be reduced, resource saving and cost reduction can be realized. Furthermore, since the width L and the feed pitch P of the strip-shaped electrical steel sheet 20 can be shortened, the mold size can be reduced and the cost for the mold can be reduced.

Embodiment 2. FIG.
FIG. 6 is a side view schematically showing an example of a side shape of rotor 100B of the electric motor according to Embodiment 2 of the present invention. Based on FIG. 6, the structure of the rotor 100B of an electric motor is demonstrated. The basic configuration of the rotor 100B of the electric motor according to the second embodiment is the same as that of the rotor 100 described in the first embodiment. In the second embodiment, differences from the first embodiment will be mainly described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.

  As shown in FIG. 6, the rotor 100 </ b> B is different from the ring portion 4 of the rotor 100 according to the first embodiment in the configuration of the ring portion. In addition, in order to distinguish from the ring part 4 of the rotor 100 which concerns on Embodiment 1, the code | symbol "B" shall be appended to the ring part 4. FIG.

  Similar to the rotor 100 according to the first embodiment, the rotor 100B includes a first yoke portion 1 formed by laminating electromagnetic steel plates in the axial direction on the rotation center side, and an outer shell of the first yoke portion 1. A plurality of permanent magnets 2 arranged on the outer circumferential side, and the same number of second yoke parts 3 as the permanent magnets 2 formed by laminating electromagnetic steel sheets in the axial direction on the outer circumferential side of each permanent magnet 2; A ring portion 4B provided on the outer peripheral side of the second yoke portion 3 and including the first yoke portion 1, the permanent magnet 2, and the second yoke portion 3 is provided.

  The ring part 4B presses down the first yoke part 1, the permanent magnet 2 and the second yoke part 3 from the outer periphery side of the second yoke part 3, and constitutes the outer periphery of the rotor 100B. That is, the ring portion 4B has a configuration in which a thin cylinder that generates an internal pressure that presses the first yoke portion 1, the permanent magnet 2, and the second yoke portion 3 toward the radial center is divided into a plurality of portions. In addition, the first yoke part 1, the permanent magnet 2 and the second yoke part 3 are configured to be press-fitted or shrink-fitted. By this ring part 4B, the 1st yoke part 1, the permanent magnet 2, and the 2nd yoke part 3 are each assembled in the state closely_contact | adhered without gap.

  Here, the ring portion 4B is assumed to be made of a nonmagnetic material. And the ring part 4B becomes a structure divided | segmented into plurality by the axial direction via the predetermined clearance gap. In FIG. 6, the divided ring portions 4B are illustrated as a ring portion 4B1, a ring portion 4B2, and a ring portion 4B3 from the lower side of the drawing for the sake of convenience. Further, in FIG. 6, the ring part 4 </ b> B having a structure divided into three parts is illustrated, but the number of divisions of the ring part 4 </ b> B is not limited to the three parts shown in FIG. 6.

  If importance is attached to strength reliability and low-cost materials during high-speed operation, a metal that is a non-magnetic material employed in a conventional SPM type rotor is employed as the ring portion. However, when the ring portion is made of metal, generation of eddy current loss becomes a problem.

  Therefore, in the second embodiment, in consideration of the case where a metal that is a nonmagnetic material is adopted as the ring portion 4B, the ring portion 4B is divided into a plurality of parts. Therefore, a predetermined gap is formed between each of the ring part 4B1, the ring part 4B2, and the ring part 4B3. For this reason, an eddy current loop (arrow C shown in FIG. 6) is generated in each of the ring portion 4B1, the ring portion 4B2, and the ring portion 4B3, and a portion without the ring portion 4B, that is, the ring portion 4B1, the ring portion 4B2, It does not occur in the gap portions formed between the ring portions 4B3. Further, since the eddy current loss generally increases in proportion to the square of the thickness (axial height) l of the ring portion 4B, the eddy current loss can be reduced as l is reduced.

  Since the mechanical strength is the sum in the axial direction of l, the sum Σl corresponding to the required rotational speed is determined, and the number of divisions of the ring portion 4B is determined in consideration of the effect of reducing the eddy current loss and the number of parts. Just decide.

  Therefore, according to the rotor 100B, similar to the rotor 100 according to the first embodiment, the effective use of the reluctance torque, which is an advantage of the conventional rotor (particularly, the IPM motor), has been a disadvantage. This can be realized by eliminating the leakage flux. Further, according to the rotor 100B, similarly to the rotor 100 according to the first embodiment, the strength reliability with respect to high-speed operation, which is an advantage of the conventional rotor (especially the SPM type motor), is ensured and there is a drawback. The occurrence of eddy current loss in the ring portion 4 can also be improved. Furthermore, according to the rotor 100B, it is possible to cope with an eddy current generated in the ring portion 4B without reducing the mechanical strength.

If a ceramic material containing silicon, aluminum, oxygen, and nitrogen is employed as the material of the ring portion 4B, both a non-magnetic material and a light weight and high strength can be ensured. Further, if the material has a volume resistivity of 10 ¹⁰ , preferably 10 ¹⁴ Ωcm or more, it can be considered to have almost no eddy current loss since it has a negligible electric resistance with respect to other electromagnetic steel sheets and permanent magnets. Examples of the material having a volume resistivity of 10 ¹⁴ Ωcm or more include sialon (a material composed of Si (silicon), Al (aluminum), O (oxygen), and N (nitrogen) (chemical formula Si3N4 · Al2O3)).

Embodiment 3 FIG.
FIG. 7 is a side view schematically showing an example of a side shape of rotor 100C of the electric motor according to Embodiment 3 of the present invention. Based on FIG. 7, the structure of the rotor 100C of an electric motor is demonstrated. The basic configuration of rotor 100C of the electric motor according to Embodiment 3 is the same as that of rotor 100 described in Embodiment 1. In the third embodiment, differences from the first and second embodiments will be mainly described, and the same parts as those in the first and second embodiments will be denoted by the same reference numerals and the description thereof will be omitted. It shall be.

  As shown in FIG. 7, the rotor 100C is different in the ring part configuration from the ring part 4 of the rotor 100 according to the first embodiment and the ring part 4B of the rotor 100B according to the second embodiment. In addition, in order to distinguish from the ring part 4 of the rotor 100 which concerns on Embodiment 1, and the ring part 4B of the rotor 100B which concerns on Embodiment 2, the code | symbol "C" shall be appended to the ring part 4. FIG.

  Similar to the rotor 100 according to the first embodiment, the rotor 100C includes a first yoke portion 1 formed by laminating electromagnetic steel plates in the axial direction on the rotation center side, and an outer shell of the first yoke portion 1. A plurality of permanent magnets 2 arranged on the outer circumferential side, and the same number of second yoke parts 3 as the permanent magnets 2 formed by laminating electromagnetic steel sheets in the axial direction on the outer circumferential side of each permanent magnet 2; A ring portion 4 </ b> C that is provided on the outer peripheral side of the second yoke portion 3 and includes the first yoke portion 1, the permanent magnet 2, and the second yoke portion 3.

  The ring part 4C presses the first yoke part 1, the permanent magnet 2 and the second yoke part 3 from the outer periphery side of the second yoke part 3, and constitutes the outer periphery of the rotor 100C. That is, the ring portion 4C has a configuration in which a thin cylinder that generates an internal pressure that presses the first yoke portion 1, the permanent magnet 2, and the second yoke portion 3 toward the radial center is divided into a plurality of portions. In addition, the first yoke part 1, the permanent magnet 2 and the second yoke part 3 are configured to be press-fitted or shrink-fitted. By this ring part 4C, the 1st yoke part 1, the permanent magnet 2, and the 2nd yoke part 3 are each assembled in the state closely_contact | adhered without gap.

  Here, the ring portion 4C is assumed to be made of a non-magnetic material. And the ring part 4C becomes a structure divided | segmented into plurality by the axial direction through the predetermined clearance gap. In FIG. 7, the divided ring portions 4C are illustrated as a ring portion 4C1, a ring portion 4C2, and a ring portion 4C3 from the lower side of the drawing for the sake of convenience. Further, in FIG. 7, the ring part 4 </ b> C having a configuration divided into three parts is illustrated, but the number of divisions of the ring part 4 </ b> C is not limited to the three parts shown in FIG. 7.

  Furthermore, a plurality of slits 4a opened along the radial direction are formed in the ring portion 4C1, the ring portion 4C2, and the ring portion 4C3. And this slit 4a is formed so that a slit opening part (namely, opening part) and a non-opening part (parts other than a slit opening part) may not correspond in an axial direction. That is, the slit 4a is formed so that the non-opening portion cannot advance straight in the rotation axis direction.

  As described in the second embodiment, when importance is attached to strength reliability at high speed operation and inexpensive materials, a metal that is a non-magnetic material adopted in a conventional SPM type rotor is adopted as the ring portion. However, the occurrence of eddy current loss becomes a problem.

  Therefore, in the third embodiment, in consideration of the case where a metal that is a nonmagnetic material is adopted as the ring portion 4C, the ring portion 4C is divided into a plurality of parts. Accordingly, a predetermined gap is formed between each of the ring part 4C1, the ring part 4C2, and the ring part 4C3. For this reason, an eddy current loop (arrow D shown in the ring part 4C3 in FIG. 7) is generated in each of the ring part 4C1, the ring part 4C2, and the ring part 4C3, and the part without the ring part 4C, that is, the ring part 4C1, It does not occur in the gaps formed between the ring part 4C2 and the ring part 4C3.

  In addition, in the third embodiment, a plurality of slits 4a are formed in each of the ring part 4C1, the ring part 4C2, and the ring part 4C3. Therefore, the eddy current loop generated in the ring portion 4C is generated in each of the ring portion 4C1, the ring portion 4C2, and the ring portion 4C3 as shown by the arrow D in FIG. This is equivalent to a reduced thickness (axial height), and eddy current loss can be reduced.

  Further, no eddy current is generated in the portion where the ring portion 4C is not provided. Furthermore, if the longitudinal direction of the slit 4a extends in parallel with the circumferential direction, it is not necessary to relatively increase the stress against the centrifugal force generated in the radial direction. Therefore, in the rotor 100C according to the third embodiment, the same effect as that described in the second embodiment can be realized without increasing the number of parts without reducing the mechanical strength.

  Therefore, according to the rotor 100C, similar to the rotor 100 according to the first embodiment, the effective use of the reluctance torque, which is an advantage of the conventional rotor (particularly, the IPM type electric motor), has been a drawback. This can be realized by eliminating the leakage flux. Further, according to the rotor 100C, similarly to the rotor 100 according to the first embodiment, the strength reliability with respect to high-speed operation, which is an advantage of the conventional rotor (especially, the SPM type motor), is ensured, which is a drawback. The occurrence of eddy current loss in the ring portion 4 can also be improved. Furthermore, according to the rotor 100C, it is possible to cope with an eddy current generated in the ring portion 4C without increasing the number of parts and without reducing the mechanical strength as in the rotor 100B according to the second embodiment. .

  The slit 4a is not particularly limited as long as the slit opening portion and the non-opening portion do not coincide with each other in the axial direction. For example, the slits 4a may be regularly formed as shown in FIG. 7, but the slits 4a may be irregularly formed. Further, the slit 4a may be formed to have an opening simulating a labyrinth structure so that the slit opening portion and the non-opening portion do not coincide with each other in the axial direction.

Embodiment 4 FIG.
FIG. 8 is a top view schematically showing an example of a planar shape of rotor 100D of the electric motor according to Embodiment 4 of the present invention. Based on FIG. 8, the structure of the rotor 100D of an electric motor is demonstrated. The basic configuration of rotor 100D of the electric motor according to the fourth embodiment is the same as that of rotor 100 described in the first embodiment. In the fourth embodiment, differences from the first to third embodiments will be mainly described, and the same parts as those in the first to third embodiments will be denoted by the same reference numerals and the description thereof will be omitted. It shall be.

  As shown in FIG. 8, the rotor 100 </ b> D includes a second yoke portion 3 (including the second yoke portion 3 </ b> A) of the rotor according to the first to third embodiments. ) Is different. In addition, in order to distinguish from the 2nd yoke part 3, the code | symbol "D" shall be appended to the 2nd yoke part 3. FIG.

  Similar to the rotor 100 according to the first embodiment, the rotor 100D includes a first yoke portion 1 formed by laminating electromagnetic steel plates in the axial direction on the rotation center side, and an outer shell of the first yoke portion 1. A plurality of permanent magnets 2 arranged on the outer peripheral side, and the same number of second yoke parts 3D as the permanent magnets 2 formed by laminating electromagnetic steel plates in the axial direction on the outer peripheral side of each permanent magnet 2; The ring portion 4 is provided on the outer peripheral side of the second yoke portion 3D and includes the first yoke portion 1, the permanent magnet 2, and the second yoke portion 3D. Instead of the ring part 4, a ring part 4B or a ring part 4C may be adopted.

  Two rows of slit grooves 3a that open in the axial direction are formed in the second yoke portion 3D. The slit groove 3a is formed in an arc shape as a part of a circle having a center on the outer peripheral side of the rotor 100D.

  As described in the first embodiment, by providing the second yoke portion 3, it is possible to generate a direction in which the magnetic flux easily passes and a direction in which it is difficult to pass, thereby generating reluctance torque. . Therefore, in the fourth embodiment, by forming the slit groove 3a in the second yoke portion 3D, the slit groove 3a acts less in the direction of magnetic flux as a magnetic resistance (FIG. 8). The solid arrow shown in FIG. 8) acts as an air gap in the direction in which it is difficult to pass, and controls the magnetic flux more difficult to pass (broken arrow shown in FIG. 8).

  With such a configuration, reluctance torque can be further generated in the rotor 100D, and the efficiency of the electric motor is improved. The reluctance torque has a different generation principle from the magnet torque. In general, the magnet torque can be increased by increasing the magnetic force and the magnitude of the permanent magnet 2. However, when such measures are taken, the counter electromotive force at the time of rotation of the motor also increases, which hinders high-speed operation. . Since the reluctance torque is not disturbed like the magnet torque in generating torque at such high speed operation, the formation of the slit groove 3a is an effective means for an electric motor that requires high speed operation.

  Therefore, according to the rotor 100D, similar to the rotor 100 according to the first embodiment, the effective use of the reluctance torque, which is an advantage of the conventional rotor (particularly, the IPM type electric motor), has been a disadvantage. This can be realized by eliminating the leakage flux. Further, according to the rotor 100D, like the rotor 100 according to the first embodiment, the strength reliability with respect to high-speed operation, which is an advantage of the conventional rotor (especially the SPM type motor), is ensured and there is a drawback. The occurrence of eddy current loss in the ring portion 4 can also be improved. Furthermore, according to the rotor 100D, it is possible to further effectively use the machine for the reluctance torque without increasing the number of parts.

Embodiment 5 FIG.
FIG. 9 is a top view schematically showing an example of a planar shape of rotor 100E of the electric motor according to Embodiment 5 of the present invention. Based on FIG. 9, the structure of the rotor 100E of an electric motor is demonstrated. The basic configuration of the rotor 100E of the electric motor according to the fifth embodiment is the same as that of the rotor 100 described in the first embodiment. In the fifth embodiment, differences from the first to fourth embodiments will be mainly described, and the same parts as those in the first to fourth embodiments will be denoted by the same reference numerals and the description thereof will be omitted. It shall be.

  As shown in FIG. 9, the rotor 100 </ b> E includes a part of the side surface of the first yoke part 1, a side part 2 a of the permanent magnet 2, a part of the side surface of the second yoke part 3, and the inner part of the ring part 4. The point which is filling the non-magnetic member 10 in the space | interval part 5 enclosed by the surrounding wall is different from the rotor which concerns on Embodiment 1-4. The inter-electrode portion 5 indicates a space formed on the inner peripheral side of the ring portion 4 and in a portion where none of the members is in contact. Instead of the ring part 4, a ring part 4B or a ring part 4C may be adopted. Moreover, you may employ | adopt 2D yoke part 3D instead of the 2nd yoke part 3. FIG.

  As described in the first embodiment, by providing the ring portion 4, each component (the first yoke portion 1, the permanent magnet 2, and the second yoke portion 3) is pressed toward the radial center by its internal pressure. Yes. However, when centrifugal force is generated during operation, a load in a direction that cancels the internal pressure of the ring portion 4 is applied to the rotor 100E. The permanent magnet 2 is subjected to inertial force during speed change and torque with the stator. Since it is applied in the tangential direction of the rotor 100E, if the internal pressure of the ring portion 4 disappears, the permanent magnet 2 will come off due to a load acting in the tangential direction (a load in a direction to cancel the internal pressure of the ring portion 4).

  Therefore, in the rotor 100E, the nonmagnetic member 10 is filled in the inter-pole portion 5. When the interpolar portion 5 is filled with the nonmagnetic member 10 and the interpolar portion 5 is filled with the nonmagnetic member 10, the displacement of the permanent magnet 2 can be restricted by the action of the nonmagnetic member 10. Therefore, even if a load in a direction to cancel the internal pressure of the ring portion 4 works, the permanent magnet 2 does not come off and the operation can be continued. Therefore, it is not necessary to generate an internal pressure in the ring portion 4 more than necessary, and strength reliability can be ensured particularly during high-speed operation. As the nonmagnetic member 10, for example, resin, wood, or the like can be used.

  Therefore, according to the rotor 100E, similar to the rotor 100 according to the first embodiment, the effective use of the reluctance torque, which is an advantage of the conventional rotor (particularly, the IPM type electric motor), has been a drawback. This can be realized by eliminating the leakage flux. Further, according to the rotor 100E, similarly to the rotor 100 according to the first embodiment, the strength reliability with respect to high-speed operation, which is an advantage of the conventional rotor (especially the SPM type motor), is secured, which is a drawback. The occurrence of eddy current loss in the ring portion 4 can also be improved. Furthermore, according to the rotor 100E, it can suppress that the permanent magnet 2 remove | deviates, and the continuity of a driving | operation improves.

  The nonmagnetic member 10 may be formed, for example, by pouring a thermoplastic material such as resin into the inter-electrode portion 5 and solidifying it, or by inserting a pre-molded solid member into the inter-electrode portion 5. May be. Further, since the nonmagnetic member 10 is nonmagnetic, it does not affect the leakage of the magnetic flux of the permanent magnet 2.

Embodiment 6 FIG.
FIG. 10 is a schematic perspective view for explaining a method for manufacturing rotor 100F of the electric motor according to Embodiment 6 of the present invention. Based on FIG. 10, the manufacturing method of the rotor 100F of an electric motor is demonstrated. The basic configuration of the rotor 100F of the electric motor according to the sixth embodiment is the same as that of the rotor 100 described in the first embodiment. In the sixth embodiment, differences from the first to fifth embodiments will be mainly described, and the same parts as those in the first to fifth embodiments will be denoted by the same reference numerals and the description thereof will be omitted. It shall be.

  Positioning each of the first yoke part 1, the permanent magnet 2 and the second yoke part 3, and then including the first yoke part 1, the permanent magnet 2 and the second yoke part 3 in the ring part 4 Have difficulty. Moreover, in order to generate an internal pressure in the ring part 4, it is necessary to make the inner diameter dimension of the ring part 4 smaller than the outer diameter dimension formed by the second yoke part 3 in the state shown in FIG. It is difficult to select. Therefore, in the sixth embodiment, the rotor 100F is manufactured as follows.

  First, the permanent magnet 2 is magnetized. Then, the magnetized permanent magnet 2 is bonded to the first yoke portion 1 so as to be in a predetermined magnetic pole direction. Thereafter, the second yoke portion 3 is bonded to the outer peripheral side of the permanent magnet 2. During this operation, positioning of the permanent magnet 2 and each yoke part (the first yoke part 1 and the second yoke part 3) is necessary. In the sixth embodiment, the magnetized permanent magnet 2 is used. Thus, the attractive force of the permanent magnet 2 can be used. For this reason, the members are brought into close contact with each other, and the outer peripheral dimensions formed by the second yoke portion 3 can be easily grasped. Moreover, if it does in this way, since each member tries to take magnetic stability, it becomes easy to take out the positional accuracy of each yoke part and the permanent magnet 2. FIG.

  After grasping the outer circumference dimension made by the second yoke part 3, if the ring part 4 having an inner diameter as a predetermined tightening margin is selected and the ring part 4 is press-fitted from the outer circumference side of the second yoke part 3, the inner pressure is reduced. A stable rotor 100F can be obtained. Depending on the material of the ring part 4, it is only necessary to select whether the ring part 4 side is to be heat-fitted or cold-fitted to cool the second yoke part 3 side, and the press-fitting process is easily realized. it can.

  As described above, the embodiments of the present invention have been described separately. However, it is not denied that the features of the embodiments are combined.

  The permanent magnet electric motor of the present invention can be obtained by installing the rotor according to the first to fifth embodiments on the inner peripheral surface side of the stator. Therefore, the permanent magnet type electric motor of the present invention has the effect of the rotor according to the first to fifth embodiments. In addition, since the permanent magnet type electric motor of the present invention is used for a compressor, a fan motor, and the like, the compressor and the fan motor also have the effect that the rotor according to the first to fifth embodiments has. Will be played. Furthermore, since the rotor of the permanent magnet type electric motor of the present invention can be manufactured by the method for manufacturing a rotor according to the sixth embodiment, the effects of the method for manufacturing a rotor according to the sixth embodiment are exhibited. become.

  DESCRIPTION OF SYMBOLS 1 1st yoke part, 1A 1st yoke part, 2 permanent magnet, 2A permanent magnet, 2a side surface part, 3rd yoke part, 3A 2nd yoke part, 3D 2nd yoke part, 3a slit groove 4 ring part, 4B ring part, 4B1 ring part, 4B2 ring part, 4B3 ring part, 4C ring part, 4C1 ring part, 4C2 ring part, 4C3 ring part, 4a slit, 5 pole part, 10 non-magnetic member, DESCRIPTION OF SYMBOLS 11 Through-hole, 20 Strip | belt-shaped electromagnetic steel plate, 21 Unnecessary part, 50 Stator, 100 rotator, 100A rotator, 100B rotator, 100C rotator, 100D rotator, 100E rotator, 100F rotator.

Claims (14)

In the rotor of a permanent magnet motor that rotates in synchronization with the change in the rotating magnetic flux of the stator,
A first yoke portion in which a plurality of electromagnetic steel sheets are laminated on the center side of the rotor;
A plurality of permanent magnets disposed on the outer periphery of the first yoke portion;
A second yoke portion in which a plurality of electromagnetic steel sheets are laminated on the outer periphery of the permanent magnet;
A ring portion that is provided on the outer peripheral side of the second yoke portion and presses the first yoke portion, the permanent magnet, and the second yoke portion from the outer periphery side of the second yoke portion toward the center side. A rotor of a permanent magnet type electric motor characterized by the above. The ring part is
The rotor of the permanent magnet electric motor according to claim 1, wherein the rotor is made of a nonmagnetic material and a nonmetallic material. The ring part is
The rotor of the permanent magnet type electric motor according to claim 1, wherein the rotor is made of a non-magnetic material. The ring part is
The rotor of a permanent magnet motor according to claim 3, wherein the rotor is made of a material having a volume resistivity of 10 ¹⁰ Ωcm or more. The ring part is
The rotor of a permanent magnet type electric motor according to claim 4, wherein the rotor is made of a ceramic material containing silicon, aluminum, oxygen, and nitrogen. The distance between the outer peripheral side of the second yoke part and the inner peripheral side of the stator is smaller than the shortest distance between the first yoke part and the second yoke part. The rotor of the permanent magnet type electric motor according to any one of claims 3 to 5. The ring part is
The rotor of the permanent magnet type electric motor according to any one of claims 3 to 6, wherein the rotor is divided into a plurality of pieces in the rotation axis direction so as to form a predetermined gap. The ring part divided into a plurality of
The rotor of a permanent magnet electric motor according to claim 7, comprising a plurality of slits opened in a radial direction. The plurality of slits are
The rotor of a permanent magnet type electric motor according to claim 8, wherein the non-opening part other than the slit opening part of the ring part is formed so as not to go straight in the rotation axis direction. The second yoke part is
The rotor for a permanent magnet electric motor according to any one of claims 1 to 9, wherein the rotor has a slit groove that opens in at least one row in the direction of the rotation axis. The slit groove is
The rotor of a permanent magnet electric motor according to claim 10, wherein the rotor is formed in an arc shape as a part of a circle having a center on an outer peripheral side of the rotor. A space formed by a part of the first yoke part, a side part of the permanent magnet, a part of the second yoke part, and an inner wall surface of the ring part is filled with a non-magnetic member. The rotor of the permanent magnet type electric motor according to any one of claims 1 to 11, wherein the rotor is a permanent magnet type electric motor. It is a manufacturing method of the rotor of the permanent magnet type electric motor according to any one of claims 1 to 12,
Magnetizing the permanent magnet;
Bonding the magnetized permanent magnet to the first yoke portion so as to have a predetermined magnetic pole direction;
Then, the step of pasting the second yoke part to the outer peripheral side of the permanent magnet,
Selecting the ring portion having an inner diameter to be a predetermined tightening margin after grasping the outer periphery dimension formed by the second yoke portion, and press-fitting the ring portion from the outer periphery side of the second yoke portion; A method for manufacturing a rotor of a permanent magnet type electric motor. The rotor of the permanent magnet type electric motor according to any one of claims 1 to 12,
A permanent magnet type electric motor comprising: a stator disposed on an outer peripheral surface side of the rotor, and a stator core having a plurality of stator windings mounted on the stator core.

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