KR102274019B1 - Manufacturing method of rotor for interior permanent magnet synchronous motor - Google Patents

Abstract

A rotor for an embedded permanent magnet synchronous motor is disclosed. A rotor for an embedded permanent magnet synchronous motor according to an exemplary embodiment of the present invention includes a stator on which a coil is wound and a rotor core disposed with a predetermined gap, and a permanent magnet is embedded in the insertion holes of the rotor core. It includes: i) a rib formed between insertion holes adjacent to each other in the rotor core; and ii) a bridge formed on the edge side of the rotor core corresponding to the stator and partitioning the insertion hole, among the rib and the bridge. At least one may be provided as a residual stress portion into which residual stress is introduced without deformation.

Description

Manufacturing method of a rotor for an embedded permanent magnet synchronous motor {MANUFACTURING METHOD OF ROTOR FOR INTERIOR PERMANENT MAGNET SYNCHRONOUS MOTOR}

An embodiment of the present invention relates to an embedded permanent magnet synchronous motor, and more particularly, to a method of manufacturing a rotor for an embedded permanent magnet synchronous motor for minimizing magnetic flux leakage of the permanent magnet.

In general, a hybrid vehicle or an electric vehicle called an eco-friendly vehicle is driven by an electric motor (hereinafter referred to as a "drive motor"), which is a power driving source that obtains rotational force with electric energy.

A hybrid vehicle runs in an EV (Electric Vehicle) mode, which is a pure electric vehicle mode that uses only the power of the driving motor, or in the HEV (Hybrid Electric Vehicle) mode, which uses both the rotational power of the engine and the driving motor as power. And a general electric vehicle is driven by using the rotational force of the driving motor as power.

Drive motors used as power sources for eco-friendly vehicles require high efficiency and power density. To satisfy these requirements, most eco-friendly vehicles use permanent magnet synchronous motors with rare earth (Nd, Dy, Tb) permanent magnets. : PMSM) is used. A permanent magnet synchronous motor includes a stator, a rotor disposed with a predetermined gap therebetween, and a permanent magnet installed in the rotor.

The rare earth components of permanent magnets applied to such permanent magnet synchronous motors are very expensive and have a high risk of price fluctuations because they are limitedly buried in some countries, such as the Middle Pole. The technological development of synchronous motors is accelerating.

On the other hand, the permanent magnet synchronous motor includes a surface permanent magnet synchronous motor (SPMM) in which a permanent magnet is installed on the surface of the rotor, and a permanent magnet in the rotor, depending on the method of installing the permanent magnet on the rotor. There are two types of embedded permanent magnet synchronous motor (IPMSM).

The surface type permanent magnet synchronous motor does not generate reluctance torque because the salient pole ratio, which is the difference in inductance between the D and Q axes, is 0 (the inductances of the D and Q axes are the same). However, the embedded permanent magnet synchronous motor has the advantage of generating reluctance torque as well as magnetic torque by the permanent magnet by increasing the salient pole ratio, so it is being used more as a drive motor for hybrid electric vehicles requiring high efficiency and power density.

In the embedded permanent magnet synchronous motor, as shown in FIG. 1 , the permanent magnet 3 is inserted and installed in the rotor 1 , and the permanent magnet 3 is inserted into the rotor 1 . Holes 5 are formed. And, each insertion hole (5) is filled with an epoxy-based molding material (7) for fixing the permanent magnet (3), the molding material (7) is cured at a certain temperature to fix the permanent magnet (3) do.

On the other hand, the rotor (1) of the embedded permanent magnet synchronous motor as described above forms the ribs (8) between the insertion holes (5). The rib 8 divides the insertion holes 5 and functions to support and fix the permanent magnet 3 inserted into the insertion holes 5 . And, the rotor (1) of the embedded permanent magnet synchronous motor forms a bridge (9) dividing the insertion hole (5) on the outer diameter side corresponding to the stator (2).

However, the ribs 8 and the bridge 9 of the rotor 1 act as a path for leaking magnetic flux by the permanent magnet 3 . That is, the magnetic flux by the permanent magnet (3) does not link up to the stator (2), and leaks into the inside of the rotor (1) through the rib (8) and the bridge (9). This leakage magnetic flux acts as a factor to reduce the torque density of the motor.

Therefore, in the prior art, the magnetic flux of the permanent magnet 3 passes to the stator 2 and flows back to the rotor 1 , without circulation occurring, and the magnetic flux passes through the ribs 8 and the bridge 9 to the rotor. As the leakage of magnetic flux flowing in the direction of the axis of (1) occurs, it may cause deterioration of the performance (torque density) of the motor.

Matters described in this background section are prepared to enhance understanding of the background of the invention, and may include matters that are not already known to those of ordinary skill in the art to which this technology belongs.

Embodiments of the present invention are to provide a method of manufacturing a rotor for an embedded permanent magnet synchronous motor capable of minimizing leakage of magnetic flux due to a permanent magnet through a rib and a bridge defining permanent magnet insertion holes.

The rotor for an embedded permanent magnet synchronous motor according to an embodiment of the present invention includes a stator on which a coil is wound and a rotor core disposed with a predetermined gap, and a permanent magnet is embedded in the insertion holes of the rotor core, i) a rib formed between the insertion holes adjacent to each other in the rotor core; and ii) a bridge formed on an edge side of the rotor core corresponding to the stator and partitioning the insertion hole; At least one of the rib and the bridge may be provided as a residual stress portion into which residual stress is introduced without deformation.

In addition, in the rotor for the embedded permanent magnet synchronous motor according to the embodiment of the present invention, the residual stress portion may be provided with a greater hardness than a portion of the rotor core excluding the residual stress portion.

In addition, in the rotor for the embedded permanent magnet synchronous motor according to the embodiment of the present invention, when the hardness of the portion excluding the residual stress portion in the rotor core is 220 ~ 265, the hardness of the residual stress portion is 270 ~ may be 290.

In addition, in the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, the rib may be provided as the residual stress portion.

In addition, in the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, the bridge may be provided as the residual stress unit.

In addition, in the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, the rib and the bridge may be provided as the residual stress portion.

In addition, in the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, the residual stress may be introduced into the residual stress portion by heating and cooling.

In addition, in the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, the residual stress may be introduced into the residual stress portion by applying a compressive force.

Further, an embodiment of the present invention includes a stator on which a coil is wound and a rotor core disposed with a predetermined gap, and manufacturing a rotor for an embedded permanent magnet synchronous motor in which permanent magnets are embedded in insertion holes of the rotor core A method comprising: (a) punching an electrical steel sheet to provide a core steel sheet having permanent magnet insertion holes, ribs and bridges; and (b) introducing residual stress without deformation to at least one of the ribs and bridges of the core steel sheet. Process, (c) stacking a plurality of the core steel sheets to which the residual stress is introduced to provide a rotor core, (d) inserting a permanent magnet into a permanent magnet insertion hole of the rotor core, and It may include a process of injecting a molding resin into the inside of the permanent magnet insertion hole.

In addition, in the method of manufacturing the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, in the process (b), at least one of the rib and the bridge may be heated and cooled through a heat treatment means.

In addition, in the method of manufacturing the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, in the step (b), a compressive force may be applied to at least one of the rib and the bridge through a compression means.

In addition, in the method of manufacturing the rotor for the embedded permanent magnet synchronous motor according to the embodiment of the present invention, in the step (b), residual stress is introduced into at least one of the ribs and bridges of the core steel plate to reduce the residual stress. can be formed

In addition, in the manufacturing method of the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, when the hardness of the portion excluding the residual stress part in the core steel sheet is 220 to 265, the hardness of the residual stress part is It may be 270-290.

Further, an embodiment of the present invention includes a stator on which a coil is wound and a rotor core disposed with a predetermined gap, and manufacturing a rotor for an embedded permanent magnet synchronous motor in which permanent magnets are embedded in insertion holes of the rotor core A method comprising: (a) punching an electrical steel sheet to provide a core steel sheet having permanent magnet insertion holes, ribs and a bridge; (b) rounding the bridge in a center direction of the core steel sheet; ( c) stacking a plurality of the core steel plates to provide a rotor core; (d) inserting a permanent magnet into a permanent magnet insertion hole of the rotor core, and injecting a molding resin into the permanent magnet insertion hole (e) curing the molding resin to form a molding material, deforming the bridge outward from the center of the rotor core by the expansion force of the molding material, and introducing a residual stress to the bridge may include

In addition, in the method for manufacturing the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, in the process (e), a cylindrical jig is mounted on the outer diameter of the rotor core, and the molding resin is The bridge, which is deformed outwardly from the center by the expansion force, may be supported through the jig.

In addition, in the method for manufacturing the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, in the step (e), a residual stress may be formed by introducing a residual stress into the bridge of the rotor core. have.

In addition, in the method of manufacturing the rotor for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, when the hardness of the portion excluding the residual stress portion in the rotor core is 220 to 265, the hardness of the residual stress portion may be 270 to 290.

According to the embodiments of the present invention, the magnetic flux by the permanent magnet 109 is the center of the axis of the rotor core through the ribs and/or bridges as the residual stress is introduced into the ribs and/or bridges of the rotor core. The leakage of magnetic flux flowing in the direction can be prevented or reduced.

Therefore, in the embodiment of the present invention, since magnetic flux leakage by the permanent magnet can be reduced and the effective magnetic flux amount can be increased by the reduced amount, the use of rare earth components of the permanent magnet is reduced to reduce the material cost of the motor and at the same time increase the no-load counter electromotive force By doing so, the performance of the motor can be increased.

Furthermore, in the embodiment of the present invention, since the amount of effective magnetic flux generating torque is increased to lower the input current, it is possible to increase the efficiency of the motor and the inverter by reducing the current.

In addition, the effects obtainable or predicted by the embodiments of the present invention are to be disclosed directly or implicitly in the detailed description of the embodiments of the present invention. That is, various effects predicted according to an embodiment of the present invention will be disclosed in the detailed description to be described later.

Since these drawings are for reference in describing an exemplary embodiment of the present invention, the technical spirit of the present invention should not be construed as being limited to the accompanying drawings.
1 is a view schematically showing a part of a buried permanent magnet synchronous motor according to an example of the prior art.
2 is a view schematically showing a part of a rotor for a buried type permanent magnet synchronous motor according to an embodiment of the present invention.
3 and 4 are views showing the residual stress portion and the hardness of the remaining region except for the residual stress portion in the rotor core of the rotor for a buried permanent magnet synchronous motor according to an embodiment of the present invention.
5 is a view for explaining the effect of the rotor for an embedded permanent magnet synchronous motor according to an embodiment of the present invention.
6A to 6D are views for explaining a method of manufacturing a rotor for an embedded permanent magnet synchronous motor according to an embodiment of the present invention.
7A to 7C are views for explaining a method of manufacturing a rotor for an embedded permanent magnet synchronous motor according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are given to the same or similar elements throughout the specification.

Since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the bar shown in the drawings, and the thickness is enlarged to clearly express various parts and regions.

In addition, in the following detailed description, the reason for dividing the names of components into first, second, etc. is to distinguish them due to the same relationship, and it is not necessarily limited to the order in the following description.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

In addition, terms such as "...unit", "...means", "...part", and "...member" described in the specification refer to a unit of a comprehensive configuration that performs at least one function or operation. it means.

2 is a diagram schematically illustrating a part of a rotor for a buried type permanent magnet synchronous motor according to an embodiment of the present invention.

Referring to FIG. 2 , an embodiment of the present invention may be applied to an Interior Permanent Magnet Synchronous Motor (IPMSM) as a power driving source for an eco-friendly vehicle that generates driving force with electric energy.

Such an embedded permanent magnet synchronous motor includes a stator 101, a rotor 100 according to an embodiment of the present invention disposed with a predetermined gap therebetween, and a plurality of installed in the rotor 100. It contains ten permanent magnets (109).

Here, the stator 101 includes a stator core 103 in which a plurality of electrical steel sheets are stacked, and a stator coil 105 is wound around the stator core 103 . The rotor 100 according to an embodiment of the present invention includes a rotor core 10 in which a plurality of electrical steel sheets are stacked in the axial direction. The rotor core 10 is fixedly installed on the outer peripheral surface of the shaft (not shown) through the rotor fixing means. And the permanent magnet 109 is inserted and installed in the insertion holes 11 provided in the rotor core 10 in an embedded manner.

Furthermore, the embedded permanent magnet synchronous motor to which the embodiment of the present invention is applied may be applied to an internal type synchronous motor in which the rotor 100 is disposed inside the stator 101 , and is located outside the stator 101 . It may be applied to an external type synchronous motor in which the rotor 100 is disposed.

In the embodiment of the present invention, the stator 101 is provided on the outside, and the rotor 100 is applied to the internal synchronous motor that rotates inside the stator 101 will be described as an example.

However, it should not be understood that the protection scope of the present invention is necessarily limited thereto, and the technical idea of the present invention may be applied to an external type synchronous motor in advance.

On the other hand, the rotor 100 for the embedded permanent magnet synchronous motor according to an embodiment of the present invention is between the insertion holes 11 for inserting the permanent magnets 109 in the axial direction in the rotor core 10 . A rib 13 for fixing the permanent magnet 109 is formed.

The rib 13 divides the insertion holes 11 in the rotor core 10 and functions to support and fix the permanent magnet 109 inserted into the insertion holes 11 . Furthermore, the rib 13 distributes the tensile stress of the rotor core 10 so that the permanent magnet 109 does not damage the rotor core 10 by centrifugal force when the rotor 100 rotates at a high speed. It acts as a support for

These ribs 13 are disposed obliquely between the insertion holes 11 of the rotor core 10 in the oblique direction, and partition between the insertion holes 11 . For example, the ribs 13 may be inclined toward one side and the other side.

Furthermore, the rotor 100 for the embedded permanent magnet synchronous motor according to an embodiment of the present invention includes a bridge 15 formed on the outer diameter edge side of the rotor core 10 corresponding to the stator 101 . contains The bridge 15 divides the insertion hole 11 on the outer diameter side of the rotor core 10, and forms a predetermined gap with the stator 101 with a set thickness.

Here, an epoxy resin-based molding material 17 is molded in some regions of the insertion holes 11 , ie, in the remaining regions except for the regions in which the permanent magnets 109 are fitted. The molding material 17 is for fixing the permanent magnet 109 to the insertion hole 11, and the molding resin 16 is filled ( injection) and curing the molding resin 16 at a set temperature.

In the rotor 100 for an embedded permanent magnet synchronous motor according to an embodiment of the present invention as described above, the ribs 13 and the bridge 15 of the rotor core 10 leak magnetic flux by the permanent magnet 109 . may serve as a pathway to

Therefore, the embodiment of the present invention is a circuit for an embedded permanent magnet synchronous motor that can minimize leakage of magnetic flux by the permanent magnet 109 in the rotor core 10 through the rib 13 and the bridge 15 . The former 100 is provided.

To this end, in the rotor 100 for the embedded permanent magnet synchronous motor according to an embodiment of the present invention, at least one of the ribs 13 and the bridge 15 in the rotor core 10 has residual stress introduced without deformation. It is provided as a residual stress part (30). Here, the residual stress portion 30 may be the rib 13 in the rotor core 10 , the bridge 15 , or the rib 13 and the bridge 15 .

The residual stress portion 30 heats the surface of the rib 13 and/or bridge 15 to a set temperature and then cools the surface of the rib 13 and/or bridge 15 to a low temperature by a thermal cycle. ) can be formed by introducing residual stresses.

In addition, the residual stress portion 30 may be formed by applying a compressive force to the surface of the rib 13 and/or bridge 15 so that residual stress is introduced into the rib 13 and/or bridge 15 . have.

Here, as in (a) of FIG. 3, the residual stress part 30 has a hardness (refer to FIG. 3(b)) excluding the residual stress part 30 in the rotor core 10. hardness) is greater.

For example, as in the graph of FIG. 4 , the hardness (indicated by “a” in the drawing) of the residual stress portion 30 is 270 to 290 at the surface side of the rib 13 and/or the bridge 15, The hardness of the portion excluding the residual stress portion 30 (indicated by “b” in the drawing) has a hardness of 220 to 265 on the surface side of the rib 13 and/or the bridge 15 .

According to the rotor 100 for the embedded permanent magnet synchronous motor according to the embodiment of the present invention as described above, the ribs 13 and/or the bridge 15 of the rotor core 10 are free from residual stress without deformation. It is composed of the introduced residual stress portion (30).

Accordingly, in the embodiment of the present invention, as residual stress is introduced into the rib 13 and/or the bridge 15, the magnetic field of the rib 13 and/or the bridge 15 is caused by the residual stress as shown in FIG. 5 . properties may be degraded.

Therefore, in the embodiment of the present invention, the magnetic flux by the permanent magnet 109 can prevent or reduce magnetic flux leakage that flows in the axial center direction of the rotor core 10 through the rib 13 and/or the bridge 15 . have.

To elaborate, in the embodiment of the present invention, since the magnetic resistance in the rib 13 and/or bridge 15 increases as residual stress is introduced into the rib 13 and/or bridge 15, the rib ( 13) and/or the leakage flux through the bridge 15 is reduced, and the effective flux amount is increased. That is, in the embodiment of the present invention, the magnetic flux by the permanent magnet 109 passes from the rotor 100 to the stator 101 , and then it is possible to promote the circulation of flowing back to the rotor 100 .

As such, in the embodiment of the present invention, the magnetic flux leakage by the permanent magnet 109 can be reduced and the effective magnetic flux amount can be increased by the reduced amount, thereby reducing the use of rare earth components of the permanent magnet 109, thereby reducing the material cost of the motor. At the same time, it is possible to increase the performance (torque density) of the motor by increasing the no-load counter electromotive force.

In addition, in the embodiment of the present invention, since the amount of effective magnetic flux generating torque is increased and the input current can be lowered, the efficiency of the motor and the inverter can be increased by reducing the current.

Hereinafter, a method of manufacturing the rotor 100 for an embedded permanent magnet synchronous motor according to an embodiment of the present invention configured as described above will be described with reference to the accompanying drawings.

6A to 6D are views for explaining a method of manufacturing a rotor for an embedded permanent magnet synchronous motor according to an embodiment of the present invention.

Referring to FIG. 6A , first, in an embodiment of the present invention, an electrical steel sheet is punched to provide a core steel sheet 10a having a permanent magnet insertion hole 11 , a rib 13 and a bridge 15 . Here, the rib 13 and the bridge 15 form an insertion hole 11 in the core steel plate 10a, and the rib 13 is provided between the insertion holes 11, and the bridge 15 is provided on the edge side of the core steel plate 10a.

Next, in the embodiment of the present invention, as in FIGS. 6b and 6c, the rib 13 and/or without deformation of the rib 13 and/or the bridge 15 of the core steel plate 10a (refer to FIG. 6a below). Alternatively, a residual stress is introduced into the bridge 15 .

For example, in an embodiment of the present invention, the rib 13 and/or the bridge 15 of the core steel plate 10a are heated and cooled through the heat treatment means 110 as shown in FIG. 6b , and the rib 13 and /or introduce residual stresses in the bridge 15 .

Here, the heat treatment means 110 heats the surface of the rib 13 and/or the bridge 15 to a set temperature, and then the rib 13 and/or the bridge 15 by a thermal cycle of cooling to a low temperature. 15) can introduce residual stress. The heat treatment means 110 may include a heater 111 and a cooler 113 of known techniques well known in the art.

As an alternative, in the embodiment of the present invention, by applying a compressive force to the rib 13 and/or the bridge 15 of the core steel plate 10a through the compression means 130, the rib 13 and /or introduce residual stresses in the bridge 15 . The compression means 130 pressurizes the rib 13 and/or the bridge 15 to a set pressure, and may include a compressor 131 of a well-known technique well known in the art.

As the residual stress is introduced into the rib 13 and/or bridge 15 of the core steel plate 10a as described above, in the embodiment of the present invention, the rib 13 and/or the bridge 15 is subjected to residual stress. It may be composed of a portion 30 . In this case, when the hardness of a portion of the core steel sheet 10a excluding the residual stress portion 30 is 220 to 265, the hardness of the residual stress portion 30 satisfies 270 to 290.

Then, in the embodiment of the present invention, as shown in FIG. 6D , a plurality of core steel plates 10a constituting the residual stress portion 30 are laminated to provide the rotor core 10 .

Next, in the embodiment of the present invention, the permanent magnet 109 is inserted into the permanent magnet insertion hole 11 of the rotor core 10, and a partial region of the insertion hole 11, that is, the permanent magnet 109 Epoxy resin-based molding resin 16 is injected into the remaining areas except for this sandwiched area. The molding resin 16 is cured at a set temperature and is formed of a molding material 17 , which fixes the permanent magnet 109 in the insertion hole 11 .

Therefore, in the embodiment of the present invention, the rib 13 and/or the rib 13 and/or the rib 13 and/or the bridge 15 by introducing residual stress to the rib 13 and/or the bridge 15 of the rotor core 10 through a series of processes as described above It is possible to manufacture the rotor 100 in which the bridge 15 is composed of the residual stress portion 30 .

7A to 7C are views for explaining a method of manufacturing a rotor for an embedded permanent magnet synchronous motor according to another embodiment of the present invention.

First, another embodiment of the present invention provides a core steel plate 10a having a permanent magnet insertion hole 11, a rib 13 and a bridge 15 by punching an electrical steel plate as shown in FIG. 6a disclosed above. .

Next, in the embodiment of the present invention, as shown in FIG. 7A , the bridge 15 is processed to be round in the center direction of the core steel plate 10a. At this time, in the embodiment of the present invention, the bridge 15 having a set thickness is bent roundly toward the center of the core steel plate 10a. Then, in the embodiment of the present invention, the rotor core 10 is provided by laminating the above-described plurality of core steel plates 10a.

Then, in the embodiment of the present invention, as shown in FIG. 7b , the permanent magnet 109 is inserted into the permanent magnet insertion hole 11 of the rotor core 10 , and the insertion hole 11 is molded inside. Resin 16 is injected.

Here, in the embodiment of the present invention, the molding resin 16 maintained at 150 to 200° C. is injected into the insertion hole 11 . In this process, in the embodiment of the present invention, a cylindrical jig 150 is mounted on the outer diameter side of the rotor core 10 .

Subsequently, in the embodiment of the present invention, the molding resin 16 injected into the insertion hole 11 is cured in a set temperature range, for example, 250° C. to 400° C., and for fixing the permanent magnet 109 . A molding material 17 is formed.

The reason for setting the injection and curing temperature of the molding resin 16 to the temperature range as described above is that the resin has excellent fluidity in the temperature range of 150 to 200 ° C, and excellent curability in the temperature range of 250 ° C to 400 ° C. Because. In addition, the reason why the curing temperature range of the molding resin 16 is limited to 400° C. or less is that when the temperature range exceeds 400° C., there is a high risk of damage to the molding material 17 .

Meanwhile, in the process of forming the molding material 17 by curing the molding resin 16 as described above, in the embodiment of the present invention, as shown in FIG. 7c , the expansion force of the molding material 17 is applied to the bridge 15 . do. Then, the bridge 15 is deformed outside the center of the rotor core 10 by the expansion force of the molding material 17 .

Here, since the cylindrical jig 150 is mounted on the outer diameter side of the rotor core 10 , the bridge 15 deformed outside the center of the rotor core 10 is restrained by the jig 150 . and forms the outer diameter surface of the rotor core 10 .

Therefore, in the embodiment of the present invention, in the process of curing the molding resin 16 into the molding material 17 , a residual stress is introduced into the bridge 15 by applying the expansion force of the molding material 17 to the bridge 15 . can do.

As the residual stress is introduced into the bridge 15 of the rotor core 10 as described above, in the embodiment of the present invention, the bridge 15 may be configured as a residual stress part 30 . In this case, when the hardness of the portion of the rotor core 10 excluding the residual stress part 30 is 220 to 265, the hardness of the residual stress part 30 satisfies 270 to 290.

Accordingly, in the embodiment of the present invention, a residual stress is introduced into the bridge 15 of the rotor core 10 through a series of processes as described above, and the bridge 15 is composed of the residual stress unit 30 . The rotor 100 can be manufactured.

Although the embodiments of the present invention have been described above, the technical spirit of the present invention is not limited to the embodiments presented in this specification, and those skilled in the art who understand the technical spirit of the present invention are within the scope of the same technical spirit, Other embodiments may be easily proposed by addition, change, deletion, addition, etc. of

10... rotor core 10a... core steel plate
11... Insertion hole 13... Rib
15... Bridge 16... Molding Resin
17... Molding material 30... Residual stress area
101... stator 103... stator core
105... stator coil 109... permanent magnet
110... Heat treatment means 111... Heater
113... cooler 130... compression means
131... Compressor 150... Jig

Claims (15)

delete delete delete delete delete delete delete delete delete delete delete delete A method of manufacturing a rotor for an embedded permanent magnet synchronous motor comprising a stator on which a coil is wound and a rotor core disposed with a predetermined gap therebetween, wherein permanent magnets are embedded in insertion holes of the rotor core,
(a) punching an electrical steel sheet to provide a core steel sheet having permanent magnet insertion holes, ribs and bridges;
(b) processing the bridge to be round in the center direction of the core steel plate;
(c) providing a rotor core by laminating a plurality of the core steel plates;
(d) inserting a permanent magnet into the permanent magnet insertion hole of the rotor core, and injecting a molding resin into the permanent magnet insertion hole; and
(e) curing the molding resin to form a molding material, deforming the bridge outward from the center of the rotor core by the expansion force of the molding material, and introducing a residual stress to the bridge;
In the process (e), a cylindrical jig is mounted on the outer diameter portion of the rotor core, and the bridge deformed outwardly from the center by the expansion force of the molding resin is supported through the jig. A method for manufacturing a rotor for a magnet synchronous motor. delete 14. The method of claim 13,
In the process (e),
A residual stress portion is formed by introducing a residual stress to the bridge of the rotor core,
When the hardness of a portion of the rotor core excluding the residual stress portion is 220 to 265, the hardness of the residual stress portion is 270 to 290.

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