JP2012060774A - Rotor of synchronous motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor of a synchronous motor for achieving the synchronous motor of low noise, high output, high efficiency and a low cost.SOLUTION: In the rotor of the synchronous motor related to this invention, by arranging openings of a first rotor core and a second rotor core at different ends of respective magnetic poles and combining the first rotor core and the second rotor core, the opening of one and the nonmagnetic part of the other or the nonmagnetic part of one and the opening of the other are communicated in an axial direction, and a fixing component comprising a nonmagnetic material is inserted to the communicated nonmagnetic part and opening.

Description

  The present invention relates to a rotor of a synchronous motor using permanent magnets.

  For example, a synchronous motor (brushless DC motor) used in a household electrical product including an air conditioner, for example, for a blower or the like is often required to have high efficiency or be small and light. In order to meet these requirements, many employ a permanent magnet having a high magnetic force, such as a NdFeB sintered magnet.

NdFeB is a compound of neodymium, iron, and boron. As a typical example, Nd ₂ Fe ₁₄ B is used in various fields by becoming a very strong permanent magnet / neodymium magnet.

  In the case of a rare earth sintered magnet such as NdFeB, a manufacturing method is often employed in which a permanent magnet having a required shape is cut from a large mass. Therefore, in order to suppress the price of the permanent magnet including the processing cost, a flat permanent magnet having a relatively simple shape is often used.

  In such a synchronous motor using a plate-like permanent magnet, an embedded permanent magnet (IPM) rotor in which a permanent magnet is arranged in a magnetic material is often used. In this case, a magnetic body (rotor core) exists between the permanent magnets arranged adjacent to each other. For this reason, the magnetic flux between the magnetic poles is short-circuited in the magnetic material portion, and the magnetic flux of the rotor interlinking with the stator winding is reduced. As the number of magnetic poles increases, the number of places where this magnetic flux is short-circuited increases, so that the magnetic flux linked to the stator windings further decreases. For this reason, generally, a method is adopted in which the magnetic material between the magnetic poles is made as thin as possible and magnetic saturation is partially caused to prevent a magnetic flux from being short-circuited between the magnetic poles.

  As a method for further suppressing the short circuit of the magnetic flux, a rotor having a form in which a magnetic body between magnetic poles is removed has been proposed. In other words, the magnetic body constituting the rotor is not configured as an integral part, but the magnetic body part on the inner peripheral side of the flat permanent magnet and the magnetic body part on the outer peripheral side of the permanent magnet are configured as separate parts, and the shaft There has been proposed a rotor configured by using a member that penetrates and integrates them from both sides in a direction (see, for example, Patent Document 1).

  In addition, the effect of suppressing the short circuit of the magnetic flux in the magnetic body that constitutes the rotor is reduced, but it is constructed by laminating the iron core in a shape that removes the magnetic body between the magnetic poles on one side of the permanent magnet, and fixed by a resin mold An outer rotor type rotor has been proposed (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 10-164784 JP 2004-25443 A

  However, the rotor described in Patent Document 1 can prevent a magnetic flux short circuit between the magnetic poles and link more magnetic flux to the stator winding, but the magnetic body inside the permanent magnet of the rotor. Since the material and the magnetic material outside the permanent magnet are separate parts, there arises a problem that the number of assembly steps increases.

  In addition, since there is no magnetic material between the magnetic poles of the rotor, the change in magnetic flux density near the magnetic poles is large, the cogging torque of the synchronous motor is increased, and this is likely to cause vibration and noise.

  The rotor described in Patent Document 2 can be integrated by molding an iron core and a permanent magnet with a resin. However, the resin and the iron core have a large linear expansion coefficient with respect to temperature changes of the material. Because of differences, the iron core and the resin may peel off during repeated environmental changes such as heat shock. In the case of the rotor described in Patent Document 2, since it is an outer rotor type rotor, the resin does not scatter even if the iron core and the resin are peeled off. However, the inner rotor type rotor does not scatter the rotor. When manufactured, the resin peeled off by the centrifugal force may be scattered, or the iron core of the outer periphery of the permanent magnet may be deformed at the thin wall portion to come into contact with the stator.

The present invention has been made to solve the above-described problems, and provides a rotor for a synchronous motor described below.
(1) A rotor of a synchronous motor for realizing an efficient synchronous motor by interlinking a larger amount of the magnetic flux of the rotor with the stator winding;
(2) A rotor of a synchronous motor that does not complicate the assembly process and can suppress an increase in processing cost;
(3) A rotor of a synchronous motor that suppresses a decrease in strength such as deformation of the iron core due to centrifugal force;
(4) A rotor of a synchronous motor for realizing a synchronous motor that can suppress an increase in cogging torque and suppress deterioration of vibration and noise.

A rotor of a synchronous motor according to the present invention is a rotation of a synchronous motor in which permanent magnets constituting magnetic poles are arranged inside a rotor core formed by laminating a predetermined number of soft magnetic materials punched into a predetermined shape. In the child
The rotor core is formed by combining a first rotor core formed by stacking a predetermined number of sheets and a second rotor core formed by stacking a predetermined number of sheets, and the first rotor core Each of the second rotor cores is
A permanent magnet insertion portion formed along the outer peripheral edge of the first rotor core or the second rotor core and into which the permanent magnet is inserted;
An inner core part formed inside the permanent magnet insertion part;
An outer peripheral core portion formed on each magnetic pole outside the permanent magnet insertion portion; and
A connecting portion for connecting the inner core portion and the outer peripheral core portion at the end of each magnetic pole, and a thin outer peripheral portion;
A non-magnetic part formed inside the outer peripheral thin part and communicating with the permanent magnet insertion part;
A connecting portion of each magnetic pole as well as an end on the opposite side to the end where the outer peripheral thin portion is provided, and an opening communicating with the permanent magnet insertion portion,
The first rotor core and the second rotor core are arranged such that openings are arranged at different ends of the magnetic poles, and the first rotor core and the second rotor core are combined. And the other non-magnetic part or one non-magnetic part and the other opening communicate with each other in the axial direction, and a fixed part made of a non-magnetic material is inserted into the communicating non-magnetic part and the opening. It is characterized by being.

  In the rotor of the synchronous motor according to the present invention, the magnetic flux of the permanent magnet can be prevented from being short-circuited inside the rotor core, and the processing cost of the rotor, the strength of the rotor can be reduced, and the cogging torque can be increased. By being suppressed, a rotor of a synchronous motor with high efficiency, low cost, and low noise can be obtained.

FIG. 5 shows the first embodiment, and is a perspective view of a rotor 200. FIG. 5 shows the first embodiment, and is a plan view of a rotor 200. FIG. 3 shows the first embodiment, and is an exploded perspective view of a rotor 200. FIG. FIG. 5 shows the first embodiment, and is a perspective view of the rotor assembly 200-1. FIG. 5 shows the first embodiment and is a plan view of the rotor assembly 200-1. FIG. 4 is a diagram showing the first embodiment, and is a perspective view of a fixing component 210. FIG. 5 shows the first embodiment, and is a perspective view of a rotor core 201. FIG. 5 shows the first embodiment, and is a plan view of a first rotor core 201-1. FIG. 5 shows the first embodiment, and is a plan view of a second rotor core 201-2. (A) is the A section enlarged view of FIG. 8, (b) is the B section enlarged view of FIG. FIG. 5 shows the first embodiment, and is a partial plan view showing a state in which a first rotor core 201-1 and a second rotor core 201-2 are overlapped. The figure which shows Embodiment 1 and the figure which compared the effective value of the induced voltage of the synchronous motor using the rotor of this Embodiment, and the synchronous motor using a common rotor. The figure which shows Embodiment 1 and the figure which compared the waveform of the induced voltage of the synchronous motor using the rotor of this Embodiment, and the synchronous motor using a common rotor. The figure which shows Embodiment 1 and the figure which compared the cogging torque amplitude of the synchronous motor using the rotor of this Embodiment, and the synchronous motor using a common rotor. The figure which shows Embodiment 1 and the figure which compared the waveform of the cogging torque of the synchronous motor using the rotor of this Embodiment, and the synchronous motor using a common rotor. FIG. 5 shows the first embodiment, and is a perspective view of a rotor 300 of a first modification. FIG. 5 shows the first embodiment, and is a plan view of a rotor 300 of a first modification. FIG. 5 shows the first embodiment, and is an exploded perspective view of a rotor 300 of a first modification. FIG. 5 shows the first embodiment, and is a perspective view of a rotor assembly 300-1 of a first modification. FIG. 3 is a diagram illustrating the first embodiment, and is a perspective view of a fixing component 310. FIG. 5 shows the first embodiment, and is a perspective view of a rotor core 301 according to a first modification. FIG. 5 shows the first embodiment, and is a plan view of a first rotor core 301-1 and a second rotor core 301-2 of Modification 1. It is a figure shown for a comparison and is a cross-sectional view of a rotor 400 of a general synchronous motor. The figure shown for a comparison and the cross-sectional view of the rotor 500 of a common synchronous motor.

  Embodiment 1 FIG.

  FIGS. 1 to 3 are views showing the first embodiment, and are perspective views of the rotor 200, FIG. 2 is a plan view of the rotor 200, and FIG. 3 is an exploded perspective view of the rotor 200. The rotor of the synchronous motor is called a rotor 200. Further, the rotor 200 may be simply referred to as a rotor.

  The synchronous motor is, for example, a brushless DC motor in which a three-phase winding is applied to a stator (not shown) and driven by an inverter.

  As shown in FIGS. 1 to 3, the rotor 200 includes at least a substantially cylindrical rotor core 201 (consisting of a first rotor core 201-1 and a second rotor core 201-2). , A flat permanent magnet 203 to be inserted into a permanent magnet insertion portion (described later) of the rotor core 201, and a rotor core 201 (first rotor core 201-1 and second rotor core 201-2). At the end of each permanent magnet insertion portion (described later) and a fixed part 210 inserted into a non-magnetic portion (described later) and the rotor core 201 at the approximate center. A rotation shaft (not shown) fixed to the shaft hole 205 formed.

  The rotor 200 shown in FIGS. 1 to 3 is an 8-pole rotor including eight permanent magnets 203 arranged so that the polarities are alternately different in the circumferential direction.

  Although not shown in the drawings, end plates for stopping the fixed component 210 and the permanent magnet 203 from coming off in the axial direction are provided at both axial ends of the rotor 200. The end plate is fixed by, for example, a rivet that penetrates the rotor core 201.

  In addition, although not shown, the permanent magnet 203 is provided with, for example, a positioning projection on the permanent magnet insertion portion 202 and is positioned in the circumferential direction by the projection. The protrusions for positioning are provided at two locations on the inner surface of the permanent magnet insertion portion 202, for example.

  The feature of the rotor 200 is that the end of each permanent magnet insertion portion 202 of a rotor core 201 (consisting of a first rotor core 201-1 and a second rotor core 201-2), which will be described later. By inserting the fixing component 210 into the formed opening (described later) and nonmagnetic part (described later), the relatively weak outer peripheral core 201a connected to the inner core 201b is fixed. Since it is fixed from both sides by the component 210, deformation due to centrifugal force can be suppressed. Reference numerals that are not shown in the reference numerals shown in FIGS. 1 to 3 will be described later.

  As shown in FIG. 3, in the rotor 200, a total of eight fixed parts 210 are inserted from openings (described later) on the axial end surface of the first rotor core 201-1. Further, in the rotor 200, a total of eight fixing parts 210 are inserted from the opening (described later) on the end surface in the axial direction of the second rotor core 201-2. Therefore, a total of 16 fixing parts 210 are used. Since the rotor 200 is an 8-pole rotor, the number of fixed components 210 is twice as many as the number of poles (8 poles) (the number of stages of the rotor core, here 2 stages).

  When the core width (axial length) of the first rotor core 201-1 and the core width (axial length) of the second rotor core 201-2 are the same, one type of fixing is performed. The component 210 may be used. FIG. 3 shows the same core width (axial length) of the first rotor core 201-1 and the same core width (axial length) of the second rotor core 201-2. This is an example in which the fixed component 210 is used.

  In the present embodiment, the core width (axial length) of the first rotor core 201-1 and the core width (axial length) of the second rotor core 201-2 are the same. However, it may not be the same. When the core width (axial length) of the first rotor core 201-1 and the core width (axial length) of the second rotor core 201-2 are different, two types of fixing are used. Part 210 is required.

  4 and 5 show the first embodiment. FIG. 4 is a perspective view of the rotor assembly 200-1 and FIG. 5 is a plan view of the rotor assembly 200-1. The one before the fixed component 210 is inserted is called a rotor assembly 200-1. The rotor assembly 200-1 before the fixed component 210 is inserted has an opening 208 formed at an end of a permanent magnet insertion portion (described later) and a non-magnetic portion 202a (except for both axial ends when the permanent magnet 203 is present). Closed space) is a space.

  In order to make the features of the rotor 200 and the rotor core 201 of the present embodiment easier to understand, a general synchronous motor rotor will be described.

  FIG. 23 is a cross-sectional view of a general synchronous motor rotor 400 for comparison. A general synchronous motor rotor 400 (hereinafter referred to as a rotor 400) includes a substantially cylindrical rotor core 401 and a flat permanent magnet 403 inserted into a permanent magnet insertion portion 402 of the rotor core 401. And a shaft hole 405 to which a rotating shaft (not shown) is fixed substantially at the center of the rotor core 401.

  As with the rotor core 201, the rotor core 401 is formed by punching a soft magnetic material (thickness of about 0.1 to 1.0 mm) typified by an electromagnetic steel sheet into a predetermined shape and laminating a predetermined number of sheets. The The soft magnetic plate punched into a predetermined shape is a general caulking (caulking portion 407) in which cut and raised protrusions formed on each soft magnetic plate are fitted and fixed by soft magnetic plates adjacent in the axial direction. ).

  In the rotor core 401, eight permanent magnet insertion portions 402 (the cross section is substantially bathtub-shaped and convex inward) are formed in a substantially regular octagon along the outer peripheral portion. With the permanent magnet insertion part 402 in between, the outer core part 401a is the outer core part than the permanent magnet insertion part 402, and the inner core part 401b is the inner core part than the permanent magnet insertion part 402.

  In the rotor core 401, between all the poles, the outer peripheral core portion 401a and the inner iron core portion 401b are connected by the connecting portion 406 and the outer peripheral thin portion 406a.

  The rotor core 401 has a magnetic body (the connecting portion 406 and the outer peripheral thin portion 406a) between the permanent magnets 403 arranged adjacent to each other. For this reason, the magnetic flux between the magnetic poles is short-circuited in the magnetic material portion, and the magnetic flux of the rotor 400 linked to the stator winding is reduced. Further, as the number of magnetic poles increases, the number of places where this magnetic flux is short-circuited increases, so that the magnetic flux linked to the stator windings further decreases. As a result, the synchronous motor using the rotor 400 has a problem that no torque is generated because the magnetic flux of the permanent magnet 403 cannot be fully utilized.

  FIG. 24 is a cross-sectional view of a general synchronous motor rotor 500 for comparison. A general synchronous motor rotor 500 (hereinafter referred to as a rotor 500) includes a rotor core 501, a flat permanent magnet 503 inserted into a permanent magnet insertion portion 502 of the rotor core 501, and a rotor core. And a shaft hole 505 to which a rotation shaft (not shown) is fixed.

  The rotor core 501 is composed of an outer peripheral core part 501a and an inner iron core part 501b. The permanent magnet 503 is provided between the outer peripheral iron core portion 501a and the inner iron core portion 501b. The divided outer core portion 501a and inner core portion 501b are integrated using a member that penetrates and integrates the outer core portion 501a and the inner core portion 501b from both sides in the axial direction, although not shown.

  Since the opening 508 is formed between the magnetic poles, it is possible to prevent a magnetic flux short circuit between the magnetic poles and to cause a larger amount of magnetic flux to be generated by the winding of the stator. Since the inner core portion 501b and the outer peripheral core portion 501a outside the permanent magnet 503 are separate parts, there arises a problem that the number of assembling steps increases.

  In addition, since there is no magnetic material between the magnetic poles of the rotor 500, the change in magnetic flux density near the magnetic poles is large, the cogging torque of the synchronous motor is increased, and this tends to cause vibration and noise.

  The rotor core 201 (the first rotor core 201-1 and the second rotor core 201-2) of the present embodiment has an outer peripheral core portion 201a and an inner core portion 201b that are on one side of one magnetic pole. It connects with the connection part 206 and the outer periphery thin part 206a between. And the opening part 208 is formed between the other poles of one magnetic pole, and the outer periphery iron core part 201a and the inner core part 201b are isolate | separated. The opening 208 is characterized in that the outer peripheral side is wider than the inner side.

  In other words, the permanent magnet insertion part 202 is not a space completely surrounded by the magnetic body in the rotor core 201 but is opened to the outer periphery of the rotor core 201 in the opening 208.

  In general, the magnetic flux generated from a permanent magnet easily passes through a magnetic body having a low magnetic resistance, and there is a gap (a narrow space of several hundred μm) in the outer periphery of the stator core (magnetic body) and the rotor. In some cases, it is easier to pass between the outer peripheral portions of adjacent magnetic poles inside the rotor than to flow to the stator core. For this reason, the magnetic flux is easily short-circuited between the magnetic poles through the adjacent outer peripheral portions of the rotor, and the magnetic flux interlinking with the stator winding is reduced. The thin-walled connecting portion (for example, the connecting portion 406 of the rotor 400 and the outer peripheral thin-walled portion 406a) increases the magnetic resistance until the magnetic flux density is saturated by reducing the cross-sectional area of the magnetic material through which the magnetic flux is to pass. The magnetic flux that is raised and short-circuited in the rotor is reduced, but it is not completely eliminated.

  FIG. 6 shows the first embodiment, and is a perspective view of the fixing component 210. As shown in FIG. 6, the fixed component 210 includes an opening insertion portion 210 a that is inserted into the opening 208 of the rotor core 201 (the first rotor core 201-1 and the second rotor core 201-2). The nonmagnetic portion insertion portion 210b inserted into the nonmagnetic portion 202a is integrally formed. The opening insertion part 210a and the nonmagnetic part insertion part 210b have substantially the same shape as the opening 208 and the nonmagnetic part 202a.

  The fixed component 210 may be made of a nonmagnetic material, and may be a metal (nonmagnetic metal) such as aluminum or stainless steel or a resin material.

  Since the fixed component 210 is inserted into the non-magnetic portion 202a inside the outer thin portion 206a, the outer peripheral core portion 201a is not moved to the outer peripheral side of the rotor 200 by the outer thin portion 206a, and the outer peripheral core portion 201a is opposite to the outer thin portion 206a. More fixed. Thereby, since the outer periphery iron core part 201a is fixed from both sides, it can suppress the deformation | transformation by centrifugal force.

  Further, the permanent magnet 203 can be positioned by forming the fixed component 210 so as to be in contact with the side surface of the permanent magnet 203. For this reason, it is not necessary to provide a projection (not shown) for positioning the permanent magnet 203 in the permanent magnet insertion portion 202. Since the magnetic flux generated from the permanent magnet 203 causes a short circuit due to the protrusions, the magnetic flux linked to the stator windings can be increased by eliminating the protrusions.

  7 to 10 show the first embodiment. FIG. 7 is a perspective view of the rotor core 201, FIG. 8 is a plan view of the first rotor core 201-1, and FIG. 9 is a second rotor. FIG. 10A is an enlarged view of a portion A in FIG. 8, and FIG. 8B is an enlarged view of a portion B in FIG. 9.

  The rotor core 201 will be described with reference to FIGS. Since this embodiment has a feature in the rotor core 201, it will be described in detail. As shown in FIG. 7, the rotor core 201 is formed by stacking a first rotor core 201-1 and a second rotor core 201-2 vertically in two stages. The rotor core 201 is formed by fitting the cut and raised protrusions formed on each soft magnetic plate with the adjacent soft magnetic plates in the axial direction while the soft magnetic plate is punched into a predetermined shape in a press die. These are laminated by general caulking (caulking portion 207) to be fixed. Therefore, the first rotor core 201-1 and the second rotor core 201-2 are connected by the caulking portion 207.

  In the first rotor core 201-1, the outer peripheral core portion 201a and the inner core portion 201b are connected between one pole at one magnetic pole (between the poles on the clockwise side at one magnetic pole in FIG. 8), The outer peripheral thin portion 206a is connected. An opening 208 is formed between the other pole of one magnetic pole (between the poles on the counterclockwise side of one magnetic pole in FIG. 8), and the outer peripheral iron core 201a and the inner iron core 201b are separated from each other. Yes.

  As shown in FIG. 8, the first rotor core 201-1 is formed with eight permanent magnet insertion portions 202 (the cross section is substantially bathtub-shaped and convex inward) along the outer peripheral portion in a substantially regular octagon. Has been. With these permanent magnet insertion portions 202 in between, the outer core portion 201a is the outer core portion than the permanent magnet insertion portion 202, and the inner core portion 201b is the inner core portion than the permanent magnet insertion portion 202. A shaft hole 205 into which a rotation shaft (not shown) is fitted is formed at the center of the first rotor core 201-1.

  As shown in FIG. 8, short-circuiting of magnetic flux between adjacent magnetic poles can be suppressed by providing only one side of each magnetic pole with thin connection parts (connection part 206, outer peripheral thin part 206a) between the magnetic poles. That is, an opening 208 communicating with the permanent magnet insertion portion 202 is provided at one end (between the poles) of each magnetic pole.

  Even in this case, a part of the magnetic flux of the permanent magnet 203 is short-circuited by the magnetic pole itself through the outer peripheral thin portion 206a, the connecting portion 206, and the inner iron core portion 201b. For this reason, short-circuiting of the magnetic flux of the permanent magnet 203 cannot be completely prevented, but the magnetic flux that is short-circuited inside the rotor 200 can be halved compared to the conventional case. As a result, more magnetic flux can be linked to the stator windings, the induction voltage of the synchronous motor can be improved, the torque can be increased, and the efficiency of the synchronous motor can be increased.

  Further, since the inner core portion 201b and the outer peripheral core portion 201a of the first rotor core 201-1 are joined by at least one outer peripheral thin portion 206a, the number of magnetic parts of the rotor 200 increases. There is nothing. For this reason, an increase in assembly cost can be suppressed.

  For example, if the rotor core 201 is configured only by the first rotor core 201-1, the inner core portion 201b and the outer peripheral core portion 201a are connected by one outer peripheral thin portion 206a. There is a possibility that centrifugal force generated by rotation (mainly centrifugal force by the permanent magnet 203) is applied to the outer thin portion 206a, and stress concentrates on the outer thin portion 206a and deforms. For this reason, in this Embodiment, the rotor core produced by a centrifugal force is combined by combining the 1st rotor core 201-1 and the 2nd rotor core 201-2 from which the position of the opening part 208 differs. The deformation of 201 is suppressed.

  On the other hand, as shown in FIG. 9, the second rotor core 201-2 includes a connecting portion 206 that connects the outer core portion 201a and the inner core portion 201b and a thin outer peripheral portion 206a in the counterclockwise direction in one magnetic pole. It is provided between the poles. Moreover, the opening part 208 is formed between the poles of the clockwise direction in one magnetic pole, and the outer periphery iron core part 201a and the inner iron core part 201b are isolate | separated. Others are the same shape as the 1st rotor iron core 201-1. For comparison between the first rotor core 201-1 and the second rotor core 201-2, see also the enlarged view of FIG.

  FIG. 11 is a diagram showing the first embodiment, and is a partial plan view showing a state in which the first rotor core 201-1 and the second rotor core 201-2 are overlapped. When the first rotor core 201-1 and the second rotor core 201-2 are overlapped and viewed from above, the opening 208 of one (first rotor core 201-1) and the other (first The non-magnetic portion 202a inside the outer thin portion 206a of the second rotor core 201-2) is present so as to overlap at the same position. In other words, the opening 208 and the nonmagnetic portion 202a communicate with each other vertically in the laminated rotor core 201. The nonmagnetic portion 202a (hatched portion) shown in FIG.

  In the rotor 200 of the present embodiment, the permanent magnet 203 is inserted into the rotor core 201 in which the first rotor core 201-1 and the second rotor core 201-2 are stacked, and then the opening 208 is inserted. Then, a non-magnetic material fixing part 210 is inserted into the non-magnetic portion 202a and fixed. By inserting the fixing component 210 into the opening 208 and the nonmagnetic portion 202a, the relatively weak outer peripheral core portion 201a connected to the inner core portion 201b and the outer peripheral thin portion is fixed from both sides by the fixing component 210. Therefore, deformation due to centrifugal force can be suppressed.

  The first rotor core 201-1 and the second rotor core 201-2 have the same shape if they are turned upside down, but it is difficult to turn them upside down in a series of operations in a press mold. Therefore, the first rotor core 201-1 and the second rotor core 201-2 have different shapes.

  FIG. 12 is a diagram showing the first embodiment, and is a diagram comparing effective values of induced voltages of the synchronous motor using the rotor of the present embodiment and the synchronous motor using a general rotor. The vertical axis represents the induced voltage, and the induced voltage of a synchronous motor using a general rotor 400 having no opening is used as a reference (100 [%]).

  The graph shown in FIG. 12 includes a general rotor 400 having no opening portion in which both sides of the outer peripheral portion are joined from the left with thin-walled connecting portions, and the outer peripheral core portion is constituted by separate parts, and the opening portions are formed on both sides of the outer peripheral core portion. The general rotor 500 provided, and the rotor of the present embodiment in which the outer peripheral core portion is joined at only one outer peripheral thin portion and the connecting portion and has an opening on one side (for example, the first rotor core 201 -1 or the second rotor iron core 201-2).

  The rotor 500 having openings on both sides of the rotor 400 having no opening has an induced voltage higher by 10% or more, and the magnetic flux not short-circuited inside the rotor is linked to the stator windings. You can see that

  The rotor of the present embodiment is provided with an opening on one side to suppress a short circuit of magnetic flux in the rotor, and thus is less effective than the rotor 500 having openings on both sides. An induced voltage larger than that of the rotor 400 is obtained.

  FIG. 13 is a diagram showing the first embodiment, and is a diagram comparing the waveforms of induced voltages of the synchronous motor using the rotor of the present embodiment and the synchronous motor using a general rotor. In FIG. 13, a solid rotor is a general rotor 400 having no opening, a triangle (blackening) is a general rotor 500 having openings on both sides, and a white circle is an opening on one side of the present embodiment. (For example, one constituted by either the first rotor core 201-1 or the second rotor core 201-2).

  As shown in FIG. 13, in the case of the rotor 400 without an opening, the waveform is close to a trapezoidal wave. The rotor 500 having openings on both sides is a highly distorted waveform having two peaks in the vicinity of the peak of the waveform, and includes a high-order harmonic component. On the other hand, the rotor of the present embodiment has a waveform with less distortion compared to the induced voltages of the general rotors 400 and 500.

  FIG. 14 is a diagram showing the first embodiment, and is a diagram comparing cogging torque amplitudes of the synchronous motor using the rotor of the present embodiment and the synchronous motor using a general rotor.

  In the graph of FIG. 14, the cogging torque generated in the synchronous motor is obtained by electromagnetic field analysis, and the cogging torque generated in the synchronous motor using the rotor of the first embodiment and the cogging generated in the synchronous motor using a general rotor. This is a comparison with torque.

  The graph of FIG. 14 shows a general rotor 400 having no opening portion in which both sides of the outer peripheral portion are joined by a thin outer peripheral portion from the left, and the outer peripheral core portion is configured as a separate part, and openings are provided on both sides of the outer peripheral core portion. The general rotor 500, the rotor of the present embodiment in which the outer peripheral core portion is coupled with the outer peripheral thin portion only on one side and an opening is provided on one side (for example, the first rotor core 201-1 or For example, a rotor 200 in which two types of cores shown in FIG. 1 are stacked is arranged. The vertical axis shows the ratio [%] based on the conventional rotor without opening (100 [%]).

  FIG. 15 is a diagram showing the first embodiment, and is a diagram comparing the cogging torque waveforms of the synchronous motor using the rotor of the present embodiment and the synchronous motor using a general rotor. A thick rotor is a general rotor 400 having no opening, a triangle (blackening) is a general rotor 500 in which an outer peripheral iron core is formed of a separate part, and openings are provided on both sides of the outer peripheral iron core, and a thin wire is an opening. The rotor of this embodiment in which the part is installed only on one side of the magnetic pole (however, for example, one constituted by either the first rotor core 201-1 or the second rotor core 201-2), one side A rotor that combines two rotor cores (first rotor core 201-1 and second rotor core 201-2) having different opening positions in the present embodiment shown in FIG. 200 waveforms.

  The general rotor 500 in which the outer peripheral core portion is configured as a separate part from the general rotor 400 having no opening portion and the opening portions are provided on both sides of the outer peripheral core portion. The change in the magnetic flux density between the gaps is large between the gap and the opening, and a large cogging torque more than twice that of the rotor 400 having no opening on the outer periphery is generated.

  In the rotor of the present embodiment in which the thin line has the opening provided only on one side of the magnetic pole, the influence is small and the increase is reduced to about 60%.

  In the case of the rotor 200 shown in FIG. 1, the position of the opening 208 differs between the upper and lower rotor cores in the axial direction, and the phases of the cogging torque generated by each of them are shifted. It can be suppressed to increase.

  16 to 22 show the first embodiment. FIG. 16 is a perspective view of a rotor 300 according to the first modification, FIG. 17 is a plan view of the rotor 300 according to the first modification, and FIG. 19 is an exploded perspective view of the rotor 300, FIG. 19 is a perspective view of the rotor assembly 300-1 of Modification 1, FIG. 20 is a perspective view of the fixed component 310, and FIG. 21 is a perspective view of the rotor core 301 of Modification 1. FIG. 22 is a plan view of the first rotor core 301-1 and the second rotor core 301-2 of the first modification.

  A rotor 300 according to the first modification will be described with reference to FIGS. 16 to 22. The rotor 300 of Modification 1 is different from the rotor 200 in that the position of the opening 308 of the permanent magnet insertion portion 302 of each of the first rotor core 301-1 and the second rotor core 301-2. Is different between adjacent magnetic poles. At adjacent magnetic poles, the opening 308 or the connecting portion 306 (including the outer peripheral thin portion 306a) is collected and disposed between the poles.

  The rotor core 301 of the first modification is laminated by rotating the first rotor core 301-1 and the second rotor core 301-2 by one magnetic pole and shifting them. There is one type of rotor core shape. When the rotor core is punched with a mold and laminated, the rotor core is rotated by 45 ° because it has eight poles in the case of FIG. In this case, the rotor 300 can be manufactured.

  Even with such a configuration, since the amount of magnetic flux that is short-circuited inside the magnetic body of the rotor 300 can be reduced, the same effect as the rotor 200 can be obtained.

  Since the rotor 300 of Modification 1 is also an eight-pole motor, the first rotor core 301-1 and the second rotor core 301-2 are each provided with four openings 308 and a non-magnetic portion 302a. Is formed.

  Therefore, in the rotor 200, a total of 16 fixed parts 210 are necessary, but in the rotor 300 of the first modification, the number is reduced to a total of 8 fixed parts 310.

  As shown in FIG. 18, in the rotor 300, a total of four fixed components 310 are inserted from the opening 308 on the axial end surface of the first rotor core 301-1. Further, in the rotor 300, a total of four fixing parts 310 are inserted from the opening (described later) on the axial end surface of the second rotor core 301-2. Accordingly, a total of eight fixed parts 310 are used. Since the rotor 300 is an 8-pole rotor, the number of fixed parts 310 is twice as many as the number of poles (8 poles) (the number of stages of the rotor core, here 2 stages).

  When the core width (axial length) of the first rotor core 301-1 and the core width (axial length) of the second rotor core 301-2 are the same, one type of fixing is performed. The part 310 may be sufficient. In FIG. 18, the core width (axial length) of the first rotor core 301-1 is the same as the core width (axial length) of the second rotor core 301-2. This is an example in which the fixed component 310 is used.

  In the present embodiment, the core width (axial length) of the first rotor core 301-1 and the core width (axial length) of the second rotor core 301-2 are the same. However, it may not be the same. When the core width (axial length) of the first rotor core 301-1 and the core width (axial length) of the second rotor core 301-2 are different, two types of fixing are used. A part 310 is required.

  As shown in FIG. 20, the fixed component 310 has a symmetrical shape with respect to a center line corresponding to the gap. The fixed component 310 also includes an opening portion insertion portion 310a and a nonmagnetic portion insertion portion 310b.

  In FIG. 16 to FIG. 22, the other numerals are changed from “2” to “3” in the first digit with respect to the numerals shown in FIG. 1 to FIG. Things refer to the same part. For example, the shaft hole 305 is the same as the shaft hole 205.

  In the rotor 300, a part of the magnetic flux of the permanent magnet 303 is short-circuited between the magnetic pole itself and the magnetic pole between the poles where the outer peripheral thin portion 306a and the connecting portion 306 gather. However, since the magnetic flux of the permanent magnet 303 is not short-circuited between the poles in which the opening 308 is formed, the magnetic flux that is short-circuited inside the rotor 300 can be halved compared to the conventional case. As a result, more magnetic flux can be linked to the stator windings.

  As an application example of the present invention, the present invention can be applied to a synchronous motor used for a blower having a relatively low operation speed.

  200 Rotor, 200-1 Rotor assembly, 201 Rotor core, 201a Outer core, 201b Inner core, 201-1 First rotor core, 201-2 Second rotor core, 202 Permanent magnet insertion Part, 202a Non-magnetic part, 203 Permanent magnet, 205 Shaft hole, 206 Connecting part, 206a Thin outer peripheral part, 207 Caulking part, 208 Opening part, 210 Fixed part, 210a Opening insertion part, 210b Non-magnetic part insertion part, 300 Rotor, 301 rotor core, 301-1 first rotor core, 301-2 second rotor core, 310 fixed part, 310a opening insertion portion, 310b non-magnetic portion insertion portion, 400 rotor, 401 Rotor core, 401a outer core, 401b inner core, 402 permanent magnet insert, 403 permanent magnet, 405 shaft hole, 406 Binding portion, 406a outer peripheral thin portion 407 caulked portion, 500 rotor, 501 rotor core, 501a outer peripheral core portion, 501b inner core portion, 502 permanent magnet insertion portion, 503 permanent magnet, 505 shaft hole 508 opening.

Claims (3)

In the rotor of a synchronous motor in which permanent magnets constituting magnetic poles are arranged inside a rotor core formed by laminating a predetermined number of soft magnetic materials punched into a predetermined shape,
The rotor core is a combination of a first rotor core formed by laminating a predetermined number of soft magnetic bodies and a second rotor core formed by laminating a predetermined number of soft magnetic bodies. The first rotor core and the second rotor core are each formed as follows:
A permanent magnet insertion portion formed along an outer peripheral edge of the first rotor core or the second rotor core, into which the permanent magnet is inserted;
An inner iron core portion formed inside the permanent magnet insertion portion;
An outer peripheral iron core portion formed on each magnetic pole outside the permanent magnet insertion portion;
A connecting portion for connecting the inner core portion and the outer peripheral core portion at the end of each magnetic pole, and a thin outer peripheral portion;
A non-magnetic portion that is formed inside the outer peripheral thin portion and communicates with the permanent magnet insertion portion;
An opening that is provided at an end opposite to the end where the connecting portion of each magnetic pole and the outer peripheral thin portion are provided, and communicates with the permanent magnet insertion portion;
In the first rotor core and the second rotor core, the openings are arranged at different ends of the magnetic poles, and the first rotor core and the second rotor core are combined. Thus, the one opening and the other non-magnetic part, or the one non-magnetic part and the other opening are communicated in the axial direction, and the communicated non-magnetic part and the opening are connected to each other. A rotor of a synchronous motor, wherein a stationary part made of a nonmagnetic material is inserted.   The rotor of a synchronous motor according to claim 1, wherein the opening is wider on the outer peripheral side than on the inner side.   The synchronous motor rotor according to claim 1, wherein the fixed component is made of a non-magnetic metal or resin.

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