JP5546413B2 - Synchronous motor rotor - Google Patents

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 rotating the first rotor core and the second rotor core by one magnetic pole and shifting them so that a predetermined number of layers are appropriately stacked, and the first rotor core and the second rotor are formed. With iron core,
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 opening portion, the connecting portion, and the thin outer peripheral portion are arranged together between the same magnetic poles in adjacent magnetic poles, and are laminated by rotating the first rotor core and the second rotor core by one magnetic pole and shifting them. Thus, one opening and the other non-magnetic part, or one non-magnetic part and the other opening communicate in the axial direction, and the communicating non-magnetic part and opening are filled with a non-magnetic material. It is characterized by that.

  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. FIG. 5 shows the first embodiment, and is a perspective view of the rotor assembly 200-1 (before resin molding). FIG. 5 shows the first embodiment, and is a plan view of the rotor assembly 200-1 (before resin molding). 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. 6, (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. 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 perspective view of a rotor 600 of a second modification. 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 (rotor 200) 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 (rotor 200) 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 (rotor 200) 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 (rotor 200) 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 700 of a third modification. FIG. 5 shows the first embodiment and is a plan view of a rotor 700 of a third modification. FIG. 5 shows the first embodiment, and is a perspective view of a rotor assembly 700-1 (before resin molding) of Modification 3. FIG. 5 shows the first embodiment, and is a plan view of a rotor assembly 700-1 (before resin molding) of Modification 3. FIG. 5 shows the first embodiment, and is a perspective view of a rotor core 701 of a third modification. FIG. 5 shows the first embodiment, and is a plan view of a first rotor core 701-1 and a second rotor core 701-2 of Modification 3. FIG. 9 shows the first embodiment, and is a perspective view of a rotor 800 of a fourth modification. FIG. 5 shows the first embodiment, and is a perspective view of a rotor 900 of a fifth modification. 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. The figure which shows Embodiment 1 and the figure which compared the waveform of the cogging torque of the synchronous motor using the rotor (rotor 700) of this Embodiment, and the synchronous motor using a common rotor.

  Embodiment 1 FIG.

  FIGS. 1 and 2 are views showing the first embodiment, and are perspective views of a rotor 200. FIG. 2 is a plan view of the rotor 200. FIG. 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 and 2, 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). And a non-magnetic material 210 (resin) filled in a non-magnetic portion (described later) formed in an end portion of each permanent magnet insertion portion (described later) and a rotor core 201. And a rotating shaft (not shown) fixed to a shaft hole 205 formed at the approximate center of the shaft.

  The rotor 200 shown in FIGS. 1 and 2 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 drawing, end plates for stopping 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. The formed opening (described later) and nonmagnetic portion (described later) are filled with a nonmagnetic material 210 (resin), and are connected to the inner core 201b by the outer peripheral thin portion, and the relatively weak outer peripheral core 201a. Is to suppress the deformation of the rotor core 201 caused by centrifugal force. Reference numerals that are not shown in the reference numerals shown in FIGS. 1 and 2 will be described later.

  3 and 4 show the first embodiment. FIG. 3 is a perspective view of the rotor assembly 200-1 (before resin molding), and FIG. 4 is a plan view of the rotor assembly 200-1 (before resin molding). It is. The state before the resin filling is referred to as a rotor assembly 200-1. The rotor assembly 200-1 before resin filling has an opening 208 formed at an end portion of a permanent magnet insertion portion 202 (described later) and a nonmagnetic portion 202a (excluding both axial ends in the state where the permanent magnet 203 exists). A 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. 24 is a view for comparison, and is a cross-sectional view of a rotor 400 of a general synchronous motor. 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. The rotor core 401 includes a shaft hole 405 that is fixed to a rotational shaft (not shown).

  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. 25 is a view for comparison, and is a cross-sectional view of a rotor 500 of a general synchronous motor. 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 a divided outer core portion 501a and inner core portion 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. The outer peripheral core portion 501a and the inner iron core portion 501b are laminated by a general caulking (caulking portion 507) in which the cut and raised protrusions formed on the soft magnetic plate are fitted and fixed by the soft magnetic plates adjacent in the axial direction. Is done.

  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.

  In the rotor core 201 of the present embodiment, the outer peripheral core part 201a and the inner iron core part 201b are connected by the connecting part 206 and the outer peripheral thin part 206a between the poles on one side in one magnetic pole. 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 portion 202 (described later) is not a space completely surrounded by the magnetic body in the rotor core 201 but opens to the outer periphery of the rotor core 201 at 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.

  5 to 8 show the first embodiment. FIG. 5 is a perspective view of the rotor core 201, FIG. 6 is a plan view of the first rotor core 201-1, and FIG. 7 is a second rotor. FIG. 8A is an enlarged view of a portion A in FIG. 6, and FIG. 8B is an enlarged view of a portion B in FIG. 7.

  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. 5, 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 to each other at one link between one side poles (in FIG. 6, between the poles on the clockwise side in one pole). The outer peripheral thin portion 206a is connected. An opening 208 is formed between the other poles of one magnetic pole (in FIG. 6, between the poles on the counterclockwise side of one magnetic pole), and the outer core part 201a and the inner core part 201b are separated from each other. Yes.

  As shown in FIG. 6, 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 periphery 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. 6, short-circuiting of magnetic flux between adjacent magnetic poles can be suppressed by providing only one side of each magnetic pole with thin connection portions (connection portion 206, outer peripheral thin-wall portion 206 a) 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. 7, the second rotor core 201-2 has a connecting portion 206 that connects the outer core portion 201a and the inner core portion 201b and a thin outer peripheral portion 206a on the counterclockwise side 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.

  FIG. 9 is a diagram showing the first embodiment, and is a partial plan view of 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 non-magnetic 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 nonmagnetic material (resin) is injected into the nonmagnetic portion 202a and fixed. As a result, the outer peripheral iron core part 201a is fixed to the inner iron core part 201b at both ends by the nonmagnetic material 210 (resin) fixed to the thin-walled connecting parts (outer peripheral thin-walled part 206a, connecting part 206). The deformation of the core iron 201 can be suppressed.

  Resin is used for the nonmagnetic material 210. What is necessary is just to shape | mold integrally by general injection molding. However, since the linear expansion coefficient differs between the resin and the iron core material with respect to the temperature change, the resin may peel from the iron core. However, in the case of the present embodiment, the nonmagnetic material 210 is filled in the space (nonmagnetic portion 202a) inside the thin connecting portion (the outer peripheral thin portion 206a and the connecting portion 206) and filled in the opening 208. And the non-magnetic material 210 can be prevented from scattering due to peeling. Further, by making the opening 208 wider on the outer peripheral side than on the inner peripheral side, the centrifugal force generated in the outer peripheral core portion 201a is received by the nonmagnetic material 210, and the centrifugal force generated in the outer peripheral core portion 201a and the permanent magnet 203 is received. It will be received on both sides of the outer peripheral core portion 201a, and the deformation of the rotor core 201 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. 10 is a diagram showing the first embodiment, and is a perspective view of a rotor 300 of the first modification. In the rotor 200, the nonmagnetic material 210 is directly injected into each nonmagnetic portion 202a or the opening 208. However, the number of gates at the time of resin injection is reduced, and the permanent magnet 203 is prevented from coming off. The rotor 300 of the modification 1 which can abbreviate | end an end plate is demonstrated.

  As shown in FIG. 10, the rotor 300 of Modification 1 is different from the rotor 200 only in that the nonmagnetic material 310 is formed in a ring shape at both axial ends of the rotor 300. The shape of the nonmagnetic material 310 (resin) formed in a ring shape at both ends in the axial direction of the rotor 300 is very similar to the end ring of the induction machine. By configuring in this way, the number of gates at the time of resin injection is reduced, and an end plate for preventing the permanent magnet from coming off can be omitted.

  The rotor core 301 of the rotor 300 of the first modification is configured by a first rotor core 301-1 and a second rotor core 301-2.

  FIG. 11 is a diagram showing the first embodiment, and is a perspective view of a rotor 600 of the second modification. In the case of the rotor core 201 shown in FIG. 5, the first rotor core 201-1 having the opening 208 on the counterclockwise side of the permanent magnet insertion portion 202 and the clockwise side of the permanent magnet insertion portion 202 are the opening. The second rotor core 201-2 which is 208 is divided into two in the axial direction. Therefore, for example, when the rotational speed of the rotor 200 increases and the centrifugal force applied to the outer peripheral thin portion 206a increases, the nonmagnetic material 210 of the opening 208 causes a distance from the nonmagnetic portion 202a inside the outer peripheral thin portion 206a. In some parts (parts away in the axial direction), the strength of the rotor 200 may be insufficient.

  In that case, the core width (length in the axial direction) of the rotor is fixed, and the rotor is not divided into two parts in the axial direction. The strength of the rotor core can be increased by reducing the volume of the filling portion of the magnetic material.

  A rotor 600 of Modification 2 shown in FIG. 11 is an example in which the rotor is divided into three in the axial direction. The rotor 600 of the second modification has the same core width (length in the axial direction) as the rotors 200 and 300. The rotor core 601 of Modification 2 is composed of two first rotor cores 601-1 and a second rotor core 601-2 sandwiched between the two first rotor cores 601-1. Is done. The core width (axial length) of the first rotor core 601-1 is ½ of the core width (axial length) of the second rotor core 601-2.

  The non-magnetic material 610 (resin) of the second rotor core 601-2 is connected to the non-magnetic portions (not shown) of the two first rotor cores 601-1 at both axial ends. Even if the centrifugal force applied to the thin outer peripheral portion (not shown) increases, there is little risk that the strength of the rotor 600 will be insufficient.

  The rotor 600 of Modification 2 is formed with ring-shaped nonmagnetic material 610 (resin) at both ends in the axial direction, but the ring-shaped nonmagnetic material 610 may be omitted.

  FIG. 12 is a diagram showing the first embodiment, and compares the effective value of the induced voltage between the synchronous motor using the rotor (rotor 200) of the present embodiment and the synchronous motor using a general rotor. FIG. 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, the rotor of the present embodiment having an opening on one side, in which the outer peripheral iron core is coupled to the outer peripheral thin-walled part and the connecting part only on one side (for example, in the case of the rotor 200, The first rotor core 201-1 or the second rotor core 201-2) is shown side by side.

  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 compares the induced voltage waveforms of the synchronous motor using the rotor (rotor 200) of the present embodiment and the synchronous motor using a general rotor. It is. 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. (However, in the case of the rotor 200, for example, it is a waveform of 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 (rotor 200) of the present embodiment and the synchronous motor using a general rotor. is there.

  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 and the rotor of this embodiment in which the outer peripheral core portion is coupled to the outer peripheral thin portion only on one side and an opening is provided on one side (for example, in the case of the rotor 200, the first A rotor 200 (two stages) formed by stacking cores having two types of shapes shown in FIG. 1, for example, one composed of the rotor core 201-1 or the second rotor core 201-2 (one stage)). ). The vertical axis shows the ratio [%] based on the conventional rotor without opening (100 [%]).

  FIG. 15 is a diagram illustrating the first embodiment, and is a diagram comparing the cogging torque waveforms of the synchronous motor using the rotor (rotor 200) of the present embodiment and the synchronous motor using a general rotor. It is. 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 iron core, and a thin wire is an opening. The rotor of the present embodiment is installed only on one side of the magnetic pole (however, in the case of the rotor 200, for example, it is constituted by either the first rotor core 201-1 or the second rotor core 201-2. 1), the white circle is the two rotor cores (the first rotor core 201-1 and the second rotor core) of the present embodiment shown in FIG. 201-2 (two stages))).

  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.

  The rotor of the present embodiment in which the opening indicated by the thin line is provided only on one side of the magnetic pole (for example, in the case of the rotor 200, the first rotor core 201-1 or the second rotor core 201- 2) (one stage))) has a small influence and is suppressed to an increase of about 60%.

  In the case of the rotor 200 shown in FIG. 1, the position of the opening 208 is different between the two upper and lower rotor cores in the axial direction, and the phases of the cogging torque generated in each of them are shifted. It is suppressed to an increase in the degree.

  The induced voltage and cogging torque in the case of using the rotor 300 of the first modification and the rotor 600 of the second modification are also the same as the characteristics of the rotor 200 shown in FIGS.

  In the above description, the rotor core is divided into blocks, and two different types of cores (for example, the first rotor core 201-1 and the second rotor core 201-2) are stacked in two or three stages. However, the method of stacking two different types of cores may be arbitrary. For example, two different types of cores may be alternately stacked. Moreover, a certain part may laminate | stack two different types of cores alternately, and may laminate | stack another part by the block unit of a different core.

  16 to 21 are diagrams showing the first embodiment. FIG. 16 is a perspective view of a rotor 700 according to the third modification. FIG. 17 is a plan view of the rotor 700 according to the third modification. 19 is a perspective view of the rotor assembly 700-1 (before resin molding), FIG. 19 is a plan view of the rotor assembly 700-1 (before resin molding) of Modification 3, and FIG. 20 is a perspective of the rotor core 701 of Modification 3. FIGS. 21A and 21B are plan views of a first rotor core 701-1 and a second rotor core 701-2 of the third modification.

  A rotor 700 of Modification 3 will be described with reference to FIGS. 16 to 21. The rotor 700 of Modification 3 is different from the rotors 200, 300, and 600 in that the openings of the permanent magnet insertion portions 702 of the first rotor core 701-1 and the second rotor core 701-2 are different. The position of the portion 708 is different between adjacent magnetic poles. In adjacent magnetic poles, the opening 708 or the connecting portion 706 (including the outer peripheral thin portion 706a) is collected and disposed between the poles.

  The rotor core 701 of Modification 3 is stacked by shifting the first rotor core 701-1 and the second rotor core 701-2 by rotating one magnetic pole. There is one type of rotor core shape. When the rotor core is punched and laminated with a mold, the rotor core is rotated by 45 ° because it is 8 poles in the case of FIG. In this case, the rotor 700 can be manufactured.

  Even in such a configuration, since the amount of magnetic flux that is short-circuited inside the magnetic body of the rotor 700 can be reduced, the same effect as the rotor 200, 300, 600 can be obtained.

  In FIG. 16 to FIG. 21, the other numerals are changed from “2” to “7” 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 705 is the same as the shaft hole 205.

  In the rotor 700, a part of the magnetic flux of the permanent magnet 703 is short-circuited between the magnetic pole itself and the magnetic pole between the poles where the outer peripheral thin portion 706 a and the connecting portion 706 are gathered. However, since the magnetic flux of the permanent magnet 703 is not short-circuited between the poles in which the opening 708 is formed, the magnetic flux that is short-circuited inside the rotor 700 can be halved compared to the conventional case. As a result, more magnetic flux can be linked to the stator windings.

  FIG. 22 is a diagram illustrating the first embodiment, and is a perspective view of a rotor 800 according to the fourth modification. In the rotor 700, the nonmagnetic material 710 is directly injected into the respective nonmagnetic portions 702a or openings 708. However, in the rotor 800 of the modified example 4, the number of gates at the time of resin injection is reduced, and the permanent magnetic material 710 is permanent. The end plate for retaining the magnet can be omitted.

  As shown in FIG. 22, the rotor 800 of Modification 4 is different from the rotor 700 only in that the nonmagnetic material 810 is formed in a ring shape at both axial ends of the rotor 800. The shape of the nonmagnetic material 810 (resin) formed in a ring shape at both axial ends of the rotor 800 is very similar to the end ring of the induction machine. By configuring in this way, the number of gates at the time of resin injection is reduced, and an end plate for preventing the permanent magnet from coming off can be omitted.

  FIG. 23 is a diagram illustrating the first embodiment, and is a perspective view of a rotor 900 according to the fifth modification. In the case of the rotor 800 shown in FIG. 22, the first rotor core 801-1 and the second rotor core 801-2 constituting the rotor core 801 are divided into two in the axial direction. Therefore, for example, when the rotational speed of the rotor 800 increases and the centrifugal force applied to the outer thin portion increases, the nonmagnetic material 810 in the opening has a portion (shaft) away from the nonmagnetic portion inside the outer thin portion. In a portion separated in the direction), the strength of the rotor 800 may be insufficient.

  In that case, the core width (length in the axial direction) of the rotor is fixed, and the rotor is not divided into two parts in the axial direction. The strength of the rotor core can be increased by reducing the volume of the filling portion of the magnetic material.

  A rotor 900 of Modification 5 shown in FIG. 23 is an example in which the rotor is divided into three in the axial direction. The rotor 900 of Modification 5 has the same core width (length in the axial direction) as the rotors 700 and 800. The rotor core 901 of the rotor 900 of Modification 5 includes two first rotor cores 901-1 and a second rotor core 901 sandwiched between the two first rotor cores 901-1. -2. The core width (axial length) of the first rotor core 901-1 is ½ of the core width (axial length) of the second rotor core 901-2.

  The non-magnetic material 910 (resin) of the second rotor core 901-2 is connected to the non-magnetic portions (not shown) of the two first rotor cores 901-1 at both axial ends. Even if the centrifugal force applied to the thin outer peripheral portion (not shown) increases, there is little risk that the strength of the rotor 900 will be insufficient.

  The rotor 900 of Modification 5 has ring-shaped nonmagnetic material 910 (resin) formed at both ends in the axial direction, but the ring-shaped nonmagnetic material 910 may not be provided.

  FIG. 26 is a diagram showing the first embodiment, and is a diagram comparing the cogging torque waveforms of the synchronous motor using the rotor (rotor 700) of the present embodiment and the synchronous motor using a general rotor. It is. 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 the present embodiment in which the part is installed only on one side of the magnetic pole (however, in the case of the rotor 700, for example, either the first rotor core 701-1 or the second rotor core 701-2) 16), the white circle is the two rotor cores (first rotor core 701-1, second rotor) of the present embodiment shown in FIG. It is the waveform of the rotor 200 which combined the iron core 701-2 (two steps)).

  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.

  The rotor according to the present embodiment in which the opening indicated by the thin line is provided only on one side of the magnetic pole (for example, in the case of the rotor 700, the first rotor core 701-1 or the second rotor core 701- 2) (one stage))) has a small influence and is suppressed to an increase of about 60%.

  In the case of the rotor 700 shown in FIG. 16, the position of the opening 708 is different between the two upper and lower rotor cores in the axial direction, and the phases of the cogging torque generated are shifted. It is suppressed to an increase in the degree.

  In addition, when using the rotor 800 of the modification 4 and the rotor 900 of the modification 5, it becomes the same as the waveform of the cogging torque of the rotor 700 shown in FIG.

  Further, the effective value of the induced voltage, the waveform of the induced voltage, and the cogging torque amplitude of the rotors 700 to 900 are substantially the same as those shown in FIGS.

  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 outer peripheral thin part, 207 crimping part, 208 opening part, 210 non-magnetic material, 300 rotor, 301 rotor iron core, 301-1 1 rotor core, 301-2 second rotor core, 310 nonmagnetic material, 400 rotor, 401 rotor core, 401a outer core, 401b inner core, 402 permanent magnet insert, 403 permanent magnet, 405 Shaft hole, 406 Connecting portion, 406a Thin outer peripheral portion, 407 Caulking portion, 500 Rotor, 501 Rotor core, 501a Outside Iron core part, 501b Inner iron core part, 502 Permanent magnet insertion part, 503 Permanent magnet, 504 Shaft hole, 507 Caulking part, 508 Opening part, 600 Rotor, 601 Rotor core, 601-1 First rotor core, 601 -2 second rotor core, 610 non-magnetic material, 700 rotor, 700-1 rotor assembly, 701 rotor core, 701-1 first rotor core, 701-2 second rotor core, 702 Permanent magnet insertion part, 702a Non-magnetic part, 703 Permanent magnet, 705 Shaft hole, 706 Connection part, 706a Thin outer peripheral part, 708 Opening part, 710 Non-magnetic material, 800 Rotor, 801 Rotor core, 801-1 1st 1 rotor core, 801-2 second rotor core, 810 non-magnetic material, 900 rotor, 901 rotor core, 901-1 first rotor core 901 - second rotor core, 910 non-magnetic material.

Claims (4)

In the rotor of a synchronous motor in which permanent magnets constituting magnetic poles are arranged inside a rotor core formed by laminating soft magnetic materials punched into a predetermined shape,
The rotor core is formed by combining a first rotor core formed by laminating a plurality of soft magnetic bodies and a second rotor core that are rotated and shifted by one magnetic pole. The rotor core and the second rotor core are respectively
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 from the outer peripheral edge to the permanent magnet insertion portion,
The opening or the outer peripheral thin portion is arranged between magnetic poles adjacent in the circumferential direction, and the opening and the outer thin portion are alternately arranged in the circumferential direction, and the first rotor core and the first The two rotor iron cores are rotated and shifted by one magnetic pole so that the one opening and the other nonmagnetic part communicate in the axial direction, and the one nonmagnetic part and the other The rotor of the synchronous motor is characterized in that the non-magnetic portion and the opening are communicated with each other in the axial direction, and the non-magnetic material integrated with the non-magnetic portion is filled in the opening.   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 nonmagnetic material is filled by injection molding.   The ring-shaped part is formed in the axial direction both ends of the said rotor with the nonmagnetic material with which the said nonmagnetic part and the said opening part are filled, The Claim 1 thru | or 3 characterized by the above-mentioned. Synchronous motor rotor.

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