JP2013051840A - Rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts, and to simplify a manufacturing process by omitting a fixing member such as a rivet in a magnet embedded rotary electric machine.SOLUTION: A cylindrical rotor core (210) is provide which is formed with a plurality of magnet slots (211) into which permanent magnets (220) are inserted. A plurality of magnet pairs (500) are provided which are configured by a plurality (for example, two) of the platy permanent magnets (220) in which plate surfaces are magnetic poles, and inserted into the magnet slots (211). Each of the permanent magnets (220) is formed with a projecting portion (220b) abutting on an end surface (210a) on one side of the rotor core (210). The two permanent magnets (220) consisting of the magnet pair (500) have different end surfaces (210a) on which the projecting portions (220b) thereof abut, and magnetic surfaces are superimposed in a direction attracting each other by magnetic force.

Description

  The present invention relates to a rotor used in a magnet-embedded rotary electric machine.

  Conventionally, as shown in Patent Document 1, some electric motors are mounted on a compressor to drive a compression mechanism, and this electric motor includes an embedded magnet type motor. The rotor of this embedded magnet type motor is composed of a rotor core having a large number of electromagnetic steel plates, a permanent magnet embedded in a slot of the rotor core, and end plates provided at both ends of the rotor core.

JP 2004-336831 A

  In a rotor of a conventional embedded magnet type motor, a permanent magnet is inserted into a rotor core and fixed integrally by rivets penetrating both sides of an end plate.

  However, in this conventional rotor, since the electromagnetic steel plate and the permanent magnet are fixed by rivets, the number of parts is increased and a fixing process using rivets is required. As a result, the conventional rotor has a problem of high cost. In addition, in order to secure the rivet insertion position, there are restrictions on the arrangement of the permanent magnets.

  The present invention has been made in view of such a point, and an object thereof is to omit a fixing member such as a rivet, to reduce the number of parts, and to simplify the manufacturing process.

In order to solve the above-mentioned problem, the first invention
A rotor having a plurality of rotor magnetic poles,
A cylindrical rotor core (210) formed with a plurality of magnet slots (211) for inserting permanent magnets (220);
A plurality of magnet pairs (500) configured by a plurality of plate-like permanent magnets (220) whose plate surfaces are magnetic poles and inserted into the magnet slots (211);
Each permanent magnet (220) is formed with a protrusion (220b) that abuts on one axial end face (210a) of the rotor core (210),
Of the permanent magnets (220) constituting the magnet pair (500), the two permanent magnets (220) that are in contact with each other have different end surfaces (210a) with which the respective protrusions (220b) abut, and magnetic forces. The magnetic pole surfaces overlap each other in the direction of attracting each other.

  In this configuration, the two magnets (220) in contact with each other in the magnet pair (500) are attracted to each other by magnetic force. When the two magnets (220) attract each other, these magnets (220) try to move to a position where the length of the magnetic path formed between them is the shortest. In the present invention, since the two magnets (220) constituting the magnet pair (500) are opposite to each other in the end surface (210a) of the rotor core (210) with which the respective protrusions (220b) abut, A force in a direction of sandwiching the rotor core (210) is applied to the rotor core (210) by the protrusions (220b) of the two magnets (220) constituting the magnet pair (500).

In addition, the second invention,
In the rotor of the first invention,
In the magnet slot (211), two plate-like permanent magnets (220) are inserted.

  In this configuration, the magnet pair (500) is formed by two permanent magnets (220).

In addition, the third invention,
In the rotor of the first or second invention,
The rotor magnetic poles adjacent to each other are characterized in that the end faces (210a) with which the protrusions (220b) of the inner peripheral side permanent magnet (220) abut are different from each other.

  In this configuration, the magnets (220) on the inner peripheral side attract each other by magnetic force between adjacent rotor magnetic poles. Therefore, these magnets (220) also try to fit in the position where the length of the magnetic path formed between them becomes the shortest. The rotor magnetic poles adjacent to each other have the end surfaces (210a) of the rotor core (210) that are in contact with the protrusions (220b) of the magnet (220) on the inner peripheral side, which are opposite to each other. Therefore, in this rotor (200), a force in the direction of sandwiching the rotor core (210) is applied by the protruding portion (220b) of the inner peripheral side magnet (220) constituting the adjacent rotor magnetic pole.

In addition, the fourth invention is
In the rotor of the first or third invention,
Each rotor magnetic pole is composed of a plurality of the magnet pairs (500) continuous in the radial direction of the rotor core (210),
The permanent magnets (220) facing each other through the iron core (210b) in the same rotor magnetic pole are characterized in that the end faces (210a) with which the projecting portions (220b) abut are different from each other.

  In this configuration, the permanent magnets (220) facing each other through the iron core (210b) in the same rotor magnetic pole tend to move to a position where the length of the magnetic path formed between them is the shortest. The opposing permanent magnets (220) have different end faces (210a) with which the protrusions (220b) come into contact with each other, so that a force in the direction of sandwiching the rotor core (210) is applied by the protrusions (220b). Will be.

In addition, the fifth invention,
In any one of the first to fourth aspects of the rotor,
The protrusion (220b) is in a non-magnetized state or in a weakly magnetized state than the magnetic pole surface.

  In this configuration, it is possible to reduce or eliminate the magnetic flux (magnetic flux flowing in the axial direction inside the rotor core) from the protrusion (220b) toward the rotor core (210).

In addition, the sixth invention,
In any one of the first to fifth aspects of the rotor,
An insertion length (Lm) of the permanent magnet (220) into the magnet slot (211) is smaller than a depth (Lc) of the magnet slot (211).

  In this configuration, a predetermined gap is provided between the tip of the magnet (220) (the end opposite to the protruding portion (220b)) and the protruding portion (220b), so that they can be prevented from interfering with each other.

In addition, the seventh invention,
In any one of the rotors of the first to sixth inventions,
The rotor core (210) is formed by laminating electromagnetic steel plates,
The electromagnetic steel plates at both ends of the rotor core (210) are thicker than the intermediate electromagnetic steel plates.

  In this configuration, the thickness of the electromagnetic steel plates at both ends is larger than that of the intermediate electromagnetic steel plates, so that the rigidity of the rotor core (210) can be increased.

Further, the eighth invention is
In any one of the rotors of the first to sixth inventions,
The rotor core (210) is formed by laminating electromagnetic steel plates, and both end faces (210a) are provided with nonmagnetic end plates (230) different from the electromagnetic steel plates,
Each end plate (230) is formed with a through hole (231) into which the permanent magnet (220) is inserted.

  In this configuration, the end plate (230) and the rotor core (210) are sandwiched and fixed by the protrusion (220b) of the magnet (220).

In addition, the ninth invention,
In any one of the first to seventh inventions,
The magnet slot (211) is characterized in that the entrance (211c) of the permanent magnet (220) is wider than the back (211d).

  A corner R may be formed between the main body (220a) and the protrusion (220b) of the magnet (220). In this configuration, since the entrance (211c) is widened, the rotor core (210 ) And the corner R can be prevented from interfering with each other.

  According to 1st invention, the force of the direction which pinches | interposes this rotor core (210) is applied to a rotor core (210) by the protrusion part (220b) provided in the magnet (220). Thereby, a fixing member such as a rivet can be omitted, the number of parts can be reduced, and the manufacturing process can be simplified.

  In addition, according to the second invention, since the number of permanent magnets (220) constituting the magnet pair (500) can be minimized, the number of parts is reduced, and manufacturing is facilitated.

  According to the third aspect of the invention, the magnetic force acting between the adjacent rotor magnetic poles generates a force such that the protrusion (220b) provided on the magnet (220) sandwiches the rotor core (210). Therefore, the rotor core (210) can be sandwiched more firmly.

  According to the fourth aspect of the present invention, a force for sandwiching the rotor core (210) is generated by the permanent magnet (220) facing each other through the iron core (210b) in the same rotor magnetic pole. Therefore, the rotor core (210) can be sandwiched more firmly.

  Further, according to the fifth aspect of the present invention, since the magnetic force directed from the protrusion (220b) to the rotor core (210) can be reduced or eliminated, generation of eddy currents in the rotor core (210) by the protrusion (220b) can be reduced. It becomes possible to prevent.

  In addition, according to the sixth invention, the tip of the magnet (220) (the end opposite to the protruding portion (220b)) and the protruding portion (220b) can be prevented from interfering with each other, so that the rotor core (210 ) Can be sandwiched between the protrusions (220b).

  Further, according to the seventh aspect, the rigidity of the rotor core (210) can be increased, so that the strength of the rotor core (210) can be increased.

  Further, according to the eighth invention, since the end plate (230) is also fixed by the magnet (220), the rotor structure (200) having the end plate (230) can be simplified in the same manner as the above invention. It becomes possible to plan.

  According to the ninth invention, the corner R between the main body (220a) and the protrusion (220b) and the rotor core (210) can be prevented from interfering with each other, so that the rotor core (210) protrudes more reliably. It becomes possible to sandwich the portion (220b).

FIG. 1 is a longitudinal sectional view schematically showing a configuration of an electric compressor to which a motor according to Embodiment 1 of the present invention is applied. FIG. 2 is a cross-sectional view of the vicinity of the motor in the electric compressor. FIG. 3 is a plan view of the rotor core as viewed from the axial direction. FIG. 4 is a cross-sectional view of the rotor. FIG. 5 is a perspective view of the magnet. FIG. 6 is a diagram illustrating an example of a cross-sectional shape of a magnet. FIG. 7 is a diagram illustrating still another example of the cross-sectional shape of the magnet. 8A and 8B are cross-sectional views of the magnet slot, in which FIG. 8A shows a state in which a magnet is inserted, and FIG. 8B shows a state in which no magnet is inserted. FIG. 9 is a cross-sectional view showing an example of the shape of the magnet slot. FIG. 10 is a diagram for explaining the overlapping state of the magnets constituting the magnet pair. FIG. 11 is a diagram illustrating the positional relationship of the protrusions in the magnets between adjacent rotor magnetic poles. FIG. 12 is a perspective view showing a state after a magnet is inserted into the rotor core. FIG. 13 is a cross-sectional view of a rotor according to Embodiment 2 of the present invention. FIG. 14 is a perspective view of a rotor core according to the second embodiment. FIG. 15 is a cross-sectional view illustrating another example of the protruding portion. FIG. 16 is a diagram illustrating an example of setting the magnet insertion length. FIG. 17 is a diagram for explaining an example of setting the thickness of the electromagnetic steel sheet. FIG. 18 is a diagram illustrating an example of a rotor having end plates. FIG. 19 is a cross-sectional view illustrating an example in which a balancer is configured with end plates. FIG. 20 is a plan view of the balancer. FIG. 21 is a diagram illustrating an example of a claw for temporarily fixing a magnet.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

Embodiment 1 of the Invention
<Overview>
FIG. 1 is a longitudinal sectional view schematically showing a configuration of an electric compressor (1) (compressor) to which a motor (10) according to Embodiment 1 of the present invention is applied. The motor (10) is an example of the rotating electric machine of the present invention. The electric compressor (1) is used for an air conditioner (not shown), for example, and is installed in an outdoor unit (not shown) of the air conditioner.

  The electric compressor (1) includes a motor (10), a compression mechanism (20), and a casing (30). As shown in the figure, the motor (10) includes a stator (100), a rotor (200), and a drive shaft (300), and is accommodated in a casing (30) of the electric compressor (1). As the compression mechanism (20), for example, various compression mechanisms such as a scroll type or a rotary type can be adopted. In FIG. 1, the stator (100) and the rotor (200) are drawn in contact with each other, but actually, the rotor (200) is rotatably opposed to the stator (100) through a small gap. The motor (10) is a brushless DC motor. More specifically, it is an embedded magnet type motor (so-called IPM motor) in which the rotor core directly faces the stator core. The motor (10) drives the compression mechanism (20).

<Configuration of motor (10)>
Below, the structure of a motor (10) is demonstrated. In the following description, the axial direction refers to the direction of the axis of the drive shaft (300), and the radial direction refers to the direction orthogonal to the axis. Further, the outer peripheral side means a side farther from the axis, and the inner peripheral side means a side closer to the axis.

<Stator>
FIG. 2 is a cross-sectional view of the vicinity of the motor (10) in the electric compressor (1). As shown in FIG. 2, the stator (100) includes a cylindrical stator core (110) and a coil (120).

  The stator core (110) is a laminated core obtained by punching an electromagnetic steel plate by press working to create a laminated plate and laminating a plurality of laminated plates in the axial direction. As shown in FIG. 2, the stator core (110) includes one back yoke portion (111), a plurality of (six in this example) teeth portions (112), and a flange portion (113).

  As shown in FIG. 2, each tooth portion (112) is a rectangular parallelepiped portion extending in the radial direction in the stator core (110). A space between the teeth portions (112) is a coil slot (114) in which the coil (120) is accommodated. A coil (120) is wound around the teeth portion (112) by a so-called concentrated winding method. That is, the coil (120) is wound for each tooth portion (112), and the wound coil (120) is accommodated in the coil slot (114). Thereby, an electromagnet is formed in each teeth part (112).

  The back yoke portion (111) has an annular shape. The back yoke portion (111) connects the teeth portions (112) on the outer peripheral side of the teeth portion (112). The stator core (110) is fixed to the inner surface of the casing (30) at the outer periphery of the back yoke portion (111).

  The brim portion (113) is a portion connected to the inner peripheral side of each tooth portion (112). The brim portion (113) has a larger width (length in the circumferential direction) than the teeth portion (112). The collar portion (113) has a cylindrical inner surface. The cylindrical surface faces the outer peripheral surface (cylindrical surface) of the rotor core (210) with a predetermined distance (air gap (G)).

<Rotor (200)>
FIG. 3 is a plan view of the rotor core (210) viewed from the axial direction. FIG. 4 is a cross-sectional view of the rotor (200). FIG. 4 corresponds to the AOB section of FIG. The rotor (200) includes a rotor core (210) and a plurality of permanent magnets (220), and has a cylindrical shape (see FIG. 2). In this example, the rotor (200) includes four magnetic poles. Hereinafter, the magnetic pole of the rotor (200) is referred to as the rotor magnetic pole in order to distinguish it from the magnetic pole of the magnet (220).

-Permanent magnet (220)-
Each permanent magnet (220) (hereinafter also simply referred to as a magnet) is a magnet using a rare earth metal. Desirably, a neodymium iron boron-based magnet has a strong magnetic force, but even a ferrite magnet or the like can provide the same effect. FIG. 5 is a perspective view of the magnet (220). As shown in FIGS. 4 and 5, the magnet (220) includes a flat plate-like main body (220a) and a protrusion (220b), and has a T-shaped cross-sectional shape. The main body (220a) and the protrusion (220b) are integrally formed of the same material. However, in FIG. 4, for convenience of explanation, the cross section of the protrusion (220b) is hatched, and the main body (220a) ) Are marked with a dot on the cross section.

  In the magnet (220), the plate surface of the main body (220a) is a magnetic pole. The thickness of the main body (220a) is slightly smaller than the half of the radial width of the magnet insertion part (211a) by the clearance between the rotor core (210) and the permanent magnet (220).

  The projecting portion (220b) is a portion that is provided only on one end side in the axial direction of the magnet (220) and is continuous to the main body portion (220a). The protruding part (220b) has a flat part (220c) parallel to the axial end face (210a) of the rotor core (210) in a state where the magnet (220) is inserted into the magnet slot (211). . The flat portion (220c) comes into contact with the end surface (210a) of the rotor core (210) in a state where the protruding portion (220b) is inserted into the magnet slot (211). The axial length (Lm) of the main body (220a) (insertion length into the magnet slot (211)) is less than the depth (Lc) of the magnet slot (211) (ie, Lc ≧ Lm). is there. FIG. 4 illustrates an example in which the insertion length (Lm) is smaller than the depth (Lc).

  The protrusion (220b) is weakly magnetized than the plate surface (magnetic pole surface). If the material for the magnet (220) is magnetized after being inserted into the magnet slot (211), the projecting portion (220b) can be in such a magnetized state. This makes it possible to reduce or eliminate the magnetic force (magnetic force in the axial direction) from the protrusion (220b) toward the rotor core (210). For example, if the magnetic force of the protrusion (220b) is large, the magnetic force may cause a magnetic flux perpendicular to the steel plate surface to flow through the rotor core (210) and increase the eddy current. In the weakly magnetized state, eddy current can be reduced or prevented.

  The magnet (220) has a tapered cross section as shown in FIG. 6, or at the tip of the main body (220a) (the end opposite to the protruding portion (220b)) as shown in FIG. A chamfer may be provided. This facilitates the insertion of the magnet (220) into the magnet slot (211).

-Rotor core (210)-
The rotor core (210) is a laminated core obtained by punching an electromagnetic steel plate by press working to create a laminated plate (P) and laminating a plurality of laminated plates (P) in the axial direction. A shaft hole (212) is formed at the center of the rotor core (210). The drive shaft (300) is fixed to the shaft hole (212) by shrink fitting, for example. The drive shaft (300) is for driving the compression mechanism (20).

  As shown in FIG. 3, the rotor core (210) is formed with four magnet slots (211) into which the magnets (220) are respectively inserted. In FIG. 3, in order to identify the four magnet slots (211), branch numbers (-1, 2,...) Are added after the reference numerals.

  Each of the magnet slots (211) is arranged at a 90 ° pitch around the axis of the rotor core (210). Each magnet slot (211) has a generally U-shaped hole shape when viewed in the axial direction, and penetrates the rotor core (210) in the axial direction. Specifically, as shown in FIG. 3, the magnet slot (211) includes a magnet insertion part (211a) orthogonal to the radius of the rotor core (210) and two barriers extending from the magnet insertion part (211a) to the outer peripheral side. Part (211b). The magnet insertion portion (211a) is rectangular in plan view in FIG.

  8 is a cross-sectional view of the magnet slot (211), in which (A) shows a state in which the magnet (220) is inserted, and (B) shows a state in which the magnet (220) is not inserted. FIG. 8 corresponds to the AOB section of FIG. In the magnet slot (211), as shown in FIG. 8, the entrance (211c) is wider (widened) than the back (211d). In this way, the width of the inlet portion (211c) is increased by the corner R (see FIG. 8) formed between the main body portion (220a) and the protruding portion (220b) of the magnet (220) and the inlet portion. (211c) This is to prevent interference with nearby electrical steel sheets. Note that the widened shape of the inlet portion (211c) shown in FIG. 8 is an example, and other shapes such as those shown in FIG. In the example of FIG. 9, the width of the entrance portion (211c) changes stepwise in accordance with the corner R.

-Mounting the magnet (220) to the rotor core (210)-
In this embodiment, as shown in FIG. 4, the magnet pair (500) is comprised by the two plate-shaped magnets (220). One magnet pair (500) (that is, two magnets (220)) is fitted into one magnet slot (211). The two magnets (220) constituting the magnet pair (500) have different end surfaces (210a) with which the respective protrusions (220b) abut. For example, in the example of FIG. 4, the outer peripheral side magnet (220) has a protrusion (220b) on the upper side in FIG. 4, and abuts on the upper end surface (210a) of the rotor core (210). Further, the magnet (220) on the inner peripheral side has a protruding portion (220b) on the lower side in FIG. 4, and is in contact with the lower end surface (210a) of the rotor core (210).

  The two magnets (220) of the magnet pair (500) have overlapping plate surfaces (magnetic pole surfaces) in the magnet slot (211). However, in the example of FIG. 4, since Lc> Lm, part of the magnetic pole faces of the magnet (220) do not overlap each other in the magnet slot (211) (see FIG. 10). The magnet surfaces (220) are magnetized so that one of the magnetic pole surfaces that overlap each other has an S pole and the other has an N pole. For example, in the magnet slot (211-1), if the inner peripheral rotor magnetic pole is N-pole, the magnet pair (500) of the magnet slot (211-1) The magnetic pole on the inner peripheral side is N-pole, and the magnet on the inner peripheral side (220) has the magnetic pole facing the outer peripheral-side magnet (220) as S-pole (see FIG. 5). That is, the two magnets (220) forming the magnet pair (500) overlap each other so as to attract each other by magnetic force.

-Relationship between protrusions (220b) between adjacent rotor magnetic poles-
This embodiment is also characterized by the relationship between the protrusions (220b) in the magnet (220) between adjacent rotor magnetic poles. FIG. 11 is a diagram illustrating the positional relationship of the protrusions (220b) in the magnet (220) between adjacent rotor magnetic poles. FIG. 12 is a perspective view showing a state after the magnet (220) is inserted into the rotor core (210).

  As shown in FIGS. 11 and 12, the rotor magnetic poles adjacent to each other are different from each other in the end surface (210a) of the rotor core (210) with which the protruding portion (220b) of the magnet (220) on the inner peripheral side abuts. . In the example of FIG. 11, in the magnet slot (211-1), the inner peripheral side magnet (220) has the protrusion (220b) abutting against the lower end surface (210a) of the rotor core (210) in FIG. Yes. If the inner peripheral side of the rotor magnetic pole in the magnet slot (211-1) has N poles, the inner peripheral side magnetic pole surface of the inner peripheral magnet (220) in the magnet slot (211-1) has N poles. . The configuration of the magnet (220) in the magnet pair (500) of the magnet slot (211-3) is the same as that of the magnet slot (211-1).

  On the other hand, in the magnet slot (211-2), the protrusion (220b) is in contact with the upper end surface (210a) of the rotor core (210) in FIG. The configuration of the magnet (220) in the magnet pair (500) of the magnet slot (211-4) is the same as that of the magnet slot (211-2). Since the magnet slot (211-2) is adjacent to the magnet slot (211-1), the rotor magnetic pole of the magnet slot (211-2) has an S pole on the inner peripheral side. Therefore, in the adjacent magnet slots (211-1, 2), the inner peripheral side magnets (220) attract each other by magnetic force. Although omitted in FIG. 11, permanent magnets are similarly inserted into the magnet slots (211-3, 211-4).

<Operation of magnet (220) in rotor core (210)>
As described above, the two magnets (220) constituting the magnet pair (500) are attracted to each other by magnetic force. When the two magnets (220) are attracted in this way, these magnets (220) are called positions where the length of the magnetic path formed between them is the shortest (hereinafter referred to as a stable position for convenience of explanation). Try to move to). Therefore, in the example of FIG. 10, the magnet (220) with the protrusion (220b) on the upper side tries to move downward, and the magnet (220) with the protrusion (220b) on the lower side moves upward. Try to move.

  In the present embodiment, the end surfaces (210a) of the rotor core (210) with which the protrusions (220b) abut each other between the two magnets (220) constituting the magnet pair (500) are opposite to each other. Since the two magnets (220) constituting the magnet pair (500) are configured such that some of the magnetic pole faces do not overlap each other, the magnets (220) are attached to the rotor core (210). When the protrusion (220b) is in contact, the magnetic path between the two is not the shortest, and a force in the direction of moving to the stable position (specifically, the axial direction) acts between the two. Therefore, in the rotor (200), a force in a direction of sandwiching each electromagnetic steel sheet is applied by the protrusions (220b) of the two magnets (220) constituting the magnet pair (500).

  When Lc = Lm, the magnet (220) is in the stable position in each magnet slot (211). Therefore, the protrusions (220b) of these magnets (220) do not exhibit a force that sandwiches the rotor core (210). However, even in this case, since both magnets (220) are stable at that position, the electromagnetic steel sheet can be fixed.

  Further, between the adjacent rotor magnetic poles, the inner peripheral side magnet (220) attracts each other by magnetic force. Therefore, these inner circumferential side magnets (220) also try to move to a position where the length of the magnetic path formed between them becomes the shortest. The rotor magnetic poles adjacent to each other have the end surfaces (210a) of the rotor core (210) that are in contact with the protrusions (220b) of the magnet (220) on the inner peripheral side, which are opposite to each other. Accordingly, a force is applied in the direction of sandwiching each electromagnetic steel sheet by the protrusions (220b) of the inner circumferential side magnets (220) constituting the rotor magnetic poles adjacent to each other.

  As described above, in the magnet-embedded motor (10), the adjacent permanent magnets (220) tend to move to a position (stable position) where the magnetic path formed between them becomes the shortest. Therefore, in the rotor (200) of the present embodiment, a force in the direction of sandwiching the electromagnetic steel plates constituting the rotor core (210) is applied by the protrusions (220b) provided on each magnet (220). Therefore, in this embodiment, the electromagnetic steel plate of the rotor core (210) can be fixed without using rivets or the like. Although an example in which two permanent magnets (220) are inserted into the magnet slot (211) has been shown, three or more permanent magnets (220) may be inserted into one magnet slot (211). . In that case, what is necessary is just to make a protrusion part (220b) into a mutually opposing side between the two permanent magnets (220) which mutually contact | connect. For example, when four permanent magnets (220) are inserted, if the first and third magnets (220) from the outer peripheral side are provided with a protrusion (220b) on one side, the second and fourth The magnet (220) is provided on the projecting portion (220b) on the other side. However, when many magnets (220) are embedded in one magnet slot (211), it is necessary to enlarge the protrusion (220b) or to change the shape of the protrusion (220b). A sheet is most desirable.

<< Effect of this embodiment >>
As described above, in the present embodiment, the electromagnetic steel sheet can be fixed by the permanent magnets constituting the rotor magnetic poles. Therefore, in this embodiment, the rivet which fixes an electromagnetic steel plate becomes unnecessary. In addition, the end plate provided for fixing the electromagnetic steel sheet in a general IPM motor is not essential. That is, according to the present embodiment, it is possible to omit a fixing member such as a rivet, reduce the number of parts, and simplify the manufacturing process.

  In the present embodiment. If the magnet (220) is demagnetized, the magnet (220) and the rotor core (210) can be easily separated, and the magnet (220), that is, the rare earth metal can be easily recycled.

  In addition, it is preferable that the rotor (200) of this embodiment makes only the overlap part (refer FIG. 10) of a magnetic pole surface oppose the stator (100). In the magnet (220) of the rotor (200), the position where the magnetic path formed between the stator (100) and the electromagnet of the stator (100) is the shortest is the most stable position. Therefore, in order to prevent the magnet (220) from moving from the position where the electromagnetic steel sheet is sandwiched, only the overlap portion should be opposed to the stator (100).

<< Embodiment 2 of the Invention >>
FIG. 13: is sectional drawing of the rotor (200) concerning Embodiment 2 of this invention. FIG. 14 is a perspective view of the rotor core (210) according to the second embodiment. FIG. 13 corresponds to the AA cross section of FIG. In FIG. 13, branch numbers (−1, 2,...) Are added after the reference numerals to identify each magnet. As shown in these drawings, one rotor magnetic pole is composed of a multilayered (two in this example) magnet pair (500) continuous in the radial direction of the rotor core (210).

  In the present embodiment, the magnets (220) facing each other through the intermediate iron core (210b) (the iron core between the magnet pairs (500) arranged in two layers. See FIG. 13) in each rotor magnetic pole The end surfaces (210a) with which the protrusions (220b) abut are different from each other. In the example of FIG. 13, the magnet (220-2) facing the intermediate iron core (210b) in the magnet pair (500) on the outer peripheral side has the protruding portion (220b) in contact with the lower end surface (210a) of FIG. ing. Further, in the magnet (220-3) facing the iron core (210b) in the magnet pair (500) on the inner peripheral side, the protruding portion (220b) is in contact with the upper end surface (210a) of FIG. Also, if the inner circumference side of the magnet (220-2) is N pole, the outer circumference side of the magnet (220-3) is S pole, and these magnets (220-2, 3) attract each other and Attempt to move to a position where the length of the magnetic path formed in the shortest is the shortest. Therefore, the intermediate iron core (210b) portion is sandwiched and fixed by the projecting portion (220b) of the magnet (220) facing through the intermediate iron core (210b).

<< Other Embodiments >>
<1> The shape of the protrusion (220b) in the first and second embodiments is an example. In addition, for example, a protrusion (220b) shown in (A) to (D) of FIG. In the magnet (220) illustrated in FIGS. 4A and 4B, the protruding portion (220b) extends only to one magnetic pole surface side, and has an L-shaped cross-sectional shape. In FIG. 4D, the protruding portion (220b) extends only to one magnetic pole surface side, and the magnetic pole surface side opposite to the protruding portion (220b) is recessed. In these examples, material for the magnet (220) can be saved. In the example of FIG. 15B, the rotor core (210) portion (see FIG. 15) on the opposite side to the extending direction of the protruding portion (220b) may be provided with a caulking that fixes the electromagnetic steel plates to each other. .

  In the example shown in (C), the projecting portion (220b) extends so that the planar view from the magnetic pole surface is T-shaped. In the shape of (C), the contact range of the magnet (220) and the rotor core (210) is smaller than in other examples, but it is possible to save the magnet material.

  <2> In the magnet (220), a predetermined corner R is formed between the main body (220a) and the protrusion (220b) depending on the manufacturing method. Therefore, in the case of adopting the example of Embodiment 1, the protrusion (220b) of FIG. 15A or 15B, the tip of the magnet (220) (the end opposite to the protrusion (220b)) ) May be adjusted so that the insertion length (Lm) does not interfere with the corner R of the paired magnets (220) (see FIG. 16). Specifically, the insertion length (Lm) of the magnet (220) is set to a value smaller than the value obtained by subtracting the size of the corner R from the depth (Lc) of the magnet slot (211).

  <3> Further, the rotor core (210) may have a thickness greater than that of the intermediate electromagnetic steel sheet at the electromagnetic steel sheets at both ends in the axial direction (see FIG. 17). By doing so, the rigidity of the rotor core (210) can be increased and the strength can be increased. In addition, even if it is an electromagnetic steel plate from which plate | board thickness differs, it is good to make the punching shape the same.

  <4> Further, as shown in FIG. 18, the rotor (200) may be provided with end plates (230) at both ends of the rotor core (210). The end plate (230) has a disc shape and is made of a nonmagnetic metal such as stainless steel. The plate thickness of the end plate (230) is set to be greater than the plate thickness of the electromagnetic steel plate constituting the rotor core (210).

  Further, as shown in FIG. 18, the end plate (230) is formed with a through hole (231) for inserting the magnet (220). The shape of the through hole (231) viewed from the axial direction is the same as the shape of the magnet slot (211) viewed from the same direction. When the magnet (220) is assembled into the magnet slot (211) through the through hole (231), the electromagnetic steel plate is sandwiched and fixed by the protruding portions (220b) together with the end plates (230) at both ends. Thus, by providing the end plate (230), it becomes possible to increase the rigidity of the rotor (200) and increase the strength. Of course, the through hole provided in the end plate is sufficient as long as the magnet with which the protruding portion abuts can penetrate. This is because the magnet with the protruding portion on the opposite side does not penetrate the end plate. By doing so, the area of the hole can be reduced, so that the strength can be further improved.

  Even if the end plate (230) is provided, the end plate (230) is fixed by the magnets constituting the rotor magnetic poles, so that it is necessary to fix the end plate to the rotor core with rivets, bolts, etc. as in the conventional IPM motor. There is no. That is, even if the end plate (230) is provided, the rotor structure can be simplified as compared with the conventional motor.

  <5> When the end plate (230) is provided on the rotor (200), the end plate (230) may also serve as a balancer. FIG. 19 is a cross-sectional view illustrating an example in which the balancer (240) is configured by the end plate (230). As shown in the figure, a groove (241) for accommodating the protruding portion (220b) may be provided. This prevents the motor (10) from becoming unnecessarily large in the axial direction. FIG. 20 is a plan view of the balancer (240). As shown in the figure, the balancer (240) has a groove (241) line-symmetric with respect to a line connecting the center of gravity of the balancer (240) and the center of the shaft hole (212) in plan view. It is preferable to do this. This facilitates the manufacture of the balancer (240).

  <6> When the magnet (220) is attached to the rotor core (210), the member for the magnet (220) is put into a temporarily magnetized state (a magnetized state weaker than the normal magnetized state), and It may be inserted into the magnet slot (211) and then magnetized in a normal state. Thus, the assembly of the rotor (200) becomes easier by setting the temporarily magnetized state.

  Further, the dimensional relationship between the magnet (220) and the magnet slot (211) may be determined so as to be in a press-fit state when the magnet (220) is mounted in the magnet slot (211). In this case, it is necessary to determine the dimensional relationship so that the magnet (220) is in a press-fit state that does not hinder the movement of the magnet (220) to the stable position (position where the magnetic path is the shortest).

  Further, as shown in FIG. 21, the magnet slot (211) may be provided with a claw (211e) for temporarily fixing the magnet (220). The claw (211e) is bent by the magnet (220) when the magnet (220) is inserted into the rotor core (210) and prevents the magnet (220) from moving to the stable position (position where the magnetic path is the shortest). The shape and dimensions are set so that the magnet (220) is temporarily fixed with a small amount of force. Providing such a claw (211e) facilitates assembly of the rotor (200).

  <7> The permanent magnet (220) is not plate-shaped, and may be, for example, an arc shape.

  <8> Further, the rotor core (210) may be formed of a dust core.

  <9> The motor (10) described as the embodiment is an example of application of the rotor according to the present invention, and can be applied to, for example, a generator.

  The present invention is useful as a rotor for use in a magnet-embedded rotary electric machine.

200 rotor 210 rotor core 210a end face 210b intermediate core (iron core)
211 Slot for magnet 211c Inlet part 211d Deep part 220 Magnet (permanent magnet)
220b Protruding portion 230 End plate 231 Through hole 500 Magnet pair

Claims (9)

A rotor having a plurality of rotor magnetic poles,
A cylindrical rotor core (210) formed with a plurality of magnet slots (211) for inserting permanent magnets (220);
A plurality of magnet pairs (500) configured by a plurality of plate-like permanent magnets (220) whose plate surfaces are magnetic poles and inserted into the magnet slots (211);
Each permanent magnet (220) is formed with a protrusion (220b) that abuts on one axial end face (210a) of the rotor core (210),
Of the permanent magnets (220) constituting the magnet pair (500), the two permanent magnets (220) that are in contact with each other have different end surfaces (210a) with which the respective protrusions (220b) abut, and magnetic forces. The rotor is characterized in that the magnetic pole faces overlap each other in the direction of attracting each other. The rotor of claim 1.
The rotor, wherein two plate-like permanent magnets (220) are inserted into the magnet slot (211). The rotor of claim 1 or claim 2,
The rotors characterized in that the rotor magnetic poles adjacent to each other are different from each other in the end surface (210a) with which the protrusion (220b) of the inner peripheral permanent magnet (220) abuts. The rotor of claim 1 or claim 3,
Each rotor magnetic pole is composed of a plurality of the magnet pairs (500) continuous in the radial direction of the rotor core (210),
The rotor, wherein the permanent magnets (220) facing each other through the iron core (210b) in the same rotor magnetic pole are different from each other in the end surfaces (210a) with which the protrusions (220b) abut. In the rotor according to any one of claims 1 to 4,
The said protrusion part (220b) is a non-magnetized state or a magnetized state weaker than the said magnetic pole surface, The rotor characterized by the above-mentioned. In the rotor according to any one of claims 1 to 5,
The insertion length (Lm) of the permanent magnet (220) into the magnet slot (211) is smaller than the depth (Lc) of the magnet slot (211). In the rotor according to any one of claims 1 to 6,
The rotor core (210) is formed by laminating electromagnetic steel plates,
The rotor is characterized in that the electromagnetic steel plates at both ends of the rotor core (210) are thicker than the intermediate electromagnetic steel plates. In the rotor according to any one of claims 1 to 6,
The rotor core (210) is formed by laminating electromagnetic steel plates, and both end faces (210a) are provided with nonmagnetic end plates (230) different from the electromagnetic steel plates,
Each end plate (230) is formed with a through hole (231) into which the permanent magnet (220) is inserted. The rotor according to any one of claims 1 to 7,
The rotor for the magnet slot (211) is characterized in that the entrance (211c) of the permanent magnet (220) is wider than the back (211d).

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