JP2012213266A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress demagnetization of a permanent magnet caused by inverse magnetic field.SOLUTION: A rotor (200) includes a mutually laminated rotor core (210) and an end plate (230). A thin wall part (235) is formed on the end plate (230) and a bimetal (251) is provided on the thin wall part (235). The bimetal (251) is provided separately from a permanent magnet (220). The bimetal (251) deforms at both ends and contacts a core outer peripheral part (217) and a core inner peripheral part (218) of the rotor core (210) when temperature increases. Thus, the core outer peripheral part (217) and the core inner peripheral part (218) become magnetically connected.

Description

    The present invention relates to a rotating electrical machine having a rotor with magnets inserted therein.

    BACKGROUND ART A rotating electrical machine such as a magnet-assisted synchronous reluctance motor (SynRM) or an interior magnet embedded motor (IPM motor) has a rotor core in which a magnet is inserted. In such a rotating electric machine, a phenomenon in which a large reverse magnetic field acts on the permanent magnet of the rotor core from the stator for some reason and the magnetic force of the permanent magnet is reduced (demagnetization) may occur.

    On the other hand, for example, Patent Document 1 discloses a countermeasure against demagnetization by devising a magnetic path of magnetic flux. In the rotor of Patent Document 1, a magnetic member is disposed on the surface of a permanent magnet. An end ring made of a magnetic material is provided so as to be magnetically coupled to the rotor iron core and to have a gap from the end of the magnetic member.

JP-A-8-51751

    By the way, in the example of patent document 1, since the space | gap is provided between the rotor main body and the end ring, if it is going to maintain the size as the whole motor conventionally, the arrangement space of a rotor iron core will become small. . That is, there is a problem that the rotor core becomes small and the performance as a rotating electric machine is lowered. On the contrary, if the size of the rotor core is ensured as usual, the size of the entire motor increases, leading to an increase in cost.

    This invention is made | formed in view of this point, The objective is to suppress the demagnetization of a magnet, without reducing performance, in the rotary electric machine which has a rotor in which the magnet was inserted.

    In order to achieve the above-described object, the present invention provides a stator by magnetically connecting the outer peripheral side portion (217) and the inner peripheral side portion (218) of the magnet slot (211) in the rotor core (210). When a reverse magnetic field is applied from (100) to the rotor core (210), the magnetic path of the magnetic flux is short-circuited.

    Specifically, the first invention includes a rotor (200) having a rotor core (210) in which a plurality of magnet slots (211) that penetrates in the axial direction and in which permanent magnets (220) are inserted are formed in the circumferential direction; The present invention is intended for a rotary electric machine including a stator (100) having a stator core (110) arranged opposite to the rotor core (210) on the outer peripheral side of the rotor core (210) with a gap. And this invention is provided apart from the said permanent magnet (220), and according to temperature, the outer peripheral side part (217) and inner peripheral side part (217) of the said magnet slot (211) in the said rotor core (210) ( 218) are magnetically connected to the magnetic connecting members (251, 252).

    In the first invention, when the magnetic connecting member (251,252) becomes high temperature or low temperature, the magnetic connecting member (251,252) transforms and is magnetically connected to the outer peripheral side portion (217) and the inner peripheral side portion (218). . Then, when a reverse magnetic field acts on the outer peripheral side portion (217) of the rotor core (210) from the stator (100), all or part of the magnetic flux does not pass through the permanent magnet (220), and the magnetic connection member ( 251,252) to the inner peripheral part (218). Therefore, demagnetization of the permanent magnet (220) due to the reverse magnetic field is suppressed. That is, according to the present invention, the magnetic field strength acting on the permanent magnet (220) is reduced by providing the magnetic connecting members (251, 252). The temperature of the magnetic connecting member (251, 252) increases or decreases depending on the ambient temperature around the rotating electrical machine. Further, when the rotary electric machine according to the present invention is provided in the casing of a compressor that compresses a fluid such as a refrigerant, the temperature of the magnetic connection member (251, 252) increases or decreases depending on the temperature of the fluid flowing in the casing. .

    In a second aspect based on the first aspect, the magnetic connecting member (251) is deformed according to temperature, and the deformation contacts the outer peripheral portion (217) and the inner peripheral portion (218). Bimetal to do.

    The magnetic connecting member (251) of the second aspect of the invention is not in contact with the outer peripheral side portion (217) and the inner peripheral side portion (218) before the temperature rises (that is, before heat is applied). When the temperature of the magnetic connecting member (251) increases (that is, when heat is applied), the magnetic connection member (251) changes its shape and comes into contact with the outer peripheral side portion (217) and the inner peripheral side portion (218). Thereby, the outer peripheral side portion (217) and the inner peripheral side portion (218) are magnetically connected via the magnetic connecting member (251).

    In a third aspect based on the second aspect, the rotor (200) has the rotor core (210) and an end plate (230) laminated in the axial direction thereof. The magnetic connection member (251) is formed in a plate shape and is provided on a surface of the thin portion (235) of the end plate (230) on the rotor core (210) side, and the magnetic connection member (251) Both ends are bent to the rotor core (210) side according to the temperature so as to come into contact with the outer peripheral side portion (217) and the inner peripheral side portion (218).

    The magnetic connecting member (251) of the third aspect of the invention is not in contact with the rotor core (210) before the temperature rises (that is, before heat is applied). When the temperature increases (ie, when heat is applied), the magnetic connecting member (251) deforms so that both ends are bent, and contacts the outer peripheral side portion (217) and the inner peripheral side portion (218), respectively. To do. Thereby, the outer peripheral side portion (217) and the inner peripheral side portion (218) are magnetically connected via the magnetic connecting member (251).

    According to a fourth invention, in the second or third invention, the permanent magnet (220) is formed in a plate shape. In the magnet slot (211), the permanent magnet (220) is the permanent magnet ( 220) are inserted with gaps at both ends in the longitudinal direction in plan view. And the said magnetic connection member (251) is comprised so that the part corresponding to the said space | gap of the said slot for magnets (211) among the said outer peripheral side part (217) and an inner peripheral side part (218) may be comprised. Yes.

    Demagnetization of the permanent magnet (220) is likely to occur at both ends of the permanent magnet (220). In the present invention, the outer peripheral side portion (217) and the inner peripheral side portion (218) are magnetically connected by the magnetic connecting member (251) on both ends of the permanent magnet (220). Therefore, demagnetization of the permanent magnet (220) is effectively suppressed.

    In a fifth aspect based on the first aspect, the magnetic connecting member (252) is provided in contact with the outer peripheral portion (217) and the inner peripheral portion (218), and is magnetic in accordance with the temperature. A temperature-sensitive magnetic member having

    The magnetic connection member (252) of the fifth invention is a temperature-sensitive magnetic member that has magnetism below a predetermined temperature, for example, but loses magnetism when the temperature is higher than the predetermined temperature. Therefore, when the temperature of the magnetic connecting member (251) is lowered, the outer peripheral side portion (217) and the inner peripheral side portion (218) are magnetically connected.

    According to a sixth invention, in the fifth invention, the permanent magnet (220) is formed in a plate shape, and the permanent magnet (220) of the permanent magnet (220) is formed in the magnet slot (211). A gap is inserted between both ends in the longitudinal direction in plan view. The magnetic connecting member (252) is inserted into the gap of the magnet slot (211) and is in contact with the inner wall of the magnet slot (211).

    Demagnetization of the permanent magnet (220) is likely to occur at both ends of the permanent magnet (220). In the present invention, the outer peripheral side portion (217) and the inner peripheral side portion (218) are magnetically connected by the magnetic connecting member (251) on both ends of the permanent magnet (220). Therefore, demagnetization of the permanent magnet (220) is effectively suppressed.

    As described above, in the present invention, the magnetic connection member (magnetic connection member) magnetically coupled to the outer peripheral portion (217) and the inner peripheral portion (218) of the magnet slot (211) in the rotor core (210) according to the temperature. 251,252). Therefore, when a reverse magnetic field is applied from the stator (100) to the outer peripheral side portion (217) of the rotor core (210), the magnetic connection member (251,252) does not allow all or part of the magnetic flux to pass through the permanent magnet (220). ) To the inner peripheral side portion (218). Thereby, demagnetization of the permanent magnet (220) due to the reverse magnetic field can be suppressed. Further, since only the magnetic connection members (251, 252) are provided, the size of the rotor core (210) can be maintained as usual. As a result, the performance as the motor (10) is not deteriorated. As described above, according to the present invention, it is possible to suppress demagnetization of the permanent magnet (220) without degrading the performance.

    Further, when the permanent magnet (220) is, for example, a neodymium magnet, demagnetization due to a reverse magnetic field is likely to occur in a high temperature region, and when the permanent magnet (220) is, for example, a ferrite magnet, the demagnetization is likely to occur. Accordingly, the magnetic connection member (251, 252) is configured to be magnetically connected to the outer peripheral side portion (217) and the inner peripheral side portion (218) in the high temperature region or the low temperature region, so that the permanent magnet (220) due to the reverse magnetic field. Can be effectively suppressed.

    According to the second invention, the bimetal deformed according to the temperature is used as the magnetic connection member (251), and according to the fifth invention, the temperature-sensitive magnetic member having magnetism according to the temperature is used as the magnetic connection member (252). ), The demagnetization of the permanent magnet (220) due to the reverse magnetic field can be suppressed with a simple and compact configuration.

    According to the third aspect of the invention, the end plate (230) laminated on the rotor core (210) is provided with the thin portion (235), and the thin portion (235) is provided with the magnetic connection member (251). According to the sixth aspect of the invention, since the magnetic connecting member (252) is inserted into the gap in the magnet slot (211), the permanent magnet (220) can be demagnetized without increasing the size of the rotor (200). Can be suppressed.

    According to the fourth or sixth invention, the outer peripheral side portion (217) and the inner peripheral side portion (218) are magnetically connected by the magnetic connecting members (251, 252) on both end sides of the permanent magnet (220). Therefore, demagnetization of the permanent magnet (220) due to the reverse magnetic field can be effectively suppressed.

FIG. 1 is a cross-sectional view illustrating a motor according to the first embodiment. FIG. 2 is a perspective view showing a part of the stator. FIG. 3 is a cross-sectional view of the teeth portion of the stator core as viewed from the inner peripheral side. FIG. 4 is an exploded perspective view showing the rotor according to the first embodiment. FIG. 5 is a plan view showing the end plate of the rotor according to the first embodiment when viewed from the inside. FIG. 6 is a side view showing the thin portion of the end plate of the rotor as viewed from the outer peripheral side. FIG. 7 is a plan view showing the rotor as viewed in the axial direction. 8 is a cross-sectional view taken along line VIII-VIII in FIG. FIG. 9 is a cross-sectional view corresponding to FIG. 8 showing a state in which the bimetal is deformed. FIG. 10 is a plan view showing the rotor core according to the second embodiment when viewed in the axial direction. 11 is a cross-sectional view taken along line XI-XI in FIG.

    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
A first embodiment of the present invention will be described. The motor (10) of the present embodiment constitutes a rotary electric machine according to the present invention, and is used, for example, in an electric compressor (not shown) that is provided in an air conditioner and compresses a refrigerant.

    As shown in FIG. 1, the motor (10) of this embodiment includes a stator (100), a rotor (200), and a drive shaft (300), and is accommodated in the casing (20) of the electric compressor. 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.

<Structure of stator>
As shown in FIG. 1, 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 (P) by press working to create a laminated plate and laminating a plurality of laminated plates in the axial direction. FIG. 2 is a perspective view of the stator (100). As shown in FIGS. 1 and 2, the stator core (110) includes one back yoke portion (111), a plurality (nine in this example) of teeth portions (112) and flange portions (113). In FIG. 2, one tooth portion (112) is mainly drawn.

    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 slot (114) in which the coil (120) is accommodated.

    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). In the stator core (110), the outer peripheral portion of the back yoke portion (111) is fixed to the inner surface of the casing (20).

    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 is opposed to an outer peripheral surface (cylindrical surface) of a rotor core (210) described later with a predetermined distance (air gap (G)).

    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 slot (114). As shown in FIG. 3, an insulator (131) is provided from both axial end surfaces of the tooth portion (112), and an insulating film (130) is provided between the coil (120) and the tooth portion (112). Is provided. In this embodiment, the insulating film (130) is a polyethylene terephthalate film.

<Configuration of rotor>
As shown also in FIG. 4, the rotor (200) includes a rotor core (210) (magnetic core), a plurality of permanent magnets (220), and two end plates (230), and the whole is formed in a substantially cylindrical shape. . The rotor (200) of the present embodiment includes six permanent magnets (220).

    The rotor core (210) is a laminated core obtained by punching an electromagnetic steel plate (P) by press working to create a laminated plate and laminating a plurality of laminated plates in the axial direction. The rotor core (210) is formed with a plurality of magnet slots (211) into which permanent magnets (220) are inserted. The slots for the magnets (211) are arranged at a 60 ° pitch in the circumferential direction (around the axis) of the rotor core (210). Each magnet slot (211) has a substantially U-shape when viewed in the axial direction, and penetrates the rotor core (210) in the axial direction. Specifically, each magnet slot (211) includes a magnet insertion part (212) orthogonal to the radius of the rotor core (210) and two barrier parts (213) extending from the magnet insertion part (212) to the outer peripheral side. It is configured. The magnet insertion part (212) has a slightly elongated rectangular shape in plan view (see also FIG. 1), and the permanent magnet (220) is inserted into the magnet insertion part (212). In the rotor core (210), the outer peripheral portion of the magnet slot (211) is the core outer peripheral portion (217), and the inner peripheral portion of the magnet slot (211) is the core inner peripheral portion (218). ing.

    The permanent magnet (220) is formed in a plate shape, and its width is shorter than the length of the magnet insertion portion (212) in plan view. That is, in the magnet insertion part (212), the permanent magnet (220) is inserted with gaps between both ends of the permanent magnet (220) in the longitudinal direction in plan view. In addition, the permanent magnet (220) is offset inward in the axial direction from the axial end of the rotor core (210) (see FIGS. 8 and 9). The permanent magnet (220) is fixed to the rotor core (210) by, for example, bonding so as not to move in the magnet insertion portion (212).

    The end plate (230) has a disc shape and is formed of a nonmagnetic metal such as stainless steel. The end plate (230) is laminated on both end sides of the rotor core (210). The rotor core (210) and the two end plates (230) are fixed with six bolts passed through the bolt holes (216, 233). In this stacked state, the axial end of the permanent magnet (220) is offset inward from the axial end of the rotor core (210) as described above, and therefore does not contact the end plate (230).

    A shaft hole (215, 232) is formed at the center of the rotor core (210) and each end plate (230), and a drive shaft (300) made of metal such as iron is fitted into the shaft hole (215). (See FIG. 1). The drive shaft (300) is for driving a compression mechanism (not shown) accommodated in the casing (20) of the electric compressor.

<Configuration of end plate>
The detailed configuration of the end plate (230) will be described with reference to FIGS. The end plate (230) includes a substantially disc-shaped main body (231). A plurality (six in this embodiment) of thin portions (235) are formed on the outer edge of the main body (231) in the circumferential direction of the main body (231). This thin part (235) is thinner than the thickness of the main body (231). The thin portion (235) is formed in a fan shape in plan view with a bolt hole (233) formed in the main body (231) as the center, and is formed up to the outer edge of the main body (231). In the thin part (235), the side wall (236) corresponding to two fan-shaped sides is tapered (see FIG. 6).

    And the bimetal (251) is attached to the thin part (235) of this embodiment. The bimetal (251) is a slightly elongated rectangular plate, and two bimetals (251) are provided for each thin portion (235). The bimetal (251) is provided along the side wall (236) in the thin portion (235). In the end plate (230), the surface to which the bimetal (251) is attached (for example, the surface shown in FIG. 5) is the inner surface that is the rotor core (210) side. The thickness of the bimetal (251) is thinner than the depth of the thin portion (235) (see FIG. 6).

    As shown in FIG. 7, in a state where the end plate (230) and the rotor core (210) are laminated, the bimetal (251) is separated from the permanent magnet (220), and the magnet of the rotor core (210) in plan view. Intersects with slot (211). Specifically, in the plan view, the bimetal (251) overlaps the magnet insertion portion (212) of the magnet slot (211) so that a portion where the permanent magnet (220) is not inserted is orthogonal. That is, the bimetal (251) is orthogonal to the gap portions on both ends in the longitudinal direction of the permanent magnet (220) in the magnet insertion portion (212) in the plan view.

    The bimetal (251) is a member that deforms when the temperature increases (that is, when heat is applied). Examples of the bimetal (251) of the present embodiment include a low expansion material and a high expansion material. As an example of the low expansion material, nickel-iron or the like is used. Examples of the high expansion material include copper, nickel, copper-zinc, nickel-copper, nickel-manganese-iron, nickel-chromium-iron, and manganese-nickel-copper. When the temperature of the bimetal (251) of this embodiment increases, both ends in the longitudinal direction bend toward the rotor core (210), and contact the core outer peripheral portion (217) and the core inner peripheral portion (218) of the rotor core (210). (See FIG. 9). That is, the bimetal (251) constitutes a magnetic connecting member that is magnetically connected to the core outer peripheral portion (217) and the core inner peripheral portion (218) 218) of the rotor core (210) by being deformed according to the temperature. ing. Further, the bimetal (251) of the present embodiment has a magnetic resistance smaller than the magnetic resistance of the magnet slot (211).

<Magnetic path during reverse magnetic field action>
As shown in FIG. 8, for example, in a state where the ambient temperature or refrigerant temperature around the motor (10) is not so high (normal temperature state), the bimetal (251) remains straight without deformation. In this state, since the thickness of the bimetal (251) is thinner than the depth of the thin portion (235), the bimetal (251) does not contact the rotor core (210).

    Even if a reverse magnetic field acts on the rotor (200) in such a normal temperature state, the demagnetization of the permanent magnet (220) due to the reverse magnetic field does not occur so much.

    As shown in FIG. 9, for example, when the ambient temperature or refrigerant temperature around the motor (10) rises to a high temperature state, both ends of the bimetal (251) are deformed so as to be bent toward the rotor core (210). Both ends of the bent bimetal (251) are in contact with the core outer peripheral portion (217) and the core inner peripheral portion (218) of the rotor core (210). That is, the bimetal (251) is in contact with the core outer peripheral portion (217) and the core inner peripheral portion (218) across the magnet insertion portion (212) while being separated from the permanent magnet (220). Specifically, the bimetal (251) is in contact with portions of the core outer peripheral portion (217) and the core inner peripheral portion (218) corresponding to the gaps present on both sides of the permanent magnet (220) in the magnet insertion portion (212). . Thereby, the core outer peripheral part (217) and the core inner peripheral part (218) are magnetically connected.

    In such a high temperature state, it is assumed that a reverse magnetic field acts on the rotor (200) and a magnetic flux acts on the core outer peripheral portion (217) of the rotor core (210) from the stator (100). In this case, the magnetic flux due to the reverse magnetic field acting on the core outer peripheral part (217) is directed entirely toward the core inner peripheral part (218) via the bimetal (251) without passing through the permanent magnet (220). (See arrow in FIG. 9). That is, since the bimetal (251) having a magnetic resistance smaller than the magnetic resistance of the magnet slot (211) is in contact with the core outer peripheral portion (217), the magnetic flux does not pass through the permanent magnet (220) ( Go through 251). As described above, in this embodiment, the part of the permanent magnet (220) is short-circuited by the bimetal (251) in the magnetic field of the reverse magnetic field that has acted on the rotor core (210). Thereby, the demagnetization of the permanent magnet (220) due to the reverse magnetic field is suppressed. The bimetal (251) returns to the shape before deformation (that is, a straight plate shape) again when the temperature is lowered.

-Effect of the embodiment-
As described above, according to the present embodiment, the magnetic connection member (bimetal (251)) magnetically connected to the core outer peripheral portion (217) and the core inner peripheral portion (218) in the rotor core (210) according to the temperature. ). Therefore, when a reverse magnetic field is applied from the stator (100) to the core outer periphery (217) of the rotor core (210), all or part of the magnetic flux passes through the magnetic connecting member (251 without passing the permanent magnet (220). ) To the inner peripheral side portion (218). Thereby, demagnetization of the permanent magnet (220) due to the reverse magnetic field can be suppressed. In addition, since only the magnetic connection member (251) is provided, it is not necessary to reduce the size of the rotor core (210), thereby preventing the performance as the motor (10) from deteriorating. As a result, demagnetization of the permanent magnet (220) can be suppressed without degrading performance.

    Further, when the permanent magnet (220) is, for example, a neodymium magnet, demagnetization due to a reverse magnetic field is likely to occur in a high temperature region. Therefore, as in the present embodiment, the magnetic connection member (bimetal (251)) is configured to be connected to the core outer peripheral portion (217) and the core inner peripheral portion (218) in a high temperature region, so that a permanent magnetic field caused by a reverse magnetic field can be obtained. It is possible to effectively suppress demagnetization of the magnet (220).

    Moreover, in this embodiment, since the bimetal (251) which deform | transforms according to temperature was used as a magnetic connection member, the demagnetization of the permanent magnet (220) by a reverse magnetic field can be suppressed with a simple and compact structure. .

    In this embodiment, the end plate (230) stacked on the rotor core (210) is provided with a thin portion (235), and the thin portion (235) is provided with a magnetic connection member (bimetal (251)). Therefore, the demagnetization of the permanent magnet (220) can be suppressed without increasing the size of the rotor (200).

    Further, demagnetization of the permanent magnet (220) is likely to occur at both ends of the permanent magnet (220). Therefore, in the present embodiment, the magnetic connection member (bimetal (251)) is in contact with the core outer peripheral portion (217) and the core inner peripheral portion (218) on both end sides of the permanent magnet (220). Demagnetization of the permanent magnet (220) due to the reverse magnetic field can be effectively suppressed.

<< Embodiment 2 >>
In this embodiment, a temperature-sensitive magnetic member (252) is provided in place of the bimetal (251) in the first embodiment. That is, the motor (10) of the present embodiment includes the temperature-sensitive magnetic member (252) as a magnetic connection member.

    As shown in FIG. 10, in the present embodiment, the temperature-sensitive magnetic member (252) is a slightly elongated rectangular plate, and is inserted into the magnet slot (211) of the rotor core (210). Two temperature-sensitive magnetic members (252) are provided for each magnet slot (211). Specifically, the temperature-sensitive magnetic member (252) is inserted into the gap portion existing on both ends of the permanent magnet (220) in the longitudinal direction of the permanent magnet (220) in the magnet insertion portion (212). In the magnet insertion part (212), the temperature-sensitive magnetic member (252) is inserted in a state of being in contact with the inner wall of the magnet insertion part (212) while being separated from the permanent magnet (220). That is, the temperature-sensitive magnetic member (252) is provided in contact with the core outer peripheral portion (217) and the core inner peripheral portion (218) of the rotor core (210). Further, the temperature-sensitive magnetic member (252) is inserted into the magnet insertion portion (212) in such a state that both ends in the axial direction are flush with the axial end surface of the rotor core (210) (see FIG. 11).

    The temperature-sensitive magnetic member (252) of this embodiment is a member having magnetism when the temperature is lowered (that is, when heat is absorbed). That is, the temperature-sensitive magnetic member (252) of the present embodiment is magnetically coupled to the core outer peripheral portion (217) and the core inner peripheral portion (218) of the rotor core (210) by having magnetism according to the temperature. . Thereby, the core outer peripheral part (217) and the core inner peripheral part (218) are magnetically connected via the temperature-sensitive magnetic member (252). An iron-nickel alloy or the like is used as the temperature-sensitive magnetic member (252). Further, the magnetic resistance of the temperature-sensitive magnetic member (252) when having magnetism is smaller than the magnetic resistance of the magnet slot (211).

    In the present embodiment, when the motor (10) is at room temperature, the temperature-sensitive magnetic member (252) loses magnetism and becomes a non-magnetic material. Even if a reverse magnetic field acts on the rotor (200) in such a normal temperature state, the demagnetization of the permanent magnet (220) due to the reverse magnetic field does not occur so much.

    In this embodiment, when the motor (10) is in a low temperature state, the temperature-sensitive magnetic member (252) becomes a magnetic material having magnetism. In this state, as shown in FIG. 11, the magnetic flux due to the reverse magnetic field applied to the core outer peripheral portion (217) of the rotor core (210) is not entirely or partially passed through the permanent magnet (220), and the temperature-sensitive magnetism. It goes to a core inner peripheral part (218) through a member (252).

    As described above, in the present embodiment, it is possible to suppress the magnetic flux due to the reverse magnetic field that has acted on the core outer peripheral portion (217) of the rotor core (210) from passing through the permanent magnet (220) in a low temperature state. Therefore, demagnetization of the permanent magnet (220) due to the reverse magnetic field can be suppressed.

    Further, when the permanent magnet (220) is, for example, a ferrite magnet, demagnetization due to a reverse magnetic field is likely to occur in a low temperature region. Therefore, as in this embodiment, the magnetic connection member (temperature-sensitive magnetic member (252)) is configured to be magnetically connected to the core outer peripheral portion (217) and the core inner peripheral portion (218) in a low temperature region. Thus, demagnetization of the permanent magnet (220) due to the reverse magnetic field can be effectively suppressed.

    In this embodiment, since the temperature-sensitive magnetic member (252) having magnetism according to temperature is used as the magnetic connection member, demagnetization of the permanent magnet (220) can be suppressed with a simple and compact configuration. it can.

    In this embodiment, since the temperature-sensitive magnetic member (252) is inserted into the magnet slot (211) formed in the rotor core (210), the permanent magnet can be obtained without increasing the size of the rotor (200). (220) demagnetization can be suppressed.

    Further, demagnetization of the permanent magnet (220) is likely to occur at both ends of the permanent magnet (220). According to this embodiment, the temperature-sensitive magnetic member (252) is a core at both ends of the permanent magnet (220). Since the outer peripheral portion (217) and the core inner peripheral portion (218) are brought into contact with each other, demagnetization of the permanent magnet (220) due to a reverse magnetic field can be effectively suppressed. Other configurations, operations, and effects are the same as those of the first embodiment.

<< Other Embodiments >>
About each said embodiment, you may make it be the following structures.

    For example, in each of the embodiments described above, the installation location of the bimetal (251) and the temperature-sensitive magnetic member (252) is not limited to that described above. In the present invention, the installation location of the bimetal (251) and the temperature-sensitive magnetic member (252) may be any location that is magnetically connected to the core outer peripheral portion (217) and the core inner peripheral portion (218) according to the temperature. .

    As described above, the present invention is useful for a rotating electric machine having a rotor in which a magnet is inserted.

10 Motor (rotary electric machine)
100 stator
110 Stator core
200 rotor
210 rotor core
211 Slot for magnet
217 Core outer peripheral part (outer peripheral part)
218 Core inner circumference (inner circumference side)
220 Permanent magnet
251 Bimetal (magnetic connection member)
252 Temperature-sensitive magnetic member (magnetic connection member)

Claims (6)

A rotor (200) having a rotor core (210) in which a plurality of magnet slots (211) penetrating in the axial direction and having permanent magnets (220) inserted therein are formed in the circumferential direction, and on the outer peripheral side of the rotor core (210) A rotating electrical machine comprising a rotor core (210) and a stator (100) having a stator core (110) arranged opposite to each other with a gap therebetween,
It is provided apart from the permanent magnet (220), and magnetically acts on the outer peripheral side portion (217) and the inner peripheral side portion (218) of the magnet slot (211) in the rotor core (210) according to the temperature. A rotating electrical machine comprising a magnetic connecting member (251, 252) connected to In claim 1,
The rotary electric machine according to claim 1, wherein the magnetic connecting member (251) is a bimetal that deforms according to temperature and contacts the outer peripheral side portion (217) and the inner peripheral side portion (218) by the deformation. In claim 2,
The rotor (200) has the rotor core (210) and an end plate (230) laminated in the axial direction thereof,
The magnetic connection member (251) is formed in a plate shape and provided on the rotor core (210) side surface of the thin wall portion (235) of the end plate (230), and both ends of the magnetic connection member (251) Is configured to be brought into contact with the outer peripheral side portion (217) and the inner peripheral side portion (218) by bending toward the rotor core (210) according to temperature. In claim 2 or 3,
The permanent magnet (220) is formed in a plate shape,
In the magnet slot (211), the permanent magnet (220) is inserted with gaps at both ends in the longitudinal direction of the permanent magnet (220),
The magnetic connecting member (251) is configured to contact a portion of the outer peripheral side portion (217) and an inner peripheral side portion (218) corresponding to the gap of the magnet slot (211). Rotating electric machine characterized by In claim 1,
The magnetic connection member (252) is a temperature-sensitive magnetic member provided in contact with the outer peripheral side portion (217) and the inner peripheral side portion (218) and having magnetism according to temperature. Rotating electrical machine. In claim 5,
The permanent magnet (220) is formed in a plate shape,
In the magnet slot (211), the permanent magnet (220) is inserted with gaps at both ends in the longitudinal direction of the permanent magnet (220),
The rotating electrical machine, wherein the magnetic connecting member (252) is inserted into the gap of the magnet slot (211) and is in contact with the inner wall of the magnet slot (211).

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