Rotors, motors, compressors, blowers, and refrigeration devices

Abstract

A rotor capable of suppressing loss caused by eddy currents generated in a conductor. A rotor (12) includes a rotor core (13), a first flux barrier (31), and a first conductor (51). The rotor core (13) has a first outer peripheral surface (21) having an arc shape centered on the axis of a rotating shaft (11), and a second outer peripheral surface (22) having an arc shape centered on the axis and located radially inward of the first outer peripheral surface (21). The first flux barrier (31) penetrates the rotor core (13) in the axial direction. The first flux barrier (31) includes a first gap (31a) having an arc shape centered on the axis and extending along the second outer peripheral surface (22), and a second gap (31b) extending linearly from an end of the first gap (31a) toward the first outer peripheral surface (21). The first conductor (51) is disposed in the first gap (31a).

Description

[Technical field]

[0001] The present disclosure relates to a rotor, an electric motor, a compressor, a blower, and a refrigeration device. [Background technology]

[0002] Patent Document 1 discloses a self-starting synchronous reluctance motor. The self-starting synchronous reluctance motor has both the characteristics of an induction motor and a reluctance motor. The self-starting synchronous reluctance motor can be started by generating torque through squirrel-cage induction, so it can be started by a commercial power source and can achieve constant speed operation by generating reluctance torque. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-537089 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the rotor structure of Patent Document 1, a squirrel-cage structure is formed by filling a conductive material into grooves on the outer periphery of the rotor core, which causes loss due to eddy currents.

[0005] An object of the present disclosure is to provide a rotor capable of suppressing losses caused by eddy currents generated in conductors. [Means for solving the problem]

[0006] A first aspect of the present disclosure is a rotor (12) configured to be rotatable around the axis of a rotating shaft (11). The rotor (12) includes a rotor core (13), a first flux barrier (31), and a first conductor (51). The rotor core (13) has a first outer peripheral surface (21) having an arc shape centered on the axis of the rotating shaft (11), and a second outer peripheral surface (22) located radially inward of the first outer peripheral surface (21) and having an arc shape centered on the axis. The first flux barrier (31) axially penetrates the rotor core (13). The first flux barrier (31) includes a first gap (31a) having an arc shape centered on the axis and extending along the second outer peripheral surface (22), and a second gap (31b) extending linearly from an end of the first gap (31a) toward the first outer peripheral surface (21). The first conductor (51) is disposed in the first gap (31a).

[0007] In the first aspect, a first gap (31a) of a first flux barrier (31) is provided on the inner peripheral side of a second outer peripheral surface (22) which is a recess in the outer periphery of the rotor core (13), and a first conductor (51) is disposed in the first gap (31a). This makes it possible to suppress loss caused by eddy currents generated in the first conductor (51).

[0008] A second aspect of the present disclosure is the rotor according to the first aspect, further comprising a second flux barrier (32) penetrating the rotor core (13) in the axial direction, and a second conductor (52). The second flux barrier (32) includes a third gap (32a) having an arc shape centered on the axis and extending along the second outer circumferential surface (22) in parallel with the first gap (31a), and a fourth gap (32b) extending linearly from an end of the third gap (32a) toward the first outer circumferential surface (21) in parallel with the second gap (31b). The third gap (32a) is located radially inward of the first gap (31a). The second conductor (52) is disposed in the fourth gap (32b).

[0009] In the second embodiment, in addition to the first conductor (51) arranged in the first gap (31a) of the first flux barrier (31), the second conductor (52) is arranged in the fourth gap (32b) of the second flux barrier (32). This increases the torque generated by the squirrel-cage induction, and therefore the starting torque.

[0010] A third aspect of the present disclosure is the second aspect, wherein the first conductor (51) is disposed radially inward from the second outer peripheral surface (22). The second conductor (52) is disposed radially inward from the second outer peripheral surface (22). When a curve is virtually drawn by extending the arc shape of the first gap portion (31a) with the same curvature, the second conductor (52) is disposed at a position overlapping the curve.

[0011] In the third aspect, the first conductor 51 and the second conductor 52 are aligned, so that a starting torque can be generated smoothly. Also, compared to a case where the second conductor 52 is arranged radially inward from the curve, the starting torque can be increased, and the generation of eddy currents can be suppressed compared to a case where the second conductor 52 is arranged radially outward from the curve.

[0012] A fourth aspect of the present disclosure is an electric motor including the rotor (12) according to any one of the first to third aspects.

[0013] In the fourth aspect, a motor with less loss can be realized.

[0014] A fifth aspect of the present disclosure is a compressor including the electric motor (10) of the fourth aspect.

[0015] In the fifth aspect, a motor with less loss can be realized.

[0016] A sixth aspect of the present disclosure is a blower including the electric motor (10) of the fourth aspect.

[0017] In the sixth aspect, a blower with low loss can be realized.

[0018] A seventh aspect of the present disclosure is a refrigeration device including the electric motor (10) of the fourth aspect.

[0019] In the seventh aspect, a refrigeration device with less loss can be realized. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is an oblique view showing the schematic configuration of a rotor of an embodiment, where (a) shows the rotor attached to a rotating shaft, (b) shows the secondary conductor with the end plate removed, and (c) shows the secondary conductor with the secondary conductor removed. [Diagram 2] FIG. 2 shows variations in the cross-sectional configuration of a rotor of an embodiment, where (a) shows a basic configuration, (b) shows a configuration having multiple flux barriers, (c) shows a modified shape of the secondary conductor, and (d) shows a modified number of layers of the secondary conductor. [Diagram 3] FIG. 3 shows variations in the cross-sectional configuration of a rotor of an embodiment, where (a) shows another variation in the number of layers of the secondary conductor, (b) shows a variation in the shape of the first outer peripheral surface, (c) shows a variation in the number of poles, and (d) shows a variation in the number of poles and the number of layers of the secondary conductor. [Figure 4] FIG. 4 is a diagram illustrating an example of a cross-sectional configuration of the electric motor according to the embodiment. [Diagram 5] FIG. 5 is a diagram for explaining the operation of the electric motor according to the embodiment. [Figure 6] FIG. 6 is a diagram for explaining the operation of the electric motor according to the embodiment. [Figure 7] FIG. 7 is a vertical cross-sectional view illustrating an example of the configuration of a compressor according to an embodiment. [Figure 8] FIG. 8 is a piping diagram showing an example of the configuration of a refrigeration device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses. In addition, in the drawings, the same reference numerals represent the same components, but the dimensions in the drawings, such as length, width, thickness, and depth, are appropriately changed from the actual scale for clarity and simplification of the drawings, and may not correspond to the actual relative dimensions.

[0022] <Rotor> 1, the rotor (12) of this embodiment is configured to be rotatable together with the rotating shaft (11). The rotor (12) mainly includes a substantially cylindrical rotor core (13) and a secondary conductor (50) having a cage structure.

[0023] In this disclosure, the axis of the rotating shaft (11) is simply referred to as the "axis," the direction in which the axis extends, i.e., the direction of the rotation axis of the rotor (12) is referred to as the "axial direction," the direction perpendicular to the direction of the rotation axis of the rotor (12) is referred to as the "radial direction," and the direction around the rotation axis of the rotor (12) is referred to as the "circumferential direction." Additionally, a cross section along the axial direction is referred to as a "longitudinal cross section," and a cross section perpendicular to the axial direction is referred to as a "transverse cross section."

[0024] The rotor core (13) has a rotor core structure of a synchronous reluctance motor (SynRM). The rotor core (13) is formed by laminating electromagnetic steel sheets. The material of the rotor core (13) may be, for example, an amorphous alloy, a nanocrystal, a powder magnetic core, or the like. A through hole (13a) (see FIG. 2) extending in the axial direction is provided in the radial center of the rotor core (13). With the rotating shaft (11) inserted into the through hole (13a), the rotor core (13) is fixed to the rotating shaft (11) by a lock nut (11b) with the end plate (11a) sandwiched therebetween. This allows the rotor (12) to rotate freely around the axis.

[0025] The secondary conductor (50) has a shape that extends in the axial direction. The secondary conductor (50) is inserted into the rotor core (13). The secondary conductor (50) is fixed to the rotor core (13) by disposing a pair of end rings (50a) on both axial ends of the rotor core (13). The secondary conductor (50) and the end rings (50a) may be electrically connected by pouring metal into the gap between them. The end rings (50a) self-short-circuit the secondary conductor (50) to form a cage structure, thereby realizing a self-starting function.

[0026] The secondary conductor (50) includes a first conductor (51) (see FIG. 2) extending in the axial direction, and may further include a second conductor (52) (see FIGS. 2 and 3) extending in the axial direction. The secondary conductor (50) is made of a conductive material such as aluminum or copper.

[0027] 2 and 3 show variations in the cross-sectional configuration of the rotor 12. The cross-sectional configuration of the rotor 12 is basically the same at any position in the axial direction, except for both axial ends where the end rings 50a are disposed.

[0028] In the basic configuration of the rotor (12) ( FIG. 2(a) ), the rotor core (13) has a first outer peripheral surface (21) having an arc shape centered on the axis, and a second outer peripheral surface (22) located radially inward of the first outer peripheral surface (21) and having an arc shape centered on the axis. The second outer peripheral surface (22) is a recess in the outer periphery of the rotor core (13). The rotor core (13) is provided with a first flux barrier (31) penetrating the rotor core (13) in the axial direction. The first flux barrier (31) includes a first gap portion (31a) having an arc shape centered on the axis and extending along the second outer peripheral surface (22), and a second gap portion (31b) extending linearly from an end of the first gap portion (31a) toward the first outer peripheral surface (21). The first gap (31a) is provided on the inner peripheral side of a second outer peripheral surface (22) which is a recess in the outer periphery of the rotor core (13).

[0029] The first conductor (51) constituting the secondary conductor (50) is disposed in the first gap (31a) of the first flux barrier (31). In this manner, by disposing the first conductor (51) radially inward of the second outer circumferential surface (22) which is a recess in the outer periphery of the rotor core (13), in other words, by not disposing a conductor on the radial surface of the rotor core (13), it is possible to suppress the generation of eddy currents. In more detail, when a motor is constructed using the rotor (12), the air gap between the second outer circumferential surface (22) of the rotor (12) and the stator is expanded, so that the first conductor (51) is less susceptible to the effect of spatial harmonic magnetic flux, and the generation of eddy current loss can be suppressed. The first conductor (51) is made of a non-magnetic material. No magnet is provided inside the first flux barrier (31). In other words, no magnet is provided in the rotor (12).

[0030] The cross-sectional shape of the first conductor (51) is not particularly limited (FIGS. 2(a) to 2(c), 3(c)). For example, the first conductor (51) may be configured in an arc shape along the first gap portion (31a) (FIGS. 2(a) and 2(b), 3(c)), or may be configured from a number of rod-shaped portions extending in the axial direction (FIG. 2(c)).

[0031] It is not necessary to dispose a conductor in the second gap (31b) of the first flux barrier (31). In particular, it is preferable not to dispose a conductor in a portion of the second gap (31b) located on the radially outer side (close to the first outer circumferential surface (21)) in order to avoid an increase in loss due to eddy currents. On the other hand, a conductor may be disposed in a portion of the second gap (31b) located on the radially inner side.

[0032] The rotor core (13) may be provided with a second flux barrier (32) penetrating the rotor core (13) in the axial direction (FIGS. 2(b) to 2(d) and 3(a) to 3(d)). The second flux barrier (32) may be provided in a plurality of layers. The second flux barrier (32) includes a third gap (32a) having an arc shape centered on the axis and extending along the second outer peripheral surface (22) in parallel with the first gap (31a), and a fourth gap (32b) extending linearly from an end of the third gap (32a) toward the first outer peripheral surface (21) in parallel with the second gap (31b). The third gap (32a) of the second flux barrier (32) is located radially inward of the first gap (31a) of the first flux barrier (31). When the first flux barrier (31) and the second flux barrier (32) are provided, the structure of the rotor core (13) may be reinforced by providing a center rib (13b) so as to cross the flux barriers (31, 32) in the radial direction. In addition to providing one center rib (13b), a rib (13c) that defines the formation areas of the first conductor (51) and the second conductor (52) may be provided to further reinforce the structure of the rotor core (13).

[0033] A second conductor (52) may be disposed in the fourth gap (32b) of the second flux barrier (32) (FIG. 2(d) and FIG. 3(a), (b), and (d)). In this case, the secondary conductor (50) is composed of a first conductor (51) and a second conductor (52). The second conductor (52) is composed of a non-magnetic material. A magnet is not provided in the second flux barrier (32). In other words, even when the first flux barrier (31) and the second flux barrier (32) are provided, a magnet is not provided in the rotor (12). When the second flux barrier (32) is provided in multiple layers, the second conductor (52) may be disposed in only one fourth gap (32b) (FIG. 2(d)), or may be disposed in each of the multiple fourth gaps (32b) (FIG. 3(a), (b), and (d)).

[0034] In order to avoid an increase in loss due to eddy currents, it is preferable not to arrange the second conductor (52) in a radially outer portion (close to the first outer peripheral surface (21)) of the fourth gap (32b) of the second flux barrier (32) (FIG. 2(d) and FIGS. 3(a), 3(b) and 3(d)). A conductor may or may not be arranged in the third gap (32a) of the second flux barrier (32). The cross-sectional shape of the second conductor (52) is not particularly limited.

[0035] The first conductor (51) and the second conductor (52) constituting the secondary conductor (50) are disposed radially inward of the second outer peripheral surface (22), and the second conductor (52) may be disposed at a position overlapping a virtual curve extending with the same curvature as the arc shape of the first gap portion (31a) in which the first conductor (51) is disposed (FIGS. 3(a) and 3(b)). In this manner, by disposing the first conductor (51) and the second conductor (52) radially inward of the second outer peripheral surface (22), which is a recess in the outer periphery of the rotor core (13), in other words, by not disposing a conductor on the radial surface of the rotor core (13), it is possible to suppress the generation of eddy currents.

[0036] The second gap (31b) of the first flux barrier (31) and the fourth gap (32b) of the second flux barrier (32) may be exposed to the first outer circumferential surface (21) of the rotor core (13) ( FIG. 3B ). In this case, in order to form the first conductor (51) and the second conductor (52) by casting, ribs (13c) that partition the formation regions of the first conductor (51) and the second conductor (52) may be provided in the first gap (31a) of the first flux barrier (31) and the fourth gap (32b) of the second flux barrier (32), respectively, so that metal can be poured into the space between the ribs (13c). In this case, the end ring (50a) may also be formed integrally with the secondary conductor (50) so that metal can be poured into the space.

[0037] The number of poles of the rotor (12) is not particularly limited. For example, the number of poles may be two (FIGS. 2(a) to 2(d) and 3(a) and 3(b)), or four (FIGS. 3(c) and 3(d)). Even in the four-pole rotor (12), one or more layers of the second flux barrier (32) may be provided (FIGS. 3(c) and 3(d)), and the second conductor (52) may be disposed in the fourth gap (32b) of the second flux barrier (32) (FIG. 3(d)). When the second flux barrier (32) is provided in multiple layers, the second conductor (52) may be disposed in only one fourth gap (32b) or in each of the multiple fourth gaps (32b) (FIG. 3(d)).

[0038] <Electric motor> As shown in FIG. 4, the electric motor (10) of this embodiment mainly includes the rotor (12) and a stator (40) facing the rotor (12) across a predetermined gap in the radial direction. The stator (40) includes a stator core (41) and a plurality of windings (42). The stator core (41) includes a back yoke (41a) and a plurality of teeth (41b). The back yoke (41a) is formed in a substantially cylindrical shape. The plurality of teeth (41b) each extend radially inward from the inner circumferential surface of the back yoke (41a). The plurality of windings (42) are wound around the plurality of teeth (41b).

[0039] The configuration of the electric motor (10) shown in FIG. 4 is an example, and the number of poles of the electric motor (10), the shape and number of teeth of the stator core (41), the winding method of the windings (42), etc. are not particularly limited.

[0040] As shown in Fig. 5, the electric motor (10) is started by passing an induced current through a secondary conductor (50), which serves as a rotor core of an induction motor, using a commercial power source (50 Hz / 60 Hz). When the motor is accelerated to a predetermined synchronous speed by squirrel-cage induction, a reluctance torque is generated by the synchronous reluctance motor structure (hereinafter referred to as synchronous machine structure) of the rotor core (13), and constant-speed operation at the synchronous speed (synchronous operation) is performed.

[0041] More specifically, when the electric motor (10) is connected to a commercial power source, it starts due to the structure of an induction motor (hereinafter referred to as induction machine structure) and accelerates to a rotation speed close to the synchronous speed, as shown in Fig. 6. From start-up to the synchronous speed, the driving power supply frequency and the rotor frequency do not match (slip), so an induced current is generated in the secondary conductor (50), and an accelerating torque is generated due to the attraction and repulsion forces between the magnetic flux generated by the induced current and the magnetic flux of the current flowing in the winding (42) of the stator (40).

[0042] When the rotation speed approaches the synchronous speed, both the induction machine structure and the synchronous machine structure operate, and the motor accelerates to the synchronous speed. When the motor reaches the synchronous speed, the slip described above disappears, and no induced current is generated in the secondary conductor (50). At this time, the frequency of the magnetic flux flowing through the rotor core (13) matches the power supply frequency of the stator (40), so that synchronous operation is performed only with the synchronous machine structure.

[0043] In addition to the power running operation in the range of rotational speeds lower than the synchronous speed, the induction motor structure also includes regenerative operation in the range of rotational speeds higher than the synchronous speed. When the rotor (12) accelerates due to fluctuations on the load side while the motor (10) is operating, and the rotational speed exceeds the synchronous speed, the motor (10) enters a regenerative operation state. In this case, the motor (10) operates as a generator, absorbing the kinetic energy of the rotor (12) and the load and sending power back to the power source.

[0044] As described above, the electric motor (10) has two advantages: the high efficiency of a synchronous reluctance motor and the ability to start up from a commercial power source of an induction motor.

[0045] In the electric motor (10), by providing the second outer peripheral surface (22), which is a recess on the outer periphery of the rotor core (13), in a path through which magnetic flux has difficulty passing, it is possible to further increase the magnetic resistance and increase the salient pole ratio of the electric motor (10), thereby improving the performance of the electric motor (10).

[0046] In the electric motor (10), by configuring the secondary conductor (50) so that the magnetic flux of the stator (40) (air gap) does not easily pass through the secondary conductor (50), it is possible to reduce losses caused by eddy currents generated in the secondary conductor (50).

[0047] In the rotor core 13 of the electric motor 10, when a curve is drawn by extending the arc shape of the first gap 31a in which the first conductor 51 is disposed, with the same curvature as the arc, the second conductor 52 is preferably disposed at a position overlapping the curve (FIGS. 3(a) and 3(b)). When the secondary conductor 50 is disposed in the gaps 31a, 31b in this manner (concentrically) along the arc of the outer circumferential surface of the rotor core 13, the starting torque of the electric motor 10 can be maximized.

[0048] In the electric motor (10), the starting performance of the electric motor (10) can be improved by increasing the amount of the secondary conductor (50) (specifically, the first conductor (51)) provided near the second outer peripheral surface (22), which is a recess in the outer periphery of the rotor core (13).

[0049] <Compressor> As shown in FIG. 7, the compressor (CC) of this embodiment mainly includes the above-mentioned electric motor (10), a casing (CC1), and a compression mechanism (CC2).

[0050] The casing (CC1) houses the compression mechanism (CC2) and the electric motor (10). In this example, the casing (CC1) is formed in a cylindrical shape that extends in the vertical direction and has both ends closed. The casing (CC1) is provided with a suction pipe (CC11) and a discharge pipe (CC12). The suction pipe (CC11) penetrates a body part of the casing (CC1) and is connected to the compression mechanism (CC2). The discharge pipe (CC12) penetrates an upper part of the casing (CC1) and communicates with the internal space of the casing (CC1).

[0051] The compression mechanism (CC2) compresses a fluid. In this example, the compression mechanism (CC2) is disposed below the electric motor (10). The compression mechanism (CC2) compresses the fluid sucked in through a suction pipe (CC11) and discharges the compressed fluid into the internal space of the casing (CC1). The fluid discharged into the internal space of the casing (CC1) is discharged through a discharge pipe (CC12). In this example, the compression mechanism (CC2) is a rotary type compression mechanism.

[0052] The rotating shaft (11) connects the electric motor (10) and the compression mechanism (CC2). In this example, the rotating shaft (11) extends in the vertical direction. The electric motor (10) drives the rotating shaft (11) to rotate. The compression mechanism (CC2) is driven by the rotation of the rotating shaft (11).

[0053] 7 is an example, and the compressor (CC) is not limited to a rotary type compressor as shown in the example. The compressor (CC) may be a swing type, scroll type, screw type, turbo type, or other type compressor.

[0054] <Refrigeration equipment> FIG. 8 illustrates the configuration of the refrigeration device (RR) of this embodiment. The refrigeration device (RR) includes a refrigerant circuit (RR1) in which a refrigerant circulates. Specifically, the refrigerant circuit (RR1) includes a compressor (CC) having an electric motor (10), a first heat exchanger (RR5), a second heat exchanger (RR6), a pressure reduction mechanism (RR7), and a four-way switching valve (RR8). In this example, the expansion mechanism (RR7) is an electronic expansion valve. The refrigerant circuit (RR1) performs a vapor compression refrigeration cycle. For example, the first heat exchanger (RR5) is a heat source heat exchanger and is provided outdoors. The second heat exchanger (RR6) is a utilization heat exchanger and is provided indoors.

[0055] In the first heat exchanger (RR5), the refrigerant flowing through the first heat exchanger (RR5) exchanges heat with the air blown by the first fan (BL1). In the second heat exchanger (RR6), the refrigerant flowing through the second heat exchanger (RR6) exchanges heat with the air blown by the second fan (BL2).

[0056] The discharge side of the compressor (CC) is connected to the first port (P1) of the four-way switching valve (RR8). The suction side of the compressor (CC) is connected to the second port (P2) of the four-way switching valve (RR8). The gas end of the first heat exchanger (RR5) is connected to the third port (P3) of the four-way switching valve (RR8). The liquid end of the first heat exchanger (RR5) is connected to the liquid end of the second heat exchanger (RR6) via the expansion mechanism (RR7). The gas end of the second heat exchanger (RR6) is connected to the fourth port (P4) of the four-way switching valve (RR8).

[0057] The four-way switching valve (RR8) can be switched between a first state (a state shown by a solid line in FIG. 8) in which the first port (P1) and the third port (P3) are connected and the second port (P2) and the fourth port (P4) are connected, and a second state (a state shown by a dashed line in FIG. 8) in which the first port (P1) and the fourth port (P4) are connected and the second port (P2) and the third port (P3) are connected.

[0058] When the four-way switching valve (RR8) is in the first state, the refrigerant discharged from the compressor (CC) releases heat in the first heat exchanger (RR5), is decompressed in the expansion mechanism (RR7), and then absorbs heat in the second heat exchanger (RR6). The refrigerant flowing out of the second heat exchanger (RR6) is sucked into the compressor (CC).

[0059] When the four-way switching valve (RR8) is in the second state, the refrigerant discharged from the compressor (CC) releases heat in the second heat exchanger (RR6), is decompressed in the expansion mechanism (RR7), and then absorbs heat in the first heat exchanger (RR5). The refrigerant flowing out of the first heat exchanger (RR5) is sucked into the compressor (CC).

[0060] The configuration of the refrigeration unit (RR) shown in FIG. 8 is an example, and the refrigeration unit (RR) may be an air conditioner that switches between cooling and heating. Alternatively, the refrigeration unit (RR) may be a dedicated cooling unit or a dedicated heating unit. In this case, the four-way switching valve (RR8) may be omitted in the refrigeration unit (RR). The refrigeration unit (RR) may be a water heater, a chiller unit, a cooling unit that cools the air inside a storage unit, or the like. The cooling unit cools the air inside a refrigerator, a freezer, a container, or the like.

[0061] In addition, in this example, the electric motor (10) is used as the motor that drives the compressor (CC). In addition to this, or instead of this, the electric motor (10) may be used as the motor (M1) that drives the first blower (BL1) and / or the motor (M2) that drives the second blower (BL2).

[0062] <Features of the embodiment> The rotor (12) of this embodiment is configured to be rotatable around the axis of the rotating shaft (11). The rotor (12) includes a rotor core (13), a first flux barrier (31), and a first conductor (51). The rotor core (13) has a first outer peripheral surface (21) having an arc shape centered on the axis of the rotating shaft (11), and a second outer peripheral surface (22) having an arc shape centered on the axis and located radially inward of the first outer peripheral surface (21). The first flux barrier (31) penetrates the rotor core (13) in the axial direction. The first flux barrier (31) includes a first gap portion (31a) having an arc shape centered on the axis and extending along the second outer peripheral surface (22), and a second gap portion (31b) extending linearly from an end of the first gap portion (31a) toward the first outer peripheral surface (21). The first conductor (51) is disposed in the first gap (31a).

[0063] In the rotor (12) of the present embodiment, a first gap (31a) of a first flux barrier (31) is provided on the inner peripheral side of a second outer peripheral surface (22) which is a recess in the outer periphery of the rotor core (13), and a first conductor (51) is disposed in the first gap (31a). This makes it possible to suppress loss caused by eddy currents generated in the first conductor (51).

[0064] The rotor (12) of the present embodiment may further include a second flux barrier (32) penetrating the rotor core (13) in the axial direction, and a second conductor (52). The second flux barrier (32) may include a third gap (32a) having an arc shape centered on the axis and extending along the second outer circumferential surface (22) in parallel with the first gap (31a), and a fourth gap (32b) extending linearly from an end of the third gap (32a) toward the first outer circumferential surface (21) in parallel with the second gap (31b). The third gap (32a) may be located radially inward of the first gap (31a). The second conductor (52) may be disposed in the fourth gap (32b). In this manner, when the second conductor (52) is disposed in the fourth gap (32b) of the second flux barrier (32) in addition to the first conductor (51) disposed in the first gap (31a) of the first flux barrier (31), the torque generated by the squirrel-cage induction can be increased, and therefore the starting torque can also be increased.

[0065] In the rotor (12) of this embodiment, the first conductor (51) and the second conductor (52) may be arranged radially inward from the second outer circumferential surface (22), and the second conductor (52) may be arranged at a position overlapping a virtual curve that is an extension of the arc shape of the first gap portion (31a) with the same curvature. By aligning the positions of the first conductor (51) and the second conductor (52) in this manner, a starting torque can be generated smoothly. Furthermore, compared to a case where the second conductor (52) is arranged radially inward from the curve, the starting torque can be increased, and the generation of eddy currents can be suppressed compared to a case where the second conductor (52) is arranged radially outward from the curve.

[0066] Since the electric motor (10) of the present embodiment includes the rotor (12), it is possible to suppress losses.

[0067] Since the compressor (CC) of the present embodiment includes the electric motor (10), it is possible to suppress losses.

[0068] Since the sending machines (BL1, BL2) of the present embodiment include the electric motor (10), it is possible to suppress losses.

[0069] The refrigeration system (RR) of the present embodiment includes the electric motor (10), which makes it possible to suppress losses.

[0070] (Other embodiments) In the rotor (12) of the above embodiment (including modified examples, the same applies below), the second flux barrier (32) in which no conductor is arranged in the arc-shaped third gap (32a) is arranged radially inside the first flux barrier (31) in which the first conductor (51) is arranged in the arc-shaped first gap (31a). However, instead of this, the first flux barrier (31) may be arranged radially inside the second flux barrier (32). However, in order to increase the amount of the secondary conductor (50) provided near the second outer circumferential surface (22) of the rotor core (13) for the purpose of improving the starting performance of the electric motor (10), it is preferable to arrange the second flux barrier (32) radially inside the first flux barrier (31).

[0071] In the rotor 12 of the above embodiment (including modified examples, the same applies below), the arc-shaped first gap 31a communicates with the linear second gap 31b in the first flux barrier 31, and the arc-shaped third gap 32a communicates with the linear fourth gap 32b in the second flux barrier 32. However, instead of this, for the purpose of ensuring the strength of the rotor core 13, forming (e.g., casting) the secondary conductor 50, or the like, a rib may be provided between the first gap 31a and the second gap 31b and / or between the third gap 32a and the fourth gap 32b.

[0072] Although the embodiments have been described above, it will be understood that various modifications of form and details are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments and modifications may be combined or substituted as appropriate. Furthermore, the descriptions "first," "second," "third," etc. in the specification and claims are used to distinguish the words to which these descriptions are attached, and do not limit the number or order of the words. [Industrial Applicability]

[0073] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for rotors, electric motors, compressors, blowers, and refrigeration devices. [Explanation of symbols]

[0074] 10 Electric motor 11 Rotation axis 12 Rotor 13 Rotor core 21 First outer surface 22 Second outer peripheral surface 31 First Flux Barrier 31a 1st cavity 31b 2nd cavity 32 Second Flux Barrier 32a 3rd cavity 32b 4th cavity 51 First conductor 52 Second Conductor CC Compressor BL1,BL2 blower RR refrigeration equipment

Claims

1. A rotor (12) configured to be rotatable about the axis of a rotating shaft (11), a rotor core (13) having a first outer peripheral surface (21) having an arc shape centered on an axis of the rotating shaft (11), and a second outer peripheral surface (22) located radially inward of the first outer peripheral surface (21) and having an arc shape centered on the axis; a first flux barrier (31) that axially penetrates the rotor core (13); A first conductor (51) Equipped with the first flux barrier (31) includes a first gap (31a) having an arc shape centered on the axis and extending along the second outer peripheral surface (22), and a second gap (31b) extending linearly from an end of the first gap (31a) toward the first outer peripheral surface (21), The first conductor (51) is disposed in the first gap (31a). Rotor.

2. The rotor of claim 1, a second flux barrier (32) that axially penetrates the rotor core (13); A second conductor (52) and Further equipped with the second flux barrier (32) includes a third gap (32a) having an arc shape centered on the axis and extending along the second outer peripheral surface (22) in parallel with the first gap (31a), and a fourth gap (32b) extending linearly from an end of the third gap (32a) toward the first outer peripheral surface (21) in parallel with the second gap (31b), The third gap (32a) is located radially inward of the first gap (31a), The second conductor (52) is disposed in the fourth gap (32b). Rotor.

3. The rotor of claim 2, the first conductor (51) is disposed radially inward of the second outer circumferential surface (22); the second conductor (52) is disposed radially inward of the second outer circumferential surface (22); When a curve is drawn by extending the arc shape of the first gap (31a) with the same curvature as the arc shape of the first gap (31a), the second conductor (52) is disposed at a position where the curve overlaps the curve. Rotor.

4. An electric motor comprising a rotor (12) according to any one of claims 1 to 3.

5. A compressor comprising an electric motor (10) according to claim 4.

6. A blower comprising the electric motor (10) of claim 4.

7. A refrigeration system comprising an electric motor (10) according to claim 4.

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