Rotor, electric motor, compressor, blower, and refrigeration device

Abstract

To provide a rotor capable of suppressing losses caused by an eddy current generated in a conductor.SOLUTION: 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) that is arc-shaped and centered on the axial center of a rotating shaft (11), and a second outer peripheral surface (22) that is arc-shaped and located radially inward of the first outer peripheral surface (21) and centered on the axial center. The first flux barrier (31) penetrates the rotor core (13) in the axial direction. The first flux barrier (31) includes a first gap (31a) that is arc-shaped and centered on the axial center and extends along the second outer peripheral surface (22), and a second gap (31b) that extends 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).SELECTED DRAWING: Figure 2

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 combines the features of both 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 from 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 that can suppress 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 about 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 31 a of the first flux barrier 31 is provided on the inner peripheral side of the second outer peripheral surface 22, which is a recess in the outer periphery of the rotor core 13, and the first conductor 51 is disposed in the first gap 31 a. This makes it possible to suppress loss due to eddy currents generated in the first conductor 51.

[0008] A second aspect of the present disclosure is the rotor of the first aspect, further including a second flux barrier (32) axially penetrating the rotor core (13) and a second conductor (52). The second flux barrier (32) includes an arc-shaped third gap (32a) centered on the axis and extending along the second outer peripheral surface (22) alongside the first gap (31a), and a fourth gap (32b) extending linearly from an end of the third gap (32a) towards the first outer peripheral surface (21) alongside 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 disposed in the first gap 31 a of the first flux barrier 31, the second conductor 52 is disposed in the fourth gap 32 b of the second flux barrier 32. This increases the torque generated by squirrel-cage induction, thereby increasing the starting torque.

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

[0011] In the third aspect, the first conductor 51 and the second conductor 52 are aligned, which allows for smooth generation of starting torque. Furthermore, compared to when the second conductor 52 is positioned radially inward from the curve, the starting torque can be increased, and the generation of eddy currents can be suppressed compared to when the second conductor 52 is positioned 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 low 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 fan 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 explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a perspective view showing the schematic configuration of a rotor of an embodiment, where (a) shows the rotor attached to a rotating shaft, (b) shows the end plate removed from the secondary conductor, and (c) shows the secondary conductor removed. [Figure 2] FIG. 2 shows variations in the cross-sectional configuration of the rotor of the embodiment, where (a) shows the basic configuration, (b) shows a configuration with multiple flux barriers, (c) shows a modified shape of the secondary conductor, and (d) shows a modified number of layers of the secondary conductor. [Figure 3] Figure 3 shows variations in the cross-sectional configuration of the rotor of the 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. [Figure 5] FIG. 5 is a diagram illustrating the operation of the electric motor according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating the operation of the electric motor according to the embodiment. [Figure 7] FIG. 7 is a vertical cross-sectional view showing 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 INVENTION

[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, the same reference numerals in the drawings represent the same components, but dimensions in the drawings, such as length, width, thickness, and depth, have been appropriately changed from the actual scale for clarity and simplification of the drawings, and may not correspond to the actual relative dimensions.

[0022] <Rotor> As shown in Fig. 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 squirrel-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." Also, 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 the 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, nanocrystals, or a powder magnetic core. 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 with a lock nut 11b sandwiching an end plate 11a. This allows the rotor 12 to rotate freely around its 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 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) that is arc-shaped and centered on the axis, and a second outer peripheral surface (22) that is arc-shaped and located radially inward of the first outer peripheral surface (21) and centered on the axis. The second outer peripheral surface (22) is a recess on the outer periphery of the rotor core (13). The rotor core (13) is provided with a first flux barrier (31) that penetrates the rotor core (13) in the axial direction. The first flux barrier (31) includes a first gap (31a) that is arc-shaped and centered on the axis and extends along the second outer peripheral surface (22), and a second gap (31b) that extends linearly from an end of the first gap (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). By disposing the first conductor (51) 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. Specifically, when a motor is constructed using the rotor (12), the air gap between the second outer peripheral surface (22) of the rotor (12) and the stator is widened, making the first conductor (51) less susceptible to spatial harmonic magnetic flux, thereby suppressing the generation of eddy current loss. The first conductor (51) is made of a non-magnetic material. No magnet is provided inside the first flux barrier (31). That is, 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) and 3(c)). For example, the first conductor (51) may be configured in an arc shape along the first gap (31a) (FIGS. 2(a) and 2(b) and 3(c)), or may be configured from multiple rod-shaped portions extending in the axial direction (FIG. 2(c)).

[0031] An electric conductor does not have to be disposed in the second gap (31b) of the first flux barrier (31). In particular, it is preferable not to dispose an electric conductor in a radially outer portion of the second gap (31b) (a portion close to the first outer peripheral surface (21)) in order to avoid an increase in loss due to eddy current. On the other hand, an electric conductor may be disposed in a radially inner portion of the second gap (31b).

[0032] The rotor core 13 may be provided with a second flux barrier 32 penetrating the rotor core 13 in the axial direction (see FIGS. 2(b) to 2(d) and 3(a) to 3(d)). The second flux barrier 32 may be provided in multiple layers. The second flux barrier 32 includes: an arc-shaped third gap 32a 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, a center rib 13b may be provided so as to radially cross the flux barriers 31, 32 to reinforce the structure of the rotor core 13. In addition to providing one center rib 13b, a rib 13c may be provided to define regions where the first conductor 51 and the second conductor 52 are formed, 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 (see (d) of FIG. 2 and (a), (b), and (d) of FIG. 3). In this case, the secondary conductor 50 is composed of a first conductor 51 and a second conductor 52. The second conductor 52 is made of a non-magnetic material. No magnet is disposed in the second flux barrier 32. That is, even when the first flux barrier 31 and the second flux barrier 32 are disposed, no magnet is disposed in the rotor 12. When the second flux barrier 32 is disposed in multiple layers, the second conductor 52 may be disposed in only one fourth gap 32b (see (d) of FIG. 2) or in each of the multiple fourth gaps 32b (see (a), (b), and (d) of FIG. 3).

[0034] In order to avoid an increase in loss due to eddy currents, it is preferable that the second conductor 52 is not disposed in a radially outer portion of the fourth gap 32b of the second flux barrier 32 (a portion close to the first outer peripheral surface 21) (FIG. 2(d) and FIGS. 3(a), 3(b), and 3(d)). A conductor may or may not be disposed 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 may be arranged radially inward of the second outer peripheral surface 22, and the second conductor 52 may be arranged at a position overlapping a virtual curve drawn by extending the arc shape of the first gap 31 a in which the first conductor 51 is arranged with the same curvature as the curve (FIGS. 3(a) and 3(b)). In this way, by arranging 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 arranging conductors on the radial surface of the rotor core 13, it is possible to suppress the generation of eddy currents.

[0036] The second gap 31 b of the first flux barrier 31 and the fourth gap 32 b of the second flux barrier 32 may be exposed to the first outer circumferential surface 21 of the rotor core 13 ( FIG. 3( b)). In this case, in order to form the first conductor 51 and the second conductor 52 by casting, ribs 13 c that define the formation areas of the first conductor 51 and the second conductor 52 may be provided in the first gap 31 a of the first flux barrier 31 and the fourth gap 32 b of the second flux barrier 32, respectively, so that metal can be poured into the space sandwiched between the ribs 13 c. In this case, the end ring 50 a 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 (see FIGS. 2(a) to 2(d) and 3(a) and 3(b)) or four (see FIGS. 3(c) and 3(d)). Even in a four-pole rotor 12, one or more layers of second flux barriers 32 may be provided (see FIGS. 3(c) and 3(d)). Second conductors 52 may be disposed in the fourth gaps 32b of the second flux barriers 32 (see FIG. 3(d)). When multiple layers of second flux barriers 32 are provided, the second conductors 52 may be disposed in only one fourth gap 32b or in each of the multiple fourth gaps 32b (see 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 that faces the rotor 12 across a predetermined radial gap. 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 winding (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 supply (50 Hz / 60 Hz). When the electric motor (10) 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 (synchronous operation) is performed at the synchronous speed.

[0041] More specifically, as shown in Fig. 6, when the electric motor (10) is connected to a commercial power supply, it starts due to the structure of the induction motor (hereinafter referred to as induction machine structure) and accelerates to a rotation speed close to the synchronous speed. From start-up to the synchronous speed, the drive 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 synchronous speed is reached, 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 synchronous operation is performed only with the synchronous machine structure.

[0043] In addition to the power running operation in the rotational speed range below the synchronous speed, the induction motor structure also includes regenerative operation in the rotational speed range above the synchronous speed. If the rotor 12 accelerates due to fluctuations on the load side while the motor 10 is running, 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 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 where 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 imaginarily 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 shape of the first gap 31a, in which the first conductor 51 is disposed, the second conductor 52 is preferably disposed at a position overlapping the curve (FIGS. 3(a) and 3(b)). In this way, when the secondary conductor 50 is disposed in the gaps 31a, 32b so as to be aligned (concentrically) with 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 secondary conductor (50) (specifically, first conductor (51)) provided near the second outer 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 vertically and is closed at both ends. The casing (CC1) is provided with a suction pipe (CC11) and a discharge pipe (CC12). The suction pipe (CC11) passes through a body of the casing (CC1) and is connected to the compression mechanism (CC2). The discharge pipe (CC12) passes through an upper part of the casing (CC1) and communicates with the interior 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 drawn in through the 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 the discharge pipe (CC12). In this example, the compression mechanism (CC2) is a rotary compression mechanism.

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

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

[0054] <Refrigeration equipment> FIG. 8 illustrates the configuration of a refrigeration system (RR) according to this embodiment. The refrigeration system (RR) includes a refrigerant circuit (RR1) through 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), heat is exchanged between the refrigerant flowing through the first heat exchanger (RR5) and the air blown by the first fan (BL1). In the second heat exchanger (RR6), heat is exchanged between the refrigerant flowing through the second heat exchanger (RR6) and 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 (state shown by solid lines in Figure 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 (state shown by dashed lines in Figure 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 drawn 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 drawn 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 selector valve (RR8) may be omitted from the refrigeration unit (RR). The refrigeration unit (RR) may also be a water heater, a chiller unit, a cooling unit that cools the air inside a storage unit, or the like. A 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). However, in addition to this, or instead of this, the electric motor (10) may be used as the motor (M1) that drives the first fan (BL1) and / or the motor (M2) that drives the second fan (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) that is arc-shaped and centered on the axis of the rotating shaft (11), and a second outer peripheral surface (22) that is arc-shaped and located radially inward of the first outer peripheral surface (21) and centered on the axis. The first flux barrier (31) penetrates the rotor core (13) in the axial direction. The first flux barrier (31) includes a first gap (31a) that is arc-shaped and centered on the axis and extends along the second outer peripheral surface (22), and a second gap (31b) that extends 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).

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

[0064] The rotor (12) of this embodiment may further include a second flux barrier (32) axially penetrating the rotor core (13) and a second conductor (52). The second flux barrier (32) may include a third void (32a) having an arc shape centered on the axis and extending along the second outer peripheral surface (22) parallel to the first void (31a), and a fourth void (32b) extending linearly parallel to the second void (31b) from an end of the third void (32a) toward the first outer peripheral surface (21). The third void (32a) may be located radially inward of the first void (31a). The second conductor (52) may be disposed in the fourth void (32b). In this way, when the second conductor (52) is arranged in the fourth gap (32b) of the second flux barrier (32) in addition to the first conductor (51) arranged in the first gap (31a) of the first flux barrier (31), the torque generated by 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 of the second outer peripheral surface (22), and the second conductor (52) may be arranged at a position overlapping a virtual curve drawn by extending the arc shape of the first gap (31a) with the same curvature. Aligning the first conductor (51) and the second conductor (52) in this manner allows for smooth generation of starting torque. Furthermore, compared to when the second conductor (52) is arranged radially inward of the curve, the starting torque can be increased, and compared to when the second conductor (52) is arranged radially outward of the curve, generation of eddy currents can be suppressed.

[0066] The electric motor (10) of this embodiment includes the rotor (12), which makes it possible to suppress losses.

[0067] The compressor (CC) of this embodiment includes the electric motor (10), which makes it possible to reduce losses.

[0068] The sending machines (BL1, BL2) of this embodiment include the electric motors (10), which makes it possible to suppress losses.

[0069] The refrigeration system (RR) of this embodiment includes the electric motor (10), which makes it possible to reduce 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 secondary conductor (50) provided near the second outer circumferential surface (22) of the rotor core (13) in order to improve 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-described embodiment (including modified examples, the same applies hereinafter), the arc-shaped first void portion 31 a and the linear second void portion 31 b are in communication with each other in the first flux barrier 31, and the arc-shaped third void portion 32 a and the linear fourth void portion 32 b are in communication with each other in the second flux barrier 32. However, instead of this, ribs may be provided between the first void portion 31 a and the second void portion 31 b and / or between the third void portion 32 a and the fourth void portion 32 b for the purpose of ensuring the strength of the rotor core 13 or for forming (e.g., casting) the secondary conductor 50.

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

[0073] 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 around the axis of a rotating shaft (11), a rotor core (13) having a first outer peripheral surface (21) in an arc shape centered on an axial center of the rotating shaft (11), and a second outer peripheral surface (22) located radially inward of the first outer peripheral surface (21) and also in an arc shape centered on the axial center; a first flux barrier (31) that axially penetrates the rotor core (13); A first conductor (51) and 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. 2. The rotor of claim 1, a second flux barrier (32) that axially penetrates the rotor core (13); A second conductor (52) and Furthermore, 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) alongside the first gap (31a); and a fourth gap (32b) extending linearly from an end of the third gap (32a) towards the first outer peripheral surface (21) alongside 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 electric conductor (51) is disposed radially inward of the second outer peripheral surface (22); the second electric conductor (52) is disposed radially inward of the second outer peripheral surface (22); When a curve is drawn imaginarily by extending the arc shape of the first gap (31a) with the same curvature, the second conductor (52) is disposed at a position overlapping the curve. Rotor.

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

5. A compressor comprising the electric motor (10) of claim 4.

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

7. A refrigeration system comprising the electric motor (10) of claim 4.

Images