Magnetic circuit parts, blowers, compressors, and refrigeration devices

Abstract

To provide a magnetic circuit component, a blower, a compressor, and a refrigeration device to reduce vibration generated in the core in the magnetic circuit component that forms part of the magnetic circuit while suppressing an increase in product cost.SOLUTION: A magnetic circuit component (31) is made of a soft magnetic material and includes a core (32) having an annular yoke portion (34) and a dynamic vibration absorber (50) provided in the core (32) to reduce vibrations of the core (32). The dynamic vibration absorber (50) includes a weight portion (51) and a connection portion (52) that elastically deforms together with connecting the weight portion (51) and the yoke portion (34). The dynamic vibration absorber (50) is formed integrally with the core (32).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a magnetic circuit component, a blower, a compressor, and a refrigeration device. [Background technology]

[0002] Conventionally, magnetic circuits that are composed of closed circuits containing magnetic flux have been known. In magnetic circuits, vibrations occur due to changes in magnetic force. In the field of magnetic circuits, there is a challenge to reduce this vibration.

[0003] Patent Document 1 discloses an electric motor, which is a type of magnetic circuit. The electric motor of Patent Document 1 has a stator core and a stator outer peripheral plate arranged on the outer periphery of the stator core. In this electric motor, a plurality of reinforcing plates are provided between the stator outer peripheral plate and the stator core. The reinforcing plate has a first beam member and a second beam member having elasticity. The first beam member and the second beam member are connected by a connecting member. This structure reduces the support rigidity of the stator core and absorbs electromagnetic vibrations generated in the stator core. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-254012 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the electric motor of Patent Document 1, the provision of multiple reinforcing plates reduces vibration, but the addition of the reinforcing plates increases costs. In addition, the manufacturing process requires an additional step of assembling the reinforcing plates to the electric motor, which further increases costs.

[0006] An object of the present disclosure is to reduce vibrations generated in a core in a magnetic circuit component that constitutes a part of a magnetic circuit while suppressing an increase in product costs. [Means for solving the problem]

[0007] The first aspect is a magnetic circuit component constituting part of a magnetic circuit, comprising a core (32) made of a soft magnetic material and having an annular yoke portion (34), and a dynamic vibration absorber (50) provided on the core (32) for reducing vibration of the core (32), the dynamic vibration absorber (50) having a weight portion (51) and a connection portion (52) connecting the weight portion (51) and the yoke portion (34) and elastically deforming, and the dynamic vibration absorber (50) is formed integrally with the core (32).

[0008] In the first aspect, a dynamic vibration absorber (50) that reduces vibration of the core (32) is provided, and the dynamic vibration absorber (50) is formed integrally with the core (32). Therefore, the vibration of the core (32) can be reduced without adding any new member. In addition, in this aspect, there is no need to assemble the dynamic vibration absorber (50) to the core (32), as compared with a case in which the dynamic vibration absorber (50) is formed as a separate member from the core (32). This makes it possible to reduce vibration generated in the core (32) while suppressing an increase in the manufacturing cost of the magnetic circuit component (31).

[0009] In the second aspect, in the first aspect, the weight portion (51) extends along the circumferential direction of the yoke portion (34).

[0010] In the second aspect, the weight portion (51) is formed to extend circumferentially around the annular yoke portion (34). This makes it possible to reduce the overall size of the core (32) while ensuring the magnetic path of the yoke portion (34).

[0011] In a third aspect, in the first or second aspect, the dynamic vibration absorber (50) is provided on the outer periphery or inside of the yoke portion (34).

[0012] In the third aspect, the vibration of the core (32) is reduced by a dynamic vibration absorber (50) provided on the outer periphery or inside of the yoke portion (34).

[0013] A fourth aspect is any one of the first to third aspects, wherein the core (32) is composed of a plurality of electromagnetic steel sheets (M) stacked on top of each other, and the plurality of electromagnetic steel sheets (M) are fastened to each other at the weight portion (51).

[0014] In the fourth aspect, since the multiple electromagnetic steel sheets (M) constituting the core (32) are fastened to each other by the weight portion (51), a fastening portion is formed in a portion where magnetic flux does not pass, and therefore an increase in iron loss due to fastening can be suppressed.

[0015] In a fifth aspect, in any one of the first to fourth aspects, the magnetic circuit includes a rotor (40) configured to be rotatable around the axis of the rotating shaft (20), and a stator (31) arranged opposite the rotor (40) in the radial direction of the rotating shaft (20), the stator (31) has a stator core (32) as the core (32) and a coil (33) wound around the stator core (32), and the dynamic vibration reducer (50) is arranged on the opposite side of the rotor (40) in the radial direction.

[0016] In the fifth aspect, the vibration of the core (32) is reduced by a dynamic vibration absorber (50) disposed on the radially opposite side of the rotating shaft (20) from the rotor (40).

[0017] A sixth aspect is any one of the first to fifth aspects, wherein the magnetic circuit component constitutes a part of an electric motor (30).

[0018] In the sixth aspect, it is possible to reduce vibration of the core (32) while suppressing an increase in the production cost of the electric motor (30).

[0019] A seventh aspect is any one of the first to fifth aspects, wherein the magnetic circuit component constitutes a part of a magnetic bearing.

[0020] In the seventh aspect, it is possible to reduce vibration of the core (32) while suppressing an increase in the production cost of the magnetic bearing.

[0021] An eighth aspect is any one of the first to fourth aspects, wherein the magnetic circuit component constitutes a part of a reactor.

[0022] In the eighth aspect, it is possible to reduce vibration of the core (32) while suppressing an increase in the production cost of the reactor.

[0023] A ninth aspect is a blower including an electric motor (30) having the magnetic circuit component according to the sixth aspect, and a fan driven by the electric motor (30).

[0024] In the ninth aspect, a blower in which vibrations are reduced while suppressing an increase in production costs can be provided.

[0025] A tenth aspect is a compressor including the magnetic circuit component according to the sixth or seventh aspect.

[0026] In the tenth aspect, a compressor can be provided in which vibration is reduced while suppressing an increase in product costs.

[0027] An eleventh aspect relates to a refrigeration system including the compressor (10) of the tenth aspect and a refrigerant circuit (R) through which the refrigerant compressed by the compressor (10) flows.

[0028] In the eleventh aspect, a refrigeration device can be provided in which vibration is reduced while suppressing an increase in product costs. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a schematic piping diagram of a refrigeration system according to the first embodiment. [Diagram 2] FIG. 2 is an axial cross-sectional view of the compressor according to the first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view in a direction perpendicular to the axial direction, which diagrammatically illustrates the cross-sectional shape of the electric motor according to the first embodiment. [Figure 4] FIG. 4 is an enlarged view of the box IV in FIG. [Diagram 5] FIG. 5 is a cross-sectional view taken along line V-V in FIG. [Figure 6] FIG. 6 is a graph showing the results of the simulation. [Figure 7] FIG. 7 is an enlarged view of a main part according to the first modification of the first embodiment. [Figure 8] FIG. 8 is an enlarged view of a main part according to the second modification of the first embodiment. [Figure 9] FIG. 9 is an enlarged view of a main part according to the third modification of the first embodiment. [Figure 10] FIG. 10 is an enlarged view of a main part according to the fourth modification of the first embodiment. [Figure 11] FIG. 11 is an enlarged view of a main part according to the fifth modification of the first embodiment. [Figure 12] FIG. 12 is a diagram corresponding to FIG. 5 according to the sixth modification of the first embodiment. [Figure 13] FIG. 13 is a diagram corresponding to FIG. 5 according to the seventh modification of the first embodiment. [Figure 14] FIG. 14 is an enlarged view of a main part according to the eighth modified example of the first embodiment. [Figure 15] FIG. 15 is a diagram corresponding to FIG. 3 according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible within the scope of the technical idea of ​​the present disclosure. Since each drawing is intended to conceptually explain the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for easy understanding.

[0031] First Embodiment A first embodiment will be described. A magnetic circuit component (31) of the present disclosure constitutes a part of an electric motor (30). The electric motor (30) of the present embodiment is provided in a compressor (10) of a refrigeration system (1).

[0032] (1) Overview of the refrigeration system As shown in Fig. 1, the refrigeration system (1) includes a compressor (10). The refrigeration system (1) has a refrigerant circuit (R) filled with a refrigerant. The refrigerant circuit (R) has a compressor (10), a radiator (2), a pressure reduction mechanism (3), and an evaporator (4). The pressure reduction mechanism (3) is an expansion valve. The refrigerant circuit (R) performs a vapor compression refrigeration cycle.

[0033] In the refrigeration cycle, the refrigerant compressed by the compressor (10) dissipates heat to the air in the radiator (2). The refrigerant that has dissipated heat is reduced in pressure by the pressure reducing mechanism (3) and evaporated in the evaporator (4). The evaporated refrigerant is drawn into the compressor (10).

[0034] The refrigeration system (1) is an air conditioner. The air conditioner may be a cooling-only unit, a heating-only unit, or an air conditioner that switches between cooling and heating. In this case, the air conditioner has a switching mechanism (e.g., a four-way switching valve) that switches the circulation direction of the refrigerant. The refrigeration system (1) may be a water heater, a chiller unit, a cooling device that cools the air inside a storage unit, or the like. The cooling device cools the air inside a refrigerator, a freezer, a container, or the like. The pressure reducing mechanism (3) may be composed of an electronic expansion valve, a temperature-sensitive expansion valve, an expander, or a capillary tube.

[0035] (2) Compressor As shown in Fig. 2, the compressor (10) includes a casing (11), an electric motor (30), a drive shaft (20), and a compression mechanism (22). The compressor (10) is a rotary type compressor. Strictly speaking, the compressor (10) is a rocking piston type compressor. The compressor (10) may be a scroll type, a screw type, or a turbo type compressor.

[0036] (2-1) Casing The casing (11) accommodates the electric motor (30), the drive shaft (20), and the compression mechanism (22). The casing (11) is a totally sealed container. The inside of the casing (11) is filled with high-pressure refrigerant discharged from the compression mechanism (22).

[0037] The casing (11) is made of a metal material. The casing (11) has a body (12), a bottom (13), and a top (14). The body (12) is a cylindrical member made of metal. An opening is formed at each end in the axial direction of the body (12). In this embodiment, the axial direction of the body (12) corresponds to the vertical direction. The bottom (13) closes the lower opening of the body (12). The top (14) closes the upper opening of the body (12).

[0038] (2-2) Electric motor The electric motor (30) shown in Figures 2 and 3 is an example of a magnetic circuit. The electric motor (30) is disposed above the compression mechanism (22). The operation frequency of the electric motor (30) is controlled by an inverter device. In other words, the compressor (10) is an inverter type compressor with a variable operation frequency.

[0039] As shown in Fig. 2, the electric motor (30) has a stator (31) and a rotor (40). The stator (31) is supported by the body part (12) of the casing (11). The stator (31) corresponds to the magnetic circuit component (31) of the present disclosure.

[0040] As shown in Fig. 3, the stator (31) has a stator core (32), a coil (33) wound around the stator core (32), and a dynamic vibration absorber (50). The stator core (32) corresponds to the core of the present disclosure. The electric motor (30) is an electromagnetic device that generates a rotational torque in the rotor (40) by passing electricity through the coil (33).

[0041] The stator core (32) is formed by stacking electromagnetic steel sheets (M), which are soft magnetic materials, on one another in the axial direction. The stator core (32) is formed in a cylindrical shape. As shown in Fig. 3, the stator core (32) has an annular yoke portion (34) and a plurality of teeth portions (35) (in this embodiment, nine teeth portions) extending radially inward from the inner periphery of the yoke portion (34).

[0042] The dynamic vibration absorber (50) is provided on the stator core (32). The dynamic vibration absorber (50) serves to reduce vibration of the stator core (32). The stator (31) will be described in detail later.

[0043] The rotor (40) is disposed inside the stator core (32). The drive shaft (20) is fixed to the axis of the rotor (40). In other words, the stator core (32) is disposed opposite the rotor (40) in the radial direction of the drive shaft (20). A plurality of permanent magnets (42) are embedded inside the rotor (40). An annular gap (so-called air gap) is formed between the teeth portion (35) of the stator (31) and the rotor (40) when viewed in the axial direction.

[0044] (2-3) Drive shaft The drive shaft (20) extends vertically along the axis of the casing (11). The drive shaft (20) is rotationally driven by an electric motor (30). The drive shaft (20) is rotatably supported by bearings (21, 29). The drive shaft (20) corresponds to the rotating shaft of the present disclosure.

[0045] (2-4) Compression mechanism The compression mechanism (22) has a cylinder (23) and a piston (24) provided inside the cylinder (23). A cylinder chamber (25) is formed between the inner peripheral surface of the cylinder (23) and the outer peripheral surface of the piston (24). In the cylinder chamber (25), the fluid is compressed by the piston (24) driven by the drive shaft (20).

[0046] (2-5) Intake pipe and discharge pipe The compressor (10) has a suction pipe (26) and a discharge pipe (27). The suction pipe (26) passes radially through the body (12) and communicates with the cylinder chamber (25). Low-pressure refrigerant in the refrigerant circuit (R) is sucked into the cylinder chamber (25) through the suction pipe (26). The discharge pipe (27) passes axially through the top (14) and communicates with the internal space of the casing (11). The refrigerant compressed by the compression mechanism (22) flows through an air gap of the electric motor (30) and is then sent to the refrigerant circuit (R) through the discharge pipe (27).

[0047] (3) Stator details The stator (31) will be described in detail with reference to Figs. 3 to 5. In the following description, unless otherwise specified, the terms "axial direction," "circumferential direction," and "radial direction" refer to the axial direction, circumferential direction, and radial direction, respectively, of the yoke portion (34) of the stator (31). In this embodiment, the axial direction of the yoke portion (34) corresponds to the axial direction of the drive shaft (20) as shown in Fig. 2.

[0048] As described above, the stator (31) includes the stator core (32), the coil (33), and the dynamic vibration absorber (50). The stator core (32) also includes an annular yoke portion (34) and a plurality of teeth portions (35).

[0049] The teeth 35 extend radially inward from the inner periphery of the yoke 34. A coil 33 is wound around each tooth 35, for example, by concentrated winding. A coil slot 36, which is a space for accommodating the coil 33, is formed between adjacent teeth 35.

[0050] In this embodiment, the multiple electromagnetic steel sheets (M) constituting the stator core (32) are fastened to one another at the yoke portion (34). In this embodiment, the electromagnetic steel sheets (M) are fastened to one another by crimping. Note that means for fastening the electromagnetic steel sheets (M) may be welding, adhesion, or the like, other than crimping.

[0051] (3-1) Support part As shown in Fig. 3, the stator core (32) has a plurality of support portions (37) (nine in this embodiment). The support portions (37) support the stator core (32) on the body portion (12) of the casing (11). The support portions (37) are arranged at predetermined intervals in the circumferential direction. The support portions (37) protrude radially outward from the outer periphery of the yoke portion (34). The support portions (37) are fitted and fixed so as to come into contact with the inner circumferential surface of the body portion (12). This holds the stator core (32) in the casing (11).

[0052] (3-2) Dynamic vibration absorber The stator (31) has a plurality of dynamic vibration absorbers (50) (18 in this embodiment). Each dynamic vibration absorber (50) is provided on the outer periphery of the yoke portion (34). Each dynamic vibration absorber (50) is disposed in a small gap (G) formed between the inner periphery of the body portion (12) and the outer periphery of the yoke portion (34). Each dynamic vibration absorber (50) is disposed on the radially opposite side to the rotor (40).

[0053] Adjacent dynamic vibration absorbers (50) are disposed on both sides in the circumferential direction, sandwiching one support portion (37). Adjacent dynamic vibration absorbers (50) may be adjacent to each other without sandwiching one support portion (37). Each dynamic vibration absorber (50) is disposed radially outward of the coil slots (36). As shown in FIG. 5, each dynamic vibration absorber (50) is formed across the stator core (32) from one end to the other end in the axial direction.

[0054] As shown in FIG. 4, the dynamic vibration absorber (50) is configured to be L-shaped when viewed in the axial direction. The dynamic vibration absorber (50) has a weight portion (51) and a connection portion (52). The weight portion (51) extends along the circumferential direction of the yoke portion (34). The weight portion (51) is formed in a substantially rectangular parallelepiped shape. When viewed in the axial direction, the weight portion (51) is formed in a substantially rectangular shape with the longer side in the circumferential direction and the shorter side in the radial direction. The weight portion (51) does not contact the inner peripheral surface of the body portion (12). Furthermore, the weight portion (51) does not contact the outer peripheral surface of the yoke portion (34).

[0055] The connection portion (52) connects the weight portion (51) and the yoke portion (34). More specifically, the connection portion (52) connects the outer periphery of the yoke portion (34) and one circumferential end portion of the weight portion (51). The connection portion (52) extends in the radial direction. The connection portion (52) is formed in a substantially rectangular parallelepiped shape. The connection portion (52) elastically deforms. As shown in FIG. 4, the circumferential length W1 of the connection portion (52) is much smaller than the circumferential length W2 of the weight portion (51). Therefore, the connection portion (52) is more easily elastically deformed than the weight portion (51).

[0056] When the yoke portion (34) of the stator core (32) vibrates at its natural frequency, the dynamic vibration absorber (50) reduces the vibration of the stator core (32) by vibrating in a phase different from that of the yoke portion (34).

[0057] Note that, in this case, "vibrating in a phase different from that of the vibration of the yoke portion (34)" includes vibrating at a frequency different from the natural frequency of the yoke portion (34). In this case, the phase difference between the natural vibration of the yoke portion (34) and the vibration of the dynamic vibration absorber (50) changes with time.

[0058] Furthermore, "vibrating at a different phase from the vibration of the yoke portion (34)" includes vibrating at the same frequency as the natural frequency of the yoke portion (34) and at a different phase from the natural vibration of the yoke portion (34). In this case, for example, when the phase difference between the natural vibration of the yoke portion (34) and the vibration of the dynamic vibration absorber (50) is 90 degrees to 270 degrees, the natural vibration of the yoke portion (34) and the vibration of the dynamic vibration absorber (50) vibrate so as to cancel each other out, thereby reducing the vibration of the stator core (32). For example, when the phase difference between the natural vibration of the yoke portion (34) and the vibration of the dynamic vibration absorber (50) is 0 degrees to 90 degrees or 270 degrees to 360 degrees, the peaks of the natural vibration of the yoke portion (34) and the vibration of the dynamic vibration absorber (50) are shifted, thereby reducing the peak of the vibration of the stator core (32).

[0059] When the rotor (40) rotates, a magnetic attraction force is generated between the rotor (40) and the stator (31). This force is called an electromagnetic force. When the electromagnetic force acts on the stator core (32), the stator core (32) vibrates.

[0060] In the dynamic vibration absorber (50) of the present embodiment, when the stator core (32) vibrates, the connection portion (52) becomes a node and the tip portion (the other circumferential end portion) of the weight portion (51) becomes an antinode, causing the vibration. In this manner, the weight portion (51) vibrates in conjunction with the vibration of the stator core (32), thereby making it possible to reduce the radial vibration of the stator core (32) caused by electromagnetic force.

[0061] Here, the dynamic vibration absorber (50) of the present disclosure can be regarded as having a cantilever structure. The natural frequency f of the cantilever can be expressed by the following equation [Mathematical formula 1].

[0062]

number

[0063] In the above formula [Equation 1], m is the mass (kg) acting on the tip of the beam, and k is the stiffness of the cantilever beam (N / m). The stiffness k of the cantilever beam can be expressed by the following formula [Equation 2].

[0064]

number

[0065] In the above formula [Equation 2], E is Young's modulus, I is the second moment of area, and L is the length of the beam.

[0066] According to the above formula [Mathematical Expression 1], for example, when the circumferential length W1 of the connection portion (52) is increased, the cross-sectional area of ​​the connection portion (52) is increased, and the second moment of area I is increased. As a result, the rigidity k of the connection portion (52) is increased, and the natural frequency f of the dynamic vibration absorber (50) can be increased. On the other hand, for example, when the circumferential length W2 of the weight portion (51) is decreased, the mass m of the weight portion (51) is decreased. Therefore, in this case, the natural frequency f of the dynamic vibration absorber (50) can be increased. In this way, in the dynamic vibration absorber (50) of the present embodiment, the natural frequency f of the dynamic vibration absorber (50) can be set to a desired natural frequency by changing the circumferential length W1 of the connection portion (52) and the circumferential length W2 of the weight portion (51).

[0067] The dynamic vibration absorber (50) is formed integrally with the stator core (32). Specifically, the dynamic vibration absorber (50) is made of the same soft magnetic material as the stator core (32), and is made of electromagnetic steel sheets (M) that form the stator core (32). The dynamic vibration absorber (50) is formed by punching out the electromagnetic steel sheets (M) using a die having a shape in which a portion corresponding to the stator core (32) and a portion corresponding to the dynamic vibration absorber (50) are integrated, by press working or the like, and then stacking the punched electromagnetic steel sheets (M). In other words, the dynamic vibration absorber (50) can be formed simultaneously during the process of forming the stator core (32).

[0068] According to the above, since the dynamic vibration absorber (50) is formed integrally with the stator core (32), the dynamic vibration absorber (50) can be provided without adding any new member to the stator (31). In addition, since a process for assembling the dynamic vibration absorber (50) is not required separately from the process for manufacturing the stator core (32), an increase in the number of assembly processes can be suppressed. Therefore, it is possible to reduce vibrations generated in the stator core (32) while suppressing an increase in the manufacturing cost of the stator (31).

[0069] Furthermore, with the above structure, there is no need to perform a process of assembling the dynamic vibration absorber (50) to the stator core (32), and therefore there is no variation in the accuracy of assembling the dynamic vibration absorber (50). As a result, it is possible to suppress variation in the performance of the dynamic vibration absorber (50) for each stator (31).

[0070] In addition, the dynamic vibration absorber (50) of this embodiment is disposed in a small gap between the inner peripheral surface of the casing (11) and the outer peripheral surface of the stator (31). Therefore, in order to provide the dynamic vibration absorber (50), it is not necessary to increase the size of the electric motor (30) itself or to reduce the size of the stator core (32). Therefore, in this embodiment, it is possible to reduce vibrations generated in the stator core (32) while maintaining the performance of the electric motor (30).

[0071] (4) Simulation A simulation was performed to confirm the vibration reduction effect of the dynamic vibration absorber (50) of this embodiment. The simulation was performed on a 6-pole, 9-slot motor. In the simulation, the acceleration of the outer circumferential surface of the stator core (32) was measured when an excitation force of the natural frequency (resonance frequency) of the stator (31) was applied to the stator (31).

[0072] Fig. 6 is a graph showing frequency-acceleration on the outer peripheral surface of the stator core (32) obtained from this simulation. The solid line in the figure shows the result when an excitation force is applied to a conventional stator not equipped with a dynamic vibration absorber. The dashed line in the figure shows the result when an excitation force is applied to a stator (31) equipped with the dynamic vibration absorber (50) of this embodiment.

[0073] In the figure, it was confirmed that the stator (31) of this embodiment had a peak acceleration value reduced by approximately 98% compared to the conventional stator at 3200 Hz to 3300 Hz. This is believed to be because the dynamic vibration absorber (50) vibrates in the opposite phase to the vibration of the stator core (32), thereby reducing the vibration of the stator core (32). This result confirmed that the dynamic vibration absorber (50) of this embodiment can achieve a stator (31) with reduced vibration of the stator core (32).

[0074] (5) Features (5-1) In the stator (31) of this embodiment, the dynamic vibration absorber (50) is formed integrally with the stator core (32). Therefore, the vibration of the stator core (32) can be reduced without adding any new member. In addition, compared to a case where the dynamic vibration absorber (50) is formed as a separate member from the stator core (32), no work is required to assemble the dynamic vibration absorber (50) to the stator core (32). This makes it possible to reduce the vibration generated in the stator core (32) while suppressing an increase in the manufacturing cost of the stator (31).

[0075] (5-2) The weight portion (51) of the present embodiment extends circumferentially around the annular yoke portion (34). Therefore, the overall size of the stator core (32) can be reduced while ensuring the magnetic path of the yoke portion (34).

[0076] (5-3) The dynamic vibration absorber (50) of the present embodiment is provided on the outer periphery of the yoke portion (34). This reduces vibration of the stator core (32) at the outer periphery of the yoke portion (34). Moreover, since the dynamic vibration absorber (50) is provided on the outer periphery of the yoke portion (34), the dynamic vibration absorber (50) can be easily formed.

[0077] (5-4) The dynamic vibration absorber (50) of the present embodiment is disposed radially opposite the rotor (40), thereby reducing vibration of the stator core (32) in the portion radially opposite the rotor (40).

[0078] (5-5) The stator (31) of this embodiment constitutes a part of the electric motor (30), thereby making it possible to reduce vibration of the stator core (32) while suppressing an increase in the manufacturing cost of the electric motor (30).

[0079] (5-6) The dynamic vibration absorber (50) of the present embodiment is disposed in the stator core (32) from one end to the other end in the axial direction, thereby reducing vibrations occurring in the axial direction. Examples of vibrations occurring in the axial direction include vibrations caused by misalignment of the drive shaft (20) and imbalance of electromagnetic forces when the drive shaft is eccentric.

[0080] (5-7) The dynamic vibration absorber (50) of the present embodiment is formed in an L-shape. This makes it easier to set the circumferential length W2 of the weight portion (51) relatively freely, and therefore makes it easier to set the natural frequency of the dynamic vibration absorber (50) to a desired natural frequency.

[0081] (5-8) The dynamic vibration absorber (50) of this embodiment is disposed radially outward of the coil slots (36). Here, in the stator core (32), a portion located radially outward of the coil slots (36) is more susceptible to vibration than a portion located radially outward of the teeth portions (35). Therefore, in this embodiment, by disposing the dynamic vibration absorber (50) radially outward of the coil slots (36), the vibration of the stator core (32) can be further reduced.

[0082] (6) Variations The above embodiment may be modified as follows. In the following description, differences from the above embodiment will be mainly described.

[0083] (6-1) Modification 1: Shape of weight 7, in the dynamic vibration absorber (50) of this embodiment, the radial length of the weight portion (51) does not have to be constant from one circumferential end to the other circumferential end when viewed in the axial direction. This modification also provides the same effects as the above embodiment.

[0084] Specifically, the weight portion (51) has a first weight portion (51a) and a second weight portion (51b) with different radial lengths. The first weight portion (51a) is the portion of the weight portion (51) closer to the connection portion (52). The second weight portion (51b) is the portion of the weight portion (51) farther from the connection portion (52). The first weight portion (51a) and the second weight portion (51b) are continuous. The connection portion (52) is connected to one circumferential end portion of the first weight portion (51a). The radial length D2 of the second weight portion (51b) is longer than the radial length D1 of the first weight portion (51a) (D1 < D2). In other words, the weight portion (51) is configured such that its tip portion is heavier than the middle portion.

[0085] In this modification, for example, as shown in FIG. 7(a), the weight portion (51) may be configured such that the positions of the outer edge portions of the first weight portion (51a) and the second weight portion (51b) are the same in the radial direction. In this case, the position of the inner edge portion of the second weight portion (51b) is located radially inward of the position of the inner edge portion of the first weight portion (51a).

[0086] Also, in this modification, as shown in FIG. 7(b), the weight portion (51) may be configured such that the positions of the outer edge portions of the first weight portion (51a) and the second weight portion (51b) are different in the radial direction. In FIG. 7(b), the outer edge portion of the second weight portion (51b) is located radially outward of the outer edge portion of the first weight portion (51a). In this case, the position of the inner edge portion of the second weight portion (51b) is located radially inward of the position of the inner edge portion of the first weight portion (51a).

[0087] (6-2) Modification 2: Shape of the weight portion As shown in FIG. 8, the dynamic vibration absorber (50) of the present embodiment may be configured in an I shape when viewed in the axial direction. In this case, the connection portion (52) is provided on the support portion (37) of the stator core (32). The connection portion (52) connects the side edge portion of the support portion (37) and one circumferential end portion of the weight portion (51). The connection portion (52) extends in the circumferential direction. This modification also has the same effect as the above-described embodiment.

[0088] In this modification, for example, as shown in FIG. 8(a), the weight portion (51) may be configured so that the radial length D is constant from one end to the other end in the circumferential direction when viewed in the axial direction.

[0089] In this modification, as shown in Fig. 8(b) and Fig. 8(c), similarly to the above modification 1, the weight portion (51) may have a first weight portion (51a) and a second weight portion (51b) having different radial lengths. In this case, as shown in Fig. 8(b), the weight portion (51) may be configured such that the position of the outer edge of the first weight portion (51a) and the position of the outer edge of the second weight portion (51b) are the same in the radial direction. As shown in Fig. 8(c), the weight portion (51) may be configured such that the position of the outer edge of the first weight portion (51a) and the position of the outer edge of the second weight portion (51b) are different in the radial direction.

[0090] (6-3) Modification 3: Shape of weight 9, the dynamic vibration absorber (50) of this embodiment may be configured in a T-shape when viewed in the axial direction. In this case, the connection portion (52) connects the outer circumferential surface of the yoke portion (34) and the circumferential center portion of the weight portion (51). This modification also provides the same effects as the above embodiment.

[0091] In this modification, for example, as shown in FIG. 9(a), the weight portion (51) may be configured so that the radial length D is constant from one end to the other end in the circumferential direction when viewed in the axial direction.

[0092] Also, in this modified example, as shown in FIGS. 9(b) and 9(c), similar to the above-described modified example 1, the weight portion (51) may have a first weight portion (51a) and a second weight portion (51b) having different radial lengths. In this modified example, the weight portion (51) has one first weight portion (51a) and two second weight portions (51b). The first weight portion (51a) is a portion formed at the center in the weight portion (51). Each second weight portion (51b) is a portion formed at each of the circumferential both ends of the first weight portion (51a). The radial length D2 of the second weight portion (51b) is longer than the radial length D1 of the first weight portion (51a) (D1 < D2). In other words, the weight portion (51) is configured such that the tip portions on both circumferential sides thereof are heavier than the middle portion.

[0093] In this modified example, as shown in FIG. 9(b), the weight portion (51) may be configured such that the position of the outer edge portion of the first weight portion (51a) and the position of the outer edge portion of the second weight portion (51b) are the same in the radial direction. Also, as shown in FIG. 9(c), the weight portion (51) may be configured such that the position of the outer edge portion of the first weight portion (51a) and the position of the outer edge portion of the second weight portion (51b) are different in the radial direction.

[0094] (6-4) Modified Example 4: Arrangement of Dynamic Vibration Absorber As shown in FIG. 10, the dynamic vibration absorber (50) may be arranged radially outward of the teeth portion (35). In FIG. 10, adjacent dynamic vibration absorbers (50) are adjacent without sandwiching one support portion (37), but in this modified example, adjacent dynamic vibration absorbers (50) may be arranged on both circumferential sides with one support portion (37) sandwiched therebetween. Also in this modified example, similar to the above-described embodiment, it is possible to reduce the vibration generated in the stator core (32) while suppressing an increase in product cost.

[0095] (6-5) Modified Example 5: Arrangement of Dynamic Vibration Absorber As shown in Fig. 11, the dynamic vibration absorber (50) may be provided inside the yoke portion (34). Specifically, a relatively small space is formed inside the yoke portion (34), and the dynamic vibration absorber (50) is accommodated in the space. In this modification, as in the above embodiment, it is possible to reduce vibrations generated in the stator core (32) while suppressing an increase in production costs. Note that, although Fig. 11 illustrates an example of the dynamic vibration absorber (50) configured in a T-shape when viewed in the axial direction, the dynamic vibration absorber (50) may be configured in an L-shape or I-shape when viewed in the axial direction as in the above embodiment and modifications 1 and 2.

[0096] (6-6) Modification 6: Axial arrangement of dynamic vibration absorber 12, the dynamic vibration absorber (50) does not have to be formed across the axial length of the stator core (32). In this case, the axial length of the dynamic vibration absorber (50) is shorter than the axial length of the stator core (32). As in the above embodiment, this modification also makes it possible to reduce vibrations generated in the stator core (32) while suppressing an increase in production costs.

[0097] In this modification, for example, as shown in Fig. 12(a) , one dynamic vibration absorber (50) may be disposed in the center in the axial direction. In this case, among the electromagnetic steel sheets (M) constituting the stator core (32), the upper and lower electromagnetic steel sheets (M) are not provided with the dynamic vibration absorber (50).

[0098] In this modification, as shown in Fig. 12(b), a plurality of dynamic vibration absorbers (50) (two in this modification) may be arranged in the axial direction. In other words, the dynamic vibration absorbers (50) do not need to be formed continuously in the axial direction. In Fig. 12(b), the dynamic vibration absorbers (50) are formed on the upper and lower electromagnetic steel sheets (M) of the electromagnetic steel sheets (M) constituting the stator core (32).

[0099] According to this modification, the mass of the weight portion (51) is changed by changing the axial length of the weight portion (51), thereby making it possible to change the natural frequency of the dynamic vibration absorber (50) to a desired natural frequency.

[0100] (6-7) Modification 7: Axial shape of dynamic vibration absorber 13, the dynamic vibration absorber (50) may be configured in a T-shape when viewed in the radial direction. Specifically, in the dynamic vibration absorber (50) of this modification, the axial length of the weight portion (51) is longer than the length of the connecting portion (52) of the weight portion (51).

[0101] In this modification, as in the above embodiment, it is possible to reduce vibrations generated in the stator core (32) while suppressing an increase in production costs. In addition, as in the above sixth modification, the mass of the weight portion (51) is changed by changing the axial length of the weight portion (51). This allows the natural frequency of the dynamic vibration absorber (50) to be changed to a desired natural frequency.

[0102] (6-8) Modification 8: Fastening position of electromagnetic steel sheets As shown in Fig. 14, the multiple electromagnetic steel sheets (M) constituting the stator core (32) are fastened to one another at the weight portion (51) of the dynamic vibration absorber (50). In this modification, the electromagnetic steel sheets (M) are fastened to one another by crimping. For example, as shown by the dashed line in Fig. 14, a fastening portion (38) formed by crimping is provided in the center of the weight portion (51).

[0103] According to this modification, the multiple electromagnetic steel sheets (M) constituting the stator core (32) are fastened to one another by the weight portion (51), so that the fastening portion (38) is formed in a portion where magnetic flux does not pass. This makes it possible to suppress an increase in iron loss due to fastening. Note that the multiple electromagnetic steel sheets (M) can be fastened to the weight portion (51) even when the means for fastening the electromagnetic steel sheets (M) is welding, adhesive, or the like.

[0104] Second Embodiment A second embodiment will be described. The electric motor (30) of the first embodiment is an inner rotor type in which the rotor (40) is disposed inside the stator (31). In contrast, the electric motor (30) of the present embodiment is an outer rotor type in which the rotor (40) is disposed outside the stator (31). Here, the electric motor (30) of the present embodiment will be described with respect to differences from the electric motor (30) of the first embodiment.

[0105] As shown in FIG. 15, the stator core (32) has an annular yoke portion (34) and teeth portions (35) extending radially outward from the yoke portion (34). The teeth portions (35) are provided with coils (33). The stator core (32) further has a plurality of support portions (37) (four in this embodiment). The stator core (32) is supported on the shaft (28) by the support portions (37). Each support portion (37) protrudes radially inward from the inner periphery of the yoke portion (34). Each support portion (37) is fixed in contact with the outer periphery of the shaft (28).

[0106] The stator (31) has a plurality of (eight in this embodiment) dynamic vibration absorbers (50). Each dynamic vibration absorber (50) is provided on the inner circumference of the yoke portion (34). Each dynamic vibration absorber (50) is disposed in a small gap formed between the inner circumference of the yoke portion (34) and the outer circumference of the shaft (28). Each dynamic vibration absorber (50) is disposed on the radially opposite side to the rotor (40). The configuration of each dynamic vibration absorber (50) is the same as in the first embodiment.

[0107] In the dynamic vibration absorber (50) of this embodiment, similarly to the first embodiment, when the yoke portion (34) of the stator core (32) vibrates at its natural frequency, the dynamic vibration absorber (50) vibrates in a phase different from that of the yoke portion (34). This reduces the vibration of the stator core (32). In this manner, the weight portion (51) vibrates in conjunction with the vibration of the stator core (32), thereby reducing the radial vibration of the stator core (32) caused by electromagnetic force.

[0108] Moreover, the dynamic vibration absorber (50) of this embodiment is formed integrally with the stator core (32). Therefore, the dynamic vibration absorber (50) can be provided without adding any new member to the stator (31). In addition, since a process for assembling the dynamic vibration absorber (50) is not required separately from the process for manufacturing the stator core (32), an increase in the number of assembly processes can be suppressed. Therefore, it is possible to reduce vibrations generated in the stator core (32) while suppressing an increase in the manufacturing cost of the stator (31).

[0109] Furthermore, with the above structure, there is no need to perform a process of assembling the dynamic vibration absorber (50) to the stator core (32), and therefore there is no variation in the accuracy of assembling the dynamic vibration absorber (50). This makes it possible to suppress variation in the performance of the dynamic vibration absorber (50) for each stator (31). Note that the first to eighth modifications of the first embodiment can also be applied to this embodiment.

[0110] Other Embodiments The above embodiment may be configured as follows.

[0111] The electric motor (30) of each of the above embodiments may be applied to devices other than the compressor (10). For example, the electric motor (30) of each of the above embodiments may be applied to a blower. The blower includes the electric motor (30) and a fan driven by the electric motor (30). The fan is not limited to a specific fan, and may be, for example, a centrifugal fan or a propeller fan.

[0112] The structures of the above-described embodiments may be adopted in other electromagnetic devices as magnetic circuits. Specifically, the other electromagnetic devices include a magnetic bearing that generates a levitation force on the rotor by passing current through a coil, and a reactor that smoothes a current pulse by passing current through a coil. This makes it possible to reduce vibration of the core (32) while suppressing an increase in the manufacturing cost of the electromagnetic device, as in the above-described embodiments.

[0113] Although the embodiment and the modified examples have been described above, it will be understood that various modifications of the form and details are possible without departing from the spirit and scope of the claims. In addition, the elements of the above embodiment, modified examples, and other embodiments may be appropriately combined or substituted.

[0114] The descriptions "first," "second," "third," etc. mentioned above 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]

[0115] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for magnetic circuit components, blowers, compressors, and refrigeration devices. [Explanation of symbols]

[0116] 1 Refrigeration equipment 10 Compressor 20 Drive shaft (rotating shaft) 30 Electric motor (magnetic circuit) 31 Stator (magnetic circuit part) 32 Stator core (core) 33 Coil 34 York 40 Rotor 50 Dynamic vibration absorber 51 Weight 52 Connection M Electrical steel sheet R Refrigerant circuit

Claims

1. A magnetic circuit component that constitutes a part of a magnetic circuit, a core (32) made of a soft magnetic material and held by a cylindrical body portion (12) of a support member (11), the core having an annular yoke portion (34); a dynamic vibration absorber (50) provided on the core (32) to reduce vibration of the core (32), The dynamic vibration absorber (50) includes a weight portion (51) and a connecting portion (52) that connects the weight portion (51) and the yoke portion (34) and that is elastically deformable, The dynamic vibration absorber (50) is formed integrally with the core (32), The weight portion (51) does not contact the inner peripheral surface of the body portion (12) and the outer peripheral surface of the yoke portion (34). Magnetic circuit components.

2. The weight portion (51) extends along the circumferential direction of the yoke portion (34). The magnetic circuit component according to claim 1 .

3. The dynamic vibration absorber (50) is provided on the outer periphery or inside of the yoke portion (34). The magnetic circuit component according to claim 1 or 2.

4. The core (32) is formed of a plurality of electromagnetic steel plates (M) stacked on top of each other, The plurality of electromagnetic steel plates (M) are fastened to each other at the weight portion (51). The magnetic circuit component according to claim 1 or 2.

5. The magnetic circuit includes a rotor (40) configured to be rotatable about the axis of a rotating shaft (20), and a stator (31) disposed opposite the rotor (40) in the radial direction of the rotating shaft (20), The stator (31) includes a stator core (32) serving as the core (32) and a coil (33) wound around the stator core (32), The dynamic vibration absorber (50) is disposed on the opposite side to the rotor (40) in the radial direction. The magnetic circuit component according to claim 1 or 2.

6. The magnetic circuit components form part of the electric motor (30). The magnetic circuit component according to claim 1 or 2.

7. The magnetic circuit components form a part of a magnetic bearing. The magnetic circuit component according to claim 1 or 2.

8. The magnetic circuit component constitutes a part of a reactor. The magnetic circuit component according to claim 1 or 2.

9. An electric motor (30) comprising the magnetic circuit component according to claim 6; and a fan driven by the electric motor (30). Blower.

10. The magnetic circuit component according to claim 6 is provided. Compressor.

11. A compressor (10) according to claim 10; a refrigerant circuit (R) through which the refrigerant compressed by the compressor (10) flows. Refrigeration equipment.

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