Compressors and air conditioners

Abstract

To provide a compressor or the like equipped with an outer rotor structure motor that drives with high efficiency. 【Solution means】The compressor 100 includes a sealed container 1, a motor 7, a crankshaft 3, and a compression mechanism portion 2. The motor 7 has an outer rotor structure in which a rotor 72 is disposed on the outer peripheral side of a stator 71. The rotor 72 includes a rotor core 72a, a plurality of permanent magnets 72b embedded in the rotor core 72a, and a rotor cup 72f disposed on the outer peripheral side of the rotor core 72a and fixed to the crankshaft 3. The rotor core 72a is fixed to the rotor cup 72f at one end side in the axial direction, and a radial gap is provided over the entire circumference within a predetermined range in the axial direction between the rotor core 72a and the rotor cup 72f.

Description

[Technical field]

[0001] The present disclosure relates to a compressor and an air conditioner. [Background technology]

[0002] Regarding a compressor equipped with an electric motor having an outer rotor structure, the techniques described in Patent Documents 1 to 3 are known, for example. That is, Patent Document 1 describes that a convex portion provided on the outer peripheral surface of the rotor yoke and a concave portion provided on the inner peripheral surface of the rotor cup are press-fitted in a fitted state.

[0003] Patent document 2 also describes forming a notch on the inner surface of the rotor cup between adjacent magnetic pole portions in the circumferential direction, and also describes fixing the rotor yoke and rotor cup by press fitting. Moreover, Patent Document 3 describes a hermetic electric compressor equipped with a motor section having an outer rotor structure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-13243 A [Patent Document 2] JP 2012-244880 A [Patent Document 3] JP 2006-177158 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the techniques described in Patent Documents 1 and 2, the rotor yoke (i.e., rotor core) and the rotor cup are fixed by press fitting, so it is necessary to ensure a sufficient contact area. As a result, the magnetic flux of the rotor yoke is likely to leak through the rotor cup, which leads to a decrease in the efficiency of the electric motor. In addition, because the rotor yoke and the rotor cup are fixed by press fitting, hysteresis loss occurs due to residual stress, which may lead to a decrease in the efficiency of the electric motor.

[0006] In addition, as described above, Patent Document 3 describes a hermetic electric compressor having a motor unit with an outer rotor structure, but does not particularly describe a configuration for suppressing magnetic flux leakage. As described above, the techniques described in Patent Documents 1 to 3 have room for improvement in terms of improving the efficiency of the motor.

[0007] In view of the above, an object of the present disclosure is to provide a compressor or the like equipped with an electric motor having an outer rotor structure that operates with high efficiency. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the compressor according to the present disclosure includes a sealed container, an electric motor having a stator and a rotor and housed in the sealed container, a shaft rotating integrally with the rotor, and a compression mechanism unit compressing a refrigerant as the shaft rotates, the electric motor has an outer rotor structure in which the rotor is disposed on the outer periphery of the stator, the rotor includes a rotor core, a plurality of permanent magnets embedded in the rotor core, and a rotor cup disposed on the outer periphery of the rotor core and fixed to the shaft, the rotor core is fixed to the rotor cup at one end side in the axial direction, In a region where the rotor core and the rotor cup face each other in a radial direction, A radial gap is provided between the rotor core and the rotor cup over the entire circumference within a predetermined range in the axial direction. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a compressor or the like equipped with an electric motor having an outer rotor structure that operates with high efficiency. [Brief description of the drawings]

[0010] [Figure 1] 1 is a vertical sectional view of a compressor according to a first embodiment. FIG. [Diagram 2] FIG. 2 is a perspective view of a rotor of an electric motor included in the compressor according to the first embodiment, with a portion of the rotor cut away. [Diagram 3] FIG. 2 is an exploded perspective view of a rotor of an electric motor included in the compressor according to the first embodiment. [Figure 4A] FIG. 2 is a plan view including a rotor of an electric motor included in the compressor according to the first embodiment. [Figure 4B] FIG. 4B is a partial enlarged view of region K1 in FIG. 4A. [Figure 5A] FIG. 11 is a perspective view of a rotor core of an electric motor included in a compressor according to a second embodiment. [Figure 5B] FIG. 11 is a partial enlarged view including a rotor core of an electric motor included in a compressor according to a second embodiment. [Figure 6A] FIG. 13 is a perspective view of a rotor core of an electric motor included in a compressor according to a first modified example of the second embodiment. [Figure 6B] 13 is a partial enlarged view including a rotor core of an electric motor included in a compressor according to a first modified example of the second embodiment. FIG. [Figure 7] FIG. 13 is a perspective view of a rotor core of an electric motor included in a compressor according to a second modified example of the second embodiment. [Figure 8] FIG. 13 is a perspective view of a rotor core of an electric motor included in a compressor according to a third modified example of the second embodiment. [Figure 9] FIG. 11 is a configuration diagram of an air conditioner according to a third embodiment. [Figure 10] 13 is a perspective view of a state in which a rotor of an electric motor included in a compressor according to a modified example is partially cut away. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] First Embodiment <Compressor configuration> FIG. 1 is a vertical sectional view of a compressor 100 according to the first embodiment. The compressor 100 shown in Fig. 1 is a scroll type compressor that compresses a gaseous refrigerant. As shown in Fig. 1, the compressor 100 includes a sealed container 1, a compression mechanism 2, a crankshaft 3 (shaft), an oil supply pump 4, a main bearing 5, an orbiting bearing 6, an electric motor 7, and a thrust bearing 8.

[0012] The sealed container 1 is a container that houses the compression mechanism 2, the crankshaft 3, the electric motor 7, etc., and is substantially sealed. The sealed container 1 is formed of a predetermined metal that is a magnetic body. Lubricating oil for lubricating the compression mechanism 2 and each bearing is sealed in the sealed container 1, and is stored as an oil reservoir D1 at the bottom of the sealed container 1. The sealed container 1 includes a cylindrical tube chamber 1a, a lid chamber 1b that closes the upper side of the tube chamber 1a, and a bottom chamber 1c that closes the lower side of the tube chamber 1a.

[0013] A suction pipe P1 and a discharge pipe P2 are inserted and fixed in the lid chamber 1b of the sealed container 1. The suction pipe P1 is a pipe that guides the refrigerant to a suction chamber (not shown) of the compression mechanism 2. The discharge pipe P2 is a pipe that guides the refrigerant compressed by the compression mechanism 2 to the outside of the compressor 100. In the example of FIG. 1, the discharge pipe P2 is inserted in the lid chamber 1b, but instead, the discharge pipe P2 may be inserted in a predetermined position in the cylindrical chamber 1a. A plurality of legs E1 for supporting the sealed container 1 are provided at the bottom of the bottom chamber 1c.

[0014] The compression mechanism 2 is a mechanism that compresses the refrigerant as the crankshaft 3 (shaft) rotates. The compression mechanism 2 includes a fixed scroll 21, an orbiting scroll 22, a frame 23, and an Oldham ring 24.

[0015] The fixed scroll 21 is a member that forms the compression chamber C1 together with the orbiting scroll 22. The fixed scroll 21 is installed on the upper side of a frame 23 and fixed to the frame 23 with bolts (not shown). As shown in Fig. 1, the fixed scroll 21 includes a base plate 21a, a support portion 21b, and a fixed wrap 21c, which are integrally formed.

[0016] The base plate 21a has a thick disk shape. A suction chamber (not shown) is provided at a predetermined location near the periphery of the base plate 21a. The suction chamber is a space into which the refrigerant is guided via a suction pipe P1. A discharge port V1 is provided near the center of the base plate 21a. The discharge port V1 is an opening that guides the refrigerant compressed in the compression chamber C1 to a discharge space C2 above the compression mechanism 2.

[0017] The support portion 21b is a cylindrical portion that supports the base plate 21a, and is provided on the periphery of the base plate 21a so as to surround the fixed wrap 21c. The annular lower surface of the support portion 21b is called the mirror plate surface 21d. The mirror plate surface 21d is a sliding surface where the support portion 21b of the fixed scroll 21 comes into contact with the mirror plate 22a of the orbiting scroll 22. The height position of the mirror plate surface 21d is approximately equal to the height position of the tooth tip of the fixed wrap 21c. The fixed wrap 21c is a portion that forms the compression chamber C1 together with the orbiting wrap 22b. The fixed wrap 21c has a spiral shape when viewed from below, and extends downward from the base plate 21a.

[0018] The orbiting scroll 22 is a member that orbits with the rotation of the crankshaft 3 and forms a compression chamber C1 between itself and the fixed scroll 21. The orbiting scroll 22 is disposed below the fixed scroll 21 and faces the fixed scroll 21 in the up-down direction. As shown in Fig. 1, the orbiting scroll 22 includes an end plate 22a, an orbiting wrap 22b, and a boss portion 22c, which are integrally formed.

[0019] The end plate 22a is a part that slides between the end plate surface 21d of the fixed scroll 21 and has a disk shape. The orbiting wrap 22b has a spiral shape in a plan view and extends upward from the end plate 22a. A compression chamber C1 is formed between the fixed wrap 21c and the orbiting wrap 22b. The boss portion 22c has a cylindrical shape and extends downward from the center of the back surface of the end plate 22a. The boss portion 22c is fitted into the eccentric portion 3c of the crankshaft 3.

[0020] The frame 23 is a member for supporting the fixed scroll 21 and for supporting the crankshaft 3 via the main bearing 5. The frame 23 has a roughly rotationally symmetrical shape and is fixed to the inner peripheral surface of the cylindrical chamber 1a by welding or the like. A predetermined flow path (not shown) for circulating the refrigerant is provided between the upper part of the frame 23 and the cylindrical chamber 1a. The lower part of the frame 23 extends in an elongated cylindrical shape along the outer peripheral surface of the crankshaft 3. A stator 71 is fixed to the lower part of the frame 23, the details of which will be described later.

[0021] The frame 23 is provided with an insertion hole (reference number not shown) through which the crankshaft 3 is inserted. The frame 23 is also provided with a lubricating oil outflow hole 23a. The lubricating oil flows up through the oil supply through hole 3d of the crankshaft 3 and lubricates each bearing, and then flows out through the outflow hole 23a of the frame 23.

[0022] The Oldham ring 24 is a ring-shaped member that receives the eccentric rotation of the eccentric portion 3c described later and orbits the orbiting scroll 22 while restraining it without rotating on its axis. The Oldham ring 24 is installed in a groove (not shown) on the lower surface of the orbiting scroll 22, and is also installed in a groove (not shown) of the frame 23.

[0023] The crankshaft 3 (shaft) is an axial member that rotates integrally with the rotor 72 of the electric motor 7. The crankshaft 3 is disposed approximately coaxially with the central axis of the fixed scroll 21 and extends in the vertical direction. As shown in Fig. 1, the crankshaft 3 includes a main shaft portion 3a, a flange portion 3b, and an eccentric portion 3c.

[0024] The main shaft portion 3a is coaxially fixed to the rotor cup 72f of the electric motor 7 and rotates integrally with the rotor 72 including this rotor cup 72f. The flange portion 3b is a portion that restricts the downward movement of the crankshaft 3 and protrudes radially outward from the main shaft portion 3a. The flange portion 3b is provided between the main shaft portion 3a and the eccentric portion 3c in the vertical direction and is locked to the frame 23 via the thrust bearing 8. Note that the thrust bearing 8 is a bearing for receiving the axial (thrust direction) load of the crankshaft 3 and is installed between the flange portion 3b and the frame 23.

[0025] The eccentric portion 3c is a portion that rotates while being eccentric with respect to the main shaft portion 3a and fits into the boss portion 22c of the orbiting scroll 22 as described above. Then, as the eccentric portion 3c rotates while being eccentric, the orbiting scroll 22 orbits in a predetermined manner.

[0026] Inside the crankshaft 3, an oil supply through hole 3d for guiding lubricating oil upward is provided in the axial direction. Also, a radial lateral hole 3e is provided so as to communicate with the oil supply through hole 3d. And a part of the lubricating oil that rises through the oil supply through hole 3d is guided to the main bearing 5 through the lateral hole 3e.

[0027] The oil supply pump 4 is a pump for sucking up lubricating oil from the oil sump D1 at the bottom of the sealed container 1 and is installed at the lower end of the crankshaft 3. As such an oil supply pump 4, for example, a centrifugal pump is used. Then, as the crankshaft 3 rotates, the lubricating oil is sucked up from the oil sump D1 through the oil supply pump 4 and the oil supply through hole 3d in sequence. This lubricating oil is used for lubricating each bearing and the compression mechanism portion 2.

[0028] The main bearing 5 rotatably supports the crankshaft 3 relative to the frame 23. The main bearing 5 is installed on the circumferential surface of an insertion hole (a hole through which the crankshaft 3 is inserted) of the frame 23. The orbiting bearing 6 rotatably supports the eccentric portion 3c of the crankshaft 3 relative to the boss portion 22c of the orbiting scroll 22, and is installed on the inner circumferential surface of the boss portion 22c.

[0029] The electric motor 7 is a motor with an outer rotor structure that rotates the crankshaft 3, and is housed in the sealed container 1. In the outer rotor structure, the rotor 72 is disposed on the outer peripheral side (i.e., radially outward) of the stator 71, which makes it easier to generate torque compared to an inner rotor structure, enabling the electric motor 7 to have a higher output and be more compact. The type of the electric motor 7 may be, for example, a permanent magnet type synchronous motor, but is not limited to this.

[0030] 1, the electric motor 7 includes a stator 71 and a rotor 72. The stator 71 is a stator for generating a predetermined rotating magnetic field, and is fixed to the lower part of the frame 23 by press fitting or the like. The stator 71 includes a cylindrical stator core 71a and a winding 71b wound around the stator core 71a.

[0031] The rotor 72 is a rotor that rotates in a predetermined manner in association with the rotating magnetic field of the stator 71. The rotor 72 is disposed on the outer periphery of the stator 71 and faces the stator 71 in the radial direction via a predetermined air gap. As shown in Fig. 1, the rotor 72 includes a rotor core 72a, a plurality of permanent magnets 72b, an end plate 72c, a non-magnetic body 72d, a plurality of fastening members 72e (see Fig. 2), and a rotor cup 72f.

[0032] Rotor core 72a is a cylindrical iron core for forming a predetermined magnetic path (see also FIG. 3). Rotor core 72a is configured by laminating thin, circular electromagnetic steel sheets in the axial direction. Multiple permanent magnets 72b (see also FIG. 3) are ferromagnetic bodies for generating magnetic attractive and repulsive forces with the rotating magnetic field of stator 71, and are embedded in rotor core 72a.

[0033] The rotor cup 72f is a metal member for rotating the rotor 72 and the crankshaft 3 together, and is fixed to the crankshaft 3. The rotor cup 72f is disposed on the outer periphery side (i.e., radially outward) of the rotor core 72a. The central axis of the rotor cup 72f is approximately coaxial with the central axis of the rotor core 72a. The rotor cup 72f is formed of a predetermined magnetic material and has a cylindrical shape with a bottom (see also FIG. 3). The rotor cup 72f faces the cylindrical chamber 1a of the sealed container 1 via a radial gap.

[0034] A through hole H1 (see FIG. 2) for allowing the crankshaft 3 to pass through in the vertical direction is provided in the center of the disk-shaped bottom of the rotor cup 72f. Although not shown, a key member for preventing rotation may be provided near the through hole H1. This key member is a member for restricting the rotation of the rotor cup 72f relative to the crankshaft 3. In addition, a plurality of flow holes H2a (see also FIG. 2) for allowing the refrigerant and lubricant to flow are provided around the through hole H1 (see FIG. 2) in the disk-shaped bottom of the rotor cup 72f.

[0035] The rotor cup 72f has a radial escape hole H2b at the bottom of the peripheral wall. The escape hole H2b has a function of allowing the lubricating oil to flow from the inside to the outside of the rotor cup 72f by centrifugal force. The end plate 72c, non-magnetic body 72d, and fastening member 72e (see FIG. 2) of the rotor 72 will be described later.

[0036] FIG. 2 is a perspective view of the rotor 72 of the electric motor with a portion cut away. 2 also illustrates a part of the cylindrical chamber 1a of the sealed container 1. As shown in FIG. 2, the rotor cup 72f includes a thick portion 721f, a bottom portion 722f, and a thin portion 723f. The thick portion 721f is a cylindrical portion having a radial thickness greater than that of the thin portion 723f. The bottom portion 722f extends radially inward from the lower end of the thick portion 721f. As described above, the bottom portion 722f is provided with a through hole H1 for inserting the crankshaft 3 (see FIG. 1) therethrough, as well as a plurality of flow holes H2a for passing the refrigerant and lubricant therethrough.

[0037] The thin portion 723f is a cylindrical portion whose radial thickness is thinner than that of the thick portion 721f, and extends upward from the upper surface of the thick portion 721f. The outer peripheral surfaces of the thick portion 721f and the thin portion 723f are smooth cylindrical surfaces. On the other hand, the upper surface of the thick portion 721f, which is located radially inward from the inner peripheral surface of the thin portion 723f, is an annular stepped surface S1 in a plan view. A total of three insertion holes (reference numbers not shown) are provided in this stepped surface S1 at equal intervals in the circumferential direction. The lower portion of the fastening member 72e is inserted into the insertion holes of the stepped surface S1.

[0038] As shown in Fig. 2, a non-magnetic body 72d is placed on the step surface S1. The non-magnetic body 72d is a thin, annular member for suppressing magnetic flux leakage. As shown in Fig. 2, the non-magnetic body 72d is axially sandwiched between the rotor core 72a and the rotor cup 72f on the lower side (one axial side) of the rotor core 72a. Examples of materials that can be used for the non-magnetic body 72d include aluminum and aluminum alloys, as well as copper alloys, titanium alloys, and non-magnetic stainless steel. The rotor core 72a and the end plate 72c are then sequentially placed on the upper side of the non-magnetic body 72d.

[0039] The end plate 72c is a thin, annular member for preventing the permanent magnet 72b from falling out of the magnet insertion hole H3 (see FIG. 3). The inner and outer diameters of the end plate 72c correspond to the inner and outer diameters of the rotor core 72a, and the end plate 72c is installed on the upper side of the rotor core 72a.

[0040] The fastening member 72e is a magnetic body for fastening the rotor core 72a and the rotor cup 72f together. The fastening member 72e also has a function of axially integrating the plurality of electromagnetic steel plates that are components of the rotor core 72a. For example, a rivet is used as such a fastening member 72e. The rotor core 72a is fixed to the rotor cup 72f at its lower end side (one end side in the axial direction) by the fastening member 72e.

[0041] Furthermore, the rotor cup 72f is fixed to the crankshaft 3 (see FIG. 1) by press fitting or shrink fitting. The rotor cup 72f rotates integrally with the crankshaft 3 together with the rotor core 72a. Although details will be described later, when rotor core 72a is fixed to rotor cup 72f at its lower end side, a radial gap G1 (see FIG. 4B) is provided around the entire periphery between rotor core 72a and rotor cup 72f.

[0042] FIG. 3 is an exploded perspective view of the rotor 72 of the electric motor. 3, the rotor core 72a is provided with a plurality of magnet insertion holes H3 for inserting the permanent magnets 72b. The permanent magnets 72b are housed in the magnet insertion holes H3 one by one. The permanent magnets 72b housed in the magnet insertion holes H3 may be divided into a plurality of magnets in the vertical or horizontal direction.

[0043] In addition, three thin, annular non-magnetic bodies 72d are placed on the step surface S1 of the rotor core 72a in a stacked state. The number of non-magnetic bodies 72d may be one or two, or may be four or more. The inner and outer diameters of the non-magnetic body 72d correspond to the inner and outer diameters of the rotor core 72a. Therefore, the non-magnetic body 72d is interposed between the rotor core 72a and the rotor cup 72f over the entire circumference in the circumferential direction. The cylindrical rotor core 72a and the thin, annular end plate 72c are sequentially placed on the upper side of the non-magnetic body 72d.

[0044] As shown in Fig. 3, the end plate 72c is provided with three insertion holes H4 at equal intervals in the circumferential direction for inserting the fastening member 72e. Similarly, the rotor core 72a is provided with three fastening holes H5, and each of the non-magnetic bodies 72d is provided with three insertion holes H6. The fastening member 72e passes through the insertion hole H4 of the end plate 72c, the fastening hole H5 of the rotor core 72a, and the insertion hole H6 of the non-magnetic body 72d in this order, and is inserted into the insertion hole of the stepped surface S1 of the rotor cup 72f (see also Fig. 2). The predetermined range R1 shown in Fig. 3 will be described later.

[0045] FIG. 4A is a plan view including rotor 72 of the motor. 4A also illustrates the cylindrical chamber 1a of the sealed container 1. FIG. 4A also illustrates a state in which an end plate 72c (see FIG. 3) and a fastening member 72e (see FIG. 3) have been removed. As shown in FIG. 4A, the rotor 72 includes a rotor core 72a, a rotor cup 72f, and six pairs of permanent magnets 72b. Each pair of permanent magnets 72b, 72b is arranged to open in a V-shape toward the central axis Z1 of the rotor 72 in a plan view. A single magnetic pole portion M1 is formed by the pair of permanent magnets 72b, 72b arranged in a V-shape.

[0046] These magnetic pole portions M1 are arranged so that adjacent magnetic poles in the circumferential direction have different polarities. In the example of Fig. 4A, the electric motor 7 is configured as a six-pole motor having six magnetic pole portions M1, but the number of poles of the electric motor 7 is not limited to six. In addition, a pair of permanent magnets 72b, 72b may be integrated so that one magnetic pole portion is formed by one permanent magnet.

[0047] As described above, the rotor core 72a is provided with three fastening holes H5 at equal intervals in the circumferential direction. More specifically, the fastening holes H5 are provided between the magnetic pole portions M1 formed by the permanent magnets 72b, 72b. In other words, the fastening holes H5 are positioned in the circumferential direction between the magnetic pole portions M1. Fastening members 72e (see FIG. 3) are installed in each of the fastening holes H5. As described above, the fastening members 72e are magnetic bodies for fastening the rotor core 72a and the rotor cup 72f together.

[0048] In this manner, fastening holes H5 are provided between the magnetic pole portions M1, and fastening members 72e (see FIG. 3) which are magnetic bodies are inserted into the fastening holes H5. This makes it possible to prevent the fastening members 72e from affecting the magnetic field of the rotor 72. Note that, as the magnetic body which is the constituent material of the fastening members 72e, for example, iron or an iron alloy is used, but the present invention is not limited thereto.

[0049] <Magnetic flux leakage> Generally, in an electric motor with an outer rotor structure, the longer the outer diameter of the rotor, the greater the output torque of the motor. However, in conventional electric motors with an outer rotor structure, when the outer diameter of the rotor is increased, the distance between the outer surface of the rotor (i.e., the outer surface of the rotor cup) and the inner surface of the sealed container becomes shorter, which tends to make magnetic flux leakage from the rotor to the sealed container more likely. When such magnetic flux leakage occurs, eddy current loss in the motor increases, resulting in a decrease in efficiency. Note that the shorter the distance between the rotor and the sealed container, the greater the degree of magnetic flux leakage tends to be.

[0050] Thus, in the conventional technology, when the outer diameter of the rotor is lengthened to obtain a large output torque, the efficiency of the electric motor is reduced due to magnetic flux leakage. Therefore, in the first embodiment, a radial gap G1 (see FIG. 4B) is provided between the rotor core 72a and the rotor cup 72f over the entire circumference. As a result, even if the outer peripheral surface of the rotor 72 is brought close to the inner peripheral surface of the sealed container 1, the gap G1 functions as a magnetic insulating layer, so that magnetic flux leakage from the rotor 72 can be suppressed. In other words, since it is possible to suppress the leakage of magnetic flux from the rotor core 72a through the rotor cup 72f to the sealed container 1, the efficiency of the electric motor 7 (see FIG. 1) can be increased.

[0051] <Gap between rotor core and rotor cup> FIG. 4B is a partial enlarged view of region K1 in FIG. 4A. As shown in FIG. 4B, a radial gap G1 is provided between rotor core 72a and rotor cup 72f over the entire circumference in a predetermined axial range R1 (see FIG. 3). The predetermined range R1 (see FIG. 3) is set in a range from the lower end (one axial end) of rotor core 72a to the upper end (the other axial end). In other words, a radial gap G1 is provided over the entire area between rotor core 72a and thin-walled portion 723f (see FIG. 2) of rotor cup 72f. As described above, rotor core 72a is fixed to rotor cup 72f at its lower end (one axial end) (see FIG. 2).

[0052] According to such a configuration, even when the outer diameter of the rotor 72 (the outer diameters of the rotor core 72a and the rotor cup 72f) is maximally lengthened, magnetic flux leakage to the sealed container 1 through the rotor cup 72f can be suppressed. Therefore, the efficiency of the electric motor 7 (see FIG. 1) can be improved. Further, while the rotor core 72a and the rotor cup 72f are axially fixed by a fastening member 72e (see FIG. 2), they are not in particular contact with each other in the radial direction. That is, since there is no particular need to press-fit the rotor core 72a into the rotor cup 72f, almost no residual stress is generated in the rotor 72. As a result, the generation of hysteresis loss associated with the residual stress can be suppressed, and the efficiency of the electric motor 7 (see FIG. 1) can be improved.

[0053] Note that the outer peripheral surface of the rotor core 72a is smooth and cylindrical (see also FIG. 3). That is, the rotor core 72a is not particularly provided with a protrusion as described in the second embodiment (see FIG. 5A). Also, the inner peripheral surface of the thin portion 723f (see FIG. 2) of the rotor cup 72f is smooth and cylindrical.

[0054] Also, the relationship between the radial distance L1 between the rotor core 72a and the rotor cup 72f and the radial distance L2 between the rotor cup 43b and the sealed container 1 is preferably set such that (L1 + L2) ≤ 4 [mm]. As described above, since the gap G1 as a magnetic insulation layer is provided, magnetic flux leakage to the sealed container 1 can be suppressed even when the rotor core 72a and the rotor cup 72f are brought quite close to the sealed container 1. Note that the magnitude relationship between the distances L1 and L2 described above is appropriately set at the design stage. For example, the distance L1 may be longer than the distance L2 (L1 > L2), vice versa (L1 < L2), or the distances L1 and L2 may be equal to each other (L1 = L2).

[0055] In addition, a non-magnetic body 72d (see FIG. 2) is sandwiched between the rotor core 72a and the rotor cup 72f in the axial direction. This can also suppress magnetic flux leakage in the axial direction from the permanent magnet 72b to the rotor cup 72f. For example, non-magnetic body 72d (see FIG. 2) made of aluminum, which has a relatively high strength, may be laminated in the axial direction. In this case, the thickness of the magnetic insulating layer formed by the non-magnetic body 72d may be 3 mm or more, but is not limited to this.

[0056] <Effects> In the first embodiment, a radial gap G1 (see FIG. 4B) is provided between the rotor core 72a and the rotor cup 72f over the entire circumference in the range from the lower end to the upper end of the rotor core 72a. With this configuration, it is possible to sufficiently suppress magnetic flux leakage to the sealed container 1 through the rotor cup 72f. Therefore, the outer diameters of the rotor core 72a and the rotor cup 72f can be maximized at the design stage, so that the performance and efficiency of the electric motor 7 can be improved. In addition, since there is no particular need to fix the rotor core 72a and the rotor cup 72f by press-fitting, it is possible to suppress deformation and distortion of the rotor core 72a due to residual stress, and thus to reduce hysteresis loss. In this way, according to the first embodiment, it is possible to provide a compressor 100 including an electric motor 7 with an outer rotor structure that operates with high efficiency.

[0057] Second Embodiment The second embodiment differs from the first embodiment in that a plurality of protrusions 722a (see FIG. 5A) are provided on the outer peripheral surface of rotor core 72Aa (see FIG. 5A). The other configurations (such as rotor cup 72f) are the same as those of the first embodiment. Therefore, only the parts that differ from the first embodiment will be described, and a description of the overlapping parts will be omitted.

[0058] FIG. 5A is a perspective view of a rotor core 72Aa of an electric motor included in a compressor according to the second preferred embodiment. As shown in Fig. 5A, the rotor core 72Aa has a cylindrical main body 721a and a plurality of protrusions 722a protruding radially outward from the outer circumferential surface of the main body 721a. In the example of Fig. 5A, three protrusions 722a are provided at equal intervals in the circumferential direction. These protrusions 722a are provided to align the axes of the rotor core 72Aa and the rotor cup 72f (see Fig. 3) (i.e., for coaxial alignment). Specifically, the plurality of protrusions 722a are provided to prevent the central axis of the rotor cup 72f (see Fig. 3) from being misaligned with respect to the central axis of the rotor core 72Aa.

[0059] It should be noted that the fitting between rotor core 72Aa and rotor cup 72f (see FIG. 3) does not necessarily require press fitting, and may be performed using, for example, a clearance fit or a slight interference fit. Therefore, the fitting with rotor cup 72f hardly causes deformation or distortion of rotor core 72Aa, and hysteresis loss can be suppressed.

[0060] In the example of FIG. 5A, the upper end of each of the protrusions 722a is substantially flush with the upper surface of the cylindrical main body 721a. The protrusions 722a extend downward from their upper ends by a predetermined length. The predetermined length is shorter than the axial length of the main body 721a. For example, the axial length of the protrusions 722a may be shorter than half the overall axial length of the rotor core 72Aa. This sufficiently reduces the contact area between the protrusions 722a and the rotor cup 72f, thereby suppressing magnetic flux leakage through the protrusions 722a.

[0061] The curvature of the circumferential surface of the protrusion 722a is approximately the same as the curvature of the inner circumferential surface of the rotor cup 72f (see FIG. 5B). The length of the protrusion 722a protruding in the radial direction from the main body 721a may be approximately equal to the radial length of the gap G1 (see FIG. 5B) between the rotor core 72Aa and the rotor cup 72f (see FIG. 5B), or may be slightly longer than the radial length of the gap G1. The number, arrangement, and dimensions of the protrusions 722a can be appropriately changed in consideration of the ease of assembly between the rotor core 72Aa and the rotor cup 72f. The predetermined range R2 shown in FIG. 5B will be described later.

[0062] FIG. 5B is a partial enlarged view including rotor core 72Aa. Note that Fig. 5B is a partially enlarged plan view of a portion of rotor core 72Aa. Fig. 5B also illustrates rotor cup 72f and cylindrical chamber 1a of sealed container 1 in addition to rotor core 72Aa. As shown in Fig. 5B, a radial gap G1 is provided between rotor core 72Aa and rotor cup 72f. This gap G1 is provided around the entire circumference of rotor core 72Aa within a predetermined range R2 (see Fig. 5A) in the axial direction.

[0063] The above-mentioned predetermined range R2 (see FIG. 5A) is a part of the range from the lower end (one end in the axial direction) to the upper end (the other end in the axial direction) of rotor core 72Aa. More specifically, the above-mentioned predetermined range R2 (see FIG. 5A) is the axial range of rotor core 72Aa excluding the range in which protrusions 722a are present. Each protrusion 722a is provided outside of the predetermined range R2 (see FIG. 5A) in the axial direction of rotor core 72Aa and contacts the inner circumferential surface of rotor cup 72f. In the example of FIG. 5B, the circumferential surface of protrusion 722a contacts the inner circumferential surface of rotor cup 72f.

[0064] The circumferential position of the protrusion 722a is preferably the circumferential center of the magnetic pole portion M1 composed of the permanent magnets 72b, 72b. The magnetic field is weaker and the magnetic flux is smaller at the circumferential center of the magnetic pole portion M1 than at other positions. Therefore, by providing the protrusion 722a at the circumferential center of the magnetic pole portion M1, it is possible to prevent the magnetic field of the rotor 72 from being distorted due to the influence of the protrusion 722a.

[0065] Moreover, it is preferable that the central angle θ1 (central angle with respect to the central axis of rotor core 72Aa) of a predetermined arc indicating the circumferential range of protrusion 722a is smaller than the polar arc angle θ2 of magnetic pole portion M1 (θ1<θ2). Here, the polar arc angle θ2 of magnetic pole portion M1 means the central angle of the arc (central angle with respect to the central axis of rotor core 72Aa) corresponding to the circumferential range of one magnetic pole portion M1. With this configuration, the contact area of ​​protrusion 722a with rotor cup 72f is reduced, thereby suppressing magnetic flux leakage through protrusion 722a.

[0066] In the example of Fig. 5B, the central angle θ1 of the arc indicating the circumferential range of the protrusion 722a is 20% or less of the pole arc angle θ2 of the magnetic pole portion M1. This makes the contact area between the protrusion 722a and the rotor cup 72f sufficiently small, so that magnetic flux leakage can be effectively suppressed. As described above, the protrusion 722a is for aligning the axial centers between the rotor core 72Aa and the rotor cup 72f, so there is no particular need to ensure a large contact area between the protrusion 722a and the rotor cup 72f in consideration of press-fitting, etc.

[0067] <Effects> According to the second embodiment, in a predetermined range R2 (see FIG. 5A) in the axial direction of the rotor core 72Aa, a radial gap G1 (see FIG. 5B) is provided between the rotor core 72Aa and the rotor cup 72f over the entire circumference. This makes it possible to suppress magnetic flux leakage to the sealed container 1 via the rotor cup 72f, thereby achieving high efficiency.

[0068] In addition, the multiple protrusions 722a of the rotor core 72Aa are in contact with the inner circumferential surface of the rotor cup 72f (see FIG. 5B). This allows the rotor core 72Aa and the rotor cup 72f to be aligned with each other. As a result, the radial length of the gap G1 (see FIG. 5B) between the rotor core 72Aa and the rotor cup 72f tends to be kept substantially uniform in the circumferential direction. In addition, by aligning the rotor core 72Aa and the rotor cup 72f with each other, vibration of the compressor 100 can be suppressed, and whirling and uneven contact of the crankshaft 3 can also be suppressed.

[0069] First Modification of the Second Embodiment FIG. 6A is a perspective view of a rotor core 72Ba of an electric motor included in a compressor according to a first modified example of the second embodiment. As shown in Fig. 6A, a protrusion 722Ba (see also Fig. 6B) having a semicircular cross section may be provided in the axial direction. In the example of Fig. 6A, three protrusions 722Ba are provided at equal intervals in the circumferential direction. A predetermined range R2 in Fig. 6A indicates a range (axial range) in which a radial gap G1 (see Fig. 6B) is provided between the rotor core 72Ba and the rotor cup 72f (see Fig. 6B), but this is the same as in the second embodiment (see Fig. 5A), so a description thereof will be omitted.

[0070] FIG. 6B is a partial enlarged view including rotor core 72Ba. 6B is a partially enlarged plan view of rotor core 72Ba, and also shows rotor cup 72f and cylindrical chamber 1a of sealed container 1 in addition to rotor core 72Ba. As shown in Fig. 6B, protrusion 722Ba having a semicircular cross section is provided. The radial tip of protrusion 722Ba is in contact with the inner peripheral surface of rotor cup 72f. As described above, protrusion 722Ba extends in the axial direction by a predetermined length (see Fig. 6A), and therefore the tip of protrusion 722Ba is in line contact with rotor cup 72f (the contact area is in line contact). Since protrusion 722Ba is for aligning the axial centers of rotor core 72Ba and rotor cup 72f, such line contact does not pose any particular problems.

[0071] The cross-sectional shape of the protrusion 722Ba is not limited to a semicircular shape, and may be another shape such as a triangular shape. Also, for example, the protrusion of the rotor core 72Ba may be made hemispherical, and this protrusion and the rotor cup 72f may be in point contact (the contact area is in point contact).

[0072] Second Modification of the Second Embodiment FIG. 7 is a perspective view of a rotor core 72Ca of an electric motor included in a compressor according to a second modified example of the second embodiment. In the example of Fig. 7, instead of the protrusion 722a (see Fig. 5A) described in the second embodiment, a pair of separate protrusions 722Ca, 722Ca is provided. The pair of protrusions 722Ca, 722Ca is arranged at a predetermined interval in the axial direction of the rotor core 72Ca. Note that the circumferential position and range of the protrusions 722Ca, 722Ca are the same as those in the second embodiment (see Fig. 5A), and therefore description thereof will be omitted.

[0073] Although not shown, a radial gap is provided between rotor core 72Ca and rotor cup 72f (see FIG. 3). This gap is provided around the entire circumference of rotor core 72Aa in a predetermined range R3 in the axial direction. The predetermined range R3 (the union of ranges R31, R32, and R33 shown in FIG. 7) is the range from the lower end to the upper end of rotor core 72Ca, excluding the range in which the pair of upper and lower protrusions 722Ca, 722Ca are present. With this configuration, the same effects as in the second embodiment can be achieved.

[0074] Third Modification of Second Embodiment FIG. 8 is a perspective view of a rotor core 72Da of an electric motor included in a compressor according to a third modified example of the second embodiment. In the example of Fig. 8, the protrusions 722Da adjacent to each other in the circumferential direction are arranged in a staggered pattern. The circumferential position of each protrusion 722Da is the center position of the magnetic pole portion M1 in the circumferential direction. A total of six protrusions 722Da are provided to correspond to a total of six magnetic pole portions M1. Note that Fig. 8 shows three protrusions 722Da on the front side of the page, and the remaining three protrusions 722Da on the back side of the page are not visible.

[0075] Although not shown, a radial gap is provided between rotor core 72Da and rotor cup 72f (see FIG. 3). This gap is provided around the entire circumference of rotor core 72Da in a predetermined range R4 in the axial direction. The predetermined range R4 (the union of ranges R41, R42, and R43 shown in FIG. 8) is the range from the lower end to the upper end of rotor core 72Da, excluding the range in which protrusion 722Da exists. With this configuration, the same effects as those of the second embodiment (see FIG. 5A) can be achieved.

[0076] Third Embodiment In the third embodiment, an air conditioner W1 (see FIG. 9) including the compressor 100 (see FIG. 1) described in the first embodiment will be described.

[0077] FIG. 9 is a configuration diagram of an air conditioner W1 according to the third embodiment. The solid arrows in FIG. 9 indicate the flow of the refrigerant in the heating cycle. On the other hand, the dashed arrows in FIG. 9 indicate the flow of the refrigerant in the cooling cycle. The air conditioner W1 is a device that performs air conditioning such as cooling operation and heating operation. As shown in Fig. 9, the air conditioner W1 includes a compressor 100, an outdoor heat exchanger 81, an outdoor fan 82, an expansion valve 83, a four-way valve 84, an indoor heat exchanger 85, and an indoor fan 86.

[0078] 9, the compressor 100, the outdoor heat exchanger 81, the outdoor fan 82, the expansion valve 83, and the four-way valve 84 are provided in the outdoor unit U1. The indoor heat exchanger 85 and the indoor fan 86 are provided in the indoor unit U2.

[0079] The compressor 100 is a device that compresses refrigerant gas, and has the same configuration as in the first embodiment (see FIG. 1). The outdoor heat exchanger 81 is a heat exchanger in which heat exchange takes place between the refrigerant flowing through its heat transfer tube (not shown) and the outside air sent in from the outdoor fan 82. The outdoor fan 82 is a fan that sends the outside air to the outdoor heat exchanger 81. The outdoor fan 82 is provided with an outdoor fan motor 82a that serves as a drive source, and is installed near the outdoor heat exchanger 81.

[0080] The indoor heat exchanger 85 is a heat exchanger in which heat exchange takes place between the refrigerant flowing through its heat transfer tube (not shown) and indoor air (air in the air-conditioned room) sent from the indoor fan 86. The indoor fan 86 is a fan that sends indoor air to the indoor heat exchanger 85. The indoor fan 86 is provided with an indoor fan motor 86a that serves as a drive source, and is installed near the indoor heat exchanger 85.

[0081] The expansion valve 83 is a valve that reduces the pressure of the refrigerant condensed in the "condenser" (one of the outdoor heat exchanger 81 and the indoor heat exchanger 85). The refrigerant reduced in pressure by the expansion valve 83 is guided to the "evaporator" (the other of the outdoor heat exchanger 81 and the indoor heat exchanger 85).

[0082] The four-way valve 84 is a valve that switches the flow path of the refrigerant depending on the operation mode of the air conditioner W1. For example, during cooling operation (see the dashed arrow in FIG. 9), the refrigerant circulates through the compressor 100, the outdoor heat exchanger 81 (condenser), the expansion valve 83, and the indoor heat exchanger 85 (evaporator) in that order. On the other hand, during heating operation (see the solid arrow in FIG. 9), the refrigerant circulates through the compressor 100, the indoor heat exchanger 85 (condenser), the expansion valve 83, and the outdoor heat exchanger 81 (evaporator) in that order.

[0083] <Effects> According to the third embodiment, since the air conditioner W1 is equipped with a highly efficient compressor 100, the overall performance and efficiency of the air conditioner W1 can be improved.

[0084] <<Variations>> Although the compressor 100 and the air conditioner W1 according to the present disclosure have been described in the respective embodiments, they are not limited to these descriptions and may be modified in various ways. For example, in the first embodiment, a thin, annular non-magnetic body 72d (see FIG. 2) is sandwiched between rotor core 72a (see FIG. 2) and rotor cup 72f (see FIG. 2). However, this is not limited to the above, and the following configuration may also be used.

[0085] FIG. 10 is a perspective view of a rotor 72E of a motor included in a compressor according to a modified example, with a portion cut away. As shown in Fig. 10, a non-magnetic annular washer 72g may be arranged around the fastening member 72e. In the example of Fig. 10, two washers 72g are placed on the step surface S1 between the thick portion 721f and the thin portion 723f in a state where they are stacked in the axial direction (the axial direction of the rotor 72E).

[0086] Fastening member 72e passes through a hole in washer 72g and is inserted into an insertion hole (not shown) in step surface S1 of rotor cup 72f. As a result, in a region that does not overlap washer 72g in a plan view, a predetermined space G2 (magnetic insulating layer) is provided in the axial direction between rotor core 72a and rotor cup 72f, thereby suppressing magnetic flux leakage in the axial direction. In this manner, a predetermined space G2 may be provided between the lower surface (end surface on one end side) of rotor core 72a and step surface S1 of rotor cup 72f that faces the lower surface of rotor core 72a.

[0087] In each embodiment, a rivet is used as the fastening member 72e (see FIG. 2) of the rotor 72, but the present invention is not limited thereto. For example, a bolt or a knock pin may be used as the fastening member 72e. In each embodiment, a plurality of electromagnetic steel sheets constituting the rotor core 72a are integrated with the fastening member 72e, but the present invention is not limited thereto. For example, the plurality of electromagnetic steel sheets may be integrated by laser welding, core caulking, or the like. In this case, a fastening hole may be provided in the lower part of the rotor core 72a, and a knock pin or the like may be inserted into the hole to perform fastening and axial alignment.

[0088] In each embodiment, the crankshaft 3 is supported at one end by using the frame 23 (see FIG. 1), but this is not limited to the above. For example, a subframe (not shown) may be provided separately to support the lower part of the crankshaft 3 (below the electric motor 7), and the crankshaft 3 may be supported at both ends by the frame 23 and the subframe.

[0089] Moreover, the respective embodiments can be combined as appropriate. For example, the second embodiment and the third embodiment may be combined so that the compressor of the air conditioner W1 (see FIG. 9) has the following configuration. That is, the compressor may have a motor in which the rotor core 72Aa (see FIG. 5A) has a plurality of protrusions 722a (see FIG. 5A). Various other combinations are also possible.

[0090] In addition, in each embodiment, the compressor 100 (see FIG. 1) is described as being used in a vertical orientation, but the present invention is not limited to this. For example, each embodiment can be applied to a case where the compressor 100 is used in a horizontal or oblique orientation. In addition, in each embodiment, the compressor 100 is a scroll compressor, but the present invention is not limited to this. For example, each embodiment can be applied to other types of compressors, such as a rotary compressor or a reciprocating compressor.

[0091] In the third embodiment, the air conditioner W1 (see FIG. 9) is provided with a four-way valve 84, but this is not limiting. That is, the four-way valve 84 may be omitted as appropriate to make the air conditioner a cooling-only or heating-only air conditioner.

[0092] The air conditioner W1 (see FIG. 9) described in the third embodiment can be applied to various types of air conditioners, such as a multi-air conditioner for a building, a packaged air conditioner, and a room air conditioner. In the third embodiment, the air conditioner W1 (see FIG. 9) equipped with the compressor 100 is described, but the present invention is not limited to this. For example, the third embodiment can be applied to other refrigeration cycle devices, such as a refrigerator, a water heater, an air-conditioning water heater, a chiller, and a refrigerator.

[0093] In addition, each embodiment has been described in detail to clearly explain the present disclosure, and is not necessarily limited to all of the configurations described. In addition, it is possible to appropriately add, delete, or replace part of the configuration of each embodiment with other configurations. Furthermore, the above-mentioned mechanisms and configurations are those considered necessary for the explanation, and do not necessarily show all mechanisms and configurations of the product. [Explanation of symbols]

[0094] 1. Airtight container 2. Compression mechanism 3 Crankshaft (shaft) 4. Fuel Pump 5 Main bearing 6 Slewing bearing 7 Electric motor 21 Fixed Scroll 22 Swivel Scroll 23 Frame 24 Oldham Ring 71 Stator 71a Stator core 71b Winding 72,72E rotor 72a, 72Aa, 72Ba, 72Ca, 72Da, rotor core 72b Permanent magnet 72c end plate 72d Non-magnetic material 72e Fastening members 72f Rota Cup 81 Outdoor heat exchanger 82 Outdoor fan 83 Expansion valve 84 Four-way valve 85 Indoor heat exchanger 86 Indoor Fan 100 Compressor 721a Main body 722a,722Ba,722Ca,722Da protrusion G1 Gap G2 space H5 Fastening hole M1 magnetic pole part R1, R2, R3, R4 specified range S1 step surface Z1 center axis

Claims

1. A sealed container; an electric motor having a stator and a rotor and housed in the sealed container; A shaft that rotates integrally with the rotor; a compression mechanism that compresses a refrigerant as the shaft rotates, the electric motor has an outer rotor structure in which the rotor is disposed on an outer circumferential side of the stator, The rotor includes a rotor core, a plurality of permanent magnets embedded in the rotor core, and a rotor cup disposed on an outer circumferential side of the rotor core and fixed to the shaft, The rotor core is fixed to the rotor cup at one axial end thereof, A compressor, wherein in a region where the rotor core and the rotor cup radially face each other, a radial gap is provided between the rotor core and the rotor cup over the entire circumference within a predetermined range in the axial direction.

2. The predetermined range is a range from one end to the other end in the axial direction of the rotor core. The compressor according to claim 1 .

3. the predetermined range is a part of a range from one end to the other end of the rotor core in an axial direction, The rotor core has a cylindrical main body and a plurality of protrusions protruding radially outward from an outer circumferential surface of the main body, Each of the protrusions is provided outside the predetermined range in the axial direction of the rotor core and is in contact with an inner circumferential surface of the rotor cup. The compressor according to claim 1 .

4. the protrusion is located at the circumferential center of the magnetic pole portion constituted by the permanent magnet; The central angle of a predetermined arc indicating the circumferential range of the protrusion is smaller than the polar arc angle of the magnetic pole portion. The compressor according to claim 3 .

5. the rotor has a fastening member that is a magnetic material that fastens the rotor core and the rotor cup together, The fastening member is installed in a fastening hole of the rotor core, The fastening holes are positioned circumferentially between the magnetic poles constituted by the permanent magnets. The compressor according to claim 1 .

6. A non-magnetic body is sandwiched between the rotor core and the rotor cup in the axial direction at the one axial end side. The compressor according to claim 1 .

7. A predetermined space is provided between the end face on the one end side of the rotor core and a step face facing the end face of the rotor cup. The compressor according to claim 1 .

8. An air conditioner comprising the compressor according to any one of claims 1 to 7, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger.

Images