Compressor

Abstract

This compressor is provided with a compression mechanism unit having an eccentric component, a motor, a rotary shaft for transmitting the driving force of the motor to the compression mechanism unit, and a first balance adjustment component. The motor includes a rotor to which a rotating shaft is fixed. The rotor includes: an annular core; and a balance part that has at least one balance hole passing through the core in an axial direction in an arc shape along a rotation shaft insertion hole when viewed in an axial direction of the rotation shaft, and that, together with the first balance adjustment component, cancels unbalance caused by the eccentric component. The at least one balance hole has a shape having an arcuate inner peripheral edge along the rotation shaft insertion hole when viewed in the axial direction, and the center of a virtual circle including the inner peripheral edge coincides with the center of the rotation shaft when viewed in the axial direction.

Description

Compressor

[0001] The present disclosure relates to a compressor equipped with a balance weight.

[0002] An example of a compressor equipped with a balance weight is a scroll compressor. The scroll compressor includes a compression mechanism having an orbiting scroll and a fixed scroll, a motor for driving the compression mechanism, a rotating shaft fixed to the motor's rotor and transmitting the motor's driving force to the compression mechanism, two balance adjustment components, and a shell that houses these components. The two balance adjustment components are used to offset centrifugal forces generated on the rotating shaft due to the orbiting motion of the orbiting scroll. One of the two balance adjustment components, a first balance adjustment component, is fixed to the rotating shaft, and the other, a second balance adjustment component, is fixed to the underside of the rotor. This type of compressor equipped with two balance adjustment components has problems such as oil leakage, which occurs when the two balance adjustment components rotate within the shell, stirring the refrigerant and refrigeration oil floating within the shell.

[0003] Therefore, there is a conventional compressor that does not have a first balance adjustment part fixed to the rotating shaft and a second balance adjustment part fixed to the rotor (see, for example, Patent Document 1). The compressor in Patent Document 1 has a configuration in which two rectangular spaces extending in the axial direction are provided in a core of a rotor fixed to the rotating shaft, and weight adjustment parts are embedded and fixed in the two spaces. By embedding the weight adjustment parts in the rotor, the compressor in Patent Document 1 prevents agitation of the refrigerant and refrigeration oil due to rotation of the two balance adjustment parts, while canceling out centrifugal force.

[0004] Patent No. 6808044

[0005] In a compressor in which a rotating shaft is fixed to a rotating shaft insertion hole formed in the center of a rotor by, for example, shrink fitting, cooling fitting, or press fitting, a high holding force of the rotor to the rotating shaft is required. The holding force of the rotor to the rotating shaft is the force that fixes the rotor to the rotating shaft so that the rotor fixed to the rotating shaft does not rotate independently, in other words, so that the rotating shaft rotates integrally with the rotor. The holding force of the rotor to the rotating shaft can be increased as the core thickness increases, and conversely, decreased as the core thickness decreases. The core thickness is the radial distance of the core portion between the rotating shaft insertion hole and the balance hole of the rotor.

[0006] In the compressor of Patent Document 1, the balance hole, which is the space into which the weight adjustment component is embedded, is rectangular in shape when viewed in the axial direction of the rotor and extends in a direction tangential to the rotary shaft insertion hole formed in the center of the rotor. Therefore, in the compressor of Patent Document 1, the core thickness of the portion having the balance hole is large at both ends in the longitudinal direction of the balance hole and small at the center in the longitudinal direction of the balance hole. In other words, the core thickness where the balance hole is formed is a mixture of thick and thin portions and is not constant in the circumferential direction of the rotary shaft insertion hole.

[0007] As described above, the compressor of Patent Document 1 has a problem in that the core thickness is not constant in the circumferential direction of the rotating shaft insertion hole, which can cause problems when fixing the rotating shaft to the rotating shaft insertion hole and can easily lead to a decrease in the holding force of the rotor against the rotating shaft.

[0008] Furthermore, the compressor of Patent Document 1 eliminates two balance adjustment parts, namely, the first balance adjustment part fixed to the rotating shaft and the second balance adjustment part fixed to the underside of the rotor, but requires two new weight adjustment parts, so it is not possible to reduce component costs and there is room for improvement.

[0009] The present disclosure is made to solve the above-mentioned problems, and has an object to provide a compressor that can reduce component costs while ensuring the force that holds the rotor against the rotating shaft.

[0010] The compressor according to the present disclosure comprises a compression mechanism having an eccentric part and compressing a refrigerant, a motor, a rotating shaft that transmits the driving force of the motor to the compression mechanism, and a first balance adjustment part, wherein the motor comprises a rotor to which the rotating shaft is fixed, and the rotor comprises an annular core having a circular rotating shaft insertion hole formed in the center to which the rotating shaft is fixed, and a balance part having at least one balance hole that is arc-shaped and follows the rotating shaft insertion hole when viewed in the axial direction of the rotating shaft and passes through the core in the axial direction, and which, together with the first balance adjustment part, offsets imbalance caused by the eccentric part, and wherein the at least one balance hole has a shape with an arc-shaped inner circumferential edge that follows the rotating shaft insertion hole when viewed in the axial direction, and the center of a virtual circle including the inner circumferential edge coincides with the center of the rotating shaft when viewed in the axial direction.

[0011] According to the present disclosure, it is possible to provide a compressor that can reduce component costs while ensuring the force of holding the rotor against the rotating shaft.

[0012] FIG. 1 is a schematic cross-sectional view showing a compressor according to a first embodiment. FIG. 2 is a schematic perspective view of a rotating shaft and a structural part around the rotating shaft of the compressor according to the first embodiment. FIG. 3 is a schematic exploded perspective view of a rotor in the compressor according to the first embodiment. FIG. 4 is a schematic plan view of a core of the rotor in the compressor according to the first embodiment. FIG. 5 is an explanatory diagram of the radial arrangement position of a balance unit in the compressor according to the first embodiment. FIG. 6 is an explanatory diagram of the positional relationship between an orbiting scroll, a first balance adjustment component, and a balance unit in the compressor according to the first embodiment. FIG. 7 is a schematic plan view of a core of the rotor in the compressor according to the second embodiment. FIG. 8 is a schematic plan view of a first modified example of the core of the rotor in the compressor according to the second embodiment. FIG. 9 is a schematic plan view of a second modified example of the core of the rotor in the compressor according to the second embodiment. FIG. 10 is a schematic plan view of a core of the rotor in the compressor according to the third embodiment. FIG. 11 is a schematic plan view of a core of the rotor in the compressor according to the fourth embodiment.

[0013] A compressor according to an embodiment will be described below with reference to the drawings. In the following drawings, components with the same reference numerals are the same or equivalent and are common throughout the embodiments described below. The configurations of the components shown in the entire specification are merely examples and are not intended to be limiting. Furthermore, the size relationships between the components in the drawings may differ from those in reality.

[0014] Embodiment 1. [Configuration of Compressor 1] Fig. 1 is a schematic cross-sectional view showing a compressor 1 according to Embodiment 1. Fig. 2 is a schematic perspective view of a rotating shaft 7 and a structural portion around the rotating shaft 7 of the compressor 1 according to Embodiment 1. The compressor 1 is, for example, a compressor in which a shell 2 is filled with a low-pressure refrigerant. The compressor 1 is applied to a refrigeration cycle device used for refrigeration or air conditioning purposes, such as a refrigerator, a freezer, a vending machine, an air conditioner, a refrigeration device, or a water heater. The compressor 1 draws in refrigerant circulating through a refrigeration cycle device's refrigerant circuit, compresses it, and discharges it in a high-temperature, high-pressure state. Fig. 1 shows a scroll compressor as an example of the compressor 1.

[0015] 1, compressor 1 includes a shell 2, an oil pump 3, a motor 4, a compression mechanism 5, a frame 6, and a rotating shaft 7. Compressor 1 further includes a suction pipe 11, a discharge pipe 12, a subframe 20, and an oil drain pipe 21. Hereinafter, the direction in which rotating shaft 7 extends will be referred to as the axial direction, the direction perpendicular to the axial direction will be referred to as the radial direction, and the direction around the rotating shaft will be referred to as the circumferential direction.

[0016] (Shell 2) The shell 2 includes a middle shell 2c, an upper shell 2a disposed above the middle shell 2c, and a lower shell 2b disposed below the middle shell 2c, and constitutes the outer shell of the compressor 1. The middle shell 2c constitutes the cylindrical peripheral wall of the shell 2. The upper end of the middle shell 2c is closed by the dome-shaped upper shell 2a. The lower end of the middle shell 2c is closed by the lower shell 2b. The shell 2 houses the oil pump 3, the motor 4, the compression mechanism 5, the frame 6, the rotating shaft 7, the subframe 20, the oil drain pipe 21, etc. The shell 2 has an oil reservoir 3a at its lower part. A discharge chamber 13 is formed between the upper shell 2a of the shell 2 and the compression mechanism 5. The discharge chamber 13 is located above the compression mechanism 5. The discharge chamber 13 is a high-pressure space that contains the refrigerant compressed and discharged by the compression mechanism 5.

[0017] (Oil Pump 3) The oil pump 3 is housed in the shell 2 and pumps oil from the oil sump 3a. The oil pump 3 is located at the bottom of the shell 2. The oil pump 3 supplies the oil pumped from the oil sump 3a to lubricated parts, such as bearings, of the compressor 1, thereby lubricating the parts. After being pumped up by the oil pump 3 and lubricating the rocking bearing 8c, the oil is stored, for example, in an internal space 6d of the frame 6 and then passes through radial oil supply grooves 6c provided in the thrust bearing 6b (described below). The oil that passes through the oil supply grooves 6c flows into the Oldham ring space in which the Oldham ring 15 (described below) is disposed, and lubricates the Oldham ring 15. One end of an oil drain pipe 21 is connected to the Oldham ring space, and the oil in the Oldham ring space is returned to the oil sump 3a through the oil drain pipe 21.

[0018] (Compression mechanism 5) The compression mechanism 5 is disposed in the shell 2 and compresses the refrigerant drawn into the shell 2 from the suction pipe 11. The compression mechanism 5 includes a fixed scroll 30 fixed to the shell 2 and an orbiting scroll 40 that orbits (i.e., revolves) relative to the fixed scroll 30. The compression mechanism 5 compresses the refrigerant by the orbiting motion of the orbiting scroll 40 relative to the fixed scroll 30. Note that the compression mechanism 5 is not limited to a scroll type and may be a rotary type. The following description will be given assuming that the compression mechanism 5 is of a scroll type.

[0019] The fixed scroll 30 is disposed, for example, at the upper end of the frame 6 so as to close the cylindrical opening of the frame 6, and is fixed to the frame 6 with fasteners such as bolts. Note that the fixed scroll 30 may be configured to be directly fixed to the middle shell 2c of the shell 2 without being fixed to the frame 6.

[0020] The fixed scroll 30 compresses the refrigerant together with the orbiting scroll 40. The fixed scroll 30 is disposed opposite the orbiting scroll 40. The fixed scroll 30 has an end plate 30a and a spiral portion 31 extending downward from the lower surface of the end plate 30a. The spiral portion 31 protrudes toward the orbiting scroll 40 from the wall surface of the end plate 30a that faces the orbiting scroll 40, and has a spiral-shaped cross section taken along a plane parallel to the end plate 30a.

[0021] The end plate 30a, together with the volute portion 31 of the fixed scroll 30 and the volute portion 41 (described later) of the orbiting scroll 40, constitutes the compression chamber 5a. The end plate 30a is fixed within the shell 2 with its outer peripheral surface facing the inner peripheral surface of the middle shell 2c and the outer peripheral portion of the lower end surface of the end plate 30a abutting against the upper end surface of the frame 6. The end plate 30a is a circular plate-shaped member, and a discharge port 32 is formed through the center of the end plate 30a to discharge the refrigerant compressed in the compression chamber 5a. A discharge valve mechanism 50 is installed on the outlet side of the discharge port 32. The discharge valve mechanism 50 includes a valve seat 52 formed around an open end 32a on the outlet side of the discharge port 32, a leaf spring-shaped reed valve 51 mounted on the valve seat 52 and opening and closing the discharge port 32 in response to the pressure difference between the inside and outside of the valve seat, and a reed valve holder 53 mounted on the valve seat 52 to limit the maximum opening degree of the reed valve 51. The discharge valve mechanism 50 prevents backflow of the refrigerant discharged from the outlet-side open end 32 a of the discharge port 32 .

[0022] The orbiting scroll 40 is disposed opposite the fixed scroll 30. The orbiting scroll 40 is eccentric with respect to the fixed scroll 30. The orbiting scroll 40 has an end plate 40a and a spiral portion 41 extending upward from the upper surface of the end plate 40a. The spiral portion 41 protrudes toward the fixed scroll 30 from the wall surface of the end plate 40a facing the fixed scroll 30, and has a spiral-shaped cross section taken along a plane parallel to the end plate 40a. The end plate 40a, together with the spiral portion 41 of the orbiting scroll 40 and the spiral portion 31 of the fixed scroll 30, constitutes the compression chamber 5a. The end plate 40a is a disc-shaped member that oscillates within the frame 6 upon rotation of the rotary shaft 7. The frame 6 supports the axial thrust load of the orbiting scroll 40. The wall surface of the end plate 40a opposite the wall surface on which the spiral portion 41 is formed acts as a thrust bearing 6b. The orbiting scroll 40 has its rotation restricted by the Oldham ring 15 and performs an orbital motion relative to the fixed scroll 30, in other words, an orbital motion.

[0023] The Oldham ring 15 is disposed on the thrust surface of the end plate 40a, which is the surface opposite to the upper surface on which the spiral portion 41 of the orbiting scroll 40 is formed, and prevents rotation of the orbiting scroll 40. The Oldham ring 15 prevents rotation of the orbiting scroll 40 and allows orbiting motion of the orbiting scroll 40. Claws (not shown) are formed on the upper and lower surfaces of the Oldham ring 15 so as to protrude perpendicular to each other. The claws of the Oldham ring 15 are fitted into Oldham grooves 15a formed in the orbiting scroll 40 and Oldham grooves 15b formed in the frame 6, respectively.

[0024] The fixed scroll 30 and the orbiting scroll 40 are housed in the middle shell 2c with the spiral portions 31 and 41 facing each other and meshing with each other. A compression chamber 5a is formed by the space where the spiral portion 31 of the fixed scroll 30 and the spiral portion 41 of the orbiting scroll 40 mesh. The orbiting scroll 40 oscillates due to the rotation of the rotary shaft 7, compressing the gaseous refrigerant in the compression chamber 5a.

[0025] (Frame 6) The frame 6 is formed in a cylindrical shape, its outer periphery is fixed to the shell 2, and its inner periphery houses the compression mechanism 5. The frame 6 holds the orbiting scroll 40 of the compression mechanism 5. The frame 6 supports the thrust bearing load generated during operation of the compressor 1 via the thrust bearing 6b of the orbiting scroll 40. The frame 6 also rotatably supports the rotating shaft 7 via the main bearing 8a. A suction port 6a is formed in the frame 6. The gaseous refrigerant sucked into the shell 2 from the suction pipe 11 flows into the compression mechanism 5 through the suction port 6a.

[0026] A sleeve 17 is provided between the frame 6 and the main bearing 8a. The sleeve 17 is a cylindrical member. The sleeve 17 absorbs the tilt between the frame 6 and the rotating shaft 7.

[0027] (Rotating Shaft 7) The rotating shaft 7 is connected to the motor 4 and the orbiting scroll 40, and transmits the driving force of the motor 4 to the orbiting scroll 40. The rotating shaft 7 has a main shaft 7a fixed to a rotor 4a (described later) of the motor 4, and an eccentric shaft 7b provided above the main shaft 7a and eccentric to the central axis of the main shaft 7a, and connected to the orbiting scroll 40. A portion of the rotating shaft 7 located above the rotor 4a is rotatably supported by a main bearing 8a provided in the frame 6. A portion of the rotating shaft 7 located below the rotor 4a is rotatably supported by a sub-bearing 8b of the sub-frame 20.

[0028] An oil pump 3 is provided at the lower end of the rotating shaft 7 to pump up oil accumulated in an oil reservoir 3a. An oil passage 7c is formed inside the rotating shaft 7, allowing the oil pumped up by the oil pump 3 to flow upward. A slider 16 is attached to the outer peripheral surface of the eccentric shaft 7b of the rotating shaft 7. The slider 16 is a cylindrical member. The slider 16 is located on the inner surface of the lower part of the orbiting scroll 40. The orbiting scroll 40 is attached to the eccentric shaft 7b of the rotating shaft 7 via the slider 16, and rotates as the rotating shaft 7 rotates. A rocking bearing 8c is provided between the orbiting scroll 40 and the slider 16.

[0029] A first balance adjustment component 18 is fixed to the rotating shaft 7. As shown in FIG. 2 , the first balance adjustment component 18 has a cylindrical portion with a semicircular arc portion fixed to the outer periphery thereof, forming an integrated shape. The first balance adjustment component 18 is fixed to the rotating shaft 7 by, for example, shrink fitting. The first balance adjustment component 18 is disposed between the frame 6 and the rotor 4a. The first balance adjustment component 18 is housed in a cylindrical balance adjustment component cover 18a. Together with a balance unit 65 (described later), the first balance adjustment component 18 offsets imbalances caused by the orbiting scroll 40 and the like.

[0030] (Main bearing 8 a and oscillating bearing 8 c) The main bearing 8 a and the oscillating bearing 8 c are sliding bearings. The sliding bearing here refers to a bearing in which a fixed cylindrical metal or resin member and a rotating metal member form a fluid film of oil by utilizing the relative motion between the sliding surfaces.

[0031] (Suction Pipe 11) The suction pipe 11 is a pipe that draws the gaseous refrigerant into the shell 2. The suction pipe 11 is provided on the side wall of the shell 2 and is connected to the middle shell 2c.

[0032] (Discharge pipe 12) The discharge pipe 12 is a pipe that discharges the refrigerant compressed by the compression mechanism 5 to the outside of the shell 2. The discharge pipe 12 is provided at the top of the shell 2 and connected to the upper shell 2a. The discharge pipe 12 connects a discharge chamber 13 in the shell 2 to a refrigerant circuit outside the shell 2.

[0033] (Subframe 20) The subframe 20 is provided below the motor 4 inside the shell 2 and is fixed to the inner peripheral surface of the middle shell 2c. The subframe 20 rotatably supports the rotating shaft 7 via the sub-bearing 8b. This sub-bearing 8b is configured as a ball bearing, but is not limited to a ball bearing and may be configured as another type of bearing. The sub-bearing 8b is fitted into a sub-bearing housing portion fixed to the center of the subframe 20.

[0034] (Oil drain pipe 21) As described above, one end of the oil drain pipe 21 communicates with the Oldham ring space and communicates with the space between the frame 6 and the orbiting scroll 40. The other end of the oil drain pipe 21 extends downward within the shell 2 and communicates with the space between the frame 6 and the subframe 20. The oil drain pipe 21 allows excess oil, of the oil circulating in the space between the frame 6 and the orbiting scroll 40, to flow into the space between the frame 6 and the subframe 20. The oil that has flowed into the space between the frame 6 and the subframe 20 passes through the subframe 20 and is returned to the oil reservoir 3a.

[0035] (Motor 4) The motor 4 has a rotor 4a and a stator 4b. The rotor 4a is fixed to the main shaft 7a of the rotary shaft 7. The rotor 4a and the main shaft 7a are fixed by shrink fitting, cold fitting, press fitting, or the like. The stator 4b is fixed to the inner circumferential surface of the middle shell 2c, below the compression mechanism 5. The stator 4b rotates the rotor 4a by power supplied from outside the compressor 1. The structure of the rotor 4a will be described in detail below.

[0036] 3 is a schematic exploded perspective view of the rotor 4a in the compressor 1 according to the first embodiment. The rotor 4a has an annular core 61 formed by stacking a plurality of electromagnetic steel plates, permanent magnets 62, and end plates 63 disposed at both axial ends of the core 61. Each of the plurality of electromagnetic steel plates has a V-shaped or other crimping portion (not shown) for crimping purposes formed in advance during the punching process of each thin plate. A pressure is applied to the crimping portion to join the electromagnetic steel plates together, thereby forming the core 61.

[0037] The core 61 is formed with a plurality of magnet insertion holes 61c. In the illustrated example, there are six magnet insertion holes 61c, but the number is not limited to six. A permanent magnet 62 is inserted into each magnet insertion hole 61c. A rotary shaft insertion hole 61a is formed in the center of the core 61, into which the main shaft 7a of the rotary shaft 7 is inserted. The rotary shaft insertion hole 61a is circular when viewed in the axial direction. In addition, the core 61 is formed with rivet insertion holes 61b around the rotary shaft insertion hole 61a, into which rivets 64 are inserted.

[0038] The end plate 63 holds the permanent magnet 62 so that it does not fall out of the magnet insertion hole 61c. The end plate 63 is formed with a rotating shaft insertion hole 63a, a rivet insertion hole 63b, and a refrigerant passage hole 63c. The rotating shaft insertion hole 63a is formed opposite the rotating shaft insertion hole 61a of the core 61. The rivet insertion holes 63b are formed opposite the rivet insertion holes 61b of the core 61, and the same number of rivet insertion holes 63b are provided. The refrigerant passage holes 63c are formed opposite balance holes 65a, which will be described later.

[0039] In the illustrated example, the refrigerant passage holes 63c have the same shape as the balance holes 65a when viewed in the axial direction, but are not limited to the same shape. The refrigerant passage holes 63c only need to be formed so that at least a portion of them overlaps with the balance holes 65a when viewed in the axial direction. The refrigerant passage holes 63c, together with the balance holes 65a, form a refrigerant flow path that axially penetrates the rotor 4a.

[0040] The core 61 is also provided with a balance portion 65 that, together with the first balance adjustment component 18, offsets imbalances caused by the orbiting scroll 40 and the like. The balance portion 65 has at least one balance hole 65a axially penetrating the core 61. The balance portion 65 in the first embodiment has one balance hole 65a and a second balance adjustment component 65c. The balance hole 65a is formed by vertically connecting holes provided in each of the multiple electromagnetic steel plates that make up the core 61. The second balance adjustment component 65c is fixed to the underside of the rotor 4a by, for example, shrink fitting. The fixing position of the second balance adjustment component 65c is not limited to the underside of the rotor 4a and may be near the rotor 4a on the rotating shaft 7. While FIG. 2 shows an example of the second balance adjustment component 65c having a semicircular arc-shaped plate shape, the shape of the second balance adjustment component 65c is not limited to the shape shown in the figure.

[0041] The balance holes 65a are formed inside the multiple magnet insertion holes 61c when viewed axially of the core 61. The rotor 4a has the rotating shaft insertion holes 61a, balance holes 65a, rivet insertion holes 61b, and magnet insertion holes 61c formed in this order from the inside to the outside in the radial direction when viewed axially. If the balance holes 65a are formed near the magnet insertion holes 61c, it will interfere with the magnetic field generated by the permanent magnets 62. For this reason, the balance holes 65a are formed between the magnet insertion holes 61c and the rotating shaft insertion hole 61a when viewed axially, closer to the rotating shaft insertion hole 61a.

[0042] The balancing unit 65 is used to shift the center of gravity of the core 61. The balancing unit 65 replaces the second balancing component that is fixed to the underside of the rotor in conventional compressors. For reference, the second balancing component 650 in the conventional compressor is shown by a dotted line in FIG. 3. The compressor 1 of the first embodiment has a second balancing component 65c in the same position as in the conventional compressor, but the second balancing component 65c is smaller in size than the conventional second balancing component 650. Details of the balancing unit 65 will be described later.

[0043] The components configured as described above are stacked in the axial direction, and when stacked, the rivet insertion holes 63b and 61b communicate with each other in the axial direction, and rivets 64 are inserted into the communicating holes to crimp and fasten the entire rotor together, thereby forming the rotor 4a. Note that although the number of rivets 64 used to fasten the entire rotor together is four in this example, it is not limited to four and can be set at any number.

[0044] 4 is a schematic plan view of the core 61 of the rotor 4a in the compressor 1 according to the first embodiment. The core 61 has the balance portion 65 as described above. The balance hole 65a constituting the balance portion 65 is formed as an arc-shaped elongated hole that is aligned with the rotating shaft insertion hole 61a when viewed in the axial direction, as shown in FIG. 4. When viewed in the axial direction, the balance hole 65a has a circumferential length that corresponds to a semicircle of 180° centered on the central axis O of the rotating shaft 7.

[0045] The balance hole 65a has an inner peripheral edge 65a1, an outer peripheral edge 65a2, and a pair of connecting edges 65a3. The inner peripheral edge 65a1 is an arc-shaped edge that follows the rotation shaft insertion hole 61a when viewed in the axial direction. The outer peripheral edge 65a2 is an arc-shaped edge that is located radially outward of the inner peripheral edge 65a1 and follows the inner peripheral edge 65a1. The pair of connecting edges 65a3 connect the ends of the inner peripheral edge 65a1 and the outer peripheral edge 65a2 on the same circumferential side. In the illustrated example, the pair of connecting edges 65a3 are arc-shaped with convex outward projections, but are not limited to this shape and may be linear.

[0046] When viewed in the axial direction, the center of an imaginary circle C1 including the inner peripheral edge 65a1 and the center of an imaginary circle C2 including the outer peripheral edge 65a2 of the balance hole 65a coincide with the center of the rotating shaft 7. In other words, the centers of the imaginary circles C1 and C2 are on the central axis O of the rotating shaft 7. With this configuration, the core thickness A, which is the radial distance between the balance hole 65a and the rotating shaft insertion hole 61a, is constant in the circumferential direction. In addition, the width L of the balance hole 65a is constant in the circumferential direction. The width L of the balance hole 65a is the radial length of the balance hole 65a.

[0047] 5 is an explanatory diagram of the radial position of the balance unit 65 in the compressor 1 according to Embodiment 1. As shown in FIG. 5 , when viewed in the radial direction of the rotating shaft 7, the balance holes 65a constituting the balance unit 65 are arranged on a straight line LG that passes through the center of gravity G1 of the first balance adjustment component 18 and is parallel to the rotating shaft 7. In other words, when viewed in the radial direction of the rotating shaft 7, the balance holes 65a constituting the balance unit 65 are arranged such that the straight line LG that passes through the center of gravity G1 of the first balance adjustment component 18 and is parallel to the rotating shaft 7 passes through the interior of the balance holes 65a.

[0048] The balance hole 65a is formed so as to be located inside the balance adjustment component cover 18a when viewed in the axial direction. The balance hole 65a is formed at a position axially opposite the lower end opening 18a1 of the balance adjustment component cover 18a. With the above configuration, refrigeration oil flowing downward along the outer circumferential surface of the rotating shaft 7 inside the balance adjustment component cover 18a can easily enter the balance hole 65a by its own weight, thereby increasing the cooling effect of the rotor 4a.

[0049] 6 is an explanatory diagram of the positional relationship between the orbiting scroll 40, the first balance adjustment component 18, and the balance unit 65 in the compressor 1 according to Embodiment 1. In Fig. 6, the first direction is a radial direction perpendicular to the axial direction of the rotating shaft 7 and a direction away from the rotating shaft 7. The second direction is a radial direction perpendicular to the axial direction of the rotating shaft 7 and a direction away from the rotating shaft 7 in the opposite direction to the first direction.

[0050] The center of gravity Ga of the orbiting scroll 40 is at a position Ra in the first direction from the rotation axis 7. The center of gravity G1 of the first balance adjustment component 18 is at a position R1 in the second direction from the rotation axis 7. The center of gravity Gb of the balancing unit 65 is at a position Rb in the first direction from the rotation axis 7. The center of gravity G3 of the core 61 is at a position R3 in the first direction from the rotation axis 7. The second balance adjustment component 65c is at a position R2 in the first direction from the rotation axis 7. Here, Wa is the weight of the orbiting scroll 40. W1 is the weight of the first balance adjustment component 18. W2 is the weight of the second balance adjustment component 65c.

[0051] The balance portion 65 has a balance hole 65a and a second balance adjustment part 65c, and the center of gravity Gb of the balance portion 65 is a center of gravity based on the center of gravity G3 of the core 61 having the balance hole 65a and the center of gravity G2 of the second balance adjustment part 65c.

[0052] 6 , the positional relationships of the centers of gravity of the orbiting scroll 40, the first balance adjustment component 18, and the balance unit 65 relative to the rotation axis 7 are as follows: The center of gravity Ga of the orbiting scroll 40 and the center of gravity Gb of the balance unit 65 are located on opposite sides of the rotation axis 7 from the center of gravity G1 of the first balance adjustment component 18. The center of gravity Ga of the orbiting scroll 40 and the center of gravity Gb of the balance unit 65 are disposed in the same first direction relative to the rotation axis 7, and the center of gravity G1 of the first balance adjustment component 18 is disposed in the opposite second direction.

[0053] [Explanation of Actions and Effects] The actions and effects of the above configuration will now be described. The balance holes 65a in the balance section 65 of the rotor 4a cause the center of gravity G3 of the rotor 4a to move from the radial center to the side of the rotating shaft 7 where the balance section 65 is not present, as shown by the arrow in FIG. 5 . The position of the center of gravity G3 of the rotor 4a itself can be adjusted by the radial positions of the balance holes 65a constituting the balance section 65, the width L of the balance holes 65a, and other factors. Here, if the balance section does not have balance holes and has only the second balance adjustment components, i.e., if the balance section has a configuration similar to the conventional configuration described above, the balance section must adjust the center of gravity position using only the second balance adjustment components. Therefore, if the balance section has only the second balance adjustment components, the second balance adjustment components 650 must be made larger, as shown by the dotted line in FIG. 3 .

[0054] In contrast, in the compressor 1, the balancing unit 65 has the second balancing component 65c and the balancing hole 65a. In the compressor 1, the balancing unit 65 can adjust the position of the center of gravity Gb of the balancing unit 65 using both the second balancing component 65c and the balancing hole 65a. In other words, the adjustment of the center of gravity position of the balancing unit 65 in the compressor 1 can be achieved not only by the second balancing component 65c but also by adjusting the balancing hole 65a. Therefore, in the compressor 1, the second balancing component 65c can be made smaller and lighter, thereby reducing component costs. As described above, the compressor 1 has the balancing unit 65, which, together with the first balancing component 18, allows the balancing of the rotational system during operation to be adjusted.

[0055] The compressor 1 includes a first balance adjustment component 10 and a balance unit 65 as components that offset the imbalance caused by the eccentric components of the compression mechanism unit 5. When the compression mechanism unit 5 is a scroll type, the eccentric component is the orbiting scroll 40. When the compression mechanism unit 5 is a rotary type, the eccentric component is the eccentric component of the rotating shaft. Specifically, the compression mechanism unit of the rotary compressor includes a cylindrical cylinder having a compression chamber therein, an eccentric component that is eccentric with respect to the axis of the rotating shaft, and a rotating piston rotatably mounted on the eccentric component. The compression mechanism unit of the rotary compressor reduces the volume of the compression chamber and compresses the refrigerant by rotating the rotating shaft and eccentrically rotating the rotating piston within the cylinder. When the compression mechanism unit 5 is a rotary type, the compressor 1 includes a first balance adjustment component 10 and a balance unit 65 as components that offset the imbalance caused by the eccentric component of the rotating shaft.

[0056] Here, the positional relationship between the first balance adjustment component 18 and the second balance adjustment component 65c of the balancing unit 65 and the eccentric component of the compression mechanism 5 will be defined. The first balance adjustment component 18 is located closer to the eccentric component of the compression mechanism 5 in the axial direction than the second balance adjustment component 65c. The second balance adjustment component 65c is located farther from the eccentric component of the compression mechanism 5 in the axial direction than the first balance adjustment component 18. In this way, the positions of the first balance adjustment component 18 and the second balance adjustment component 65c are defined relative to the eccentric component of the compression mechanism 5.

[0057] As described above, in the compressor of Patent Document 1, the balance holes are rectangular in shape and extend in a direction tangential to the rotating shaft insertion hole formed in the center of the rotor when viewed in the axial direction of the rotor. Therefore, in the compressor of Patent Document 1, the core thickness is not constant in the circumferential direction of the rotating shaft insertion hole in the portion where the balance holes are formed, and the holding force of the rotor to the rotating shaft is likely to decrease.

[0058] Here, shrink fitting of the rotating shaft into the rotor is performed, for example, as follows: First, a heating coil is inserted into the rotating shaft insertion hole of the core, and the core is heated. As the core is heated, the diameter of the rotating shaft insertion hole of the core thermally expands and increases. The heating coil is removed from the expanded diameter rotating shaft insertion hole of the core, and then the rotating shaft is inserted into the rotating shaft insertion hole. Then, as the core is cooled, the diameter of the rotating shaft insertion hole decreases, and the core and the rotating shaft are fixed together.

[0059] In the compressor of Patent Document 1, the core thickness where the balance holes are formed is not constant in the circumferential direction of the rotary shaft insertion hole, which causes variations in heat conduction from the inner peripheral portion to the outer peripheral portion of the core during shrink fitting. As a result, in the compressor of Patent Document 1, uneven heating temperatures occur around the rotary shaft insertion hole of the core, resulting in shrink fitting defects.

[0060] In contrast, in the compressor 1, when viewed in the axial direction, the center of an imaginary circle C1 including the inner peripheral edge 65a1 of the balance hole 65a that constitutes the balance portion 65 coincides with the center of the rotating shaft 7. Therefore, in the compressor 1, the core thickness A of the balance portion 65 is ensured to be constant in the circumferential direction of the rotating shaft insertion hole 61a, and heat conduction from the inner peripheral portion to the outer peripheral portion of the core 61 is uniform during shrink fitting. This allows the compressor 1 to uniformize the heating temperature around the rotating shaft insertion hole 61a of the core 61 in the circumferential direction, thereby suppressing shrink fitting defects. As a result, the compressor 1 can ensure the holding force of the rotor 4a on the rotating shaft 7.

[0061] Furthermore, in the compressor 1, in addition to the imaginary circle C1, the center of an imaginary circle C2 including the outer circumferential edge 65a2 of the balance hole 65a constituting the balance portion 65 coincides with the center of the rotating shaft 7 when viewed in the axial direction. Therefore, in the compressor 1, the radial size of the balance hole 65a itself is ensured to be constant in the circumferential direction, and heat transferred to the core wall thickness A portion during shrink fitting can be dissipated and transferred uniformly in the circumferential direction to the space within the balance hole 65a, thereby maintaining a more uniform heating temperature in the circumferential direction. Note that the compressor 1 is sufficient as long as the center of the imaginary circle C1 coincides with the center of the rotating shaft 7; it is not necessarily required that the center of the imaginary circle C2 coincide with the center of the rotating shaft 7, but having such a configuration is effective in maintaining a more uniform heating temperature in the circumferential direction.

[0062] In the compressor 1, the core 61 and the rotating shaft 7 are not limited to being fixed by shrink fitting, and fixing failures can be suppressed even when the core 61 is fixed by cool fitting or press fitting, thereby ensuring the holding force of the rotor 4a on the rotating shaft 7. In other words, the compressor 1 can uniformize the physical quantities acting on the core 61 during cool fitting or press fitting, such as heat or force in the circumferential direction around the rotating shaft insertion hole 61a, and as a result, the holding force of the rotor 4a on the rotating shaft 7 can be ensured.

[0063] Furthermore, the compressor of Patent Document 1 requires two weight adjustment components to be provided on the rotor. In contrast, the compressor 1 has a first balance adjustment component 18 and a balance portion 65 as balance adjustment components, and the balance portion 65 has a balance hole 65a and a second balance adjustment component 65c. In the compressor 1, the balance portion 65 has the balance hole 65a and the second balance adjustment component 65c, so that the second balance adjustment component 65c can be made lighter as described above compared to when the balance portion 65 is composed of only the second balance adjustment component 65c. This allows the compressor 1 to reduce component costs.

[0064] As described above, the compressor 1 having the above configuration can reduce the cost of parts while ensuring the holding force of the rotor 4a on the rotary shaft 7.

[0065] Furthermore, balance holes 65a constituting the balance portion 65 penetrate the core 61 in the axial direction. Therefore, the balance holes 65a communicate the space above the rotor 4a with the space below the rotor 4a via the refrigerant passage holes 63c in the end plate 63, and serve as a refrigerant flow path through which refrigerant containing refrigerating machine oil passes. By serving as a refrigerant flow path through which refrigerant containing refrigerating machine oil passes, the balance holes 65a also function as cooling holes that cool the rotor 4a. Therefore, in the compressor 1, the core 61 having the balance holes 65a can cool the rotor 4a more effectively than a configuration in which the core 61 does not have the balance holes 65a.

[0066] Furthermore, compared to conventional compressors equipped with first and second balance adjustment parts, compressor 1 allows the second balance adjustment part, which is fixed to rotor 4a and rotates together with rotor 4a, to be made smaller as described above, making it possible to reduce stirring loss due to oil being swirled up.

[0067] In the above description, the compressor 1 has been described as having a configuration in which the balancing section 65 includes the balancing hole 65a and the second balancing component 65c. However, the compressor 1 may have a configuration in which the balancing section 65 does not include the second balancing component 65c. In other words, the balancing section 65 of the compressor 1 may be configured with at least one balancing hole 65a.

[0068] In this configuration, the position of the center of gravity G3 of the rotor 4a itself is adjusted by at least one balance hole 65a, and the balancing of the rotational system during operation can be adjusted together with the first balance adjustment component 18. In this configuration, the compressor 1 does not have the second balance adjustment component 65c, which makes it possible to further reduce component costs and stirring loss.

[0069] Effect of First Embodiment As described above, the compressor 1 of the first embodiment includes the compression mechanism 5 having an eccentric part and compressing a refrigerant, the motor 4, the rotating shaft 7 that transmits the driving force of the motor 4 to the compression mechanism 5, and the first balance adjustment part 18. The motor 4 includes the rotor 4a to which the rotating shaft 7 is fixed. The rotor 4a includes the annular core 61 having a circular rotating shaft insertion hole 61a formed in the center thereof to which the rotating shaft 7 is fixed, and the balance part 65 that, together with the first balance adjustment part 18, offsets imbalance caused by the eccentric part. The balance part 65 has at least one balance hole 65a that is arc-shaped along the rotating shaft insertion hole 61a as viewed in the axial direction of the rotating shaft 7 and penetrates the core 61 in the axial direction. The balance part 65 may also include at least one balance hole 65a and a second balance adjustment part 65c that is positioned axially farther from the eccentric part than the first balance adjustment part. The balance hole 65a has an arc-shaped inner peripheral edge 65a1 that is aligned with the rotary shaft insertion hole 61a when viewed in the axial direction. When viewed in the axial direction, the center of an imaginary circle C1 that includes the inner peripheral edge 65a1 of the balance hole 65a coincides with the center of the rotary shaft 7. As described above, the eccentric part is the orbiting scroll 40 when the compression mechanism 5 is of a scroll type, and is the eccentric part of the rotary shaft when the compression mechanism 5 is of a rotary type.

[0070] With the above configuration, the compressor 1 can equalize the physical quantity acting on the core 61 in the circumferential direction around the rotating shaft insertion hole 61a of the core 61 when the core 61 and the rotating shaft 7 are fixed, thereby ensuring the holding force of the rotor 4a relative to the rotating shaft 7. Furthermore, in the compressor 1, the balancing unit 65 has at least one balancing hole 65a, or at least one balancing hole 65a and a second balancing component 65c. By having the balancing unit 65 have at least one balancing hole 65a, the compressor 1 can adjust the position of the center of gravity G3 of the rotor 4a itself. Therefore, the compressor 1 does not rely solely on the second balancing component 65c to adjust the center of gravity position, and therefore the second balancing component 65c can be made smaller or eliminated, resulting in reduced component costs.

[0071] At least one balance hole is located radially outward from the inner peripheral edge, has an outer peripheral edge that runs along the inner peripheral edge, and a pair of connecting edges that connect the ends of the inner peripheral edge and the outer peripheral edge, and when viewed in the axial direction, the center of an imaginary circle including the outer peripheral edge coincides with the center of the rotation axis.

[0072] With the above configuration, the compressor 1 can equalize the physical quantities acting on the core 61 in the circumferential direction around the rotating shaft insertion hole 61a of the core 61 when the core 61 and the rotating shaft 7 are fixed together, thereby more effectively securing the holding force of the rotor 4a against the rotating shaft 7.

[0073] The center of gravity Ga of the eccentric part and the center of gravity Gb of the balance part 65 are located on opposite sides of the rotation axis 7 to the center of gravity G1 of the first balance adjustment part 18 .

[0074] With the above-described configuration, the compressor 1 can suppress imbalance caused by eccentric parts.

[0075] The balance hole 65 a is disposed on a straight line LG that passes through the center of gravity G 1 of the first balance adjustment component 18 and is parallel to the rotation axis 7 .

[0076] With the above-described configuration, the compressor 1 can adjust the imbalance caused by the eccentric parts by using the balance holes 65a together with the first balance adjustment parts 18 by adjusting the position of the balance holes 65a on the straight line LG.

[0077] The core 61 is formed to extend in the axial direction and has a magnet insertion hole 61c into which a permanent magnet 62 is inserted, and at least one balance hole 65a is formed between the magnet insertion hole 61c and the rotating shaft insertion hole 61a when viewed in the axial direction, closer to the rotating shaft insertion hole 61a.

[0078] With the above-described configuration, the compressor 1 can prevent at least one balance hole 65 a from interfering with the next formation of the permanent magnet 62 .

[0079] Embodiment 2 The compressor 1 of embodiment 2 differs from embodiment 1 in the configuration of the balance unit 65. The following description will focus on the configuration of embodiment 2 that differs from embodiment 1, and configurations that are not described in embodiment 2 are the same as embodiment 1.

[0080] FIG. 7 is a schematic plan view of the core 61 of the rotor 4a in the compressor 1 according to the second embodiment. While the balance portion 65 in the first embodiment is configured with at least one balance hole 65a, the balance portion 65 in the second embodiment is configured with a plurality of balance holes 65b axially penetrating the core 61. The balance portion 65 in the second embodiment may or may not include a second balance adjustment component 65c. The balance portion 65 in the second embodiment is configured with a plurality of balance holes 65b spaced apart in the circumferential direction within a range of a length equivalent to a 180° semicircle centered on the central axis O of the rotating shaft 7 as viewed in the axial direction. While the number of balance holes 65b is four in the illustrated example, it is not limited to four and may be two, three, five, or more.

[0081] The balance hole 65b is formed in an arc shape that follows the rotary shaft insertion hole 61a when viewed in the axial direction. The balance hole 65b has an inner peripheral edge 65b1, an outer peripheral edge 65b2, and a pair of connecting edges 65b3. The inner peripheral edge 65b1 is an arc-shaped edge that follows the rotary shaft insertion hole 61a when viewed in the axial direction. The outer peripheral edge 65b2 is located radially outward of the inner peripheral edge 65b1 and is an arc-shaped edge that follows the inner peripheral edge 65b1. The pair of connecting edges 65b3 connect the ends of the inner peripheral edge 65b1 and the outer peripheral edge 65b2 on the same circumferential side. In the illustrated example, the pair of connecting edges 65b3 are linear, but are not limited to this shape and may be, for example, arc-shaped with a convex outward curve.

[0082] The balance portion 65 of the second embodiment is configured with a plurality of balance holes 65b spaced apart in the circumferential direction, and the portions of the core 61 between the plurality of balance holes 65b form ribs 67 extending radially when viewed in the axial direction. The balance portion 65 of the second embodiment can be said to have a configuration in which the balance holes 65a of the first embodiment, each having a length equivalent to a 180° semicircle, have ribs 67 that circumferentially separate the interior of the balance holes 65a. The ribs 67 extend radially and axially. The ribs 67 are formed by overlapping the electromagnetic steel sheet portions between the holes spaced apart in the circumferential direction in each of the plurality of electromagnetic steel sheets that make up the core 61, by laminating the plurality of electromagnetic steel sheets.

[0083] FIG. 8 is a schematic plan view of a first modified example of the core 61 of the rotor 4a in the compressor 1 according to the second embodiment. FIG. 9 is a schematic plan view of a second modified example of the core 61 of the rotor 4a in the compressor 1 according to the second embodiment. In FIGS. 8 and 9 , the balance holes 65ba at both circumferential ends of the plurality of balance holes 65b have a different shape from the balance hole 65bb at the circumferential center. The balance holes 65ba in FIG. 8 have a shape that tapers toward the circumferential ends. The balance holes 65ba in FIG. 9 have a shape that is an elongated hole extending in the circumferential direction and narrows in the radial direction at the center.

[0084] In the compressor 1, of the multiple balance holes 65b, the central balance hole 65bb, which has a center of gravity located close to the center of gravity of the orbiting scroll 40 and the first balance adjustment component 18, is important in eliminating imbalance between the orbiting scroll 40 and the first balance adjustment component 18. Conversely, of the multiple balance holes 65b, the balance holes 65ba at both circumferential ends of the compressor 1 are less able to eliminate imbalance than the balance hole 65bb at the circumferential center. For this reason, the shapes of the balance holes 65ba at both circumferential ends are not limited to the same shape as the balance hole 65bb at the circumferential center, and may be different without any problems, as shown in Figures 8 and 9.

[0085] [Effects of embodiment 2] The compressor 1 of embodiment 2 has the same effects as embodiment 2, and since the core 61 has ribs 67, the holding force of the rotor 4a against the rotating shaft 7 can be increased compared to the compressor 1 of embodiment 1.

[0086] Embodiment 3 In the compressor 1 of embodiment 3, the dimensional relationship between the balance hole 65b and the rib 67 is specified. The following description will focus on the configuration of embodiment 3 that is different from embodiment 2, and the configuration not described in embodiment 3 is the same as embodiment 2.

[0087] 10 is a schematic plan view of the core 61 of the rotor 4a in the compressor 1 according to the third embodiment. In the compressor 1 according to the third embodiment, the rotor 4a has a relationship of A>B. A is the radial distance between the inner peripheral edge 65b1 of the balance hole 65b and the rotary shaft insertion hole 61a, and is the core thickness. B is the circumferential width of the rib 67. B is also the distance between adjacent balance holes 65b.

[0088] [Effects of Embodiment 3] The compressor 1 of Embodiment 3 has the same effects as those of Embodiment 2, and in addition, by having the relationship A>B in the rotor 4a, it is possible to prevent heat from escaping when the rotor is heated during shrink-fitting of the rotating shaft 7 to the rotor 4a, and to ensure a balance of heat conduction in the circumferential direction of the rotor 4a. As a result, the compressor 1 of Embodiment 3 can fix the rotating shaft 7 to the rotor 4a without bias in the circumferential direction.

[0089] Embodiment 4. The compressor 1 of embodiment 4 differs from embodiments 1 to 3 in the configuration of the rotor 4a. In the compressor 1 of embodiment 4, the rotor 4a has heat-shielding slits. The following description will focus on the configuration of embodiment 4 that differs from embodiments 1 to 3, and configurations that are not described in embodiment 4 are the same as embodiments 1 to 3.

[0090] FIG. 11 is a schematic plan view of the core 61 of the rotor 4a in the compressor 1 according to the fourth embodiment. In the compressor 1 according to the fourth embodiment, the rotor 4a has a heat-shielding slit 70. The heat-shielding slit 70 is a slit provided on the opposite side of the balance hole 65b to maintain circumferential thermal balance when the inner periphery of the rotor is heated during shrink-fitting of the rotating shaft 7 to the rotor 4a, i.e., to uniformly heat the inner periphery of the rotor. The heat-shielding slit 70 is formed to penetrate the core 61 in the axial direction. The heat-shielding slit 70 is formed as an elongated hole having an arc shape that is aligned with the rotating-shaft insertion hole 61a when viewed in the axial direction. The arc-shaped inner peripheral edge 70a on the radially inner side of the heat-shielding slit 70 and the inner peripheral edge 65b1 of the balance hole 65b are located on the same circle centered on the central axis O of the rotating shaft 7, in other words, the central axis of the rotating-shaft insertion hole 61a. The radial width L2 of the heat shielding slit 70 is set smaller than the radial width L1 of the balance hole 65b.

[0091] A plurality of heat shielding slits 70 are provided at intervals in the circumferential direction of the core 61. Although a plurality of heat shielding slits 70 are provided in the illustrated example, it is sufficient that at least one heat shielding slit 70 is provided.

[0092] The heat shielding slits 70 are formed on the opposite side of the balance holes 65b with respect to the rotary shaft insertion hole 61a as viewed in the axial direction. The heat shielding slits 70 are formed in a range of 180° as viewed in the axial direction opposite to the range of 180° around the central axis O of the rotary shaft 7 in which the balance holes 65b are formed. Furthermore, the heat shielding slits 70 are arranged in the same first direction (see FIGS. 6 and 11 ) as the orbiting scroll 40 as viewed in the axial direction.

[0093] Effect of Fourth Embodiment The compressor 1 of the fourth embodiment not only provides the same effects as those of the first to third embodiments, but also provides the following effect due to the core 61 having the heat-shielding slits 70. Due to the core 61 having the heat-shielding slits 70, the compressor 1 can make the heating temperature around the rotary shaft insertion hole 61a of the core 61 more uniform in the circumferential direction during shrink fitting compared to a configuration without the heat-shielding slits 70.

[0094] The arc-shaped inner peripheral edge 70a on the radially inner side of the heat-shielding slit 70 and the inner peripheral edge 65b1 of the balance hole 65b are located on the same circle centered on the central axis O of the rotating shaft 7, in other words, the central axis of the rotating-shaft insertion hole 61a. With the above-described configuration, the compressor 1 can achieve a uniform balance of heat conduction from the inner peripheral portion to the outer peripheral portion of the core 61 in the circumferential direction during shrink fitting, thereby further suppressing shrink fitting defects.

[0095] The heat shielding slits 70 are provided in the first direction, which is the same as the center of gravity of the orbiting scroll 40, and are therefore positioned in a direction that causes imbalance. Therefore, if the heat shielding slits 70 are large, it will affect the elimination of imbalance. However, the radial width L2 of the heat shielding slits 70 is set smaller than the radial width L1 of the balance holes 65b, and the size of the heat shielding slits 70 is set to a size that does not affect the elimination of imbalance. The size of the heat shielding slits 70 is as small as possible compared to the balance holes 65b. In other words, the size of the heat shielding slits 70 is set to a size that does not affect the elimination of imbalance. Therefore, in the compressor 1, by having the heat shielding slits 70 in the core 61, shrink fitting defects can be further suppressed without affecting the elimination of imbalance.

[0096] REFERENCE SIGNS LIST 1 Compressor, 2 Shell, 2a Upper shell, 2b Lower shell, 2c Middle shell, 3 Oil pump, 3a Oil reservoir, 4 Motor, 4a Rotor, 4b Stator, 5 Compression mechanism, 5a Compression chamber, 6 Frame, 6a Intake port, 6b Thrust bearing, 6c Oil supply groove, 6d Internal space, 7 Rotating shaft, 7a Main shaft, 7b Eccentric shaft, 7c Oil passage, 8a Main bearing, 8b Sub-bearing, 8c Swing bearing, 11 Intake pipe, 12 Discharge pipe, 13 Discharge chamber, 15 Oldham ring, 15a Oldham groove, 15b Oldham groove, 16 Slider, 17 Sleeve, 18 First balance adjustment component, 18a Balance adjustment component cover, 18a1 Lower end opening, 20 Subframe, 21 Oil drain pipe, 30 Fixed scroll, 30a End plate, 31 Volute portion, 32 Discharge port, 32a Open end, 40 Swing scroll, 40a End plate, 41 Volute portion, 50 Discharge valve mechanism, 51 Reed valve, 52 Valve seat, 53 Reed valve retainer, 61 Core, 61a Rotating shaft insertion hole, 61b Rivet insertion hole, 61c Magnet insertion hole, 62 Permanent magnet, 63 End plate, 63a Rotating shaft insertion hole, 63b Rivet insertion hole, 63c Refrigerant passage hole, 64 Rivet, 65 Balance portion, 65a Balance hole, 65a1 Inner peripheral edge, 65a2 Outer peripheral edge, 65a3 Connecting edge, 65b Balance hole, 65b1 Inner peripheral edge, 65b2 Outer peripheral edge, 65b3 Connecting edge, 65ba Balance hole, 65bb Balance hole, 65c Second balance adjustment part, 67 Rib, 70 Heat shielding slit, 70a inner peripheral edge, 650 second balance adjustment part, A core thickness, B circumferential width of rib, C1 virtual circle, C2 virtual circle, G center of gravity, G1 center of gravity, G2 center of gravity, G3 center of gravity, Ga center of gravity, Gb center of gravity, O central axis.

Claims

1. A compression mechanism having an eccentric component that compresses the refrigerant, A motor positioned below the compression mechanism, A rotating shaft that transmits the driving force of the motor to the compression mechanism, A first balance adjustment component fixed between the compression mechanism and the motor in the axial direction of the rotating shaft, It comprises a cylindrical balance adjustment component cover that houses the first balance adjustment component inside, The aforementioned motor is The rotor is fixed to the aforementioned rotating shaft, The rotor is An annular core having a circular rotating shaft insertion hole formed in its center, to which the rotating shaft is fixed, The system includes a balance section having at least one balance hole that is arc-shaped and passes through the core in the axial direction, as viewed in the axial direction of the rotating shaft, and which, together with the first balance adjustment component, cancels out the imbalance caused by the eccentric component. The at least one balance hole is, When viewed in the axial direction, it has a shape with an arc-shaped inner periphery along the rotation shaft insertion hole, Viewed in the axial direction, the center of the virtual circle including the inner periphery coincides with the center of the axis of rotation. A compressor formed on the inside of the balance adjustment component cover, as viewed in the axial direction, at a position facing the motor-side opening of the balance adjustment component cover in the axial direction.

2. The at least one balance hole is, Located radially outward from the aforementioned inner periphery, and having an outer periphery that runs along the aforementioned inner periphery, It has a pair of connecting edges that connect the ends of the inner edge and the outer edge, The compressor according to claim 1, wherein, when viewed in the axial direction, the center of the virtual circle including the outer edge coincides with the center of the rotation axis.

3. The compressor according to claim 1 or claim 2, wherein the balance section has a second balance adjustment component positioned further from the eccentric component than the first balance adjustment component in the axial direction.

4. The compressor according to claim 1 or claim 2, wherein the center of gravity of the eccentric part and the center of gravity of the balance part and the center of gravity of the first balance adjustment part are located on opposite sides of the rotation axis.

5. The compressor according to claim 1 or 2, wherein at least one balance hole is arranged on a straight line parallel to the rotation axis passing through the center of gravity of the first balance adjustment component.

6. The core is formed extending in the axial direction and has a magnet insertion hole into which a permanent magnet is inserted. The compressor according to claim 1 or 2, wherein at least one balance hole is formed between the magnet insertion hole and the rotating shaft insertion hole, viewed in the axial direction, and is positioned toward the rotating shaft insertion hole.

7. The compressor according to claim 1 or claim 2, wherein the at least one balance hole is one balance hole.

8. The aforementioned at least one balance hole is a plurality of balance holes, The plurality of balance holes are formed with spacing in the circumferential direction around the rotation axis, The compressor according to claim 1 or claim 2, wherein the core portion between the plurality of balance holes constitutes a radially extending rib.

9. The compressor according to claim 8, wherein A, which is the radial distance between the inner periphery of each of the plurality of balance holes and the rotating shaft insertion hole, and B, which is the width of the rib in the circumferential direction, have the relationship A > B.

10. The compressor according to claim 1 or 2, wherein the core is formed on the opposite side of the balance portion from the rotation shaft insertion hole when viewed in the axial direction, and has at least one heat shielding slit that penetrates the core in the axial direction.

11. The at least one heat shielding slit is formed in the shape of an arc-shaped elongated hole along the rotation shaft insertion hole when viewed in the axial direction, The compressor according to claim 10, wherein the radially inward arc-shaped inner edge of at least one heat shielding slit and the inner edge of at least one balance hole are located on the same circle centered on the central axis of the rotation shaft.

12. The compressor according to claim 10, wherein the radial width of the at least one heat shielding slit is set to be smaller than the radial width of the at least one balance hole.

13. The aforementioned at least one thermal shielding slit is a plurality of thermal shielding slits, The compressor according to claim 10, wherein the plurality of heat shielding slits are formed at intervals in the circumferential direction around the rotation axis.