JP6524268B2 - Hermetic compressor and refrigeration cycle device - Google Patents

Description

  Embodiments of the present invention relate to a hermetic compressor and a refrigeration cycle apparatus.

 A hermetic compressor used in a refrigeration cycle apparatus such as an air conditioner includes a motor unit and a compression mechanism unit housed in a hermetic case. The motor unit has a stator fixed to the inner peripheral surface of the sealed case, and a rotor connected to the compression mechanism unit via a rotation shaft. The rotor is coaxially positioned inside the stator, and a narrow air gap (motor gap) is formed between the outer peripheral surface of the rotor and the inner peripheral surface of the stator.

 In this type of hermetic compressor, from the viewpoint of energy saving, environmental protection, etc., higher efficiency and resource saving of the motor unit are required. As a countermeasure against this, in recent years, a hermetic compressor has been provided in which a permanent magnet type rotor is adopted for a motor unit. A permanent magnet type rotor has an iron core on which a plurality of electromagnetic steel plates are laminated, and a plurality of permanent magnets embedded inside the iron core, and an end plate and a balance weight are disposed on the end face of the iron core There is.

 The end plate is an element for preventing the permanent magnet from falling off the core. The balance weight is used to stabilize the rotation of the rotary shaft and to stabilize the operating state of the entire rotor and compressor.

 According to the conventional permanent magnet type rotor, the balance weight is configured by laminating a plurality of punched silicon steel plates. The laminated silicon steel plates are integrated with the iron core using rivets and project from part of the end face of the iron core.

JP-A-4-185247

 When the balance weight protrudes from the end face of the core, it is inevitable that a large air resistance is generated when the rotor rotates. This increases the windage loss of the rotor, resulting in energy loss. Furthermore, when the balance weight is repeatedly subjected to resistance by windage, a rivet that fixes the balance weight to the iron core may cause fatigue failure, and the balance weight may be separated from the iron core.

  Since the silicon steel plate forming the balance weight is a magnetic body, the magnetic flux generated from the permanent magnet embedded in the iron core leaks in the axial direction of the rotor. As a result, the effective flux linkage with the stator disposed outside the rotor decreases, making it difficult to exhibit the performance required of the motor section.

  In addition, when the compression mechanism portion is driven by the motor portion, the lubricating oil stored in the oil reservoir portion of the inner bottom portion of the sealed case is sucked up by the compression mechanism portion. The suctioned lubricating oil is supplied to various sliding parts of the compression mechanism. At this time, the lubricating oil is stirred by the balance weight projected from the rotor, and the amount of the lubricating oil discharged to the outside of the sealed case increases.

  The object of the present invention is to suppress the wind loss due to the end plate and the balance weight and to improve the performance of the motor section by increasing the effective linkage flux, and simplify the shape of the end plate and the balance weight to reduce the cost. It is an object of the present invention to provide a hermetic compressor which can reduce the

The hermetic compressor according to the present embodiment includes a hermetic case, a compression mechanism portion that compresses a refrigerant inside the hermetic case, and a motor portion housed in the hermetic case and driving the compression mechanism portion. There is. The motor unit includes a rotor connected to the compression mechanism unit, and a stator fixed to the sealed case in a state surrounding the rotor. The rotor includes an iron core having a plurality of permanent magnets embedded in a plurality of laminated electromagnetic steel plates, and a balance weight provided on an end face facing the compression mechanism portion of the iron core. .
The balance weight is provided on the end face of the iron core, is made of a nonmagnetic material, and is laminated on an annular first weight plate having a balance hole, and the first weight plate, and is made of a magnetic material And an annular second weight plate having a balance hole, wherein the inner peripheral edge and the outer peripheral edge of the first weight plate and the inner peripheral edge and the outer peripheral edge of the second weight plate have the same dimensions as each other It has a shape.

FIG. 1 is a cross-sectional view of a hermetic compressor used in a refrigeration cycle apparatus according to a first embodiment. FIG. 2A is a side view of a core of a rotor used in the first embodiment. FIG. 2B is a plan view showing the shape of the first end plate when the second balance weight positioned at the lower end of the core is cut along the F2B-F2B line of FIG. 2A. FIG. 2C is a plan view showing the shape of the first weight plate when the second balance weight positioned at the lower end of the core is cut along the F2C-F2C line of FIG. 2A. FIG. 2D is a plan view showing the shape of a second weight plate when the second balance weight positioned at the lower end of the core is cut along the F2D-F2D line of FIG. 2A. FIG. 2E is a plan view showing the shape of the second end plate when the second balance weight positioned at the lower end of the core is cut along the F2E-F2E line of FIG. 2A. FIG. 3 is a plan view taken along line F3-F3 of FIG. 2A. FIG. 4A is a plan view of a rotor according to a second embodiment. FIG. 4B is a cross-sectional view of the rotor taken along line Aa-O-Ab of FIG. 4A. FIG. 4C is a bottom view of a rotor according to a second embodiment.

First Embodiment
Hereinafter, a first embodiment will be described with reference to the drawings.
FIG. 1 shows a refrigeration cycle circuit R of the refrigeration cycle apparatus 1. The refrigeration cycle circuit R includes, as main components, a hermetic compressor K, a radiator 2, an expansion device 3, an evaporator 4 which is a heat absorber, and an accumulator 5. The various elements constituting the refrigeration cycle circuit R are connected in series via a refrigerant pipe P through which the refrigerant circulates.

  The refrigerant used in the refrigeration cycle circuit R is, for example, an HFC refrigerant, an HFO refrigerant, an HC (hydrocarbon) refrigerant, or a carbon dioxide (CO2) refrigerant.

  The hermetic compressor K is a so-called vertical rotary compressor, and includes a hermetic case 10, a motor unit 11, and a compression mechanism unit 12 as main components. The motor unit 11 is accommodated in an intermediate portion in the sealed case 10. The compression mechanism portion 12 is accommodated in the lower portion in the sealed case 10. The motor unit 11 is connected to the compression mechanism unit 12 via the rotation shaft 13.

  The motor unit 11 is, for example, a brushless DC synchronous motor driven by an inverter. The motor unit 11 includes a cylindrical stator 14 fixed to the inner peripheral surface of the sealed case 10 and a rotor 15 surrounded by the stator 14.

  An oil reservoir 16 is formed at the bottom of the sealed case 10. The oil reservoir 16 stores lubricating oil. As a lubricating oil, for example, a polyol ester oil, an ether oil, a mineral oil, an alkybenzene oil, a single oil or a mixed oil of a PAG oil is used.

  As shown in FIG. 1, the compression mechanism 12 is immersed in the lubricating oil stored in the oil reservoir 16. The compression mechanism unit 12 includes a cylinder 18. The cylinder 18 is inserted into the inside of the sealed case 10, and the outer peripheral surface of the cylinder 18 is fixed to the inner peripheral surface of the sealed case 10.

  A main bearing 19 is mounted on the top of the cylinder 18. Further, a sub bearing 20 is attached to the lower surface of the cylinder 18. The main bearing 19 and the sub bearing 20 close the inner diameter portion of the cylinder 18. A space surrounded by the inner diameter portion of the cylinder 18, the main bearing 19 and the sub bearing 20 constitutes a cylinder chamber S. The cylinder chamber S is connected to the accumulator 5 via a suction pipe 17 which is a part of the refrigerant pipe P.

  The rotating shaft 13 is rotatably supported by the main bearing 19 and the auxiliary bearing 20, and is coaxially positioned on a vertical line V1 passing through the center of the sealed case 10. The main bearing 19 rotatably supports the middle portion of the rotating shaft 13. The sub bearing 20 rotatably supports the lower end portion of the rotating shaft 13. Furthermore, the rotating shaft 13 is provided with an eccentric portion 13a. The eccentric portion 13 a is located between the main bearing 19 and the sub bearing 20 and is accommodated in the cylinder chamber S.

  A ring-shaped roller 21 is fitted to the outer peripheral surface of the eccentric portion 13a. The roller 21 eccentrically moves inside the cylinder chamber S when the rotating shaft 13 rotates. As a result, a part of the outer peripheral surface of the roller 21 is slidably in line contact with the inner peripheral surface of the cylinder chamber S.

  The cylinder 18 has a guide groove (not shown). The guide groove linearly extends along the radial direction of the cylinder 18 and has one end opened to the cylinder chamber S. A blade (not shown) is accommodated in the guide groove so as to be capable of reciprocating. The blade has an arc-shaped curved tip, and the tip is slidably pressed against the outer peripheral surface of the roller 21.

  The blade cooperates with the roller 21 to divide the cylinder chamber S into a suction region and a compression region, and follows the eccentric movement of the roller 21 to project into the cylinder chamber S or move in a direction to withdraw from the cylinder chamber S It is supposed to As a result, the volumes of the suction area and the compression area of the cylinder chamber S change, and the gas phase refrigerant sucked into the cylinder chamber S from the suction pipe 17 is compressed.

  As shown in FIG. 1, the discharge muffler 22 is mounted on the main bearing 19. The discharge muffler 22 covers the discharge valve mechanism 23 provided on the main bearing 19. The discharge valve mechanism 23 opens when the gas phase refrigerant pressurized in the cylinder chamber S reaches a predetermined pressure. As a result, the high temperature / high pressure gas phase refrigerant pressurized in the cylinder chamber S is discharged to the inside of the discharge muffler 22.

  A high temperature / high pressure gas phase refrigerant is led to the upper part of the sealed case 10 through a gas guide path provided between various parts constituting the motor unit 11 and is led to the radiator 2 via the refrigerant pipe P. .

  The high temperature / high pressure gas phase refrigerant introduced to the radiator 2 is condensed, for example, by heat exchange with air, and changes to a high pressure liquid phase refrigerant. The high-pressure liquid-phase refrigerant is decompressed in the process of passing through the expansion device 3 and changes to a low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant takes heat from the air in the process of passing through the evaporator 4 and evaporates, and changes to a low-temperature low-pressure gas-phase refrigerant. The air passing through the evaporator 4 is cooled by the latent heat of evaporation of the liquid-phase refrigerant, and becomes cold air, and is sent to, for example, a place to be air-conditioned.

  The gas phase refrigerant that has passed through the evaporator 4 is led to the accumulator 5. The liquid phase refrigerant that has not been evaporated by the evaporator 4 is separated from the gas phase refrigerant by the accumulator 5. The gas phase refrigerant separated from the liquid phase refrigerant is sucked into the cylinder chamber S of the hermetic compressor K through the suction pipe 17. The gas phase refrigerant sucked into the cylinder chamber S is compressed again into a high temperature / high pressure gas phase refrigerant, discharged from the closed case 10 to the refrigerant pipe P, and the above-mentioned operation is repeated.

  Next, the motor unit 11 of the hermetic compressor K will be described in detail.

  The stator 14 includes a yoke fixed to the inner circumferential surface of the sealed case 10, and a plurality of teeth formed on the inner circumferential surface of the yoke. The number of teeth can be represented by 3n. In the present embodiment, the number of teeth is nine by setting n = 3.

  Furthermore, the teeth are projected from the inner circumferential surface of the yoke toward the outer circumferential surface of the rotor 15. The teeth are arranged at intervals in the circumferential direction of the stator 14 and lead wires are concentrated around each tooth.

  As shown in FIG. 2, the rotor 15 includes an iron core 25. The iron core 25 is configured, for example, by laminating a plurality of electromagnetic steel plates in the axial direction of the sealed case 10. The upper portion of the rotating shaft 13 is coaxially fixed to the central portion of the iron core 25. The outer peripheral surface of the iron core 25 faces the inner peripheral surface of the stator 14 via a minimal air gap.

  The number of magnetic poles of the rotor 15 can be represented by 2n. n is an integer of 2 or more. In the present embodiment, the number of magnetic poles of the rotor 15 is six by setting n = 3. Specifically, as shown in FIG. 3, six plate-like permanent magnets 26 are embedded in the core 25. The six permanent magnets 26 are individually inserted into six magnet housing holes 27 provided on the outer periphery of the iron core 25.

  Furthermore, the six permanent magnets 26 are disposed on the outer peripheral portion of the iron core 25 in a posture along the circumferential direction of the iron core 25 and are arranged at intervals in the circumferential direction of the iron core 25.

  As shown in FIG. 1, the rotor 15 includes a first balance weight 30A and a second balance weight 30B. The first balance weight 30A and the second balance weight 30B reduce the vibration of the hermetic compressor K by counteracting the amount of rotational unbalance of the rotary shaft 13 associated with the eccentric movement of the roller 21. The first balance weight 30A is disposed at the upper end of the iron core 25. The second balance weight 30 </ b> B is disposed at the lower end of the core 25 facing the compression mechanism 12.

  As shown in FIG. 2A, the second balance weight 30B includes a first end plate 31, a first weight 32, a second weight 33, and a second end plate 34 as main elements. . The first end plate 31 is made of a nonmagnetic plate material. The first weight portion 32 is configured by laminating a plurality of nonmagnetic plate members to one another. The second weight portion 33 is configured by laminating a plurality of plate members of a magnetic body with each other. The second end plate 34 is made of a magnetic plate.

  The first end plate 31, the first weight portion 32, the second weight portion 33 and the second end plate 34 are laminated to one another and, for example, by fastening and caulking using a rivet, the iron core 25 is It is integrally fixed to the lower end face.

  Specifically, the first end plate 31 is superimposed on the lower end surface of the iron core 25. As shown in FIG. 2B, the first end plate 31 is formed in an annular shape having a circular inner peripheral edge n and a circular outer peripheral edge m. Four rivet holes 36 a are provided in the first end plate 31. The rivet holes 36 a are arranged at intervals in the circumferential direction of the first end plate 31. In the present embodiment, the four rivet holes 36a are arranged in line symmetry with the central axis C1 such that the two rivet holes 36a are aligned with the central axis C1 passing through the center of the rotor 15 therebetween. ing.

  An oil return hole 37 a and a balance hole 38 are provided in the first end plate 31. The oil return hole 37a and the balance hole 38 are provided at positions facing each other across the central axis C1. The oil return hole 37 a has a laterally long opening shape along the circumferential direction of the first end plate 31. The balance hole 38 is larger than the oil return hole 37 a and has an opening shape curved in an arc shape along the circumferential direction of the first end plate 31. Furthermore, the balance hole 38 is opened at a position closer to the inner peripheral edge n than the outer peripheral edge m of the first end plate 31.

  As best shown in FIG. 3, the balance holes 38 of the first end plate 31 are out of the two magnet receiving holes 27 provided in the iron core 25. Therefore, even the lower end surface of the permanent magnet 26 inserted into the magnet accommodation hole 27 is completely removed from the balance hole 38 so as not to overlap with the balance hole 38.

  The lower end surface of the permanent magnet 26 does not have to be completely separated from the balance hole 38, and a part of the lower end surface of the permanent magnet 26 may be exposed to the balance hole 38. In addition, the balance hole 38 is not an essential element and may be omitted from the first end plate 31.

  As shown in FIG. 2C, the first weight portion 32 adjacent to the first end plate 31 is formed in an annular shape having a circular inner peripheral edge n and a circular outer peripheral edge m. As shown in FIG. 2D, the second weight 33 adjacent to the first weight 32 is formed in an annular shape having a circular inner peripheral edge n and a circular outer peripheral edge m. The shapes and dimensions of the first weight portion 32 and the second weight portion 33 are the same as those of the first end plate 31.

  Four rivet holes 36 b and oil return holes 37 b are provided in the first weight portion 32. The rivet holes 36b and the oil return holes 37b have the same shape and dimensions as the rivet holes 36a and the oil return holes 37a of the first end plate 31, and the rivet holes 36a and the oil return holes 37a of the first end plate 31 It is provided at the matching position.

  Similarly, four rivet holes 36 c and an oil return hole 37 c are provided in the second weight portion 33. The rivet holes 36c and the oil return holes 37c have the same shape and dimensions as the rivet holes 36b and the oil return holes 37b of the first weight portion 32, and the rivet holes 36b and the oil return holes 37b of the first weight portion 32 It is provided at the matching position.

  Furthermore, balance holes 39 are provided in the first weight portion 32 and the second weight portion 33, respectively. The balance hole 39 of the first weight portion 32 has an opening shape curved in an arc shape along the circumferential direction of the first weight portion 32. The balance hole 39 of the second weight portion 33 has an opening shape curved in an arc shape along the circumferential direction of the second weight portion 33. The balance holes 39 of the first weight portion 32 and the second weight portion 33 match each other and have the same dimensions.

  As shown in FIG. 3, the inner peripheral edge of each balance hole 39 matches the inner peripheral edge of the balance hole 38 of the first end plate 31. On the other hand, the outer peripheral edge of each balance hole 39 is shifted to the outside along the radial direction of the first weight portion 32 and the second weight portion 33 than the outer peripheral edge of the balance hole 38 of the first end plate 31 There is. In other words, the balance hole 39 has an opening area larger than that of the balance hole 38, and the outer peripheral portion of the balance hole 39 is closed by the first end plate 31.

 As shown in FIG. 2E, the second end plate 34 is formed in an annular shape having a circular inner peripheral edge n and a circular outer peripheral edge m. The shape and dimensions of the second end plate 34 are the same as those of the first weight 32 and the second weight 33.

  Four rivet holes 36 d and oil return holes 37 d are provided in the second end plate 34. The rivet hole 36d and the oil return hole 37d have the same shape and dimensions as the rivet hole 36a and the oil return hole 37a of the first end plate 31, and the rivet hole 36a and the oil return hole 37a of the first end plate 31 It is provided at the matching position. In addition, the second end plate 34 closes the balance holes 38, 39 from below.

  As shown in FIG. 2A, the first end plate 31, the first weight portion 32, the second weight portion 33 and the second end plate 34 may be a perfect circle or a perfect circle having a diameter equal to or less than the diameter of the iron core 25. Has a shape in which a part of the The center of the outer peripheral edge m of each of the first end plate 31, the first weight portion 32, the second weight portion 33 and the second end plate 34 is on the central axis C 1 passing through the center of the rotor 15. It is located.

  On the other hand, the inner peripheral edge n of each of the first end plate 31, the first weight portion 32, the second weight portion 33 and the second end plate 34 is two curved portions curved in an arc shape. And two straight portions connecting the curved portions have an elliptical shape.

  Specifically, as shown in FIG. 3, a straight line passing through the center of rotation O1 of the second balance weight 30B located on the central axis C1 of the rotor 15 and the center 39a along the circumferential direction of the balance hole 39 XX intersects with the inner peripheral edge n of the first weight portion 32 and the second weight portion 33 at two locations along the radial direction. Assuming that the intersections of the straight line XX and the inner peripheral edge n are n1 and n2, the center O2 between the intersection n1 and the intersection n2 is shifted in the direction of the balance hole 39 relative to the rotation center O1.

  Therefore, in the first weight portion 32 and the second weight portion 33, the distance along the straight line XX from the intersection point n1 to the outer peripheral edge m is the distance along the straight line XX from the intersection point n2 to the outer peripheral edge m In comparison, the center O2 is shortened by the amount of deviation from the rotation center O1. Therefore, as shown in FIG. 3, the area of the lower half of the first weight portion 32 and the second weight portion 33 in which the balance hole 39 is opened is located on the opposite side across the rotation center O1. The area is smaller than the area of the upper half of the first weight portion 32 and the second weight portion 33.

  Furthermore, the presence of the balance holes 39 further reduces the effective areas of the lower halves of the first weight portion 32 and the second weight portion 33, and the upper half portions of the first weight portion 32 and the second weight portion 33. The amount of imbalance is sufficiently secured.

  The shapes of the inner peripheral edge n of the first end plate 31, the first weight portion 32, the second weight portion 33 and the second end plate 34 are not limited to an ellipse, and the amount of imbalance of the second balance weight 30 B The inner peripheral edge n may be, for example, a perfect circle, as long as it can be secured.

  As a nonmagnetic material which comprises the 1st end plate 31 and the 1st weight part 32, the stainless steel plate is used, for example. As a magnetic body which comprises the 2nd weight part 33 and the 2nd end plate 34, the electromagnetic steel plate is used, for example.

  The electromagnetic steel sheet used for the second weight portion 33 is thicker than the electromagnetic steel sheet used for the iron core 25. The stainless steel plate used for the first weight portion 32 has a thickness similar to that of the electromagnetic steel plate used for the second weight portion 33.

  The electromagnetic steel sheet can increase the accuracy as the balance weight because the accuracy of the plate thickness is high. According to the present embodiment, the electromagnetic steel plate used for the iron core 25 has a thickness of 0.35 mm, and the electromagnetic steel plate used for the second weight portion 33 has a thickness of 0.5 mm.

Furthermore, the electromagnetic steel sheet used for the second weight portion 33 has a silicon content less than that of the electromagnetic steel sheet used for the iron core 25 and has a large specific gravity. Specifically, the density of the magnetic steel sheet used for the second weight portion 33 is 7.8 kg / cm ³ . On the other hand, the density of the magnetic steel sheet used for the iron core 25 is 7.6 kg / cm ³ .

  When the difference between the diameter of the iron core 25 and the diameter of the second balance weight 30B is equal to or less than the air gap between the rotor 15 and the stator 14, the thickness of the first weight portion 32 It is good to set to double or three times or more.

  In the present embodiment, a nonmagnetic material such as a stainless steel plate is used as a material forming the first end plate 31 and the first weight portion 32, and the second weight portion 33 and the second end plate 34 are configured. A magnetic material such as a magnetic steel sheet is used as the material, and these different materials are punched out using the same mold.

  When the plate thickness of the nonmagnetic material is L1 and the plate thickness of the magnetic material is L2, it is preferable to satisfy the following equation (1).

L1-0.1 ≦ L2 ≦ L1 + 0.1 (mm) (1)
Next, when manufacturing the second balance weight 30B, an outline of a pressing process, which is one of the manufacturing processes, will be described.

  First, a sheet-like metal material is subjected to a punching process, and a plurality of balance holes 38 and 39 are made in the metal material. The balance hole 38 of the first end plate 31 and the balance hole 39 of the first weight portion 32 and the second weight portion 33 have different sizes and shapes. Therefore, a plurality of punches and dies of different shapes are attached to the progressive die, and any punch is selected to operate.

  Thereafter, the metal material is subjected to a punching process to form a plurality of circular inner peripheral edges n at positions adjacent to the balance holes 38 and 39. The inner peripheral edge n of the first end plate 31, the first weight portion 32, the second weight portion 33 and the second end plate 34 have the same size and shape in common, so they can be smoothly made of metal material. It can be processed.

  Thereafter, a plurality of rivet holes 36a, 36b, 36c, 36d and a plurality of oil return holes 37a, 37b, 37c, 37d are opened around the respective inner peripheral edges n by subjecting the metal material to a drilling process. Subsequently, the metal material is punched to form a plurality of circular outer peripheral edges m so as to surround the rivet holes 36a, 36b, 36c, 36d, the oil return holes 37a, 37b, 37c, 37d and the balance holes 38, 39. . The rivet holes 36a, 36b, 36c, 36d, the oil return holes 37a, 37b, 37c, 37d and the outer peripheral edge m have a first end plate 31, a first weight 32, a second weight 33, and a second Since all of the end plates 34 have the same size and shape, the metal material can be processed smoothly.

  As a result, the first end plate 31, the first weight 32, the second weight 33, and the second end plate 34 can be obtained simultaneously.

  The first balance weight 30A located at the upper end of the rotor 15 includes an end plate and a weight portion as main elements. The end plate is formed of a nonmagnetic material such as a stainless steel plate, for example, and has the same shape and size as the first end plate 31 of the second balance weight 30B.

  The weight portion is configured by laminating nonmagnetic materials such as, for example, a plurality of stainless steel plates on one another. Furthermore, the weight portion has the same shape and size as the first weight portion 32 of the second balance weight 30B.

  According to the first embodiment, the end plate and the weight portion of the first balance weight 30A located at the upper end portion of the rotor 15 are respectively made of nonmagnetic material such as stainless steel plate. The second balance weight 30 B located at the lower end of the rotor 15 is located below the first end plate 31 and the first end plate 31 superimposed on the lower end surface of the iron core 25 of the rotor 15. The first weight portion 32 is made of a nonmagnetic material such as a stainless steel plate.

  Therefore, the magnetic flux generated from the permanent magnet 26 embedded in the iron core 25 can be prevented from leaking in the axial direction of the rotor 15, and the magnetic flux flows to the side of the stator 14 surrounding the rotor 15. Therefore, the effective flux linkage with the stator 14 is increased, and the performance required of the motor unit 11 can be sufficiently satisfied.

  At the same time, the rotation of the rotor 15 can be smoothened to suppress windage loss, and the load on the motor unit 11 that drives the rotor 15 can be reduced.

  Furthermore, in the second balance weight 30B, the inner peripheral edge n and the outer peripheral edge m of the first end plate 31, the first weight portion 32, the second weight portion 33 and the second end plate 34 are mutually different. It has an annular shape with the same dimensions. Therefore, the first end plate 31, the first weight portion 32, the second weight portion 33, and the second end plate 34 can be pressed using the same mold. Thus, the manufacturability of the second balance weight 30B is improved.

 In addition, since the diameter of the inner peripheral edge n of the second balance weight 30B is constant, the inner peripheral surface of the second balance weight 30B has a smooth shape. As a result, when the gas phase refrigerant discharged from the compression mechanism 12 into the sealed case 10 passes inside the second balance weight 30B, the gas phase refrigerant is strongly stirred by the rotating second balance weight 30B. Can be suppressed.

 The gas phase refrigerant discharged from the compression mechanism 12 into the sealed case 10 is provided in an air gap between the rotor 15 and the stator 14, an oil passage provided in the iron core 25, and the second balance weight 30B. It is smoothly led to the refrigerant pipe P connected to the upper end of the sealed case 10 through the oil return holes 37a, 37b, 37c, 37d and the gas guide path provided in the stator 14.

 When the compression mechanism 12 is in operation, the lubricating oil stored in the oil reservoir 16 of the sealed case 10 is agitated. The stirred lubricating oil becomes droplets and floats in the closed case 10. In the present embodiment, since the inner peripheral surface of the second balance weight 30B has a smooth shape, it is possible to suppress the occurrence of a vortex in the vicinity of the inner peripheral surface. Therefore, it is possible to prevent the droplets of the lubricating oil floating in the sealed case 10 from being sucked up by the rotating second balance weight 30B, and the amount of the lubricating oil discharged to the outside of the sealed case 10 is reduced.

 According to the present embodiment, a material cheaper than the first weight portion 32 can be used as the second weight portion 33, which contributes to the reduction of the cost of the second balance weight 30B.

 As shown in FIG. 3, the difference G between the diameter of the outer peripheral surface of the rotor 15 and the diameter of the outer peripheral edge m of the second balance weight 30B is equal to the air gap between the rotor 15 and the stator 14 or If smaller, it is desirable to set the thickness of the first weight portion 32 to two to three times the air gap or more.

 That is, it is known that the magnetic force of the permanent magnet 26 is output in inverse proportion to the square of the distance. Therefore, in the first weight portion 32 made of a nonmagnetic material such as a stainless steel plate, for example, the thickness of the first weight portion 32 is fixed to 2 to 3 times the air gap, and thereafter the price is expensive. It is preferable to replace the stainless steel plate with a second weight portion 33 using a magnetic material such as a relatively inexpensive electromagnetic steel plate. Thereby, the original performance of the second balance weight 30B can be maintained while reducing the cost of the second balance weight 30B.

  The electromagnetic steel plate constituting the second weight portion 33 is advantageous in increasing the accuracy of the balance weight because the accuracy of the plate thickness is high. In the present embodiment, the iron core 25 is formed of an electromagnetic steel plate having a thickness of 0.35 mm, and the second weight portion 33 is formed of an electromagnetic steel plate having a thickness of 0.5 mm. Thereby, the number of electromagnetic steel plates constituting the second weight portion 33 is reduced, the manufacturability of the second balance weight 30B is improved, and the cost of the second balance weight 30B can be reduced.

  The electromagnetic steel sheet used for the second weight portion 33 has a silicon content smaller than that of the electromagnetic steel sheet used for the iron core 25 and has a large specific gravity. That is, by forming the second weight portion 33 with an electromagnetic steel sheet having a large specific gravity, the number of electromagnetic steel sheets used for the second weight portion 33 can be reduced. Thus, the manufacturability of the second balance weight 30B is further improved, and the cost of the second balance weight 30B is reduced.

  In the present embodiment, a stainless steel plate, which is an example of a nonmagnetic material, is used for the first weight portion 32. For this reason, the variation in press processability that is affected by the hardness and the shear resistance of the metal material can be made smaller compared to the electromagnetic steel sheet. Therefore, press processability using the same mold can be improved.

In this embodiment, when the thickness of the stainless steel plate used for the first weight portion 32 is L1 and the thickness of the electromagnetic steel plate used for the second weight portion 33 is L2,
L1-0.1 ≦ L2 ≦ L1 + 0.1 (mm)
To meet the relationship of That is, it is possible to suppress the cost required for the mold by performing the pressing process on the metal sheet using the same mold with the difference in thickness of the different metal sheets being within 0.1 (mm) or less. . Furthermore, the degree of freedom in selecting a metal plate to be a material is increased.

  As shown in FIG. 3, the balance hole 38 provided in the first end plate 31 is provided at a position deviated from the permanent magnet 26 so as not to overlap with the end face of the permanent magnet 26 embedded in the iron core 25. ing. Thus, the first end plate 31 can be used to prevent the permanent magnet 26 from falling off the core 25 and to add a function as a balance weight to the first end plate 31 that prevents the permanent magnet 26 from falling off. Can.

  Furthermore, since the first end plate 31 also functions as a balance weight, the number of stainless steel plates used for the first weight portion 32 can be reduced. This contributes to the reduction of the cost of the second balance weight 30B.

  In the present embodiment, if the balance hole 39 is provided at a position away from the permanent magnet 26 so that the balance hole 39 of the first weight portion 32 does not overlap with the end face of the permanent magnet 26 embedded in the iron core 25, The first weight portion 32 can be used to prevent the permanent magnet 26 from falling off the iron core 25. As a result, the first end plate 31 can be omitted from the second balance weight 30B.

  The first weight portion 32 is made of a stainless steel plate having the same thickness as the electromagnetic steel plate of the second weight portion 33. For this reason, in comparison with the magnetic steel sheet, the difference in press processability which is affected by the hardness and the shear resistance of the metal sheet may be smaller than, for example, brass or the like. Therefore, press processability using the same mold is improved.

  According to the present embodiment, a straight line XX passing through the center of rotation O1 of the second balance weight 30B and the center 39a of the balance hole 39 along the circumferential direction is at two points with respect to the inner peripheral edge n of the second weight portion 33. At the intersection. Assuming that the intersections of the straight line XX and the inner peripheral edge n are n1 and n2, the center O2 between the intersection n1 and the intersection n2 is shifted in the direction of the balance hole 39 relative to the rotation center O1. Thus, the distance along the straight line XX from the intersection point n1 to the outer peripheral edge m is shorter than the distance along the straight line XX from the intersection point n2 to the outer peripheral edge m.

  As a result, the imbalance amount of the second balance weight 30B is increased, and the balance between the rotor 15 and the hermetic compressor K can be reliably maintained when the rotor 15 rotates.

  The second end plate 34 of the second balance weight 30 B faces the oil surface of the lubricating oil stored in the oil reservoir 16 of the sealed case 10. Since there is no balance hole in the second end plate 34, stirring of the lubricating oil can be prevented and windage loss can be suppressed.

Second Embodiment
4A, 4B and 4C disclose a second embodiment.

  The second embodiment is different from the first embodiment in the configuration of part of the rotor 15. The other configuration is the same as that of the first embodiment. Therefore, in the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

  4A is a plan view of the rotor 15, FIG. 4B is a cross-sectional view of the rotor 15 taken along line Aa-O-Ab in FIG. 4A, and FIG. 4C is a bottom view of the rotor 15. As shown in FIGS. 4A and 4B, four degassing holes 25a, fitting holes 25b, four rivet holes 40 and a single oil passage 41 are provided in the iron core 25.

  The fitting hole 25 b is an element to which the rotation shaft 13 is fitted, and is positioned coaxially with the central axis C 1 of the rotor 15. The degassing holes 25a have an arc-shaped opening along the circumferential direction of the iron core 25, and are arranged at intervals in the circumferential direction of the iron core 25 so as to surround the fitting holes 25b. The rivet holes 40 are arranged at intervals in the circumferential direction of the iron core 25 so as to correspond to the rivet holes 36a of the first end plate 31 of the second balance weight 30B. The oil passage 41 is located between two adjacent rivet holes 40. The degassing holes 25a, the rivet holes 40 and the oil passage 41 respectively penetrate the iron core 25 in the axial direction.

  The first balance weight 30A located at the upper end portion of the iron core 25 includes an end plate 43 laminated on the upper end surface of the iron core 25 and a weight portion 44 stacked on the end plate 43. The end plate 43 is made of a nonmagnetic material such as a stainless steel plate, and is formed to have the same dimensions as the first end plate 31 of the second balance weight 30B. The weight portion 44 is formed by laminating nonmagnetic materials such as a plurality of stainless steel plates to one another, and is formed in an annular shape having the same dimensions as the first weight portion 32 of the second balance weight 30B. It is done. Therefore, the end plate 43 and the weight portion 44 have an annular shape having a circular inner peripheral edge n and an outer peripheral edge m.

  Furthermore, the end plate 43 has a balance hole 45 and four rivet holes 46. The balance hole 45 has an opening shape curved in an arc shape in the circumferential direction of the end plate 43. The rivet holes 46 are provided at positions corresponding to the rivet holes 40 so as to lead to the rivet holes 40 of the iron core 25.

  The weight portion 44 has a balance hole 47 and four rivet holes 48. The balance hole 47 has an opening shape curved in the circumferential direction of the weight portion 44 and is provided at a position matching the balance hole 45 of the end plate 43. According to the present embodiment, the balance hole 47 has an opening shape larger than the balance hole 45, and the outer peripheral portion of the balance hole 47 is closed by the end plate 43. The rivet holes 48 are provided at positions corresponding to the rivet holes 46 so as to lead to the rivet holes 46 of the end plate 43.

  As shown in FIGS. 4A and 4C, the degassing holes 25a and the fitting holes 25b of the iron core 25 are the inside of the inner peripheral edge n of the weight portion 44 of the first balance weight 30A and the second of the second balance weight 30B. Of the inner peripheral edge n of the end plate 34 of FIG.

  In other words, the degassing hole 25a is formed in the sealed case 10 through the inside of the inner peripheral edge n of the weight portion 44 of the first balance weight 30A and the inner periphery of the inner peripheral edge n of the second end plate 34 of the second balance weight 30B. It is in communication with In this embodiment, the distance from the outer peripheral edge of the degassing hole 25a to the rotation center of the rotor 15 is set equal to the radius of the inner peripheral edge n of the end plate 44 and the radius of the inner peripheral edge n of the second end plate 34. It is done.

  As shown in FIG. 4A, the upper end of the oil passage 41 of the iron core 25 is opened at the central portion of the balance hole 47 of the weight portion 44 of the first balance weight 30A. The upper end of the oil passage 41 has a circular opening shape.

  The lower end of the oil passage 41 of the iron core 25 is in communication with the oil return holes 37a, 37b, 37c and 37d of the second balance weight 30B. Therefore, the oil return holes 37a, 37b, 37c and 37d of the second balance weight 30B communicate with the top of the weight portion 44 which is the upper surface of the first balance weight 30A via the oil passage 41.

  According to the second embodiment, the lubricating oil accumulated on the upper surface of the first balance weight 30A is sealed from the oil passage 41 of the core 25 through the oil return holes 37a, 37b, 37c, 37d of the second balance weight 30B. The oil reservoir portion 16 of the case 10 can be quickly returned. Therefore, it is possible to prevent the liquid level of the lubricating oil stored in the oil reservoir 16 from being lowered.

  In the above embodiment, the one-cylinder hermetic compressor K has been described. However, the present embodiment is not limited to this, and for example, the present invention is also applicable to a two-cylinder hermetic compressor.

 Furthermore, the hermetic compressor is not limited to the vertical hermetic compressor K in which the rotary shaft 13 is placed vertically, but can be applied to, for example, a horizontal hermetic compressor in which the rotary shaft is placed horizontally. It is.

  The present embodiment has been described above, but the above-described embodiment is presented as an example, and it is not intended to limit the scope of the embodiment. This novel embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

DESCRIPTION OF SYMBOLS 10 ... Sealing case 11, 11 ... Motor part, 12 ... Compression mechanism part, 14 ... Stator, 15 ... Rotor, 25 ... Iron core, 26 ... Permanent magnet, 30B ... Balance weight (2nd balance weight), 32 ... 32nd 1 weight part 33 second weight part 39, 45 balance hole n inner circumferential edge m outer circumferential edge K sealed compressor 2 radiator radiator 3 expansion device 4 evaporation , P ... refrigerant pipe, R ... refrigeration cycle circuit.

Claims (7)

A sealed case,
A compression mechanism portion that compresses a refrigerant inside the sealed case;
A sealed compressor including a motor unit housed in the sealed case and driving the compression mechanism unit;
The motor unit includes a rotor connected to the compression mechanism unit, and a stator fixed to the sealed case in a state surrounding the rotor, and the rotors are stacked on one another. An iron core having a plurality of permanent magnets embedded inside the magnetic steel sheet, and a balance weight provided on an end face facing the compression mechanism portion of the iron core,
The balance weight is
An annular first weight portion provided on the end face of the iron core and made of a nonmagnetic material and having a balance hole;
And an annular second weight portion which is laminated on the first weight portion and is made of a magnetic material and has a balance hole,
A hermetic compressor having an inner peripheral edge and an outer peripheral edge of the first weight portion, and an inner peripheral edge and an outer peripheral edge of the second weight portion, which have the same dimensions.   The sealed type according to claim 1, wherein the first weight portion is formed of a stainless steel plate, and the second weight portion is formed of an electromagnetic steel plate thicker than the thickness of the electromagnetic steel plate constituting the iron core. Compressor.   The hermetic type compressor according to claim 2, wherein the electromagnetic steel sheet constituting the second weight portion has a specific gravity larger than that of the electromagnetic steel sheet constituting the iron core.   The balance weight further includes an annular end plate formed of a nonmagnetic material and having a balance hole, and the end plate is provided between the end face of the iron core and the first weight portion. The hermetic compressor according to claim 1, wherein the balance hole of the end plate is provided at a position not completely overlapping with one end face of the permanent magnet. The balance hole of the first weight portion and the balance hole of the second weight portion each have a shape curved in an arc along the circumferential direction of the first weight portion and the second weight portion. Have
A straight line passing through the rotation centers of the first weight portion and the second weight portion and the circumferential center of the balance hole corresponds to the inner peripheral edge of the first weight portion and the second weight portion. On the other hand, the centers of the two intersections where the straight line intersects with the inner peripheral edge are shifted in the direction of the balance hole with respect to the center of rotation, while intersecting at two locations along the radial direction of the inner peripheral edge. The hermetic compressor according to 1.   The rotor has an oil passage which penetrates the iron core and is open on the upper surface of the rotor, and the balance weight is provided on the lower end surface of the iron core and communicated with the oil passage The hermetic compressor according to claim 1, having an oil return hole. A refrigerant pipe through which the refrigerant circulates and to which a radiator, an expansion device and an evaporator are connected;
The sealed compressor according to any one of claims 1 to 6, connected to the refrigerant pipe between the radiator and the evaporator.
Refrigeration cycle device equipped with.

Images