[Name of Document]

DESCRIPTION

[Title of Invention]

HERMETIC COMPRESSOR AND REFRIGERATION CYCLE DEVICE INCLUDING SAME

[Technical Field]

[0001] The present invention relates to a hermetic compressor, and a refrigeration cycle device including the hermetic compressor.

[Background Art]

[0002] In conventional rotary hermetic compressors, in order to prevent a rotor of a motor from vertically pulsating due to influence of magnetic pulsations, and colliding with an eccentric shaft part of the crankshaft and a bearing or an intermediate plate to cause abnormal sound, an upper end face of the rotor is displaced upward with respect to the upper end face of a stator to shift the magnetic center so that a downward force is always exerted on the rotor (see, for example, Patent Literature 1).

[0003] There are also compressors in which, in order to prevent a rotor from vertically pulsating due to differences in pressure pulsation within the compressor, and colliding with the eccentric shaft part of the crankshaft and the bearing or the intermediate plate to cause abnormal sound, a spring is provided in the gap between the bearing and the eccentric shaft part of the crankshaft to impart a downward thrust force (see, for example, Patent Literature 2). [Citation List] [Patent Literature]

[0004]

[Patent Literature 1] Japanese Examined Utility Model Registration Application Publication No. 1-024398 (page 4, Fig. 1)

[Patent Literature 2] Japanese Examined Patent Application Publication No. 7-103857 (page 4, Fig. 1)

[Summary of Invention]

[Technical Problem]

[0005] However, with a hermetic compressor in which the bearing is received within the counter bore provided in the rotor core to lower the center of gravity in order to suppress the vibration of the compressor, a problem exists in that a difference tends to occur between pressure pulsations within the counter bore and pressure pulsations within the upper space of the rotor, resulting in impossibility to suppress abnormal sound caused by the vertical motion of the rotor alone by the force caused by the shift of the magnetic center. The method of providing a spring between the bearing and the eccentric shaft part of the crankshaft has a problem in that not only the number of components increases, resulting in higher cost, but also it is difficult to ensure reliability owing to variations in spring force or changes of the spring force with time.

[0006] The present invention has been made to overcome the problems stated above. Accordingly, a first object of the present invention is to obtain a low-noise/low-vibration hermetic compressor that suppresses abnormal sound caused by the vertical motion of the rotor without increasing the number of components, and a refrigeration cycle device including the hermetic compressor.

[0007] A second object of the present invention is to obtain a highly efficient and highly reliable hermetic compressor that reduces the amount of refrigerating machine oil circulating within the refrigeration cycle, and a refrigeration cycle device including the hermetic compressor.

[Solution to Problem]

[0008] A hermetic compressor according to the present invention is a hermetic compressor including a compression mechanism part that compresses refrigerant gas, and an electric motor element part that drives the compression mechanism part, the hermetic compressor accommodating the compression mechanism part and the electric motor element part inside the hermetic compressor, in which a part of a main bearing of a crankshaft constituting the compression mechanism part is received inside a counter bore part, the counter bore part being provided in a rotor constituting the electric motor element part which is coaxially secured to the crankshaft, and the rotor includes an air hole that communicates with the counter bore part, the air hole being provided along an axial direction of the rotor from an upper end of the rotor.

[0009] A refrigeration cycle device according to the present invention includes the hermetic compressor according to the present invention.

[Advantageous Effects of Invention]

[0010] According to the present invention, the rotor includes an air hole provided along the axial direction of the rotor from the upper end of the rotor and communicating with the counter bore part. Therefore, it is possible to obtain a low-noise/low-vibration hermetic compressor that prevents the occurrence of a difference in pressure pulsation between the inside of the counter bore and the upper space of the rotor, and suppresses abnormal sound caused by the vertical motion of the rotor, and a refrigeration cycle device including the hermetic compressor.

[Brief Description of Drawings]

[0011] [Fig. 1] Fig. 1 is a cross-sectional view illustrating a hermetic compressor according to Embodiment 1 of the present invention.

[Fig. 2] Fig. 2 is a cross-sectional view illustrating a motor according to Embodiment 1 of the present invention.

[Fig. 3] Fig. 3 is a structural drawing illustrating a rotor according to Embodiment 1 of the present invention.

[Fig. 4] Fig. 4 is a structural drawing illustrating a rotor according to Embodiment 2 of the present invention.

[Fig. 5] Fig. 5 is a schematic diagram illustrating a refrigeration cycle according to Embodiment 2 of the present invention.

[Fig. 6] Fig. 6 is a cross-sectional view illustrating a hermetic compressor according to Embodiment 3 of the present invention.

[Fig. 7] Fig. 7 is a cross-sectional view illustrating a motor according to Embodiment 3 of the present invention.

[Fig. 8] Fig. 8 is a structural drawing illustrating a rotor according to Embodiment 3 of the present invention. [Description of Embodiments]

[0012] Embodiment 1 Fig. 1 is a cross-sectional view illustrating a hermetic compressor 100 according to Embodiment 1 of the present invention. With reference to Fig. 1, the overall configuration of the hermetic compressor 100 will be described. As the hermetic compressor 100, a two-cylinder rotary compressor will be described by way of example. In the hermetic compressor 100, a compression mechanism part 2 that compresses refrigerant, and an electric motor element part 3 that drives the compression mechanism part 2 are received within a hermetic container 1 that includes an upper container 1a, a middle container 1b, and a lower container 1c. The compression mechanism part 2 and the electric motor element part 3 are connected by a crankshaft 4. The compression mechanism part 2 is received in a lower part of the hermetic container 1, and the electric motor element part 3 is received in an upper part of the hermetic container 1.

[0013] As illustrated in Fig. 1, the electric motor element part 3 includes a stator 5 and a rotor 6. For example, the electric motor element part 3 is a brushless DC motor. Fig. 2 is a cross-sectional view illustrating a motor according to Embodiment 1 of the present invention. Fig. 3 is a structural drawing illustrating the rotor 6 according to Embodiment 1 of the present invention. The configuration of the electric motor element part 3 will be described with reference to Figs. 2 and 3.

[0014] The stator 5 includes a stator core 5a, slots 7, a slot insulation 8, a wedge 9, a winding 10, and a lead 11 (see Fig. 1). The stator core 5a is formed by laminating stator core sheets punched out from a thin magnetic steel sheet. The slots 7 are used for receiving the winding 10 in the stator core 5a. The slot insulation 8 is formed by a low oligomer film such as PET inserted into the slots 7 to provide electrical insulation between the stator core 5a and the winding 10. The wedge 9 is inserted between a slot opening, which is provided on the more central side than the stator 5 and used for inserting the winding 10 into the slots 7, and the winding 10 so that there is no leakage of the inserted winding 10 from the opening. The winding 10 is made of copper wires that are distributed-wound around multiple slots 7 and having an insulation coating that exhibits high reliability even in a refrigerant atmosphere (e.g. a multi-layered coating of polyester-imide and polyamide-imide). The lead 11 is connected to a power source.

[0015] The rotor 6 is formed by laminating rotor core sheets punched out from a thin magnetic steel sheet. The rotor 6 has a shaft hole 12 at the center for securing the rotor 6 by shrink-fitting onto the crankshaft 4 for transmitting a drive force to the compression mechanism part. A counter bore part 13 is provided at the end face of the rotor 6 corresponding to the compression mechanism part 2 side. The counter bore part 13 is larger in diameter than the shaft hole 12, and does not axially penetrate the rotor 6. The rotor 6 is provided with an air hole 14 (there are 12 air holes 14 in the example in Fig. 2). The air hole 14 communicates with the counter bore part 13 in an upper part of the counter bore part 13, and axially penetrates the rotor 6. In plan view, the air hole 14 is provided on the more central side than the sidewall of the counter bore part 13 of the rotor 6.

[0016] On the outer circumference side of the counter bore part 13, there are provided a rotor core 6a, a permanent magnet 15, an end plate 18, an upper balance weight 19a and a lower balance weight 19b, and a rivet 20. The rotor core 6a has a magnet insertion hole 16 in which the permanent magnet 15 is clearance-fitted, and a rivet hole 17 (an example of hole formed in the axial direction; there are four rivet holes 17 in the example in Fig. 2). The permanent magnet 15 (an Nd-Fe-B-based rare-earth magnet with a coating for preventing corrosion of the magnet applied to the magnet surface is used in this example) is inserted into the magnet insertion hole 16. The end plate 18 is arranged at both ends of the rotor core 6a and prevents scattering of the permanent magnet 15. The upper balance weight 19a (arranged at the upper end of the rotor core 6a in the hermetic compressor 100) and the lower balance weight 19b (arranged at the lower end of the rotor core 6a in the hermetic compressor 100) are used to reduce vibration of the compressor. The rivet 20 fixes the upper balance weight 19a, the lower balance weight 19b, and the rotor core 6a in place. Multiple slit-like air gaps 21 are provided on the outer circumference side of the magnet insertion hole 16. The air gaps 21 make the flux distribution of the permanent magnet 15 close to a sinusoidal one to reduce the harmonic components of the magnetic flux distribution, thereby suppressing noise during operation of the compressor. The rivet 20 is inserted into the rivet hole 17.

[0017] The upper balance weight 19a and the lower balance weight 19b may be shaped to be integrated with the end plate 18 so as to close the magnet insertion hole 16.

[0018] The axial center of the rotor 6 is shifted to the upper side with respect to the axial center of the stator 5. Therefore, a downward force is always exerted on the rotor 6 by the magnetic thrust generated by the shift of the magnetic center and the own weight of the rotor 6, thereby preventing the vertical motion of the rotor 6. Although the magnetic thrust due to the magnetic center can be made larger by increasing the amount of shift, the amount of effective magnetic flux that links the coil formed by the winding 10 in the stator 5 decreases, leading to performance deterioration.

[0019] The compression mechanism part 2 includes the crankshaft 4 having an eccentric shaft part 22 at two locations and to which the stator 5 is secured, an upper rolling piston 23a and a lower rolling piston 23b that are fitted to the eccentric shaft part 22 of the crankshaft 4, an upper cylinder 24a and a lower cylinder 24b that have cylinder chambers 2a in which the upper rolling piston 23a and the lower rolling piston 23b can move, respectively, and an unillustrated vane that reciprocates in the radial direction within a groove defined in each of the upper cylinder 24a and the lower cylinder 24b, and a compression chamber is defined by these components.

[0020] The openings at opposite axial ends of the upper cylinder 24a and lower cylinder 24b are closed by a main bearing 26 of the crankshaft 4 and an intermediate plate 25, and a sub bearing 27 of the crankshaft 4 and the intermediate plate 25, respectively. The main bearing 26 and the sub bearing 27 are provided with a discharge valve 28. A discharge muffler 29 for reducing the fluid sound of discharged refrigerant is positioned in each of the main bearing 26 and the sub bearing 27.

[0021] A passage 30 for refrigerating machine oil is defined in the crankshaft 4. The passage 30 extends upward from the lower end of the crankshaft 4. In a lower part of the passage 30, there is disposed a baffle plate 31 that pumps the refrigerating machine oil stored in a lower part of the hermetic container 1 upward along the passage 30, and oil supply holes are bored in portions that fit to the bearing (the main bearing 26, the sub bearing 27) and the rolling piston (the upper rolling piston 23a, the lower rolling piston 23b) in order to supply refrigerating machine oil. In an upper part of the passage 30, an opening (gas vent hole 32) is formed between the rotor 6 and the main bearing 26.

[0022] An accumulator 39 (see Fig. 5) that stores liquid refrigerant, and a suction muffler 33 having the function of muffling refrigerant sound are provided adjacent to the hermetic container 1. The suction muffler 33 is connected to the cylinder 24 by a suction connecting pipe 34.

[0023] Next, operation will be described. In the hermetic compressor 100 configured as described above, a low-pressure refrigerant sucked from the suction muffler 33 is compressed in the compression chamber within the cylinder. When the pressure of the compressed refrigerant becomes higher than the pressure inside the hermetic container 1, the resulting differential pressure causes the discharge valve 28 to open, and the refrigerant is discharged into the discharge muffler 29. The refrigerant passes through a discharge hole 29a for refrigerant (corresponding to a refrigerant outlet according to the present invention) bored in the discharge muffler 29. Then, through passages defined by the air hole 14 provided in the electric motor element part 3, the gap between the stator 5 and the hermetic container 1, the gap in the slots, and the gap between the stator 5 and the rotor 6, the refrigerant exits toward the upper space of the electric motor element part 3, and is sent out to a refrigeration cycle device from a discharge pipe 50 provided in the upper container 1 a.

[0024] As described above, the discharge operation of the compression mechanism part 2 causes pressure pulsations. Depending on the state of the refrigerant, the pressure pulsations become unevenly distributed within the hermetic container 1, and as the pressure difference varies continuously between the lower space and the upper space of the rotor 6, a force that vertically moves the rotor 6 is exerted, causing the crankshaft 4 secured to the rotor 6 to also move vertically together with the rotor 6. The eccentric shaft part 22 of the crankshaft 4, which is sandwiched by the bearing (the main bearing 26, the sub bearing 27) and the intermediate plate 25, has a clearance in the axial direction to allow lubrication with the refrigerating machine oil. Therefore, when vertical motion of the rotor 6 occurs, the eccentric shaft part 22 of the crankshaft 4 collides with the bearing (the main bearing 26, the sub bearing 27) or the intermediate plate 25, causing abnormal sound.

[0025] In contrast, in the hermetic compressor 100 according to Embodiment 1, in order to suppress the vibration of the compressor, the main bearing 26 is received within the counter bore part 13 of the rotor 6, and the rotor 6 includes the air hole 14 provided along the axial direction of the rotor 6 from the upper end of the rotor 6 and communicating with the counter bore part 13. Therefore, the occurrence of a difference in pressure pulsation between the inside of the counter bore part 13 and the upper space of the rotor 6 is prevented, and abnormal sound caused by the vertical motion of the rotor 6 can be suppressed, thereby reducing noise or vibration. Moreover, abnormal sound is suppressed even if the magnetic thrust caused by the shift of the magnetic center is small, thereby also achieving higher efficiency.

[0026] Embodiment 2 While Embodiment 1 is directed to a configuration that suppresses abnormal sound by providing the air hole 14 extending through the rotor 6 within the counter bore part 13 of the rotor 6, Embodiment 2 is directed to a configuration that reduces the amount of refrigerating machine oil circulating to the outside of the compressor when the amount of circulation is large.

[0027] Fig. 4 is a structural drawing illustrating a rotor 6 according to Embodiment 2 of the present invention. In Embodiment 2, an opening 13A is formed on the sidewall side of a counter bore part 13 of the rotor 6. The opening 13A faces and communicates with an air hole 14.

[0028] Fig. 5 is a schematic diagram illustrating a refrigeration cycle according to Embodiment 2 of the present invention. The refrigeration cycle is formed by sequentially connecting, via pipes, a hermetic compressor 100, a four-way switching valve 35 that switches the flow of refrigerant from the hermetic compressor 100, an outdoor-side heat exchanger 36, a pressure reducing device such as an electric expansion valve 37, an indoor-side heat exchanger 38, and an accumulator 39 that is connected to the suction side pipe of the hermetic compressor 100 and stores refrigerant.

[0029] Next, the operation of the refrigeration cycle configured as described above will be described in the order of a heating operation and a cooling operation.

[0030] First, when a heating operation is started, the four-way switching valve 35 is connected to the side indicated by solid lines in Fig. 5. Thus, a refrigerant at high temperature and high pressure that has been compressed in the hermetic compressor 100 flows to the indoor-side heat exchanger 38, and condenses and liquefies. Thereafter, the refrigerant is throttled by the electric expansion valve 37 into a two-phase state at low temperature and low pressure, and flows to the outdoor-side heat exchanger 36 where the refrigerant evaporates and gasifies. Then, the refrigerant passes through the four-way switching valve 35 and the accumulator 39, and returns to the hermetic compressor 100 again. That is, the refrigerant circulates as indicated by solid arrows in Fig. 5.

[0031] Next, when a cooling operation is started, the four-way switching valve 35 is connected to the side indicated by dotted lines in Fig. 5. Thus, a refrigerant at high temperature and high pressure that has been compressed in the hermetic compressor 100 flows to the outdoor-side heat exchanger 36, and condenses and liquefies. Thereafter, the refrigerant is throttled by the electric expansion valve 37 into a two-phase state at low temperature and low pressure, and flows to the indoor-side heat exchanger 38 where the refrigerant evaporates and gasifies. Then, the refrigerant passes through the four-way switching valve 35 and the accumulator 39, and returns to the hermetic compressor 100 again. That is, when a heating operation changes to a cooling operation, the indoor-side heat exchanger 38 changes from a condenser to an evaporator, and the outdoor-side heat exchanger 36 changes from an evaporator to a condenser. At this time, if the amount of circulation of oil is large, the refrigerating machine oil discharged from the hermetic compressor 100 stays in the outdoor-side heat exchanger 36, the indoor-side heat exchanger 38, or the like within the refrigeration cycle, causing deterioration of heat exchange efficiency.

[0032] In contrast, in the hermetic compressor 100 according to Embodiment 2, the opening 13Athat faces and communicates with the air hole 14 is formed on the sidewall side of the counter bore part 13 of the rotor 6. Therefore, the air hole 14 acts as a fin, and the refrigerating machine oil is centrifugally separated. As a result, the amount of circulation of oil can be reduced, thereby achieving higher efficiency of the refrigeration cycle using this compressor. Moreover, exhaustion of refrigerating machine oil is prevented, thereby improving the reliability of the compressor.

[0033] Embodiment 3 While Embodiment 1 is directed to a configuration that suppresses abnormal sound by providing the air hole 14 extending through the rotor 6 within the counter bore part 13 of the rotor 6, and Embodiment 2 is directed to a configuration that reduces the amount of circulation of oil, Embodiment 3 is directed to a configuration that reduces the amount of circulation of oil in a compressor having a structure in which the gas vent hole 32 provided in the crankshaft 4 is provided between the rotor 6 and the main bearing 26.

[0034] Fig. 6 is a cross-sectional view illustrating a hermetic compressor 100 according to Embodiment 3 of the present invention. With reference to Fig. 6, the general configuration of the hermetic compressor 100 will be described.

[0035] As the hermetic compressor 100, a one-cylinder rotary compressor will be described by way of example. In the hermetic compressor 100, a compression mechanism part 2 that compresses refrigerant, and an electric motor element part 3 that drives the compression mechanism part 2 are received within a hermetic container 1 that includes an upper container 1a and a lower container 1c. The compression mechanism part 2 and the electric motor element part 3 are connected by a crankshaft 4. The compression mechanism part 2 is received in a lower part of the hermetic container 1, and the electric motor element part 3 is received in an upper part of the hermetic container 1.

[0036] The electric motor element part 3 includes a stator 5 and a rotor 6. For example, the electric motor element part 3 is a brushless DC motor. Fig. 7 is a cross-sectional view illustrating a motor according to Embodiment 3 of the present invention. Fig. 8 is a structural drawing illustrating the rotor 6 according to Embodiment 3 of the present invention. The configuration of the electric motor element part 3 will be described with reference to the cross-sectional view of the motor in Fig. 7 and the structural drawing of the rotor in Fig. 8.

[0037] The stator includes a stator core 5a, slots 7, a slot insulation 8, a winding 10, and a terminal. The stator core 5a is formed by laminating stator core sheets punched out from a thin magnetic steel sheet. The slots 7 are used for receiving the winding 10 in the stator core 5a. The slot insulation 8 is fitted to multiple teeth, which are formed on the more central side than the stator core 5a, so as to be split in two in the axial direction, and is resin molded with engineering plastic such as LCP. The winding 10 is made of copper wires that are concentrated-wound around adjacent slots 7 and having an insulation coating that exhibits high reliability even in a refrigerant atmosphere (e.g. a multi-layered coating of polyester-imide and polyamide-imide). The terminal provides connection between the copper wires or between each copper wire and a lead 11 on the slot insulation 8.

[0038] The rotor 6 is formed by laminating rotor core sheets punched out from a thin magnetic steel sheet. The rotor 6 has a shaft hole 12 at the center for securing the rotor 6 by shrink-fitting onto the crankshaft 4 for transmitting a drive force to the compression mechanism part 2. A first counter bore part 13a is provided at the lower end face (end face corresponding to the compression mechanism part 2 side) of the rotor 6. The first counter bore part 13a is larger in diameter than the shaft hole 12, does not axially extend through the rotor 6, and communicates with an air hole 14. The air hole 14 (there are three air holes 14 in the example in Fig. 7) is provided on the more central side than the sidewall of the first counter bore part 13a. The air hole 14 is in the shape of an elongated hole that axially penetrates the rotor 6. Moreover, a second counter bore part 13b is provided above the first counter bore part 13a and on the more central side of the rotor 6 than the air hole 14. The second counter bore part 13b communicates with the air hole 14 via the first counter bore part 13a.

[0039] On the outer circumference side of the second counter bore part 13b, there are provided a rotor core 6a, a permanent magnet 15, an upper balance weight 19a and a lower balance weight 19b, and a rivet 20. The rotor core 6a has a magnet insertion hole 16 in which the permanent magnet 15 is clearance-fitted, and a rivet hole 17 (an example of hole formed in the axial direction; there are three rivet holes 17 in the example in Fig. 7). The permanent magnet 15 (a ferrite magnet is used in this example) is inserted into the magnet insertion hole 16. The upper balance weight 19a (arranged at the upper end of the rotor core 6a in the hermetic compressor 100) and the lower balance weight 19b (arranged at the lower end of the rotor core 6a in the hermetic compressor 100) are arranged at opposite ends of the rotor core 6a, and each double as an end plate 18 that prevents scattering of the permanent magnet 15. The rivet 20 fixes the upper balance weight 19a, the lower balance weight 19b, and the rotor core 6a in place. The rivet 20 is inserted into the rivet hole 17.

[0040] A ferrite magnet has a low remanent magnetic flux density in comparison to a rare-earth magnet. Accordingly, in Embodiment 3, the amount of magnetic flux that links the winding 10 of the rotor 6 is improved by making the axial length of the rotor 6 large in comparison to the stator 5. The upper balance weight 19a and the lower balance weight 19b may be parts separate from the end plate 18.

[0041] The axial center of the rotor 6 is shifted to the upper side with respect to the axial center of the stator 5. Therefore, a downward force is always exerted on the rotor 6 by the magnetic thrust generated by the shift of the magnetic center and the own weight of the rotor 6, thereby preventing the vertical motion of the rotor 6. As described above, a ferrite magnet has a low remanent magnetic flux density in comparison to a rare-earth magnet, resulting in small magnetic thrust in comparison to a rare-earth magnet, which reduces the effect of suppressing abnormal sound caused by a difference in pressure pulsation. In contrast, in Embodiment 3, the rotor 6 includes the air hole 14 provided along the axial direction of the rotor 6 from the upper end of the rotor 6 and communicating with the counter bore part 13. Therefore, abnormal sound caused by a difference in pressure pulsation can be suppressed.

[0042] In the compression mechanism part 2, a compression chamber is defined by the crankshaft 4 having an eccentric shaft part 22 at one location and to which the stator 5 is secured, a rolling piston 23 that is fitted to the eccentric shaft part 22 of the crankshaft 4, a cylinder 24 having a cylinder chamber in which the rolling piston 23 can move, and an unillustrated vane that reciprocates in the radial direction within a groove provided in the cylinder 24.

[0043] The openings at opposite axial ends of the cylinder 24 are closed by a main bearing 26 and a sub bearing 27 of the crankshaft 4, respectively. The main bearing 26 is provided with a discharge valve 28. A discharge muffler 29 for reducing the fluid sound of discharged refrigerant is positioned in the main bearing 26. A discharge hole 29a for blowing out gas upward is formed in the discharge muffler 29. The discharge hole 29a is located on the more outer side than the sidewall of the first counter bore part 13a and the side wall of the second counter bore part 13b. Moreover, the area of a passage defined by the gap between the first counter bore part 13a and the main bearing 26 is larger than the area of a passage defined by the gap between the second counter bore part 13b and the crankshaft 4.

[0044] A passage 30 for refrigerating machine oil is defined in the crankshaft 4. The passage 30 extends upward from the lower end of the crankshaft 4. In a lower part of the passage 30, there is disposed a baffle plate 31 that pumps the refrigerating machine oil stored in a lower part of the hermetic container 1 upward along the passage 30, and oil supply holes are bored in portions that fit to the main bearing 26, the sub bearing 27, and the rolling piston 23 in order to supply refrigerating machine oil. In an upper part of the passage 30, an opening (gas vent hole 32) is formed between the rotor 6 and the main bearing 26. The height position of the gas vent hole 32 is substantially the same as the height position of the second counter bore part 13b.

[0045] As illustrated in Fig. 5, an accumulator that stores liquid refrigerant, and a suction muffler 33 having the function of muffling refrigerant sound are provided adjacent to the hermetic container 1. The suction muffler 33 is connected to the cylinder 24 by a suction connecting pipe 34.

[0046] Next, operation will be described. In the hermetic compressor 100 configured as described above, as the crankshaft 4 rotates, the refrigerating machine oil sealed in the hermetic container 1 is pumped to the upper part of the passage 30 from the lower end of the passage 30 by the pumping action of the baffle plate 31 that rotates together with the crankshaft 4, and the refrigerating machine oil is supplied to the compression mechanism part 2 and other sliding parts to thereby maintain the air-tightness of each sliding part and exert a lubricating action. Then, excess refrigerating machine oil passes through the gas vent hole 32, and is released into the second counter bore part 13b of the rotor 6. At this time, the rotation of the crankshaft 4 causes a centrifugal force to act on the excess refrigerating machine oil released into the second counter bore part 13b. Under this centrifugal force, the refrigerating machine oil strongly collides with the sidewall surface of the second counter bore part 13b, and coagulates on the wall surface and drops downward by gravity.

[0047] As described above, in the hermetic compressor 100 according to Embodiment 3, the first counter bore part 13a is provided at the lower end face (end face corresponding to the compression mechanism part 2 side) of the rotor 6, and the second counter bore part 13b that does not communicate with the air hole 14 is provided above the first counter bore part 13a and on the more central side of the rotor 6 than the air hole 14. The height position of the gas vent hole 32 is set to be substantially the same as the height position of the second counter bore part 13b. This makes it possible to prevent the refrigerating machine oil released from the passage 30 of the crankshaft 4 from being whirled up by the refrigerant gas ascending within the hermetic container 1. That is, because the refrigerating machine oil is released from the passage 30 in the form of a spray, the refrigerating machine oil is likely to rise with the ascending current of refrigerant gas. However, the refrigerating machine oil coagulates on the wall surface and turns into droplets, which makes the refrigerating machine oil less likely to rise with this ascending current. Therefore, the amount of refrigerating machine oil that is released to the refrigeration cycle device from the inside of the hermetic container 1 through the discharge pipe 50 can be reduced, thereby preventing performance degradation of the refrigeration cycle device and performance degradation of the compressor itself caused by an increase in the amount of circulation of oil. In a case where the refrigerant gas is dissolved in the refrigerating machine oil in the cylinder chamber 2a or the like of the compression mechanism part 2, as this refrigerating machine oil collides with the sidewall surface of the second counter bore part 13b, the refrigerant gas and the refrigerating machine oil are separated. Therefore, the refrigerating machine oil is returned to the state in which its original air-tightness performance and lubrication performance are maintained, and its function as refrigerating machine oil is recovered, thereby indirectly preventing performance degradation of the compressor.

[0048] Moreover, in the hermetic compressor 100 according to Embodiment 3, the discharge hole 29a is provided on the more outer side than the sidewall of each of the first counter bore part 13a and the second counter bore part 13b. Therefore, gas that is ejected upward hits the lower surface of the rotor 6. As a result, it is possible to prevent an ascending current of refrigerant gas, and further reduce the amount of circulation of oil, thereby improving the efficiency of the refrigeration cycle using this compressor. Moreover, exhaustion of refrigerating machine oil is prevented, thereby improving the reliability of the compressor.

[0049] Moreover, in the hermetic compressor 100 according to Embodiment 3, the area of the passage defined by the gap between the first counter bore part 13a and the main bearing 26 is larger than the area of the passage defined by the gap between the second counter bore part 13b and the crankshaft 4. As a result, the velocity of flow of the ascending current of refrigerant passing through the air hole 14 provided within the first counter bore part 13a can be lowered to reduce the influence of the ascending current on the second counter bore part 13b, and the amount of circulation of oil can be further reduced, thereby improving the efficiency of the refrigeration cycle using this compressor. Moreover, exhaustion of refrigerating machine oil is prevented, thereby improving the reliability of the compressor.

[Reference Signs List]

[0050] 1: hermetic container, 1a: upper container, 1b: middle container, 1c: lower container, 2: compression mechanism part, 2a: cylinder chamber, 3: electric motor element part, 4: crankshaft, 5: stator, 5a: stator core, 6: rotor, 6a: rotor core, 7: slot, 8: slot insulation, 9: wedge, 10: winding, 11: lead, 12: shaft hole, 13: counter bore part, 13A: opening, 13a: first counter bore part, 13b: second counter bore part, 14: air hole, 15: permanent magnet, 16: magnet insertion hole, 17: rivet hole, 18: end plate, 19: balance weight, 19a: upper balance weight, 19b: lower balance weight, 20: rivet, 21: air gap, 22: eccentric shaft part, 23: rolling piston, 23a: upper rolling piston, 23b: lower rolling piston, 24: cylinder, 24a: upper cylinder, 24b: lower cylinder, 25: intermediate plate, 26: main bearing, 27: sub bearing, 28: discharge valve, 29: discharge muffler, 29a: discharge hole of discharge muffler, 30: passage for refrigerating machine oil, 31: baffle plate, 32: gas vent hole, 33: suction muffler, 34: suction connecting pipe, 35: four-way switching valve, 36: outdoor-side heat exchanger, 37: electric expansion valve, 38: indoor-side heat exchanger, 39: accumulator, 50: discharge pipe, 100: hermetic compressor

[Name of Document]

CLAIMS

[Claim 1] A hermetic compressor comprising: a compression mechanism part that compresses refrigerant gas; and an electric motor element part that drives the compression mechanism part, the hermetic compressor accommodating the compression mechanism part and the electric motor element part inside the hermetic compressor, wherein a part of a main bearing of a crankshaft constituting the compression mechanism part is received inside a counter bore part, the counter bore part being provided in a rotor constituting the electric motor element part which is coaxially secured to the crankshaft, and the rotor includes an air hole that communicates with the counter bore part, the air hole being provided along an axial direction of the rotor from an upper end of the rotor.

[Claim 2] The hermetic compressor of claim 1, wherein in plan view, the air hole is provided on a more central side than a sidewall of the counter bore part of the rotor.

[Claim 3] The hermetic compressor of claim 1, wherein in the counter bore part of the rotor, an opening that faces and communicates with the air hole is formed on a sidewall side of the counter bore part.

[Claim 4] The hermetic compressor of claim 3, wherein: the counter bore part includes a first counter bore part that is provided at a lower end face of the rotor, the first counter bore part communicating with the air hole, and a second counter bore part that is provided above the first counter bore part, the second counter bore part communicating with the air hole via the first counter bore part; a gas vent hole is formed in the crankshaft, the gas vent hole establishing communication between a passage of refrigerating machine oil defined inside the crankshaft, and a side face of the crankshaft; and a height position of the gas vent hole is substantially the same as a height position of the second counter bore part.

[Claim 5] The hermetic compressor of any one of claims 1 to 4, wherein a refrigerant outlet of a discharge muffler provided to the compression mechanism part is provided on a more outer side than a side wall of the counter bore part.

[Claim 6] The hermetic compressor of claim 4 or claim 5 as dependent on claim 4, wherein an area of a passage defined by a gap between the first counter bore part and the main bearing is larger than an area of a passage defined by a gap between the second counter bore part and the crankshaft.

[Claim 7] A refrigeration cycle device comprising the hermetic compressor of any one of claims 1 to 6.