JP2013076332A - Hermetic compressor and refrigerating cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lubricate sliding portions of a compression mechanism part by a low-cost and simple structure, and to prevent the occurrence of seizure due to the shortage of lubricating oil guided to the sliding portions.SOLUTION: A hermetic compressor 2 includes a working fluid suction passage 28 for guiding the working fluid in a sealed case 7 to the compression mechanism part 9, and a lubricating oil suction passage one end of which communicates with the working fluid suction passage 28 and the other end of which is immersed in the lubricating oil reserved at the bottom of the sealed case 7. The lubricating oil contained in the working fluid compressed by the compression mechanism part is guided to the compression mechanism part 9 after being separated by an oil separator 3, and lubricates the sliding portions in the compression mechanism part 9. The hermetic compressor 2 includes a control part 15 which makes continue the operation of the compression mechanism part 9 for a second operation time at a second operation frequency higher in frequency than a first operation frequency when the operation of the compression mechanism part 9 continues for a first operation time at an operation frequency of equal to or less than the first operation frequency.

Description

  Embodiments described herein relate generally to a hermetic compressor and a refrigeration cycle apparatus using the hermetic compressor.

  An electric motor part and a compression mechanism driven by the electric motor part are accommodated in a sealed case storing lubricating oil at the bottom, and a circulating gas refrigerant (working fluid) is once flowed into the sealed case, As a hermetic compressor that introduces and compresses the gas refrigerant that has flowed into the compression mechanism, for example, the one described in Patent Document 1 below is known.

  In the hermetic compressor described in Patent Document 1, a positive displacement oil pump is provided at the lower portion of the compression mechanism portion, and lubricating oil stored at the bottom of the hermetic case is supplied to the compression mechanism portion using the positive displacement oil pump. doing. The lubricating oil supplied to the compression mechanism is guided to the oil separator together with the gas refrigerant compressed by the compression mechanism, and after being separated by the oil separator, is guided to the compression mechanism. Lubricate.

  The lubricating oil guided to the compression mechanism after being separated by the oil separator is higher than the pressure in the sealed case, and the sliding part is caused by the differential pressure between the pressure in the sealed case and the pressure of the lubricating oil. Passes and is discharged into the sealed case. The lubricating oil discharged into the sealed case becomes part of the lubricating oil stored at the bottom of the sealed case, and is supplied again to the compression mechanism using a positive displacement oil pump.

JP 2011-58472 A

  However, since the hermetic compressor described in Patent Document 1 uses a positive displacement oil pump, the cost is high.

  An object of an embodiment of the present invention is that the sliding portion of the compression mechanism portion can be lubricated by an inexpensive and simple structure, and further, seizure occurs due to insufficient lubricating oil guided to the sliding portion. It is an object of the present invention to provide a hermetic compressor and a refrigeration cycle apparatus using the hermetic compressor.

  According to the hermetic compressor of the embodiment, the electric motor unit and the compression mechanism unit driven by the electric motor unit are housed in the hermetic case in which lubricating oil is stored in the bottom, and the operation is guided to the space in the hermetic case. A working fluid suction passage is provided to guide the fluid to the compression mechanism, and one end is connected to the working fluid suction passage and the other end is provided with a lubricating oil suction passage immersed in the lubricating oil stored in the bottom of the sealed case. In the hermetic compressor, the lubricating oil contained in the working fluid compressed by the compression mechanism is separated by the oil separator and then guided to the compression mechanism to lubricate the sliding portion in the compression mechanism. When the operation of the part is continued for the first operation time at an operation frequency equal to or lower than the first operation frequency, the control unit for continuing the operation of the compression mechanism unit at the second operation frequency having a frequency higher than the first operation frequency. Is provided.

It is the schematic of the refrigerating-cycle apparatus containing the hermetic compressor of 1st Embodiment. It is a graph which shows the relationship between the operating frequency of a compression mechanism part, and the suction | inhalation amount of the lubricating oil in a cylinder chamber. It is a graph which shows the control content of the driving frequency by a control part. It is a graph which shows the relationship between the discharge | emission amount of the lubricating oil from a sliding part, and differential pressure | voltage in 2nd Embodiment. It is a table | surface which shows the control content of the driving frequency by a control part. It is a table | surface which shows the control content of the operating frequency by a control part in 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
1st Embodiment is described based on FIG. 1 thru | or FIG. As shown in FIG. 1, the refrigeration cycle apparatus 1 includes a hermetic compressor 2, an oil separator 3 connected to the hermetic compressor 2, a condenser 4 connected to the oil separator 3, and a condenser. 4, and an evaporator 6 connected between the expansion device 5 and the hermetic compressor 2. In this refrigeration cycle apparatus 1, the refrigerant that is the working fluid circulates while changing in phase between a gaseous gas refrigerant and a liquid liquid refrigerant, and is dissipated in the process of phase change from the gas refrigerant to the liquid refrigerant. Heat is absorbed during the phase change of the gas refrigerant, and heating, cooling, heating, cooling, and the like are performed using these heat dissipation and heat absorption.

  The hermetic compressor 2 has an airtight sealed case 7 formed in a substantially cylindrical shape, and an electric motor part 8 and a compression mechanism part 9 for compressing a gas refrigerant are accommodated in the sealed case 7. The sealed case 7 is installed with the center of the cylinder directed in the vertical direction, the electric motor unit 8 is disposed on the upper side in the sealed case 7, and the compression mechanism unit 9 is disposed below the motor unit 8. Lubricating oil is stored at the bottom of the sealed case 7. The space in the sealed case 7 is filled with the gas refrigerant before being compressed by the compression mechanism unit 9.

  The electric motor unit 8 includes a stator 10, a rotor 11, a rotation shaft 12, and a connection terminal unit 13. The stator 10 is formed in a cylindrical shape, and is fixed to the inner peripheral portion of the sealed case 7 by shrink fitting, press fitting, welding, or the like. The rotor 11 is rotatably inserted inside the stator 10, and a rotating shaft 12 is fitted to the center of the rotor 11. The rotary shaft 12 is rotatably supported by later-described bearings (main bearing 22 and sub-bearing 23) provided in the compression mechanism unit 9, and the rotary shaft 12 and the rotor 11 rotate integrally. A lead wire (not shown), an inverter 14 that varies the operating frequency of the compression mechanism unit 9, and a control unit 15 that drives the inverter 14 are connected to the connection terminal unit 13.

  The rotating shaft 12 is formed with two eccentric portions 16 and 17 that are eccentrically projected toward the outer peripheral side of the rotating shaft 12. The eccentric parts 16 and 17 are formed at positions spaced apart by a set dimension along the axial direction of the rotary shaft 12 and at positions spaced 180 ° along the rotational direction of the rotary shaft 12.

  The compression mechanism unit 9 is a part that compresses a low-pressure gas refrigerant into a high-pressure / high-temperature gas refrigerant. The compression mechanism unit 9 is a pair of cylinders 18 and 19 arranged above and below, and an upper and lower arranged between the cylinders 18 and 19. It has a pair of partition plates 20, 21, a main bearing 22 disposed above one cylinder 18, and a sub-bearing 23 disposed below the other cylinder 19.

  In one cylinder 18, a cylinder chamber 24 whose upper end side is closed by a main bearing 22 and whose lower end side is closed by a partition plate 20 is formed. In the other cylinder 19 is formed a cylinder chamber 25 whose upper end is closed by a partition plate 21 and whose lower end is closed by a sub-bearing 23.

  The rotating shaft 12 is inserted into the cylinder chambers 24 and 25, and one eccentric portion 16 formed on the rotating shaft 12 is located in the cylinder chamber 24, and the other eccentric portion 17 formed on the rotating shaft 12 is the cylinder chamber. 25. A roller 26 is fitted to the eccentric part 16, and a roller 27 is fitted to the eccentric part 17. These rollers 26 and 27 roll in the cylinder chambers 24 and 25 while a part of the outer peripheral portion is brought into contact with the inner peripheral surfaces of the cylinder chambers 24 and 25 as the rotary shaft 12 rotates.

  Further, a blade (not shown) is slidably provided in the cylinder chambers 24 and 25, and the tip of the blade is urged by an urging body such as a spring to the outer peripheral surfaces of the rollers 26 and 27. It is in contact. A part of the outer peripheral surface of the rollers 26 and 27 is brought into contact with the inner peripheral surface of the cylinder chambers 24 and 25, and the tip of the blade is brought into contact with the outer peripheral surface of the rollers 26 and 27. The interior is partitioned into two spaces whose volumes vary as the rollers 26 and 26 roll. The gas refrigerant flows into one space, and the volume of the space decreases as the rollers 26 and 27 roll, whereby the gas refrigerant in the space is compressed.

  Between the cylinder chambers 24 and 25 and the space in the sealed case 7, a gas refrigerant passage 28, which is a working fluid suction passage for sucking and guiding the gas refrigerant in the space in the sealed case 7 into the cylinder chambers 24 and 25, is provided. It has been. The auxiliary bearing 23, the cylinder 19, the partition plates 20, 21, and the cylinder 18 have one end communicating with the gas refrigerant passage 28 and the other end immersed in the lubricating oil stored in the sealed case 7. 29 is formed.

  The partition plates 20 and 21 are formed with discharge chambers 30 into which gas refrigerant compressed in the cylinder chambers 24 and 25 is discharged. A discharge valve 31 is provided between the cylinder chambers 24 and 25 and the discharge chamber 30 that is opened when the pressure of the gas refrigerant in the cylinder chambers 24 and 25 rises to a predetermined value. Connected between the discharge chamber 30 and the oil separator 3 is a discharge pipe 32 that guides the gas refrigerant discharged to the discharge chamber 30 after being compressed in the cylinder chambers 24 and 25 to the oil separator 3. In the oil separator 3, the lubricating oil contained in the gas refrigerant compressed in the cylinder chambers 24 and 25 is separated.

  Further, the partition plates 20 and 21 are formed with a lubricant return chamber 33 into which the lubricant separated by the oil separator 3 is guided. An oil return pipe 34 is connected between the lubricating oil return chamber 33 and the lower portion of the oil separator 3 to guide the lubricating oil separated from the gas refrigerant in the oil separator 3 to the lubricating oil return chamber 33. Yes. The lubricating oil guided to the lubricating oil return chamber 33 via the oil return pipe 34 is used for lubricating the sliding portion of the compression mechanism unit 9.

  In the condenser 4, the gas refrigerant from which the lubricating oil has been separated in the oil separator 3 is condensed and becomes a liquid refrigerant.

  In the expansion device 5, the liquid refrigerant condensed in the condenser 4 is decompressed.

  In the evaporator 6, the liquid refrigerant decompressed by the expansion device 5 evaporates and becomes a gas refrigerant.

  The gas refrigerant evaporated in the evaporator 6 is guided to the space in the sealed case 7 via the suction pipe 35 connecting the evaporator 6 and the hermetic compressor 2.

  In such a configuration, when the electric motor unit 8 is driven and the rotating shaft 12 rotates, the gas refrigerant in the space in the sealed case 7 flows through the gas refrigerant passage 28 and is sucked into the cylinder chambers 24 and 25. The diluted gas refrigerant is compressed in the cylinder chambers 24 and 25. When the gas refrigerant flows through the gas refrigerant passage 28, the lubricating oil stored at the bottom in the sealed case 7 is sucked into the gas refrigerant passage 28 through the lubricating oil suction passage 29, and the sucked lubricating oil is gas It is sucked into the cylinder chambers 24 and 25 together with the refrigerant.

  The lubricating oil sucked into the cylinder chambers 24 and 25 is guided into the oil separator 3 together with the gas refrigerant compressed in the cylinder chambers 24 and 25, and the lubricating oil is separated from the gas refrigerant in the oil separator 3. The The lubricating oil separated in the oil separator 3 has a high pressure, and the high-pressure lubricating oil is guided to the oil return chamber 33 through the oil return pipe 34, and the sliding portion of the compression mechanism unit 9 from the oil return chamber 33. For example, it is used for lubrication of a sliding portion between the main bearing 22 or the sub bearing 23 and the rotary shaft 12. The lubricating oil used to lubricate the sliding portion is higher than the pressure inside the sealed case 7, and the lubricating oil that lubricates the sliding portion is the differential pressure “ΔP (MPa) between the pressure of the lubricating oil and the pressure inside the sealed case 7. ) ”Passes through the sliding portion and moves toward the space in the sealed case 7, lubricates the sliding portion, and then is discharged into the space in the sealed case 7. The lubricating oil discharged into the space in the sealed case 7 is stored at the bottom of the sealed case 7 and is sucked into the cylinder chambers 24 and 25 again through the lubricating oil suction passage 29.

  Accordingly, the inside of the sealed case 7 has a simple and inexpensive structure in which one end is connected to the gas refrigerant passage 28 and the other end is provided with the lubricating oil suction passage 29 immersed in the lubricating oil stored in the bottom of the sealed case 7. The sliding portion of the compression mechanism portion 9 can be lubricated using a lubricant store stored at the bottom of the compressor.

  Here, FIG. 2 is a graph showing the relationship between the operating frequency of the compression mechanism section 9 and the amount of lubricating oil sucked into the cylinder chambers 24 and 25 through the lubricating oil suction passage 29. When the operating frequency of the compression mechanism unit 9 increases, the amount of lubricating oil sucked into the cylinder chambers 24 and 25 increases in a quadratic function. This is because the flow rate of the gas refrigerant flowing through the gas refrigerant passage 28 increases as the operating frequency of the compression mechanism 9 increases, and the amount of lubricating oil sucked through the lubricating oil suction passage 29 is increased accordingly. This is because it increases.

  For this reason, when the compression mechanism 9 is operated at a low operating frequency, it is sucked into the gas refrigerant passage 28 through the lubricating oil suction passage 29 and further into the cylinder chambers 24, 25. The amount of lubricating oil that is sucked is reduced.

  When the amount of the lubricating oil sucked into the cylinder chambers 24 and 25 is small, the amount of the lubricating oil guided into the oil separator 3 together with the compressed gas refrigerant is reduced, and the lubrication separated in the oil separator 3 is achieved. The amount of oil is reduced. Accordingly, the amount of lubrication guided to the lubricating oil return chamber 33 after being separated in the oil separator 3 is reduced, and the amount of lubricating oil guided to the sliding portion of the compression mechanism portion 9 is reduced. May cause seizure.

  Therefore, as shown in FIG. 3, the control unit 15 controls the operation frequency of the compression mechanism unit 9, and the operation of the compression mechanism unit 9 is performed at a first operation time “T1” at an operation frequency equal to or lower than the first operation frequency “X”. “If continued, the second operating time“ T2 ”compression mechanism unit 9 is operated at a second operating frequency“ Y ”that is higher than the first operating frequency“ X ”. As a result, even when the amount of lubricating oil sucked into the cylinder chambers 24 and 25 through the lubricating oil suction passage 29 during operation at the first operating frequency “X” or less is small, the second operation is performed. During operation at the frequency “Y”, the amount of lubricating oil sucked into the cylinder chambers 24 and 25 through the lubricating oil suction passage 29 can be increased, and the oil separator 3 from the cylinder chambers 24 and 25 can be increased. The amount of lubricating oil introduced into the inside can be increased. Therefore, the amount of lubricating oil separated in the oil separator 3 can be increased, and the lubricating oil guided to the sliding portion of the compression mechanism portion 9 after being separated in the oil separator 3 is insufficient. The occurrence of a situation where the sliding portion of the compression mechanism portion 9 causes seizure due to the lack of lubricating oil can be prevented.

  Here, the first operation frequency “X”, the second operation frequency “Y”, the first operation time “T1”, and the second operation time “T2” are appropriately determined according to the size and performance of the hermetic compressor 2. The value to be set.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIGS. Note that, in the second embodiment and subsequent embodiments, the same components as those described in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted. Moreover, the external configuration of the hermetic compressor 2 and the refrigeration cycle apparatus 1 of the second embodiment will be described with reference to FIG.

  The amount of lubricating oil discharged into the space in the sealed case 7 after the sliding portion of the compression mechanism 9 is lubricated, the pressure of the lubricating oil guided from the oil separator 3 to lubricate the sliding portion, and the sealed case The relationship between the pressure difference 7 and the pressure difference “ΔP (MPa)” is as shown in the graph of FIG. According to the graph of FIG. 4, it can be seen that as the differential pressure “ΔP” increases, the amount of lubricating oil discharged into the space in the sealed case 7 after lubricating the sliding portion increases.

  Therefore, in the control unit 15 of the second embodiment, as shown in the table of FIG. 5, the first operation time “T1” operated at the operation frequency equal to or lower than the first operation frequency “X” is set to the differential pressure “ΔP”. The control to change is performed.

  Specifically, when the differential pressure “ΔP” is 0 to less than 1, “T1” is set to 15 minutes, and when the differential pressure “ΔP” is 1 to less than 2, “T1” is set to 10 minutes. When the differential pressure “ΔP” is 2 or more, “T1” is set to 5 minutes.

  Further, the differential pressure “ΔP” is estimated by the control unit 15 based on the measurement result of the temperature sensor that measures the temperature of the condenser 4 and the measurement result of the temperature sensor that measures the temperature of the evaporator 6.

  In such a configuration, in the second embodiment, the first operation duration “T1” at the operation frequency equal to or lower than the first operation frequency “X” is changed in accordance with the differential pressure “ΔP” to change the differential pressure “ΔP”. The first operation time “T1” is shortened as ΔP ”increases. As a result, when the differential pressure “ΔP” becomes large, the amount of lubricating oil sucked into the cylinder chambers 24 and 25 through the lubricating oil suction passage 29 is small, and the operation is performed at the first operating frequency “X” or less. The first operation time “T1” operated at the frequency becomes shorter, and the second operation time “T2” operated at the second operation frequency “Y” where the amount of the lubricating oil sucked into the cylinder chambers 24 and 25 is large. The ratio is high. For this reason, even when the amount of lubricating oil discharged from the sliding portion into the space in the sealed case 7 is large because the differential pressure “ΔP” is large, the operation is performed at an operation frequency equal to or lower than the first operation frequency “X”. By shortening the first operating time “T1”, it is possible to prevent occurrence of a situation where the lubricating oil guided to the sliding portion of the compression mechanism portion 9 after being separated in the oil separator 3 is insufficient. . For this reason, it is possible to prevent the sliding portion of the compression mechanism portion 9 from being seized due to lack of lubricating oil.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG. In the third embodiment, as shown in the table of FIG. 6, the value of the first operating frequency “X” is changed according to the differential pressure “ΔP”.

  Specifically, when the differential pressure “ΔP” is 0 to less than 1, the first operating frequency is “Xa”, and when the differential pressure “ΔP” is 1 or more to less than 2, the first operating frequency is set. Is “Xb (where Xa <Xb)” and the differential pressure “ΔP” is 2 or more, the first operating frequency is “Xc (where Xb <Xc)”. The first operating frequencies “Xa”, “Xb”, and “Xc” are values that are appropriately set according to the size and performance of the hermetic compressor 2.

  In such a configuration, in the third embodiment, the first operating frequency is changed to “Xa”, “Xb”, “Xc” according to the differential pressure “ΔP”, and as the differential pressure “ΔP” increases. The first operating frequency “X” is increased. For this reason, even when the amount of lubricating oil discharged from the sliding portion to the space in the sealed case 7 is large because the differential pressure “ΔP” is large, the cylinder chambers 24, 25 pass through the lubricating oil suction passage 29. The amount of lubricating oil sucked into the inside can be increased, and the amount of lubricating oil introduced into the oil separator 3 from the cylinder chambers 24 and 25 can be increased. Therefore, the amount of lubricating oil separated in the oil separator 3 can be increased, and the lubricating oil guided to the sliding portion of the compression mechanism portion 9 after being separated in the oil separator 3 is insufficient. Can be prevented. For this reason. Generation | occurrence | production of the situation where a sliding part of the compression mechanism part 9 raise | generates by the lack of lubricating oil can be prevented.

  According to each embodiment described above, the operation frequency of the compression mechanism unit 9 is controlled by the control unit 15, and the first operation time “T1” is operated at an operation frequency equal to or lower than the first operation frequency “X”. When the operation is continued, the operation of the compression mechanism unit 9 is continued for the second operation time “T2” at the second operation frequency “Y”, which is higher than the first operation frequency “X”. As a result, even when the amount of lubricating oil sucked into the cylinder chambers 24 and 25 through the lubricating oil suction passage 29 during operation at the operating frequency equal to or lower than the first operating frequency “X” is small, The amount of lubricating oil sucked into the cylinder chambers 24 and 25 through the lubricating oil suction passage 29 during operation at the two operating frequency “Y” can be increased, and the oil separator 3 from the cylinder chambers 24 and 25 can be increased. The amount of lubricating oil introduced into the inside can be increased. Therefore, even if it is a simple and inexpensive configuration in which one end is in communication with the gas refrigerant passage 28 and the other end is provided with a lubricating oil suction passage 29 that is immersed in the lubricating oil stored in the bottom of the sealed case 7, The occurrence of a situation where the lubricating oil guided to the sliding portion of the mechanism portion is insufficient can be prevented, and the occurrence of a situation where the sliding portion of the compression mechanism portion 9 is seized due to the lack of the lubricating oil can be prevented. it can.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Refrigeration cycle apparatus, 2 ... Sealed compressor, 3 ... Oil separator, 4 ... Condenser, 5 ... Expansion device, 6 ... Evaporator, 7 ... Sealed case, 8 ... Electric motor part, 9 ... Compression mechanism part, DESCRIPTION OF SYMBOLS 15 ... Control part, 28 ... Gas refrigerant path (working fluid suction path), 29 ... Lubricating oil suction path

Claims (4)

A working fluid in which a motor part and a compression mechanism driven by the motor part are housed in a sealed case in which lubricating oil is stored at the bottom, and a working fluid guided to a space in the sealed case is guided to the compression mechanism part A suction passage is provided, one end is connected to the working fluid suction passage, and the other end is provided with a lubricant suction passage immersed in the lubricant stored in the bottom of the sealed case, and compressed by the compression mechanism. In a hermetic compressor in which the lubricating oil contained in the working fluid is separated by an oil separator and guided to the compression mechanism unit to lubricate the sliding portion in the compression mechanism unit.
When the operation of the compression mechanism unit is continued for a first operation time at an operation frequency equal to or lower than the first operation frequency, the operation of the compression mechanism unit is performed for a second operation time at a second operation frequency higher than the first operation frequency. A hermetic compressor provided with a control unit for continuing.   The control unit changes the first operating time based on a differential pressure between a pressure in the sealed case and a pressure of lubricating oil separated by the oil separator and guided to the compression mechanism, and the differential pressure 2. The hermetic compressor according to claim 1, wherein the first operation time is shortened as the value increases.   The control unit changes the first operating frequency based on a differential pressure between a pressure in the sealed case and a pressure of lubricating oil separated by the oil separator and guided to the compression mechanism unit, and the differential pressure 2. The hermetic compressor according to claim 1, wherein the first operating frequency is increased as the value increases. The hermetic compressor according to any one of claims 1 to 3, a condenser connected to the hermetic compressor, an expansion device connected to the condenser, the expansion device and the hermetic type A refrigeration cycle apparatus including an evaporator connected to a compressor.