JP2006258002A - Hermetic compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hermetic compressor, for preventing oil shortage in a sliding portion of each member. <P>SOLUTION: In this hermetic compressor, an electric motor part and a compression mechanism part connected with the electric motor part through a rotational shaft are housed in a sealed case in which lubricating oil is stored in its bottom part, refrigerant is sucked into the compression mechanism part through a space in the sealed case, an oil separator is connected with a discharge passage, and the lubricating oil separated by the oil separator is supplied into the sliding portion of the compression mechanism part. An oil level of the lubricating oil of the sealed case in the stop is set to be higher than an opening part on the compression mechanism part side of an oil return passage. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hermetic compressor, and more particularly to a hermetic compressor having an improved oil supply structure for a sliding portion of a compression mechanism portion of lubricating oil.

  In a conventional hermetic compressor that uses a suction gas in the sealed case, high-pressure lubricating oil is applied to each member sliding part and seal part using differential pressure, as in the case of the discharge gas inside the case. It was difficult to refuel.

  In order to solve this problem, in the horizontal type, there has been a proposal that oil separation means is provided on the discharge side of the compression mechanism section, and lubricating oil having a discharge pressure separated therefrom is supplied to each member sliding section ( Patent Document 1).

However, since this horizontal compressor does not consider a method for controlling the amount of lubricating oil in the oil separating means, there is a possibility that oil will run out at each member sliding portion.
JP 2004-169617 A

  The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a hermetic compressor that does not run out of oil in the sliding portion of each member.

  In order to achieve the above-described object, a hermetic compressor according to the present invention houses an electric motor unit and a compression mechanism unit connected to the electric motor unit via a rotating shaft in a hermetic case storing lubricating oil at the bottom. The refrigerant is sucked into the compression mechanism through the space inside the sealed case, and an oil separator is connected to the discharge passage, and the lubricating oil separated by the oil separator is slid on the compression mechanism through the oil return passage. In the hermetic compressor that is supplied to the moving part, the oil level height of the lubricating oil in the hermetic case at the time of stop is higher than the height of the compression mechanism side opening of the oil return passage. To do.

  An object of the hermetic compressor according to the present invention is to provide a hermetic compressor that does not run out of oil in each member sliding portion.

  Hereinafter, a hermetic compressor according to a first embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a longitudinal sectional view of a hermetic compressor according to the first embodiment.

  As shown in FIG. 1, a hermetic compressor 1 according to the present invention is a compressor of a type in which a hermetic case 2 is filled with a low-pressure gas, and an electric motor unit 3 and a compression mechanism unit 4 are provided inside the hermetic case 2. The interior is composed.

  In the compression mechanism section 4, a rotating shaft 5 extending from the motor section 3 is inserted into a main bearing 6 and a sub bearing 7, and a cylinder 8 is disposed between the main bearing 6 and the sub bearing 7. In the cylinder chamber 9, a cylindrical roller 10 is fitted to an eccentric portion 5 a formed on the rotary shaft 5, and a vane 12 that slides in a vane groove 11 provided in the cylinder 8 is disposed. ing.

  The vane 12 is constantly pressed in the direction of the roller 10 by a spring 14 housed in a vane chamber 13 forming a lubricating oil reservoir, and the vane groove 11 is in sliding contact with the outer peripheral surface of the roller in accordance with the rotation of the eccentric portion 5a and the roller 10. The inside of the cylinder chamber 9 communicates with the suction pipe 9a, and plays a role of pressure partitioning into a suction chamber and a compression chamber (not shown).

  Further, the discharge side of the cylinder chamber 9 is communicated with an oil separator 15 that separates the lubricating oil by a discharge pipe 16, and the oil separator 15 is further slid by an oil return passage 17 indicated by a line in the drawing of the compression mechanism section 4. It is connected to the moving part 18 (18a, 18b).

  The oil separator 15 is attached to the sealed case 2 such that the separator bottom 15a is positioned higher than the case bottom 2a of the sealed case 2, the discharge pipe 16 is L-shaped in side view, and the open end 16a is oil. The separator 15 opens upward at a position where the height is approximately 1/3 from the bottom.

  Further, the oil return passage 17 has a stepped shape when viewed from the side, and the opening one end portion 17a opens upward at the separator bottom portion 15a, and further, the step-like long side portion is located higher than the opening one end portion 17a. 17b communicates with the first sliding portion 18a, and the other open end portion 17c communicates with the second sliding portion 18b. That is, the long side portion 17 b communicates with the vane chamber 13 that forms a lubricating oil reservoir for supplying oil to the first sliding portion 18 a in which the vane 12 and the vane groove 11 slide, and the other open end portion 17 c is connected to the rotating shaft 5. The main bearing 6, the rotary shaft 5 and the sub-bearing 7, and both the bearings 6 and 7 and the oil supply passages 6 a and 7 b for supplying oil to the second sliding portions 18 b on both end surfaces of the roller 10 are communicated. In addition, by providing the first sliding portion 18a and the second sliding portion 18b in the oil return passage 17, the configuration becomes simpler than in the case of providing a separate oil return passage, which improves productivity and reduces costs. It becomes possible.

  The oil supply passage 6a is provided around the shaft through hole 6b of the main bearing 6, has a ring shape and an L-shaped vertical cross section, and the oil supply passage 7a is provided around the shaft through hole 7b of the auxiliary bearing 7, And has an L-shaped longitudinal section.

  In addition, shaft seal portions 18b1 and 18b2 each having a space on the open end side of both bearings 6 and 7 of the second sliding portion 18b and having a height H of 1/10 or more of the shaft diameter D of the rotary shaft 5 are provided. Preferably, it is formed. As a result, high-pressure lubricating oil can be prevented from flowing out to the sealed case 2 at the shaft seal portions 18b1 and 18b2, and high reliability and high performance can be realized.

  Further, it is preferable to provide a balance passage 19 for balancing the pressure between the sealed case 2 and the oil separator 15 and an opening / closing valve 20 in the balance passage 19. Thereby, by opening the on-off valve 20, the oil level of the lubricating oil can be quickly returned to the pressure balance state, and the oil supply to the sliding portion becomes more reliable.

  On the other hand, the oil level height L1 of the lubricating oil O of the sealed case 2 when the compressor is stopped is higher than the height of the compression mechanism side opening of the oil return passage, that is, the height L2 of the long side portion 17b. Lubricating oil is enclosed in the sealed case 2.

  In the hermetic compressor of the first embodiment, during operation of the hermetic compressor, the low-pressure gas in the hermetic case 2 is compressed by the roller 10 that rotates eccentrically in the cylinder 8, and a discharge hole and a discharge pipe (not shown). 16 is ejected from the opening end portion 16 a toward the upper side of the oil separator 15. By this ejection, the lubricating oil is separated from the high-pressure gas containing the lubricating oil, and stays in the lower part of the oil separator 15.

  On the other hand, since the oil separator 15 is filled with high-pressure gas and has a high pressure, the lubricating oil retained in the lower part is pressed by the pressure of the high-pressure gas, and the opening end of the oil return passage 17 is caused by the differential pressure. The oil flows from 17a to the long side portion 17b and is supplied to the vane 12 and the vane groove 11 which are the first sliding portions 18a through the vane chamber 13 which is the lubricating oil reservoir. The lubricating oil flowing out from the other open end 17c is supplied to the rotary shaft 5, the main bearing 6, the rotary shaft 5, the auxiliary bearing 7, and the both bearings 6 as the second sliding portion 18b via the oil supply passages 6a, 7a. , 7 and both ends of the roller 10 are lubricated and lubricated. At this time, since the shaft seal portions 18b1 and 18b2 are provided, high-pressure lubricating oil is prevented from flowing out to the sealed case 2.

  When the hermetic compressor is stopped, the refrigeration cycle and the pressure in the hermetic compressor are balanced, and the oil level of the lubricating oil in the hermetic case 2 and the oil level of the lubricating oil in the oil separator 15 are the same. Since the oil level of the lubricating oil 15 is always higher than the height of the compression mechanism side opening of the oil return passage, that is, the height of the long side portion 17b and the opening other end portion 17c, at the time of pressure balance (stop) However, even in a compressor of a type in which the low-pressure gas is filled in the sealed case, the lubricating oil can be reliably supplied to the sliding portion 18 (18a, 18b) by the differential pressure, and the reliability is improved. .

  Further, since the lubricating oil is supplied to the sliding portion 18 at the time of pressure balance, the oil can be reliably lubricated without entering the sliding portion 18 at the time of startup, and the reliability can be improved.

  Next, a hermetic compressor according to a second embodiment of the present invention will be described.

  In the second embodiment, a throttle means is added to the oil return passage of the first embodiment.

  For example, as shown in FIG. 2, a throttle means such as a capillary tube 21 is connected to the oil return passage 17 of the hermetic compressor 1 of the second embodiment, and the first sliding portion 18a is connected to the opening 21a. Are communicated with a vane chamber 13 forming a lubricating oil reservoir for supplying oil. As a result, the pressure in the vane chamber is reduced more than the discharge pressure, so that the pressing force of the vane against the roller caused by the differential pressure between the vane chamber and the compression chamber can be reduced, and the amount of leakage from the gap around the vane is reduced. As a result, reliability and performance are improved.

  In particular, as the amount of leakage from the gap around the vane increases, the amount of lubricating oil that passes through the throttle means increases, resulting in more pressure loss, and the lubricating oil flowing into the vane chamber is depressurized and compressed with the vane chamber. The pressure difference in the chamber is further reduced, the amount of leakage can be suppressed, and the performance can be improved and stabilized.

  Moreover, it is preferable to provide the pressure regulating valve 22 in a direction that opens from the vane chamber to the space in the discharge pressure state. Thereby, even when the lubricating oil in the vane chamber is compressed by the reciprocating motion of the vane in the vane chamber, it is possible to prevent the discharge pressure from being exceeded. Further, as shown in FIG. 3, it is preferable to provide a seal member 23 such as a chip seal made of a cross-linked PTFE material or a member coated with cross-linked PTFE on the end surface of the roller 10. As a result, the sealing performance of the roller end face is improved and the performance is improved. In addition, the lubricating oil leaked from the vane chamber can be returned to the oil separator together with the discharged gas without escaping into the sealed case. The oil level of the vessel can be stabilized. The wear resistance of the sealing member constituted by the cross-linked PTFE material or the member coated with the cross-linked PTFE is greatly improved and the coefficient of friction can be reduced, which is effective in improving reliability and performance. Furthermore, since the cross-linked PTFE material is a resin and has elasticity, the sealing property between the members can be improved.

  In addition, since another structure is not different from the hermetic compressor shown in FIG. 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  A hermetic compressor according to a third embodiment of the present invention will be described.

  In contrast to the first embodiment in which the sealed case is filled with low-pressure gas, the third embodiment is a type in which the sealed case 2 is filled with high-pressure gas.

  For example, as shown in FIGS. 4 and 5, the accumulator 31 is communicated with the suction chamber 9 s of the cylinder chamber 9 of the hermetic compressor 1 of the third embodiment via the suction pipe 30, and the compression chamber 9 d is connected to the discharge hole. 9d1 and the discharge valve 9d2 are communicated with the sealed case 2 filled with high-pressure gas.

  An oil supply passage 32 communicates with the vicinity of the bottom 2a of the sealed case 2, and further, a capillary tube 33 is connected to the oil supply passage 32, and a vane chamber for supplying oil to the first sliding portion 18a through the opening 33a. 13 is communicated.

  As a result, even in a compressor of the type in which the high-pressure gas is filled in the sealed case, the pressure in the vane chamber is reduced more than the discharge pressure, so the vane roller generated by the differential pressure between the vane chamber and the compression chamber The pressing force can be reduced, and the amount of leakage from the gap around the vane can be reduced, so that reliability and performance are improved. In particular, as the amount of leakage from the gap around the vane increases, the amount of lubricating oil that passes through the throttle means increases, resulting in more pressure loss, and the lubricating oil flowing into the vane chamber is depressurized and compressed with the vane chamber. The pressure difference in the chamber is further reduced, the amount of leakage can be suppressed, and the performance can be improved and stabilized.

  In addition, it is preferable to provide the pressure regulating valve 22 in a direction that opens from the vane chamber to the space in the discharge pressure state. Thereby, even when the lubricating oil in the vane chamber is compressed by the reciprocating motion of the vane in the vane chamber, it is possible to prevent the discharge pressure from being exceeded.

  A hermetic compressor according to a fourth embodiment of the present invention will be described.

  While the third embodiment has a single compression mechanism portion composed of a cylinder and a roller, the fourth embodiment has two compression mechanism portions.

  For example, as shown in FIG. 6, an oil supply passage 32 is communicated with the vicinity of the bottom 2 a of the hermetic case 2 of the hermetic compressor 1 of the fourth embodiment, and a capillary tube 33 is connected to the oil supply passage 32. The opening 33 a communicates with the vane chamber 13 of the first compression mechanism 4. A second compression mechanism 45 including a vane 44 that slides in the cylinder 41, the roller 42, and the vane groove 43 is provided above the first compression mechanism 4.

  The eccentric directions of the rotary shafts 5 of the first and second compressor units 4 and 45 are shifted from each other by approximately 180 °, and the vane chamber 13 of the first compression mechanism unit 4 and the second compression mechanism unit 4 The vane chamber 46 is in communication.

  As a result, the reciprocating directions of the vanes in the respective vane chambers are opposite to each other, so that the amount of change in the total volume of the vane chambers can be suppressed by communicating between the vane chambers. Can be prevented from being compressed.

  According to the hermetic compressor of each embodiment as described above, a hermetic compressor that does not run out of oil in each member sliding portion is realized.

  As shown in FIG. 7, a refrigeration cycle apparatus 50 according to the present invention includes a hermetic compressor 1 according to the above-described invention, a condenser 51 connected to the hermetic compressor 1 via an oil separator 15, and An expansion device 52 connected to the condenser 51 and an evaporator 53 connected to the expansion device 52 and connected to the hermetic compressor 1 are provided, and at least one of a hydrocarbon-based refrigerant and carbon dioxide is used as the refrigerant. Suitable for use. As a result, a refrigeration cycle apparatus having a hermetic compressor that does not run out of oil in each member sliding portion is realized, and the amount of enclosed refrigerant can be reduced. When used, it becomes safer.

  In addition, when carbon dioxide with a high operating pressure is used, the pressure resistance design of the sealed case is facilitated, and furthermore, since the differential pressure between the high and low pressures is large, the lubricating oil can be reliably supplied from the sliding portion. .

  Note that the hermetic compressor according to the present invention is of a multistage compression type, and can be applied to the one in which the inside of the hermetic case has an intermediate pressure by providing the oil separating means on the highest discharge side. Further, the present invention is not limited to a rotary hermetic compressor, and can be applied to a hermetic compressor such as a scroll hermetic compressor.

1 is a longitudinal sectional view of a hermetic compressor according to a first embodiment of the present invention. The longitudinal cross-sectional view of the hermetic compressor which concerns on 2nd Embodiment of this invention. The longitudinal cross-sectional view of the compressor part which shows the use condition of the sealing member used for the hermetic compressor which concerns on this invention. The longitudinal cross-sectional view of the hermetic compressor which concerns on 3rd Embodiment of this invention. The conceptual diagram of the hermetic compressor concerning a 3rd embodiment of the present invention. The longitudinal cross-sectional view of the hermetic compressor which concerns on 4th Embodiment of this invention. The conceptual diagram of the refrigerating-cycle apparatus which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Sealed compressor, 2 ... Sealed case, 3 ... Electric motor part, 4 ... Compression mechanism part, 5 ... Rotary shaft, 6 ... Main bearing, 7 ... Secondary bearing, 8 ... Cylinder, 9 ... Cylinder chamber, 10 ... Roller , 11 ... Vane groove, 12 ... Vane, 13 ... Vane chamber, 14 ... Spring, 15 ... Oil separator, 16 ... Discharge pipe, 16a ... Open end, 17 ... Oil return passage, 17a ... Open end, 17b ... Long side part, 17c ... Opening other end part, 18 ... Sliding part, 18a ... First sliding part, 18b ... Second sliding part, 19 ... Balance passage, 20 ... Open / close valve.

Claims (4)

A motor case and a compression mechanism unit connected to the motor unit via a rotating shaft are accommodated in a sealed case storing lubricating oil at the bottom, and refrigerant is sucked into the compression mechanism unit via the inner space of the sealed case. In a hermetic compressor in which an oil separator is connected to the discharge passage, and the lubricating oil separated by the oil separator is supplied to the sliding portion of the compression mechanism portion through the oil return passage A hermetic compressor, wherein the height of the lubricating oil level of the case is higher than the height of the compression mechanism side opening of the oil return passage. The compression mechanism includes a cylinder that forms a cylinder chamber, a roller that rotates eccentrically in the cylinder chamber, a vane that abuts against an outer peripheral surface of the roller and divides the cylinder chamber into a suction chamber and a compression chamber, and the cylinder A main bearing and a sub-bearing that cover the cylinder chamber in contact with the end surface of the shaft and pivotally support the rotating shaft, and form a vane chamber on the back side of the vane and connect the oil return passage to the vane chamber The hermetic compressor according to claim 1, wherein 3. The hermetic compressor according to claim 2, wherein a throttle means is provided in the oil return passage. A hermetic compressor according to any one of claims 1 to 3, a condenser, an expansion device, and an evaporator, wherein any one of a hydrocarbon-based refrigerant and carbon dioxide is used as a refrigerant. A refrigeration cycle apparatus characterized by.

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