JP2006214335A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly efficient and highly reliable scroll compressor, by restraining an overturning phenomenon of a revolving scroll in low compression ratio operation, by reducing a sliding loss in a sliding surface of an end plate of the revolving scroll and an end plate of a fixed scroll. <P>SOLUTION: Oil 6 is always supplied to the sliding surface 13a, by arranging a communicating passage 80 having one opening part opening in the sliding surface 13a of the end plate 12a of the fixed scroll 12 and the end plate 13a of the revolving scroll 13 and having another one opening part always opening in a high pressure part 30, inside the end plate 13a of the revolving scroll 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a scroll compressor used in a cooling device such as an air conditioning air conditioner or a refrigerator, or a heat pump type hot water supply device.

  Conventionally, in a scroll compressor, in order to keep the sliding surface contact between the revolving and fixed end plates in a good state and reduce friction loss, one opening is provided inside the revolving scroll end plate and the fixed scroll. It opens to the sliding part of the end plate, and the other opening part is provided on the back of the orbiting scroll, and has a configuration in which a passage is opened intermittently by the sliding partition ring to the high-pressure part inside the sliding partition ring. (For example, see Patent Document 1).

FIG. 6 is a cross-sectional view of a compression mechanism portion of a conventional scroll compressor described in Patent Document 1. As shown in FIG. 6, an oil passage 50 is provided in the end plate 13 a of the orbiting scroll 13, and the opening of the oil passage 50 faces the center side from the sliding partition ring 78 as the orbiting scroll 13 turns. By guiding the oil at 30 to the sliding surface 13b between the end plate 13a of the orbiting scroll 13 and the fixed scroll 12, a good lubricating condition is achieved and the friction loss is reduced.
JP-A-6-307354

  When carbon dioxide refrigerant is used, the pressure is about three times that of the conventional HFC refrigerant, and an excessive pressing force is generated on the sliding surface of the end plate of the orbiting scroll and the end plate of the fixed scroll. In this case, sliding loss increases, or galling and abnormal wear occur. Also, in a system with a large capacity and multiple refrigerants, during transient operation where the return of the liquid refrigerant is severe, the carbon dioxide liquid refrigerant, which is highly washable, causes oil shortage and temperature rise on the thrust surface of the orbiting scroll. There is a risk of seizure.

  Therefore, as in the conventional configuration described above, high-pressure oil is supplied to the surface on which the end plate of the orbiting scroll and the end plate of the fixed scroll slide, but because it is intermittent oiling accompanying the rotation of the orbiting scroll, Even if temporarily, an oil-free state will occur. Further, since a high pressure is intermittently applied to the sliding surface between the end plate of the orbiting scroll and the end plate of the fixed scroll, a force for separating the end plate of the orbiting scroll is generated intermittently.

  In particular, in a heat pump hot water supply system using carbon dioxide, the scroll compressor may be operated at a very low compression ratio due to the characteristics of the system. Under such operating conditions, the orbiting scroll is pulled away from the fixed scroll, It will drive | operate, generating the one side contact in a contact part.

  The present invention solves the above-mentioned conventional problems, and reduces sliding loss on the sliding surface between the end plate of the orbiting scroll and the end plate of the fixed scroll, and suppresses the overturning phenomenon of the orbiting scroll under a low compression ratio operation. And it aims at providing a highly efficient and reliable scroll compressor.

In order to solve the above-mentioned conventional problems, the scroll compressor of the present invention uses carbon dioxide as a refrigerant, and provides a high-pressure oil by providing a communication path or the like on a part of the surface on which the fixed scroll and the end plate of the orbiting scroll slide. The structure is such that it is always guided.

  With this configuration, high pressure oil is always guided to the sliding surface of the end plate of the orbiting scroll and the end plate of the fixed scroll, so that force to pull away the end plate of the orbiting scroll is generated intermittently or an oil-free state occurs. The oil film thickness can be increased, sliding loss can be reduced, and galling and abnormal wear on the sliding surface can be suppressed.

  The scroll compressor of the present invention can improve the compression efficiency under the low compression ratio operation, and can realize high efficiency and high reliability of the refrigeration air-conditioning equipment.

  The first aspect of the invention is a scroll compressor in which carbon dioxide is used as a refrigerant, and high-pressure oil is constantly guided to a part of a surface on which the fixed scroll and the end plate of the orbiting scroll slide.

  Conventionally, since high-pressure oil is supplied to the surface on which the end plate of the orbiting scroll and the end plate of the fixed scroll slide, the oil supply is intermittent and an oil-free state occurs. In particular, when carbon dioxide is used as the refrigerant, an excessive pressing force is generated on the surface on which the end plate of the orbiting scroll and the end plate of the fixed scroll slide, which increases sliding loss or causes galling or abnormal wear. However, according to the configuration of the present invention, the surface on which the end plate of the orbiting scroll and the end plate of the fixed scroll slide can be refueled with a stable pressure at all times, so that sliding loss can be reduced and galling on the sliding surface can be reduced. Abnormal wear can be suppressed, and a highly efficient and highly reliable scroll compressor can be realized.

  The second invention is the first invention, in particular, in the orbiting scroll end plate, one opening opens to the surface on which the end plate of the fixed scroll and the end plate of the orbiting scroll slide, and the other opening is A communication passage that is always open is provided in the high-pressure portion. As a result, oil can be reliably supplied from the oil reservoir at the bottom of the compressor through the inside of the orbiting scroll to the surface on which the end plate of the orbiting scroll and the end plate of the fixed scroll slide, which is highly efficient and highly reliable. The scroll compressor can be realized.

  In the third aspect of the invention, particularly in the communication path of the second aspect of the invention, the opening that opens on the surface where the end plate of the fixed scroll and the end plate of the orbiting scroll slide is open to the compression chamber even if the orbiting scroll rotates. It is provided at a position where it is not. As a result, there is no suction heating due to high-pressure oil flowing from the communication path, and a highly efficient scroll compressor can be realized.

  The fourth invention is the first invention, in particular, in the end plate of the fixed scroll, one opening is open to the surface where the end plate of the fixed scroll and the end plate of the orbiting scroll slide, and the other opening is A communication passage that opens to a high-pressure portion in the rear surface of the fixed scroll end plate is provided. This ensures that the oil accumulated in the high-pressure part on the back of the fixed scroll end plate passes through the communication path inside the fixed scroll and supplies the oil to the surface on which the end plate of the orbiting scroll and the end plate of the fixed scroll slide. It is possible to realize a highly efficient and highly reliable scroll compressor.

  The fifth aspect of the invention is particularly the first to fourth aspects of the invention, in which a throttle portion is provided in a part of the communication path that opens on the surface where the end plate of the fixed scroll and the end plate of the orbiting scroll slide. Accordingly, an appropriate amount of oil can be constantly supplied to the surface on which the end plate of the fixed scroll and the end plate of the orbiting scroll slide, and a highly efficient scroll compressor can be realized.

The sixth invention is the first to fifth inventions in particular, and in the fixed scroll, a groove communicating with the suction port of the fixed scroll is formed on the surface on which the end plate of the fixed scroll and the end plate of the orbiting scroll slide. is there. Thus, conventionally, a relatively high oil film pressure is generated on the surface on which the end plate of the fixed scroll and the end plate of the orbiting scroll slide, and the orbiting scroll tends to be separated from the fixed scroll. Even if a high-pressure communication path opens on the surface where the end plate of the fixed scroll and the end plate of the orbiting scroll slide, the suction pressure acts in the groove and the back pressure is increased by the communicating groove. Even under specific operation, the orbiting scroll can be prevented from hitting. Therefore, a highly efficient scroll compressor can be provided.

  The seventh aspect of the invention is the sixth aspect of the invention, in particular, in which the opening that opens to the surface on which the end plate of the fixed scroll and the end plate of the orbiting scroll slide is provided at a position that does not communicate with the groove that communicates with the suction port of the fixed scroll. It is a thing. As a result, the inside of the groove communicating with the suction port of the fixed scroll can be reliably set to the suction pressure, and the orbiting scroll can be prevented from hitting even under low compression ratio operation. In addition, high-pressure oil does not return to the suction port through the groove communicating with the suction port of the fixed scroll from the opening that opens to the surface on which the end plate of the fixed scroll and the end plate of the orbiting scroll slide. An efficient scroll compressor can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a scroll compressor according to the first embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a main part of a compression mechanism portion of FIG. The operation and action of the scroll compressor configured as shown in the figure will be described below.

  As shown in FIG. 1, the scroll compressor of the present invention includes a main bearing member 11 of a crankshaft 4 fixed by welding or shrink fitting in an airtight container 1, and a fixed bolted on the main bearing member 11. The scroll-type compression mechanism 2 is configured by sandwiching the orbiting scroll 13 that meshes with the fixed scroll 12 between the scroll 12 and prevents the orbiting scroll 13 from rotating between the orbiting scroll 13 and the main bearing member 11. A rotation restricting mechanism 14 such as an Oldham ring that guides the orbital motion is provided, and the orbiting scroll 13 is eccentrically driven by the eccentric shaft portion 4a at the upper end of the crankshaft 4, thereby causing the orbiting scroll 13 to move in a circular orbit. Thereby, the compression chamber 15 formed between the fixed scroll 12 and the orbiting scroll 13 is small while moving from the outer peripheral side to the center portion. The refrigerant gas is sucked and compressed from the suction pipe 16 communicating with the outside of the hermetic container 1 and the suction port 17 on the outer peripheral portion of the fixed scroll 12, and the refrigerant gas exceeding the predetermined pressure is fixed. The reed valve 19 is pushed open from the discharge port 18 at the center of the scroll 12 and discharged into the sealed container 1 repeatedly.

  A sliding partition ring 78 disposed on the main bearing member 11 is provided on the back surface portion of the orbiting scroll 13, and the high pressure portion that is an inner region of the sliding partition ring 78 is formed by the sliding partition ring 78 while performing the orbiting motion. 30 and a back pressure space 29 set to an intermediate pressure of high pressure and low pressure, which is an outer region. By applying pressure on the back surface, the orbiting scroll 13 is stably pressed against the fixed scroll 12, reducing leakage and performing stable circular orbit movement.

  Further, the fixed scroll 12 includes a back pressure adjusting valve 9 that controls the pressure in the back pressure space 29 on the back surface of the orbiting scroll 13.

During operation of the compressor, a pump 25 is provided at the other downward end of the crankshaft 4 and is driven simultaneously with the scroll compressor. As a result, the pump 25 sucks up the oil 6 in the oil reservoir 20 provided at the bottom of the hermetic container 1 and vertically passes through the crankshaft 4.
To the compression mechanism 2. The supply pressure at this time is substantially equal to the discharge pressure of the scroll compressor, and also serves as a back pressure source for the orbiting scroll 13. As a result, the orbiting scroll 13 does not move away from the fixed scroll 12 and does not come into contact with each other, and the predetermined compression function is stably exhibited.

  A part of the oil 6 supplied in this way is obtained by a supply pressure or its own weight so as to obtain a clearance, between the fitting portion between the eccentric shaft portion 4a and the orbiting scroll 13, and between the crankshaft 4 and the main bearing member 11. Then, the oil enters the bearing portion 66, lubricates the respective portions, falls, and returns to the oil sump 20. Another part of the oil 6 supplied to the high-pressure unit 30 passes through a passage 54 having an opening in the high-pressure unit 30, and slides 13 d between the end plate of the fixed scroll 12 and the wrap 13 c of the orbiting scroll 13, In addition to lubricating the sliding portion 13d and the sliding portion of the rotation restricting mechanism 14 by branching into the back pressure space 29 around the outer peripheral portion of the scroll 13 where the rotation restricting mechanism 14 is located, The back pressure of the orbiting scroll 13 is applied in the back pressure space 29.

  The oil 6 entering the back pressure space 29 is set to an intermediate pressure that is intermediate between the pressures of the high pressure portion 30 and the low pressure side of the compression chamber 15 by the throttle action of the throttle 57. The back pressure space 29 is sealed between the high pressure portion 30 and the high pressure side by an annular partition ring 78. The pressure increases as the incoming oil is filled, and when the pressure exceeds a predetermined pressure, the back pressure adjusting valve 9 Acts to return to the suction portion of the compression chamber 15 and enter.

  The approach of the oil 6 is repeated at a predetermined cycle, and the timing of this repetition is determined by the combination of the repetitive cycle of suction, compression and discharge and the relationship between the pressure reduction setting by the throttle 57 and the pressure setting by the back pressure adjusting mechanism 9. In addition, intentional lubrication of the sliding portion 13d between the fixed scroll 12 and the wrap 13c of the orbiting scroll 13 is achieved. This intentional lubrication is always ensured by the opening of the communication path 10 into the recess 105 by the back pressure regulating valve 9 as described above. The oil 6 supplied to the suction port 17 moves to the compression chamber 15 along with the orbiting motion of the orbiting scroll 13 and serves to prevent leakage between the compression chambers 15.

  Further, as shown in FIGS. 1 and 2, one opening opens inside the end plate 13 a of the orbiting scroll 13 to the sliding surface 13 b on which the fixed scroll 12 and the end plate 13 a of the orbiting scroll 13 slide. One communicating portion is provided with a communication path 80 that is always open to the high-pressure portion 30.

  Usually, an excessive pressing force is generated on the sliding surfaces of the end plate of the fixed scroll 12 and the end plate 13 a of the orbiting scroll 13. In particular, when carbon dioxide is used as the refrigerant, this pressing force becomes very large. Therefore, it is difficult to form an oil film on the sliding surface 13b between the end plate of the fixed scroll 12 and the end plate 13a of the orbiting scroll 13, and sliding loss is reduced. Although the performance is increased and the performance is reduced, the high pressure oil 6 is always positively supplied to the sliding surface 13b through the communication passage 80, so that the oil film thickness is increased and the sliding loss is reduced. Improved machine efficiency and higher reliability can be realized.

  Further, by providing a throttle part in a part of the communication path 80, an appropriate amount of oil 6 can be supplied to the sliding surface 13b of the end plate of the fixed scroll 12 and the end plate 13a of the orbiting scroll 13. Efficiency can be realized.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a plan view of the fixed scroll of the scroll compressor according to the second embodiment of the present invention as viewed from below, and the locus of the fixed scroll 12 at the opening of the communication passage 80 provided in the orbiting scroll 13 is shown. Show. As shown in the figure, with the orbiting motion of the orbiting scroll 13, the opening of the communication path 80 is set so as not to face the compression chamber 15, and a certain seal length is provided. As a result, there is no suction heating due to the high-pressure oil 6 flowing into the compression chamber 15 via the communication passage 80, and a highly efficient scroll compressor can be realized.

(Embodiment 3)
A third embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a cross-sectional view of a compression mechanism portion of a scroll compressor according to the third embodiment of the present invention. Inside the end plate 12 a of the fixed scroll 12, one opening opens to the sliding surface 13 b between the end plate 12 a of the fixed scroll 12 and the end plate 13 a of the orbiting scroll 13, and the other opening is on the back of the end plate of the fixed scroll 12. A communication passage 81 that opens to the high-pressure space 31 with the discharge muffler 77 is provided.

  Oil is dissolved in the refrigerant discharged from the compression chamber 15 to the high-pressure space 31, but a part of the oil 6 is separated and accumulates on the rear surface of the fixed scroll 12. Then, the oil 6 passes through a communication passage 81 provided inside the end plate of the fixed scroll 12 and is supplied to the sliding surface 13 b between the fixed scroll 12 and the orbiting scroll 13.

  Usually, an excessive pressing force is generated on the sliding surface 13 b between the fixed scroll 12 and the orbiting scroll 13. In particular, when carbon dioxide is used as the refrigerant, the pressing force becomes very large, so that it is difficult to form an oil film on the sliding surfaces 13b of the fixed scroll 12 and the orbiting scroll 13, and the sliding loss increases, resulting in a performance degradation. However, by actively supplying the high pressure oil 6 to the sliding surface 13b of the fixed scroll 12 and the orbiting scroll 13 through the communication passage 81, the oil film thickness is increased and the sliding loss is reduced. Improvement of compressor efficiency and high reliability can be realized.

(Embodiment 4)
The fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a plan view of the fixed scroll 12 of the scroll compressor according to the fourth embodiment of the present invention. A groove 90 communicating with the suction port 17 of the fixed scroll 12 is formed on the sliding surface between the end plate 12 a of the fixed scroll 12 and the end plate 13 a of the orbiting scroll 13.

  As in the first to third embodiments, in the case where high pressure oil is provided on the surface on which the end plates of the fixed scroll 12 and the orbiting scroll 13 slide and is provided with the communication passages 80 and 81, the opening in the communication passages 80 and 81 is provided. Due to the high pressure, a force that separates the orbiting scroll 13 from the fixed scroll 12 is generated.

  However, the groove 90 communicating with the suction port 17 of the fixed scroll 12 causes a suction pressure to act in the groove 90 and the back pressure is increased, so that the surface on which the end plate of the fixed scroll 12 and the orbiting scroll 13 slides has a high pressure. Even if the communication passages 80 and 81 are opened, the overturning phenomenon of the orbiting scroll 13 is suppressed even under the low compression ratio operation. Therefore, a highly efficient scroll compressor can be provided.

  In the communication path 80 in the second embodiment, the opening that opens on the sliding surface of the end plate 13 a of the fixed scroll 12 and the orbiting scroll 13 does not communicate with the groove 90 that communicates with the suction port 17 of the fixed scroll 12. It should be provided at the position. As a result, the inside of the groove 90 communicating with the suction port 17 of the fixed scroll 12 can be reliably set to the suction pressure, and the overturning phenomenon of the orbiting scroll 13 is suppressed even under the low compression ratio operation. Further, the high-pressure oil 6 may be returned to the suction port 17 through the groove 90 communicating with the suction port 17 of the fixed scroll 12 from the opening portion opened in the sliding surface of the end plate of the fixed scroll 12 and the orbiting scroll 13. And a highly efficient scroll compressor can be provided.

  As described above, the scroll compressor according to the present invention can improve the compression efficiency even under the low compression ratio operation, and the air scroll compressor, the vacuum pump, the scroll type expansion can be realized without limiting the working fluid to the refrigerant. It can also be applied to the use of scroll fluid machines such as machines.

Sectional drawing of the scroll compressor in Embodiment 1 of this invention Sectional drawing of the compression mechanism part of the scroll compressor in Embodiment 1 of this invention The top view of the fixed scroll of the scroll compressor in Embodiment 2 of this invention Sectional drawing of the compression mechanism part of the scroll compressor in Embodiment 3 of this invention The top view of the fixed scroll which is the principal part of the scroll compressor in Embodiment 4 of this invention Sectional view of a conventional scroll compressor

Explanation of symbols

6 Oil 11 Main bearing member 12 Fixed scroll 12a End plate 13 Orbiting scroll 13a End plate 13b Sliding surface 14 Rotation restricting mechanism 15 Compression chamber 17 Suction port 29 Back pressure space 30 High pressure portion 31 High pressure space 78 Sliding partition ring 80, 81 Communication path 90 groove

Claims (7)

By engaging the fixed scroll and the orbiting scroll where the spiral wrap rises from the end plate, and moving the orbiting scroll along a circular orbit under the regulation of rotation, it moves while changing the volume, so that suction, compression, A compression chamber for discharging is formed, and a ring-shaped groove is provided in a bearing member that substantially supports the orbiting scroll and the back side of the end plate, and a high pressure is applied to the bearing member and the central part on the back side of the end plate by lubricating oil. The high pressure portion to be applied and the high pressure portion are partitioned by a ring-shaped sliding partition ring having a joint portion attached to the groove portion, and a predetermined pressure lower than that of the high pressure portion is applied to the outer peripheral portion of the rear surface of the orbiting scroll end plate In a scroll compressor provided with a back pressure space to
A scroll compressor characterized in that carbon dioxide is used as a refrigerant, and high-pressure oil is always guided to a part of a surface on which the end plate of the fixed scroll and the end plate of the orbiting scroll slide. Inside the end plate of the orbiting scroll, one opening is open to the surface where the end plate of the fixed scroll and the end plate of the orbiting scroll slide, and the other opening is always open to the high pressure portion. The scroll compressor according to claim 1, further comprising a passage. An opening of the communication path that opens in a surface on which the end plate of the fixed scroll and the end plate of the orbiting scroll slide is provided at a position that does not open in the compression chamber even when the orbiting scroll rotates. The scroll compressor according to claim 2, wherein Inside the end plate of the fixed scroll, one opening opens to a surface where the end plate of the fixed scroll and the end plate of the orbiting scroll slide, and the other opening is a high pressure on the back of the end plate of the fixed scroll. The scroll compressor according to claim 1, wherein a communication passage opening in the space is provided. The scroll compressor according to claim 1, wherein a throttle portion is provided in a part of the communication path. 6. The fixed scroll according to claim 1, wherein a groove communicating with the suction port of the fixed scroll is formed on a surface on which the end plate of the fixed scroll and the end plate of the orbiting scroll slide. The scroll compressor according to one item. An opening that opens in a surface of the passage where the end plate of the fixed scroll and the end plate of the orbiting scroll slide is provided at a position that does not communicate with the groove that communicates with the suction port of the fixed scroll. The scroll compressor according to claim 6.

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