JP2007032294A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of slide loss at a surface on which end plates of a fixed scroll and a turning scroll slide and leak loss on a compression chamber in a scroll compressor following improvement of efficiency and application of high pressure refrigerant such as carbon dioxide in refrigeration air conditioning devices of late years. <P>SOLUTION: A communication passage 80 of which one opening part intermittently opens to the compression chamber 15 and the slide surface 13a of the end plate 12a of the fixed scroll 12 and the end plate 13a of the turning scroll 13 and of which another opening part always open to the high pressure part 30 is provided inside of the end plate 13a of the turning scroll 13. Consequently, sliding loss is reduced by always supplying oil 6 to the slide surface 13a and improvement of compression efficiency and improvement of reliability are materialized by reducing leak loss of the compression chamber 15. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a scroll compressor used in a cooling device such as a cooling / heating 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 end. 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. 4 is a cross-sectional view of a compression mechanism portion of a conventional scroll compressor described in Patent Document 1. As shown in FIG. 4, 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.

  When carbon dioxide refrigerant is used, the pressure difference between the discharge pressure and the suction pressure of the compressor is about 7 to 10 times higher than the pressure difference of the conventional refrigeration cycle using chlorofluorocarbon as the refrigerant. For this reason, the performance was further deteriorated due to leakage in the compression chamber.

  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 to reduce the friction loss on the thrust surface of the orbiting scroll. It does not take into account the volumetric efficiency drop due to leakage.

  The present invention solves the above-mentioned conventional problems, and reduces the sliding loss on the sliding surface between the end plate of the orbiting scroll and the end plate of the fixed scroll, and also reduces leakage in the compression chamber, and is highly efficient and reliable. An object of the present invention is to provide a highly efficient scroll compressor.

  In order to solve the above-described conventional problems, the scroll compressor according to the present invention intermittently applies the oil in the high pressure portion to a part of the surface on which the end plate of the fixed scroll and the end plate of the orbiting scroll slide by driving the orbiting scroll. And a communication passage for intermittently guiding the oil in the high pressure section is provided in the compression chamber.

With this configuration, high-pressure oil is guided to the sliding surfaces of the end plate of the orbiting scroll and the end plate of the fixed scroll, so that the oil film thickness can be increased, sliding loss can be reduced, and sliding with good lubrication with oil is possible. It is possible to suppress galling and abnormal wear on the surface. In addition, since an appropriate amount of oil is introduced into the compression chamber, leakage loss in the compression chamber can be reduced without deterioration in performance due to suction heating.

  The scroll compressor of the present invention can improve the efficiency of the compressor by reducing the sliding loss and leakage loss even when the pressure difference between the discharge pressure and the suction pressure is high. High reliability can be achieved on the thrust surface where sliding is severe.

  According to the first aspect of the invention, by driving the orbiting scroll, the high pressure oil is intermittently guided to a part of the surface on which the fixed scroll end plate and the orbiting scroll end plate slide, and the high pressure oil is introduced into the compression chamber. A communication path that leads intermittently is provided.

  In particular, when a high differential pressure is generated, an excessive pressing force is generated on the surface where the end plate of the orbiting scroll and the end plate of the fixed scroll slide, so that an increase in sliding loss, or galling and abnormal wear occurs. However, the configuration of the present invention allows oil to be supplied to the surface on which the end plate of the orbiting scroll and the end plate of the fixed scroll slide with a stable pressure, so that sliding loss can be reduced and galling and abnormalities on the sliding surface can be reduced. A highly efficient and reliable scroll compressor that can suppress wear can be realized. Further, if the pressure difference between the discharge pressure and the suction pressure of the compressor is high, the performance is degraded due to leakage in the compression chamber. According to the present invention, since an appropriate amount of oil is introduced into the compression chamber, leakage loss in the compression chamber can be reduced, and a more efficient scroll compressor can be realized.

  The second invention is a compression chamber that is compressed more than the compression start point of the compression chamber formed by the outer wall surface of the swirl wrap of the orbiting scroll and the inner wall surface of the swirl wrap of the fixed scroll, in particular, in the first invention. In addition, the oil in the high pressure part is guided. As a result, there is no performance degradation due to suction heating that is caused when high-temperature oil is guided to the suction section of the compression chamber, and an appropriate amount of oil is guided to the compression chamber, so that leakage loss in the compression chamber can be reduced, and a highly efficient scroll compressor Can be realized.

  The third invention is particularly the first and second inventions, in which the communication path is provided inside the end plate of the orbiting scroll. As a result, the oil in the high-pressure section is relatively easily supplied from the oil reservoir at the bottom of the compressor, through the inside of the orbiting scroll, and into the compression chamber and the surface where the end plate of the orbiting scroll and the end plate of the fixed scroll slide. Thus, a highly efficient and highly reliable scroll compressor can be realized.

  According to a fourth aspect of the present invention, a part of the communication path is a narrow hole having a throttling effect. Accordingly, an appropriate amount of oil can be supplied to the surface on which the fixed scroll end plate and the orbiting scroll end plate slide and the compression chamber, and a highly efficient scroll compressor can be realized.

The fifth invention is the first to fourth inventions, in particular, using carbon dioxide as a working refrigerant.
Since the carbon dioxide refrigerant is a high differential pressure 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. It will cause abnormal wear. When carbon dioxide refrigerant is used, the pressure difference between the discharge pressure and the suction pressure of the compressor is about 7 to 10 times higher than the pressure difference of the conventional refrigeration cycle using chlorofluorocarbon as a refrigerant. Furthermore, the performance was reduced. According to the first to fourth inventions, the high pressure oil is guided to the sliding surfaces of the end plate of the orbiting scroll and the end plate of the fixed scroll, so that the oil film thickness can be increased, the sliding loss is reduced, and the oil is good. Lubrication can suppress galling and abnormal wear on the sliding surface. In addition, since an appropriate amount of oil is introduced into the compression chamber, the leakage loss in the compression chamber can be reduced without deterioration in performance due to suction heating, and a highly efficient and highly reliable scroll compressor can be realized.

  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 the 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 the rotation of the orbiting scroll 13 between the orbiting scroll 13 and the main bearing member 11 is prevented. 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 supplies it to the compression mechanism 2 through the oil supply hole 26 extending vertically through the crankshaft 4. 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. 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 is driven by the orbiting scroll 13 to pass through the passage 54 having an opening at 30 to slide between the end plate of the fixed scroll 12 and the wrap 13c of the orbiting scroll 13. The portion 13d and the back pressure space 29 around the outer peripheral portion of the orbiting scroll 13 where the rotation restricting mechanism 14 is located branch and enter to lubricate the sliding portion 13d and the sliding portion of the rotation restricting mechanism 14. At the same time, 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 portion inside the end plate 13 a of the orbiting scroll 13 slides between the fixed scroll 12 and the end plate 13 a of the orbiting scroll 13 as the orbiting scroll 13 is driven. The sliding surface 13b is intermittently opened (FIG. 2A) and intermittently opened to the compression chamber 15 (FIG. 2B), and the other opening is always open to the high-pressure portion 30. A passage 80 is provided.

  FIG. 3 is a plan view of the fixed scroll 12 of the scroll compressor as viewed from below, and shows the locus of the fixed scroll 12 at the opening of the communication passage 80 provided in the orbiting scroll 13. As shown in the drawing, the oil 6 of the high-pressure unit 30 is intermittently applied to the sliding surface 13 b on which the fixed scroll 12 and the end plate 13 a of the orbiting scroll 13 slide and the compression chamber 15 along with the orbiting motion of the orbiting scroll 13. ((A)).

  When the orbiting scroll 13 is in the position as shown in FIG. 2A by driving the orbiting scroll 13, the oil 6 of the high pressure section 30 passes through the communication path 80 and the end plate 13 a of the fixed scroll 12 and the orbiting scroll 13. Are intermittently supplied to the sliding surface 13b.

  Thereby, under high differential pressure operation, an excessive pressing force is generated on the sliding surfaces of the end plate of the fixed scroll 12 and the end plate 13a of the orbiting scroll 13, and the end plate of the fixed scroll 12 and the end plate 13a of the orbiting scroll 13 On the sliding surface 13b, it is difficult to form an oil film, the sliding loss increases, and the performance is likely to deteriorate. However, by supplying the high pressure oil 6 to the sliding surface 13b through the communication path 80, the oil film thickness is reduced. Can be reduced to reduce the sliding loss, and improve the compressor efficiency and increase the reliability.

  Further, when the orbiting scroll 13 is driven and the orbiting scroll 13 is in the position as shown in FIG. 2B, the oil 6 of the high-pressure unit 30 is intermittently supplied to the compression chamber 15 through the communication path 80. Is done.

  Thereby, when the pressure difference between the discharge pressure and the suction pressure of the compressor is high, the performance is deteriorated due to leakage in the compression chamber. However, since an appropriate amount of oil 6 is introduced to the compression chamber 15, the compression chamber 15 Leakage loss can be reduced, and a highly efficient scroll compressor can be realized.

Further, by providing a throttle part in a part of the passage 80, an appropriate amount of oil 6 can be supplied to the sliding surface 13b and the compression chamber 15 of the end plate of the fixed scroll 12 and the end plate 13a of the orbiting scroll 13. Higher efficiency can be realized.

(Embodiment 2)
In the scroll compressor according to the second embodiment of the present invention, the communication path 80 causes the oil 6 of the high-pressure unit 30 to flow between the outer wall surface of the spiral wrap 13d of the orbiting scroll 13 and the inner wall surface of the spiral wrap 12b of the fixed scroll 12. The position is set so as to lead to the compressed compression chamber 15 from the compression start point of the compression chamber 15 to be formed (not shown).

  As a result, there is no deterioration in performance due to suction heating that is caused when the high-temperature oil 6 is guided to the suction portion of the compression chamber 15, and an appropriate amount of oil 6 is guided to the compression chamber 15. An efficient scroll compressor can be realized.

(Embodiment 3)
The scroll compressor according to the third embodiment of the present invention uses carbon dioxide as a working refrigerant. 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 surface 13b on which the end plate 13a of the orbiting scroll 13 and the end plate 12a of the fixed scroll 12 slide. However, according to the first and second embodiments of the present invention, the high-pressure oil 6 is supplied to the sliding surface 13b through the communication path 80. Therefore, the oil film thickness can be increased to reduce the sliding loss, and the compressor efficiency can be improved and the reliability can be improved.

  When carbon dioxide refrigerant is used, the pressure difference between the discharge pressure and the suction pressure of the compressor is about 7 to 10 times higher than the pressure difference of the conventional refrigeration cycle using chlorofluorocarbon as a refrigerant, and leakage in the compression chamber 15 However, according to the first and second embodiments of the present invention, the oil 6 of the high-pressure unit 30 is guided to the compression chamber 15 through the communication passage 80 in an appropriate amount. Leakage loss can be reduced, and a highly efficient scroll compressor can be realized.

  As described above, the scroll compressor according to the present invention can improve the compression efficiency even under high differential pressure 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 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 Communication passage 90 Groove

Claims (5)

By meshing 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, the volume is changed, 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 the scroll compressor provided with the back pressure space, the end plate of the fixed scroll and the end plate of the orbiting scroll are driven by the orbiting scroll. The high pressure of the oil in a part of the sliding surfaces with intermittent leads, scroll compressor, characterized in that a communicating path intermittently guiding the high pressure of the oil in the compression chamber. Oil in the high-pressure section is compressed into the compression chamber compressed by the communication path from the compression start point of the compression chamber formed by the outer wall surface of the spiral wrap of the orbiting scroll and the inner wall surface of the spiral wrap of the fixed scroll. The scroll compressor according to claim 1, wherein the scroll compressor is guided. The scroll compressor according to claim 1, wherein the communication path is provided inside a mirror plate of the orbiting scroll. The scroll compressor according to any one of claims 1 to 3, wherein a part of the communication path is a narrow hole having a throttling effect. The scroll compressor according to any one of claims 1 to 4, wherein carbon dioxide is used as a working refrigerant.

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