JP2006046205A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make dead volume small while suppressing deformation of a fixed scroll. <P>SOLUTION: A dug part 12a is provided on an end plate surface in an oppose side to a compression chamber 15 of the fixed scroll 12 and a delivery opening 18 and lead valve 19 is constructed in the dug part 12a, and a groove 12b is provided on the end plate surface in the oppose side to the compression chamber 15 of the fixed scroll 12. Consequently, deformation of the fixed scroll is made small and high efficiency can be materialized while preventing drop of efficiency due to re-expansion of refrigerant even at a time of high load high compression ratio operation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, the fixed scroll and the orbiting scroll where the spiral wrap rises from the end plate are meshed to form a compression chamber therebetween, and the orbiting scroll is orbited along a circular orbit under the restriction of rotation by the rotation restricting mechanism. The present invention relates to a scroll compressor that sometimes performs suction, compression, and discharge by moving a compression chamber while changing its volume.

Conventionally, there is a scroll compressor of this type in which a discharge passage and a reed valve mechanism are provided inside a fixed scroll end plate. (For example, see Patent Document 1)
FIG. 5 shows a sectional view of the fixed scroll provided with a discharge passage and a discharge valve mechanism inside the end plate. In such a compressor, since the volume of the discharge port can be reduced, it is possible to prevent a decrease in efficiency due to the re-expansion of the refrigerant in the discharge port to the compression chamber, particularly during high load / high compression ratio operation. . Further, in the scroll compressor of the type in which the inside of the hermetic container is set to the suction pressure, since it can be configured so that the discharge pressure (high pressure) cannot be received on the end plate surface opposite to the compression chamber of the fixed scroll, The pressure deformation of the fixed scroll can be prevented. In this type of scroll compressor that uses a discharge pressure in the sealed container, the reed valve can be configured without reducing the rigidity of the fixed scroll while minimizing the volume of the discharge port. In this case, the pressure deformation of the fixed scroll can be prevented. If pressure deformation of the fixed scroll can be prevented, it becomes easier to control the gap between the orbiting scroll and the wrap tip of the fixed scroll, and as a result, abnormal wear due to one-sided contact and leakage during compression can be effectively suppressed. .
JP-A-63-239392

  However, since the discharge passage and the reed valve mechanism are formed inside the end plate of the fixed scroll, there is a problem that the number of production steps increases. In addition, since the discharge passage and the compression chamber are close to each other, heat is easily transferred from the discharged high-temperature refrigerant to the low-temperature refrigerant immediately after suction, resulting in a decrease in volumetric efficiency due to refrigerant overheating during the suction process. Had the problem of doing.

  On the other hand, by providing a digging portion on the opposite side of the compression chamber of the fixed scroll and providing a discharge port and a reed valve in the digging portion, the refrigerant in the discharge port can be transferred to the compression chamber without increasing production man-hours. There is a method to prevent efficiency reduction due to re-expansion. Furthermore, in this configuration, since the discharge port and the compression chamber can be formed far away, heat is not easily transmitted from the discharged high-temperature refrigerant to the low-temperature refrigerant immediately after the suction, and as a result, in the suction process Refrigerant overheating is reduced and volume efficiency is not reduced.

  However, since the rigidity of the fixed scroll is reduced by the digging portion, the fixed scroll is deformed particularly during high load / high compression ratio operation, and the gap between the orbiting scroll and the fixed scroll wrap tip is reduced. End up. As a result, abnormal wear due to contact per piece occurs especially during operation at a high load and a high compression ratio. In order to avoid this phenomenon, if the gap at the tip of the lap is made large, the gap is too wide during normal operation, and there is a problem in that the efficiency increases due to increased leakage during compression. Further, in order not to reduce the rigidity of the fixed scroll, it is necessary to reduce the digging portion. In this case, the efficiency reduction due to the re-expansion of the refrigerant in the discharge port to the compression chamber is increased. There was a problem such as.

  The present invention solves the above-described conventional problems, and reduces the amount of deformation of the fixed scroll during operation while preventing a decrease in efficiency due to re-expansion of the refrigerant in the discharge passage into the compression chamber. An object is to provide a scroll compressor to be realized.

  In order to solve the above-mentioned conventional problems, the scroll compressor of the present invention is provided with a digging portion on the end plate surface opposite to the compression chamber of the fixed scroll, and a discharge port and a reed valve are formed in the digging portion, In addition, a groove is provided on the end plate surface opposite to the compression chamber of the fixed scroll. Accordingly, an object of the present invention is to provide a scroll compressor that realizes high efficiency by reducing deformation of the fixed scroll while preventing a decrease in efficiency due to re-expansion of the refrigerant even during high load / high compression ratio operation. To do.

  The scroll compressor of the present invention can prevent the deformation of the fixed scroll, particularly during high load / high compression ratio operation.

  1st invention provides a digging part in the end plate surface on the opposite side to the compression chamber of a fixed scroll, and comprises a discharge port and a reed valve in the digging part, and the end plate on the opposite side to the compression chamber of a fixed scroll A groove is provided on the surface. As a result, it is possible to provide a highly efficient scroll compressor with reduced deformation of the fixed scroll, even during high load / high compression ratio operation, while preventing efficiency reduction due to re-expansion of the refrigerant.

  In the second invention, in particular, the length obtained by adding the height of the spiral wrap of the fixed scroll and the depth of the dug portion of the first invention is 0. 3 times to 0.8 times. Thereby, even during high load / high compression ratio operation, the amount of deformation of the fixed scroll can be further suppressed, so that a more efficient scroll compressor can be provided.

  In particular, the third aspect of the present invention can reduce the number of man-hours for forming grooves by forming continuous grooves in the first or second aspect of the invention. Since the amount of deformation can be suppressed, a highly efficient and inexpensive scroll compressor can be provided.

  In the fourth aspect of the invention, in particular, in the first or second aspect of the present invention, by forming a plurality of discontinuous grooves, while absorbing the deformation at the place where the moment to try to deform the fixed scroll is large, Since it can be selectively formed so that the rigidity of the end plate of the fixed scroll is not reduced at the portion where the moment is small, the deformation amount of the fixed scroll can be further suppressed even during high load / high compression ratio operation. A more efficient scroll compressor can be provided.

  In the fifth aspect of the invention, in particular, the main bearing member of the compression mechanism and the sealed container of the first to fourth aspects of the invention are fixed by welding. As a result, the end plate of the fixed scroll tends to distort in the direction opposite to the deformation due to the pressure due to the welding distortion generated in the main bearing member, so that the distortion at the time of high load / high compression ratio operation is canceled. As a result, since the deformation amount of the fixed scroll can be further suppressed, a more efficient scroll compressor can be provided.

In the sixth aspect of the invention, in particular, the high-pressure refrigerant, for example, carbon dioxide, is used as the refrigerant of the first to third aspects, so that the fixed scroll can be effectively deformed even in the case of carbon dioxide having a large pressure difference. It is possible to provide a scroll compressor that is highly effective and highly reliable.
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 sectional view of a scroll compressor according to the first embodiment of the present invention, and FIG. 2 is an enlarged view of a fixed scroll. An orbiting scroll 13 that meshes with the fixed scroll 12 between the main bearing member 11 of the crankshaft 4 fixed by welding or shrink fitting in the sealed container 1 and the fixed scroll 12 bolted on the main bearing member 11. The scroll-type compression mechanism 2 is configured by sandwiching the rotating scroll 13 and an anti-rotation mechanism 14 such as an Oldham ring that guides the orbiting scroll 13 between the orbiting scroll 13 and the main bearing member 11 to prevent the orbiting scroll 13 from rotating. The orbiting scroll 13 is eccentrically driven by the main shaft portion 4a at the upper end of the crankshaft 4 to cause the orbiting scroll 13 to move in a circular orbit, thereby forming between the fixed scroll 12 and the orbiting scroll 13. A suction pipe that communicates with the outside of the hermetic container 1 by utilizing the fact that the compression chamber 15 is smaller while moving from the outer peripheral side to the center. 6 and the refrigerant gas sucked from the suction port 17 in the outer peripheral portion of the fixed scroll 12 and compressed and the refrigerant gas becomes a predetermined pressure or more pushes the reed valve 19 from the discharge port 18 in the central portion of the fixed scroll 12. Repeatedly discharging into the sealed container 1.

  Further, the end plate on the opposite side of the compression chamber 15 of the fixed scroll 12 is formed with a digging portion 12a and an annular groove 12b. A discharge port 18 and a reed valve 19 are formed in the dug portion 12a.

  FIG. 3 is a sectional view in which the pressure acting on the fixed scroll 12 during operation is enlarged with respect to the compression mechanism 2. The force for deforming the fixed scroll 12 is a differential pressure between the compression chamber 15 and the discharge pressure acting on the opposite side of the fixed scroll 12 to the compression chamber 15. Looking at FIG. 2 focusing on this differential pressure, the pressure difference is small because the pressure is high in the central portion of the compression chamber 15, and the differential pressure is large because the outer peripheral portion is close to the suction pressure. That is, a bending moment that tends to greatly distort the fixed scroll 12 is generated in the outer peripheral portion of the compression chamber 15. This bending moment is absorbed by the groove 12b. On the other hand, the digging portion has reduced rigidity, but since the pressure difference between the upper and lower sides is small, it does not affect the distortion amount of the fixed scroll 12 as a whole. Regarding the distortion during operation with and without the groove 12b, the presence of the groove 12b can reduce the amount of distortion of the fixed scroll 12 by about 10%.

  Note that the length obtained by adding the spiral wrap height of the fixed scroll 12 and the depth of the digging portion 12 a is 0.3 times or more the end plate thickness of the fixed scroll 12, so The effect of efficiency reduction due to the re-expansion of the refrigerant into the compression chamber 15 can be suppressed, and the length obtained by adding the spiral wrap height of the fixed scroll 12 and the depth of the dug portion 12a is the fixed scroll 12. Since the rigidity of the fixed scroll 12 at the time of high load / high compression ratio operation can be ensured by setting it to 0.8 times or less of the thickness of the end plate, the spiral wrap height of the fixed scroll 12 and the dug portion By adding the length of 12a to 0.3 mm or more and 9.8 times or less of the end plate thickness of the fixed scroll 12, a more efficient blackboard can be obtained. It is possible to provide a Le compressor.

  By forming the groove 12b in an annular continuous groove, the deformation amount of the fixed scroll 12 can be suppressed even during a high load / high compression ratio operation while reducing the production man-hours for formation. The continuous groove 12b is not limited to an annular shape, and has the same effect even if it is a rectangle or other shapes.

  In addition, by forming the grooves 12b discontinuously, the rigidity of the end plate of the fixed scroll 12 is reduced at a portion where the moment when the moment to try to deform the fixed scroll 12 is particularly large, while absorbing the deformation. It is also possible to configure so that it does not occur (not shown). In this case, since the amount of deformation of the fixed scroll 12 can be further suppressed even during high load / high compression ratio operation, a more efficient scroll compressor can be provided.

  FIG. 4 shows the distortion when the compression mechanism 2 is fixed to the sealed container 1 by welding. The welding place is the main bearing member 11, and the fixed scroll 12 is approximated as a plate. As can be seen from this figure, the fixed scroll 12 is distorted in the opposite direction to the pressure deformation, and as a result, the distortion at the time of high load / high compression ratio operation is canceled. Further, since the deformation amount of the welding distortion of the fixed scroll 12 can be controlled by adjusting the welding temperature and the amount of penetration, a high load and a high compression when the refrigerant is a high-pressure refrigerant, for example, carbon dioxide. Even during the specific operation, the deformation amount of the fixed scroll 12 during the operation can be further suppressed by adjusting the welding distortion so as to be canceled as the pressure distortion.

  Note that if the refrigerant is a high-pressure refrigerant, for example, carbon dioxide, it is effective as a technique for suppressing deformation of the fixed scroll even in the case of carbon dioxide with a large pressure difference, and it is highly efficient by minimizing changes in the leakage gap due to deformation. In addition, it is possible to provide a scroll compressor in which high reliability is ensured by preventing abnormal wear due to one piece.

  As described above, the scroll compressor according to the present invention is provided with the digging portion on the end plate surface opposite to the compression chamber of the fixed scroll, the discharge port and the reed valve are formed in the digging portion, and the fixed scroll. A groove is provided on the end plate surface opposite to the compression chamber. As a result, it is possible to provide a scroll compressor that realizes high efficiency by reducing the deformation of the fixed scroll while preventing a decrease in efficiency due to re-expansion of the refrigerant even during high load / high compression ratio operation. The working fluid is not limited to a refrigerant, and can be applied to applications of scroll fluid machines such as an air scroll compressor and a scroll expander.

Sectional drawing of the scroll compressor in Embodiment 1 of this invention The enlarged view of the fixed scroll in Embodiment 1 of this invention Sectional drawing which expanded the pressure which acts on the fixed scroll in driving | operation in Embodiment 1 of this invention regarding a compression mechanism. The figure which shows the distortion at the time of welding compression fixing to the airtight container in Embodiment 1 of this invention Sectional view of a fixed scroll in a conventional scroll compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Compression mechanism 4 Crankshaft 4a Main shaft part 11 Main bearing member 12 Fixed scroll 12a Digging part 12b Groove 13 Orbiting scroll 14 Rotation restricting mechanism 15 Compression chamber 16 Intake pipe 17 Inlet 18 Outlet 19 Reed valve

Claims (6)

A compression chamber is formed between the fixed scroll and the orbiting scroll where the spiral wrap rises from the end plate, and the compression chamber is turned when the orbiting scroll is orbited along a circular path under the restriction of rotation by the rotation restriction mechanism. In a scroll compressor including a compression mechanism that performs suction, compression, and discharge by moving while changing the volume, and a discharge port and a reed valve provided between the compression space and the discharge space, A digging portion is provided in the end plate surface opposite to the compression chamber of the fixed scroll, the discharge port and the reed valve are formed in the digging portion, and the denting portion on the opposite side of the compression chamber of the fixed scroll is provided. A scroll compressor characterized in that a groove is provided on the end plate surface. A length obtained by adding the height of the spiral wrap of the fixed scroll and the depth of the digging portion is 0.3 to 0.8 times the thickness of the end plate of the fixed scroll. The scroll compressor according to claim 1. The scroll compressor according to claim 1 or 2, wherein the groove is formed by a continuous groove. The scroll compressor according to claim 1 or 2, wherein the groove is formed by a plurality of discontinuous grooves. The scroll compressor according to any one of claims 1 to 4, wherein the main bearing member of the compression mechanism section and the sealed container are fixed by welding. The scroll compressor according to any one of claims 1 to 5, wherein the refrigerant is a high-pressure refrigerant.