JP2006009614A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll compressor capable of realizing high efficiency and high reliability by suppressing a lowering of sealing force of an annular seal member even when using a high pressure refrigerant such as CO<SB>2</SB>and preventing an increase of compression loss, an increase of sliding loss, a lowering of volumetric efficiency, or the like caused by a leakage of high-temperature and high-pressure oil to a compression mechanism part. <P>SOLUTION: An outer peripheral radial clearance between the annular seal member and an annular groove to which the annular seal member is fitted, is set to a clearance almost disappearing with the thermal expansion of the annular seal member during the operation of the scroll compressor, and the annular seal member is provided with a cutout part having a flexible structure part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a scroll compressor used in a refrigeration air conditioner for business use, home use, or vehicle use, or a heat pump hot water supply system.

  Conventionally, there has been an annular seal member of this type of scroll compressor as shown in FIG. (For example, refer to Patent Document 1).

  The annular seal member is fitted and mounted in an annular groove provided on the surface of the bearing component that faces the rear face of the end plate, and the annular seal member is a ring shape that has a normal cutting location and is substantially straight in a substantially radial direction. A cutting portion having a cutting surface is provided, and an angle formed between a direction substantially parallel to the cutting surface and a circumferential direction of the annular seal member is set to 20 ° to 60 °, and the cross-sectional shape thereof is a rectangle. This cutting part plays a role of preventing the leakage of the annular seal member in the axial direction of the annular seal member by tightly fitting in the outer circumferential direction of the annular groove by sliding the cut part due to the high pressure caused by the discharge pressure during operation of the scroll compressor Was played.

As described above, this annular seal member is compressed in the compression work space in the space (inward side of the annular seal member) surrounded by the annular seal member between the rear surface of the swivel end plate and the bearing component and the swivel drive engaging portion. A high pressure is applied due to the discharge pressure of the refrigerant gas, and this high pressure generates a back pressure (axial pressure) on the back of the swivel end plate, and the annular seal member is pressed against the back side (sliding surface side) of the swivel end plate with the same pressure. Yes. Further, between the back surface of the swivel mirror plate opposite to the swirl spiral blade and the bearing part, the pressure applied to the back surface of the mirror plate and the pressure applied to the back surface of the swivel mirror plate lower than the discharge pressure are partitioned. This annular seal member can maintain a differential pressure between the inner side of the annular seal member, that is, the crankshaft side, and the outer side, that is, the outer peripheral side of the swirl spiral blade end plate, by close contact with the sliding parts that slide relative to each other. I have to.
Japanese Patent Laid-Open No. 10-196560

  However, in the conventional configuration, the cutting portion of the annular seal member, which has been responsible for preventing leakage of the annular seal member in the outer circumferential axis direction, becomes a leakage path from the high-pressure side to the low-pressure side as the working fluid increases in pressure. The specific gravity has increased and has become a major factor in reducing efficiency. For example, when changing from R22 refrigerant to R410A refrigerant, etc., the difference in pressure between the high pressure and the low pressure was about twice as large. Therefore, leakage due to optimization of the material of the annular seal member and the shape of the cut portion It was possible to maintain the same level as before. However, when the transition from the R410A refrigerant to the high-pressure refrigerant of CO2 which is a natural refrigerant occurs, a differential pressure more than 5 times that of R410A is generated, so it is difficult to prevent leakage with the conventional method, and the performance must be reduced. There wasn't. Furthermore, because of the very large differential pressure, the outer peripheral side cut end of the cut portion of the annular seal member is deformed to the outer peripheral side of the back of the swivel end plate configured with a pressure lower than the discharge pressure. As the annular seal member is deformed in this manner, the sealing force is reduced, and high temperature and high pressure oil leaks from the high pressure portion to the low pressure portion.

Moreover, in the case of the prior art which does not provide the cutting part in the annular seal member, there is no leakage from the cutting part. However, in such a conventional technique, when the temperature of the annular seal member rises during high load operation, the annular seal member is deformed due to thermal expansion, and a gap is formed between the circumferential direction of the annular seal member and the swivel end plate. . As a result, leakage of high-temperature high-pressure oil or the like from the high-pressure part to the low-pressure part was caused, and as a result, the performance under high load was reduced.

  In order to solve the above-described conventional problems, the present invention sets the clearance between the annular groove engaged with the annular seal member and the outer circumferential radial direction of the annular seal member so that it is substantially eliminated by the thermal expansion of the annular seal member during the operation of the scroll compressor. Thus, the annular seal member is provided with a notch for providing the flexible structure.

  With this configuration, the flexible structure portion of the annular seal member is deformed at a high operating temperature of the scroll compressor, and the abnormal deformation due to thermal expansion can be absorbed while ensuring the sealing performance.

  The scroll compressor of the present invention can suppress a decrease in the sealing force of the annular seal member even when a high-pressure refrigerant such as CO2 is used, and an increase in compression loss due to leakage of high-temperature high-pressure oil or the like to the compression mechanism. An increase in sliding loss and a decrease in volumetric efficiency can be prevented, and high efficiency and high reliability can be realized.

  According to a first aspect of the present invention, the outer circumferential radial gap between the annular groove and the annular seal member to be engaged with each other is set so as to be substantially eliminated by thermal expansion of the annular seal member when the scroll compressor is operated. This is a configuration in which a notch for holding the portion is provided. With such a configuration, even if the annular seal member undergoes thermal expansion at a high operating temperature of the scroll compressor, the flexible structure portion provided in the annular seal member absorbs deformation due to thermal expansion, and the flexible structure portion has a high pressure. It is deformed by a low-pressure differential pressure, enhances the close fit between the annular groove and the annular seal member, and suppresses leakage of high-temperature high-pressure oil or the like from the high-pressure part to the low-pressure part.

  The second invention is particularly the first invention, wherein the notch is provided in the axial thickness on the outer peripheral side of the annular seal member, and the thermal expansion and pressure in the outer peripheral axial direction of the annular seal member The deformation | transformation by becomes easy and can improve the close fitting property of an annular groove and an annular seal member.

  The third invention is the first invention in particular, in which the notch is provided on the outer peripheral portion of the sliding contact surface with the swirl spiral part of the annular seal member, and has the same effect as the second invention, Since the slidable contact area between the annular seal member and the swirl spiral component can be reduced, the sliding loss on the slidable contact surface can be reduced.

  The fourth aspect of the invention is particularly the second or third aspect of the invention, wherein when the outer peripheral side thickness of the annular seal member is b1 and the inner peripheral side thickness is b2, b2 <b1. With this configuration, the pressing force in the outer circumferential direction of the annular seal member due to the pressure difference can be increased, and the close fitting property between the annular groove and the annular seal member can be further enhanced, and the annular seal member is in the relationship of b2 <b1. Since the inner peripheral side rigidity of the sheet is low, it is possible to further improve the close fit by deformation.

  The fifth invention is the first to fourth inventions, in particular, using high pressure and high differential pressure carbon dioxide as the working fluid. In the case of carbon dioxide, the differential pressure at the time of operation is larger than that of the conventional working fluid and the operating temperature is increased, so that the effects of the first to fourth inventions can be more effectively exhibited than the conventional working fluid. Therefore, it is possible to suppress a decrease in efficiency of the scroll compressor when using carbon dioxide, which is generally used.

(Embodiment 1)
FIG. 1 shows a cross-sectional view of a scroll compressor according to an embodiment of the present invention. A compression mechanism 2 and a stator 3 a of an electric motor 3 that drives the compression mechanism 2 are fixed, and a crankshaft 4 that drives the compression mechanism 2 is coupled to a rotor 3 b of the electric motor 3. The compression mechanism 2 includes a fixed spiral blade part 12 having a fixed spiral blade 12b formed integrally with the fixed mirror plate 12a, and a swirl spiral blade 13b that meshes with the fixed spiral blade 12b to form a plurality of compression work spaces. The swirl spiral blade part 13 formed on 13a, the rotation restraint part 14 for preventing the rotation of the swirl swirl blade part 13 and turning only, and the swivel provided on the opposite side of the swirl mirror blade 13b of the swirl end plate 13a The swing engagement plate 5 includes a drive engagement portion 5, an eccentric drive engagement portion 4 a into which the crankshaft 4 provided on the inward side of the swing drive engagement portion 5 is fitted, and a bearing component 11 that supports the crankshaft 4. The pressure applied to the back surface of the swivel end plate 13a is applied to the back surface on the center side of the swivel end plate 13a between the back surface (end surface of the end plate) opposite to the swirl spiral blade 13b of 13a and the bearing component 11. An annular seal member 46 is provided to partition the output pressure and the pressure applied to the back surface on the outer peripheral side of the swivel end plate 13a lower than the discharge pressure, and the annular seal member 46 is provided on the surface of the bearing component 11 facing the back surface of the swivel end plate 13a. The annular groove 47 is fitted and mounted. The lubricating oil 6 stored in the hermetic container 1 is supplied to the inside of the annular seal member 46 through the through hole 26 provided in the crankshaft 4. The annular seal member 46 is made of, for example, a fluorine-based synthetic resin material having a substantially rectangular cross section with good heat resistance and wear resistance.

  The outer circumferential radial gap between the annular groove 47 and the annular seal member 46 fitted into the annular seal member 46 is set so as to be substantially eliminated by thermal expansion of the annular seal member 46 during operation of the scroll compressor. This can be configured because the thermal expansion coefficient of the annular seal member 46 is larger than that of the bearing part 11. In the present embodiment, the annular seal member 46 is made of a fluorine-based synthetic resin material or the like, and the bearing component 11 in which the annular groove 47 is formed is made of an iron-based material.

  FIG. 2 is a plan view of the annular seal member 46 according to the embodiment of the present invention, and FIG. 3 is a cross-sectional view of the annular seal member 46 according to the embodiment of the present invention taken along line AA in FIG. is there. As shown in FIG. 3, the annular seal member 46 is provided with a notch 101 for providing a flexible structure. In FIG. 3, as a representative example, the notch 101 is provided in the axial thickness on the outer peripheral side of the annular seal member 46, but within the axial thickness on the inner peripheral side, the swirl spiral blade 13 and A cutout portion 101 (a cut-out portion) may be provided on the anti-sliding contact surface side or inside the annular seal member 46.

  The clearance between the annular groove 47 and the annular seal member 46 fitted into the annular seal member 46 is set so as to be substantially eliminated by thermal expansion of the annular seal member 46 during operation of the scroll compressor. There is some assembling gap between the annular groove 47 and the annular seal member 46 when the operation is stopped or when the operation is stopped, but the temperature of each part rises during the operation of the scroll compressor, and the annular seal member 46 is also in close contact with the annular groove 47 due to thermal expansion. I agree. When the annular seal member 46 does not have a flexible structure, the deformation of the annular seal member 46 due to thermal expansion becomes large and distorted, and the close fitting property with the annular groove 47 is reduced, and the swirl spiral blade 13 and As a result, the adhesion of the slidable contact surface is impaired and leakage occurs. The flexible structure part plays a role of absorbing such a terrible deformation.

  Even when the annular seal member 46 has a structure in which the thermal expansion of the annular seal member 46 is small, even if a larger thermal deformation occurs due to the provision of the flexible structure portion by providing the notch 101, the adhesive compatibility is achieved. High sealing performance can be ensured while maintaining the above.

  When the close fitting property between the annular groove 47 and the annular seal member 46 or the close contact property on the sliding contact surface side with the swirling spiral blade 13 is lowered, the performance is greatly deteriorated for the following reason. This is an extremely important item for improving efficiency and reliability.

As the scroll compressor is driven, compression is performed in a space (inside of the annular seal member 28) surrounded by the annular seal member 46 and the orbiting drive engagement portion 5 between the back surface of the orbiting end plate 13 a and the bearing component 11. A high pressure is generated by the discharge pressure of the refrigerant gas 27 compressed in the space. Due to this high pressure, back pressure (axial pressure) is generated on the back surface of the swivel end plate 13a, and the annular seal member 46 is pressed against the back side (sliding surface side) of the swivel end plate 13a with the same pressure. A differential pressure is generated via the annular seal member 28 on the outer peripheral side of the pressure lower than the discharged pressure. At this time, the annular seal member 46 is configured to close a gap existing between the back surface of the swivel end plate 13 a and the bearing component 11. This means that the annular seal member 46 protrudes from the annular groove 47 of the bearing part 11 by a gap existing between the back surface of the turning end plate 13 a and the bearing part 11. In this state, a high pressure is applied radially to the annular seal member 46, so that the high-temperature and high-pressure lubricating oil 6 leaks to the outer peripheral side of the back surface of the swivel end plate 13a configured with a low pressure. When such a state occurs, the high-temperature and high-pressure lubricating oil 6 leaks from the high-pressure part to the low-pressure part, and the high-temperature and high-pressure lubricating oil 6 also leaks to the suction part of the compression mechanism 2. The volume efficiency of the compression mechanism 2 is deteriorated and the compression performance is lowered.

  However, by using this embodiment, it is possible to provide a scroll compressor in which the sealing performance of the annular seal member 46 is enhanced and high reliability and high compressor efficiency are maintained.

  When the notch 101 is provided in the axial thickness on the outer peripheral side of the annular seal member 46, the sealing effect can be further enhanced as follows.

  FIG. 4 shows an enlarged cross-sectional view of the main parts of the turning drive engagement portion 5, the annular seal member 46, and the annular groove 47 in the embodiment of the present invention.

  As described above, during the operation of the scroll compressor, the annular seal member 46 is deformed by pressure and thermal expansion, but is moderately relaxed by the flexible structure and a good seal is secured. Further, as shown in FIG. 4, when the notch 101 is provided in the axial thickness on the outer peripheral side of the annular seal member 46, the outer peripheral lower end portion of the annular seal member 46 is swirl spirally due to the differential pressure in the axial direction. Deformation in the direction of the blade component 13. Due to this deformation, even when the surface property of the outer periphery of the annular seal member 46 is not good, the sealing performance between the annular seal member 46 and the annular groove 47 is further enhanced. Further, since the notch 101 also acts as an oil reservoir for the lubricating oil 6, the sealing performance between the annular seal member 46 and the annular groove 47 is improved from this viewpoint.

  As described above, when the notch 101 is provided in the axial thickness on the outer peripheral side of the annular seal member 46, the outer peripheral axial direction of the annular seal member 46 is easily deformed by thermal expansion and pressure, The tight fit between the annular groove 47 and the annular seal member 46 can be further enhanced, and a higher performance scroll compressor can be provided.

(Embodiment 2)
FIG. 5 shows an enlarged cross-sectional view of the main parts of the turning drive engagement portion 5, the annular seal member 46, and the annular groove 47 in the second embodiment of the present invention.

  As shown in FIG. 5, the cutout portion 101 is provided on the outer peripheral portion of the sliding contact surface of the annular seal member 46 with the swirl spiral component 13. Although the effect of the flexible structure portion by the notch 101 is substantially the same as that of the first embodiment, the sliding contact area between the annular seal member 46 and the swirl spiral member 13 can be reduced. The sliding loss on the surface can be reduced. Further, since the notch 101 is provided in the vicinity of the most slidable contact surface as the temperature rise during operation of the annular seal member 46, the maximum effect can be expected as thermal deformation relaxation of the flexible structure portion. .

As described above, in the present embodiment, not only leakage from the periphery of the annular seal member 46 can be suppressed and efficiency can be improved, but also a reduction in sliding loss between the annular seal member 46 and the swirling spiral component 13 can be realized. And a more efficient scroll compressor can be provided.

(Embodiment 3)
FIG. 6 shows an enlarged cross-sectional view of the main parts of the turning drive engagement portion 5, the annular seal member 46, and the annular groove 47 in the third embodiment of the present invention. The notch 101 is an embodiment provided in the axial thickness on the outer peripheral side of the annular seal member 46.

  When the outer peripheral side thickness of the annular seal member 46 is b1 and the inner peripheral side thickness is b2, b2 <b1. With this configuration, the gap between the bottom surface of the annular seal member 46 and the annular groove 47 is formed in a wedge shape so that high pressure can easily enter, and the pressing force of the annular seal member 46 against the swirling spiral component 13 is increased, so The sex can be further enhanced.

(Embodiment 4)
In the first to third embodiments of the present invention, when carbon dioxide, which is a high-pressure refrigerant, is used as the refrigerant, the differential pressure at the time of operation is larger than that of the conventional working fluid, and the operating temperature is increased, so that the first to third embodiments are used. It is possible to further effectively enhance the effect of the fourth invention.

  When carbon dioxide is used as the working fluid, the differential pressure during operation reaches 5 times or more that when the HFC working fluid is used, and the operating temperature rises by about 50 ° C. or more. The scroll compressor using carbon dioxide has a problem that the efficiency of the compressor is greatly reduced with respect to the conventional working fluid due to the problems of high differential pressure and high temperature operation. However, by using the embodiment of the present invention, it is possible to effectively suppress a decrease in efficiency due to leakage around the annular seal member 46 in particular, and to provide a scroll compressor that approaches the compressor efficiency of a conventional working fluid. Is possible.

  As described above, the scroll compressor according to the present invention can achieve high performance by suppressing leakage from the periphery of the annular seal member by effectively utilizing the thermal deformation and pressure deformation of the annular seal member. In addition, the working fluid is not limited to the conventional HFC-based refrigerant, but can also be applied to a heat pump type hot water supply system using carbon dioxide, which is a natural refrigerant, an air scroll compressor, a vacuum pump, a scroll type expander It can also be applied to the use of scroll fluid machines such as.

Sectional drawing of the scroll compressor in Embodiment 1 of this invention The top view of the cyclic | annular sealing member in Embodiment 1 of this invention The principal part expanded sectional view of the cyclic | annular seal member in Embodiment 1 of this invention. The principal part expanded sectional view of the annular seal member periphery in Embodiment 1 of this invention The principal part expanded sectional view of the annular seal member periphery in Embodiment 2 of this invention The principal part expanded sectional view of the annular seal member periphery in Embodiment 3 of this invention Plan view of a conventional annular seal member

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Compressor mechanism 3 Electric motor 3a Stator 3b Rotor 4 Crankshaft 4a Eccentric drive engagement part 5 Rotation drive engagement part 6 Lubricating oil 11 Bearing part 12 Fixed spiral blade part 12a Fixed end plate 12b Fixed spiral blade 13 Rotation Swirl blade part 13a Swivel end plate 13b Swirl spiral blade 26 Through hole 46 Annular seal member 47 Annular groove 101 Notch 201 Cut part

Claims (5)

An airtight container is provided with an electric motor and a compression mechanism that drives the electric motor to compress the working fluid, and the compression mechanism includes a fixed spiral blade component having a fixed spiral blade formed on a fixed end plate, and the fixed spiral blade. A swirl swirl vane component formed on a swirl end plate that engages with the component to form a plurality of compression working spaces; A crankshaft that pivotally drives the spiral component, a bearing component having a main bearing that supports the main shaft formed on the crankshaft, and an eccentricity provided on the crankshaft on the back surface of the pivot plate opposite to the swirl spiral blade And a swirl drive engagement part that engages with the drive engagement part to drive the swirl swirl blade part, and the thrust force of the swirl swirl blade part is supported by the fixed swirl blade part, and In order to partition the pressure applied to the rear face of the end plate on the outer side of the rotary drive engaging section into a discharge pressure applied to the swivel drive engaging section side and a pressure lower than the discharge pressure applied to the outer peripheral side of the rear face engaging section. In the scroll compressor in which the annular seal member is provided in the annular groove formed in the bearing part, the outer circumferential radial clearance between the annular groove and the annular seal member is substantially increased by the thermal expansion of the annular seal member during operation of the scroll compressor. A scroll compressor characterized in that a gap is set to be eliminated, and a cutout portion is provided for allowing the annular seal member to have a flexible structure portion. The scroll compressor according to claim 1, wherein the notch is provided in an axial thickness on the outer peripheral side of the annular seal member. 2. The scroll compressor according to claim 1, wherein the notch is provided on the outer peripheral portion of the sliding contact surface with the swirl spiral member of the annular seal member. The scroll compressor according to any one of claims 2 to 3, wherein b2 <b1 when the outer peripheral side thickness of the annular seal member is b1 and the inner peripheral side thickness is b2. The scroll compressor according to any one of claims 1 to 4, wherein the working fluid is carbon dioxide.