JP2004060535A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of properly adjusting a pressure introduced into a swirl scroll back pressure thrust support mechanism without installing a control valve in a back pressure introduction line irrespective of a variation in pressure of compressed refrigerant gas in a scroll compressor having the support mechanism. <P>SOLUTION: This swirl scroll back pressure thrust support mechanism comprises a spiral swirl scroll, a spiral fixed scroll engaged with the spiral swirl scroll, and the swirl scroll back pressure thrust support mechanism. The thrust support mechanism comprises a back pressure chamber into which the compressed refrigerant gas is introduced and a back pressure leading hole having one end part connected to the back pressure chamber to introduce fluid into the back pressure chamber. The swirl scroll is supported by the refrigerant gas introduced into the back pressure chamber. The other end part of the back pressure leading hole is provided at at least one of a groove for the tip seal of the swirl scroll or the tip seal of the fixed scroll. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a scroll compressor, and more particularly, to a support mechanism for an orbiting scroll of a scroll compressor.
[0002]
[Prior art]
A scroll compressor is generally used for compressing a refrigerant of a vehicle air conditioner. As a support structure for supporting the orbiting scroll against the thrust force acting on the orbiting scroll of the scroll compressor, a support structure having a back pressure chamber on the back side of the orbiting scroll is formed, and the refrigerant compressed in the back pressure chamber Background Art A back pressure type thrust support structure for supporting a orbiting scroll in a thrust direction by introducing gas is known.
Such a structure having a back pressure type thrust support mechanism is a kind of gas bearing, which suppresses contact between solids on a sliding surface, provides play in the support direction, and has a spring and damping action by gas. However, it has an excellent advantage as a load supporting structure.
[0003]
While the back pressure type thrust support mechanism has the above-mentioned advantages, since the compressed gas of the compressor is guided to the back pressure chamber, a back pressure load according to the cross-sectional area of the back pressure chamber can be obtained. Thrust load varies greatly. Therefore, an excessive or insufficient back pressure load occurs, and when the back pressure is excessive, the frictional force in the tip seal or the like increases, and when the back pressure is too small, the seal in the tip seal becomes insufficient, causing refrigerant gas leakage, As a result, the compression efficiency is reduced.
In addition, it is conceivable to provide a control valve on the back pressure introduction line in order to adjust the pressure of the refrigerant gas introduced into the thrust support mechanism. However, the number of parts increases, the cost increases, and the size of the entire compressor increases. Also invite.
[0004]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and when a back pressure type thrust support mechanism is used as a support mechanism of an orbiting scroll of a scroll compressor, a control valve for adjusting the back pressure is not provided. It is an object of the present invention to provide a device capable of appropriately and automatically adjusting the pressure introduced into the thrust support mechanism regardless of the fluctuation of the pressure of the compressed refrigerant gas. It is another object of the present invention to prevent the back pressure load from becoming excessive or insufficient, not to reduce the compression efficiency, and to extend the life of the tip seal.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, in order to achieve the above-described object, the scroll compressor has a housing that forms a main structure with an outer shell of the compressor, and is partially supported by the housing and partially supported by the housing. A rotary shaft having an eccentric crank portion, a orbiting scroll having a spiral blade portion and an end plate and revolving by being driven by the crank portion of the rotary shaft, and a spiral blade engaged with the rotary scroll A fixed scroll having a portion and an end plate and fixed to the housing; and a thrust support mechanism for supporting the orbiting scroll in the axial direction of the rotating shaft. When the orbiting scroll makes a revolving motion, while the plurality of working chambers formed between the orbiting scroll blades and the fixed scroll blades move from the outer periphery toward the center, A continuous reduction in the volume of the working chamber compresses the fluid in the working chamber. The compressor includes a groove provided at a tip of a blade portion of the orbiting scroll, a tip seal provided at the groove, a groove provided at a tip of a blade portion of the fixed scroll, and a chip provided at the groove. And a thickness of the tip seal is greater than a depth dimension of the groove in which the tip seal is installed. Since the thrust support mechanism has a back pressure chamber into which the compressed fluid is introduced, and a back pressure conducting hole having one end connected to the back pressure chamber to introduce the fluid, The orbiting scroll is supported by the fluid introduced into the back pressure chamber. Since the other end of the back pressure conducting hole is connected to at least one of the groove for the tip seal of the orbiting scroll or the groove for the tip seal of the fixed scroll, the working chamber The compressed fluid is introduced into the back pressure chamber, and the opening / closing of the conduction hole is enabled by the tip seal.
[0006]
With this configuration, even if the back pressure fluctuates without providing a control valve for adjusting the back pressure in the back pressure type thrust support mechanism, the tip seal can be housed in order to obtain an optimum back pressure load. When the back pressure load is larger than the thrust load (excess back pressure), the orbiting scroll is pressed against the fixed scroll by providing the back pressure conducting hole in the groove formed, so that the tip seal is crushed and the back pressure conducts. Blocks the holes and suppresses the supply of excessive back pressure. When the back pressure is insufficient (back pressure load ≦ thrust load), the orbiting scroll moves in the direction away from the fixed scroll, so that the conduction hole is opened and the insufficient back pressure can be supplied.
Accordingly, the pressure introduced into the thrust support mechanism can be appropriately and automatically adjusted without providing a control valve for adjusting the back pressure in the back pressure introduction line, regardless of the fluctuation of the pressure of the compressed refrigerant gas as the back pressure. In addition, the back pressure can be adjusted without excessive or insufficient back pressure, the compression efficiency is not reduced, and the life of the tip seal can be extended.
[0007]
According to a second aspect of the present invention, in the first aspect, the thrust support mechanism is disposed between a back surface of an end plate of the orbiting scroll and a portion of the housing facing the back surface. It is characterized by.
With this configuration, the second aspect of the present invention discloses an embodiment that embodies the present invention.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, one embodiment of a scroll compressor of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a schematic cross-sectional view of a scroll compressor according to one embodiment of the present invention. The compressor of the present embodiment is a hermetic type and is a compressor of an air conditioner for a vehicle or the like. The compressor includes a cylindrical housing 1 surrounding the entire compressor, and lids 2 and 3 at both ends, which are hermetically joined by welding. In the housing 1, a motor part 30 as a driving part is provided at a front part, a middle housing 6 constituting a central part of the housing 1 at a center part, and a compression part 40 for compressing a refrigerant at a rear part. .
[0009]
The motor unit 30 includes a stator 4 fixed to the housing 1, an armature 5 formed of a plurality of permanent magnets therein, and a rotating shaft 8 passing through the center inside the motor. Is configured. The armature 5 is fixedly supported by a rotating shaft 8, and the rotating shaft 8 is rotatably supported by the lid 2 and the middle housing 6 via bearings 7a and 7b.
[0010]
The crank-shaped end 8a of the rotating shaft 8 is connected to the compression section 40 via a revolution drive section, and transmits the driving force of the motor section 30 to the compression section 40. That is, the shaft end 8a, the bush 9, the bearing 7c, and the boss 10a of the orbiting scroll 10 form a revolution drive unit. The fixed scroll 11 is fixed to the middle housing 6, and an automatic prevention mechanism 12 is provided between the fixed scroll 11 and the end plate 10 b of the orbiting scroll 10 to allow only the revolution of the orbiting scroll 10 and prevent the orbiting scroll from rotating. Have been The orbiting scroll 10 has a spiral blade 10c and an end plate 10b. The fixed scroll 11 has a spiral blade 11c and an end plate 11b that mesh with the spiral blade 10c of the orbiting scroll 10. Have. The compression unit 40 includes the orbiting scroll 10, the fixed scroll 11, the revolving drive unit, and the like.
[0011]
With the above configuration, when the rotating shaft 8 rotates, the rotating force is transmitted to the orbiting scroll 10 via the end 8a of the rotating shaft 8, the bush 9, and the bearing 7c. Since the end 8a is eccentric with respect to the rotation shaft 8 and the rotation of the orbiting scroll 10 is prevented by the rotation preventing mechanism 12, the transmitted rotational force causes the spiral orbiting scroll 10 to also fix the spiral orbit. The scroll 11 is revolved. At this time, an operating chamber 13 is formed between the orbiting scroll 10 and the fixed scroll 11, and the volume of the operating chamber 13 continuously decreases from the outer peripheral side toward the center according to the revolving motion of the orbiting scroll 10. As a result, the refrigerant sucked from the outer peripheral side of the working chamber 13 is compressed and discharged to the discharge chamber 16 through the discharge port 23 provided at the center of the fixed scroll 11. In this way, the compressor operates by the rotation of the motor.
[0012]
In the operation of the compressor as described above, in order to perform good compression, both the end portions of the orbiting scroll 10 and the fixed scroll 11 need to be sealed so as to prevent leakage of the refrigerant. Accordingly, grooves 25, 24 are provided on the end faces of the blade portions 10c, 11c of the orbiting scroll 10 and the fixed scroll 11, respectively, and chip seals 21, 22 are provided in the respective grooves 25, 24. . The tip seals 21 and 22 are preferably made of an elastic material such as rubber.
[0013]
An axial thrust force of the rotating shaft 8 due to gas compression or the like acts on the orbiting scroll 10 together with the rotating force. A thrust support mechanism 20 is provided to receive the thrust force. The thrust support mechanism 20 is provided between the middle housing 6 and the rear surface of the end plate of the orbiting scroll 10 as shown in FIG. In the present embodiment, the scroll support mechanism 20 includes a concave portion 15 provided in the middle housing 6 and a convex portion 14 provided in the orbiting scroll 10, and the convex portion 14 is provided in the concave portion 15. The back pressure chamber 15a is formed by being arranged to be accommodated. A compressed refrigerant is introduced into the back pressure chamber 15a, and supports the orbiting scroll 10 in the axial direction by the pressure of the refrigerant. The size of the back pressure chamber 15a is set so that the thrust force of the back pressure chamber 15a is slightly larger than the thrust force of the compressor so as to oppose the thrust force of the compressor and exert the sealing force at the tip seals 21 and 22. Selected. Therefore, in this way, the pressure of the high-pressure gas in the back pressure chamber 15a and the tip seals 21 and 22 cooperate to seal the space between the orbiting scroll 10 and the fixed scroll 11, thereby preventing leakage of the refrigerant gas in the working chamber 13. I do.
[0014]
In the present embodiment, when a compressor is used for an air conditioner, when the load of the air conditioner changes, the operating pressure of the compressor changes, so that the pressure in the back pressure chamber 15a is not constant. Therefore, if the pressure in the back pressure chamber 15a is too high, the pressure for pressing the tip seals 21 and 22 will be too high, causing problems such as increased wear of the tip seals 21 and 22. On the other hand, if the pressure in the back pressure chamber 15a is too low, there arises a problem that the tip seals 21 and 22 are insufficiently sealed.
In order to cope with such a problem, in the present embodiment, a conduction hole 17 is provided as a passage for introducing the refrigerant gas into the back pressure chamber 15a, and one end of the conduction hole 17 is provided with the protrusion 14. The other end is connected to the groove 25 of the orbiting scroll 10. Therefore, the conduction hole 17 is provided in the orbiting scroll 10. FIG. 2 shows a front view of the blade portion of the orbiting scroll 10 and shows an example of a position of the conduction hole 17 in the groove 25. By providing the refrigerant gas inlet of the communication hole 17 in the groove 25, the pressure of the working chamber 13 is introduced into the back pressure chamber 15a, and the communication hole 17 can be opened and closed by the operating pressure of the refrigerant gas.
[0015]
Next, the opening and closing mechanism of the back pressure conducting hole 17 in the present embodiment will be described with reference to FIGS.
In FIG. 3, since the condition of thrust load ≦ back pressure load is satisfied, the load of the orbiting scroll 10 pressed against the fixed scroll 11 increases, and the load is supported by the tip seals 21 and 22. At this time, since the thickness of the tip seal 21 is larger than the depth of the groove 25 of the tip seal, the back pressure conducting hole 17 is closed. Therefore, the pressure in the back pressure chamber 15a does not increase any more, and the pressing force on the tip seals 21 and 22 is limited.
[0016]
In FIG. 4, since the state of thrust load ≧ back pressure load is satisfied, the load of the orbiting scroll 10 in the direction away from the fixed scroll 11 increases, and the thrust load is supported by the thrust support mechanism 20 on the end plate side of the orbiting scroll 10. Is done. At this time, the tip seal 21 floats toward the fixed scroll 11 due to the back pressure acting on itself, and the back pressure conducting hole 17 is opened. Therefore, in this case, the state in which the refrigerant gas is always introduced into the back pressure chamber 15a is maintained. The tip seal 21 is held by a gas having compressibility (elasticity), and proper pressure is applied to the tip seals 21 and 22 to prevent a defective seal.
[0017]
Next, effects and operations of the above embodiment will be described.
The following effects can be expected from the compressor of the above embodiment of the present invention.
-The conduction hole can be opened and closed appropriately by the tip seal, and the pressure of the gas introduced into the thrust support mechanism can be automatically and appropriately adjusted.
・ It is not necessary to provide a control valve for back pressure adjustment in the back pressure introduction line.
The pressure introduced into the thrust support mechanism can be appropriately adjusted irrespective of fluctuations in the pressure of the refrigerant gas to be compressed.
-By doing so, the compression efficiency of the compressor can be prevented from lowering without the back pressure load becoming excessive or insufficient.
・ The life of the tip seal can be extended.
-To provide a compressor with stable efficiency and reliability by always maintaining good sealing performance in chip seals.
[0018]
[Another embodiment]
The above embodiment is an example of the present invention, and the present invention is not limited by the embodiment, but is defined only by matters described in the claims. It is feasible.
Apart from the present embodiment, the conduction hole 17 may be connected to the groove 24 of the fixed scroll 11. In this case, the conduction hole 17 can be provided so as to pass through the fixed scroll 11 and the middle housing 6.
Since the optimum control pressure is determined by the cross-sectional area of the back pressure chamber 15a, the position of the back pressure conducting hole 17 may be any position of the grooves 25 and 24 of the tip seal.
[0019]
Further, in the thrust support mechanism 20, a sealing means such as an O-ring may be provided between the convex portion 14 and the concave portion 15.
In the present embodiment, the concave portion 15 and the convex portion 14 are formed integrally with the middle housing 6 and the orbiting scroll 10, respectively, but may be provided separately.
Further, in the present embodiment, the convex portion 14 is provided on the orbiting scroll 10 side, and the concave portion 15 for accommodating the convex portion 14 is provided on the opposed middle housing 6 side. Conversely, the concave portion 15 is provided on the orbiting scroll 10 side. It is also possible to provide the convex portion 14 on the middle housing 6 side, and a similar effect can be obtained.
[0020]
In this embodiment, an example of a so-called hermetic scroll compressor having a built-in drive motor has been described. However, the present invention can be similarly applied to a so-called open scroll compressor that performs compression by obtaining external power such as an engine. .
In the above description of the embodiment, the scroll compressor of the present invention has been described for use in an air conditioner, but the present invention is not limited to this.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a scroll compressor according to an embodiment of the present invention.
FIG. 2 is a schematic front view of the orbiting scroll of the scroll compressor according to one embodiment of the present invention, in which a conduction hole is provided in a groove of a tip seal.
FIG. 3 shows an opening / closing mechanism of a conduction hole in the thrust support mechanism of the orbiting scroll according to one embodiment of the present invention, and shows a state in which the conduction hole is closed.
FIG. 4 shows an opening / closing mechanism of a conduction hole in the thrust support mechanism of the orbiting scroll according to one embodiment of the present invention, and shows a state where the conduction hole is opened.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Lid 3 ... Lid 4 ... Stator 5 ... Armature 6 ... Middle housing 8 ... Rotating shaft 9 ... Bush 10 ... Revolving scroll 11 ... Fixed scroll 13 ... Working chamber 14 ... Convex part 15 ... Concave part 15a ... Back Pressure chamber 16 Discharge chamber 17 Conducting hole 20 Thrust support mechanism 21 Tip seal 22 Tip seal 24 Groove 25 Groove 30 Motor part 40 Compression part

Claims (2)

In a scroll compressor for compressing a fluid, the compressor includes:
A housing forming a main structure with an outer shell of the compressor;
A rotating shaft which is supported by the housing and has a partially eccentric crank portion,
An orbiting scroll having a spiral blade portion and an end plate and having a revolving motion driven by a crank portion of the rotating shaft;
A fixed scroll having a spiral blade portion and an end plate that mesh with the orbiting scroll and fixed to the housing;
A thrust support mechanism that supports the orbiting scroll in the axial direction of the rotating shaft,
When the orbiting scroll makes a revolving motion, while the plurality of working chambers formed between the orbiting scroll blades and the fixed scroll blades move from the outer periphery toward the center, The volume of the working chamber is continuously reduced to compress the fluid in the working chamber,
The compressor is
A groove provided at the tip of the blade portion of the orbiting scroll, a tip seal provided at the groove, a groove provided at a tip of the blade portion of the fixed scroll, and a tip seal provided at the groove. Have,
The thickness of the tip seal is greater than the depth dimension of the groove where the tip seal is installed,
The thrust support mechanism,
A back pressure chamber into which the compressed fluid is introduced;
A back-pressure chamber having one end connected to the back-pressure chamber and introducing a fluid, so that the orbiting scroll is supported by the fluid introduced into the back-pressure chamber,
The other end of the back pressure conducting hole is connected to at least one of the groove for the tip seal of the orbiting scroll or the groove for the tip seal of the fixed scroll,
Thereby, the compressed fluid in the working chamber is introduced into the back pressure chamber, and the opening / closing of the conduction hole is enabled by the tip seal. The apparatus of claim 1, wherein the thrust support mechanism is disposed between a back surface of the end plate of the orbiting scroll and a portion of the housing facing the back surface.

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