JPH0727063A - Scroll type compressor - Google Patents

Abstract

PURPOSE:To attain an operation of higher reliability excellent in a starting characteristic at restarting time by preventing excessive pressing force from being generated between a fixed scroll and a turning scroll immediately after stopping the operation. CONSTITUTION:A compressor comprises a sealed case 20, fixed scroll 33 provided unturnably and vertically movably in a frame 22 fixed to this case 20 and a turning scroll 27 combined with this fixed scroll 33 through compression space 30 and driven to be turned to compress a fluid sucked into the compression space 30. Further in the case 20, a compliance mechanism is constituted between the case and a back surface side of the fixed scroll 33, to also provide a back pressure plate 35 for partitioning this fixed scroll 33 and a delivery chamber 36, and in the center of this back pressure plate 35, a check valve 37 for preventing a high pressure fluid in this delivery chamber 36 from reversely flowing in the back surface side of the fixed scroll 33 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type compressor in which a swirling body having two blades processed into a spiral shape is combined and a working fluid such as a refrigerant is compressed by a relative swirling motion between them. Is.

[0002]

2. Description of the Related Art A scroll type compressor is a combination of two spirally processed blades, namely, a fixed scroll blade and a swirl scroll blade. It is for compression.

That is, as shown in FIG. 2, the scroll type compressor has a swirl scroll 2 having the swirl scroll vanes 2a in the upper part of a closed case 1 and a fixed scroll.
The compression mechanism section 4 is formed by combining the fixed scroll 3 having the blades 3a.

The swivel scroll 2 is loosely fitted to the upper end of a crankshaft 5 of a motor (not shown) provided in the lower portion of the hermetic case 1, and swivels with respect to the fixed scroll 3. It is designed to be driven. On the other hand, the fixed scroll 3 is a frame fixed in the closed case 1.
It is fixed to the arm 6 in a non-turnable state.

In this scroll type compressor, the fixed scroll 3 is swung with respect to the fixed scroll 3 so that the fixed scroll blade 2a and the swirl scroll blade 3a are rotated.
While moving the compression space 7 partitioned by and, the fixed scroll 3 is moved from the outside in the radial direction to the center,
The sucked working fluid (refrigerant, etc.) is compressed.

The compressed working fluid is discharged to the upper part from a discharge port 8 formed in the center of the fixed scroll 3 as shown by a dotted arrow in the figure, and then to the upper part of the fixed scroll 3. The discharge chamber 9 provided is once filled. The discharge chamber 9 is provided with a discharge pipe 10 for discharging the working fluid to the outside, and the compressed working fluid is supplied to the heat exchanger or the like through the discharge pipe 10.

By the way, there is a compressor provided with a so-called compliance mechanism in order to maintain the airtight state of the compression space 7 defined by the fixed scroll blade 3a and the swirl scroll blade 2a.

The scroll compressor shown in FIG. 2 is a compressor provided with this compliance mechanism. Hereinafter, this coherence mechanism will be described. In this compliance mechanism, a guide post shown by 11 in the figure is erected on the frame 6, and along the guide post 11, the fixed scroll 3 is slightly moved in the axial direction with respect to the frame 6. Hold movably.

A back pressure plate 12 is provided on the back side of the fixed scroll 3, and an intermediate pressure chamber 13 is provided between the back pressure plate 12 and the back pressure plate 12 to take out and fill the refrigerant in the middle of compression. Further, the discharge port 8 of the fixed scroll 3 is provided with a check valve 14 which prevents the compressed refrigerant in the discharge chamber 9 from flowing back into the compression space 7.

Due to this compliance mechanism, the scroll type compressor is operated by the pressure of the high pressure working fluid filled in the discharge chamber 9 and the pressure of the intermediate pressure working fluid filled in the intermediate pressure chamber 13. The fixed scroll 3 is pressed against the swivel scroll 2 to keep the compression space 7 airtight.

Further, according to this compliance mechanism, when the pressure in the compression space 7 rises abnormally due to the so-called liquid back operation and becomes equal to or higher than the discharge pressure, the fixed scroll is caused by the pressure in the compression space 7. -Rule 3 is driven upward against the pressures in the intermediate pressure chamber 13 and the discharge chamber 9.

As a result, the fixed scroll blade 3 is provided.
Since the distance between a and the swirl scroll blade 2a is expanded, the working fluid in the compression space 13 is released, and the stress applied to the fixed scroll blade 3a and the swirl scroll blade 2a is eliminated. It is possible to prevent damage before it happens.

[0013]

By the way, generally, in a scroll type compressor, immediately after the operation of the motor is stopped and the operation of the compressor is stopped, the pressure in the compression space 7 is higher than the pressure in the compression space 7. Also, a state occurs in which the pressure in the discharge chamber 9 becomes abnormally high.

This state is resolved as time passes, and finally the pressure in the compression space 7 and the pressure in the discharge chamber 9 reach an equilibrium state. However, if the operation of the compressor is started before the equilibrium state is reached, the problems described below occur.

That is, in the compressor, when the operation is restarted before the equilibrium state is reached, the fixed scroll 3 is strongly pressed against the swirl scroll 2 due to the excessive pressure in the discharge chamber 9. However, the start-up characteristics may be deteriorated.

Further, even after the start-up, the orbiting scroll 2 and the fixed scroll 3 are pressed against each other with excessive pressure until the pressure in the compression space 7 rises sufficiently, and the pressure between them is increased. Since excessive frictional force would be generated, there was a risk of galling at the blade tips.

On the other hand, the above-mentioned problem occurs because the check valve 14 is provided on the fixed scroll 3 side and the fixed scroll 3 is pressed by the excessive pressure in the discharge chamber 9. Therefore, the check valve 14 is attached to the discharge pipe 1.
A method of providing it within 0 may be considered.

However, in this case, since the volume of the discharge chamber 9 is large, the high-pressure refrigerant in the discharge chamber 9 flows back into the compression space 7 immediately after the stop, and the swirl scroll is performed. -There is a possibility that noise and seizure of the bearing may occur due to reversing of the rule 2.

The present invention has been made in view of such circumstances, and prevents an excessive pressing force from being generated between the fixed scroll and the swivel scroll immediately after the stop, and at the time of restarting. It is an object of the present invention to provide a scroll type compressor which has excellent starting characteristics and is capable of more reliable operation.

[0020]

The present invention comprises a case,
A fixed scroll provided in the case in a non-rotatable and axially movable manner is combined with the fixed scroll via a compression space, and is swivel-driven with respect to the fixed scroll. Thus, the swirl scroll for compressing the fluid sucked into the compression space and the discharge chamber for arranging the swirl scroll on the back side of the fixed scroll for discharging the compressed fluid are defined, and at the same time, the fixed scroll is provided. The back pressure plate that presses the fixed scroll against the swivel scroll by the pressure of the fluid by once filling the fluid drawn from the compression space between the back pressure plate and the back surface of the roll. And a check valve for preventing the fluid discharged to the discharge chamber from flowing backward from the discharge chamber side to the back side of the fixed scroll.

[0021]

With this structure, it is possible to prevent the pressure in the discharge chamber from acting on the fixed scroll immediately after the operation is stopped.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows a scroll type compressor of the present invention. In the figure, 20 is a closed case. A support frame 22 is fixed in the closed case 20. The support frame 22 has an upper end 23a.
Eccentrically supports the crankshaft 23, which is rotatably supported.

The lower portion of the crankshaft 23 is connected to a motor (not shown) provided below the frame 22 (inside the closed case 1) so that the crankshaft 23 can be rotationally driven by the motor. Has become.

A compression mechanism portion 25 is provided on the frame 22. This compression mechanism section 25
An Oldham ring provided in a gap between the turning scroll 27 loosely fitted to the upper end portion 23a of the crankshaft 23 and the frame 22 and the turning scroll 27 to prevent the turning scroll 27 from rotating. 28, a thrust load receiving surface 29 that is also provided on the upper surface of the frame 22 and receives the thrust load of the swivel scroll 27, is combined with the swivel scroll 7 through the compression space 30, and The frame 22 is composed of a fixed scroll 33 which is non-rotatably and vertically movable by a support pin 31 which is provided upright on the outer edge of the upper surface of the frame 22.

The swivel scroll 27 and the fixed scroll 33 are provided with mirror plates 27a and 33a, respectively, and the swirl scroll blades 27b and the fixed scroll which are erected on the facing surfaces of the mirror plates 27a and 33a, respectively. It is provided with a wing 33b. Then, the plurality of compression spaces 30 are defined by bringing the tip surfaces of the respective scroll blades 27b and 33b into contact with the respective end plates 33a and 27a.

In the compression space 30, the motor operates and the swivel scroll 27 is driven to rotate,
The fixed scroll 33 moves from the outer peripheral portion of the fixed scroll 33 to the center while turning, and at the same time, the volume thereof is reduced to perform a compression action. This scroll type compressor utilizes such an action to make a working fluid such as a refrigerant (hereinafter referred to as "fluid").
Is continuously performed, and the compressed fluid is discharged through the discharge port 34 provided at the center of the fixed scroll 33.
Is discharged from above to above the fixed scroll 33.

A back pressure plate 35 is provided above the fixed scroll 33 with a narrow gap from the upper surface of the fixed scroll 33 to partition the upper end of the closed case 20. ing. The back pressure plate 35 is fixed to the closed case 20 and has a through hole 3 at the center.
5a and a check valve 37 provided in the through hole 35a.

The upper end of the closed case 20 and the back pressure plate 3
A space defined by the upper surface of 5 is a discharge chamber 36, and the compressed working fluid discharged from the discharge port 34 of the fixed scroll 33 is a check valve provided at the center of the back pressure plate 35. It passes through 37 and is led to this discharge chamber 36. Further, the discharge chamber 36 is provided with a discharge pipe 38 for discharging the compressed working fluid to the outside of the closed case 20.

On the lower surface of the back pressure plate 35, a first annular protrusion 40 and an annular step 41 having different radii around the check valve 37 are integrally formed. On the other hand, on the upper surface of the fixed scroll 33, with a radius slightly smaller than those of the first annular protrusion 40 and the annular step 41, 2
Three third and fourth annular protrusions 42 and 43 are integrally formed.

Then, the first annular projections 4 adjacent to each other
The first and second seal rings 45 and 46 are provided between the 0, the third annular protrusion 42, the annular step 41, and the fourth annular protrusion 43, respectively.

As a result, the first annular projection 40 is formed in the central portion between the back pressure plate 35 and the fixed scroll 33.
A high pressure discharge chamber 47 is defined by the third annular protrusion 42, and an intermediate pressure chamber 48 is defined outside the high pressure discharge chamber 47 by the annular step 41 and the fourth annular protrusion 43. The fixed scroll 33 is provided with a communication pipe 49 that connects the intermediate pressure chamber 48 and the compression space 31 and fills the intermediate pressure chamber 48 with a compressed working fluid having an intermediate pressure.

Next, the operation of this scroll compressor will be described. The compression operation has already been described and will not be described. During the normal compression operation as shown in FIG. 1, the swivel scroll 27 and the fixed scroll 33 are
The back pressure applied to the fixed scroll 33 by the high pressure discharge chamber 47 and the intermediate pressure chamber 48 is combined at an appropriate pressure (compliance function).

As a result, the swirl scroll blade 2 is provided.
The compression space 30 defined by the 7b and the fixed scroll blade 33b can maintain a necessary airtight state. At this time, the fixed scroll 33 is held so as to be movable upward along the pin 31.

Next, the operation when the pressure in the compression space 30 is abnormally increased due to the liquid back operation or the like will be described. In this case, the pressure in the compression space 30 becomes larger than the pressure in the high pressure discharge chamber 47, so that the pressure in the compression space 30 causes the fixed scroll 33 to move.
Is driven slightly higher (compliance function). As a result, the fixed scroll blade 33b and the swirl scroll are rotated.
Since the airtightness of the rotor blades 27b is lost and the compressed fluid can escape, abnormal stress is effectively prevented from being applied to the tip ends of the swirling scroll blades 27b and the fixed scroll blades 33b.

Next, the operation when the scroll compressor is once stopped and then restarted will be described. As described in the section of the conventional example, immediately after the scroll type compressor is stopped, the pressure in the discharge chamber 36 becomes abnormally higher than the pressure in the compression space 30.

However, this pressure is prevented from acting on the back surface of the fixed scroll 33 provided under the back pressure plate 35 by the back pressure plate 35 and the check valve 37 provided on the back pressure plate 35. To be done. Therefore, even if the compressor is restarted before the pressure in the discharge chamber 36 and the pressure in the compression space 30 reach an equilibrium state, the swirl scroll vanes 27b and the fixed scroll are rotated. The blades 33b are not pressed against the end plates 33a and 27a by excessive pressure.

According to the configuration as described above, there are the following effects. That is, in the scroll type compressor of the present invention, a back pressure plate 35 for partitioning the high pressure discharge chamber 47 and the intermediate pressure chamber 48 is provided on the back side of the fixed scroll 33, and the back plate 35 is provided at the center thereof. The check valve 34 is provided.

In the conventional example, the fixed scroll 3 is used.
Since the check valve is provided on the upper portion of 3, the excessive pressure of the discharge chamber 36 directly acts on the back surface of the fixed scroll 33 immediately after the operation is stopped. For this reason, if the compressor is started immediately after the stop, the starting characteristic may be deteriorated or the compression mechanism portion 25 may be damaged.

However, according to the present invention, the discharge chamber 36 and the fixed scroll 33 are partitioned by the back pressure plate 35, and the check valve is provided on the back pressure plate 35. It does not act on the fixed scroll 33. Therefore, even if the compressor is restarted after the operation is stopped and before the pressures in the discharge chamber 36 and the compression space 36 reach an equilibrium state, an excessive amount of space is generated between the swirl scroll 27 and the fixed scroll 33. Of excessive pressure is prevented. Therefore, it is possible to prevent the start-up characteristic from being deteriorated and prevent the compression mechanism portion 25 from being damaged, and it is possible to perform more reliable operation.

[0040]

As described above, according to the present invention, the case, the fixed scroll which is non-rotatable and axially movable in the case, and the fixed scroll are provided. A swirl scroll that is combined through a compression space and is swivel-driven with respect to the fixed scroll to compress the fluid sucked into the compression space, and is disposed on the back side of the fixed scroll. , The discharge chamber from which the compressed fluid is discharged is partitioned, and the fluid discharged from the compression space is once filled between the discharge chamber and the back surface of the fixed scroll, and the pressure of the fluid causes the fixed scroll to flow. -A back pressure plate for pressing the roll against the swivel scroll and a fluid provided in the back pressure plate for preventing the fluid discharged into the discharge chamber from flowing back from the discharge chamber side to the back side of the fixed scroll. And a check valve It is intended.

According to this structure, it is possible to prevent the excessive pressure in the discharge chamber from acting on the fixed scroll immediately after the operation is stopped, and the fixed scroll and the swivel scroll are pressed against each other abnormally strongly. Therefore, there is an effect that the operation characteristics at the time of restarting are excellent and more reliable operation can be performed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a conventional example.

[Explanation of symbols]

20 ... hermetically sealed case (case), 27 ... swivel scroll,
30 ... Compression space, 33 ... Fixed scroll, 35 ... Back pressure plate, 36 ... Discharge chamber, 37 ... Check valve

Claims (1)

[Claims] 1. A case, a fixed scroll which is non-rotatably and axially movable in the case, and combined with the fixed scroll through a compression space,
A swirl scroll for swirling the fixed scroll to compress the fluid sucked into the compression space, and a partition arranged on the back side of the fixed scroll to partition the case, A discharge chamber for discharging the compressed fluid is defined on the side opposite to the side where the fixed scroll is provided, and
A back pressure plate that presses the fixed scroll against the orbiting scroll by the pressure of the compressed fluid by once filling the compressed fluid derived from the compression space with the back surface of the fixed scroll. , Which is disposed on the back side of the fixed scroll to define a discharge chamber from which the compressed fluid is discharged, and the fluid discharged from the compression space is once provided between the fixed scroll and the back side of the fixed scroll. The back pressure plate that presses the fixed scroll against the swirl scroll by the pressure of the fluid by filling it, and the fluid discharged to the discharge chamber from the discharge chamber side is provided on the back pressure plate. A scroll type compressor, comprising: a check valve for preventing reverse flow to the rear side of a fixed scroll.