JPH06264877A - Scroll compressor - Google Patents

Abstract

PURPOSE:To provide a scroll compressor normally exerting the compliance function and capable of being operated with high reliability. CONSTITUTION:A scroll compressor is provided with a fixed scroll 13 arranged on a frame 2 provided in a sealed case 1, a rotary scroll 7 combined with the fixed scroll 13 across a compression space and compressing a fluid sucked into the compression space 10 when it is turned, and a back pressure plate 15 arranged on the back side of the fixed scroll 13 and pressing the fixed scroll 13 to the rotary scroll 7 via the pressure of the compressed fluid discharged from the compression space 10. The frame 2 and the back pressure plate 15 are connected and fixed to each other by a support pin 11 extended along the axial direction of the fixed scroll 13, and the fixed scroll 13 is provided movably in the axial direction at the middle section in the longitudinal direction of the support pin 11.

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 gas (fluid) is compressed by a relative swirling motion of these swirling bodies. is there.

[0002]

2. Description of the Related Art A scroll compressor is a combination of two spirally processed blades, namely, a fixed scroll blade and a swirl scroll blade, and a gas is compressed by relative movement of these blades. Is.

That is, a scroll compressor has a fixed scroll equipped with the swirl scroll having the swirl scroll blades.
By rotating the fixed scroll equipped with a scroll blade, the compression space defined by the fixed scroll blade and the swirl scroll blade is swung, and the radial outside of the fixed scroll is obtained. To move to the central part and compress the gas. The compressed gas is discharged to the outside from a discharge port formed in the center of the fixed scroll.

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

This compliance mechanism holds the fixed scroll so that it can move a little in the axial direction, and
A back pressure plate is provided on the back side of the fixed scroll to provide a filling space for temporarily filling the compressed gas discharged from the discharge port. Then, the fixed scroll is pressed against the swirl scroll by the pressure of the compressed gas filled in the filled space to keep the compressed space airtight.

Further, according to this compliance mechanism, when the pressure in the compression space abnormally rises 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. It is driven upward against the pressure in the filling space. As a result, the distance between the fixed scroll blade and the swirl scroll blade is expanded, so that the gas in the compression space escapes and the stress applied to the fixed scroll blade and the swirl scroll blade is reduced. It can be solved and damage can be prevented.

[0007]

In the conventional scroll type compressor, the back pressure plate is welded to a hermetically sealed case,
The frame holding the fixed scroll is also welded to the closed case to fix the two separately.

However, when the back pressure plate and the frame are welded, the hermetic case may be deformed by heat. When the closed case is deformed, the positional relationship between the fixed scroll attached to the frame and the back pressure plate is deviated, and the upper surface of the fixed scroll and the back pressure plate are separated from each other. There arises a problem that the sealability of the seal portion which is airtightly connected and divides the filled space is reduced.

As a result, there is a problem that the compliance mechanism does not work normally. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a scroll compressor capable of operating the compliance mechanism normally and performing more reliable operation. Is.

[0010]

A first means of the present invention is a fixed scroll provided on a frame provided in a case so as not to be rotatable and axially movable, and the fixed scroll. A swirl scroll which is combined with a scroll through a compression space and is swivel driven with respect to the fixed scroll to compress the fluid sucked into the compression space, and a rear side of the fixed scroll. Is fixed to the frame and is filled with the compressed fluid discharged from the compressed space between the fixed scroll and the back surface of the fixed scroll, and the pressure of the compressed fluid causes the fixed scroll to flow. And a back pressure plate that presses against the swivel scroll.

The second means is the same as the first means,
The frame and the back pressure plate are connected and fixed to each other by a support pin extending along the axial direction of the fixed scroll, and the fixed scroll is provided at an axially intermediate portion of the support pin. It is characterized in that it is provided so as to be movable in any direction.

[0012]

According to this structure, the positional deviation between the frame and the back pressure plate can be prevented, and as a result, the positional deviation between the fixed scroll attached to the frame and the back pressure plate. Therefore, the compressed fluid discharged from the compression space can be satisfactorily filled between the back surface of the fixed scroll and the back pressure plate.

[0013]

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 according to the present invention.

Reference numeral 1 in the drawing denotes a closed case.
A support frame 2 is fixed in the closed case 1. The support frame 2 rotatably supports a crankshaft 3 having an eccentric upper end 3a.

The lower part of the crankshaft 3 is connected to a motor (not shown) provided below the frame 2 (inside the closed case 1) so that the crankshaft 3 can be driven to rotate. Has become.

A compression mechanism 5 is provided on the frame 2. The compression mechanism portion 5 is provided in the gap between the turning scroll 7 loosely fitted to the upper end portion 3a of the crankshaft 3 and the frame 2 and the turning scroll 7, and the turning scroll 7 is provided. Of the Oldham ring 8 for preventing the rotation of the rotating shaft, a thrust load receiving surface 9 provided on the upper surface of the frame 2 for receiving the thrust load of the swivel scroll 7, the swirl scroll 7 and the compression space 1.
And a fixed scroll 13 which is not rotatable but vertically movable by a support pin 11 provided upright on the outer edge of the upper surface of the frame 2.

The above-mentioned turning scroll 7 and fixed scroll 1
3 includes end plates 7a and 13a, respectively.
a and 13a, the turning scrolls are erected on the opposite surfaces.
The blades 7b and the fixed scroll blades 13b are provided. Then, the plurality of compression spaces 10 are defined by bringing the tip surfaces of the respective scroll blades 7b and 13b into contact with the respective end plates 13a and 7a.

The compression space 10 moves while rotating from the outer peripheral portion of the fixed scroll 13 to the center when the motor 4 is operated and the turning scroll 7 is driven to rotate. At the same time, the volume is reduced and a compression action is performed.
This scroll compressor continuously compresses the gas by utilizing such an action, and the compressed gas is discharged through the discharge port provided in the central portion of the fixed scroll 13. It is adapted to be discharged from 14 to above the fixed scroll 13.

A back pressure plate 1 is provided above the fixed scroll 13 with a narrow gap from the upper surface of the fixed scroll 13 to partition the upper end of the closed case 1.
5 are provided.

The upper end of the support pin 11 which is erected from the frame 2 is fitted into the back pressure plate 15, and the back pin 15 and the frame 2 are fitted by the support pin 11.
Are connected and fixed to each other. The upper support pin 11
Although not shown in the figure, a plurality of stands are provided upright at predetermined intervals along the circumferential direction of the frame 2, and the frames 2 and the back pressure plate 15 are connected in a positioned state.

On the other hand, the space defined by the upper end of the closed case 1 and the upper surface of the back pressure plate 15 is a discharge chamber 16, and the compression discharged from the discharge port 14 of the fixed scroll 13 is performed. The gas passes through a check valve 17 provided at the center of the back pressure plate 15 and is guided to the discharge chamber 16. Further, the discharge chamber 16 is provided with a discharge pipe 18 for discharging the compressed gas to the outside of the closed case 1.

On the lower surface of the back pressure plate 15, a first annular projection 20 and an annular step 21 having different radii around the check valve 17 are integrally formed. On the other hand, the fixed scroll 13 has an upper surface with a radius slightly smaller than those of the first annular projection 20 and the annular step 21.
The third and fourth annular protrusions 22 and 23 are integrally formed.

Then, the first annular protrusions 2 adjacent to each other
The first and second seal rings 25 and 26 are provided between the 0, the third annular protrusion 22, the annular step 21, and the fourth annular protrusion 23, respectively.

As a result, the first annular projection 20 is formed in the central portion between the back pressure plate 15 and the fixed scroll 13.
The high pressure discharge chamber 27 is defined by the third annular protrusion 22, and the annular step 21 and the fourth annular member 2 are provided outside the high pressure discharge chamber 27.
The intermediate pressure chamber 28 is defined by 3. The intermediate pressure chamber 28 and the compression space 1 are provided in the fixed scroll 13.
There is provided a communication pipe 29 for communicating 1 with each other and filling the intermediate pressure chamber 28 with a compressed gas having an intermediate pressure.

The frame 2 is provided with a flange portion 13c of the fixed scroll 13 as shown at 31 in FIG.
Is provided so as to pass through the fixed scroll 13 at the upper end.
Is provided with a stopper 31 having a collar portion 31a for restricting the rise of the. The flange portion 31 of the stopper 31 is provided with a predetermined gap from the upper surface of the flange portion 13c of the fixed scroll 13 and has a function of preventing the fixed scroll 13 from rising too much.

Next, the operation of this scroll compressor will be described. The compression operation has already been described and will not be described.

As shown in FIG. 1, during normal compression operation, the swirl scroll 7 and the fixed scroll 13 are added to the fixed scroll 13 by the high pressure discharge chamber 27 and the intermediate pressure chamber 28. Combined by pressure. As a result, the compression space 10 defined by the swirl scroll vane 7b and the fixed scroll vane 13b can maintain a necessary airtight state.

At this time, the fixed scroll 13 is used.
Are held so as to be movable upward while maintaining a narrow gap with the lower surface of the flange portion 31a of the stopper 31.

Next, the operation when the pressure in the compression space 10 rises abnormally due to the liquid back operation or the like will be described.

In this case, the pressure in the compression space 10 becomes larger than the pressure in the high pressure discharge chamber 27, so that
The pressure in the compression space 10 drives the fixed scroll 13 to rise slightly (compliance function). As a result, the airtightness of the fixed scroll vane 13b and the swirl scroll vane 7b is lost, and the compressed fluid can be released, so that the swirl scroll vane 7b and the fixed scroll vane 13b are abnormal. Effective stress is effectively prevented.

According to the above-mentioned structure, the following effects can be obtained.

A frame for holding the fixed scroll 13
The frame 2 and the back pressure plate 15 for partitioning the high pressure discharge chamber 27 and the intermediate pressure chamber 28 on the back side of the fixed scroll 13 are connected and fixed in a state of being positioned by the plurality of support pins 11. .

Conventionally, the frame 2 and the back pressure plate 15 are
Since they are separately fixed in the closed case 1 by welding, when the closed case 1 is thermally deformed by heating during welding, the fixed scroll 13 and the back pressure plate 15 It is conceivable that the compliance function does not work properly due to the deviation of the first and second seal rings 22 and 23 or the loss of airtightness. .

According to the present invention, however, even when the frame 2 or the back pressure plate 15 is welded to the closed case 1, the support pins 11 are used to connect and fix the frames to each other. It is possible to prevent the displacement between the frame 2 and the back pressure plate 15. As a result, the compliance function can be normally operated, so that there is an effect that more reliable operation can be performed.

Further, according to this structure, the frame 2 and the back pressure plate 15 can be easily positioned by using the support pin 11, and only the frame 2 is sealed. Since the back pressure plate 15 can be fixed in the closed case 1 only by welding, the workability during assembly is improved.

The present invention is not limited to the above-mentioned embodiment, but can be variously modified without departing from the spirit of the invention.

For example, in the above-described embodiment, the back pressure plate 15 and the frame 2 are connected by the support pin 11, but the present invention is not limited to this, and the back pressure plate 1 is not limited thereto.
The frame 5 and the frame 2 may be integrally formed so that they are connected to each other.

[0039]

As described above, according to the first structure of the present invention, the fixed scroll provided on the frame provided in the case so as not to rotate and to move in the axial direction, The fixed scroll is combined with the fixed scroll through a compression space, and is swung with respect to the fixed scroll to compress the fluid sucked into the compression space, and the fixed scroll. The fixed scroll is disposed on the back side so as to be filled with the compressed fluid discharged from the compressed space between the fixed scroll and the rear side of the fixed scroll, and the fixed scroll is caused by the pressure of the compressed fluid. And a back pressure plate for pressing the roll against the swivel scroll.

The second configuration is the same as the first configuration,
The frame and the back pressure plate are connected and fixed to each other by a support pin extending along the axial direction of the fixed scroll, and the fixed scroll is provided at an axially intermediate portion of the support pin. It is characterized in that it is provided so as to be movable in any direction.

According to such a configuration, the compliance function can be normally operated, and there is an effect that a more reliable operation can be performed.

[Brief description of drawings]

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

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sealing case (case), 2 ... Frame, 7 ... Revolving scroll, 10 ... Compression space, 11 ... Support pin, 13 ... Fixed scroll.

Claims (2)

[Claims] 1. A fixed scroll which is non-rotatably and axially movable in a frame provided in the case, and is combined with the fixed scroll through a compression space,
A swirl scroll that compresses the fluid sucked into the compression space by being swivel-driven with respect to the fixed scroll, and is fixed to the frame on the back side of the fixed scroll. A back pressure plate that presses the fixed scroll against the orbiting scroll by the pressure of the compressed fluid by filling the compressed fluid discharged from the compressed space between the fixed scroll and the back surface of the fixed scroll. And a scroll type compressor. 2. The frame and the back pressure plate are connected and fixed to each other by a support pin extending along the axial direction of the fixed scroll, and a midway portion of the support pin in the longitudinal direction is
2. The scroll type compressor according to claim 1, wherein the fixed scroll is provided so as to be movable in the axial direction.