JPH08170592A - Shaft through type two-stage scroll compressor - Google Patents

Abstract

PURPOSE: To enable compression with high efficiency in a small-sized compressor, and to reduce the thrust force applied to a swivel scroll end plate from high pressure stage to low pressure stage. CONSTITUTION: A crankshaft 500 is passed through a swivel scroll 300, laps 311, 312, the vortex shapes of which are symmetrical and the tooth heights of which are different are erected on both sides of the end plate, the pressure receiving surfaces of an upper compression space and a lower compression space are symmetrical, and the built-in compression ratios of both compression spaces are the same. Thus, a difference in load applied to the swivel scroll end plate is reduced, the pressure ratios of the first stage and the second stages are the same, a two-stage compressor is decreased in size, the efficiency is made highest, and a shaft is passed through the swivel scroll end plate to reduce the thrust force applied to the end plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor in which an orbiting scroll makes an orbiting motion without rotating, and a crankshaft penetrates the orbiting scroll and a fixed scroll to improve efficiency in two-stage compression. A penetration two-stage scroll compressor.

[0002]

2. Description of the Related Art U.S. Pat. No. 3,600,114,
A mechanism is shown in which a drive shaft is passed through the orbiting scroll, wraps are provided on both sides of an end plate, a fixed scroll is combined with each of the wraps to form a compression chamber, and both compression chambers are used in parallel to simultaneously compress. However, this example does not show an example in which compression chambers on both sides are used in series to perform two-stage compression.

In Japanese Unexamined Patent Publication (Kokai) No. 5-60078, wraps are provided on both sides of an end plate of an orbiting scroll, and a fixed scroll is combined with each to form a compression chamber. A lower compression chamber serves as a first-stage compressor, and an upper compression is provided. A structure is shown in which the chamber is the second-stage compression chamber, but the bearing is at the bottom of the end plate and does not penetrate the orbiting scroll. The upper and lower scroll wraps had different shapes.

[0004]

The efficiency of the two-stage compressor is maximized when the pressure ratio of the first-stage compression section and the pressure ratio of the second-stage compression section are equal. However, in the conventional method,
Due to the different upper and lower wrap shapes, the upper and lower intrinsic compression ratios are different, and the efficiency of the compressor is not the highest. Also, since the center of the end plate of the orbiting scroll does not penetrate, the discharge pressure of the high pressure stage acts on the central region, and the load due to the differential pressure from the suction pressure acting on the central region of the low pressure stage increases, There was a problem that the orbiting scroll was pressed from the high-pressure stage side to the low-pressure stage side with a strong thrust force, sliding loss increased on one side, and a gap was created on the other side, increasing leakage loss. .

[0005]

In order to solve the above-mentioned problems, a shaft-penetrating two-stage scroll compressor according to the present invention comprises a fixed scroll member and an orbiting scroll member, each having an end plate in which a spiral wrap is upright. A scroll compressor in which the wraps are opposed to each other, are combined in an eccentric manner, and the crankshaft provided through the orbiting scroll and the fixed scroll causes the orbiting scroll member to orbit without causing rotation to compress gas. In the orbiting scroll, wraps are erected on both sides of the end plate, the first fixed scroll wrap is combined with the first wrap on one surface to form the first suction chamber and the first compression chamber, and the second wrap on the other surface. And a second fixed scroll wrap to form a second suction chamber and a second compression chamber, and the orbiting drive shaft is provided at the center of the end plate of the orbiting scroll. A slewing bearing that penetrates is provided, a first fixed bearing that supports one end of the drive shaft is provided at the center of the end plate of the first fixed scroll, and the drive shaft is provided at the center of the end plate of the second fixed scroll. A second fixed bearing supporting the other end of the first suction chamber is installed, and the swirling roll is swung to compress the gas sucked into the first suction chamber in the first compression chamber, and the compressed gas is discharged to the first position. It is characterized in that it is transferred to two suction chambers and re-compressed in the second compression chamber.Generally, the drive shaft is passed through the orbiting scroll, and the wraps are symmetrical on both sides of the end plate and have different tooth heights. Upright so that the pressure receiving surfaces of the upper compression chamber and the lower compression chamber are symmetrical, and the intrinsic compression ratios of both compression chambers are the same.

[0006]

[Function] By making the pressure ratio of the first-stage compression section equal to the pressure ratio of the second-stage compression section, downsizing can be achieved, and at the same time, the efficiency of the second-stage compressor can be maximized and the scroll scroll can be used. By penetrating the drive shaft, the thrust force acting from the high pressure stage side to the low pressure stage side is reduced.

[0007]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view showing the overall structure of a first embodiment of a hermetic scroll compressor of the present invention. Inside the hermetic container 100, a first fixed scroll 210, a compression unit including a orbiting scroll 300 in which wraps are upright on both sides of an end plate and a second fixed scroll 220, and an orbiting scroll 30.
Crankshaft 500 for driving 0, electric motor 700 for driving
Are stored together. The eccentric shaft 520 of the crankshaft 500 penetrates the orbiting scroll 300, the shafts on both sides penetrate the end plates of the first fixed scroll 210 and the second fixed scroll 220, respectively, and the first central shaft 510 first fixes. A second fixed bearing 22 in which a second central shaft 530 is provided in the center of the end plate of the second fixed scroll 230 is attached to a first fixed bearing 212 provided in the center of the end plate of the scroll 210.
Each is supported by 2. Rotor 7 of electric motor 700
A bearing 721 that supports the rotating shafts of 20 is provided at the top.

The orbiting scroll 300 is restrained from rotating by a rotation preventing mechanism 400 using an Oldham ring provided between an outer peripheral portion of an end plate 320 on the second lap side of the orbiting scroll 300 and an outer peripheral portion of a second fixed scroll. The eccentric shaft 520 is driven to rotate by the rotation of the crankshaft 500. The crankshaft 500 has a first balance weight 519 and a second balance weight 53 for canceling centrifugal force of the orbiting scroll 300 and preventing vibration.
9 is attached. The gas is sucked into the first suction chamber 213 from the suction pipe 110, is compressed in the first compression chamber 214 formed by the first fixed scroll 210 and the orbiting scroll 300, and is discharged from the first discharge hole 321 in the central portion to the orbiting scroll end. It is discharged into the communication passage 322 provided in the plate, is sucked into the second suction chamber 223 formed by the second fixed scroll 220 and the orbiting scroll 300, is compressed in the second compression chamber 224, and is discharged from the second discharge hole 225. It is discharged into the closed container 100. Then, the gas is discharged from the discharge pipe 120 to the outside of the closed container.

One of the plurality of first compression chambers 214 in the low pressure stage
The first compression chamber is formed such that the minimum closed volume immediately before the two compression chambers are opened to the first discharge hole 321 and the maximum closed volume when the second compression chamber 224 in the high pressure stage starts compression are substantially equal. The wraps 211 and 311 that form the second wrap and the wraps 221 and 312 that form the second compression chamber have the same spiral shape, and the tooth height ratio is set to be substantially equal to the ratio of the minimum closed volume and the maximum closed volume, and A passage 322 that connects the two chambers is provided so that the upper unique compression ratio and the lower unique compression ratio are the same.

FIG. 2 shows an example of the two-stage compression refrigeration cycle. The compressor 1000 includes a first stage compression unit 1010 and a second stage compression unit 1020. The gas sucked from the first-stage suction port 1 is excessively sucked from the intermediate suction port 1800 between the first-stage discharge port 2 and the second-stage suction port 3 and is discharged from the second-stage discharge port 4. . The discharge gas passes through the four-way valve 1100,
The first expansion valve 1 is condensed by passing through the indoor heat exchanger 1200.
The pressure of the refrigerant is reduced by 300, and the mainstream refrigerant is further reduced by the second expansion valve 1500, evaporated through the outdoor heat exchanger 1600, passed through the four-way valve 1100, and again sucked into the compressor from the suction port 1. A part of the refrigerant is branched at the branching part 6 and the third expansion valve 170
The pressure is reduced to 0 and reaches the intermediate suction port 1800. During this time, the mainstream refrigerant and the branched refrigerant exchange heat with each other in the refrigerant heat exchanger 1400, the mainstream refrigerant is cooled and liquefied, and the branched refrigerant is heated and partially evaporated to become a two-phase flow.

The state change of this cycle is shown in the Mollier diagram as shown in FIG. The horizontal axis is enthalpy per unit weight, and the vertical axis is pressure. The gas sucked from the first-stage suction port 1 is compressed in the first-stage compression section, and the intermediate-pressure two-phase flow refrigerant is sucked between the first-stage discharge port 2 and the second-stage suction port 3 to temporarily reduce the enthalpy. It is reduced, compressed again in the second-stage compression section, and discharged from the second-stage discharge port 4 to the cycle.
The states in the cycle are indicated by the same numbers corresponding to the positions 5 to 10 in FIG. The power of the compressor in this cycle is smaller than that in the case of compressing from the pressure of 1 to the pressure of 4 in one stage, and the efficiency is improved. Efficiency is 1 to 2
Is highest when the pressure ratios of 3 and 4 are equal, and the efficiency is maximized by making the pressure ratio of the first compression chamber and the pressure ratio of the second compression chamber substantially equal.

According to the first embodiment, since the first and second compression chambers are formed on both sides of one orbiting scroll 300, a small and lightweight two-stage compressor having a small diameter can be realized. The efficiency is maximized by making the pressure ratio of the compression chamber and the pressure ratio of the second compression chamber substantially equal. In addition, since the first-stage and second-stage communication passages 322 are provided in the orbiting scroll end plate 320, piping for communication is unnecessary, and the structure is simplified.
Further, since the eccentric shaft 520 penetrates through the central portion of the scroll compression portion, substantially the same pressure acts on the upper and lower end surfaces of the shaft, so that an excessive thrust force does not act on the scroll portion. Therefore, the problem described in the section of the problem, that is, the discharge pressure of the high pressure stage acts on the central region, the load due to the differential pressure with the suction pressure acting on the central region of the low pressure stage becomes large, and the orbiting scroll has a high pressure. Since the thrust force is pressed from the stage side to the low pressure stage side, sliding loss increases on one surface, and a gap is generated on the other surface to increase the leakage loss. In the first embodiment described above, by maximizing the efficiency by making the pressure ratio of the first compression chamber and the pressure ratio of the second compression chamber substantially equal, and by penetrating the eccentric shaft into the central portion of the scroll compression portion. Since substantially the same pressure acts on the upper and lower end surfaces of the shaft, it is the same in each of the following embodiments that an excessive thrust force does not act on the scroll portion.

4 to 7 are diagrams showing a second embodiment of the present invention. FIG. 4 shows a sectional view of the whole. FIG. 5 is a cross-sectional view of the compression mechanism portion viewed from the viewpoint of FIG. 4 and the direction of 90 °. FIG. 6 shows an example of the Oldham ring 400 that constitutes the rotation preventing mechanism used in this embodiment. FIG. 7 shows an example of an orbiting scroll, a bearing, and a frame used in this embodiment. End plate 32 of orbiting scroll
The structure of 0 is divided into a first end plate 320a having a first wrap 311 and a second end plate 320b having a second wrap 312. The first end plate 320a and the second end plate 320b are
The Oldham ring 400 of FIG. 6 is sandwiched with a minute gap, and is fixed with a spacer 340 at a distance. The Oldham ring 400 is provided with a turning side key 401 and a frame side key 402 on an annular main body such as a circle or an ellipse. At this time, the turning side key 401 of the Oldham ring 400
Is inserted into a key groove 323 provided on the end plate. The Oldham ring 400 includes a first end plate 320a and a second end plate 320b.
It can move in the direction of the keyway 323 between.

The orbiting scroll 300, the Oldham ring 400, and the frame 600, which are integrated with each other, are arranged such that the frame-side key 402 is fitted in the key groove 601 of the frame. Two
The two fixed scrolls are fixed to the frame 600 by sandwiching between the 10 and the second fixed scroll 220. The first fixed scroll and the second fixed scroll are assembled by sandwiching a cylindrical frame thicker than the thickness of the end plate of the orbiting scroll by a fine dimension. First end plate 320a and second end plate 3
The space between 20b is the first discharge hole 321 and the second suction chamber 2
It is also used as a communication passage 322 that connects 23. The first balance weight 519 is provided on the first central shaft 510, and the second balance weight 539 is provided on the second central shaft 530.

According to the second embodiment, the rotation prevention mechanism 40
Since 0 is built in the end plate 320 of the orbiting scroll 300, it is not necessary to incorporate a mechanism irrelevant to compression on the lap side surface, and the size can be further reduced. Moreover, since the load applied to the Oldham ring 400 is completely symmetrical, a force that tilts the ring is not generated. In addition, the balance weights 519 and 539 are provided on both sides of the orbiting scroll, so that stable behavior can be performed, reliability is improved, and vibration and noise are reduced.

A third embodiment of the present invention is shown in FIG. In this embodiment, the discharge path is changed and the oil supply path to the bearing is shown. From the first central axis 510 to the eccentric axis 5
An oil supply passage 511 is provided over 20. From this oil supply passage toward the first fixed bearing 212, the oil supply port 5
12, the refueling port 522 is provided toward the slewing bearing 330.

The inside of the compressor container 1 is the discharge pressure, and the hydraulic pressure in the oil tank is also the discharge pressure. Since the central chamber pressure of the first compression chamber is an intermediate pressure lower than the discharge pressure, the differential pressure causes the oil to pass through the oil supply passage 511, the oil supply ports 512 and 522 and reach the first fixed bearing 212 and the orbiting bearing 330, respectively. Be refueled. The gas path from the first compression chamber to the second compression chamber is the same as in the second embodiment. A discharge passage 533 communicating with the second discharge hole is provided in the second central shaft 530, and the gas compressed in the second compression chamber 224 is guided to the upper part in the closed container 100 through the passage and discharged. It is discharged from the pipe 120. At this time, the oil contained in the discharge gas is centrifugally separated by the trap 534 and oil is supplied from the oil supply hole 532 to the second fixed bearing 222. An electric motor 70 is attached to the upper end of the shaft.
Rolling bearing 721 supporting the rotating shaft of the rotor 720 of 0
Is installed and is lubricated by the oil mist contained in the discharge gas.

According to the third embodiment, even if the suction pressure and the discharge pressure fluctuate considerably, the oil supply differential pressure to the first fixed scroll bearing 212 is always generated, and the first fixed bearing 21
2 and the oil supplied to the orbiting bearing 333 merge and pass through the trap 534, so that the second fixed bearing 222 is centrifugally supplied without exhaustion regardless of the pressure condition.
Highly reliable.

A fourth embodiment of the present invention is shown in FIG. In the present embodiment, the compression part including the fixed scrolls 210 and 220 and the orbiting scroll 300 is installed in the upper part and the electric motor 700 is installed in the lower part. The rotor 720 has a first central axis 510.
Attached to. An oil introduction pipe 540 is attached to the lower end of the shaft. First central axis 510 to swivel axis 52
An oil supply passage 511 is provided from 0 to 0. Oil supply holes 512 and 522 are provided from the oil supply passage toward the first fixed bearing 212 and the orbiting bearing 330, respectively. The pressure inside the closed container 100 is the discharge pressure, and the upper end of the first fixed bearing and the lower end of the slewing bearing 330 are the first compression chamber 214.
Is communicated with the central chamber of the bearing and has an intermediate pressure, so that the oil 800 is fed to the respective bearings by the differential pressure. Electric motor 700
A rotor bearing 721 that supports the rotating shaft of the rotor 710 is installed, an oil supply hole 513 is provided toward the bearing, and oil is supplied by centrifugal force. The gas path from the oil supply passage first compression chamber to the second compression chamber is the same as in the second embodiment. A discharge passage 533 communicating with the second discharge hole is provided in the second central shaft 530, and the gas compressed in the second compression chamber 224 is guided to the upper part in the closed container 100 through the passage and discharged. It is discharged from the pipe 120. At this time, the oil contained in the discharge gas is centrifugally separated on the way and the oil supply hole 5
Oil is supplied from 32 to the second fixed bearing 222.

In the fourth embodiment, since the second fixed bearing 222 at the uppermost portion can also be forcedly lubricated, all the bearings can be constituted by sliding bearings. Further, since the compression part is located at the upper part, even if the liquid refrigerant falls into the closed container 100, the risk of falling into the compression chamber is reduced.

A fifth embodiment of the present invention is shown in FIG. This embodiment is different from the fourth embodiment in that the orbiting scroll is divided into 300a and 300b, and the orbiting bearings 330a and 330b are attached to the orbiting scrolls 330a and 330b.
The point is that the center is positioned by mounting on. As shown in FIG. 11, the orbiting scroll end plate 3
The reference numeral 20a does not have a reference hole (hole) for positioning with the fixed scroll on the other side, and only the protruding ring 350 for a spacer is formed on the end plate 320b. Therefore, the orbiting scroll is positioned in the radial direction by the positional relationship between the bearing and the eccentric shaft. Also, the positioning in the rotation direction is performed by the Oldham key 410 and the key groove 32.
It is made by the positional relationship of 3.

According to the fifth embodiment, the Oldham ring 400 is previously attached to the orbiting scroll end plates 320a and 32a.
Since it is not necessary to re-process after sandwiching between 0b and all the individual parts can be incorporated at the time of assembly, processing and assembly are facilitated.

A sixth embodiment of the present invention is shown in FIG. The structure of the scroll is the same as that of the fourth embodiment shown in FIG. Comparing the axial gas force on the first compression chamber 214 side of the orbiting scroll 300 and the axial gas force on the second compression chamber 224 side, the second compression chamber 224 side has a higher pressure and a larger axial gas force. To occur. Therefore, the orbiting scroll 300 is pressed toward the first compression chamber 214, and the tip of the first fixed scroll wrap 211 and the orbiting scroll 3 are pressed.
The tip of the first lap 311 of 00 is in close contact with the tooth bottom of the companion scroll and the gap becomes 0, but the tip of the second fixed scroll wrap 312 and the tip of the second wrap 221 of the orbiting scroll 300 are slightly A gap is created. In this embodiment, the tip seal 900 is attached to the tip of the second wrap 221 of the orbiting scroll 300 to prevent leakage of this portion. Of course, the second fixed scroll wrap 22
If a tip seal is also attached to the tip of 1, the effect of preventing leakage becomes greater.

According to the sixth embodiment, since the leakage between the second compression chambers can be reduced, the performance of the compressor can be improved.

A seventh embodiment of the present invention is shown in FIG. In a closed container 100 having a suction pressure atmosphere, a compression unit including a first fixed scroll 210, a second fixed scroll 220, an orbiting scroll 300 and the like is installed in an upper part, and an electric motor 700 is installed in a lower part. A discharge cover 230 is covered on the upper part of the second fixed scroll to form a discharge chamber 231 inside, and the discharge pipe 230 communicates with the outside of the closed container. The suction pipe 110 is open to the closed container 100, and the suction gas is guided into the closed container. Then, after being introduced into the first suction chamber 213 and compressed in the first compression chamber 214, it is introduced into the second suction chamber through the first discharge port 321, the communication passage 322, and compressed in the second compression chamber 224. It is discharged from the second discharge port 225 to the discharge chamber 231, and discharged from the discharge pipe 120 to the outside of the compressor. An oil pump 810 is attached to the lower end of the crankshaft 500, and oil 800 is supplied to each bearing via an oil introduction pipe 540 and an in-shaft oil supply passage 511.

According to the sixth embodiment, 100 in a closed container.
Since the inside of the container is a suction pressure atmosphere, the container meat pressure can be thinned and the weight can be reduced. Also, the electric motor 70
Since 0 is in a low temperature atmosphere, the winding temperature is low, the reliability is high, and the copper loss is low, so that the motor can be used in a high efficiency state.

[0028]

According to the present invention, the crankshaft is passed through the orbiting scroll, and wraps having symmetrical vortex shapes and different tooth heights are erected on both sides of the end plate, and the pressure receiving surfaces of the upper compression chamber and the lower compression chamber are provided. And the compression ratios of both compression chambers are the same, the load difference acting on the orbiting scroll end plate can be reduced, and the compression ratio of the first stage and the compression ratio of the second stage can be reduced. In the same manner, the pressure ratios of the two can be made the same, and the two-stage compressor can be made compact and the efficiency can be maximized.

[Brief description of drawings]

FIG. 1 is an overall structural cross-sectional view of a hermetic scroll compressor of the present invention.

FIG. 2 is a diagram showing an example of a two-stage refrigeration cycle of the present invention.

[Fig. 3] Mollier diagram of the refrigeration cycle

FIG. 4 is a sectional view of the entire structure of a compressor of a second embodiment of the present invention.

5 is a partial cross-sectional view as seen from the direction perpendicular to FIG.

FIG. 6 is a structural diagram of an Oldham ring according to a second embodiment of the present invention.

FIG. 7 is an orbiting scroll assembly diagram of a second embodiment of the present invention.

FIG. 8 is a sectional view of the overall structure of a third embodiment of the present invention.

FIG. 9 is a sectional view of the overall structure of a fourth embodiment of the present invention.

FIG. 10 is a sectional view showing the overall structure of a fifth embodiment of the present invention.

FIG. 11 is an orbiting scroll assembly diagram of a fifth embodiment of the present invention.

FIG. 12 is an assembly drawing of an orbiting scroll according to a sixth embodiment of the present invention.

FIG. 13 is a sectional view of the entire structure of a seventh embodiment of the present invention.

[Explanation of symbols]

100-Closed container 110-Suction pipe 120-Discharge pipe 130-Injection pipe 131-Injection port 210-First fixed scroll 211-First fixed scroll wrap 212-First fixed bearing 213- First suction chamber 214--First compression chamber 220--Second fixed scroll 221--Second fixed scroll wrap 222-Second fixed bearing 223-Second suction chamber 224-Second compression chamber 225-- Second discharge hole 300-orbiting scroll 311--orbiting scroll first wrap 312-orbiting scroll second lap 320--end plate 321-first discharge hole 322-communication passageway 323-key groove 330- -Slewing bearing 340 --- Pin 341-Hole 350 --- Ring ring 400 --- Oldham ring 410 --- Oldham key 00--crank shaft 510--first central shaft 511--oil supply passage 512--oil supply hole 519--first balance weight 520--eccentric shaft 521--oil supply passage 522--oil supply hole 530--second center Shaft 531- Oil supply passage 532- Oil supply hole 533- Discharge passage 539- Second balance weight 540- Oil introduction pipe 600- Frame 700- Electric motor 710- Stater 720- Rotor 800 --- Oil 900 --- Tip seal 1000 --- Compressor 1010 --- Low-stage side compression part 1020 --- High-stage side compression part 1100--Four-way valve 1200--Indoor heat exchanger 1300--First expansion valve 1400--Refrigerant Heat exchanger 1500 --- Second expansion valve 1600--Outdoor heat exchanger 1700--Third expansion valve 1800 --- Intermediate inlet

Claims (12)

[Claims] 1. A crankshaft provided through a rotary scroll and a fixed scroll, wherein a fixed scroll member having an end plate in which a spiral wrap is erected upright, and an orbiting scroll member are combined so that the wraps face each other and are eccentric to each other. In a scroll compressor in which the orbiting scroll member is orbitally moved without rotating to compress gas, in the orbiting scroll, wraps are made upright on both sides of an end plate, and a first wrap on one side is first. The fixed scroll wrap is combined to form the first suction chamber and the first compression chamber, the second wrap on the other surface is combined with the second fixed scroll wrap to form the second suction chamber and the second compression chamber, and the swirling is performed. An orbiting bearing through which an orbiting drive shaft penetrates is provided at the center of the end plate of the scroll, and at the center of the end plate of the first fixed scroll,
A first fixed bearing that supports one end of the drive shaft is installed, a second fixed bearing that supports the other end of the drive shaft is installed at the center of the end plate of the second fixed scroll, and the orbiting roll is By being driven to rotate, the gas sucked into the first suction chamber is compressed in the first compression chamber, the compressed gas is transferred to the second suction chamber, and recompressed in the second compression chamber. A shaft penetrating two-stage scroll compressor. 2. The shaft-penetrating two-stage scroll compressor according to claim 1, wherein the minimum closed volume of the first compression chamber and the maximum closed volume of the second compression chamber are substantially equal. 3. The first fixed scroll wrap and the second fixed scroll wrap have a spiral symmetry in a spiral shape so that the minimum closed volume of the first compression chamber and the maximum closed volume of the second compression chamber are substantially equal. The shaft-penetrating two-stage scroll compressor according to claim 2, wherein the tooth height ratio is set. 4. The shaft-penetrating two-stage scroll compressor according to claim 1, wherein the pressure ratio of the first compression chamber and the pressure ratio of the second compression chamber are substantially equal. 5. The first fixed scroll wrap and the second fixed scroll wrap have a spiral shape in a plane symmetry, and a tooth height ratio is substantially equal to a ratio between the maximum closed volume and the minimum closed volume of the first compression chamber. The shaft-penetrating two-stage scroll compressor according to claim 1. 6. An orbiting scroll end plate is provided with a first discharge hole for releasing gas compressed in the first compression chamber, and a communication passage communicating between the discharge hole and the second suction chamber is formed as an end plate of the orbiting scroll. The shaft-penetrating two-stage scroll compressor according to claim 1, which is provided inside. 7. The shaft-penetrating two-stage scroll compressor according to claim 1, wherein the rotation preventing mechanism is provided within the thickness range of the orbiting scroll end plate. 8. The orbiting scroll can be divided into two within the range of the thickness of the end plates, and a rotation preventing mechanism component is sandwiched between the end plates so as to be movable in the plane. Axial penetration two-stage scroll compressor. 9. A first fixed scroll and a second fixed scroll are assembled by sandwiching a cylindrical frame thicker than the thickness of an end plate of an orbiting scroll by a slight dimension, and a guide groove of a rotation preventing mechanism is provided in the frame. The shaft-penetrating two-stage scroll compressor according to claim 5, wherein 10. The rotation preventing mechanism comprises a circular or elliptical ring member, and a pair of point-symmetrical keys protruding at right angles to at least one ring surface and fitted in a guide groove of an orbiting scroll end plate, The shaft-penetrating two-stage scroll compressor according to claim 5, wherein the shaft-penetrating two-stage scroll compressor has a shape in which a pair of keys are provided which are radially projected at a position displaced by 90 ° from the keys and are fitted into the guide grooves of the frame. 11. The orbiting scroll first wrap and the first fixed scroll wrap are made flat at their tips, and a seal member is attached to either or both of the orbiting scroll second wrap tip and the second fixed scroll wrap tip. The shaft-penetrating two-stage scroll compressor according to claim 1. 12. A high pressure atmosphere side bearing of a first fixed bearing mounted on a first fixed scroll from an oil supply passage extending from the oil pool side end surface of the crankshaft to the inside of the first central shaft and the orbiting shaft. The bearing surface near the end and the oil supply holes that open toward the bearing surface near the high pressure atmosphere side bearing end of the orbiting bearing provided in the orbiting scroll are respectively provided, and the discharge gas of the second compression chamber passes through the second central shaft. The shaft-penetrating two-stage scroll compressor according to claim 1, wherein a gas passage is provided, and an oil supply hole for supplying the oil centrifugally separated from the passage to the second fixed bearing is provided.