JPH09100784A - Scroll gas compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To furnish a shape of a drive shaft easy to carry out change, connection and disconnection at the time of assembly and a bearing and an oiling passage to support it. SOLUTION: A crankshaft 714 provided on a head end of a drive shaft 704 to engage with a revolving bearing 818b of a revolving scroll 818 is made in dimension and a shape so that a diameter of a rotating locus relative to a main spindle of the drive shaft 704 of its outer peripheral surface is set to be smaller than a bearing inside diameter of a main bearing 812 supporting the drive shaft 704 and the drive shaft 704 can be sequentially inserted into the main bearing 812 and the revolving bearing 818b from the side of a motor 703. By this constitution, it becomes possible to carry out connection, disconnection and change the drive shaft 704 without changing an assembly state of a main body frame 805 having a fixed scroll 815, the revolving scroll 818 and the main bearing 812, to select and assemble the drive shaft 704 adaptable to dimensions of the fixed scroll 815, the revolving scroll 818 and the main bearing 812 and to provide a small clearance in the radial direction of a compression chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the shape of a drive shaft of a scroll gas compressor and an oil supply passage.

[0002]

2. Description of the Related Art A scroll compressor having low vibration and low noise characteristics has a suction chamber at the outer periphery of a spiral compression chamber formed by a combination of a fixed scroll and an orbiting scroll.
Since the discharge port is provided in the center of the spiral, the flow of compressed fluid is unidirectional, and there is no need for a discharge valve such as a reciprocating compressor or rotary compressor to compress the fluid. If there is no significant change in the operating compression ratio determined by, the volume ratio determined by the suction volume of the compression chamber and the final compression chamber volume is set to an appropriate value, and the discharge pulsation is small and a large discharge space is required. Therefore, the practical application research of the usage expansion to each field has been done.

However, since there are many seal portions in the compression chamber, there is a lot of leakage of the compressed fluid. Particularly, in the case of a scroll gas compressor having a small displacement capacity such as a refrigerant compressor for home air conditioning,
In order to reduce the leakage gap of the compression part, it is necessary to make the dimensional accuracy of the spiral part extremely high.

[0004] However, due to the complexity of the shape of parts, the cost of the scroll gas compressor is high and the performance varies greatly due to variations in dimensional accuracy of the spiral part. It has the disadvantages of high leakage rate and lower compression efficiency than reciprocating compressors and rotary compressors.

Therefore, as a measure for solving this type of problem, in order to prevent gas leakage during compression, the combined accuracy of the scroll part size of both scrolls, the setting of the eccentric amount of the crank mechanism part of the drive shaft, and the optimization of the bearing clearance are made. While assembling the compression chamber in a minute gap by the method, as described in JP-A-57-8386, an appropriate amount of lubricating oil is injected into the compression chamber during compression, and compression is performed by the oil film sealing action using the lubricating oil. A means for improving the compression efficiency by the chamber gap sealing effect has been proposed.

In particular, scroll refrigerant compressors have been put into practical use in the field of refrigeration and air conditioning, and various types of medium to large class compressors, such as packaged air conditioners and chiller units, having a relatively large refrigerant volume per one suction stroke have been developed. Improvements have been made and mass production has already been realized.

FIG. 15 shows an example of a general structure of a medium to large class scroll refrigerant compressor having a closed case (chamber) having a high-pressure space. In the figure, the compression unit and the discharge chamber 1031 are at the top, the motor (electric element) is at the bottom,
An oil sump is provided at the bottom at the discharge pipe 104 which is the final outlet of the compressor.
2 is disposed in the vicinity of the motor (electric element), and after the discharge refrigerant gas and the lubricating oil are separated in the discharge chamber 1031, the lubricating oil is stored in the motor (electric element) through oil drain holes 1035 and 1036. Returning to the space, the refrigerant gas is collected in the oil reservoir at the bottom, and the discharged refrigerant gas is discharged from the discharge pipe 1042 again after passing through the space accommodating the motor (electric element) from the upper part of the discharge chamber 1031 through another passage. You. In addition, in order to reduce the axial gap of the compression chamber, lubricating oil on which the discharge pressure acts on the bottom of the closed case (chamber) 1013 is provided inside a drive shaft (crankshaft) 1008 with an oil-lifting hole 1019 and a drive shaft ( Crankshaft) 1
After lubricating the bearing sliding surface through the clearance of the bearing of the body frame (frame) 1009 supporting the 008 and fixing the fixed scroll 1003, and the clearance of the crankshaft of the drive shaft (crankshaft) 1008, the orbiting scroll 1
The intermediate pressure lubricating oil, which has been reduced in the middle of the path, flows into the back pressure chamber 1025 provided on the rear surface of the orbit 006. Energize. As a result, the back pressure biasing force is set so as not to separate the orbiting scroll 1006 from the fixed scroll against the compression chamber gas pressure.

The lubricating oil in the back pressure chamber 1025 is supplied to a back pressure hole 1017 provided in the end plate 1004 of the orbiting scroll 1006.
After being flown into the compression chamber 1015 in the middle of compression via, the gas is compressed and discharged together with the suction refrigerant gas while sealing the gap of the compression chamber 1015, and is discharged to the discharge chamber 1031. The shape of the drive shaft (crankshaft) 1008 is described in JP-A-59
This is different from the configuration disclosed in Japanese Patent Publication No. 60092, in which the shaft outer diameter of the tip of the drive shaft is increased and the shaft portion of the orbiting scroll is slidably engaged with the eccentric hole provided in the portion.
The drive shaft (crank shaft) 1008 is provided with a crank shaft portion at its tip to reduce the bearing sliding resistance by reducing the diameter of the bearing portion that supports the drive shaft (crank shaft) 1008 (Japanese Patent Laid-Open No. 56- 165788).

[0009]

However, the structure shown in FIG. 15 has the following problems.

The gist of the problem is that it is impossible to simply attach and detach the drive shaft (crankshaft) after the temporary assembly of the compression portion, and it takes time to select the optimum eccentricity amount of the drive shaft (crankshaft).

That is, the outer diameter of the bearing portion of the drive shaft (crankshaft) 1008 supported by the frame 1009 is
Since the diameter of the rotation locus of the outer peripheral surface of the upper crankshaft (crankpin portion) is smaller, the drive shaft (crankshaft) 1008 is mounted on the frame 100 with the compression portion temporarily assembled.
It is a structure that cannot be desorbed due to inhibition by 9. As a result, in order to reduce the leakage of the compressed refrigerant gas, it is difficult to secure the dimensional accuracy of the spiral portion.
The eccentricity of the crankshaft (crank pin portion) of the drive shaft (crankshaft) 1008 is appropriately adjusted in accordance with the combination of the orbiting scroll 1006 and the fixed scroll 1003 in order to make the radial gap of the compression chamber 1015 formed by It is necessary to set the amount.

For that purpose, it is necessary to confirm the rearrangement of the drive shaft (crankshaft) 1008 by exchange and removal. As a result, every time the drive shaft (crank shaft) 1008 is replaced, the frame 1009 and the fixed scroll 10 are replaced.
There is a problem in that the time required to select the amount of eccentricity of the drive shaft (crankshaft) becomes long and the assembly cost becomes very high because temporary fastening and disassembly with No. 03 is required.

SUMMARY OF THE INVENTION The present invention is to solve such a conventional problem, and provides a scroll gas compressor having a shape of a drive shaft which can be easily exchanged and detached at the time of assembly, a bearing for supporting the shape, and an oil supply passage. With the goal.

[0014]

In order to solve the above problems, according to the present invention, a crankshaft provided at a tip end of a drive shaft for engaging with an orbiting bearing of an orbiting scroll has its outer peripheral surface with respect to a main shaft of the drive shaft. The diameter of the rotation locus is set to be equal to or smaller than the bearing inner diameter of the main bearing that supports the drive shaft, and the drive shaft has a size and shape that can be sequentially inserted into the main bearing and the swing bearing from the motor side.

Due to the dimension and shape of the crankshaft, the drive shaft can be attached / detached and replaced without changing the assembly state of the fixed scroll, the orbiting scroll and the main bearing, and the drive shaft adapted to the dimensions of the fixed scroll, the orbiting scroll and the main bearing. By selectively assembling, a minute gap in the radial direction of the compression chamber can be obtained.

[0016]

According to a first aspect of the present invention, at least a part of the lubricating oil supplied to the orbiting bearing of the orbiting scroll engaged with the drive shaft is lubricated on the sliding contact surface of the lap supporting disk of the orbiting scroll. After that, in the configuration in which either the compression chamber or the suction chamber is supplied, the crankshaft provided at the tip of the drive shaft so that the drive shaft engages with the slewing bearing has a rotation locus with respect to the main shaft of the drive shaft on its outer peripheral surface. Is set to be equal to or smaller than the bearing inner diameter of the main bearing that supports the drive shaft, and the drive shaft has a dimension and shape that can be sequentially inserted into the main bearing and the swing bearing from the motor side. With this configuration, the drive shaft can be attached / detached and replaced without changing the assembling state of the fixed scroll, the orbiting scroll, and the main bearing, and the drive shaft can be selectively assembled to suit the dimensions of the fixed scroll, the orbiting scroll, and the main bearing. It is possible to micro-assemble the compression chamber radial direction gap and seal the compression chamber gap with the oil film of the lubricating oil supplied to the compression chamber.

According to the second aspect of the invention, the upper bearing for supporting the drive shaft together with the main bearing is arranged on the side opposite to the compression chamber of the motor, while the length of the main bearing is shortened. According to this configuration, the drive shaft can be easily inserted into and removed from the main bearing and the slewing bearing, the time required for removing and replacing the drive shaft can be shortened, and damage to the drive shaft and the main bearing due to the removal can be prevented.

According to the third aspect of the present invention, the axial movement of the drive shaft is restricted by the main body frame having the main bearing and the upper bearing. Further, according to this configuration, it is possible to prevent axial vibration of the drive shaft and the motor during operation of the compressor.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A scroll refrigerant compressor according to an embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 1, reference numeral 801 denotes an iron hermetically sealed case in which a fixed scroll 815, whose interior meshes with an orbiting scroll 818 to form a compression chamber, is bolted to support a drive shaft 704. 80
5, it is partitioned into an upper motor chamber 806 and a lower accumulator chamber 846.

The motor chamber 846 is in a high-pressure atmosphere, the motor 703 is arranged in the upper part, the compression part is arranged in the lower part, and the main body frame 805 supporting the drive shaft 704 to which the rotor 703a of the motor 703 is fixedly connected is slidable and welded. Made of eutectic graphite cast iron, which has excellent properties, and protrusions 879 provided on the outer peripheral surface thereof.
a is an upper closed case 801a and a lower closed case 801b
Is in contact with each inner wall surface and end surface of the
The upper closed case 801a and the lower closed case 801b are hermetically welded by a single welding bead 879b.

The upper sealed case 801a is composed of a body shell 801a1 for supporting the stator 703b of the motor 703 and an upper shell 801a2 on which a glass terminal 88 for connecting the motor power source is arranged, and one end of the drive shaft 704 is supported therebetween. The upper frame 126 is arranged.

Discharge pipe 831 and glass terminal 88
And the motor 703 side, the upper frame 126 is made of gray cast iron.
9a is in contact with the inner wall and the end surface of the upper shell 801a2 and the body shell 801a1.
9b seals and fixes the upper shell 801a2 and the body shell 801a1 and also the protrusion 77 of the upper frame 126.
The outer peripheral portion of 9a is sandwiched and fixed. In other words,
The weld bead 779b forms an alloy structure between the upper shell 801a2 made of soft iron and the body shell 801a1, but does not form an alloy structure with the surface of the upper frame 126 made of gray cast iron to prevent the influence of welding strain. Weld bead 7 without affecting
79b surrounds and fixes the periphery of the upper frame 126.

The oil separation chamber 128 provided in the upper portion of the upper frame 126 communicates with the motor chamber 706 through a gas hole 129 provided in the upper frame 126.

The drive shaft 7 supported by the upper frame 126.
04, the surface of the upper end shaft 704d has a spiral oil groove 741 in a direction in which the lubricating oil separated from the discharge gas in the oil separation chamber 128 is guided to the motor chamber 806 when the drive shaft 704 rotates forward.
d is provided.

An upper balance weight 775 and a lower balance weight 776 are attached to the upper and lower ends of the rotor 703a of the motor 703, so that the axial movement of the rotor 703a causes the end of the upper frame 126 and the main body frame 80 to move.
It is regulated with the end of 5.

The upper frame 126 and the body frame 805
The diameter D of the main bearing 812 of the drive shaft 704 supported by
Is the diameter d of the crankshaft 714 and the crank eccentricity (e)
It is set to be larger than the sum of twice the
Is configured so that it can be pulled out in the upper direction.

The lower surface of the lower balance weight 776 is in contact with the thrust bearing 713 at the upper end of the main body frame 805 to support the drive shaft 704 and the rotor 703a.

The oil sump 772 at the upper part of the main bearing 812 is provided with the back pressure chamber 83 of the orbiting scroll 718 through the oil hole B738b.
I am familiar with 9.

The high pressure oil chamber A778a is a main body frame 80.
5 through the oil hole A838a provided in the discharge chamber oil reservoir 34
Leads to.

Discharge chamber 2 communicating with the discharge port 16 of the compression chamber
Communicates with the motor chamber 806 via a discharge passage 880 described later.

The discharge passage 880 (see FIG. 1) is provided in the discharge chamber 2 and the fixed scroll 815 formed by the discharge cover 2a and the mirror plate 815b which are mounted on the mirror plate 815b so as to cover the check valve device 50. Gas passage B88
0b, gas passage A88 provided in the main body frame 805
0a, a main frame 805 and a discharge guide 881 attached to the main frame 805 so as to surround the main bearing 812.
The gas passage A880a and the gas passage B880b are provided at symmetrical positions, respectively (see FIG. 12).

A large number of small holes 81a are provided on the upper surface of the discharge guide 881 as shown in FIG.

The accumulator chamber 846 communicating with the evaporator side of the refrigerating cycle is formed by the lower closed case 801b, the fixed scroll 815 and the main body frame 805, and the suction pipe 47 communicating therewith is provided on the side surface of the lower closed case 801b. Suction holes 43 are provided in the fixed scroll 815 at two positions, which are separated by about 90 degrees from the position facing the suction pipe 47 (see FIG. 12).

Oil hole A8 provided in the main body frame 805
Oil chamber A778a communicating with the discharge chamber oil sump 34 via 38a
Is an orbiting scroll 8 by an annular ring 94 attached to the end of the orbiting boss 818e of the orbiting scroll 818.
The excessive leakage of lubricating oil to the back pressure chamber 839 of 18 is prevented.

As shown in FIGS. 1 and 8, the oil chamber A778a
Communicates with the discharge chamber oil sump 34 via an oil hole A 838 a provided in the main body frame 805.

Revolving boss portion 818 of revolving scroll 818
An annular seal groove 95, which is concentric with the center of the slewing bearing 818b, is provided on the end surface of the main frame 805 on the side of e, and the annular seal groove 95 is cut partially as shown in FIG. And a flexible annular ring 94 made of resin is attached. The outer peripheral surface of the annular ring 94 is
Thermal expansion of the annular ring 94 and the annular ring 9 during operation of the compressor
Due to the lubricating oil pressure inside 4, the cutouts 94b that are in close contact with the side surfaces of the annular seal groove 95 and have an inclination angle with respect to the outer peripheral surface of the annular ring 94 are arranged in close contact with each other. The annular ring 94 prevents excessive leakage from the oil chamber A 778 a on the side of the main bearing 812 supporting the drive shaft 704 to the back pressure chamber 839 of the orbiting scroll 818 formed by the orbiting scroll 818, the main body frame 805 and the thrust bearing 220. Sealed to prevent.

The oil chamber A 778a includes a spiral oil groove 741b provided on the outer peripheral surface of the crankshaft 714 and a crankshaft 71.
Oil chamber B778b provided at the end of No. 4, an axial oil hole 112d provided in the drive shaft 704, and a spiral oil groove 74.
1a, an oil sump 772, an oil hole B738b provided in the body frame 705, and communicates with the back pressure chamber 739,
The open end of the oil hole B738b is interrupted intermittently by the turning motion of the annular ring 94.

The fixed scroll 815 is made of a high silicon aluminum alloy having a coefficient of thermal expansion equivalent to an intermediate value between pure aluminum and eutectic graphite cast iron, and has a spiral fixed scroll wrap 815a and an end plate as shown in FIG. 815b, the discharge port 16 that opens at the winding start portion of the fixed scroll wrap 515a is provided in the center of the end plate 815b in communication with the discharge passage 880 that opens to the motor chamber 806, and the outer peripheral portion of the fixed scroll wrap 815a. The suction chamber 17 is provided in the.

A non-return valve device 50 is mounted on the end plate 815b on the side of the anti-orbiting scroll so as to cover the discharge port 16, and the non-return valve device 50, as will be described in detail with reference to FIGS. A valve body 50b (or a valve body 50e having a discontinuous annular hole 50ea) made of a thin copper plate having a shape in which an outer peripheral portion is cut out at several places, a check valve hole 50a, and a central hole 50g.
And valve case 9 having a plurality of discharge holes 50h around the valve case 9
9 and a spring device 50c interposed between the valve body 50b and the valve case 99. The spring device 50c contracts when its own temperature exceeds 50 ° C., and its own temperature rises to 50 ° C.
A compressor that has a shape memory characteristic of expanding below ℃, contracts to the bottom surface of the check valve hole 50a under the discharge refrigerant gas pressure during operation of the compressor, and the temperature of itself is below 50 ℃. During the stop, the valve body 50 is set to be pressed against the end plate 15b so as to close the discharge port 16.

As shown in FIGS. 1 and 12, a spiral orbiting scroll wrap 818a that meshes with the fixed scroll wrap 815a to form a side wall of the compression chamber, and the drive shaft 7.
04 slewing boss 818e engaged with the crankshaft 714
The orbiting scroll 818 made of an aluminum alloy, which is composed of an upright wrap support disk 818c, is arranged surrounded by a fixed scroll 815 and a main body frame 805. The wrap support disk 818c and the orbiting scroll wrap 818a have Hardening treatment such as porous nickel plating is performed. As shown in FIG. 3, a spiral tip seal groove 98 is provided at the tip of the orbiting scroll wrap 818a, and a resin-made tip seal 98a is mounted in the tip seal groove 98 with a minute gap. There is. When the orbiting scroll 818 is pressed in the axial direction of the fixed scroll 815, the flat portion of the lap support disk 818c contacts the tip of the fixed scroll wrap 815a.
The tip of the orbiting scroll wrap 818a does not come into contact with the fixed scroll 815 and maintains a minute distance of about several microns.

The low pressure oil reservoir 846a at the bottom of the accumulator chamber 846 and the suction hole 43 communicate with the oil suction hole A9a provided in the discharge cover 2a and the small diameter oil suction hole B9b provided in the fixed scroll 815. The oil suction holes (9a, 9b) are set so that the refrigerant liquid and the lubricating oil accumulated in the low pressure oil reservoir 846a are sucked up by the negative pressure generated when the refrigerant gas passes through the suction hole 43. There is.

A flat plate-shaped thrust bearing 22 which can be moved only in the axial direction by being restricted from moving in the rotational direction by the parallel pin 19 in the shape of a split pin fixed to the main body frame 805.
0 is disposed between the lap support disk 818c and the main body frame 805, and the elastic force of the annular seal ring (made of rubber) 70 (see FIG. 10) interposed between the thrust bearing 220 and the main body frame 805. Is in contact with the end plate mounting surface 15b1 between the main body frame 805 and the fixed scroll 815.

Lap support disk 8 of orbiting scroll 818
The height from the end plate sliding surface 15b2 that is in sliding contact with the end plate 18c to the end plate mounting surface 15b1 is to improve the sealing performance of the sliding portion by the oil film of the lap supporting disk 818c.
It is set to be about 0.015 to 0.020 mm larger than the thickness of 18c.

The annular thrust bearing 220 is made of a sintered alloy which is easy to form a hole, and as shown in FIGS. 10 and 11, two guide holes 93 into which the split pin 19 is movably inserted, an annular oil groove 92, and an oil. It has a hole 91 and is mounted in the thrust ring groove 890 of the main body frame 805.

Body frame 805 and thrust bearing 220
A release gap 827 of about 0.05 mm is provided between and, and an annular groove 28 for mounting the seal ring 70 is provided outside the release gap 827. The seal ring 70 seals between the release gap 827 and the back pressure chamber 839.

A plurality of coil springs 131 are arranged at equal intervals on the back side of the thrust bearing 220 on the side opposite to the compression chamber. The end faces of the coil springs 131 are pressed by a discharge guide 881 attached to the body frame 805 of the coil springs 131, and the thrust bearings are supported. 220 is an end plate 815b of the fixed scroll 815
Is pressed against.

The back side of the thrust bearing 220 communicates with the discharge chamber oil sump 34 through a coil spring mounting hole 132 provided in the main body frame 805 and an oil introduction hole 133 provided in the discharge guide 881.

On the back side of the thrust bearing 220, the seal ring A70a is mounted only on the inner side, and on the outer peripheral side,
The thrust bearing 220 is sealed by pressing against the end plate 815b.

As shown in FIGS. 1 and 2, the thrust bearing 2
The rotation preventing member (hereinafter referred to as Oldham ring) 24 of the orbiting scroll 818 arranged inside 20 is made of a light alloy or a reinforced fiber composite material suitable for sintering molding, injection molding, etc., and has a flat ring shape. Both sides are provided with parallel key-shaped key portions that are orthogonal to each other. The key portion on the upper surface side is a key groove 71a provided on the main body frame 805, and the key portion on the lower surface side is a key provided on the lap support disk 818c. It engages with the groove 71 and slides.

The thickness of the Oldham ring 24 is such that when the Oldham ring 24 reciprocates,
5 and the lap support disk 818c are slid smoothly and no jumping phenomenon occurs.

As shown in FIGS. 1, 10 and 12, the back pressure chamber 839 has about 18 points before the first refrigerant compression chambers 61a and 61b, which communicate with the suction chamber 17 intermittently, have been closed.
The oil groove 291, the outer peripheral space 37 outside the lap support disk 818c, and the oil groove 8 provided on the sliding surface of the end plate 815b are provided within the swing angle range of 0 degree.
It is connected to the suction chamber 17 via 91 in order.

In FIG. 13, the horizontal axis represents the rotation angle of the drive shaft 704, the vertical axis represents the refrigerant pressure, the pressure change state of the refrigerant gas in the intake / compression / discharge processes, and the solid line 6
2 shows the pressure change at the time of normal pressure operation, and the dotted line 63 shows the pressure change at the time of abnormal pressure rise.

The operation of the scroll refrigerant compressor configured as described above will be described.

1 to 13, when the drive shaft 704 is rotationally driven by the motor 703, the orbiting scroll 8
18 is a drive shaft 7 driven by a crank mechanism of the drive shaft 704.
04 to rotate around the main axis, but the key portion on the side of the orbiting scroll 818 of the Oldham ring 24 (see FIG. 2)
Engages with the key groove 71 of the orbiting scroll 818, and the key portion on the opposite side engages with the key groove 71a (see FIG. 1) of the main body frame 805, so that the rotation is prevented and the fixed scroll performs the orbital motion. The volume of the compression chamber is changed together with 815, and the refrigerant gas is sucked and compressed.

The release clearance 27 on the back side of the thrust bearing 20 which communicates with the discharge chamber oil reservoir 34 which communicates with the discharge port 16 of the compression chamber is filled with the lubricating oil under the pressure of the discharged refrigerant gas.

The thrust bearing 20 is pressed against the end plate mounting surface 15b1 of the fixed scroll 15 by the high pressure lubricating oil, the elastic force of the coil spring 131 and the elastic force of the seal ring 70 with the lapse of time after the start of compression. As a result, the lap support disk 818c of the orbiting scroll 818 is attached to the end plate sliding surface 1
5b2 and the thrust bearing 220 are clamped (15 to 20).
Micron assembly gap).

Then, the suction refrigerant of the gas-liquid mixture containing the lubricating oil from the refrigeration cycle connected to the compressor flows into the accumulator chamber 846 from the suction pipe 47 and collides with the outer surface of the end plate 15b of the fixed scroll 815. , Via the upper space of the accumulator chamber 846, two suction holes 4
3 (see FIG. 12) to flow into the suction chamber 17.

On the other hand, the liquid refrigerant and the lubricating oil separated from the refrigerant gas by the weight difference between the gas and the liquid and the inertial force at the time of changing the inflow direction are temporarily collected at the bottom of the accumulator chamber 846 and the sucked refrigerant gas is sucked into the suction hole 43. Due to the negative pressure generated when passing through, the oil is sucked up into the suction hole 43 in an atomized state through the oil suction hole A9a and the oil suction hole B9b, and is mixed into the suction refrigerant gas again.

The suction refrigerant gas separated into gas and liquid is supplied to the suction chamber 1
7. The first compression units 61a and 61b (see FIG. 12) formed between the orbiting scroll 818 and the fixed scroll 815 are enclosed in the compression chamber, and the second compression chamber 51
a, 51b and the third compression chambers 60a, 60b are sequentially transferred and compressed, and then discharged from the central discharge port 16 to the check valve chamber 50a, the discharge chamber 2, the gas passage B80b, and the gas passage A8.
0a and the discharge chamber 2b in this order to the motor chamber 80
6 is discharged.

Since the compression chamber and the discharge port 16 are opened immediately after the completion of compression, the compressed refrigerant gas undergoes a rapid primary expansion when flowing into the check valve chamber 50a from the compression chamber, and the discharge immediately after that occurs. From the completion stroke to the compression completion stroke, the refrigerant gas discharged from the check valve chamber 50a primarily flows back into the compression chamber.

As a result, the refrigerant gas intermittently flows out of the third compression chamber (60a, 60b).
a, 60b), while flowing out from the third compression chamber (60a, 60b) to the discharge chamber 2 as a whole flow, the refrigerant gas discharged from the check valve chamber 50a and the discharge chamber 2 is the third flow. Pressure fluctuations occur during the inflow and outflow to and from the compression chambers (60a, 60b), causing a pulsation phenomenon.

The discharged refrigerant gas undergoes secondary expansion when flowing out toward the spherical wall surface forming the discharge chamber 2 through the discharge small hole 50h of the check valve device 50, and further collides with the spherical wall surface. Distribute evenly. After that, the two discharge passages 880 arranged at symmetrical positions merge in the discharge chamber 2c and the motor chamber 806, so that the discharge gas pulsations from the discharge passages 880 cancel each other out, and the third,
The fourth expansion causes the motor chamber 80 to be further attenuated in sequence.
The pressure pulsation of 6 is extremely small.

When the discharge refrigerant gas instantaneously flows back from the discharge chamber 2 to the check valve chamber 50a, the valve body 50b tries to move in the direction of closing the discharge port 16 following the flow, but During operation of the machine, the coil spring 50c having a shape memory characteristic is completely contracted due to the ambient temperature and does not exert a force on the valve body 50b, and the valve body 50b is discharged from the discharge port 1.
6 is not blocked.

The discharged refrigerant gas dispersed from the small holes 81a of the discharge guide 881 and discharged into the motor chamber 806 collides with the annular shield plate 86 and the winding of the motor 703, and then the cooling passage 35 outside the stator 703b. While flowing through the inner and inner passages, the motor 703 flows to the upper side of the motor chamber 806 while being cooled, and is discharged from the discharge pipe 831 to the external refrigeration cycle.

At this time, a part of the lubricating oil in the discharged refrigerant gas adheres to the surface of the lower winding of the motor 703 and is separated from the refrigerant gas and collected in the discharge chamber oil sump 34. The lubricating oil in the discharged refrigerant gas passing through the outer peripheral portion of the weight 775 and the lower balance weight 776 is centrifugally separated by the rotation of the upper balance weight 775 and the lower balance weight 776, and diffused to the inner surface of the winding of the motor 703. , Flows out to the lower part along the inner space of the winding bundle, and collects in the discharge chamber oil sump 34.

Lubricating oil in the discharge chamber oil sump 34 is passed through a route described later to form an oil chamber A778a, an oil chamber B778b, and a back pressure chamber 8.
While finally flowing into the suction chamber 17 via 39, the orbiting scroll 81 is gradually fed by the lubricating oil pressure in the oil supply path.
The back pressure applying force to 8 becomes large.

Following the pressure increase in the motor chamber 806, the lap support disk 818c gradually contacts the end plate sliding surface 15b2 of the fixed scroll 815 with an appropriate pressing force. The tip of the fixed scroll wrap 815a and the orbiting scroll 818
The gap between the lap support disk 818c and the lap support disk 818c is eliminated, the compression chamber is sealed, the suction refrigerant gas is efficiently compressed, and stable operation is continued.

The axial gap between the tip of the orbiting scroll wrap 818a and the end plate 815b of the fixed scroll 815 is defined by the tip seal groove 98 (see the figure) when the refrigerant gas during compression leaks to the low pressure side compression chamber of the adjacent chamber. 3), and the gas back pressure presses the tip seal 98a against the side surface of the low compression chamber of the tip seal groove 98a and the end plate 815b of the fixed scroll 815 to seal the tip scroll 98a.

When the compressor is stopped, the orbiting scroll 818 instantaneously makes a reverse swirling motion due to the reverse flow due to the pressure difference of the refrigerant gas in the compression chamber, but since the refrigerant gas flows backward from the compression chamber to the suction chamber 17, In the orbiting scroll 818, as shown in FIG. 12, the first compression chambers 61a and 61b are the suction chambers 17
Stop at the turning angle that leads to. As shown in FIG. 8, in this stopped state, the annular ring 94 closes the lubricating oil inflow port to the back pressure chamber 839.

Further, when the compressor is stopped, the refrigerant gas in the compression chamber flows back to the suction chamber 17 so that the pressure of the refrigerant gas in the discharge port 16 drops sharply, and the refrigerant gas pressure difference between the discharge port 16 and the discharge chamber 2 is reduced. As a result, the valve body 50b is
To prevent continuous backflow of the refrigerant gas discharged from the discharge chamber 2 to the compression chamber.

Due to the temporary backflow of the discharged refrigerant gas immediately after the compressor is stopped and the reverse orbit of the orbiting scroll 818, the magnetic valve body 50b is separated from the bottom surface of the check valve chamber 50a.
The valve body 51b keeps closing the discharge port 16 due to the pressure difference until the refrigeration cycle balances the pressure. At the same time, the temperature of the coil spring 50 having a shape memory characteristic is lowered and the coil spring 50 expands.
0b continues to block the discharge port 16.

When the compressor is stopped for a long time, the pressure in the compressor is equalized, and the liquid refrigerant flows not only into the accumulator chamber 846 but also into the compression chamber. The thrust force in the direction opposite to the discharge port 16 acts on the orbiting scroll 818 by the pressure of the liquid compression refrigerant in the compression chamber. As a result, the orbiting scroll 818
Moves away from the fixed scroll 815 in the axial direction, reducing the compression load.

On the other hand, the back pressure chamber 839 in the initial stage of starting when the compressor is cold.
Since the increase in the lubricating oil pressure in the discharge chamber oil sump 34 is low, the pressure is substantially equivalent to the suction pressure. As a result, the lap support disk 818c of the orbiting scroll 818 is separated from the end plate sliding surface 15b2 while the back pressure is applied only by the lubricating oil in the oil chamber A778a having a low pressure rise, and the thrust bearing 20
Is supported by retracting to the lap support disk 818c and the tip of the fixed scroll wrap 815a (about 0.0
15-0.020 micron), the pressure in the compression chamber drops, and the compression load in the initial stage of starting is reduced.

If liquid compression occurs in the compression chamber and the pressure in the compression chamber rises abnormally instantaneously during continuous operation, the thrust force acting on the orbiting scroll 818 may be applied to the rear surface of the orbiting scroll 818. It becomes larger than the applied back pressure biasing force, the orbiting scroll 818 moves in the axial direction,
It is supported by the thrust bearing 220. Then, the sealing of the compression chamber is released in the same manner as described above, the compression chamber pressure is reduced, and the compression load is reduced.

The back pressure chamber 839 is the first compression chamber 61.
Since a and 61b communicate with the outer peripheral space 37 through the oil groove 291 provided in the thrust bearing 220 within the swivel angle range of about 180 degrees before the completion of the intake refrigerant gas confinement,
Lubricating oil in the back pressure chamber 839 does not continuously flow into the compression chamber via the oil groove 891 and the suction chamber 17, and suppresses oil compression generation in the compression chamber.

The lubricating oil in the discharge chamber oil sump 34 at the initial stage of starting when the compressor is cold is the spiral oil groove 741 provided in the drive shaft 704.
Oil hole A838 by screw pump action of a, 741b
It is sucked into the oil chamber A778a via a.

After that, part of the lubricating oil is spiral oil groove 741.
b, the oil chamber B778b, and the oil supply hole 112d are sequentially passed, and the sliding surface of the slewing bearing 818b is lubricated, supplied to the sliding surface of the main bearing 812, and delivered to the oil sump 772.

The main bearing 812 is provided by the spiral oil groove 741a.
The lubricating oil supplied to the oil merges with the lubricating oil that has passed through the oil chamber B778b in the oil sump 772, and then a part of the lubricating oil is decompressed in the throttle passage portion of the oil hole B738b (see FIG. 8) and the back pressure is reduced. The chamber 839 is intermittently refueled. The remaining lubricating oil is re-collected in the discharge chamber oil sump 34 after lubricating the sliding surface of the thrust bearing 713 supporting the own weight of the drive shaft 704 and the rotor 703a.

The refrigerant gas in the motor chamber 806 is accumulated in the oil sump 77 by the lubricating oil passing through the thrust bearing portion 713.
Backflow to 2 is blocked.

The drive shaft 7 generated by the end surface of the lower balance weight 776 slidingly contacting the thrust bearing 713 at high speed.
The vertical vibration of 04 is regulated by the end surface of the upper balance weight 775 coming into contact with the end portion of the upper bearing 711.

Oil is supplied to the upper bearing 711 by the cooling passage 3
5, the lubricating oil separated from the refrigerant gas flowing into the oil separation space 128a through the vent hole 129 of the upper frame 126 and collected in the central portion of the upper frame 126 is the spiral oil groove 741d.
Supplied by screw pump action.

The pressure of the refrigerant gas discharged from the motor chamber 806 rises following the lapse of time after the cold start of the compressor, and the lubricating oil in the oil reservoir 34 of the discharge chamber is also oiled by the pressure difference between it and the back pressure chamber 839. Supply to chamber A778a, spiral oil grooves 741a, 741
Oil is supplied to the back pressure chamber 839 together with the screw pump action of b. The pressure in the back pressure chamber 839 gradually increases, and the oil chamber A77
The combined force with the lubricating oil pressure corresponding to the discharge pressure of 8a acts on the lap support disk 818c of the orbiting scroll 818. As a result, the thrust load acting to separate the orbiting scroll 818 from the fixed scroll 815 by the refrigerant gas pressure in the compression chamber is offset, and the thrust force acting on the orbiting scroll 818 is reduced.

Therefore, while the pressure in the motor chamber 806 is low after the cold start of the compressor, the force exerted on the orbiting scroll 818 by the lubricating oil pressure in the oil chamber A778a and the back pressure chamber 839 is the refrigerant gas pressure in the compression chamber. Orbiting scroll 81
It is smaller than the thrust load on No.8. As a result, the orbiting scroll 818 separates from the fixed scroll 815 and is supported by the thrust bearing 220 that receives the elastic force of the coil spring 131 and the seal ring 70 and the back pressure due to the lubricating oil introduced from the discharge chamber oil sump 34.

When the differential pressure between the discharge pressure and the suction pressure exceeds the required pressure, the force imparted to the orbiting scroll 818 by the lubricating oil pressure in the oil chamber A778a and the back pressure chamber 839 is orbited by the refrigerant gas pressure in the compression chamber. It becomes larger than the thrust load on the scroll 818. Then, the orbiting scroll 818
Are supported by the fixed scroll 815.

The center of the compression chamber, the center of the slewing bearing 818e,
In the arrangement in which the centers of the annular rings 94 are substantially coincident with each other, the annular rings 94 orbit together with the orbiting scroll 818, so that the inertial force at that time attempts to jump out from the annular seal groove 95 provided in the orbiting boss portion 818e. . Further, the annular ring 94 expands its inner diameter by the pressure difference between the oil chamber A778a and the back pressure chamber 839, and closes the cut end 94b together with the thermal expansion. By these actions, the annular ring 94 is pressed against the outer surfaces of the main body frame 805 and the annular seal groove 95, and the oil scraping action of the annular ring 94 causes the annular seal groove 95 and the annular ring 94 to move.
Lubricating oil is pushed in between and to prevent excessive leakage of lubricating oil between the oil chamber A 778a and the back pressure chamber 839.

Further, the resinous annular ring 94 having excellent flexibility expands its inner diameter along the outer side surface of the annular seal groove 95 due to the pressure difference between the back pressure chamber 839 and the oil chamber A778a, and heat The cut 94b is closed together with the expansion and is pressed against the outer side surface of the annular seal groove 95, so that the leakage between both spaces is further reduced.

The annular ring 94 is formed by an oil film of the lubricating oil accumulated in the oil groove 94a provided on the surface of the annular groove 94.
By lubricating the sliding surface between the main body frame 805 and the main body frame 805, wear and sliding resistance of the sliding surface are reduced.

During normal operation of the compressor, the high pressure oil chamber A778
The orbiting scroll 818 is given back pressure to the fixed scroll 815 side by the lubricating oil pressure of a and the lubricating oil pressure of the back pressure chamber 839, and the lap support disk 818c and the end plate sliding surface 15b.
It slides smoothly between 2 and while maintaining an appropriate contact force.
The axial clearance of the compression chamber is minimized.

The lubricating oil flowing into the back pressure chamber 839 intermittently flows into the outer peripheral space 37 through the oil groove 291 provided in the thrust bearing 220, and further through the oil groove 891 provided in the end plate 815b. Flow into the suction chamber 17. The lubricating oil lubricates each sliding surface in the middle of the passage and seals the sliding gap.

The lubricating oil flowing into the compression chamber (compression space) together with the suction refrigerant gas seals the minute gap between the adjacent compression chambers with an oil film to prevent the compressed refrigerant gas from leaking, while lubricating the sliding surface of the compression space. The compressed refrigerant gas is discharged again to the motor chamber 806 through the discharge port 16.

In the oil supply path from the discharge chamber oil reservoir 34 to the suction chamber 17 via the back pressure chamber 839, the back pressure chamber 839 maintains a proper intermediate pressure between the discharge pressure and the suction pressure.

Further, since the compression ratio of the scroll refrigerant compressor is constant, when the differential pressure between the suction chamber 17 and the discharge chamber 2 is small as immediately after cold start, or abnormal liquid compression occurs. In the case, the orbiting scroll 8 is used as described above.
18 is separated from the fixed scroll 815 and is supported by the thrust bearing 220.

However, the thrust bearing 220 biased by the back pressure cannot support the abnormally increased pressure load of the compression chamber, and is retracted in the direction of decreasing the release gap 27 and fixed to the lap support disk 818c of the orbiting scroll 818. The axial gap between the scroll 815 and the tip of the fixed scroll wrap 815a increases. As a result, a large amount of leakage occurs between the compression chambers, and the pressure in the compression chamber suddenly drops during compression, as indicated by the alternate long and short dash line 63a in FIG.

The orbiting scroll 818 is the fixed scroll 8
Since the maximum distance apart from 15 in the axial direction is regulated to about 70 microns, an oil film remains in each gap between the sliding surfaces on both sides of the lap support disk 818c, and the lubricating oil from the outer peripheral space 37 to the suction chamber 17 After the change in pressure of the back pressure chamber 839 due to excessive inflow is suppressed and the compression load is instantly reduced, the thrust bearing 220 can be instantly returned to its original position, and stable operation is resumed.

When the orbiting scroll 818 retracts toward the thrust bearing 220, the orbiting scroll wrap 81
The axial dimension between the tip of 8a and the fixed scroll 815 also increases, but since the tip seal 98a is pressed toward the fixed scroll 15 by the gas pressure on its back surface, leakage of the compressed refrigerant gas from this portion does not occur. It hardly happens.

On the other hand, the gap between the lap support disk 818c of the orbiting scroll 818 and the tip of the fixed scroll wrap 815b of the fixed scroll 815 expands, and compressed refrigerant gas leaks in the compression chamber, resulting in a rapid compression chamber pressure. descend.

Also, when foreign matter is caught in the axial gap between the orbiting scroll 818 and the fixed scroll 815, the thrust bearing 220 retreats and removes the foreign matter as described above.

Further, the pressure in the compression chamber when instantaneous liquid compression occurs at the initial stage of cold start-up or during steady operation causes abnormal overcompression as indicated by the dotted line 63 in FIG.
The high pressure space volume communicating with the
0a, the discharge chamber 2, and the discharge chamber 2c are sequentially expanded, and the pressure in the motor chamber 806 hardly changes.

In the above embodiment, the oil pressure B 738b of the main body frame 805, the oil groove 291 of the thrust bearing 220, and the oil groove 891 of the end plate 815b are adjusted so that the back pressure chamber 839 has an intermediate pressure between the discharge pressure and the suction pressure. However, the back pressure chamber 839 may be set so as to correspond to the suction pressure in accordance with the compressor load condition. In this case, the orbiting scroll 81
The application of back pressure to No. 8 depends only on the lubricating oil pressure in the oil chamber A778a.

Further, in the above embodiment, the outer peripheral space 37 is communicated with the suction chamber 17, but the outer peripheral space 37 is provided with the oil hole 83 provided in the lap support disk 818c of the orbiting scroll 818.
It may communicate with the first compression chambers 61a and 61b via 8c (see FIG. 10).

As described above, according to the above-described embodiment, it is possible to obtain the operational effects of the embodiments described below.

That is, according to the first embodiment, the orbiting bearing 8 of the orbiting scroll 818 that engages with the drive shaft 704.
After lubricating the sliding contact surface of the lap support disk 818c of the orbiting scroll 818 with at least a part of the lubricating oil supplied to the sliding surface of 18b, the suction chamber 17 (first compression chambers 61a, 61a
b), the crankshaft 714 provided at the tip of the drive shaft 704 so that the drive shaft 704 engages with the slewing bearing 818b has a diameter of a rotation locus with respect to the main shaft of the drive shaft 704 on the outer peripheral surface thereof. The dimensions are set so as to be equal to or smaller than the bearing inner diameter of the main bearing 812 provided in the main body frame 805 supporting the shaft 704, and the drive shaft 704 can be sequentially inserted into the main bearing 812 and the swing bearing 818b from the motor 703 side. It was done. Further, according to this configuration, the drive shaft 7 is maintained without changing the assembling state of the fixed scroll 815, the orbiting scroll 818, and the main body frame 805.
04 can be attached / detached and replaced, and while the drive shaft 704 adapted to the dimensions of the fixed scroll 815, the orbiting scroll 818, and the main bearing 812 is attached / detached and replaced, the radial gap in the compression chamber is minutely assembled and supplied to the compression chamber. By combining with the oil film action of the lubricating oil, the compression chamber gap can be sealed and the compression efficiency can be improved.

According to the second embodiment, the anti-compression chamber side of the drive shaft 704 is supported by the upper frame 126, while the main bearing 812 and the crank shaft 714 that support the compression chamber side of the drive shaft 704 are engaged. The length of the main bearing 812 is shortened so that the main bearing 812 can be easily inserted into the orbiting bearing 818b. Further, according to this configuration, it is possible to shorten the detachment / replacement time of the drive shaft 704 and prevent the drive shaft 704 and the main bearing 812 from being damaged due to the detachment.

According to the third embodiment, the upper bearing 811 for supporting the drive shaft 704 together with the main bearing 812 is arranged on the side opposite to the compression chamber of the motor 703, and the main frame 812 having the main bearing 812 and the upper bearing 811 are provided. The movement of the drive shaft 704 in the axial direction is restricted by. With this configuration, it is possible to prevent axial vibration of the drive shaft 704 and the motor 703 when the compressor is operating.

(Embodiment 2) In FIG. 14, the oil hole B738b provided in the main body frame 805 in FIG. 1 is abolished, and the oil chamber B878b and the back of the oil chamber B878b are provided through a small hole 840 provided in the orbiting boss portion of the orbiting scroll 818. The lubricating oil in the oil chamber A878a is first decompressed in the sliding gap of the crankshaft 714a and flows into the oil chamber B878b, and is secondarily decompressed through the narrow hole 840 to the back pressure chamber 839. Inflow. Other configurations and operations are the same as those in the first embodiment.

Further, although the refrigerant compressor has been described in the above-mentioned embodiment, the same effect can be expected in the case of other gas compressors such as oxygen, nitrogen and helium which use lubricating oil.

Further, in the above embodiment, the configuration of the vertical compressor is shown and the effect thereof is explained, but the same operational effect can be expected in the configuration of the horizontal compressor.

[0109]

As is apparent from the above embodiment, claim 1
The invention described in (1), after lubricating the sliding contact surface of the lap support disk of the orbiting scroll with at least a part of the lubricating oil supplied to the orbiting bearing of the orbiting scroll engaged with the drive shaft, In the configuration of supplying to either one, the crankshaft provided at the tip of the drive shaft so that the drive shaft engages with the slewing bearing, the diameter of the rotation trajectory of the outer peripheral surface of the crankshaft with respect to the main shaft supports the drive shaft. It is set so that it is less than the bearing inner diameter of the main bearing, and the drive shaft is dimensioned so that it can be inserted into the main bearing and the orbiting bearing in order from the motor side. The drive shaft can be removed and replaced without changing the bearing assembly state, and the fixed scroll, orbiting scroll, and drive shafts that fit the dimensions of the main bearing can be selectively assembled while the drive shaft is removed and replaced, and the clearance in the compression chamber radial direction can be maintained. And subassemblies, an effect that was combined with an oil film action of the lubricating oil supplied to the compression chamber to seal the compression chamber gap may improve the compression efficiency.

According to the second aspect of the invention, the bearing portion for supporting the drive shaft together with the main bearing is arranged on the side opposite to the compression chamber of the motor, while the length of the main bearing is shortened. It is possible to reduce the time required for detaching and replacing the drive shaft and prevent damage to the drive shaft and the main bearing due to the detachment.

According to a third aspect of the present invention, the axial movement of the drive shaft is restricted by a bearing portion for supporting the drive shaft together with the main bearing on the side opposite to the compression chamber of the motor, and a main body frame having the main bearing. According to this configuration, there is an effect that the vibration of the drive shaft and the rotor of the motor during the operation of the compressor is prevented in the axial direction to reduce the vibration of the compressor.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a scroll refrigerant compressor showing one embodiment of the present invention.

FIG. 2 is an exploded view of main parts of the compressor.

FIG. 3 is a partial sectional view of a check valve device arranged at a discharge port of the compressor.

FIG. 4 is a perspective view of components of the check valve device in FIG. 3;

FIG. 5 is a perspective view of a main part of the check valve device.

FIG. 6 is a perspective view of a main part of the check valve device.

FIG. 7 is an exploded perspective view of small parts in the compressor.

FIG. 8 is a partial cross-sectional view of a main bearing in the compressor.

FIG. 9 is a perspective view of a seal component in the compressor.

FIG. 10 is a partial cross-sectional view of a thrust bearing portion of the compressor.

11 is a perspective view of the thrust bearing in FIG.

FIG. 12 is a transverse sectional view taken along line AA in FIG. 1;

FIG. 13 is a characteristic diagram showing a change in pressure of the refrigerant gas from a suction stroke to a discharge stroke of the compressor.

FIG. 14 is a longitudinal sectional view of a scroll refrigerant compressor showing another embodiment of the present invention.

FIG. 15 is a longitudinal sectional view of a conventional scroll compressor.

[Explanation of symbols]

 2 Discharge chamber 16 Discharge port 17 Suction chamber 24 Rotation prevention member 34 Discharge chamber oil sump 126 Upper frame 220 Thrust bearing 703 Motor 704 Drive shaft 801 Sealing case 805 Body frame 806 Motor chamber 811 Upper bearing 812 Main bearing 815 Fixed scroll 815a End plate 815b Fixed scroll wrap 818 Orbiting scroll 818a Orbiting scroll wrap 818b Orbiting bearing 818c Lapping support disk

Claims (3)

[Claims] 1. An orbiting scroll wrap on a lap support disk forming a part of an orbiting scroll is rotatably and rotatably meshed with a spiral fixed scroll wrap formed on one surface of an end plate forming a part of the scroll. , A scroll-shaped compression space is formed between both scrolls, a discharge port is provided at the center of the fixed scroll wrap, and a suction chamber is provided outside the fixed scroll wrap. To the main body frame having a main bearing that supports the drive shaft and is close to the compression chamber in order to compress the fluid by being divided into a plurality of compression chambers that continuously move toward the compression chamber. The lap support disk is provided in a loose state between the lap support disk and a thrust bearing supporting the side opposite to the compression chamber, and the wrap support disk and the main body frame are provided with the rotary shaft. A hermetically sealed case includes a scroll compression mechanism for rotating the orbiting scroll through an orbiting bearing in which the drive shaft and the lap support disk engage with each other and a motor connected to the drive shaft. The lubricating oil separated from the discharge gas in the closed case is supplied to the sliding parts of the main bearing and the orbiting bearing, and at least a part of the lubricating oil supplied to the orbiting bearing is supplied to the wrap. A crankshaft provided at the tip of the drive shaft so that the drive shaft engages with the orbiting scroll in a configuration in which the sliding contact surface of the support disk is lubricated and then supplied to either the compression chamber or the suction chamber. Is set such that the diameter of the rotation trajectory of the outer peripheral surface of the drive shaft with respect to the main shaft is equal to or smaller than the bearing inner diameter of the main bearing, and the drive shaft is connected to the main bearing from the motor side. Scroll gas compressor that sequentially insertable dimensions in time bearing. 2. The scroll gas compressor according to claim 1, wherein an upper bearing that supports the drive shaft together with the main bearing is arranged on the side opposite to the compression chamber of the motor, and the length of the main bearing is shortened. 3. The scroll gas compressor according to claim 1 or 2, wherein movement of the drive shaft in the axial direction is restricted by the main body frame and the upper bearing.