JPH073230B2 - Scroll gas compressor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a scroll gas compressor.

2. Description of the Related Art A scroll compressor with low vibration and low noise characteristics has a suction chamber at the outer periphery, a discharge port at the center of the spiral, and a compressed fluid flow in one direction reciprocating compressor or It is generally known that a discharge valve for compressing fluid such as a rotary compressor is not required, the compression ratio is constant, the discharge pulsation is relatively small, and a large discharge space is not required.

However, especially when compressing gas, it is necessary to make the dimensional accuracy of the spiral part extremely high in order to reduce the leakage gap of the compression part, but due to the complexity of the part shape and the dimensional accuracy, scroll gas compression There was a problem that the cost of the machine was high and the dispersion of the performance was large.

Therefore, as a measure to solve this kind of problem, it is often expected that the dimensional accuracy of the spiral part will be optimized and the compressor performance will be stabilized by the sealing effect using a lubricating oil film to prevent gas leakage during compression. The configuration shown in FIG. 12 is considered, and a part of the lubricating oil supplied to the sliding portion is caused to flow into the compression chamber together with the suction gas, and after the compression discharge, the lubricating oil is separated from the compressed gas, and then the oil is returned through the oil return passage. Based on the idea of returning to the space leading to the lubricating oil reservoir again to reduce the lubricating oil outflow to the outside of the compressor, the lubricating oil separated from the compressed gas in the space 520 inside the cap 519 provided in the discharge space 582 is Hole 522 to Hole 58
It was configured to be returned to the space 580 serving as the suction passage through the oil return passage 4 and collected in the oil reservoir 508 and supplied again to the sliding portion by the pump device (JP-A-60-75795).

The configuration shown in FIG. 13 is also conceivable, in which the lubricating oil contained in the compressed gas is separated by the oil separation element 672 provided in the discharge chamber 674, and the lubricating oil is collected in the oil sump 673 on the fixed scroll end plate 603. Fixed scroll 601 and orbiting scroll 606
After the differential pressure oil is supplied to the sliding surface 631 between and, the lubricating oil is made to flow into the suction chamber 699 to reduce the compressed gas leakage in the compression chamber due to the sealing effect of the oil film (JP-A-56- 1657
No. 87).

Also, as shown in FIGS. 14 and 15, a configuration in which lubricating oil is directly flown into the compression chamber during compression is also conceivable.
The structure is such that the motor 703 is arranged in the upper part of the 701 and the compression part is arranged in the lower part so that the closed container inner space 702 is used as the discharge chamber, and the lubricating oil in the oil reservoir 710 at the bottom of the discharge chamber is compressed via the oil suction pipe 722. The structure is such that it directly flows into the compression chamber 723 on the way (JP-A-57
No. 8386 gazette), FIG. 15 shows that the compression part is arranged in the upper part of the closed container 801 and the motor 803 is arranged in the lower part of the closed container 801.
With 02 as the discharge chamber, the back pressure chamber 808 in the intermediate pressure state provided on the rear surface of the orbiting scroll 804 on the side opposite to the compression chamber is relayed in order to reduce the thrust force acting on the gas compression of the orbiting scroll 804. Oil hole 89 in the drive shaft 802 provided at the front and rear
9. Through the oil supply pipe 815, the lubricating oil in the oil reservoir 809 at the bottom of the closed container 801 is made to flow into the compression chamber 823 during compression by differential pressure (Japanese Patent Laid-Open No. 59-110893).

Problems to be Solved by the Invention However, the oil return passage (hole 522) as shown in FIG.
~ The structure in which the discharge space 582 and the low-pressure side space 580 are always in communication with each other through the hole 584), even if the lubricating oil always exists in the space 520 and the discharge space 582, the rotational speed of the compressor drive shaft is Along with the change, the amount of oil supplied to the sliding part changes, the amount of lubricating oil contained in the compressed gas also changes, and the discharge space 582
It is extremely difficult to set the oil return passage that returns the lubricating oil without excess or deficiency because the differential pressure between the low pressure side space 580 and the viscosity of the lubricating oil also changes. It is impossible to prevent a large amount of lubricating oil from flowing out of the compressor due to the large discharge amount.

In addition, while the compressor is stopped, the lubricating oil in the space 520 and the discharge space 582 flows into the oil reservoir 508 at the bottom of the compressor due to the differential pressure and its own weight, etc., and then in the space 520 and the discharge space 582 for a while after the compressor is restarted. There is not enough lubricating oil, and a large amount of compressed gas is used in the oil return passage (hole 522
~ There was a problem that it would flow into the space 580 on the low pressure side through the holes 584) and cause a significant decrease in suction efficiency and compression efficiency and deterioration of durability.

Further, in the configuration as shown in FIG. 13 in which the lubricating oil in the oil sump 673 on the fixed scroll end plate 603 is caused to flow into the suction chamber 699 through the sliding surface 631, the compressor drive is performed as in the case of FIG. When the shaft rotates at a high speed and the gas discharge amount increases, there is also a state where there is no lubricating oil in the oil reservoir 673. In such a case, a large amount of compressed gas in the discharge chamber 674 flows into the suction chamber 699 via the sliding surface 631,
Not only the suction efficiency and compression efficiency decrease significantly, but also the sliding surface 63
There was a problem such as causing wear and seizure of 1.

Further, as shown in FIG. 14 above, the compression chamber in the middle of compressing the lubricating oil in the oil reservoir 710 at the bottom of the space 702 in the closed container having the same discharge pressure.
In the case of using a pressure difference to the 723, when used in a refrigerant compressor, etc., a large amount of the refrigerant returned from the refrigeration cycle outside the compressor to the compressor due to its own weight or the pressure difference while the compressor is stopped is liquefied and oiled. In some cases, the refrigerant liquid and lubricating oil may flow into the compression chamber 723 through the oil suction pipe 722 and fill up in the lower part of the motor 703 above the sump 710. It is impossible, and even if the motor 703 has a large starting torque and can be restarted, the compressor will be damaged.

In addition, the lubricating oil in the oil sump 710 may run short depending on the compressor operating conditions.In such a state, the compressed gas flows into the compression chamber 723 to cause a significant decrease in compression efficiency and an increase in the abnormal pressure in the compression chamber. There was a problem of causing damage.

Further, in the configuration as shown in FIG. 15 above, in which the lubricating oil is supplied to the compression chamber 823 during compression via the back pressure chamber 808 in the intermediate pressure state leading to the oil reservoir 809 at the bottom of the compressor, As in the case of the figure, there is a problem that when the lubricating oil in the oil sump 809 is insufficient, the compression efficiency is significantly reduced and the durability is reduced.

On the other hand, as shown in FIG. 16 and FIG. 17, when the compressor is operating, the oil supply passage 919 leading to the oil sump 916 at the bottom of the discharge chamber 910 is opened to supply differential pressure to the compression portion, and the oil supply passage is closed when the compressor is stopped. Although the invention of the configuration is also known from Japanese Patent Publication No. 59-44517, the present invention discloses that the discharge valve 9 is provided downstream of the discharge port 907.
Discharge valve of slide vane type rotary compressor that requires 08
It is configured to operate the plunger 922 and control the open / close valve 925 of the oil supply passage 919 by utilizing the differential pressure between the pressure of the cylinder 927 before passing through the discharge valve 908 and the pressure of the discharge chamber 910 after passing through the discharge valve 908.

However, for a while immediately after the cold start operation of the compressor,
Since the pressure in the discharge chamber 910 is low, the discharge valve 908 opens from the initial compression process in the cylinder 927, and the pressure difference between the discharge chamber 910 and the cylinder 927 is small. For this reason, since the on-off valve 925 does not open and there is no oil supply to the compression section, there is a problem that the jumping phenomenon of the vanes 905 occurs, resulting in abnormal noise and reduction in compression efficiency, and there is no influence on the compressor operating conditions. The practical application of was desired.

Therefore, the present invention focuses on the fact that the scroll compressor does not need a discharge valve for increasing the pressure of the compression chamber and has a constant compression ratio, and thus the suction chamber and the compression chamber not communicating with the discharge chamber and the suction chamber The present invention provides a scroll gas compressor having high efficiency and durability by putting into practical use an oil supply passage control device having a wide application range by utilizing a pressure difference.

Means for Solving the Problems In order to solve the above problems, the scroll gas compressor of the present invention has an oil reservoir in the discharge chamber or an oil reservoir communicating with the discharge chamber and a pressure lower than the oil reservoir and sucking into the discharge chamber. The second that does not communicate with the room
An oil supply passage control valve device including an opening / closing valve for opening / closing the oil supply passage and an actuator for controlling the opening / closing valve is provided in the middle of the oil supply passage so that the compression chamber communicates with the compression passage.
The actuator is provided with a valve body and a back pressure chamber A and a back pressure chamber B of the valve body arranged on both sides of the valve body, and a spring device for urging the valve body. The back pressure chamber A serves as a discharge chamber and a suction chamber. Also communicates with the first compression chamber in the post-compression stage rather than the second compression chamber, the back pressure chamber B communicates with the suction chamber, the third compression chamber leading to the suction chamber, or the suction side leading to the suction chamber, and the back pressure chamber When there is a differential pressure between A and the back pressure chamber B, and the differential pressure is within the range of the first set value, the valve body moves forward against the spring device to open the on-off valve, and the differential pressure becomes In the case of a second set value range larger than the first set value, the valve body further advances to close the open / close valve, and when there is no pressure difference, the valve body retracts to close the open / close valve. It is a configuration provided.

Effect of the Invention With the above structure, the compressor starts, the orbiting scroll orbits, and the gas in the suction chamber is sucked into the compression chamber and compressed to a certain compression ratio to be discharged to the discharge chamber. A pressure difference is generated between the back pressure chamber A and the back pressure chamber B of the oil supply passage control valve device provided in the middle of the operation of the valve body to move the valve body forward to open the opening / closing valve to communicate the oil supply passage, Lubricating oil in the oil reservoir (oil reservoir leading to the discharge chamber) is supplied to the second compression chamber.

If there is no lubricating oil in the oil reservoir of the discharge chamber (oil reservoir leading to the discharge chamber), a large amount of high-temperature and high-pressure compressed gas will flow into the second compression chamber through the oil supply passage, and the pressure of the first compression chamber will increase. The pressure in the back pressure chamber A rises abnormally and the pressure in the back pressure chamber A also rises abnormally.
The differential pressure between and exceeds the set value, and the valve body further advances against the biasing force of the spring device to close the on-off valve and close the oil supply passage. When the compressor stops, the pressure in the compression space becomes almost equal to the pressure in the suction chamber through the gap between the compression chambers (immediately after the compressor is stopped, if a check valve is provided between the compression space and the discharge chamber, When the pressure between the compression chamber and the suction chamber is the pressure on the suction side, and the check valve is on the suction side, the pressure in the compression chamber and the suction chamber is the pressure in the discharge chamber, and when there is no check valve. The orbiting scroll reverses and the pressure difference between the compression chamber and the suction chamber disappears instantly), the valve element retracts due to the biasing force of the spring device and the weight of the valve element, and closes the on-off valve to shut off the oil supply passage. It is possible to prevent wasteful drainage of lubricating oil in the oil reservoir of the discharge chamber (oil reservoir leading to the discharge chamber), and to improve compression efficiency and durability by using beneficial lubricating oil.

Example Hereinafter, a scroll gas compressor according to a fifth example of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical cross-sectional view of a hermetic scroll refrigerant compressor according to a first embodiment of the present invention, and FIG. 2, FIG. 3, FIG.
The drawing shows a vertical cross-sectional view for explaining the operation of the oil supply passage control valve device in FIG. 1, FIG. 5 shows a cross-sectional view of the compression portion taken along the line AA in FIG. 1, and FIG. 8 is a comparative explanatory view of the pressure change in the compression chamber that is not in communication with the discharge chamber and is close to the discharge chamber and the pressure change introduced into the oil supply passage control valve device, and FIG.
FIG. 11 is a vertical sectional view and a partial sectional view of a hermetic scroll refrigerant compressor according to another embodiment of the present invention.

In FIG. 1, 1 and 2 are iron-made sealed cases, 3 is an iron frame, and the outer peripheral surface thereof is welded and sealed together with the sealed cases 1 and 2 by a single weld bead 4, and the inside of the sealed cases 1 and 2 is discharged to the upper side. It is partitioned into a chamber 5 and a lower drive chamber 6 (low pressure side).

In the eccentric hole 9 at the upper end of the drive shaft 8 which is rotatably driven by the motor 7 which is supported by the frame 3 and whose operation is controlled by an inverter power supply (not shown), the orbiting shaft of the orbiting scroll 10 is provided.
11, the rotation preventing component 12 of the orbiting scroll 10 is engaged with the orbiting scroll 10 and the frame 3, and the fixed scroll 13 meshing with the orbiting scroll 10 is bolted to the frame 3, and the end plate 14 of the fixed scroll 13 is fixed to the end plate 14. Discharge port 15
The check valve 16 for closing the opening end of the discharge port 15 and the oil supply passage control valve device 17e are attached to the upper surface of the end plate 14. The bottom of the discharge chamber 5 is a discharge chamber oil sump 18, and an umbrella-shaped punching metal 19 having a large number of small holes is attached to the sealed case 1 at the upper part thereof, and a thin iron wire is provided between the sealed case 1 and the punching metal 19. The discharge chamber 5 is filled with the filter 20 and the discharge chamber 5 is provided on the upper surface of the closed case 1.
The low pressure side drive chamber 6 is connected to the low pressure side drive chamber 6 through the external refrigeration cycle piping system through the suction pipe 22 provided on the side surface of the hermetically sealed case 2, and the motor chamber oil sump 23 is provided at the bottom of the drive chamber 6 for eccentricity. Eccentric oil hole that connects hole 9 and motor chamber oil sump 23
The lower end of the drive shaft 8 having 24 is buried in the motor chamber oil sump 23.

2, 3, 4, and 5, the oil supply passage control valve device 17e is attached to the end plate 14 with the gasket 25 sandwiched therebetween, and is provided in the main body case 26e and one end of which is provided with a blind plug 2.
A plunger 30 having an outer peripheral groove 29 is movably mounted in the cylinder 28e closed by 7. Cylinder
28e is divided into two back pressure chambers by a plunger 30, a back pressure chamber B31 on the side of the blind plug 27 communicates with a suction chamber 33 by a gas hole 32, and the other back pressure chamber A34 has a very fine pressure introduction hole 35.
Does not communicate with the discharge port 15 but communicates with the compression chamber A36 (first compression chamber) closest to the discharge port 15. Back pressure chamber B
The spring device 38 is inserted into and supported by a cylindrical hole 37 provided at one end of the plunger 30, and applies a biasing force to the plunger 30.
Is formed of a double structure of a coil spring A38a and a coil spring B38b, the coil spring A38a made of a shape memory alloy arranged outside the coil spring B38b has a free length longer than that of the coil spring B38b, and the spring constant of the coil spring B38b is the coil spring A38a.
Is set to be extremely larger than that, the biasing force of the coil spring A38a moves the plunger 30 by a certain amount to expand the volume of the back pressure chamber B31 when there is almost no pressure difference between the suction chamber 33 and the compression chamber A36, When the plunger 30 stops at the position shown in FIG. 3 and there is a pressure difference between the suction chamber 33 and the compression chamber A36 and the pressure difference is within the set value range, the pressure difference used for the plunger 30 is The plunger 30 is advanced so as to reduce the volume of the back pressure chamber B31 against the coil spring A38a.
The plunger 30 stops at the position shown in FIG. 2 where B38b is slightly contracted, and when the temperature of the coil spring A38a itself exceeds the set temperature (for example, 130 ° C.), the spring constant sharply increases and the urging force is increased. Return 30 to the position shown in FIG.

If the pressure in the back pressure chamber A34 that communicates with the compression chamber A36 via the pressure introduction hole 35 rises abnormally and the differential pressure between the back pressure chamber A34 and the back pressure chamber B31 exceeds the set value, the plunger 30 is a coil spring
It moves against A38a and coil spring B38b, and stops at the position shown in FIG.

The compression chamber B39 (third compression chamber) (compression chamber Ba39a), which is located between the suction chamber 33 and the compression chamber A36 and does not communicate with the suction chamber 33, is
Extra-fine oil injection hole 40 (injection pipe 40
a), the outer peripheral groove 29, and an extremely fine oil suction hole 41 communicate with the bottom of the discharge chamber oil reservoir 18 through an oil supply passage, and the plunger 30 is stopped to connect or disconnect the oil supply passage.

In FIG. 6, the horizontal axis represents the rotation angle of the drive shaft 8 and the vertical axis represents the refrigerant pressure, which represents the pressure change state when the refrigerant gas is normal or abnormal during the suction, compression, and discharge processes.

In FIG. 7, the horizontal axis represents the rotation angle of the drive shaft 8, the vertical axis represents the refrigerant pressure, and the solid line 42 represents the compression chamber A36 during normal operation.
, The dotted line 71 is the pressure in the compression chamber A36 when the abnormal pressure rises,
The alternate long and short dash line 43 indicates the pressure in the back pressure chamber B34 during normal operation, and the alternate long and two short dashes line 7
2 represents the pressure in the back pressure chamber A34, which changes when the pressure in the compression chamber A36 abnormally rises.

FIG. 8 is a vertical cross-sectional view of a scroll refrigerant compressor of another embodiment, in which the discharge chamber oil sump 18 is connected to the drive chamber 6 and the frame 3a via the oil supply passage control valve device 17e attached to the end plate 14a of the fixed scroll 13a. Of the bearing oil sump 44. That is, the discharge chamber oil sump 18 includes the oil suction hole 41a provided in the end plate 14a of the fixed scroll 13a and the plunger 3 of the oil supply passage control valve device 17e.
The outer peripheral groove 29 of 0, an oil hole A45 provided in the end plate 14a and having a built-in check valve device in the middle (not shown), an oil hole B46 and an oil hole C46c provided in the frame 3a It communicates with the bearing oil sump 44 or the drive chamber 6 via the.

FIG. 9 is a cross-sectional view of a scroll refrigerant compressor of another embodiment, in which 1b and 2b are iron hermetically sealed cases, 45 is an iron support plate, and the outer peripheral surface portion thereof is a single welded bead together with hermetically sealed cases 1b and 2b. It is welded and sealed, a fixed scroll 13b is attached to the upper surface of the support plate 45 with the orbiting scroll 10b interposed therebetween, and a frame 3b that supports the drive shaft 8b is attached to the lower surface, and the discharge chamber 5b and the drive chamber 6b are fixed scroll 13b. The discharge gas passage 46a opened on the upper surface of the end plate 14b and the discharge gas passage 46b provided in the support plate 45 communicate with each other, and the intermediate pressure back pressure chamber 47 formed by the orbiting scroll 10b, the support plate 45, and the frame 3b. Is a bearing that engages with the shaft center oil hole 48 provided in the drive shaft 8b and the drive shaft 8b.
49, 50, slewing bearing 51
While communicating with 23b, it also communicates with the suction chamber 33b through an ultrafine bypass hole 50 provided in the orbiting scroll 10b. The annular oil groove 53 provided on the lower surface of the end plate 14b of the fixed scroll 13b against which the orbiting scroll 10b is pressed by the pressure of the intermediate pressure back pressure chamber 47 is a discharge chamber through an oil supply passage control valve device 17e attached to the upper end of the end plate 14b. It leads to the oil sump 18b. That is, the oil supply passage from the oil reservoir 18b of the discharge chamber to the annular oil groove 53 includes an oil suction hole 41b provided in the end plate 14b of the fixed scroll 13b, an outer peripheral groove 29 of the plunger 30 of the oil supply passage control valve device 17e, and an end plate 14b. The oil holes 54 provided in the are sequentially connected.

The suction pipe 22b penetrates the closed case 1b and the end plate 14b, and the suction chamber 33
A check valve 16b is provided between the end of the suction pipe 22b and the suction chamber 33b, and the discharge pipe 21b is provided in the closed case 2b and communicates with the drive chamber 6b.

FIG. 10 is a vertical cross-sectional view of a scroll refrigerant compressor of another embodiment, in which the entire inside of the closed case 1c is a discharge chamber 5c, the motor 7 is fixed to the upper part, and the compression part and the oil supply passage control valve device 17c are fixed to the lower part. Attached to the end plate 14c of the scroll 13c, the bottom oil sump 23c
The oil supply passage (hereinafter referred to as the first oil supply passage) from the oil sump 23c to the suction chamber 33c is disposed by being immersed in the oil supply passage control valve device 17
Oil suction pipe 41g attached to the body case 26c of c, outer peripheral groove 29g, oil hole 55 provided in the end plate 14c, oil hole 5 provided in the support plate 45c sandwiched between the frame 3c and the fixed scroll 13c
6, an oil hole 57 provided in the frame 3c, a minute bearing gap of the bearing 58 supporting the drive shaft 8c, an intermediate pressure back pressure chamber 47c formed by the frame 3c, the support plate 45c, and the orbiting scroll 10c, the drive shaft Orbiting bearing 51c provided at the lower end of 8c and orbiting scroll 1
Small axis gap between orbit 0c and orbit 11c, orbit scroll 1
It consists of oil hole 59 and bypass hole 52c provided in 0c
The oil supply passage (referred to as the second oil supply passage) from 23c to the compression chamber B39c (second compression chamber) is composed of an oil suction hole 41c, an outer peripheral groove 29c, and an injection hole 40c provided in the end plate 14c,
When the plunger 30c is in the position shown in the drawing, the suction chamber 33
The first oil supply passage up to c and the second oil supply passage from the oil reservoir 23c to the compression chamber B39c are opened, and when the plunger 30c moves to the left until the volume of the back pressure chamber B is minimized, the first oil passage is opened. The second oil supply passage is closed, and the plunger 30c is moved to the right until the volume of the back pressure chamber A34 is minimized. Both the first oil supply passage and the second oil supply passage are cut off. .

The compressed gas passage from the discharge port 15c to the discharge chamber 5c is a discharge gas passage 60 formed by the fixed scroll 13c and the main body case 26c, the fixed scroll 13c, the support plate 45c, and the frame 3c.
Of the discharge gas passages 61, 62, 63 respectively provided in the.

In addition, the drive shaft facing the bearing 64 provided on the frame 3c
A spiral oil groove 65 is provided on the surface of 8c, and the winding direction of the oil groove 65 is an oil hole due to the screw pump action accompanying the rotation of the drive shaft 8c.
The lubricating oil 57 is provided so as to be able to supply the upper opening end of the bearing 64.

Further, the suction pipe 22c penetrates the closed case 1c and is inserted into the fixed scroll 13c, communicates with the suction chamber 33c via a check valve (not shown), and the discharge pipe 21c is provided on the upper side surface of the closed case 1c. ing.

FIG. 11 is a partial cross-sectional view of a scroll refrigerant compressor of another embodiment in which the opening / closing valve portion of the oil supply passage control valve device is provided inside the end plate 14d of the fixed scroll 13d, and the cylinder 28d is provided at the end plate 14d, and the discharge is performed. The compression chamber A36 and the back pressure chamber A34d on the side closest to the discharge chamber 5 without communicating with the chamber 5 are communicated with each other through the pressure introducing hole 35d through the minute gap between the embedded screw 66 and the screw hole, and the suction chamber 3
The compression chamber B39, which is not in communication with the suction chamber 33, and the outer peripheral groove 29 of the plunger 30 are formed by the injection hole 40d provided in the end plate 14d, the end plate 14d, the gasket 25d, and the gasket retainer 67. The spring device 38, which communicates with the extra-fine injection passage 68 and gives an urging force to the plunger 30, strengthens the urging force when the temperature exceeds the set temperature (for example, 130 ° C) as described above, and the outer peripheral groove 29 and the injection. It is made of a shape memory alloy material with the above-mentioned spring characteristics that actuates the plunger 30 to cut off the communication with the passage 68, and the oil supply passage from the discharge chamber oil reservoir 18 to the compression chamber B39 has an oil suction hole 41d, an outer periphery. The groove 29, the injection passage 68, and the injection hole 40d.

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

In FIG. 1 to FIG. 7, when the drive shaft 8 is rotationally driven by the motor 7, the orbiting scroll 10 orbits, and the suction refrigerant gas is sucked from the refrigeration cycle connected to the compressor.
After passing through 22 to the driving chamber 6, a part of the lubricating oil contained therein is separated and then sucked into the suction chamber 33, and this suction refrigerant gas is formed between the orbiting scroll 10 and the fixed scroll 13. Enclosed in compression chamber, orbiting scroll
Discharge port in the central part, which is sequentially compressed with 10 swiveling motions
15, part of the lubricating oil contained in the discharged refrigerant gas is discharged to the discharge chamber 5 through the check valve 16 and its surface when passing through its own weight and the small hole of the punching metal 19 or the filter 20 made of fine iron. Are separated from the discharge refrigerant gas by being attached to the discharge chamber oil reservoir 18, and the remaining lubricating oil is discharged to the external refrigeration cycle through the discharge pipe 21 together with the discharge refrigerant gas, and again sucked together with the suction refrigerant gas into the suction pipe. Return to the compressor through 22.

On the other hand, the lubricating oil collected in the bottom motor chamber oil sump 23 separated from the suction refrigerant gas in the drive chamber 6 is eccentric oil hole 24 of the drive shaft 8.
By the centrifugal pump action by the eccentric oil hole 24, the bearing clearance related to the drive shaft 8 (including the clearance between the eccentric hole 9 and the orbiting shaft 11), the thrust bearing part related to the orbiting scroll 10 and the rotation preventing component 12
The sliding surface is sequentially lubricated and flows into the suction chamber 33 together with the suction refrigerant gas, and the gap between the adjacent compression spaces is sealed with an oil film to reduce the leakage of the compression refrigerant gas.

Further, the pressure of the compression chamber A36 which is not in communication with the discharge chamber 5 and is closest to the discharge port 15 during the compressor operation largely changes as shown in FIG. 6, but is introduced through the extra-fine pressure introduction hole 35. Since the back pressure chamber A pressure 43 has little change, the compression chamber B pressure 42
Greater than the maximum value of a. Therefore, the pressure in the back pressure chamber A34 is stable and larger than the pressure in the back pressure chamber B31 communicating with the suction chamber 33, and therefore the plunger 30 moves forward against the biasing force of the coil spring A38a and is also attached to the coil spring B38b. Give power.
Moreover, since the biasing force of the coil spring B38b is large, the plunger 30 is stopped at the position shown in FIG. 2 to open the oil supply passage, and the lubricating oil in the discharge chamber oil sump 18 is filled with the oil suction hole 41, the outer peripheral groove 29,
Injection hole 40e (or injection tube 40
a), it is gradually decompressed through the injection hole 40 and is intermittently supplied with oil to the compression chamber B39, and this lubricating oil is supplied from the motor chamber oil sump 23, and together with the intake refrigerant gas, passes through the intake chamber 33 and the compression chamber.
It joins with the lubricating oil conveyed to B39, further seals the gap between the adjacent compression chambers with an oil film, and is discharged into the discharge chamber 5 together with the compressed refrigerant gas.

In addition, if the refrigeration cycle piping system is clogged during operation of the compressor, there is no return of lubricating oil to the compressor, and there is not enough lubricating oil in the discharge chamber oil sump 18, and the oil is discharged at high temperature and low viscosity through the oil supply passage. When a large amount of refrigerant gas flows into the compression chamber B39, the pressure in the compression chamber abnormally rises as shown by the dotted line 70 as shown in FIG. 6, and the compression chamber A at the opening of the pressure introducing hole as shown in FIG. The pressure 72 also has a high average pressure. As a result,
The plunger 30 moves forward against the biasing force of the coil spring B38b, stops at the position shown in FIG. 4, and shuts off the oil supply passage. Further, after the compressor is stopped, the plunger 30 retreats to the position shown in FIG. 13 and shuts off the oil supply passage as described above.

Also, the temperature inside the compression chamber and the discharge chamber 5 rises abnormally and the coil spring
When A38a exceeds a set temperature (for example, 130 ° C.), the biasing force and free length of the coil spring A38a made of a shape memory alloy material increase, the plunger 30 moves to the position shown in FIG. 3, and the oil supply passage is shut off. .

Further, after the compressor is stopped, the check valve 16 is closed, and the pressure of the discharge chamber 5 is maintained at the discharge pressure state for a few minutes, but the gap between the compression chambers where there is no relative sliding motion has no sealing effect due to the oil film. The pressure in the port 15 and each compression chamber becomes the same as that in the suction chamber 33 due to the instantaneous reversal of the orbiting scroll.

As a result, the plunger 30 is moved by the urging force of the coil spring A38a, the oil supply passage is blocked as shown in FIG. 3, and the oil supply from the discharge chamber oil sump 18 to the compression chamber B39 is stopped.

In FIG. 8, the lubricating oil in the discharge chamber oil sump 18 during operation of the compressor is constituted by the oil suction hole 41a, the outer peripheral groove 29, the oil hole A45, and the oil hole B46 by the operation of the plunger 30 as described above. First
Properly and gradually reduced the pressure from the middle of the oil supply passage and the oil hole B46 through the second oil supply passage that bypasses to the drive chamber 6 via the oil hole C46c, and is used for oil supply to the bearing oil sump 44 and oil return to the drive chamber 6. After that, the lubricant flows into the low pressure side drive chamber 6 and the suction chamber 33 while lubricating the sliding surfaces such as the bearing portion related to the drive shaft 8 and the thrust bearing portion of the orbiting scroll 10. The lubricating oil that has flowed into the suction chamber together with the suction refrigerant gas seals the gap between the adjacent compression chambers with an oil film as described above to improve compression efficiency, and the lubricating oil that has flowed into the drive chamber 6 is the motor chamber oil sump 23 at the bottom. After being collected in the above, it is supplied to each sliding surface as described above by the centrifugal pump action of the eccentric oil hole 24 provided in the drive shaft 8.

Note that the interruption of the oil supply passage after the compressor is stopped, the flow of the refrigerant gas, the separation of the lubricating oil in the refrigerant gas, and the like are the same as those described above, and a description thereof will be omitted.

In FIG. 9, the drive shaft 8 is rotationally driven by the motor 7 to cause the orbiting scroll to make an orbiting motion, and the suction refrigerant gas from the refrigeration cycle connected to the compressor passes through the suction pipe 22b and is provided at the end portion thereof. Intake chamber 3 against check valve 16b
3b, after being compressed to a certain compression ratio in the compression chamber, is discharged to the discharge chamber 5b, a part of the lubricating oil contained in the discharge refrigerant gas is separated from the discharge refrigerant gas by its own weight, etc. Collected in the discharge chamber oil sump 18b. After that, the discharged refrigerant gas is conveyed to the drive chamber 6b through the discharged refrigerant gas passages 46a and 46b, and part of the lubricating oil in the discharged refrigerant gas is also separated in the drive chamber 6b and collected in the bottom motor chamber oil sump 23b. It The lubricating oil in the motor chamber oil sump 23b is caused by the differential pressure between the intermediate pressure back pressure chamber 47 and the shaft center oil hole 48 in the drive chamber 8b, the minute gap in the orbiting bearing 51, and the frame 3
After the pressure is gradually reduced through the small gap between the bearings 49 and 50 of b, the intermediate pressure back pressure chamber 47 is lubricated, the suction chamber 33 is passed through the bypass hole 52.
It flows into b and seals the gap between adjacent compression chambers with an oil film to improve compression efficiency.

Also, the lubricating oil pressure in the intermediate pressure back pressure chamber 47 is the orbiting scroll 10
A thrust force that presses b against the surface of the end plate 14b of the fixed scroll 13b is generated.

Further, the plunger 30 of the oil supply passage control valve device 17e opens the oil supply passage during the operation of the compressor as described above, and the discharge chamber oil sump 18b
The lubricating oil is differentially pressure-fed to the annular oil groove 53 of the end plate 14b through the oil suction hole 41b, the outer peripheral groove 29, and the oil hole 54, and after being provided for lubrication of the sliding surface between the end plate 14b and the orbiting scroll 10b, It also flows into the suction chamber 33b and contributes to sealing the gap between the adjacent compression chambers.
Further, after the compressor is stopped, the check valve 16b closes the suction pipe 22b, the compression chamber pressure becomes equal to the discharge chamber pressure, and the plunger 30 shuts off the oil supply passage as described above.

In FIG. 10, the suction refrigerant gas flowing into the suction chamber 33c through the suction pipe 22c is compressed and then discharged into the discharge chamber 5c through the discharge port 15c and the discharge gas passages 60, 61, 62, 63, and the discharge refrigerant is discharged. A part of the lubricating oil contained in the gas is separated from the discharged refrigerant gas by its own weight, etc., and is separated from the bottom motor chamber oil sump 23c.
The remaining lubricating oil is collected in the discharge pipe together with the discharge refrigerant gas.
It is carried out to the outside refrigeration cycle through 21c.

As described above, during the operation of the compressor, the plunger 30c of the oil supply passage control valve device 17c operates to open the oil supply passage, and the lubricating oil in the motor chamber oil sump 23c absorbs the oil suction pipe 41g, the outer peripheral groove 29g, the oil hole 55,
56, 57, minute gap between drive shaft 8c and bearing 58, intermediate pressure back pressure chamber 47c, minute gap between swivel shaft 11c and swivel bearing 51c, oil hole
The compression chamber B39c is gradually decompressed through the 59, bypass hole 52c, and the first oil supply passage flowing into the suction chamber 33c while lubricating the sliding surface, the oil suction hole 41c, the outer peripheral groove 29c, and the injection hole 40c. The oil is differentially pressure-fed to the compression space through the second oil supply passage that flows in and is again compressed and discharged together with the suction refrigerant gas. In the process, the gap between the compression chambers is sealed with an oil film to reduce the leakage of the compressed refrigerant gas.

Note that part of the lubricating oil in the oil hole 57 is carried out to the discharge chamber 5c by the screw pump action of the spiral oil groove provided on the outer periphery of the drive shaft 8c, and lubricates the sliding surface of the bearing 64.

When the lubricating oil in the compressor is temporarily insufficient and the oil level of the oil sump 23c drops to the opening end of the oil suction hole 41c, the discharge refrigerant gas flows into the compression chamber B39c through the second oil supply passage, and As described above, the plunger 30c further advances to close the second oil supply passage to prevent the lack of lubricating oil, but the first oil passage continues to be opened, and lubricating oil is differentially supplied to the sliding surface such as the bearing portion.

Further, as described above, after the compressor is stopped, the plunger 30c shuts off the oil supply passage.

In FIG. 11, when the lubricating oil in the discharge chamber oil sump 18 is insufficient during the operation of the compressor, the compressed refrigerant gas having a high temperature and a low viscosity is supplied to the oil supply passage (the oil suction hole 41d, the outer peripheral groove 29, the injection passage 68). , Compression chamber B3 through injection hole 40d)
A large amount of gas flows into 9, causing the pressure and temperature of the compressed refrigerant gas to rise abnormally. As a result, the coil spring 38 made of the shape memory alloy material mounted inside the end plate 14d is
Direct heat transfer from B39, discharge chamber 5, etc., quickly exceeds the set temperature (for example, 130 ℃) and the urging force increases and the plunger 3
Reverse 0 to shut off the oil supply passage.

Further, the discharge chamber oil reservoir 18 has sufficient lubricating oil, and the opening and closing of the oil supply passage during normal compressor operation or after stoppage is as described above.

As described above, according to the above embodiment, the bottom of the discharge chamber oil reservoir 18 and the suction chamber 33 and the discharge chamber 5 are not passed, and the compression chamber B39 on the side close to the suction chamber 33 (between the suction pressure and the discharge pressure). Intermediate pressure) between oil suction hole 41, outer peripheral groove 29, and ejection holes 40e, 40
A fuel passage control valve device 17e composed of an plunger and a plunger 30 that opens and closes the fuel passage is provided in the middle of the fuel passage, and the actuator 30 is provided on the plunger and both sides thereof. Arranged back pressure chamber
A34, a back pressure chamber B31, and a spring device 38 for urging the plunger 30 toward the back pressure chamber A34 are provided. The back pressure chamber A34 does not communicate with the discharge chamber 5 or the suction chamber 33, and is more compressed than the compression chamber B39. The compression chamber A36 in the post-compression stroke communicates with the back pressure chamber B31 with the suction chamber 33.
When there is a differential pressure between the A34 and the back pressure chamber B31 and the differential pressure is within the range of the first set value, the plunger 30 moves forward against the spring device and communicates with the oil reservoir 18 of the discharge chamber. The suction hole 41 and the injection hole 40e communicating with the compression chamber B39 are communicated with each other through the outer peripheral groove 29 of the plunger 30, and the differential pressure between the back pressure chamber A34 and the back pressure chamber B31 is greater than the first set value. In the range of the second set value which is also large, the plunger 30 further advances against the spring device 38 to shut off the gap between the oil suction hole 41 and the injection hole 40e to close the oil supply passage, thereby reducing the back pressure. When there is no differential pressure between the chamber A34 and the back pressure chamber B31, the plunger 30 retracts due to the urging force of the spring device 38 to shut off between the oil suction hole 41 and the injection hole 40e to close the oil supply passage. Since the oil supply passage control valve device 17e is provided, the compression ratio of the refrigerant gas is constant during operation of the compressor. Compression chamber A36
Is reliably affected by the pressure in the discharge chamber 5 and rises to a constant multiple of the pressure in the suction chamber 33, and the plunger 30 of the actuator advances due to the differential pressure to open the oil supply passage immediately after the compressor is started. , The lubricating oil in the discharge chamber oil sump 18 is injected into the compression chamber B39 from the initial stage of compression, and the gap between the adjacent compression chambers is sealed with an oil film without reducing the suction volume efficiency, and compression is performed from the initial stage of compressor startup. The efficiency can be improved and the abnormal temperature rise of the compressed refrigerant gas can be prevented to improve the durability. Further, the oil injection into the compression chamber makes it possible to optimize the machining dimension accuracy of the scroll portion and reduce the compressor cost. Further, the lubricating oil in the discharge chamber oil reservoir 18 is insufficient, and the viscosity of the discharged refrigerant gas is low and the discharge refrigerant gas with an extremely small passage resistance is compressed by the compression chamber.
Even when it flows into B39, the pressure in the compression chamber abnormally rises, the differential pressure exceeds the set value, and the plunger 30 is further advanced to close the oil supply passage, thereby preventing a reduction in compression efficiency.

Further, after the compressor is stopped, the pressure difference between the suction chamber 33 and the compression chamber A36 disappears and the oil supply passage is shut off, so that wasteful lubricating oil inflow from the discharge chamber oil sump 18 to the compression chamber B39 is prevented and lubrication is performed. It is also possible to improve the durability of the sliding surface and the compression efficiency by effectively using the oil, and prevent the compressor from being damaged by the oil compression when the compressor is restarted.

Further, according to the above-mentioned embodiment, the spring device 38 is composed of the coil spring A38a and the coil spring B38b having different spring constants and free lengths.
The stop position of the plunger 30 that moves forward against the urging force of the valve 38 is stable even when the differential pressure slightly fluctuates. As a result, the plunger 30 opens the oil supply passage,
The chattering phenomenon does not occur in the cutoff, and the plunger 30 does not move forward to close the oil supply passage during operation of the compressor that requires oil supply, and stable differential pressure oil supply contributes to stable improvement in compression efficiency.

In addition, an injection hole 40 between the plunger 30 and the compression chamber A36, a drive chamber 6 having a motor chamber oil sump 23 at the bottom thereof and also serving as a suction passage and an oil supply device by a centrifugal pump action of the drive shaft 8, Oil hole A45, oil hole B46, oil hole between the bearing oil reservoir 44 provided between the bearings supporting the drive shaft
By communicating with the oil return passage composed of C46c, the opening / closing valve (plunger 30) of the oil supply passage is opened during operation of the compressor, and the lubricating oil separated from the discharge refrigerant gas in the discharge chamber is applied to the bearing sliding surface. While refueling, it is returned to the oil reservoir of the lubrication system to prevent wasteful lubricating oil from flowing out of the compressor, improving the compression efficiency by the oil injection effect to the compression chamber B39 and improving the durability by reducing the sliding part wear. At the same time, the performance of the heat exchanger arranged in the compressor external refrigeration cycle can be improved.

Although the operation of the refrigerant compressor has been described in the above embodiment, similar effects can be expected in the case of other gas compressors such as oxygen, nitrogen, and helium that use lubricating oil.

Further, in the above embodiment, the outer peripheral groove 29 of the plunger 30 and the compression chamber A36 are communicated with each other by using the injection pipe 40a, but the passage may be provided in the end plate 14 instead of the injection pipe 40a.

In addition, although the back pressure chamber B31 and the suction chamber 33 are communicated with each other in the above-described embodiment, the size of the plunger 30, the coil spring 38, and the like are appropriately selected so that the compression chamber (third chamber)
The compression chamber) may be connected to the back pressure chamber B31.

Further, in the above embodiment, the oil supply passage control valve device is attached to the end plate of the fixed scroll so that the plunger moves in the horizontal direction, and when the pressure difference between the back pressure chamber A and the back pressure chamber B disappears, the spring is released. Although the plunger is retracted by the urging force of the device, the back pressure chamber A is arranged on the lower side and the back pressure chamber B is arranged on the upper side, and when the pressure difference between the two chambers disappears, A standing type oil supply passage control valve device that retreats due to its own weight and shuts off the on-off valve may be attached to the upper surface or the side surface of the end plate.

Further, in the above embodiment, the spring device 38 is composed of the coil spring A38a and the coil spring B38b having different spring constants and free lengths, but the spring constant increases sharply while the displacement is in progress (for example, a conical coil spring) or In the case where the coil springs are composed of a plurality of coil springs having different free lengths, the same operational effect is produced.

Further, in the above embodiment, no special seal member is provided on the outer peripheral portion of the plunger 30, but a piston ring made of Teflon or a rubber O-ring (O-ring) coated with Teflon coating is used for the plan. Axial leakage from the outer periphery of the jar 30 may be reduced.

EFFECTS OF THE INVENTION As described above, according to the present invention, the oil reservoir of the discharge chamber or the oil reservoir communicating with the discharge chamber and the second compression chamber having a lower pressure than the oil reservoir and not communicating with the discharge chamber or the suction chamber are provided in the oil supply passage. To communicate with
An oil supply passage control valve device consisting of an opening / closing valve for opening and closing the oil supply passage and an actuator for controlling the opening / closing valve is provided in the middle of the oil supply passage, and the actuator has a valve body and a valve body arranged on both sides of the valve body. The back pressure chamber A, the back pressure chamber B, and the spring device for urging the valve body are provided. The back pressure chamber A does not communicate with the discharge chamber and the suction chamber, The back pressure chamber B communicates with the compression chamber, and the back pressure chamber B communicates with the suction side that communicates with the third compression chamber or the suction chamber that communicates with the suction chamber or the suction chamber, and there is a pressure difference between the back pressure chamber A and the back pressure chamber B. When the pressure is in the range of the first set value, the valve body moves forward against the spring device to open the open / close valve, and when the differential pressure is in the range of the second set value larger than the first set value, the valve is opened. The body must be equipped with a fuel passage control valve device that advances further to close the on-off valve, and retracts the valve body to close the on-off valve when there is no differential pressure. Accordingly, the order in compressor operation, a compression ratio of the compressed gas in the scroll compression mechanism is constant 1
The pressure in the compression chamber is surely increased to a constant multiple of the pressure in the suction chamber without being influenced by the pressure in the discharge chamber, and the back pressure chamber A communicating with the first compression chamber and the suction chamber (or the third compression chamber or the suction chamber). The valve body of the actuator advances and opens the on-off valve due to the pressure difference between the back pressure chamber B and the back pressure chamber B that communicates with the suction side), which opens the on-off valve. The lubricating oil in the oil reservoir leading to the discharge chamber is injected into the second compression chamber to reduce the suction volume efficiency without reducing the suction volume efficiency, and the compressed gas leakage in the compression space is reduced from the initial stage of compressor startup. It is possible to improve the compression efficiency, prevent abnormal temperature rise of the compression part, improve durability, and optimize the machining dimensional accuracy of the scroll part for mass production to reduce the compressor cost.

In addition, during high-speed operation of the compressor, the flow velocity of the discharge gas in the discharge chamber (or in the oil separation device) increases, causing the phenomenon of lubricating oil being entrained, and the separation of the lubricant oil in the discharge chamber (or in the oil separation device). If the efficiency is deteriorated and there is not enough lubricating oil in the oil reservoir in the discharge chamber, or the external piping system connected to the compressor is clogged, there is no return of lubricating oil to the compressor and When the lubricating oil is insufficient, a large amount of the discharged gas flows into the second compression chamber through the oil supply passage, and the pressure of the first compression chamber in the post-compression stroke abnormally rises higher than that of the second compression chamber, and this is followed. The pressure in the back pressure chamber A also abnormally rises, the differential pressure between the back pressure chamber A and the back pressure chamber B increases, and the valve body further advances against the biasing force of the spring device to close the oil supply passage. It prevents the discharge gas from flowing into the second compression chamber and prevents the pressure in the compression chamber and the temperature of the compression part from rising abnormally. Efficiency and durability (breakage, such sliding portions wear) can prevent a decrease in the.

After the compressor is stopped, the suction chamber (or the third compression chamber leading to the suction chamber or the suction side leading to the suction chamber) and the first compression chamber have the same pressure, and the back pressure chamber A and the back pressure chamber B are separated from each other. Since the pressure difference disappears and the valve element retracts due to the urging force of the spring device, the on-off valve is closed and the oil supply passage is shut off, waste from the oil reservoir in the discharge chamber (or the oil reservoir leading to the discharge chamber) into the compression chamber. It is possible to improve the durability of the discharge chamber by preventing the inflow of lubricating oil (inflow to the suction side if there is no reverse rotation prevention valve on the suction side) to eliminate insufficient oil supply immediately after restarting the compressor or to eliminate oil compression and improve durability. A highly responsive oil supply passage control valve device that has a function of detecting the operating state of the compressor (stopped or running) and the presence or absence of lubricating oil in the oil reservoir without being affected, and a function of controlling the opening and closing of the oil supply passage Can be realized.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a hermetic scroll refrigerant compressor according to a first embodiment of the present invention, and FIGS. 2, 3, and 4 explain the operation of the oil supply passage control valve device in FIG. FIG. 5 is a longitudinal cross-sectional view of a main part, FIG. 5 is a cross-sectional view of the compression section taken along the line AA in FIG. 1, FIG. 6 is an explanatory view of the pressure change of gas from the suction stroke to the compression stroke, and FIG. A comparative explanatory view of changes in pressure at a fixed point of the chamber, FIG. 8, FIG. 9, and FIG. 10 are vertical sectional views of a hermetic scroll refrigerant compressor of different embodiments of the present invention, and FIG. Partial sectional view of a scroll type refrigerant compressor according to another embodiment of the invention, FIGS. 12 to 15 are vertical sectional views and partial sectional views of respectively different conventional scroll type gas compressors, and FIG. 16 is a conventional refueling. FIG. 17 is a vertical sectional view of a rotary type gas compressor provided with a passage control device, FIG.
It is a longitudinal cross-sectional view taken along the line AA of the figure. 1,2 ... Closed case, 5 ... Discharge chamber, 6 ... Drive chamber, 7
...... Motor, 10 ...... Orbiting scroll, 13 ...... Fixed scroll, 15 …… Discharge port, 17 …… Oil supply passage control valve device,
18 …… Discharge chamber oil sump, 23 …… Motor room oil sump, 30 …… Plunger, 31 …… Back pressure chamber B, 33 …… Suction chamber, 34 …… Back pressure chamber A, 36 …… Compression chamber A , 38 ...... Coil spring, 39 ...... Compression chamber B, 40 ...... Injection hole, 41 ...... Oil suction hole,
44 …… Bearing oil sump, 47 …… Intermediate pressure back pressure chamber.

Claims (3)

[Claims] 1. A plurality of orbiting scrolls are meshed with a fixed scroll so that the orbiting scroll can oscillate and rotate, and a spiral compression space is formed between the scrolls, and the compression space continuously shifts from the suction side toward the discharge side. A scroll-type compression mechanism that is divided into individual compression chambers to compress a fluid is formed, and the pressure is lower than the oil sump in the discharge chamber or the oil sump leading to the discharge chamber and the oil sump, both in the discharge chamber and the suction chamber. An oil supply passage control valve device including an on-off valve for opening and closing the oil supply passage and an actuator for controlling the on-off valve is provided in the middle of the oil supply passage so as to communicate with the second compression chamber which does not communicate with each other. The actuator is provided with a valve body and a back pressure chamber A and a back pressure chamber B of the valve body arranged on both sides of the valve body, and a spring device for urging the valve body, and the back pressure chamber A is the discharge chamber. And the suction chamber without communicating with the above The back pressure chamber B communicates with the first compression chamber which is in a post-compression stage than the compression chamber, the back pressure chamber B communicates with the suction chamber, a third compression chamber communicating with the suction chamber, or a suction side communicating with the suction chamber, and the back pressure chamber A When there is a differential pressure between the back pressure chamber B and the back pressure chamber B, and the differential pressure is within the range of the first set value, the valve body moves forward against the spring device to open the on-off valve, Is in a range of a second set value larger than the first set value, the valve body further advances to close the on-off valve, and when there is no differential pressure, the valve body retreats to open and close the on-off valve. A scroll gas compressor equipped with a fuel supply passage control valve device that closes. 2. The scroll gas compression system according to claim 1, wherein the spring device comprises a spring whose spring constant increases rapidly during the progress of displacement, or a plurality of springs having different free lengths or different free lengths. Machine. 3. An oil return passage connects the oil supply passage between the on-off valve and the first compression chamber with an oil reservoir chamber provided with an oil supply device downstream thereof or with a sliding portion. The scroll gas compressor according to claim 1 or 2.