JPS63150491A - Scroll gas compressor - Google Patents

Abstract

PURPOSE:To obtain the captioned device having high efficiency and the superior durability by realizing an oil feeding passage controller having a wide application range by utilizing the pressure difference between in a suction chamber and compression chamber which does not communicate to a discharge chamber and the suction chamber. CONSTITUTION:A compressor starts operation, and a swirl scroll 10 performs a turning movement to inhale the gas in a suction chamber 33 into a compression chamber, and said gas is compressed to a certain compression ratio and then discharged into a discharge chamber 5. Further, a differential pressure is generated between the back pressure chambers of an oil feeding passage control valve device 17e installed midway in an oil feeding passage, and an opening/closing valve is opened to communicate to the oil feeding passage, and the lubricating oil in the oil reservoir 18 of the discharge chamber 5 is supplied to a compression chamber B39. When no lubricating oil exists in the discharge chamber oil reservoir 18, a large quantity of the compressed gas having high pressure and high temperature flows into the compression chamber B39 through the oil feeding passage, and the differential pressure between the both back pressure chambers exceeds a set value, and the valve body is closed to close the oil feeding passage. When the compressor stops, the valve body is retreated by a piston spring 38, etc., aud the opening/closing valve is closed. Therefore, the inutile flow out of the lubricating oil in the discharge chamber oil reservoir 18 is prevented, and the effective use of the lubricating oil is permitted.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a scroll gas compressor.

Conventional technology A scroll compressor with low vibration and low noise characteristics has a suction chamber on the outer periphery and a discharge port in the center of the spiral. It is generally known that a rotary compressor does not require a discharge valve for compressing fluid, has a constant compression ratio, has relatively small discharge pulsation, and does not require a large discharge space.

However, especially when compressing gas, it is necessary to make the dimensional accuracy of the scroll part extremely high in order to reduce the leakage gap in the compression part. The problem was that the machine cost was high and performance varied greatly.

Therefore, as a measure to solve this type of problem, it is highly 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, in which a part of the lubricating oil supplied to the sliding part and moistened in the can flows into the compression chamber together with the suction gas, and after the lubricating oil is separated from the compressed gas after being compressed and discharged, the oil return passage is Based on the concept of reducing lubricating oil leakage to the outside of the compressor by returning it to the space communicating with the lubricating oil reservoir via the The lubricating oil was returned to the space 580 serving as the suction passage through the oil return passages of the holes 522 to 584, collected in the oil reservoir 508, and supplied to the sliding parts again by the pump device (Japanese Patent Application Laid-Open No. 60-1999). -75795
Publication No.).

In addition, the configuration shown in FIG. 1a is also considered, in which the lubricating oil contained in the compressed gas is separated by an oil separation element 672 provided in the discharge chamber 674, and the lubricating oil is collected in an oil reservoir 673 on the fixed scroll end plate 1303. After the sliding surface 631 between the fixed scroll 601 and the orbiting scroll 606 is lubricated with differential pressure, lubricating oil is allowed to flow into the suction chamber 699 to reduce leakage of compressed gas in the compression chamber by the sealing effect of the oil film. (Japanese Unexamined Patent Publication No. 165787/1987).

Alternatively, a configuration may be considered in which the lubricating oil is directly flowed into the compression chamber during compression as shown in FIGS. 14 and 15. In FIG. It has a structure in which the internal space 702 of the sealed container is used as a discharge chamber, and the lubricating oil in the oil sump 710 at the bottom of the discharge chamber is directly flowed into the compression chamber 723 in the middle of compression via the oil suction pipe 722. Publication No. 57-8386), No. 1
Figure 5 shows a structure in which a compression section is placed in the upper part of a closed container 801 and a motor 803 is placed in the lower part, and the space 802 inside the closed container is used as a discharge chamber, thereby reducing the thrust force that acts when the orbiting scroll 804 compresses gas. Orbiting scroll for 80
A back pressure chamber 80 in an intermediate pressure state provided on the back side of No. 4 on the opposite compression chamber side.
Oil filler 8 in the drive shaft 802 provided before and after the relay B
99, the lubricating oil in the oil reservoir 809 at the inner bottom of the closed container 801 was caused to flow through the oil supply pipe 815 into the compression chamber 823 in the middle of compression by differential pressure (Japanese Patent Laid-Open No. 59-11089).
Publication No. 3).

Problems to be Solved by the Invention However, if the oil return passage (hole 5
In a configuration in which the discharge space 582 and the low-pressure side space 580 are always in communication through the holes 584), even if lubricating oil is always present in the space 520 and the discharge space 582, the rotational speed of the compressor drive shaft With the change in the amount of oil supplied to the sliding parts, etc., the amount of lubricating oil contained in the compressed gas also changes, and the differential pressure between the discharge space 582 and the low-pressure side space 580 and the viscosity of the lubricating oil also change. Therefore, it is extremely difficult to set up an oil return passage that returns lubricating oil in just the right amount, and when the compressor is operating at high speed, the amount of lubricating oil discharged is large and it is difficult to prevent large amounts of lubricating oil from leaking outside the compressor. It is possible.

Furthermore, while the compressor is stopped, lubricating oil in the space 520 and discharge space 582 flows into the oil sump 508 at the bottom of the compressor due to differential pressure and dead weight, and remains in the space 520 and discharge space 582 for a while after the compressor is restarted. There is not enough lubricating oil, and a large amount of compressed gas passes through the oil return passage (holes 522 to 584) to the space 5 on the low pressure side.
There was a problem in that the suction efficiency and compression efficiency were significantly lowered and the durability was deteriorated.

Furthermore, a fixed scroll end plate 60 as shown in FIG.
In the configuration in which the lubricating oil in the oil reservoir 673 above 3 flows into the suction chamber 699 through the sliding surface 631, when the compressor drive shaft rotates at high speed and the gas discharge amount increases, as in the case of FIG. There is also a state where there is no lubricating oil in the 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, causing not only a significant decrease in suction efficiency and compression efficiency but also wear and seizure of the sliding surface 631. There were other problems.

In addition, a configuration in which the lubricating oil in the oil reservoir 710 at the bottom of the closed container internal space 702, which is equal to the discharge pressure as shown in FIG. When the compressor is stopped, a large amount of refrigerant that returns into the compressor from the refrigeration cycle outside the compressor due to its own weight and differential pressure accumulates in a liquefied state up to the bottom surface of the motor 703 above the oil sump 710, causing refrigerant liquid and lubricant. In some cases, oil may flow into the compression chamber 723 through the oil suction pipe 722 and fill it, and in such a state, the compression load is too large and restart operation is impossible.Even if the starting torque of the motor 703 is large, restart is possible. Both may cause damage to the compressor.

Furthermore, depending on the compressor operating conditions, there may be a shortage of lubricating oil in the oil reservoir 710. In such conditions, compressed gas may flow into the compression chamber 723, resulting in a significant decrease in compression efficiency or an abnormal pressure increase in the compression chamber, causing the compressor to malfunction. There was a problem that it caused damage.

In addition, the oil sump 809 at the bottom of the compressor as shown in FIG.
Even with the configuration in which lubricating oil is supplied to the compression chamber 823 in the middle of compression via the back pressure chamber 808 in an intermediate pressure state leading to However, there was also the problem that compression efficiency was significantly lowered and durability was lowered.

On the other hand, as shown in FIGS. 16 and 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 oil to the compression section, and when the compressor is stopped, the oil supply passage is closed. The invention of the structure is also known from Japanese Patent Publication No. 59-44517, and this invention is a slide vane rotary compressor that requires a discharge valve 908 downstream of the discharge port 907. 92
7 and the pressure in the discharge chamber 910 after passing through the discharge valve 908 is used to operate the plunger 922 to control the on-off valve 925 of the oil supply passage 919.

However, for a while immediately after compressor cold startup operation,
Since the pressure in the discharge chamber 910 is low, the discharge valve 908 opens from the cylinder 927 internal pressure line cutoff stroke, and the discharge chamber 910 and the cylinder 9 open.
The pressure difference with 27 is small.

There are problems such as abnormal noise and reduction in compression efficiency, and it has been desired to put into practical use an oil supply passage control device that is not affected by compressor operating conditions.

Therefore, the present invention focuses on the fact that a scroll compressor does not require a discharge valve to increase the pressure in the compression chamber and has a constant compression ratio. The objective is to provide a scroll gas compressor with high efficiency and excellent durability by putting into practical use a fuel supply passage control device that utilizes pressure differences and has a wide range of applications.

Means for Solving the Problems In order to solve the above problems, the scroll gas compressor of the present invention has an oil sump in the discharge chamber or an oil sump leading to the discharge chamber, and an oil sump that is lower in pressure than the oil sump and also has suction in the discharge chamber. The second room doesn't even lead to the room.
The compression chamber is communicated with the oil supply passage, and in the middle of the oil supply passage there is provided an oil supply passage control valve device consisting of an on-off valve that opens and closes the oil supply passage and an actuator that controls the on-off valve.
The actuator is equipped with a valve body, a back pressure chamber A of the valve body placed on both sides of the valve body, and a spring device that biases the valve body. The back pressure chamber does not communicate with the first compression chamber □ in the post-compression stroke than the second compression chamber, and the back pressure chamber communicates with the suction chamber, the third compression chamber that communicates with the suction chamber, or the suction side that communicates with the suction chamber, and the back pressure When there is a pressure difference between chamber A and the back pressure chamber and the pressure difference 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 pressure difference is increased. Refueling passage control valve device in which the valve body advances further to close the on-off valve when the second set value is greater than the first set value, and the valve body moves back to close the on-off valve when there is no differential pressure. It is a configuration with.

According to the above configuration, the compressor is started, the orbiting scroll performs an orbiting motion, and the gas in the suction chamber is sucked into the compression chamber, compressed to a constant compression ratio, and discharged to the discharge chamber. A differential pressure is generated between back pressure chamber A and back pressure chamber B of the oil supply passage control valve device provided in the middle of the passage, and the valve body moves forward to open the on-off valve and communicate the oil supply passage, and the discharge chamber The lubricating oil in the oil sump (an oil sump communicating with the discharge chamber) is supplied to the second compression chamber.

In the unlikely event that there is no lubricating oil in the oil sump in the discharge chamber (the oil sump connected to the discharge chamber), a large amount of high-temperature, high-pressure compressed gas will flow into the second compression chamber through the oil supply passage, causing the pressure in the first compression chamber to rise. The pressure in the back pressure chambers also rose abnormally, causing back pressure chambers A and B to rise abnormally.
The differential pressure between the two also exceeds the set value, and the valve body moves further forward against the biasing force of the spring device, closing the on-off valve and closing the oil supply passage. When the compressor stops, the pressure in the compression space and the pressure in the suction chamber become equal to ζ through the gap between the compression chambers (immediately after the compressor stops, a reverse prevention valve is installed between the compression space and the discharge chamber. In this case, the pressure deficit between the compression chamber and suction chamber becomes the pressure on the suction side, and if a reverse prevention valve is installed on the suction side, the pressure in the compression chamber and suction chamber becomes the discharge chamber pressure, preventing reverse rotation. (If there is no valve, the orbiting scroll reverses and the pressure difference between the compression chamber and the suction chamber disappears instantly), and the valve body moves back due to the biasing force of the spring device and its own weight, closing the on-off valve. By blocking the oil supply passage, wasteful loss of lubricating oil in the oil sump in the discharge chamber (oil sump communicating with the discharge chamber) can be prevented, and compression efficiency and durability can be improved by using useful lubricating oil.

EXAMPLES Below, scroll gas compressors according to five embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a vertical cross-sectional view of a hermetic scroll refrigerant compressor in a first embodiment of the present invention, and FIGS.
The figure shows a longitudinal 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 section taken along line A-A in Fig. 1, and Fig. 6 shows the discharge side. Figure 8-
FIG. 11 shows a longitudinal sectional view and a partial sectional view of a hermetic scroll refrigerant compressor in another embodiment of the present invention.

In Fig. 1, 1.2 is an iron sealed case, and 3 is an iron frame, which is welded and sealed together with the sealed case 1.2 on the outer peripheral surface by a single weld bead 4, and the inside of the sealed cases 1 and 2 is shown on the upper side. discharge chamber 5 and lower drive chamber 6 (low pressure side)
It is divided into

An orbiting shaft 11 of an orbiting scroll 10 is fitted into an eccentric hole 9 at the upper end of a drive shaft 8 which is supported by a frame 3 and rotationally driven by a motor 7 whose operation is controlled by an inverter power supply (not shown). The rotation prevention part 12 engages with the orbiting scroll 10 and the frame 3, the fixed scroll 13 that meshes with the orbiting scroll 10 is bolted to the frame 3, and the end plate 1 of the fixed scroll 13
4 is provided with a discharge port 15, and a check valve 16 for closing the open end of the discharge port 15 and an oil supply passage control valve device 17 are attached to the upper surface of the end plate 14. The bottom of the discharge chamber 5 is a discharge chamber oil reservoir 168, and the upper part thereof is an umbrella-shaped punching metal 19 with many small holes attached to the closed case 1, and a thin iron wire is connected between the closed case 1 and the punched metal 19. The discharge chamber 5 is filled with a filter 20 provided on the upper surface of the sealed case 1, passes through the external refrigeration cycle piping system, and then passes through the suction pipe 22 provided on the side of the sealed case 2 to the low-pressure side. A motor chamber oil reservoir 23 is provided at the bottom of the drive chamber 6 and communicates with the drive chamber 6.
Eccentric oil filler 24 that communicates eccentric hole 9 and motor chamber oil sump 23
The lower end of the drive shaft 8 having a diameter is buried in the motor chamber oil sump 23.

In FIGS. 2, 3, 4, and 5, the oil supply passage control valve device 17e is attached to the end plate 14 with a gasket 25 in between, and is provided in the main body case 26e, with one end thereof being closed by a blind stopper 27. A plunger 30 having an outer circumferential groove 29 is movably mounted inside the detached cylinder 2ae. The cylinder 28 is partitioned into two back pressure chambers by a plunger 30, and the back pressure chamber B on the side of the blind plug 27
31 communicates with the suction chamber a3 through a gas hole 32, and the other back pressure chamber A34 does not communicate with the discharge port 15 through an extremely thin pressure introduction hole 35, but is connected to the compression chamber A3 closest to the discharge port 15.
6 (first compression chamber). In the back pressure chamber 831, a spring device 38 is inserted and supported in 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 coil spring A38a and coil spring B58b, and coil spring A38m made of a shape memory alloy and placed outside of coil spring B58b has a free length longer than that of coil spring B58b, and the spring constant of coil spring B58b is the same as that of coil spring A38m. The biasing force of the coil spring A38a is set extremely larger than that of the back pressure chamber 83 when there is almost no differential pressure between the suction chamber 33 and the compression chamber A36.
The plunger 30 is moved by a certain amount in order to increase the volume of 1, and the plunger 30 stops at the position shown in FIG. When the pressure difference is within the range, the differential pressure acting on the plunger 30 advances the plunger 30 to narrow the volume of the back pressure chamber B31 against the coil spring A38-. The plunger 30 stops at the position shown in the figure, and when the temperature of the coil spring A38m exceeds the set temperature (for example, 130°C), the spring constant rapidly increases and the biasing force is strengthened to move the plunger 30 to the third position.
Return to the position shown in the figure.

Back pressure chamber A communicating with compression chamber A36 via pressure introduction hole 35
34 pressure rises abnormally and back pressure chamber A34 and back pressure chamber 831
If the differential pressure between the two exceeds the set value, the plunger 30 releases the coil spring A38m.

It moves against the coil spring B58b and stops at the position shown in FIG.

The suction chamber 33 is located between the suction chamber 33 and the compression chamber A36.
Compression chamber B59 (third compression chamber) (compression chamber B
a39a) is connected to the discharge chamber oil sump 1 through an oil supply passage consisting of an extremely thin oil injection hole 40 (injection pipe 40m), an outer circumferential groove 29, and an extremely thin oil suction hole 41.
8, and the oil supply passage is communicated or blocked depending on the stop position of the plunger 30.

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

In FIG. 7, the horizontal axis represents the rotation angle of the drive axle load, the vertical axis represents the refrigerant pressure, and the solid line 42 represents the compression chamber A during normal operation.
36 pressure, dotted line 71 is compression chamber A36 at the time of abnormal pressure rise
The one-dot chain line 43 represents the pressure in the back pressure chamber 834 during normal operation, and the two-dot chain line 72 represents the pressure in the back pressure chamber A34 that changes following an abnormal increase in the pressure in the compression chamber A36.

FIG. 8 is a longitudinal sectional view of a scroll refrigerant compressor according to another embodiment, in which a discharge chamber oil sump 18 is connected to a drive chamber 6 via an oil supply passage control valve device 17 attached to an end plate 14m of a fixed scroll 13-. It communicates with the bearing oil sump 44 of the frame 3.

That is, the discharge chamber oil reservoir 18 is formed by an oil suction hole 41 provided in the end plate 14m of the fixed scroll 13-, and an outer circumferential groove 29 of the plunger 30 of the oil supply passage control valve device 17e. Oil-filled A45. installed on the end plate 14 m and with a built-in check valve device in the middle (not shown). It communicates with the bearing oil section 44 or the drive chamber 6 through an oil supply passage constituted by an oil hole B46 and an oil hole C46a provided in the frame 3-.

FIG. 9 is a cross-sectional view of a scroll refrigerant compressor of another embodiment, in which tb and 2b are an iron closed case, 45 is an iron support plate, and its outer peripheral surface is connected to the closed case tb.

A fixed scroll 13b is attached to the upper surface of the support plate 45, sandwiching the orbiting scroll 10b, and a frame 3b supporting the drive shaft 8b is attached to the lower surface of the support plate 45. The drive chamber 6b communicates with a discharge gas passage 46a opened on the upper surface of the end plate 14b of the fixed scroll 13b and a discharge gas passage 461 provided in the support plate 45, and the orbiting scroll 1
0b, the support plate 45, and the frame 3b, the intermediate pressure back pressure chamber 47 has an axial oil/water 48 provided on the drive shaft 8b, bearings 49, 50, and a swing bearing 51 that engage with the drive shaft 8b.
It communicates with the motor chamber oil sump 23b via each minute gap, and also communicates with the suction chamber 33b via an extremely thin bypass hole 50 provided in the orbiting scroll tab. An 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 discharges oil through an oil supply passage control valve device 17 attached to the upper surface of the end plate 14b. It leads to the room oil sump tab. That is, the oil supply passage from the discharge chamber oil reservoir 18b to the annular oil groove 53 is connected to the fixed scroll 13b.
oil suction hole 41b provided in end plate 14b, outer peripheral groove 29 of plunger 30 of oil supply passage control valve device 17e.
The oil holes 54 provided in the mirror plate 14b communicate with each other in sequence.

The suction pipe 22b passes through the sealed case 1b and the end plate 14b to reach the suction chamber 33, and the end of the suction pipe 22b and the suction chamber 3
A check valve 16t) is provided between the discharge pipe 21 and the discharge pipe 21.
b is provided in the closed case 2b and communicates with the drive chamber 6b.

FIG. 10 is a longitudinal cross-sectional view of a scroll refrigerant compressor according to another embodiment, in which the entire interior of a sealed case 1C is a discharge chamber 5c, a motor 7 is provided in the upper part, and a compression section and an oil supply passage control valve device 17c are provided in the lower part.
is attached to the end plate 14c of the fixed scroll 13c and is immersed in the oil reservoir 23c at the bottom, and the oil supply passage (referred to as the first oil supply passage) from the oil reservoir 23c to the suction chamber 33a is connected to the oil supply passage control valve device 17c. An oil suction pipe 41g and an outer peripheral groove 29g are attached to the main body case 26c.

Oil container 55 provided on the mirror plate 14c. Oil hole 56 provided in support plate 45c sandwiched between frame 3c and fixed scroll 13c. Oil hole 57 provided in frame 3c. The small bearing gap of the bearing 58 that supports the drive shaft 8c, the frame 3
an intermediate pressure back pressure chamber 47c formed by the support plate 45c and the orbiting scroll 10a, an orbiting bearing 51c provided at the lower end of the drive shaft 8c, and the orbiting shaft 11a of the orbiting scroll 10o.
A small bearing gap between the oil tank 59 and the oil tank provided in the orbiting scroll 10c. It is composed of a bypass hole 52c, and the oil sump 2
The oil supply passage (referred to as the second oil supply passage) from 3c to the compression chamber 839c (second compression chamber) is composed of an oil suction hole 41c, an outer peripheral groove 29c, and an injection hole 40a provided in the end plate 14a, and the plunger 30c In the illustrated position, the first oil supply passage from the oil reservoir 23c to the suction chamber 33c and the second oil supply passage from the oil reservoir 23c to the compression chamber B59c are opened, and the plunger 30c is opened until the volume of the back pressure chamber becomes minimum. When the plunger 30c moves to the left, the first oil supply passage continues to open, but the second oil supply passage is blocked, and when the plunger 30c moves to the right, the first oil supply passage and the second oil supply passage are closed until the volume of the back pressure chamber A34 becomes the minimum. are configured so that both are blocked.

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. It is composed of a fixed scroll 13c, a support plate 45a, and discharge gas passages 61, 62, and 63 provided in the frame 3G, respectively.

Further, a spiral oil groove 65 is provided on the surface of the drive shaft 8c facing the bearing 64 provided on the frame 3c, and the winding direction of the oil groove 65 is determined by the screw pump action accompanying the rotation of the drive shaft 8o. The lubricating oil of 57 can also be supplied to the upper open end of the bearing 64.

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

FIG. 11 is a partial sectional view of a scroll refrigerant compressor of another embodiment in which the on-off valve part 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 on the end plate 1td, and the discharge Discharge chamber 5 without communicating with chamber 5
The compression chamber A 36 and the back pressure chamber A 34 d, which are closest to each other, communicate with each other through a pressure introduction hole 35 d through a small gap between the embedded screw 66 and the screw hole, and do not communicate with the suction chamber 33 .
The compression chamber 839 on the side closer to and the outer circumferential groove 2 of the plunger 30
9 is an injection hole 40 provided in the mirror plate 14d.
d. The spring device 38, which communicates with the extremely thin injection passage 68 formed by the end plate 14d, the gasket 25d, and the gasket retainer 67, and which applies a biasing force to the plunger 30, has its own set temperature (for example, 130
The discharge chamber oil is made of a shape memory alloy material with the above-mentioned spring characteristics that increases the biasing force and operates the plunger 30 to cut off the communication between the outer circumferential groove 29 and the injection passage 68 when the temperature exceeds ℃). From reservoir 18 to compression chamber 839
The oil supply passage up to the oil suction hole 41d and the outer circumferential groove 29. It consists of an injection passage 68° and an injection hole 40d.

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

In FIGS. 1 to 7, when the drive shaft 8 is rotationally driven by the motor 7, the orbiting scroll 10 makes an orbiting motion,
Suction refrigerant gas from the refrigeration cycle connected to the compressor flows into the drive chamber 6 through the suction pipe 22, and after a part of the lubricating oil contained therein is separated, it is sucked into the suction chamber 33, and this suction refrigerant gas is Orbiting scroll 10 and fixed school 1
3, and is sequentially compressed as the orbiting scroll 10 rotates, and is discharged from the central discharge port 15. A part of the lubricating oil contained in the discharged refrigerant gas is discharged into the discharge chamber 5 through the check valve 16 and adheres to the surface of the punched metal 19 when it passes through its own weight and the filter 20 made of small holes and fine iron wire. The remaining lubricating oil is separated from the discharged refrigerant gas and collected in the discharge chamber oil sump 18, and the remaining lubricating oil is carried out to the external refrigeration cycle through the discharge pipe 21 together with the discharged refrigerant gas, and is again passed through the suction pipe 22 together with the suctioned refrigerant gas. Return to the compressor.

On the other hand, the lubricating oil collected in the motor chamber oil sump 2a at the bottom separated from the suction refrigerant gas in the drive chamber 6 is pumped into the eccentric oil reservoir 24 by the centrifugal pump action by the eccentric oil/water 24 of the drive shaft 8. The bearing gap related to the drive shaft 8 (including the gap between the eccentric hole 9 and the rotating shaft 11), the thrust bearing part related to the orbiting scroll 10, and the sliding surfaces of the rotation prevention component 12 are sequentially lubricated and the suction chamber is filled with the suction refrigerant gas. 33, and seals the gap between adjacent compression chambers with an oil film to reduce leakage of compressed refrigerant gas.

In addition, the pressure in the compression chamber A36, which is not connected to the discharge chamber 5 and is closest to the discharge port 15, changes greatly during compressor operation as shown in FIG. The back pressure chamber A pressure 43 changes less and is larger than the maximum value of the compression chamber daily pressure 42-. For this reason, back pressure chamber A
34 is stably higher than the pressure in the back pressure chamber B31 that communicates with the suction chamber 33, so that the plunger 30 moves forward against the biasing force of the coil spring A38a and
A biasing force is also applied to 58b. However, coil spring B58
Since the biasing force of b is large, the plunger 30 stops at the position shown in FIG. Injection hole 40e (or injection tube 40a)
) + The pressure is gradually reduced through the injection hole 40 and the compression chamber B39 is intermittently supplied with oil, and this lubricating oil is supplied from the motor chamber oil sump 23 and conveyed together with the suction refrigerant gas to the compression chamber B39 through the suction chamber 33. It merges with the lubricating oil, further seals the gap between adjacent compression chambers with an oil film, and is discharged to the discharge chamber 5 together with the compressed refrigerant gas.

In addition, in the unlikely event that lubricating oil is not returned to the compressor due to a clogging phenomenon in the refrigeration cycle piping system during compressor operation, lubricating oil in the discharge chamber oil sump 18 becomes insufficient, and high temperature and low viscosity oil is discharged through the oil supply passage. When a large amount of refrigerant gas flows into the compression chamber B39, the pressure in the compression chamber increases abnormally as indicated by the dotted line 7o as shown in FIG. 6, and as shown in FIG. The pressure cuff 2 also has a higher average pressure. As a result, the plunger 3o moves forward against the biasing force of the coil spring 38b and stops at the position shown in FIG. 4, thereby blocking the oil supply passage. Further, after the compressor is stopped, the plunger 30 retreats to the position shown in FIG. 13 to block the oil supply passage as described above.

Further, when the temperature inside the compression chamber or the discharge chamber 5 rises abnormally and the coil spring A38a exceeds the set temperature (for example, 130 degrees Celsius), the biasing force and free length of the coil spring A38a made of a shape memory alloy material increase and the plunger 30 moves to the position shown in FIG. 3, and the oil supply passage is blocked.

In addition, after the compressor is stopped, the check valve 16 is closed, and the pressure in the discharge chamber 5 is maintained at the discharge pressure state for several minutes, but the gap between the compression chambers where there is no relative sliding movement is not sealed by the oil film.
The pressure in the discharge boat 15 and each compression chamber becomes the same as that in the suction chamber 33 by instantaneous reversal of the orbiting scroll.

As a result, the plunger 30 is moved by the biasing force of the coil spring A38, and as shown in FIG. 3, the oil supply passage is blocked and the supply of oil from the discharge chamber oil sump 18 to the compression chamber 39 is stopped.

In FIG. 8, the lubricating oil in the discharge chamber oil sump 18 during compressor operation is transferred to the oil suction hole 41-1 outer circumferential groove 29° by the operation of the plunger aO as described above. Oil hole B4
6 and a second oil supply passage that bypasses the oil hole C46c from the middle of the oil hole B46 to the drive chamber 6. After that, the oil is returned to the drive chamber 6 and suction chamber a on the low pressure side while lubricating the sliding surfaces such as the bearings related to the drive shaft 8 and the thrust bearings of the orbiting scroll 10.
3. The lubricating oil that has flowed into the suction chamber together with the suction refrigerant Ganu seals the gap between adjacent compression chambers with an oil film to increase compression efficiency, as described above, and the lubricating oil that has flowed into the drive chamber 6 flows into the motor chamber oil reservoir at the bottom. After being collected at 23, the oil 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 shutoff of the oil supply passage, the flow of refrigerant gas, the separation of lubricating oil in refrigerant gas, etc. after the compressor is stopped are the same as 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 orbit, and suction refrigerant gas is supplied from the refrigeration cycle connected to the compressor to the suction pipe 22. b, flows into the suction chamber 33b against the back pressure valve 16b provided at the terminal end thereof, is compressed to a constant compression ratio in the compression chamber, is discharged to the discharge chamber 5b, and is discharged into the discharged refrigerant gas. A part of the lubricating oil contained in the refrigerant gas is separated from the discharged refrigerant gas due to its own weight and collected in the discharge chamber oil sump 18b.

Thereafter, the discharged refrigerant gas flows through the discharged refrigerant gas passage 46a.

A part of the lubricating oil in the discharged refrigerant gas is separated in the drive chamber 6b and collected in the motor chamber oil sump 23b at the bottom. The lubricating oil in the motor chamber oil sump 23b flows through the shaft center oil hole 48. of the drive chamber 8b due to the differential pressure with the intermediate pressure back pressure chamber 47. The pressure is gradually reduced through the small gap between the swing bearing 51 and the small gap between the bearings 49 and 50 of the frame 3b, and the oil is supplied to the intermediate pressure back pressure chamber 47.Then, the oil flows into the suction chamber 33b through the bypass hole 52, and then flows into the adjacent compression chamber. Seal the gap with an oil film to increase compression efficiency.

Further, the lubricating oil pressure in the intermediate pressure back pressure chamber 47 generates a thrust force that presses the orbiting scroll 10b against the surface of the end plate 14b of the fixed scroll 13b.

Further, the plunger 30 of the oil supply passage control valve device 17e opens the oil supply passage during compressor operation as described above, and the lubricating oil in the discharge chamber oil sump 18b flows through the oil suction hole 41b, the outer circumferential groove 29. Oil is supplied to the annular oil groove 53 of the head plate 14b through the oil hole 54 under a differential pressure, and after lubricating the sliding surfaces of the head plate 14b and the orbiting scroll 10b, it flows into the suction chamber 33b and flows between adjacent compression chambers. It also helps seal gaps. 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 blocks the oil supply passage as described above.

In FIG. 10, the suction chamber 33 is passed through the suction pipe 22c.
After being compressed, the suction refrigerant gas that has flowed into the refrigerant gas is discharged into the discharge chamber 5c via the discharge port 15c and the discharge gas passages 60, 61, 62, 63, and some of the lubricating oil contained in the discharged refrigerant gas is The lubricating oil is separated from the discharged refrigerant gas due to its own weight and collected in the motor chamber oil sump 23c at the bottom, and the remaining lubricating oil is carried out to the external refrigeration cycle through the discharge pipe 21c together with the discharged refrigerant gas.

As mentioned above, during compressor operation, the oil supply passage control valve device 17c
The plunger 30c operates to open the oil supply passage, and the lubricating oil in the motor chamber oil sump 23o flows into the oil suction pipe 419. Outer circumferential groove 299. Oil holes 55, 56.

57, a minute gap between the drive shaft 8c and the bearing 58;

Intermediate pressure back pressure chamber 47c, minute gap between pivot shaft 11a and pivot bearing 51c, oil/water 59. A first oil supply passage through which the pressure is gradually reduced through the bypass hole 52c and flows into the suction chamber 33c while lubricating the sliding surface, the oil suction hole 41c, and the outer circumferential groove 29c.
The pressure is gradually reduced through the injection hole 40c and the second oil supply passage flows into the compression chamber 839c, and the compression space is supplied with oil under a differential pressure, and is again compressed and discharged together with the sucked refrigerant gas. In the process, the gap between the compression chambers is filled with an oil film. to reduce leakage of compressed refrigerant gas.

A portion of the lubricating oil in the oil hole 57 is pumped into the discharge chamber 5 by the screw pump action of a spiral oil groove provided on the outer periphery of the drive shaft 8c.
c is also carried out to lubricate the sliding surface of the bearing 64.

If the lubricating oil in the compressor is temporarily insufficient and the oil level in the oil reservoir 23c drops to the open end of the oil suction hole 41c, the discharged refrigerant gas flows into the compression chamber 839c through the second oil supply passage, and the above-mentioned As shown, the plunger 30a further advances to close the second oil supply passage to prevent lubricant shortage, but the first oil supply passage remains open and lubricant is supplied to sliding surfaces such as bearings under differential pressure.

Also, as mentioned above, after the compressor is stopped, the plunger 30
a blocks the refueling passage.

In FIG. 11, when the lubricating oil in the discharge chamber oil sump 18 runs out during compressor operation, high temperature and low viscosity compressed refrigerant gas is supplied to the oil supply passage (oil suction hole 41d, outer circumferential groove 29.
Injection passage 68° Injection hole 40d
) and flows into the compression chamber 839 in large quantities, causing the pressure and temperature of the compressed refrigerant gas to rise abnormally. As a result, the coil spring 38 made of a shape memory alloy material mounted inside the end plate 14d moves into the compression chamber A36. Immediately set temperature (for example, 130°C) by direct heat transfer from compression chamber B39, discharge chamber 5, etc.
The biasing force increases beyond this point, causing the plunger 3o to retreat and cutting off the oil supply passage.

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

As described above, according to the above embodiment, the bottom of the discharge chamber oil sump 18 and the compression chamber B59 (between the suction pressure and the discharge pressure intermediate pressure) and the oil suction hole 41. Outer circumferential groove 29. Injection hole 40a.

A refueling passage control valve device 17 is provided in the middle of the refueling passage, which is composed of a plunger 30 that opens and closes the refueling passage and seven actuators, and the actuator has the plunger 30 and an actuator. Back pressure chamber A34, back pressure chamber 831 and plunger 3 arranged on both sides
A spring device 38 is provided that biases 0 toward the back pressure chamber A34,
The back pressure chamber A34 does not communicate with the discharge chamber S or the suction chamber 33, but rather communicates with the compression chamber A36 in the post-compression stroke than the compression chamber B39, and the back pressure chamber 831 communicates with the suction chamber 33 and is connected to the back pressure chamber A34 and the back pressure chamber A34. When there is a pressure difference between the pressure chamber 8a1 and the pressure difference within the range of the first set value, the plunger 30 moves forward against the spring device to open the oil suction hole 41 which communicates with the discharge chamber oil sump 18. and the injection hole 4o, which communicates with the compression chamber 839, are communicated via the outer circumferential groove 29 of the plunger 30, and the back pressure chamber A
When the differential pressure between the plunger 34 and the back pressure chamber B31 is within the range of the second set value that is larger than the first set value, the plunger 30
moves further against the spring device 38 and opens the oil suction hole 4.
1 and the injection hole 40e to close the oil supply passage, and when there is no differential pressure between the back pressure chamber A34 and the back pressure chamber 831, the plunger 30 is moved back by the urging force of the spring device 38. By providing the oil supply passage control valve device 17e that closes the oil supply passage by blocking the oil suction hole 41 and the injection hole 40. The pressure of the compressor increases reliably to a constant multiple of the pressure of the suction chamber 3a without being affected by the pressure of the discharge chamber 5, and the actuator shell plunger 30 moves forward due to the differential pressure to open the oil supply passage immediately after starting the compressor. Discharge base oil! Lubricating oil of fI418 is injected into the compression chamber 839 from the initial compression stroke to seal the gap between adjacent compression chambers with an oil film without reducing suction volumetric efficiency, increasing compression efficiency from the initial stage of compressor startup and compressing. It prevents abnormal temperature rise of refrigerant gas and improves durability. In addition, by injecting oil into the compression chamber, the machining dimensional accuracy of the scroll portion can be optimized and the cost of the compressor can be reduced. Furthermore, even if the lubricating oil in the discharge chamber oil sump 18 is insufficient and discharged refrigerant gas with low viscosity and extremely low passage resistance flows into the compression chamber 839, the compression chamber pressure will abnormally rise and the differential pressure will exceed the set value. The plunger 30 is moved further forward to close the oil supply passage and prevent compression efficiency from decreasing.

In addition, after the compressor is stopped, the differential pressure between the suction chamber 33 and the compression chamber A36 disappears, and the oil supply passage is cut off.
8 to the compression chamber B39 is prevented,
It is also possible to improve the durability of sliding surfaces and compression efficiency by effectively using lubricating oil, and to prevent damage to the compressor due to oil compression when restarting the compressor.

Further, according to the above embodiment, the spring device 38 includes a coil spring A38m and a coil spring B58 having different spring constants and free lengths.
By using the spring b, the discontinuation position of the plunger 30, which moves forward against the urging force of the spring device 38 due to the differential pressure between the back pressure chambers, remains stable even if the differential pressure varies slightly. As a result, no chattering phenomenon occurs when the plunger 30 opens and closes the oil supply passage, and the plunger 30 does not move forward and close the oil supply passage when the compressor requires oil supply, resulting in a stable differential pressure. Oil supply contributes to stable compression efficiency improvement.

Further, there is an injection hole 40 between the plunger 30 and the compression chamber A36, and a drive chamber 6 which has a motor chamber oil reservoir 23 at its bottom and is also a suction passage and is equipped with an oil supply device by the centrifugal pump action of the drive shaft 8. Oil-filling A45 between the bearing oil reservoir 44 provided between
．． The lubricating oil separated from the discharged refrigerant gas in the discharge chamber is released by opening the on-off valve (plunger 30) of the oil supply passage during compressor operation by communicating with the oil return passage consisting of oil hole B46゜oil filler〇46c. The lubricating oil is returned to the oil reservoir of the oil supply device while lubricating the sliding surfaces of the bearings, preventing unnecessary lubricating oil from leaking to the outside of the compressor, and improving compression efficiency through the effect of oil injection into the compression chamber.

It is possible to improve the durability by reducing the wear of the sliding parts, and also to improve the performance of the heat exchanger placed in the refrigeration cycle outside the compressor.

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

Further, in the above embodiment, the injection pipe 40a was used to communicate the outer circumferential groove 29 of the plunger 30 and the compression chamber A36, but the end plate 1 was used instead of the injection pipe 40a.
4 may be provided with the passage.

Further, in the above embodiment, the back pressure chamber 831 and the suction chamber 33 are communicated with each other, but by appropriately selecting the dimensions of the plunger 30, the coil spring 38, etc. ) and the back pressure chamber 831 may be communicated with each other.

In addition, 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 differential pressure between the back pressure chamber A and the back pressure chamber B disappears, the spring is activated. The configuration is such that the plunger is retracted by the biasing force of the device, but the back pressure chamber A is placed on the lower side and the back pressure chamber B is placed on the upper side, so that when the differential pressure between the chambers disappears, the plunger will move under its own weight. A vertical oil supply passage control valve device that retreats to shut off the on-off valve may be attached to the top or side surface of the end plate.

Further, in the above embodiment, the spring device 38 is a coil spring A38a and a coil spring B58b having different spring constants and free lengths.
However, similar effects can be obtained when the spring is constructed with a spring whose spring constant rapidly increases during the course of displacement (for example, a cylindrical coil spring), or with a plurality of coil springs with different free lengths.

Further, in the above embodiment, a special sealing member is not provided on the outer circumference of the plunger 3o, but for example, a Teflon piston ring or a rubber O-ring (0-ring) coated with Teflon is used to seal the plunger. -30 Axial leakage from the outer circumference may be reduced.

Effects of the Invention As described above, the present invention provides an oil supply path that connects the oil reservoir in the discharge chamber or the oil reservoir communicating with the discharge chamber, and the second compression chamber, which has a lower pressure than the oil reservoir and does not communicate with either the discharge chamber or the suction chamber. communicated by
A refueling passage control valve device is provided in the middle of the refueling passage, which is composed of an on-off valve that opens and closes the refueling passage and an actuator that controls the on-off valve. A spring device is provided to bias the back pressure chamber A and back pressure chamber B and the valve body. The back pressure chamber B communicates with the suction chamber or the third compression chamber that communicates with the suction chamber or the suction side that communicates with 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 within the range of the first set value, the valve body moves forward against the spring device to open the on-off valve, and when the differential pressure is within the range of the second set value, which is greater than the first set value, the valve is opened. By providing an oil supply passage control valve device in which the body moves forward further to close the on-off valve, and when there is no differential pressure, the valve body moves back and closes the on-off valve, the compressed gas is compressed in the scroll compression mechanism during compressor operation. Because the ratio is constant, the first
The pressure in the compression chamber is not affected by the pressure in the discharge chamber and reliably rises to a pressure that is a constant multiple of the pressure in the suction chamber. Due to the differential pressure between the back pressure chamber B and the back pressure chamber B that leads to the suction side (which leads to The lubricating oil in the oil reservoir leading to the discharge chamber is injected into the second compression chamber to seal the gap between the compression chambers without reducing the suction volumetric efficiency, thereby reducing leakage of compressed gas from the compression space from the beginning of compressor startup. This makes it possible to increase compression efficiency, prevent abnormal temperature rises in the compression section, improve durability, and make the machining dimensional accuracy of the scroll section suitable for mass production, thereby reducing compressor costs.

In addition, when the compressor is operated at high speed, the flow velocity of the discharged gas in the discharge chamber (or oil separator) increases, causing lubricant oil entrainment phenomenon, which causes the lubricant to separate in the discharge chamber (or oil separator). If efficiency deteriorates and there is a shortage of lubricating oil in the oil sump in the discharge chamber, or if there is a blockage in the external piping system connected to the compressor, the lubricating oil is not returned to the compressor and the oil sump in the discharge chamber becomes insufficient. When lubricating oil is insufficient, a large amount of discharged gas flows into the second compression chamber through the oil supply passage, and the pressure in the first compression chamber in the post-compression stroke increases abnormally compared to the second compression chamber. The pressure in the back pressure chamber A also rises abnormally, and the differential pressure between the back pressure chamber A and the back pressure chamber mortar increases, and the valve body moves further against the biasing force of the spring device to close the oil supply passage. It is possible to prevent the discharge gas from flowing into the second compression chamber, prevent the pressure in the compression chamber and the temperature of the compression section from rising abnormally, and prevent a decrease in compression efficiency and durability (damage, wear of sliding parts, etc.).

In addition, 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 mill are at the same pressure. When the differential pressure disappears, the valve body retreats due to the biasing force of the spring device, closes the on-off valve, and shuts off the oil supply passage, so the oil sump in the discharge chamber (
This prevents unnecessary lubricating oil from flowing into the compression chamber from the oil sump (or oil sump leading to the discharge chamber) (if there is no reverse prevention valve on the suction side, it will also flow into the suction side). It has a function that detects the operating status of the compressor (stopped or running) and the presence or absence of lubricating oil in the oil sump, and controls the opening and closing of the oil supply passage without being affected by discharge chamber pressure, such as eliminating compression and improving durability. It is possible to realize a highly responsive refueling passage control valve device having the following functions.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-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. 1. 5 is a cross-sectional view of the compression section taken along the line A-A in FIG. 8, 9, and 10 are longitudinal sectional views of hermetic scroll refrigerant compressors according to different embodiments of the present invention, and FIG. Partial sectional views of a scroll type refrigerant compressor according to another embodiment of the invention, FIGS.
5 is a longitudinal sectional view and a partial sectional view of different conventional scroll-type gas compressors, FIG. It is a longitudinal cross-sectional view taken along the line AA in the figure. 1.2... Sealed 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, 3
1... Back pressure chamber B133... Suction chamber, 3
4... Back pressure chamber A136... Compression chamber A1
38... Coil spring, 39... Compression chamber B140... Injection hole, 41...
・・Oil suction hole, 44・・・・Bearing oil sump, 47・
...Intermediate pressure back pressure chamber. Name of agent: Patent attorney Toshio Nakao and 1 other person10
- One turn scroll 26e - Main body case η - Blind stopper & - Cylinder 10 - One turn scroll +3-! ] Hikisu Scroll 5 --- Discharge Boat 33 -- Freeman! 5-pressure 27 grooves missing χ-pressure #treasure A,? ? ---Pressure S chamber B 59a If m 'JE Be -11 Injiexicon pipe 69- Pressure at normal 1st turn Fig. 6 No-Tatsune pressure upper limit Pressure thread driving shaft rotation angle l (rad), drive shaft o umbrella angle Breaking xByy6-Cantering rotation Fig. 9 lb, 2b
- % Case 3b - Frame 5 - Discharge chamber Atsushi - Affirmative pressure neck A l mountain - Fixed scroll Sea pressure force adjustment - Temperature plate
36- Compression! A 15-Touta Bo h 33-Ba Jotou 118-Duta Senda Eyebrow 1-Pressure Urari B Shinobi...-Gas Ke 9 To Theft-Inji Ictions β
- Schilling - 41d - Missed class including overnight stay - Out of gas 68 - Ishijiekushi day i1% 33
-Barry in! 211 Figure 10 C/C--Snow case 3C-Frame 5C-Discharge chamber 7-Motor button-j [Moving shaft α-Orbiting scroll^c-Main main body Mace Engine crayon hole 51cm-One turning transfer 52cm-Bypass missing 55.56.517 One night missing, μ- Bearing Figure 12 Figure 13 Figure 14 Figure 15

Claims (3)

[Claims] (1) An orbiting scroll is engaged with a fixed scroll so as to be able to swing and rotate freely, and a spiral-shaped compression space is formed between both scrolls. A scroll-type compression mechanism is formed that is divided into a compression chamber and compresses fluid, and an oil sump in the discharge chamber or an oil sump that communicates with the discharge chamber has a lower pressure than the oil sump and does not communicate with either the discharge chamber or the suction chamber. The second compression chamber is communicated with the oil supply passage, and in the middle of the oil supply passage there is provided an oil supply passage control valve device comprising an on-off valve that opens and closes the oil supply passage and an actuator that controls the on-off valve. is provided with a valve body, a back pressure chamber A and a back pressure chamber B of the valve body disposed on both sides of the valve body, and a spring device for biasing the valve body, and the back pressure chamber A is also connected to the discharge chamber. The back pressure chamber B communicates with the suction chamber or a third compression chamber that communicates with the suction chamber or the suction chamber rather than the second compression chamber without communicating with the suction chamber. The valve element advances against the spring device when there is a pressure difference between the back pressure chamber A and the back pressure chamber B and the pressure difference is within a first set value. and when the on-off valve is opened and the differential pressure is within a second set value range larger than the first set value, the valve body moves further to close the on-off valve, and when there is no differential pressure, A scroll gas compressor comprising an oil supply passage control valve device in which the valve body retreats to close the on-off valve. (2) The scroll gas compressor according to claim 1, wherein the spring device comprises a spring whose spring constant rapidly increases during displacement, or a plurality of springs whose spring constants and free lengths differ. (3) A patent in which an oil return passage communicates between the oil supply passage between the on-off valve and the first compression chamber and an oil reservoir chamber equipped with an oil supply device on the downstream side or between the sliding part. A scroll gas compressor according to claim 1 or 2.