JPH0639952B2 - Scroll gas compressor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll gas compressor having a device for returning lubricating oil separated from compressed gas on the high pressure side of a compressor to a compression chamber.

2. Description of the Related Art Scroll compressors with low vibration and low noise characteristics have a suction chamber on the outer periphery and a discharge port at the center of the spiral winding. It is well known that a discharge valve for compressing fluid such as a rotary compressor is not required, discharge pulsation is relatively small, and a large discharge space is not required.

However, especially in the case of compressing gas, it is necessary to make the dimensional accuracy of the eddy coil extremely high in order to reduce the leakage gap of the compression part, but the cost of the scroll compressor is high due to the complexity of the part shape and the dimensional variation. There was a problem that there were large variations in performance.

Therefore, as a measure for solving this type of problem, the dimensional accuracy of the spiral part is optimized and the compressor performance is stabilized by the sealing effect using a lubricating oil film to prevent gas leakage between the compression chambers during compression. As expected, a configuration is known in which the lubricating oil is caused to directly flow into the compression chamber during compression as shown in FIG. The structure shown in the figure has a structure in which a motor 703 is arranged in the upper part of a closed container 701 and a compression part is arranged in the lower part to use a space 702 inside the closed container as a discharge chamber.
The lubricating oil of No. 0 is directly introduced into the compression chamber 723 in the middle of compression through the oil suction pipe 722 having the throttle passage inserted and fixed in the end plate 705a of the fixed scroll 705.

Problems to be Solved by the Invention However, in the configuration in which the compression chamber 723 and the oil sump 710 are always in communication as shown in FIG. 8 described above, a discharge valve for fluid compression is not required in the scroll compression mechanism, and the compression ratio is reduced. Is constant, the oil reservoir 710 in the airtight space 702 remains in a lower pressure state than the compression chamber 723 for a while after the cold start of the compressor that is operated by connecting to the closed cycle piping system. During the compression of the compression chamber 723, the gas flows back into the oil sump 710, and the lubricating oil in the oil sump 710 is diffused by the backflow gas and flows out to the external piping system of the compressor together with the discharge gas, and disappears. Therefore, even when the pressure in the closed container internal space 702 rises and becomes higher than the pressure in the compression chamber 723 some time after the compressor is started, the lubricating oil is compressed until it is collected in the oil sump 710 again. There is no sealing effect between the compression chamber gaps due to the oil inflow into the chamber 723, and conversely, the compressed gas in the space 702 inside the closed container flows into the compression chamber 723, and the sliding part durability due to a significant decrease in compression efficiency and an abnormal temperature rise. There was a problem such as a decrease in.

Therefore, in the present invention, a check valve device having a fine gas leakage passage is provided in the middle of the oil supply passage to prevent the reverse flow of the compressed gas from the compression chamber to the oil reservoir, thereby improving the compression efficiency by effectively utilizing the lubricating oil. A scroll gas compressor having excellent durability is provided.

Means for Solving the Problems In order to solve the above problems, the scroll gas compressor of the present invention is provided with a backflow prevention valve device at the discharge port, and the oil reservoir of the discharge chamber or the oil reservoir communicating with the discharge chamber is on the upstream side. An oil supply passage having a throttle passage having a first compression chamber that is lower in pressure than the oil reservoir and does not communicate with the discharge chamber or a second compression chamber that communicates with the suction chamber on the downstream side is provided, and a thin plate is provided in the middle of the oil supply passage as a valve body. A non-return valve device is provided on the end plate of the fixed scroll that is in contact with the discharge chamber and above the oil reservoir, and the valve retainer of the valve body and part of the oil supply passage that is on the downstream side of the valve body due to the valve body and the end plate. Is formed, and the sintered molded member is made of a porous material that communicates finely.

Operation According to the present invention, with the above configuration, the compressor is started at the cold time, the intake gas flowing into the compressor and mixed with the lubricating oil in the middle of the suction passage is discharged to the discharge chamber through the suction chamber and the compression chamber, and the lubricating oil Is partially separated and the discharge chamber pressure is gradually increased.

However, while the pressure of the compression chamber (first compression chamber or second compression chamber) that opens in the oil supply passage is higher than the discharge chamber pressure, the check valve device operates to close the oil supply passage, and The oil is sequentially compressed into the oil reservoir of the discharge chamber without being bypassed, and is discharged to the discharge chamber after the compression is completed.

After that, when the pressure of the discharge chamber becomes higher than the pressure of the compression chamber opening in the oil supply passage, the oil supply passage opens and the lubricating oil accumulated in the oil reservoir of the discharge chamber (or the oil reservoir leading to the discharge chamber) flows into the compression chamber and is compressed. The minute gaps between the chambers are sealed with an oil film to prevent compressed gas leakage.

After the compressor is stopped, the check valve device closes the discharge port and the compression chamber becomes the suction side pressure, and the lubricating oil flows into the compression chamber from the oil reservoir of the discharge chamber (or the oil reservoir leading to the discharge chamber). ,
The discharge gas gradually decreases in pressure through the fine passage of the valve retainer in contact with the discharge chamber and flows into the compression chamber, and the differential pressure between the discharge chamber and the compression chamber falls below the set value, and the inflow of lubricating oil into the compression chamber stops. The compressor works to improve the compression efficiency by using an oil film during the operation of the compressor and the durability of the sliding part by the effect of cooling the compression part, and prevents the inflow of lubricating oil into the compression chamber early after the operation is stopped. This reduces unnecessary oil leakage and load when the compressor is restarted.

Examples Hereinafter, for the scroll gas compressor of the embodiment of the present invention,
A description will be given with reference to the drawings.

FIG. 1 is a vertical sectional view of a scroll gas compressor according to a first embodiment of the present invention, FIG. 2 is a lateral sectional view of a compression section taken along the line AA in FIG. 1, and FIG. FIG. 4 is a characteristic view showing a pressure change of the gas up to the stroke, FIG. 4 is a characteristic view showing a pressure change at a fixed point in each compression chamber, FIG. 5 is a partial cross-sectional view of the check valve device mounting portion in FIG. The figure is the fifth
The partial external view of a figure is shown.

In FIG. 1, reference numerals 1 and 2 denote an iron-made hermetically sealed case, 3 denotes an iron-made frame whose outer peripheral surface is welded and hermetically sealed together with the hermetically sealed cases 1 and 2 by a single welding beat 4.
The inside of 2 is divided into an upper discharge chamber 5 and a lower drive chamber 6 (low pressure side).

The orbiting shaft 11 of the orbiting school 10 is fitted into 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 is controlled by an inverter power supply (not shown). The rotation preventing component 12 engages 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.
A discharge port 15 is provided on the upper end of the end plate 14, and a reed valve type backflow prevention device 16 and a check valve device 17 that close the opening end of the discharge port 15 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 in the upper part thereof is a closed case 1.
Attached to the closed case 1 and bunching metal 19
A filter 20 made of a fine metal wire is packed between and, and the discharge chamber 5 is provided on the side surface of the closed case 2 via an external refrigeration cycle piping system through a discharge pipe 21 provided on the upper surface of the closed case 1. It communicates with the low-pressure side drive chamber 6 through the suction pipe 22, and the motor chamber oil sump 23 is provided at the bottom of the drive chamber 6.
Is provided.

In FIG. 1, FIG. 2, FIG. 5, and FIG. 6, the end plate 14 is provided between the first compression chamber 39b and the discharge chamber oil sump 18, which do not communicate with the discharge chamber 5 or the suction chamber 33. The valve retainer 4 of the check valve device 17 attached to the oil suction hole 41 and the end plate 14 together with the valve plate 42 made of a thin steel plate also serving as the discharge chamber partition plate.
3 and the end plate 14 are formed with a valve space 44 and a valve plate 42.
Of the first compression chamber 39a and the oil reservoir 18 of the discharge chamber are communicated with each other by a first oil supply passage having a throttle passage composed of a punched groove 45 of the above, and an injection hole 30b of an ultrafine passage provided in the end plate 14. Injection communication hole 5 provided on the end plate 14 branched from the hole 30b
9, a second oil supply passage having a throttle passage formed by the injection hole 20a.

Between the discharge chamber oil sump 18 and the low pressure side drive chamber 6, the valve space 44, the punching groove 45 of the valve plate 42, the oil hole 46 provided in the end plate 14, and the frame are branched from the middle of the first oil supply passage. Three
The oil hole 47 of the ultrafine passage, the upper bearing hole 48 that supports the drive shaft 8 and is provided in the frame 3, the bearing gap of the upper bearing 49, the gap between the swivel shaft 11 and the eccentric hole 9, and the drive shaft 8. The eccentric oil hole 24, the lateral oil hole 50, the bearing oil sump 52 between the lower bearing 51 and the upper bearing 49, which support the drive shaft 8 and are provided at the lower end of the frame 3, and the bearing gap of the lower bearing 51, Is connected by a third oil supply passage having a throttle passage consisting of.

The reed valve 53 of the check valve device 17 and the reed valve 54 of the check valve device 16 are configured by punching out a part of the valve plate 42, and the valve retainer 43 of the check valve device 17 can slightly pass gas. It is made of a porous sintered alloy molded product, a part of which also serves as the valve retainer 55 of the check valve device 16, and shallow holes 56 and 57 which also serve as oil reservoirs are provided on the upper surface of the valve retainer 43. There is.

In FIG. 3, the horizontal axis represents the rotation angle of the drive shaft 8, the vertical axis represents the refrigerant pressure, and the pressure change state of the refrigerant gas in the intake, compression, and discharge processes.

In FIG. 4, the horizontal axis represents the rotation angle of the drive shaft 8, the vertical axis represents the refrigerant pressure, and the solid line 60 represents the discharge chamber 5 as well as the suction chamber 3.
3 shows the pressure change at the opening positions of the injection holes 30a, 30b of the first compression chambers 39a, 39b that also do not communicate with 3, and the dotted line 61 indicates the second compression chamber 4 communicating with the suction chamber 33.
0a, 40b (refer to FIG. 2) represents pressure change at a fixed point, and an alternate long and short dash line 62 indicates a fixed point of the third compression chamber 63a, 63b (refer to FIG. 2) communicating with the discharge chamber 5 via the check valve device 16. And the two-dot chain line 64 represents the pressure change at a fixed point between the first compression chambers 39a, 39b and the second compression chambers 40a, 40b.

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

In FIG. 1 to FIG. 6, when the drive shaft 8 starts to rotate by the motor 7, the orbiting scroll 10 orbits, and the refrigerant gas sucked from the refrigeration cycle connected to the compressor enters the driving chamber 6 through the suction pipe 22. After flowing in and separating a part of the lubricating oil contained therein, the lubricating oil is sucked into the suction chamber 33, and this suction refrigerant gas is formed in the second compression chamber 40a (formed between the orbiting scroll 10 and the fixed scroll 13). 40
Orbiting scroll 1 confined in the compression chamber via b)
With the swirling motion of 0, the transfer chamber 5 is transferred to the first compression chamber 39a (39b) and the third compression chamber 63a (63b) in order and compressed, and then discharged through the discharge port 15 and the backflow prevention valve device 16 at the central portion.
A part of the lubricating oil discharged into the discharge refrigerant gas is separated from the discharge refrigerant gas by adhering to its own weight and the surface thereof when passing through the small holes of the punching metal 19 or the filter 20 composed of a fine metal wire. Then, it is collected in the discharge chamber oil sump 18 and the shallow holes 56, 57 of the valve retainer 43, and the remaining lubricating oil is discharged to the external refrigeration cycle through the discharge pipe 21 together with the discharge refrigerant gas, and is again sucked into the suction pipe together with the suction refrigerant gas. Return to the compressor through 22.

For a while after the cold start of the compressor, the pressure in the discharge chamber 5 is lower than the pressure in the first compression chamber 39a (39b) as shown in FIG. No differential pressure oil is supplied through the first oil supply passage, and the gas in the middle of compression does not flow back into the discharge chamber oil sump 18 from the first compression chamber 39a (39b) due to the effect of the check valve device.

Some time after the cold start of the compressor, the pressure in the discharge chamber 5 rises above the pressure in the first compression chamber 39a (39b), and then the lubricating oil in the discharge chamber oil sump 18 contains the check valve device 17 (17a). Against the urging force of the reed valve 53, the pressure is gradually reduced through the first oil supply passage (second oil supply passage), the differential pressure oil is supplied to the first compression chamber 39a (39b), and the oil is branched from the middle of the first oil supply passage. Punching hole 45 and oil hole 4 of the third oil supply passage configured as
The pressure is gradually reduced through 6 and 47, adjusted to an intermediate pressure between the discharge side pressure and the suction side pressure, and differential pressure oil is also supplied to the upper bearing hole 48 on the side opposite to the compression chamber of the orbiting scroll 10.

The lubricating oil differentially supplied to the first compression chamber 39a (39b) merges with the lubricating oil that has flowed into the compression chamber together with the suction refrigerant gas and seals a minute gap in the adjacent compression space with an oil film to prevent compressed gas leakage. It is prevented and is discharged again to the discharge chamber 5 together with the compressed gas while lubricating the sliding surface between the compression chambers.

On the other hand, part of the lubricating oil differentially supplied to the upper bearing hole 48 lubricates the sliding surface portion with the frame 3 supporting the thrust load acting on the orbiting scroll 10 and the sliding surface of the rotation preventing component 12. It is mixed with the suction refrigerant gas and flows into the compression chamber again. The remaining lubricating oil flows into the bearing oil sump 52 through the gap between the swivel shaft 11 and the eccentric hole 9, the eccentric hole 9, the eccentric oil hole 24, the oil passage passing through the lateral oil hole 50 and the gap of the upper bearing 49. Then, the pressure is finally reduced through the minute gap of the lower bearing 51 and flows into the drive chamber 6, a part of which is mixed with the suction refrigerant gas and flows into the compression chamber again. The remaining lubricating oil is the motor chamber oil sump 2
Collected in 3.

The lubricating oil in the motor chamber oil sump 23 is diffused to the lower end portion of the rotor of the motor 7 when the oil level rises to some extent, and the driving quality 6
It is mixed with the suctioned refrigerant gas inside and again flows into the compression chamber, and is finally collected in the discharge chamber oil sump 18.

After the compressor is stopped, the reed valve 54 of the check valve device 16 closes the discharge port 15, and the pressure of the compression space from the discharge port 15 to the second compression chamber 40a (40b) passes through the gap between the compression chambers and the suction chamber 33. Equal to the pressure of. Therefore, the lubricating oil in the discharge chamber oil sump 18 immediately after the compressor is stopped passes through the first oil supply passage, the second oil supply passage, and the third oil supply passage to the first compression chamber 3
9a (39b) and the upper bearing hole 48 slightly, but compressed gas gradually flows into the valve space 44 through the fine particles of the valve retainer 43 made of a sintered alloy material, and the pressure in the discharge chamber 5 and the valve space 44 is increased. The inflow of lubricating oil is stopped. The pressure in the first compression chamber 39a (39b) and the upper bearing hole 48 flows into the valve space 44 due to the sealing effect of the lubricating oil in the middle of the passage because the passage of the injection hole 30a (30b) and the passage of the oil hole 47 are narrow. Since the inflow of compressed gas is small, the pressure is not increased.

Further, the valve plate 42 prevents the lubricating oil surface of the discharge chamber oil sump 18 from being diffused by the discharge gas.

As described above, according to the above-described embodiment, in the scroll compressor having the check valve device 16 for closing the discharge port 15, the discharge chamber oil sump 18 is on the upstream side, and the discharge pressure is lower than that of the discharge chamber oil sump 18. The first compression chamber 39a (3
9b) on the downstream side, the oil suction hole 41, the valve space 44,
The first oil supply passage formed by the punching groove 45 of the valve plate 42, the injection hole 30b of the ultrafine passage and the second oil supply constituted by the injection communication hole 59 branched from the middle of the injection hole 30b and the injection hole 30a of the ultrafine passage. A reed valve type check device 17 is provided on the upper surface of the end plate 14 to close the oil suction hole 41 that opens to the upper surface of the end plate 14 of the fixed scroll 13 in the middle of the first oil supply passage. 43, the reed valve 53, and the end plate 14, which are on the downstream side of the reed valve 53.
By forming a part of the oil supply passage and forming the valve retainer 43 as a finely communicated porous sintered molded member, the discharge chamber can be used during a loose period after the cold start of the compressor or after a slow restart. Even if the pressures of the first compression chambers 39a and 39b in which the first and second oil supply passages are open are higher than the pressure of 5, the gas in the middle of compression is discharged by the check valve action of the check valve device 17. Pool 1
8 does not flow back to 8, but is discharged to the discharge chamber 5 after completion of compression to accelerate the pressure rise in the discharge chamber 5, and the lubricating oil in the discharge chamber oil reservoir 18 is diffused by the backflow gas and flows out to the refrigeration cycle outside the compressor. Since it is possible to prevent this, the oil injection into the first compression chambers 39a, 39b after the pressure in the discharge chamber has risen can be started earlier, and the gap between the compression chambers can be sealed by the oil film to achieve an early effect of improving the compression efficiency. .

After the compressor is stopped, the check valve device 17 closes the discharge port 15 and the space from the discharge port 15 to the suction chamber 33 becomes the suction side pressure, so that the lubricating oil is kept in the discharge chamber oil reservoir for a very short time. Although it flows into the first compression chambers 39a, 39b from 18, the discharge gas is gradually depressurized through the fine passages of the valve retainer 43 which is in contact with the discharge chamber 5, and the first compression chambers 39a, 39b.
9b, the differential pressure between the discharge chamber 5 and the first compression chambers 39a, 39b becomes equal to or lower than a set value corresponding to the biasing force of the reed valve 53, and the first compression chambers 39a, 39b of the lubricating oil flow in. Since the engine is stopped, it is possible to prevent the lubricating oil from flowing into the first compression chamber at an early stage, prevent wasteful lubricating oil outflow, and prevent liquid compression when the compressor is restarted, thereby reducing the starting load.

Further, during operation of the compressor, the valve retainer 43 forming the oil supply passage is
The fine interparticle gaps of the valve retainer 43 are sealed with an oil film by the permeating action of the lubricating oil passing through the inner wall surface of the scroll gas compressor, which provides a scroll gas compressor excellent in compression efficiency and durability without compression loss due to discharge gas inflow. Is.

In the above embodiment, the first compression chambers 39a and 39b are provided on the downstream side of the first oil supply passage and the second oil supply passage.
Even when the second compression chambers 40a and 40b communicating with the above are used, the same operation and effect are obtained, and instead of the discharge chamber oil sump 18 in the discharge chamber 15, an oil sump is provided on the high pressure side outside the compressor to provide a closed shell. Oil may be supplied to the compression chamber by an oil supply pipe penetrating through 1.

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

EFFECTS OF THE INVENTION As described above, the present invention forms the scroll type compression mechanism that discharges to the discharge chamber through the discharge port provided in the fixed scroll and the check valve device that closes the discharge port, and the oil reservoir or discharge of the discharge chamber is formed. The oil reservoir communicating with the chamber is provided on the upstream side, and the oil supply passage having the throttle passage having the downstream side of the first compression chamber not communicating with the discharge chamber whose pressure is lower than that of the oil reservoir or the second compression chamber communicating with the suction chamber is provided. A check valve device using a thin plate as a valve element is provided in the middle of the passage on the end plate of the fixed scroll that is in contact with the discharge chamber and above the oil reservoir, and the valve retainer of the thin plate valve element and the valve element and end plate Also, by forming a part of the oil supply passage on the downstream side and using a porous sintered molded member that finely communicates the valve retainer, the compression ratio of the scroll type compression mechanism is constant and compression does not communicate with the discharge quality. The chamber pressure affects the discharge chamber pressure. For a while after the cold start of the compressor or the restart of the compressor when the compressor is cold, even if the pressure of the first compression chamber or the second compression chamber where the oil supply passage opens is higher than the pressure of the discharge chamber, compression is performed. The gas in the middle does not flow back into the discharge chamber oil sump (or the oil sump leading to the discharge chamber) due to the check valve action of the check valve device, but is discharged to the discharge chamber after the completion of compression to accelerate the pressure rise in the discharge chamber, and Can prevent the lubricating oil in the discharge chamber oil sump (or the oil sump leading to the discharge chamber) from diffusing by the backflow gas and flowing out to the piping system outside the compressor, so that the first compression after the discharge chamber pressure rises It is possible to start the oil injection into the chamber or the second compression chamber early and to seal the gap between the compression chambers with the oil film to start the early effect of improving the compression efficiency.

In addition, after the compressor is stopped, the check valve device closes the discharge port, and the discharge port and the compression chamber become the suction side pressure, and the lubricating oil flows to the oil reservoir (or the discharge chamber) of the discharge chamber for a very short time. Gas from the oil reservoir) into the compression chamber, but the gas in the discharge chamber flows into the compression chamber while gradually depressurizing through the fine particles of the valve retainer, and the differential pressure between the discharge chamber and the compression chamber causes Since the inflow of lubricating oil to the compression chamber is stopped when the pressure falls below the set value corresponding to the power, the inflow of lubricating oil to the compression chamber is blocked early, resulting in wasteful lubricating oil outflow and liquid compression when the compressor is restarted. Can be prevented and the starting load can be reduced.

Further, during operation of the compressor, the gap between the fine particles of the valve retainer is sealed with an oil film by the permeating action of the lubricating oil that passes through the inner wall surface of the valve retainer that constitutes the oil supply passage, so the valve retainer functions to prevent backflow of gas. It is equipped with many excellent effects such as no compression loss due to inflow of discharge gas into the compression chamber.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a gas compressor according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of a compression section taken along the line AA in FIG. 1, and FIG. 3 is a suction stroke to a discharge stroke. 4 is a characteristic diagram showing the pressure change of the gas up to, FIG. 4 is a characteristic diagram showing the pressure change at a fixed point in each compression chamber, FIG. 5 is a partial cross-sectional view of the check valve device mounting portion in FIG. 1, and FIG. 5 is a partial external view of FIG. 5, and FIG. 7 is a sectional view of a scroll gas compressor having a conventional oil supply passage. 1, 2 ... sealed case, 5 ... discharge chamber, 6 ... drive chamber,
7 ... Motor, 10 ... Orbiting scroll, 13 ... Fixed scroll, 14 ... End plate, 15 ... Discharge port, 16
...... Check valve device, 17 ...... Check valve device, 18 ...... Discharge chamber oil sump, 21 ...... Discharge pipe, 22 ...... Suction pipe, 23 ......
Motor chamber oil sump, 30a, 30b ... Injection hole, 33 ... Suction chamber, 39a, 39b ... First compression chamber,
40a, 40b ... second compression chamber, 41 ... oil suction hole, 43 ... valve retainer, 45 ... punching hole, 53,5
4 ... Reed valve, 55 ... Valve retainer, 59 ... Injection communication hole.

Claims (1)

[Claims] 1. A plurality of orbiting scrolls are oscillatably meshed with a fixed scroll to form a spiral compression space between the scrolls, and the compression spaces continuously move from the suction side toward the discharge side. Is formed in the compression chamber of the fixed scroll to discharge the fluid to the discharge chamber through a discharge port provided in the fixed scroll and a check valve device that closes the discharge port. Alternatively, an oil supply passage having a throttle passage in which an oil reservoir communicating with the discharge chamber is on the upstream side and a pressure lower than the oil reservoir is lower than the first compression chamber communicating with the discharge chamber or the second compression chamber communicating with the suction chamber is the downstream side A check valve device having a thin plate as a valve element is provided in the middle of the oil supply passage on the end plate of the fixed scroll that is in contact with the discharge chamber and above the oil reservoir, and the valve retainer of the valve element and the valve Body and front Than the valve body and the end plate forming part of said oil supply passage on the downstream side, scroll gas compressor which was sintered molded member formed of a porous communicating fine said valve retainer.