JPH01170780A - Scroll gas compressor - Google Patents

Abstract

PURPOSE:To improve oil feed performance and to improve durability by disposing a plurality of compression spaces formed between a rotary scroll and a fixed scroll and communicating a suction chamber and the compression spaces which do not communicate with a discharge port with a discharge chamber oil sump by an oil feed passage. CONSTITUTION:The interior of a sealed case 1 is partitioned into upper and lower motor room and discharge chamber by a main body frame 5 of a compression portion supporting a driving shaft 4 of a motor, and a fixed scroll 15 is fixed to the lower end surface of the main body frame 5. A rotary scroll 18 having a lap 18a engaged with a lap 15a of the fixed scroll 15 is accommodated in a space surrounded by the fixed scroll 15, the main body frame 5 and the driving shaft 4. A plurality of compression spaces 61a, 61b, 51a, 51b, 60a, 60b adapted to continuously move are formed between both laps 15a, 18a. In this case, the second compression spaces 51a, 51b and a discharge chamber oil sump 34 are communicated with one another through an eccentric hearing space 36, an outer peripheral portion space 37 and injection holes 52a, 52b.

Description

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

Conventional technology Scroll compressors with low vibration and low noise characteristics have a suction chamber on the outer periphery and a discharge port in the center of the spiral. It is generally known that a compressor does not require a discharge valve to compress fluid, has a constant compression ratio, has relatively small discharge pulsation, and does not require a large discharge space. It has been put into practical use in fields with large gas displacement volumes, such as commercial compressors and office air conditioning compressors.

However, in order to reduce the leakage gap in the compression part, the dimensional accuracy of the spiral part needs to be extremely high, but due to the complexity of the parts shape and the variation in dimensional accuracy, the cost of scroll gas compressors is high and the performance varies. The problem was that it was big.

Therefore, as a measure to solve this type of problem, a configuration has been considered in which the gas leaks during compression by using a sealing effect using a lubricating oil film to flow directly into the compression chamber while the dimensional accuracy of the spiral part is being optimized. The figure shows a configuration in which a motor 703 is placed in the upper part of a sealed container 701, a compression part is placed in the lower part, and the internal space 702 of the sealed container is used as a discharge chamber. There is a configuration in which the suction pipe 722 directly flows into the compression chamber 723 during compression from the bottom thereof (Japanese Patent Application Laid-Open No. 57-8386).

Problems to be Solved by the Invention However, in fields such as household air conditioning compressors that require a small gas displacement volume and compressor downsizing, a discharge valve for compression is used to reduce noise. Since there is no compressor, a number of spirals is required to ensure the required compression ratio, and the suction/compression section is large, which has been a major hindrance in reducing the size of the compressor.

Further, in the configuration shown in FIG. 12, in which the passage resistance of the oil suction pipe is fixed and the lubricating oil in the oil reservoir 710 is simply caused to flow into the appropriate compression chamber 723 during compression by an appropriate differential pressure, the motor 703 When the compressor is operated while the rotational speed of the compressor changes, the compression efficiency cannot necessarily be improved by supplying lubricating oil to the compression chamber. In other words, the amount of compressed gas leaking from the gap between compression chambers per intake gas volume is:
More when the compression time is long and less when the compression time is short. Therefore, when the compressor is operated at high speed, lubricating oil is more actively supplied to the compression chamber to reduce leakage of compressed gas and improve compression efficiency. However, when the compressor is operated at high speed, this does not lead to an improvement in compression efficiency; on the contrary, there is little compressed gas leakage, and the inflow of refrigerant gas mixed in the lubricating oil increases the compression chamber pressure and increases the compression torque.

In addition, when the compressor is operated at high speed, the discharge fluid velocity is high and it is difficult to effectively separate the lubricating oil contained in the discharged fluid, resulting in a large amount of lubricating oil being discharged to the outside of the compressor, resulting in a shortage of lubricating oil inside the compressor. However, there is a problem in that the sliding part may seize.

For these reasons, when the compressor is operated over a wide range from low speed to high speed, it is necessary to adjust the amount of lubricating oil flowing into the compression chamber. Of course, even with the configuration shown in the above diagram, the lubricating oil inflow opening from the oil suction pipe 722 is temporarily blocked by the orbiting scroll and is intermittently opened and closed, which somewhat limits the supply and oil amount during high-speed operation. Because the blockage section is short, the oil supply amount adjustment range is also small, so scroll compressors with small gas displacement volumes used for variable speed operation have had the problem that it is difficult to actively supply oil to the compression chamber. .

Therefore, the present invention provides a scroll gas compressor that has excellent compression efficiency and durability by reducing the number of turns in the spiral portion that forms the compression chamber and by controlling the amount of oil supplied to the compression chamber according to the compressor operating speed. It is something to do.

Means for Solving the Problems In order to solve the above problems, the scroll gas compressor of the present invention has an orbiting scroll disposed between a main body frame supporting a drive shaft and a fixed scroll, and a first A second valve that does not communicate with either the compression chamber or suction chamber or the discharge port.
The compression chamber and the oil sump in the discharge chamber leading to the discharge port or the oil sump leading to the discharge chamber communicate with each other through an oil supply passage having a constriction part, and the number of turns of the fixed scroll wrap of the fixed scroll and the orbiting scroll wrap of the orbiting scroll is substantially the same. It is constructed with the minimum number of windings that can form the second compression chamber, and furthermore, the oil supply passage is intermittently opened and closed by a lap support disk in conjunction with the orbiting movement of the orbiting scroll.

According to the above-described structure, the compressor, which is made smaller by reducing the volume ratio during suction/compression compared to the usual one, is started, and the suction gas is discharged into the discharge chamber through the compression space, and the pressure in the discharge chamber is gradually increased. let

When the pressure in the discharge chamber becomes higher than the pressure in the compression space where the oil supply passage opens, the lubricating oil in the oil sump in the discharge chamber (or in the oil sump leading to the discharge chamber) leaks every time the orbiting scroll's lap support disk rotates. The passage is opened and closed, and the compression space is intermittently supplied with oil through the oil supply passage, and the oil supply is adjusted such that when the rotation speed is slow, the amount of oil supplied per revolution is large, and when the rotation speed is high, the amount of oil supplied per revolution is reduced. When the compressor is operating at high speed, the amount of oil supply and heating for the intake gas is increased, and the oil film sealing effect in the gap between the compression chambers reduces the amount of compressed gas leakage and increases the pressure in the compression chamber. The purpose is to reduce the amount of oil supplied to the compression chamber per revolution and the leakage of compressed gas, thereby suppressing excessive rise in pressure in the compression chamber and reducing compression power loss.

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

FIG. 1 shows a longitudinal sectional view of a scroll refrigerant compressor according to a first embodiment of the present invention, FIG. 2 shows an exploded view of main parts, and FIG. 3 shows a cross section taken along line A-A in FIG. 1. 4 shows the position of the check valve at the suction pipe connection part in FIG. 3, and FIG.
6 shows an external view of the check valve used in the oil supply passage, FIGS. 7 and 8 show an explanatory diagram of movement of the compression chamber in the discharge port, and FIG. A characteristic diagram showing the pressure change of refrigerant gas from the suction stroke to the discharge stroke is shown, FIG. 10 is a characteristic diagram showing the pressure change at a fixed point in each compression chamber, and FIG. 11 is a characteristic diagram showing the pressure change at a fixed point in each compression chamber. An explanatory diagram of the compression chamber arrangement in the minimum state is shown.

In Fig. 1, reference numeral 1 denotes a closed case made of iron, the entire inside of which communicates with a discharge chamber 2 in a high-pressure atmosphere, and a motor 3 on the top.
A compression section is disposed in the lower part, and the inside of the sealed case 1 is partitioned into a motor chamber 6 and a discharge chamber by a main body frame 5 of the compression section that supports a drive shaft 4 fixed to a rotor 3m of a motor 3. The main body frame 5 is made of an aluminum alloy with excellent heat conduction properties, with the main purpose of reducing weight and dissipating heat from the bearing part.A liner 8 made of iron with excellent weldability is fixed to the outer periphery by shrink fitting. The outer circumferential surface of the sealing case 1 is entirely inscribed in the sealed case 1 and partially fixed by welding.

The outer peripheral portions of both ends of the stator 3b of the motor 3 are supported and fixed by a bearing frame 9 and a main body frame 5 which are internally fixed to the sealed case 1. The drive shaft 4 includes an upper bearing 10 provided on a bearing frame 9, a lower bearing 11 provided on the upper end of the main body frame 5, a main bearing 12 provided in the center of the main body frame 5, and an upper end surface of the main body frame 5. It is supported by a thrust ball bearing 13 provided between the lower end surface of the rotor 3- of the motor 3, and an eccentric bearing 14 eccentric from the main axis of the drive shaft 4 is provided at its lower end.

A fixed scroll 15 made of aluminum alloy is fixed to the lower end surface of the main body frame 5, and the fixed scroll 15 consists of a spiral fixed scroll wrap 15a and an end plate 15b.
A discharge boat 16 that opens at the beginning of winding of the scroll wrap 15a is also provided to open to the discharge chamber 2, and a suction chamber 17 is provided at the outer periphery of the fixed scroll wrap 15a.

A spiral orbiting scroll wrap that meshes with the fixed scroll wrap 15a to form a compression chamber and a drive shaft 4
An orbiting scroll 18 made of aluminum alloy, which consists of a rotation shaft 18b supported by an eccentric bearing 14 and a lap support disk 18c standing upright, is surrounded by a fixed scroll 15, a main body frame 5, and a drive shaft 4. A sleeve 19 made of high-tensile steel material is shrink-fitted to the outer periphery of the pivot shaft 18b, and the surface of the lap support disk 18C is hardened.

The spiral curves of the fixed scroll wrap 15a and the orbiting scroll wrap 18a are as shown in FIG. 11, as also described in US Pat. No. 4,441,870.

That is, the beginning of the winding begins with a circular arc having a diameter equal to the groove width between adjacent wraps, the spiral curve that follows it is an involute curve, and the tip of the winding begins with a small circular arc 80. Therefore, the substantial boundary point of the spiral curve that forms the compression space that does not communicate with the discharge boat 16 is the point A 7.

A spacer 21 is provided between the thrust bearing 20, which is restrained by a parallel pin 19 fixed to the main body frame 5 and can only move in the axial direction, and the end plate 15b of the fixed scroll 15, and the axial dimension of the spacer 21 is The thickness is set approximately 0.015 to 0.020 mm larger than the thickness of the lap support disk 18c in order to improve the sealing performance of the sliding surface by an oil film.

The eccentric bearing space 36 between the bottom of the eccentric bearing 14 of the drive shaft 4 and the end of the orbiting shaft 18b of the orbiting scroll 1B and the outer peripheral space 37 of the lap support disc 18c are defined by the orbiting shaft 18b and the lap support disc 18c. It is connected by an oil film A38m provided in the.

As shown in FIG. 2, the thrust bearing 2o is formed through a central portion into a shape consisting of two parallel straight sections and two arcuate curved sections connected thereto.

The Oldham ring 24 for preventing rotation of the orbiting scroll is made of a light alloy or resin material suitable for sinter molding or injection molding, and as shown in Figure 2, it is made of a thin annular plate with parallel surfaces and provided on one side of the ring. The outer contour of the annular plate consists of two parallel straight parts and two arcuate curved parts connected to the two parallel straight parts, and the straight part is slightly attached to the straight part of the thrust bearing 20 as shown in FIG. The parallel key portion engages with a gap and can slide, and the parallel key portion engages with a pair of key grooves 71 provided in the lap support disk 18c of the orbiting scroll 18 with a small gap as shown in FIGS. 1 and 2. It is set in a slidable shape.

As shown in FIG. 1, a release gap 27 of approximately 0.1 mm is provided between the main body frame 5 and the thrust bearing 20, and an annular groove 28 is provided in the main body frame 5 opposite to the release gap 27. A rubber seal ring 7o surrounding the annular groove 2B connects the main body frame 5 and the thrust bearing 20.
It is installed between.

The upper part of the motor chamber 6 and the discharge chamber 2 communicate with each other via a bypass discharge pipe 29 that passes through the side wall of the sealed case 1 and is connected to the upper part of the motor chamber 6. The opening position of the bypass discharge pipe 29 to the motor chamber 6 is located at the stator 3b. The discharge pipe 31, which faces the side surface of the upper coil end 30 of and the bearing frame 9, and communicate with each other via a punching metal 33 having a large number of small holes.

A discharge chamber oil reservoir 34 provided in the lower part of the motor chamber 6 is communicated with the upper part of the motor chamber 6 by a cooling passage 35 provided by cutting a part of the outer periphery of the stator 3b of the motor 3. In addition, the discharge chamber oil reservoir 34 is formed by an oil film B provided on the main body frame 5.
The back pressure chamber 3 of the orbiting scroll 18 communicates with the annular groove 28 via 58b and in which the Oldham ring 24 is arranged.
9 through a small gap in the sliding portion of the main bearing 12, and further communicates with the eccentric bearing space 36 through an oil groove A40a provided in the eccentric bearing 14.

The oil film B58b provided on the main body frame 5 also communicates with the spiral oil groove 41 provided on the surface of the lower shaft portion 4a facing the lower bearing 11 of the drive shaft 4.
The winding direction is set so that a screw pump action using the viscosity of the lubricating oil occurs when the drive shaft 4 rotates forward, and the end thereof is formed halfway to the lower bearing 4a.

As shown in FIGS. 3 and 4, the fixed scroll 15 is provided with an arc-shaped suction passage 42 that communicates both ends of the suction chamber 17, and a circular suction hole 43 perpendicular to the arc-shaped suction passage 42 is formed on the side surface of the fixed scroll wrap 15a. The bottom of the suction hole 43 is flat and reaches the side surface of the suction passage 42 . As shown in FIG. 5, the center of the suction hole 43 is offset from the bottom surface 44 of the suction passage 42, and the opening dimension W45 to the suction passage 42 is set smaller than the diameter dimension of the suction hole 43. Further, a suction pipe 47 of an accumulator 46 is connected to the suction hole 43, and between the bottom surface 44 of the suction hole 43 and the suction pipe end surface 48, there are the inner diameter dimensions of the suction pipe 47, the suction pipe end surface 4B, and the bottom surface 44. Suction hole depth dimension L4 between
A check valve 50 made of a circular thin steel plate having a diameter larger than 9 and an opening size W45 is disposed. The surface of the check valve 50 is coated with Teflon, which has poor oil wettability and is highly elastic.

A second compression chamber 51 that does not communicate with either the suction chamber 17 or the discharge chamber 2
and the outer peripheral space are open to the second compression chamber 51 and have an end plate 15.
Small diameter injection hole 52 provided in b, mirror plate 1
5b and an injection groove 54 formed by a resin heat insulating cover 53, and an injection passage 55 consisting of a stepped oil filler C38c that opens into the outer peripheral space 37, and communicates with the large diameter portion 56 of the oil filler C38c. As shown in FIG. 6, a check valve 58 made of a thin steel plate having a notch 57 in a part of its outer periphery and a coil spring 59 are arranged, and the coil spring 59 is pressed by a heat insulating cover 53 to operate the check valve. Always energized. As shown in FIGS. 7 and 8, the opening position of the oil filling C38c into the outer peripheral space 37 is such that the orbiting scroll 1B is close to the end of the volume reduction stroke of the third compression chamber 6o communicating with the discharge boat 16. When moving (see Figure 7)
The outer circumferential space 37 and the oil filler C38c communicate with each other, and at other times (see FIG. 8), the outer circumferential space 37 and the oil filler C38c communicate with each other, and are blocked by the lap support disk 18C.

In FIG. 9, the horizontal axis represents the rotation angle of the drive shaft 4, the vertical axis represents the refrigerant pressure, and represents the pressure change state of the refrigerant gas in the suction, compression, and discharge strokes, and the solid line 62 represents the pressure during normal pressure operation. 62a represents the pressure change during under-compression operation without oil injection into the compression chamber, and dotted line 6
3 represents the pressure change during abnormal pressure increase operation.

In FIG. 10, the horizontal axis represents the rotation angle of the drive shaft 4,
The vertical and horizontal lines represent the refrigerant pressure, and the solid line 64 indicates the injection hole 52a of the second compression chamber 51m, 51b that does not communicate with either the discharge chamber 2 or the suction chamber 17.

52b represents the pressure change at the opening position, and the dotted line 65 represents the pressure change at the opening position of the first compression chamber 61m, 61b (third
(see figure) represents the pressure change at a fixed point, - dotted chain line 66
represents pressure changes at fixed points in the third compression chamber 60a and Sob communicating with the discharge chamber 2, and the two-dot chain line 67 represents the pressure change at a fixed point in the third compression chamber 60a and Sob communicating with the discharge chamber 2.
3ia, 61b and the second compression chambers 51a, 51b, and the double dotted line 68 indicates the back pressure chamber 39.
represents the pressure change.

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

1 to 10, the drive shaft 4 is driven by the motor 3.
starts rotating, the orbiting scroll 18 performs an orbiting motion, and suction refrigerant gas containing lubricating oil is supplied from the refrigeration cycle connected to the compressor to the suction pipe 47 connected to the accumulator 46, the suction hole 43, and the suction passage. 42 and then suction chamber 17
The second compression chamber 5 flows into the compression chamber, passes through the first compression chambers 61a and 61b formed between the orbiting scroll 18 and the fixed scroll 15, and is confined within the compression chamber, and becomes a closed space at all times.
1a, 51b, third compression chambers 60a, 60b, and the pressure is not increased due to the small compression ratio as shown by curve 62a in FIG. It is discharged to 2.

The discharged refrigerant gas containing lubricating oil returns to the motor chamber 6 inside the compressor through a bypass discharge pipe 29 connected to the outside of the compressor, and then is carried out to an external refrigeration cycle through a discharge pipe 31. After separating a part of the lubricating oil by colliding with the side surface of the upper coil end 30 of the motor 3 and adhering to the surface of the motor winding when flowing into the chamber 6, the lubricating oil is separated from a part of the lubricating oil by the extraction hole 32 provided in the bearing frame 9. The lubricating oil is effectively separated by the inertia of the lubricating oil and adhesion to the surface when the lubricating oil changes its flow direction or passes through the small holes of the punched metal 33.

A portion of the lubricating oil separated from the discharged refrigerant gas lubricates the sliding surface of the upper bearing, and then flows into the cooling passage 35 together with the remaining lubricating oil.
The oil passes through the motor 3 and is collected in the lower discharge chamber oil sump 34 while cooling the motor 3.

The lubricating oil in the discharge chamber oil sump 34 is supplied to the thrust ball bearing 13 by the screw pump action of the spiral oil groove 41 provided on the surface of the lower shaft portion 4a of the drive shaft 4, and the lubricating oil is supplied to the thrust ball bearing 13 by the micro bearing at the end of the lower bearing 4a. When the lubricating oil passes through the gap, the sealing action of the oil film causes the discharge of the refrigerant gas atmosphere in the motor chamber 6 and the main bearing 1
The upstream space of No. 2 is cut off. After the pressure in the motor chamber 6 increases to a certain extent, the lubricating oil containing the dissolved discharged refrigerant gas in the discharge chamber oil sump 34 is reduced to an intermediate pressure between the discharge pressure and the suction pressure as it passes through a small gap in the main bearing 12. back pressure chamber 3
9, and then flows into the outer peripheral space 37 via the oil groove A40a of the eccentric bearing 14, the eccentric bearing space 36, and the hole A3B passing through the orbiting scroll 18, and furthermore, the oil inlet C38c, which opens intermittently, and the injection groove 54. , second compression chambers 51a, 51b via injection holes 52m, 52b.
and lubricates the sliding surfaces along its path.

The lubricating oil supplied to the back pressure chamber 39 at a differential pressure acts on the orbiting scroll 18 with an intermediate pressure urging force together with the elastic force of the seal ring 70 to move the lap support disk 18c onto the end plate 15.
A pressure oil film is sealed on the sliding surface between the thrust bearing 20 and the suction chamber 17 to block communication between the outer peripheral space 37 and the suction chamber 17, and the gap between the sliding surface between the thrust bearing 20 and the lap support disk 18c is also lubricated and sealed. .

In addition, for a while after the cold start of the compressor, the pressure in the discharge chamber 2 is lower than the pressure in the second compression chambers 51m and 51b, as can be understood from FIGS. 9 and 10. Gas tries to flow back from the second compression chambers 51m and 51b to the back pressure chamber 39 via the injection passage 55, but the backflow to the outer space 37 is prevented by the check action of the check valve 58, and the discharge chamber oil As the pressure in the discharge chamber 2 increases, the lubricating oil in the reservoir 34 is supplied to the back pressure chamber 39 and the outer peripheral space 37 at a differential pressure.

Therefore, the back pressure urging force on the thrust bearing 20 at the initial stage of cold start is generated by the pressure in the compression chamber, and the orbiting scroll moves slightly backward, thereby expanding the axial clearance between the orbiting scroll 1 and the fixed scroll 15. A leak occurs in the compression space, lowering the compression chamber pressure and reducing the compression load at the initial stage of startup.

Thereafter, as the pressure in the discharge chamber 2 increases, the lubricating oil in the outer peripheral space 37 is metered through the injection hole 52 and 52b against the biasing force of the coil spring 59 so as to be inversely proportional to the rotational speed of the drive shaft 4. controlled second compression chamber 51m;
51b.

In addition, the discharge chamber oil reservoir 34 is connected to the annular groove 2B and the release gap 27.
The thrust bearing 20 is urged by the back pressure and comes into contact with the end face of the spacer 21, and the lap support disk 18C of the orbiting scroll 18 is connected between the thrust bearing 20 and the end plate 15b of the fixed scroll 15. A small gap is maintained between the end face of the fixed scroll wrap 15!1 and the wrap support disk 18c, as well as between the end face of the orbiting scroll wrap 18 and the mirror plate 15.
The gap between the compressor and the compressor is also kept small to reduce gas leakage from the adjacent compression space.

Injection holes 5 in second compression chambers 51 m and 51 b
2m, the opening of 52b has a pressure change 64 as shown in Figure 10.
The back pressure chamber pressure 6 changes in accordance with the pressure in the discharge chamber 2.
Although it is momentarily higher than 8, the average pressure is lower, so the back pressure chamber 39
The lubricating oil flows intermittently into the second compression chambers 51a, 51b through the injection passage 55 while being intermittently opened and closed by the sliding surface of the lap support disk 18c at the opening end of the end plate of the oil filler C38c and being supplied with oil. Back pressure chamber pressure 6 during normal operation
The compressed refrigerant gas in the second compression chamber 51 and 51b is instantaneously higher than that in the second compression chamber 51b through the narrow injection holes 52a and 52b.
There is no instantaneous backflow to the injection groove 54, and the pressure within the injection groove 54 does not become higher than the back pressure chamber pressure 68.

Note that the flow rate is adjusted so that the amount of lubricating oil flowing from the outer circumferential space 37 to the oil filler C38c per rotation of the drive shaft 4 increases when the rotation speed of the drive shaft 4 is slow, and decreases when the rotation speed of the drive shaft 4 is fast. , the amount of oil injected into the second compression chambers 51a, 51b also increases or decreases accordingly.

The lubricating oil injected into the second compression chamber 51m151b merges with the lubricating oil that has flowed into the compression chamber together with the suction refrigerant gas, and seals the gap between adjacent compression chambers with an oil film to prevent compressed gas leakage. The lubricating oil in the discharged refrigerant gas is discharged into the motor chamber 2 together with the compressed gas while lubricating the sliding surfaces of the motor chamber 6. almost separated,
During high-speed operation, some of the lubricating oil is discharged to the outside.

At this time, due to the heating effect of the lubricating oil that has flowed in due to the injection and the compressed refrigerant gas contained therein, the pressure in the compression chamber increases compared to the case without oil injection, and the required discharge pressure increases as shown by curve 62 in Figure 9. It exhibits changes during steady operation when it reaches .

In addition, when instantaneous liquid compression occurs due to oil injection or other causes during the initial cold start or stable operation, the compression chamber pressure will cause an abnormal pressure rise and overcompression as shown by the dotted line 63 in Figure 9. Since the volume of the discharge chamber 2 and the high-pressure space communicating therewith is large, the increase in pressure in the discharge chamber is extremely small.

Furthermore, due to liquid compression, the pressure in the injection groove 54 communicating with the second compression chambers 51a, 51b increases abnormally.
Due to the throttling effect of the small-diameter oil filler C38c and the non-return action of the check valve 58, the outer space 37 and the injection groove 54 are shut off, and the pressure in the back pressure chamber 39 remains unchanged, and the back pressure of the thrust bearing 20 is There is no fluctuation in the back pressure force that acts, and as a result, when the liquid is compressed, the excessive thrust force that acts on the orbiting scroll 1B causes the thrust bearing 20 to
moves back and the compression chamber pressure drops, after which normal operation continues.

As the thrust bearing 20 retreats during liquid compression, the pressure in the compression chamber drops midway as shown by the dashed line 63a in FIG.

After the compressor stops, the orbiting scroll 1
A reverse rotation torque is generated at 8, the orbiting scroll 18 rotates in the reverse direction, and the discharged refrigerant gas flows back to the suction side. Following this backflow of the discharged refrigerant gas, the check valve 50 moves from the position shown in FIG. 3 to the position shown in FIG. to stop the reverse flow of the discharged refrigerant gas, and the reverse rotation of the orbiting scroll 18 is stopped.
The space between the suction passage 42 and the discharge port 16 maintains the discharge pressure.

In addition, the passage that communicates with the compression chamber with the check valve 58 of the injection passage 55 as a border has a discharge pressure, but the space between the outer peripheral space 37 and the back pressure chamber 39 maintains an intermediate pressure for a while. However, due to a slight inflow of lubricating oil from the discharge chamber oil reservoir 34, the pressure gradually approaches the discharge pressure. When the compressor is stopped, the orbiting scroll 18 rotates in reverse, the third compression chamber 60b expands, and stops at a position where no reverse rotation torque is generated, and the oil filler C38a
The opening to the outer peripheral space 37 is the wrap support disk 18c.
is blocked by

After the compressor is stopped, the check valve 58 or the injection passage 55 is blocked by the biasing force of the coil spring 59, so that no lubricating oil flows from the outer peripheral space 37 into the compression chamber.

As described above, according to the above embodiment, the orbiting scroll 18 is connected to the main body frame 5 supporting the drive shaft 4 and the fixed scroll 1.
5, and does not communicate with either the suction chamber 17 or the discharge port 16! I, 51b and discharge port 1
6 communicates with the discharge chamber oil reservoir 34 through an oil supply passage via an injection passage 55 having a small diameter oil filler C38c and a small diameter injection hole 52-152b at both ends thereof, and forms a part of the fixed scroll 15. The number of spirals of the spiral-shaped fixed scroll wrap 15a and the spiral-shaped orbiting scroll wrap 18m forming a part of the orbiting scroll 18 is substantially the second, except for the arc portion at the beginning of the spiral.
By setting the number of turns to the minimum that can form the compression chambers 51m and 51b, the volume change rate of the compression chambers is reduced, but on the other hand, lubricating oil is supplied to the compression discharge through the oil supply passage, and the gap between the compression chambers is sealed with an oil film. The pressure curve 82a in FIG. 9 changes to the pressure curve 62 by accelerating the pressure rise in the compression chamber by heating the oil supply (including the compressed refrigerant gas mixed in the lubricating oil). As described above, the suction refrigerant gas can be pressurized to just the right discharge pressure. Therefore, the power loss due to overcompression as shown in the shaded area 1 of the pressure curve 62 in FIG. 9 is reduced, and the suction chamber and compression chamber portions are made smaller, making it possible to downsize the compressor.

Further, according to the above embodiment, the injection passage 55 in the middle of the oil supply passage is connected to the lap support disk 1 of the orbiting scroll 18.
8c and the end plate 15b of the fixed scroll 15, and is provided in the end plate 15b so that the upstream opening of the oil synjection passage 55 is connected to the orbiting movement of the orbiting scroll 18 and is opened by the lap support disk 18c. By being intermittently opened and closed, the second compression chamber 51m from the discharge chamber oil sump 34,
The amount of lubricating oil flowing into 51b is controlled so that it increases when the orbiting scroll takes a long time to make one revolution in a day, and decreases when it is short. For this reason, the second compression chamber 51m,
The amount of oil injected into 51b increases or decreases in inverse proportion to the rotation speed of the drive shaft 4, so if the compression time is long and the amount of refrigerant gas leaks during compression is large, such as when the compressor is operated at low speed, The oil film seal created by oil supply can improve the sealing between compression chambers and improve compression efficiency.

In addition, when the compression time is short and the amount of refrigerant gas leaking during compression is small, such as when the compressor is running at high speed, the amount of oil supplied is reduced to suppress heating and the amount of inflow of refrigerant gas dissolved in the lubricating oil. It prevents temperature rise and overcompression in the chamber, reducing power loss and increasing durability.

In addition, even when the compressor is operated at high speed, where the flow rate of the discharged refrigerant gas is high and oil separation efficiency deteriorates, the amount of lubricating oil mixed in the discharged refrigerant gas is small, so the amount of oil discharged to the refrigeration cycle outside the compressor is also reduced. It prevents the heat exchange performance of the heat exchanger of the cycle from deteriorating, and by securing lubricating oil inside the compressor, it is possible to improve the durability of the compressor and to achieve the effect of oil injection into the compression chamber.

Further, in the above embodiment, the injection holes 52a, 52
b opens into the second compression chamber, but the first opening leading to the suction chamber 17
It may open into the compression chamber 6l-261b.

Furthermore, in the above embodiment, the refrigerant compressor was explained, but
Similar effects can be expected with other gas compressors such as oxygen, nitrogen, and helium that use lubricating oil.

Effects of the Invention As described above, the present invention has an orbiting scroll disposed between a main body frame supporting a drive shaft and a fixed scroll,
The first compression chamber that communicates with the suction chamber or the second compression chamber that does not communicate with either the suction chamber or the discharge port and the oil sump in the discharge chamber that communicates with the discharge port (or the oil sump that communicates with the discharge chamber) are oil supply passages that have a constricted part. By making the number of turns of the fixed scroll wrap that forms part of the fixed scroll and the orbiting scroll wrap that forms part of the orbiting scroll the minimum number of turns that can substantially form the second compression chamber, the compression chamber While reducing the rate of change in the volume of the gas to reduce the gas compression ratio, lubricating oil is supplied to the compression chamber through the oil supply passage, sealing the oil film in the gap between the compression chambers, and heating the oil supply appropriately to promote pressure rise in the compression chamber. Since the intake gas can be pressurized to just the right discharge pressure, it is possible to downsize the compressor by making the compression section smaller while ensuring the discharge pressure.

In addition, in the present invention, the oil supply passage is intermittently opened and closed by the lap support disk in conjunction with the orbiting movement of the orbiting scroll, so that a sufficient size for closing the oil supply passage can be secured, so that the oil sump in the discharge chamber ( The amount of lubricating oil flowing into the compression space from the oil reservoir (or oil reservoir communicating with the discharge chamber) can be controlled so that it increases when the time for one revolution of the orbiting scroll is long, and decreases when the time for one revolution of the orbiting scroll is short. For this reason, the amount of oil injected into the compression space increases or decreases in inverse proportion to the rotational speed of the drive shaft, so if the compression time is long and the amount of gas leaking during compression increases, such as when the compressor is running at low speed, The oil film seal provided by sufficient oil supply improves the seal between the compression chambers, improving compression efficiency and ensuring discharge pressure.Also, when the compression time is short and the amount of gas leaking during compression is reduced, such as when the compressor is running at high speed. reduces power loss by reducing the amount of oil supplied, suppressing the heating caused by the lubricating oil and the inflow of lubricating oil dissolved gas, and reducing overcompression in the final compression process to prevent temperature and pressure rises in the compression chamber. and durability can be increased.

In addition, even during compressor high-speed operation, where the flow rate of discharged gas is high and oil separation efficiency deteriorates, the amount of lubricating oil mixed in with the discharged gas is small, so the amount of oil discharged to the outside of the compressor is also reduced. There is no need for recovery, and it has many excellent effects such as improving compressor durability by securing lubricating oil inside the compressor, achieving the effect of oil injection into the compression space, and reducing the installation space and cost of the compressor external piping system. This realizes a small scroll gas compressor.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a scroll refrigerant compressor according to an embodiment of the present invention, Fig. 2 is an exploded perspective view of main parts related to Fig. 1, and Fig. 3 is a cross section taken along line A-A in Fig. 1. figure,
Fig. 4 is an explanatory diagram of the position of the check valve at the suction pipe connection in Fig. 3, Fig. 5 1°C is the number of longitudinal sections taken along the line B-B in Fig. 4, and Fig. 6 is the non-return valve used in the oil supply passage. The external view of the valve, Figures 7 and 8 are diagrams explaining the movement of the compression chamber in the discharge port section, Figure 9 is a characteristic diagram showing the pressure change of refrigerant gas from the suction stroke to the discharge stroke, and Figure 10 is a diagram illustrating the movement of the compression chamber in the discharge port section. Characteristic diagram showing fixed point pressure changes in the compression chamber,
FIG. 11 is an explanatory view of the arrangement of the compression chambers in a state where the volume of the compression chambers connected to the discharge ports is at a minimum, and FIG. 12 is a vertical cross-sectional view of a conventional scroll compressor equipped with an oil supply passage. 2...Discharge chamber, 3...Motor, 4...
... Drive shaft, 5 ... Body frame, 12.
...Main bearing, 15...Fixed scroll,
15a...Fixed scroll wrap, 16...
...Discharge port, 17...Suction chamber, 18...
...Orbiting scroll, 18a...Orbiting scroll wrap, 18c...Wrap support disk, 3
4...Discharge chamber oil sump, 38a...Oil chamber C
139...Back pressure chamber, 51 m, 51 b=...
・-Second compression chamber, 52-152b... Injection hole, 54... Injection groove, 5
5...Oil injection passage, 58...
... Check valve, 59 ... Coil spring, 60
m, 60b...Third compression chamber, 6l-161b.
...First compression chamber. Name of agent: Patent attorney Toshio Nakao and 1 other person15
- One fixed scroll 61b s7-vt notch 5δ series stop valve ωaωb-3rd EjlllN

Claims (2)

[Claims] (1) Shake the spiral fixed scroll wrap formed on the wrap support disk that forms part of the orbiting scroll with respect to the spiral fixed scroll wrap formed on one surface of the end plate that forms part of the fixed scroll. The scrolls are engaged in a rotatable manner to form a spiral compression space between the two scrolls, a discharge port is provided in the center of the fixed scroll wrap, and a suction chamber is provided outside the fixed scroll wrap.
The compression space is divided into a plurality of compression chambers that continuously move from the suction side to the discharge side to form a scroll compression mechanism that compresses fluid, and the orbiting scroll is connected to a main body frame that supports a drive shaft and the fixed scroll. and a first compression chamber that communicates with the suction chamber or a second compression chamber that does not communicate with either the suction chamber or the discharge port, and an oil sump in a discharge chamber that communicates with the discharge port or that communicates with the discharge chamber. A scroll gas compressor that communicates with an oil reservoir through an oil supply passage having a constriction part, and wherein the number of turns of the fixed scroll wrap and the orbiting scroll wrap is the minimum number of turns that can substantially form the second compression chamber. (2) The scroll gas compressor according to claim 1, wherein the oil supply passage is intermittently opened and closed by a lap support disk in conjunction with the orbiting motion of the orbiting scroll.