JP2870490B2 - Scroll gas compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing oil supply passage of a scroll gas compressor and a biasing force applied to the oil supply passage to a rear surface of a scroll member.

[0002]

2. Description of the Related Art In a scroll compressor having low vibration and low noise characteristics, a suction chamber is provided at an outer peripheral portion, a discharge port is provided at a central portion of a spiral, and a flow of a compressed fluid is reciprocated in one direction. It does not require a discharge valve for compressing fluid like a compressor or rotary compressor, has a constant compression ratio, has a small discharge pulsation, and does not require a large discharge space. Chemical research is being conducted.

However, since there are many seal portions in the compression chamber, there is a lot of leakage of the compressed fluid. Particularly, in the case of a scroll gas compressor having a small displacement capacity such as a refrigerant compressor for home air conditioning,
It is necessary to increase the dimensional accuracy of the spiral part extremely in order to reduce the leakage gap of the compression part.However, the cost of the scroll gas compressor is high due to the complexity of the parts shape and the dimensional accuracy variation of the spiral part, and the performance is uneven. In particular, when the compressor is operating at a low speed, the gas leakage rate during compression is high, and the compression efficiency is lower than that of a reciprocating compressor or a rotary compressor.

Therefore, as a measure for solving this kind of problem, it is desired to optimize the spiral part dimensional accuracy and improve the compression efficiency by an oil film sealing effect using a lubricating oil to prevent gas leakage during compression. Large, JP-A-57-838
As described in Japanese Patent Laid-Open No. 6, a proposal has been made to improve the above-mentioned drawbacks by injecting an appropriate amount of lubricating oil into a compression chamber in the middle of compression, sealing the gap in the compression chamber with an oil film of the lubricating oil.

FIG. 20 shows a general structure example of a medium to large class scroll refrigerant compressor having a high-pressure space inside a closed case. In the figure, the compression unit and the discharge chamber 1031 are at the top, the motor (electric element) is at the bottom, the oil sump is at the bottom,
The discharge pipe 1042, which is the final outlet of the compressor, is arranged near the motor (electric element). After the discharge refrigerant gas and the lubricating oil are separated in the discharge chamber 1031, the lubricating oil is drained from the oil drain holes 1035, 1036. And returns to the space for storing the motor (electric element), and is collected in the oil reservoir at the bottom, and the discharged refrigerant gas passes through the space for storing the motor (electric element) from the upper part of the discharge chamber 1031 through another passage. Are discharged from the discharge pipe 1042.

Further, in order to reduce leakage of refrigerant gas during compression from the initial stage of starting the compressor in which the pressure in the high-pressure space in the closed case is low, the refrigerant gas in the compression chamber 1015 is supplied to the end plate 1004 provided on the end plate 1004 of the orbiting scroll 1006. Pressure hole 1017
And presses the orbiting scroll 1006 toward the fixed scroll 1003 from the initial stage of compressor startup by the refrigerant gas pressure to reduce the axial gap of the compression chamber 1015.

Further, in order to seal the gap between the compression chambers, lubricating oil at the bottom of a sealed case (chamber) 1013 is provided with an oil pumping hole 1 provided inside a drive shaft (crankshaft) 1008.
019, a bearing sliding surface through a clearance of a bearing of a main body frame (frame) 1009 supporting a drive shaft (crankshaft) 1008 and fixing a fixed scroll 1003, and a clearance of a crankshaft portion of the drive shaft (crankshaft) 1008. After the lubrication of the orbiting scroll 1006, the lubricating oil is caused to flow into a back pressure chamber 1025 provided on the back of the orbiting scroll 1006, and the back of the orbiting scroll 1006 is lubricated with intermediate-pressure lubricating oil depressurized in the middle of the path and high-pressure lubricating oil above the crankshaft. The back pressure is set so that the energized orbiting scroll 1006 does not always separate from the fixed scroll 1003.

The lubricating oil in the back pressure chamber 1025
After flowing into the compression chamber 1015 in the middle of compression via the compressor 7, it is compressed and discharged together with the suctioned refrigerant gas while sealing the gap of the compression chamber 1015, and discharged to the discharge chamber 1031 (Japanese Patent Application Laid-Open No. 56-165788). No.).

[0009]

However, the drive shaft (crankshaft) 1008 as shown in FIG.
The main body frame (frame) 10 supporting the drive shaft (crankshaft) 1008
09 and the upper bearing impelling part and the orbiting scroll 1006
In a configuration in which a sufficient amount of lubricating oil is supplied to the bearing sliding portion of the crank portion for turning the lubricating portion, and the lubricating oil flows into the compression chamber 1015, the location and amount of inflow into the compression chamber 1015 are large, and Since the heated lubricating oil and the refrigerant gas mixed in the lubricating oil flow into the compression chamber 1015 during compression,
There was a problem that the compression efficiency was reduced.

In the initial stage of starting the compressor, the compression chamber 1015
The pressure of the back pressure chamber 1025 into which the refrigerant gas flows from is higher than the lubricating oil pressure at the bottom of the closed case (chamber) 1013.
There was a problem that the differential pressure lubrication to the bearing portion supporting the 1008 could not be performed, resulting in seizure of the drive shaft (crankshaft) 1008 at the initial stage of starting the compressor.

When continuous liquid compression or the like occurs in the compression chamber 1015, the back pressure hole 1017 is removed from the compression chamber 1015.
The abnormal high pressure refrigerant gas flows into the back pressure chamber 1025 through the back pressure chamber, and the back pressure chamber 1025 abnormally rises in pressure from the discharge pressure,
The orbiting scroll 1006 is excessively pressed by the fixed scroll 1003, and the compression load increases rapidly. as a result,
There is a problem that the differential pressure oil cannot be supplied from the oil reservoir at the bottom to the bearing portion supporting the drive shaft (crankshaft) 1008, and the drive shaft (crankshaft) 1008 is seized.

[0012] As a measure for solving the above various problems,
When the compression chamber pressure rises abnormally, the orbiting scroll is always pressed to the fixed scroll side from the initial stage of compressor startup without excessively pressing the orbiting scroll to the fixed scroll side, thereby reducing the axial gap in the compression chamber and driving the compressor. There has been proposed a compressor capable of sufficiently supplying oil to a bearing portion of a shaft and supplying oil to a compression chamber through another oil supply passage.

FIGS. 21 and 22 show the orbiting scroll 142.
4, a back pressure region 1450 having a large back area on which the discharge pressure acts is provided, and a low pressure region 145 is provided on the outer periphery thereof.
1 and to form a back pressure region 1450, the back surface of the orbiting scroll 1424 is slidably sealed with an annular thrust seal 1449 fixed to the frame 1413 and having a large back pressure urging area.
24 is constantly pressed against the fixed scroll 1426. Also,
The lubricating oil at the bottom of the closed case is reduced in pressure through the small tube, and the outer periphery of the orbiting scroll 1424 and the fixed scroll 1426
Is lubricated with differential pressure.

Further, a high-pressure lubricating oil at the bottom of the sealed case is pumped up by a centrifugal pump action by an oil passage (not shown) provided in the drive shaft 1417, and an annular thrust seal 1449 passes through a bearing portion of the drive shaft 1417. After refueling the inside of the closed case, it is returned to the inner bottom of the closed case again (the specification of US Pat. No. 4,522,575).

However, since the orbiting scroll 1424 is constantly pressed against the fixed scroll 1426, it is necessary to secure the amount of oil supply to the contact portion in the axial direction between the two scrolls. Therefore, the amount of oil supply to the suction chamber and the compression chamber through the narrow tube is reduced. More than is required for sealing and the compression input increases.

Another problem is that the friction loss at the sliding portion in the axial direction between the two scrolls is large.

Therefore, there has been a demand for an oil supply passage which can supply an appropriate amount of oil to the compression chamber and reduce the input of friction loss between the two scrolls.

The present invention solves such a conventional problem, and provides a configuration of an oil supply passage capable of reducing friction loss between both scrolls during normal operation and reducing overload when abnormal pressure of a compression chamber rises. The purpose is to:

[0019]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method for applying a lubricating oil supplied to a bearing portion of a drive shaft to a back surface of an orbiting scroll on the side opposite to a compression chamber, by applying a lubricating oil.
The orbiting scroll is limited to be supported on both sides of the compression chamber side and the anti-compression chamber side.

The lubricating oil exerts a force on the back surface of the orbiting scroll, so that the axial contact force between the orbiting scroll and the fixed scroll is reduced, and the loss of the sliding portion can be reduced.

Further, the overload can be reduced by the orbiting scroll coming off the fixed scroll when the abnormal pressure of the compression chamber rises.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to an orbiting scroll lap supporting disk provided between a head plate of a fixed scroll and a thrust bearing provided on a main body frame for supporting a drive shaft, at least on both sliding surfaces of the lap supporting disk. A orbiting bearing sliding portion that is disposed at a minute gap where an oil film can be formed, is disposed on the anti-compression chamber side of the orbiting scroll and inside the thrust bearing, is adjacent to the lap support disk, and engages the drive shaft and the orbiting scroll. And an oil chamber partitioned and arranged adjacent to the main bearing, in a state where the discharge pressure acts on the lubricating oil in a discharge chamber oil reservoir which communicates with a discharge port and is disposed at a lower part of a motor chamber which houses a motor. In a configuration having a passage for supplying and supplying the lubricating oil in the discharge chamber oil reservoir to the main bearing and the slewing bearing portion near the compression chamber of the drive shaft and the compression space, the lubricating oil in the discharge chamber oil reservoir is supplied to the slewing bearing Oil to the department It is supplied by the screw pump action of the helical oil groove provided in the bearing sliding portion of the drive shaft and the pump action of at least one of the positive displacement pump devices driven by the drive shaft, and is supplied to the main bearing and the slewing bearing section. After supplying oil to the oil chamber for supply, most of the lubricating oil supplied to the oil chamber is compressed.
While returning to the discharge chamber oil reservoir without passing through the compression space , the remaining lubricating oil is depressurized and reduced through the thrust bearing, the locking portion of the rotation preventing member, and the sliding surface between the end plate and the lap support disk. A differential pressure oil supply passage for supplying to one of the first compression chamber and the suction chamber intermittently communicating with the suction chamber, while the lap support disk is operated at a low speed including the initial stage of compressor start-up and the pressure of the compression chamber. The back pressure is applied to the orbiting scroll by the lubricating oil supplied to the anti-compression side of the orbiting scroll so that the thrust bearing is supported by the thrust bearing when the abnormal pressure rises and is supported by the head plate at least during rated load operation. The back pressure applying force is set by the back pressure applying force by the oil chamber so as to be applied substantially by the lubricating oil pressure of the oil chamber. According to this configuration, a sufficient amount of lubricating oil is supplied to the bearing portion of the drive shaft, and the axial contact force between the orbiting scroll and the fixed scroll is small. And a quiet compression function works.

When the pressure of the compression chamber rises abnormally higher than the discharge pressure, the orbiting scroll separates from the fixed scroll in the axial direction, and is smoothly supported by a thrust bearing supplied with reduced pressure oil from the oil chamber. The pressure is reduced and the compression load is reduced.

In the initial stage of starting the compressor, the rise in the lubricating oil pressure in the discharge chamber oil reservoir is low. For this reason, the orbiting scroll reduces the compression load at the start of the compressor while being supported by the thrust bearing, thereby avoiding a sudden rise in the compression load.

[0025]

【Example】

(Embodiment 1) Hereinafter, a scroll refrigerant compressor according to a first embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a closed case made of iron.
The fixed scroll 15, the inside of which meshes with the orbiting scroll 18 to form a compression chamber, is bolted and the drive shaft 4
Is divided into an upper motor chamber 6 and a lower accumulator chamber 46 by the main body frame 5 supporting the motor.

The motor chamber 6 is in a high-pressure atmosphere. The main body frame 5 supporting the drive shaft 4 in which the motor 3 is arranged at the upper part and the compression part is arranged at the lower part, and the rotor 3a of the motor 3 is connected and fixed, has sliding characteristics and welding. It is made of eutectic graphite cast iron having excellent heat resistance, and a protrusion 79a provided on the outer peripheral surface thereof is in contact with the inner wall surface and the end surface of the upper sealed case 1a and the lower sealed case 1b. Sealed case 1a and lower sealed case 1
and b are hermetically welded by a single welding bead 79b.

The drive shaft 4 includes an upper bearing 11 provided at the upper end of the main body frame 5, a main bearing 12 provided at the center,
A orbiting scroll 18 is provided with a crankshaft 14 at a lower end portion, which is provided on an upper end surface of the main body frame 5 and is supported by a thrust bearing portion 13 having a plurality of radially shallow grooves 7 and is eccentric from the main shaft of the drive shaft 4. It is engaged with the turning bearing 18b of the turning boss 18e.

The fixed scroll 15 is made of a high silicon aluminum alloy whose coefficient of thermal expansion corresponds to an intermediate value between that of pure aluminum eutectic graphite cast iron, and has a spiral fixed scroll wrap 15a and a mirror plate 15b as shown in FIG. Consisting of
A fixed scroll wrap 15a is provided at the center of the end plate 15b.
The discharge port 16 which is open at the winding start portion is provided in communication with a discharge passage 80 which opens to the motor chamber 6, and a suction chamber 17 is provided on the outer peripheral portion of the fixed scroll wrap 15a.

On the end plate 15b on the anti-orbiting scroll side,
A check valve device 50 is attached so as to cover the discharge port 16, and the check valve device 50 is formed of a thin steel plate having a shape in which the outer peripheral portion is cut out at several places as described in detail in FIGS. 3 to 6. A valve case 99 having a valve body 50b (or a valve body 50e having a discontinuous annular hole 50ea), a check valve hole 50a, a central hole 50g, and a plurality of small discharge holes 50h around the valve hole 99a.
And a spring device 50c interposed between the valve body 50b and the valve case 99. The spring device 50c contracts when its own temperature exceeds 50 ° C., and its own temperature becomes 50 ° C.
It has a shape memory characteristic that expands below. During operation of the compressor, it receives the refrigerant gas pressure and shrinks to the bottom of the check valve hole 50a, and stops the compressor when its own temperature is 50 ° C or less. The inside is set so as to press the valve body 50 against the end plate 15b so as to close the discharge port 16.

As shown in FIGS. 1 and 14, a spiral scroll wrap 18a meshing with the fixed scroll wrap 15a to form a compression chamber side wall, and a rotary boss 18e engaged with the crankshaft 14 of the drive shaft 4. The orbiting scroll 18 made of an aluminum alloy, which is composed of a lap supporting disk 18c having the wrap supporting disk 18c upright, is disposed so as to be surrounded by the fixed scroll 15 and the main body frame 5, and the lap supporting disk 1
The surfaces of 8c and the orbiting scroll wrap 18a are subjected to a hardening treatment such as porous nickel plating. As shown in FIG. 3, a spiral tip seal groove 98 is provided at the tip of the orbiting scroll wrap 18a, and a resin tip seal 98a is mounted in the tip seal groove 98 with a small gap. I have. When the orbiting scroll 18 is pressed in the axial direction of the fixed scroll 15, the flat portion of the wrap support disk 18c contacts the tip of the fixed scroll wrap 15a, but the tip of the orbiting scroll wrap 18a does not A minute distance of about a micron is maintained.

The discharge passage 80 (see FIG. 1) is provided in the fixed scroll 15 and the discharge chamber 2 formed by the discharge cover 2a mounted on the end plate 15b so as to cover the check valve device 50 and the end plate 15b. Gas passage B80b, gas passage A80a provided in main body frame 5, main bearing 12
, A discharge guide 81 attached to the main body frame 5 so as to surround the main body frame 5, and a discharge chamber 2b formed by the main body frame 5, the gas passage A80a and the gas passage B8.
0b is provided at each target position (see FIG. 14).

On the upper surface of the discharge guide 81, as shown in FIG.
Many small holes 81a are provided.

An accumulator chamber 46 communicating with the evaporator side of the refrigeration cycle is formed by the lower sealed case 1b, the fixed scroll 15, and the main body frame 5, and a suction pipe 47 communicating therewith is provided on a side surface of the lower sealed case 1b. Two suction holes 43 are provided in the fixed scroll 15 at positions separated by about 90 degrees from the position facing the suction pipe 47 (see FIG. 14).

The low-pressure oil reservoir 46a at the bottom of the accumulator chamber 46 communicates with the suction hole 43 through an oil suction hole A9a provided in the discharge cover 2a and a small-diameter oil suction hole B9b provided in the fixed scroll 15. The oil suction holes (9a, 9b) are set so that the refrigerant liquid and the lubricating oil accumulated in the low-pressure oil reservoir 46a are sucked up by the generation of negative pressure when the refrigerant gas passes through the suction holes 43. I have.

A plate-shaped thrust bearing 20 which is restricted in movement in the rotation direction by a split pin-shaped parallel pin 19 fixed to the main body frame 5 and is movable only in the axial direction is provided.
The main body frame is disposed between the lap support disk 18c and the main body frame 5 by the elastic force of an annular seal ring (made of rubber) 70 (see FIG. 10) interposed between the thrust bearing 20 and the main body frame 5. 5 and the fixed scroll 15 are in contact with the end plate mounting surface 15b1.

The lap support disk 18 of the orbiting scroll 18
c from the sliding surface 15b2 of the end plate slidingly in contact with the end plate mounting surface 1
The height up to 5b1 is set to be approximately 0.015 to 0.020 mm larger than the thickness of the lap support disk 18c in order to improve the sealing property of the sliding portion by the oil film of the lap support disk 18c.

As shown in FIGS. 1 and 8, an annular seal groove 95 concentric with the center of the orbital bearing 18b is provided on the end face of the orbiting boss 18e of the orbiting scroll 18 on the body frame 5 side. As shown in FIG. 9, a flexible resin annular ring 9 partially cut away is shown in FIG.
4 is attached. The outer peripheral surface of the annular ring 94 is arranged so as to be in close contact with the side surface of the annular seal groove 95 due to the thermal expansion of the annular ring 94 and the lubricating oil pressure inside the annular ring 94 during operation of the compressor. The orbiting scroll 18, the main body frame 5, and the thrust bearing 20 are arranged from the side of the oil chamber A 98 a on the side of the main bearing 12 that supports the drive shaft 4.
The orbiting scroll 18 is sealed so as to prevent excessive leakage of lubricating oil into the back pressure chamber 39.

The annular thrust bearing 20 is made of a sintered alloy whose hole can be easily formed. As shown in FIGS. 10 and 11, two guide holes 93 into which the split pins 19 are movably inserted and the annular oil groove 9 are formed.
It has an oil hole 91 and is mounted in the thrust ring groove 90 of the main body frame 5.

A release gap 27 of about 0.05 mm is provided between the main body frame 5 and the thrust bearing 20, and a seal ring 7 is provided inside and outside the release gap 27.
0 is provided in the annular groove 28. The seal ring 70 seals between the release gap 27 and the back pressure chamber 39.

The release gap 27 is formed by the thrust back pressure introducing hole A89a provided in the main frame 5 and the thrust back pressure introducing hole B89b provided in the fixed scroll 15 in the third compression chamber 60b (FIG. 14) in the final compression stroke. See also).

As shown in FIGS. 1 and 2, the thrust bearing 2
The rotation preventing member (hereinafter referred to as the Oldham ring) 24 of the orbiting scroll 18 disposed inside the inner ring 0 is made of a light alloy or a reinforcing fiber composite material suitable for sinter molding, injection molding, or the like. A key portion having a parallel key shape orthogonal to each other is provided on both surfaces. The key portion on the upper surface is provided in a key groove 71a provided in the main body frame 5, and the key portion on the lower surface is provided in a lap support disk 18c. It engages with the groove 71 and slides.

The thickness of the Oldham ring 24 is set so that the Oldham ring 24 slides smoothly between the main frame 5 and the lap support disk 18c and does not cause a jumping phenomenon when the Oldham ring 24 reciprocates. I have.

A discharge pipe 31 is attached to the outer peripheral portion of the upper end wall of the upper sealed case 1a, and a glass terminal 88 for connecting a motor power supply is attached to a central portion.

An oil separator 87 attached to the upper sealed case 1a separates the side of the discharge pipe 31 and the glass terminal 88 from the side of the motor 3. The rotor 3a of the motor 3, which is positioned in the axial direction by the stepped portion of the drive shaft 4, is bolted to the drive shaft 4 together with the upper balance weight 75, and the upper balance weight 75 has a disk shape, and its outer diameter is rotating. It is set larger than the outer diameter of the child 3a.

Between the lower balance weight 76 attached to the lower end of the rotor 3a and the discharge guide 81, a shielding plate 86 attached to the main frame 5 is arranged close to the lower balance weight.

The discharge chamber oil reservoir 34 provided at 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 out a part of the outer periphery of the stator 3b of the motor 3. .

Further, the discharge chamber oil reservoir 34 is
The oil chamber A78a is located at an intermediate position between the main bearing 12 and the slewing bearing 18b via an oil hole A38a provided in the main shaft 12a.

As shown in FIGS. 1 and 8, the lubricating oil in the oil chamber A78a is provided on the surface of the sliding shaft portion 4a of the drive shaft 4 and the surface of the crankshaft 14 when the drive shaft 4 rotates forward.
The oil chamber B78b formed by the oil pump and the crankshaft 14 and the helical oil groove 41 in the direction in which the screw pump oil is supplied to the motor 3 side.
a, 41b are provided, the upper end of which is the thrust bearing 1
It has reached three.

The oil chamber B78b and the surface of the main bearing 12 correspond to the drive shaft 4
The oil reservoir 72 and the back pressure chamber 39 between the upper bearing 11 and the main bearing 12 communicate with each other through an oil supply hole 73a provided in the main body frame 5. The oil hole B has a throttle passage portion provided in the main body frame 5.
38b, and the opening end of the oil hole B38b on the back pressure chamber 39 side is a discontinuous oil groove 94 provided in the annular ring 94.
a is intermittently opened, and is provided at a position intermittently opened and closed by an annular ring 94.

As shown in FIGS. 1, 10, and 14, the back pressure chamber 39 is provided with the first compression chamber 6 intermittently communicating with the suction chamber 17.
1a and 61b are approximately 180 degrees before the suction refrigerant gas is completely confined.
The oil hole 91 provided in the thrust bearing 20 and the outer peripheral space 3 outside the lap support disk 18c within the turning angle range of degrees.
7, an oil hole C38c provided in the lap support disk 18c,
Small-diameter injection holes 52 arranged at symmetric positions
a, 52b
4 communicates with the first compression chambers 61a and 61b,
The oil hole 91 provided in the thrust bearing 20 is opened and closed intermittently by the lap support disk 18c.

As shown in FIGS. 12 and 13, a back pressure control valve device 25 for controlling the pressure of the back pressure chamber 39 is mounted on the lap support disk 18c.

The back pressure control valve device 25 is provided with the lap support disc 1
8c is a stepped cylinder 2 which is provided in the radial direction and comprises a large-diameter cylinder 26a and a small-diameter cylinder 26b.
6, a stepped plunger 29 movable in the cylinder, a cap 32 for closing a part of an opening end on the outer peripheral space 37 side of the cylinder 26, a cap 32 and the plunger 2
9 and the plunger 29 and the crankshaft 1
Coil spring 53 biasing to the side of 4 and large diameter portion cylinder 26
The oil hole 5 for communicating the suction shaft 17 with the crankshaft 14 side of FIG.
4a, an oil hole 5 for communicating the crankshaft 14 side of the small diameter portion cylinder 26b with the oil chamber B78b and the back pressure chamber 39, respectively.
4b and 54c. The operation is performed when the pressure in the back pressure chamber 39 is within an appropriate range, as shown in FIG.
When the small-diameter end face of the plunger 29 closes the cylinder-side opening end of the oil hole 54b and the pressure in the back pressure chamber 39 is insufficient, as shown in FIG. The plunger 29 moves toward the outer peripheral space 37 due to the biasing force acting on both sides of the oil hole 54.
The biasing force of the coil spring 53 and the dimensions of each part of the cylinder 26 are set so that the cylinder-side opening end of b is opened, and the oil chamber B78b and the back pressure chamber 39 communicate with each other.

Reference numeral 55 denotes an O-ring mounted on the small-diameter portion cylinder 26b for sealing the small-diameter outer peripheral portion of the plunger 29.

In FIG. 15, the horizontal axis represents the rotation angle of the drive shaft 4, the vertical axis represents the refrigerant pressure, the pressure change state of the refrigerant gas during the suction, compression and discharge processes, and the solid line 62 operates at normal pressure. The dotted line 63 shows the pressure change when the abnormal pressure rises.

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

In FIG. 1 to FIG. 16, when the drive shaft 4 is driven to rotate by the motor 3, the orbiting scroll 18 tries to rotate around the main axis of the drive shaft 4 by the crank mechanism of the drive shaft 4. The key portion (see FIG. 2) on the side of the orbiting scroll 18 is
Since the key portion 71 of the main frame 5 is engaged with the key groove 71a of the main body frame 5 (see FIG. 1), the rotation is prevented and the orbital motion is made. To perform the suction / compression action of the refrigerant gas.

Then, from the refrigerating cycle connected to the compressor, the suction refrigerant of the gas-liquid mixture containing the lubricating oil flows from the suction pipe 47 into the accumulator chamber 46, and the fixed scroll 1
After colliding with the outer surface of the end plate 15b, the air flows into the suction chamber 17 through two suction holes 43 (see FIG. 14) through the space above the accumulator chamber 46.

On the other hand, the liquid refrigerant and the lubricating oil separated from the refrigerant gas by the weight difference between the gas and the liquid and the inertia force at the time of changing the inflow direction are once collected at the bottom of the accumulator chamber 46, and the suction refrigerant gas is collected at the suction hole 43. Is sucked up into the suction hole 43 in an atomized state through the oil suction holes A9a and B9b by the negative pressure generated when passing through, and is again mixed into the suction refrigerant gas.

The suction refrigerant gas separated into gas and liquid is supplied to the suction chamber 1
7. Enclosed in the compression chamber via first compression chambers 61a, 61b (see FIG. 14) formed between the orbiting scroll 18 and the fixed scroll 15, and the second compression chambers 51a, 51
b, after sequentially transferring and compressing to the third compression chambers 60a and 60b,
The gas is discharged from the central discharge port 16 to the check valve chamber 50a, the discharge chamber 2, the gas passage B80b, the gas passage A80a,
The liquid is discharged to the motor chamber 6 via the discharge chamber 2b sequentially.

Immediately after the compression is completed, the third compression chambers 60a, 60b
When the compressed refrigerant gas flows into the check valve chamber 50a from the third compression chambers 60a and 60b, the compressed refrigerant gas undergoes rapid primary expansion, and the compression completion stroke starts immediately after the discharge completion stroke. During this time, the refrigerant gas discharged from the check valve chamber 50a temporarily flows backward to the third compression chambers 60a and 60b.

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

The pulsation of the discharged refrigerant gas is transmitted to the discharge chamber 2 having a spherical wall surface through the small discharge hole 50h of the check valve device 50.
Expansion at the time of flowing into the discharge chamber 2b, and two discharge passages 80 disposed at symmetric positions are formed in the discharge chamber 2b and the motor chamber 6
, The discharge gas pulsation from each discharge passage 80 is further attenuated sequentially by the function of attenuating each other and the third and fourth expansions, so that there is almost no pressure fluctuation in the motor chamber 6. .

When the discharged refrigerant gas instantaneously flows backward from the discharge chamber 2 to the check valve chamber 50a, the valve body 50b attempts to move in the direction of closing the discharge port 16 following the flow. During operation of the machine, the coil spring 50c having the shape memory characteristic is completely contracted due to the ambient temperature and does not exert an urging force on the valve body 50b, and the magnetic valve body 50b is attracted to the bottom surface of the check valve chamber 50a. The valve 50 b does not block the discharge port 16.

The refrigerant gas discharged from the small holes 81 a of the discharge guide 81 and discharged to the motor chamber 6 is discharged to the annular shielding plate 8.
6. After colliding with the windings of the motor 3, it flows to the upper side of the motor chamber 6 while cooling the motor 3 through the cooling passage 35 on the outside of the stator 3 b and the passage on the inside of the stator 3 b. To the refrigeration cycle.

At this time, a part of the lubricating oil in the discharged refrigerant gas adheres to the surface of the lower winding of the motor 3 and is separated from the refrigerant gas and collected in the discharge chamber oil reservoir 34. The lubricating oil in the discharged refrigerant gas passing through the outer periphery of the weight 75 and the lower balance weight 76 is centrifugally separated by the rotation of the upper balance weight 75 and the lower balance weight 76 and diffused to the inner surface of the winding of the motor 3. ,
It flows down to the lower part along the internal space of the winding bundle, and the discharge chamber oil reservoir 3
Collect at 4.

The release gap 27 on the back side of the thrust bearing 20 communicating with the compression chamber in the final compression stroke (the compression space in the stroke immediately before the compression chamber communicates with the discharge port 16) is filled with high-pressure refrigerant gas as time elapses after the start of compression. Is done. The thrust bearing 20 is pressed against the end plate mounting surface 15b1 of the fixed scroll 15 by the back pressure and the elastic force of the seal ring 70. As a result, the lap support disk 18c of the orbiting scroll 18 is sandwiched between the end plate sliding surface 15b2 and the thrust bearing 20 (an assembly gap of 15 to 20 microns).

The lubricating oil in the discharge chamber oil reservoir 34 flows into the oil chamber A 78a, the oil chamber B 78b, and the back pressure chamber 39 via a path to be described later, and the back pressure applying force to the orbiting scroll 18 gradually increases. Following the pressure increase of the motor chamber 6, the lap support disk 18c gradually comes into contact with the end plate sliding surface 15b2 of the fixed scroll 15 with an appropriate pressing force. There is no gap between the tip of the fixed scroll wrap 15a and the wrap support disk 18c of the orbiting scroll 18, whereby the compression chamber is sealed, the suction refrigerant gas is efficiently compressed, and stable operation is continued.

The axial gap between the tip of the orbiting scroll wrap 18a and the end plate 15b of the fixed scroll 15 is provided with a chip seal groove 98 (see FIG. 4) when the refrigerant gas during compression leaks to the adjacent low pressure side compression chamber. 3), and the tip seal 98a is sealed by being pressed against the low compression side surface of the tip seal groove 98a and the end plate 15b of the fixed scroll 15 by the gas back pressure.

When the compressor is stopped, the orbiting scroll 18 instantaneously reverses orbits due to the reverse flow based on the pressure difference of the refrigerant gas in the compression chamber.
7, the orbiting scroll 18 stops at the orbital angle where the first compression chambers 61a and 61b communicate with the suction chamber 17, as shown in FIG. As shown in FIG. 8, in this stopped state, the annular ring 94 blocks the lubricating oil inflow port to the back pressure chamber 39.

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

Due to the temporary reverse flow of the discharged refrigerant gas immediately after the compressor is stopped and the reverse rotation of the orbiting scroll 18, the magnetic valve body 50b is separated from the bottom surface of the check valve chamber 50a, and the refrigeration cycle is pressure-balanced. Until the pressure difference, the valve element 51b keeps closing the discharge port 16. At the same time, the temperature of the coil spring 50 having the shape memory characteristic decreases and the coil spring 50 expands.
b keeps closing the discharge port 16.

The first compression chambers 61a and 61b, which intermittently communicate with the suction chamber 17, and the back pressure chamber 39 are first compression chambers 61a and 61
1b is communicated via an oil hole 91 (see FIG. 10) provided in the thrust bearing 20 only when the angle is within 180 degrees before the closing is completed, and a lubricating oil film is formed between the thrust bearing 20 and the lap support disk 18c. So that the refrigerant gas does not flow backward from the compression chamber to the back pressure chamber 39 during compression.

When the compressor is stopped for a long time, the pressure in the compressor is balanced, and the liquid refrigerant flows into the accumulator chamber 46 as well as into the compression chamber. A thrust force in the direction opposite to the discharge port 16 acts on the orbiting scroll 18 by the pressure of the liquid compressed refrigerant in the compression chamber. As a result, the orbiting scroll 18 is separated from the fixed scroll 15 in the axial direction, and the compression load is reduced.

On the other hand, the pressure in the back pressure chamber 39 at the initial stage of the start-up when the compressor is cold is substantially equivalent to the suction pressure because the pressure rise in the discharge chamber oil reservoir 34 is low. As a result, the lap supporting disk 18c of the orbiting scroll 18 is separated from the end plate sliding surface 15b2 and is supported by retreating to the thrust bearing 20 in a state where the back pressure is applied only by the lubricating oil in the oil chamber A78a having a low pressure rise. Wrap support disk 18c and fixed scroll wrap 1
A gap is formed between the tip of 5a and the compression chamber pressure decreases,
The compression load at the beginning of startup is reduced.

In the event that liquid compression or the like occurs in the compression chamber and the pressure in the compression chamber rises successively during continuous operation, the thrust force acting on the orbiting scroll 18 is applied to the back of the orbiting scroll 18. The orbiting scroll 18 moves in the axial direction, and is supported by the thrust bearing 20. Then, the sealing of the compression chamber is released in the same manner as described above, the compression chamber pressure is reduced, and the compression load is reduced.

The back pressure chamber 39 includes a first compression chamber 61a,
An oil hole 9b provided in the thrust bearing 20 is provided within a swirl angle range of about 180 degrees before the suction refrigerant gas is completely confined.
Since it communicates with the outer peripheral space 37 via 1, liquid compression does not occur within this communication turning range.

Therefore, in any operating state of the compressor including the occurrence of the liquid compression in the compression chamber, the backflow of the refrigerant gas in the compression chamber to the back pressure chamber 39 is prevented, and the reduction of the compression load is not hindered.

The lubricating oil in the discharge chamber oil reservoir 34 at the beginning of the cold start of the compressor is supplied to the spiral oil grooves 41 a and 41 provided on the drive shaft 4.
The oil is sucked into the oil chamber A78a via the oil hole A38a by the screw pump action of b.

Thereafter, a part of the lubricating oil is
The lubricating surface of the swing bearing 18b is lubricated while passing through the oil chamber B 78b and the oil supply hole 73a sequentially, and is supplied to the sliding surface of the main bearing 12 and sent out to the oil sump 72.

The lubricating oil supplied to the main bearing 12 by the helical oil groove 41a joins with the lubricating oil passing through the oil chamber B78b in the oil sump 72, and then a part of the lubricating oil is turned into the oil hole B.
38b (see FIG. 8), the pressure in the throttle passage
9, the remaining lubricating oil lubricates the sliding surfaces of the upper bearing 11 and the thrust bearing 13 and then discharges the oil in the discharge chamber oil reservoir 34.
Will be collected again.

The refrigerant gas in the motor chamber 6 is prevented from flowing back to the oil sump 72 by the lubricating oil passing through the upper bearing 11.

The refrigerant gas pressure discharged from the motor chamber 6 rises following the passage of time after the cold start of the compressor, and the discharge chamber oil reservoir 34
The lubricating oil is also supplied to the oil chamber A7 by the pressure difference between the oil and the back pressure chamber 39.
8a, the oil is supplied to the back pressure chamber 39 together with the screw pump action of the spiral oil grooves 41a, 41b. The pressure in the back pressure chamber 39 gradually increases, and a combined force with the lubricating oil pressure corresponding to the discharge pressure of the oil chamber A 78a acts on the lap support disk 18c of the orbiting scroll 18. As a result, the orbiting scroll 18 is fixed to the fixed scroll 15 by the refrigerant gas pressure in the compression chamber.
The thrust load acting to move away from is offset,
The thrust force acting on the orbiting scroll 18 is reduced.

Therefore, while the pressure rise in the motor chamber 6 after the cold start of the compressor is low, the force exerted on the orbiting scroll 18 by the lubricating oil pressure in the oil chamber A 78a and the back pressure chamber 39 increases the refrigerant gas pressure in the compression chamber. Is smaller than the thrust load on the orbiting scroll 18 due to this. As a result, the orbiting scroll 18 separates from the fixed scroll 15, and is supported by the thrust bearing 20 which receives the elastic force of the seal ring 70 and the back pressure by the refrigerant gas introduced from the compression chamber in the final compression stroke.

When the differential pressure between the discharge pressure and the suction pressure exceeds the required pressure, the force applied to the orbiting scroll 18 by the lubricating oil pressure in the oil chamber A 78a and the back pressure chamber 39 causes the orbiting by the refrigerant gas pressure in the compression chamber. It becomes larger than the thrust load on the scroll 18. The orbiting scroll 18 is supported by the fixed scroll 15.

In an arrangement in which the center of the compression chamber, the center of the orbiting bearing 18e, and the center of the annular ring 94 are substantially coincident with each other, the annular ring 94 orbits together with the orbiting scroll 18, so that the inertial force at that time causes the orbital boss portion. 18
Attempts to jump out of the annular seal groove 95 provided in e. Further, the annular ring 94 includes the oil chamber A 78 a and the back pressure chamber 3.
The inner diameter is expanded by the pressure difference with the pressure 9, and the cut is closed together with the thermal expansion. By these actions, the annular ring 94 is pressed against the outer surface of the main body frame 5 and the annular seal groove 95, and lubricating oil is generated between the annular seal groove 95 and the annular ring 94 by the oil scraping action of the annular ring 94. And prevents excessive leakage from the oil chamber A 78a to the back pressure chamber 39.

Further, the resin-made annular ring 94 having excellent flexibility expands its inner diameter along the outer surface of the annular seal groove 95 due to a pressure difference between the back pressure chamber 39 and the oil chamber A 78 a, thereby reducing heat. The incision is closed together with the expansion, and the cut is pressed against the outer surface of the annular seal groove 95, so that direct leakage between the two spaces is further reduced.

The annular ring 94 is formed by an oil film of the lubricating oil accumulated in the oil groove 94a provided on the surface of the annular groove 94.
The sliding surface between the main body frame 5 and the main body frame 5 is lubricated to reduce wear and sliding resistance of the sliding surface.

During the normal operation of the compressor, the high-pressure oil chamber A 78a
The orbiting scroll 18 is provided with a back pressure on the fixed scroll 15 side by the lubricating oil pressure of the back pressure chamber 39 and the lubricating oil pressure of the back pressure chamber 39, and a suitable contact force is maintained between the lap support disk 18c and the end plate sliding surface 15b2. While sliding smoothly to minimize the axial clearance of the compression chamber.

The lubricating oil which has flowed into the back pressure chamber 39 intermittently flows into the outer peripheral space 37 via an oil hole 91 provided in the thrust bearing 20, and further flows into an oil hole C38c provided in the lap support disk 18c. , A small-diameter injection hole 52a,
The pressure is gradually reduced through 52b (see FIG. 14) and flows into the first compression chambers 61a and 61b. The lubricating oil lubricates each sliding surface in the middle of the passage and seals the sliding gap.

The lubricating oil injected into the first compression chambers 61a and 61b joins with the lubricating oil flowing into the compression chamber (compression space) together with the suctioned refrigerant gas, and seals a minute gap between adjacent compression chambers with an oil film. The compressed refrigerant gas is discharged again to the motor chamber 6 through the discharge port 16 together with the compressed refrigerant gas while preventing the leakage of the compressed refrigerant gas and lubricating the sliding surfaces between the compression chambers.

In the oil supply path from the discharge chamber oil reservoir 34 via the back pressure chamber 39 to the first compression chambers 61a and 61b, the back pressure chamber 39 maintains an appropriate intermediate pressure between the discharge pressure and the suction pressure. .

Further, since the compression ratio of the scroll refrigerant compressor is constant, when the differential pressure between the suction chamber 17 and the discharge chamber 2 is small, such as immediately after a cold start, or abnormal liquid compression occurs. In such a case, as described above, the orbiting scroll 1
8 separates from the fixed scroll 15 and the thrust bearing 20
Supported by

However, the thrust bearing 20 urged by the back pressure cannot support the abnormally increased compression chamber pressure load.
The retracted scroll 27 is retracted in a direction to decrease the release gap 27, and the lap support disk 18c of the orbiting scroll 18 and the fixed scroll 1
The gap in the axial direction between the fixed scroll wrap 15a and the tip of the fixed scroll wrap 15a increases. As a result, a large amount of leakage occurs between the compression chambers, and the pressure in the compression chamber suddenly drops during the compression as shown by the dashed line 63a in FIG.

The orbiting scroll 18 is fixed scroll 15
Is restricted to about 70 microns in the axial direction, so that the pressure change in the back pressure chamber 39 due to the direct communication between the outer peripheral space 37 and the suction chamber 17 is suppressed,
After the compression load is instantaneously reduced, the thrust bearing 20 can instantly return to the original position, and the stable operation resumes.

When the orbiting scroll 18 retreats toward the thrust bearing 20, the axial dimension between the tip of the orbiting scroll wrap 18a and the fixed scroll 15 also increases. Compressed refrigerant gas leakage hardly occurs from this portion because the compressed refrigerant gas is pressed to the fixed scroll 15 side.

On the other hand, the gap between the wrap support disk 18c of the orbiting scroll 18 and the tip of the fixed scroll wrap 15b of the fixed scroll 15 increases, and compressed refrigerant gas leaks in the compression chamber, causing a sudden increase in the pressure in the compression chamber. descend.

Also, when foreign matter is caught in the axial gap between the orbiting scroll 18 and the fixed scroll 15, the thrust bearing 20 retreats and removes the foreign matter as described above.

In the initial stage of cold start or during steady-state operation, the pressure in the compression chamber when instantaneous liquid compression occurs is abnormally over-compressed as shown by a dotted line 63 in FIG.
The high pressure space volume communicating with the
0a, the discharge chamber 2 and the discharge chamber 2b are sequentially expanded while passing through the discharge chamber 2b, and the pressure in the motor chamber 6 hardly changes.

Further, as the operating speed of the compressor increases, the leakage of refrigerant gas in the compression chamber per unit time decreases. On the other hand, the injection holes 52a, 52 per one turning motion
b, the amount of oil injection into the compression chamber per one turning motion is suppressed, unnecessary oil compression is reduced, and the passage between the oil hole B38b and the back pressure chamber 39 is increased by the number of shutoffs. The resistance is increased, the amount of lubricating oil flowing into the back pressure chamber 39 from the oil chamber A 78a is suppressed, and the pressure in the back pressure chamber 39 is appropriately maintained.

Further, when the scroll refrigerant compressor incorporated in the heat pump refrigeration cycle and operating is switched from the heating operation to the defrosting operation, for a short time, the high pressure side becomes the evaporator and the low pressure side becomes the condenser side. Due to the connection, the pressure in the motor chamber 6 decreases instantaneously. Oil hole B following it
38b, the oil sump 72, and the oil chamber A78a sequentially reduce the pressure of the back pressure chamber 39 and the pressure of the outer peripheral space 37, which communicate with the motor chamber 6, while temporarily reducing the pressure of the suction chamber 17 and the compression chamber. If the back pressure rises and the proper back pressure cannot be maintained, the plunger 29 of the back pressure control valve device 25 provided on the lap support disk 18c as shown in FIG.
1 against the back pressure of the lubricating oil communicating with the coil spring 53 and the back pressure chamber 39 by the lubricating oil pressure of the oil hole 54b communicating with the oil hole 54b.
3 and move toward the outer peripheral space 37, and the oil chamber B78b
The high-pressure lubricating oil flows into the back pressure chamber 39, and the back pressure chamber 39 is returned to an appropriate pressure.
The plunger 29 is moved to the oil chamber B78b side as described above, and the oil chamber B78b and the back pressure chamber 39 are shut off.

When the heat load on the evaporator side is high and the condensation capacity on the condenser side is high, the operation is performed with the suction pressure relatively high and the discharge pressure relatively low.

In such a case, since the pressure in the compression chamber is higher than that in the normal operation, it is necessary to make the pressure in the back pressure chamber higher than usual. The lubricating oil pressure in the oil hole 54b communicating with the oil chamber B78b and the refrigerant pressure on the suction side communicating with the suction chamber 17 through the oil hole 54a resist the back pressure of the lubricating oil communicating with the coil spring 53 and the back pressure chamber 39. 13, the oil chamber B78b and the back pressure chamber 39 intermittently (or partially) communicate with each other, and the high-pressure lubricating oil flows into the back pressure chamber 3 as shown in FIG.
9 to maintain the back pressure chamber 39 at an appropriate pressure.

Naturally, the plunger 29 is
Under the influence of the inertial force and the frictional force acting on the plunger 29, the communication area between the small-diameter portion cylinder 26b and the oil hole 54c is increased in an attempt to move toward the outer peripheral space 37. The pressure increases as the compressor operating speed increases.

In the above embodiment, the compressed refrigerant gas during the final compression stroke is introduced into the release gap 27 provided on the back surface of the thrust bearing 20, but the discharge in the region where the compression chamber and the discharge port 16 communicate with each other in the final compression stroke. Refrigerant gas may be introduced into the release gap 27.

In the above embodiment, the orbiting scroll 18
The sliding gap between the lap support disk 18c and the thrust bearing 20 was sealed only with an oil film of lubricating oil, but as disclosed in Japanese Patent Application No. 63-159996 by the inventor,
An annular ring (82) may be attached to the back side of the lap support disk 18c to improve the sealing performance of the sliding portion gap between the back pressure chamber 39 and the outer peripheral space 37.

In FIG. 8, the oil hole B38b and the back pressure chamber 3
9 are intermittently communicated with each other, the number of sections per one turning motion is set large. However, in the case of a compressor operating condition where the compression load is relatively small, the oil hole B38b and the back pressure chamber 39 per one turning motion are set. The opening position of the oil hole B38b is moved toward the center of the main body frame 5 so that the communication section is reduced, and the oil chamber A7 is closed.
It will be apparent from the description of the prior art that it is necessary to reduce the amount of the lubricating oil 8a flowing into the back pressure chamber 39 and the compression chamber. Accordingly, the pressure in the back pressure chamber 39 and the outer space 37 also decreases.

As described above, according to the above-described embodiment, during the period from the start of the compressor to the steady operation, and when the pressure in the compression chamber rises abnormally due to liquid compression or the like.
When the lap support disk 18c of the orbiting scroll 18 separates from the end plate 15b of the fixed scroll 15, the thrust bearing 20
The high-pressure lubricating oil supplied to the oil chamber A 78a on the anti-compression side of the orbiting scroll and the reduced pressure are supplied to the back pressure chamber 39 so as to be supported by the end plate 15b when the rated load is applied as in the steady operation. The back pressure applying force to the orbiting scroll 18 by the lubricating oil can be set.

Even if the load specification of the compressor is small, only the amount of oil supplied to the back pressure chamber 39 is reduced without changing the arrangement of the oil chamber A 78a in accordance with the specification, and the back pressure applying force is reduced. With a small size, the orbiting scroll 18 can be operated as described above.

That is, the setting of the back pressure applying force to the orbiting scroll 19 can be easily adjusted according to the compressor load specification.

Thus, excessive axial contact between the orbiting scroll 18 and the fixed scroll 15 and between the orbiting scroll 18 and the thrust bearing 20 can be avoided.
It is possible to prevent overcompression, reduce the compression input, and improve the durability of the sliding portion.

(Embodiment 2) FIG. 16 is a longitudinal sectional view of a scroll refrigerant compressor according to a second embodiment of the present invention. In addition to the screw pump function shown in FIG. 1 shows a configuration of a bearing lubrication that can be provided, and in particular, can maintain extremely low speed operation of a compressor.

That is, as shown in FIG. 16, the stepped inner wall of the high-pressure oil chamber A378a which communicates with the discharge chamber oil reservoir 34 through the oil hole A338a provided in the main body frame 305, as shown in FIG. 101 is press-fitted,
The oil chamber A 378a is disposed so as to cover the flange portion 102 of the drive shaft 304, and partitions the oil chamber A 378a into a main bearing 312 side and a swing bearing 318b side.

The orbiting boss 318 of the orbiting scroll 318
A swing bearing 318b is press-fitted in e, and a trochoid pump device 106 including an outer rotor 106a and an inner rotor 106b is mounted on the bottom thereof.

The trochoid pump device 106 is
4 is connected to and driven by a drive end shaft 107 provided at the end of the crankshaft 314 at the end of the fourth end. The crankshaft 314 and the drive end shaft 107 are concentric.

As shown in FIG. 18, a suction hole 108 is provided between the slewing bearing 318b and the trochoid pump device 106.
And a partition plate 110 having a central hole 109 is fixedly mounted.

Wrap support disk 3 of orbiting scroll 318
The oil groove 111 provided at the central portion of 18c serves as a discharge port of the trochoid pump device 106.
The sliding surface of the main bearing 312 is in communication with an axial oil hole 112 and a radial oil hole 113 provided in the drive shaft 304.

The discharge chamber oil reservoir 34 and the back pressure chamber 339 of the orbiting scroll 318 are connected to an oil hole A338a, an oil chamber A378a,
Oil supply passage A communicating with the oil sump 72 via the spiral oil groove 341b, the suction hole 108, the trochoid pump device 106, the oil groove 111, the axial oil hole 112, the radial oil hole 113, and the bearing gap of the main bearing 312. And an oil supply passage C composed of an oil supply passage B which communicates with the oil sump 72 from the oil chamber A 378a via the spiral oil groove 341a, and an oil hole B38b.

The other configuration is the same as that of FIG. 1, and the description is omitted. According to this embodiment, the oil hole A 338a and the oil chamber A 378 are operated from the extremely low speed operation at the initial stage of the compressor startup.
The lubricating oil in the discharge chamber oil reservoir 34 can be sucked in by the trochoid pump device 106 through a, and can be supplied to the sliding surface between the crankshaft 314 and the main bearing 312 in a required amount.

Accordingly, even when the pressure rise in the motor chamber 6 is small, the orbiting scroll 318 can be mounted on the thrust bearing 3.
20 and the back pressure chamber 339 and the thrust bearing 3
20 to improve the lubrication of the sliding part and the compression efficiency
The differential pressure oil supply to the compression chamber 61a can be performed. As a result, extremely low speed operation for energy saving operation can be maintained.

(Embodiment 3) FIG. 19 is a longitudinal sectional view of a scroll refrigerant compressor according to a third embodiment of the present invention. Inside of a sealed case 801 made of soft iron is similar to that of FIG. 7
The upper sealed case 801a is divided into an upper sealed case 801a side and a lower sealed case 801b side by a main body frame 805 that supports the first sealed case 801b.
Constitutes an accumulator chamber 846 with a low-pressure space communicating with the downstream side of the evaporator.

The drive shaft 704 connecting the motor 703 is
Main bearing 812 of main body frame 805 and upper frame 12
6 and supported.

The discharge chamber 2 is connected to a high pressure side via a gas passage B 880b provided in the fixed scroll 815, a gas passage A 880a provided in the main frame 805, and a discharge chamber 2c formed by the main frame 805 and the discharge guide 81. Of the motor room 806.

The discharge pipe 831 provided at the upper end of the upper sealed case 801a communicates with the motor chamber 806 via a gas hole 129 provided in the upper frame 126.

A plurality of coil springs 131 are arranged at equal intervals on the back side of the thrust bearing 220 on the opposite side of the compression chamber, and the end faces of the coil springs 131 are held down by a discharge guide 881 attached to the main body frame 805, so that the thrust is reduced. The bearing 220 is fixed to the end plate 815 of the fixed scroll 815.
b.

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

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

The outer peripheral space 37 of the orbiting scroll 818
Communicates intermittently with the back pressure chamber 839 via the shallow groove 891 provided in the thrust bearing 220, and does not communicate with the first compression chambers 61a and 61b which intermittently communicate with the suction chamber 17,
The fixed scroll 815 communicates with the suction chamber 17 via an oil groove 899 provided on the sliding surface of the end plate 815b.

Further, according to this embodiment, the oil chamber A87
The back pressure chamber 839 maintains a pressure close to the pressure of the suction chamber 17 even when the amount of lubricating oil flowing into the back pressure chamber 839 from 8a fluctuates to some extent.

Therefore, the back pressure applying force to the orbiting scroll 818 acting on the fixed scroll 815 side is equal to only depending on the lubricating oil pressure in the oil chamber A 878a.

According to this back pressure application mode, the wrap support disk 818c of the orbiting scroll 818 during the period from the start of the compressor to the steady operation, and when the pressure in the compression chamber rises abnormally due to liquid compression or the like. Moves away from the end plate 815b of the fixed scroll 815 and the thrust bearing 22
0, and the back pressure applied to the orbiting scroll 818 by the high-pressure lubricating oil supplied to the oil chamber A 878a on the anti-compression side of the orbiting scroll so as to be supported by the end plate 815b when the rated load is applied as in the steady operation. Power can be set.

Thus, between the orbiting scroll 818 and the fixed scroll 815, and between the orbiting scroll 81
Excessive axial contact between the thrust bearing 8 and the thrust bearing 220 can be avoided to prevent excessive compression, reduce compression input, and improve the durability of the sliding portion and the smooth startability.

It should be noted that the positive displacement pump device shown in FIG. 16 can be added to the end of the drive shaft 704 to maintain the extremely low speed operation.

In the above embodiment, the main bearing 12 and the slewing bearing 18b are arranged adjacent to each other in the main shaft direction of the drive shaft 4. However, Japanese Patent Application Laid-Open Nos. 58-79684 and 63-20
As described in Japanese Patent No. 5490, even in the case of a configuration in which the slewing bearing is disposed inside the main bearing, the same operation and effect as described above can be expected.

In the above-described embodiment, the operation and effects of the vertical compressor are described. The upstream side of the oil hole A (38a and others) in FIG.
The same operation and effect can be expected in the case of a configuration of a horizontal compressor having the bottom side of the compressor. In the case of the configuration of the horizontal compressor, an oil hole for guiding the lubricating oil in the discharge chamber oil reservoir 34 to the oil chamber (378a) in FIG.
As in the case of No. 1, it is possible to easily provide it in the drive shaft 304, and it is clear that the same operation and effect as described above can be expected.

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

[0137]

As is apparent from the above embodiment, the present invention is directed to a wrap supporting disk for an orbiting scroll between a head plate for a fixed scroll and a thrust bearing provided on a main frame having a main bearing for supporting a drive shaft. A small gap capable of forming at least an oil film on both sliding surfaces of the lap support disk, disposed on the anti-compression chamber side of the orbiting scroll and inside the thrust bearing, adjacent to the lap support disk and the drive shaft A discharge chamber disposed in a lower part of a motor chamber that communicates with a discharge port and is disposed in an oil chamber that is partitioned and disposed adjacent to a orbiting bearing sliding portion and a main bearing portion in which the orbiting scroll is engaged. In a configuration having a passage for supplying the lubricating oil in the oil reservoir with the discharge pressure acting thereon and supplying the lubricating oil in the discharge chamber oil reservoir to the main bearing, the swivel bearing, and the compression space, Is a whirl A screw pump effect of the spiral oil groove provided in the bearing sliding portion of the drive shaft to the oil chamber communicating with the bearing section,
Most of the lubricating oil supplied to the oil chamber is supplied by the pump action of at least one of the positive displacement pump devices driven by the drive shaft and supplied to the main bearing and the slewing bearing, and then supplied to the oil chamber. While returning to the discharge chamber oil reservoir without passing through the compression space , the remaining lubricating oil is depressurized and
The differential pressure supplied to one of the first compression chamber and the suction chamber intermittently communicating with the suction chamber via the locking portion of the rotation preventing member of the orbiting scroll and the sliding surface between the end plate and the lap support disk. A refueling passage is provided, and the orbiting scroll is supported by the thrust bearing when the lap support disk is operated at low speed including the initial stage of compressor operation and when the pressure in the compression chamber rises abnormally, and is supported by the end plate at least during rated load operation. The back pressure applying force to the orbiting scroll by the lubricating oil supplied to the anti-compression side of the oil chamber is set, and the back pressure applying force is substantially applied mainly by the lubricating oil pressure of the oil chamber. According to this configuration, the increase in the lubricating oil pressure in the oil chamber of the discharge chamber is small at the initial stage of starting the compressor, so that the back pressure applying force to the orbiting scroll by the lubricating oil in the oil chamber is small. For this purpose, the orbiting scroll is supported by thrust bearings in a state where the thrust force has been offset, and the lubrication of the sliding part at the early stage due to pump oil supply and the sudden increase in pressure in the compression chamber are avoided to reduce the input and achieve smooth compression. The compressor can be operated at a low speed for start-up and energy saving.

In addition, even when abnormal over-compression occurs, there is no change in the back pressure applying force to the orbiting scroll due to the lubricating oil pressure in the oil chamber, so that the orbiting scroll can be easily separated from the fixed scroll. The reliability of the overload reduction function can be improved.

Further, during a steady load operation including a rated load operation, the orbiting scroll is brought into contact with the fixed scroll side with an appropriate force, so that the compression input can be reduced and the compression efficiency can be improved by sealing the compression chamber gap.

In particular, since the lubricating oil pressure in the oil chamber can act as the main back pressure applying force to the orbiting scroll, the back pressure applying force can be stabilized without being affected by the pressure reduction in the throttle passage in the differential pressure oil supply passage. Can be done. As a result, it is possible to set the sliding portion friction loss reduction and the sealing / releasing action of the compression chamber gap corresponding to the continuous compression load without being affected by the instantaneous compression chamber pressure fluctuation. This has the effect that performance and high quality can be ensured and stabilized.

[Brief description of the drawings]

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

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

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

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

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

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

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

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

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

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

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

FIG. 12 is a sectional view for explaining the operation of the back pressure control valve device in the compressor.

FIG. 13 is a sectional view for explaining the operation.

FIG. 14 is a cross-sectional view taken along line AA in FIG. 1;

FIG. 15 is a characteristic diagram showing a change in pressure of refrigerant gas from a suction stroke to a discharge stroke of the compressor.

FIG. 16 is a longitudinal sectional view of a scroll refrigerant compressor showing another embodiment of the present invention.

FIG. 17 is a partial cross-sectional view of a main bearing portion of the compressor.

FIG. 18 is a perspective view of a partition plate used in the trochoid pump device in FIG.

FIG. 19 is a longitudinal sectional view of a scroll refrigerant compressor showing still another embodiment of the present invention.

FIG. 20 is a longitudinal sectional view of a conventional scroll compressor.

FIG. 21 is a longitudinal sectional view of another conventional scroll compressor.

FIG. 22 is a transverse sectional view taken along line 3-3 in FIG. 21;

[Explanation of symbols]

 Reference Signs List 4 drive shaft 5 main body frame 12 main bearing 15 fixed scroll 16 discharge port 17 suction chamber 18 turning scroll 18c lap support disk 15b end plate 18 turning bearing 20 thrust bearing 24 rotation preventing member 34 discharge chamber oil sump 41a spiral oil groove 41b spiral Oil groove 61a First compression chamber 78a Oil chamber A 78b Oil chamber B 106 Trochoid pump device 220 Thrust bearing 304 Drive shaft 305 Body frame 312 Main bearing 318 Orbiting scroll 320 Thrust bearing 378a Oil chamber A 704 Drive shaft 805 Body frame 812 Main bearing 815 Fixed scroll 818 Orbiting scroll 815b End plate 878a Oil chamber A 878b Oil chamber B

Claims (1)

(57) [Claims] An orbiting scroll wrap on a wrap support disk forming a part of a orbiting scroll is rotatably engaged with a spiral fixed scroll wrap formed on one surface of a head plate forming a part of a fixed scroll. To form a spiral compression space between the two scrolls,
A discharge port is provided at the center of the wrap, a suction chamber is provided outside the fixed scroll wrap, and the compression space is divided into a plurality of compression chambers that continuously transition from the suction side to the discharge side to flow fluid. A scroll compression mechanism for rotating the orbiting scroll by engaging the rotation preventing member of the orbiting scroll between the orbiting scroll and a main body frame having a main bearing for supporting a drive shaft at a center portion for compression. The scroll compression mechanism and a motor connected to the drive shaft are housed in a sealed case, and the lap support disk is provided between the end plate and a thrust bearing provided on the main body frame. In a configuration in which at least a minute gap capable of forming an oil film is arranged on the moving surface, the arrangement is arranged on the anti-compression chamber side of the orbiting scroll and inside the thrust bearing. The wrap adjacent the supporting disk and the oil chamber partitioned disposed through adjacent to the main bearing and the orbiting bearing sliding portion where the drive shaft and said orbiting scroll are engaged,
Lubricating oil in a discharge chamber oil reservoir, which communicates with the discharge port and is provided at a lower portion of a motor chamber that houses the motor, is supplied in a state where discharge pressure acts thereon, and lubricating oil in the discharge chamber oil reservoir is supplied to the main bearing. The lubricating oil of the discharge chamber oil reservoir is provided in a bearing sliding portion of the drive shaft in the oil chamber communicating with the swivel bearing. The oil pump is supplied by the screw pump action of the spiral oil groove and at least one pump action of the positive displacement pump device driven by the drive shaft, and is supplied to the oil chamber to be supplied to the main bearing and the swivel bearing portion. After the supply, most of the lubricating oil supplied to the oil chamber is returned to the discharge chamber oil sump, while the remaining lubricating oil is depressurized to reduce the amount of the lubricating oil, the thrust bearing, the locking portion of the rotation preventing member, End plate and wrap support A differential pressure oil supply passage is provided for supplying one of the first compression chamber and the suction chamber intermittently communicating with the suction chamber via a sliding surface with the disk. The lubrication supplied to the anti-compression side of the orbiting scroll to be supported by the thrust bearing at the time of low-speed operation including when the pressure of the compression chamber abnormally rises and to be supported by the head plate at least at the time of rated load operation. A scroll that sets a back pressure applying force by the oil chamber so that the back pressure applying force is applied to the orbiting scroll by oil and the back pressure applying force is substantially applied by the lubricating oil pressure of the oil chamber. Gas compressor.