JP2790126B2 - 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 pressure control of a back pressure chamber of an orbiting scroll of a scroll gas compressor.

[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. A discharge valve for compressing fluid such as a compressor or a rotary compressor is not required, and when there is no large fluctuation in the operation compression ratio determined by the suction pressure and the discharge pressure, the discharge pulsation is small and a large discharge space is provided. Since it is not required, research on practical application of utilization development in various fields has been 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 such as a refrigerant compressor for home air conditioning,
In order to reduce the leakage gap of the compression part, it is necessary to make the dimensional accuracy of the spiral part extremely high. However, due to the complexity of the part shape, the cost of the scroll gas compressor is high and the performance varies greatly due to variations in the dimensional accuracy of the spiral part, etc., especially when the compressor is operating at low speed, the gas leakage rate during compression is low. In many cases, the compression efficiency is lower than that of a reciprocating compressor or a rotary compressor.

Therefore, as measures for solving this kind of problem, it is expected to optimize the dimensional accuracy of the spiral part in order to prevent gas leakage during compression and to improve the compression efficiency by an oil film sealing effect using lubricating oil. And JP-A-57-83
As described in Japanese Patent Publication No. 86, a proposal has been made to improve the above-mentioned disadvantages by injecting a proper amount of lubricating oil into a compression chamber in the middle of compression, sealing a gap in the compression chamber with an oil film of lubricating oil.

In particular, scroll refrigerant compressors have been put into practical use in the field of refrigeration and air conditioning, and various types of medium to large class compressors having a relatively large refrigerant volume per suction stroke, such as package air conditioners and chiller units, have been developed. Improvements have been made and mass production has already been realized.

FIG. 16 shows an example of a general structure of a medium to large class scroll refrigerant compressor having a high-pressure space inside a closed case (chamber). In the figure, the compression unit and the discharge chamber 1031 are at the top, the motor (electric element) is at the bottom,
An oil sump is provided at the bottom at the discharge pipe 104 which is the final outlet of the compressor.
2 is disposed in the vicinity of the motor (electric element), and after the discharge refrigerant gas and the lubricating oil are separated in the discharge chamber 1031, the lubricating oil is stored in the motor (electric element) through oil drain holes 1035 and 1036. Returning to the space, the refrigerant gas is collected in the oil reservoir at the bottom, and the discharged refrigerant gas is discharged from the discharge pipe 1042 again after passing through the space accommodating the motor (electric element) from the upper part of the discharge chamber 1031 through another passage. You. In addition, in order to reduce the axial gap of the compression chamber, lubricating oil on which the discharge pressure acts on the bottom of the closed case (chamber) 1013 is provided inside a drive shaft (crankshaft) 1008 with an oil-lifting hole 1019 and a drive shaft ( Crankshaft) 1
After lubricating the bearing sliding surface through the clearance of the bearing of the body frame (frame) 1009 supporting the 008 and fixing the fixed scroll 1003, and the clearance of the crankshaft of the drive shaft (crankshaft) 1008, the orbiting scroll 1
The lubricating oil of the intermediate pressure reduced in the middle of the path flows into the back pressure chamber 1025 provided on the back of the orifice 006, and the lubricating oil of the intermediate pressure is mixed with the high-pressure lubricating oil on the upper part of the crankshaft to make the back of the orbiting scroll 1006 It is urged toward the fixed scroll 1003. Thereby, the back pressure biasing force is set so as not to separate the orbiting scroll 1006 from the fixed scroll against the compression chamber gas pressure.

The lubricating oil in the back pressure chamber 1025 is supplied to a back pressure hole 1017 provided in the end plate 1004 of the orbiting scroll 1006.
Then, after flowing into the compression chamber 1015 in the middle of compression, the compressed gas is compressed / discharged together with the suction refrigerant gas while sealing the gap of the compression chamber 1015 with an oil film, and then discharged to the discharge chamber 1031. (JP-A-56-165788).

[0008]

However, when the pressure in the back pressure chamber 1025 is not appropriate, various problems described below are caused.

That is, when the differential pressure between the suction pressure and the pressure in the discharge chamber 1031 is small, as in the early stage of the compressor startup, the compression chamber 1 is being compressed more than the oil reservoir to which the discharge pressure acts.
In some cases, differential pressure lubrication cannot be performed because the pressure of 015 is higher. Further, even if there is a slight differential pressure, it is difficult for a highly viscous lubricating oil to pass through the minute gap of the bearing sliding portion, so that the sliding portion engaging with the crankshaft 1008 causes seizure. there were.

In the initial stage of starting the compressor, the drive shaft (crankshaft) 100 is supplied from the oil reservoir at the bottom as described above.
Not only cannot the differential pressure lubrication to the bearing part supporting the bearing 8 be performed, but also the compressed refrigerant gas in the compression chamber 1015 during compression passes through the back pressure chamber 1025 to the drive shaft (crankshaft) 100.
8, the lubricating oil flowing through the minute bearing gap of the drive shaft (crankshaft) 1008 flows out. As a result, there is a problem that the seizure of the drive shaft (crankshaft) 1008 is promoted in the early stage of the compressor startup.

Also, when the liquid refrigerant is compressed in the compression chamber 1015 and abnormal pressure rises, the orbiting scroll 100
The high-pressure refrigerant gas flows backward from the compression chamber 1015 to the back pressure chamber 1025 through the back pressure hole 1017 provided in the end plate 1004 of No. 6 to promote seizure of the crankshaft 1008 in the same manner as described above.

Further, there has been a problem that the orbiting scroll 1006 is excessively pressed toward the fixed scroll 1003 and the compressor input is abnormally increased.

On the contrary, when the final pressure of the compression chamber is higher than the discharge chamber pressure, the compression chamber refrigerant gas force becomes larger than the back pressure urging force to the orbiting scroll 1006, and the orbiting scroll 1006 separates from the fixed scroll 1003. As a result, a significant leakage of the compressed refrigerant gas occurs, and the compression efficiency is significantly reduced.

On the other hand, as a measure for improving the above problem, FIG.
As shown in FIGS. 7 to 19, the pressure in the back pressure chamber of the orbiting scroll is set such that the oil reservoir on which the discharge pressure acts is on the upstream side, the lubricating oil in the oil reservoir is introduced under reduced pressure, and the compression chamber during compression is on the downstream side. There have been proposed two means for adjusting the pressure (Japanese Unexamined Patent Publication No.
2-178789).

That is, the first means is that the discharge chamber 22
01a and orbiting scroll (orbiting scroll member) 220
6 (the passages 2233 and 2233).
A back pressure control valve 2230 for opening and closing 232, 2234b) is disposed on the end plate 2205a of the fixed scroll 2205, and the back pressure control valve 2230 is connected to the discharge chamber 2201a and the back pressure chamber 2220.
Is greater than the set value, the valve 2235 is
It operates to open the downward communication passage against 37, whereby the gas in the discharge chamber 2201a is introduced into the back pressure chamber 2220, the pressure in the back pressure chamber 2220 increases, and the orbiting scroll (orbiting scroll member) 2206 Is prevented from separating from the fixed scroll 2205.

The discharge chamber 2201a and the back pressure chamber 2220
Is smaller than the set value, the valve 2235 is
37 to move toward the valve seat 2234 to close the communication passage.

The second means is a communication oil passage (passages 2253, 225) between the suction chamber 2208 and the back pressure chamber 2220.
5,2256) is disposed on the end plate 2205a of the fixed scroll 2205, and the valve body 2257 is connected to the spring 2258 during normal operation in which the pressure difference between the discharge chamber 2201a and the back pressure chamber 2220 is large. Valve seat 2 against
251a to communicate oil passages (passages 2253, 223).
55, 2256), the discharge chamber 2201a and the back pressure chamber 2
At the time of abnormal operation with a small pressure difference from 220, the communication oil passages (passages 2253, 2255, 2256) are opened and the oil supply hole 2214c provided in the drive shaft (rotary shaft) 2014, the bearing portion 2211a, and the eccentric shaft 2214a are opened. In this configuration, lubricating oil in an intermediate pressure state, which has been differentially supplied to the back pressure chamber 2220 from the bottom of the sealed case (sealed container) 2201 through the bearing gap, flows into the suction chamber 2208.

However, in the case of the first means, when the pressure difference between the discharge chamber 2201a and the back pressure chamber 2220 is equal to or larger than the set value, the gas in the back pressure chamber introduced from the discharge chamber is turned orbiting (orbiting scroll member). Since the gas flows into the compression chamber 2209 during compression through the fine holes 2221 provided in the wrap support disk (end plate) 2206a of 2206, there is a problem that the compression efficiency is significantly reduced.

In the case of the second means, the discharge chamber 220
In the abnormal operation in which the pressure difference between the back pressure chamber 221 and the back pressure chamber 2220 is small, the lubricating oil in the back pressure chamber 2220 supplied with the differential pressure from the bottom of the sealed case (sealed container) 2201 is excessively suction chamber 220
8, the compression input is increased.

The present invention solves such a conventional problem, and can prevent abnormal pressure drop in the back pressure chamber of the orbiting scroll without causing insufficient oil supply to the drive shaft, and can always maintain high compression efficiency. An object is to provide a compressor.

[0021]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a discharge chamber oil reservoir on which a discharge pressure acts, a bearing sliding portion relating to a drive shaft, a back pressure chamber of a orbiting scroll, and a compression chamber. And a passage opening / closing means that allows lubricating oil to flow into the back pressure chamber from the bearing sliding portion when the differential pressure between the bearing sliding portion and the back pressure chamber is equal to or greater than a set value. Having a bypass refueling passage.

By providing the bypass oil supply passage, it is possible to adjust the back pressure chamber pressure of the orbiting scroll that does not cause gas inflow, and to avoid insufficient back pressure biasing force on the orbiting scroll.

[0023]

DETAILED DESCRIPTION OF THE INVENTION The invention according to claim 1 is arranged on a side opposite to the compression chamber of the orbiting scroll and inside a thrust bearing that supports the side of the orbiting scroll opposite to the compression chamber.
An oil chamber is provided adjacent to the lap support disk of the orbiting scroll and adjacent to the main bearing and the orbital bearing sliding portion where the drive shaft and the orbiting scroll are engaged. The lubricating oil in the discharge chamber oil sump
Through a screw pump provided by a bearing sliding portion of the drive shaft and an oil hole communicating between the discharge chamber oil reservoir and the oil reservoir by at least one of the pump operations of the positive displacement pump device driven by the drive shaft. Then, after supplying the oil chamber to the main bearing and the slewing bearing to supply it to the oil chamber, 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. And a differential pressure oil supply passage that flows into one of the compression chamber and the suction chamber via a back pressure chamber disposed outside the oil chamber and on the side opposite to the compression chamber of the lap support disk on which the thrust bearing is disposed. In addition to the above, when the differential pressure between the back pressure chamber and the oil chamber is equal to or higher than a set value, a bypass oil supply passage having a passage opening / closing means for opening the passage between the oil chamber and the back pressure chamber and cutting off at other times is provided. It is a thing. And according to this configuration,
When there is no shortage of lubrication to the sliding parts of the main bearing and the orbiting bearing, and a refueling passage to the back pressure chamber where gas does not flow can be configured, and when the back pressure biasing force to the orbiting scroll is insufficient, Lubricating oil flowing through the bearing sliding portion related to the drive shaft flows into the back pressure chamber, and the back pressure chamber pressure can be appropriately maintained.

According to a second aspect of the present invention, the passage opening / closing means is provided with a check valve mechanism for permitting lubricating oil to flow only from the oil chamber to the back pressure chamber. According to this configuration, when the pressure of the compression chamber downstream of the differential pressure oil supply passage is higher than the pressure of the discharge chamber oil reservoir, such as at the initial stage of compressor startup, the compression chamber passes through the back pressure chamber. Thus, it is possible to reduce the backflow of the gas during compression into the bearing sliding portion, thereby preventing the bearing sliding portion from being damaged.

According to a third aspect of the present invention, when the differential pressure between the oil chamber and the back pressure chamber is equal to or greater than a set value, the passage opening / closing means receives the urging force due to the oil chamber pressure and the suction chamber pressure and turns. A plunger that moves in the radial direction within the wrap support disk of the scroll is provided, and the plunger receives the pressure of the oil chamber and the pressure of the suction chamber against the urging force on the side where the pressure of the back pressure chamber acts, and the plunger moves outward. When the urging force on the side on which the pressure in the back pressure chamber acts is greater than the urging force due to the oil chamber pressure and the suction chamber pressure, the plunger retreats to the center side of the lap support disk. It operates to close the passage. According to this configuration, the back pressure chamber pressure is controlled to correspond to the discharge pressure and the suction pressure to the orbiting scroll, and an appropriate back pressure biasing force can always be applied to the orbiting scroll.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A scroll refrigerant compressor according to a first embodiment of the present invention will be described below 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 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 characteristics. 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 is equivalent to an intermediate value between pure aluminum and eutectic graphite cast iron, and has a spiral fixed scroll wrap 15a and a head plate as shown in FIG. 15b, and a fixed scroll wrap 1 is provided at the center of the end plate 15b.
The discharge port 16 opening at the winding start portion of the motor chamber
A suction chamber 17 is provided on the outer periphery 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 orbiting scroll wrap 18a meshing with the fixed scroll wrap 15a to form a compression chamber side wall, and a orbiting 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 discharge chamber 2 and the fixed scroll 15 formed by the discharge cover 2a mounted on the end plate 15b and the end plate 15b so as to cover the check valve device 50. 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, and a gas passage A80a and a 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 and the suction hole 43 communicate with an oil suction hole A9a provided on the discharge cover 2a and a small-diameter oil suction hole B9b provided on the fixed scroll 15. The oil suction holes (9a, 9b) are set so that the refrigerant liquid and the lubricating oil retained 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 rotational direction by a split pin-shaped parallel pin 19 fixed to the main body frame 5 and can move 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 head sliding on
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
Thermal expansion of the annular ring 94 and the annular ring 9 during operation of the compressor
4 is arranged so as to be in close contact with the side surface of the annular seal groove 95 by the lubricating oil pressure inside the ring 4. The annular ring 94 is moved from the oil chamber A 98 a on the side of the main bearing 12 supporting the drive shaft 4 to the orbiting scroll 18, the main body frame 5, and the thrust bearing 20.
The orbiting scroll 18 is sealed to reduce 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, the two guide holes 93 into which the split pins 19 are movably inserted and the annular oil groove 9 are formed.
2, which 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 ring of the Oldham ring 24 is such that the
And the lap support disk 18c are set so that they slide smoothly and no jumping phenomenon occurs.

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 through an oil hole A38a provided at the center.

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 and 41b are provided, and the upper end thereof is provided with the thrust bearing 1
It has reached three.

The oil chamber B78b communicates with the surface of the main bearing 12 through a lubrication hole 73a provided in the drive shaft 4, and the upper bearing 1
The oil sump 72 and the back pressure chamber 39 between the first bearing 12 and the main bearing 12 are provided with an oil hole B3 having a throttle passage portion provided in the main body frame 5.
8b, and the opening end of the oil hole B38b on the back pressure chamber 39 side is a discontinuous oil groove 94a provided in the annular ring 94.
The opening is intermittently opened and is 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, and the 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.

1 to 15, when the drive shaft 4 is driven to rotate by the motor 3, the orbiting scroll 18 tries to rotate around the main shaft 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 of No. 5, the air flows into the suction chamber through two suction holes 43 (see FIG. 14) via 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 the suction port A9a and the oil suction hole B9b, and 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 transferred to the third compression chambers 60a and 60b and compressed,
The gas is discharged from the central discharge port 16 into the check valve chamber 50a, and is discharged from 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. During this time, the refrigerant gas discharged from the check valve chamber 50a flows back to the third compression chambers 60a and 60b temporarily.

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 2, and two discharge passages 80 arranged at symmetric positions are formed by the discharge chamber 2 b 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 the pressure fluctuation in the motor chamber 6 becomes almost zero. .

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 by the ambient temperature and does not exert an urging force on the valve body 50b.
Will not block.

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, flows through the cooling passage 35 on the outside of the stator 3b and the passage on the inside to the upper side of the motor chamber 6 while cooling the motor 3; 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,
Collect at 4.

The release gap 27 on the back side of the thrust bearing 20, which communicates with the compression chamber in the final compression stroke (the compression space just before the compression chamber communicates with the discharge port 16), is filled with high-pressure refrigerant gas immediately after the start of compression. 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. Thereby, the lap support disk 18c of the orbiting scroll 18 is held 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 pressed against the side face of the low compression chamber of the tip seal groove 98a and the end plate 15b of the fixed scroll 15 by the gas back pressure to be sealed.

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.

The reverse flow of the temporarily discharged refrigerant gas immediately after the compressor stops and the reverse rotation of the orbiting scroll 18 cause the valve body 50 to rotate.
b is released from the bottom surface of the check valve chamber 50a and the valve body 51b
Keep closing the discharge port 16. At the same time, the coil spring 50 having the shape memory characteristic is reduced in temperature and expanded,
The valve body 50b keeps closing the discharge port 16 by the urging force of the coil spring 50.

The first compression chambers 61a, 61b intermittently communicating with the suction chamber 17 and the back pressure chamber 39 are formed by the first compression chambers 61a, 61a.
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 of the cold operation of the compressor is almost equivalent to the suction pressure because the rise in the lubricating oil pressure in the discharge chamber oil reservoir 34 is low. As a result, the lap support disk 18c of the orbiting scroll 18 is in the oil chamber A where the pressure rise is low.
In a state where the back pressure is applied only by the lubricating oil 78a, the thrust bearing 20 is retracted and supported away from the end plate sliding surface 15b2, and a gap is generated between the lap support disk 18c and the tip of the fixed scroll wrap 15a. As a result, the compression chamber pressure is reduced, and the compression load at the initial stage of the startup is reduced.

In the event that liquid compression or the like occurs in the compression chamber during continuous operation and the pressure in the compression chamber rises abnormally instantaneously, 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 is provided with the 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
b, the oil chamber B 78b, and the lubrication hole 73a, lubricating the sliding surface of the slewing bearing 18b on the way, 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
After lubricating the sliding surfaces of the upper bearing 11 and the thrust bearing 13, the remaining lubricating oil is collected again in the discharge chamber oil reservoir 34.

The refrigerant gas is shut off between the oil sump 72 and the motor chamber 6 by the sealing effect of the oil film that lubricates 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 lubricating oil and the back pressure chamber 39.
8a, and 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. As a result, the lubricating oil leaks between the oil chamber A 78a and the back pressure chamber 39 is reduced.

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 cut end is closed together with the expansion, and the cut is pressed against the outer surface of the annular seal groove 95, so that leakage between the two spaces is further reduced.

The annular ring 94 is formed by an oil film of the lubricating oil staying in the oil groove 94a provided on the surface of the annular groove 94.
The sliding surface between the body and the 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 that has flowed into the back pressure chamber 39 intermittently flows into the outer peripheral space 37 through 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. The pressure is gradually reduced through the small-diameter injection hole 52 (see FIG. 14), and the first compression chamber 61a,
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 merges 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.
Retreating in the direction to reduce the release gap 27, the axial gap between the wrap support disk 18c of the orbiting scroll 18 and the tip of the fixed scroll wrap 15a of the fixed scroll 15 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. As a result, the compressed refrigerant gas is hardly leaked from this portion because it is pressed toward the fixed scroll 15.

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, the expansion is repeated while passing sequentially, 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 A 78a sequentially reduce the pressure in the back pressure chamber 39 and the pressure in the outer peripheral space 37, which communicate with the motor chamber 6, while temporarily reducing the pressure in 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 back pressure chamber 39 and the outer peripheral space 3
The pressure of 7 also decreases.

In the above embodiment, the outer peripheral space 37 is communicated with the first compression chambers 61a and 61b. However, the end plate 15b slidingly contacting the lap support disk 18c of the orbiting scroll 18 is provided.
An oil groove is provided on the sliding surface of the outer peripheral space 37 and the suction chamber 17.
May be communicated with. In this case, the pressure of the back pressure chamber 39 can be set lower than in the case where the pressure is communicated with the first compression chambers 61a and 61b, and can be reduced to the suction pressure.

In the above embodiment, the lubricating oil in the discharge chamber oil reservoir 34 is supplied to the main bearing 12 and the slewing bearing 1 by the screw pump action of the spiral oil grooves 41a and 41b provided on the drive shaft 4.
8b, supplied to the sliding portion of the upper bearing 11, for example, by connecting a positive displacement pump device such as a trochoid pump to the tip of the crankshaft 71a, the lubricating oil in the discharge chamber oil reservoir 34 is turned into the main bearing 12, It may be supplied to the sliding portion of the bearing 18b and the upper bearing 11.

In this case, required oil can be supplied to the bearing sliding portion even at the extremely low speed operation of the compressor. As described above, according to the above-described embodiment, the drive shaft 4 is disposed inside the thrust bearing 20 that supports the anti-compression chamber side of the orbiting scroll 18, and is adjacent to the lap support disk 18 c of the orbiting scroll 18. Orbiting bearing 18b engaged with orbiting scroll 18
The lubricating oil in the discharge chamber oil reservoir 34 on which the discharge pressure acts is applied to the oil chamber 78a partitioned and arranged adjacent to the sliding portion by the screw pump action of the spiral oil grooves 41a and 41b provided on the drive shaft 4. Supply the lubricating oil in the oil chamber 78a to the slewing bearing 18b.
The main bearing 1 on the side near the compression chamber that supports the sliding part and the drive shaft 4
After being supplied to the upper bearing 11 and the upper bearing 11, a bearing oil supply passage for returning to the discharge chamber oil reservoir 34 is formed, and a part of the lubricating oil supplied to the sliding portion of the swing bearing 18b and the main bearing 12 is decompressed. Outside the oil chamber 78a and via the back pressure chamber 39 of the lap support disk 18c in which the thrust bearing 20 is arranged, the first compression chamber 6
1a and 61b, a differential pressure oil supply passage is provided. When the differential pressure between the back pressure chamber 39 and the oil chamber 78a is equal to or greater than a set value, the gap between the oil chamber 78a and the back pressure chamber 39 is opened. A bypass refueling passage having a passage opening / closing means that shuts off at the time of the above is provided. According to this configuration, an oil supply passage to the back pressure chamber 39 can be provided without causing a shortage of oil supply to the sliding portions of the main bearing 12 and the orbiting bearing 18b and in which gas does not flow. When the back pressure biasing force is insufficient, the lubricating oil flows through the bearing sliding portion related to the drive shaft 4 into the back pressure chamber 39 to appropriately maintain the back pressure chamber pressure, and the orbiting scroll 18 is fixed. 15 can be prevented, and a decrease in compression efficiency can be prevented.

Further, according to the above-described embodiment, the passage opening / closing means is provided with the check valve mechanism for permitting the lubricating oil to flow only from the oil chamber 78a to the back pressure chamber 39. According to this configuration, when the pressure of the first compression chambers 61a and 61b downstream of the differential pressure oil supply passage is higher than the pressure of the discharge chamber oil reservoir 34, such as in the initial stage of compressor startup, the first compression is performed. Rooms 61a, 6
1b through the back pressure chamber 39 and the oil hole B38b to prevent the backflow of the gas during compression to the sliding portion of the upper bearing 11 and the main bearing 12, thereby preventing the sliding portion of the bearing from being damaged. .

Further, according to the above-described embodiment, when the pressure difference between the oil chamber 78a and the back pressure chamber 39 is equal to or greater than the set value, the urging force due to the pressure of the oil chamber 78a and the pressure of the suction chamber 17 is provided. Receiving disk 18c of the orbiting scroll 18
A plunger 29 that moves in the radial direction is provided, and the plunger 29 is opened by advancing outward against the biasing force of the back pressure chamber 39 on the side where the pressure acts, and the back pressure chamber 3 is opened.
When the urging force on the side on which the pressure 9 acts is greater than the urging force due to the pressure in the oil chamber 78a and the pressure in the suction chamber 17, the plunger 29 is retracted to the center side of the lap support disk 18c to close the passage. Is what you do. According to this configuration, the pressure of the back pressure chamber 39 of the orbiting scroll 18 is controlled to match the discharge pressure and the suction pressure, and an appropriate back pressure biasing force is always applied to the orbiting scroll 18 so that the orbiting scroll 18 and the fixed scroll 15 can be prevented from excessively contacting in the axial direction, thereby reducing the loss input of the sliding portion.

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.

Further, in the above-described embodiment, the effect of the configuration of the vertical compressor is described. However, the same effect can be expected for the configuration of the horizontal compressor.

[0115]

As is apparent from the above embodiment, the first aspect of the present invention is as follows.
The invention described in (1) is arranged on the anti-compression chamber side of the orbiting scroll and inside the thrust bearing that supports the anti-compression chamber side of the orbiting scroll, and is adjacent to the lap support disk of the orbiting scroll and the drive shaft and the orbiting scroll. And an oil chamber partitioned adjacent to the slewing bearing sliding portion and the main bearing, which engages with the main bearing, and drives the lubricating oil in the discharge chamber oil reservoir on which the discharge pressure acts and is disposed at the bottom of the motor. A screw pump function provided in the bearing sliding portion of the shaft, and an oil hole communicating between the discharge chamber oil reservoir and the oil chamber by at least one pump function in the positive displacement pump device driven by the drive shaft. After supplying the oil chamber to the main bearing and the slewing bearing to supply the oil to the oil chamber, a large part of the lubricating oil supplied to the oil chamber is returned to the discharge chamber oil reservoir, while the remaining lubricating oil is depressurized. The thrust bearing outside the oil chamber Via the back pressure chamber of the placed lap support disk, and provide a differential pressure oil supply passage that flows into either the compression chamber or the suction chamber, and when the differential pressure between the back pressure chamber and the oil chamber is greater than the set value. , Opening between the oil chamber and the back pressure chamber,
A bypass oil supply passage having a passage opening / closing means that shuts off at other times is provided. According to this configuration, there is no shortage of oil supply to the sliding portions of the main bearing and the slewing bearing, and gas inflow occurs. When there is insufficient back pressure biasing force to the orbiting scroll, lubricating oil flows into the back pressure chamber via the bearing sliding part related to the drive shaft, and the back pressure This has the effect of maintaining the chamber pressure appropriately, preventing the orbiting scroll from separating from the fixed scroll, and preventing a decrease in compression efficiency.

According to a second aspect of the present invention, the passage opening / closing means is provided with a check valve mechanism for permitting lubricating oil to flow only from the oil chamber to the back pressure chamber. As in the initial stage, when the pressure in the compression chamber downstream of the differential pressure oil supply passage is higher than the pressure in the discharge chamber oil reservoir, gas that is being compressed from the compression chamber to the bearing sliding section via the back pressure chamber is returned. This has the effect of reducing backflow, preventing lubricating oil from flowing out of the bearing sliding portion, and preventing damage to the bearing sliding portion.

According to a third aspect of the present invention, when the differential pressure between the oil chamber and the back pressure chamber is equal to or greater than a set value, the passage opening / closing means receives the urging force due to the oil chamber pressure and the suction chamber pressure and turns. A plunger that moves in the radial direction within the wrap support disk of the scroll is provided, and the plunger receives the pressure of the oil chamber and the pressure of the suction chamber against the biasing force on the side where the pressure of the back pressure chamber acts, and the plunger moves outward. When the urging force on the side on which the pressure in the back pressure chamber acts is greater than the urging force due to the oil chamber pressure and the suction chamber pressure, the plunger retreats to the center side of the lap support disk. According to this configuration, the back pressure chamber pressure of the orbiting scroll is controlled to match the discharge pressure and the suction pressure, so that an appropriate back pressure biasing force is always applied to the orbiting scroll to orbit. Axial excess between scroll and fixed scroll To prevent contact an effect that it is possible to reduce the sliding portion loss input.

[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 sectional view of a main bearing part of 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 different conventional scroll compressor.

FIG. 17 is a longitudinal sectional view of a different conventional scroll compressor.

18 is a partial cross-sectional view of each of the back pressure chamber pressure adjusting valve devices shown in FIG. 17;

FIG. 19 is a partial cross-sectional view of the back pressure chamber pressure adjusting valve device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing case 4 Drive shaft 5 Main frame 12 Main bearing 15 Fixed scroll 16 Discharge port 17 Suction chamber 18 Orbiting scroll 18c Wrap support disk 15b End plate 18 Orbiting bearing 29 Plunger 20 Thrust bearing 24 Rotation prevention member 34 Discharge chamber oil sump 41a Spiral Oil groove 41b spiral oil groove 61a first compression chamber 78a oil chamber A

Claims (3)

(57) [Claims] An orbiting scroll wrap on a wrap supporting 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. In addition, a spiral compression space is formed between both scrolls, a discharge port is provided at the center of the fixed scroll wrap, and a suction chamber is provided outside the fixed scroll wrap, and the compression space is discharged from the suction side. Between the main frame and the orbiting scroll, which are divided into a plurality of compression chambers that continuously move toward the side and compress the fluid, supporting the drive shaft and having a main bearing near the compression chamber at the center. A scroll compression mechanism for engaging the rotation preventing member of the orbiting scroll to orbit the orbiting scroll, and connecting the scroll compression mechanism to the drive shaft. The lap support disk has a gap between the end plate and a thrust bearing provided on the main body frame at least on both sliding surfaces of the lap support disk so that an oil film can be formed. A orbiting bearing disposed on the anti-compression chamber side of the orbiting scroll and inside the thrust bearing, and adjacent to the lap support disk, wherein the drive shaft and the orbiting scroll are engaged. An oil chamber partitioned adjacent to the sliding portion and the main bearing is disposed, and a discharge pressure acts and lubricating oil in a discharge chamber oil reservoir disposed at the bottom of the motor is supplied to the drive shaft. A screw pump provided in the bearing sliding portion and an oil hole communicating between the discharge chamber oil reservoir and the oil chamber by at least one of a positive displacement pump device driven by the drive shaft. Before After supplying the main bearing and the slewing bearing to the oil chamber to supply the oil chamber, most of the lubricating oil supplied to the oil chamber is configured to return to the discharge chamber oil reservoir, while the remaining lubricating oil is formed. By depressurizing, via a back pressure chamber disposed outside the oil chamber and on the side opposite to the compression chamber of the lap support disk where the thrust bearing is disposed,
A differential pressure oil supply passage for flowing into one of the compression chamber and the suction chamber is provided, and when the differential pressure between the back pressure chamber and the oil chamber is equal to or greater than a set value, the oil chamber and the back pressure chamber are A scroll gas compressor provided with a bypass oil supply passage having passage opening / closing means for opening the gap between the openings and cutting off at other times. 2. The scroll gas compressor according to claim 1, wherein the passage opening / closing means includes a check valve mechanism that allows lubricating oil to flow only from the oil chamber to the back pressure chamber. 3. The passage opening / closing means receives an urging force due to the pressure of the oil chamber and the pressure of the suction chamber when the differential pressure between the oil chamber and the back pressure chamber is equal to or higher than a set value, and is provided within the lap support disk of the orbiting scroll. A plunger that moves in the radial direction, and the plunger moves outward by receiving the pressure of the oil chamber and the pressure of the suction chamber against the urging force on the side on which the pressure of the back pressure chamber acts. When the biasing force on the side on which the pressure of the back pressure chamber acts is greater than the biasing force due to the pressure of the oil chamber and the pressure of the suction chamber, the plunger moves toward the center of the lap support disk. 2. The scroll gas compressor according to claim 1, wherein the scroll gas compressor operates to retreat and close the passage.