JP2785805B2 - 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 an apparatus for reducing a compression load by sealing and releasing a compression chamber 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. 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,
In order to reduce the leakage gap of the compressor, it is necessary to make the dimensional accuracy of the spiral part extremely high.

[0004] However, the cost of the scroll gas compressor is high and the performance of the scroll gas compressor is large due to the complicated shape of the parts and the variation in the dimensional accuracy of the spiral part. In particular, when the compressor is operated at a low speed, the gas leakage rate during compression is large. However, it has a disadvantage that the compression efficiency is lower than that of a reciprocating compressor or a rotary compressor.

[0005] Therefore, as measures to solve 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, such as packaged air conditioners and chiller units, having a relatively large refrigerant volume per one suction stroke have been developed. Improvements have been made and mass production has already been realized.

However, the following problems still remain. FIG. 17 shows an example of a structure in which the sealing of the compression chamber of a medium to large class scroll refrigerant compressor having a high-pressure space in the sealed case is further improved. The figure shows that the compression section and the discharge chamber 1031 are at the top, the motor (electric element) is at the bottom, the oil reservoir is at the bottom, and the discharge pipe 1 which is the final outlet of the compressor.
Reference numeral 042 denotes a configuration in which the motor (electric element) is disposed 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 stored in the motor (electric element) through the 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 cooled from the upper part of the discharge chamber 1031 through another space through the space for accommodating the motor (electric element). It is discharged again from the discharge pipe 1042. In addition, in order to reduce the axial gap of the compression chamber, the end plate 1004 of the orbiting scroll 1006 supports the drive shaft (crankshaft) 1008 and fixes the fixed scroll 1003 to the main frame (frame) 1009 and the fixed scroll 1003. A lubricating oil, which is provided at the bottom of a closed case (chamber) 1013 and has a discharge pressure acting on the bottom of a closed case (chamber) 1013, is provided inside a drive shaft (crankshaft) 1008, an oil pumping hole 1019, and a main body. Frame (frame)
1009 bearing clearance, drive shaft (crankshaft) 1
After lubricating the bearing sliding surface through the gap of the crankshaft portion 008, lubricating oil at an intermediate pressure reduced in the middle of the path flows into a back pressure chamber 1025 provided on the back of the orbiting scroll 1006, The orbiting scroll 1006 is urged to the back of the fixed scroll 1003 with the intermediate pressure lubricating oil and the high pressure lubricating oil at the upper part of the crankshaft. This rear biasing force is set to be large so that the orbiting scroll 1006 does not always separate from the fixed scroll against the compression chamber refrigerant gas pressure even when the suction pressure and the pressure of the discharge chamber 1031 slightly fluctuate. I have.

Further, the lubricating oil in the back pressure chamber 1025 is supplied to the back pressure hole 1 provided in the end plate 1004 of the orbiting scroll 1006.
After flowing into the compression chamber 1015 in the middle of compression via 017,
The compression chamber 1015 is compressed / discharged together with the suction refrigerant gas while sealing the gap between the compression chambers 1015 with an oil film, and discharged to the discharge chamber 1031.

[0009] The pressure rise in the sealed case 1013 is small as in the initial stage of starting the compressor and the like.
When the differential pressure lubrication to the
The refrigerant gas in the middle of compression is guided from the compression chamber 1015 in the middle of compression to the back pressure chamber 1025 through the back pressure hole 1017 provided in the end plate 1004 of No. 06, and the orbiting scroll 1006 is biased against the fixed scroll by the refrigerant gas pressure. The technical idea is to always keep the compression chamber sealed (JP-A-56-16).
No. 5788).

[0010]

However, in the configuration shown in FIG. 17 of the related art, even after the compressor is stopped, the sealed case (chamber) 1 is not affected by the residual pressure difference until the pressure balances.
The lubricating oil at the bottom of 013 flows into the compression chamber 1015 and fills it. In this state, when the compressor is restarted, the lubricating oil in the middle of compression flows into the back pressure chamber 1025 to urge the orbiting scroll 1006 against the fixed scroll to back pressure, and the sealing of the compression chamber 1015 cannot be released. As a result, there is a problem that an oil compression phenomenon occurs and the compressor cannot be started or the compressor is damaged. In addition, a similar problem occurs when the pressure in the compression chamber abnormally rises during the normal operation of the compressor.

Therefore, the inventor of the present invention disclosed in Japanese Patent Laid-Open No. 1-177482.
In the publication, a fluid equivalent to the discharge pressure or a fluid equivalent to an intermediate pressure between the discharge pressure and the suction pressure is introduced into the back of the thrust bearing to support the anti-compression chamber side of the orbiting scroll,
It has been proposed to provide a means for restricting the range in which the thrust bearing moves toward the orbiting scroll so that the orbiting scroll can always make an orbital movement with an axial gap between the fixed scroll and the thrust bearing.

[0012] However, only with the configuration of this proposal,
It has been found that the required overload reduction operation is not always performed when the amount of back surface applied to the orbiting scroll is excessive or insufficient.

In addition, a simple configuration for realizing a smooth start-up of the compression action at the initial stage of starting the compressor is required.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a simple structure for stabilizing a smooth compression operation and an overload reduction operation at the initial stage of starting the compressor. .

[0015]

In order to solve the above-mentioned problems, the present invention has a mode in which the orbiting scroll is supported by both the end plate of the fixed scroll and the thrust bearing. A throttle passage is provided. By the support form of the orbiting scroll and the configuration of the introduction passage to the back of the thrust bearing, it is possible to smoothly start the compressor and stabilize the overload reduction mechanism.

[0016]

According to a first aspect of the present invention, there is provided a thrust bearing in which a part of lubricating oil introduced into a non-compression chamber side of an orbiting scroll is provided on a main body frame supporting a drive shaft. After lubricating the sliding contact surface of the bearing and the end plate of the fixed scroll with the wrap support disk of the orbiting scroll, an oil supply passage is formed that is allowed only to flow into one of the compression chamber and the suction chamber. When the differential pressure between the suction pressure and the discharge pressure is small as in the case of extremely low speed operation of the compressor including the compressor, the lap support disk is mainly supported by the thrust bearing, and the suction pressure as in the steady operation including the rated operation of the compressor. When the pressure difference between the thrust bearing and the discharge pressure is large, the back pressure is applied to the orbiting scroll so that the lap support disk is mainly supported by the end plate, and the thrust bearing is allowed to move only in the axial direction. Provided with means for urging the crawl side,
Means for regulating the moving distance of the thrust bearing toward the orbiting scroll so that the lap support disk of the orbiting scroll can maintain at least a minute gap capable of forming an oil film between the sliding surface of the mirror surface of the fixed scroll and the thrust bearing. When the thrust load acting on the orbiting scroll by the compression chamber pressure is larger than the back pressure applying force to the orbiting scroll,
While the lap support disk is supported by the thrust bearing, if the thrust load is greater than the combined force of the back pressure applying force to the orbiting scroll and the back pressure applying force to the thrust bearing, the thrust bearing retreats and turns. The axial gap between the scroll and the fixed scroll is configured to be further expanded,
As means for biasing the back surface of the thrust bearing, a gas in the middle of compression is introduced, and a throttle passage is provided in the middle of the introduction path. According to this configuration, the compression chamber gas at the initial stage of the compressor startup gradually flows into the back surface of the thrust bearing via the throttle passage, delaying the back pressure bias on the thrust bearing, and the orbiting scroll from the fixed scroll. It becomes easy to separate, and the load at the time of starting can be reduced by widening the gap in the compression chamber axial direction.

After the compressor is started, the compressed gas pressure acts on the rear surface of the thrust bearing from the initial stage of the compressor and supports the thrust bearing without being affected by the size of the discharge side space including the sealed case. Suppress thrust bearing retreat. As a result, the distance that the orbiting scroll separates from the fixed scroll is reduced, and the compression rise is accelerated.

According to a second aspect of the present invention, a spring device is provided as means for urging the rear surface of the thrust bearing. According to this configuration, a large fluctuation does not occur in the thrust bearing back surface urging force, and the overload limit can be kept constant.

According to a third aspect of the present invention, a spring device is provided as a means for urging the rear surface of the thrust bearing.
This is a supplementary addition of the lubricating oil pressure at which the discharge pressure acts. According to this configuration, there is no need for an excessive spring biasing force, and the size of the spring device is reduced.

[0020]

【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 disposed at the upper part and the compression part is disposed 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. The fixed scroll 15 has a spiral fixed scroll wrap 15a 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
The 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. 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 are provided. The orbiting scroll 18 made of an aluminum alloy, which is composed of an upright lap support disk 18c, is disposed so as to be surrounded by the fixed scroll 15 and the main body frame 5, and is provided with a wrap support disk 18c.
The hardening process such as porous nickel plating is performed on the surfaces of the c and the orbiting scroll wrap 18a. 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 formed by the discharge cover 2a attached to the end plate 15b so as to cover the check valve device 50 and the end plate 15b, and the gas provided in the fixed scroll 15. It comprises a passage B80b, a gas passage A80a provided in the main body frame 5, a discharge guide 81 attached to the main body frame 5 so as to surround the main bearing 12, and a discharge chamber 2b formed by the main body frame 5. Gas passage B80
b are provided at target positions (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 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 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 rotation direction by a split pin-shaped parallel pin 19 fixed to the main body frame 5 and can be moved only in the axial direction,
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 wrap 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 94 having a cutout 94b is attached to the 95, as shown in FIG. Annular ring 9
The outer peripheral surface of the annular ring 94 is 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 the operation of the compressor. Are arranged so as to be in close contact with each other. The annular ring 94 includes the drive shaft 4
The orbiting scroll 18 formed by the orbiting scroll 18, the main frame 5 and the thrust bearing 20 from the side of the oil chamber A 98 a on the side of the main bearing 12 for supporting the orbiting scroll 18 is sealed so as to prevent excessive leakage to the back pressure chamber 39. I have.

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.
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 has a small-diameter thrust back pressure introducing hole A89a provided in the main body frame 5 and a small-diameter thrust back pressure introducing hole B8 provided in the fixed scroll 15.
9b communicates with the third compression chamber 60b (see FIG. 14) in the final compression stroke.

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.

The discharge pipe 31 is attached to the outer peripheral portion of the upper end wall of the upper sealed case 1a, and the glass terminal 88 for connecting the motor power supply is attached to the 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 formed 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, on 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 lubricating oil in the oil chamber A78a is provided with the slewing bearing 18b.
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 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 a first compression chamber 61 intermittently communicating with the suction chamber 17.
The outer peripheral space 3 outside the wrap support disk 18c and the oil hole 91 provided in the thrust bearing 20 within the turning angle range of about 180 degrees before the suction refrigerant gas is completely confined.
7. an oil hole C38c provided in the lap support disk 18c;
Small-diameter injection holes 52 arranged at symmetric positions
a and 52b communicate with the first compression chambers 61a and 61b by an injection passage, and an oil hole 91 provided in the thrust bearing 20 is provided in the lap support disc 1.
8c is opened and closed intermittently.

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 supporting 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 cylinder 26b for sealing the small-diameter outer peripheral portion of the plunger 29.

In FIG. 15, the horizontal axis indicates the rotation angle of the drive shaft 4, the vertical axis indicates the refrigerant pressure, the pressure change state of the refrigerant gas during the suction, compression and discharge processes, and the solid line 62 indicates the operation 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. 15, 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 into the accumulator chamber 46 from the suction pipe 47, 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 the change of the inflow direction are once collected at the bottom of the accumulator chamber 46, and the refrigerant gas is drawn into 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 completion of the compression, 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 discharged refrigerant gas undergoes secondary expansion when flowing toward the spherical wall surface constituting the discharge chamber 2 through the small discharge hole 50h of the check valve device 50, and further collides with the spherical wall surface. Distribute evenly. Thereafter, the two discharge passages 80 arranged at the symmetrical positions are merged in the discharge chamber 2b and the motor chamber 6, so that the pulsation of the discharge gas from each discharge passage 80 is attenuated. Due to the fourth expansion, the pressure is further attenuated, and the pressure in the motor chamber 6 hardly fluctuates.

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. And the valve body 50b
Does not block the discharge port 16.

The refrigerant gas discharged from the small hole 81a of the discharge guide 81 and discharged into 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.

In the final compression stroke, the release gap 27 on the back side of the thrust bearing 20 which communicates with the third compression chamber 60b (a compression space in which the compression chamber intermittently communicates with the discharge port 16) has a small refrigerant gas diameter after the start of compression. Thrust back pressure introduction hole 89a,
It is gradually introduced through 89b, and gradually increases in pressure. Then, the refrigerant is finally filled with the refrigerant gas at the final pressure of the compression chamber without being affected by the pressure of the refrigerant discharged from the closed case 1. 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 becomes the end plate sliding surface 15b.
2 and the thrust bearing 20 (an assembly clearance of 15 to 20 microns).

Therefore, the back pressure biasing force of the thrust bearing 20 is small at the initial stage of the compressor startup, gradually increases, and finally has a size capable of supporting the rear surface of the orbiting scroll 18.

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 described later, and the back pressure applying force to the orbiting scroll 18 gradually increases.

Following the pressure increase in 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 end of the orbiting scroll wrap 18a and the end plate 15b of the fixed scroll 15 is provided with a tip 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 side of the low compression chamber of the tip seal groove 98 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 makes a reverse orbiting motion 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 backward to the suction chamber 17 so that the pressure of the refrigerant gas in the discharge port 16 rapidly drops, and the difference in refrigerant gas pressure 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 element 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, 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 compression chamber as well as in the accumulator chamber 46, so that liquid compression easily occurs in the initial stage of the cold start of the compressor. 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 of 78a, the thrust bearing 20 is retracted and supported away from the end plate sliding surface 15b2, and a gap (approximately) is provided between the lap support disk 18c and the tip of the fixed scroll wrap 15a. 0.015-0.
020 microns), lowering the compression chamber pressure and reducing the initial compression load.

When the thrust load acting on the orbiting scroll 18 at the initial stage of activation is larger than the back pressure applying force acting on the back surface of the thrust bearing 20, the thrust bearing 20 retreats and the lap support disk 18c and the fixed scroll wrap 15
The gap with the tip of “a” further increases, and the compression load is reduced.

If, for example, liquid compression 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 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 compressor operating state including the occurrence of liquid compression in the compression chamber, the backflow of the refrigerant gas in the compression chamber to the back pressure chamber 39 is avoided, 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 in 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
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 supplied to the upper bearing 1
The lubricating oil passing through 1 prevents backflow to oil sump 72.

The refrigerant gas pressure discharged from the motor chamber 6 rises following the passage of time after the cold start of the compressor.
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.
The oil is supplied to the back pressure chamber 39 together with the screw pump action of the spiral oil grooves 41a and 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.

Accordingly, while the pressure increase 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 is separated 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 third compression chamber 60b in the final compression stroke.

When the pressure difference 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 the 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 orbital boss portion by the inertia force at that time. 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.
9, the inner diameter is expanded, and the cutout 94b 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. It is pushed in to prevent excessive leakage of lubricating oil between the oil chamber A 78a and 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 the pressure difference between the back pressure chamber 39 and the oil chamber A 78 a, so that heat is removed. The cutout 94b is closed together with the expansion, and at the same time, the cutout 94b 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 accumulated in an 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 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 that has flowed into the compression chamber (compression space) together with the suctioned refrigerant gas, compresses a minute gap in the adjacent compression space by sealing an oil film, and compresses. The refrigerant gas is discharged to the motor chamber 6 again through the discharge port 16 together with the compressed refrigerant gas while preventing the leakage of the 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 the start in cold operation, 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.

When the orbiting scroll 18 is the fixed scroll 15
Is restricted to about 70 microns, so that an oil film remains in each gap between the sliding surfaces on both sides of the lap support disk 18c, and the outer peripheral space 37 and the suction chamber 17 communicate directly. The pressure change in the back pressure chamber 39 due to this is suppressed, and the compression load is instantaneously reduced.
Can return to the original position instantly, and 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 the cold start or during the steady operation, when the instantaneous liquid compression occurs, the compression chamber pressure 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.

As a matter of course, 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 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.

As described above, according to the above embodiment, the refrigerant gas in the third compression chamber 60b gradually flows through the small-diameter thrust back pressure introducing holes 89a and 89b at the initial stage of the compressor startup. And the back pressure on the thrust bearing 20 is delayed, while the back pressure applying force to the orbiting scroll 18 is smaller than the thrust load due to the compression chamber refrigerant gas. As a result, the thrust bearing 20 is fixed to the fixed scroll 15.
The orbiting scroll 18 that has moved away from the shaft cannot be supported and retreats, thereby increasing the axial clearance in the compression chamber and reducing the compression load.

Thereafter, the refrigerant gas in the third compression chamber 60b acts stably on the rear surface of the thrust bearing 20 without being affected by a gradual increase in pressure in the discharge-side space including the closed case 1, and the thrust bearing Suppress 20 retreat. Accordingly, following the increase of the back pressure applying force to the orbiting scroll 18, the distance of the orbiting scroll 18 separating from the fixed scroll 15 is reduced, and the compression start-up can be accelerated.

At the time of abnormal over-compression, the refrigerant gas does not flow instantaneously from the third compression chamber 60b to the back surface of the thrust bearing 20 because it passes through the small-diameter thrust back pressure introducing holes 89a and 89b. Does not change instantaneously, the thrust bearing 20 that supports the rear surface of the orbiting scroll 18 is easily retracted, and the overload can be reduced.

(Embodiment 2) FIG. 16 is a longitudinal sectional view of a scroll refrigerant compressor according to a second embodiment of the present invention. The inside of a sealed case 801 made of soft iron is driven similarly to the case of FIG. An upper sealed case 801a and a lower sealed case 801b are partitioned by a main body frame 805 supporting a shaft 704. The inside of the upper sealed case 801a is a high-pressure space in which a motor 703 is built, and the lower sealed case 801
The inside of b constitutes an accumulator chamber 846 with a low-pressure space communicating with the downstream side of the evaporator.

A 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 the 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 side opposite to 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, and the thrust bearings 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 on the outer side,
The thrust bearing 220 is sealed by pressing 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 61 a and 61 b 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 back pressure chamber 83
9 holds a pressure close to the pressure of the suction chamber 17.

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

According to this back pressure application mode, the wrap supporting disk 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. 818c moves away from the end plate 815b of the fixed scroll 815 and the thrust bearing 2
Back pressure is 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. Set the force.

As described above, according to the above-described embodiment, the rear surface of the thrust bearing 220 is urged by the coil spring 131, and the urging force on the rear surface of the thrust bearing 220 is not affected by the compression chamber pressure. The overload limit during the overload reduction operation can be made constant.

Further, the lubricating oil pressure in the discharge chamber oil reservoir 34 is supplementarily added to the back of the thrust bearing 220 together with the coil spring 131, so that the urging force of the coil spring 131 can be reduced, and the size of the coil spring 131 is reduced. It can be downsized.

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

Further, in the above-described embodiment, the structure and the operation and effect of the vertical compressor are described.
The same operation and effect can be expected for the configuration of a horizontal compressor in which the upstream side of (38a and others) is the bottom side of the sealed case (1 and others).

[0123]

As is apparent from the above embodiment, the first aspect of the present invention is as follows.
According to the invention described in (1), a part of the lubricating oil introduced into the anti-compression chamber side of the orbiting scroll has a thrust bearing provided on the main body frame supporting the drive shaft and a sliding contact of the end plate of the fixed scroll with the lap support disk of the orbiting scroll. After lubricating the surface, an oil supply passage that allows only inflow to either the compression chamber or the suction chamber is formed, and the suction pressure and the discharge pressure as in the case of extremely low speed operation of the compressor including the initial stage of starting the compressor. When the differential pressure of the orbiting scroll is small, the wrap support disk of the orbiting scroll is mainly supported by a thrust bearing provided on the main body frame supporting the drive shaft, and the suction pressure and the discharge pressure as in the steady operation including the rated operation of the compressor. In the case where the pressure difference is large, the back pressure applying force to the orbiting scroll is set so that the lap support disk is mainly supported by the end plate of the fixed scroll, and the slide is allowed to move only in the axial direction. A means for biasing the anti-orbiting scroll side of the bearing is provided so that the lap support disk of the orbiting scroll can maintain at least a minute gap capable of forming an oil film between the sliding surface of the mirror surface of the fixed scroll and the thrust bearing. The lap support disk serves as a means for regulating the moving distance of the thrust bearing toward the orbiting scroll, and when the thrust load acting on the orbiting scroll due to the compression chamber pressure is larger than the back pressure applying force to the orbiting scroll, When the thrust load is larger than the combined force of the back pressure applying force to the orbiting scroll and the back pressure applying force to the thrust bearing while being supported by the bearing, the thrust bearing retreats and the The axial gap is configured to be further enlarged, and as a means for urging the back of the thrust bearing, gas during compression is introduced and introduced. Which was a throttle passage provided in the middle road, the compressor starts early According to this configuration,
The compressed gas in the compression chamber intermittently communicating with the discharge port gradually flows into the back surface of the thrust bearing via the throttle passage, delaying the back pressure to the thrust bearing, and applying the back pressure to the orbiting scroll. Is smaller than the thrust load caused by the compression chamber gas. As a result, the thrust bearing retreats without supporting the orbiting scroll separated from the fixed scroll, thereby increasing the axial gap in the compression chamber and reducing the compression load.

The compressed gas in the compression chamber intermittently communicating with the discharge port stably acts on the back surface of the thrust bearing without being affected by the gradual pressure increase in the discharge side space including the sealed case. Suppress bearing retreat. As a result, the distance that the orbiting scroll separates from the fixed scroll is reduced following the increase of the back pressure applying force to the orbiting scroll, so that the compression start of the gas can be accelerated.

Also, in the case of abnormal over-compression, the compressed gas passes through the throttle passage, so that it does not instantaneously flow from the compression chamber, which intermittently communicates with the discharge port, to the back surface of the thrust bearing, and the applied force does not change instantaneously. The thrust bearing 20 that supports the rear surface of the orbiting scroll is easily retracted, and an effect of stably reducing overload can be obtained.

According to a second aspect of the present invention, a spring device is provided as a means for urging the rear surface of the thrust bearing.
According to this configuration, since there is no variation in the biasing force of the rear surface of the thrust bearing, there is an effect that the overload limit is fixed, unnecessary overload reduction operation is suppressed, and the occurrence of vibration of the compressor can be reduced. .

According to a third aspect of the present invention, a spring device is provided as a means for urging the rear surface of the thrust bearing.
This is a supplementary addition of the lubricating oil pressure at which the discharge pressure acts.
This configuration eliminates the need for excessive spring bias,
There is an effect that the size of the spring device can be reduced and the size of the compressor can be reduced.

[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 longitudinal sectional view of a conventional scroll compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing case 4 Drive shaft 5 Main frame 15 Fixed scroll 15a Fixed scroll wrap 15b End plate 16 Discharge port 17 Suction chamber 18 Orbiting scroll 18a Orbiting scroll wrap 18c Lapping support disk 20 Thrust bearing 24 Rotation prevention mechanism 34 Discharge chamber oil reservoir 60a Third Compression chamber 89a Thrust back pressure introduction hole 89b Thrust back pressure introduction hole 131 Coil spring 220 Thrust bearing

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F04C 18/02 311 F04C 29/02 311

Claims (3)

(57) [Claims] 1. A swirling orbiting scroll wrap on a wrap support disk which forms a part of an orbiting scroll with respect to a spiral fixed scroll wrap formed on one surface of a head plate forming a part of a fixed scroll. Freely meshing, forming a spiral compression space between the two scrolls, providing a discharge port at the center of the fixed scroll wrap, providing a suction chamber outside the fixed scroll wrap, A thrust bearing provided on a main body frame supporting the drive shaft is disposed in a mating state between the end plate and the end plate, and further rotatably supported by the drive shaft via a rotation preventing mechanism of the lap support disk, A closed casing is provided with a scroll-type compression mechanism that compresses fluid by utilizing a change in volume of a compression chamber formed between both scrolls and a motor connected to the drive shaft. The lubricating oil of a discharge chamber oil reservoir, which communicates with the discharge port and is disposed at a lower part of a motor chamber that houses the motor, is introduced to the non-compression chamber side of the lap support disk, and the orbiting scroll is rotated. In the configuration in which the back pressure is applied to the fixed scroll side, after a part of the lubricating oil introduced into the non-compression chamber side lubricates the sliding contact surfaces of the thrust bearing and the end plate with the lap support disk, And an oil supply passage allowed only to flow into one of the suction chambers, and when the differential pressure between the suction pressure and the discharge pressure is small as in the case of extremely low-speed operation of the compressor including the initial stage of starting the compressor. When the differential pressure between the suction pressure and the discharge pressure is large as in the steady operation including the rated operation of the compressor, the lap support disk is mainly supported by the end plate. Means for setting the back pressure applying force to the orbiting scroll, and biasing the thrust bearing on the opposite side of the orbiting scroll, which is allowed to move only in the axial direction, to provide the lap support disk of the orbiting scroll. Means for regulating a moving distance of the thrust bearing toward the orbiting scroll so that at least a minute gap capable of forming an oil film is maintained between the sliding surface of the end plate of the fixed scroll and the thrust bearing. When the thrust load acting on the orbiting scroll due to the compression chamber pressure is larger than the back pressure applying force to the orbiting scroll, the lap support disk is supported by the thrust bearing, while the thrust load is If the combined force of the back pressure applying force to the orbiting scroll and the back pressure applying force to the thrust bearing is larger, the thrust bearing moves backward. By so doing, the axial gap between the orbiting scroll and the fixed scroll is configured to be further enlarged, and as a means for urging the back surface of the thrust bearing, gas during compression is introduced, and a throttle passage is provided in the introduction path. Scroll gas compressor. 2. A swirling orbiting scroll wrap on a wrap support disk forming a part of a orbiting scroll with respect to a spiral fixed scroll wrap formed on one surface of a head plate forming a part of a fixed scroll. Freely meshing, forming a spiral compression space between the two scrolls, providing a discharge port at the center of the fixed scroll wrap, providing a suction chamber outside the fixed scroll wrap, A thrust bearing provided on a main body frame supporting the drive shaft is disposed in a mating state between the end plate and the end plate, and further rotatably supported by the drive shaft via a rotation preventing mechanism of the lap support disk, A closed casing is provided with a scroll-type compression mechanism that compresses fluid by utilizing a change in volume of a compression chamber formed between both scrolls and a motor connected to the drive shaft. The lubricating oil of a discharge chamber oil reservoir, which communicates with the discharge port and is disposed at a lower part of a motor chamber that houses the motor, is introduced to the non-compression chamber side of the lap support disk, and the orbiting scroll is rotated. In the configuration in which the back pressure is applied to the fixed scroll side, after a part of the lubricating oil introduced into the non-compression chamber side lubricates the sliding contact surfaces of the thrust bearing and the end plate with the lap support disk, And an oil supply passage allowed only to flow into one of the suction chambers, and when the differential pressure between the suction pressure and the discharge pressure is small as in the case of extremely low-speed operation of the compressor including the initial stage of starting the compressor. When the differential pressure between the suction pressure and the discharge pressure is large as in the steady operation including the rated operation of the compressor, the lap support disk is mainly supported by the end plate. Means for setting the back pressure applying force to the orbiting scroll, and urging the anti-orbiting scroll side of the thrust bearing, which is allowed to move only in the axial direction, to provide a lap support disk for the orbiting scroll. In order to maintain at least a minute gap capable of forming an oil film between the sliding surface of the end plate of the fixed scroll and the thrust bearing, a means for regulating a moving distance of the thrust bearing toward the orbiting scroll is provided. When the thrust load acting on the orbiting scroll due to the compression chamber pressure is larger than the back pressure applying force to the orbiting scroll,
While the lap support disk is supported by the thrust bearing, when the thrust load is greater than the combined force of the back pressure application force to the orbiting scroll and the back surface application force to the thrust bearing, the thrust bearing is A scroll gas compressor in which the axial gap between the orbiting scroll and the fixed scroll is further enlarged by retreating, and a spring device is provided as a means for urging the rear surface of the thrust bearing. 3. The scroll gas compressor according to claim 2, wherein a lubricating oil pressure at which a discharge pressure acts is added as means for urging the rear surface of the thrust bearing.