JPH08303359A - Scroll gas compressor - Google Patents

Abstract

PURPOSE: To provide a back pressure energizing means from the opposite side of a compression chamber side where an upsetting moment action is not applied on a turning scroll. CONSTITUTION: A drive shaft 4 is surroundedly arranged between a main body frame 5 for supporting the drive shaft 4 and a turning scroll 18 so as to sealingly partition the side of bearing parts 12, 18b continuing to a delivery chamber oil sump 34 in a high pressure side concerning to the drive shaft 4 from a back pressure chamber 39 of the turning scroll 18 in its outer circumferential part. A ring movably mounted on the turning scroll 18 is so arranged that its center is almost accorded with the center of the turning scroll 18. Therefore, the turning scroll 18 is always received the back pressure energizing force at its center and slidably contacts with a fixed scroll 15 without receiving any upsetting moment action so that the clearance of the compression chamber can be held in the micro state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a back pressure biasing of an orbiting scroll in a scroll gas compressor toward the side opposite to the compression chamber.

[0002]

2. Description of the Related Art A scroll compressor having low vibration and low noise characteristics has a suction chamber at the outer peripheral portion, a discharge port at the center of a spiral, and a reciprocating compression flow of a compressed fluid in one direction. Since it does not require a discharge valve for compressing fluid such as compressors and rotary compressors, has a constant compression ratio, has a small discharge pulsation, and does not require a large discharge space, it can be used in various fields. Chemical research is being done.

However, since the compression chamber has a large number of sealing portions, a large amount of compressed fluid leaks. Especially, in the case of a scroll gas compressor having a small exclusion capacity 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, the cost of the scroll gas compressor is high due to the complexity of the shape of the parts and the dimensional accuracy of the spiral portion, and the performance varies greatly. Especially in the low speed operation state of the compressor, the gas leakage rate during compression is high. However, it has a drawback that the compression efficiency is lower than that of a reciprocating compressor or a rotary compressor.

Therefore, as a measure for solving this kind of problem, it is expected that the dimensional accuracy of the spiral portion is optimized and the compression efficiency is improved by the oil film sealing effect using lubricating oil for preventing gas leakage during compression. Largely, as described in JP-A-57-8386, an appropriate amount of lubricating oil is injected into the compression chamber during compression, and the oil film of the lubricating oil seals the gap in the compression chamber to improve the above-mentioned drawbacks. A proposal has been made.

In particular, scroll refrigerant compressors have been put into practical use in the field of refrigeration and air conditioning, and various types of compressors of medium to large class having a relatively large refrigerant volume per one suction process such as packaged 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 the structure of a medium to large class scroll refrigerant compressor having a high-pressure space in the closed case. This figure shows a structure in which the compression mechanism is located at the top, the motor is located at the bottom, the oil sump is located at the bottom, and the discharge pipe that is the final outlet of the compressor is located near the motor. A back pressure region 1450 having a large back area where the discharge pressure acts is provided on the back surface, while a low pressure region 1451 is provided on the outer periphery of the back pressure region 1450.
In order to form the back pressure area 1450, the back surface of the orbiting scroll 1424 is slidably sealed by the annular thrust seal 1449 fixed to the frame 1413 and having a large back pressure urging area to fix the orbiting scroll 1424. Scroll 1426
Orbiting scroll 1424 by pressing constantly
Do not let go away from 26. In addition, the lubricating oil on the inner bottom of the closed case is decompressed through a thin tube, and after the differential pressure oil is supplied to the outer peripheral portion of the orbiting scroll 1424 and the sliding contact surface of the fixed scroll 1426, it is compressed via the suction chamber arranged inside. And the oil film seals the compression chamber gap.

Further, a centrifugal pump action by an oil passage (not shown) provided in the drive shaft 1417 pumps up high-pressure lubricating oil at the bottom of the inside of the hermetically sealed case, and the annular thrust seal 1449 passes through the bearing portion of the drive shaft 1417. After refueling the inside of the case, it is returned to the inner bottom of the closed case again. (US Patent No.
4522575 specification).

[0009]

However, in the above structure, since the orbiting scroll 1424 makes an orbiting motion, the center of the back pressure urging surface to the orbiting scroll 1424 and the orbiting scroll 1424 are rotated.
The center of the drive short shaft 1424a which is the center of the downward thrust force acting on the 1424 [Generally, in order to reduce the inclination of the orbiting scroll due to compression pressure, the center of the compression chamber and the shaft part of the orbiting scroll (drive short Often aligned with axis 1424a) or separated by only a small distance]
With no match, the orbiting scroll 1424 constantly
The center of the back pressure urging surface moves to. As a result, the direction in which the orbiting scroll 1424 is inclined between the downward thrust force acting on the orbiting scroll 1424 due to the liquid compression in the compression chamber and the upward discharge back pressure acting on the back surface of the orbiting scroll 1424. An alternating overturning moment occurs. This allows the orbiting scroll 1424 and fixed scroll to momentarily
Along with the 1426, a gap in the axial direction or a fall occurs, which causes deterioration of compression performance, and the orbiting scroll 1424 and the fixed scroll 14
Generation of abnormal noise due to collision with 26 and orbiting scroll 1424
Drive shaft for driving the and orbiting scroll 1424 drive short shaft 1424
There is a problem that durability is deteriorated due to the one-sided contact phenomenon of the coupling bearing portion with a.

In view of the above-mentioned conventional problems, it is an object of the present invention to provide a back pressure chamber structure capable of constantly biasing the center of the orbiting scroll with a back pressure.

[0011]

In order to achieve the above-mentioned object, the present invention seals the bearing side, which communicates with the oil reservoir on the high-pressure side of the drive shaft, and the back pressure chamber of the orbiting scroll on the outer periphery thereof. In order to achieve this, an annular ring, which is arranged so as to surround the drive shaft between the main body frame supporting the drive shaft and the orbiting scroll and is movably mounted on the orbiting scroll, has its center substantially coincident with the center of the orbiting scroll. It was placed in. The orbiting scroll is always subjected to a back pressure biasing force at its central portion, and is always in sliding contact with the fixed scroll without being affected by the overturning moment, so that the compression chamber gap can be kept minute.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, the present invention according to claim 1 provides a main frame supporting a drive shaft with a main bearing on the side closer to the orbiting scroll, while imparting orbiting motion to the orbiting scroll. Therefore, the orbiting bearing part for slidingly connecting the drive shaft and the orbiting scroll is provided on the lap support disk of the orbiting scroll, and the main bearing is operated by the discharge pressure and communicates with the oil reservoir arranged in the sealed case. An annular ring that divides the oil chamber communicating with the orbiting bearing portion adjacent to the orbiting bearing portion and the back pressure chamber side provided outside the oil chamber and on the side opposite to the compression chamber of the orbiting scroll between the main body frame and the orbiting scroll. The orbiting scroll is mounted on the orbiting scroll so that the center of the orbiting ring and the center of the orbiting scroll substantially coincide with each other. As a result, the high-pressure back pressure chamber of the orbiting scroll follows the orbiting motion of the orbiting scroll, and while being orbitally moved, the back pressure is always biased to the center of the orbiting scroll, so that the orbiting scroll is inclined with respect to the fixed scroll. Can be prevented.

According to the second aspect of the present invention, the annular ring is arranged in the annular seal groove provided in the slewing bearing boss portion which constitutes the slewing bearing portion which is provided so as to project from the lap supporting disk. This allows the annular ring to be arranged without reducing the rigidity of the lap support disk.

[0014]

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 is an iron closed case,
A main body frame 5 that fixes the fixed scroll 15 that forms a compression chamber by meshing with the orbiting scroll 18 and that supports the drive shaft 4 is partitioned into an upper motor chamber 6 and a lower accumulator chamber 46. There is.

The motor chamber 6 has a high-pressure atmosphere, the motor 3 is arranged in the upper part, the compression part is arranged in the lower part, and the main body frame 5 supporting the drive shaft 4 to which the rotor 3a of the motor 3 is fixedly connected is slidable and welded. Made of eutectic graphite cast iron, which has excellent properties, and the protrusions 79a provided on the outer peripheral surface of the protrusion contact the inner wall surface and the end surface of the upper closed case 1a and the lower closed case 1b.
A, the upper closed case 1a, and the lower closed case 1b are hermetically welded by a single welding bead 79b.

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

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

A check valve device 50 is mounted on the end plate 15b on the side opposite to the orbiting scroll so as to cover the discharge port 16,
The check valve device 50 is a valve body made of a thin plate steel plate having a shape in which the outer peripheral portion is cut out at several places, as illustrated in detail in FIGS.
50b (or valve body 50e with a discontinuous annular hole 50ea)
A valve case 99 having a check valve hole 50a, a central hole 50g and a plurality of discharge small holes 50h around it, a valve body 50b and a valve case 99.
And a spring device 50c interposed therebetween. Spring device 50
c has a shape memory characteristic that it contracts when its own temperature exceeds 50 ° C and expands when its own temperature is 50 ° C or less. During operation of the compressor, it receives discharge refrigerant gas pressure and is a check valve. hole
The valve body is contracted to the bottom surface of 50a and the discharge port 16 is closed while the compressor is stopped when the temperature of itself is 50 ° C or less.
It is set so as to press 50 onto the end plate 15b.

As shown in FIGS. 1 and 14, a spiral orbiting scroll wrap 18a that meshes with a fixed scroll wrap 15a to form a compression chamber side wall, and an orbiting boss portion 18e engaged with the crankshaft 14 of the drive shaft 4. The orbiting scroll 18 made of an aluminum alloy, which is made up of a lap support disk 18c which is upright, is arranged so as to be surrounded by the fixed scroll 15 and the main body frame 5, and the surfaces of the lap support disk 18c and the orbiting scroll wrap 18a are perforated. Hardened by high quality nickel plating. As shown in FIG. 3, a spiral tip seal groove is formed at the tip of the orbiting scroll wrap 18a.
A chip seal 98a made of resin is mounted in the chip seal groove 98 with a minute gap. When the orbiting scroll 18 is pressed in the axial direction of the fixed scroll 15, the flat portion of the lap support disk 18c contacts the tip of the fixed scroll wrap 15a.
The tip of 18a does not contact the fixed scroll 15 and maintains a minute distance of about several microns.

The discharge passage 80 (see FIG. 1) has a check valve device 50.
Discharge cover 2a mounted on the end plate 15b so as to cover the
And the end plate 15b, a discharge chamber 2, a gas passage B80b provided in the fixed scroll 15, a gas passage A80a provided in the main body frame 5, and 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, and the gas passage A80a and the gas passage B80b are provided at target positions (see FIG. 14).

As shown in FIG. 7, a large number of small holes 81a are provided on the upper surface of the discharge guide 81. The accumulator chamber 46 that communicates with the evaporator side of the refrigeration cycle has a lower closed case 1
b, the fixed scroll 15 and the main body frame 5,
Suction pipes 47 communicating with the suction pipe 47 are provided on the side surface of the lower closed case 1b, and the suction pipes 47 are connected to the suction pipes 47 from positions opposite to each other by about 9
The suction holes 43 are fixed scrolls at two positions 0 degrees apart.
(See Figure 14).

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

A flat 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 body frame 5 and is movable only in the axial direction is a lap support disk 18c and the body frame 5 Between the main body frame 5 and the fixed scroll 15 by the elastic force of the annular seal ring (made of rubber) 70 (see FIG. 10) interposed between the thrust bearing 20 and the main body frame 5. Is in contact with the end plate mounting surface 15b1 of.

The height from the end plate sliding surface 15b2, which is in sliding contact with the lap support disk 18c of the orbiting scroll 18, to the end plate mounting surface 15b1 is to improve the sealing property of the sliding part by the oil film of the lap support disk 18c. About 0.01 than the thickness of 18c
It is set larger by 5 to 0.020 mm.

As shown in FIGS. 1 and 8, an orbiting scroll
An annular seal groove 95, which is concentric with the center of the orbiting bearing 18b, is provided on the end surface of the orbiting boss portion 18e on the main body frame 5 side, and the annular seal groove 95 has a part thereof as shown in FIG. An annular ring 94 made of a cut flexible resin is attached. The outer peripheral surface of the annular ring 94 is arranged so as to be in close contact with the side surface of the annular seal groove 95 by the thermal expansion of the annular ring 94 and the lubricating oil pressure inside the annular ring 94 during the operation of the compressor. The annular ring 94 is excessive from the side of the main bearing 12 supporting the drive shaft 4 to the back pressure chamber 39 of the orbiting scroll 18 formed by the orbiting scroll 18, the body frame 5 and the thrust bearing 20 from the oil chamber A 98a side. Sealed to prevent leakage of lubricating oil.

The annular thrust bearing 20 is made of a sintered alloy which is easy to form a hole, and as shown in FIGS. 10 and 11, two guide holes 93 into which the split pin 19 is movably inserted, an annular oil groove 92, and an oil. It has a 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 body frame 5 and the thrust bearing 20, and an annular groove 28 for mounting a seal ring 70 is provided inside and outside the release gap 27. . Seal ring 70 is a release gap
A seal is made between 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 body frame 5 and the thrust back pressure introducing hole B89b provided in the fixed scroll 15 in the third compression chamber 60b in the final compression stroke (see FIG. 14). Refer to).

As shown in FIGS. 1 and 2, the thrust bearing 20
The rotation preventing member (hereinafter referred to as the Oldham ring) 24 of the orbiting scroll 18 arranged inside the inner wall of the orbiting scroll 24 is made of a light alloy or a reinforced fiber composite material suitable for sintering molding or injection molding method, and has a flat ring on both sides. Parallel key-shaped key portions that are orthogonal to each other, the key portion on the upper surface side is a key groove 71a provided on the main body frame 5, and the key portion on the lower surface side is a key groove provided on the lap support disk 18c. It engages with 71 and slides.

The ring thickness of the Oldham ring 24 is set so that when the Oldham ring 24 reciprocates, it smoothly slides between the main body frame 5 and the lap support disk 18c and no jumping phenomenon occurs. There is.

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

An oil separator 87 attached to the upper closed case 1a partitions the discharge pipe 31 and the glass terminal 88 from the motor 3 side. The rotor 3a of the motor 3 axially positioned by the stepped portion of the drive shaft 4 is bolted to the drive shaft 4 together with the upper balance weight 75,
The upper balance weight 75 has a disk shape, and its outer diameter is set to be larger than the outer diameter of the rotor 3a.

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

Discharge chamber oil sump provided at the bottom of the motor chamber 6
The cooling passage 35 is formed by cutting out a part of the outer circumference of the stator 3b of the motor 3 so as to communicate with the upper portion of the motor chamber 6.

The discharge chamber oil sump 34 also has a main bearing 12 and a slewing bearing 18b through an oil hole A38a provided in the main body frame 5.
It also communicates with the oil chamber A78a at an intermediate position between.

As shown in FIGS. 1 and 8, on the surfaces of the sliding shaft portion 4a of the drive shaft 4 and the crankshaft 14, when the drive shaft 4 rotates forward, the lubricating oil in the oil chamber A78a is slewing bearing 18b. Helical oil grooves 41a, 41b are provided in the oil chamber B78b formed by the crankshaft 14 and the motor 3 in the direction of screw pump oil supply, and the upper end thereof reaches the thrust bearing portion 13.

The oil chamber B78b and the surface of the main bearing 12 are communicated with each other by the oil supply hole 73a provided in the drive shaft 4, and the oil sump 72 between the upper bearing 11 and the main bearing 12 and the back pressure chamber 39 are the main frame. 5
Is communicated with by an oil hole B38b having a throttle passage portion provided at the back pressure chamber 39 side of the oil hole B38b.
It is provided at a position where it is intermittently opened to the discontinuous oil groove 94a provided in the and is opened and closed intermittently by the annular ring 94.

As shown in FIGS. 1, 10, and 14, the back pressure chamber
Reference numeral 39 denotes the first compression chambers 61a, 61b which communicate with the suction chamber 17 intermittently.
Within the swivel angle range of about 180 degrees before the completion of the suction refrigerant gas confinement, the oil hole 91 provided in the thrust bearing 20, the outer peripheral space 37 outside the lap support disk 18c, the lap support disk 18
An oil passage C38c provided in c and an injection passage 74 constituted by injection holes 52a and 52b having small diameters symmetrically arranged communicate with the first compression chambers 61a and 61b and are provided in the thrust bearing 20. The oil hole 91 thus opened is opened and closed intermittently by the lap support disk 18c.

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

The back pressure control valve device 25 is a lap support disk 18c.
Of the stepped shape cylinder 26, which is provided in the radial direction of the large diameter part cylinder 26a and the small diameter part cylinder 26b, the stepped shape plunger 29 movable in the cylinder, and the outer peripheral part space 37 side of the cylinder 26. Cap that closes part of the open end
32, a coil spring arranged between the cap 32 and the plunger 29 to urge the plunger 29 toward the crankshaft 14 side.
53, an oil hole 54a for communicating the crankshaft 14 side of the large diameter cylinder 26a with the suction chamber 17, and a crankshaft of the small diameter cylinder 26b
It is constituted by oil holes 54b and 54c which respectively communicate the 14 side with the oil chamber B 78b and the back pressure chamber 39. Its operation is
When the pressure in the back pressure chamber 39 is in the proper range, as shown in FIG. 12, when the small-diameter end surface of the plunger 29 blocks 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. As shown in, the plunger with the large diameter part of the plunger 29 as the boundary
The plunger 29 moves to the outer peripheral space 37 side due to the biasing force difference acting on both sides of 29, the cylinder side opening end of the oil hole 54b is opened, and the coil spring 53 so that the oil chamber B78b and the back pressure chamber 39 communicate with each other. The urging force and the dimensions of each part of the cylinder 26 are set.

Numeral 55 is 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 shows the rotation angle of the drive shaft 4, the vertical axis shows the refrigerant pressure, the pressure change state of the refrigerant gas in the intake, compression, and discharge processes, and the solid line 62 operates at normal pressure. The pressure change with time is shown, and the dotted line 63 shows the pressure change with abnormal pressure rise.

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

In FIGS. 1 to 16, when the drive shaft 4 is rotationally driven 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, but of the Oldham ring 24. The key portion (see FIG. 2) on the side of the orbiting scroll 18 is the key groove 71 of the orbiting scroll 18.
And the key portion on the opposite side is engaged with the key groove 71 of the main body frame 5.
Since it is engaged with a (see FIG. 1), it is prevented from rotating and revolves to change the volume of the compression chamber together with the fixed scroll 15 to perform the suction / compression action of the refrigerant gas.

Then, the suction refrigerant of the gas-liquid mixture containing the lubricating oil from the refrigeration cycle connected to the compressor flows into the accumulator chamber 46 from the suction pipe 47 and collides with the outer surface of the end plate 15b of the fixed scroll 15 after the collision. , Through the upper space of the accumulator chamber 46, into the suction chamber 17 through the two suction holes 43 (see FIG. 14).

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 inertial force at the time of changing the inflow direction are temporarily collected at the bottom of the accumulator chamber 46,
Due to the negative pressure generated when the suction refrigerant gas passes through the suction hole 43, the suction refrigerant gas is sucked up into the suction hole 43 in an atomized state through the oil suction holes A9a and B9b and is mixed into the suction refrigerant gas again.

The suction refrigerant gas separated into gas and liquid is drawn into the suction chamber 1
7. The first compression chambers 61a, 61b (see FIG. 14) formed between the orbiting scroll 18 and the fixed scroll 15 are enclosed in the compression chambers, and the second compression chambers 51a, 51b, the third compression chamber 60a,
After being sequentially transferred to 60b and compressed, it is discharged from the central discharge port 16 into the check valve chamber 50a, and then sequentially passes through the discharge chamber 2, the gas passage B80b, the gas passage A80a, and the discharge chamber 2b to the motor chamber 6. Is ejected.

Immediately after the compression is completed, the third compression chambers 60a, 60b and the discharge port 16 are opened, whereby the compressed refrigerant gas is
A sudden primary expansion occurs when flowing into the check valve chamber 50a from the third compression chambers 60a and 60b, and the refrigerant gas discharged from the check valve chamber 50a is primarily discharged between the discharge completion process and the compression start process immediately after that. Backflow to the third compression chambers 60a and 60b.

As a result, the refrigerant gas intermittently flows out of the third compression chamber (60a, 60b) and the third compression chamber (60a, 60b).
Repeating the inflow to b), the total flow becomes the third
Although it flows out from the compression chambers (60a, 60b) to the discharge chamber 2, the discharge refrigerant gas from the check valve chamber 50a and the discharge chamber 2 flows into the third compression chamber (60).
Pressure fluctuations occur during inflow and outflow to a and 60b), and pulsation phenomenon is exhibited.

The pulsation of the discharged refrigerant gas causes a secondary expansion when flowing into the discharge chamber 2 having a spherical wall surface through the discharge small hole 50h of the check valve device 50, and further, at the symmetric positions. When the two discharge passages 80 merge in the discharge chamber 2b and the motor chamber 6, the discharge gas pulsations from the discharge passages 80 are attenuated by each other, and the third and fourth expansions further reduce the discharge pulsation sequentially. The pressure in the motor chamber 6 hardly changes.

When the discharged refrigerant gas instantaneously flows back from the discharge chamber 2 to the check valve chamber 50a, the flow of the discharged refrigerant gas follows the flow of the valve element 5
0b tries to move in the direction of closing the discharge port 16, but during operation of the compressor, the coil spring 50c having a shape memory characteristic does not fully contract due to the ambient temperature and does not exert a force on the valve body 50b, Since the valve body 50b having the ridge is attracted to the bottom surface of the check valve chamber 50a and does not separate, the valve body 50b does not block the discharge port 16.

The discharged refrigerant gas dispersed from the small holes 81a of the discharge guide 81 and discharged into the motor chamber 6 collides with the annular shielding plate 86 and the winding of the motor 3, and then the cooling passage 35 on the outer side of the stator 3b. While flowing through the inner and inner passages, the motor 3 flows to the upper side portion of the motor chamber 6 while being cooled, and is discharged from the discharge pipe 31 to the external 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 sump 34. The lubricating oil in the discharge refrigerant gas that passes through the outer periphery of the weight 75 and the lower balance weight 76 is
5. The lower balance weight 76 is centrifuged by the rotation, diffused to the inner surface of the winding of the motor 3, flows down to the lower portion along the inner space of the winding bundle, and is collected in the discharge chamber oil sump 34.

The release clearance 27 on the back side of the thrust bearing 20 which communicates with the compression chamber of the final compression stroke (the compression space of the stroke immediately before the compression chamber communicates with the discharge port 16) is filled with high-pressure refrigerant gas with the lapse of time after the start of compression. To be done. The thrust bearing 20 is pressed against the end plate mounting surface 15b1 of the fixed scroll 15 by the back pressure bias and the elastic force of the seal ring 70. As a result, the lap support disk 18c of the orbiting scroll 18 is clamped between the end plate sliding surface 15b2 and the thrust bearing 20 (15 to 2).
0 micron assembly gap).

The lubricating oil in the discharge chamber oil sump 34 flows into the oil chamber A 78a, the oil chamber B 78b, and the back pressure chamber 39 via a route described later,
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 contacts the end plate sliding surface 15b2 of the fixed scroll 15 with an appropriate pressing force. The gap between the tip of the fixed scroll wrap 15a and the wrap support disk 18c of the orbiting scroll 18 disappears, thereby sealing the compression chamber and efficiently compressing the sucked refrigerant gas, so that 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 defined by the following:
The gas flows into the tip seal groove 98 (see FIG. 3), and the gas back pressure causes the tip seal 98a to be pressed by the side surface of the low compression chamber of the tip seal groove 98a and the end plate 15b of the fixed scroll 15 for sealing.

When the compressor is stopped, the orbiting scroll 18 instantaneously makes a reverse orbital motion due to the reverse flow based on the pressure difference of the refrigerant gas in the compression chamber, but since the refrigerant gas flows backward from the compression chamber to the suction chamber 17, The orbiting scroll 18 is as shown in FIG.
The first compression chambers 61a and 61b stop at the turning angle in a state where they communicate with the suction chamber 17. As shown in FIG. 8, in this stopped state, the annular ring 94 closes the lubricating oil inflow port to the back pressure chamber 39.

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 suddenly drops, and the difference in the refrigerant gas pressure between the discharge port 16 and the discharge chamber 2 is caused. Thus, the valve body 50b closes the discharge port 16 and prevents the continuous backflow of the discharged refrigerant gas from the discharge chamber 2 to the compression chamber.

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

First compression chamber 61, which communicates intermittently with the suction chamber 17
The a and 61b communicate with the back pressure chamber 39 through the oil hole 91 (see FIG. 10) provided in the thrust bearing 20 only when the first compression chambers 61a and 61b are within 180 degrees before the closing is completed. With
Since the lubricating oil film seals between the thrust bearing 20 and the lap support disk 18c, 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 not only into the accumulator chamber 46 but also into the compression chamber. The thrust force in the direction opposite to the discharge port 16 acts on the orbiting scroll 18 due to 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 of the back pressure chamber 39 at the initial stage of starting when the compressor is cold is almost equivalent to the suction pressure because the pressure rise in the discharge chamber oil sump 34 is low. As a result, the lap support disk 18c of the orbiting scroll 18 is supported by moving backward from the end plate sliding surface 15b2 to the thrust bearing 20 in a state where back pressure is applied only by the lubricating oil in the oil chamber A78a having a low pressure rise. A gap is created between the lap support disk 18c and the tip of the fixed scroll wrap 15a, the pressure in the compression chamber drops, and the compression load at the initial stage of startup is reduced.

In the unlikely event that liquid compression occurs in the compression chamber during continuous operation and the pressure in the compression chamber suddenly rises abnormally, the thrust force acting on the orbiting scroll 18 is applied to the rear surface of the orbiting scroll 18. It becomes larger than the applied back pressure biasing force, the orbiting scroll 18 moves in the axial direction, and the thrust bearing
Supported by 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 the first compression chamber 61a, 61b.
Is communicating with the outer peripheral space 37 through the oil hole 91 provided in the thrust bearing 20 within the swirling angle range of about 180 degrees before the completion of the suction refrigerant gas confinement, so liquid compression is performed within this communicating swirling range. Does not occur.

Therefore, in any compressor operating state including generation of liquid compression in the compression chamber, 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 sump 34 at the initial stage of the cold start of the compressor enters the oil chamber A78a via the oil hole A38a by the screw pump action of the spiral oil grooves 41a, 41b provided in the drive shaft 4. Be sucked.

After that, a part of the lubricating oil is added to the spiral oil groove 41b,
The sliding surface of the slewing bearing 18b is lubricated during the course of passing through the oil chamber B78b and the oil supply hole 73a in order, and is supplied to the sliding surface of the main bearing 12 to collect the oil.
Sent to 72.

The lubricating oil supplied to the main bearing 12 by the spiral oil groove 41a merges with the lubricating oil that has passed through the oil chamber B78b in the oil sump 72, and then a part of the lubricating oil is in the oil hole B38b (FIG. 8). (Refer to (3)), the pressure is reduced in the throttle passage and is intermittently supplied to the back pressure chamber 39, and the remaining lubricating oil is re-collected in the discharge chamber oil sump 34 after lubricating the sliding surfaces of the upper bearing 11 and thrust bearing 13. To be done.

The refrigerant gas in the motor chamber 6 is the upper bearing.
Lubricating oil passing through 11 prevents backflow to sump 72.

The pressure of the refrigerant gas discharged from the motor chamber 6 rises following the passage of time after the compressor is started cold, and the lubricating oil in the oil reservoir 34 of the discharge chamber is also oiled due to the pressure difference between it and the back pressure chamber 39. The oil is sucked into the chamber A 78a and supplied to the back pressure chamber 39 together with the screw pump action of the spiral oil grooves 41a and 41b. The pressure of the back pressure chamber 39 gradually increases, and the combined force with the lubricating oil pressure corresponding to the discharge pressure of the oil chamber A78a acts on the lap support disk 18c of the orbiting scroll 18. As a result, the thrust load acting to separate the orbiting scroll 18 from the fixed scroll 15 is canceled by the pressure of the refrigerant gas in the compression chamber, and the thrust force acting on the orbiting scroll 18 is reduced.

Therefore, while the pressure rise in the motor chamber 6 after the compressor is cold is low, the force exerted on the orbiting scroll 18 by the lubricating oil pressure in the oil chamber A78a and the back pressure chamber 39 is the refrigerant gas pressure in the compression chamber. It is smaller than the thrust load on the orbiting scroll 18 due to. As a result, the orbiting scroll 18 is separated from the fixed scroll 15 and supported by the thrust bearing 20 which receives the elastic force of the seal ring 70 and the back pressure due to the refrigerant gas introduced from the compression chamber in the final compression stroke.

When the pressure difference between the discharge pressure and the suction pressure exceeds the required pressure, the force imparted to the orbiting scroll 18 by the lubricating oil pressure in the oil chamber A78a and the back pressure chamber 39 turns 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 slewing bearing 18e, and the center of the annular ring 94 are substantially coincident with each other,
Since the annular ring 94 makes an orbiting motion together with the orbiting scroll 18, the inertial force at that time causes the annular ring 94 to pop out from the annular seal groove 95 provided in the orbiting boss portion 18e. Further, the annular ring 94 expands its inner diameter by the pressure difference between the oil chamber A 78a and the back pressure chamber 39, and closes its cut end together with thermal expansion. Due to these actions, the annular ring 94 is pressed against the outer surfaces of the main body frame 5 and the annular seal groove 95, and the oil scraping action of the annular ring 94 causes the annular seal groove 95 and the annular ring 95 to move.
Lubricating oil is pushed between the oil chamber A94a and the back pressure chamber 3
Prevent excessive leakage to 9.

Furthermore, an annular ring made of resin having excellent flexibility
94 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 78a, closes the cut end together with thermal expansion, and closes the annular seal groove 95. Being pressed against the outer surface further reduces direct leakage between the two spaces.

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

During steady operation of the compressor, the orbiting scroll 18 is provided with back pressure on the fixed scroll 15 side by the lubricating oil pressure of the high pressure oil chamber A78a and the lubricating oil pressure of the back pressure chamber 39, and the lap support disk 18c and the end plate. The sliding surface 15b2 slides smoothly while maintaining an appropriate contact force to minimize the axial clearance of the compression chamber.

The lubricating oil which has flowed into the back pressure chamber 39 is intermittently passed through the oil holes 91 provided in the thrust bearing 20 to intermittently form the outer peripheral space 37.
To the oil hole c3 provided in the lap support disk 18c.
8c, small diameter injection holes 52a, 52b (see Fig. 14)
The pressure is gradually reduced through and flows into the first compression chambers 61a and 61b. The lubricating oil lubricates each sliding surface in the middle of the passage and seals the sliding gap.

The lubricating oil injected into the first compression chambers 61a, 61b merges with the lubricating oil that has flowed into the compression chamber (compression space) together with the suction refrigerant gas, and seals a minute gap between the adjacent compression chambers with an oil film. The compressed refrigerant gas is prevented from leaking, and the sliding surface between the compression chambers is lubricated, and the compressed refrigerant gas is discharged again to the motor chamber 6 through the discharge port 16.

The first from the discharge chamber oil reservoir 34 via the back pressure chamber 39
In the oil supply path to the 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 as immediately after the cold start, or abnormal liquid compression occurs. In some cases, the orbiting scroll 18 is separated from the fixed scroll 15 and supported by the thrust bearing 20 as described above.

However, the thrust bearing 20 biased by the back pressure cannot support the abnormally increased pressure load of the compression chamber, and is retracted in the direction of decreasing the release gap 27 and fixed to the lap support disk 18c of the orbiting scroll 18. The axial gap between the scroll 15 and the tip of the fixed scroll wrap 15a increases. This causes a lot of leakage between the compression chambers and
As indicated by the alternate long and short dash line 63a, the compression chamber pressure sharply drops during compression.

Since the maximum distance in which the orbiting scroll 18 is separated from the fixed scroll 15 in the axial direction is regulated to about 70 μm, the pressure in the back pressure chamber 39 due to the direct communication between the outer peripheral space 37 and the suction chamber 17. After the change is suppressed and the compression load is instantly reduced, the thrust bearing 20 can be instantly returned to its original position, and stable operation is resumed.

The orbiting scroll 18 is the thrust bearing 20.
When retreating toward, the axial dimension between the tip of the orbiting scroll wrap 18a and the fixed scroll 15 also increases, but since the tip seal 98a is pressed toward the fixed scroll 15 by the gas pressure on its back surface. , Leakage of compressed refrigerant gas from this portion hardly occurs.

On the other hand, the lap support disk of the orbiting scroll 18
The gap between 18c and the tip of the fixed scroll wrap 15b of the fixed scroll 15 expands, compressed refrigerant gas leaks in the compression chamber, and the compression chamber pressure drops sharply.

The orbiting scroll 18 and the fixed scroll
Even when foreign matter is caught in the axial clearance between the foreign matter and 15, the thrust bearing 20 retreats and removes the foreign matter in the same manner as described above.

The pressure in the compression chamber when instantaneous liquid compression occurs at the initial stage of cold start or during steady operation is shown by the dotted line 63 in FIG.
Although abnormal over-compression occurs, the volume of the high pressure space communicating with the discharge port 16 is large, and the expansion is repeated while sequentially passing through the check valve chamber 50a, the discharge chamber 2 and the discharge chamber 2b, and the motor chamber The pressure change of 6 hardly occurs.

Further, as the compressor operating speed increases, the refrigerant gas leakage in the compression chamber per unit time decreases. On the other hand, the opening time of the injection holes 52a and 52b per turning motion is shortened, the amount of oil injection into the compression chamber per turning motion is suppressed, and unnecessary oil compression is reduced. The passage resistance increases due to an increase in the number of interruptions with the pressure chamber 39, the amount of lubricating oil flowing from the oil chamber A 78a into the back pressure chamber 39 is also suppressed, and the pressure in the back pressure chamber 39 is appropriately maintained.

In addition, the scroll refrigerant compressor which is incorporated into the heat pump refrigeration cycle and is in operation, when the heating operation is switched to the defrosting operation, the high pressure side becomes the evaporator side and the low pressure side becomes the condenser side for a short time. The pressure in the motor chamber 6 is instantaneously reduced due to the communication with each other. Following that, oil hole B
The pressure in the back pressure chamber 39 and the pressure in the outer peripheral space 37, which communicate with the motor chamber 6 via the 38b, the oil sump 72, and the oil chamber A78a in this order, decrease, while the pressures in the suction chamber 17 and the compression chamber temporarily increase. When it rises and the proper back pressure cannot be maintained, the back pressure control valve device 25 provided on the lap support disk 18c as shown in FIG.
The plunger 29 moves to the outer peripheral space 37 as shown in FIG. 13 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 chamber B78b. Then, the oil chamber B78b and the back pressure chamber 39 communicate with each other, high-pressure lubricating oil flows into the back pressure chamber 39, the back pressure chamber 39 is returned to the proper pressure, and the plunger 29 is oiled again as shown in FIG. By moving to the side of the chamber B78b, 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 condensing capacity on the condenser side is large, the suction pressure is relatively high and the discharge pressure is relatively low.

In such a case, since the pressure in the compression chamber becomes higher than that in the normal operation, it is necessary to make the pressure in the back pressure chamber higher than the normal pressure. By the lubricating oil pressure of 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, the back pressure of the lubricating oil communicating with the coil spring 53 and the back pressure chamber 39 is resisted. As shown in FIG. 13, it moves toward the outer peripheral space 37, the oil chamber B 78b and the back pressure chamber 39 communicate with each other intermittently (or partially), and high-pressure lubricating oil flows into the back pressure chamber 39, The pressure chamber 39 is maintained at an appropriate pressure.

As a matter of course, the plunger 29 is affected by the inertial force and the frictional force acting on the plunger 29 to move toward the outer peripheral space 37 so that the small-diameter portion cylinder 26b and the oil hole 54c move. Since the communication area between them is widened, the pressure in the back pressure chamber 39 increases as the compressor operating speed increases.

Further, in the above embodiment, the compressed refrigerant gas during the final compression stroke was introduced into the release gap 27 provided on the back surface of the thrust bearing 20.
The discharged refrigerant gas in a region communicating with 16 may be introduced into the release gap 27.

Further, in the above embodiment, the sliding gap between the lap support disk 18c of the orbiting scroll 18 and the thrust bearing 20 is sealed only by the oil film of the lubricating oil.
-Ring ring (82), as proposed in -159996 publication
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, a large number of sections per swing motion in which the oil holes B38b and the back pressure chamber 39 communicate intermittently are set, but in the case of a compressor operating condition where the compression load is relatively small, , The opening position of the oil hole B38b is moved to the center side of the main body frame 5 so that the communication section per one turning motion of the oil hole B38b and the back pressure chamber 39 is reduced, and the lubricating oil in the oil chamber A78a is removed. It will be apparent from the description of the prior art that it is necessary to reduce the amount of flow into the back pressure chamber 39 and the compression chamber. Along with this, the pressures in the back pressure chamber 39 and the outer peripheral space 37 also decrease.

As described above, according to the above-described embodiment, the main bearing 12 part and the orbiting scroll 18 which support the drive shaft 4 and are provided on the main body frame 5 near the orbiting scroll 18 are provided.
Drive shaft 4 and orbiting scroll 18
And a swivel bearing 18b which is slidably coupled with the above-mentioned bearing (1) which communicates with the discharge chamber oil sump 34 on which the discharge pressure acts.
2, 18b) on the high-pressure lubricating oil space (oil chamber A78a) side and on the anti-compression chamber side of the orbiting scroll 18 on the back-pressure chamber 39 side provided outside the high-pressure lubricating oil space (oil chamber A78a). By disposing the partitioning annular ring 94 between the main body frame 5 and the orbiting scroll 18, the annular ring 94 is attached to the orbiting scroll 18, and the center of the annular ring 94 and the center of the orbiting scroll 18 are substantially aligned. Since the high pressure side back pressure chamber (oil chamber A78a) concentric with the orbiting scroll 18 orbits following the orbiting motion of the orbiting scroll 18, the high pressure lubricating oil is always biased to the center of the orbiting scroll 18 by back pressure. The orbiting scroll 18 can be evenly pressed to the fixed scroll 15 side. As a result, it is possible to prevent the orbiting scroll 18 from inclining with respect to the fixed scroll 15, prevent biased expansion of the compression chamber gap, reduce compressed gas leakage, and prevent deterioration of compression efficiency.

The orbiting scroll 18 is a fixed scroll.
Since it does not incline with respect to 15, the sliding surface of the slewing bearing 18b part is not unevenly contacted, and the bearing durability can be improved.

The orbiting scroll 18 and the fixed scroll
No collision with 15 occurs, and it is possible to prevent damage to parts and noise and vibration.

Also, in the above embodiment, the annular ring 94 is provided so as to protrude from the lap supporting disk 18c, and the slewing bearing portion 18b is provided.
The annular seal groove 95 provided on the slewing bearing boss portion 18e
The annular ring 94 can be arranged without weakening the rigidity of the lap supporting disk 18c.

In the above embodiment, the main bearing 12 and the slewing bearing 18b are arranged adjacent to each other in the main axis direction of the drive shaft 4, but they are disclosed in JP-A-58-79684 and JP-A-63-20549.
Even in the case of the structure in which the slewing bearing is arranged inside the main bearing as shown in Japanese Patent No. 0, the same actions and effects as described above can be expected.

In the above embodiment, the construction of the vertical compressor is shown and its operation and effect are explained. For example, the upstream side of the oil hole A (38a etc.) in FIG. 1 is a closed case (1 other).
Similar effects can be expected in the case of a configuration of a horizontal compressor with the bottom side of the.

Further, in the above embodiment, the outer peripheral space 37 is communicated with the first compression chambers 61a and 61b which are intermittently communicated with the suction chamber 17, but the outer peripheral space 37 may be communicated with the suction chamber 17. ,
In the case of this configuration, the pressure of the back pressure chamber 39 can be set to a pressure close to that of the suction chamber 17.

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

[0104]

As is apparent from the above embodiment, claim 1
The present invention described in claim 1, the main frame for supporting the drive shaft is provided with a main bearing on the side closer to the orbiting scroll, while the orbiting bearing is slidably coupled between the drive shaft and the orbiting scroll in order to impart orbiting motion to the orbiting scroll. Part is provided on the lap support disk of the orbiting scroll, and the oil chamber is connected to the main bearing and the orbiting bearing part through the oil reservoir under the discharge pressure and arranged in the closed case, and the oil chamber An annular ring, which is located outside and on the side of the back pressure chamber provided on the side opposite to the compression chamber of the orbiting scroll, is arranged between the main body frame and the orbiting scroll, and the annular ring is attached to the orbiting scroll. The center of the orbiting scroll and the orbiting scroll are made to substantially coincide with each other. With this configuration, the high-pressure side back pressure chamber concentric with the orbiting scroll orbits following the orbiting motion of the orbiting scroll, so that the orbiting scroll is always The high-pressure lubricating oil to the back urge posture, centered in Le, can be equally pressed orbiting scroll side of the fixed scroll. As a result, it is possible to prevent the orbiting scroll from inclining with respect to the fixed scroll, prevent biased expansion of the compression chamber gap, reduce compressed gas leakage, and prevent deterioration of compression efficiency.

Further, since the orbiting scroll is not inclined with respect to the fixed scroll, the sliding surface of the orbiting bearing portion is not unevenly contacted, and the bearing durability can be improved.

Further, there is an effect that the orbiting scroll and the fixed scroll do not collide with each other, and it is possible to prevent the damage of parts and the generation of abnormal noise and vibration.

According to a second aspect of the present invention, the annular ring is arranged on the slewing bearing boss portion which constitutes the slewing bearing portion which is provided so as to project from the wrap support disk. The annular ring can be arranged without compromising the rigidity of the lap support disc.

[Brief description of drawings]

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

[Fig. 2] Exploded view of main parts of the compressor

FIG. 3 is a partial cross-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.

FIG. 5 is a perspective view of the same.

FIG. 6 is a perspective view of the same.

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

FIG. 8 is a partial sectional view of a main bearing portion of the compressor.

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

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

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

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

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

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

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

FIG. 16 is a vertical sectional view of a conventional scroll compressor.

FIG. 17 is a cross-sectional view taken along the line 3-3 in FIG.

[Explanation of symbols]

 4 Drive shaft 5 Main frame 12 Main bearing 15 Fixed scroll 16 Discharge port 17 Suction chamber 18 Orbiting scroll 18c Lap support disk 15b End plate 18 Slewing bearing 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 78b Oil chamber B

Claims (2)

[Claims] 1. An orbiting scroll wrap on a lap support disk forming a part of an orbiting scroll is swingably rotatable with respect to a spiral fixed scroll wrap formed on one surface of an end plate forming a part of the fixed scroll. 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. A rotation preventing member of the orbiting scroll is engaged between the orbiting scroll and a main body frame supporting a drive shaft so as to compress the fluid by being divided into a plurality of compression chambers that continuously move toward the discharge side. A scroll compression mechanism for orbiting the orbiting scroll is formed, the scroll compression mechanism is housed in a closed case, and the orbiting scroll is attached to the main body frame. While providing the side main bearing near the Le,
An orbiting bearing portion, which is slidably coupled between the drive shaft and the orbiting scroll so as to impart an orbiting motion to the orbiting scroll, is provided on the lap support disk, and a discharge pressure acts and is disposed in the sealed case. And an oil chamber communicating with the main bearing and the orbiting bearing portion adjacent to the oil reservoir, and a back pressure chamber side provided outside the oil chamber and on the side opposite to the compression chamber of the orbiting scroll. A scroll gas compressor in which an annular ring is disposed between the body frame and the orbiting scroll, and the annular ring is attached to the orbiting scroll, and the center of the annular ring and the center of the orbiting scroll are substantially aligned. . 2. The scroll gas compressor according to claim 1, wherein the annular ring is arranged in an annular seal groove provided in a slewing bearing boss portion forming a slewing bearing portion provided so as to project from the lap supporting disk.