JPH09100786A - Scroll gas compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously realize high compression efficiency in a scroll gas compressor and reduction of a lubricating pump input. SOLUTION: This scroll gas compressor is provided with a differential pressure lubricating passage to finally supply lubricating oil of a discharge chamber oil reservoir 34 through a sliding part of a revolving bearing 218e and a bearing lubricating passage to suck lubricating oil of the discharge chamber oil reservoir 34 arranged at height equivalent to a main bearing 212 by a screw pump effect by an oil groove 241a provided on a sliding surface of the main bearing 212 and to return it to the discharge chamber oil reservoir 34 again by branching it from the differential pressure lubricating passage after discharging. Consequently, it is possible to realize sufficient lubrication to the main bearing 212 by a simple and low input lubricating means and to carry out oil film sealing of a clearance of the compression chamber by proper quantity lubrication to the compression chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to oil supply to a bearing portion of a scroll gas compressor and an oil supply passage passing through the rear surface of an orbiting scroll.

[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 compressed gas is reciprocated in one direction. If there is no need for a discharge valve for compressing fluid such as a compressor or rotary compressor, and there is no large variation in the operating compression ratio determined by the suction pressure and the discharge pressure, the suction volume of the compression chamber and the final compression Since the discharge pulsation is small and a large discharge space is not required by setting the volume ratio determined by the chamber volume to an appropriate value, research on practical use of various fields has been conducted.

However, since there are many seal portions in the compression chamber, there is a lot of leakage of the compressed fluid. Particularly, in the case of a scroll gas compressor having a small displacement capacity such as a refrigerant compressor for home air conditioning,
It is necessary to make the dimensional accuracy of the spiral section extremely high in order to reduce the leakage gap of the compression section, but the cost of the scroll gas compressor is high due to variations in the dimensional accuracy of the spiral section due to the complexity of the parts shape. However, there is a large variation in performance, and particularly in the low speed operation state of the compressor, the gas leakage rate during compression is large, and the compression efficiency is lower than that of the reciprocating compressor and the rotary compressor.

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

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

FIG. 18 shows an example of a general structure of a medium to large class scroll refrigerant compressor in which a closed case (chamber) has a high-pressure space. In the figure, the compression unit and the discharge chamber 1031 are at the top, the motor (electric element) is at the bottom,
An oil sump is provided at the bottom at the discharge pipe 104 which is the final outlet of the compressor.
2 is disposed in the vicinity of the motor (electric element), and after the discharge refrigerant gas and the lubricating oil are separated in the discharge chamber 1031, the lubricating oil is stored in the motor (electric element) through oil drain holes 1035 and 1036. Returning to the space, the refrigerant gas is collected in the oil reservoir at the bottom, and the discharged refrigerant gas is discharged from the discharge pipe 1042 again after passing through the space accommodating the motor (electric element) from the upper part of the discharge chamber 1031 through another passage. You. In addition, in order to reduce the axial gap of the compression chamber, lubricating oil on which the discharge pressure acts on the bottom of the closed case (chamber) 1013 is provided inside a drive shaft (crankshaft) 1008 with an oil-lifting hole 1019 and a drive shaft ( Crankshaft) 1
After lubricating the bearing sliding surface through the clearance of the bearing of the body frame (frame) 1009 supporting the 008 and fixing the fixed scroll 1003, and the clearance of the crankshaft of the drive shaft (crankshaft) 1008, the orbiting scroll 1
The intermediate pressure lubricating oil, which has been reduced in the middle of the path, flows into the back pressure chamber 1025 provided on the rear surface of the orbit 006. Energize. As a result, the back pressure biasing force is set so as not to separate the orbiting scroll 1006 from the fixed scroll against the compression chamber gas pressure.

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

[0008]

However, the structure as shown in FIG. 18 has the following two problems.

The gist of the first problem is that it is necessary to sufficiently supply oil to the two bearing portions, so that the amount of oil supplied to the compression chamber is inevitably large and the incompressible lubricating oil is compressed. That is, the compression input becomes large and the compression efficiency is reduced.

That is, the drive shaft (crankshaft) 1
Two bearing sliding parts engaging with 008 [upper bearing sliding part provided on main body frame (frame) 1009 supporting drive shaft (crankshaft) 1008 and crank sliding bearing for rotating orbiting scroll 1006 Section], motor (electric motor) and drive shaft (crankshaft) 100
In the configuration in which the lubricating oil is supplied to the thrust bearing portion that supports its own weight with 8, and then the lubricating oil is made to flow into the compressor 1015, the amount of inflow to the compression chamber 1015 increases due to the necessity of sufficient oil supply to the bearing sliding portion. However, there is a problem that the compression efficiency is lowered due to the fact that the lubricating oil heated at high pressure and the refrigerant gas mixed in the lubricating oil flow into the compression chamber 1015 during compression.

The gist of the second problem is that a large amount of lubricating oil flows into the compression chamber, which causes an increase in the size of the compressor.

That is, the discharge chamber 1031 having a volume necessary for separating the lubricating oil in the refrigerant gas is the compression chamber 101.
5, the motor (the rotor 1011 and the stator 1012) and the oil sump are arranged in the lower part, the space for separating the lubricating oil from the refrigerant gas and the motor (the rotor 1
Since the space for housing 011 and the stator 1012) and the space for cooling the motor are different from each other, there has been a problem that the outer size of the compressor becomes large.

On the other hand, as a measure for improving the above problem (increased size), as shown in FIG. 19, a closed case (closed container) 1
A compression unit is provided at the bottom of 201 and a motor (electric motor) 12 is provided at the top
03, a discharge chamber oil sump (oil sump) 1215 is arranged at the bottom, and a discharge gas discharge pipe (delivery pipe) 1217 is arranged at the upper wall, and a compressed refrigerant gas is discharged through a discharge pipe 1214 to a motor (electric motor) 1
It is guided to a space for housing 203 (not shown), and after cooling the motor (electric motor) 1203 and separating the lubricating oil in the refrigerant gas, it is discharged from the discharge pipe (delivery pipe) 1217 to the outside of the machine while the drive shaft ( The bearing portion and the compression chamber supporting the crankshaft 1204 are immersed in the discharge chamber oil sump (oil sump) 1215, and provided on the boss portion 1205a of the main body frame (frame) 1205 supporting the drive shaft (crankshaft) 1204. And a bearing gap of a main bearing (bearing portion) that supports the drive shaft (crankshaft) 1204, a back pressure chamber (intermediate chamber) 1208 provided between the main body frame (frame) 1205 and the orbiting scroll 1206. , Orbiting scroll 12
The lubricating oil of the discharge chamber oil sump (oil sump) 1215 is differentially supplied to the compression chamber 1216 through the communication hole 1211 provided in the compressor 06, and the compressor is miniaturized and the discharge chamber oil sump at the initial stage of compressor start-up. Even if the pressure rise in the (oil sump) 1215 is small, the bearing sliding portion can be lubricated (JP-A-57-35184).

However, as in the case of FIG. 18 described above, the total amount of lubricating oil that lubricates the main bearing (bearing portion) that supports the drive shaft (crankshaft) 1204 is the compression chamber 1216.
In addition to the self-weight of at least the drive shaft (crankshaft) 1204 and the motor (electric motor) 1203, the discharge chamber oil reservoir (oil reservoir) 1215 and the back pressure chamber (intermediate chamber) 1208 Since the downward thrust force acting on the drive shaft (crankshaft) 1204 due to the differential pressure must be supported by the orbiting scroll 1206, the compression chamber 1216
There was a problem that the amount of lubricating oil flowing into the tank further increased, resulting in a significant decrease in compression efficiency.

As described above, it is difficult to simultaneously solve the reduction of the compressor input and the compression efficiency and the downsizing of the compressor by simply combining the conventional techniques.

The present invention is intended to solve such a conventional problem, and an object thereof is to provide a small scroll gas compressor having a low input and a high compression efficiency.

[0017]

In order to solve the above-mentioned problems, the present invention provides a differential pressure oil supply passage for finally supplying the lubricating oil of the oil reservoir of the discharge chamber to the compression chamber via the sliding portion of the slewing bearing. On the other hand, the lubricating oil of the discharge chamber oil reservoir arranged at a considerable height from the main bearing is sucked and discharged by the screw pump action by the oil groove provided on the sliding surface of the main bearing, and then returned to the discharge chamber oil reservoir again. A bearing oil supply passage is provided.

With the structure of the bearing oil supply passage and the differential pressure oil supply passage, sufficient oil supply to the main bearing can be realized by a simple and low input oil supply means, while an appropriate amount of oil is supplied to the compression chamber to seal the oil film in the compression chamber gap. it can.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the invention described in claim 1, the scroll compression mechanism is housed in the lower part of the hermetic case, the motor connected to the drive shaft is housed in the upper part of the hermetic case, and the gas discharged from the discharge port is After the motor is cooled, a discharge gas passage for discharging to the outside of the hermetically sealed case is provided, and a discharge chamber oil sump on which discharge pressure acts is provided below the motor and supporting the drive shaft and a main bearing on the side close to the compression chamber. Arranged at a considerable height, and through the sliding part of the orbiting bearing where the drive shaft and the orbiting scroll engage with each other and the anti-compression chamber side of the orbiting scroll, one of the discharge chamber oil sump is In a configuration in which a differential pressure oil supply passage for supplying lubricating oil is provided, it is arranged inside a thrust bearing provided in a main body frame that supports the drive shaft and is adjacent to the main bearing, the slewing bearing, and the lap support disc. Differential pressure supply to the arranged oil chamber A bearing oil supply passage that is located in the middle of the passage and is branched from the differential pressure oil supply passage to return the lubricating oil in the oil chamber to the discharge chamber oil sump by the screw pump action of the spiral oil groove provided on the sliding surface of the main bearing. Is formed. According to this configuration, when the lubricating oil in the oil reservoir of the discharge chamber is introduced into the oil chamber by the screw pump action of the spiral oil groove, the suction action due to the differential pressure between the compression chamber (or the suction chamber) is received. It becomes easy to introduce lubricating oil into the oil chamber, and low speed ~
It becomes easy to secure the required pump oil supply amount at the time of high speed operation, and the pump oil supply passage is shortened, so that the pump input of the screw pump mechanism by the spiral oil groove becomes extremely low. Further, the lubricating oil in the oil chamber urges the anti-compression side of the orbiting scroll to reduce the thrust force acting on the orbiting scroll, thereby reducing the frictional resistance of the axial sliding contact surface of the orbiting scroll.

According to a second aspect of the present invention, at least the thrust bearing portion for supporting the weight of the drive shaft and the motor is disposed in the middle of the bearing oil supply passage. Further, according to this configuration, the damage caused by the lubricating oil whose temperature has risen in the thrust bearing portion flowing into the compression chamber is reduced.

According to a third aspect of the invention, the thrust bearing portion is arranged at the end of the bearing oil supply passage. Further, according to this configuration, while avoiding the adverse effect of the lubricating oil whose temperature has risen in the thrust bearing portion flowing into the compression chamber,
It is possible to avoid adverse effects on the lubrication performance of the main bearing.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A scroll refrigerant compressor according to an embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIGS. 1 to 15, reference numeral 1 denotes an iron-made sealed case, the contents of which are an orbiting scroll 218.
A main body frame 2 that bolts a fixed scroll 15 that meshes with and forms a compression chamber and that supports the drive shaft 204.
By 05, the upper motor chamber 6 and the lower accumulator chamber 46 are partitioned.

The motor chamber 6 has a high-pressure atmosphere, the motor 3 is arranged in the upper part, and the compression part is arranged in the lower part.
Is made of eutectic graphite cast iron having excellent sliding properties and weldability, and the protrusions 79a provided on the outer peripheral surface thereof are in contact with the inner wall surface and the end surface of the upper closed case 1a and the lower closed case 1b. The protruding strip 79a, the upper closed case 1a, and the lower closed case 1b are hermetically welded by a single welding beat 79b.

The drive shaft 204 has an upper bearing 211 provided at the upper end of the main body frame 205, a main bearing 212 provided at the center, and a plurality of radial shallow grooves 7 provided on the upper end surface of the main body frame 205. Thrust bearing portion 21
The crankshaft 214 at the lower end portion, which is supported by 3 and is eccentric from the main shaft of the drive shaft 204, is engaged with the orbiting bearing 218b of the orbiting boss portion 218e provided on the orbiting scroll 218.

The fixed scroll 15 is made of a high silicon aluminum alloy whose coefficient of thermal expansion corresponds to an intermediate value between pure aluminum and eutectic graphite cast iron. The fixed scroll 15 has a spiral fixed scroll wrap 15a and an end plate as shown in FIG. 15b, and a fixed scroll wrap 1 is provided at the center of the end plate 15b.
The discharge port 16 opening at the winding start portion of the motor chamber
A suction chamber 17 is provided on the outer periphery of the fixed scroll wrap 15a.

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

As shown in FIGS. 1 and 14, a spiral orbiting scroll wrap 218a meshing with the fixed scroll wrap 15a to form a compression chamber side wall, and a drive shaft 20.
The orbiting scroll 218 made of an aluminum alloy, which is composed of a lap support disk 218c in which an orbiting boss portion 218e engaged with the crankshaft 214 of No. 4 and which is upright, is arranged surrounded by the fixed scroll 15 and the main body frame 205. The surfaces of the lap support disk 218c and the orbiting scroll wrap 218a are subjected to a hardening treatment such as porous nickel plating.

As shown in FIG. 3, a spiral tip seal groove 98 is provided at the tip of the orbiting scroll wrap 218a, and a resin tip seal 98a has a minute gap in the tip seal groove 98. It is installed. When the orbiting scroll 218 is pressed in the axial direction of the fixed scroll 15, the flat portion of the lap support disk 218c contacts the tip of the fixed scroll wrap 15a, but the tip of the orbiting scroll wrap 218a does not contact the fixed scroll 15. It keeps a microscopic distance.

The discharge passage 80 (see FIG. 1) is provided in the discharge chamber 2 and the fixed scroll 15 formed by the discharge cover 2a and the mirror plate 15b mounted on the mirror plate 15b so as to cover the check valve device 50. Gas passage B80b, gas A80a provided in the main body frame 205, main bearing 21
2 is composed of a discharge guide 81 attached to the body frame 205 so as to surround 2 and a discharge chamber 2b formed by the body frame 205, and the gas passage A80a and the gas passage B80b are respectively 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.

The accumulator chamber 46 communicating with the evaporator side of the refrigeration cycle is formed by the lower closed case 1b, the fixed scroll 15 and the main body frame 205, and the suction pipe 47 communicating therewith is provided on the side surface of the lower closed case 1b. About 90 each from the position facing the suction pipe 47
The suction holes 43 are fixed at two positions spaced apart from each other.
5 (see FIG. 14).

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

A flat plate-shaped thrust bearing 22 that can be moved only in the axial direction by being restrained from moving in the rotational direction by a parallel pin 19 of a split pin type fixed to the main body frame 205.
0 is arranged between the lap support disk 218c and the main body frame 205, and the elastic force of the annular seal ring (made of rubber) 70 (see FIG. 13) interposed between the thrust bearing 220 and the main body frame 205. By the end plate mounting surface 15b between the main body frame 5 and the fixed scroll 15
It is in contact with 1.

Lap support disk 2 of orbiting scroll 218
The height from the end plate sliding surface 15b2 that is in sliding contact with the end plate 18c to the end plate mounting surface 15b1 is set in order to improve the sealing property of the sliding portion by the oil film of the lap supporting disk 218c.
It is set to be about 0.015 to 0.020 mm larger than the thickness of 18c.

As shown in FIGS. 1 and 8, an annular seal groove 9 concentric with the center of the orbiting bearing 218b is formed on the end surface of the orbiting boss 218e of the orbiting scroll 218 on the body frame 205 side.
5, an annular ring 94 made of a flexible resin is attached to the annular seal groove 95, as shown in FIG.
The outer peripheral surface of the annular ring 94 comes into close contact with the side surface of the annular seal groove 95 due to thermal expansion of the annular ring 94 and the lubricating oil pressure inside the annular ring 94 during operation of the compressor, and also to the outer peripheral surface of the annular ring 94. Cut 94 with angle of inclination
b are arranged to be in close contact with each other. Annular ring 94
Is the orbiting scroll 21 formed by the orbiting scroll 218, the main body frame 205, and the thrust bearing 220.
No. 8 back pressure chamber 39 and a main bearing 212 supporting the drive shaft 204
Is sealed between the oil chamber A278a on the side of the
It is sealed so as to prevent excessive leakage from a to the back pressure chamber 239.

The annular thrust bearing 220 is made of a sintered alloy that is easy to form holes, and as shown in FIGS. 12 and 13, 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 205.

Body frame 205 and thrust bearing 220
A release gap 27 of about 0.05 mm is provided between the release gap 27 and the release gap 27, and an annular groove 28 for mounting a seal ring 70 is provided inside and outside the release gap 27. The seal ring 70 seals between the release gap 27 and the back pressure chamber 239.

The release gap 27 is formed by the body frame 205.
The thrust back pressure introducing hole A89a provided in the fixed scroll 15 and the thrust back pressure introducing hole B89b provided in the fixed scroll 15 communicate 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 Oldham ring) 24 of the orbiting scroll 218 arranged inside 20 is made of a light alloy or a reinforced fiber composite material suitable for sintering molding, injection molding, etc., and has a flat ring shape. The both sides are provided with parallel key-shaped key portions which are orthogonal to each other. The key portion on the upper surface side is a key groove 71a provided on the main body frame 205, and the key portion on the lower surface side is a key provided on the lap support disk 218c. It engages with the groove 71 and slides.

The thickness of the Oldham ring 24 is determined by the thickness of the body frame 20 when the Oldham ring 24 reciprocates.
5 and the lap support disk 218c are set so as to slide smoothly and the jumping phenomenon does not occur.

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, which is axially positioned by the stepped portion of the drive shaft 204, drives the drive shaft 20 together with the upper balance weight 75.
4, 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 shielding plate 86 attached to the main body frame 205 is arranged close to the lower balance weight.

The discharge chamber oil sump 34 provided in the lower portion of the motor chamber 6 communicates with the upper portion of the motor chamber 6 by a cooling passage 35 provided by cutting out a part of the outer periphery of the stator 3b of the motor 3. .

The discharge chamber oil sump 34 is formed by the body frame 2
05 through the oil hole A238a provided in the main bearing 212
And an oil chamber A 278a at an intermediate position between the rotary bearing 218b and the rotary bearing 218b.

As shown in FIGS. 1 and 8, on the surface of the sliding shaft portion 204a of the drive shaft 204 and the crankshaft 214,
When the drive shaft 204 rotates in the forward direction, the lubricating oil in the oil chamber A278a forms an oil chamber B278b formed by the slewing bearing 218b and the crankshaft 214 and the spiral oil grooves 241a and 241b in the direction of screw pump oil supply to the motor 3 side. Provided,
The upper end thereof reaches the thrust bearing portion 213.

Oil hole A2 provided in the main body frame 205
High pressure oil chamber A2 communicating with the discharge chamber oil sump 34 via 38a
A partition cap 101 made of steel plate having an external shape as shown in FIG. 9 is press-fitted into the stepped inner wall of 78a and is arranged so as to cover the brim portion 102 of the drive shaft 204 as shown in FIG. . A part of the cap 101 has a cut 1
01a, the cut 101a is closed in a state where the oil chamber A278a is mounted on the stepped inner wall of the oil chamber A278a, and the oil chamber A278a is divided into the main bearing 212 side and the slewing bearing 218b side.

Revolving boss portion 218 of revolving scroll 218
e is a slewing bearing 2 whose external shape is shown in FIG.
18b is press-fitted. Slewing bearing 21 having a cylindrical shape
A part of the outer peripheral portion of 8b is flattened, and the step C is set to about 100 microns. As shown in FIG. 8, the step C forms the throttle passage 103 while being pressed into the turning boss 218e.

An annular groove 104 and a small-diameter oil hole 105 are provided in the turning boss portion 218e. The discharge chamber oil sump 34 and the back pressure chamber 239 communicate with the oil hole A238a, the oil chamber A278a, the spiral oil groove 241b, the oil chamber B278b, the throttle passage 103, the annular groove 104, and the oil hole 105.

As shown in FIGS. 1, 13, and 14, the back pressure chamber 239 has about 18 points before the first refrigerant compression chambers 61a, 61b, which communicate with the suction chamber 17 intermittently, are closed.
Within the swing angle range of 0 degree, the oil groove 291, the outer peripheral space 37 outside the lap support disk 218c provided in the thrust bearing 220, the oil hole C38c provided in the lap support disk 218c, and the symmetrical positions are provided. And the oil passages 291 provided in the thrust bearing 220 are intermittently opened and closed by the lap support disk 218c. To be done.

In FIG. 15, the horizontal axis represents the rotation angle of the drive shaft 4, the vertical axis represents the refrigerant pressure, the pressure change state of the refrigerant gas 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 score 63 shows the pressure change with abnormal pressure rise.

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

1 to 15, when the drive shaft 204 is rotationally driven by the motor 3, the orbiting scroll 218 is rotated.
Is driven by the crank mechanism of the drive shaft 204.
Try to rotate around the main axis of the Oldham ring 24
The key portion on the side of the orbiting scroll 218 (see FIG. 2) is engaged with the key groove 71 of the orbiting scroll 218, and the key portion on the opposite side is the key groove 71a of the body frame 205 (see FIG. 1).
Since it is engaged with, the rotation is prevented, and the orbital motion is performed to change the volume of the compression chamber together with the fixed scroll 15, and the refrigerant gas is sucked and compressed.

The release gap 27 on the rear side of the thrust bearing 220, 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 a high-pressure refrigerant gas with the lapse of time immediately after the start of compression. Charged. Due to the back pressure bias and the elastic force of the seal ring 70, the thrust bearing 220 is attached to the end plate mounting surface 1 of the fixed scroll 15.
It is pressed against 5b1. Thereby, the orbiting scroll 2
The lap support disk 218c of 18 is sandwiched between the end plate sliding surface 15b2 and the thrust bearing 220 (an assembly gap of 15 to 20 microns).

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

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

The suctioned refrigerant gas separated into gas and liquid is sucked into the suction chamber 1.
7. First compression chambers 61a and 61b formed between the orbiting scroll 218 and the fixed scroll 15 (see FIG. 14)
Through the second compression chamber 51a, 5
1b, 3rd compression chambers 60a, 60b are sequentially transferred and compressed, and then discharged from the central discharge port 16 to the check valve chamber 50a to discharge chamber 2, gas passage B80b, gas passage A80.
A is sequentially discharged to the motor chamber 6 through the discharge chamber 2b.

Since the compression chamber and the discharge port 16 are opened immediately after completion of the compression, the compressed refrigerant gas undergoes a rapid primary expansion when flowing into the check valve chamber 50a from the compression chamber, and the discharge immediately after that. From the completion stroke to the compression completion stroke, the refrigerant gas discharged from the check valve chamber 50a primarily flows back into the compression chamber.

As a result, the refrigerant gas intermittently flows out of the third compression chamber (60a, 60b) and the third compression chamber (60).
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 out toward the spherical wall surface forming the discharge chamber 2 through the discharge small hole 50h of the check valve device 50, and further collides with the spherical wall surface. Distribute evenly. After that, the two discharge passages 80 arranged at symmetrical positions merge in the discharge chamber 2b and the motor chamber 6, so that the discharge gas pulsations from the respective discharge passages 80 and the third and third discharge passages are attenuated. Due to the fourth-order expansion, the pressure is further attenuated in sequence, and there is almost no pressure fluctuation in the motor chamber 6.

When the discharged refrigerant gas instantaneously flows back from the discharge chamber 2 to the check valve chamber 50a, the valve body 50b tries to move in the direction of closing the discharge port 16 following the flow, but the compression is performed. During operation of the machine, the coil spring 50c having a shape memory characteristic is completely contracted by the ambient temperature and does not exert a force on the valve body 50b, and the magnetic valve body 50b is attracted to the bottom surface of the check valve chamber 50a. 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 is an 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 winding on the lower part 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 discharged refrigerant gas passing through the outer peripheral portions of the weight 75 and the lower balance weight 76 is centrifugally separated by the rotation of the upper balance weight 75 and the lower balance weight 76, and diffused to the inner surface of the winding of the motor 3. ,
It flows down to the lower part along the internal space of the winding bundle,
Collect at 4.

The lubricating oil in the discharge chamber oil sump 34 is passed through a route described later, and the oil chamber A278a, the oil chamber B278b and the back pressure chamber 2 are supplied.
39, and the back pressure applying force to the orbiting scroll 218 gradually increases.

Following the increase in pressure in the motor chamber 6, the lap support disk 218c 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 218c of the orbiting scroll 218 is eliminated, thereby sealing the compression chamber and efficiently compressing the sucked refrigerant gas to continue stable operation.

The axial gap between the tip of the orbiting scroll wrap 218a and the end plate 15b of the fixed scroll 15 is such that the tip seal groove 98 (Fig. 3)) and the gas back pressure causes the tip seal 98a to be pressed against 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 218 instantaneously makes a reverse orbiting 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 218 is shown in FIG.
As shown in FIG. 4, the first compression chambers 61a and 61b stop at the turning angle in a state where the first compression chambers 61a and 61b communicate with the suction chamber 17.

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

Due to the temporary backflow of the discharged refrigerant gas immediately after the compressor is stopped and the reverse orbit of the orbiting scroll 218, the magnetic valve body 50b is separated from the bottom surface of the check valve chamber 50a.
The valve body 51b keeps closing the discharge port 16 due to the pressure difference until the refrigeration cycle balances the pressure. At the same time, the temperature of the coil spring 50 having a shape memory characteristic is lowered and the coil spring 50 expands.
0b continues to block the discharge port 16.

The first compression chambers 61a, 61b and the back pressure chamber 39, which communicate intermittently with the suction chamber 17, are the first compression chambers 61a, 6a.
Oil groove 291 provided in thrust bearing 220 only when 1b is within 180 degrees before completion of closing (see FIG. 13)
Since the thrust bearing 220 and the lap support disk 218c are sealed with a lubricating oil film, the refrigerant gas does not flow backward from the compression chamber to the back pressure chamber 239 during compression.

When the compressor is stopped for a long time, the pressure inside 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 218 by the pressure of the liquid compressed refrigerant in the compression chamber. As a result, the orbiting scroll 218 is separated from the fixed scroll 15 in the axial direction, and the compression load is reduced.

On the other hand, the back pressure chamber 239 in the initial stage of starting when the compressor is cold.
Since the increase in the lubricating oil pressure in the discharge chamber oil sump 34 is low, the pressure is substantially equivalent to the suction pressure. As a result, the lap support disk 218c of the orbiting scroll 218 is separated from the end plate sliding surface 15b2 in a state in which the back pressure is applied only by the lubricating oil in the oil chamber A278a having a low pressure rise, and the thrust bearing 22.
It is retracted to 0 and supported, and a gap (about 0.0 mm) is formed between the lap support disk 218c and the tip of the fixed scroll wrap 15a.
15-0.020 micron), the pressure in the compression chamber drops, and the compression load in the initial stage of starting is reduced.

If liquid compression occurs in the compression chamber and the pressure in the compression chamber rises abnormally instantaneously during continuous operation, the thrust force acting on the orbiting scroll 218 will be applied to the rear surface of the orbiting scroll 218. It becomes larger than the back pressure biasing force that acts, the orbiting scroll 218 moves in the axial direction,
It is supported by the thrust bearing 220. 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 239 is the first compression chamber 61.
Since a and 61b communicate with the outer peripheral space 37 through the oil groove 291 provided in the thrust bearing 220 within the swivel angle range of about 180 degrees before the completion of the intake refrigerant gas confinement,
Liquid compression does not occur within this communication swirl range. 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 239 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 starting when the compressor is cold is the spiral oil groove 241 provided in the drive shaft 204.
By the screw pump action of a and 241b, the oil hole A238
It is sucked into the oil chamber A278a via a.

At this time, the partition cap 101 guides the lubricating oil so that it passes near the surface of the drive shaft 204 and flows into the oil chamber A 278a and the spiral oil groove 241b. As a result, when the lubricating oil flows into the oil chamber A278a from the oil hole A238a, the screw shaft is sucked into the spiral oil groove 241a without being affected by centrifugal diffusion due to the high speed rotation of the drive shaft 204, and a good screw pump oil supply is performed. Be seen.

After that, the lubricating oil in the oil chamber A278a lubricates the sliding surface of the slewing bearing 218b through the spiral oil groove 241b, is supplied to the oil chamber B278b, is decompressed through the throttle passage 103, and the annular groove 104, the oil. While flowing into the back pressure chamber 239 through the hole 105, it is sequentially supplied to each sliding surface of the main bearing 212, the upper bearing 211, and the thrust bearing portion 213 by the screw pump action of the spiral oil groove 241a, and the discharge chamber oil reservoir Return to 34.

The refrigerant gas in the motor chamber 6 is prevented from flowing back to the oil sump 72 by the lubricating oil passing through the upper bearing 211.

The discharge refrigerant gas pressure in the motor chamber 6 rises following the lapse of time after the compressor starts cold, and the discharge chamber oil sump 34
The lubricating oil in the oil chamber A is also affected by the differential pressure between the lubricating oil and the back pressure chamber 239.
It is supplied to the back pressure chamber 239 together with the screw pump action of the spiral oil groove 241b. Back pressure chamber 239
Is gradually increased, and the combined force with the lubricating oil pressure corresponding to the discharge pressure of the oil chamber A 278a acts on the lap support disk 218c of the orbiting scroll 218. As a result, the thrust load acting to separate the orbiting scroll 218 from the fixed scroll 15 is offset by the refrigerant gas pressure in the compression chamber, and the thrust force acting on the orbiting scroll 218 is reduced.

Therefore, while the pressure rise in the motor chamber 6 after the cold start of the compressor is low, the oil chamber A 278a and the back pressure chamber 23 are
The force applied to the orbiting scroll 218 by the lubricating oil pressure of No. 9 is smaller than the thrust load on the orbiting scroll 218 by the refrigerant gas pressure in the compression chamber. As a result, the orbiting scroll 218 is separated from the fixed scroll 15 and is supported by the thrust bearing 220 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 218 by the lubricating oil pressure of the oil chamber A 278a and the back pressure chamber 239 is the orbiting scroll by the refrigerant gas pressure of the compression chamber. It becomes larger than the thrust load on 218. The orbiting scroll 218 is supported by the fixed scroll 15.

The center of the compression chamber, the center of the slewing bearing 218e,
In the arrangement in which the centers of the annular rings 94 are substantially coincident with each other, the annular rings 94 orbit together with the orbiting scroll 218, so that the inertial force at that time attempts to jump out from the annular seal groove 95 provided in the orbiting boss portion 218e. . Further, the annular ring 94 expands its inner diameter by the pressure difference between the oil chamber A 278a and the back pressure chamber 239, and closes the cut end 94b together with the thermal expansion. By these actions, the annular ring 94 is pressed against the outer surfaces of the main body frame 205 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 94 to move.
Lubricating oil is pushed in between and to prevent excessive leakage of lubricating oil from the oil chamber A 278a to the back pressure chamber 239.

Further, the resinous annular ring 94 having excellent flexibility expands its inner diameter along the outer side surface of the annular seal groove 95 due to the pressure difference between the back pressure chamber 239 and the oil chamber A 278a, and heat The cut 94b is closed together with the expansion and is pressed against the outer side surface of the annular seal groove 95, so that the leakage between both spaces is further reduced.

The annular ring 94 is formed by the oil film of the lubricating oil accumulated in the oil groove 94a provided on the surface of the annular groove 94.
By lubricating the sliding surface between the main body frame 205 and the main body frame 205, abrasion and sliding resistance of the sliding surface are reduced.

During normal operation of the compressor, the high pressure oil chamber A278
The orbiting scroll 218 is given back pressure to the fixed scroll 15 side by the lubricating oil pressure of a and the lubricating oil pressure of the back pressure chamber 239, and the lap support disk 218c and the end plate sliding surface 15b2.
Smoothly slides while maintaining an appropriate contact force, and minimizes the axial clearance of the compression chamber.

The lubricating oil flowing into the back pressure chamber 239 intermittently flows into the outer peripheral space 37 via the oil groove 291 provided in the thrust bearing 220, and further the lap supporting disk 218c.
Is gradually reduced through an oil hole C38c provided in the cylinder and injection holes 52a and 52b (see FIG. 14) having a small diameter,
It flows into the first compression chambers 61a and 61b. The lubricating oil lubricates each sliding surface in the middle of the passage and seals the sliding gap.

The lubricating oil injected into the first compression chambers 61a and 61b 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.

In the oil supply path from the discharge chamber oil sump 34 via the back pressure chamber 239 to the first compression chambers 61a, 61b,
The back pressure chamber 239 maintains a proper 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 the case such as the above, the orbiting scroll 2 is used as described above.
18 is separated from the fixed scroll 15, and the thrust bearing 2
Supported by 20.

However, the thrust bearing 220 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 218c of the orbiting scroll 218. The axial gap between the scroll 15 and the tip of the fixed scroll wrap 15a increases. As a result, a large amount of leakage occurs between the compression chambers, and the pressure in the compression chamber suddenly drops during the compression as shown by the dashed line 63a in FIG.

The orbiting scroll 218 is the fixed scroll 1.
Since the maximum distance apart from 5 in the axial direction is regulated to about 70 microns, an oil film remains in each gap between the sliding surfaces on both sides of the lap support disk 218c, and the outer peripheral space 37 and the suction chamber 1
The pressure change in the back pressure chamber 239 due to the direct communication with 7 is suppressed, the compression load is instantly reduced, and then the thrust bearing 220 can be instantly returned to the original position, and the stable operation is resumed.

When the orbiting scroll 218 retracts toward the thrust bearing 220, the orbiting scroll wrap 21
The axial dimension between the tip of 8a 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,
Almost no compressed refrigerant gas leaks from this portion.

On the other hand, the gap between the wrap support disk 218c of the orbiting scroll 218 and the tip of the fixed scroll wrap 15b of the fixed scroll 15 expands, and compressed refrigerant gas leaks in the compression chamber, resulting in a sudden pressure increase in the compression chamber. descend.

Also, when foreign matter is caught in the axial gap between the orbiting scroll 218 and the fixed scroll 15, the thrust bearing 20 retreats and removes the foreign matter in the same manner as described above.

Further, in the initial stage of cold start-up or during steady operation, the pressure in the compression chamber when instantaneous liquid compression occurs causes abnormal overcompression as indicated by the 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.

Also, as the compressor operating speed increases, the refrigerant gas leakage in the compression chamber per unit time decreases. On the other hand, the injection holes 52a, 52 per one turning motion
The opening time of b is shortened, the amount of oil injection into the compression chamber per turning motion is suppressed, and unnecessary oil compression is reduced.

Further, in the above embodiment, the thrust bearing 220
Although the compressed refrigerant gas in the final compression stroke is introduced into the release gap 27 provided on the back surface of the above, the discharged refrigerant gas in the region where the compression chamber and the discharge port 16 communicate with each other in the final compression stroke may be introduced into the release gap 27. .

In the above embodiment, the orbiting scroll 21 is used.
Although the sliding gap between the lap support disk 218c of No. 8 and the thrust bearing 220 was sealed only with an oil film of lubricating oil, an annular ring as proposed by the inventor of Japanese Patent Application No. 63-159996 was used. It may be mounted on the back side of the lap support disk 218c to improve the sealing performance of the sliding portion gap between the back pressure chamber 239 and the outer peripheral space 37.

The injection hole 52 communicating with the first compression chambers 61a, 61b, which communicates intermittently with the suction chamber 17, is provided.
By changing the opening positions of a and 52b, the back pressure chamber 2
The pressure of 39 can be set to an intermediate pressure close to the suction pressure.

In the above embodiment, the annular ring 94 is arranged in the annular seal groove 95 provided in the orbiting boss portion 218e of the orbiting scroll 218.
As described in Japanese Patent Publication No. 8396, when the annular seal groove and the annular ring are provided in the main body frame 205, the same operation as described above is performed.

As described above, according to the above embodiment, the effects of the embodiments described below can be obtained.

That is, in the first embodiment, the scroll compression mechanism is housed in the lower part of the closed case 1, and the drive shaft 20
The motor 3 to be connected to 4 is stored in the upper part of the sealed case 1,
After the discharge refrigerant gas discharged from the discharge port 16 cools the motor 3, a discharge refrigerant gas passage that is discharged to the outside of the closed case 1 is provided, and the discharge chamber oil sump 34 on which the discharge pressure acts is provided below the motor 3. The drive shaft 204 is supported and is disposed at a considerable height with the main bearing 212 on the side close to the compression chamber.
04 and the orbiting scroll 218 are engaged with the orbiting bearing 21.
In the configuration in which the differential pressure oil supply passage for supplying the lubricating oil of the discharge chamber oil sump 34 is provided to the first compression chambers 61a and 61b via the sliding portion of 8b and the anti-compression side of the orbiting scroll 218, An oil chamber A 278a, which is arranged inside the thrust bearing 202 provided in the supporting main body frame 205 and is arranged adjacent to the main bearing 212, the slewing bearing 218b, and the lap support disk 218c, is provided in the middle of the differential pressure oil supply passage. And the lubricating oil in the oil chamber A 278a is branched from the differential pressure oil supply passage by the screw pump action of the spiral oil groove 241a provided on the sliding surface of the main bearing 212.
A bearing oil supply passage for returning to the bearing is formed.

According to this configuration, the discharge chamber oil sump 34
When the lubricating oil of No. 1 is introduced into the oil chamber A 275a by the pumping action of the spiral oil groove 241a, the first compression chamber 61
With the aid of the suction action due to the differential pressure between the a and 61b, it becomes easy to introduce the lubricating oil into the oil chamber A278a, and it is possible to easily secure the required pump oil supply amount during low speed to high speed operation, and the pump oil supply passage is short Therefore, the pump input of the screw pump mechanism by the spiral oil groove 241a can be made extremely low.
In addition, the lubricating oil in the oil chamber A 278a is the orbiting scroll 218.
It is also possible to reduce the thrust force acting on the orbiting scroll 218 by urging the anti-compression side thereof to reduce the frictional resistance of the axial sliding contact surface of the orbiting scroll 218.

In the second embodiment, the thrust bearing portion 213 that supports the own weight of the drive shaft 204 and the rotor 3a of the motor 3 is used.
Is disposed in the middle of the bearing oil supply passage. Further, according to this configuration, it is possible to reduce thermal adverse effects caused by the lubricating oil whose temperature has risen in the thrust bearing portion 213 flowing into the first compression chambers 61a and 61b.

In the third embodiment, the thrust bearing portion 21
3 is arranged at the end of the bearing oil supply passage. Further, according to this configuration, the lubricating oil whose temperature has risen in the thrust bearing portion 213 does not flow into the first compression chambers 61a and 61b, so that reduction in compression efficiency is prevented and the main bearing 212 is prevented.
It is possible to avoid adverse effects on the lubrication performance.

(Embodiment 2) FIG. 16 is a vertical sectional view of a scroll refrigerant compressor according to a second embodiment of the present invention. The inside of a hermetically sealed case 2001 is a high pressure space, and a discharge chamber oil sump 203 is provided below.
4 and the scroll compressor groove, and the motor 3 is arranged on the upper part.

The suction chamber 17 is made of a steel sealed case 2001.
Through a suction pipe 2047 passing through the side wall of the compressor.

The main body frame 2005 made of cast iron fixes the fixed scroll 2015 and also seals the case 200.
One side wall is fixed by welding at several places.

The drive shaft 2004 connected to the motor 3 has a main bearing 2012 on the side close to the compression portion of the main body frame 2005.
And the upper bearing 2011 on the motor side,
The crankshaft 2014 is slidably connected to the orbiting bearing 2018b of the orbiting scroll 2018.

The discharge chamber oil sump 2034 is the body frame 20.
05 and an oil suction passage 2038 provided in the fixed scroll 2015, and communicates with an oil chamber A 2078 a on the compression chamber side of the main bearing 2012.

Crankshaft 2014 and slewing bearing 2018b
Is formed in the orbiting scroll 2
218 of the turning boss portion 2018e
0 to the back pressure chamber 2039 and the slewing bearing 2
It communicates with the oil chamber A2078a through the sliding gap of the portion 018b.

Outer space 20 of orbiting scroll 2018
37 and the back pressure chamber 2039, the Oldham ring 202
Key groove 2071 of the orbiting scroll 2018 which engages with No. 4
The first compression chambers 61a and 61b (see FIG. 14) are intermittently communicated with each other via the oil groove 291 provided in the thrust bearing 220 only while communicating with the suction chamber 17.

Oil groove 291 and key groove 2 provided at two locations
Numerals 071a are arranged at opposite positions, and are intermittently connected between the back pressure chamber 2039 and the outer peripheral space 2037 at a phase angle of 180 degrees.

Since the other structure is similar to that of the first embodiment, the description thereof will be omitted. Next, the operation of this embodiment will be described.

Due to the pressure difference between the discharge chamber oil sump 2034 and the compression chamber where the discharge pressure acts, the lubricating oil in the discharge chamber oil sump 2034 flows into the compression chamber through the following differential pressure path, and in the middle of that passage. Lubrication of the sliding portion, back pressure for pressing the orbiting scroll 2018 toward the fixed scroll 2015, and oil film sealing for preventing gas leakage in the sliding portion gap are provided.

That is, the lubricating oil in the discharge chamber oil sump 2034 is supplied to the oil chamber A2 via the oil suction passage 2038 provided in the main body frame 2005 and the fixed scroll 2015.
078a.

The lubricating oil in the oil chamber A2078a is supplied to the drive shaft 20.
The main oil bearing 2012
It is supplied to the upper bearing 2011, and the crankshaft 2
The primary pressure is reduced through the bearing gap between 014 and the slewing bearing 2018b, flows into the oil chamber B2078b, and the fine hole 204
After being depressurized secondarily through 0, it flows into the back pressure chamber 2039.

The openings to the back pressure chamber 2039 of the small holes 2040 provided at the two positions of the turning boss portion 2018e are in the vicinity of the key groove 2071a of the engaging sliding portion between the Oldham ring 2024 and the main body frame 2005. And the lubricating oil flowing from the oil chamber B2078b into the back pressure chamber 2039 is
The sliding surface of the key groove 2071a is forcibly lubricated.

Lubricating oil in the back pressure chamber 2039 passes through two key grooves 2071 provided in the orbiting scroll 2018 and two shallow grooves 291 provided in the thrust groove receiver 220, and slides in the key groove 2071. While lubricating the surface, a phase angle of 180 degrees is formed, and the pressure is thirdly reduced and flows into the outer peripheral space 2037 intermittently from positions on the opposite sides.

The lubricating oil inflow path from the outer peripheral space 2037 to the compression chamber is the same as in the case of the first embodiment.

Due to the pressure difference between the oil chamber A 2078 a and the oil chamber B 2078 b, the drive shaft 2004 abuts against the end face of the orbiting boss portion 2018 e of the orbiting scroll 2018 and is slidably supported.

Fixed scroll 2015 and body frame 2
The outer surface of the connection surface with the refrigerant 005 is surrounded by the lubricating oil of the discharge chamber oil reservoir 2034, and the refrigerant gas on the high pressure side flows into the outer peripheral space 2037 through the connection surface and is confined in the connection surface. Since the blocked oil film prevents the high-pressure refrigerant gas from flowing into the outer peripheral space 2037.

The refrigerant gas flowing into the suction chamber 17 through the suction pipe 2047 is compressed and then discharged into the discharge chamber 2,
After being discharged to the discharge chamber 2002b through two discharge passages 2080 provided at symmetric positions, the motor chamber 200
6 and is sent from the discharge pipe 2031 to an external refrigeration cycle.

The discharge passages 20 provided at symmetrical positions
The pressure pulsation and the discharge sound of the discharge refrigerant gas discharged from the discharge chamber 2002b to the discharge chamber 2002b interfere with each other and are attenuated. Attenuated. As a result, the motor room 200 communicating with the external piping system
The pressure fluctuation of 6 is attenuated to the extent that it does not affect the vibration of the external piping system.

Further, the compressed refrigerant gas flows from the compression chamber to the discharge chamber 2.
Is discharged by the lubricating oil in the discharge chamber oil reservoir 2034 surrounding the compression chamber and the discharge chamber 2, and is less likely to be transmitted to the outside of the closed case 2001.

Further, the compressed refrigerant gas flows from the compression chamber to the discharge chamber 2.
The discharge sound at the time of discharge to the compressor increases following the compressor operating speed.
600 rpm) or less, the discharge chamber 200
In some cases, the discharge refrigerant gas is directly discharged from the two discharge passages 2080 provided at symmetrical positions to the motor chamber 2006 without using 2b.

Although the above first and second embodiments have been described, these embodiments may be combined appropriately according to the compressor operating conditions.

Further, in the above embodiment, the lubricating oil in the back pressure chamber is made to flow into the first compression chambers 61a, 61b, but other compression chambers (operating speed, compression load, etc.) may be selected depending on the compressor operating conditions (operating speed, compression load, etc.). A compression chamber that does not communicate with the suction chamber 17 or the discharge port 16) or an oil supply passage that allows the oil to flow into the suction chamber 17 may be configured. When the oil supply passage for flowing into the suction chamber 17 is formed, the back pressure chamber can be set to a pressure close to the suction pressure.

As described above, according to the above embodiment, the scroll compression mechanism is housed in the lower part of the hermetically-sealed case 2001, and the motor 3 connected to the drive shaft 2004 is hermetically-sealed.
A discharge refrigerant gas passage which is stored in the upper part of the discharge port 16 and is discharged from the discharge port 16 to cool the motor 3 and then is discharged to the outside of the closed case 2001 is provided with a discharge chamber oil sump 2034 on which the discharge pressure acts. The drive shaft 2004 is supported and disposed at a considerable height with respect to the main bearing 2012 on the side closer to the compression chamber, and the drive shaft 2004 and the orbiting scroll 2018 are engaged with each other.
The first compression chambers 61a, 61b via the side opposite to the compression chambers 18
In the configuration in which the differential pressure oil supply passage for supplying the lubricating oil of the discharge chamber oil sump 2034 is provided in the main chamber frame 2005 supporting the drive shaft 2004, the main bearing 2012 and the slewing bearing are arranged inside the thrust bearing 202. 2018b
The oil chamber A 2078 a, which is partitioned and arranged adjacent to the lap support disc 2018 c, is arranged in the middle of the differential pressure oil supply passage, and the spiral oil groove 2041 a provided on the sliding surface of the main bearing 2012.
A bearing oil supply passage for returning the lubricating oil in the oil chamber A2078a to the discharge chamber oil sump 2034 by the pumping action by the above is formed. And according to this structure, the discharge chamber oil sump 2
When the lubricating oil 034 is introduced into the oil chamber A2075a by the pumping action of the spiral oil groove 2041a, the oil chamber receives the suction action due to the weight of the lubricating oil and the pressure difference between the oil chamber A2075a and the first compression chambers 61a and 61b. The lubricating oil can be easily introduced into the A2078a, the required pump oil supply amount can be easily ensured during the low speed to high speed operation, and the pump oil supply passage resistance is reduced. Therefore, the pump input of the screw pump mechanism by the spiral oil groove 2041a can be performed. Can be extremely low.

Further, the lubricating oil in the oil chamber A 2078 a urges the anti-compression side of the orbiting scroll 2018 to reduce the thrust force acting on the orbiting scroll 2018, and the frictional resistance of the axial sliding contact surface of the orbiting scroll 2018 is reduced. It can be reduced.

(Third Embodiment) FIG. 17 is a vertical cross-sectional view of a scroll refrigerant compressor according to a third embodiment of the present invention. The inside of a sealed case 801 made of soft iron is driven as in the case of FIG. A main body frame 805 supporting the shaft 704 divides the upper sealed case 801a side from the lower sealed case 801b side, and the inside of the upper sealed case 801a is a high-pressure space containing the motor 703.
The inside of b constitutes an accumulator chamber 846 with a low-pressure space communicating with the downstream side of the evaporator.

The drive shaft 704 connecting the motor 703 is
From the motor chamber 806 side to the main bearing 8 of the main body frame 805
12 is supported by a main bearing 812 and an upper frame (not shown).

The discharge chamber 2 has a gas passage B880b provided in the fixed scroll 815, a gas passage A880a provided in the main body frame 805, a discharge chamber 2c formed by the main body frame 805 and the discharge guide 81, and a high pressure side. Of the motor room 806.

A discharge pipe (not shown) provided at the upper end of the upper closed case 801a communicates with the motor chamber 806.

A spiral oil groove 841 provided on the drive shaft 704.
By the screw pump action of a and the spiral oil groove 841b,
The lubricating oil in the oil reservoir 34 of the discharge chamber is the oil chamber A878a and the oil chamber A87.
An oil supply passage is provided so as to be introduced into 8b. The lubricating oil in the oil chamber A878b is decompressed through the fine holes 2040a provided in the lap support disk 818c of the orbiting scroll 818 and flows into the back pressure chamber 839, while the main bearing 812
Is also supplied to the main bearing 8 through the spiral oil groove 841a.
After merging with the lubricating oil supplied to 12, the bearing oil supply passage is configured to return to the discharge chamber oil sump 34 via the thrust bearing portion 813 that supports the weight of the rotor 703a of the motor 703 and the drive shaft 704.

A plurality of coil springs 131 are arranged at equal intervals on the back compression side of the thrust bearing 220. The end faces of the coil springs 131 are pressed by the discharge guides 881 attached to the main body frame 805, and the thrust bearings are supported. 220 is an end plate 815b of the fixed scroll 815
Is pressed against.

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

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

Outer space 37 of orbiting scroll 818
Is intermittently communicated with the back pressure chamber 839 via the shallow groove 891 provided in the thrust bearing 220, and the fixed scroll 8
The suction chamber 17 communicates with an oil groove 899 provided in the sliding surface of the end plate 818b of the nozzle 18.

According to this embodiment, the back pressure chamber 83
9 holds a considerable pressure with the suction chamber 17.

Therefore, the application of back pressure to the orbiting scroll 818 acting on the fixed scroll 815 side depends only on the lubricating oil pressure in the oil chamber A878a.

According to this back pressure application form and the differential pressure oil supply passage form, immediately after the compressor is started, the oil chamber A878a and the oil chamber B are
Lubricating oil in the discharge chamber oil sump 34 can be supplied to 878b, and oil can be easily supplied to the bearing sliding surface adjacent thereto even during extremely low speed operation of the compressor.

In the above embodiment, the main bearing 212 and the slewing bearing 218b are arranged adjacent to each other in the main axis direction of the drive shaft 204, but they are disclosed in JP-A-58-79684 and JP-A-63.
It is obvious that the same action and effect as described above can be expected even in the case where the slewing bearing is arranged inside the main bearing as disclosed in Japanese Patent Publication No. 205490/1985.

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

[0146]

As is apparent from the above-described embodiment, according to the invention described in claim 1, the scroll compression mechanism is housed in the lower part of the hermetic case, and the motor connected to the drive shaft is housed in the upper part of the hermetic case. After the gas discharged from the discharge port cools the motor, a discharge gas passage is provided to the outside of the hermetically sealed case, and the discharge chamber oil reservoir under the discharge pressure acts under the motor and supports the drive shaft and compresses the compression chamber. It is placed at a considerable height with the main bearing on the side close to, and either the compression chamber or the suction chamber is passed through the sliding part of the orbiting bearing where the drive shaft and the orbiting scroll engage and the anti-compression chamber side of the orbiting scroll. In the structure in which the differential pressure oil supply passage for supplying the lubricating oil of the oil reservoir of the discharge chamber is provided on one side, the main bearing, the slewing bearing, and the lap support circle are arranged inside the thrust bearing provided in the main body frame supporting the drive shaft. Adjacent to the board The oil chamber is placed in the middle of the differential pressure oil supply passage, and the spiral oil groove provided on the sliding surface of the main bearing causes the screw pump action to branch from the differential pressure oil supply passage and discharge the lubricating oil in the oil chamber. The bearing oil supply passage that returns to the chamber oil sump is formed.With this configuration, when the lubricating oil in the discharge chamber oil sump is introduced into the oil chamber by the pumping action of the spiral oil groove, the self-weight of the lubricating oil And compression chamber (or suction chamber)
With the aid of the suction action due to the differential pressure between and, it becomes easier to introduce lubricating oil into the oil chamber, and it becomes easier to secure the required pump oil supply amount during low-speed to high-speed operation, and the pump oil supply passage resistance decreases. The pump input of the screw pump mechanism by the spiral oil groove can be made extremely low. In addition, the lubricating oil in the oil chamber urges the anti-compression side of the orbiting scroll to reduce the thrust force acting on the orbiting scroll, reducing the frictional resistance of the axial sliding contact surface of the orbiting scroll, and reducing the pump effect. There is an effect that the compressor input can be reduced and the durability can be improved synergistically.

According to the second aspect of the present invention, at least the thrust bearing portion for supporting the own weight of the drive shaft and the motor is arranged in the middle of the bearing oil supply passage. It is possible to reduce an adverse effect caused by the oil flowing into the compression chamber and prevent a decrease in compression efficiency.

According to the third aspect of the present invention, the thrust bearing portion is arranged at the end of the bearing oil supply passage. According to this configuration, the lubricating oil whose temperature has risen in the thrust bearing portion flows into the compression chamber. In addition to avoiding the adverse effect, the adverse effect on the lubrication performance for the main bearing can be avoided, the compression efficiency can be prevented from lowering, and the durability of the bearing sliding portion can be improved.

[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 partition cap and a bearing component in the compressor.

FIG. 10 is a perspective view of the partition cap and the bearing component.

FIG. 11 is a perspective view of a seal part of the compressor.

FIG. 12 is a perspective view of a thrust bearing in the compressor.

FIG. 13 is a partial sectional view of a thrust bearing portion of the compressor.

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 vertical cross-sectional view of a scroll refrigerant compressor showing a second embodiment of the present invention.

FIG. 17 is a vertical sectional view of a scroll refrigerant compressor showing a third embodiment of the present invention.

FIG. 18 is a vertical sectional view of a conventional scroll compressor.

FIG. 19 is a vertical sectional view of another conventional scroll compressor.

[Explanation of symbols]

 1 Closed Case 15 Fixed Scroll 15a Fixed Scroll Wrap 15b End Plate 16 Discharge Port 17 Suction Chamber 24 Rotation Preventing Mechanism 34 Discharge Chamber Oil Reservoir 60a Third Compression Chamber 204 Drive Shaft 205 Body Frame 212 Main Bearing 218 Orbiting Scroll 218a Orbiting Scroll Wrap 218b Revolving Bearing part 218c Lap support disk 220 Thrust bearing 241a, 241b Oil groove 278a Oil chamber A 278b Oil chamber B 213 Thrust bearing part

Claims (3)

[Claims] 1. An orbiting scroll wrap on a lap support disk forming a part of an orbiting scroll is rotatably and rotatably bitten with respect to a spiral fixed scroll wrap formed on one surface of an end plate forming a part of the fixed scroll. In addition, a spiral compression space is formed between both scrolls, a discharge port is provided at the center of the fixed scroll wrap or the orbiting scroll wrap, and a suction chamber is provided outside the fixed scroll wrap, and the compression space is provided. Is a partition of a plurality of compression chambers that continuously transition from the suction side to the discharge side to compress the fluid, and the lap support disk supports the end plate and the drive shaft, and is located on the side close to the compression chamber. The lap support disk and the main body frame are arranged between a main body frame having a bearing and a thrust bearing supporting the anti-compression chamber side of the lap support disk. A rotation preventing member of the orbiting scroll is engaged between the drive shaft and the orbiting scroll wrap to form a scroll compression mechanism for orbiting the orbiting scroll via an orbiting bearing engaged with the orbiting scroll wrap; The scroll compression mechanism is housed in the lower part of the hermetically sealed case, the motor connected to the drive shaft is housed in the upper part of the hermetically sealed case, and the gas discharged from the discharge port cools the motor. A discharge gas passage to be discharged is provided, and a discharge chamber oil reservoir on which discharge pressure acts is arranged at a lower portion of the motor and at a considerable height with respect to the main bearing, and an anti-compression of the sliding portion of the orbiting bearing and the orbiting scroll. Inside the thrust bearing, in a configuration in which a differential pressure oil supply passage for supplying lubricating oil of the discharge chamber oil reservoir is provided to either one of the compression chamber and the suction chamber via the chamber side. A spiral provided on the sliding surface of the main bearing, in which an oil chamber arranged and partitioned adjacent to the main bearing, the slewing bearing, and the lap support disc is arranged in the middle of the differential pressure oil supply passage. A scroll gas compressor having a bearing oil supply passage that branches from the differential pressure oil supply passage and returns the lubricating oil in the oil chamber to the oil reservoir in the discharge chamber by a screw pump action of the oil groove. 2. The scroll gas compressor according to claim 1, wherein a thrust bearing portion for supporting at least the weight of the drive shaft and the motor is disposed in the middle of the bearing oil supply passage. 3. The scroll gas compressor according to claim 1, wherein the thrust bearing portion is arranged at the end of the bearing oil supply passage.