JP2785806B2 - Scroll gas compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for reducing a compression load by sealing and releasing a compression chamber of a scroll gas compressor.

[0002]

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

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

[0004] Therefore, as a measure for solving this kind of problem, in order to prevent gas leakage during compression, it is expected to optimize the dimensional accuracy of the spiral part and improve the compression efficiency by an oil film sealing effect using lubricating oil. And JP-A-57-83
As described in Japanese Patent Publication No. 86, a proposal has been made to improve the above-mentioned disadvantages by injecting a proper amount of lubricating oil into a compression chamber in the middle of compression, sealing a gap in the compression chamber with an oil film of lubricating oil.

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

However, there remains an important problem as described below. FIG. 25 shows an example of a structure in which the compression chamber of a middle- to large-sized scroll refrigerant compressor having a high-pressure space inside the sealed case is further improved. In the figure, the compression section and the discharge chamber 1031 are arranged at the top, the motor (electric element) is arranged at the bottom, the oil reservoir is arranged at the bottom, and the discharge pipe 1042 as the final outlet of the compressor is arranged near the motor (electric element). After the discharged refrigerant gas and the lubricating oil are separated from each other in the discharge chamber 1031, the lubricating oil returns to the space for housing the motor (electric element) through the oil drain holes 1035 and 1036 and is collected in the oil sump at the bottom. At the same time, the discharged refrigerant gas is discharged from the discharge pipe 1042 again after cooling the motor (electric element) through a space for accommodating the motor (electric element) from the upper part of the discharge chamber 1031 through another passage. In addition, in order to reduce the axial gap of the compression chamber, the end plate 1004 of the orbiting scroll 1006 supports the drive shaft (crankshaft) 1008 and fixes the fixed scroll 1003 to the main frame (frame) 1009 and the fixed scroll 1003. A lubricating oil, which is provided at the bottom of a closed case (chamber) 1013 and has a discharge pressure acting on the bottom of a closed case (chamber) 1013, is provided inside a drive shaft (crankshaft) 1008, an oil pumping hole 1019, and a main body. After lubricating the bearing sliding surface via the clearance of the bearing of the frame (frame) 1009 and the clearance of the crankshaft of the drive shaft (crankshaft) 1008, the back pressure chamber 1025 provided on the back of the orbiting scroll 1006 The intermediate pressure lubricating oil that has been depressurized in the course of The orbiting scroll 1006 in a high-pressure lubricating oil of the shaft upper to the back bias on the side of the fixed scroll 1003. This rear biasing force is set to be large so that the orbiting scroll 1006 does not always separate from the fixed scroll against the compression chamber refrigerant gas pressure even when the suction pressure and the pressure of the discharge chamber 1031 slightly fluctuate. I have.

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

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

In order to further improve the sealing of the compression chamber, as shown in FIGS.
0 is sandwiched between the fixed scroll 1110 and the main body frame (housing) 148, and the fluid passage 12 is provided on the back of the orbiting scroll 1130 from outside the compressor.
And presses the orbiting scroll 1130 against the fixed scroll 1110, and the spiral wrap 11 of these two scrolls.
32 and 1116, spiral tip seals (seal members) 1117, 1117 urged by springs 1170 and 1181 into spiral grooves 1146 (see FIGS. 27 and 28) provided at the tips.
The surface 1133 of the end plate 1131 of the orbiting scroll 1130 and the fixed scroll 1110 are attached.
Of the fixed scroll 1110 and the end plate (end plate) 11 of the fixed scroll 1110.
There is a configuration in which compression chamber sealing is prioritized to seal between the surface 1136 of the orbit 11 and the tip 1149 of the orbiting scroll wrap (lap) 1132 of the orbiting scroll 1130 (US Pat. No. 3,994,636).

[0010]

However, in the above-described conventional configuration shown in FIG. 25, the sealed case (chamber) 1 is not affected by the residual pressure difference until the pressure is balanced even after the compressor is stopped.
The lubricating oil at the bottom of 013 flows into the compression chamber 1015 and fills it. In this state, when the compressor is restarted, the lubricating oil in the middle of compression flows into the back pressure chamber 1025 to urge the orbiting scroll 1006 against the fixed scroll to back pressure, and the sealing of the compression chamber 1015 cannot be released. As a result, there is a problem that an oil compression phenomenon occurs and the compressor cannot be started or the compressor is damaged. In addition, a similar problem occurs when the pressure in the compression chamber abnormally rises during the normal operation of the compressor.

On the other hand, as shown in FIG. 26, in the configuration in which the compression chamber gap is further sealed, the orbiting scroll 1130 is moved to the fixed scroll 1110 due to the occurrence of liquid compression in the compression chamber.
When trying to release the axial sealing of the compression chamber by moving away from the axial direction, the tip seal (seal member) 1117 at both ends,
1118 prevents the sealing of the compression chamber from being released, and as a result, the liquid compression in the compression chamber continues, causing an abnormal pressure rise, and there is a problem that the compressor cannot be started or the compressor is further damaged.

Further, from Japanese Patent Application Laid-Open Nos. 59-176486 and 55-46081 and 55-125386, the thrust bearing is provided on the side of the orbiting scroll opposite to the compression chamber. While supporting and depressurizing the high-pressure lubricating oil and finally supplying the suction chamber with a differential pressure, the tip of the orbiting scroll wrap (wrap) of the orbiting scroll is made into a spiral tip seal (seal member) as shown in FIG. There has been proposed a combination configuration in which the compression chamber is mounted with a higher priority by mounting the. However, in this configuration, the orbiting scroll cannot move in the direction to enlarge the axial gap of the compression chamber,
There has been a problem that it is more difficult to avoid the oil compression phenomenon at the initial stage of starting the compressor.

On the other hand, as a measure for solving the above-mentioned problem, there has been proposed a means for opening the space between the compression chamber and the discharge chamber when the pressure in the compression chamber abnormally rises, thereby reducing the overload.

That is, as shown in FIGS. 29 and 30, a orbiting scroll (movable scroll) 17 supported via an Oldham ring 1712 on a main body frame (frame) 1704 fixed to a sealed case (sealed container) 1701.
A tip seal 1710c is attached to the tip of the orbiting scroll wrap (spiral body) 1710 to seal the compression chamber gap. Then, the discharge chamber 1 is placed on the end plate (end plate) 1706 of the fixed scroll 1705 from the compression chamber 1715 side.
A plurality of non-return valve devices 1725 are provided to allow fluid outflow only to the side of the compression chamber 171.
The compression chamber 1715 and the discharge chamber 17
16 is opened. Further, the compressor has a shape memory characteristic function for opening the space between the compression chamber 1715 and the discharge chamber 1716 at a low temperature such as at the initial stage of compressor start. This is a configuration of a scroll air compressor devised so as to reduce the compression load by lowering the compression load (Japanese Utility Model Laid-Open No. 1-63790).

However, the above configuration causes an increase in cost for arranging the plurality of check valve devices 1725.

In practice, the provision of the check valve device 1725 creates a compression dead space in the compression chamber 1715, and the compressed gas remaining in the compression dead space re-expands to lower the compression efficiency. Therefore, it has been desired to realize a scroll gas compressor which is inexpensive and can easily configure the sealing and release of the compression chamber.

The present invention has been made to solve the above-mentioned conventional problems. In the normal operation of the compressor, the gap of the compression chamber is sealed, and when the pressure inside the compression chamber rises abnormally, the compression from the axial gap of the compression chamber is performed. It is an object of the present invention to quickly perform fluid leakage and reduce a compression load due to an instantaneous decrease in pressure.

[0018]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a lubricating oil which is guided from a discharge chamber oil sump to a side opposite to a compression chamber from which a discharge pressure acts to urge the orbiting scroll to a back pressure. In the configuration provided with an oil supply passage that does not generate backflow that finally supplies the orifice to the compression chamber, the back pressure biasing force to the orbiting scroll is set to a small value, and the orbiting scroll is set on the fixed scroll and the anti-compression chamber side of the orbiting scroll. In this embodiment, a spiral tip seal is provided only at one of the tip of the orbiting scroll wrap and the tip of the fixed scroll wrap.

By applying the back pressure to the orbiting scroll and disposing the tip seal, it is possible to improve the compression efficiency and realize an overload reducing mechanism.

[0020]

According to a first aspect of the present invention, there is provided an orbiting scroll disposed on a lower side of a motor chamber which communicates with a discharge port on a side opposite to a compression chamber of a lap support disk and accommodates a motor. The main body frame that introduces the lubricating oil from the discharge chamber oil reservoir provided to urge the orbiting scroll to the fixed scroll side with back pressure, and that a part of the lubricating oil introduced into the anti-compression chamber side supports the drive shaft. The lubrication contact surface between the thrust bearing and the lap support disk provided on the end plate and the end plate is lubricated, and an oil supply passage is formed that is allowed to flow only into one of the compression chamber and the suction chamber. In the state in which the end of the orbiting scroll wrap and the fixed scroll are in contact with the end plate of the orbiting scroll, and between the end of the fixed scroll wrap and the orbiting scroll, at least an oil film can be formed. In the configuration having a small gap, when the differential pressure between the suction pressure and the discharge pressure is small as in the case of extremely low-speed operation of the compressor including the initial stage of compressor startup, the lap support disk is provided on the main body frame mainly supporting the drive shaft. When the differential pressure between the suction pressure and the discharge pressure is large as in the steady operation including the rated operation of the compressor,
While the back support bias is set to the orbiting scroll so that the lap support disk is mainly supported by the end plate of the fixed scroll, the spiral tip seal groove and the spiral disposed in a free state in the tip seal groove Is provided at the tip of only one of the orbiting scroll wrap and the fixed scroll wrap. According to this configuration, while the compressor is stopped, the orbiting scroll is rotated even when the compressor starts up and liquid compression occurs in a state in which lubricating oil or gas condensate in the discharge chamber oil reservoir flows into and fills the compression chamber. Away from the fixed scroll, the axial sealing in the compression chamber is released on the side where the tip seal is not provided, the compression chamber pressure is reduced, and the compression load is reduced, so that the startability of the compressor is improved. Also, at the time of the compressor steady operation, the orbiting scroll is in a state close to the fixed scroll in axial contact, and not only the tip of the scroll wrap provided with the tip seal but also the tip of the scroll wrap not provided with the tip seal. And the gap in the axial direction of the compression chamber is sealed with a lubricating oil film.

When the compression chamber pressure rises abnormally, the orbiting scroll operates to reduce the compression load in the same manner as when the compressor is started.

According to a second aspect of the present invention, the wrap supporting disk of the orbiting scroll disposed between the end plate of the fixed scroll and the thrust bearing has an allowable maximum movement amount of about 70 microns for separating from the end plate to the thrust bearing. It is regulated. According to this configuration, the orbiting scroll is separated from the fixed scroll by a maximum of about 70 microns due to overcompression such as liquid compression at the initial stage of starting the compressor to reduce the pressure in the compression chamber. Start-up operation by input can be started. The axial gap of about 70 microns in the axial direction of the compression chamber is the maximum allowable range in which the effective oil film formation and compression rise of the compression chamber gap is possible. The final compression pressure gradually increases and the pressure in the discharge chamber oil reservoir increases, leading to orbiting scroll. , The orbiting scroll is urged toward the fixed scroll, the compression chamber gap is sealed, and normal operation continues. When the pressure of the compression chamber rises abnormally and the orbiting scroll separates from the fixed scroll, the pressure of the compression chamber decreases instantaneously, but the back pressure applying force to the orbiting scroll does not fluctuate greatly and is normal as in the initial stage of startup. Return to operation.

According to a third aspect of the present invention, the gap between the end plate of the fixed scroll and the thrust bearing of the wrap support disk of the orbiting scroll is set to secure at least about 20 microns. According to this configuration, when the orbiting scroll makes a high-speed orbital motion, a lubricating oil film is formed on the sliding surfaces on both sides of the lap support disk, and the slidable motion of the lap support disk and load reduction during overcompression are effective. Can be acted upon.

[0024]

【Example】

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

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

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

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

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

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

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

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

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

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

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

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

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

As shown in FIGS. 1 and 8, an annular seal groove 95 which is concentric with the center of the orbital bearing 18b is provided on the end face of the orbiting boss 18e of the orbiting scroll 18 on the body frame 5 side. As shown in FIG. 9, a flexible resin annular ring 94 having a cutout 94b is attached to the 95, as shown in FIG. Annular ring 9
The outer peripheral surface of the annular ring 94 is in close contact with the side surface of the annular seal groove 95 due to the thermal expansion of the annular ring 94 and the lubricating oil pressure inside the annular ring 94 during the operation of the compressor. Are arranged so as to be in close contact with each other. The annular ring 94 includes the drive shaft 4
The orbiting scroll 18 formed by the orbiting scroll 18, the main body frame 5 and the thrust bearing 20 from the side of the oil chamber A 98 a on the side of the main bearing 12 for supporting the orbiting scroll 18 to the back pressure chamber 39 is sealed to prevent excessive leakage. I have.

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

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

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

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

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

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

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

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

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

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

As shown in FIGS. 1 and 8, on the sliding shaft portion 4a of the drive shaft 4 and the surface of the crankshaft 14, when the drive shaft 4 rotates forward, the lubricating oil in the oil chamber A78a is provided with the slewing bearing 18b.
The oil chamber B78b formed by the oil pump and the crankshaft 14 and the helical oil groove 41 in the direction in which the screw pump oil is supplied to the motor 3 side.
a, 41b are provided, the upper end of which is the thrust bearing 1
It has reached three.

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

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

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

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

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

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

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

1 to 15, when the drive shaft 4 is driven to rotate by the motor 3, the orbiting scroll 18 tries to rotate around the main axis of the drive shaft 4 by the crank mechanism of the drive shaft 4. The key portion (see FIG. 2) on the side of the orbiting scroll 18 is
Since the key portion 71 of the main frame 5 is engaged with the key groove 71a of the main body frame 5 (see FIG. 1), the rotation is prevented and the orbital motion is made. To perform the suction / compression action of the refrigerant gas.

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

On the other hand, the liquid refrigerant and the lubricating oil separated from the refrigerant gas by the weight difference between the gas and the liquid and the inertia force at the time of the change of the inflow direction are once 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 via the oil suction hole A9a and the oil suction hole B9b, and is mixed into the suction refrigerant gas again.

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

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

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

The discharged refrigerant gas undergoes secondary expansion when flowing out toward the spherical wall surface forming the discharge chamber 2 through the small discharge hole 50h of the check valve device 50, and further collides with the spherical wall surface to be uniform. Spread. Thereafter, the two discharge passages 80 disposed at further symmetrical positions are joined by the discharge chamber 2b and the motor chamber 6, so that the discharge gas pulsation from each discharge passage 80 attenuates each other. Due to the fourth-order expansion, the pressure is further attenuated, and the pressure in the motor chamber 6 hardly fluctuates.

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

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

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

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

The lubricating oil in the discharge chamber oil reservoir 34 flows into the oil chamber A 78a, the oil chamber B 78b, and the back pressure chamber 39 via a path described later, and the back pressure applying force to the orbiting scroll 18 gradually increases.

Following the increase in the pressure of the motor chamber 6, the lap supporting disk 18c gradually comes into contact with the end plate sliding surface 15b2 of the fixed scroll 15 with an appropriate pressing force. There is no gap between the tip of the fixed scroll wrap 15a and the wrap support disk 18c of the orbiting scroll 18, whereby the compression chamber is sealed, the suction refrigerant gas is efficiently compressed, and stable operation is continued.

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

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

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

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

The first compression chambers 61a and 61b, which intermittently communicate with the suction chamber 17, and the back pressure chamber 39 are first compression chambers 61a and 61
Only when 1b is within the range of 180 degrees before the closing is completed, it communicates through the oil hole 91 (see FIG. 10) provided in the thrust bearing 20 and the gap between the thrust bearing 20 and the lap support disk 18c is provided. Since it is sealed by the lubricating oil film, the refrigerant gas does not flow backward from the compression chamber to the back pressure chamber 39 during compression.

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

On the other hand, the pressure in the back pressure chamber 39 at the initial stage of the start of the cold operation of the compressor is substantially equivalent to the suction pressure because the pressure rise of the lubricating oil in the discharge chamber oil reservoir 34 is low. As a result, the lap support disk 18c of the orbiting scroll 18 is in the oil chamber A where the pressure rise is low.
In a state where the back pressure is applied only by the lubricating oil of 78a, the thrust bearing 20 is retracted and supported away from the end plate sliding surface 15b2, and a gap (approximately) is provided between the lap support disk 18c and the tip of the fixed scroll wrap 15a. 0.015-0.
020 microns), lowering the compression chamber pressure and reducing the initial compression load.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

When the orbiting scroll 18 retreats toward the thrust bearing 20, the axial dimension between the tip of the orbiting scroll wrap 18a and the fixed scroll 15 also increases. As a result, the compressed refrigerant gas is hardly leaked from this portion because it is pressed toward the fixed scroll 15.

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

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

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

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

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

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

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

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

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

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

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

As described above, according to the above embodiment, while the compressor is stopped, the compressor is started and the condensate of the lubricating oil and gas in the discharge chamber oil reservoir 34 flows into and fills the compression chamber. Even when compression occurs, since the back pressure applying force to the orbiting scroll 18 is small, the orbiting scroll 18 is
, And is supported by the thrust bearing 20 to release the axial compression of the compression chamber to reduce the compression chamber pressure, thereby realizing smooth compressor startability while reducing the compression load.

In the normal operation of the compressor, the orbiting scroll 18 keeps proper axial contact with the fixed scroll 15, and the tip seal is not provided as well as the tip of the scroll wrap provided with the tip seal. The gap at the tip of the scroll wrap is minimized, and the gap in the axial direction of the compression chamber is sealed with a lubricating oil film, so that high compression efficiency can be obtained.

Further, even if the pressure in the compression chamber rises abnormally during the continuous operation, the orbiting scroll 18 is operated in the same manner as when the compressor is started to reduce the overload, and the clearance between the compression chamber and the sealing function is simplified. it can.

Further, the maximum distance of the orbiting scroll 18 from the fixed scroll 15 in the axial direction is restricted to about 70 μm, and the axial gap in the compression chamber is effective for forming an effective oil film and enabling the compression to start efficiently. Tolerable,
Even when the orbiting scroll 18 separates from the fixed scroll 15, the back pressure applied to the orbiting scroll 18 does not greatly change, and the normal operation can be restored as in the initial stage of startup.

The gap between the lap support disk 18c of the orbiting scroll 18 and the end plate 15b of the fixed scroll 15 and the thrust bearing 20 is set so as to secure 15 to 20 microns. During high-speed turning movement, the end plate 15 of the lap support disk 18c
A good lubricating oil film can be formed on both sliding contact surfaces between b and the thrust bearing 20. The gap with the oil film interposed therebetween allows the lap support disk 18c to slide smoothly.

Further, the orbiting scroll 18 is separated from the fixed scroll 15 in the axial direction by this gap, so that the overcompression load can be substantially reduced.

(Embodiment 2) FIG. 16 is a vertical sectional view of a scroll refrigerant compressor according to a second embodiment of the present invention. The scroll refrigerant compressor is provided in a discharge chamber oil reservoir 34 through an oil hole A 238a provided in a main body frame 205. A partitioning cap 101 made of a steel plate having an external shape as shown in FIG. 17 is press-fitted into the stepped inner wall of the high-pressure oil chamber A 278a, and covers the brim portion 102 of the drive shaft 204 as shown in FIG. It is arranged in a form. The cap 101 has a cut 101a in a part thereof, and the cut 101 is attached to the stepped inner wall of the oil chamber A278a.
a, the oil chamber A 278a is partitioned into the main bearing 212 side and the swing bearing 218b side.

The orbiting boss 218 of the orbiting scroll 218
e shows a slewing bearing 2 whose appearance 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. 19, the step C is formed by the turning boss 218e.
The throttle passage 103 is formed in a state in which the throttle passage 103 is press-fitted.

The turning boss 218e is provided with an annular groove 104 and a small diameter oil hole 105. The discharge chamber oil reservoir 34 and the back pressure chamber 239 communicate with each other through an oil hole A 238a, an oil chamber A 278a, a spiral oil groove 241b, an oil chamber B 278b, a throttle passage 103, an annular groove 104, and an oil hole 105.

As shown in FIG. 20, the outer peripheral space 37 and the back pressure chamber 239 are connected to the thrust bearing 220 only when the first compression chambers 61a and 61b are within the turning angle range of about 180 degrees before the closing is completed. Through the shallow groove 291 provided on the surface of the orbiting scroll 218, so as to be cut off by the lap support disk 218c of the orbiting scroll 218 at other times.
Position 1 is set. Other configurations are the same as those in FIG.

According to this embodiment, the motor chamber 6 filled with the refrigerant gas discharged with the lapse of time after the start of the compressor.
The pressure inside rises gradually.

The lubricating oil in the discharge chamber oil reservoir 34 at the bottom of the motor chamber 6 is provided on the main body frame 205 by the screw pump action of the spiral oil grooves 241a and 241b provided on the drive shaft 204, as in the case of FIG. The oil is sucked into the oil chamber A278a through the oil hole A238a. At this time, the partition cap 101 guides the lubricating oil to pass through the vicinity of the surface of the drive shaft 204 and flow into the oil chamber A 278a and the spiral oil groove 241b. As a result, the lubricating oil becomes oil hole A238a.
When the oil flows into the oil chamber A 278a, the oil is sucked into the spiral oil groove 241a without being affected by centrifugal diffusion caused by the high speed rotation of the drive shaft 204, and excellent screw pump oiling is performed.

The lubricating oil supplied to the oil chamber B 278b by the pressure difference between the discharge chamber oil reservoir 34 and the back pressure chamber 239 of the orbiting scroll 218 and the screw pump action of the helical oil groove 241b passes through the orbital bearing in the middle of the passage. After lubricating the sliding surface of 218b, it flows into the back pressure chamber 239 via the throttle passage 103, the annular groove 104, and the oil hole 105.

On the other hand, the lubricating oil of the oil chamber A 278a is in contact with the back pressure chamber 2 of the seal ring between the oil ring A 278a and the main frame 205 of the annular ring 94 that separates the oil chamber A 278a from the back pressure chamber 239.
Lubricated by allowing micro leaks to 39,
The seal durability of the seal sliding contact surface and reduction of sliding friction loss are guaranteed.

Oil chamber A27 almost equal to the pressure of motor chamber 6
The lubricating oil 8a is divided into two parts: a throttle passage 103 which can be secured simply and as a precision throttle passage, a precision pressure reduction passage via an oil hole 105, and a sliding pressure reduction passage via a seal sliding contact surface of an annular ring 94. The pressure is supplied to the back pressure chamber 239 through the two pressure reducing passages. As a result, the differential pressure oil supply amount to the back pressure chamber 239 is stabilized, and the inside of the back pressure chamber 239 can be maintained at an appropriate pressure.

The lubricating oil in the discharge chamber oil reservoir 34 is
1b, in addition to the screw pumping action of FIG. 1b, is supplied to the sliding portion of the orbiting bearing by the differential pressure with the back pressure chamber 239, whereby the amount of oil supply to the back pressure chamber 239 can be stabilized. Can be smoothly supported by sufficient lubrication.

The space between the outer peripheral space 37 and the back pressure chamber 239 is
As in the case of FIG. 1, since the fluid is communicated via the oil groove 291 provided on the surface of the thrust bearing 220, the lubricating oil in the back pressure chamber 239 is intermittently supplied to the outer peripheral space 37.

Thereafter, the lubricating oil is supplied to the compression chamber in the same manner as in FIG. 1 and is discharged again to the motor chamber 6 together with the compressed refrigerant gas, and is used for sealing the compression chamber gap in the process.

In the above embodiment, the annular ring 94 is provided in the annular seal groove 95 provided in the orbiting boss 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.

(Embodiment 3) FIG. 21 is a longitudinal sectional view of a scroll refrigerant compressor according to a third embodiment of the present invention. In addition to the screw pump function shown in FIG. The arrangement of a bearing lubrication that can be arranged and that can sustain extremely low speed operation of the compressor is shown.

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

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

[0130] The trochoid pump device 106 is
4 is connected to and driven by a drive end shaft 107 provided at the end of the crankshaft 314 at the end of the fourth end. The crankshaft 314 and the drive end shaft 107 are concentric.

As shown in FIG. 23, a suction hole 108 is provided between the slewing bearing 318b and the trochoid pump device 106.
And a partition plate 110 having a central hole 109 is fixedly mounted.

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

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

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

Further, the oil can be supplied to the back pressure chamber 339 and the thrust bearing 320 through the oil hole B38b from the initial stage of the start of the compressor to support the rear surface of the orbiting scroll.

Thus, even when the pressure rise in the motor chamber 6 is small, the annular ring 94 is expanded outward by the lubricating oil pressure difference between the oil chamber A 378a and the back pressure chamber 339, and the cut 94b of the annular ring 94 is cut. And annular ring 9
4 and the outer surface of the annular seal groove 95 can be sealed. Also, the lubricating oil leaks from the oil chamber A 378a to the back pressure chamber 39 in accordance with the pressure difference between the inside and outside of the seal sliding surface of the annular ring 94 to lubricate the seal sliding surface of the annular ring 94, and the anti-compression of the orbiting scroll 18 The amount of oil supplied to the first compression chambers 61a and 61b (the suction chamber 17) via the back pressure chamber 39 on the chamber side can be stabilized. As a result, extremely low speed operation for energy saving operation can be maintained.

(Embodiment 4) FIG. 24 is a longitudinal sectional view of a scroll refrigerant compressor according to a fourth embodiment of the present invention. The inside of a sealed case 801 made of soft iron is driven similarly to the case of FIG. An upper sealed case 801a and a lower sealed case 801b are partitioned by a main body frame 805 supporting a shaft 704. The inside of the upper sealed case 801a is a high-pressure space in which a motor 703 is built, and the lower sealed case 801
The inside of b constitutes an accumulator chamber 846 with a low-pressure space communicating with the downstream side of the evaporator.

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

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

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

A plurality of coil springs 131 are arranged at equal intervals on the back side of the thrust bearing 220 on the opposite side of the compression chamber. The coil springs 131 are pressed at their end faces by a discharge guide 881 attached to the main body frame 805 to be thrusted. The bearing 220 is fixed to the end plate 815 of the fixed scroll 815.
b.

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

The back surface of the thrust bearing 220 is provided with a seal ring A70a only on the inside, and the outer peripheral side is sealed by the thrust bearing 220 pressing against the end plate 815b.

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

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

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

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

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

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

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

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

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

[0153]

As is apparent from the above embodiment, the invention according to the first aspect is arranged at the lower part of the motor chamber which communicates with the discharge port of the orbiting scroll lap support disk on the side opposite to the compression chamber and houses the motor. The main body frame that introduces the lubricating oil from the discharge chamber oil reservoir provided to urge the orbiting scroll to the fixed scroll side with back pressure, and that a part of the lubricating oil introduced into the anti-compression chamber side supports the drive shaft. The lubricating contact surface between the thrust bearing and the lap support disk provided on the end plate and the end plate is lubricated, and an oil supply passage which is allowed to flow only into one of the compression chamber and the suction chamber is formed. An axial direction in which at least an oil film can be formed between the tip of the orbiting scroll wrap and the fixed scroll and between the tip of the orbiting scroll wrap and the orbiting scroll while in contact with the end plate of the fixed scroll via In the configuration having a small gap, when the differential pressure between the suction pressure and the discharge pressure is small as in the case of extremely low-speed operation of the compressor including the initial stage of starting the compressor, the lap support disk is mainly attached to the main body frame supporting the drive shaft. When the differential pressure between the suction pressure and the discharge pressure is large, such as during normal operation including the rated operation of the compressor, the lap support disk is supported by the thrust bearing provided so that the lap support disk is mainly supported by the fixed scroll end plate. While setting the back pressure bias to the scroll, the spiral tip seal groove and the spiral tip seal disposed in a free state in the tip seal groove can be provided by either the orbiting scroll wrap or the fixed scroll wrap. According to this configuration, when the compressor is stopped, the compressor is started while lubricating oil or gas condensate in the discharge chamber oil reservoir flows into and fills the compression chamber. Even if the compression occurs, because the back urge feudal era police rank to the orbiting scroll is small,
The orbiting scroll separates from the fixed scroll to release the compression chamber axial density, thereby reducing the compression chamber pressure and reducing the compression load, thereby improving the compressor startability.

In the normal operation of the compressor, the orbiting scroll keeps proper axial contact with the fixed scroll, and the lubricating oil supplied to the compression chamber seals the gap between the chip seal groove and the chip seal with an oil film. To improve the compression efficiency by minimizing the gap at the tip of the scroll wrap not provided with the tip seal, as well as the tip of the scroll wrap provided with the seal, to seal the gap in the axial direction of the compression chamber with the lubricating oil film. Can be.

When the pressure in the compression chamber rises abnormally, the orbiting scroll is activated and the overcompression load can be reduced in the same manner as at the start of the compressor. The lubrication path of the sliding contact surface for supporting the lubrication can be realized with a simple configuration.

According to a second aspect of the present invention, the wrap supporting disk of the orbiting scroll disposed between the end plate of the fixed scroll and the thrust bearing has an allowable maximum movement amount of about 70 microns for separating from the end plate to the thrust bearing side. According to this configuration, the axial gap in the compression chamber can be set to the maximum allowable range that enables effective oil film formation and efficient compression start-up, and can greatly reduce overload.

Further, even when the orbiting scroll separates from the fixed scroll, a large fluctuation of the back pressure on the orbiting scroll is prevented, and the normal operation can be restored as in the initial stage of starting.

According to a third aspect of the present invention, the gap between the end plate of the fixed scroll and the thrust bearing of the wrap supporting disk of the orbiting scroll is set to ensure at least about 20 microns. According to the above, when the orbiting scroll makes a high-speed orbital motion, a lubricating oil film can be formed on the sliding surfaces on both sides of the lap support disk, and the lap support disk can effectively slide smoothly and reduce the load at the time of overcompression. The effect that it becomes possible to act is produced.

[Brief description of the drawings]

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

FIG. 17 is a perspective view of a partition cap component in the compressor.

FIG. 18 is a perspective view of a bearing part of the compressor.

FIG. 19 is a partial cross-sectional view of a main bearing in the compressor.

FIG. 20 is a partial sectional view of a thrust bearing portion in the compressor.

FIG. 21 is a longitudinal sectional view of a scroll refrigerant compressor showing still another embodiment of the present invention.

FIG. 22 is a partial cross-sectional view of a main bearing in the compressor.

FIG. 23 is a perspective view of a partition plate used in the trochoid pump device in FIG. 23;

FIG. 24 is a longitudinal sectional view of a scroll refrigerant compressor showing still another embodiment of the present invention.

FIG. 25 is a longitudinal sectional view of a conventional scroll compressor.

FIG. 26 is a longitudinal sectional view of another conventional scroll compressor.

FIG. 27 is a partial cross-sectional view of the compression chamber seal portion in FIG. 26;

FIG. 28 is a partial sectional view of the compression chamber seal portion.

FIG. 29 is a longitudinal sectional view of a conventional scroll compressor.

30 is a partial cross-sectional view of the check valve device for letting out gas in the middle of overcompression in FIG. 29;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing case 4 Drive shaft 5 Main frame 15 Fixed scroll 15a Fixed scroll wrap 15b End plate 16 Discharge port 17 Suction chamber 18 Orbiting scroll 18a Orbiting scroll wrap 18c Lap support disk 20 Thrust bearing 24 Rotation preventing member 34 Discharge chamber oil reservoir 98 Tip seal Groove 98a Tip seal

Claims (3)

(57) [Claims] 1. A swirling orbiting scroll wrap on a wrap support disk forming a part of an orbiting scroll with respect to a spiral fixed scroll wrap formed on one surface of a head plate forming a part of a fixed scroll. Freely meshing, forming a spiral compression space between the two scrolls, providing a discharge port at the center of the fixed scroll wrap, providing a suction chamber outside the fixed scroll wrap, Is disposed in a loose state between the thrust bearing provided on the main body frame supporting the drive shaft and the end plate,
Further, a scroll-type compression mechanism which is rotatably supported by the drive shaft via a rotation-preventing mechanism of the lap support disk and compresses a fluid by utilizing a volume change of a compression chamber formed between both scrolls. And a motor connected to the drive shaft is housed in a closed case, and a discharge chamber oil sump is provided at a lower portion of the motor chamber that communicates with the discharge port on the side opposite to the compression chamber of the lap support disk and houses the motor. A lubricating oil is introduced, and the orbiting scroll is urged against the fixed scroll by a back pressure, and a part of the lubricating oil introduced into the anti-compression chamber side is a part of the thrust bearing and the lap support disk, the end plate, A lubricating passage that lubricates the sliding contact surface and allows only the inflow into one of the compression chamber and the suction chamber, and the lap support disk is in contact with the end plate via an oil film. A configuration in which the gap between the tip of the orbiting scroll wrap and the end plate and the gap between the tip of the fixed scroll wrap and the wrap support disk have at least an axial minute clearance in which an oil film can be formed, When the differential pressure between the suction pressure and the discharge pressure is small as in the case of extremely low speed operation of the compressor, the lap support disk is mainly supported by the thrust bearing, and the suction pressure as in the steady operation including the rated operation of the compressor. When the pressure difference between the pressure and the discharge pressure is large, the back pressure applying force to the orbiting scroll is set so that the lap support disk is mainly supported by the end plate, while the spiral tip seal groove and the tip The spiral-shaped tip seal, which is disposed in the sealing groove in a loose state, is attached to the tip of only one of the orbiting scroll wrap and the fixed scroll wrap. Scroll gas compressor be disposed. 2. The scroll gas compressor according to claim 1, wherein the lap support disk regulates an allowable maximum amount of movement away from the head plate toward the thrust bearing to about 70 microns. 3. The scroll gas compressor according to claim 1, wherein a gap between the end plate and the thrust bearing of the lap supporting disk is set to ensure at least about 20 microns.