JPH09119381A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a compressor provided with a load reducing means having little input loss and high compression efficiency. SOLUTION: In a constitution for supporting a turning scroll 18 by giving energizing force to the side opposite to compression room of a thrust bearing 20, the moving range in the axial direction toward the compression room and the thrust bearing 20 is restrained from moving in the axial direction toward the compression room and is prevented from moving in the radial direction such that the thrust bearing 20 does not press the turning scroll 18 on a fixed scroll 15. Therefore good oil film is formed on the sliding surface of the turning scroll 18 and reduces wear loss and, when excessively pressed, the gap of the compression room is expanded to reduce the load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and more particularly to sealing and releasing a compression chamber.

[0002]

2. Description of the Related Art A scroll compressor having low vibration and low noise characteristics has a suction chamber at the outer peripheral portion, a discharge port provided at the center of a spiral, and a reciprocating compressor in which the flow of compressed fluid is unidirectional. It is generally known that a discharge valve for compressing fluid such as a rotary compressor is not required, the compression ratio is constant, the discharge pulsation is relatively small, and a large discharge space is not required.

Further, in order to further improve the vibration and noise characteristics, the constitutions of FIGS. 16 and 17 are considered as a measure for reducing the jumping phenomenon of the orbiting scroll during the high speed operation of the compressor.

In the figure, the end plate 1001a of the orbiting scroll 1001 connected to the drive pin 1007a at the tip of the drive shaft 1007 is the end plate 1001 of the fixed scroll 1002.
2a and the frame 1008 are supported by a small gap,
The orbiting scroll 100 is used when the compression load, the inertial force of the rotating member, or the like changes when the compressor is started, stopped, or operated at high speed.
Orbiting scroll 1 that prevents 1a from jumping
A small gap in the axial direction between 001 and the fixed scroll 1002 is secured to seal the compression chamber to improve the compression efficiency, and at the same time, a device for preventing abnormal noise, vibration, and durability deterioration of the sliding portion caused by the collision between the members. Have been made (Japanese Patent Laid-Open No. 55-
142902, U.S. Pat. No. 3,994,633, etc.).

However, since the scroll compressor does not require a discharge valve for compressing fluid, unlike a reciprocating compressor or a rotary compressor, an abnormal pressure is generated in the compression chamber due to liquid compression or the like. When the pressure rises, the clearance between the compression chambers is expanded to leak the compressed fluid and the pressure in the compression chamber cannot be lowered. Therefore, the compression load increases, the parts are damaged, and the durability of the sliding part is reduced. There are machine-specific problems.

As a measure for solving this liquid compression problem, the structure shown in FIG. 18 is considered.

In the figure, the fixed scroll 2001e is configured to be movable in the axial direction, and the discharge pressure is introduced into the back pressure chamber 2015 by the urging force of the leaf spring 2023e to move the fixed scroll 2001e into the orbiting scroll 2001d. Press the orbiting scroll 2001d and the fixed scroll 20.
The compression chamber is sealed by eliminating the axial gap between the fixed scroll 2001e and the stationary scroll 2001e when the liquid compression occurs in the compression chamber.
It is configured to separate from 1d in the axial direction to reduce the pressure in the compression chamber and reduce the load (US Pat. No. 3,600,114).

[0008]

However, in the above-mentioned conventional structure, in the structure in which the fixed scroll 2001e is constantly pressed against the orbiting scroll 2001d, the biasing force is increased so that the fixed scroll 2001e does not move unnecessarily in the axial direction. However, there is a problem that durability is reduced due to friction and wear of both scroll contact surfaces, and input loss is large.

Further, since the center portion of the annular support plate 2013 is pressed by the leaf spring 2023, the annular support plate 201 is pressed.
3 is likely to be warped at the central portion thereof, and the annular support plate 20
Because of the configuration in which the fixed scroll 2001e is supported only in the central portion of 13, the fixed scroll 2001e is unstablely supported when retracting to the side opposite to the compression chamber. As a result, the fixed scroll 2001e tilts with respect to the orbiting scroll 2001d, and the fixed scroll 2001e and the orbiting scroll 2001d partially contact with each other in the radial direction, which causes various problems such as abnormal noise, vibration, and component damage. It has been desired to realize a scroll compressor equipped with an overload reducing means that does not impair the property.

The present invention is intended to solve such a conventional problem, and an object thereof is to provide an overload reducing means having a small input loss and a high compression efficiency.

[0011]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a thrust bearing that supports an anti-compression side of an orbiting scroll and applies a biasing force to the compression chamber side. The axial movement range of the thrust bearing toward the fixed scroll and the radial movement of the thrust bearing are restricted so as not to press against the scroll.

Due to the movement restriction of the thrust bearing, the thrust is maintained during normal operation of the compression chamber and when the compression chamber pressure rises abnormally and the thrust bearing retracts while supporting the orbiting scroll to release the compression chamber sealing. The bearing can stably support the orbiting scroll.

[0013]

DETAILED DESCRIPTION OF THE INVENTION A first aspect of the present invention is a thrust bearing which is provided on a side of a main body frame which supports a drive shaft, supports an anti-compression chamber side of an orbiting scroll, and is movable in an axial direction. An orbiting scroll is disposed between the thrust bearing and the main body frame, and a means for urging the thrust bearing in the direction of the orbiting scroll and a release gap that allows the thrust bearing to retract toward the anti-compression chamber are provided between the thrust bearing and the body frame. Provided so that the thrust bearing can stably support the orbiting scroll without deflecting the axial gap of the compression chamber, and the sliding contact part of the thrust bearing is formed at a position opposite to the region outside the compression chamber leading to the discharge port. In the above configuration, the orbiting scroll is provided between the fixed scroll and the thrust bearing,
Means for restricting the range in which the thrust bearing moves toward the fixed scroll in order to stably maintain at least the axial minute gap capable of forming an oil film and prevent the vibration of the thrust bearing.
A means for restricting at least radial movement of the thrust bearing is provided. According to this configuration, when the compression pressure of the compression chamber, which is normal and is sequentially transferred, acts on the orbiting scroll and the thrust force toward the thrust bearing is smaller than the urging force acting on the back surface of the thrust bearing. Provides stable support of the back surface of the orbiting scroll in a stationary state in which the thrust bearing is restricted in its axial movement range toward the orbiting scroll side and at least its radial movement, and a good oil film is formed. Then, the minute gap in the axial direction between the orbiting scroll and the fixed scroll is stably maintained without being deflected, the compression chamber is kept sealed, and an efficient compression action is performed. Further, even when the load changes to some extent, during acceleration / deceleration operation, or during high-speed operation, jumping and tilt of the orbiting scroll are prevented, and quiet compression operation with less vibration continues.

In the unlikely event that liquid compression occurs and the pressure in the compression chamber rises abnormally instantaneously, the thrust force acting on the orbiting scroll becomes larger than the urging force acting on the back surface of the thrust bearing, and the thrust bearing The orbiting scroll moves in a direction to reduce the gap between the orbiting scroll and the body frame while supporting the orbiting scroll stably, and only the axial gap between the orbiting scroll and the fixed scroll increases. As a result, while avoiding a radial collision between the orbiting scroll and the fixed scroll, only the axial sealing of the compression chamber is released and the pressure in the compression chamber drops, reducing the compression load without causing abnormal noise and vibration. can get.

According to a second aspect of the present invention, as a means for urging the thrust bearing in the direction of the orbiting scroll, the thrust bearing can be uniformly urged between the rear surface of the thrust bearing on the anti-compression side and the body frame. An elastic body is arranged. Further, according to this configuration, the deformation of the thrust bearing is reduced, the orbiting scroll can be stably supported, and it is possible to prevent the axial gap of the compression chamber from being deflected and the axial gap of the compression chamber from expanding.

According to the third aspect of the present invention, the annular elastic body is arranged at a position facing the sliding contact portion of the thrust bearing. According to this structure, the deformation of the thrust bearing can be reduced, the oil film on the sliding contact surface with the orbiting scroll can be favorably formed, and the jumping phenomenon in the axial direction of the orbiting scroll can be suppressed.

According to a fourth aspect of the present invention, the release gap is defined by the annular elastic body to form the thrust bearing back pressure chamber,
The thrust bearing back pressure chamber is a fluid in which a discharge pressure acts. According to this structure, the elastic force of the annular elastic body can be reduced and the annular elastic body can be downsized.

According to a fifth aspect of the present invention, another elastic body is arranged on the rear surface of the thrust bearing on the side opposite to the compression side, and the thrust bearing is biased in the direction of the orbiting scroll. According to this structure, the preload on the thrust bearing can be strengthened and the compression rise can be accelerated.

According to a sixth aspect of the present invention, the annular elastic body is an annular spring device, and the annular spring device is arranged in an annular groove provided in the main body frame. And according to this structure, the unnecessary radial movement of the annular spring device is suppressed,
A stable and uniform biasing force can be applied to the thrust bearing to stabilize the thrust bearing and stabilize the axial clearance sealing action in the compression chamber during normal operation.

According to a seventh aspect of the invention, the radial movement of the thrust bearing is regulated and held through a columnar fixing part fixed to the main body frame. Further, according to this configuration, the columnar fixing component can simultaneously permit the axial movement of the thrust bearing and regulate the radial movement thereof.

According to an eighth aspect of the invention, the columnar fixing component is a split parallel pin. With this configuration, it is possible to easily prevent the radial movement of the thrust bearing.

According to a ninth aspect of the present invention, in the structure in which the rotation preventing member of the orbiting scroll is arranged between the fixed scroll and the main body frame, the retraction distance of the thrust bearing to the side opposite to the compression chamber is determined by the lap support disc. Is larger than the axial minute gap sandwiched between the fixed scroll and the thrust bearing, and the rotation preventing member is arranged so as not to regulate the backward distance of the orbiting scroll. According to this structure, the orbiting scroll smoothly performs the orbiting motion during the overload reduction operation, and the orbiting scroll can be stably supported by the thrust bearing.

According to the tenth aspect of the present invention, the rotation preventing member is arranged between the thrust bearing and the orbiting scroll so as to move together with the axial movement of the thrust bearing. According to this structure, the sliding engagement of the rotation preventing member is always smooth.

[0024]

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 FIG. 1, reference numeral 1 is an iron-made hermetic case, the entire interior of which is a high-pressure atmosphere communicating with the discharge chamber 2.
The inside of the closed case 1 is partitioned into an upper motor chamber 6 and a lower discharge chamber 2 by a main body frame 5 of a compression unit that supports a drive shaft 4 fixed to the rotor 3a of the motor 3. The main body frame 5 is made of an aluminum alloy having excellent heat conduction characteristics mainly for weight reduction and heat dissipation of the bearing portion, and an iron liner 8 having excellent weldability is shrink-fitted and fixed to the outer periphery of the aluminum alloy. The outer peripheral portion is inscribed in the entire circumference of the closed case 1 and is partially welded and fixed.

The outer peripheral portions of both ends of the stator 3b of the motor 3 are supported and fixed by a bearing frame 9 and a main body frame 5 which are fixedly inscribed in the sealed case 1. The drive shaft 4 includes an upper bearing 10 provided on the bearing frame 9, a lower bearing 11 provided on an upper end portion of the main body frame 5, a main bearing 12 provided on a central portion of the main body frame 5, an upper end surface of the main body frame 5. It is supported by a thrust ball bearing 13 provided between the lower end surface of the rotor 3a of the motor 3 and an eccentric bearing 14 which is eccentric from the main shaft of the drive shaft 4 at its lower end. A fixed scroll 15 made of aluminum alloy is fixed to the lower end surface of the main body frame 5, and the fixed scroll 15 is composed of a spiral fixed scroll wrap 15a and an end plate 15b. The end of the fixed scroll wrap 15a is wound at the center of the end plate 15b. A discharge port 16 opening to the portion is provided so as to also open to the discharge chamber 2, and the fixed scroll wrap 15a
The suction chamber 17 is provided on the outer periphery of the suction chamber.

A spiral orbiting scroll wrap 18 which meshes with the fixed scroll wrap 15a to form a compression chamber.
a and a revolving shaft 18b supported by the eccentric bearing 14 of the drive shaft 4.
The orbiting scroll 18 made of an aluminum alloy, which is composed of a lap support disk 18c which is upright with a fixed scroll 1
5, the main body frame 5 and the drive shaft 4 are arranged, and a sleeve 19 made of a high-tensile steel material is shrink-fitted and fixed to the outer periphery of the rotary shaft 18b, and the surface of the lap supporting disk 18c is hardened. Is being processed.

Fixed to the thrust bearing 20 which is constrained by the split parallel pin 19 fixed to the main body frame 5 and is movable only in the axial direction and which supports the lap support disk 18c at a position facing the suction chamber 17. End plate 15 of scroll 15
A spacer 21 is provided between the lap support disk 18c and the spacer 21b, and the axial dimension of the spacer 21 is about 0.015 to 0.
It is set larger by 040 mm.

The eccentric bearing space 36 between the bottom of the eccentric bearing 14 of the drive shaft 4 and the end of the orbiting shaft 18b of the orbiting scroll 18 and the outer peripheral space 37 outside the lap support disk 18c are the orbiting shaft 18b. An oil hole A38a provided in the lap support disk 18c communicates with each other.

As shown in FIGS. 2 and 5, the thrust bearing 20 is formed by penetrating a central portion thereof into two parallel straight line portions 22 and two arcuate curved line portions 23 connected to the straight line portions 22.

The Oldham ring 24 (referred to as a rotation preventing member) for preventing the rotation of the orbiting scroll from rotating is made of a light alloy, a resin material or a composite material thereof suitable for sintering molding, injection molding, etc., as shown in FIG. Is composed of a thin annular plate 24a whose both sides are parallel to each other and a pair of parallel key portions 24b provided on one surface of the annular plate 24a. The outer contour of the annular plate 24a is two parallel straight line portions 25 and two arcuate curved line portions 26 connected to the straight line portions 25. The linear portion 25 is slidable by engaging the linear portion 22 of the thrust bearing 20 with a small clearance as shown in FIG. 5, and the side surface 24c of the parallel key portion 24b is at the central portion of the linear portion 25. 1 and 2, they are orthogonal to each other and engage with a pair of key grooves 71 provided on the lap support disk 18c of the orbiting scroll 18 with a minute gap, and are set to be slidable. The inner contour of the annular plate 24a is similar to the outer contour. The dent portion 24d provided at the base of the parallel key portion 24b also serves as a passage for the lubricating oil.

The Oldham ring 24 (rotation preventing member) is arranged in a size and shape that does not hinder the orbiting scroll 18 from moving in the axial direction.

As shown in FIG. 1 and FIG.
A release gap 27 of about 0.1 mm is provided between the thrust bearing 20 and the thrust bearing 20, and an annular groove 28 is also provided in the main body frame 5 so as to face the release gap 27. The seal rings 70 are attached to the inner portion and the outer portion between the body frame 5 and the thrust bearing 20 respectively to form the thrust bearing back pressure chamber 27a, and the seal ring 70 uniformly compresses the thrust bearing 20. The thrust bearing 20 is arranged to apply a force to reduce the distortion of the thrust bearing 20.

The upper portion of the motor chamber 6 and the discharge chamber 2 are communicated with each other through a bypass discharge pipe 29 that penetrates through the side wall of the closed case 1 and is connected to the motor chamber 6 of the bypass discharge pipe 29.
The opening position of the coil 3 faces the side surface of the upper coil end 30 of the stator 3b. Further, the discharge pipe 31 connected to the upper surface of the closed case 1 is provided with the through hole 3 provided in the bearing frame 5.
2. It communicates with the upper open end of the bypass discharge pipe 29 through the punching metal 33 having a large number of small holes arranged between the upper surface of the closed case 1 and the bearing frame 9.

The discharge chamber oil sump 34 provided in the lower part of the motor chamber 6 communicates with the upper part of the motor chamber 6 through a cooling passage 35 provided by cutting a part of the outer periphery of the stator 3b of the motor 3. ing. Further, the discharge chamber oil sump 34 branches from an oil hole B38b provided on the side surface of the main body frame 5 and communicates with the thrust bearing back pressure chamber 27a, and the Oldham ring 24 is arranged at the end of the oil hole B38b. The back pressure chamber 39 of the orbiting scroll 18 and the sliding portion of the main bearing 12 communicate with each other through a minute gap. Further, the back pressure chamber 39 communicates with the eccentric bearing space 36 via an oil groove A40a provided in the eccentric bearing 14.

An oil hole B provided in the main body frame 5
38b is a lower shaft portion 4 corresponding to the lower bearing 11 of the drive shaft 4.
a also communicates with the spiral oil groove 41 provided on the surface of
The spiral oil groove 41 is provided such that the lubricating oil in the discharge chamber oil sump 34 is supplied to the thrust ball bearing 13 side by the screw pump action when the drive shaft 4 rotates in the forward direction, and the end thereof is at the bottom. The shaft portion 4a is formed partway. The gap of the lower shaft portion 4a is set larger than the gap of the main bearing 12, and the drive shaft 4 is substantially supported by the upper bearing 10 and the main bearing 12.

As shown in FIGS. 6 and 7, the fixed scroll 15 is provided with an arc-shaped suction passage 42 which communicates both ends of the suction chamber 17, and a circular suction hole 43 orthogonal to the suction passage 42 is formed in the fixed scroll wrap 15a. The suction hole 43 is also provided in a direction perpendicular to the side surface, and the bottom portion of the suction hole 43 is a plane and reaches the side surface of the suction passage 42. As shown in FIG.
Is centered off the bottom surface 44 of the suction passage 42, and the dimension W45 of the opening to the suction passage 42 is smaller than the diameter dimension of the suction hole 43. A suction pipe 47 of an accumulator 46 is connected to the suction hole 43. Between the bottom surface of the suction hole 43 and the suction pipe end face 48, the inner diameter of the suction pipe 47 and the suction pipe end face 48 and the suction passage 42 are connected. Bottom 44
A check valve 50 made of a circular thin steel plate that is larger than the suction hole depth dimension L49 between and between and is larger than the opening dimension W45 is arranged. The surface of the check valve 50 is coated with Teflon or rubber, which has poor oil wetting characteristics and is highly elastic.

As shown in FIG. 1 and FIG. 6, the second compression chambers 51a and 51b and the outer peripheral space 37, which are normally closed spaces and do not communicate with the suction chamber 17 or the discharge chamber 2, are the second compression chamber 51.
a, 51b and injection holes 5a and 52b formed in the mirror plate 15b and having a small diameter, and the injection groove 5 formed by the mirror plate 15b and the heat insulating cover 53 made of resin.
4, stepped oil hole C38 opened to the outer peripheral space 37
They are communicated with each other through an injection passage 55 composed of c and c. As shown in FIG. 9, a check valve 58 made of a thin steel plate having a notch 57 in a part of the outer circumference thereof and a coil spring 59 are disposed in the large diameter portion 56 of the stepped oil hole C38c. The coil spring 59 is pressed by the heat insulating cover 53 and constantly urges the check valve 58. The opening position of the oil hole C38c to the outer peripheral space 37 is as shown in FIGS.
The orbiting scroll 18 reaches near the end of the volume reduction process of the third compression chambers 60a, 60b communicating with the discharge port 16.
Has moved (see FIG. 10) and the outer peripheral space 37 and the oil hole C
38c and at other times (for example, see FIG. 11)
Is provided at a position blocked by the lap support disk 18c.

In FIG. 12, the horizontal axis shows the rotation angle of the drive shaft 4, the vertical axis shows the refrigerant pressure in the compression chamber, and shows the pressure change state of the refrigerant gas in the intake, compression, and discharge processes. Solid line 6
2 shows the pressure change during normal pressure operation, and the dotted line 63 shows the pressure change during abnormal pressure increase operation.

In FIG. 13, the horizontal axis represents the rotation angle of the drive shaft 4, the vertical axis represents the refrigerant pressure in the compression chamber, and the solid line 64.
Indicates the pressure change at the opening positions of the injection holes 52a, 52b of the second compression chambers 51a, 51b, which are normally closed spaces that do not communicate with the discharge chamber 2 or the suction chamber 17, and the dotted line 65 indicates intermittently with the suction chamber 17. First compression chamber 61 communicating
a, 61b (see FIG. 6) at fixed points, the alternate long and short dash line 66 indicates the pressure at fixed points in the third compression chambers 60a, 60b that communicate intermittently with the discharge chamber 2, and the alternate long and two short dashes line 67 indicates 1st compression chamber 61a, 61b and 2nd compression chamber 5
The pressure change at the fixed point of the compression chamber between 1a and 51b is shown, and the double dotted line 68 shows the pressure change in the back pressure chamber 39.

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

1 to 13, when the drive shaft 4 is rotationally driven by the motor 3, the orbiting scroll 18 makes an orbiting motion, and the suction refrigerant gas containing lubricating oil from the refrigeration cycle connected to the compressor is transferred to the accumulator 46. It flows into the suction chamber 17 through the connected suction pipe 47, suction hole 43, and suction passage 42, and is confined in the compression chamber through the first compression chambers 61a and 61b formed between the orbiting scroll 18 and the fixed scroll 15. Then, they are sequentially transferred and compressed to the second compression chambers 51a and 51b and the third compression chambers 60a and 60b which are always closed spaces, and are discharged to the discharge chamber 2 through the discharge port 16 at the center.

The discharge refrigerant gas containing lubricating oil returns to the motor chamber 6 in the compressor again via the bypass discharge pipe 29 which is circumvented to the outside of the compressor, and is then discharged from the discharge pipe 31 to the external refrigeration cycle piping system. To be done. However, when the discharged refrigerant gas flows into the motor chamber 6, it collides with the side surface of the upper coil end 30 of the motor 3, and the lubricating oil in the discharged refrigerant gas adheres to the surface of the motor winding. As a result, a part of the lubricating oil in the discharged refrigerant gas is separated. After that, the discharged refrigerant gas collides with the side wall of the motor of the bearing frame 9 and the discharge hole 3
2, when changing the flow direction, when the punching metal 33 collides with the side wall of the motor or when passing through a small hole, the lubricating oil gradually and effectively separates due to inertial force of the lubricating oil or surface adhesion. To be done.

A part of the lubricating oil separated in the upper space of the bearing frame 9 is collected in the central concave portion of the bearing frame 9, and after lubricating the sliding surface of the upper bearing 10, another lubricating oil is separated. Together with the motor winding gap and the cooling passage 35,
While cooling the motor 3, it flows down and is collected in the discharge chamber oil sump 34.

The lubricating oil in the discharge chamber oil sump 34 is passed through the oil hole B by the screw pump action of the spiral oil groove 41 provided on the surface of the lower shaft portion 4a of the drive shaft 4, and the thrust ball bearing 13
Refueled. When the lubricating oil passes through the minute bearing gap at the end of the lower shaft portion 4a, the sealing action of the oil film seals the discharge refrigerant gas atmosphere of the motor chamber 6 and the upstream space of the main bearing 12 with the oil film. The refrigerant gas in the chamber 6 does not flow into the main bearing 12 through the gap of the lower shaft portion 11.

The lubricating oil containing the dissolved and discharged refrigerant gas in the discharge chamber oil sump 34 is reduced to an intermediate pressure between the discharge pressure and the suction pressure when passing through the minute gap of the main bearing 12, and the back pressure chamber 39.
Flows into. After that, the oil flows into the outer peripheral space 37 through the oil groove A40a of the eccentric bearing 14, the eccentric bearing space 36, and the oil hole A38 provided in the orbiting scroll 18, and is further opened intermittently by the orbiting motion of the lap support disk 18c. After passing through the oil hole C38c, the injection groove 54, and the injection holes 52a and 52b, the oil flows into the second compression chambers 51a and 51b and lubricates each sliding surface in the middle of the passage.

Further, since the discharge chamber oil sump 34 also communicates with the thrust bearing back pressure chamber 27a, the thrust bearing 20 is urged by its back pressure and abuts against the end face of the spacer 21. The wrap support disk 18 of the orbiting scroll 18
c is the end plate 1 of the thrust bearing 20 and the fixed scroll 15
A small gap is held between the fixed scroll wrap 15a and the wrap support disc 18c and the orbiting scroll wrap 18b.
The gap between the end face of a and the end plate 15b is also kept small to reduce refrigerant gas leakage in the adjacent compression space.

The opening portions of the injection holes 52a and 52b of the second compression chambers 51a and 51b undergo a pressure change 64 as shown in FIG. 13, and the back pressure chamber pressure 68 which follows the pressure of the discharge chamber 2 changes. Is instantaneously high, but the average pressure is low.
Therefore, the lubricating oil from the back pressure chamber 39 intermittently flows into the second compression chambers 51a and 51b, and the lubricating oil in the second compression chambers 51a and 51b is instantaneously higher than the back pressure chamber pressure 68 during normal operation. The compressed refrigerant gas is injected into the injection holes 52a having a small diameter,
The instantaneous backflow to the injection groove 54 is reduced due to the passage resistance of 52b, and the pressure in the injection groove 54 does not become higher than the back pressure chamber pressure 68.

The lubricating oil injected into the second compression chambers 51a and 51b merges with the lubricating oil that has flowed into the compression chamber together with the suction refrigerant gas, and seals a minute gap in the adjacent compression space with an oil film to leak the compressed refrigerant gas. And the sliding surface of the compression space is lubricated, and the compressed refrigerant gas is discharged again to the discharge chamber 2.

The intermediate-pressure lubricating oil differentially supplied to the back pressure chamber 39 urges the orbiting scroll 18 to seal the lap support disk 18c against the sliding surface of the end plate 15b by pressing an oil film, and the outer circumference. The communication between the partial space 37 and the suction chamber 17 is cut off, and the gap between the sliding surfaces of the thrust bearing 20 and the lap support disk 18c is also lubricated and sealed.

The oil film adhesive force on the sliding surface tends to cause the thrust bearing 20 to swivel, but the split parallel pin 1
When the thrust bearing 20 is kept stationary by the restraint by 9, and a good oil film is formed on the sliding surface, the thrust bearing 20 stably supports the orbiting scroll 18 on the oil film, and the lubricating seal effect is improved.

For a while after the cold start of the compressor, as can be understood from FIGS. 12 and 13, the pressure in the discharge chamber 2 is lower than the pressure in the second compression chambers 51a and 51b, and the pressure is in the middle of compression. Refrigerant gas tries to flow back from the second compression chambers 51a, 51b to the back pressure chamber 39 via the injection passage 55, but the check valve 58 prevents the refrigerant gas from flowing back to the outer peripheral space 37, so that the discharge chamber The lubricating oil in the oil sump 34 is differentially supplied to the back pressure chamber 39 and the outer peripheral space 37 as the pressure in the discharge chamber 2 rises.

Therefore, when the pressure in the discharge chamber 2 at the initial stage of cold start is low, the back pressure biasing force based on the discharge equivalent pressure to the thrust bearing 20 and the back pressure chamber 3 to the orbiting scroll 18 are set.
The combined force of the back pressure biasing force based on the intermediate pressure of 9 causes the orbiting scroll 18 to move to the fixed scroll 1 based on the compression chamber pressure.
5 is smaller than the thrust load to be separated from the thrust bearing 5, the seal ring 70 and the thrust bearing 20 uniformly biased to the back by the lubricating oil exerted by the discharge pressure do not incline with respect to the fixed scroll 15.
8 is stably supported while retreating slightly, and only the axial gap of the compression chamber between the orbiting scroll 18 and the fixed scroll 15 is enlarged. This causes leakage in the compression space, lowers the pressure in the compression chamber, and reduces the compression load in the initial stage of starting.

Then, as the pressure in the discharge chamber 2 rises, the lubricating oil in the outer peripheral space 37 is injected into the second compression chambers 51a, 51b from the injection holes 52a, 52b against the biasing force of the coil spring 59. .

Further, the pressure of the compression chamber when a momentary liquid compression occurs at the initial stage of cold start or at the time of steady operation causes a rapid pressure increase and overcompression as shown by the dotted line 63 in FIG. 2 and the high-pressure space communicating with it are large, the pressure rise in the discharge chamber 2 is extremely small.

Further, the second compression chambers 51a, 51
Abnormal pressure rises also in the injection groove 54 communicating with 1b, but the throttle effect of the small diameter oil hole C38c and the check valve 5
Due to the check action of 8, the space between the outer peripheral space 37 and the injection groove 54 is shut off. As a result, the pressure in the back pressure chamber 39 does not change, and the back pressure biasing force acting on the back surface of the thrust bearing 20 and the back pressure biasing force due to the intermediate pressure of the back pressure chamber 39 acting on the back surface of the orbiting scroll 18 also vary. Absent.
As a result, during liquid compression, the thrust bearing 20 retracts as described above due to the excessive thrust force acting on the orbiting scroll 18, and the pressure in the compression chamber drops, after which normal operation continues.

Since the thrust bearing 20 retracts during the liquid compression, the pressure in the compression chamber is increased by the alternate long and short dash line 63 in FIG.
As shown in a, the pressure is reduced on the way.

After the compressor is stopped, the discharge refrigerant gas in the discharge chamber 2 tries to flow back into the compression chamber, and a reverse swirl torque is generated in the orbiting scroll 18 by the pressure. Backflow. Following the reverse flow of the discharged refrigerant gas, the check valve 50 moves from the position of FIG. 6 to the position of FIG. 7, and the Teflon coating applied to the surface of the check valve 50 seals the suction pipe end surface 48. As a result, the reverse flow of the discharged refrigerant gas is stopped, the reverse orbit of the orbiting scroll 18 is stopped, and the space between the suction passage 42 and the discharge port 16 holds the discharge pressure.

Further, the passage communicating with the compression chamber with the check valve 58 of the injection passage 55 as a boundary is at the discharge pressure, but the space between the outer peripheral portion space 37 and the back pressure chamber 39 remains for a while. The intermediate pressure is maintained and the discharge pressure gradually approaches the discharge pressure due to a slight inflow of lubricating oil from the discharge chamber oil sump 34. When the compressor is stopped, the orbiting scroll 18 rotates in the reverse direction, the third compression chambers 60a and 60b stop at the enlarged position as shown in FIG. 11, and the opening of the oil hole C38c to the outer peripheral space 37 is the wrap support circle. It is blocked by the plate 18c. After the compressor stops,
The check valve 58 shuts off the injection passage 55 even by the urging force of the coil spring 59, so that no lubricating oil flows from the outer peripheral space 37 into the compression chamber.

During operation of the compressor, the oil supply upstream side of the main bearing 12 communicates with the discharge chamber oil sump 34, and the oil supply downstream side of the main bearing 12 communicates with the back pressure chamber 39 at an intermediate pressure state between them. A differential pressure is generated, and the drive shaft 4 to which the rotor 3a of the motor 3 is fixed is urged toward the orbiting scroll 18. This urging force is supported by the main body frame 5 via the thrust ball bearing 13 to prevent the drive shaft 4 from falling over within the range of the bearing gap between the upper bearing 10 and the main bearing 12 and prevent the bearing from partially hitting. . Also, this urging force reduces jumping up and down due to the unevenness of the rolling surface when the ball bearing of the thrust ball bearing 13 rolls on the rolling surface, and reduces vertical vibration of the drive shaft 4. Contributes to low noise and low vibration.

When the temperature rises during operation of the compressor, the main body frame 5 made of aluminum alloy thermally expands to expand the iron liner 8 to strengthen the adhesion between the outer peripheral surface of the liner 8 and the inner wall of the closed case 1. As a result, the airtightness between the discharge chamber oil sump 34 and the discharge chamber 2 is improved, and the main body frame 5 and the hermetically sealed case 1 are strengthened to help improve their rigidity.

In the above embodiment, the lubricating oil in the discharge chamber oil sump 34 is injected into the second compression chambers 51a and 51b. However, the first compression chamber 61a which communicates with the suction chamber 17 depending on operating conditions such as compressor operating speed and pressure. , 61b may be filled with oil.

Further, in the above embodiment, the lubricating oil of the discharge chamber oil sump 34 is introduced into the release gap 27 and the annular groove 28 provided on the back surface of the thrust bearing 20. Depending on the shape and size of the bearing 20, the refrigerant gas may be introduced from the refrigerant gas discharged from the motor chamber 6 or the second compression chambers 51a and 51b in an intermediate pressure state.

Although the elastic force of the seal ring 70 is used as the preload biasing force to the thrust bearing 20 in the above embodiment, when the thrust bearing 20 is insufficient in the back pressure area, the biasing force is applied by a spring device or the like. You may add.

Even if the lubricating oil of the discharge chamber oil sump 34 or the pressure of the compression chamber is not particularly introduced into the release gap 27 and the annular groove 28, the back surface setting biasing force of the thrust bearing 20 may be adjusted as necessary. Replacing the leaf spring or the like shown in FIG. 18 with the seal ring 70 of FIGS. 1 to 3 also makes it possible to easily obtain the rear surface biasing force to the thrust bearing 20. Further, it is possible to easily combine these.

According to the above embodiment, the orbiting scroll 18
Is disposed between the main body frame 5 supporting the drive shaft 4 and the fixed scroll 15, is provided on the main body frame 5 side, supports the side opposite to the compression chamber of the orbiting scroll 18, and is movable in the axial direction. Thrust bearing 20 and fixed scroll 1
5, which is arranged between the thrust bearing 20 and the main body frame 5 and which biases the thrust bearing 20 in the direction of the orbiting scroll 18 (lubrication introduced from the seal ring 70 and the discharge chamber oil sump 34). Hydraulic pressure) and thrust bearing 20
Provides a releasable release gap 27 on the side opposite to the compression chamber so that the thrust bearing 20 can stably support the orbiting scroll 18 without deflecting the axial gap of the compression chamber.
In the structure in which the sliding contact portion of the thrust bearing 20 is formed at a position facing the region outside the compression chamber communicating with the discharge port 16, the orbiting scroll 18 can form at least an oil film between the fixed scroll 15 and the thrust bearing 20. Means (spacer 21) for restricting the range in which the thrust bearing 20 moves toward the fixed scroll 15 in order to stably hold the axial minute gap (0.015 to 0.040 mm) and prevent the vibration of the thrust bearing 20. By providing means for restricting the radial movement of the thrust bearing 20 with the split parallel pin 19, the orbiting scroll 18 is axially fixed to the fixed scroll 15 even when the back biasing force on the thrust bearing 20 becomes excessive. Without pressing, a good oil film is formed on the sliding contact surface of the thrust bearing 20 to stably support the orbiting scroll 18, and the compression chamber It is possible to not cause deflection of the direction gap. As a result, the back biasing force on the thrust bearing 20 does not bring the orbiting scroll 18 into axial contact with the fixed scroll 15, thus preventing an increase in input.

When the compression chamber pressure is operating normally,
Since the orbiting scroll 18 is sandwiched between the fixed scroll 15 and the thrust bearing 20 with a minute gap capable of forming an oil film,
It is possible to prevent the orbiting scroll 18 from making a smooth orbital motion without colliding with the sliding surface due to jumping with respect to the fixed scroll 15 or jumping or causing one-sided contact, and to prevent radial vibration of the thrust bearing 20.

As a result, a small axial gap in the compression chamber is ensured to prevent compressed refrigerant gas leakage, maintain high compression efficiency, and prevent noise and vibration from the orbiting scroll 18 and thrust bearing 20 to prevent both scrolls and thrust. The durability of the bearing 20 can be improved.

Also, a large amount of liquid refrigerant returns from the refrigeration cycle to the compressor at the initial stage of cold start of the compressor, liquid compression occurs in the compression process, and the pressure in the compression chamber begins to rise abnormally. Even when the thrust force acting in the direction of separating 18 is temporarily excessive, the thrust bearing 20 retracts toward the motor chamber 6 while stably supporting the back surface of the orbiting scroll 18, so that the orbiting scroll 18 is fixed. 15 is widened only in the axial direction, and the axial sealing of the compression chamber is released without collision between the orbiting scroll wrap 18a and the fixed scroll wrap 15a, and the compression chamber pressure is instantly reduced to reduce the compressor load. It can reduce the durability and increase the durability.

Even when liquid compression does not occur, since the suction pressure is high in the initial stage of starting, the compression ratio of the scroll compressor is constant, so the compression chamber pressure becomes extremely higher than that during normal operation. By properly setting the back pressure urging force on the thrust bearing 20, the thrust bearing 20 supporting the orbiting scroll 18 can be retracted to reduce the load at the initial stage of startup.

According to the above embodiment, the thrust bearing 2
As means for urging 0 in the direction of the orbiting scroll 18,
By disposing the seal ring 70 between the rear surface of the thrust bearing 20 on the anti-compression side and the main body frame 5 to uniformly urge the thrust bearing 20, the thrust bearing 20 is less deformed and the orbiting scroll 18 is stabilized. It can be supported, the axial gap of the compression chamber can be prevented from being deflected, the compression chamber axial sealing action can be enhanced, and the compression efficiency can be improved.

According to the above embodiment, the seal ring 7
0 is arranged at a position opposed to the sliding contact portion of the thrust bearing 20 to reduce the deformation of the thrust bearing 20 and to improve the oil film formation on the sliding contact surface with the orbiting scroll 18, thereby making The jumping phenomenon can be suppressed. As a result, collision of the orbiting scroll 18 is eliminated and low noise
Low vibration can be realized.

According to the above embodiment, the seal ring 7
The release gap 27 is divided by 0 to form the thrust bearing back pressure chamber 27a, and the lubricating oil that exerts the discharge pressure is introduced into the thrust bearing back pressure chamber 27a, so that the tightness of the seal ring 70 is reduced. The durability of the ring 70 can be improved. Further, it is possible to prevent the damage to the compressor by improving the responsiveness of the overload reducing operation at the initial stage of starting the compressor or when the pressure in the compression chamber rises abnormally.

According to the above embodiment, the thrust bearing 2
By further disposing an annular leaf spring on the back surface of the No. 0 anti-compression side and urging the thrust bearing 20 toward the orbiting scroll 18, the preload on the thrust bearing 20 can be strengthened. Thereby, the compression rise can be accelerated.

Further, according to the above-described embodiment, the annular leaf spring is arranged in the annular groove (the groove in which the seal ring 70 is mounted) provided in the main body frame 5 or the annular groove 28 to arrange the thrust bearing 20.
By applying a biasing force to the, it is possible to suppress the unnecessary radial movement of the annular leaf spring, thereby,
Since it is possible to apply a stable and uniform biasing force to the thrust bearing 20, it is possible to stabilize the thrust bearing 20.
It is possible to enhance the function of sealing the gap in the axial direction of the compression chamber during normal operation.

According to the above embodiment, the main body frame 5
Fixing part (split parallel pin 1)
By restricting and holding the radial movement of the thrust bearing 20 via 9), the axial movement of the thrust bearing 20 can be allowed and the radial movement can be restricted at the same time.

According to the above embodiment, the main body frame 5
Since the thrust bearing 20 is held by the split parallel pin 19 fixed to the above, the radial movement of the thrust bearing 20 can be prevented by a simple means.

Further, according to the above-described embodiment, in the structure in which the rotation preventing member (Oldham ring) 24 of the orbiting scroll 18 is arranged between the fixed scroll 15 and the main body frame 5, the thrust bearing 20 to the side opposite to the compression chamber is provided. The retreat distance (about 0.1 mm) is larger than the axial minute gap (0.015 to 0.040 mm) in which the lap support disk 18c is sandwiched between the fixed scroll 15 and the thrust bearing 20, and Since the blocking member (Oldham ring) 24 is arranged in a size and shape that does not regulate the retreat distance,
Since the orbiting scroll 18 swivels smoothly during the overload reduction operation, the orbiting scroll 18 can be stably supported by the thrust bearing 20.

(Embodiment 2) FIG. 14 is a vertical cross-sectional view of a scroll refrigerant compressor of another embodiment. 101a and 101b are iron hermetically sealed cases, and 180 is an iron-made body frame 105 and a soft steel partition to which bolts are fixed. The plate is a single weld bead 1 with its outer peripheral surface together with the sealed cases 101a and 101b.
81, and is sealed by welding.
The inside of 1b is partitioned into an upper discharge chamber 102 and a lower drive chamber 106 (low pressure side). The orbiting shaft 118b of the orbiting scroll 118 is fitted into the eccentric hole 136 at the upper end of the drive shaft 104, which is rotatably driven by the motor 103 supported by the main body frame 105 and controlled by an inverter power supply (not shown). The Oldham ring 124 for preventing rotation of the orbiting scroll 118 is attached to the main body frame 10.
The orbiting scroll 118 is supported at a position opposite to the first compression chamber, which is constrained by a split parallel pin (not shown) fixed to No. 5, is movable only in the axial direction, and intermittently communicates with the suction chamber 117. A fixed scroll 115 that engages with the thrust bearing 120 and each groove of the orbiting scroll 118 and meshes with the orbiting scroll 118 is bolted to the partition plate 180, and the end plate 115b of the fixed scroll 115 is provided with the discharge port 116. A reed valve type oil supply passage control valve device 182 is attached to the upper surface of 115b.

The thrust bearing 120 is constantly urged toward the orbiting scroll 118 by the elastic force of the seal ring 170 arranged on the outer surface of the rear surface thereof, and comes into contact with the flat surface on one side of the partition plate 180 to cause the orbiting scroll 118 to move. Axial movement to is restricted. However, the plate thickness of the partition plate 118 is such that the elastic force of the seal ring 170 via the thrust bearing 120 does not press the orbiting scroll 118 against the fixed scroll 115 and hinder the smooth orbiting motion of the orbiting scroll 118. An orbiting scroll 118 sandwiched between a fixed scroll 115 and a thrust bearing 120.
The dimension setting is such that a small axial gap (about 0.020 mm) is secured.

The bottom of the discharge chamber 102 serves as the discharge chamber oil sump 134, and an umbrella-shaped punching metal 133 having a large number of small holes is attached to the upper part of the sump case 101a.
A filter 183 made of a fine resin wire is packed between the closed case 101a and the punching metal 133. The discharge chamber 102 is provided with a discharge pipe 131 provided on the upper surface of the closed case 101a and a suction pipe 1 provided on the side surface of the closed case 101b via an external refrigeration cycle piping system.
Through 47, it communicates with the driving chamber 106 on the low pressure side. A motor chamber oil sump 184 is provided at the bottom of the drive chamber 106.

An oil suction hole provided at the bottom of the end plate 115b is provided between the discharge chamber oil reservoir 134 and the second compression chamber 151, which is a normally closed space that does not communicate with the discharge chamber 102 or the suction chamber 117. 185, the valve space 188 formed between the valve retainer 187 of the oil supply passage control valve device 182 attached to the end plate 115b together with the thin steel plate reed valve 186, and the punched hole 189 of the reed valve 186,
It communicates with a first oil supply passage having a throttle passage formed of an injection hole 152 of an ultrafine passage provided in the end plate 115b.

The back pressure chamber 1 formed by the lap support disk 118b for supporting the orbiting scroll wrap 118a of the orbiting scroll 118, the thrust bearing 120 and the drive shaft 104.
Reference numeral 39 denotes a valve space that branches off from the middle of the first oil supply passage.
8, punched hole 189a of reed valve 186, end plate 115
b, an oil hole A138a provided in b, an oil hole B138b of an ultrafine passage provided in the partition plate 180, the main body frame 105
Oil hole C138c provided in the bearing, the release bearing 127 provided between the thrust bearing 120 and the main body frame 105, the outer peripheral portion of which is supported and sealed by a rubber seal ring 170, and the oil provided in the thrust bearing 120. Hole D13
8d communicates with the discharge chamber oil sump 134 by an oil supply passage constituted by 8d.

Between the back pressure chamber 139 and the low pressure side drive chamber 106, the bearing gap of the main bearing 112 of the main body frame 105, the gap of the eccentric bearing 114, the eccentric oil hole 190 provided in the drive shaft 104, and the lateral oil are provided. A lower bearing 192 provided at the lower end of the body frame 105 to support the hole 191 and the drive shaft 104.
Oil reservoir 193 and lower bearing 19 between
The first lubricating passage having a throttle passage constituted by two bearing gaps communicates with each other.

Further, between the back pressure chamber 139 and the suction chamber 117, the second lubrication formed by the sliding surface between the thrust bearing 120 and the lap supporting disk 118b and the sliding surface of the Oldham ring 124 is provided. It is connected by a passage.

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

In FIG. 14 and FIG. 15, when the drive shaft 104 starts to rotate by the motor 103, the orbiting scroll 118 makes an orbiting motion, and the suction refrigerant gas passes through the suction pipe 147 from the refrigeration cycle piping system connected to the compressor. After flowing into the drive chamber 106 and part of the lubricating oil contained therein is separated, it is sucked into the suction chamber 117 through the suction passage. The sucked refrigerant gas is confined in the compression chamber through the first compression chamber that is formed between the orbiting scroll 118 and the fixed scroll 115 and intermittently communicates with the suction chamber 117, and is always accompanied by the orbiting motion of the orbiting scroll 118. The second compression chamber, which is a closed space, and the third compression chamber, which communicates intermittently with the discharge port, are sequentially transferred and compressed, and the discharge port 1 in the central portion is compressed.
The liquid is discharged to the discharge chamber 102 through the nozzle 16.

A part of the lubricating oil contained in the discharged refrigerant gas adheres to the surface of the small hole of the punching metal 133 and the filter 183 made of fine resin wire when it passes through the discharged refrigerant gas. It separates and flows down along the inner wall of the closed case 101a, and the discharge chamber oil reservoir 134
Will be collected. The remaining lubricating oil is carried out to the external refrigeration cycle piping system together with the discharge refrigerant gas through the discharge pipe 131, and returns to the compressor through the suction pipe 147 together with the suction refrigerant gas.

For a while after the cold start of the compressor, since the pressure in the discharge chamber 102 is lower than the pressure in the second compression chamber as described above, the lubricating oil in the discharge chamber oil sump 134 passes through the first oil supply passage. The differential pressure oil is not supplied, and the refrigerant gas does not flow backward from the second compression chamber to the discharge chamber oil sump 134 due to the action of the check valve, and the release gap 127 of the thrust bearing 120 and the back pressure chamber 139 of the orbiting scroll 118 are not supplied. The residual lubricating oil of each sliding portion lubricates each sliding surface without flowing into the sliding surface.

The back pressure chamber 139 and the release gap 127
Since the pressure is low, the thrust bearing 120 slightly retracts in the initial stage of starting to widen the gap in the compression chamber axial direction to sharply reduce the pressure in the compression chamber, thereby reducing the initial load of starting.

Some time after the cold start of the compressor, the pressure in the discharge chamber 102 rises above the pressure in the second compression chamber, and then the lubricating oil in the discharge chamber oil sump 134 is supplied to the oil supply passage control valve device 182.
Through the first oil supply passage against the biasing force of the reed valve 186. Then, the pressure is gradually reduced, differential pressure oil is supplied to the second compression chamber, and the pressure is gradually reduced via the oil holes 138a, 138b, 138c of the second oil supply passage formed by branching from the middle of the first oil supply passage. The pressure is adjusted to an intermediate pressure between the pressure and the suction side pressure, and differential pressure oil is supplied to the release gap 127 and the back pressure chamber 139.

The lubricating oil differentially supplied to the second compression chamber merges with the lubricating oil that has flowed into the compression chamber together with the suction gas, and seals a minute gap between adjacent compression chambers with an oil film to prevent compressed refrigerant gas leakage. The compressed refrigerant gas is discharged again to the discharge chamber 102 while preventing it and lubricating the sliding surface between the compression chambers.

The intermediate clearance lubricating oil supplied to the release gap 127 and the back pressure chamber 139 gives an urging force by the back pressure to the orbiting scroll 118, and tries to separate from the fixed scroll 115 based on the compression chamber pressure. 1
The downward thrust force acting on 18 is reduced, the thrust load acting on the sliding surface between the orbiting scroll 118 and the thrust bearing 120 is reduced, and the thrust bearing 120 is urged to contact the partition plate 180. Then, the orbiting scroll 118 is sandwiched between the fixed scroll 115 and the thrust bearing 120 with a minute gap, so that the orbiting scroll 118 can smoothly orbit. Further, since the back pressure of the back pressure chamber 139 is adjusted so that the orbiting scroll 118 does not separate from the thrust bearing 120, the orbiting scroll 118 and the thrust bearing 120 are always in sliding contact with each other, and this sliding contact portion is the boundary. The back pressure chamber 139 and the suction chamber 117 are hermetically sealed so that the sliding contact surfaces thereof can be appropriately lubricated to allow leakage of lubricating oil. Therefore, the back pressure chamber 139
The lubricating oil supplied to (1) is depressurized when passing through the sliding contact surface, lubricates the sliding surface of the Oldham ring 124, mixes with the suction refrigerant gas, and flows into the compression chamber again.

Further, the remaining lubricating oil passes through the first lubricating passage and the gap between the swivel shaft 118b and the eccentric hole 136, the eccentric hole 1
36, the eccentric oil hole 190, the lateral oil hole 191, and the gap between the main bearing 112 and the oil supply passage, and then flows into the bearing oil sump 193,
The final pressure is reduced through the minute gap of the lower bearing 192. Then, it flows into the drive chamber 106, a part of it is mixed with the suction refrigerant gas and flows into the compression chamber again, but the remaining lubricating oil is collected in the motor chamber oil sump 184. The lubricating oil in the motor chamber oil sump 184 is cooled by natural abandonment via the sealed case 101b, and when the oil level rises to some extent, the motor 103
Is diffused into the lower end portion of the rotor, mixed with the suction refrigerant gas in the drive chamber 106, flows into the compression chamber again, and is finally collected in the discharge chamber oil sump 134.

When an abnormal pressure rise occurs in the second compression chamber, which is always a closed space, due to the instantaneous liquid compression occurring at the initial stage of cold start or at the time of steady operation, the reed valve 186 is operated as described above.
Due to the non-return action, the compressed refrigerant gas does not flow back into the discharge chamber oil sump 134, does not flow into the release gap 127 or the back pressure chamber 139, and the back pressure does not increase, so that the thrust bearing 120 retracts. To prevent continuous abnormal pressure rise.

After the compressor stops, the suction chamber 117 and the drive chamber 10
A check valve (not shown) provided in the suction passage between the discharge chamber 102 and the suction chamber 117
Up to the pressure of the discharge chamber 102 through the gap of the compression space, and the reed valve 186 closes the opening end of the oil suction hole 185. As a result, the lubricating oil in the discharge chamber oil reservoir 134 immediately after the compressor is stopped is not differentially supplied to the second compression chamber and the back pressure chamber 139, and the lubricating oil in the back pressure chamber 139 is supplied to the drive chamber through the first oil supply passage. The pressure is gradually returned to 106 until the pressure difference becomes a certain value or less.

According to the above-described embodiment, since the rotation preventing member (Oldham ring 124) is arranged between the thrust bearing 120 and the orbiting scroll 118 so as to move together with the axial movement of the thrust bearing 120, the rotation preventing member. The sliding engagement of the (Oldham ring 124) is always smooth, and the durability of the sliding engagement portion of the rotation preventing member (Oldham ring 124) can be improved.

In the above embodiment, the release gap 12
7, the lubricating oil in the discharge chamber oil reservoir 134 was reduced to an intermediate pressure to the back pressure chamber 139 and the thrust bearing 120 and the back pressure chamber 13.
The pressure need not be reduced due to the dimensional configuration of FIG.

In the above embodiment, the refrigerant compressor has been described, but other gas compressors such as oxygen, nitrogen, and helium that use lubricating oil can be expected to have the same effects.

[0100]

As is apparent from the above embodiment, in the invention according to claim 1, the orbiting scroll is arranged between the main body frame supporting the drive shaft and the fixed scroll, and is provided on the side of the main body frame. The orbiting scroll is arranged between a fixed scroll and a thrust bearing that supports the side opposite to the compression chamber and is movable in the axial direction.The thrust bearing is provided between the thrust bearing and the main body frame in the direction of the orbiting scroll. The thrust bearing and the thrust bearing are provided with a releasable clearance on the side opposite to the compression chamber so that the orbiting scroll can be stably supported by the thrust bearing without deflecting the axial clearance of the compression chamber. In the configuration in which the sliding contact portion is formed at a position facing the region outside the compression chamber communicating with the discharge port, the orbiting scroll is formed by combining the fixed scroll and the thrust bearing. In order to stably hold at least the axial minute gap in which the oil film can be formed and to prevent the vibration of the thrust bearing, a means for restricting the range in which the thrust bearing moves toward the fixed scroll, and at least radial movement of the thrust bearing are According to this configuration, even if the back surface biasing force on the thrust bearing becomes excessive, the orbiting scroll does not axially press the fixed scroll in the axial direction, and the sliding contact surface of the thrust bearing is good. A stable oil film can be formed to stably support the orbiting scroll, and the deflection of the clearance in the axial direction of the compression chamber can be prevented. As a result, the back surface biasing force on the thrust bearing does not bring the orbiting scroll into axial contact with the fixed scroll, so that an increase in input does not occur. When the compression chamber pressure is normal, the orbiting scroll is sandwiched between the fixed scroll and the thrust bearing with a minute gap that allows the formation of an oil film. It is possible to make a smooth swivel motion without causing collision and partial contact, and to prevent radial vibration of the thrust bearing.

As a result, a small axial gap in the compression chamber is ensured to prevent compressed refrigerant gas leakage, maintain high compression efficiency, and prevent noise and vibration from the orbiting scroll and thrust bearing to prevent the scroll and thrust bearing from contacting each other. The durability can be improved.

Further, liquid compression occurs in the compression process during the initial stage of cold start of the compressor and the pressure in the compression chamber starts to rise abnormally, and the thrust force acting in the direction of separating the orbiting scroll from the fixed scroll becomes temporarily excessive. In this case, since the thrust bearing retracts to the side opposite to the compression chamber while stably supporting the back surface of the orbiting scroll, the orbiting scroll widens only the axial gap between the orbiting scroll and the fixed scroll, and the gap between the orbiting scroll and the fixed scroll is increased. The axial sealing of the compression chamber can be released without causing a collision, the pressure of the compression chamber can be instantaneously reduced, the load on the compressor can be reduced, and the durability can be improved.

Even when liquid compression does not occur, since the suction pressure is high at the initial stage of start-up, the compression ratio of the scroll compressor is constant, so the compression chamber pressure becomes extremely higher than that during normal operation. By properly setting the back pressure biasing force applied to the thrust bearing, it is possible to retract the thrust bearing that supports the orbiting scroll and reduce the load at the initial stage of startup.

According to a second aspect of the present invention, as means for urging the thrust bearing in the direction of the orbiting scroll, an annular elastic member capable of uniformly urging the thrust bearing between the rear surface of the thrust bearing on the anti-compression side and the body frame. With this configuration, the orbiting scroll can be stably supported because the thrust bearing is less deformed, the axial clearance of the compression chamber is prevented from being deflected, and the compression chamber axial sealing is performed. There is an effect that the action can be enhanced and the compression efficiency can be improved.

According to the third aspect of the present invention, the annular elastic body is arranged at a position facing the sliding contact portion of the thrust bearing. According to this configuration, deformation of the thrust bearing is reduced and the orbiting scroll is used. It is possible to suppress the jumping phenomenon in the axial direction of the orbiting scroll by favorably forming the oil film on the sliding contact surface. As a result, there is an effect that low noise and low vibration can be realized without the collision of the orbiting scroll.

According to a fourth aspect of the present invention, the release gap is defined by the annular elastic body to form the thrust bearing back pressure chamber,
The thrust bearing back pressure chamber is introduced with a fluid that exerts a discharge pressure. According to this configuration, the elastic body can be made less tight and the elastic body can be made smaller and its durability can be improved. Further, there is an effect that the responsiveness of the overload reducing operation at the initial stage of starting the compressor or when the pressure in the compression chamber abnormally rises can be enhanced to prevent damage to the compressor.

According to a fifth aspect of the present invention, another elastic body is arranged on the back surface of the thrust bearing on the side opposite to the compression side, and the thrust bearing is biased in the direction of the orbiting scroll. The preload on the can be increased. As a result, there is an effect that the compression rise can be accelerated.

According to a sixth aspect of the present invention, the annular elastic body is an annular spring device, and the annular spring device is arranged in an annular groove provided in the main body frame. According to this configuration, the annular spring device is provided. Unnecessary radial movement of the thrust bearing can be suppressed, and a stable and uniform biasing force can be applied to the thrust bearing, which stabilizes the thrust bearing and reduces the axial direction of the compression chamber during normal operation. An effect that the gap sealing action can be enhanced is exhibited.

According to a seventh aspect of the present invention, the radial movement of the thrust bearing is regulated and held via a columnar fixing part fixed to the main body frame. This has the effect of permitting axial movement and restricting radial movement at the same time.

According to the eighth aspect of the present invention, the columnar fixing component is a split parallel pin. According to this configuration,
The effect that the radial movement of the thrust bearing can be prevented by a simple means is obtained.

According to a ninth aspect of the present invention, in the structure in which the rotation preventing member of the orbiting scroll is arranged between the fixed scroll and the main body frame, the retraction distance of the thrust bearing toward the side opposite to the compression chamber is determined by the lap support disc. Is larger than the small axial gap sandwiched between the fixed scroll and the thrust bearing, and the rotation prevention member is arranged so as not to regulate the backward distance of the orbiting scroll. Since the orbiting scroll orbits smoothly during operation, the orbiting scroll can be stably supported by the thrust bearing.

According to the tenth aspect of the present invention, the rotation preventing member is arranged between the thrust bearing and the orbiting scroll so as to move along with the axial movement of the thrust bearing. The sliding engagement is always smooth, and the durability of the sliding engagement portion of the rotation preventing member can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a scroll refrigerant compressor according to a first embodiment of the present invention.

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

FIG. 3 is a detailed partial sectional view of a seal portion of a thrust bearing in the compressor.

FIG. 4 is an external view of an Oldham ring in the compressor.

FIG. 5 is an external view of the assembly of the Oldham mechanism in the compressor.

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

FIG. 7 is an explanatory view of the position of the check valve in the suction pipe connecting portion of the compressor.

8 is a partial cross-sectional view taken along the line BB in FIG.

FIG. 9 is an external view of a check valve used in the oil supply passage of the compressor.

FIG. 10 is an explanatory diagram of movement of a compression chamber in the vicinity of a discharge port of the compressor.

FIG. 11 is an explanatory diagram of the same.

FIG. 12 is a characteristic diagram showing the pressure change of the refrigerant gas from the suction stroke to the discharge stroke of the compressor.

FIG. 13 is a characteristic diagram showing pressure change at a fixed point in each compression chamber.

FIG. 14 is a vertical sectional view of a scroll refrigerant compressor according to a second embodiment of the present invention.

FIG. 15 is an external view of a reed valve installation of the oil supply passage control valve device in the compressor.

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

FIG. 17 is a partially enlarged view of FIG.

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

[Explanation of symbols]

 4 Drive shaft 5 Body frame 15 Fixed scroll 15a Fixed scroll wrap 15b End plate 16 Discharge port 17 Intake chamber 18 Orbiting scroll 18a Orbiting scroll wrap 18c Wrap support disk 19 Split parallel pin 20 Thrust bearing 24 Rotation blocking member 27 Release gap 27a Thrust bearing back pressure chamber 34 Discharge chamber oil sump 70 Seal ring 118 Orbiting scroll 120 Thrust bearing 124 Rotation prevention member

Claims (10)

[Claims] 1. An orbiting scroll wrap on a lap support disk forming a part of an orbiting scroll is swingably rotatable with respect to a spiral fixed scroll wrap formed on one surface of an end plate forming a part of the fixed scroll. A spiral compression space is formed between both scrolls, a discharge port is provided at the center of the fixed scroll wrap, and a suction chamber is provided outside the fixed scroll wrap. A scroll compression mechanism is formed that is divided into a plurality of compression chambers that continuously move toward the discharge side to compress a fluid, and the orbiting scroll is disposed between the main body frame that supports a drive shaft and the fixed scroll, The thrust bearing and the fixed scroll, which are provided on the main body frame side, support the anti-compression chamber side of the orbiting scroll, and are movable in the axial direction. Between the thrust bearing and the main body frame, means for urging the thrust bearing in the direction of the orbiting scroll, and a release gap in which the thrust bearing can retract toward the anti-compression chamber side. A region outside the compression chamber communicating the sliding contact portion of the thrust bearing with the discharge port so that the orbiting scroll can be stably supported by the thrust bearing without deflecting the axial gap of the compression chamber. In a configuration formed in a position opposed to, between the fixed scroll and the thrust bearing, the orbiting scroll stably holds at least an axial minute gap capable of forming an oil film and prevents vibration of the thrust bearing, Means for restricting the range of movement of the thrust bearing toward the fixed scroll, and at least radial movement of the thrust bearing. Scroll compressor provided with a means for regulating the. 2. An annular elastic body that can uniformly urge the thrust bearing is disposed between a rear surface on the anti-compression side of the thrust bearing and a main body frame as a means for urging the thrust bearing in the direction of the orbiting scroll. The scroll compressor according to claim 1. 3. The scroll compressor according to claim 2, wherein the annular elastic body is arranged at a position opposed to the sliding contact portion of the thrust bearing. 4. The scroll compressor according to claim 2, wherein a release gap is defined by an annular elastic body to form a thrust bearing back pressure chamber, and a fluid having a discharge pressure is introduced into the thrust bearing back pressure chamber. 5. The scroll compressor according to claim 4, wherein another elastic body is arranged on the rear surface of the thrust bearing on the side opposite to the compression side, and the thrust bearing is biased in the direction of the orbiting scroll. 6. The scroll compressor according to claim 2, wherein the annular elastic body is an annular spring device, and the annular spring device is arranged in an annular groove provided in the body frame. 7. The scroll compressor according to claim 1, wherein the radial movement of the thrust bearing is regulated and held through a columnar fixing part fixed to the main body frame. 8. The scroll compressor according to claim 7, wherein the columnar fixing part is a split parallel pin. 9. A revolving distance of the thrust bearing toward the side opposite to the compression chamber in the structure in which the rotation preventing member of the orbiting scroll is arranged between the fixed scroll and the main body frame, the lap supporting disk is fixed to the fixed scroll and the thrust. The scroll compressor according to claim 1, wherein the rotation preventing member is arranged so as to be larger than an axial minute gap sandwiched between the rotation preventing member and the bearing so as not to regulate a backward distance of the orbiting scroll. 10. The scroll compressor according to claim 9, wherein a rotation preventing member is arranged between the thrust bearing and the orbiting scroll so as to move along with the axial movement of the thrust bearing.