JPH01177482A - Scroll compressor - Google Patents

Abstract

PURPOSE:To improve compression efficiency and to further improve vibration and noise characteristics, by a method wherein a revolving scroll is situated between a body frame and a stationary scroll, and is nipped between a thrust bearing and a stationary scroll with a fine gap therebetween. CONSTITUTION:A revolving scroll 18 is situated between a body frame 5 for supporting a drive shaft 4 and a stationary scroll 15. The revolving scroll is nipped between a thrust bearing 20 located on the body frame 5 side and movable only in an axial direction and the stationary scroll 15 with a fine gap therebetween. The revolving scroll 18 performs revolving movement, which is prevented from collision with a slide surface and the occurrence of sided- contact and silent and reduces production of vibration, without being affected by the moment and jumping phenomenon. This constitution enables increase of compression efficiency and further improvement of noise and vibration characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to overload mitigation of scroll compressors.

Conventional technology Scroll compressors with low vibration and low noise characteristics have a suction chamber on the outer periphery and a discharge port in the center of the spiral. It is generally known that this type of compressor does not require a discharge valve for compressing fluid, has a constant compression ratio, has relatively small discharge pulsation, and does not require a large discharge space.

Furthermore, in order to further improve vibration and noise characteristics, the configurations shown in FIGS. 16 and 17 have been considered as a measure to reduce the jumping phenomenon of the orbiting scroll during high-speed operation of the compressor.

The figure shows the drive pin 100 at the tip of the drive shaft 1007.
End plate t001 of the orbiting scroll 1001 connected to 7a
The fixed scroll 1002 (7) is supported with a small gap between the i-plate 1002a and the frame 1008, and is used when the compression load or the inertia of rotating members changes, such as when starting, stopping, or high-speed operation of the compressor. This prevents the orbiting scroll 1001m from jumping, ensures a small gap in the axial direction between the orbiting scroll 10o1 and the fixed scroll 1002, and seals the compression chamber to improve compression efficiency, and also prevents abnormal noises caused by collisions between members. Efforts have been made to prevent vibration and deterioration of the durability of sliding parts (Japanese Patent Application Laid-open No. 55-14290).
2, U.S. Pat. No. 3,994,633, etc.).

Problems to be Solved by the Invention However, since scroll compressors have a constant compression ratio, if the pressure inside the compression chamber increases abnormally due to liquid compression, etc., the gap between the compression chambers is widened and the compressed fluid leaks, causing the compression chamber to leak. Since the pressure cannot be lowered, there are problems unique to scroll compressors, such as increased compression load, damage to parts, and decreased durability of sliding parts.

In addition, as a measure to solve this liquid compression problem, the 18th
The composition of the figure has been considered.

The figure shows a structure in which the fixed scroll 2001e is movable in the axial direction, and the urging force of the leaf spring 2023e and the back pressure chamber 2015
Introducing discharge pressure to the fixed scroll 2 and its back pressure
001e is pressed against the orbiting scroll 2001b, the axial gap between the orbiting scroll and the fixed scroll is eliminated, the compression chamber is sealed, and the compression efficiency is increased. When liquid compression occurs in the compression chamber, the fixed scroll 2001. is separated from the orbiting scroll 2001d in the axial direction to lower the compression chamber pressure and reduce the load (US Pat. No. 3,600,114).

However, the fixed scroll 2001 and the orbiting scroll 2
In the configuration in which the pressure is constantly pressed to 001d, it is necessary to increase the urging force, and there are problems in that durability is reduced due to friction and wear of the contact surfaces of both scrolls, and input loss is also large.

Additionally, as a measure to prevent overload, a structure in which the orbiting scroll is moved in a direction perpendicular to the main axis of the drive shaft, such as in U.S. Pat. Due to the high cost and large external dimensions of the compressor, there was a desire for a scroll compressor that could simultaneously improve vibration and noise characteristics and reduce overload.

Means for Solving the Problems In order to solve the above problems, the scroll compressor of the present invention has an orbiting scroll disposed between a main body frame supporting a drive shaft and a fixed scroll, and provided on the side of the main body frame. The thrust bearing, which can move only in the axial direction, and the fixed scroll are sandwiched with a small gap between them. It is always biased in the direction of the orbiting scroll by using the intermediate fluid pressure between the discharge pressure and the suction pressure.

According to the above-mentioned structure, when the compression chamber pressure is normal and the thrust force acting on the orbiting scroll and directed toward the thrust bearing is smaller than the urging force acting on the thrust bearing due to the compression pressure in the compression chamber changing sequentially. A small gap is maintained in the axial direction between the orbiting scroll and the fixed scroll to maintain the sealing of the compression chamber and provide efficient compression, as well as during moderate load fluctuations, acceleration/deceleration operation, and high-speed operation. This prevents the orbiting scroll from jumping or tilting, allowing quiet compression operation with little vibration.

If compression chamber pressure suddenly rises abnormally due to liquid compression, the thrust force acting on the orbiting scroll becomes greater than the urging force acting on the thrust bearing, and the thrust bearing The axial clearance between the orbiting scroll and the fixed scroll increases. As a result, the compression chamber is unsealed, the pressure in the compression chamber is lowered, the compression load is reduced, and normal compression operation is restored to reduce power loss. It is possible to provide an efficient scroll compressor that prevents wear, reduces vibration, noise, and has excellent durability.

Embodiments Hereinafter, scroll compressors according to embodiments of the present invention will be described with reference to the drawings.

In Fig. 1, reference numeral 1 denotes a sealed iron case, the entire interior of which is in a high-pressure atmosphere communicating with a discharge chamber 2, with a motor 3 in the upper part and a compression part in the lower part, which is fixed to the rotor 3a of the motor 3. Main body frame 5 of the compression part that supports the drive shaft 4
Is it a closed case? The inside of 1 is partitioned into a motor chamber 6 and a discharge weight.

The main body frame 5 is made of an aluminum alloy with excellent heat conduction properties, with the main purpose of reducing weight and dissipating heat from the bearing part, and an iron liner 8 with excellent weldability is fixed to the outer periphery by shrink fitting.
The outer peripheral surface of the liner 8 is inscribed in the sealed case 1 all around and is partially fixed by welding.

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 internally fixed to the sealed case 1. The drive shaft 4 includes an upper bearing 10 provided on a bearing frame 9, a lower bearing 11 provided on the upper end of the main body frame 5, a main bearing 12 provided in the center of the main body frame 5, and 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 eccentric from the main axis of the drive shaft 4 is provided 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 consists of a spiral fixed scroll wrap 15a and an end plate 15b.
A discharge port 16 that opens at the beginning of the winding is also opened to the discharge chamber 2, and a suction chamber 17 is provided at the outer periphery of the fixed scroll wrap 15.

It is made of aluminum alloy and consists of a spiral orbiting scroll lamp 113a that engages with a fixed scroll wrap 15m to form a compression chamber, and a wrap support disk 18c that stands upright with a rotation shaft 18b supported by an eccentric bearing 14 of a drive shaft 4. The orbiting scroll 18 is arranged surrounded by the fixed scroll 15, the main body frame 5, and the drive shaft 4, and a sleeve 19 made of high-strength steel material is attached to the outer periphery of the orbiting shaft 18b.
are fixed by shrink fit, and the surface of the lap support disk 18a is hardened.

A spacer 21 is provided between the thrust bearing 20, which is restrained by a parallel pin 19 fixed to the main body frame 5 and can only move in the axial direction, and the end plate 15b of the fixed scroll 15, and the axial dimension of the spacer 21 is The thickness is set approximately 0.015 to 0.020 mm larger than the thickness of the lap support disk 18a in order to improve the sealing performance of the sliding surface by an oil film.

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 1 and the outer peripheral space 37 of the lap support disk 18c are defined by the orbiting axis tab and the lap support disk. It is communicated by oil water A38m provided at 18c.

As shown in FIGS. 2 and 6, the thrust bearing 20 is formed through a central portion into a shape consisting of two parallel straight portions 22 and two arcuate curved portions 23 connected thereto.

The Oldham ring 24 for preventing rotation of the orbiting scroll is made of a light alloy or resin material suitable for sinter molding, injection molding, etc., and is provided on one side of a thin annular plate 24m with parallel surfaces as shown in Fig. 4. The outer contour of the annular plate 24m consists of two parallel straight parts 25 and two arcuate curved parts 26 connected thereto, and the straight parts 25 are thrust bearings as shown in FIG. The side surface 24c of the parallel key part 24b is orthogonal to the straight part 25 at the center of the straight part 25, and as shown in FIGS. 1 and 2, it is slidable. It is set in a shape that allows it to engage with a pair of key grooves 71 provided in the 18 lap support disks 18o with a small gap and to be able to slide.

Note that the inner contour of the annular plate 24a has a shape similar to the outer contour. Further, a recessed portion 24d provided at the root of the parallel key portion 24b also serves as a passage for lubricating oil.

As shown in Figures 1 and 3, there is a release gap 27 of approximately 0.1 mm between the main body frame 5 and the thrust bearing 2o.
An annular groove 28 is also provided in the main body frame 5 opposite to the release gap 27, and a rubber seal ring 70 surrounding the annular groove 28 is installed between the main body frame 5 and the thrust bearing 20. ing.

The upper part of the motor chamber 6 and the discharge chamber 2 communicate with each other via a bypass discharge pipe 29 that passes through the side wall of the sealed case 1 and is connected to the upper part of the motor chamber 6. The discharge pipe 31, which faces the side surface of the upper coil end 30 and is connected to the upper open end of the bypass discharge pipe 29 and the upper surface of the sealed case 1, has a hole 32 provided in the bearing frame 5, and the upper surface of the sealed case 1. It communicates with the bearing frame 9 via a punching metal 33 having a large number of small holes.

A 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 a part of the outer periphery of the stator 3b of the motor 3. Further, the discharge chamber oil reservoir 34 is an oil chamber B provided in the main body frame 5.
58b to the annular W1j28, and also to the back pressure chamber 39 of the orbiting scroll 18 in which the Oldham ring 24 is disposed, through a small gap in the sliding part of the main bearing 12, and further provided in the eccentric bearing 14. It also communicates with the eccentric bearing space 36 via the oil groove A40m.

Also. The oil chamber B58b provided in the main body frame 5 also communicates with the spiral oil groove 41 provided on the surface of the lower bearing 4a corresponding to the lower bearing 11 of the drive shaft 4.
The winding direction of No. 1 is provided so that a screw pump action using the viscosity of the lubricating oil occurs when the drive shaft 4 rotates forward, and the end thereof is formed halfway to the lower bearing 4a.

As shown in FIGS. 6 and 7, the fixed scroll 15 is provided with an arc-shaped suction passage 42 that communicates both ends of the suction chamber 17, and a circular suction hole 43 perpendicular to the arc-shaped suction passage 42 is formed on the side surface of the fixed scroll wrap 15m. The bottom of the suction hole 43 is flat and reaches the side surface of the suction passage 42 . As shown in FIG. 8, the center of the suction hole 43 is offset from the bottom surface 44 of the suction passage 42, and the opening dimension W45 to the suction passage 42 is set smaller than the diameter dimension of the suction hole 43. Further, a suction pipe 47 of an accumulator 46 is connected to the suction hole 43, and between the bottom surface 44 of the suction hole 43 and the suction pipe end surface 48, the inner diameter dimension of the suction pipe 47 and the suction pipe end surface 48 and the bottom surface 44 are connected. Suction hole depth dimension L4 between
A check valve 50 made of a circular thin steel plate having a diameter larger than 9 and an opening size W45 is disposed. The surface of the check valve 50 is coated with Teflon or rubber, which has poor oil wettability and is highly elastic.

A second compression chamber 51 that does not communicate with either the suction chamber 17 or the discharge chamber 2
The outer peripheral space 37 includes a small diameter injection hole 52 opened to the second compression chamber 51 and provided in the end plate 15b, an injection groove 54 formed by the end plate 15b and a resin heat insulating cover 53, and an outer peripheral part. An injection passage 5 consisting of a stepped oil chamber C38c opening into the space 37
A check valve 58 made of a thin steel plate having a notch 57 in a part of its outer periphery and a coil spring 59 are disposed in the large diameter portion 56 of the oil chamber C38a as shown in FIG. . The coil spring 59 is pressed by the heat insulating cover 53 and always biases the check valve 58. Oil chamber C to outer peripheral space 37
The opening position of 38c is as shown in FIGS. 10 and 11.
When the orbiting scroll 18 moves close to the end of the volume reduction stroke of the third compression chamber 60 that communicates with the discharge port 16 (see FIG. 10), the outer peripheral space 37 and the oil chamber C38c communicate with each other, and the other At the time (see FIG. 11), it is provided at a position where it is blocked by the lap support disk 113c+.

In FIG. 12, the horizontal axis indicates the rotation angle of the drive shaft 4,
The vertical axis shows the refrigerant pressure, and shows the pressure change state of the refrigerant gas during the suction, compression, and discharge processes.The solid line 62 shows the pressure change during normal pressure operation, and the dotted line 63 shows the pressure change during abnormal pressure rise operation. represent.

In FIG. 13, the horizontal axis indicates the rotation angle of the drive shaft 4,
The vertical axis indicates the refrigerant pressure, and the solid line 64 indicates the injection holes 52m of the second compression chambers 51a and 51b that do not communicate with either the discharge chamber 2 or the suction chamber 17.

The dotted line 65 indicates the first compression chamber 61a that communicates with the suction chamber 17.

61b (see Figure 6) shows the pressure change at a fixed point,
- the dotted chain line 66 indicates a third compression chamber 60a communicating with the discharge chamber 2;
60b shows the pressure change at a fixed point, and the two-dot chain line 67 indicates the first compression chamber etm, 61b and the second compression chamber 51m, 51b.
The double dotted line 68 shows the pressure change in the back pressure chamber 39.

FIG. 14 is a vertical cross-sectional view of a scroll refrigerant compressor of another embodiment, where 101 m and 101b are iron closed cases, 180
is a mild steel partition plate to which an iron main body frame 105 is fixed with bolts.
The upper discharge chamber 1 is welded and sealed together with 1b by a single weld bead 181, and the inside of the sealed case 101m and 10Ib is connected to the upper discharge chamber 1.
02 and a lower drive chamber 106 (low pressure side).

An orbiting shaft 118b of an orbiting scroll 118 is fitted into an eccentric hole 136 at the upper end of a drive shaft 104 which is supported by a frame 105 and is rotationally driven by a motor 103 whose operation is controlled by an inverter power supply (not shown). Oldham ring 12 for preventing the rotation of the orbiting scroll 118
4 is a parallel pin (rf
! A fixed scroll 1 that engages with each groove of the orbiting scroll 118 and a thrust bearing 120 that is restrained by the orbiting scroll 118 (not shown) and can move only in the axial direction.
15 is bolted to a partition plate 180, a discharge port 116 is provided on the end plate 115b of the fixed scroll 115, and a reed valve type oil supply passage control valve device 182 is attached to the upper surface of the end plate 115b.

The thrust bearing 120 is always urged toward the orbiting scroll 118 by the elastic force of the seal ring 170, and the partition plate 1
80 and its movement is restricted. However, the dimensions in the axial direction are set such that a minute gap (approximately 0.020 mm) can be secured so that the orbiting scroll 118 is not pressed against the fixed scroll 115 and the smooth orbiting movement of the orbiting scroll 118 is not obstructed.

The bottom of the discharge chamber 102 becomes a discharge chamber oil reservoir 134, and the upper part is an umbrella-shaped punching metal 13 with many small holes.
3 is attached to the sealed case 101a, and the sealed case 1
A filter 183 made of a thin resin wire is packed between the punching metal 133 and the punching metal 133. Discharge chamber 10
2 is a discharge pipe 13 provided on the upper surface of the sealed case 101-
1. It communicates with the drive chamber 106 on the low pressure side through an external refrigeration cycle piping system and a suction pipe 147 provided on the side surface of the sealed case 101b. In addition, the drive chamber 106
A motor chamber oil reservoir 184 is provided at the bottom of the motor chamber.

Between the second compression chamber 151, which does not communicate with either the discharge chamber 102 or the suction chamber 117, and the discharge chamber oil reservoir 134, an oil suction hole 185 provided in the end plate 115b and a reed valve 186 made of a thin steel plate are provided in the end plate 115b. Between the valve chambers 188 formed between the valve holder 187 and the end plate 115b of the attached oil supply passage control valve device 182, and the punched hole 1 of the reed valve 186
89, and the injection hole 152, which is an extremely narrow passage provided in the end plate 115b, communicates with the first oil supply passage having a throttle passage.

A back pressure chamber 13 formed by a wrap support disk 118b that supports the orbiting scroll wrap 118a of the orbiting scroll 118 disposed between the fixed scroll 115 and the thrust bearing 120, the thrust bearing 120, and the drive shaft 104.
9 is branched from the middle of the first oil supply passage and is connected to the valve chamber 1.
88, punched hole 189 of reed valve 186, mirror plate 11
Oil chamber A138m provided in 5b, oil chamber B1313b1 with extremely narrow passage provided in partition plate 180, main body frame 1
Oil chamber C138c provided in 05, thrust bearing 120
A release gap 127 is provided between the main body frame 105 and the outer periphery thereof is supported and sealed by a rubber seal ring 170, and an oil chamber R is provided in the thrust bearing 120.
138d through a fuel supply passage.

Between the back pressure chamber 139 and the drive chamber on the low pressure side are the bearing gap of the main bearing 112, the gap of the eccentric bearing 114, the eccentric oil chamber 190 provided in the drive shaft 104, the side hole 191, and the drive shaft 104.
The first lubrication passage supports the main body frame 105 and has a throttle passage composed of a bearing oil reservoir 193 between the lower bearing 192 and the main bearing 112 provided at the lower end of the main body frame 105, and a bearing clearance of the lower bearing 192. It's communicating.

Further, the back pressure chamber 139 and the suction chamber 117 are communicated through a second lubrication passage formed through the sliding surface of the thrust bearing 120 and the lamp support disk 118b and the sliding surface of the Oldham ring 124. are doing.

The operation of the scroll gas compressor configured as above will be explained.

1 to 13, the drive shaft 4 is driven by the motor 3.
When is driven to rotate, the orbiting scroll 18 makes an orbiting motion,
Suction refrigerant gas containing lubricating oil from the refrigeration cycle connected to the compressor flows into the suction pipe 4 connected to the accumulator 46.
7. It flows into the suction chamber 17 through the suction hole 43 and the suction passage 42 sequentially, passes through the first compression chambers 61m and 61b formed between the orbiting scroll 18 and the fixed scroll 15, and is confined in the compression chamber, so that it is always sealed. Second compression chamber 51 serving as space
a, 51b, the third compression chamber 60a, and Sob, where it is sequentially transferred and compressed, and is discharged into the discharge chamber 2 through the discharge port 16 in the center.

The discharged refrigerant gas containing lubricating oil returns to the motor chamber 6 inside the compressor via the bypass discharge pipe 29 piped to the outside of the compressor, and then is discharged from the discharge pipe 31 to the external refrigeration cycle. 6, it collides with the side surface of the upper coil end 30 of the motor 3 and adheres to the surface of the motor winding.

As a result, a part of the lubricating oil is separated, and then the lubricating oil is changed in flow direction when passing through the punch hole 32 provided in the receiving frame 9, or when passing through the small hole in the punching metal 33. Lubricating oil is effectively separated due to inertia and surface adhesion.

A part of the lubricating oil separated from the discharge gas lubricates the sliding surface of the upper bearing, and then passes through the cooling passage 35 along with the remaining lubricating oil, and is collected in the lower discharge chamber oil sump 34 while cooling the motor 3. be done.

The lubricating oil in the discharge chamber oil sump 34 is supplied to the thrust ball bearing 13 by the screw pump action of the spiral oil groove 41 provided on the surface of the lower shaft portion 4m of the drive shaft 4, and is supplied to the thrust ball bearing 13 at the end of the lower shaft portion 4a. When the lubricating oil passes through the minute bearing gap, the sealing action of the oil film blocks the discharged refrigerant gas atmosphere of the motor chamber 6 from the upstream space of the main bearing 12.

The lubricating oil containing the dissolved discharged refrigerant gas in the discharge chamber oil sump 34 is
When passing through the small gap in the main bearing 12, the pressure is reduced to an intermediate pressure between the discharge pressure and the suction pressure, and the fluid flows into the back pressure chamber 39.

Thereafter, the oil groove A 40 a of the eccentric bearing 14 flows into the outer circumferential space 37 via the oil chamber A 38 that passes through the eccentric bearing chamber 36 and the orbiting scroll 18, and then the oil chamber C that opens intermittently.
38c, injection groove 54, injection hole 52a.

It flows into the second compression chambers 5ta and 51b via 52b, and lubricates each sliding surface in the middle of the passage.

In addition, the discharge chamber oil reservoir 34 is connected to the annular groove 28 and the release gap 2.
7, the thrust bearing 20 is urged by the back pressure and comes into contact with the end of the spacer 21. The lap support disk 18c of the orbiting scroll 18 slides smoothly with a slight gap maintained between the thrust bearing 20 and the end plate 15b of the fixed scroll 15, and the end surface of the fixed scroll wrap 15a and the lap support disk 18c. Board 18c
Also, the gaps between the end face of the orbiting scroll wrap 18a and the end plate 15b are kept small to reduce gas leakage between adjacent compression chambers.

Injection holes 52a of second compression chambers 51g and 51b
, 52b, the pressure changes 64 as shown in FIG. 13, and the average pressure is lower than the back pressure chamber pressure 68, which changes in accordance with the pressure in the discharge chamber 2, although it is instantaneously higher. Therefore, back pressure chamber 3
The lubricating oil from 9 is intermittently supplied to the second pressure chambers 51a and 51b.
The compressed refrigerant gas in the second compression chambers 51m, 51b, which flows into the back pressure chamber 68 during normal operation and which is instantaneously higher than the back pressure chamber pressure 68 during normal operation, is attenuated by the small diameter injection holes 52m, 52b and instantaneously injected. There is less backflow to the groove 54,
The pressure within the injection groove 54 does not become higher than the back pressure chamber pressure 68.

The lubricating oil injected into the second compression chambers 51m and 51b joins with the lubricating oil that has flowed into the compression chambers together with the suction refrigerant gas, and the minute gaps between adjacent compression chambers are sealed with an oil film to prevent compressed gas leakage. The compressed gas is again discharged into the discharge chamber 2 while lubricating the sliding surfaces between the compression chambers.

In addition, the lubricating oil supplied to the back pressure chamber 39 exerts an intermediate pressure urging force on the orbiting scroll 18 together with the elastic force of the seal ring 70 to move the lap support disk 18a onto the end plate 1.
A pressure oil film is sealed on the sliding surface between the thrust bearing 20 and the lap support disk 18a, thereby blocking communication between the outer peripheral space 37 and the suction chamber 17, and sealing the gap between the sliding surface between the thrust bearing 20 and the lap support disk 18a with lubrication. .

In addition, for a while after the compressor starts cold, as shown in Fig. 12,
As can be understood from Fig. 13, the pressure in the discharge chamber 2 is
The refrigerant gas is in the second compression chamber 51a, which is lower than the pressure in the compression chambers 51m and 51b and is in the middle of being compressed.

51b to the back pressure chamber 39 via the injection passage 55.
However, the backflow to the outer circumferential space 37 is prevented by the non-return action of the check valve 58, and as the pressure in the discharge chamber 2 increases, the lubricating oil in the discharge chamber 2 flows into the back pressure chamber 39 and the outer circumference. Differential pressure oil is supplied to the inner space 37.

Therefore, a back pressure urging force is generated on the thrust bearing 20 by the compression chamber pressure at the initial stage of cold start, and the thrust bearing 20 moves slightly backward while resisting the thrust load that tends to separate the orbiting scroll 18 from the fixed scroll 15. As a result, the axial clearance between the orbiting scroll 18 and the fixed scroll 15 is expanded. This causes leakage in the compression space, lowering the compression chamber pressure and reducing the compression load at the initial stage of startup.

Thereafter, as the pressure in the discharge chamber 2 increases, the lubricating oil in the outer peripheral space 21 flows from the injection holes 52a and 52b into the second compression chamber 51a against the urging force of the coil spring 5'9.
, 51b.

In addition, when instantaneous liquid compression occurs at the initial stage of a cold start or during steady operation, the pressure in the compression chamber will be abnormally increased and overcompressed as shown by the dotted line 63 in Fig. 12. Since the volume of the high-pressure space communicating therewith is large, the rise in the discharge chamber pressure is extremely small.

Furthermore, due to liquid compression, the pressure in the injection groove 54 communicating with the second compression chambers 51m and 51b also increases abnormally.
Due to the throttling effect of the small diameter oil chamber C38c and the check action of the check valve 58, the space between the outer peripheral space 37 and the injection groove 54 is cut off. As a result, the pressure in the back pressure chamber 39 does not change, and the back pressure urging force acting on the back surface of the thrust bearing 20 does not change. As a result, during liquid compression, the thrust bearing 20 retreats as described above due to the excessive thrust force acting on the orbiting scroll 18, the pressure in the compression chamber decreases, and normal operation continues thereafter.

In addition, as the thrust bearing 20 retreats during liquid compression, the pressure in the compression chamber drops midway as shown by the dashed line 63m in FIG.

After the compressor stops, the orbiting scroll 1
A reverse rotation torque is generated at 8, the orbiting scroll 18 rotates in the reverse direction, and the discharged refrigerant gas flows back to the suction side. Following this backflow of the discharged refrigerant gas, the check valve 50 moves from the position shown in FIG. 6 to the position shown in FIG. The airtight seal prevents the reverse flow of the discharged refrigerant gas, the reverse rotation of the orbiting scroll 18 is stopped, and the space between the suction passage 42 and the discharge port 16 maintains the discharge pressure.

In addition, the passage communicating with the compression chamber with the check valve 58 of the injection passage as a border has a discharge pressure, but the space between the outer peripheral space 37 and the back pressure chamber a9 maintains an intermediate pressure for a while. However, due to the slight inflow of lubricating oil from the discharge chamber oil reservoir 34, the pressure gradually approaches the discharge pressure. When the compressor is stopped, the orbiting scroll 18 reverses and stops at a position where the third compression chamber 60a and sob are enlarged, and the opening of the oil/water C38c to the outer peripheral space 37 is blocked by the lap support disk 18c. After the compressor is stopped, the check valve 58 blocks the injection passage 55 due to the biasing force of the coil spring 59, so no lubricating oil flows into the compression chamber from the outer peripheral space 37.

Also, during compressor operation, the oil supply upstream side of the main bearing 12 communicates with the discharge chamber oil sump a4, and the oil supply downstream side communicates with the back pressure chamber 39 in an intermediate pressure state, and a pressure difference is generated between them, and the motor 3 The drive shaft to which the rotor 3a of the rotor 3a is fixed is urged in the direction of the four-power orbiting scroll 18. This biasing force is supported by the main body frame 5 via the thrust ball bearing 13, and the drive shaft 4 is supported by the upper bearing 1.
o. To prevent the bearing from falling down within the gap between it and the main bearing 12, and to prevent uneven bearing contact.

Furthermore, due to temperature fluctuations during compressor operation, the aluminum alloy body frame 5 thermally expands and expands the iron liner 8, which strengthens the close contact between the outer peripheral surface of the liner 8 and the inner wall of the sealed case 1, and discharges. This improves the airtightness between the chamber oil reservoir 34 and the discharge chamber 2, and strengthens the fixation between the main body frame 5 and the sealed case 1, which helps to improve the rigidity of each other.

In the above embodiment, the lubricating oil in the discharge chamber oil sump 34 was injected into the second compression chambers 51m and 51b.
Oil injection may be performed at 1 m and 61b.

Furthermore, in the above embodiment, the lubricating oil from the discharge chamber oil reservoir 34 is introduced into the release gap 27 and the annular groove 28 provided on the back surface of the thrust bearing 22, but the lubricating oil from the discharge chamber oil sump 34 and the discharged refrigerant gas from the motor chamber 6 and the second compression chambers 51m and 51b are An intermediate-pressure refrigerant gas may be introduced from, for example.

Furthermore, in the above embodiment, the elastic force of the seal ring 70 is used to preload the thrust bearing 22, but if the back pressure area of the thrust bearing 22 is insufficient, a spring device or the like may be used to apply the biasing force. Good too.

Next, the operation of another embodiment of the present invention will be explained with reference to FIGS. 14 and 15.

14 and 15, when the drive shaft 104 starts rotating by the motor 103, the orbiting scroll 11
8 makes a rotating motion, and suction refrigerant gas flows into the drive chamber through the suction pipe 147 from the refrigeration cycle connected to the compressor.
After a part of the lubricating oil contained therein is separated, it is sucked into the suction chamber 11-7 through the suction passage. This suction refrigerant gas is formed between the orbiting scroll 118 and the fixed scroll 115, passes through a first compression chamber communicating with the suction chamber 117, and is confined in the compression chamber. 151m.

151b, and is sequentially transferred and compressed to the third compression chamber, and is discharged to the discharge chamber 102 through the discharge port 116 in the center.

A part of the lubricating oil contained in the discharged refrigerant gas is separated from the discharged refrigerant gas due to its own weight and adheres to the surface of the punched metal 133 when passing through the small holes of the punching metal 133 and the filter 183 made of thin resin wire. The oil is collected in the discharge chamber oil sump 134. The remaining lubricating oil flows into the discharge pipe 1 along with the discharged refrigerant gas.
31 to the external refrigeration cycle, 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, the pressure in the discharge chamber 102 remains at the second compression chamber 151m as described above.

151b, the lubricating oil in the discharge chamber oil reservoir 134 is not supplied under differential pressure through the first oil supply passage, and due to the check valve effect, the lubricating oil in the discharge chamber oil sump 134 is supplied to the second compression chamber 151m.

The gas during compression does not flow back into the discharge chamber oil reservoir 134 from 151b, nor does it flow into the release gap 127 of the thrust bearing 120 or the back pressure chamber 139 of the orbiting scroll 118, and the residual lubricating oil in each sliding part Moving surfaces are lubricated.

In addition, since the pressure in the back pressure chamber 139 and the release gap 127 is low, the thrust bearing 120 moves back slightly at the initial stage of startup to reduce the initial startup load as described above.

After a while after the cold start of the compressor, the pressure in the discharge chamber 102 rises above the pressure in the second compression chambers 151a and 151b, and then the lubricating oil in the discharge chamber oil sump 134 is transferred to the lead of the oil supply passage control valve device 182. The oil passes through the first oil supply passage against the biasing force of the valve 186. Then, the pressure is gradually reduced, and the second compression chamber 151m
, 151b, and an oil chamber 138m of a second oil supply passage which is branched from the middle of the first oil supply passage.
.

The pressure is gradually reduced through 138b and 138a, and the pressure is adjusted to an intermediate pressure between the discharge side pressure and the suction side pressure, and the release gap 12
7 and the back pressure chamber 139 are supplied with differential pressure oil.

The lubricating oil supplied to the second compression chamber 151m (151b) at a differential pressure merges with the lubricating oil that has flowed into the compression chamber together with the suction gas, and the minute gap between adjacent compression chambers is sealed with an oil film to prevent compressed gas leakage. The compressed gas is then discharged into the discharge chamber 102 again together with the compressed gas while lubricating the sliding surfaces between the compression chambers.

The intermediate pressure lubricating oil supplied to the release gap 127 and the back pressure chamber 139 applies an urging force to the orbiting scroll 118 due to the back pressure, and the pressure in the compression chamber causes the fixed scroll 11 to
The downward thrust force acting on the orbiting scroll 118 that is trying to move away from the orbiting scroll 118 is reduced, and the orbiting scroll 118
In addition to reducing the thrust load acting on the sliding surface between the fixed scroll 115 and the thrust bearing 120, the thrust bearing 120 is urged to contact the partition plate, and the orbiting scroll 118 is placed between the fixed scroll 115 and the thrust bearing 120. are sandwiched by a minute gap to enable smooth orbiting movement of the orbiting scroll 118. In addition, the back pressure in the back pressure chamber 139 is adjusted so that the orbiting scroll 118 does not separate from the thrust bearing 120, so the back pressure chamber 139 and the suction chamber 117 are always in close contact with each other, and the lubricating oil covers this sliding surface. After being depressurized as it passes through, it lubricates the sliding surface of the Oldham ring 124, mixes it into the suction refrigerant gas, and flows into the compression chamber again.

In addition, the remaining lubricating oil is passed through the first lubricating passage to the pivot shaft 1.
18b and the eccentric hole 136, the oil supply passage passing through the eccentric hole 136, the eccentric oil hole 1901, the horizontal oil hole 191, and the main bearing 11
The oil flows into the bearing oil reservoir 193 through the gap in the lower bearing 1.
The final pressure is reduced through 92 minute gaps. The lubricating oil then flows into the drive chamber 106, and part of it mixes with the suction refrigerant gas and flows into the compression chamber again, but the remaining lubricating oil flows into the motor chamber oil sump 106.
Collected at 84. The lubricating oil in the motor chamber oil sump 184 is cooled by natural heat radiation through the sealed case 101b.
When the oil level rises to a certain level, it is diffused to the lower end of the rotor of the motor 103, mixed with the suction refrigerant gas in the drive chamber 106, flows into the compression chamber again, and finally ends up in the discharge chamber oil sump 1.
Collected on 34th.

In addition, if instantaneous liquid compression occurs during the initial stage of cold start or steady operation and abnormal pressure rises inside the second compression chambers 151@, 151b, the check valve action of the reed valve 186 prevents compression. Since the refrigerant gas does not flow back into the discharge chamber oil sump 134, nor does it flow into the release gap 127 or the back pressure chamber 139, nor does the back pressure increase, the thrust bearing 120 retires and continues to malfunction. Prevent pressure rise.

After the compressor is stopped, a check valve (not shown) provided in the suction passage between the suction chamber 117 and the drive chamber 106 closes the suction passage, and the pressure from the discharge chamber 102 to the suction chamber 117 is reduced to the pressure in the compression space. The pressure becomes equal to the pressure in the discharge chamber 102 through the gap, and the reed valve 186 closes the open end of the oil suction hole 185. As a result, the lubricating oil in the discharge chamber oil sump 134 immediately after the compressor stops is transferred to the second compression chambers 151m, 151b and the back pressure chamber 139.
The lubricating oil in the back pressure chamber 139 is not supplied with differential pressure to the drive chamber 106 through the first oil supply passage until the differential pressure becomes below a certain value.

In addition, in the above embodiment, the release gap 127 and the back pressure chamber 1
Although the lubricating oil in the discharge chamber oil reservoir 134 is reduced to an intermediate pressure, it may not be necessary to reduce the pressure depending on the dimensions of the thrust bearing 120 and the back pressure chamber 139.

As described above, according to the above embodiment, the orbiting scroll 18 includes the main body frame 5 supporting the drive shaft 4 and the fixed scroll 1.
5, and is sandwiched with a small gap (approximately 0.020 mm) between the thrust bearing 20, which is provided on the main body frame 5 side and is movable only in the axial direction, and the fixed scroll 15. The thrust bearing 20 is attached to the main body frame 5.
By using the lubricating oil pressure in the discharge chamber oil sump 34 and always applying back pressure in the direction of the orbiting scroll 15 while maintaining an appropriate release gap 27 between the During normal operation, the orbiting scroll 1B, which is sandwiched between the fixed scroll 15 and the thrust bearing 20 with a small gap, performs a smooth orbiting motion without collisions with sliding surfaces or uneven contact caused by falling or jumping.

As a result, it is natural to secure a small axial gap between compression chambers to prevent compressed refrigerant gas leakage, maintain high compression efficiency, and provide a highly durable compressor with less noise and vibration. A large amount of liquid refrigerant returns to the compressor from the refrigeration cycle at the beginning of startup, etc., and liquid compression occurs during the compression process, and the pressure in the compression chamber begins to rise abnormally, causing a thrust that acts on the orbiting scroll 18 in the direction fζ away from the fixed scroll 15. Even if the force becomes temporarily excessive, the thrust bearing 20 retreats toward the motor chamber 6, so the orbiting scroll 18 widens the axial gap with the fixed scroll 15, releases the seal between the compression chambers, and reduces the compression. The chamber pressure drops instantly, reducing the load on the compressor and increasing durability.

In addition, even when liquid compression does not occur, the compression ratio is constant, so the suction pressure is relatively high at startup, and the compression chamber pressure is much higher than during stable operation, but the constant biasing force of the thrust bearing 2o is appropriate. Depending on the settings, the startup load can be reduced.

Further, according to the embodiment h, the back pressure chamber 39 of the orbiting scroll 18 is formed on the side of the thrust bearing 20 of the lap support disk 18c, and the back pressure chamber 39 and the discharge chamber oil sump 34 are By communicating through the gap, the back pressure chamber 39 is set to an intermediate pressure, and the back pressure constantly urges the orbiting scroll 18 toward the compression space, thereby reducing the urging force due to the back pressure acting on the thrust bearing 20. As a result, due to liquid compression, etc., the pressure in the compression space increases abnormally and the orbiting scroll 18
When the thrust bearing 20 separates from the fixed scroll 15, the backward response of the thrust bearing 20 is good, and the compression space pressure at the time of abnormal compression can be quickly lowered. In addition, thrust bearing 2
By reducing the size of the compressor, the compressor can also be made smaller.

In addition, according to the above embodiment, the thrust bearing 20 is preloaded using the elastic force of the seal ring 70 and the spring device (not shown) (thereby, the pressure in the compression chamber temporarily increases, and the pressure in the back pressure chamber increases). Even in the early stages of compressor startup when the pressure at 39 is low, the thrust bearing 20 does not move back significantly due to the thrust force acting on the orbiting scroll 18, and the gap between the fixed scroll 15 and the orbiting scroll 18 is maintained appropriately.
In addition to preventing the inability to compress due to an excessive compression chamber gap, the release gap 27 of the thrust bearing 20 can be set large, and load reduction coordination during liquid compression can be improved.

Further, according to the above embodiment, preload is applied by utilizing the elastic force of the rubber seal ring 70 for forming the thrust bearing back pressure chamber provided between the thrust bearing 20 and the main body frame 5. , it is possible to realize an inexpensive compression load @ reduction device.

Furthermore, in the above embodiment, the refrigerant compressor was explained, but
Similar effects can be expected in the case of other gas compressors such as oxygen, nitrogen, and helium compressors that use lubricating oil.

Effects of the Invention As described above, the present invention has an orbiting scroll disposed between a main body frame supporting a drive shaft and a fixed scroll,
The thrust bearing, which is installed on the side of the main body frame and can move only in the axial direction, is sandwiched between the fixed scroll with a small gap, and the thrust bearing has an appropriate axial gap between it and the main body frame. By constantly biasing the orbiting scroll in the direction of the orbiting scroll using the discharge fluid pressure or the intermediate fluid pressure between the discharge pressure and the suction pressure while maintaining the compression chamber pressure, when the compression chamber pressure is in a normal and stable state, the fixed scroll and The orbiting scroll, which is sandwiched between the thrust bearing and the sliding surface with a small gap, is free from the moment or jumping phenomenon that tends to overturn the orbiting scroll due to compression action, inertia force, sliding resistance, etc. It performs quiet turning motion with less vibration and no collisions or uneven hits. Thereby, it is possible to secure a minute gap in the axial direction between the compression chambers, prevent leakage of compressed fluid, increase compression efficiency, and further improve noise and vibration characteristics. In addition, if the pressure in the compression chamber begins to rise abnormally due to liquid compression during the compression process, and the thrust load acting on the orbiting scroll in the direction away from the fixed scroll becomes temporarily excessive, the thrust bearing may Since the orbiting scroll moves backward in the direction of narrowing the gap, the orbiting scroll widens the axial gap with the fixed scroll, releases the seal between the compression chambers, lowers the compression chamber pressure, reduces the compression load, and increases durability. can.

In addition, even when liquid compression does not occur, the compression ratio is constant, so the suction pressure is relatively high at the beginning of the startup of a compressor used in a closed piping system, and the compression load is also much higher than during stable operation. However, by appropriately setting the constant biasing force on the thrust bearing, it is possible to provide a scroll compressor that has excellent effects in compression efficiency, vibration and noise characteristics, and durability, such as reducing the startup load.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a scroll refrigerant compressor according to the first embodiment of the present invention, Fig. 2 is an exploded view of the main parts of the compressor, and Fig. 3 is details of the seal portion of the thrust bearing in the compressor. FIG. 4 is an external view of the Oldham ring in the same compressor, FIG. 5 is an assembled external view of the Oldham mechanism in the same compressor, and FIG. 6 is A in FIG. 1.
- A cross-sectional view taken along line A, FIG. 7 is an explanatory diagram of the position of the check valve at the suction pipe connection part of the same compressor, and FIG. 8 is a partial cross-sectional view taken along line B-8 in FIG. 7. Figure 9 is an external view of a check valve used in the oil supply passage of the compressor, Figures 10 and 11 are explanatory diagrams of movement of the compression chamber near the discharge port of the compressor, and Figure 12 is of the same compressor. 13 is a characteristic diagram showing the pressure change of refrigerant gas from the suction stroke to the discharge stroke, FIG. 13 is a characteristic diagram showing the pressure change at a fixed point in each compression chamber, and FIG.
The figure 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 the reed valve installation of the oil supply passage control valve device in the same compressor, and FIGS. 16 and 18 are
The figures are longitudinal sectional views of scroll compressors showing different conventional examples, and FIG. 17 is a partially enlarged view of FIG. 16. 2...Discharge chamber, 3...Motor, 4...
... Drive shaft, 5 ... Body frame, 15.
...Fixed scroll, 15m...Fixed scroll wrap, 15b... End plate, 16...
...Discharge port, 17...Suction chamber, 18...
...Orbiting scroll, 18a...Orbiting scroll wrap, 18G...Wrap support disk, 2
0...Thrust bearing, 34...Discharge chamber oil sump, 39...Back pressure chamber, 70...Seal ring, 105...Main body Frame, 115...
... Fixed scroll, 118 ... Orbiting scroll, 120 ... Thrust bearing, 139 ...
...Back pressure chamber. Name of agent: Patent attorney Toshio Nakao and 1 other person No.5
- Fixed scroll Fig. 6 6/1) 9-m - Check valve Fig. 8 Four Confucian XZ --- Oil hole A Fig. 16

Claims (3)

[Claims] (1) The orbiting scroll wrap on the wrap support disk, which is part of the orbiting scroll, is engaged with the spiral fixed scroll wrap formed on one surface of the end plate, which is part of the fixed scroll, so that it can swing and rotate freely. , a spiral compression space is formed between both scrolls, a discharge port is provided in the center of the fixed scroll wrap, a suction chamber is provided on the outside of the fixed scroll wrap, and the compression space is arranged from the suction side to the discharge side. Forms a scroll compression mechanism that compresses fluid by partitioning into a plurality of compression chambers that continuously move toward
The orbiting scroll is disposed between a main body frame that supports a drive shaft and the fixed scroll, and a minute roller is disposed between the fixed scroll and a thrust bearing provided on the side of the main body frame and capable of moving only in the axial direction. The thrust bearing always maintains an appropriate axial clearance with the main body frame by utilizing the discharge fluid pressure or the intermediate fluid pressure between the discharge pressure and the suction pressure. A scroll compressor biased in the direction of the orbiting scroll. (2) Scroll compression according to claim 1, wherein a back pressure chamber of the orbiting scroll is formed on the thrust bearing side of the wrap support disk, and the back pressure chamber is communicated with a compression space or a space communicating with a discharge chamber. Machine. (3) A scroll compressor according to claim 1 or 2, wherein the thrust bearing is preloaded. (4) The scroll compressor according to claim 3, wherein the scroll compressor is preloaded using the elastic force of the thrust bearing back pressure chamber forming seal member provided between the thrust bearing and the main body frame.