JPH05187370A - Scroll gas compressor - Google Patents

Abstract

PURPOSE:To provide a scroll compressor excellent in durability by securing lubricating oil in a back pressure chamber, preventing abnormal rise of back pressure and other means. CONSTITUTION:An oil feed passage passing in sequence a lubricating oil feed source on which discharge gas pressure is exerted. back pressure chamber 20, and suction chamber 22, is provided, and a check valve device for allowing fluid to flow from the back pressure chamber 20 only into the suction chamber 22 is provided between the back pressure chamber 20 and the suction chamber 22 on the way of the oil feed passage.

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 prevention of outflow of lubricating oil in a back pressure chamber and a sliding portion of an orbiting scroll.

[0002]

2. Description of the Related Art In recent years, scroll compressors, which have been put into practical use with the development of machine tools and have been attracting attention as compressors having low vibration and low noise characteristics, have been disclosed in, for example, Japanese Patent Laid-Open No. 59-59.
As also disclosed in Japanese Patent No. 49386, the suction chamber is provided at the outer peripheral portion and the discharge port is provided at the center of the vortex winding, and since the flow of the compressed fluid is in one direction, the fluid resistance during high-speed operation is small and the compression efficiency is high. High is generally well known.
Further, a compressor having a high-pressure gas closed shell structure of this type has a structure shown in FIG. 5 as known from Japanese Patent Laid-Open No. 59-49386 or a structure shown in FIG. 6 as known from Japanese Laid-Open Patent No. 55-148994. The structure shown, or the above-mentioned JP-A-55
A configuration of JP-A-57-68579, in which the compressor of JP-A-148994 is turned upside down, is proposed, and the thrust force in the axial direction is reduced by appropriately setting the back pressure chamber. Lubrication of each sliding portion was configured as follows. That is, in FIG. 5, the fixed scroll wrap 123 is fixed to the end plate 121 attached to the main body frame 102 supporting the drive shaft 105, the orbiting scroll wrap 116 is fixed to the lap support disk 115, and the wrap support disk 115 is End plate 121 and body frame 102
Is arranged in a back pressure chamber 120 between and in a loose state with a slight gap, and is rotatably supported via an Oldham ring 118 having a rotation preventing function and a back pressure chamber partitioning function, and further at the end. Driving motor 110 and driving shaft 1 having an eccentric part
A turning movement is carried out by 05. Then, the sucked and compressed gas is discharged into the closed shell 101. Lubricating oil separated from the discharge gas is collected in an oil sump at the bottom of the closed shell 101, is opened in the lower end of the drive shaft 105 and is provided in an eccentric oil hole 106, and a minute gap in the bearing that supports the drive shaft 105. While being gradually depressurized, the high pressure is introduced to the back pressure chamber 120 by utilizing the centrifugal pump action. Further, the lubricating oil, which has been reduced in pressure to the intermediate pressure between the discharge pressure and the suction pressure through the minute gap in the sliding portion of the Oldham ring 118, flows into the suction chamber 122 through the fine balance passage 126 provided in the end plate 121. The sliding part was lubricated by. Further, in FIG. 6, the back pressure chamber 220 is not partitioned by the Oldham ring 218, and the suction chamber 2
The lap support disk 215 orbits the lap support disk 215 in an orbiting manner by a fine hole balance path 226 provided in the lap support disk 215 of the orbiting scroll. By being opened and closed to form an intermittent oil supply passage between the back pressure chamber 220 and the compression chamber 240.
No. 0 sliding part and each bearing part of the drive shaft 205 are the oil reservoir 209 at the bottom of the closed shell 201 filled with the discharge gas, and the oil hole 206 provided in the drive shaft 205 and the bearing supporting the drive shaft 205. It is communicated by a minute gap and oil is supplied by a differential pressure with a centrifugal pump.

[0003]

However, in the structure shown in FIG. 5 having only the fine hole communicating oil supply passage from the inside of the back pressure chamber 120 to the suction chamber 122, this scroll compressor is incorporated into the heat pump refrigeration cycle to compress the refrigerant. When used as a machine, immediately after switching from the heating operation refrigeration cycle to the defrosting operation refrigeration cycle, the refrigerant gas flows from the suction chamber 122 to the low pressure state and the high suction chamber pressure. The balance passage 126 is provided in the back pressure chamber 120.
Through the back pressure chamber 120 and the bearing sliding parts of the drive shaft 105 to the oil reservoir 9 and the refrigerant gas flowing back into the oil reservoir 9 causes the lubricating oil in the oil reservoir 9 to flow back. It diffuses and flows out to the compressor external piping system together with the discharged refrigerant gas, and a shortage of lubricating oil in the oil sump 9 occurs temporarily. For this reason,
The back pressure in the back pressure chamber 120 is unstable, the lubricating oil is insufficient, and the lubricating oil is insufficient in the bearing sliding portion almost at the same time.
There was a problem of causing abnormal noise and abnormal wear due to the inclination of the head and collision with related parts. In addition, as shown in FIG. 6 described above, a narrow hole balance passage 2 is provided between the back pressure chamber 220 and the compression chamber 240.
The configuration in which the communication is only performed at 26 has the same problem as in the case of FIG. 5 described above. That is, immediately after switching from the heating operation refrigeration cycle to the defrosting operation refrigeration cycle, the suction chamber pressure becomes a high pressure state, the compression chamber in the middle of compression rises in abnormal pressure, and the refrigerant gas passes through the balance passage 226 and the back pressure chamber 220 flows. Backflow to the same, causing the same shortage of lubricating oil as described above. Immediately after starting the compressor, since the discharge pressure and the back pressure chamber pressure are low, the refrigerant gas during compression flows back into the back pressure chamber 220, and as a result, the pressure in the back pressure chamber 220 is higher than the pressure in the oil sump 209. In this state, there is a problem that the oil cannot be supplied from the oil sump 209 to the back pressure chamber 220 and the sliding portion is damaged. Also, the refrigerant liquid and a large amount of lubricating oil are compressed to raise the abnormal pressure in the compression chamber,
Even during overload operation due to the so-called liquid compression phenomenon, the refrigerant gas flows back into the back pressure chamber 220 and abnormally increases the back pressure to the scroll, so that the orbiting scroll is separated from the fixed scroll in the axial direction to expand the compression chamber gap. There is a problem in that the pressure in the compression chamber is prevented from dropping sharply and the compressor is significantly damaged. Therefore, the present invention provides a scroll compressor excellent in durability by providing a check valve device in the middle of the oil supply passage on the downstream side from the back pressure chamber to secure lubricating oil in the back pressure chamber and prevent an abnormal rise in back pressure. It is a thing.

[0004]

In order to solve the above problems, the scroll compressor of the present invention sequentially passes through a lubricating oil supply source, a back pressure chamber, and a suction chamber (or a compression chamber) on which a discharge gas pressure acts. A check valve device provided with an oil supply passage and between the back pressure chamber and the suction chamber (or compression chamber) in the middle of the oil supply passage, allowing a fluid to flow only from the back pressure chamber to the suction chamber (or compression chamber) Is.

[0005]

With the above-described structure, the present invention has a discharge side pressure immediately after a cold start of the compressor or a switching of the high and low pressure side piping system.
When the back pressure chamber pressure is low and the suction side pressure is high, backflow of gas from the suction chamber (or compression chamber) to the back pressure chamber is blocked by the operation of the check valve device. A scroll compressor with excellent compression efficiency and durability that prevents rising and prevents outflow of lubricating oil that accumulates in the back pressure chamber and upstream of the back pressure chamber, and ensures the lubricating oil and appropriate back pressure in the back pressure chamber. Is provided.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A scroll compressor according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view of a scroll refrigerant compressor according to an embodiment of the present invention,
FIG. 2 is a detailed explanatory diagram of the portion A in FIG. In FIG. 1, 1 is a closed shell, 2 is a closed shell 1
The main body frame is press-fitted into the main body frame 3, 3 and 4 are bearings provided in the central portion of the main body frame 2, and 5 is an oil hole 6 supported by the bearings 3 and 4 and an oil hole 6 at a position facing the bearing 4. The drive shaft has an oil hole 7 penetrating therethrough. An eccentric shaft portion 8 is provided at the upper end of the drive shaft, and the lower end of the drive shaft extends to an oil reservoir 9 at the bottom of the closed shell 1 and is immersed therein. Reference numeral 10 denotes a motor, a rotor 11 of which is fixed to the drive shaft 5 and a stator 12 of which is fixed to the hermetic shell 1 by press fitting. The wrap support disk 15 of the orbiting scroll 14, which is connected to the eccentric shaft portion 8 and has the bearing portion 13 at the center thereof to form the back pressure chamber C20c by the eccentric shaft portion 8 and the bearing portion 13, is the orbiting scroll upright on the upper surface thereof. The wrap 16 is integrally formed, and the lower surface of the wrap 16 is supported by a thrust bearing seat 17 projecting into an upper opening hole of the main body frame 2. The orbiting scroll wrap 16 has a spiral shape in a plan view,
The vertical cross section is rectangular and adjacent orbiting scroll wraps 16 are parallel to each other. The rotation-preventing Oldham ring 18 is provided with parallel key-shaped key portions orthogonal to each other on both sides of a flat ring, and is provided between the lap support disk 15 and the thrust bearing seat 17. The key portion on the upper surface side of the Oldham ring 18 is fitted in the key groove (not shown) provided on the back surface of the lap support disk 15, and the key portion on the lower surface side is fitted in the key groove 19 provided in the thrust bearing seat 17. The rotation of the drive shaft 5 causes the bearing portion 13 of the wrap support disk 15 to make a circular motion around the axis of the drive shaft 5, and the orbiting scroll wrap 16 makes an orbiting motion. Also,
A fixed scroll 34 is formed as a back pressure chamber 20 of the lap support disk 15 by closing an upper end opening hole in the upper end surface of the main body frame 2.
The end plate 21 is attached together with the thrust bearing seat 17 so as to sandwich the orbiting scroll 14 with a minute gap. Back pressure chamber 2
0 is divided by a lap support disk 15 and is divided into a back pressure chamber 20a on the outer peripheral surface thereof and a back pressure chamber 20b on the back surface side. The end plate 21 is provided with an annular suction chamber 22 inside thereof, and further, inside thereof, the inside of the closed shell 1 is discharged at the center of the spiral scroll of the fixed scroll wrap 23 having the same shape and size as the orbiting scroll wrap 16. A discharge port 25 is provided, and the balance passage 26 is a narrow hole that opens in the sliding surface with the lap support disk 15 and connects the suction chamber 22 and the back pressure chamber 20a, the back pressure chamber 20a, and the back pressure chamber 20b. A fine hole balance passage 27 that communicates with the end plate 21 and the thrust bearing seat 17 are provided, and the lap support disk 15 communicates only when the wrap support disc 15 is in a predetermined swivel angle range (a swirl angle range in which the compression chamber is the suction stroke). , Refrigerant gas leaking during compression is suction chamber 2
2 are respectively arranged so as not to flow back to the balance passage 26 to the back pressure chamber 20. In the middle of the balance passage 26, a case 40 is press-fitted into an end plate 21 as shown in FIG. A steel ball 41 is mounted on the upstream side of the central portion of the passage, and a coil spring 42 is mounted on the downstream side of the passage.
When the temperature of the coil spring 42 rises, the coil spring 42 expands to bias the steel ball 41 to close the balance passage 26, and when the temperature of the coil spring 42 decreases, the coil spring 42 contracts to weaken the bias to the steel ball 41. The steel ball 41 has a shape memory characteristic such that the steel ball 41 opens the balance passage 26 against the back pressure acting on the steel ball 41 based on the pressure difference between the back pressure chamber 20 and the suction chamber 22. 41 is always energized. In addition, the annular suction chamber 2
A suction pipe 28 penetrating the hermetic shell 1 from the side is connected to 2 and a discharge pipe 29 opening to the inner side surface of the hermetic shell 1 is connected to the upper surface of the hermetic shell 1. A groove 30 is provided on the outer surface of the main body frame 2 that is press-fitted and fixed to the closed shell 1, and the groove 30 is formed on the end plate 2 of the closed shell 1.
The discharge space 24 on the side of 1 and the side of the motor 10 communicate with each other. The operation of the scroll refrigerant compressor configured as described above will be described below with reference to FIGS. 1 and 2. First, FIG. 1 is a vertical cross-sectional view of a scroll refrigerant compressor, and FIG. 2 is a detailed view of a portion A in the vicinity of the balance passage 26 in FIG. 1, in which a rotor 11 is rotated by a motor 10 and a drive shaft 5 is rotationally driven. Then, the orbiting scroll 14 orbits, and the refrigerant gas is sucked into the suction chamber 22 through the suction pipe 28. The refrigerant gas is trapped in the compression chamber formed between the orbiting scroll wrap 16 and the fixed scroll wrap 23. The lubricating oil contained in the refrigerant gas is compressed by the orbiting scroll wrap 16 and is discharged from the discharge port 25 to the discharge space 24. A part of the lubricating oil contained in the refrigerant gas is separated from the refrigerant gas by its own weight and the closed shell 1 is formed. Collected in the oil sump 9 at the bottom through the groove 30 between the main body frame 2 and the like, and the remaining lubricating oil passes through the discharge pipe 29 together with the discharge refrigerant gas to the external refrigeration cycle. It is carried out. On the other hand, the differential pressure oil supply from the high pressure side oil reservoir 9 to the low pressure side suction chamber 22 via the back pressure chamber 20 formed by being separated from the discharge space 24 by the end plate 21 of the fixed scroll 34 and the main body frame 2 is performed. This is done as follows. That is, the temperature of each part in the compressor immediately after the cold start is low, and
Indicates that the coil spring 42 is in the open state by releasing the urging force to the steel ball 41 when the coil spring 42 is contracted, and after the compressor is started, the low-viscosity lubricating oil in the oil sump 9 at the bottom of the closed shell 1 filled with the discharge refrigerant gas. Is gradually depressurized by passing through the minute gaps of the oil holes 6 and 7 provided in the drive shaft 5 and the bearings 3 and 4 supporting the drive shaft 5 and the bearing portion 13 of the eccentric shaft portion 8 and the suction chamber pressure and the discharge pressure. It is supplied to the back pressure chamber 20b at an intermediate pressure state between. Further, the lubricating oil is the wrap support disk 1 of the orbiting scroll 14.
5 is intermittently refueled to the back pressure chamber 20a through the balance passage 27 of a small hole which is opened and closed intermittently by the turning movement of No. 5, is intermittently replenished to the suction chamber 22 through the balance passage 26, and is compressed and discharged again together with the suction refrigerant gas. .. Also, after starting the compressor,
When the temperature inside the compressor rises as the discharge chamber pressure rises and the temperature of the coil spring 42 exceeds the set value, the coil spring 42
Expands to urge the steel ball 41, sandwich the balance passage 26, and improve the differential pressure and fluidity between the oil sump 9 and the back pressure chamber 20. The lubricating oil forms the end plate 21 and the lap support disk 15. Flows into the suction chamber 22 through the sliding surface of the. This scroll refrigerant compressor is incorporated into a heat pump type refrigeration cycle, and when the heating operation refrigeration cycle is switched to the defrosting operation refrigeration cycle, the discharge chamber pressure is in a low pressure state, and the suction chamber pressure is in a high pressure state, The refrigerant gas tries to flow backward from the suction chamber 22 to the back pressure chamber 20 via the balance passage 26, but the passage is closed by the check valve action of the steel ball 41 of the oil supply passage control device 43 provided in the balance passage 26, Refrigerant gas flows back to the oil reservoir 9 via the back pressure chamber 20 and prevents abnormal pressure rise in the back pressure chamber, thereby preventing the lubricating oil from flowing out of the back pressure chamber 20 and the bearing sliding surface. According to this differential pressure oil supply system, the lap support disk can be freely set from a state close to the discharge pressure to a state close to the suction pressure by adjusting the passage resistance of the oil supply passage of the back pressure chamber 20 on the back surface of the lap support disk 15. The load difference between the gas pressure load acting on the back surface of 15 and the gas pressure load in the compression chamber can be freely adjusted, whereby the lap support disk 15
Can be pressed toward the side of the end plate 21 or can be pressed away from the end plate 21 and toward the side of the thrust bearing seat 17. In the present embodiment, the lap support disk 15 in the case where the viscosity of the lubricating oil is low, such as during steady operation, acts so that the thrust force acts on the end plate 21 side, and in the case where the viscosity of the lubricating oil is high, such as immediately after cold start, The support disk 15 is provided with a balance passage 2 so that the thrust force acts on the thrust bearing seat 17 side.
The passage resistance of 6 is adjusted to provide the function of the oil supply passage control device. In the present embodiment, the downstream opening of the balance passage 26 is connected to the end of the coil spring 42. However, as shown in FIG. 3, the coil spring 42 is located near the center of the coil spring 42 or on the steel ball 41 side. It may be configured to communicate with the vicinity, further, a configuration in which the oil supply passage control device 43b is provided in the balance passage 27 as shown in FIG. 4, or a combination thereof. Further, in the above embodiment, the downstream side of the oil supply passage of the back pressure chamber 20 is used as the suction chamber. However, as in the case of FIG. 6, the downstream side of the oil supply passage of the back pressure chamber 20 may be used as the compression chamber during the compression stroke. An oil supply passage control device similar to that shown in FIG. 2 may be provided in the middle of the oil supply passage. The oil supply passage control device in this oil supply passage configuration also has a check valve function described below.
That is, immediately after the cold start of the compressor, the pressure in the discharge chamber communicating with the compressor external piping system is low, and the pressure from the oil reservoir 9 to the back pressure chamber 2 is reduced.
Since the lubricating oil flow into 0 is small, the pressure in the back pressure chamber 20 may be intermittently lower than the pressure in the compression chamber communicating with the back pressure chamber 20. Therefore, the refrigerant gas being compressed is
However, due to the check valve action of the oil supply passage control device, the lubricating oil flows out from the back pressure chamber 20 into the oil reservoir 9 due to the blowout of the refrigerant gas in the oil supply passage, and the seizure of the sliding portion is prevented. Further, the refrigerant gas is prevented from flowing back to the back pressure chamber 20 when the abnormal pressure in the compression chamber increases due to the compression of the refrigerant liquid or a large amount of lubricating oil during the compression (liquid compression development). As a result, an increase in the pressure of the back pressure chamber 20 and an increase in the back pressure biasing force to the orbiting scroll 14 are prevented, and the orbiting scroll 14 is separated from the fixed scroll 34 in the axial direction,
It is also possible to suddenly reduce the pressure in the compression chamber and perform an overload reducing action. As described above, according to the above-described embodiment, the oil reservoir 9 on which the discharge gas pressure acts, the oil hole 6 provided in the drive shaft 5,
7 and the bearings 3 and 4 for supporting the drive shaft 5 and the minute gap in the bearing portion 13 of the eccentric shaft portion 8, the back pressure chamber of the orbiting scroll 14 (back pressure chamber C20c, back pressure chamber B20b, back pressure chamber A20a), suction An oil supply passage control device 43 is provided which has an oil supply passage sequentially passing through the chamber 22 and is provided between the back pressure chamber 20a and the suction chamber 22 in the middle of the oil supply passage to allow fluid to flow only from the back pressure chamber 20a into the suction chamber 22. As a result, when this scroll compressor is incorporated into a heat pump type refrigeration cycle and immediately after switching from the heating operation refrigeration cycle to the defrosting operation refrigeration cycle, the discharge chamber pressure becomes low and the suction chamber pressure becomes high. Also, the refrigerant gas flows from the suction chamber 22 to the back pressure chamber 20.
The back pressure chamber 20 is prevented from flowing back to a, and the abnormal pressure in the back pressure chamber 20 rises, the lubricating oil stored in the back pressure chamber 20 flows into the oil reservoir 9 on the upstream side of the oil supply passage, or the refrigerant gas flows back to the oil reservoir 9. It is possible to prevent the lubricating oil from flowing out of the compressor due to this.
As a result, the durability of the sliding surface of the back pressure chamber 20 (such as the end plate 21 slidingly contacting the lap support disk 15 and the thrust bearing seat 17) is prevented from lowering, and a lubricating oil film is provided on the sliding contact surface of the lap support disk 15. Noise and vibration due to the oil film straining action can be reduced. Also, the back pressure chamber 20
Since there is no abnormal increase in pressure, the orbiting scroll 14 is not pushed too far toward the fixed scroll 34, and when the pressure in the compression chamber increases abnormally, the orbiting scroll 14 separates from the fixed scroll 34 in the axial direction and the compression chamber shaft It is possible to prevent overload operation and increase durability by expanding the direction gap and reducing the pressure in the compression chamber.

[0007]

As described above, according to the present invention, the lubricating oil supply source, the back pressure chamber, and the suction chamber (or the compression chamber), which are subjected to the discharge gas pressure, are sequentially provided, and the back pressure in the middle of the oil supply passage is provided. A check valve device that allows fluid to flow from the back pressure chamber to the suction chamber (or compression chamber) between the suction chamber (or the compression chamber) and the suction chamber (or the compression chamber) is provided. Prevents backflow of gas from the suction chamber (or compression chamber) to the back pressure chamber when the pressure on the discharge side and the pressure in the back pressure chamber are low and the pressure on the suction side is high, such as immediately after switching the piping system. It is possible to prevent an abnormal pressure rise in the chamber and prevent the lubricating oil stored in the back pressure chamber from flowing out to the lubricating oil supply source on the upstream side of the oil supply passage. Further, it is possible to prevent the lubricating oil from flowing out of the compressor by blocking the gas inflow to the lubricating oil supply source.
As a result, it is possible to prevent the durability of the sliding surface related to the back pressure chamber from decreasing. Further, by interposing a lubricating oil film in the gap of the sliding portion, it is possible to reduce noise and vibration generated from the sliding portion due to the oil film relaxation action. Also, by preventing an abnormal rise in pressure in the back pressure chamber, it is possible to prevent excessive pressure on the orbiting scroll fixed scroll in the axial direction.
Even if the pressure in the compression chamber rises abnormally, the orbiting scroll is separated from the fixed scroll in the axial direction, and the pressure drop in the compression chamber prevents overload operation, increasing the durability of the compressor, and other advantages. It is a thing.

[Brief description of drawings]

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

FIG. 2 is a sectional view of part A in FIG.

FIG. 3 is a partial cross-sectional view of a scroll refrigerant compressor showing another embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of a scroll refrigerant compressor showing different embodiments of the present invention.

FIG. 5 is a vertical cross-sectional view of different conventional scroll compressors.

FIG. 6 is a vertical cross-sectional view of different conventional scroll compressors.

[Explanation of symbols]

 1 Sealed Shell 2 Main Frame 5 Drive Shaft 10 Motor 14 Orbiting Scroll 15 Lap Support Disc 16 Orbiting Scroll Wrap 20 Back Pressure Chamber 21 End Plate 22 Suction Chamber 23 Fixed Scroll Lap 25 Discharge Port 26, 27 Balance Passage 34 Fixed Scroll 41 Steel Ball 42 Coil spring 43 Oil supply passage control device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area F04C 29/06 D 6907-3H

Claims (1)

[Claims] 1. An orbiting scroll wrap on a lap support disk forming a part of an orbiting scroll is engaged with a spiral scroll-shaped fixed scroll wrap formed on one surface of an end plate forming a part of the fixed scroll. A suction chamber is formed on the outside of the wrap, and the wrap support disk is formed between the body frame supporting the drive shaft and the end plate and communicates with a lubricating oil supply source outside the body frame. Volume of the compression chamber formed between the fixed scroll wrap and the orbiting scroll wrap, which is arranged in a loose state in the back pressure chamber and is rotatably supported by the rotation preventing mechanism of the wrap support disk. A scroll-type compression mechanism that compresses a fluid by utilizing changes is formed, and the lubricating oil supply source, the back pressure chamber, An oil supply passage that sequentially passes through the suction chamber or the compression chamber is provided, and between the back pressure chamber and the suction chamber (or the compression chamber) in the middle of the oil supply passage, the back pressure chamber to the suction chamber (or the compression chamber) is provided. Scroll gas compressor equipped with a check valve device that allows fluid to flow only into the chamber.