JPH0633787B2 - Scroll gas compressor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll gas compressor having a device for returning lubricating oil separated from compressed gas on the high pressure side of a compressor to a compression chamber or the like.

2. Description of the Related Art A scroll compressor with low vibration and low noise characteristics has a suction chamber at the outer periphery, a discharge port at the center of the spiral, and a compressed fluid flow in one direction reciprocating compressor or It is 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 an actual scroll gas compressor or the like, it is also known that a check valve is provided in a discharge port or a suction passage to prevent reverse flow of compressed fluid in order to prevent reverse rotation immediately after stoppage (Japanese Patent Laid-Open No. Sho 5).
9-192890, JP-A-59-110884).

However, especially when compressing gas, it is necessary to make the dimensional accuracy of the spiral part extremely high in order to reduce the leakage gap of the compression part, but due to the complexity of the part shape and the dimensional accuracy, scroll gas compression There was a problem that the cost of the machine was high and the dispersion of the performance was large.

Therefore, as a measure for solving this kind of problem, it is highly expected that the dimensional accuracy of the spiral part and the compressor performance will be stabilized by the sealing effect using a lubricating oil film to prevent gas leakage during compression. The configuration shown in FIG. 3 is conceivable. Lubricating oil contained in the compressed gas is separated by the oil separating element 672 provided in the discharge chamber 674 to collect the lubricating oil in the oil sump 673 on the end plate 603 of the fixed scroll 601.
After the differential pressure oil is supplied to the sliding surface 631 between the fixed scroll 601 and the orbiting scroll 606, the lubricating oil is introduced into the suction chamber 699 to reduce the leakage of compressed gas in the compression chamber due to the sealing effect of the oil film. (JP-A-56-1657
No. 87).

Problems to be Solved by the Invention However, the check valve is not provided in the gas passage as shown in FIG. 3, and the oil sump 6 on the end plate 603 of the fixed scroll 601 is not provided.
The lubricating oil of 73 is applied to the lower suction chamber 69 via the sliding surface 631.
In the configuration in which the gas is introduced into the compressor 9, the compressor reverses immediately after the compressor is stopped due to the reverse flow of the compressed gas, resulting in a significant reduction in compression efficiency. Even if a check valve is provided in the discharge port or the suction passage, various problems occur. was there. That is, for example, JP-A-59
When a check valve is provided in the discharge port as in Japanese Patent Laid-Open No. 192890, the pressure in the compression chamber immediately after the compressor is stopped becomes the pressure on the suction side, so that the lubricating oil in the oil reservoir 673 continues to flow into the compression chamber. Oil sump 673 even after the pressure inside the compressor is balanced
Due to its own weight, it takes a long time to gradually flow into and fill the sealed space that does not communicate with the discharge chamber via the suction chamber 699, so that the viscosity of the lubricating oil is large when the compressor is cold restarted. The compression chamber is well sealed, the starting torque is extremely high, and the engine cannot be started, or even if it can be started, liquid compression occurs, causing lubricating oil to leak out of the compressor, abnormal vibration, abnormal noise, and damage to the compressor. There was a problem of inviting. Further, in the case where a check valve is simply provided in the intake passage as in JP-A-59-110884, for example, when the compressor is cold, the lubricating oil flows in after the pressure inside the compressor is balanced. There were problems that the engine could not be started at the time of restart and the compressor was damaged.

Therefore, in the present invention, a check valve is provided in the middle of the gas suction passage, and a part of the oil supply passage is made higher than the oil surface of the oil reservoir to prevent the lubricating oil from flowing into the compression chamber immediately after the operation is stopped. hand,
It is intended to provide a scroll gas compressor excellent in vibration / noise characteristics at starting, compression efficiency, and durability.

Means for Solving the Problems In order to solve the above problems, the scroll gas compressor of the present invention has an oil reservoir of the discharge chamber, an oil reservoir communicating with the discharge chamber, or an oil reservoir of the intermediate pressure chamber on the upstream side, and A first compression chamber that has a lower pressure than the oil sump and does not pass through the discharge chamber and is located at a position equal to or lower than the oil sump, a second compression chamber that communicates with the suction chamber, or a throttle passage having the suction chamber on the downstream side. Is provided, a part of the oil supply passage is arranged at a position higher than the oil level of the oil reservoir, and the check valve device is provided in the middle of the suction passage upstream of the suction chamber.

Operation According to the present invention, the lubricating oil in the oil reservoir is supplied to the first compression chamber or the second compression chamber or the suction chamber through the oil supply passage due to the differential pressure during operation of the compressor, and the gap between the compression chambers is filled with the oil film. Seal to prevent compressed gas leakage. After the compressor is stopped, the space from the check valve device to the discharge chamber becomes the same pressure, and the differential pressure oil supply stops, and the condensed liquid of the compressed gas and the lubricating oil from the piping system outside the compressor have a differential pressure or dead weight. Even if the oil level in the oil sump rises above the compression chamber due to the fact that the lubricating oil or condensate does not flow into the compression chamber, the restart load is reduced and the starting durability is improved. It is intended.

Embodiment A scroll gas compressor according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a vertical cross-sectional view of a scroll gas compressor in an embodiment of the present invention, and FIG. 2 shows a horizontal cross-sectional view of a compression section taken along the line AA of FIG.

In FIG. 1, 1 and 2 are iron-made hermetically sealed cases, 3 is an iron-made frame whose outer peripheral surface is welded and hermetically sealed together with the hermetically sealed cases 1 and 2 by a single weld bead 4,
The inside of 2 is divided into an upper discharge chamber 5 and a lower drive chamber 6 (low pressure side).

An orbiting shaft 11 of an orbiting scroll 10 is fitted into an eccentric hole 9 in an upper end portion of a drive shaft 8 which is rotatably driven by a motor 7 which is supported by a frame 3 and is driven and controlled by an inverter power source (not shown). The rotation inhibiting component 12 of the fixed scroll 13 is engaged with the orbiting scroll 10 and the frame 3, and the fixed scroll 13 meshing with the orbiting scroll 10 is fixed to the frame 3. The end plate 14 of the fixed scroll 13 is provided with the discharge port 15 and The partition plate 35 is provided on the upper surface and one end thereof is immersed in the discharge chamber oil sump 18 provided at the outer peripheral portion of the fixed scroll 13 at the bottom portion of the discharge chamber 5, and the other end thereof is provided with a partition plate 35 for preventing oil surface diffusion in the passage direction. The oil supply pipes 26a and 26b made of an annealed copper capillary tube are placed in the upper part of the discharge chamber 5 and attached to the closed case 1. Vignetting is attached to bypass to the vicinity of the umbrella-like punching metal 19 having many small holes. The connecting portions of the oil supply pipes 26a and 26b to the end plate 14 are opened in the end plate 14 and part of them are press-fitted and fixed in the injection holes 30a and 30b having a small diameter.

The injection holes 30a and 30b communicate with the discharge port 15 arranged substantially in the center of the compression section as shown in FIG. 2, and do not communicate with the suction chamber 33 arranged on the outer periphery of the compression section. The openings 39a and 39b are opened, and the opening positions are arranged so that the compression rates are equal to each other.

A fuher 20 made of fine iron wire is packed between the closed case 1 and the punching metal 19, and the discharge chamber 5 has an external pipe system (refrigeration cycle pipe system) through a discharge pipe 21 provided at the upper end of the closed case 1. After that, it communicates with the low pressure side drive chamber 6 through a suction pipe 22 provided on the side surface of the closed case 2, and a motor chamber oil sump 23 is provided at the bottom of the drive chamber 6, and an eccentric hole 9 and a motor chamber oil sump 23 are provided. The lower end of the drive shaft 8 having an eccentric oil hole 24 that communicates with each other is buried in the motor chamber oil sump 23.

The drive chamber 6 and the suction chamber 33 are communicated with each other by a suction passage A50 provided in the frame 3 and a suction passage B51 provided in the end plate 14 of the fixed scroll 13, and a free valve made of a thin plate is provided at an upper end of the suction passage B51. The check valve device 16 including the coil spring 53 and the coil spring 53 is arranged. The free valve 52 has its own weight and the coil spring 5 when there is no flow of the suction refrigerant gas.
The suction passage A50 is closed by the urging force of No. 3, and the suction passage B51 is moved so as to widen the opening degree when the flow velocity of the suction refrigerant gas is high.

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

1 and 2, when the drive shaft 8 is rotationally driven by the motor 7, the orbiting scroll 10 makes an orbiting motion,
The pressure in the suction chamber 33 and the suction passage B51 is reduced, and the drive chamber 6
When the pressure difference between the suction chamber 33 and the drive chamber 6 exceeds the set value, the check valve device 16 moves upward and the suction chamber 33 and the drive chamber 6 communicate with each other. Then, the suction refrigerant gas from the refrigeration cycle connected to the compressor flows into the drive chamber 6 through the suction pipe 22, and a part of the lubricating oil contained therein is separated and then sucked into the suction chamber 33. The gas is confined in a compression chamber formed between the orbiting scroll 10 and the fixed scroll 13, is sequentially compressed as the orbiting scroll 10 orbits, and is discharged to the discharge chamber 5 through the discharge port 15 at the central portion.
A part of the lubricating oil contained in the discharged refrigerant gas is separated from the discharged refrigerant gas by adhering to the surface of the lubricating oil when passing through the weight of the lubricating oil and the hole 20 of the punching metal 19 or the fuser 20 made of fine iron wire. The remaining lubricating oil collected in the oil sump 18 is discharged to the external refrigeration cycle through the discharge pipe 21 together with the discharge refrigerant gas, and returns to the compressor through the suction pipe 22 together with the suction gas.

On the other hand, the lubricating oil collected in the bottom motor chamber oil sump 23 separated from the suction refrigerant gas in the drive chamber 6 is a centrifugal pump action by the eccentric oil hole 24 of the drive shaft 8 and bearings related to the eccentric oil hole 24 and the drive shaft 8. The clearance (including the clearance between the eccentric hole 9 and the orbiting shaft 11), the thrust bearing portion related to the orbiting scroll 10 and the sliding surfaces of the rotation preventing component 12 are sequentially lubricated and flow into the suction chamber 33 together with the suction refrigerant gas.

In addition, the lubricating oil in the oil reservoir 18 of the discharge chamber is supplied with oil supply pipes 26a and 26b having throttle passages and injection holes 30a.
The first compression chambers 39a and 39b, which are in the middle of compression while being gradually decompressed through 30b, are differentially supplied with oil, and the lubricating oil of the motor chamber oil sump 23 that has flowed into the compression chambers via the suction chamber 33 is adjacent to the compression chambers. The gap between them is sealed with an oil film to reduce the leakage of compressed refrigerant gas.

After the compressor is stopped, the check valve device shuts off the connection between the suction chamber 33 and the drive chamber, so that the pressures in the first compression chambers 39a and 39b become the same as the discharge chamber 5 due to the instantaneous reversal of the orbiting scroll 10. From the discharge chamber oil sump 18 to the first compression chambers 39a, 39b
The inflow of lubricating oil to the oil supply stops, and there is no inflow of lubricating oil on the oil level lower than that of the oil supply pipes 26a and 26b even during a long period of time thereafter.

As described above, according to the above-described embodiment, the discharge chamber oil sump 18 is located on the upstream side, the pressure is lower than that of the discharge chamber oil sump 18, the discharge chamber 5 cannot be reached, and the discharge chamber oil sump 18 is at the same height position. The oil supply pipes 26a and 26b, which are capillary tubes having the arranged first compression chambers 39a and 39b on the downstream side, are provided with passages, and a part of the oil supply pipes 26a and 26b is located at a position higher than the oil level of the discharge chamber oil sump 18. The check valve device 16 is provided in the middle of the suction passage B51 between the suction chamber 33 and the drive chamber 6 on the upstream side of the suction chamber 33, so that the refrigerant liquid returned from the refrigeration cycle after the compressor is stopped passes through the suction passage. It does not flow into the suction chamber 33, and immediately after the compressor stops, the discharge chamber oil sump 18 and the first compression chamber 39
Since there is no pressure difference between a and 39b, the discharge chamber oil sump 1
8 from the first compression chambers 39a, 39b is stopped, and while the compressor is stopped in the pressure balance state inside the compressor, the amount is increased by the lubricating oil or refrigerant liquid returned from the high pressure side of the refrigeration cycle by its own weight. Even if the oil level of the discharge chamber oil reservoir 18 becomes higher than that of the first compression chambers 39a, 39b, the check valve action of the check valve device 16 and the high-position pipes of the oil supply pipes 26a, 26b in the discharge chamber 5 As a result, the lubricating oil in the discharge chamber oil sump 18 does not flow into the compression chamber, no compression of the lubricating liquid occurs at the time of restart, and the check valve device closes the suction passage, so the pressure in the suction chamber 33 is low. Because of the small compression load and other factors, it is possible to smoothly start the operation, which is characteristic of a scroll-type compressor, in which vibration at the time of starting is extremely small.

Further, in the above embodiment, the first compression chamber is located on the downstream side of the oil supply pipes 26a and 26b, but the second compression chambers 40a and 40b (see FIG. 2) communicating with the suction chamber 33 and the discharge chamber oil sump 18 are piped. The same operation is performed when communicating.

Further, although the oil supply pipes 26a and 26b are arranged only in the discharge chamber 5 in the above-mentioned embodiment, the cooling effect of the supplied lubricating oil may be achieved by penetrating the closed shell 1 and extending to the outside of the compressor.

As described above, the present invention has the oil reservoir of the discharge chamber or the oil reservoir communicating with the discharge chamber on the upstream side, has a lower pressure than the oil reservoir and does not communicate with the discharge chamber, and has the same height position as the oil reservoir. Alternatively, an oil supply passage having a throttle passage whose downstream side is the first compression chamber or the second compression chamber or the suction chamber communicating with the suction side which is arranged at a low position is provided, and a part of the oil supply passage is located above the oil level of the oil sump. By placing it in a high position and installing a check valve device in the middle of the suction passage upstream of the suction chamber, the condensate returned from the piping system connected to the compressor after the compressor has stopped is sucked through the suction passage. Immediately after the compressor stops, the pressure difference between the oil sump and the first compression chamber (or the second compression chamber or the suction chamber) disappears immediately after the compressor stops, and the pressure difference to the first compression chamber, etc. disappears. When the pressure oil supply is stopped and the compressor is stopped for a long time,
From the high pressure side of the closed piping system including the compressor, the weight of the closed pipe system is fed back due to its own weight and the pressure difference immediately after the operation is stopped, and the amount of oil is increased by the condensate of the lubricating oil or compressed gas, and the oil sump (or the oil sump leading to the discharge chamber) Even when the oil level is higher than that in the first compression chamber, the high position of the oil supply passage prevents the lubricating liquid in the oil sump and the condensed liquid of the compressed gas from flowing into the suction chamber and the compression chamber through the oil supply passage. When the machine is restarted, there is no liquid compression due to lubricant, etc., and even if the discharge chamber is small, the lubricating oil does not jump out of the compressor, and the check valve device closes the suction passage to reduce the pressure in the suction chamber. There is no abnormal vibration or damage to the bearing or compression part because the compression load due to synergistic effects such as low is small, smooth running start peculiar to the scroll type compressor is possible, durability is improved and discharge chamber oil sump etc. Always secure and compress the lubricating oil of The oil film sealing effect between the gaps, can provide superior compressor in compression efficiency in which excellent effects such as.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a scroll gas compressor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a compression section taken along the line AA in FIG. 1, and FIG. 3 is a conventional oil supply passage. Figure 3 shows a cross-sectional view of a scroll gas compressor. 1, 2 ... sealed case, 5 ... discharge chamber, 6 ... drive chamber,
7 ... Motor, 10 ... Orbiting scroll, 13 ... Fixed scroll, 14 ... End plate, 15 ... Discharge port, 16
...... Check valve device, 18 ... Discharge chamber oil sump, 21 ... Discharge pipe, 22 ... Suction pipe, 23 ... Motor chamber oil sump, 26a,
26b ... Oil supply pipe, 30a, 30b ... Injection hole, 33 ... Suction chamber, 39a, 39b ... First compression chamber, 40a, 40b ... Second compression chamber, 50 ... Suction passage A, 51 ... Inhalation passage B.

Claims (1)

[Claims] 1. A plurality of orbiting scrolls are meshed with a fixed scroll so that the orbiting scroll can oscillate and rotate, and a spiral compression space is formed between the scrolls, and the compression space continuously shifts from the suction side toward the discharge side. A scroll-type compression mechanism that is divided into individual compression chambers and compresses a fluid is formed, and the oil reservoir of the discharge chamber, the oil reservoir communicating with the discharge chamber, or the oil reservoir of the intermediate pressure chamber is on the upstream side, and The pressure is too low to reach the discharge chamber,
An oil supply passage having a first compression chamber disposed at a height position or a low position equivalent to the oil reservoir, a second compression chamber communicating with the suction chamber, or an oil passage having a throttle passage having the suction chamber on the downstream side is provided. A part of the scroll gas compressor is disposed at a position higher than the oil surface of the oil sump, and a check valve device is provided in the suction passage upstream of the suction chamber.