JPH08210280A - Scroll compressor - Google Patents

Abstract

PURPOSE: To provide a high reliability scroll compressor which is constituted in such a manner that even during vacuum operation, a volume type oil pump is normally worked and a necessary amount of oil is fed to a bearing. CONSTITUTION: Since owing to provision of a microleak flow passage through which a delivery space 31 and a suction space 30 are intercommunicated, a very small amount of refrigerant gas always leaks through the delivery space 31 to a suction space 30, even during vacuum operation, a pressure in a suction space 30 is not reduced to a value lower than a necessary pressure and the suction head of a volume type oil pump 13 is ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed scroll compressor used for refrigerators and air conditioners.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view showing a conventional scroll compressor disclosed in the specification of Japanese Patent Application No. 2-186181 filed by the applicant earlier. Is a fixed scroll, 2 is an orbiting scroll composed of a base plate, a spiral portion and a shaft portion, 3 is a crankshaft for transmitting a driving force to the orbiting scroll 2, 4 is a frame for accommodating the orbiting scroll 2, 4a is a frame 4 Shrink fitting portions, 5, 6 are main bearings and auxiliary bearings that support the crankshaft 3, 7 and 8 are swing bearings and thrust bearings that support the swing scroll 2, respectively, and 9 is a rotation prevention of the swing scroll 2. Oldham ring, 10 is a motor rotor, 11 is a motor stator,
12 is a sub-frame for accommodating the auxiliary bearing 6, 13 is a positive displacement oil pump mounted in the sub-frame 12, 14 is a discharge hole, 15 is a discharge valve, 20 is a suction pipe, 21 is a discharge pipe, 2
2 is a shell, 23 is lubricating oil, 30 is a suction space, and 31 is a discharge space.

Next, the operation will be described. The torque generated by the electric motor is transmitted by the crankshaft 3 that is shrink-fitted and fixed to the electric motor rotor 10, and is transmitted to the orbiting scroll 2 coupled to the crankshaft 3. As a result, the orbiting scroll 2 revolves around the Oldham ring 9, and the refrigerant gas is compressed in accordance with the change in the capacity of the compression chamber formed between the orbiting scroll 2 and the fixed scroll 1. On this occasion,
The refrigerant gas is sucked through the suction pipe 20, and the shell inner space 30
After being flown into the chamber, it is sucked into the compression mechanism unit that is combined by the fixed scroll 1 and the orbiting scroll 2, and after being compressed in the compression chamber, it passes through the discharge hole 14, enters the discharge space 31, and through the discharge pipe 22. It is discharged to the outside of the shell 22.

Here, the seal for preventing the leakage of the refrigerant from the discharge space 31 to the suction space 30 is performed by the shrink fitting portion 4a of the frame. Further, when the crankshaft 3 rotates, a positive displacement oil pump coupled to the crankshaft 3 rotates, the lubricating oil 23 accumulated at the bottom of the shell 22 is sucked, and passes through an oil supply passage provided in the crankshaft 3 to the main passage. Bearing 5, secondary bearing 6, rocking bearing 7, thrust bearing 8
After being lubricated and lubricated, the gravity returns to the bottom of the shell 22 again.

[0005]

The conventional scroll compressor is constructed as described above, and when operated in a state where the valve of the external pipe connected to the suction pipe cannot be opened,
The compression mechanism sucks the refrigerant in the pipe from the inside of the shell and the suction pipe to the valve of the external pipe, the refrigerant is compressed in the compression chamber, passes through the discharge hole, enters the discharge space, and exits the shell through the discharge pipe. Since the suction space inside the shell is rapidly decompressed and reaches a vacuum state, the suction head (suction force) of the positive displacement oil pump is extremely small because it is proportional to the ambient pressure of the oil pump. As a result, the lubricating oil at the bottom of the shell cannot be sucked up. Therefore, the main bearing, sub bearing, oscillating bearing, thrust bearing, etc. cannot be lubricated and lubricated, which causes the bearing to seize. .

The present invention has been made in order to solve the above-mentioned problems, and the volumetric oil pump operates normally even during vacuum operation, so that the required amount of oil can be supplied to the bearing with high reliability. The purpose is to obtain a scroll compressor.

[0007]

A scroll compressor according to the present invention is provided with a minute leak flow passage which connects a discharge space and a suction space.

Since the scroll compressor according to the present invention is provided with the minute leak flow passage which connects the discharge space and the suction space, a small amount of the refrigerant gas is always leaked from the discharge space to the suction space. However, the pressure in the suction space does not fall below the required pressure, and the suction head of the positive displacement oil pump can be secured.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment of the Invention The first embodiment of the present invention will be described below with reference to FIGS. In the figure, 4b is a shrink fitting portion 4.
The notch provided in “a” serves as a minute leak flow path that connects the discharge space 31 and the suction space 30. Here, the size of the notch 4b serving as the minute leak flow path is set to be equal to or less than the size that the suction head of the positive displacement oil pump 13 can supply the total amount of oil supply required for each bearing during the vacuum operation. It is set to the minimum pressure that does not prevent it.

Next, the operation will be described. During normal operation, the refrigerant gas flowing into the shell 22 from the suction pipe 20 is sucked into the compression mechanism section and compressed, and then passes through the discharge hole 14 to push up the discharge valve 15 to push up the discharge space 31.
The gas enters and is discharged to the outside of the shell 22 through the discharge pipe 22. At this time, a minute amount of the refrigerant gas in the discharge space 31 always flows through the minute leak flow path to the suction space 30 on the low pressure side. The amount of refrigerant gas that leaks to the low pressure side through this minute leak flow path is extremely small, and therefore has almost no effect on the performance of the compressor.

Further, during the vacuum operation when the valve of the external pipe connected to the suction pipe 20 is not opened, the compression mechanism portion causes the inside of the shell 22 and the suction pipe 20 to operate.
To the valve of the external pipe, the refrigerant in the pipe is sucked in,
After being compressed, it enters the discharge space 31 through the discharge hole 14 and the discharge valve 15 and is discharged to the outside of the shell 22 through the discharge pipe 21, so that the suction space 30 inside the shell 22 is rapidly decompressed and is in a vacuum state. However, the minute amount of the refrigerant gas in the discharge space 31 passes through the minute leak flow path, and the suction space 30
Therefore, the discharge space 31 does not fall below a certain pressure. This pressure has a size of the cutout 4b of the minute leak passage so that the displacement type oil pump 13 (which increases in proportion to the pressure in the suction space 30) has a minimum pressure capable of supplying the required oil supply amount of all the bearings. It is set by Therefore, the oil pump 13 operates normally even during vacuum operation, and a highly reliable scroll compressor capable of supplying the required amount of oil to the bearing can be obtained.

Second Embodiment of the Invention In the above embodiment, the minute leak flow path is the notch 4b provided in the shrink-fitting portion 4a of the frame. However, as shown in FIG. 3, a groove 22a is formed on the shell 22 side of the shrink-fitting portion 4a of the frame to make a minute gap. A leak channel may be formed, and the same effect as that of the above-described embodiment is obtained.

Third Embodiment of the Invention Further, as a place for forming the minute leak flow passage, as shown in FIG. 4, the base plate of the fixed scroll 1 may be formed with a minute hole 1a which connects the discharge space 31 and the suction chamber 4c in the frame 4 to each other.

[0014]

As described above, according to the present invention, by providing the minute leak flow path which communicates the discharge space and the suction space, a small amount of refrigerant gas is always leaked from the discharge space to the suction space. The pressure in the suction space does not drop below the required pressure even during vacuum operation, and the suction head of the positive displacement oil pump can be secured, so the positive displacement oil pump operates normally and the required amount of oil can be supplied to the bearings. There is an effect that a highly reliable one can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a scroll compressor according to Embodiment 1 of the present invention.

FIG. 2 is a perspective view showing a cutout of the frame of FIG.

FIG. 3 is a sectional view showing a scroll compressor according to Embodiment 2 of the present invention.

FIG. 4 is a sectional view showing a scroll compressor according to Embodiment 3 of the present invention.

FIG. 5 is a sectional view showing a conventional scroll compressor.

[Explanation of symbols]

 1 Fixed Scroll 2 Oscillating Scroll 3 Crank Shaft 4 Frame 4b Notch 4c Suction Chamber 13 Oil Pump 22 Shell 22a Groove 23 Lubricating Oil 30 Suction Space 31 Discharge Space

Claims (1)

[Claims] 1. A scroll-type compression mechanism in which a fixed scroll and an orbiting scroll are combined in a shell,
Lubricating oil is supplied to a bearing that axially supports the crankshaft that transmits the driving force to the orbiting scroll, the fixed scroll and the orbiting scroll, and divides the shell into a discharge space and a suction space, and a bearing. In a scroll compressor including a positive displacement oil pump, a scroll compressor having a minute leak passage that connects the discharge space and the suction space.