JPH0454296A - Scroll compressor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a scroll compressor, and is particularly used in refrigerators such as air conditioners and refrigerators.

[Conventional technology]

Conventional compressors, for example, as described in JP-A-61-167193, supply lubricating oil stored at the bottom of a high-pressure sealed container to the bearings by a pressure difference that occurs before and after the bearings. . This lubricating oil performs a lubricating action while flowing through the gap between the shaft and the bearing due to the pressure difference.

[Problem to be solved by the invention]

In the bearings according to the prior art described above, the lubricating oil flows inside the bearing due to the pressure difference before and after the bearing. During this period, a drop in pressure occurs, and the refrigerant dissolved in the lubricating oil may be generated as gas. Therefore, this gas becomes bubbles and mixes into the lubricating oil, reducing the load capacity of the bearing, and depending on the load and rotation speed, the oil film may break, and as a result,
Burning may occur.

An object of the present invention is to provide a compressor that reduces the amount of refrigerant gas mixed into lubricating oil supplied to the load surface of a bearing and maintains the load capacity of the bearing.

[Means to solve the problem]

To achieve the above object, the present invention provides a lubricating oil supply groove that communicates with a high-pressure lubricating oil reservoir in order to supply lubricating oil with a small pressure drop in the bearing. A gas vent groove was provided near the front in the rotational direction to separate refrigerant gas generated by pressure fluctuations in the bearing and discharge it to the low pressure section of the compression mechanism.

[Effect]

Refrigerant gas generated due to pressure fluctuations and pressure drops in the bearings is discharged to the low pressure side of the compressor through a gas vent groove, and the amount of gas mixed in is reduced through a lubricating oil supply groove provided at the rear of the gas vent groove in the rotational direction. Supply less lubricant. Thereby, the amount of bubbles mixed in by the refrigerant gas in the lubricating oil on the load surface of the bearing can be reduced, and a decrease in load capacity can be prevented.

Additionally, both the lubricating oil supply groove and the gas venting groove communicate with only one of the high-pressure side and low-pressure side of the bearing.6 Therefore, it is difficult to maintain an appropriate amount of lubricating oil flowing through these grooves. Therefore, deterioration in compressor performance due to refrigerant gas leaking together with lubricating oil into the suction gas chamber of the compression mechanism section communicating with the low pressure side can be minimized.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. First, the overall configuration will be explained.

FIG. 1 is a longitudinal cross-sectional view of a scroll compressor according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1.

The scroll compressor shown in FIG. 1 has a compression mechanism section housed in the upper part of a closed container 1, an electric motor section housed in the lower part, and a reservoir section containing lubricating oil at the bottom part. The compression mechanism section includes a fixed scroll 2. Orbiting scroll 3. Frame 4. The main component is an Oldham ring 27. A suction pipe 8 connected to an external refrigeration cycle is provided at the suction lower of the fixed scroll 2.

The fixed scroll 2 and the orbiting scroll 3 have spiral wrap portions that stand upright on their base plate surfaces and engage with each other inwardly to form a compression chamber 6.

The boss part of the orbiting scroll 3 has an eccentric part 5 of the crankshaft 5.
a is rotatably fitted through a swing bearing 20, and an Oldham ring 27 is slidably disposed in a groove (not shown) in the base plate portion and a groove (not shown) in the frame 4.

Further, the pedestal of the orbiting scroll 3 is provided with a communication hole 18a that passes through the pedestal and communicates with the compression chamber 6 during the compression process, so that the space surrounded by the frame 4 and the pedestal of the orbiting scroll 3 is connected to the closed container 1. An intermediate pressure chamber 21 having a lower pressure than the inside is formed. The base plate of the orbiting scroll 3 rotates while being pressed against the fixed scroll 2 by the pressure difference between the intermediate pressure and the suction pressure of the compression mechanism.

The outer periphery of the frame 4 is fixed to the closed container 1 by welding or the like, and the fixed scroll 2 is fastened to the frame 4 with bolts 29.

A rotor 10 constituting the electric motor is fitted onto the crankshaft 5 by shrink fitting or the like, and a stator 9 constituting the electric motor is fixed within the closed container 1 by shrink fitting or the like.

22 is a main bearing that supports the crankshaft 5 by the frame 4, and 13 is a sub-bearing that supports the lower part of the crankshaft 5. The lower end of the crankshaft 5 is immersed in lubricating oil 25,
Further, an oil supply passage 25 is provided that passes through the crankshaft 5 in the axial direction and communicates with the swing bearing 20 at one end. Furthermore, a lubricating oil supply hole 23 is provided in the middle of the oil supply passage 25, passing through the crankshaft 5 in the radial direction and communicating with the main bearing 22.

The operation of a scroll compressor will be explained.

The rotor 10 receives rotational force from the stator 9, the crankshaft 5 rotates, and the orbiting scroll 3 eccentrically rotates (revolutions) without rotating due to the action of the Oldham ring 27. Due to the eccentric rotation of the orbiting scroll 3, the refrigerant gas sucked through the suction pipe 8 is gradually compressed in the compression chamber 6 from the suction lower of the fixed scroll 2, and is discharged into the closed container 1 from the discharge port 28. The released refrigerant gas cools the motor section and is supplied from the discharge pipe 14 to the external refrigeration cycle.

Next, a method of supplying lubricating oil to each bearing will be explained.

The lubricating oil stored at the bottom of the closed container 1 is heated to the crankshaft 5 due to the pressure difference between the intermediate pressure chamber 21 and the closed container 1.
The oil passes through the oil supply path 24 and is sucked up to one end of the swing bearing 20. The lubricating oil sucked up into the oil supply path 24 due to the pressure difference is supplied to the main bearing 22 through the lubricating oil supply hole 23 . Further, the sub bearing 13 at the lower part of the crankshaft 5 is immersed in a lubricating oil reservoir.

Next, embodiments of the present invention will be described with reference to FIGS. 1 to 6.

3 is an explanatory diagram showing the structure of the main bearing, FIG. 4 is a sectional view taken along the line IV-rV in FIG. 3, FIG. 5 is an explanatory diagram showing the structure of the slewing bearing, and FIG. 5 is a sectional view taken along the line ■-■ in FIG. 5. FIG.

In FIGS. 3 and 4, 3o is a lubricating oil supply groove cut into the crankshaft 5, one end of which opens into a lubricating oil supply hole 23 installed in the crankshaft 5 and communicating with the lubricating oil 25, A seal portion 32 is provided between the other end and the intermediate pressure chamber 21 . 31 is a gas vent groove provided in front of the lubricating oil supply groove 30 in the rotational direction U, sandwiching the seal portion 34 and adjacent thereto;
One end of the thrust bearing is connected to the intermediate pressure chamber 21 by an annular groove 35. A seal portion 33 is provided between the opening via the radial groove 36 and the space inside the closed container 1 on the other side.

In FIGS. 5 and 6, 40 is a lubricating oil supply groove cut into the eccentric shaft portion 5a of the crankshaft 5 of the swing bearing 20, and one end is connected to the outlet of the oil passage 24 provided in the crankshaft 5. It opens in the concave part of the boss part of the orbiting scroll 3, and has an intermediate pressure chamber 21 at the other end.
A seal portion 43 is provided between the two. Reference numeral 41 denotes a gas vent groove provided in front of the lubricating oil supply groove 40 in the rotational direction U in close proximity to the seal portion 44, and one end of which is connected to the intermediate pressure chamber 2.
1, and a seal portion 42 is provided between the other end and the recess of the boss portion of the orbiting scroll 3.

According to this embodiment, as shown in FIG. 4, the lubricating oil supplied from the lubricating oil supply groove 30 provided in front of the load surface of the main bearing 22 that receives the load Fa in the rotational direction is After passing through a gap or due to a pressure drop in the bearing, the refrigerant dissolved in the lubricating oil becomes gas, and this gas is transferred to the low-pressure intermediate pressure chamber 21 by the gas vent groove 31. is discharged.

Similarly, in the slewing bearing 20, as shown in FIG. Due to the pressure drop in the bearing, the gasified refrigerant is discharged into the intermediate pressure chamber 21 through the gas vent groove 41 .

According to this embodiment, the refrigerant gas from the lubricating oil, which is generated due to pressure fluctuations in each bearing as it passes through the load surface and pressure drops caused by pressure differences before and after the bearing, is removed by the gas vent groove into the intermediate pressure chamber. Since the gasified refrigerant can be discharged into the newly supplied lubricating oil in the form of bubbles, the amount of the gasified refrigerant mixed into the newly supplied lubricating oil can be reduced, and the load capacity of the bearing can be maintained large.

Furthermore, since the pressure drop in the lubricating oil supply groove is small, lubricating oil that does not turn into gas can be supplied to the vicinity of the upper part of the main bearing and the lower part of the slewing bearing, where the load distribution is large, so that the lubricating performance of the bearing can be maintained in good condition.

Furthermore, since both the lubricating oil supply groove and the gas venting groove are open only on either the front or rear side of the bearing, the amount of lubricating oil flowing through them can be appropriately restricted, and the refrigerant flows from the intermediate pressure chamber to the compression chamber together with the lubricating oil. By minimizing the amount of gas, it is possible to prevent deterioration of compressor performance.

〔Effect of the invention〕

According to the present invention, even if the refrigerant dissolved in the lubricating oil becomes gas due to pressure drop or pressure fluctuation in the bearing and bubbles are generated, the bubbles can be removed from the front of the lubricating oil supply groove in the direction of rotation. The gas vent groove provided in the bearing allows the gas to be removed to the low pressure side, so lubricating oil with a small amount of air bubbles is always supplied to the bearing load surface, providing a highly reliable compressor that maintains good lubrication performance. be able to.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a scroll compressor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along arrows -■ in FIG. 1, and FIG. 3 is a structure of the main bearing in FIG. 1. An explanatory diagram showing the
5 is an explanatory diagram showing the structure of the swing bearing shown in FIG. 1, and FIG. 6 is a sectional view taken along the line Vl-■ in FIG. 5.

Claims (1)

[Claims] 1. An electric motor and a compression mechanism connected to the electric motor are housed in a closed container, spiral wraps are provided upright on each base plate, and the wraps are engaged with each other to form a compression chamber. A fixed scroll and an orbiting scroll, a crankshaft that transmits rotational force to the orbiting scroll, a frame including a bearing that supports the crankshaft, and an anti-rotation mechanism that maintains an angular relationship between the frame and the orbiting scroll. In the scroll compressor, the inside of the closed container is maintained at a high pressure equivalent to the discharge pressure of the compression mechanism, lubricating oil is stored at the bottom of the container, and one end is connected to the low suction pressure of the compression mechanism. A scroll characterized in that a lubricating oil supply groove communicating with a high-pressure lubricating oil reservoir is provided on the shaft side of the communicating bearing, and a gas venting groove communicating with a low pressure side in the forward direction of rotation adjacent to the lubricating oil supply groove. compressor.