JPH09203383A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the inflow of a compressed gas into a rolling piston from a cylinder chamber, prevent abrasion by the sliding with the bearing of a rolling piston. SOLUTION: In a cylinder chamber, an eccentric part 5a, provided on a crank shaft 5 supported by main and sub bearings 9 and 10, is fitted into a rolling piston 7 to revolutionally move the piston 7, along the outer peripheral surface of a cylinder chamber, by the eccentric rotation of the eccentric part 5a, thereby compressing a refrigerant gas in the cylinder chamber. Facing surfaces 7a and 7b to the main and sub bearings 9 and 10 in the piston 7 are surface-treated, excellent in a load-withstanding property, a lubricating-oil- retaining characteristic, and an initial running-in characteristic; to provide surface-treating layers 15 on the facing surfaces 7a and 7b respectively. The projection parts of the surfaces 7c and 7d of these surface treating layers 15, are removed by initial action to be smoothed. This can reduce a clearance between the piston 7 and the main and sub bearings 9 and 10.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention mainly relates to an air conditioner,
The present invention relates to a rotary compressor used in a refrigerator, and relates to a rotary compressor having a structure suitable for improving performance.

[0002]

2. Description of the Related Art FIG. 3 is a vertical cross-sectional view showing an entire structure of a conventional example of a rotary compressor. 1 is an electric motor part, 2 is a compression mechanism part, 3 is a stator, 4 is a rotor, and 5 is a rotor. Crankshaft, 5
a is an eccentric part, 5b is an oil supply hole, 6 is a cylinder, 7 is a rolling piston, 8 is a vane, 9 is a main bearing, 10 is a sub bearing, 11 is a sealed container, 12 is lubricating oil, 13 is a spring, 14
Is a space in the cylinder 6.

In FIG. 3, generally, in a rotary compressor, an electric motor section 1 composed of a stator 3 and a rotor 4 is housed in an upper part of a hermetically sealed container 11, and a compression mechanism section 2 is housed in a lower part thereof. Lubricating oil 12 is stored at the bottom of the closed container 11 which is connected by the shaft 5.

The compression mechanism section 2 includes a cylinder 6 fixed to an inner wall of a hermetically sealed container 11 between a main bearing 9 and a sub bearing 10,
The eccentric portion 5 of the crankshaft 5 provided in the cylinder 6
It is composed of a rolling piston 7 in which a is inserted and a vane 8. The vane 8 is constantly pressed by the spring 13 by the rolling piston 7 and reciprocates following the revolving motion of the rolling piston 7. The main bearing 9 and the sub bearing 10 seal the both ends of the cylinder 6 and support the crankshaft 5.

The rotary compressor configured as described above is
The rotor 4 rotates, the crankshaft 5 rotates, and the cylinder 6
The rolling piston 7 revolves along the inner wall of the cylinder 6 due to the eccentric rotation of the eccentric portion 5a.

FIG. 4 is a transverse sectional view taken along the section line A--A in FIG. 3, in which 14 is a space (cylinder chamber), 14a is a suction chamber, and 14b is a compression chamber, corresponding to FIG. Are given the same symbols.

In the figure, the rolling piston 7 follows the orbital motion of the rolling piston 7 in the direction of arrow B.
The vane 8 pressed against moves reciprocally in the direction of arrow C. In the cylinder 6, a space (cylinder chamber) 14 between the inner wall of the cylinder 6 and the rolling piston 7 is partitioned by a vane 8, one of which constitutes a suction chamber 14a for sucking a refrigerant gas, and the other of which compresses the refrigerant gas. The compression chamber 14b is configured.

That is, due to the orbital motion of the rolling piston 7, the volume of the compression chamber 14b is gradually reduced and the refrigerant gas therein is compressed, and as a high pressure refrigerant gas, the closed container 11 is closed.
While being discharged into the suction chamber 14a, the volume of the suction chamber 14a is gradually increased, and the refrigerant gas to be compressed next is sent into the suction chamber 14a. Therefore, the inside of the closed container 11 is compressed to have a discharge pressure by the refrigerant gas, and generally, the space (cylinder chamber) 14 formed in the rolling piston 7 is formed.
And the inside of the closed container 11 communicate with each other through an oil supply hole 5b provided in the crankshaft 5, so that the space (cylinder chamber) 14 in the rolling piston 6 also has a discharge pressure.

FIG. 5 is an enlarged vertical sectional view showing an essential part of the compression mechanism section 2 in FIG. 3, in which 7a and 7b are opposed surfaces, and the portions corresponding to FIG. There is.

In general, the main bearing 9 of the rolling piston 7 is considered in consideration of variations in processing accuracy and dimensions of the rolling piston 7, the cylinder 6, the main bearing 9, and the auxiliary bearing 10.
By promoting the supply of the lubricating oil 12 (FIG. 3) to the facing surface 7a of the rolling piston 7 and the facing surface 7b of the auxiliary bearing 10, the facing surfaces 7a and 7b of the rolling piston 7 and the main bearing 9 and the auxiliary bearing 10 are In order to prevent seizure and wear, as shown in FIG. 5, the axial height of the rolling piston 7 (opposing surface 7a,
Between the distance 7b) A and the height B of the space 14 in the cylinder 6 formed by the main bearing 9 and the auxiliary bearing 10 (the distance between the side surface of the main bearing 9 and the side surface of the auxiliary bearing 10) B. A gap C (clearance) is provided by providing a difference.

In order to prevent the seizure of the sliding surface,
For example, as disclosed in Japanese Patent Laid-Open No. 63-263278, the crankshaft 5, the rolling piston 7, etc. are subjected to surface treatment.

[0012]

In the rotary compressor of the prior art described above, in FIG. 4, due to the pressure difference between the compression chamber 14b and the space formed in the rolling piston 7 in the compression process, A gap (clearance) due to the difference between the axial height A of the rolling piston 7 shown in FIG. 5 and the height B of the space (cylinder chamber) 14 in the cylinder 6 formed by the main bearing 9 and the auxiliary bearing 10. High-pressure refrigerant gas having a discharge pressure flows into the space 14 in the cylinder 6 from the space formed in the rolling piston 7 via C. Therefore, the high-pressure refrigerant gas that has flowed in is compressed in the compression chamber 14b.
There is a problem in that it re-expands inside, which causes a decrease in compression capacity and an increase in power required for compression, resulting in a decrease in compression efficiency.

When a surface treatment is applied to a part as in the prior art disclosed in Japanese Patent Laid-Open No. 63-263278, it is common to perform the surface treatment on the entire surface, but in particular, When the entire surface of the rolling piston 7 is surface-treated, sliding between the inner surface of the rolling piston 7 and the eccentric portion 5a of the crankshaft 5 and between the outer peripheral surface of the rolling piston 7 and the vanes 8 are performed. Sliding is not performed evenly on the entire circumference of the rolling piston 7 due to the revolution movement of the rolling piston 7 and the fluctuation of the compression load.
The inner surface and the outer peripheral surface of the rolling piston 7 are peeled off or fallen off during the initial familiarization, resulting in non-uniform wear. As a result, the shape accuracy of the inner diameter and the outer diameter of the rolling piston 7 is deteriorated, and there is a problem that abnormal local wear and the resulting increase in compression power occur.

The object of the present invention is to solve the above problems,
To provide a rotary compressor with high compression efficiency by reducing high-pressure refrigerant gas flowing from the space inside the rolling piston into the cylinder chamber and preventing abnormal local wear and seizure on the sliding surface of the rolling piston. is there.

[0015]

In order to achieve the above object, the present invention applies a surface treatment to at least one of the facing surfaces of a rolling piston facing a main bearing and a sub bearing.

Between the axial height of the rolling piston and the height of the cylinder chamber formed by the main bearing and the sub bearing, due to the characteristics of the surface treatment, which are excellent in load bearing capacity, lubricating oil retention, and initial conformability. Even if the clearance provided in the rolling bearing is reduced, it is possible to prevent seizure and wear between the main bearing and the sub bearing and the surface of the rolling piston facing the main bearing and the sub bearing. Therefore, even if a pressure difference occurs between the cylinder chamber and the space inside the rolling piston, the high-pressure refrigerant gas at the discharge pressure flowing into the cylinder chamber from the space inside the rolling piston is reduced through such a clearance. As a result, it is possible to reduce a decrease in compression capacity and an increase in power required for compression due to re-expansion of the high-pressure refrigerant gas that has flowed into the compression chamber, and it is possible to improve compression efficiency.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged vertical sectional view showing a compression mechanism part which is a main part of an embodiment of a rotary compressor according to the present invention. Reference numeral 15 is a surface treatment layer, and parts corresponding to FIG. 6 are the same. A reference numeral is given and a duplicate description is omitted.

This embodiment also has an overall configuration shown in FIG.
Is the same as that shown in FIG.

In FIG. 1, the rolling piston 7 has a surface 7a facing the main bearing 9 and a surface 7b facing the sub bearing 10, respectively, which are surface-treated.
The surface treatment layer 15 is provided on the facing surfaces 7a and 7b.

Examples of such a surface treatment include a phosphate coating treatment, and the coating has a fine crystalline body and a load resistance,
It has excellent lubricating oil retention and initial compatibility. Further, the axial height D of the rolling piston 7 including the surface treatment layer 15 is reduced by the surface treatment.
The clearance E between the end surface of the auxiliary bearing 10 and the end surface of the sub bearing 10 is set to be smaller than the clearance C in the conventional rotary compressor shown in FIG. ing.

FIG. 2 shows the rolling piston 7 in FIG.
FIG. 2 is a diagram schematically showing the surface state of the facing surfaces 7a, 7b of the main bearing 9 and the sub bearing 10 of FIG. 1, in which 7c and 7d are the surface of the surface treatment layer 15, and 16 is a protruding portion. Corresponding parts are designated by the same reference numerals.

In the figure, undulations and irregularities caused by the manufacturing process of the facing surfaces 7a and 7b of the rolling piston 7 facing the main bearing 9 and the sub bearing 10 are covered with a surface treatment layer 15. The portion 16 protruding due to the initial conformability in the layer 15 is peeled and dropped without seizing due to a local load caused by the sliding between the rolling piston 7 and the main bearing 9 and the auxiliary bearing 10, and the rolling piston 7 has Smoothed facing surface 7 with the main bearing 9 and the sub bearing 10
c, 7d are obtained.

According to this structure, the main bearing 9 and the sub bearing 1
Even if the clearance (clearance) E between 0 and the rolling piston 7 is smaller than the clearance (clearance) C in the conventional rotary compressor, due to the load bearing capacity of the surface treatment layer 15 and the lubricating oil retaining ability, the rolling piston Opposing surface 7
It is possible to prevent seizure and wear between the surfaces 7c and 7d of the surface treatment layer 15 on the surfaces a and 7b and the main bearing 9 and the auxiliary bearing 10.

As a result, the clearance C
Even if a pressure difference is generated between the internal space of the rolling piston 7 and the cylinder chamber 14, the inflow amount of the high pressure refrigerant gas at the discharge pressure from the internal space of the rolling piston 7 to the cylinder chamber 14 can be made smaller. It is possible to drastically reduce the compression capacity, and it is possible to prevent the reduction of the compression capacity and the increase of the power required for the compression to achieve the improvement of the compression efficiency.

The facing surface 7 of the rolling piston 7
Since the surface treatment layer 15 can cover the undulations and the unevenness due to the fabrication processing of a and 7b, the control of the surface roughness of these facing surfaces 7a and 7b of the rolling piston 7 can be relaxed.

In the above embodiment, the facing surfaces 7a and 7b of the rolling piston 7 are each surface-treated.
Either one of these may be surface-treated. Particularly in the case of a vertical type rotary compressor, surface treatment may be applied only to the facing surface 7b of the rolling piston 7 on the lower side, and substantially the same effect is obtained.

[0027]

As described above, according to the present invention,
Even if the clearance between the axial height of the rolling piston and the distance from the main bearing to the sub bearing is reduced, the facing surface of the rolling piston facing the main bearing and the sub bearing becomes smooth, and the main bearing 9. Since seizure and wear with the sub-bearing 10 can be prevented, this clearance can be reduced, and therefore the amount of high-pressure refrigerant gas flowing from the space inside the rolling piston into the cylinder chamber. Can be significantly reduced, and the compression efficiency can be significantly increased.

[Brief description of drawings]

FIG. 1 is an enlarged vertical cross-sectional view showing a compression mechanism part that is a main part of an embodiment of a rotary compressor according to the present invention.

FIG. 2 is a main bearing of the rolling piston shown in FIG.
It is a schematic diagram which shows the surface state of the opposing surface with a sub bearing.

FIG. 3 is a vertical cross-sectional view showing a conventional general rotary compressor.

4 is a cross-sectional view taken along the section line AA in FIG.

FIG. 5 is an enlarged vertical sectional view showing a compression mechanism portion of the rotary compressor in FIG.

[Explanation of symbols]

 1 Electric Motor Section 2 Compression Mechanism Section 5 Crankshaft 6 Cylinder 7 Rolling Piston 7a Face Face of Rolling Piston with Main Bearing 7b Face Face of Rolling Piston with Secondary Bearing 7c Face of Surface Treatment Layer 7a Face 7d Face Face Surface of surface treatment layer on surface 7b 8 Vane 9 Main bearing 10 Secondary bearing 11 Closed container 14 Cylinder chamber space 14a Suction chamber 14b Compression chamber 15 Surface treatment layer

Claims (3)

[Claims] 1. A rolling piston in which an electric motor section and a compression mechanism section are connected and housed in a closed container by a crankshaft, and an eccentric section of the crankshaft is fitted in a cylinder chamber in the compression mechanism section, A rotary compressor in which the eccentric rotation of the eccentric portion accompanying the rotation of the crankshaft causes the refrigerant gas to revolve and compress the refrigerant gas, and the main bearing and the auxiliary bearing that support the crankshaft seal the cylinder chamber. A rotary compressor characterized in that at least one of the main bearing and the sub bearing of the rolling piston facing each other is surface-treated. 2. The rotary compressor according to claim 1, wherein a clearance between the rolling piston and the main bearing and the sub bearing is set to be smaller than that when the facing surface is not surface-treated. 3. The rotary compressor according to claim 1, wherein the surface treatment is a phosphate coating treatment which is excellent in load resistance, lubricating oil retention characteristics and initial acclimatization characteristics.