JP2010255481A - Rotary compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problems: since an HFC-based refrigerant as the substitute refrigerant of an HCFC-based refrigerant conventionally used in a compressor causes the inside of the compressor to become high in pressure during operation in comparison with the HCFC-based refrigerant and is inferior in oil lubricity, seizure and galling occur between a shaft and the end of an oil groove in the vicinity of a compression mechanism part, in particular, the end surfaces of a main bearing and a sub bearing on the side of a compression chamber. <P>SOLUTION: In this rotary compressor, a notch is formed in an angle position where a bearing load is maximized during one rotation of the shaft in the portion of the shaft sliding with the inner periphery of the main bearing and the inner periphery of the sub bearing. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotary compressor used in an air conditioner or the like, and more particularly to a rotary compressor that improves the reliability of a compression mechanism.

  Generally, a rotary compressor is known as a compressor used for an air conditioner, a refrigerator, or the like. The rotary compressor stores oil in an electric motor part and a compression mechanism part connected to the electric motor part and a bottom part in a sealed container, and the compression mechanism part partitions the plurality of cylindrical cylinders and the plurality of cylinders. A partition plate, a main bearing and a sub-bearing that constitute a compression chamber on both end faces of the plurality of cylindrical cylinders, a piston that revolves in the compression chamber, a shaft that is coupled to the electric motor that revolves the piston, and the shaft It consists of a vane that further divides the cylindrical inner peripheral surface of a plurality of cylinders into a plurality of sealed spaces, and an oil groove is generally provided in the inner periphery of the main bearing and the sub-bearing to supply oil to the inner periphery of the bearing. (For example, refer to Patent Document 1). This oil groove is generally provided at an angular position where the bearing load is greatest during one rotation of the shaft.

Japanese Utility Model Publication No.59-152189

  HCFC-based refrigerants that have been used for compressors in the past are said to contain chlorine and destroy the ozone layer, and the use of the HCFC-based refrigerants has been moving forward because it has an adverse effect on the global environment. As an alternative refrigerant, an HFC refrigerant not containing chlorine, for example, R-32, R-134a, and the like can be given. However, the HFC refrigerant has a higher pressure in the compressor during operation than the HCFC refrigerant, and is inferior in oil lubricity. Problems such as seizure and galling occurred between the end and the shaft.

  The present invention solves the above-described problems, and provides a rotary compressor capable of improving the reliability of the compression mechanism by providing an end of the oil groove on the shaft and a notch to avoid seizure and galling. The purpose is to do.

  In order to achieve the above-mentioned object, the present invention stores an oil in an electric motor part and a compression mechanism part connected to the electric motor part and a bottom part in a sealed container. The compression mechanism part includes a plurality of cylindrical cylinders and a plurality of cylinders. An intermediate partition plate that partitions the cylinder, a main bearing and a sub bearing that constitute a compression chamber on both end faces of the plurality of cylindrical cylinders, a piston that revolves in the compression chamber, and the electric motor that imparts a revolving motion to the piston, In a rotary compressor having as constituent elements a vane that divides a combined shaft and cylindrical inner peripheral surfaces of the plurality of cylinders into a plurality of sealed spaces, the shaft slides with an inner periphery of a main bearing and an inner periphery of a sub-bearing. A notch is made at an angular position where the bearing load becomes the largest during one rotation of the shaft.

  According to the present invention, the notch of the shaft and the oil groove ends of the main bearing and the sub-bearing are not in contact with each other, and no galling or seizure occurs, so that a highly reliable rotary compressor can be obtained.

Sectional view of a rotary compressor according to the present invention Positional relationship diagram of shaft and main bearing in Embodiment 1 of the present invention Explanatory drawing of the shaft in Embodiment 1 of this invention

  Embodiments of the present invention will be described below with reference to the drawings of FIGS. The rotary compressor in the embodiment of the present invention will be described by taking a two-stage rotary compressor as an example, but is not limited thereto, and can be applied to a one-stage rotary compressor or a multistage compressor having three or more stages. Needless to say.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a rotary compressor according to the present invention. Reference numeral 1 in FIG. 1 denotes a sealed container, in which an electric motor part and a compression mechanism part and a shaft 9 for transmitting the rotational force of the electric motor to the compression mechanism part are housed. An oil 16 is stored in the closed container 1 at the bottom. The electric motor unit includes a stator 14 and a rotor 13. The compression mechanism includes two cylindrical cylinders 5 and 7, an intermediate partition plate 6 that partitions the cylinders 5 and 7, a main bearing 4 that constitutes a compression chamber on both end surfaces of the cylindrical cylinders 5 and 7, and a secondary bearing. 8, a piston 10 that revolves in the compression chamber, a shaft 9 that is coupled to the electric motor that revolves the piston 10, and an upper muffler chamber 2 that reduces noise caused by pulsation of gas discharged from the compressor section The lower muffler chamber 3 and the cylindrical inner peripheral surfaces of the plurality of cylinders 5 and 7 are further composed of a vane 11 that partitions the plurality of sealed spaces. In this configuration, it is the shaft that slides with the inner periphery of the main bearing and the inner periphery of the auxiliary bearing.

  FIG. 2 shows the positional relationship between the shaft and the main bearing in the first embodiment, and FIG. 3 shows the shaft in the first embodiment. An oil groove 17 is provided on the inner periphery of the main bearing. This oil groove is provided at an angular position where the bearing load becomes maximum during one rotation of the shaft. As shown in FIG. 3, by providing the notch 18 in the shaft at the angular position where the bearing load becomes the largest, the oil groove end portion and the shaft are not galled or seized, thereby improving the reliability. Note that this embodiment can also be applied to a secondary bearing by providing a notch corresponding to the position of the oil groove of the secondary bearing in the shaft.

(Embodiment 2)
The rotary compressor having this structure can be used for an HFC refrigerant not containing chlorine.

(Embodiment 3)
Furthermore, in recent years, compressors using natural refrigerants such as carbon dioxide, helium, and ammonia have been developed from the viewpoint of preventing global warming. The present invention can also be applied to a rotary compressor using such a natural refrigerant. In particular, since carbon dioxide has a higher pressure in the compression mechanism than HFC refrigerant, the present invention is more effective.

(Embodiment 4)
Furthermore, from the viewpoint of preventing global warming, it is possible to apply the present invention to a rotary compressor using a next-generation refrigerant HFO-1234yf having a low global warming coefficient or a mixed refrigerant thereof.

(Embodiment 5)
Normally, various types of oil are used in the compressor depending on the refrigerant used and the material used for the compression mechanism. The present invention relates to natural products or oils derived from natural products such as naphthenic oil, paraffin oil and alkylbenzene oil, which are mainly used in compressors, and synthetic oils such as polyether oils and polyol ester oils, or the above natural oils. It is also possible to apply to mixed oils of oils derived from products or natural products and synthetic oils.

(Embodiment 6)
In order to improve mechanical properties, various additives may be added to the oil. The present invention comprises a copper deactivator such as benzotriazole, a sulfur-based extreme pressure additive, a halogen-based extreme pressure additive, a phosphorus-based extreme pressure additive, an organometallic compound-based extreme pressure additive, and combinations thereof. It can also be applied to a rotary compressor containing an effective amount of an extreme pressure additive or the like.

  As described above, according to the rotary compressor of the present invention, by avoiding the discontinuity of the compression chamber side end surfaces of the main bearing and the sub bearing, the seizure with the piston end surface is avoided, and the reliability is improved. Since a high rotary compressor can be obtained, it can be applied not only to air conditioners, but also to heat pump applications such as dehumidifiers, dryers, and water heaters.

1 Airtight container
2 Upper muffler chamber 3 Lower muffler chamber 4 Main bearing 5 Upper cylinder 6 Intermediate partition plate 7 Lower cylinder 8 Sub bearing 9 Shaft 10 Piston 11 Vane 12 Oil pickup 13 Rotor 14 Stator 16 Oil 17 Oil groove 18 Shaft notch

Claims (6)

Oil is stored in the motor unit and a compression mechanism unit connected to the motor unit and a bottom part in the hermetic container, and the compression mechanism unit includes a plurality of cylindrical cylinders, an intermediate partition plate that partitions the cylinders, and the plurality of cylinders A main bearing and a sub-bearing that constitute a compression chamber on both end faces of the cylindrical cylinder, a piston that revolves in the compression chamber, a shaft that is coupled to the electric motor that revolves the piston, and a cylinder of the plurality of cylinders A rotary compressor having a vane that divides the inner peripheral surface into a plurality of sealed spaces as a component, and an oil groove is provided at an angular position where the bearing load is maximized on the inner periphery of the main bearing and the auxiliary bearing, A rotary compressor characterized in that the shaft has a notch in the axial direction at a portion sliding with the inner periphery of the main bearing and the inner periphery of the auxiliary bearing. The rotary compressor according to claim 1, wherein HFC or the like not containing chlorine is used as a refrigerant. The rotary compressor according to claim 1, wherein a natural refrigerant such as carbon dioxide, ammonia or helium is used as the refrigerant. The rotary compressor according to claim 1, wherein HFO-1234yf or a mixed refrigerant thereof is used as a refrigerant. Synthetic oils such as naphthenic oils, paraffinic oils, alkylbenzene oils and the like, and synthetic oils such as polyether oils and polyol ester oils, or oils derived from the natural products or natural products. The rotary compressor according to any one of claims 1 to 4, wherein a mixed oil of oil is used. The oil comprises a copper deactivator such as benzotriazole, a sulfur-based extreme pressure additive, a halogen-based extreme pressure additive, a phosphorus-based extreme pressure additive, an organometallic compound-based extreme pressure additive, and combinations thereof. The rotary compressor according to any one of claims 1 to 4, wherein an effective amount of other known additives such as an extreme pressure additive is blended.