JPH05126076A - Compressor - Google Patents

Abstract

PURPOSE:To improve the adhesiveness of lubricating oil to a vane so as to prevent abnormal abrasion due to shortage or coagulation or the like of oil, by providing a hydrophilic film of specified contact angle to water on sliding faces, for a vane sliding contacted to the outer periphery of a rotor while sliding on a groove of a cylinder. CONSTITUTION:When a shaft 9 is rotated with a motor consisting of a stator 7 and a rotor 8, a roller 10 is rotated eccentrically to compress a gas consisting of refrigerant 1.1.1.2 tetrafluoroethane introduced in a cylinder 11 through an intake tube 14. By pumping action of spiral grooves 9a on the outer periphery of the shaft 9, lubricating oil 16 consisting of glycol based oil or ester based oil stored in the bottom of a hermetic shell 6 is supplied to portions to be lubricated through an oil intake tube 17. Where, on sliding faces 1 of a vane 18 sliding contacted to the outer periphery of the roller 10 while sliding on the groove of the cylinder 11, a hydrophilic film 2 of less than 30 degree in contact angle to water is produced. Thereby the adhesiveness of the lubricating oil 16 to the vane 18 can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor used for a refrigerating machine, an air conditioner and the like, and a sliding material therefor.

[0002]

2. Description of the Related Art In recent years, chlorofluorocarbons (hereinafter referred to as C
Environmental problems such as ozone depletion and global warming due to the effects of FC) are drawing attention. From such a point of view, reducing the amount of CFC used as a refrigerant has become an extremely important theme. Conventionally, the completely halogenated carbon compounds that have been used as CFCs contain at least one hydrogen.
Substitution to halogenated carbon compounds containing more than one is being sought.

More specifically, dichlorodifluoromethane (hereinafter referred to as R12) which is a typical CFC refrigerant.
Is being investigated for the change to 1,1,1,2 tetrafluoroethane (hereinafter referred to as R134a), which is a halogenated carbon compound containing two hydrogens, which has little effect on ozone destruction.

However, various problems occur when R134a is applied. For example, D issued in October 1978
uDisc Research Disclosu
According to the description of re, R134a is poorly compatible with any conventional oil and causes two-layer separation in all temperature ranges, and dissolves only in glycol-based oil. However, since glycol-based oil has poor electrical insulation, it is difficult to apply it to a hermetic compressor such as a compressor for a refrigerator having a built-in motor unit.

Therefore, studies have been conducted mainly on ester oils since then. For example, in US Pat. No. 4,851,144, a mixture of ester oil and glycol oil is R13.
It has been shown to dissolve in 4a. In recent studies, even ester-based oils alone have been found to dissolve in R134a, and their application studies are being promoted. For example,
Pude CFC Conference 1990 7
It is reported in Proceedings p. 190-195 held in March. Further, in order to improve the hydrolysis characteristics, which has been a problem with ester-based oils, new types of ester-based oils having a carbonate structure in which only carbon dioxide is generated even when hydrolyzed are being proposed.

A conventional refrigerant R will now be described with reference to the drawings.
An example of the compressor for 12 and its sliding material will be described. FIG. 9 shows a sectional view of a conventional compressor. 5 is a compressor. Reference numeral 6 is a closed shell, 7 is a stator shrunk in the closed shell 6, 8 is a rotor that constitutes a motor with the stator 7, and 9 is a shaft shrunk in the rotor 8.
10 is a roller incorporated in the eccentric part of the shaft 9,
Reference numeral 11 is a cylinder for accommodating the roller 10, 12 is a main bearing of the shaft 9, 13 is a sub bearing of the shaft 9, and 14 is a suction pipe press-fitted into the sub bearing 13 and welded to the closed shell 6. FIG. 10 is a sectional view taken along line BB of FIG.
Is housed in the groove of the cylinder 11 and the groove 11 of the cylinder 11
It slides on a and its tip is in sliding contact with the outer periphery of the roller 10.

Next, the operation will be described. A shaft 9 is rotated by a motor composed of the stator 7 and the rotor 8, and the roller 10 is eccentrically rotated accordingly, so that the refrigerant gas R12 introduced into the cylinder 11 through the suction pipe 14 is compressed. Further, as the shaft 9 rotates, the spiral groove 9 formed on the outer periphery of the shaft 9
Due to the pump effect of a, the lubricating oil (naphthenic mineral oil) 19 at the bottom of the closed shell 6 passes through the oil supply pipe 17 and the shaft 9,
It is supplied to the main bearing 12 and the sub bearing 13, and further supplied to the entire machine section through the clearances of the respective sections.

The naphthenic mineral oil used as the lubricating oil 19 has a viscosity at 40 ° C. of about 50 mPa · s.

The sliding materials used in the conventional compressor are as follows. Vane 15 has Rockwell C hardness
High-speed tool steel with a scale of 55 to 65, roller 10 is cast iron with a hardness of Rockwell C of 45 to 55, shaft 9, main bearing 12, sub bearing 13, cylinder 11 is cast iron with a hardness of Vickers and 160 to 250 More formed.

FIG. 8 is a sectional view of the conventional vane 15.
20 is a sliding surface of the vane 15 that slides with the cylinder 11, 2
Reference numeral 1 is a base material of the vane 15 made of high speed tool steel, 22 is a carbide particle contained in the base material 21, and 23 is a matrix alloy of the base material 21. With this configuration, the carbide particles 22 exposed on the sliding surface 20 support the load, and the matrix alloy 23
It is intended to prevent abrasion and seizure.

[0011]

However, the above-mentioned structure is considered on the premise of the conventional refrigerant R12 and naphthenic mineral oil, and when the refrigerant R134a and glycol-based oil or ester-based oil are used, The problem like this occurs.

Generally, glycol-based oils and ester-based oils are
Compared with naphthenic mineral oil, it has a higher viscosity index and less increase in viscosity at low temperature. Therefore, in order to adjust the oil viscosity at high temperature during the operation of the compressor to the same value, it is necessary to use a glycol-based oil or ester-based oil having a lower viscosity grade than the naphthene-based mineral oil.

Therefore, when glycol-based oil or ester-based oil is used, the oil retaining property is deteriorated when the compressor is stopped or when the refrigerant is backed up in the initial stage of the operation, and the oil flows out from the sliding portion between the vane and the groove of the cylinder. Run out of oil. Then, the metals forming the sliding surface come into contact with each other to cause considerable wear, which reduces the durability of the compressor.

Further, against such oil shortage, even in the conventional steel material containing carbide particles, the matrix alloy and the mating material are easily seized, so that it is impossible to prevent the sliding portion from being significantly worn.

Therefore, a compressor specification in which abrasion due to such oil shortage is unlikely to occur has been desired. In view of the above problems, the present invention proposes a sliding material specification for a compressor that uses a refrigerant R134a to suppress wear of a sliding portion of a cylinder groove and a vane, and improves durability of the compressor. ..

[0016]

In order to solve the above problems, a compressor of the present invention comprises a shaft, a bearing, a roller, a cylinder and a vane as constituent elements of the compressor, and the surface of the vane is made of sodium silicate. A hydrophilic film formed of water glass containing as a main component and having a water contact angle of 30 degrees or less is formed.

Further, the compressor of the present invention comprises a shaft, a bearing, a roller, a cylinder and a vane as constituent elements of the compressor, and the surface of the vane is made of water containing iron oxide containing iron trioxide as a main component. A hydrophilic film having a contact angle of 30 degrees or less is formed.

Further, the compressor of the present invention comprises a shaft, a bearing, a roller, a cylinder and a vane as constituent elements of the compressor, and the surface of the vane is composed of water containing a phosphate containing manganese phosphate as a main component. A hydrophilic film having a contact angle of 30 degrees or less is formed.

[0019]

The present invention has the above-described structure to enhance the adsorption of the glycol-based oil or the ester-based oil to the vane and prevent the oil retained in the clearance between the vane and the groove of the cylinder from running out. As a result, The durability of the compressor is improved by suppressing damage to the bearing portion due to abnormal wear such as adhesion.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a sectional view of a compressor which is an embodiment of the present invention. 5 is a compressor. Reference numeral 6 is a closed shell, 7 is a stator shrink-fitted in the closed shell 6, 8 is a rotor which constitutes a motor together with the stator 7, and 9 is a shaft shrink-fitted in the rotor 8. Further, 10 is a roller incorporated in the eccentric portion of the shaft 9, 11 is a cylinder for housing the roller 10, 12 is a main bearing of the shaft 9, 13 is the shaft 9
The auxiliary bearing 14 is a suction pipe press-fitted into the auxiliary bearing 13 and welded to the closed shell 6. FIG. 3 is a sectional view taken along the line AA of FIG. 2, in which the vane 18 is housed in the groove of the cylinder 11 and slides with the groove 11a of the cylinder 11, and its tip portion is in sliding contact with the outer peripheral portion of the roller 10.

Next, the operation will be described. The shaft constituted by the motor constituted by the stator 7 and the rotor 8 rotates, and the roller 10 eccentrically rotates accordingly, whereby the refrigerant gas R134a introduced into the cylinder 11 through the suction pipe 14 is compressed. Further, the rotation of the shaft 9 causes the pumping effect of the spiral groove 9 a formed on the outer periphery of the shaft 9 to cause the lubricating oil (ester-based oil) 16 at the bottom of the hermetic shell 6 to pass through the oil supply pipe 17 and pass through the shaft 9.
It is supplied to the journal bearing portion constituted by the sub bearing 13, the roller 10 and the main bearing 12, and further supplied to the entire machine portion through the clearance of each portion.

The ester oil used as the lubricating oil 16 has a viscosity at 40 ° C. of about 20 mPa · s in order to match the viscosity during operation of the compressor with that of a conventional naphthene-based mineral oil.
And adjusted to about 40% of naphthenic mineral oil.

The vane 18 is precision-finished from a high-speed tool steel having a hardness of 55-65 on the Rockwell C scale, which is the same as the conventional vane, and is then precision-finished, and then an aqueous solution of silica sand and sodium carbonate is applied and heated. It is cured to form a water glass film 2 containing sodium silicate as a main component on the surface thereof. The roller 10 has a hardness of 45 to 55 on the Rockwell C scale, the cast iron, the shaft 9 and the main bearing 1.
2, the auxiliary bearing 13 and the cylinder 11 have Vickers hardness of 1
It is made of cast iron of 60 to 250.

FIG. 1 shows a sectional view of the vane of the present invention. 1
Is a sliding surface of the vane 18 that slides with the groove 11a of the cylinder 11, 2 is a hydrophilic film of water glass having a thickness of about 0.5 μm, which is applied to the sliding surface 1, and 3 is an adsorption film on the hydrophilic film 2. It is a lubricating oil. The water contact angle of the film 2 is about 15 degrees. The water contact angle is obtained by measuring the contact angle between the sliding surface 1 having a surface roughness Rz of about 0.5 μm and a water drop at room temperature in the atmosphere. It can be said that the smaller the numerical value of the water contact angle, the easier the wetting of the sliding surface 1, that is, the higher the adsorptivity of water to the sliding surface 1.

The characteristics of the lubricating oil 4 applied to the R134a compressor will be described below. R13
The glycol-based oil or ester-based oil applied as the lubricating oil 4 of the compressor for 4a uses R13 by utilizing a hydrogen bond.
In order to enhance the compatibility with 4a, the oil itself has an oxygen-containing hydrophilic group such as an ether group or an ester group in its molecular structure. Therefore, it is considered that the lubricating oil 4 adsorbs a hydrophilic group such as an ether group or an ester group toward the sliding surface 2, and this point is a characteristic regarding the adsorbability of the lubricating oil 4 applied to the compressor for R134a. Is becoming Therefore, it is considered that the hydrophilicity of the sliding surface 1, that is, the water contact angle of the sliding surface 1 is reduced to improve the adsorption of the lubricating oil 4 to the sliding surface 1.

With this construction, the affinity between the sliding surface 1 and the lubricating oil 4 made of ester-based oil is increased, and the lubricating oil 3a is adsorbed to the sliding surface 1a even when the compressor is stopped and the oil supply is stopped. The purpose is to prevent running out of oil when the compressor is started. Therefore, vane 1 due to repeated shutdowns
8 and the groove 11a of the cylinder can be prevented from being damaged, and the durability of the compressor can be improved without causing abnormal wear such as adhesion.

As described above, according to the present embodiment, the vane having the hydrophilic film formed on its surface is effective in preventing wear under the condition that oil shortage is likely to occur when the compressor is stopped.

In this embodiment, the material of the vane is a high speed tool steel having a hardness of 55 to 65 on the Rockwell C scale, but if the material is steel, iron-based sintered material or cast iron, water is similarly used. A hydrophilic film of glass can be formed and the same effect can be expected.

Further, the water contact angle of the hydrophilic film of the water glass of this embodiment is about 15 degrees, but it may be smaller than the normal water contact angle of cast iron material or steel material of 50 to 60 degrees, Particularly, 30 degrees or less is excellent.

Next, the refrigerant R1 according to the second embodiment of the present invention
A compressor to which 34a is applied will be described with reference to the drawings. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 5 shows a sectional view of the compressor of the second embodiment of the present invention. The vane 18a is made of high-speed tool steel with a hardness of 55 to 65 on the Rockwell C scale, which has the same hardness as the conventional vane, and is precision-finished. The iron oxide film 2a having a thickness of 2 μm and containing as a main component is produced. Further, the cylinder 11 has a Vickers hardness of 160 to
It is made of 250 cast iron.

FIG. 4 shows a sectional view of the vane of the present invention. 1
a is a sliding surface of a vane 18a that slides with the groove 11a of the cylinder 11, 2a is a hydrophilic film of iron oxide having a thickness of about 2 μm applied to the sliding surface 1a, and 3a is absorbed by the hydrophilic film 2a. It is a lubricating oil. And the film 2a made of this iron oxide
In addition to the hydrophilic nature of the coating, the surface of the coating has fine irregularities in the process of forming the coating, which further enhances the hydrophilicity.
As a result, the water contact angle of the film 2a becomes about 15 degrees.

With this structure, the affinity between the sliding surface 1a and the lubricating oil 4 is increased in the same manner as in the first embodiment, and the lubricating oil 3 is applied to the sliding surface 1a even when the compressor is stopped and oil supply is interrupted.
By adsorbing a, the oil is prevented from running out when the compressor is started. Therefore, damage to the sliding portion between the vane 18a and the groove 11a of the cylinder due to repeated operation stop is suppressed, and the durability of the compressor can be improved without causing abnormal wear such as adhesion.

Since the iron oxide film is more resistant to strong acid than the water glass film, the temperature becomes high during the compression process and the refrigerant R13
Even under severe conditions in which 4a is decomposed and hydrofluoric acid is generated, its characteristics can be maintained.

As described above, according to the present embodiment, the vane having the hydrophilic coating of iron oxide formed on its surface is effective for preventing wear under the condition that oil is easily out when the compressor is stopped. In addition, the characteristics can be maintained even under the condition that a strong acid that is a refrigerant decomposition product is generated.

In this embodiment, the vane material is a high-speed tool steel having a hardness of 55 to 65 on the Rockwell C scale, but if the material is steel, iron-based sintered material or cast iron, it is similarly oxidized. A hydrophilic iron film can be formed and the same effect can be expected.

The water contact angle of the hydrophilic coating of iron oxide of this embodiment is about 15 degrees, but it is sufficient if it is smaller than the normal water contact angle of cast iron material or steel material of 50 to 60 degrees. Particularly, 30 degrees or less is excellent.

Next, the refrigerant R1 according to the third embodiment of the present invention.
A compressor to which 34a is applied will be described with reference to the drawings. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 7 is a sectional view of a compressor according to the third embodiment of the present invention. The vane 18b is made of high-speed tool steel with the same hardness as that of the conventional Rockwell C scale of 55 to 65, and is subjected to precision finishing. A phosphate coating 2b having a thickness of 2 μm as a component is produced. The cylinder 11 is made of cast iron having a Vickers hardness of 160 to 250.

FIG. 6 shows a sectional view of the vane of the present invention. 1
Reference numeral b denotes a sliding surface of a vane 18b which slides in the groove 11a of the cylinder 11, 2b denotes a hydrophilic coating of manganese phosphate having a thickness of about 2 μm, which is applied to the sliding surface 1b, and 3b adsorbs to the hydrophilic coating 2b. It is a lubricating oil. Further, the coating film 2b made of the phosphate is hydrophilic in itself, and becomes a surface having fine irregularities in the process of forming the coating film, so that the hydrophilicity is further enhanced. As a result, the water contact angle of the film 2b becomes about 15 degrees.

With this configuration, the affinity between the sliding surface 1a and the lubricating oil 4 is increased in the same manner as in the first and second embodiments, and the sliding surface is even when the compressor is stopped when oil supply is interrupted. By adsorbing the lubricating oil 3a to 1a, the oil is prevented from running out when the compressor is started. Therefore, damage to the sliding portion between the vane 18b and the groove 11a of the cylinder due to repeated operation stoppages can be suppressed, and the durability of the compressor can be improved without causing abnormal wear such as adhesion.

Further, the manganese phosphate film 2b is superior in adhesion to the base material of the vane 18 and abrasion resistance of the film itself, as compared with the water glass film 2 and the iron oxide film 2a, so that the film itself slides. Vane 18 and cylinder groove 11a with severe conditions
In the sliding portion, the damage of the film is suppressed and the hydrophilic property can be maintained for a long time.

As described above, according to this embodiment, the vane having the hydrophilic coating of manganese phosphate formed on its surface is effective for preventing wear under the condition that oil is easily run out when the compressor is stopped. In addition, the characteristics can be maintained for a long time and the durability of the compressor can be improved.

In this embodiment, the vane material is a high-speed tool steel having a hardness of 55 to 65 on the Rockwell C scale, but if the material is steel, iron-based sintered material or cast iron, phosphorus is similarly used. A hydrophilic film of manganese acid can be formed and the same effect can be expected.

Although a hydrophilic coating of manganese phosphate was used in this embodiment, the same effect can be expected because a phosphate coating of zinc phosphate or the like shows similar hydrophilicity.

The water contact angle of the hydrophilic coating film of manganese phosphate of this embodiment is about 15 degrees, but it may be smaller than the normal water contact angle of cast iron material or steel material of 50 to 60 degrees. Especially, 30 degrees or less is excellent.

[0048]

As described above, according to the present embodiment, the gas to be compressed is the refrigerant R134a, the lubricating oil is the ester oil, and the shaft, the bearing, the roller, the cylinder, and the vane are the constituent elements of the compressor. In a compressor, by using a vane with a hydrophilic film formed on its surface,
Even under severe conditions against oil shortage such as when the compressor is stopped or when liquid is backed up, abrasion and seizure of the sliding portion between the vane and the cylinder can be suppressed, and the durability of the compressor is improved.

In this example, the effect of using the ester synthetic oil as the lubricating oil was explained. However, since the glycol oil also shows the similar adsorption property as described above, almost the same effect is obtained. can get.

Although a hydrophilic coating having a thickness of 0.5 to 2 μm is used in this embodiment, if the water contact angle is 30 degrees or less, the effect can be expected regardless of the thickness of the coating and the type of coating. However, it is considered that water glass, iron oxide, and phosphate coatings are superior in terms of dimensional accuracy and heat resistance and chemical resistance to refrigerants and lubricating oils that should be taken into consideration when applied to sliding materials for compressors.

[Brief description of drawings]

FIG. 1 is a sectional view of a vane according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the compressor according to the first embodiment of the present invention.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view of a vane according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a compressor according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a vane according to a third embodiment of the present invention.

FIG. 7 is a sectional view of a compressor according to a third embodiment of the present invention.

FIG. 8 is a sectional view of a vane in a conventional example.

FIG. 9 is a sectional view of a compressor in a conventional example.

10 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 18 vanes 2 Hydrophilic coating of water glass

Claims (4)

[Claims] 1. A compressed gas composed of refrigerants 1, 1, 1, and 2 tetrafluoroethane, a lubricating oil composed of glycol oil or ester oil, a shaft as a constituent element of a compressor, and supporting the shaft. A bearing, a roller attached to an eccentric part of the shaft, a cylinder for housing the roller, a vane housed in a groove of the cylinder and having a tip portion slidingly contacting the outer circumference of the roller, and the vane. A hydrophilic film having a water contact angle of 30 degrees or less formed on the surface of the compressor. 2. The compressor according to claim 1, wherein the hydrophilic film is a water glass film containing sodium silicate as a main component. 3. The compressor according to claim 1, wherein the hydrophilic film is an iron oxide film containing triiron tetraoxide as a main component. 4. The compressor according to claim 1, wherein the hydrophilic film is a phosphate film containing manganese phosphate as a main component.