JPH07145787A - Compressor - Google Patents

Abstract

PURPOSE:To improve the durability of a compressor by strengthening a vane tip portion by means of a complex hardening film consisting of a ceramic coating layer and a nitrification treatment layer underneath it, bringing this into slide contact with the outer periphery of a roller formed of high alloy steel or the like, and preventing the wear of both. CONSTITUTION:A compressor 1 compresses the gas in a cylinder 4 by rotating a roller 6 fitted to the eccentric portion of a shaft 2 to be subjected to motor rotation while the roller 6 is coming into contact with the inner periphery of a cylinder 4 and the tip of a vane 7. In this case, the roller 6 is formed of alloy steel whose surface hardness shows the value of HV800-2000 and which contains vanadium, chrome, molybdenum and tungsten, or carbon steel or the like on whose surface a nickel phosphorus compound plating layer containing carbonized silicon corpuscles is formed. Meanwhile, the vane 7 is made of a sintered material of an iron system or alloy steel containing chrome, and nitrification treatment is administered at the tip portion, and a chemical compound layer of iron, chrome and nitrogen is formed, and then formation is carried out by administering the ceramic coating of nitrified chrome on the tip portion surface alone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor used in a refrigerating machine, an air conditioner or the like.

[0002]

2. Description of the Related Art In recent years, the use conditions of compressors for refrigerating and refrigerating machines and air conditioners have become stricter as the performance and performance of the compressors have become higher, and it is desired to improve the durability.

On the other hand, due to refrigerants such as difluorodichloromethane (hereinafter referred to as R12) and difluorochloromethane (hereinafter referred to as R22) containing chlorine in the molecule, which have been conventionally used due to environmental problems such as ozone depletion, etc. A change to a chlorine-free refrigerant 1, 1, 1, 2 tetrafluoroethane (hereinafter referred to as R134a) is under consideration. However, R134a, which does not contain chlorine in its molecule, has poor lubrication performance and it is necessary to improve the characteristics of the sliding material of the compressor.

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. 5 shows a sectional view of a conventional compressor. 1 is a compressor. 2 is a shaft, 3 is a roller, 4 is a cylinder, and 5 is a vane. A roller 3 attached to an eccentric part of a shaft 2 rotated by a motor (not shown) is a cylinder 4
The gas in the cylinder 4 is compressed by rotating while contacting the inner circumference of the vane and the tip of the vane 5. At this time, the vane 5 is in the cylinder 4
Reciprocates in the groove.

In order to maintain the durability of the contact portion between the vane 5 and the roller 3 which is the most severe sliding condition among these sliding portions, the vane 5 is a high speed tool steel having hardness HV800 to 850, and the roller 3 Was formed of cast iron having a hardness of HV500 to 550. FIG. 6 shows a cross-sectional view of the vane. Figure 6
As shown in FIG. 5, the vane 5 is made of a homogeneous material with no difference in its tip and side surface. Further, the cylinder 4 is formed of cast iron having a hardness of HV160 to 250, which has low hardness and excellent workability.

[0006]

However, in the above sliding material specifications, the vane tip and the roller which is the mating material are increased due to the increase of the load accompanying the high performance of the compressor and the use of the refrigerant R134a having low lubricity. There was a problem that the durability of the compressor could not be maintained due to adhesion wear on the outer periphery.

Therefore, there has been a demand for a sliding material specification for a compressor which is compatible with an increase in load accompanying the performance improvement of the compressor and the use of the refrigerant R134a having low lubricity.

As a means for avoiding the adhesive wear of the tip of the vane, for example, Japanese Patent Laid-Open No. 59-128992 proposes a method of applying a ceramic coating to the tip of the vane. In particular, non-ferrous materials having such a high melting point are effective for avoiding adhesive wear, but the following problems have been difficult to apply to vanes.

When the entire vane or a part of the vane is formed of a ceramic material by a method such as thermal spraying, there is a problem that it is not suitable for mass production because it takes a lot of time to finish the ceramic part with precision. On the other hand, when a ceramic material is chemically vapor-deposited by a CVD method using an iron-based material as a base material, post-processing is unnecessary because the film thickness can be precisely controlled, but the hardness difference with the base material is large and the adhesion is poor. Therefore, there is a problem that cracks and peeling of the ceramic coating are likely to occur under the condition that a large load is locally applied such as the tip of the vane.

Further, since the ceramic coating of chromium nitride by the ion plating method has a high hardness of HV2000 or more, the coating itself has excellent wear resistance and is applied to the cutting tool bit, but it is applied to machine parts. In this case, the coating is too hard, which causes a problem of increasing wear of the mating material. In other words, even if the vane tip can be prevented from cohesive wear when ceramic coating is applied to the vane material of the compressor, the amount of wear on the outer circumference of the mating roller roller and the inner surface of the groove of the cylinder may increase. is expected.

In view of the above problems, the present invention avoids the adhesive wear of the vane and the roller with respect to the compressor having a severe load and the compressor using the refrigerant R134a, and the amount of wear of the vane, the roller and the cylinder. It proposes a sliding material specification that suppresses the above, and improves the durability of the compressor.

[0012]

In order to solve the above-mentioned problems, a compressor of the present invention comprises a shaft, a roller, a cylinder and a vane as constituent elements of the compressor, the roller being made of vanadium, chromium, molybdenum and tungsten. Is formed from an alloy steel containing 10 to 30% by weight in total, and the vane is subjected to a nitriding treatment to an alloy steel containing chromium or a base material made of an iron-based sintered material, and then a chromium nitride ceramic is provided only on the tip surface. It is coated.

The compressor of the present invention comprises a shaft, a roller, a cylinder and a vane as constituent elements of the compressor, and a nickel phosphorus composite plating layer containing 1 to 10% by weight of silicon carbide fine particles on the surface of the roller. And a vane is formed on the base material made of a chromium-containing alloy steel or an iron-based sintered material, and then a chromium nitride ceramic coating is applied only to the tip surface of the vane.

Further, the compressor of the present invention comprises a shaft, a roller, a cylinder and a vane as constituent elements of the compressor, an iron boride layer is formed on the surface of the roller, and the vane contains chromium. A base material made of alloy steel or an iron-based sintered material is subjected to a nitriding treatment, and then a chromium nitride ceramic coating is applied only to the surface of the tip portion.

[0015]

According to the present invention, the vane tip portion reinforced by the composite hardened coating consisting of the ceramic coating layer and the nitriding layer thereunder and the hardness of HV800 have the above-mentioned structure.
The wear of the vane and the roller is prevented by sliding the outer periphery of the roller formed of high alloy steel of 1000 to 1000 or the roller reinforced by the nickel phosphorus composite plating layer and the iron boride layer of which hardness is HV800 to 2000. It prevents and improves the durability of the compressor.

Further, according to the present invention, by applying the ceramic coating layer only to the tip portion of the vane, the side surface of the vane is a metal base material having a hardness of HV1000 or less or a nitriding layer and the side surface of the vane. The object is achieved while suppressing an increase in wear of the inner surface of the groove of the sliding cylinder.

[0017]

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

FIG. 1 is a sectional view of a compressor which is a first embodiment of the present invention. 1 is a compressor. 2 is a shaft, 6
Is a roller, 4 is a cylinder, and 7 is a vane. The roller 6 attached to the eccentric part of the shaft 2 rotated by a motor (not shown) rotates while contacting with the inner circumference of the cylinder 4 and the tip of the vane 7 to compress the gas in the cylinder 4. At this time, the vane 7 reciprocates in the groove of the cylinder 4.

FIG. 2 is a sectional view of the vane of this embodiment. The vane 7 was precision-finished by using a high-speed tool steel (JIS: SKH51) having a hardness of HV800 to 850 as a base material 7a, and then a compound layer 7c of iron, chromium, and nitrogen was formed on the outermost surface by a salt bath nitriding method to a thickness of about 2 μm. A nitrogen diffusion layer 7b having a thickness of about 30 μm is formed thereunder, and chromium nitride 7d is chemically vapor-deposited on the tip surface by an ion plating method to have a thickness of about 2 μm.

The roller 6 has a hardness of HV800-850.
The high-speed tool steel (JIS: SKH51) is used as a base material for precision finishing.

The cylinder 4 is made of cast iron having a hardness of HV160 to 250 which is low in hardness and excellent in workability.

In order to verify the effect of the above structure in a short time, a vane and roller wear test was carried out as follows.

A friction tester of the type in which the tip of a vane is pressed against the outer circumference of a rotating roller was used to evaluate the amount of wear and the state of the sliding surface. The sliding condition is a value close to the actual sliding condition of the vane and roller of the compressor, speed 2 m / s, load 1
00N was set, and polyalkylene glycol was used as the lubricating oil and R134a was used as the refrigerant gas. Here, about 1 cc of lubricating oil was applied to the sliding part between the vane and the roller before the test was started.
The refrigerant gas was dropped, and the test piece installation part of the friction tester was semi-sealed to continuously supply the refrigerant gas at atmospheric pressure.

The above-described high speed tool steel of the present embodiment was used as a base material, and a vane reinforced by a composite hardened film composed of a chromium nitride layer and a nitriding layer below the vane and a roller of the high speed tool steel of the present embodiment were used. As a result of the test, the chromium nitride layer at the tip of the vane and the outer circumference of the roller were good without any wear or damage to the sliding surface.

Further, as Comparative Example 1, a vane reinforced by a composite hardened film consisting of the high speed tool steel of the present embodiment as a base material and a chromium nitride layer and a nitriding layer thereunder, and a hardness of HV500 to As a result of testing the cast iron roller of 550, the chromium nitride layer at the tip of the vane was good without any wear or damage to the sliding surface, but significant scratches were generated on the outer circumference of the roller, and normal wear could be maintained. There wasn't.

In Comparative Example 2, a high speed tool steel was used as a base material and a compound layer of about 2 μm was formed by the same nitriding treatment as in this Example.
As a result of using a vane having a nitriding layer having a diffusion layer of about 30 μm and a roller made of the high-speed tool steel of this embodiment, abnormal wear such as adhesive wear did not occur, but nitriding of the vane tip was performed. The progress of wear of the treated layer is remarkable.

As Comparative Example 3, a vane having a chromium nitride layer of about 2 μm formed by high-speed tool steel as a base material by the same ion plating as in this example and a roller made of the high-speed tool steel of this example were used. As a result of the trial, the chromium nitride layer at the tip of the vane was abraded and partly peeled off.

Further, as Comparative Example 4, the vane formed only of the base material of the high speed tool steel and the roller made of the high speed tool steel of this example were tested, and the tendency of adhesion wear and the vane were recognized. The wear of the tip is remarkable.

Further, in Comparative Examples 2 to 4, the hardness H which has been conventionally used in place of the roller made of the high speed tool steel of this embodiment is used.
As a result of testing cast iron rollers of V500 to 550,
In all cases, significant adhesive wear occurred.

From the above results of the vane-roller friction test, it was confirmed that the nitriding treatment at the tip of the vane, the chromium nitride film and the roller made of high speed tool steel were effective in reducing adhesive wear, but the wear was completely suppressed. The combination of a vane reinforced by a composite hardened coating consisting of a chromium nitride layer and a nitriding layer under the high-speed tool steel of the present example as a base material and a roller of the high-speed tool steel of the present example is used. It turned out to be the most effective.

This is because the original properties of chromium nitride can be exhibited by forming a nitriding layer consisting of a compound layer and a diffusion layer having excellent adhesion to the base material and high hardness under the chromium nitride layer at the tip of the vane. And the synergistic effect of increasing the surface hardness of the roller to HV800 to 850 so as to withstand the attack of chromium nitride. Therefore, it is considered necessary to form the chromium nitride film only on the tip of the vane in order to suppress the wear of the groove of the cylinder that is in sliding contact with the side surface of the vane.

As described above, according to this embodiment, the vane reinforced by the composite hardened film consisting of the chromium nitride layer and the nitriding layer thereunder and the roller made of high speed tool steel are combined and applied to the compressor. As a result, the wear of the vane and the roller can be prevented and the durability of the compressor can be improved.

In this embodiment, the hardness is HV 800-85.
The roller was formed of high speed tool steel of 0, but in order to obtain the same effect, hardness HV80 in which vanadium, chromium, molybdenum and tungsten were added in a total amount of 10 to 30% by weight.
It is desirable to form the roller from 0-2000 alloy steel. If the addition amount is too small, the surface hardness of the outer circumference of the roller may be reduced and wear may progress, and if the addition amount is large, the workability of the roller may be reduced and a predetermined dimensional accuracy cannot be obtained.

Although the vane nitride layer is formed by the salt bath nitriding method in this embodiment, an ion nitriding method exhibiting similar wear characteristics and adhesiveness may be used instead of the salt bath nitriding method. The same effect can be obtained.

A second embodiment of the present invention will be described below 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. 3 shows a sectional view of a compressor which is a second embodiment of the present invention. Further, FIG. 2 shows a cross-sectional view of the vane of this embodiment. The vane 7 has a hardness HV8 as in the first embodiment.
After precision finishing using a high speed tool steel of 00 to 850 (JIS: SKH51) as a base material 7a, a compound layer 7c of iron, chromium and nitrogen is formed on the outermost surface by a salt bath nitriding method to about 2
.mu.m and a nitrogen diffusion layer 7b of about 30 .mu.m are formed thereunder,
Further, chromium nitride 7d is chemically vapor-deposited by about 2 μm on the surface of the tip portion by the CVD method.

The roller 8 is made of chrome molybdenum steel (J
(IS: SCM435) is used as a base material for precision finishing, and then a nickel phosphorus composite plating layer having 3 to 5% by weight of silicon carbide fine particles dispersed therein is formed on the entire surface by electroless plating to form a nickel phosphorus composite plating layer of about 10 μm and a temperature of about 400 ° C. The surface hardness was adjusted to HV1000 to 1100 by heat treatment for a period of time.

With this structure, in the same manner as in the first embodiment, a nitriding layer composed of a compound layer and a diffusion layer having excellent adhesion to the base material and high hardness was formed under the chromium nitride layer at the tip of the vane. Thus, the original characteristics of chromium nitride can be exhibited, and by increasing the surface hardness of the roller to HV1000 to 1100, the abrasion resistance of chromium nitride can be endured and good wear characteristics can be obtained. Therefore, it is possible to prevent the adhesive wear between the vane and the roller and improve the durability of the compressor.

Further, since the base material of the roller on which the composite plating layer is formed does not need wear resistance, there is an advantage that it is inexpensive carbon steel and can be easily processed.

As described above, according to this embodiment, the vane reinforced by the composite hardened film consisting of the chromium nitride layer and the nitriding layer thereunder and the roller having the composite plating layer are combined and applied to the compressor. As a result, the wear of the vane and the roller can be prevented and the durability of the compressor can be improved at a relatively low cost.

In this embodiment, the nickel phosphorus composite plating layer in which the silicon carbide fine particles are dispersed in the amount of 3 to 5% by weight is formed on the surface of the roller.
Similar effects can be obtained even when dispersed by weight. If the content of the silicon carbide fine particles is less than 1% by weight, the wear resistance is reduced. Further, when 10% by weight or more of silicon carbide fine particles are dispersed, the uniformity and surface roughness of the film deteriorate.

Although the vane nitride layer is formed by the salt bath nitriding method in this embodiment, an ion nitriding method exhibiting similar wear characteristics and adhesiveness may be used instead of the salt bath nitriding method. The same effect can be obtained.

A third embodiment of the present invention will be described below 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. 4 shows a sectional view of a compressor which is a third embodiment of the present invention. Further, FIG. 2 shows a cross-sectional view of the vane of this embodiment. The vane 7 has a hardness HV8 as in the first embodiment.
After precision finishing using a high speed tool steel of 00 to 850 (JIS: SKH51) as a base material 7a, a compound layer 7c of iron, chromium and nitrogen is formed on the outermost surface by a salt bath nitriding method to about 2
.mu.m and a nitrogen diffusion layer 7b of about 30 .mu.m are formed thereunder,
Further, chromium nitride 7d is chemically vapor-deposited by about 2 μm on the surface of the tip portion by the CVD method.

The roller 9 is made of chromium molybdenum steel (J
(IS: SCM435) is used as a base material for precision finishing, and then a boronizing treatment by a powder method is performed at 800 to 900 ° C. to form an iron boride layer of about 50 μm on the entire surface, and the surface is polished by 15 μm to obtain dimensional accuracy. It was done. The hardness of the iron boride layer of the roller is HV1.
It is 500-1700.

With this structure, in the same manner as in the first embodiment, a nitriding layer composed of a compound layer and a diffusion layer having excellent adhesion to the base material and high hardness was formed under the chromium nitride layer at the tip of the vane. By virtue of this, the original characteristics of chromium nitride can be exhibited, and by increasing the surface hardness of the roller to HV 1500 to 1700, the abrasion resistance of chromium nitride can be endured and good wear characteristics can be obtained. Therefore, it is possible to prevent the adhesive wear between the vane and the roller and improve the durability of the compressor.

The iron boride layer is HV 1500-170.
In addition to having a high hardness of 0, it also has self-lubricating properties and does not seize even under dry friction conditions.
It is effective under a refrigerant such as 34a.

As described above, according to this embodiment, the vane reinforced by the composite hardened film consisting of the chromium nitride layer and the nitriding layer thereunder and the roller formed with the iron boride layer are combined and applied to the compressor. By doing so, it is possible to prevent cohesive wear of the vane and the roller and improve the durability of the compressor, especially under the condition of using a refrigerant such as R134a having poor lubricity.

In this embodiment, the iron boride layer was formed on the surface of the roller at 800 to 900 ° C. by the powder method.
You may use the molten salt method which can process at a low temperature of 700 degreeC or less.

Further, in this embodiment, the nitriding layer of the vane was formed by the salt bath nitriding method. However, instead of the salt bath nitriding method, an ion nitriding method exhibiting similar wear characteristics and adhesiveness may be used. The same effect can be obtained.

[0051]

As described above, according to the present embodiment, the vane tip portion reinforced by the composite hardened coating consisting of the ceramic coating layer and the nitriding layer thereunder, and the roller formed of the high alloy steel. Alternatively, by sliding the outer periphery of the roller reinforced with the nickel-phosphorus composite plating layer or the iron boride layer into contact with each other, abrasion of the vane and the roller is prevented and it is effective in improving the durability of the compressor.

In this embodiment, the hardness of the roller made of high alloy steel is HV800 to 850 and the hardness of the roller reinforced with the nickel-phosphorus composite plating layer is HV1000 to HV11.
00 Hardness of roller reinforced with iron boride layer is HV150
Although 0 to 1700 is set, the same effect can be obtained without damaging the ceramic coating layer in a range HV 800 to 2000 that does not exceed the hardness of the ceramic coating layer at the tip of the vane.

[Brief description of drawings]

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

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

FIG. 3 is a sectional view of a compressor according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a compressor according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a compressor in a conventional example.

FIG. 6 is a sectional view of a vane in a conventional example.

[Explanation of symbols]

 6 roller 7 vane 7c compound layer 7d ceramic coating layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takanori Ishida 3-22, Takaidahondori, Higashi-Osaka City, Osaka Prefecture Matsushita Refrigerating Machinery Co., Ltd.

Claims (4)

[Claims] 1. A shaft as a constituent element of a compressor, a roller attached to an eccentric part of the shaft, a cylinder for accommodating the roller piston, a groove accommodated in a groove of the cylinder, and a tip of the roller. The surface hardness of the roller is H.
V800-2000 and the vane is made of an alloy steel or an iron-based sintered material containing chromium, and at least the tip of the vane is subjected to nitriding treatment to form a compound layer of iron, chromium and nitrogen, and then the tip surface Compressor with chromium nitride ceramic coating only on. 2. The compressor according to claim 1, wherein the roller is made of an alloy steel containing vanadium, chromium, molybdenum, and tungsten in a total amount of 10 to 30% by weight. 3. The roller is made of carbon steel, and a nickel-phosphorus composite plating layer containing 1 to 10% by weight of silicon carbide fine particles is formed on the surface of the roller.
The described compressor. 4. The compressor according to claim 1, wherein the roller is made of carbon steel and an iron boride layer is formed on the surface of the roller.