JPH0544674A - Compressor - Google Patents

Abstract

PURPOSE:To improve the frictional resistance and durability by forming a slidable member from the sintered alloy in which the austenite structure of the iron group sintered alloy having a prescribed structure is reduced and the quantity of the iron oxide is set within a prescribed range. CONSTITUTION:Each roller 10a, 10b is formed from the sintered alloy which consists of 1-8wt.% Ni, 0.8-3wt.% Cr, 0.5-3wt.% Mo, at most 0.2wt.% Cu, 1-2.5wt.% C, and the rest Fe and has the area ratio of the austenite structure of the alloy of 5% and the content of the iron oxides is 5-10vol.%. While, each vane 11a, 11b is made of the alloy which consists of 3.9-4.4wt.% Cr, 4.9-20wt.% Mo, 5.6-6.5wt.% W, 0.5-2wt.% V, 0.8-2wt.% C, and the rest Fe and has the area ratio of the austenite structure of 5% or less. Accordingly, the stable frictional redistance and durability can be obtained even under the used condition of high temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor, and more particularly to a compressor having excellent wear resistance and seizure resistance under high temperature conditions and having excellent durability.

[0002]

2. Description of the Related Art In refrigerators, refrigerators, air conditioners and showcases, a compressor for compressing a refrigerant is equipped as a main device. As a compressor generally used in the above application examples, there is a hermetic rotary compressor as shown in FIGS. 1 and 2.

In this compressor 1, a motor 3a and a compression element 3b are installed inside a casing 2, and the compression element 3b inserts a rotary shaft 4 extending from the motor 3 into a main bearing 5 and a sub bearing 6. Two cylinders 8a and 8b are arranged between the main bearing 5 and the sub bearing 6 with a partition plate 7 interposed therebetween.
In a and 8b, cylindrical rollers 10a and 10b are fitted into eccentric portions 9a and 9b formed on the rotary shaft 4, respectively, while the rollers 10a and 10b are eccentrically rotated as shown in FIG. The vanes 11a and 11b are arranged so as to be constantly pressed against each other and come into contact with each other. The vanes 11a and 11b include the eccentric portions 9a and 9b and the roller 1.
It reciprocates according to the rotation of 0a and 10b, and each cylinder 8
It plays a role of partitioning the insides of a and 8b by pressure. Thus, the compressor 1 drives the motor 3 to drive the roller 1
By eccentrically rotating the cylinders 0a and 10b in the cylinders 8a and 8b, the gas sucked into the cylinders 8a and 8b is compressed and discharged.

In the compressor 1 as described above, wear is particularly remarkable in sliding portions such as the main and auxiliary bearings 5 and 6, the rotating shaft 4, the cylinder 8 and the vane 11, the partition plate 7 and the roller 10, which are in sliding contact with each other. Therefore, it is necessary to use a material having high wear resistance.

Conventionally, as a material of this kind, a high speed steel or a melting material of eutectic graphite cast iron, and more specifically 2.2S.
i-3.4C-FC200 material consisting of balance Fe, SMF
SMF-4 type material such as 4030 (iron-carbon-copper alloy)
A material having improved wear resistance is generally used. As a wear-resistant material constituting a roller that requires particularly high seizure resistance and wear resistance, Mo-Ni-Cr-Si is used.
-Fe alloy (monichrome cast iron) is widely used, SKH-51 is generally used as a vane material, and a cast material in which graphite is dispersed is generally used as a cylinder material.

[0006]

However, in recent years,
CFCs, which were commonly used as refrigerants for compressors such as refrigerators, refrigerators, and air conditioners, were found to be a cause of environmental damage, and the development of new refrigerants that replace CFCs has progressed. ing.

However, since the operating temperatures of all new refrigerants that are in the development stage up to the present time are significantly higher than those of conventional CFCs, various conventional compressors having sliding parts made of wear-resistant materials have various operating temperatures. It has been confirmed that the problem of occurs.

That is, the change of the refrigerant inevitably raises the operating environment temperature, so that the dimensions of the sliding members such as rollers change due to thermal expansion, and the minute clearance between the sliding members expands to compress the refrigerant. There is a problem that the efficiency is lowered and finally the cooling capacity is lowered.

Further, it has been confirmed that as the operating temperature rises, the hardness and wear resistance of the alloy composition of the sliding material are lowered due to the transformation of the alloy structure, and the performance of the compressor is reduced. There is.

The present invention has been made to solve the above-mentioned problems, and even when the operating temperature rises due to the change of the refrigerant, the dimensional change and the hardness decrease of the sliding material constituting the compressor are achieved. An object of the present invention is to provide a compressor that exhibits stable wear resistance and durability with little loss.

[0011]

In order to achieve the above-mentioned object, the inventors of the present invention have variously changed the alloy material constituting the sliding portion of the compressor and compared and examined the sliding characteristics. As a result of researching a method for preparing a material capable of forming a stable alloy structure even under high temperature use conditions of each alloy material, it is an iron-based sintered alloy having a predetermined structure, and reduces its austenite structure, Furthermore, when a sliding member was formed from a sintered alloy in which the amount of iron oxide was set in a predetermined range, a compressor having extremely stable wear resistance and durability even under high temperature use conditions was obtained. The present invention has been completed based on the above findings.

That is, the compressor according to the present invention is a compressor provided with a roller that makes an eccentric rotary motion by sliding contact with the inner surface of a casting cylinder, and a vane material that comes in and out of the cylinder in contact with the roller, wherein the roller is % By weight of Ni is 1 to 8%, Cr is 0.5 to 3%, Mo is 0.5 to 3%,
Cu is 0.2% or less, C is 1 to 2.5%, and the balance is Fe, and the area ratio of the austenite structure of the alloy is 5% or less and the content of iron oxide is% by volume. 5 to 10% by weight of the sintered alloy, while the vane material is 5% by weight of Cr, 3.9 to 4.4% of Cr, and 4.9% of Mo.
-20%, W 5.6-6.5%, V 0.5-2%,
It is characterized in that it is formed from an alloy having 0.8 to 2% C, the balance being Fe, and having an austenite structure area ratio of 5% or less.

Further, the density of the sintered alloy is 7.0 to 7.7 g.
It is recommended that the configuration be set in / cm ³ .

Further, the alloy constituting the vane material is a sintered body, and the content of iron oxide contained in this sintered body is expressed in volume%.
In the range of 5 to 18%, and the content of sulfur or nitrogen added to the sintered alloy constituting the vane material is% by weight.
It is also possible to further improve the sliding characteristics or the wear resistance by setting it in the range of 0.1 to 0.7%.

The reasons for limiting the composition of the roller material used in the compressor according to the present invention will be described below.

Ni is an element that suppresses seizure of the roller, and is added in an amount of 1 to 8 wt% (wt%). When the amount of Ni added is less than 1 wt%, the effect of imparting seizure resistance is small, while when the amount added exceeds 8 wt%, the proportion of the austenite structure remaining in the sintered alloy described later increases, Stability and hardness will decrease.

Cr is an element that improves the wear resistance of the roller, and is added in an amount of 0.5 to 3 wt%. If the amount of Cr added is less than 0.5 wt%, the effect of the addition is small, while if the amount added exceeds 3 wt%, the formability is impaired.

Mo is added in the range of 0.5 to 3 wt% in order to improve the wear resistance and sliding characteristics of the roller. If the Mo addition amount is less than 0.5 wt%, the effect of the addition decreases, while if the Mo addition amount exceeds 3 wt%,
Like Cr, it hinders formability.

Cu is an element that improves the initial sliding characteristics of the roller used as a sliding member, but is also an element that induces seizure. In particular, when the added amount exceeds 0.2 wt%, seizure is likely to occur, so the added amount is set to 0.2 wt% or less.

C is an element that reacts with Fe forming the sintered alloy matrix to form pearlite having wear resistance, and is dispersed as free graphite in the matrix to improve the lubricity of the sliding surface. To prevent galling of the roller as a sliding material and to improve the initial sliding characteristics, 1 to 2.5% by weight (wt.
%) Is added. When the amount of C added is less than 1%, the effect of improving the sliding characteristics is small, while when the amount added exceeds 2.5%, embrittlement occurs and the formability decreases, resulting in high density and high strength sintering. It's hard to get a body. The amount of free graphite dispersed in the matrix is preferably 30% or more of the total amount of C added.

It has been confirmed by experiments by the present inventors that the area ratio of the austenite structure of the sintered alloy is greatly related to the stability of the roller. That is, when the area ratio of the austenite structure of the sintered alloy exceeds 5%,
The thermal stability of the roller decreases, and the dimensional change of the roller increases under high temperature conditions. In particular, when the sliding member of the compressor is formed of this material, the clearance between the sliding members is increased, and it becomes difficult to maintain airtightness, and the volumetric efficiency of the refrigerant is likely to be lowered. On the other hand, by setting the area ratio to 5% or less, it is possible to obtain a material that is not easily affected by dimensional change and hardness decrease in the operating temperature range of 300 ° C. or less.

The area ratio of the austenite structure of the sintered alloy is adjusted by the temperature and time of the tempering treatment of the sintered alloy.

Further, iron oxide improves the retaining property (oil retaining property) of the lubricating oil filled in the compressor, and improves the airtightness and sliding property of the sintered alloy as described later, so that the sintered alloy is used. The volume is set to be 5 to 10%.

By the way, in recent years, a compressor is often operated under severe conditions such that its rotation speed largely changes due to inverter control. At the moment when the rotation speed suddenly increases, the lubricating state deteriorates and seizure occurs. The risk of causing is also high. However, the risk of seizure can be reduced by forming the sliding member from a sintered body that can be impregnated with lubricating oil like the material of the present application.

The wear resistant material for a compressor of the present invention which exhibits the above-mentioned various properties is manufactured by the following procedure. That is, first, a predetermined amount of the element powder and the lubricant is added to iron powder to form a mixed powder, and the obtained mixed powder is molded at a molding pressure of 600 to
After compressing at 700 MPa to form a molded body of a predetermined shape,
The obtained molded body is heated at a temperature of 500 to 700 ° C. for 1 to 1 in a reducing gas atmosphere such as hydrogen or a non-oxidizing gas atmosphere.
Degrease for 2 hours. Further, the degreased molded body is heated at a temperature of 1000 to 1 in a reduced pressure atmosphere or a reducing gas atmosphere.
After heating at 200 ° C. for 1.5 to 3 hours to form a sintered body, the sintered body is held at a temperature of 850 to 950 ° C. for 40 to 90 minutes, and then subjected to gas cooling for quenching treatment. Further, the sintered body which has been subjected to the quenching treatment is oxidized by steam treatment, and at the same time, a sealing treatment and a tempering treatment are carried out to obtain 5-10v.
While ol% iron oxide is dispersed in the alloy, the area ratio of the retained austenite structure is set to 5% or less.

Here, the density of the sintered alloy is 7.0 to 7.7 g.
A range of / cm ³ is preferred. If the density is less than 7.0 g / cm ³ , the structural strength and hardness of the sliding material as a part will be reduced, while if the density exceeds 7.7 g / cm ³ , the iron-oxidizing property of the lubricating oil will be excellent. The production amount of the product is reduced, so that the sliding property and the durability are both deteriorated.

Here, the steam treatment is performed at a temperature of 500 to 650.
The sintered body is held in superheated steam at a temperature of 0.03 to 0.1 MPa for 1 to 4 hours.

By this steam treatment, iron oxide is dispersed and generated in the pores of the matrix structure of the sintered alloy. The amount of iron oxide may be set to 5 to 10 vol% with respect to the total volume of the sintered body. This iron oxide not only improves the wear resistance of the sintered alloy, but also serves to seal the pores of the matrix structure of the sintered alloy (sealing action) to provide airtightness. By carrying out this sealing treatment, the refrigerant gas in the compressor can be prevented from passing through the sintered body, so that the volumetric efficiency of the compressor can be greatly improved. Iron oxide is also excellent in oil retaining property of lubricating oil. If the amount of iron oxide produced is less than 5 vol%, the above-mentioned effect is small. On the other hand, if the amount produced exceeds 10 vol%, the strength of the sintered body decreases. Further, the steam treatment causes the nitrogen content existing in the matrix structure of the sintered alloy to diffuse and form a solid solution in the particles of the matrix structure, greatly improving the embrittlement of the sintered body due to the presence of the nitrogen content. it can.

By heating under the conditions of the steam treatment, that is, at a temperature of 500 to 650 ° C. for 1 to 4 hours, the tempering treatment of the sintered body is carried out at the same time as the treatment for forming the oxide. By this tempering treatment, the amount of retained austenite in the sintered body can be adjusted to 5% or less, and it becomes possible to almost eliminate the dimensional change or hardness reduction rate of the material under a high temperature condition of about 300 ° C. ..

Next, the reasons for limiting the composition of the vane material that is in sliding contact with the roller having the above composition will be described below.

A portion of Cr is solid-dissolved in the matrix and a portion thereof becomes a carbide, which is effective in improving the hardness by improving the hardenability of the vane material, and is 3.9 to 4.4% by weight (wt%). Is added. When the Cr addition amount is less than 3.9 wt%, the hardenability improving effect is small, while when the addition amount exceeds 4.4 wt%, a remarkable effect cannot be obtained.

Similar to W, Mo is added in an amount of 4.9 to 20 wt% in order to improve the wear resistance of the vane material. When the amount of Mo added is less than 4.9 wt%, the effect of improving wear resistance is not recognized, while when added in excess to exceed 20 wt%, no significant effect is obtained.

In order to improve the wear resistance of the vane material by combining W with W to form a high hardness double carbide, W is in the range of 5.5 to 5.
6.5 wt% is added. When the amount of W added is less than 5.6 wt%, the effect of improving wear resistance is small, while when the amount added exceeds 6.5 wt%, the roller, which is the mating material, is worn.

V is 0.5 to 2 wt% in order to improve the wear resistance of the vane material by forming carbide with high hardness like W.
% Is added. If the amount of addition of V is less than 0.5 wt%, the wear resistance effect is small, and if the amount of addition of V exceeds 2 wt%, the wear of the roller as the mating material becomes remarkable.

C is added in an amount of 0.8 to 2 wt% in order to combine with Mo, Cr, W and V to form a hard compound and to improve the wear resistance strength of the vane material. C addition amount is 0.8
If it is less than wt%, a sufficient amount of double carbide is not formed, while if the amount added is more than 2 wt%, the strength of the vane material is lowered.

Any alloy having the above composition may be a molten material or a sintered body. The reason for limiting the area ratio of the austenite structure in the vane material and the content of iron oxide in the case where the vane material is formed of a sintered alloy,
The reason for limiting the density of the sintered alloy is the same as the reason for limiting the roller material.

The manufacturing method when the above vane material is formed of a molten material is as follows. That is, after ingoting an iron-based alloy ingot having the above composition, a cossing process for refining carbides is performed, and after forging, 8
Annealing is performed at a temperature of 00 to 880 ° C. Next, after cutting the annealed material into a predetermined vane shape,
Quenching at 0 ° C, then 2 at 560 ° C
By performing the tempering treatment once, a vane material having an area ratio of the retained austenite structure reduced by 5% is manufactured.

Further, the manufacturing method in the case of forming the vane material with a sintered alloy substantially conforms to the manufacturing method of the roller.

Further, in order to further improve the wear resistance and seizure resistance of the vane material formed of the sintered alloy, a sulfurizing treatment in which sulfur (S) or nitrogen (N) is diffused and permeated into the surface of the sintered body. Or nitriding is recommended.

That is, the sulfurization treatment is a method of diffusing and permeating sulfur into the surface of the sintered body. The surface layer becomes porous and the hardness does not increase so much, but the sulfur diffusion layer formed on the surface portion and the sintered body are sintered. Sulfides formed around the holes reduce sliding friction resistance and improve initial sliding properties, wear resistance and seizure resistance. The amount of sulfur added by the sulfur treatment is 0.1 to 0.
It is set in the range of 7 wt%. S addition amount is 0.1 wt%
If less than, while the effect of improving the initial sliding characteristics is small,
If the amount of S added exceeds 0.7 wt%, the strength of the vane material will decrease. Therefore, the sulfur content is set within the above range.

Further, the nitriding treatment is a treatment for diffusing and permeating nitrogen into the surface of the sintered body to form a hard nitriding layer. In the gas nitriding treatment which is generally carried out, the sintered body is usually heated in an ammonia gas stream at 450 ° C. Heat to ~ 600 ° C,
It is carried out by holding for 100 hours. Ammonia is decomposed by this heating, and part of it becomes nascent nitrogen and is adsorbed on the surface of the sintered body, producing nitride and nitrogen solid solution around the sintered pores, while passing through the porous part and into the inside. Diffuse, Cr,
The iron-based sintered body containing V and Mo is significantly hardened to significantly improve the wear resistance strength and the fatigue strength of the vane material.

The amount of nitrogen added by the above nitriding treatment is set in the range of 0.1 to 0.7 wt%. When the amount of N added is less than 0.1 wt%, the effects of improving the initial sliding characteristics and seizure resistance are not recognized, and 0.7 wt%
Since the addition of an excessive amount exceeding the above causes a decrease in the strength of the vane material, the content is set within the above range.

On the other hand, as a casting forming the cylinder,
Among all graphite dispersed in the base, ASTM standard A247
Size A or Type B specified in No. Three
To No. 5 or D type or E type, the size is No. 6 to No. It is preferable to use cast iron in which graphite having a shape and size of 8 is evenly distributed so that 70% or more of the entire graphite is occupied by the area ratio.

The reasons for limiting the shape and size of graphite in the cast iron and the amount of distribution thereof will be described below.

That is, the graphite shape is ASTM standard A247.
In case of A type and B type, the size is N
o. If it is larger than 3, or if it is the D type and the E type and the size is No. If it is larger than 6, the oil retaining property is excellent, but the graphite is coarse, the matrix structure tends to be coarse, and the matrix tends to be weak. Further, the edge portion of the graphite is easily broken by the sliding pressure and abnormal wear is caused. There are many cases that cause it. On the other hand, in the case of A type and B type, the size is No. When the size is less than 5, or in the case of D type and E type, the size is No. When it is less than 8, the oil pockets in graphite are too small and the oil retaining property is poor, and further, the self-lubricating property is low, so that the lubricating effect cannot be exhibited as a whole cylinder.

Next, of the graphite dispersed in the matrix even when A-type and B-type graphite are mixed, or when D-type and E-type are mixed,
When the area ratio of the graphite having the shape and size of the graphite is 70% or less of the whole graphite, it is impossible to sufficiently satisfy the lubricating effect based on the self-lubricating property and oil wettability of the graphite. In particular, it has been confirmed by experiments by the inventors that seizure is likely to occur at a portion in contact with the vane material when the cylinder is made of cast iron having a shape and size other than the above graphite shape and size. Therefore, the cast iron material having the above-mentioned properties is used as the casting material forming the cylinder.

The above cast iron contains, for example, Si of 1.5 to 4%,
Cooling rate 1 to 3 for C containing 2 to 5% of C and the balance of Fe
It is manufactured to have the above-mentioned properties by setting a large value of ° C / sec and promoting the precipitation of a predetermined flake graphite.

This cast iron has an excellent lubricating effect based on the self-lubricating property and oil wettability of graphite, and has excellent compatibility with the roller and vane material having the above composition.

[0049]

EXAMPLE An example of a compressor according to the present invention will now be described by taking a rotary compressor having a roller and a vane material as sliding members as an example and comparing it with a conventional example.

The rollers used in the compressors of Examples 1-5 were prepared as follows. That is, Fe powder having an average particle size of 70 μm, Fe powder having an average particle size of 10 μm, and average particle size of 70 μm
No. SUS410L powder, Ni powder having an average particle size of 10 μm, Mo powder having an average particle size of 10 μm and graphite powder are weighed in predetermined amounts, and finally, the respective powders are mixed so as to have the composition shown in the left column of Table 1. Then, 1 part by weight of a lubricant was added to 100 parts by weight of this mixed powder and mixed to prepare a uniform mixture of 5 kinds.

Next, each mixture is molded at a molding pressure of 600 to 700 MP.
By pressurizing with a, a molded product having an outer diameter of 33 mm, an inner diameter of 23 mm, a height of 15 mm and a molding density of 6.8 to 7.0 g / cm ³ was obtained. Then, each molded body was degreased by heating in a hydrogen gas atmosphere at a temperature of 600 ° C. for 2 hours.

Then, the degreased compacts were sintered in a depressurized hydrogen gas atmosphere at a temperature of 1100-1190 ° C. for 2 hours and gradually cooled. And 40-90 at a temperature of 850-950 ° C
After holding for a minute, gas cooling was performed to quench each sintered body, and as a result, a sintered body having a density of 7.2 to 7.5 g / cm ³ was obtained.

Next, each of the quenched and sintered sintered bodies was heated to a temperature of 500 to
2-3 in superheated steam at 650 ° C and pressure of 0.05 MPa
At the same time as the sealing treatment for forming Fe oxide by performing the steam treatment for holding for a time, the tempering treatment was performed. As a result, 5 to 8 vol% of iron oxide was dispersed, and ring-shaped rollers of Examples 1 to 5 in which the area ratio of the retained austenite structure was 2 to 4% were manufactured.

On the other hand, in order to make a comparison with the above-mentioned sintered alloy roller, as Comparative Example 1, a conventional material such as monichrome cast iron (Fe) was used.
-0.3Mo-0.3Ni-0.8Cr-2.2Si-
3.4C) A roller having the same dimensions as in Examples 1 to 5 was manufactured using the molten product.

Next, a vane material used in combination with each of the above rollers was prepared by the following procedure. That is, for the vane material (melting material) corresponding to the roller of Example 1, after ingoting the ingot having the composition shown in the right column of Table 1, in order to reduce the size of the carbide, after cosching and forging, the temperature was set to 800.
Annealing is performed at ~ 880 ℃, then 15mm in length x 2 in width
Cut into 0 mm x 3 mm thick plate shape, and then the temperature is 1210
It was prepared by quenching at 0 ° C. and tempering twice at a temperature of 560 °, and finally the area ratio of the retained austenite structure was set to 5%.

Vane materials (sintered bodies) corresponding to the rollers of Examples 2 to 5 were prepared by the following procedure. That is, 1% of a lubricant was added to an alloy powder having the composition shown in the right column of Table 1 to prepare a mixed powder, and the obtained mixed powder was molded at a molding pressure of 600 to
Pressurized at 700MPa, length 15mm, width 20mm, thickness 3
A molded product having a size of mm and a molding density of 6.5 to 6.6 g / cm ³ was obtained. Then, each molded body was degreased by heating in a hydrogen gas atmosphere at a temperature of 600 ° C. for 2 hours.

Next, the degreased molded bodies were sintered in a hydrogen gas atmosphere under reduced pressure at a temperature of 1190 to 1210 ° C. for 2 hours and gradually cooled. Then, after holding at a temperature of 1190 ° C. for 40 to 90 minutes, gas cooling was performed to quench each sintered body, and as a result, a sintered body having a density of 6.6 to 6.7 g / cm ³ was obtained.

Next, among the above-mentioned quench-treated sintered bodies, the sintered body for Example 3 was immersed in a sulfur solution, taken out, dried, and then heated at a temperature of 200 to 500 ° C. for 5 to 60 minutes to be baked. Sulfurization treatment was performed to generate sulfides around the pores of the aggregate.

On the other hand, the sintered bodies for Examples 4 to 5 were placed in an ammonia stream and held at a temperature of 550 to 600 ° C. for 30 to 60 minutes to form a nitride and a solid solution around the pores of the sintered body. Nitriding treatment was performed.

Then, Examples 2 to 5 treated as described above
The temperature of each sintered body is 500-650 ° C and the pressure is 0.05M.
A tempering treatment was carried out at the same time as a sealing treatment for forming Fe oxide by performing a steam treatment of holding in superheated steam of Pa for 1 to 4 hours. As a result, 13 vol%
The vane materials to be combined with the rollers of Examples 1 to 5 in which the iron oxides in Example 1 are dispersed and the area ratio of the retained austenite structure is 5% were manufactured.

On the other hand, in order to compare with the vane material made of the ingot or the sintered alloy, the conventional material SK as Comparative Example 1 is used.
H51 (Fe-4.1Cr-6.2W-1.1V-0.
9C-5.2Mo) melt product was used to manufacture vane materials having the same dimensions as the vane materials for Examples 1 to 5.

The cylinder is Fe-2.4Si-3.2.
By pouring the molten metal having the composition of C into the mold and setting the cooling rate to 2 ° C./sec which is faster than the normal cooling rate to solidify, the shape of the flake graphite in the matrix is determined by ASTM standard A
Type or B type with size No. 3 to No. 5
Alternatively, the size of the D and E types is No. 6 to No. 8
Was manufactured so that 70% or more of the total graphite occupied the area ratio.

[0063]

[Table 1]

Each roller, vane material and cylinder of Examples 1 to 5 and Comparative Example 1 thus manufactured are mounted on the rotary compressor shown in FIGS. 1 and 2, and high speed operation and low speed operation are performed at predetermined intervals by inverter control. A durability test was conducted in which the conditions under which the lubricating condition deteriorates the most were set, and the temperature of the refrigerant gas to be compressed was set to 300 ° C. and operation was continued for 3000 hours. And the driving time is 3000
The dimensional change rate and wear amount of each roller, the tip of the vane material, and the inner surface of the cylinder at the time when the time was reached were measured, and the volume efficiency of each compressor was measured, and the results shown in Table 2 below were obtained.

[0065]

[Table 2]

As is clear from the results shown in Table 2, in the compressors according to Examples 1-5, the roller material, the vane material, and the cylinder were made of materials having excellent wear resistance, lubricity and thermal stability. Since the sliding portion is configured, the dimensional change rate and the wear amount of the sliding portion are formed by the conventional material shown in Comparative Example 1 even after operating for a long time under high temperature and severe motion conditions. It is smaller than the machine and has excellent durability. In addition, the roller surface roughness is also small, so that galling is less likely to occur in the sliding part, and abnormal wear phenomena such as seizure, especially on the inner surface of the cylinder, are not observed, confirming that the initial sliding characteristics are also improved. It was

In particular, in Examples 1 to 5, since the roller was formed of the sintered alloy which was subjected to the sealing treatment by the steam treatment, the holding property of the impregnated lubricating oil was excellent, and there was a risk of so-called oil shortage. And the amount of wear is reduced.

Further, since the iron oxide is formed and the sealing treatment is carried out, the refrigerant gas is less likely to pass through the rollers, and the volume efficiency of the compressor as a whole is not lowered.

Further, since the area ratio of the thermally unstable austenite structure is set as small as 5% or less, the dimensional change and hardness reduction of the roller and vane material are small even under the high temperature use condition, and the stick or the like is not deteriorated. It is possible to provide a compressor in which there is little failure and reduction in compression efficiency.

In the above embodiments, the present invention is applied to a rotary compressor, but the application is not limited to the rotary compressor. For example, various types such as a scroll compressor and a reciprocating compressor can be used. The same can be applied to the compressor of (1).

[0071]

As described above, according to the compressor of the present invention, compared with the conventional material, it is stable under high temperature conditions and has excellent wear resistance, lubricity and seizure resistance. Since the sliding portion is formed of the material having the compressor, it is possible to provide a compressor that exhibits excellent durability even when it is operated under severe conditions for a long period of time.

Particularly, in the material structure of the sliding portion, the ratio of the thermally unstable austenite structure is set to a small value. Therefore, even if the operating temperature rises due to the change of the refrigerant, the dimension of the sliding material is increased. It is possible to provide a compressor that has little change and hardness reduction and has a long life.

Further, since the sliding portion is formed of the sintered body which is formed of iron oxide and is subjected to the sealing treatment, it is excellent in the retaining property and airtightness of the lubricating oil, and the compressed gas such as the refrigerant gas can be retained. It does not penetrate. Therefore, it is possible to provide a compressor having excellent wear resistance without impairing the volumetric efficiency of the compressor.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the structure of a hermetic rotary compressor.

FIG. 2 is a plan sectional view showing a rotor portion of the compressor shown in FIG.

[Explanation of symbols]

 1 compressor 2 casing 3a motor 3b compression element 4 rotary shaft 5 main bearing 6 auxiliary bearing 7 partition plate 8, 8a, 8b cylinder 9, 9, a, 9b eccentric part 10, 10a, 10b roller 11, 11a, 11b vane

Claims (6)

[Claims] 1. A compressor provided with a roller that makes eccentric rotary motion in sliding contact with the inner surface of a cast cylinder, and a vane material that comes in and out of the cylinder in contact with this roller, wherein the roller is made up of 1% Ni by weight. ~ 8%, Cr 0.5 ~ 3
%, Mo 0.5 to 3%, Cu 0.2% or less, C 1
˜2.5% and the balance Fe, a sintered alloy having an austenite structure area ratio of 5% or less and an iron oxide content of 5 to 10% by volume. While forming, the vane material contains 3.9% by weight of Cr.
~ 4.4%, Mo 4.9 to 20%, W 5.6 to 6.
5%, V 0.5-2%, C 0.8-2%, balance Fe
And a compressor having an austenite structure area ratio of 5% or less. 2. A casting which constitutes a cylinder is of type A or type B specified in ASTM standard A247 out of all graphite dispersed in a matrix and has a size of No. 3 to No.
5 or D type or E type, the size is No. 6 to No. 2. The compressor according to claim 1, wherein the graphite having the shape and size of 8 is made of cast iron that is uniformly distributed so as to occupy 70% or more of the entire graphite in an area ratio. 3. The density of the sintered alloy is 7.0 to 7.7 g / cm.
The compressor according to claim 1, wherein the compressor is ³ . 4. The alloy constituting the vane material is a sintered body, and the content of iron oxide contained in the sintered body is volume%.
The compressor according to claim 1, wherein the compressor is set in a range of 5 to 18%. 5. The compressor according to claim 4, wherein the content of sulfur added to the sintered alloy forming the vane material is set in the range of 0.1 to 0.7% by weight. .. 6. The compressor according to claim 4, wherein the content of nitrogen added to the sintered alloy forming the vane material is set in the range of 0.1 to 0.7% by weight. ..