JPH05340369A - Compressor - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a compressor equipped with an iron-based sintered vane that is resistant to the use of HFC-based refrigerants, and has excellent corrosion resistance and wear resistance. [Structure] The vane 6 of the hermetic rotary compressor 40 contains C 1.5 to 4.5% by weight, Si 1.5% or less, and Mn.
1.0% or less, Cr 3 to 6%; W 30% or less, M
o 20% or less of 1 or 2 is W + 2Mo and is 24 to
40%; 5 or 15% of one or two of V and Nb; Co
20% or less; one or more of Ti, V, Zr, Nb, Hf, Ta nitride particles and carbonitride particles are added to the high-speed steel base consisting of the balance Fe and impurities, based on the vane weight. And an Fe-based alloy with 3 to 15% dispersed therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor which constitutes a refrigeration cycle, and more particularly to a vane suitable for a rotary compressor which uses chlorine-free alternative CFC as a refrigerant.

[0002]

2. Description of the Related Art A compressor that circulates a refrigerant is used in a refrigeration cycle of a car air conditioner, a refrigerator-freezer, a commercial low-temperature equipment and the like. For example, in an oscillating rotary compressor (rotary compressor for short), the rotor rotates eccentrically inside the cylinder, the tip of the vane fitted in the cylinder slides on the rotor, and the side surface of the vane slides on the cylinder. The gas serving as a refrigerant is compressed by moving the gas and changing the volume of the space formed. That is, the general configuration of a rotary compressor is an electric element for rotating a rotor in a closed case, a compression element driven by the electric element,
This compression element contains compressor oil, and this compression element is installed in the eccentric part of the shaft, a cylinder that houses the rotor, and is housed in the groove of this cylinder, and its tip part slides on the outer circumference of the rotor. And a vane in contact therewith, and compresses the refrigerant gas circulating in the refrigeration cycle in this cylinder. Freon gas has been conventionally used as the refrigerant gas.

Materials generally used for the vanes include low alloy steel and high speed steel. These materials are materials in which high-hardness carbides are dispersed and precipitated in a high-hardness matrix and have excellent wear resistance themselves, but the amount of wear of the mating material in sliding contact with the vane increases.
Further, rubbing wear occurs due to falling of the carbide particles.
This tendency becomes remarkable as the rotation speed increases. A compressor related to this type of compressor is disclosed in, for example, Japanese Patent Laid-Open No. Hei 3
No. 217687 is cited.

[0004]

As described above, the characteristics required of the vane are that the vane itself has wear resistance and that the amount of wear of the mating material that is in sliding contact with the vane is minimized. On the other hand, when chlorofluorocarbons (hereinafter referred to as CFCs), which are commonly used as refrigerants for compressors in recent years and are commonly called CFCs, diffuse and reach the stratosphere, chlorine decomposed by ultraviolet rays causes the ozone layer to disappear. The phenomenon of destruction has become a problem, and it is now being taken up as an environmental destruction problem worldwide.

From such a background, development of harmless refrigerant agents has progressed, and chlorine-free hydrofluorocarbon (hereinafter referred to as HFC) type CFCs are now most promising. However, HFC-based CFCs are slightly inferior to conventional CFC-based CFCs in terms of energy efficiency, and it is necessary to increase the load on the components of the compressor. In addition, conventional mineral oil-based lubricating oils use HFC-based CFCs. Because of its poor compatibility with polyalkylene glycol (hereinafter,
PAG) -based oil is used, but it has a high solubility in water, and moreover, the PAG-based oil is easily decomposed into carboxylic acids (organic acids) such as formic acid and acetic acid during use, so rust resistance New characteristics have come to be demanded for the material of the vane, such as the requirement of a member having good corrosion resistance and corrosion resistance. Furthermore, as a lubricating oil for hermetic rotary compressors, ester oils are promising because of their excellent electrical insulation and low water solubility, but in this case as well, if the oils deteriorate, they will undergo thermal decomposition or hydrolysis. As a result, organic acids are generated and the total acid value of the lubricating oil is increased, so that for members such as vanes, members having good rust resistance and corrosion resistance are also required.

The present invention has been made in view of the above problems, and an object of the present invention is to enhance the wear resistance of the vane itself and to reduce the wear of the mating material slidingly contacting the vane. Moreover, it is another object of the present invention to provide a compressor including an iron-based sintered vane that can withstand the use of HFC-based refrigerant.

[0007]

The present invention has been made based on the following findings as a result of various experiments. That is, the tip of the vane is pressed against a cast iron rotor such as FC25 which is heat-treated to have a hardness of about HRC50,
Sliding at high speed (1 to 3 m / s). In particular, the vane targeted by the present invention has a large load applied to the vane and is placed in a relatively high temperature environment because HFC-based CFCs are used as the refrigerant. For this reason, the conventional SKH5
In the 1-class high-speed steel vanes, in addition to rubbing wear, the mating material of the vane and the seizing adhesion wear act synergistically to cause abnormal wear, and the performance as a practical compressor is not obtained. ..

In order to prevent the vane itself and the rotor from being worn under the above conditions, the base hardness of the vane is set to HRC6.
0 or more, softening resistance is increased, and fine carbide, carbonitride, and nitride particles are dispersed uniformly and in a large amount to improve wear resistance and adhesion wear resistance and reduce wear resistance. I found the importance of doing things.

Therefore, the vane material of the present invention is characterized by being Fe-based and manufactured by a sintering method in order to disperse a large amount of fine carbide, carbonitride and nitride particles. Further, it is characterized in that it has a structure in which carbonitrides and nitrides are added as powders and dispersed in addition to the carbides generated in the powder of the preliminary alloy.

Based on such knowledge, an object of the present invention is to provide an electric element for rotating a rotor in a closed case,
The compression element driven by the electric element and the compressor oil are housed, and the compression element is housed in the rotor mounted on the eccentric part of the shaft, the cylinder housing the rotor, and the groove of the cylinder. And a vane whose tip portion is in sliding contact with the outer periphery of the rotor, wherein the vane has a weight ratio of C 1.5
~ 4.5%, Si 1.5% or less, Mn 1.0% or less,
Cr 3-6%; W 30% or less, Mo 20% or less 1 or 2 is W + 2Mo, 24-40%; V, Nb
5% to 15% of 1 or 2 of Co; 20% or less of Co; a high-speed steel base consisting of the balance Fe and impurities, Ti,
One or two or more of V, Zr, Nb, Hf, Ta nitride particles and carbonitride particles are added to the vane weight in a total of 3
This is accomplished with a compressor composed of a Fe-based alloy with ~ 15% dispersion.

The lubricating oil that serves as the compressor oil is preferably ester oil corresponding to the HFC that constitutes the refrigerant.

[0012]

The function of each element constituting the vane of the present invention and the reason for limiting the numerical values will be described below. C combines with W, Mo, V, etc. added together to form a hard carbide. Moreover, a part of C is solid-dissolved in the matrix to increase the hardness of the matrix. As described above, in order to form a solid solution of carbide and a part of the solid solution in the matrix, the amount of C forming element and the balance of C are taken into consideration.
Is required. According to the present invention, when C is less than 1.5%, the hardness of the matrix is insufficient and the amount of carbide formed is small. Further, if it exceeds 4.5%, the toughness decreases, so
C is 1.5 to 4.5%.

Si serves as a deoxidizing element to improve the steel quality, and also has the effect of forming a solid solution in the matrix to increase the hardness in the matrix.
If Si exceeds 1.5%, the toughness decreases, so Si is set to 1.5% or less. Like Mn, Mn has an effect of improving the steel quality as a deoxidizing element, so Mn is made 1.0% or less. Cr has the effect of forming carbides and increasing wear resistance. Further, in addition to enhancing the hardenability by forming a solid solution in the matrix, it also improves the corrosion resistance of the matrix. When the alternative CFC targeted by the present invention is used as a refrigerant, P that replaces the conventional mineral oil system is used.
AG-based lubricating oils have high water solubility and form organic acids during use, and therefore, even ester-based lubricating oils, which have low water solubility and excellent insulation properties, do not undergo thermal decomposition or hydrolysis. The vanes are also required to be corrosion resistant as they receive and form organic acids. If Cr is less than 3%, the above effect is small, and if it exceeds 6%, it is difficult to obtain the desired hardness by heat treatment. Therefore, Cr is set to 3 to 6%.

W and Mo combine with C to form an M ₆ C type carbide, which has the effect of enhancing wear resistance and adhesion wear resistance. In addition, a part of W and Mo is solid-dissolved in the matrix and also has an effect of increasing tempering softening resistance. W and Mo do not necessarily need to be added in combination, but in order to achieve the object of the present invention and to provide a vane with excellent properties, W 30% or less, Mo2
It is necessary that the content of one or two of 0% or less is 24% or more in the amount of W + 2Mo, which is unprecedented. But,
If the W + 2Mo amount exceeds 40%, the toughness is significantly reduced, so the W + 2Mo amount is set to 24 to 40%.

V and Nb combine with C to form a homogeneous and fine MC-type carbide in the matrix, which has the effect of significantly improving wear resistance and adhesive wear resistance. It is an important element for achieving the purpose of the invention. It is not always necessary to add V and Nb in combination, and at least 5% of one or two of V and Nb is required to obtain the above effects. However, if it exceeds 15%, it is difficult to dissolve, and the toughness decreases, so the content is set to 5 to 15%.

Co has the effect of forming a solid solution in the matrix to increase the hardness of the matrix, and also has the effect of suppressing corrosion with respect to organic acids. However, if Co exceeds 20%, the toughness decreases, so Co is set to 20% or less.

According to the present invention, Ti, V, Zr, Nb,
Dispersing one or more of Hf and Ta nitrides and carbonitride particles in the matrix of high-speed steel having the above composition is one of the most important constituent requirements. That is,
Usually, since the rotor and the cylinder are made of cast iron, by dispersing the nitride particles or carbonitride particles having a small affinity for iron in the matrix of the high-speed steel composition, the friction coefficient is improved together with the improvement of wear resistance. It is significantly reduced, and therefore the adhesive wear of the vane with the mating material is significantly reduced. Therefore, the vanes themselves are less likely to wear, and the wear of the mating rotor and cylinder is significantly reduced. If the amount is less than 3% with respect to the vane weight, the above effect is insufficient. On the contrary, if it exceeds 15%, the sinterability becomes unstable. -15%. Similar effects can be obtained by adding and dispersing the carbide particles together with the above-mentioned nitride and carbonitride particles.

The vane of the present invention is used for the vane of the present invention for the reason that the carbide particles dispersed in the base steel are also finely and uniformly dispersed, and the purpose of uniformly dispersing the nitride and carbonitride particles. The material is preferably manufactured by powder metallurgy. Furthermore, by providing a surface hardening treatment layer such as a nitriding treatment or an oxynitriding treatment on at least the sliding surface of the vane made of the Fe-based alloy of the present invention, not only the wear resistance of the vane body is enhanced but also the mating Adhesive wear of the rotor and cylinder is significantly suppressed.

[0019]

EXAMPLES The present invention will be described in detail below based on examples. <Example 1> As a vane material, alloy powder having the composition shown in Table 1 was produced by a water atomizing method. In addition, sample No. 1 in Table 1. 14 is a vane material having a conventional composition prepared as a comparative example. As is clear from the table, when comparing the hardness of the vane materials (tempering hardness HRC display), the sample No. 1 to 13 are conventional sample N
o. It was confirmed that it was remarkably improved as compared with 14.

[0020]

[Table 1]

<Example 2> The vane material prepared in Example 1 was subjected to a forced deterioration test, and the results are shown in Table 2. The test items were the following three items.

(1) Corrosion weight loss (mg / cm ² · h) test: Immersion in 5% formic acid-5% acetic acid aqueous solution (60 ° C.) for 30 hours. Under this condition, the pH is considerably higher than that of the organic acid which is a decomposition product of the lubricating oil when the compressor is actually driven.

(2) Abrasion amount (mm ³ ) test: According to Ohkoshi type abrasion test. The test method is as shown in FIG.
The roller 7 serving as a rotor that rotates is pressed against the roller 7 with a predetermined load F, the lubricating oil 8 is dropped on the contact surface, and the volume of the recessed portion formed on the surface of the vane piece 6 due to wear is measured. I asked. <Test conditions> -Lubricant oil: Polyol ester oil-Roller material: HRC50 of heat-treated continuous cast iron-Roller rotation speed: 1.14 m / s-Load: 18.9 kgf-Abrasion distance: 3000 m-Vane piece: Implemented The samples shown in Table 1 of Example 1.

(3) Actual machine test: Using the vane material of Example 1,
It was mounted on the hermetic rotary compressor shown in FIG. 2 (longitudinal sectional view), and a forced test was performed on the wear resistance characteristics of the vane 6 and the roller 7. The structure of the compressor itself is a conventional structure, and in the figure, 1a is a rotor, 1b is a stator, and 2 is a crankshaft (rotating shaft), which constitutes an electric element M. Reference numeral 2a denotes an eccentric part of the rotating shaft, which slides on the inner circumference of the roller 7 serving as a rotor, thereby causing the roller 7 to eccentrically rotate in the cylinder 3. The vane 6 is pressed by the spring 9 and its tip comes into sliding contact with the surface of the roller 7. Four
Is a main bearing, and 5 is a sub-bearing, which are assembled to form a compression element. Reference numeral 8 is a compressor oil (lubricating oil), which is supplied to the rotary shaft 2 from the bottom of the closed case 10 by the pump mechanism, and is also supplied to the vane 6, the roller 7, and the cylinder 3. FIG. 3 shows a schematic cross-sectional view of the compression element of FIG. Note that this actual machine test was carried out on the wear resistance characteristics of both the vane 6 and the roller 7, and the results are shown in Table 2 by making a relative comparison based on a conventional comparative example. The upper row in the table is the vane, the lower row is the amount of wear of the rollers (both are relative values), the left row is the case where the surface treatment is not applied to the vane 6, and the right row is the surface treatment of the well-known oxynitriding treatment. The respective cases are shown.

<Test conditions> Lubricating oil: polyol ester oil, but adjusted to a total acid value of 0.21 mgKOH / g in advance for the forced deterioration test. This shows an acid state in which KOH requires 0.21 mg to neutralize 1 g of oil.-Lubricating oil temperature: 130 ° C-Roller: HRC50 obtained by heat-treating continuous cast iron.-Rotating speed: 3000 rpm-Test time : 3 months continuous operation test.

The above test results are summarized and displayed in Table 2. Each of them will be described in order. First, regarding the corrosion weight loss of (1), all the vane materials of the present invention were sample Nos. Compared with No. 14, it is almost half, and it can be seen that the corrosion resistance is excellent.

Next, regarding the wear amount test of (2), the sample No. of the comparative example was also used. In contrast to the wear amount of 6.9 mm ^{3 of} 14,
It can be seen that each of the vane materials of the present invention has a significantly small amount of 1.0 to 3.0 mm ³ and is excellent in wear resistance.

Further, in the actual machine test of (3), when the wear amount of the vane 6 of the comparative example not subjected to the surface treatment was set to 20 and the wear amount of the roller 7 was set to 100, a relative comparison was made. As shown in the row, the vane wear amount is 5
-10, and that of the roller was 25-50, all showing good abrasion resistance. Further, when the abrasion amount of the roller 7 when the abrasion amount of the vane 6 of the comparative example subjected to the surface treatment was 80 was set to 80 and the relative comparison was made, as shown in the right column of the table, the vane abrasion amount was 4 .About.9, that of the roller was 10 to 40, and by the surface treatment of the vane, the wear resistance property was further improved.

[0029]

[Table 2]

<Embodiment 3> An example in which a refrigeration cycle is constructed using the compressor having the construction used in the actual equipment test of Embodiment 2 is shown in FIG.
Shown in. However, in this case, the compressor oil (lubricating oil) 8 is a new ester oil without deterioration and has a viscosity of 32 cSt.
(Centi Stokes), total acid value 0.01mgKOH /
The thing of g was used. In FIG. 4, 40 is a compressor, 41 is a condenser, 42 is an expansion mechanism, 43 is an evaporator, 4
5 is a dryer (for drying the refrigerant). HFC as the refrigerant
Was used. This type of refrigeration cycle showed highly reliable performance as a refrigerator / freezer and an air conditioner (room air conditioner, car air conditioner).

[0031]

As described above, according to the present invention, the intended purpose can be achieved. That is, it is possible to obtain a compressor equipped with an iron-based sintered vane having excellent corrosion resistance and wear resistance that can be sufficiently adapted to an HFC-based refrigerant that is a substitute refrigerant CFC, and to realize a highly reliable refrigeration cycle. did it.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a wear amount characteristic test of a vane according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the compressor.

FIG. 3 is a transverse sectional view of the compressor.

FIG. 4 is a block diagram of a refrigeration cycle of the same.

[Explanation of symbols]

1a ... Stator, 1b ... Rotor, 2 ... Crankshaft (rotating shaft), 2a ... Eccentric part of the rotating shaft, 3 ... Cylinder,
4 ... Main axis, 5 ... Secondary axis,
6 ... Vane, 7 ... Roller,
8 ... Lubricating oil, 9 ... Spring,
10 ... Case, M ... Electric motor.

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[Procedure amendment]

[Submission date] June 11, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

[0020]

[Table 1]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

[0029]

[Table 2]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideki Yazawa Inventor Hideki Yazawa 800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Stock company Hitachi Co., Ltd. Tochigi factory (72) Inventor Daiji Sakamoto 2107-2, Yasugi-cho, Yasugi-shi, Shimane Prefecture Hitachi Metals Co., Ltd. Yasugi Plant (72) Inventor Hideki Nakamura 2107-2 Yasugi-cho, Yasugi-shi, Shimane Prefecture Hitachi Metals Ltd. Yasugi Plant (72) Inventor Kensei Uchida 2107-2, Yasugi-cho, Yasugi-shi, Shimane Prefecture Hitachi Metals Inside the Yasugi Factory (72) Inventor Takashi Takehara 2107-2 Yasugi Town, Yasugi City, Shimane Prefecture 2 Hitachi Metals Inside the Yasugi Factory

Claims (7)

[Claims] Claim: What is claimed is: 1. A rotor comprising an electric element for rotating a rotor, a compression element driven by the electric element, and compressor oil contained in a sealed case, the compression element being attached to an eccentric portion of a shaft. And a cylinder for accommodating the rotor, and a vane accommodated in the groove of the cylinder and having a tip portion slidingly in contact with the outer periphery of the rotor, the compressor comprising:
1.5-4.5%, Si 1.5% or less, Mn 1.0
% Or less, Cr 3 to 6%; W 30% or less, Mo 20% or less 1 type or 2 types is W + 2Mo, 24 to 40%; V,
5 to 15% of one or two of Nb; Co 20% or less;
In the high-speed steel base consisting of the balance Fe and impurities, Ti,
One or two or more of V, Zr, Nb, Hf, Ta nitride particles and carbonitride particles are added to the vane weight in a total of 3
A compressor composed of an Fe-based alloy having 15% dispersed therein. 2. The compressor according to claim 1, wherein the compressor oil is filled with an ester oil. 3. C 1.5-4.5% in weight%, Si 1.
5% or less, Mn 1.0% or less, Cr 3 to 6%; W 3
One or two of 0% or less and Mo of 20% or less is W + 2
Mo Mo 24-40%; V, Nb 1 or 2 5
15%; Co 20% or less; Ti, V, Zr, Nb, Hf, Ta in a high-speed steel base consisting of the balance Fe and impurities.
A vane formed of an Fe-based alloy in which one or more of the above-mentioned nitride particles and carbonitride particles are dispersed in a total amount of 3 to 15% based on the weight of the vane. 4. A refrigeration cycle comprising a compressor, a condenser, a dryer, an expansion mechanism, and an evaporator, wherein the compressor comprises the compressor according to claim 1 or 2. A refrigeration cycle consisting of. 5. The refrigeration cycle according to claim 4, wherein the refrigerant in the refrigeration cycle is an HFC refrigerant. 6. A freezer-refrigerator comprising the refrigeration cycle according to claim 4 or 5. 7. An air conditioner comprising a refrigeration cycle according to claim 4 or 5.