JPH08261187A - Fluid compressor - Google Patents

Abstract

PURPOSE: To provide a fluid compressor wherein improving compatibility with lubricating oil is attained thus to obtain improvement of wear resistance and ensuring durability and reliability, on condition that an HFC (hydrofluorocarbon) refrigerant is applied. CONSTITUTION: A helical blade type compression mechanism part 22 is provided, to use an HFC system refrigerant as the refrigerant, and as lubricating oil used with this refrigerant, lubricating oil of mixing one kind of ester oil, polyether oil, alkylbenzene oil Teflon oil or mixing two kinds or more of each oil is used. A turning force transmitting mechanism as a sliding member of constituting the helical blade type compression mechanism part is formed in an Oldham's mechanism 40, to use gray cast iron or spherical graphite cast iron in a piston 27 of constituting the one sliding member, and to use silicon nitride ceramics or surface hardening treated carbon steel or special steel in an Oldham,'s receiver (second cylinder bearing) 33 of constituting the other sliding member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a compressor for compressing refrigerant in a refrigeration cycle, and more particularly to a fluid compressor having a helical blade type compression mechanism.

[0002]

2. Description of the Related Art A fluid compressor having a helical blade type compression mechanism is known. In this, the piston is eccentrically arranged in a cylinder in which the electric motor part is fitted. The piston is formed with a spiral groove whose pitch is gradually reduced from one end side to the other end side, and a blade is fitted therein so that the blade can freely move in and out.

The space between the cylinder and the piston is divided into a plurality of spaces by the blade, and a compression chamber whose volume is gradually reduced from one end side to the other end side is formed in the cylinder. It

The rotational force of the cylinder is transmitted to the piston through the transmission mechanism, and the cylinder and the piston rotate synchronously at a relative peripheral speed while maintaining the positional relationship. Along with these rotations, the blade protrudes and retracts in the radial direction of the piston.

For example, if the refrigerant gas in the refrigeration cycle is
It is sucked into the cylinder through the suction passage, gradually transferred from the compression chamber closest to the suction side among the compression chambers to the compression chamber closest to the discharge side, and gradually compressed.

When reaching the compression chamber on the most discharge side, the pressure rises to a predetermined pressure, and once through the discharge passage, the closed case 1
It will be guided inside. Then, the filled high-pressure gas is introduced into the refrigeration cycle from the discharge pipe connected to the closed case.

In this type of fluid compressor, conventionally, CFC (chlorofluorocarbon) 12 is used as a refrigerant.
A refrigerant (hereinafter, referred to as R12) or an HCFC (hydrochlorofluorocarbon) 22 (hereinafter, referred to as R22) refrigerant is used. Further, naphthene-based or paraffin-based mineral oil is used as a lubricating oil for smoothly maintaining the drive of the compression mechanism section.

[0008]

However, the above-mentioned R
12 Refrigerant is a completely halogenated chlorofluorocarbon containing chlorine. Therefore, there is a strong risk of destroying the ozone layer, which is scientifically stable in the atmosphere, so it is a regulated specific CFC whose production has been decided to be abolished in the future.

On the other hand, the R22 refrigerant is a designated CFC that contains chlorine but contains hydrogen but is easily decomposed in the atmosphere and weak in depleting the ozone layer. The regulation of the total amount of usage has started, and it is planned to abolish the principle in the future.

Under these circumstances, there is a demand for new refrigerants that can replace these specified CFCs or designated CFCs, and as a result of promoting the development of new alternative substances centered on the lack of ozone layer depletion, chlorine atoms are included. HFC (hydrofluorocarbon) -based refrigerants have been adopted.

The HFC type refrigerant as an alternative refrigerant is characterized in that the refrigerant does not contain chlorine atoms. for that reason,
The wear resistance of the sliding member may be adversely affected, and the wear resistance of the sliding member must be fully considered.

The present invention has been made based on the above circumstances, and its purpose is to improve the compatibility with the lubricating oil and to improve the compatibility of the sliding member on the assumption that the HFC refrigerant is used. An object of the present invention is to provide a fluid compressor capable of improving wear resistance and ensuring durability and reliability.

[0013]

In order to achieve the above object, a fluid compressor according to a first aspect of the present invention comprises, as claim 1, a helical blade type compression mechanism, and uses an HFC type refrigerant as a refrigerant. As a lubricating oil used with a refrigerant, an ester-based oil, a polyether-based oil, an alkylbenzene-based oil, one of Teflon-based oils, or a fluid compressor using a lubricating oil obtained by mixing two or more of the above-mentioned oils, One of the sliding members in the helical blade type compression mechanism part is gray cast iron or spheroidal graphite cast iron, and the other is silicon nitride ceramics or surface-hardened carbon steel or special steel.

According to a second aspect of the present invention, in the helical blade type compression mechanism section according to the first aspect, both end portions of the cylinder are rotatably supported by bearings through cylinder bearings, and both end shaft portions. Are eccentrically supported by the bearing and are eccentrically arranged in the cylinder between the shafts, and are formed on the peripheral surface of the rotor at a pitch that gradually decreases along the axial direction. A spiral groove, a spiral blade fitted in and out of the groove, a plurality of compression chambers partitioned by the blade to gradually reduce the volume, and a relative peripheral speed between the cylinder and the rotating body. And a rotational force transmission mechanism that rotates in synchronization with each other and gradually compresses and discharges the refrigerant gas that is sucked into the compression chamber while being transferred to the compression chamber.

According to a third aspect of the present invention, the torque transmission mechanism according to the second aspect is an Oldham mechanism, one of the sliding members is an Oldham ring, and the other is an Oldham portion of a piston or an Oldham receiver. .

According to a fourth aspect, the piston member according to the third aspect is composed of gray cast iron or spheroidal graphite cast iron,
Further, the ferrite ratio of these is 25% or less, and at least the free graphite portion is excluded on the sliding surface with the Oldham ring to form a quench hardened layer having a hardness of HV0.05 750 or more and a thickness of 20 μm or more. Characterize.

According to a fifth aspect of the present invention, the Oldham ring member is formed of silicon nitride ceramics and has a bending strength of 70 Kgf / mm ² or more. According to a sixth aspect, the Oldham ring member according to the third aspect is made of carbon steel or special steel that has been subjected to a surface hardening treatment, and has an HV0.05 by carburizing treatment or nitriding treatment.
The surface hardened layer having a hardness of 750 or more and a thickness of 10 μm or more is formed.

According to a seventh aspect, the Oldham receiving member according to the third aspect is made of carbon steel or special steel which has been subjected to a surface hardening treatment, and which has a HV0.
It is characterized in that a surface hardened layer having a hardness of 750 or more and a thickness of 10 μm or more is formed.

In order to achieve the above object, the fluid compressor of the second invention comprises, as claim 8, a helical blade type compression mechanism portion, uses an HFC type refrigerant as a refrigerant, and lubricates with this refrigerant. Ester-based oil,
In a fluid compressor using a polyether oil, an alkylbenzene oil, one kind of Teflon oil, or a lubricant oil in which two or more kinds of the respective oils are mixed, one of the sliding members in the helical blade type compression mechanism section is used. The present invention is characterized in that gray cast iron or spheroidal graphite cast iron is used, and the other is gray cast iron or spheroidal graphite cast iron or an iron-based sintered alloy subjected to a sealing treatment.

According to a ninth aspect of the present invention, in the helical blade type compression mechanism section, both ends thereof are a cylinder rotatably supported by bearings via cylinder bearings and both end shaft sections. A rotating body which is eccentrically supported by the bearing and is eccentrically arranged in the cylinder between the shaft portions, and a spiral which is provided on the peripheral surface of the rotating body and is formed at a pitch that gradually decreases along the axial direction. -Shaped groove, a spiral blade fitted in and out of the groove, a plurality of compression chambers partitioned by the blade to gradually reduce the volume, the cylinder and the rotating body at a relative peripheral speed. And a rotational force transmitting mechanism for synchronously rotating the refrigerant gas sucked into the compression chamber and gradually compressing the refrigerant gas while discharging the refrigerant gas into the compression chamber.

According to a tenth aspect, the sliding member according to the eighth aspect is characterized in that one of the sliding members is a piston shaft portion or a cylinder bearing, and the other is a bearing member that rotatably supports these.

According to an eleventh aspect, the piston shaft portion or the cylinder according to the tenth aspect is constituted by gray cast iron or spheroidal graphite cast iron, and has a ferrite ratio of 25% or less.

According to a twelfth aspect of the present invention, the bearing assembly according to the tenth aspect is made of an iron-based sintered alloy that has been subjected to a pore-sealing treatment. % Or more.

In order to achieve the above object, a fluid compressor according to a third aspect of the present invention includes, as a thirteenth aspect, a helical blade type compression mechanism portion, an HFC type refrigerant is used as a refrigerant, and a lubrication is used together with this refrigerant. In the fluid compressor using one of ester-based oil, polyether-based oil, alkylbenzene-based oil, Teflon-based oil or a mixture of two or more of the above-mentioned respective oils as oil, the helical blade compression mechanism section One or the other of the sliding members constituting the above is made of gray cast iron or spheroidal graphite cast iron.

According to a fourteenth aspect of the present invention, in the helical blade type compression mechanism section according to the thirteenth aspect, both end portions thereof are a cylinder rotatably supported by a bearing tool via a cylinder bearing and both end shaft portions. A rotating body which is eccentrically supported by the bearing and is eccentrically arranged in the cylinder between the shaft portions, and a spiral which is provided on the peripheral surface of the rotating body and is formed at a pitch that gradually decreases along the axial direction. -Shaped groove, a spiral blade fitted in and out of the groove, a plurality of compression chambers partitioned by the blade to gradually reduce the volume, and the cylinder and the rotating body. And a rotational force transmission mechanism that rotates at a constant peripheral speed and synchronously, and gradually compresses and discharges the refrigerant gas sucked into the compression chamber while gradually transferring it to the compression chamber. As a fifteenth aspect, the sliding member according to the fourteenth aspect is characterized in that one of the sliding members is a piston and the other is a cylinder.

[0026]

Operation: A helical blade type compression mechanism is provided, an HFC refrigerant is used as a refrigerant, and a lubricating oil used with this refrigerant is an ester oil, a polyether oil, an alkylbenzene oil, or a Teflon oil. It is premised to use one kind of oil or a lubricating oil in which two or more kinds of the respective system oils are mixed.

In the first invention, one of the sliding members constituting the compression mechanism section is gray cast iron or spheroidal graphite cast iron, and the other is silicon nitride ceramics or surface-hardened carbon steel or special steel. did.

In the second invention, one of the sliding members in the compression mechanism section is gray cast iron or spheroidal graphite cast iron, and the other is gray cast iron or spheroidal graphite cast iron or an iron-based sintered alloy having a sealing treatment. And

In the third invention, one or the other of the sliding members constituting the compression mechanism is gray cast iron or spheroidal graphite cast iron. Therefore, while it does not contain chlorine atoms and there is no risk of ozone layer depletion, it does not have extreme pressure.
Even under severe lubrication conditions using the C-based refrigerant, the amount of wear of the compression mechanism sliding member can be reduced by selecting the lubricating oil and the compression mechanism material.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The fluid compressor of the present invention is used in a refrigeration cycle apparatus, and the refrigerant used is an HFC refrigerant. More specifically, here, R32 / R125 / R
A three-component mixed refrigerant of 134a is used.

The compressor body 20 shown in FIG. 1 has a hermetically sealed case 21 in which the axial direction is oriented horizontally and both ends are closed.
And a helical blade type compression mechanism section 22 and an electric motor section 23 housed in this closed case.

The compression mechanism section 22 has a cylinder 24 whose both ends are open, and a rotor 25 is fitted to the outer peripheral surface of this cylinder via a cylinder cover 24a.
A stator 26 is fitted on the inner peripheral surface of the closed case 21, and the electric motor portion 23 is configured together with the rotor 25.

A piston 27 as a rotating body is eccentrically arranged in the cylinder 24. Since the piston 27 is eccentrically arranged in the cylinder 24, a part of the peripheral wall along the axial direction of the piston is brought into rolling contact with the inner peripheral wall of the cylinder.

A spiral groove 28 whose pitch is gradually reduced from one end side to the other end side is formed on the circumferential surface of the piston 27, and a spiral blade 29 is fitted in the groove 28 so as to be able to move in and out. The space between the cylinder 24 and the piston 27 (shown in a simplified form in the drawing) is partitioned into a plurality of spaces by the blades 29, and inside the cylinder 24 from one end side to the other end side of the cylinder, that is, from the suction side to the discharge side. A plurality of compression chambers S ... whose volume is gradually reduced are formed.

A main shaft part 27a is formed at one end of the piston 27 in the axial direction and a sub shaft part 27b is formed at the other end, and the main shaft part 30 is fixed to the inner wall of the hermetically sealed case 21.
The auxiliary bearing 31 is inserted into the pivot hole portions 30a and 31a and pivotally supported so as to be rotatable.

The pivot holes 30a and 31a are the main bearing members 3
0, the auxiliary bearing 31 is eccentrically provided, and the piston 27 inserted therein is pivotally supported at an eccentric position.

The main bearing member 30 and the sub bearing member 31 are respectively provided with flange portions 30b and 31b mounted and fixed to the inner wall of the hermetically sealed case 21, and pivot shaft portions 30c and 31c integrally provided on the flange portions. Consists of.

On the other hand, on the inner peripheral surfaces of both ends of the cylinder 24,
Cylinder bearings 32 and 33, which are made of metal, are press-fitted and fitted, and are interposed between the outer peripheral surfaces of the pivot shaft portions 30c and 31c of the main and auxiliary bearing members 30 and 31, respectively.

Here, the cylinder bearing interposed between the main bearing tool pivotally supporting shaft portion 30c and one end of the cylinder 24 is referred to as a first cylinder bearing 32, and the auxiliary bearing tool pivotally supporting shaft portion 31c and the other end of the cylinder 24. The cylinder bearing that is interposed between the two parts is referred to as a second cylinder bearing 33.

The first cylinder bearing 32 is formed in a thick ring shape, and one side surface thereof is the cylinder 24.
Aligned with the end face. Cylinder 24 which is the other side
A part of the inner side end surface projects, and this projecting portion faces the end of the blade 29. Due to the setting of the position, the protruding portion serves as the blade pressing portion 32a.

The second cylinder bearing 33 constitutes a part of the Oldham mechanism 40 as a rotational force transmitting mechanism which will be described later. A suction pipe 41 is connected to one side surface of the closed case 21, and an open end of the suction case 41 communicates with a pivot support hole portion 30 a of the main bearing member 30. Main shaft portion 2 of the piston 27
A suction guide passage 42 is provided from the end surface of the piston 7a along the axial direction, and this passage is open to the outer peripheral surface of the end portion of the piston 27.

A blade stopper 43 is provided near the Oldham mechanism 40 of the cylinder 24. The blade stopper 43 faces a recessed portion provided at the end of the piston 27 and projects to a position close to the recessed portion, and a lead-out guide hole 44 is opened along the axial direction.

That is, the blade stopper 43 is
The lead-out guide hole 44 projects so as to face the end of the blade 29 wound around the circumference of the piston 27, and
4 The inside of the closed case 21 communicates with the inside. Further, a discharge pipe 45 is connected to the end of the closed case 21.

An oil sump 46 for collecting lubricating oil is formed along the inner bottom of the closed case 21. The lubricating oil collected in the oil reservoir 46 is one of ester-based oil, polyether-based oil, alkylbenzene-based oil, Teflon-based oil, or a mixture of two or more of each of the above-mentioned oils. Here, a lubricating oil equivalent to a tetravalent ester VG68 (JIS viscosity grade) is used.

The main bearing member 30 and the sub bearing member 31 are integrally provided with oil suction passages 47a and 47b whose lower ends are extended so as to be immersed in the lubricating oil of the oil sump portion 46. The upper ends of the oil suction passages 47a and 47b penetrate the main bearing member 30 and the auxiliary bearing member 31 and open into the pivotal support holes 30a and 31a.

On the other hand, both shaft portions 27b and 27b of the piston 27 facing the upper end openings of the oil suction passages 47a and 47b.
The oil supply pumps 48, 48 each including a helical blade are wound around.

Next, the Oldham mechanism 40 will be described in detail. As shown in an exploded view in FIG. 2, a pair of screw holes 34 are provided on the other end side of the cylinder 24 in the vicinity of the cylinder end surface, and a recessed hole is formed in a peripheral surface portion of the second cylinder bearing 33 facing the screw holes 34. 35 are provided.

Then, with the second cylinder bearing 33 inserted in the inner peripheral surface of the cylinder 24, the screw hole 3 of the cylinder is inserted.
A set screw 36 is screwed into 4 and its tip end is abutted against the recessed hole 35 of the cylinder bearing 33. By tightening the set screw 36, the cylinder bearing 33 can be firmly fixed to the cylinder 24.

Further, the second cylinder bearing 33 is
It has a thick ring shape, and one side surface thereof is flush with the cylinder end surface while being fitted and fixed to the inner peripheral surface of the cylinder.

On the end face on the cylinder inner side, which is the other end, 1
Engagement parts 37, 37 which are a pair of key parts at 80 ° symmetrical positions
Are provided integrally. These engaging portions 37, 37 have an inner space dimension substantially coincident with the inner diameter dimension of the cylinder bearing 33, and an outer space dimension substantially coincident with the outer diameter dimension. It has a substantially rectangular shape when viewed from the front, and the left and right side surfaces of each are sufficiently polished.

On the other hand, the piston 27 is provided with a piston Oldham portion 27c which is a key portion adjacent to the auxiliary shaft portion 27b. The piston Oldham portion 27c is the auxiliary shaft portion 27.
It is composed of a pair of parallel planes having a spacing dimension which is the same as or slightly larger than the diameter dimension of b and which are machined with an accurate parallelism.

This piston Oldham portion 27c and the second
An Oldham ring 38 is interposed between the engaging portions 37, 37 of the cylinder bearing 33. That is, the second cylinder bearing 33 functions as a so-called Oldham receiver.

The Oldham ring 38 is provided on one side surface thereof with a pair of first key grooves 39a, 39a slidably engaged with the piston Oldham portion 27c at positions facing each other by 180 °. On the other side surface, a pair of second key grooves 39b, 39b slidably engaged with the engaging portions 37, 37 of the cylinder bearing 33 are provided at positions facing each other by 180 °.

The above-mentioned first keyway 39a and second keyway 3
9b are provided at positions orthogonal to each other. The inner diameter of the Oldham ring 38 is set to be larger than the shaft diameter so as not to interfere with the auxiliary shaft portion 27b, and the outer diameter is substantially the same as the outer diameter of the piston 27.

A compressor constructed in this way,
The rotor 25 and the cylinder 24 rotate together with the energization of the electric motor unit 23. Since the cylinder 24 and the first and second cylinder bearings 32 and 33 are integrally formed, they rotate at the same time. In particular, the rotation of the second cylinder bearing 33 is transmitted to the second key grooves 39b, 39b of the Oldham ring 38 via the pair of engaging portions 37, 37 provided therein, and the Oldham ring 38
Rotates.

The rotation of the Oldham ring 38 is transmitted to the piston 27 because the piston Oldham portion 27c of the piston 27 is engaged with the first key grooves 39a, 39a of the Oldham ring 38.

The piston 27 is pivotally supported at an eccentric position with respect to the cylinder 24, but since the Oldham ring 38 has the first and second key grooves 39a and 39b, the cylinder 24 and the piston 27 are Due to the difference in their radii, they rotate at a relative peripheral speed and in synchronism while maintaining their mutual positional relationship.

The blade 29 moves in and out of the groove 28 as the cylinder 24 and the piston 27 rotate.
It sank in the radial direction of the piston. Due to the influence, the compression chamber S has a negative pressure, and the low-pressure refrigerant gas in the refrigeration cycle is sucked into the suction pipe 4.
Inhaled from 1.

Refrigerant gas, which is an HFC-based refrigerant, has a support hole 30a formed in the main bearing 30 and a suction guide passage 42.
Is introduced into the cylinder 24 via. Then, among the compression chambers S, the compression chamber located closest to the suction side is sequentially transferred to the compression chamber located closest to the discharge side, and gradually compressed during this period.

When it is transferred to the compression chamber S on the most discharge side, the pressure rises to a predetermined pressure, and this high-pressure gas is introduced into the blade stopper 43 and the guide hole 4 provided in the cylinder cover 24a.
It is led out into the closed case 21 through 4.

The high-pressure gas, once filled in the closed case 21, is guided to the discharge pipe 45 and then to the external refrigeration cycle equipment. At the same time, the piston shaft 27
With the rotation of a and 27b, the oil supply pumps 48 and 48 wound around the a and 27b are brought into a driving state, and the lubricating oil that collects in the oil sump portion 46 is sucked up through the oil suction passages 47a and 47b. Lubricating oil is supplied to each sliding member constituting the compression mechanism section 22 to ensure its lubricity. As the fluid compressor according to the first aspect of the present invention, the conditions are set as shown in Examples 1 and 2 of Table 1 below.

[0062]

[Table 1]

The piston 27 of the Oldham mechanism 40, which is one of the sliding members constituting the helical blade type compression mechanism section 22, is gray cast iron or spheroidal graphite cast iron corresponding to FC250 in both Example 1 and Example 2. Ferrite ratio (ratio of area where ferrite is deposited) is 5
Set to%.

As the first embodiment, the Oldham ring 38 uses silicon nitride ceramics. The bending strength in this case must be 70 Kgf / mm ² or more. Second
As an example of, a special steel equivalent to JIS SUS430 that has been subjected to surface nitriding treatment is used. In this case, a surface hardened layer having a hardness of HV0.05 750 or more and a thickness of 10 μm or more must be formed.

In any of the examples, at least the surface of the piston Oldham portion 27c, which is the sliding surface with respect to the Oldham ring 38, is HV0.05 except for the free graphite portion.
A quench-hardened layer having a hardness of 750 or more and a thickness of 20 μm or more is formed.

Under the conditions of Embodiments 1 and 2 as described above, FIG.
As shown in, the characteristic of the sum of the wear amount of the piston / Oldham ring with respect to the operating time is shown by an A curve. That is, after the total amount of wear reaches a predetermined amount (about 5 μm) at the very early stage (about 300 hours), a predetermined continuous operation time (about 5,000
It can be seen that there is almost no change over time, and the wear resistance of these is improved.

On the other hand, Comparative Example 1 and Comparative Example 2
The characteristics of the sum of the wear amount of the piston / Oldham ring with respect to the operating time are shown as a B curve (Comparative Example 1) and a C curve (Comparative Example 2).

The conditions specified in Comparative Examples 1 and 2 are as shown in Table 1 above. That is, in Comparative Example 1, the refrigerant and the lubricating oil used were the same as in Examples 1 and 2, the piston was equivalent to FC250, and the surface hardening treatment was performed, but the ferrite ratio was 30%. The Oldham ring adopts JIS S45C equivalent carbon steel.

In Comparative Example 2, the refrigerant used was the same as in Examples 1 and 2. Lubricating oil is naphthenic mineral oil V
G56 is used. The piston is equivalent to FC250, and the ferrite ratio is 30% although the surface hardening treatment is performed. The Oldham ring adopts JIS S45C equivalent carbon steel.

As shown in FIG. 3 again, the B curve of Comparative Example 1 is in a state where the total amount of wear is high (about 20 μm) at an extremely early stage (about 500 hours), and is gradually increased thereafter to be used. I can't stand it. In the C curve of Comparative Example 2, the wear amount is inferior because the sum of wear amounts (about 15 μm) is almost three times that of Examples 1 and 2 in a predetermined continuous time (about 5,000 hours). First
The conditions as shown in Examples 3 and 4 of Table 2 are set as the fluid compressor corresponding to Claims 5 to 7 of the invention.

[0071]

[Table 2]

That is, a three-component mixed refrigerant is used as the refrigerant and a tetravalent ester VG68 equivalent is used as the lubricating oil. In Example 3, the Oldham ring 3 which is one of the sliding members
8 uses silicon nitride ceramics. The other Oldham receiver (second cylinder bearing 33) is made of JIS S45C equivalent carbon steel, and is subjected to a nitriding treatment to obtain a surface-hardened layer.

In the fourth embodiment, the Oldham ring is
A special steel equivalent to JIS SUS430 is used, and a nitriding treatment is applied to obtain a surface-hardened layer. Oldham receiver is powder high-speed steel (SK
H56 equivalent high-speed steel) is used for quenching and resin sealing.

In any of the embodiments, the second cylinder bearing 33, which is an Oldham's bearing, is formed with a surface hardened layer having a hardness of HV0.05 750 or more and a thickness of 10 μm or more by the surface hardening treatment.

On the other hand, in Comparative Example 3, the refrigerant and the lubricating oil used are the same as in Examples 3 and 4. The Oldham ring and Oldham receiver use JIS S45C equivalent carbon steel.
In Comparative Example 4, an HCFC22 (R22) refrigerant is used as the refrigerant, and a naphthene-based mineral oil is used as the lubricating oil. For Oldham ring and Oldham receiver, use carbon steel equivalent to JIS S45C.

As shown in FIG. 4, under the condition setting as shown in Table 2, the sum of the wear amount of the Oldham ring / Oldham receiver with respect to the operating time is about 20% after the operation in Examples 3 and 4.
After reaching a certain amount (about 5 μm) at 0 hours, there is almost no change even after a predetermined continuous operation time (about 5,000 hours), and the wear resistance is excellent.

On the other hand, in Comparative Example 3, the maximum wear was 25 μm in a short time (about 2,000 hours),
It is hardly suitable for practical use. In Comparative Example 4, when a predetermined continuous operation time (5,000 hours) has elapsed, there is a total wear amount (about 20 μm) about four times that of Examples 3 and 4, and the difference is obvious. As the fluid compressor corresponding to claims 8 to 12 of the second invention, the conditions shown in Examples 5 and 6 of Table 3 are set.

[0078]

[Table 3]

That is, a three-component mixed refrigerant is used as the refrigerant, and a tetravalent ester VG68 equivalent is used as the lubricating oil. In the fifth embodiment, the piston 27, which is one of the sliding members,
FC250 equivalent gray cast iron or spheroidal graphite cast iron is used. The ferrite rate is 5%. The main bearing tool 30 and the sub-bearing tool 31, which are the other, also use gray cast iron or spheroidal graphite cast iron corresponding to FC250. This ferrite rate is also 5%
And

In the sixth embodiment, the piston 27 is FC
It is gray cast iron or spheroidal graphite cast iron equivalent to 250, and the ferrite rate is 5%. The main bearing member 30 and the sub-bearing member 31 are
It is a sintered alloy equivalent to JIS SMF-4 and has a resin sealing treatment.

The iron-based sintered alloy subjected to the pore-sealing treatment in Example 6 was infiltrated or impregnated with a resin material or a metal having high ductility to have a density of 85% or more. on the other hand,
In Comparative Example 5, the refrigerant and the lubricating oil used are the same as in Examples 5 and 6. Both piston and bearing are F
Gray cast iron or spheroidal graphite cast iron equivalent to C250 is used, but the ferrite ratio is 30%.

In Comparative Example 6, R22 refrigerant was used as the refrigerant,
As the lubricating oil, Teften mineral oil VG56 is used. FC250-equivalent gray cast iron or spheroidal graphite cast iron is used for both the piston and the bearing, but the ferrite ratio is 30%.

As shown in FIG. 5, under the condition setting as shown in Table 3, the sum of the wear amount of the piston / bearing member with respect to the operating time is, in Examples 5 and 6, after the start of operation (about 1,000 hours).
After reaching a certain amount (about 2 μm), there is almost no change over a predetermined continuous operation time (about 5,000 hours), and the wear resistance is excellent.

On the other hand, in Comparative Example 5, almost four times (about 8 μm) as compared with each Example after a predetermined continuous operation time elapsed.
In Comparative Example 6, after the same time,
There is a sum of wear amounts about twice as much as each embodiment (about 4 μm or more). Therefore, the superiority of the embodiment is secured.

In any of the fifth and sixth embodiments,
It goes without saying that the same improvement in wear resistance can be obtained by setting the same conditions as described above for the cylinder bearings 30 and 31 instead of the piston 27. As a fluid compressor corresponding to claim 13 to claim 15 of the third invention, conditions are set as shown in Example 7 of Table 4.

[0086]

[Table 4]

That is, in Example 7, the refrigerant used was a mixed refrigerant of three kinds, and the lubricating oil used was a tetravalent ester VG68. The piston 27, which is one of the sliding members, is FC2
Use gray cast iron or spheroidal graphite cast iron equivalent to 50. This ferrite rate is 5%. The other cylinder 24
Also, gray cast iron or spheroidal graphite cast iron corresponding to FC250 is used. This ferrite rate is also 5%.

On the other hand, in Comparative Example 7, both the refrigerant and the lubricating oil used are the same as in Example 7. For the piston and the bearing tool, gray cast iron or spheroidal graphite cast iron corresponding to FC250 is used, but the ferrite ratio is 30%.

In Comparative Example 8, the refrigerant is R22 refrigerant,
As the lubricating oil, naphthenic mineral oil VG56 is used. Both the piston and the cylinder use gray cast iron or spheroidal graphite cast iron equivalent to FC250, but the ferrite ratio is 30%.

As shown in FIG. 6, the piston blade groove 29 with respect to the operating time was set under the conditions shown in Table 4.
And the amount of wear on the inner surface of the cylinder 24 is a fixed amount (about 2 μm) by the predetermined time (about 2,000 hours) in the seventh embodiment.
After reaching 0, there is almost no change over a long continuous operation time (about 5,000 hours), and the wear resistance is excellent.

On the other hand, in Comparative Example 7, the sum of the wear amounts suddenly increased by the lapse of an early time (about 1,000 hours), and then gradually increased. Long continuous operation time (approx.
It is less than 3 times (about 8 μm) as compared with the embodiment over 5,000 hours, and the wear resistance is poor.

In Comparative Example 8, the early time (about 1,20
By the time 0 hours), the total amount of wear has risen sharply and continues to increase thereafter. Long-term continuous operation time (5,000 hours)
The wear resistance is inferior to that of the embodiment (a little less than about 5 μm).

In the above comparative examples, by setting the ferrite ratio in the gray cast iron or spheroidal graphite cast iron equivalent to FC250 to 30%, it is recognized that the hardness decreases and the tendency of adhesion tends to occur.

In the above embodiment, the H used
The FC type refrigerant has been described by applying the R32 / R125a / R134a ternary mixed refrigerant, but the FC type refrigerant is not limited to this, and the R32 / R134a binary mixed refrigerant or the R125 / R143a binary mixed refrigerant is used. be able to.

It is also possible to use a single refrigerant. That is, difluoromethane (R32), pentafluoroethane (R125), 1,1,2,2-tetrafluoroethane (R134a), 1,1,2-trifluoroethane (R143), 1,1,1-tri Fluoroethane (R1
43a), 1,1-difluoroethane (R152a),
Monofluoroethane (R161) and the like.

Among these single refrigerants, R134, R13
4a, R143, and R143a are conventional CFC12 (R1
It has a boiling point close to that of the refrigerant 2) and is preferable as an alternative refrigerant.

[0097]

As described above, according to the claims of the present invention, the wear resistance of the sliding member is improved on the premise of the combination of the HFC refrigerant and the lubricating oil having a good compatibility, A fluid compressor having improved durability and reliability can be provided.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a fluid compressor according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the Oldham mechanism of the embodiment.

FIG. 3 is a characteristic diagram of Examples 1 and 2 and Comparative Examples 1 and 2.

FIG. 4 is a characteristic diagram of Examples 3 and 4 and Comparative Examples 3 and 4.

FIG. 5 is a characteristic diagram of Examples 5 and 6 and Comparative examples 5 and 6.

6 is a characteristic diagram of Example 7 and Comparative Examples 7 and 8. FIG.

[Explanation of symbols]

22 ... Helical blade type compression mechanism section, 30 ... Main bearing tool, 31 ... Sub bearing tool, 32, 33 ... Cylinder bearing, 2
4 ... Cylinder, 27 ... Rotating body (piston), 28 ... Groove,
29 ... Blade, S ... Compression chamber, 40 ... Oldham mechanism, 3
8 ... Oldham ring, 33 ... Oldham receiver (second cylinder bearing), 27c ... Piston Oldham part.

Claims (15)

[Claims] 1. A helical blade type compression mechanism is used, and an HFC type refrigerant is used as a refrigerant. As a lubricating oil used with this refrigerant, an ester type oil, a polyether type oil, an alkylbenzene type oil or a Teflon type oil is used. In a fluid compressor that uses one or a mixture of two or more of each of the above system oils, one of the sliding members in the helical blade type compression mechanism section is gray cast iron or spheroidal graphite cast iron, and the other is silicon nitride. A fluid compressor characterized in that it is made of ceramics or surface-treated carbon steel or special steel. 2. The helical blade type compression mechanism section has a cylinder whose both ends are rotatably supported by bearings through cylinder bearings, and both ends of the cylinder are eccentric to the bearings. A rotating body supported between the shafts and eccentrically arranged in the cylinder, a spiral groove provided on the peripheral surface of the rotating body at a pitch that gradually decreases along the axial direction, and the groove. A spiral blade fitted in and out of the cylinder, a plurality of compression chambers partitioned by the blade to gradually reduce the volume, and the cylinder and the rotating body at a relative peripheral speed and synchronized with each other. 2. The fluid compressor according to claim 1, further comprising: a rotational force transmission mechanism for rotating the refrigerant gas to gradually compress and discharge the refrigerant gas sucked into the compression chamber. 3. The fluid compression system according to claim 2, wherein the rotational force transmission mechanism is an Oldham mechanism, one of the sliding members is an Oldham ring, and the other is an Oldham portion of a piston or an Oldham receiver. Machine. 4. The piston member is made of gray cast iron or spheroidal graphite cast iron and has a ferrite ratio (ratio of areas where ferrite is deposited) of 25% or less, and at least slides with an Oldham ring. The fluid compressor according to claim 3, wherein a quench hardened layer having a hardness of HV0.05750 or more and a thickness of 20 µm or more is formed on the surface excluding the free graphite portion. 5. The Oldham ring member is made of silicon nitride ceramics and has a bending strength of 70 Kgf / mm ²
It is above, The fluid compressor of Claim 3 characterized by the above-mentioned. 6. The Oldham ring member is made of carbon steel or special steel that has been surface hardened, and has a hardness of HV0.05 750 or more by carburizing or nitriding.
The fluid compressor according to claim 3, wherein a surface-hardened layer having a thickness of 10 µm or more is formed. 7. The Oldham receiving member is made of surface-hardened carbon steel or special steel, and has a hardness of HV0.05 750 or more and a thickness of 1 by carburizing or nitriding.
The fluid compressor according to claim 3, wherein a surface-hardened layer having a thickness of 0 µm or more is formed. 8. A helical blade type compression mechanism is used, an HFC type refrigerant is used as a refrigerant, and a lubricating oil used together with this refrigerant is selected from ester type oils, polyether type oils, alkylbenzene type oils and Teflon type oils. In a fluid compressor using one or a mixture of two or more of each of the above system oils, one of the sliding members in the helical blade type compression mechanism section is gray cast iron or spheroidal graphite cast iron, and the other is gray cast iron. Alternatively, a fluid compressor characterized by being made of spheroidal graphite cast iron or an iron-based sintered alloy that has been subjected to a sealing treatment. 9. The helical blade type compression mechanism section includes a cylinder whose both ends are rotatably supported by bearings through cylinder bearings, and both end shafts are eccentric to the bearings. A rotating body supported between the shafts and eccentrically arranged in the cylinder, a spiral groove provided on the peripheral surface of the rotating body at a pitch that gradually decreases along the axial direction, and the groove. A spiral blade fitted in and out of the cylinder, a plurality of compression chambers partitioned by the blade to gradually reduce the volume, and the cylinder and the rotating body at a relative peripheral speed and synchronized with each other. 9. The fluid compressor according to claim 8, further comprising: a rotational force transmission mechanism that causes the refrigerant gas that is mechanically rotated and is gradually transferred to the compression chamber to be compressed and discharged while being gradually transferred to the compression chamber. 10. The sliding member according to claim 8, wherein one of the sliding members is a piston shaft portion or a cylinder bearing, and the other is a bearing tool for rotatably supporting them.
The described fluid compressor. 11. The piston shaft portion or cylinder is
The fluid compressor according to claim 10, which is made of gray cast iron or spheroidal graphite cast iron and has a ferrite ratio of 25% or less. 12. The bearing is made of an iron-based sintered alloy that has been subjected to a sealing treatment, and is made to have a density ratio of 85% or more by infiltration or impregnation with a resin material or a metal having high ductility. The fluid compressor according to claim 10. 13. A helical blade type compression mechanism section is provided,
An HFC type refrigerant is used as a refrigerant, and as a lubricating oil used with this refrigerant, one type of ester type oil, polyether type oil, alkylbenzene type oil, Teflon type oil, or a mixture of two or more types of each type oil is used. A fluid compressor using oil, characterized in that one or the other of the sliding members constituting the helical blade type compression mechanism section is gray cast iron or spheroidal graphite cast iron. 14. The helical blade type compression mechanism section includes a cylinder whose both ends are rotatably supported by bearings through cylinder bearings, and both ends of the cylinder are eccentric to the bearings. A rotating body supported between the shafts and eccentrically arranged in the cylinder, a spiral groove provided on the peripheral surface of the rotating body at a pitch that gradually decreases along the axial direction, and the groove. And a plurality of compression chambers that are gradually divided into smaller volumes by the blades, and the cylinder and the rotating body are rotated at a relative peripheral speed and synchronously. 14. The fluid compressor according to claim 13, further comprising: a rotational force transmission mechanism that compresses and discharges the refrigerant gas sucked into the compression chamber while gradually transferring it to the compression chamber. 15. The sliding member according to claim 1, wherein one of the sliding members is a piston and the other is a cylinder.
4. The fluid compressor according to 4.