JPH08121365A - Rotary type motor-driven compression device - Google Patents

Abstract

PURPOSE: To prevent deterioration of refrigerating machine oil and a refrigerant and to prevent the generation of sludge by a method wherein a vane is formed of high speed tool steels on the surface of which nitrifying treatment and physical deposition treatment of chrome nitride are doubly applied and a rotor is formed of a quenched material of continuous casting cast iron. CONSTITUTION: After continuous casting cast iron on a market is cut in a given shape and cut and polished, the casting cast iron is held approximately at 930 deg.C for approximately one hour and thereafter, quenching is applied to produce a rotor 20. Meanwhile, in a vane 30, high speed tool steels on a market are cut in a given shape and cut and polished, a given nitride layer with a given thickness of, for example 60-70μm is formed on a surface layer. Further, a layer of chrome nitride is formed on the nitride layer through a physical deposition method. Surface hardness of the vane 30 is set to approximate Hv200. Thus, wear of the rotor and the vane being a slide member is low, refrigerating machine oil and a refrigerant are prevented from deterioration owing to the generation of heat at the slide part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric compressor which drives a compression mechanism of an eccentric circular piston while closely contacting the inner circumference of a circular cylinder with an electric motor.

A rotary electric compressor of this type is constructed such that a crescent-shaped gap chamber formed between an eccentric circular piston and a circular cylinder is partitioned by a sliding pendulum to form a suction chamber and a compression chamber. There is a pendulum type compression mechanism, and further, a rotasco type compression mechanism (hereinafter, referred to as the first conventional art) in which one sliding pendulum mechanism is configured to move in and out on the outer peripheral side of the cylinder, and a plurality of sliding pendulum mechanisms are provided in the piston. The movable wing type compression mechanism (hereinafter referred to as the second conventional technology) configured to move in and out on the inner peripheral side is disclosed in
It is disclosed in Chapter 2, "Volume type blowers and compressors", etc., 10th edition of the Mechanical Engineering Handbook issued in September 1993.

In addition, an electric compression mechanism having a structure in which an eccentric circular piston of a Rotasco type compression mechanism similar to that of the above-mentioned first prior art is rotated by an electric motor is provided in a hermetically sealed container for both buffering pressure fluctuation and accumulating pressure. The configuration of the rotary type electric compression device housed in the above (hereinafter referred to as the third prior art) is related to the application of the applicant of the present application, which is Japanese Patent Publication No. 4-72074 and Japanese Patent Laid-Open No. 4-16669
No. 6 and the like.

This third conventional rotary electric compressor 5
As shown in FIG. 3, the functional configuration of 00 is such that the Rotasco type compression mechanism, that is, the rotary compression mechanism 100 is rotated by the electric motor 200, and the compressed fluid 120 (for example, CFC (chlorofluorocarbon) -12 or the like CFC gas) is sucked. The pressurized fluid 130 sucked in through the hole 51 and compressed by the rotary compression mechanism, and the compressed pressurized fluid 130 is discharged through the discharge hole 52 into the load pipe 300, for example, the cooling unit of the refrigerating machine, and the necessary equipment and its auxiliary pipes. After being stored in the accumulator 400, which also serves as a buffer for pressure fluctuation and a storage portion of fluid, it is returned to the suction hole 51 side.

The front portion of the suction hole 51 and the discharge hole 52
Check valves 53 and 54 are provided in the rear portion for the purpose of avoiding a short circuit between the pressurized side and the pressurized side during the compression operation of the rotary compression mechanism 100.

A cross-sectional view of a specific structure of the rotary compression mechanism 100 shows a cylinder 10 and a cylinder 10, as shown in FIG.
The rotor 20 serving as a piston, the vane 30 serving as a sliding pendulum, and the spring 40 that pushes the vane 30 with an elastic force are mainly configured, and the rotor 20 is rotated by the electric motor 200. A shaft 60 for rotating the 20 in an eccentric state is driven by the electric motor 200.

The cylinder 10 has a circular inner surface 11 having an inner diameter D1 and a height A1 (not shown) in the direction perpendicular to the plane of the drawing.
And an outer surface 21 of the rotor 20 is a circle having an outer diameter D2 which is eccentric from the center 12 of the inner surface 11 of the cylinder 10 by an eccentric amount E, and is perpendicular to the paper surface. A cylindrical shape having a height A2 (not shown) is formed.

Then, the rotor 20 rotates about the center 12 of the inner surface 11 of the cylinder 10 while keeping the outer surface 21 in close contact with the inner surface 11 of the cylinder 10, and both sides of the height A2 of the rotor 20, that is, the paper surface. The parallel outer surface and both surfaces having the height A1 of the cylinder 10, that is, the inner surface parallel to the paper surface, are configured to move in close contact with each other.

Therefore, between the cylinder 10 and the rotor 20, a crescent-shaped gap chamber 50 having a maximum width B which is twice the width of the eccentricity E is formed.
The crescent-shaped position of the interstitial chamber 50 is rotating along the inner surface 11 of the cylinder 10 together with the rotation of the cylinder.

The vane 30 has a flat outer shape,
Since the portion having the thickness T is not in close contact with the guide hole 14 provided in the outer wall portion 13 of the cylinder 10, it is assembled so as to be able to go in and out of the outer wall portion 13 of the cylinder 10, and the height A3 (not shown).
Is the same as the height A2 of the rotor 20, and both sides of the height A3, that is, the plane parallel to the paper surface move in close contact with both sides of the height A1 of the cylinder 10 that is, the plane parallel to the paper surface.

The outer wall portion 13 of the cylinder 10 adjacent to the vane 30 is provided with a suction hole 51 on one side and a discharge hole 52 on the other side, and the rear end side 31 of the vane 30 has an anti-compression type elastic force. By pushing out with the spring 40 that has
The amount of protrusion X of the vane 30 changes according to the rotation of the rotor 20, and the tip end side 32 of the vane 30 is brought into close contact with the outer surface of the rotor 20.

The clearance chamber 50 changes in the order of (A) → (B) → (C) as the rotor 20 rotates, and the chamber portion on the suction hole 51 side is covered with the vane 30 as a boundary. The suction-side suction chamber 50A serves as the pressurizing side, and the chamber portion on the discharge hole 52 side serves as the compression-side compression chamber 50B.

When the compressed fluid 120 taken into the suction chamber 50A from the suction hole 51 is compressed while being transferred to the compression chamber 50B by the rotation of the rotor 20, the friction between the rotor 20 and the vane 30 causes the contact sliding portion to wear. To avoid this, conventionally, the rotor 20 is formed of, for example, Mo—Ni—Cr-added cast iron, and the vane 30 is formed of high-speed tool steel (for example, S
KH-51).

[0014]

However, in the structure of the third prior art described above, HCFC (hydrochlorofluorocarbon) -22, -123, -141b, which is a CFC substitute for the specified CFC in the fluid to be compressed, When HFC (hydrofluorocarbon) -134a or the like is used, the compatibility with mineral oil or synthetic oil that has been conventionally used as a refrigerating machine oil is poor, so that it is separated into two liquids and the sliding surface is worn,
There is a problem that it is easily damaged. Further, there is also a problem that heat is generated in the scratched sliding portion, which easily deteriorates the refrigerating machine oil or the refrigerant, thereby easily generating sludge.
Then, even when a special ester such as a hindered ester is used as the refrigerating machine oil, there is a problem that the deterioration of the refrigerating machine oil and the refrigerant and the generation of sludge cannot be avoided, and these problems are solved. Was there.

[0015]

According to the present invention, a cylinder having a circular inner surface as described above and a rotor having a circular outer surface eccentric from the center of the circular inner surface are provided, and the circular inner surface and the circular outer surface are provided. By closely rotating the rotor, the crescent-shaped clearance chamber formed between the cylinder and the rotor is rotated, and the vane for partitioning the clearance chamber into the suction chamber and the pressurization chamber is elastically driven by the spring. A rotary electric compression device for pressurizing a fluid by driving a rotary compression mechanism having a constitution of pushing out by means of an electric motor, wherein a high speed tool in which the vane is subjected to double nitriding treatment and chromium nitride physical vapor deposition treatment The rotor is made of steel, and the rotor is made of a hardened material of continuous cast iron so that the above problems can be solved.

[0016]

[Function] The vane is formed of high speed tool steel whose surface is subjected to double nitriding and physical vapor deposition of chromium nitride.
Since the rotor is made of a hardened material of continuous cast iron, wear on the sliding surface is small and scratches are unlikely to occur. For this reason, the sliding part generates heat and the refrigerating machine oil and refrigerant deteriorate,
It is also prevented that sludge is generated.

[0017]

EXAMPLE An example of the present invention will be described in more detail below. The present invention is a new material of the prior art, and its shape is not different from that of the prior art. Therefore, description will be given using the drawings used for explaining the prior art.

In the rotary electric compressor of the present invention,
A commercially available continuous cast iron, for example, a continuous cast bar manufactured by Rainbow Technology Co., Ltd. (FC25 with Ni of 0.1 to 0.2 Wt% and Cr of 0.
2% by weight or less, 0.07 to 0.2% by weight of Mo, and 0.25% by weight or less of Ti) are cut into a desired shape, cut, and polished, and then held at 930 ° C. for 1 hour, Rotor 2 with oil quenching and hardness of Hv460-480
0 was created.

The rotor 20 is a turquoise manufactured by Nippon Piston Ring Co., Ltd. (FC30 has 0.04 W of B).
t% added) or alloy Turkaloy (FC30
0.2 wt% of Cu and Ni combined, 0.9 w of Cr
t%, 0.2 wt% of Mo added) or the like.

On the other hand, the vane 30 is a commercially available high speed tool steel,
For example, after SKH-51 is cut, cut, and polished into a desired shape, for example, an ion nitriding method using a direct current glow discharge plasma, that is, a processing temperature: 520 ° C., a processing time: 3
0 minutes, atmospheric pressure; 4 torr, working gas N ₂ / H ₂ ;
Ion nitriding is performed under the condition of 7/3, and about 60-7
A nitride layer (not shown) having a thickness of 0 μm was formed, and a layer of chromium nitride (not shown) having a thickness of 5 μm, for example, was formed on the nitride layer by physical vapor deposition, for example, arc ion plating. And the surface hardness of the vane 30 is
It was Hv2000.

The rotary electric compressor provided with the rotor 20 and the vane 30 formed as described above is used as the rotary compression mechanism 100 of FIG. 3, ester oil is used as refrigerating machine oil, and HFC-134a is used as the refrigerant. The refrigeration cycle used is configured to perform continuous operation for 720 hours (24 hours x 30 days), and the sliding surface of the rotor 20 and the vane 30 is observed, the deterioration state of the refrigerating machine oil, and the amount of sludge generated. As a result of investigation, the sliding surface between the rotor 20 and the vane 30 was almost the same as that at the time of manufacturing, was smooth and had no flaws, and the refrigerating machine oil had a total acid value of 0.0.
The amount was 1 mgKOH / g or less, sludge was hardly generated, and the operation could be further continued in any of the inspection items.

On the other hand, the rotor 20 is made of high-speed tool steel SKH-.
In the conventional refrigeration cycle in which the rotary electric compression device having the vane 30 made of Mo-Ni-Cr added cast iron is used as the rotary compression mechanism 100 in FIG. 3, ester oil is used as refrigerating machine oil and a refrigerant is used. HFC-134
When the operation was carried out using a, the rotary electric compressor generated severe vibration and abnormal sound after only 200 hours of continuous operation, so the operation was stopped. Then, when the sliding surface between the rotor 20 and the vane 30 at this point was observed and the deterioration state of the refrigerating machine oil and the amount of sludge generated were investigated, numerous scratches were generated on the sliding surface between the rotor 20 and the vane 30. However, the refrigerating machine oil had a total acid value of 1.0 mgKOH / g or more, and a large amount of sludge was generated.

The rotor 20 has been described as having a structure in which a member having an eccentric circular outer shape is directly formed in a crankshaft shape and rotated, but in practice, as shown in FIG. 2, the rotor 20 is worn out. In order to reduce the above, the outer peripheral portion 20A outside the portion of the dotted line F is formed by the hard material, that is, the hardened material of continuous cast iron, with the portion indicated by the dotted line F being the dividing portion inside the rotor 20. , The outer surface 21 of the outer peripheral portion 20A of the rotor 20 makes rolling contact with the inner surface 11 of the cylinder 10 by forming a ball bearing between the member on the crankshaft 25 side, that is, a portion near the position of the dotted line F. Is configured as follows.

By the way, since the present invention is not limited to the above-mentioned embodiments, various modifications can be made without departing from the scope of the claims.

For example, the nitride layer formed on the vane 30 is
The sample may be formed by heating the sample in an ammonia gas atmosphere and diffusing nascent nitrogen decomposed from the ammonia gas into the steel.

For example, the method of forming the chromium nitride layer on the surface may be another physical vapor deposition method performed by high frequency heating, electron beam heating, laser heating, or the like.

Further, the continuously cast iron for forming the rotor 20 and the high speed tool steel for forming the vanes 30 may be commercially available ones or specially melted products in which the main components are adjusted to the prescribed components. It may be. Further, an iron-based material having excellent nitridability, such as nitride steel or high Cr steel, may be used.

[0028]

As described above, according to the present invention, the cylinder having the circular inner surface and the rotor having the circular outer surface eccentric from the center of the circular inner surface are provided, and the circular inner surface and the circular outer surface are closely contacted with each other. By rotating the rotor, a crescent-shaped clearance chamber formed between the cylinder and the rotor is rotated, and a vane for partitioning the clearance chamber into a suction chamber and a pressure chamber is pushed out by a spring or the like. In a rotary electric compressor for pressurizing a fluid by driving a rotary compression mechanism having an electric motor, the vane is formed of a high speed tool steel in which a nitriding treatment and a physical vapor deposition treatment of chromium nitride are double-treated. Then, since the rotor is a rotary electric compression device formed by a hardened material of continuous cast iron,

The rotor and the vane, which are sliding members, have little wear and are not easily scratched. For this reason, it is effectively prevented that heat is generated in the sliding portion to deteriorate the refrigerating machine oil or the refrigerant or generate sludge.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of an apparatus.

FIG. 2 is a cross-sectional view showing the main parts of the device.

FIG. 3 is a block diagram of a refrigeration cycle.

[Explanation of symbols]

 10 cylinder 11 inner surface 20 rotor 21 outer surface 30 vane 31 rear end side 32 front end side 40 spring 51 suction hole 52 discharge hole 53 check valve 54 check valve 100 rotary compression mechanism 120 compressed fluid 130 pressurized fluid 200 electric motor 300 load Pipe line 400 Accumulator 500 Rotary electric compressor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuo Hagiwara 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (1)

[Claims] 1. A cylinder having a circular inner surface and a rotor having a circular outer surface eccentric from the center of the circular inner surface are provided.
By rotating the rotor while closely contacting the circular inner surface and the circular outer surface, the crescent-shaped gap chamber formed between the cylinder and the rotor is rotated, and the gap chamber is pressurized with the suction chamber. In a rotary electric compression device that presses a fluid by driving a rotary compression mechanism that pushes a vane for partitioning into a chamber with a spring etc., a nitriding treatment on the surface of the vane and a physical vapor deposition treatment of chromium nitride And a rotor made of a hardened material of continuous cast iron, the rotary electric compressor.