JP2004211651A - Gas compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent welding of metal between a rotor and a cylinder and improve performance by improving sealability between the rotor and the cylinder. <P>SOLUTION: Protection thin film 20 is formed on one or both of an outer circumferential surface of the rotor 18 and an inner circumferential surface of the cylinder 13 of a compressor man body. Ratio (T×2/A×2) of thickness of the protection thin film (T)×2 to the minimum clearance (A×2) between the rotor 18 under condition that the protection thin film is formed and both sides of the cylinder 13 in a radial direction is 0.7 or less. Gas leak is reduced by reducing clearance between the outer circumference and a short diameter part of the cylinder to improve performance. Even when the protection thin film is chipped, welding or the like of metal is avoided and performance as a gas compressor is secured. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gas compressor that is used for air conditioning of automobiles and buildings and compresses and discharges gas such as refrigerant gas.
[0002]
[Prior art]
As a gas compressor used for air conditioning of automobiles and buildings, for example, the one shown in FIG. 3 is used (for example, Patent Document 1). The gas compressor 1 will be described with reference to FIGS. 3 and 4. The gas compressor 1 includes a cylindrical cylinder 13 having an inner periphery, and a front side block 14 and a rear side block 15 at both axial ends of the cylinder 13. . A rotor 18 fixed to a rotating shaft 17 is rotatably arranged in the cylinder 13, and a vane 16 is housed in a vane groove provided on an outer peripheral portion of the rotor 18 so as to be able to protrude and retract. The compressor body 10 is constituted by the cylinder 13, the front side block 14, the rear side block 15, the rotor 18 and the vane 16, and is partitioned by the rotor 18, the vane 16 and the cylinder 13 to form a cylinder compression chamber 19. Is formed.
[0003]
Each of the above members is incorporated in the front housing 11 and the rear housing 12. The front housing 11 has a refrigerant inlet 22, and the rear housing 12 has a discharge port 33. In the front housing 11, a suction chamber 23 communicating with the suction port 22 is provided, and the suction chamber 23 and the cylinder compression chamber 19 communicate with each other. A check valve 24 is provided in a gas flow path between the suction port 22 and the suction chamber 23. When the rotation of the rotor 18 is stopped, the check valve 24 causes the backflow of the refrigerant gas and the oil from the high-pressure side to the low-pressure side only in the gas compressor 1 and to the evaporator side (not shown). It is provided to prevent backflow. This reduces the reverse rotation noise immediately after the operation of the gas compressor 1 is stopped and prevents the hot air from being blown out from the air conditioner outlet due to the backflow of the high-temperature refrigerant gas to the evaporator.
[0004]
A discharge chamber 30 communicating with the cylinder compression chamber 19 is provided in a space formed by the rear side block 15 built in the front side of the rear housing 12 and the rear side of the rear housing 12. The discharge chamber 30 communicates with the discharge port 33. In the discharge chamber 30, an oil separator 31 is provided in the rear side block 15, and gas compressed in the cylinder compression chamber 19 flows from a discharge passage (not shown) formed in the rear side block 15 to the oil separator 31. The oil is guided and passed through the oil separator 31 to be discharged to the discharge chamber 30.
[0005]
In the gas compressor 1, when the rotor 18 is rotated by a rotating shaft 17 that rotates via a belt pulley 21 using a motor (not shown) as a driving source, the volume of the cylinder compression chamber 19 changes, and the suction port 22 and the suction chamber are changed. The refrigerant introduced through 23 is compressed in the cylinder compression chamber 19. The compressed refrigerant is discharged from the cylinder compression chamber 19, discharged to the oil separator 31 through the discharge passage of the rear side block 15, and separates the lubricating oil contained in the compressed gas. The separated lubricating oil drops and stays in the oil reservoir 32, and the compressed gas from which the lubricating oil has been separated is discharged to the discharge chamber 30. The oil in the oil reservoir 32 is fed to a sliding portion of the compressor by a pressure difference due to a pressure difference inside the compressor, and is used for prevention of wear and sealing by an oil film.
[0006]
In the cylinder compression chamber 19, the better the sealing performance between the rotor 18 and the minor diameter portions 13a, 13a of the cylinder 13, the higher the refrigerant compression efficiency and the better the performance. However, the rotor 18 and the cylinder 13 usually use the same metal, and when the outer peripheral surface of the rotor 18 and the inner peripheral surface of the cylinder short diameter portion 13a come into contact with each other, the metals are immediately welded to each other. Therefore, in order to prevent contact, in consideration of the component accuracy of each component, rattling due to clearance of the sliding part, deformation due to assembling, deformation due to operation, etc., a clearance (several tens of μm) that does not make contact between them is considered. You have set.
There is also known a rotor 18 in which a protective thin film such as a fluorine-based resin, copper plating, or lead plating (for example, Patent Document 2) is formed on the outer peripheral surface of the rotor 18 in consideration of the intrusion of foreign matter. When a fluorine resin thin film or the like is applied, even if foreign matter enters, the thin film prevents the foreign matter from being caught. In this case, the ratio between the thickness of the protective thin film × 2 and the minimum clearance on both sides in the radial direction of the rotor and the cylinder in the state where the protective thin film is formed is about 0.3 to 0.6.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-195179 [Patent Document 2]
Japanese Utility Model Publication No. 60-34589
[Problems to be solved by the invention]
By the way, as described above, the sealing performance is improved by reducing the clearance between the outer periphery of the rotor and the short diameter portion of the cylinder, so that the performance as a compressor is improved. In the case where the above-mentioned thin film such as the fluororesin is applied, there is an effect of preventing foreign matter from being caught, and since direct contact between the rotor and the cylinder is avoided, the clearance can be reduced to improve the performance. It is possible. However, when the operation is performed under severe operating conditions and the load is excessive, the thin film of the fluororesin or the like on the outer peripheral surface of the rotor may be scraped off or peeled off. If the protective thin film is lost, metal-to-metal contact occurs with insufficient clearance, causing problems such as welding. Therefore, even when a thin film of a fluororesin or the like is formed on the outer periphery of the rotor, the clearance must be increased to some extent, and it is considered that it is difficult to improve the performance by improving the sealing performance.
[0009]
The present invention has been made in view of the above circumstances, and it is possible to form a protective thin film on the outer periphery of the rotor to improve the sealing property, and also to weld metals even if the protective thin film is peeled off. It is an object of the present invention to provide a gas compressor in which the gas pressure is prevented.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an invention according to claim 1 of the gas compressor of the present invention is provided with a cylindrical cylinder, side blocks at both ends in the axial direction of the cylinder, and rotatably disposed in the cylinder. Having a compressor body that sucks, compresses and discharges a refrigerant gas in the cylinder and discharges the refrigerant gas, and an outer periphery of the rotor. A protective thin film is formed on one or both of the surface and the inner peripheral surface of the cylinder, and the ratio of the thickness of the protective thin film × 2 to the minimum clearance on both sides in the radial direction of the rotor and the cylinder when the protective thin film is formed. Is 0.7 or more.
[0011]
The invention of a gas compressor according to a second aspect is the invention according to the first aspect, wherein the protective thin film is made of a fluororesin.
[0012]
According to a third aspect of the present invention, in the gas compressor according to the first or second aspect, a ratio of the thickness x2 of the protective thin film to the minimum gap amount in a state where the protective thin film is formed is 1.7 or less. It is characterized by being.
[0013]
[Action]
That is, according to the present invention, the clearance between the outer periphery of the rotor and the cylinder is reduced, thereby reducing gas leakage and improving performance.
Further, even when a load is applied to the outer periphery of the rotor and the inner peripheral surface of the cylinder by pressure or the like by operating the gas compressor, welding does not occur because there is no contact between the same kind of metals.
Further, even when the operation is performed under severer conditions and the load becomes excessive, and the coating film is scraped or peeled off, welding between the metals can be avoided because the clearance is sufficiently secured.
[0014]
Hereinafter, numerical conditions defined in the present invention will be described.
Ratio of thickness of protective thin film × 2 / minimum gap amount after formation of protective thin film: 0.7 or more If the above ratio is too small, the clearance after peeling of the protective thin film becomes insufficient. Therefore, the above ratio is essential to be 0.7 or more, and more preferably 0.75 or more. On the other hand, if the above ratio is too large, the thickness of the protective thin film becomes large, which makes production difficult. Therefore, it is desirable to set the upper limit of the ratio to 1.7. When the protective thin film is formed on both the rotor and the cylinder, it is necessary that both the protective thin films satisfy the above conditions. Further, the above-mentioned gap amount is the sum of the gap amounts on both sides in the radial direction between the rotor and the cylinder. In the above ratio, the minimum clearance is the sum of the clearances on both sides between the rotor and the cylinder short diameter portion.
[0015]
In the present invention, the above-described gas compressor main body is provided, and the other components are generally provided with a suction port, a suction chamber, a discharge port, and a discharge chamber.
The protective thin film is formed on one or both of the outer peripheral surface of the rotor and the inner peripheral surface of the cylinder as described above. The protective thin film is desirably made of a material having high strength and excellent lubricity, preferably a fluororesin.
The protective thin film may be formed on either the outer peripheral surface of the rotor or the inner peripheral surface of the cylinder as described above, or may be formed on both of them. Further, the protective thin film may be formed over the entire outer peripheral surface and inner peripheral surface, but may be formed only on a part of the surface including a portion having a minimum gap amount. Good. The method for forming the protective thin film is not particularly limited, and it can be performed by a conventional method such as a spray coating method or a screen coating method.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a gas compressor according to an embodiment of the present invention will be described with reference to FIGS. The gas compressor of this embodiment has the same configuration as that of a conventional gas compressor except for a part, and the description of the same configuration will be omitted or simplified.
This gas compressor includes a cylinder 13 having a cylindrical inner periphery and a front side block 14 and a rear side block 15 at both ends in the axial direction of the cylinder 13 as in the conventional compressor. A rotor 18 fixed to a rotating shaft 17 is rotatably disposed in the cylinder 15, and a vane 16 is housed in a vane groove provided in the rotor 18 so as to be able to protrude and retract. The compressor body 10 is constituted by the cylinder 13, the front side block 14, the rear side block 15, the rotor 18 and the vane 16, and is partitioned by the rotor 18, the vane 16 and the cylinder 13 to form a cylinder compression chamber 19. Is formed. In this embodiment, the minimum clearance between the short diameter portion 13a of the cylinder 13 and the outer peripheral surface of the rotor 18 is shown in FIG. 2B.
[0017]
On the outer peripheral surface of the rotor 18, a protective thin film 20 made of a fluorine-based resin is formed to a predetermined thickness (T in FIG. 2) by a method such as spray coating or screen coating. The amount of clearance (A in FIG. 2) between the outer surface of the protective thin film 20 and the minor diameter portion 13a of the cylinder 13 is equal to the thickness (T) × 2 of the protective thin film 20 in the total amount (A × 2) on both sides. (T × 2 / A × 2) is set to be 0.7 or more (preferably 1.7 or less).
[0018]
In the gas compressor 1, when the rotor 18 is rotated by the rotating shaft 17 rotating via the belt pulley 21 using a motor (not shown) as a driving source, the volume of the cylinder compression chamber 19 changes as in the conventional compressor. The refrigerant introduced through the suction port 22 and the suction chamber 23 is compressed in the cylinder compression chamber 19. The compressed refrigerant is discharged from the cylinder compression chamber 19 to the discharge chamber 30 through the rear side block 15.
[0019]
During the rotation of the rotor 18, the outer peripheral surface of the rotor 18 including the protective thin film 20 and the inner peripheral surface of the short diameter portion 13a of the cylinder 13 have a minimum clearance, and are compressed by high sealing performance. Excellent efficiency. Further, even when the load is excessively operated under severe conditions, the protective thin film 20 prevents the outer peripheral surface of the rotor 18 and the inner peripheral surface of the cylinder 13 from coming into direct contact with each other, thereby preventing welding between metals. You. Also, in the unlikely event that the protective thin film 20 is shaved or peeled off by an excessive load, the outer peripheral surface of the rotor 18 and the short-diameter portion 13a of the cylinder 13 have a sufficient gap amount that can prevent welding between metals. Is secured.
[0020]
【The invention's effect】
As described above, according to the gas compressor of the present invention, a cylindrical cylinder, side blocks at both axial ends of the cylinder, a rotor rotatably disposed in the cylinder, and the rotor A compressor body for sucking, compressing and discharging refrigerant gas in the cylinder, and an outer peripheral surface of the rotor and an inner peripheral surface of the cylinder. A protective thin film is formed on one or both of the surfaces, and the ratio of the thickness of the protective thin film × 2 to the minimum clearance on both sides in the radial direction of the rotor and the cylinder when the protective thin film is formed is 0.7 or more. Therefore, it is possible to reduce the clearance between the outer periphery of the rotor and the short diameter portion of the cylinder, reduce gas leakage, and improve the performance. Further, even when the protective thin film is missing, welding between metals is avoided, and the performance as a gas compressor is ensured.
[Brief description of the drawings]
FIG. 1 is a view showing a longitudinal sectional view according to an embodiment of the present invention.
FIG. 2 is an enlarged schematic view similarly showing a gap between an outer peripheral surface of a rotor and an inner peripheral surface of a cylinder short diameter portion.
FIG. 3 is a front sectional view showing a conventional gas compressor.
FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Compressor main body 11 Front housing 12 Rear housing 13 Cylinder 13a Short diameter part 14 Front side block 15 Rear side block 16 Vane 17 Rotating shaft 18 Rotor 20 Protective thin film 22 Suction chamber 23 Suction port 30 Discharge chamber 31 Oil separator 32 Oil reservoir

Claims (3)

A refrigerant comprising: a cylindrical cylinder; side blocks at both axial ends of the cylinder; a rotor rotatably arranged in the cylinder; and a vane provided on the rotor so as to be able to protrude and retract in the radial direction. A compressor main body that sucks, compresses, and discharges the gas in the cylinder, and has a protective thin film formed on one or both of an outer peripheral surface of the rotor and an inner peripheral surface of the cylinder; A gas compressor, wherein a ratio of a thickness of the thin film × 2 to a minimum clearance on both sides in a radial direction of the rotor and the cylinder in a state where the protective thin film is formed is 0.7 or more. The gas compressor according to claim 1, wherein the protective thin film is made of a fluororesin. 3. The gas compressor according to claim 1, wherein a ratio of the thickness of the protective thin film × 2 to the minimum gap amount in a state where the protective thin film is formed is 1.7 or less. 4.

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