JPH05256282A - Rotary compressor - Google Patents

Abstract

PURPOSE:To prevent a piston peripheral surface from wearing by forming a piston into a double structure having a single inner and outer roller, and drilling holes of connecting both internal and external surfaces of the one roller, so as to decrease a slip speed of the piston in the point end of a blade. CONSTITUTION:When a piston 16 mounted on an eccentric part 18 of a shaft 17 is eccentrically rotated along an internal wall of a cylinder 15 in a closed vessel 14 of a rotary compressor 13, a refrigerant is sucked to a suction chamber 21 and further compressed by a compression chamber 2. Here is formed the piston 16 into a double structure to generate a slip between two rollers 16a, 16b and also to decrease (delay) an angular speed of rotation of the one roller 16a on its own axis. Lubricating oil supplied to an internal peripheral side of the piston 16 from the shaft 17 is supplied to pass through a communication hole 24 of the other roller 16b to a clearance between both the rollers 16a, 16b. In this way, a slip speed of the piston 16 in the point end of a blade 19 is decreased thus to prevent wear in a peripheral surface of the piston 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor used in an air conditioner or the like.

[0002]

2. Description of the Related Art In recent years, as the speed of rotary compressors has increased, the wear of the outer peripheral surface of the roller has increased due to the sliding between the roller and the blade, resulting in a decrease in performance and a tendency to cause locking. The tendency is stronger than in the past, and improvement of wear on the outer peripheral surface of the roller is strongly desired.

An example of a rotary compressor (Japanese Patent Laid-Open No. 62-48984) will be described below with reference to the drawings.

FIGS. 3 and 4 are vertical and horizontal sectional views of the rotary compressor, FIG. 5 is a perspective view showing a method of manufacturing the roller, and FIG.
Is a sectional view of the roller, and FIG. 7 is a graph showing abrasion resistance.

In FIG. 3, reference numeral 1 is a case body. An electric motor unit 2 and a compressor unit 3 are provided inside the case body 1. The electric motor unit 2 is provided with an eccentric portion 6 on a shaft 5 which rotates integrally with the roller 4, and the eccentric portion 6 is adapted to eccentrically rotate in a cylinder 7 of the compressor unit 3. A roller 8 is fitted to the eccentric portion 6 as shown in FIG. 4, and a blade 9 is in sliding contact with the roller 8. The roller 8 is made of an aluminum material, and the surface thereof, that is, the outer peripheral portion, the upper surface portion, and the lower surface portion are coated with the ceramic coating film 10. The ceramic coating film 10 is specifically an amorphous silicon film, which is a film containing at least one atom of carbon and nitrogen, and has excellent wear resistance.

A method of manufacturing the roller 8 will be described. First, as shown in FIG. 5, an aluminum material is continuously extruded into a pipe shape to form a roller material 11. Next, the roller body 11 is formed by cutting the roller material 11 into a predetermined length.
2, a ceramic coating is applied to the surface as shown in FIG. When applying this coating, amorphous Si
_{Since 3} N ₄ and SiC can be deposited by a CVD method or the like at a low temperature and at a relatively high speed, they are highly producible in mass production.

Moreover, as described above, the wear resistance can be improved by applying the ceramic coating to the surface of the roller 8.

That is, as shown in FIG. 7, in the case of Si ₃ N _{4 with} each other, the seizure load becomes extremely low without oil, but by combining cast iron and Si ₃ N ₄ , oil・ The seizure load will be high regardless of nothing. This is because the melting points of the ceramic material and the metal are extremely different, so that no adhesion occurs. Moreover, since it is in the Freon atmosphere, iron chloride is formed on the iron-based side, which is effective in reducing friction.

[0009]

However, in the above-mentioned structure, the corners of the outer peripheral surface of the roller are liable to come into contact with the end plate having the bearing, and the peeling of the ceramic coating layer is likely to occur. It is necessary to take measures such as the above, but this leads to a large decrease in performance. Also,
On the outer peripheral surface of the roller, blade jumping occurs at the time of excessive operation such as starting or defrosting, an impact load is applied to the outer peripheral surface of the roller, and the ceramic coating layer is broken or peeled. Furthermore, the difference in the coefficient of thermal expansion between the aluminum-based material used as the base material of the roller and the ceramic coating layer is large, and cracks and delamination occur in the ceramic coating layer due to thermal fatigue associated with ON-OFF operation.

In addition to the above-mentioned decrease in reliability, there is a problem that the cost increases because the ceramic coating layer is formed. In particular, when the PVD method is used, the yield is poor and the tendency is strong.

In view of the above problems, the present invention provides a highly reliable rotary compressor capable of preventing abrasion of the outer peripheral surface of the roller during high speed operation.

[0012]

In order to solve the above-mentioned problems, a rotary compressor according to the present invention has a piston, which is eccentrically rotated along an inner wall of a cylinder, having a first outer roller and a second inner roller. The second roller has a double-layered structure and has a hole through which the inner surface and the outer surface of the second roller communicate with each other.

[0013]

According to the present invention, with the above-described structure, sufficient lubrication is supplied to the gap between the first roller and the second roller through the communication hole of the second roller to cause slippage on the first roller, and The sliding speed of the first roller is reduced to prevent abrasion of the outer peripheral surface of the piston.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotary compressor according to an embodiment of the present invention will be described below with reference to the drawings.

First, as described above, the object of the present invention is to provide a highly reliable rotary compressor which prevents abrasion of the outer peripheral surface of the piston as described above, and is capable of high-speed defrosting and high-speed starting. A rotary compressor is provided. Especially for high-speed defrosting, lubricating oil flows out of the compressor due to forming at the start of defrosting and heating return, and temporary lack of lubricating oil occurs in the sliding part of the piston and shaft, which may prevent high-speed defrosting. Is becoming

For high-speed start, the sliding of the eccentric part of the shaft and the piston causes the piston to expand faster and greatly than the cylinder, and comes into contact with the end plates at the upper and lower parts of the piston to cause a start failure, resulting in a high-speed start. It is an obstacle. FIG. 1 is a cross-sectional view of a rotary compressor according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a piston.

In FIG. 1, reference numeral 13 is a rotary compressor, and a cylinder 15 is welded and fixed to the inside of a closed container 14. 16 is a piston, the first roller 1 on the outside
6a and a second roller 16b on the inside, are fitted into the eccentric portion 18 of the shaft 17, and the cylinder 15 is rotated as the shaft 17 rotates.
It makes an eccentric rotation motion along the inner wall of the.

As shown in FIG. 2, a hole 24 is formed in the second roller 16b of the piston 16 so that the first roller 16a and the shaft 17 communicate with each other. Further, a gap is formed between the first roller 16a and the second roller 16b, and
The outer diameter of the roller 16b is set to be smaller in the upper and lower portions than in the central portion in the height direction. That is, the gap in the central portion of the second roller 16b is set to be equal to the gap between the eccentric portion 18 and the second roller 16b in the range of height equal to or higher than the eccentric portion 18 of the shaft 17, The lower clearance is set larger than the central clearance. Furthermore, the coefficient of thermal expansion of the second roller 16b depends on the shaft 17, the cylinder 15 and the first roller.
Is smaller than the roller 16a. Reference numeral 19 denotes a blade, which is urged by a spring 20 and a back pressure to constantly contact the outer periphery of the first roller 16a, and divides the internal space of the cylinder 15 into a suction chamber 21 on the low pressure side and a compression chamber 22 on the high pressure side. .. Incidentally, 23 is a suction pipe, which is connected to the suction chamber 21.

The operation of the rotary compressor configured as described above will be described below with reference to FIG.

The rotation of the shaft 17 causes the piston 16 to eccentrically rotate along the inner wall of the cylinder 15, so that the refrigerant is sucked in the suction chamber 21, and the compression and discharge valve (not shown) of the refrigerant in the compression chamber 22. Closed container 14 via
Discharging to the inside. However, since the piston 16 is rotatably attached to the eccentric portion 18 of the shaft 17,
The movement is a combination of the movement performed with the center of the eccentric portion 18 and the movement around the center of the eccentric portion 18, and the blade 19
The sliding velocity V of the piston 16 at the tip of is given by the following equation.

V = r · Wp + e · Ws · cos θ / cos α where r = piston radius, e: eccentricity, Wp, Ws:
Piston rotation angular velocity, shaft rotation angular velocity, θ: crank angle, α = sin ⁻¹ ((R−r / r) sin θ), R: cylinder radius.

The rotational movement of the piston 16 mainly occurs in the piston 1.
A friction moment due to the oil film of the inner circumference of 6 and the eccentric part 17,
It is determined by the tangential force at the sliding portion between the outer circumference of the piston 16 and the tip of the blade 19, and as the rotation speed of the shaft 17 increases, the rotation angular velocity of the piston 16 increases, and the sliding speed of the piston 16 at the tip of the blade 19 increases due to the above formula. Become. However, the piston 16 has a double structure, slippage occurs between the first roller 16a and the second roller 16b, and the rotation angular velocity of the first roller 16a is small and slow. Further, the lubricating oil supplied from the shaft 17 to the inner peripheral side of the piston 16 passes through the communication hole 24 of the second roller 16b and the first
Since it is supplied to the gap formed between the roller 16a and the second roller 16b, the friction moment due to the oil film is further reduced.

As a result, the sliding speed of the first roller 16a at the tip of the blade 19, that is, the piston 16, is very small, and the outer peripheral surface of the piston 16 can be prevented from being worn. Further, the power loss generated at the tip of the blade 19 is small, the efficiency of the rotary compressor can be improved, and the power consumption of the air conditioner can be reduced. Furthermore, since the second roller 16b has a smaller coefficient of thermal expansion than the cylinder 15, the height of the cylinder 15 is not reached until the temperature of the compressor 13 is balanced, and a sufficient gap in the height direction is secured. Therefore, contact between the piston 16 and the upper and lower end plates does not occur. That is, it is possible to provide an air conditioner that enables a smooth high-speed start and has a quick rise in temperature. Furthermore, since the room temperature can be raised to the set temperature in a short time, the annual power consumption can be reduced and a highly efficient air conditioner can be provided.

[0024]

As described above, according to the present invention, the piston that eccentrically rotates along the inner wall of the cylinder has a double structure of the outer first roller and the inner second roller, and the inner surface of the second roller is A hole that connects the outer surface with the outer surface is formed, so that not only can the wear of the outer circumference of the piston be prevented and the reliability of the rotary compressor can be improved, but also the efficiency can be improved. It also has the effect of improving the start-up performance and comfort of the device.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rotary compressor according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a piston according to a second embodiment of the present invention.

FIG. 3 is a vertical sectional view of a conventional rotary compressor.

FIG. 4 is a transverse sectional view of a conventional rotary compressor.

FIG. 5 is a perspective view showing a manufacturing process of a roller of a conventional rotary compressor.

FIG. 6 is a vertical sectional view of a roller of a conventional rotary compressor.

FIG. 7 is a graph showing wear resistance of a roller material of a conventional rotary compressor.

[Explanation of symbols]

 15 Cylinder 16 Piston 16a First Roller (Outer) 16b Second Roller (Inner) 24 Communication Hole

Claims (3)

[Claims] 1. An electric motor element, a crank shaft driven by the electric motor element, a piston rotatably fitted to an eccentric portion of the crank shaft, and a reciprocating motion with the tip of the piston in contact with the electric motor element. A blade that divides the inside of the cylinder into a suction chamber and a compression chamber, and a compressor element that is formed by a bearing end plate that supports the crankshaft and closes both end openings of the cylinder are housed, and the piston is placed on the outer side. 1
2. The rotary compressor having a double structure including the second roller inside and the second roller, and having a hole through which the inner surface and the outer surface of the second roller communicate with each other. 2. The rotary compressor according to claim 1, wherein a gap is formed between a first roller outside the piston and a second roller inside the piston. 3. The rotary compressor according to claim 2, wherein the coefficient of thermal expansion of the second roller is smaller than that of the cylinder or the first roller.