JPH02207189A - Rotary compressor - Google Patents

Abstract

PURPOSE:To prevent the abrasion on the outer periphery of a piston and improve compression efficiency by forming the piston eccentrically rotated along the inner wall of a cylinder with the outside and inside rollers and forming multiple oil sumps between the rollers. CONSTITUTION:A cylinder 15 is fixed inside the enclosed container 14 of a rotary compressor 13. Rollers 16a and 16b are provided on the outside and the inside of the piston 16, and they are coupled with the eccentric section 18 of a shaft 17 and eccentrically rotated along the inner wall of the cylinder 15 as the shaft 17 is rotated. Multiple notches 24 and 25 are symmetrically formed at the center in the height direction on the outer periphery of the inside roller 16, and multiple oil sumps 26 and 27 are formed with the inner periphery of the outside roller 16a. Multiple lubricant guide paths 28 and 29 guiding the lubricant inside the outside roller 16a to the oil sumps 26 and 27 are opened at the lower section of the eccentric section 18 of the shaft 17.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rotary compressor used in air conditioners and the like.

Conventional technology In recent years, as the speed of rotary compressors has increased, wear on the outer peripheral surface of the rollers has increased due to the sliding between the rollers and blades, which has tended to reduce performance and cause locks to occur more easily. It is strongly desired to be stronger than conventional rollers and to improve wear on the outer circumferential surface of the roller.

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

Figures 3 and 4 are longitudinal and cross-sectional views of the rotary compressor, Figure 5 is a perspective view showing the method of manufacturing the roller, Figure 6 is a cross-sectional view of the roller, and Figure 7 shows the wear resistance. This is a graph showing.

In FIG. 3, 1 is the case body. An electric motor section 2 and a compressor section 3 are provided inside the case body l. In the electric motor section 2, an eccentric section 6 is provided on a shaft 5 that rotates together with a roller 4, and this eccentric section 6 has the above-mentioned pressure mm.
It is adapted to perform eccentric rotational movement within the cylinder 7 of the section 3. A roller 8 is fitted into 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 aluminum material, and a ceramic coating film 10 is applied to its surface, that is, the outer circumference, upper surface, and lower surface.
This ceramic coating film 10 is specifically an amorphous silicon film containing atoms of at least one of carbon and nitrogen, and has excellent wear resistance.

A method of manufacturing the roller 8 will be explained.

First, as shown in FIG. 5, an aluminum material is continuously extruded into a pipe shape, thereby forming a roller material 11. Next, a roller body 12 is formed by cutting this roller material 11 into a predetermined length, and a ceramic coating is applied to the surface of this roller body 12 as shown in FIG. During this coating, amorphous S
L, N, and SIC are highly mass-producible because they can be deposited at low temperatures and at relatively high speeds using the CVD method or the like.

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

In other words, as shown in Fig. 7, in the case of 5isNn, the seizure load is extremely low in the absence of oil, but
By combining cast iron and 5isNn, the seizure load becomes high regardless of the presence or absence of oil. This is because the melting points of the ceramic material and the metal are extremely different, so no adhesion occurs, and since it is in a Freon atmosphere, iron chloride is formed on the iron-based side, which is effective in reducing friction. be.

Problems to be Solved by the Invention However, with the above configuration, the corners of the outer peripheral surface of the roller come into contact with the end plate having the bearing, and the ceramic coating layer is likely to peel off.To prevent this, chamfering or other measures are required. Countermeasures are required, but this will lead to a significant drop in performance.Furthermore, blade jumping will occur on the outer circumferential surface of the roller during excessive operations such as starting or defrosting, and impact loads will be applied to the outer circumferential surface of the roller. , destruction or peeling of the ceramic coating layer occurs. Furthermore, there is a large difference in thermal expansion coefficient between the aluminum material used as the base material of the roller and the ceramic coating layer, and the ceramic coating layer may crack or peel due to thermal fatigue associated with ON-OFF operation.

In addition to the above-mentioned deterioration in reliability, there is also the problem of high costs due to the formation of a ceramic coating layer. In particular, when the PVD method is used, the yield rate tends to be poor.

In view of the above-mentioned problems, the present invention provides a highly reliable rotary compressor that can prevent wear of the outer circumferential surface of the roller during high-speed operation.

Means for Solving the Problems In order to solve the above problems, the rotary compressor of the present invention has the following features:
A piston that eccentrically rotates along the inner wall of a cylinder is constructed in two layers, and a plurality of oil reservoirs are provided between a first roller on the outside of the piston and a second roller on the inside.

According to the above-described structure, the present invention uniformly supplies lubricating oil from the oil reservoir to the gap formed between the first roller and the second roller, causing the first roller to slip, and causing the blade to slip. This reduces the sliding speed of the first roller to prevent wear on the outer peripheral surface of the piston.

EXAMPLE Hereinafter, a rotary compressor according to an example of the present invention will be described with reference to the drawings.

First, an object of the present invention is to provide a rotary compressor that prevents wear on the outer circumferential surface of the piston and is highly reliable as described above, as well as to provide a rotary compressor that can be started at high speed. The purpose is also

In particular, regarding the latter, during a cold start, the inside of the piston thermally expands faster and more greatly than the other parts due to the sliding between the eccentric part of the shaft and the inner diameter surface of the piston, and it contacts the end plates at the top and bottom of the piston, causing sudden The increase in current causes starting problems, which hinders high-speed starting.

FIG. 1 is a cross-sectional view of a rotary compressor according to an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of a piston.

In FIG. 1, 13 is a rotary compressor, and a cylinder 15 is welded and fixed inside a closed container 14. 1
6 is a piston, which has a first roller 16a on the outside and a second roller 16b on the inside, is fitted into the eccentric portion 18 of the shaft 17, and eccentrically rotates along the inner wall of the cylinder 15 as the shaft 17 rotates. exercise.

As shown in FIG.
A gap is formed between a and the second low'near 16b,
Two notches 24.25 are cut at symmetrical positions near the center of the outer circumference of the second roller 16b in the height direction, and oil reservoirs 26.27 are formed with the inner circumferential surface of the first roller 16a. . Reference numerals 28 and 29 denote lubricating oil introduction passages that lead the lubricating oil inside the first roller 16a to the oil reservoirs 26 and 27;
It opens at the lower part of the eccentric part 18 (double-dashed line) of No.7. Further, the coefficient of thermal expansion of the second roller 16b is set smaller than that of the first roller 16a and the cylinder 15. Furthermore, the gap between each roller 16a, 16b and the gap between the second roller 16b and the eccentric portion 18 of the shaft 17 are set to be optimal under a standard load.

The operation of the rotary compressor configured as described above will be explained below using FIG. 1.

The rotation of the shaft 17 causes the piston 16 to rotate eccentrically along the inner wall of the cylinder 15, thereby sucking refrigerant into the suction chamber 21, compressing the refrigerant in the compression chamber 22, and discharging the refrigerant through a discharge valve (not shown). Discharge into the inside of the closed container 14 is performed. However, since the piston 16 is rotatably attached to the eccentric part 18 of the shaft 17, its movement is a combination of movement with the center of the eccentric part 18 and movement around the center of the eccentric part 18, and the movement at the tip of the blade 19 The sliding speed V of the piston 16 is given by the following equation.

V-r-Wp+e-Ws-cosθ/cosα where, r-piston radius, e: eccentricity, Wp, crank angle, α=sing' (sinθ), R" indicates the cylinder radius.

The rotational movement of the piston 16 is mainly caused by the friction moment caused by the oil film between the inner circumference of the piston 16 and the eccentric part 17, and by
The piston 1
6 increases, and the sliding speed of the piston 16 at the tip of the blade 19 increases according to the above equation.

However, the piston 16 has a double structure and each roller 6a
, 16b have small rotational inertia, and the pressure difference between the pressure inside the second roller 16b and the pressure at the upper and lower end surfaces of the gaps between the rollers 16a and 16b makes it possible to lubricate the inside of the second roller 16b. Oil is supplied to each lubricating oil introduction path 28.29
and each roller 1 from a symmetrical position via each oil sump 26, 27.
6a and 16b, and the first roller 16a
Since the sliding motion of the second roller 16b is in a fluid lubrication state with low frictional resistance, the influence of the frictional force at the tip of the blade 19 appears to be large, and the first roller 16a greatly slides with respect to the second roller 16b. .

As a result, the rotational angular speed of the first roller 16a becomes very slow, the sliding speed at the tip of the blade 19 becomes sufficiently small, and no wear occurs on the outer circumferential surface of the piston 16. Furthermore, since the sliding speed is low, power loss due to sliding of the tip of the blade 19 is also small, and the efficiency of the rotary compressor and air conditioner can be improved.

On the other hand, at the time of startup, the temperature of the compressor 13 is low, and the second roller 1
The gap between 6b and the eccentric portion 18 is large.

By starting the compressor 13, the shaft 17 rotates at high speed and the second
However, since the gap between the second roller 16b and the eccentric portion 18 is large, the friction moment due to the oil film is small, allowing smooth starting, and more lubricating oil is supplied. temperature rise is slow. Furthermore, since the second roller 16b has a smaller thermal expansion coefficient than the cylinder 15, it does not reach the height of the cylinder 15 before the temperature of the compressor 13 is balanced, and a sufficient gap in the height direction is secured. . Therefore, no contact occurs between the piston 16 and the upper and lower end plates.

In other words, it is possible to provide an air conditioner that can start smoothly and at high speed, and whose temperature rises quickly. Furthermore, since the room temperature can be raised in a short time, annual power consumption can be reduced and a highly efficient air conditioner can be provided. Further, similar functions and effects can be obtained even if a material having a higher thermal conductivity than the cylinder 15 and the first roller 16a is used.

Effects of the Invention As described above, the present invention has a double piston that rotates eccentrically along the inner wall of the cylinder, and a plurality of rollers between the first roller on the outside of the piston and the second roller on the inside. It is equipped with an oil reservoir, and has the advantage of not only being able to realize a highly reliable compressor, but also being able to provide a highly efficient compressor and air conditioner.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a rotary compressor according to a first embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a piston of the first embodiment, and FIG. 3 is a longitudinal sectional view of a conventional rotary compressor. FIG. 4 is a cross-sectional view of a conventional rotary compressor, FIG. 5 is a perspective view showing a method of manufacturing a roller of a conventional rotary compressor, FIG. 6 is a vertical cross-sectional view of a roller of a conventional rotary compressor, and FIG. FIG. 7 is a graph showing the wear resistance of the roller material of a conventional rotary compressor. 15...Cylinder, 16...Piston, 16a...First roller, 16b...
・Second roller, 26.27...Oil sump. Name of agent: Patent attorney Shigetaka Awano Figure 15 - Cylinder 16 - Piston

Claims (2)

[Claims] (1) A rotary compressor with a double piston that rotates eccentrically along the inner wall of a cylinder, and a plurality of oil reservoirs provided between a first roller on the outside of the piston and a second roller on the inside. . (2) The rotary compressor according to claim (1), in which the coefficient of thermal expansion of the second roller is set smaller than that of the first roller and cylinder.