JPS6248983A - Rotary compressor for cooling and heating - Google Patents

Abstract

PURPOSE:To prevent the seizing of a sliding part, reduce the quantity of abra sion, and improve heat exchanging efficiency by forming the inner peripheral wall surface or the sliding part of a cam ring with a sintered alloy of cast iron fiber containing graphite and giving a self-lubricating property to said inner peripheral wall surface. CONSTITUTION:When a rotor 7 rotates, the temperature of a rotor 3 part and a cam ring 2 rises. Since the material of the cam ring 2 is of a sintered alloy of cast iron containing a graphite of 2.5-30% in weight. Therefore, the inner peripheral wall surface of the cam ring 2 acts as a self-lubricating member in the clearance between the sliding part 8 and the rotor 7. Accordingly, friction coefficient between the sliding part 8 and the rotor 7 can be reduced suppressing rise in temperature of the rotor 3 and the cam ring 2 low, and resistance to seizing between the sliding part 8 and the rotor 7 is improved. Also, the feed of lubricating oil can be reduced, the quantity of lubricating oil dissolved in a refrigerant can be reduced, and the heat exchanging efficiency of a rotary compressor for cooling and heating as a whole can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a rotary compressor for air conditioning and heating, and more particularly to the material of the inner circumferential wall surface of a cam ring.

<+7) Prior Art and Problems Conventionally, as a rotor recombiner nozzle for heating and cooling, there is known, for example, the one shown in FIG. 6, disclosed in Japanese Utility Model Application No. 58-106579.

As shown in the figure, a rotor portion is housed within the cam ring a. Inlet ports c, c are provided on the inner peripheral wall surface a1 of the cam ring a.
and discharge ports d, d are opened, and sliding portions r, r on which the rotor e of the rotor portion slides are formed in a part of the inner circumferential wall surface a1 near the discharge holes c, c. As the material for the cam ring a, an FC material containing 2 to 3% carbon is used. The rotor part has vanes g in grooves on the outer peripheral wall of the rotor e.

g2+ g:++ has g4. The refrigerant sucked in from the suction port C rotates while being compressed between adjacent vanes (for example, between g4 and g1) due to the rotation of the rotor portion, and is discharged from the discharge port d. Freon gas is used as a refrigerant.

However, in the conventional rotor recombinant for heating and cooling, FC material is used as the material for the cam ring. Therefore, problems such as seizure and abnormal wear occur, especially in the sliding portion f.

This trend has become more pronounced as the usage conditions have become more severe as air-conditioning compressors become smaller and rotate at higher speeds.

On the other hand, since Freon gas is used as the refrigerant, there is a problem in that lubricating oil with a large heat capacity dissolves in the refrigerant, reducing the overall heat exchange efficiency.

(c) Purpose of the Invention The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a heating and cooling compressor that suppresses seizure and abnormal wear of cam rings and improves heat exchange efficiency. That's true.

Structure of the Invention In order to achieve the above object, the present invention has a rotor, a suction port and a discharge port on an inner circumferential wall surface of the rotor, and a rotor that accommodates the rotor, and a rotor that slides on the inner circumferential wall surface near the discharge port. In a rotary compressor for air conditioning and heating that compresses and discharges refrigerant through the rotation of the rotor, the entire inner peripheral wall surface or the sliding part of the cam ring is made of graphite-containing cast iron fiber sintered. It is composed of bonded metal.

(E) Effect of the Invention According to the present invention having the above configuration, since the inner circumferential wall surface of the cam ring is made of graphite-containing cast iron fiber sintered alloy, the cam ring The inner peripheral wall surface acts as having self-lubricating properties.

In addition, since the inner peripheral wall surface has self-lubricating properties,
It is possible to reduce the amount of ifJ slide oil.

Kube) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

゛Figure 1 shows a rotary compressor for heating and cooling according to this embodiment.

A rotary compressor 1 for heating and cooling according to this embodiment of Kaede is composed of a cam ring 2 and a rotor section 3 housed within the cam ring 2. The inner circumferential wall surface 4 of the cam ring 2 is formed into a substantially elliptical shape. Suction ports 5, 5 and discharge ports 6, 6 are provided on the inner peripheral wall surface 4, and a sliding portion 8.8 on which the rotor 7 of the rotor section 3 slides is provided on a part of the inner peripheral wall surface 4. It is formed near the exits 6, 6. As the material of the cam ring 2, a graphite-containing cast iron fiber sintered alloy is used. The graphite-containing cast iron fiber sintered alloy was developed at the University of Tokyo's Institute of Industrial Science and Technology, and consists of graphite with a flat grain size of approximately 40 microns and self-lubricating properties, and cast iron fibers with a length of 1.2 mm + and a diameter of approximately 30 microns. It is an alloy material made by mixing and sintering. Generally, the total amount of carbon contained in cast iron is limited to 2 to 3% by weight, but this material can contain up to 30% by weight, and has characteristics as a self-lubricating, oil-less material.

To manufacture this graphite-containing cast iron fiber sintered alloy, cast iron fibers and graphite powder are first mixed and molded under a predetermined pressure. This was then heated to 114 ml in ammonia decomposition gas.
Sinter by heating at a temperature of 0° C. for 45 minutes.

It is then recompressed and resintered by heating it at a temperature of 1140° C. for 45 minutes in ammonia decomposition gas.

The general physical properties of the graphite-containing cast iron fiber sintered alloy are shown in the table below.

The graphite content is typically 5 to 15% by weight when considering sliding properties, workability, strength, etc., but 2.5 to 30% by weight is possible if sliding properties are mainly considered. It is.

The rotor portion 3 includes a rotor 7 and horns 9a, 9b, 9 that are fitted into grooves 7b of an outer peripheral wall surface 7a of the rotor 7 so as to be able to protrude freely.
c, 9d. The rotor 7 is made of structural alloy steel with a hard surface. Hoene 9a, 9
As the material of b, 9c, and 9d, an aluminum silicon type material is used. There is a clearance of about 50 microns between the sliding parts 8, 8 of the cam ring 2 and the rotor 7.

Note that lubricating oil is supplied between the rotor portion 3 and the cam ring 2 using a normal method. Further, Freon gas is used as a refrigerant.

Next, the operation of the rotary compressor for heating and cooling according to this embodiment will be explained.

Refrigerant is drawn into a space 10 formed by the cam ring 2, rotor 7, and vanes (eg, 9a, 9b) through the suction ports 5,5. The refrigerant in this space 10 rotates while being compressed by the rotation of the rotor section 3. When the rotating vane 9b passes through the discharge port 6, the compressed refrigerant is discharged from the discharge port 6 in a state where rotational movement is prevented since the sliding portion 8 and the rotor 7 are in a quasi-contact state. .

According to the air-conditioning compressor having the above configuration,
When the rotor 7 rotates, the temperature of the rotor part 3 and the cam ring 2 rises, and the sliding part 8 of the cam ring 2 increases due to thermal expansion.
The clearance between the rotor 7 becomes narrower, and the sliding portion 8 of the cam ring 2 and the rotor 7 may even come into contact with each other. Here, since the cam ring 2 is made of a graphite-containing cast iron fiber sintered alloy, it has self-lubricating properties, and therefore the wear rate between the sliding part 8 and the rotor 7 is reduced as shown in FIG. It becomes smaller as shown in Figure 4. In addition, since the cam ring 2 has self-lubricating properties, the PJ friction coefficient between the sliding portion 8 and the rotor 7 becomes small, as shown in FIG. Therefore, the amount of frictional heat generated is small, the temperature rise of the rotor part 3 and the cam ring 2 is suppressed to a low level, and the clearance between the sliding part 8 of the cam ring 7 and the rotor 7 does not change from the state in which the temperature does not rise. few. That is, the seizure resistance between the sliding portion 8 and the rotor 7 is improved.

In addition, since the cam ring 2 is made of a self-lubricating graphite-containing cast iron fiber sintered alloy, it relies entirely on lubricating oil to reduce friction and wear between the rotor 7 and the sliding portion 8 of the cam ring 2. There is no need to do so. Therefore,
The amount of lubricating oil supplied is reduced, and the amount of lubricating oil dissolved in the refrigerant is also reduced, which in turn improves the overall heat exchange efficiency of the air-conditioning rotary compressor.

In this embodiment, a graphite-containing cast iron fiber sintered alloy is used for the entire cam ring, but graphite is used only for the sliding part 8A of the cam ring 2A (as shown in Figure 5) or only for the entire inner peripheral wall surface of the cam ring. Cast iron fiber sintered alloys can be used.

(G) Effects of the Invention As described above, according to the present invention, it is possible to prevent seizure and reduce the amount of wear on the sliding parts of cam rings, and to improve the heat exchange efficiency of rotary compressors for air conditioning and heating. It has the effect of being able to

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a rotary compressor for air conditioning and heating according to an embodiment of the present invention, and Fig. 2 is a conventional cam ring (FC material).
A diagram showing a comparison of the wear rate of the cam ring according to this example and
FIG. 3 is a diagram showing the relationship between carbon content and wear rate, FIG. 4 is a diagram showing the relationship between carbon content and wear rate, and FIG. 5 is a diagram showing the relationship between carbon content and wear rate. FIG. 5 is a diagram showing the relationship between carbon content and wear rate. 6 shows a sectional view of a conventional rotary compressor for heating and cooling. DESCRIPTION OF SYMBOLS 1... Rotary compressor for air conditioning and heating according to this embodiment, 2... Cam ring, 3... Rotor portion, 4... Inner peripheral wall surface, 5... Suction port, 6... Discharge port, 7 ...Rotor, 8...Sliding part, 9a, 9b, 9c, 9d---
Vane, IO... Space.゛Me12' Log friction, j-el (m97N-m) S it rate (m
m3/m-N) A(φro((μ
)

Claims (2)

[Claims] (1) Equipped with a rotor and a cam ring that houses the rotor and has an inlet and a discharge port on its inner circumferential wall surface, and a sliding portion on which the rotor slides is formed on the inner circumferential wall surface near the discharge port. , a rotary compressor for air conditioning and heating which compresses and discharges refrigerant by rotation of a rotor, characterized in that the entire inner peripheral wall surface or the sliding part of the cam ring is made of a graphite-containing cast iron fiber sintered alloy. compressor. (2) Graphite-containing cast iron fiber sintered alloy is 2.5 to 30
The rotary compressor for air conditioning and heating according to claim 1, characterized in that it contains graphite in an amount of % by weight.