KR950001868B1 - Heat pump type room air conditioner - Google Patents

Abstract

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Description

Heat Pump Type Room AECON

1 is a longitudinal sectional view of a rotary compressor.

2 is a cross-sectional view taken along the line A-A of FIG.

3 is a refrigeration cycle diagram when heating the heat pump type room air conditioner.

4 is a longitudinal cross-sectional view of the crankshaft.

5 is an enlarged view near the surface of the crankshaft.

6 shows the change in time-load of abrasion test.

7 is an explanatory diagram of a wear test method.

The present invention relates to a heat pump type room air conditioner of the present invention, and more particularly, to a heat pump type room air conditioner suitable for heating operation.

In general, the refrigerant encapsulated in the room air conditioner is Freon 22 (CHClF ₂ ), which dissolves well in the naphthenic refrigeration oil, which is mainly used as a compressor lubricant, and the lubricant is diluted to have a very low viscosity (usually 2-10 in a cooling operation state). It is said that there are many reasons for lubrication problems such as abrasion and sintering of the sliding parts in the refrigerant compressor, but conventional room air conditioners have been the mainstream. In recent years, there has been a tendency to increase the heat pump type air conditioner capable of heating operation, and in recent years, the variable speed model has been designed to change the rotational speed of the compressor according to the load and to shorten the rise time of the room temperature or the defrost time. This type of heat pump has been shown to be remarkably elongated. The reason is as follows:

1. At the start of heating operation, it is more likely that the air temperature has been left at a low temperature (below 0 ° C) until then, and the viscosity is significantly lowered (below 1 cm Stokes) because the coolant dissolves at lower temperatures. It is a state.

Therefore, it becomes very difficult to form an oil film between a shaft and a bearing, and it is difficult to avoid metal contact. In addition, since the temperature of the lubricating oil gradually rises after starting, but the outside air temperature is low, the speed is slow, and several minutes are required until the metal contact is avoided.

2. When it enters the normal operation, frost is gradually attached to the outdoor equipment and the heat exchange capacity is lowered. Therefore, the refrigerant gradually returns to the compressor. As a result, the viscosity of the lubricating oil is lowered again. Defrosting operation generally does not significantly reduce the viscosity of the lubricating oil, but there is a problem that the suction pressure is very low and the amount of oil supply to the shaft is reduced. After the defrost operation is completed, the preheating operation is generally performed and the compressor is operated with the blower of the indoor unit stopped. Thus, the discharge pressure suddenly rises during severe liquid circulation, which leads to a very severe condition. . That is, high load conditions in the state of low viscosity of lubricating oil generate | occur | produce.

3. The variable speed model changes the rotational speed of the compressor according to the load by about 60Hz-150Hz as compared to 60Hz, which is a conventional product power supply. In particular, high speed operation is required under the severe conditions as described above. It becomes even more intense and there is a need for a structure of sliding parts that can withstand this. For the above reasons, the use condition of the compressor of the heat pump type is in a very severe state, and various durability improvement has been examined than before.

For example, the shaft of a conventional rotary compressor is a method of forming a chemical conversion film of manganese phosphate (Mn) based on cast iron, carbon steel, or alloy steel, or of a molybdenum disulfide which is a solid lubricant on a manganese phosphate film. Although there is a method of forming the coating by coating, these coatings are effective in the initial familiarity, but in the case of heat pumps in which continuous boundary lubrication occurs, they are peeled off and consumed in a short time, so that the iron body is formed. We expose and there is problem in endurance. In addition, there is a method of adjusting the material by heat treatment or increasing the hardness by nitriding, but both have improved abrasion resistance but are poor in familiarity with the counterpart material and need to insert a soft member into the counter bearing material. As described above, none of the conventional methods satisfies both the characteristics and the economics.

An object of the present invention is to provide a heat pump type air conditioner using a rotary compressor having excellent durability in heating operation.

A high temperature and high strength is applied to the surface layer portion by subjecting the axis of the heat pump type rotary air compressor rotary compressor which has a high metal contact ratio and cannot be repeatedly generated. A porous layer composed mainly of a mixture of nitrogen compounds, self-lubricating and extreme pressure sulfur compounds is produced, and a compact, high hardness monolayer mainly composed of nitrogen compounds is formed under the porous layer. Further, in the lower layer, a diffusion layer in which nitrogen diffuses into the base material and the hardness is increased is formed. After the porous layer is prevented from initial sintering or interlocking due to the retention and familiarity of the porous layer, and the porous layer is dropped and consumed, the shaft and bearing are made familiar, and then the monolayer and the diffusion layer of the high hardness nitrogen compound As a result, wear resistance is improved so that abnormal wear does not occur even when contacted for a long time.

1 is a longitudinal sectional view of a typical rolling piston rotary compressor.

2 is a cross-sectional view taken along the line A-A of FIG. In the figure, the transmission part 1 which consists of the stator 1 and the rotor 3 in the upper part, the cylinder 2, the upper bearing 5, the lower bearing 6, the piston 8, and partitions in the lower part Compressor sphere (2) consisting of plates (9) is arranged, and the transmission section (1) and compressor sphere (2) are connected with crankshafts (7), which are casings (10), (10 '), (10'). It is a structure which was accommodated in the hermetically sealed chamber 102 formed of the " The piston 8 is fixed to the eccentric portion 7 ′ of the crankshaft 7 so that rotation is freely inserted, and the refrigerant sucked from the suction hole 100 is divided into the partition plate 9, the piston 8, and the cylinder ( 2) is stored in the compression chamber 101 formed by the upper bearing 5, the lower bearing 6 is compressed with the rotation of the eccentric portion 7 ', the pressure in the compression chamber 101 is closed ( When the pressure is slightly higher than the pressure of 102, the discharge valve 11 opens and flows out into the sealed chamber 102. Lubrication oil 12 is accumulated in the lower part of the sealed chamber 102, and the oil is pulled up by the pumping action of the oil supply piece 12 ′ and the torsion plate 13 in accordance with the rotation of the crankshaft 7. Lubricating oil is conveyed to each sliding part by the oil supply hole of 7). The material of the crankshaft 7 of this embodiment is a process graphite cast iron of a ferrite material, and the upper bearing 5 and the lower bearing 6 are flake graphite of a perlite material. It is cast iron. Conventionally, manganese phosphate treatment, the upper bearing 5, and the lower bearing 6 were generally used in the shaft 7 without treatment.

3 shows a refrigeration cycle of a typical heat pump type room air conditioner. In the figure, reference numeral 32 denotes a compressor composed of the above-described components. Numeral 33 denotes a first heat exchanger which performs heat dissipation during heating. 34 is a 2nd heat exchanger which evaporates at the time of heating. Reference numeral 35 denotes a switching valve, which is used when switching to cooling or heating. 4 and 5 show the structure of the crankshaft 7 of this embodiment, and FIG. 5 is an enlarged view of the vicinity of the surface of the crankshaft 7. As shown in FIG. The treatment is performed by immersing the machined crankshaft in a molten salt solution of an alkali metal salt based on sulfur containing cyanate held at 565 ° C. for about 30 to 120 minutes. The fine porous layer 20 in which a sulfur compound and a nitrogen compound are mixed is formed on the uppermost surface of the sulphur-nitrided crankshaft. In addition to having self-lubricating properties and extreme pressure action, the porous layer 20 is porous, and thus has excellent retention due to oil action, has a low coefficient of wear, and good friendliness to the relative bearing material. Under the porous layer 20, there exists a single phase 21 of a nitrogen compound. This single phase is very hard at 450-1200 on the micro vickers scale, and has a low coefficient of wear and a high melting point. Therefore, even in the state of boundary lubrication, strength decreases even if the temperature rises due to frictional heat. It does not exhibit excellent wear resistance. Below the single phase 21 is a diffusion layer 22 of nitrogen. As the diffusion layer 22 becomes shorter in the base material, the hardness difference with the base material is shortened, but the hardness is increased to about 0.05% of the base material (275 for the base material 175) on the micro Vickers scale up to about 0.05 at the surface. It is to improve the overall rigidity.

Next, an example of the effect of this sulphur nitriding treatment is described.

6 shows the wear resistance of the conventional manganese phosphate treatment and the sulphur nitriding treatment. The horizontal axis represents time from the start of the test, and the vertical axis represents the load applied to the test piece. FIG. 7 illustrates the method of this test, in which the surface-treated pin 31 is inserted into both blocks 30 to increase the load W at a speed of 250 kgf / sec starting at 200 kgf. The pin was rotated at 300 RPM and left in a dry state without lubricating oil. Block 30 is a heat-treated alloy cast iron, fin 31 is a ferrite-processed graphite cast iron manganese phosphate treatment and sulphate nitriding treatment for about 60 minutes and the thickness of A in the compound to about 10㎛ It is. According to FIG. 5, it can be seen that the time until sintering is about 500% and the load is about 300% nitriding and nitriding. In addition, according to this embodiment, the thickness of the compound layer A is suppressed to 2-20 µm, and the reason is that in the case of a material having poor thermal conductivity such as cast iron, it is cracked in the treated layer due to the difference in the coefficient of thermal expansion between the base material and the treated layer. This is because there is a risk of this.

In addition, in the present embodiment, since the crankshaft 7 is subjected to the needle-sulfur nitriding treatment, the upper bearing 5, the lower bearing 6, and the piston 8, which are counterparts, can use untreated cast iron, a small alloy, or the like. There is abundant economy.

In addition, since the process graphite cast iron is used as the material of the shaft, and the flake graphite cast iron or the iron-based small alloy is used as the counterpart material, a material having good workability can be used as it is, and additional parts such as metals are also unnecessary. Is good. On the other hand, since the wear coefficient with the bearing of the crankshaft becomes small, the efficiency of the motor is increased. Therefore, it is possible to provide a heat pump type air conditioner with a remarkably small power consumption.

According to the present invention, in a heat pump type air conditioner using freon (CHClF ₂ ) and switching to cooling and heating, a porous layer made of sulfide and nitride formed by immersion nitriding on the shaft of the compressor, Since the lower layer of the porous layer has a single layer made of nitride formed by the sulphur nitriding treatment and a diffusion layer formed by diffusion of nitrogen into the base material under the single layer, a heat pump using a rotary compressor having excellent durability during heating operation. Can provide a room air conditioning.

Claims (4)

In a heat pump type air conditioner comprising a heat exchanger, a pressure reducer, a compressor, etc., using a freon as a refrigerant and switching to cooling and heating, the compressor is formed of sulfides and nitrides formed by immersion nitriding on its shaft. A heat pump type air conditioner, comprising: a porous layer formed below, a single layer formed of a nitride formed by the sulphurization nitriding treatment below the porous layer, and a diffusion layer formed by diffusion of nitrogen into the base material below the single layer. The heat pump type air conditioner according to claim 1, wherein the total thickness of the porous layer and the single layer is 2-20 µm. The heat pump type air conditioner according to claim 1, wherein the hardness of the single layer is 400 micro Vickers scale. The heat pump type air conditioner according to claim 1, wherein the shaft material is eutectic graphite iron, and the bearing material of the shaft is flake graphite iron or iron-based small alloy.

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