Complete set and purpose of elements of piston compressors for a refrigerator
If you look behind your refrigerator, you can see a small black metal tank with a flattened collar with several tubes extending from it. This is the compressor. Its casing is sealed, and the supply copper pipes are routed to the cooling grilles of the refrigerator located on its rear panel.
Inside the casing there is a mechanism for the compressor unit, consisting of a motor, a piston cylinder with an adjacent valve, fasteners and copper tubes, ornately twisted around the unit itself. There are only three such tubes in modern compressors.Two of them, located nearby, are responsible for supplying and returning freon to the system, which constantly circulates in the system under a certain pressure. This pressure is what the compressor is designed to create.
The third tube is usually sealed at the end. It is located on the opposite side from the previous ones, and through it the system is charged with freon. This tube leads to a plastic muffler, which smoothes out the noise from the freon entering the housing.
The compressor motor is most often asynchronous, consisting of vertically located windings (stator) and a movable armature (rotor), to the end of which is attached a crankshaft with a linkage or connecting rod that drives the piston. The engine housing is combined with the compressor cylinder, and is placed on an independent suspension of four springs, smoothing out vibration from the engine and making the compressor operate almost silently.
During operation of the compressor, the installation together with the engine heats up quite strongly, and its temperature inside the casing can reach about 100 degrees Celsius. This happens due to the high pressure pumped by the compressor to distill freon, in the environment of which the engine is forced to operate. At the bottom of the casing there is a certain amount of mineral or synthetic oil (about 200 g), which under temperature and pressure turns into an aerosol and, mixing with the refrigerant, enters the cooling system of the refrigerator. A centrifugal oil pump, which is located inside the rotor shaft, is responsible for supplying oil to the bearings, valves and piston of the compressor unit.
The start-up protection relay, equipped with a temperature sensor, is located on the outside of the compressor casing and performs several very important functions:
- Regulates the supply of electricity to the compressor unit;
- It cuts off the supply of electricity to a compressor motor that is jammed due to any breakdowns, protecting the stator winding from overheating and combustion. After some time, re-feed occurs, and in case of a problem, shutdown;
- Protects wiring from fire in case of overheating of the contact group and the wires connected to it. An extremely useful function, since a huge number of household fires still occur due to wiring fires.
General principle of operation of the cooling system
As a result of the high pressure pumped by the compressor and valves, the freon becomes very hot, entering the refrigerator condenser grille, which is located on the rear wall. Changing its state of aggregation, that is, passing from vapor to liquid, the refrigerant, through a capillary tube that reduces its pressure, enters the evaporative radiator, in which it again turns into steam. The cyclic movement of freon through the cooling system is accompanied by the release of heat through the radiator grille into the environment. And in the evaporative radiator cooling occurs, which is then transferred to the refrigerator chamber.
Practical advice
- Do not tilt or tilt the refrigerator to a horizontal position. If tilted excessively, the compressor mechanism can easily jump off the shock-absorbing springs of the independent suspension, and will never be able to stand on them again. After the refrigerator is returned to its original vertical position, the main unit - the compressor - will need repairs.
- If the compressor does not turn on at all, you must first check the starting relay, contact group and supply cable.Perhaps this way it will be possible to avoid service repairs of the refrigerator.
- Although the compressor casing consists of two parts, they are usually tightly sealed. Therefore, in the event of a malfunction, the shortcomings of the compressor unit itself cannot be easily determined. Sometimes you even have to cut the body to find the cause of the breakdown. In such cases, it would be more rational to replace the unit with a new one.
Those wishing to dismantle the refrigerator compressor themselves at home must ensure good ventilation or airing of the room, since freon vapors can be toxic. This is especially true for old Soviet-era refrigerators. Repairing a refrigerator, replacing a filter, cutting and soldering copper tubes, dismantling and repairing a compressor, and refilling the refrigeration system have a lot of nuances, which makes it wiser to entrust this work to professional craftsmen or service maintenance.
