Lubrication
The oil in all the parts is forced up from the bottom of the front side block along the oil passages by the pressure on the high pressure side to lubricate the rotor front end. The oil passed through the oil port at the bottom of the cylinder lubricates the rear end of the rotor. The oil that has lubricated each of the ends of the rotor is returned to the low pressure side by the internal pressure of the compressor.
The oil contained in the gaseous refrigerant returned from the evaporator passes through the low pressure chamber and lubricates the rear bearing. Furthermore, the oil passes through the guide hole provided in the drive shaft and lubricates the front bearing and shaft seal before returning to the suction portion of the cylinder.
Since the pressure in the suction portion of the cylinder is slightly lower than that in the low pressure side, the oil that has lubricated all the parts is returned to the suction chamber.
Lubrication Of A/C Compressor. Scheme 121
The high-temperature and high-pressure gaseous refrigerant discharged from the compressor is cooled down and turned into the liquid state in the condenser which is cooled by the ambient air delivered by the cooling fan.
The condenser is composed of tubes and radiating fins.
The heat from hot refrigerant radiates to the ambient air when high-temperature gaseous refrigerant passes through the condenser tubes.
Identifying Condenser Mechanism Function. Scheme 122
The amount of refrigerant circulating varies with the heat load changes. The receiver drier supplies the amount of refrigerant necessary for the cycle according to such changes.
Scheme 123
- It removes bubbles from the condensed refrigerant so that only liquid refrigerant may be delivered to the expansion valve. (If bubbles are present, the refrigerant passing through the expansion valve varies in quantity, temperature, and pressure, resulting in insufficient cooling.)
- It removes moisture from the refrigerant.
- It removes foreign substance from the refrigerant. The receiver-drier consists of a strainer to remove foreign substance, desiccant to absorb moisture from refrigerant. (Scheme 123): Identifying Receiver Drier Components