Plastic pulley with vibration damper
Pic. 1.103. Plastic pulley with vibration damper
The pulley has a damper for torsional vibrations due to changes in engine torque and a safety mechanism that protects the drive belt in the event of a compressor lock. When the compressor is blocked, the safety pins are destroyed and the pulley begins to rotate independently of the compressor. To reduce weight, the pulley rim is made of plastic (pic. 1.103).
Compressor
Pic. 1.104. Compressor
The compressor consists of a shaft, a disk with pushers, pistons, pads, a working chamber, cylinders and an electromagnetic control valve. Together with the shaft, an inclined disk with pushers rotates. When the inclined disk rotates, the force is transmitted through the pads to the pistons, which move forward in the cylinders. Thus, the suction, compression and release of the refrigerant takes place (pic. 1.104).
Pic. 1.105. Working chamber of the air conditioner compressor
The working chamber is connected to the inlet channel. Between inlet (low pressure) and outlet channel (high pressure) control solenoid valve installed. The solenoid valve cycles the compressor cylinders according to signals from the A/C control unit or ECU. The control system with solenoid valve provides a linear change in compressor capacity in the range from 0 to 100% (pic. 1.105).
Pic. 1.106. Compressor control solenoid valve
If the control solenoid valve is closed (energized electromagnet winding), a pressure difference is created, and the pressure in the working chamber decreases. Then the pressure on the right side of the piston becomes higher than the pressure on the left side of the piston. In this case, the spring is compressed, and the disc with pushers tilts. As a result, the piston stroke increases, and the compressor performance increases (pic. 1.106).
If the control solenoid valve opens (solenoid valve coil de-energized), the pressure difference disappears. The pressure on the left side of the piston then becomes equal to the pressure on the right side of the piston. In this case, the spring is unclenched and eliminates the inclination of the disc with pushers. As a result, the piston stroke is zero, and the compressor capacity becomes zero.
Refrigerant heater (Hot gas tank)
Pic. 1.107. Refrigerant heater
On the new model, a heater is installed around the hot gas tank to directly heat the refrigerant. This increases the pressure of the refrigerant, and the hot gas heater can work effectively even at low outside temperatures (approx. -30°C).
The refrigerant heater operates under the following conditions:
- electric heater switch and fan switch in position «On». («ON»);
- the regulator of a ratio of streams of cold and warm air in position «MAX» «HOT»;
- low outside air and coolant temperature.