A/C Compressor

Design


Purpose
The A/C compressor (A9) is responsible for sucking in and compressing the refrigerant.


A/C compressor "general" function
The A/C compressor has a stationary spiral (2) and a rotating spiral (1), which rotate in one another with a phase difference of 180°. The two spirals form chambers which are completely closed. The rotation of the rotating spirals move the chambers from the intake to the pressure side and simultaneously reduces the volume.

In addition, the A/C compressor (A9) has a continuously adjustable stroke. Compressed gas can flow back from the high pressure side (Pd) to the vacuum side (Ps) through a pressure compensation connection passage (5) between the high pressure side (Pd) and vacuum side (Ps). The quantity flowing back is control led by the control valve (6). The control variable for this regulation is the intake vacuum (Ps). This value is always kept constant regardless of the load and speed of the A/C compressor (A9).

The refrigerant can flow into a chamber through the corresponding check valves during compression through the high pressure connection passage (3) and the pressure compensation connection (5) in the stationary spiral (2). Gas flows back to the intake vacuum side (Ps) through a passage whose cross section can be varied by a piston.

Control valve:
The position of the piston on the control valve (6) and therefore the quantity of coolant flowing back is determined by the pressure difference on the piston and the spring force. There is intake vacuum (Ps) at the bottom . The cylinder chamber on the top of the piston is connected to the high pressure side (Pd) of the A/C compressor (A9) by a connection passage (4). The pressure in this cylinder chamber is controlled by a bellows valve installed in the piston.






A/C compressor "maximum output" function
If the power required is high in relation to the A/C compressor drive speed and if the intake vacuum (Ps) is higher than the specified value, the bellows valve (9) retracts. This causes the ball valve (10) to close and the control pressure (Pc) at the top of the piston increases. The increasing pressure difference on the piston (8) moves it against a spring (7) closing the connection passage between the high pressure side (Pd) and the intake vacuum side (Ps). The A/C compressor then operates at maximum output.






A/C compressor "regulated power" function
If the output required is low in relation to the A/C compressor drive speed and the intake vacuum (Ps) is lower than the set value, the bellows valve (9) expands. This causes the ball valve (10) to close and the control pressure (Pc) at the top of the piston is reduced through the open ball valve (10) and the piston (8) is moved by the spring force due to the low pressure difference. The A/C compressor operates at various outputs whereby the intake vacuum (Ps) always remains at the specified value for the bellows valve (9).






A/C compressor "minimum output" function
If the output required is minimal in relation to the A/C compressor drive speed, the bellows valve (9) expands to the maximum size. The control pressure (Pc) at the top of the piston is reduced as far as possible and the piston (8) completely opens up the connection passage cross section. The A/C compressor then operates at minimum output.