GF83.55-D-4000H Roof Air Conditioning Refrigerant Compressor, Component Description
GF83.55-D-4000H Roof Air Conditioning Refrigerant Compressor, Component Description
- with CODE (H08) High-performance air conditioning
Shown on engine OM642
A9/7 2nd refrigerant compressor
Shown on engine OM646
A9/7 2nd refrigerant compressor
Shown on engine M272
A9/7 2nd refrigerant compressor
Location
The 2nd refrigerant compressor is located on the right at the engine block with all engine variants.
Task
The 2nd refrigerant compressor draws in the gaseous refrigerant via the low-pressure side, compresses the refrigerant and returns it as a liquid under high pressure to the high-pressure side.
Design and function
1 Refrigerant compressor shaft
2 Clutch plate
3 Alignment pin
4 Swash plate
5 Sliding shoe
6 Piston
7 Intake valve
8 Pressure control valve
9 Swash-plate chamber
After the 2nd refrigerant compressor magnetic clutch (A9/7y1) has established the frictional connection between the automotive engine and the 2nd refrigerant compressor, the refrigerant compressor shaft drives the swash plate via the clutch plate and the 2 guide pins.
The rotation of the inclined swash plate induces linear travel in the pistons. Here the pistons are connected over sliding shoes.
Gaseous refrigerant is drawn in over the intake valve during the intake stroke.
When the piston moves back it feeds gaseous refrigerant over the pressure valve to the compressor outlet.
The gaseous refrigerant is then compressed and heated.
In the 2nd refrigerant compressor, dampers are installed on both the intake side and the pressure side and compensate for the resonances that are generated during intake and compression.
Delivery rate control
At a low vehicle speed and low engine speed, the efficiency of the heavy duty rear automatic air conditioning (roof air conditioning) is considerably impaired due to the few power strokes of the 2nd refrigerant compressor and the reduced cooling of the gaseous refrigerant in the roof air conditioning condenser. In such a situation one speaks of an increase in the thermal load. The 2nd refrigerant compressor is designed such that it has a sufficient delivery rate, even at low rotational speeds.
As the engine speed and speed increase, the thermal load drops and the delivery rate of the 2nd refrigerant compressor increases. To ensure that the 2nd refrigerant compressor does not consume engine output unnecessarily and that the refrigerant circuit is maintained despite this, the 2nd refrigerant compressor reduces its output. The output of the 2nd refrigerant compressor is regulated by activating and deactivating the 2nd refrigerant compressor magnetic clutch.