FRAME ASSEM. 2V0846 - Caterpillar

Illustration 1 g00296421
(1) Pulley (2) Hose (low pressure) (3) Hose (high pressure) (4) Pressure switch (5) Service valve (low pressure) (6) Service valve (high pressure) (7) Plug (oil change) (8) Belt (engine driven component)The flow of refrigerant in the air conditioning system begins at the compressor. The compressor circulates the refrigerant through the air conditioning system. The compressor is a swashplate assembly. Pistons are located in the compressor. The linear movement of the pistons provides the suction and discharge of the refrigerant.Suction
Suction of refrigerant into the compressor is obtained through the down stroke of the pistons. As the piston moves down in the cylinder, the suction valves on the compressor open. Refrigerant is sucked into the compressor from the discharge of the evaporator. This refrigerant passes through the suction valve into the piston cylinder.Discharge
The discharge of refrigerant is obtained through the up stroke of the pistons. As the piston reaches the bottom of the down stroke, reduced suction pressure closes the suction valves. This seals the refrigerant in the piston cylinder. During the up stroke of the piston, pressure builds up in the cylinder. Pressure builds up due to the compression of the refrigerant. The refrigerant pressure builds up enough to open the discharge valves. The refrigerant is discharge from the cylinder chamber and into the cylinder head. The refrigerant is then discharged from the compressor.Valves
The compressor valves are disk valves. These disk valves are similar to spring metal diaphragms that are installed in the valve plate of the compressor. The valve plate is located between the cylinder head and the cylinder chamber. Both the suction and discharge valves are located in the valve plate. The suction valve is opened toward the cylinder chamber, while the discharge valve is opened away from the cylinder chamber. As the piston is on the down stroke, a vacuum condition pulls the suction valve open, while the discharge valve is closed. On the up stroke, the pressure in the cylinder closes the suction valve. The cylinder pressure opens the discharge valve.Magnetic Clutch
Illustration 2 g00336808
(1) Magnetic clutch (2) Drive plate (3) Rotor (4) Core (5) CompressorThe compressor is driven by the engine crankshaft through a belt. The belt is also on the clutch and pulley assembly of the magnetic clutch. The drive plate is fastened to the shaft of the compressor. The clutch and pulley assembly turns on the bearing. The clutch and pulley assembly is not connected to the compressor shaft. The electric current from the thermostat causes a magnetic field in the coil assembly.The magnetic field pulls the drive plate against the clutch and pulley assembly. The clutch and pulley assembly operates the compressor by turning the shaft. When the current to the coil assembly is stopped, the magnetic field is removed. This allows the drive plate to move away from the clutch and pulley assembly. This causes the clutch and pulley assembly to turn freely on the bearing. The sequence of connecting and disconnecting the pulley to the compressor shaft is called