PUMP GP-F PRM 5371735 - Caterpillar

Illustration 1 g01113326
Signal Resolver Network
(1) Passage to Hydraulic Oil Tank
(2) Passage from Ripper Tip Control Valve
(3) Passage from Ripper Lift Control Valve
(4) Passage from Blade Tilt Control Valve
(5) Passage from Blade Lift Control Valve
(6) Float Boost Signal
(7) Passage to Pump Compensator
(8) External Resolver
(GG) Tank Pressure
(FF) Activated Components
(PP) Pilot Pressure The resolver network consists of a resolver (ball check valve) in each implement control valve. Each resolver compares the pressure signal from the previous control valve and the pressure signal from the current control valve. The resolver ball shifts in order to allow the higher signal to flow to the next resolver.For example, Illustration 1 shows the resolver network when the ripper tip control valve is activated. The ball in the resolver for the ripper tip control valve shifts downward. This allows the signal to flow to the resolver for the ripper lift control valve. The ball in this resolver shifts upward. This allows the signal to flow to the resolver for the blade tilt control valve. The ball in this resolver shifts upward. This allows the signal to flow to the resolver for the blade lift control valve. The ball in this resolver will shift upward. This allows the signal to flow to external resolver (8). External resolver (8) compares the signal from the ripper tip control valve to float boost signal (6). The highest signal is sent to the pump compensator valve. In this case, the signal from the ripper tip control valve is sent to the pump compensator valve.The signal instructs the pump to vary output in order to meet the highest load requirement. Also, the pump compensator valve adds margin pressure to the load requirement.Note: The resolver network does not add various loads together. Instead, the single highest resolved load governs the pump output.When the blade lift control valve is in the FLOAT or LOWER position, pilot oil enters the resolver network through an external line at float boost signal (6). The float boost signal is compared to the highest signal that is sent from the implement control valves at external resolver (8). When the blade lift control valve is in FLOAT and none of the other implements are activated, float boost signal (6) is sent to the pump compensator valve. This adjusts the pump output in order to maintain the necessary supply pressure that is required for pilot oil to keep the valve spool in the FLOAT position.When all of the implements are in HOLD, the pressure in the resolver network is at tank pressure. The pump compensator valve keeps the implement pump at LOW PRESSURE STANDBY until an implement is activated.