Displacement Limiters; Charge Check / High Pressure Relief Valves - Danfoss Series 42 Service Manual

Service Manual
Functional Description

Displacement limiters

Charge check / high pressure relief valves

14
Series 42 Axial Piston Closed Circuit Pumps
Filtration adapters
Full flow
pressure
filtration
Series 42 pumps are available with mechanical displacement limiters in the servo covers. The
displacement limiters can limit displacement of the pump to any value from maximum to zero in either
direction.
Displacement limiters
Displacement limiter
(factory set for maximum displacement)
Servo control
cylinder
Displacement limiter
(set for reduced maximum displacement)
All series 42 pumps have a combination charge check/high pressure relief valve. The charge check
function allows pressurized flow from the charge pump to enter the low pressure side of the loop. This
flow is necessary to replenish fluid discharged to the pump/motor case for lubrication and cooling
requirements. Since the pump can operate in either direction, it uses two charge check valves to direct
the charge supply into the low pressure side.
520L0638 • Rev 0300 • July 2015
Partial flow
pressure
filtration
Full flow
suction
filtration
P108 066E