Hc Controls; Operation; Functional Description; Check Valve - Danfoss 51 Series Service Manual

Service Manual

HC Controls

Operation

Repair

28
Series 51 Hydraulic Proportional Controls Service Manual

Functional Description

The HC control consists of a ported housing, mounted directly on the end cap. It contains a check valve, a
shuttle valve, a piston, a connecting pin, and a bias spring. The HC control does not have pressure
compensating override (PCOR) function.

Check Valve

The check valve resolves which port (system A or B) is at higher pressure. It routes that higher pressure to
the 4-way valve to power the servo piston.

Shuttle Valve

The shuttle valve ports higher signal pressure to the top of the servo piston. It ports lower signal pressure
to the bottom of the servo piston.

Connecting Pin

The connecting pin links the piston to the 4-way valve. The bias spring holds the piston and pin against
the 4-way valve. A threshold spring and ramp spring(s) act on the opposite end of the 4-way valve.
HC Schematic Diagram
A
Max.
displ.
B

Diassembly

1. Using a 10 mm wrench, loosen locknut (M40).
2. Using a 4 mm internal hex, remove bleed valve (M38).
3. Using a 1/4-inch internal hex, remove plug (M48)
11009446 • Rev BA • July 2014
M4
M3
M1
L1
L2
M5
M2
X2
P101 875