Flow Amplifier System Operation; No Steer - Komatsu 930E-2 Shop Manual

FLOW AMPLIFIER SYSTEM OPERATION

Refer to figures 4-6 through 4-9 for oil flow paths during
the following conditions:
Neutral
Steering Left
Steering Right
External shock load
L4-8

No Steer

(Refer to Figure 4-6):
High pressure oil from the steering pump and steering
accumulators is available through the steering bleed-
down manifold to the "HP" port on the flow amplifier
assembly.
Upon entering the priority valve, it goes past the spool
to the closed amplifier valve and also out port "P"
through a hose to port "P" on the steering control unit.
In the steering control unit, it goes to a closed area in
the control.
As pressure builds up in these two areas, oil passes
through orifices in the end of the priority valve and
builds pressure on the end of the valve and port PP.
When pressure reaches approximately 500 psi (3.5
MPa), the spool moves, compressing its spring and
closes off oil supply through area "A" resulting in high
pressure at "PP", but only 500 psi (3.5 MPa) at the
amplifier spool and steering control unit.
Steering Circuit L04031