DEUTZ-FAHR AGROTRON 106 MK3, Workshop Manual

Page: 92 / 150

10-74
c. When the flow rate stabilises
•
When the pump delivery reaches the demand from the auxiliary control valve, the pump delivery pressure PP present
in the chamber b of the LS valve balances the combined force of the pressure PLS of the LS in chamber a and the
force exerted by the spring (6).
On reaching this state of equilibrium, the piston (1) comes to a stop in an intermediate position.
•
In this condition, the passage connecting chamber c to chamber d remains partially open, thereby maintaining the
pressure in chamber d .
An oil flow enters the control piston (6) at a sufficient pressure to balance the force exerted by the spring (5).
•
The stability of this equilibrium is ensured by a stabilised flow from the restrictor g .
•
The force of the spring (2) is regulated so that the piston (1) is balanced when
PP -- PLS =
∆
PR = 22 bar (319 psi).
•
In practical terms, pump delivery is made proportional to the aperture of the auxiliary control valve, maintaining the pressure
difference
∆
PR = 22 bar (319 psi).
•
This condition remains unaltered until there is a change in the operating conditions (e.g. a change in engine speed, reduction
or increase in the demand for flow or pressure, etc.).
M
D0004870
2 1
6 5
d
c
X
PLS
T PP
PP
PEN
g
g
c
d
HYDRAULIC SYSTEM LOAD SENSING VALVE, PRESSURE CUT-OFF VALVE