Instruction Manual
Voith Turbo
I/H Converter DSG-BXX112
I/H Converter DSG-BXX102
09 / 03 cet - Ochs/ZAN1
Voith Turbo GmbH & Co, KG
Page: 10 / 21
3.626 - 018877 en
D – 74564 Crailsheim
3.2
Operating characteristics
(see fig. 3.1.1)
A set signal w = 0/4...20 mA generates a magnetic force F
Mag
in the
VRM, the limits of which can be adjusted by means of the X0 and X1
potentiometers and which is then transmitted onto the control piston via
tappet.
The hydraulic force F
Hyd
being proportional to the output signal pressure
P
A
acts against this force.
In the case of the two forces being equal, the control piston is positioned
in the “hydraulic center” as shown in fig. 3.1.1 and the output signal
pressure P
A
corresponds to the set signal w.
In the “hydraulic center“ position the control piston performs minimum
oscillating movements in the area of the guiding edges P
®
P
A
and P
A
®
T,
in order to keep the output pressure P
A
on the value set by F
Mag
.
When increasing the set signal and thus F
Mag
from this condition, the
control piston position changes and thus connects the output pressure P
A
to the feed pressure P and blocks P
A
towards the tank return line T1.
Now pressure P
A
and thus the hydraulic force F
Mag
will increase until the
same has returned the control piston to the “hydraulic center” and P
A
corresponds to the new set signal.
In case of I/H converters with regulating range 0..X a pressure spring is
installed between cover, item 8, and the control piston.
This spring generates a force-offset F
Fed
towards the effective direction of
F
Hyd
in order to guarantee the I/H converter function for output pressures
of approx. 0 bar, too.
The internal leakage is fed back into tank return line T2.
Function of manual operation knob:
The control magnet of I/H converter DSG-BXX112 is provided with a
manual operation knob, by means of which an adjustable spring force
can be set instead of the magnetic force F
Mag
. This spring force affects
the control piston via magnet armature and tappet. The hydraulic force
F
Hyd
, being proportional to the output signal pressure P
A
also acts
against this spring force here. Thus adjustment of output pressure is
possible without electric connection.
