Travel Motor Tg405 - Fayat Bomag BW 900-50 Service Manual

Hydraulic system – Description of hydraulic components
Pos Designation
High pressure relief and charge
pressure valve

5.3.2 Travel motor TG405

Torque motor TG405, gerotor motor
110
Pos Designation
T Leak oil
1
T Leak oil
2
X X Port for control pressures, pressure in front of nozzle
1 2
High pressure relief valves with integrated boost check valves
Pressure peaks occurring during very fast swashing processes, as
well as the maximum pressures are safeguarded by superordinate
high pressure relief valves, which open when the adjusted value is
exceeded and relieve oil into the low pressure side. The fluid quan-
tity always remains constant in the closed hydraulic circuit. Leak-
ages in pump and motor are compensated by the charge pump.
The boost check valves are integrated in the high pressure relief
valves. These valves open to the low pressure side and let cool
and filtered oil flow from the charge oil circuit into the closed
hydraulic circuit, in order to compensate leaks and flushing quanti-
ties.
Charge pressure relief valve
The charge pressure valve belongs to the group of safety elements
in a closed hydraulic circuit. This valve limits the pressure in the
charge circuit to the pre-adjusted value.
Gerotor motors are slow running hydraulic motors with high torque.
With a given oil flow and a given pressure the displacement of the
motor (nominal size of motor) determines both the speed and the
torque.
This means:
a) that the speed is determined by the supplied oil flow and
b) the torque depends on the available pressure.
BW 900-50