Claas QUANTUM 2500 K, Service Parts

Page: 144 / 208

Hydraulics QUANTUM TIC
11-78 10/04
4.2 Function
4.2.1 Free circulation
(solenoids not
energized)
Oil supply from the tractor is via port (P).
The most favourable way of connecting is to let the return oil from the
forage wagon flow into a direct port to the tank (pressureless return line).
The oil quantity from the tractor should not exceed approx. 60 l/min., as
otherwise the circulation pressure and consequently the oil temperature
may increase.
The normal circulation pressure is below 20 bar (at an oil temperature of
50°C).
The oil pressure switch (2) activates the electric system at a circulation
pressure of 2 bar. A red control light in the control box lights up for 3
seconds.
The electric system is now ready for operation.
From port (P), the pump flow is directed to the circulation valve (4) via
filter (1).
As the solenoids of the 4/3 way solenoid valves (9) and (12) are de-
energized, the flow returns to the tank via the spool (5) of the circulation
valve (4).
The spring space of the spool (5) is relieved via the control bore (orifice
plate 6, shut-off screw 7, load change valves 11 and the spools of the 4/3
way solenoid valves (9) and (12)).
Note: On tractors with a closed hydraulic system (constant pressure system),
the shut-off screw (7) must be fully screwed in.
The tractor’s hydraulic pump is reset by the backside build-up of
pressure.
On tractors with a power beyond port, the shut-off screw (7) must be fully
screwed in.
The LS pump is controlled by building up pressure in the control line (port
6a). The control line ends at the control unit of the LS pump.
This ensures that the LS pump will always make the required volume flow
available.
4.2.2 Loading and
unloading the wagon
(floor conveyor On)
The solenoid valve (9 – M1) is actuated. The flow from the pump flows to
the hydraulic motor (14) via the spool of the solenoid valve (9).
The volume flow to the hydraulic motor (14) is determined by the volume
flow of the tractor’s hydraulic pump. When the hydraulic motor (14)
reaches a pressure of 200 bar, the pressure relief valve (8) opens.
The spool of circulation valve (5) controls the volume flow into the tank.