Reelmaster 5010 Series Hydraulic System (Rev. C)Page 4 -- 13
Lift Circuit: Raise Cutting Units
A four section gear pump is coupled to the piston (trac-
tion) pump. Gear pump section (P4) supplies hydraulic
flow to the lift control manifold and ultimately for the lift
cylinders. The gear pump takes its suction from the hy-
draulic reservoir. Lift circuit pressure is limited to 2000
PSI (138 bar) by a solenoid r elief valve (SVRV) located
in the lift control manifold.
The lift control manifold includes four (4) electrically op-
erated solenoid valves. Valve (SVRV) is used to direct
gear pump flow to the lift cylinders w hen energized or
bypass pump flow back to the reservoir when de--ener-
gized. Valve (SV2) is used to direct oil flow to retract the
lift cylinders when energized or extend them when de--
energized. Valve (SV1) allows hydraulicflow to the front
lift cylinders when energized. Valve (SV3) allows hy-
draulic flow to the rear lift cylinders when energized.
Lift circuit pressure can be monitored at lift controlman-
ifold port G4.
The Electronic Control Module (ECM) uses inputs from
various machine switches to determine when lift man-
ifold solenoid valves (SV1, SV2, SV3 and SVRV) are to
be energized. The ECM also provides a partial raise
position of the front outside cutting units.
During conditions of not raising or lowering the cutting
units(joystick inthe neutral(center)position), allfour (4)
liftmanifold solenoidvalves (SV1,SV2,SV3 andSVRV)
are de--energized. Hydraulic flow from gear pump sec-
tion(P4) by--passes theliftcylinders tothe oilcoolerand
then to the hydraulic reservoir.
Raise Cutting Units (Fig. 11)
When the joystick is moved to the raise position, sole-
noid valve (SVRV)energizes alongwith solenoidvalves
(SV1), (SV2) and (SV3).The energized solenoid valves
direct gearpump section P4 oilflow to therod end of the
lift cylinders. Hydraulic pressure against the rod s ide of
the cylinderscauses the shafts to retract,and raises the
cutting units. Fixed orifices in the lift control manifold
(C1L, C4L, C5L and C23L) control the lifting speed by
providing a restriction for the return flow from the lift cyl-
inders.
When the joystick is returned to the neutral (center)
position, the solenoid valves are de--energized and the
lift cylinders (and cutting units) are held in the raised
position. Piloted check valves in the lift control manifold
(CV1, CV4, CV5 and CV23) prevent the lift cylinders
(and cutting units) from dropping after they have been
raised.
Hydraulic
System
