Toro GroundsmasterR 4300-D User Manual

Groundsmaster 4300--DHydraulic System Page 4 -- 14
Mow Circuit Cutting Deck Blade Braking
When the operator turns the PTO switch OFF or if the
decksareraisedwith thePTOswitchON,the deckcon-
trol manifold proportional relief valves (PRV1 and
PRV2) are de--energized causing circuit flow to bypass
thedeck motorsandreturn tothereservoir outmanifold
portT(refertoinformationinMowCircuitinthissection).
Without circuit flow, the manifold relief valve (RV1 or
RV2)returnstoitsneutralpositionw hichcausesthelog-
ic cartridge (LC1 or LC2) to shift to its neutral position,
blocking return flow from the deck motors and slowing
the cutting blades (Fig. 13).
Theinertiaoftherotatingcuttingblades,however,effec-
tively turns the deck motors into pumps causing an in-
creasein pressureasthe flowfromthemotor comesup
against the closed logic cartridge (LC1 or LC2). When
this pressure builds to approximately 1500 PSI (105
bar), the relief valve (RV1 or RV2) re--opens which al-
lows a small amount of hydraulic flow to return to tank
through a manifold sensing line (Fig. 14). This flow
causes a pressure differential that shifts the logic car-
tridge(LC1 or LC2)to onceagain allowoil flow fromthe
motors (Fig. 15). When return pressure drops below
1500 PSI (105 bar), the relief v alve (RV1 or RV2) re-
seats and causes the logic cartridge (LC1 or LC2) to
close again, blocking return flow from the deck motors
tofurtherslowthecuttingblades.Thisactiono ftherelief
valve opening and the logic cartridge shifting occurs
severaltimesin averyshorttimeframe astheblades fi-
nallycometoastop.Oncethebladeshavestopped,the
logiccartridge (LC1orLC2) remainsinthe neutralposi-
tion to keep the deck motors from rotating.
Figure 13
DECK
CONTROL
MANIFOLD
FROM
GEAR
PUMP
TO
OIL
COOLER
FROM
FRONT
MOW
CIRCUIT
ORIFICE
DECK
CONTROL
MANIFOLD
FROM
GEAR
PUMP
TO
OIL
COOLER
FROM
FRONT
MOW
CIRCUIT
ORIFICE
Figure 14
DECK
CONTROL
MANIFOLD
FROM
GEAR
PUMP
TO
OIL
COOLER
FROM
FRONT
MOW
CIRCUIT
ORIFICE
Figure 15
DECK
CONTROL
MANIFOLD
FROM
GEAR
PUMP
TO
OIL
COOLER
FROM
FRONT
MOW
CIRCUIT
ORIFICE

Toro GroundsmasterR 4300-D Specifications

General

Brand	Toro
Model	GroundsmasterR 4300-D
Category	Lawn Mower
Language	English