Multi Pro 1200/1250 Hydraulic SystemPage 4 -- 9
Hydraulic Flow Diagrams
Steering Circuit
Asingles ection,beltdrivengearpumpsupplieshydrau-
lic flow to the steering control valve and steering cylin-
der.Thegearpumptakesitss uction fromthetransaxle.
Steering circuit pressure is limited to 1000 PSI (69 bar)
by a relief valve located in the gear pump.
Hydraulicflowandpressuretothesteeringcontrolvalve
can be monitored at the outlet of the gear pump.
With the steering wheel in the neutral position and the
engine running, flow enters the steering control valve
and goes through the steering control spool valve, by--
passing the r otary meter (V1) and steering cylinder.
Flowleavesthe control valve, totheoil filter andreturns
to the transaxle.
Left Turn
When a left turn is made with the engine running, the
turningofthesteeringwheelpositionsthespoolvalveso
thatflowgoesthroughthetopofthespool.Flowentering
the steering control valve from the pump goes through
the spool, to the rotary meter (V1) and out the L port.
Pressure contracts the steeringcylinder piston for a left
turn.Therotarymeterensuresthattheoilflowtothecyl-
inder is proportional to the amount of the turning on the
steering wheel. Fluid leaving the cylinder flows back
through the steering control spool valve, then to the oil
filter and returns to the transaxle.
Thesteeringcontrolvalvereturnstotheneutralposition
when turning is completed.
Right Turn
When a right turn is made with the engine running, the
turningofthesteeringwheelpositionsthespoolvalveso
thatflow goes through thebottomofthe spool. Flow en-
tering the steering control valve from the pump goes
through the spool, to the rotary meter (V1) and out the
Rport.Pressureextendsthesteeringcylinderpistonfor
a right turn. The rotary meter ensures that the oil flow to
the cylinder is proportional to the amount of the turning
on the steering wheel. Fluid leaving the cylinder flows
back through the steering control spool valve, then to
the oil filter and returns to the transaxle.
Thesteeringcontrolvalvereturnstotheneutralposition
when turning is completed.
Figure 8
STEERING CYLINDER
STEERING
T
R
P
L
CONTROL
NEUTRAL POSITION
NO PISTON MOVEMENT
STEERING
T
R
P
L
PISTON MOVEMENT
CONTROL
LEFT TURN
STEERING CYLINDER
STEERING CYLINDER
STEERING
T
R
P
L
PISTON MOVEMENT
CONTROL
RIGHT TURN
Hydraulic
System
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