Toro 03200 Reelmaster 3100-D, Service Manual

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The gear pump (P2) is directly coupled to the hydrostat. It supplies hydraulic
pressure to the power steering valve for turning the rear wheel and maintaining
6.9 to 10.0 bar (100 to 150 PSI) to the low pressure side of the traction circuit.
The pump takes its suction from the hydraulic tank.
With the steering wheel in the neutral position, the engine running, and the
lift/sidewinder spool valve in the center position, flow enters the steering control
valve at the P port and goes through the valve, by−passing the rotary meter
(V1) and steering cylinder. Flow leaves the steering control valve through the E
port, passes through the lift/sidewinder valve, hydraulic manifold, hydrostat and
charge relief valve, and continues on to the gear pump inlet and hydraulic tank.
Right Turn
When a right turn is made with the engine running, the turning of the steering
wheel positions the steering control spool valve so that flow goes through the
bottom of the spool. Flow entering the steering control valve at the P port goes
through the spool and is routed to two places. First, most of the flow through the
steering control valve is by−passed out the E port back through the lift/sidewinder
valve, hydraulic manifold, hydrostat and charge relief valve, and continues on
to the gear pump inlet and hydraulic tank. Second, the remainder of the flow is
drawn through the rotary meter (V1) and out port (R). Pressure retracts the
piston for a right turn. The rotary meter (V1) ensures that the fluid flow to the
cylinder is proportional to the amount of steering wheel rotation. Fluid leaving the
cylinder flows back through the steering control spool valve and through the T
port. Return flow passes through the hydraulic manifold, hydrostat and charge
relief valve, and continues on to the gear pump inlet and hydraulic tank.
The steering control valve returns to the neutral position when turning is
complete.
Left Turn
When a left turn is made with the engine running, the turning of the steering
wheel positions the steering control spool valve so that flow goes through the top
of the spool. Flow entering the steering control valve at the P port goes through
the spool and is routed to two places. Most of the flow through the steering
control valve is by− passed out the E port back through the lift/sidewinder valve,
hydraulic manifold, hydrostat and charge relief valve, and continues on to the
gear pump inlet and hydraulic tank (as in a right turn). The remainder of the flow
is drawn through rotary meter (V1) but during a left turn the flow goes out port (L).
Pressure extends the piston for a left turn. The rotary meter (V1) ensures that the
fluid flow to the cylinder is proportional to the amount of steering wheel rotation.
Fluid leaving the cylinder flows back through the spool valve then through the T
port. Return flow passes through the hydraulic manifold, hydrostat and charge
relief valve, and continues on to the gear pump inlet and hydraulic tank.
The steering control valve returns to the neutral position when turning is
complete.
Hydraulic System: Hydraulic Flow Diagrams Page 5–26 Reelmaster ® 3100-D/3105-D
20252SL Rev A