Toro 04510 Greensmaster 3300 TriFlex, Service Manual

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Greensmaster 3300/3400 Hydraulic System Page 5 -- 19
Mow and Backlap
The tandem gear pump is directly coupled to the piston
(traction) pump. The front gear pump section supplies
hydraulic flow for the mow circuit. The gear pump takes
its suction from the hydraulic reservoir and supplies oil
flow to the mow control manifold and to the cutting reel
motors. Maximum circuit pressure is limited by the pro-
portional relief valve (PRV) located in the mow control
manifold.
With the functional control lever and joystick not in the
mow position, proportional relief valve (PRV) in the mow
control manifold is de--energized. The de--energized
PRV routes gear pump flow directly to the hydraulic res-
ervoir by--passing the cutting reel motors. Additionally,
manifold pressure reducing valve (PORV) will remain
seated to prevent the reel motors (and reels) from rotat-
ing.
Mow
With the engine running, the functional control lever in
MOW and the joystick moved to the reels lower position,
proportional relief valve (PRV) is energized by the TEC
controller. In the energized position, this valve directs oil
flow toward the reel motors and also functions as the
mow circuit relief valve.
Oil flow from manifold port P flows through the flow con-
trol valve (FC) used to adjust reel speed. Flow across
the flow control valve is pressure compensated by the
logic cartridge valve (LC). The logic cartridge valve
maintains a pressure differential of 75 PSI (5.2 bar)
across the speed control valve. Any excess flow above
the speed control valve setting is by--passed to the res-
ervoir through the logic cartridge valve. With the backlap
valve (MV) in the mow position, oil flows through the
backlap valve, out manifold port (M1) and to the reel mo-
tors that are connected in series. Oil flows through the
left (#2), right (#3) and then center reel motor (#1) as it
turns the motors in the mow direction.
When in the mow position, mow circuit pressure will
cause the mow control manifold pilot piston to shift and
open the pressure reducing valve (PORV). The shifted
pressure reducing valve allows circuit oil to return to the
reservoir through the manifold block.
Backlap
Backlapping operation is the same as mowing opera-
tion, except for the position of the backlap valve (MV) in
the mow control manifold. When the backlap valve (MV)
is in the backlap position, oil flows through the center
(#1), right (#3) and then left (#2) reel motor as it turns the
motors in the backlap direction.
Hydraulic System