Theory of Operation
ePowrReverser Control Valve Operation
YZ4243
The ePowrReverser hydraulic system receives its supply
from the power steering return line. This oil then runs
through a filter. When the filter begins to clog up, the
pressure drop across the filter increases. The filter bypass
monitors this pressure drop. If the pressure drop is equal or
greater than 38 psi, the filter bypass opens and directs the
flow to lube circuit by passing the control valves.
The filtered oil then is regulated to a nominal pressure of
160-psi for the traction clutches and hydraulic system. The
flow that passes through the pressure regulator lubricates
the clutches. The lube circuit also has a relief valve. If the
lube pressure rises above 44 psi, the valve opens and
allows the pressure to be relieved.
The oil that is regulated to 160-psi supplies the Main PTO,
mid PTO, MFWD and traction clutches. Two proportional
valves, one for forward and one for reverse, control the
traction clutches. When the direction is selected, the
corresponding proportional valve opens and allows the oil
to go to the clutch and activate it. The pressure transducer
checks for the correct pressure.