Toro Reelmaster 5510 Series, Service Manual

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Hydraulic Flow Diagrams
(5410/5410-D/5510/5510-D/5610)
Traction Circuit (5410/5410-D/5510/5510-D/5610)
The hydraulic traction circuit consists of a variable displacement piston pump
(P5) connected in a closed loop, parallel circuit to 2 orbital roller vane wheel
motors. The traction pump input shaft is rotated by a driveshaft that is driven
from the engine flywheel.
Traction circuit pressure (forward and reverse) can be measured at test ports
located in the hydraulic tubes that connect the front wheel motors.
Forward Direction
Pushing the top of the traction pedal angles the traction pump swash plate to
create a flow of fluid. This fluid flow is directed to the wheel motors via hydraulic
hoses and tubes to drive the wheels in the forward direction. Forward traction
pressure is limited to 25,000 kPa (3,625 psi) by the forward traction relief valve
(R3) located in the traction pump.
Fluid flowing from the wheel motors returns to the variable displacement pump
and is continuously pumped through the traction circuit as long as the traction
pedal is pushed.
The angle of the swash plate determines pump flow and ultimately traction
speed. When the traction pedal is pressed a small amount, a small swash plate
rotation results in low pump output and lower traction speed. When the traction
pedal is pressed fully, the pump swash plate rotates fully to provide maximum
pump output and traction speed.
Gear pump section (P3) supplies fluid flow for the steering circuit and also
provides a constant supply of charge fluid to the closed loop traction circuit.
This charge fluid provides lubrication for traction circuit components and also
replenishes traction circuit fluid that is lost due to internal leakage in the traction
circuit.
Gear pump (P3) takes its suction from the hydraulic reservoir. Charge pump flow
is directed to the low pressure side of the closed loop traction circuit. Charge
pressure is limited by the charge relief valve (R5) located in the traction pump.
The charge relief pressure to 1,400 kPa (200 psi).
The piston pump (P5) includes a flushing valve (R10) that bleeds off a small
amount of hydraulic fluid for cooling of the closed loop traction circuit. The charge
system replenishes fluid that is bled from the traction circuit by the flushing valve.
Reverse Direction
The traction circuit operates essentially the same in reverse as it does in the
forward direction. However, the flow through the circuit is reversed. Pushing the
bottom of the traction pedal rotates the traction pump swash plate to create a
flow of fluid. This fluid is directed to the wheel motors to drive the wheels in the
reverse direction. Reverse traction pressure is limited to 25,000 kPa (3,625 psi)
by the reverse traction relief valve (R4) located in the traction pump.
Fluid flowing from the wheel motors returns to the traction pump and is
continuously pumped through the closed loop traction circuit as long as the
traction pedal is pushed.
The charge circuit and flushing valve (R10) function the same in reverse as
they do in the forward direction.
Hydraulic System: Hydraulic Flow Diagrams
(5410/5410-D/5510/5510-D/5610)
Page 6–20 Reelmaster ® 5410/5510/5610 Series
15216SL Rev C