PUMP DRIVE SYSTEM.
The hydraulic pump drive system consists of the paving
machine engine, pump drive gearbox, and five hydraulic
The Perkins T4.236 turbosupercharged diesel engine
flywheel is shaft coupled to the input of the attached
pump drive gearbox. The gearbox input drives two
output gears at a 1:1 input-to-output ratio.
There are five hydraulic pumps attached in a tandem
configuration to the oil-filled gearbox. Coupled directly to
the gearbox are two hydraulic propulsion pumps. They
provide 5000 psi (34 500 kPa) at 2.8 cu in./rev (46,6
cc/rev) to the left and right hydraulic propulsion motors.
Attached in tandem to the right propulsion pump is one
shaftdriven auxiliary hydraulic pump with two outputs.
One output provides 0.7 cu in./rev (11,6 cc/rev) while the
second output provides 0.58 cu in./rev (9,67 cc/rev), both
at 2500 psi (17 200 kPa). Attached to the left propulsion
pump is a hydraulic auxiliary vibration pump that
provides 0.24 cu in./rev (4,00 cc/rev) at 2000 psi (13 800
kPa). Connected to the vibration pump is a second
auxiliary pump with two outputs, the same as the
auxiliary pump on the right side.
Both outputs of the left auxiliary pump, and the 0.7 cu
in./rev (11,7 cc/rev) output of the right auxiliary pump, are
used for the auger/conveyor motor. The 0.58 cu in./rev
(9,67 cc/rev) output of the right auxiliary pump is split
through a 50/50 flow divider. Half the fluid is used for the
tensioning, and screed lift cylinders). The other half of
the output fluid is used for tow point cylinders and to
supplement screed vibration.