TM 5-3895-373-10
SECTION III. PRINCIPLES OF OPERATION
1.12
PAVING MACHINE.
The paving machine consists of the tractor and screed.
It is normally manned with one paving machine operator
and two screed crew members. The tractor unit pushes
a haul truck while the haul truck unloads paving material
into the tractor hopper. The twin dual slat conveyor
system on the tractor unit carries the paving material
from the hopper to the augers. Two electrically-
controlled flow gates, mounted behind the hopper,
regulate the amount of material fed to the augers at the
back of the tractor. The augers spread the paving
material evenly along the length of the leading edge of
the screed. As the tractor unit moves forward, it tows the
screed over the paving material. Burners on the screed
heat the screed plate and maintain its temperature equal
to that of the paving material to prevent sticking. The
screed is equipped with a vibrating screed plate, which
provides a high degree of compaction to the paving
material passing underneath it.
Both the tractor and screed units are equipped with
controls that impact the paving operation. The paving
machine operator can operate virtually all machine
functions. The screed crew control boxes contain
controls limited to paving functions.
1.13
TRACTOR.
The tractor is powered by a Perkins T4.236 turbocharged
diesel engine coupled to a pump drive gearbox that
provides power to five hydraulic pumps. Two hydraulic
propulsion pumps are attached to the gearbox and
provide hydraulic oil pressure to drive the propulsion
motors mounted on the track frame. Two hydraulic
auxiliary pumps and a hydraulic auxiliary vibration pump
are attached in tandem to the propulsion pumps. These
pumps provide hydraulic oil power to auger/conveyor
motors, vibration motors, and all hydraulic
cylinder functions on the paving machine. Additional
components such as push rollers, hopper wings, and
flow gates are discussed in the following paragraphs.
1.13.1
Track Drive. The paving machine is mounted on
steel crawler tracks equipped with rubber track pads
mounted on steel track pad plates. The hydraulically-
powered track drive evenly distributes and supports the
weight of the paving machine for greater stability. The
tracks operate individually in the forward and reverse
directions at variable speeds. The tracks can be
counter-rotated for quick turning maneuvers.
1.13.2
Push Rollers. The push rollers are located on
the front of the paving machine. The push rollers contact
the tires of the haul truck and allow the tractor to push it
while receiving paving material. To compensate for
misalignment between tractor and haul truck, the push
rollers are mounted on a pivoting bumper.
1-7
