Screed Vibrators. The screed is equipped with
four hydraulic vibrators: two main screed vibrators and
two extension screed vibrators. The vibrators compact
the paving material. A single hydraulic vibration motor
drives both main screed vibrators. Each extension
screed is equipped with a separate vibrator and hydraulic
vibration motor. The vibrators vibrate at a frequency set
by the paving machine operator. As the eccentric shaft
in each vibrator spins, the eccentric weight in the shaft
causes vibrations due to its off-center weight. The
vibrators mount directly to the screed plate and cause
the plate to vibrate with them. This vibrating motion
provides the initial compaction to the paving material
beneath the screed.
extension screeds are equipped with burner/blower pairs.
Each burner/blower pair operates together to increase
the temperature of the screed plates to 300°F (150°C).
Each half of the main screed, and each extension
screed, is equipped with an individual burner/blower pair.
Diesel fuel sprays into the burners and ignites from the
heat of a glow plug. The blower evenly distributes the
heat from the burner across the screed plate. Each
screed crew control box contains control switches for the
burners and blowers. The left control box has the only
control for the screed burner fuel pump. Both the right
and left control boxes include controls for the burner