ARM AS-TIGHTENER 4W4456 - Caterpillar

Illustration 1 g06054664
General Information
The principal working component in the vibratory system is the eccentric weight. The vibratory motor rotates this weight on a shaft inside the rolling drum. The rotation of the weight generates a dynamic (or centrifugal) force that is greater in magnitude than the static weight of the machine.The machine must be operating at high idle or in ECO mode in order to operate the vibratory system. At high idle, the engine operates at an engine speed of 2200 rpm. When operating the vibratory system in ECO mode, the engine operates at 2000 rpm.The rotational speed of the eccentric weight shafts determines the vibratory frequency. Frequency is expressed in Hertz (Hz) (vibrations per second) or in vibrations per minute (VPM). The vibratory frequency on the standard machine is controlled by the engine speed. On machines which are equipped with the variable frequency vibratory system, the machine ECM can vary the vibratory frequency at a given engine speed.
Illustration 2 g06054670
Vibratory Control System
(1) Machine ECM
(2) Display
(3) Vibratory solenoid "A"
(4) Vibratory solenoid "B"
(5) Engine ECM
(6) Keypad
(7) Propel lever
(8) Speed sensorMachine ECM (1) monitors input signals from the following components in order to control the vibratory system:
Engine ECM (5)
Keypad (6)
Propel lever (7)
Speed sensor (8) (on machines with variable-frequency vibratory system)Machine ECM (1) evaluates the input signals and determines if an output should be sent to vibratory solenoid "A" (3) or vibratory solenoid "B" (4). The output signal is not proportional on machines with the fixed-frequency vibratory system. The output signal is proportional on machines with a variable-frequency vibratory system.Note: On fixed-frequency vibratory systems, the output signals from the machine ECM are a fixed value. Vibratory frequency on these machines is affected by engine speed. Vibratory frequency will differ slightly, depending on whether the machine is operating in ECO mode or high idle.Machine ECM (1) uses display (2) in order to provide information to the operator about the vibratory system during operation.