Important Compactor Plate Design Aspects

A compactor plate basically contains of an upper and lower assemblage. The upper assemblage consists of the powertrain comprising of the engine, engine console and centrifugal clutch. The lower assemblage contains the exciter, which provides vibration, and is securely mounted to the base plate.

Specially designed rubber mounts separate the powertrain from the exciter, where transmission from the engine to the exciter is accomplished using V-belts. Depending on the model of the machine, the guiding handle is attached to the upper or lower assemblages. To help reduce operator fatigue, further specially designed rubber mounts absorb shock produce by the machine.

The operation and effectiveness of a compactor plate is governed by the machine’s powertrain and exciter locations, the exciter design and vibration frequency, and the overall static weight of the machine.

Engine Location In Relation To The Exciter

An important design aspect of a compactor plate is the relevant location of the machine’s engine in relation to its exciter component. A machine that produces uniform amplitude at the front and rear of the base plate has the engine located directly and centrally over the exciter. However, a machine with an engine located at the rear and the exciter at the front will produce more amplitude at the front of the base plate than the rear. This particular design provides a faster forward speed, lower centre of gravity and a better ability to compact soils with a specific amount of cohesive elements.

The Significance Of Static Weight

Machines having a static weight of between 68kg to 136kg (150 to 300lb) are dependant upon the centrifugal force generated by the exciter to produce the necessary vibratory action to successfully compact soils. Larger vibratory plates having a static weight of over 136kg (300lb) have the advantage of combining the static weight together with the vibratory action produced by the exciter. This arrangement not only vibrates soil elements but also squeezes them to provide better compaction.

The Design Of The Exciter

A compactor plate’s exciter component is the fundamental element of the machine. To create centrifugal force, the exciter principally works by rotating an unbalanced eccentric weight at high velocity. In doing so, the exciter produces vibration and forward movement that compacts soils. The exciter component can be greased or oil lubricated. If oil lubricated, then care must be taken to ensure the precise amount of oil is installed within the exciter. Too much oil will overheat the exciter bearings and have a negative effect on compaction performance whilst too little oil will damage the exciter bearings.

Frequencies Produced By The Exciter

Each soil particle reacts differently to the variety of vibratory frequencies produced by a machine’s exciter. Smaller soil particles respond significantly better to rapid vibratory frequencies whilst larger soil particles respond to slower vibratory frequencies. Consequently, it is essential that the vibration frequency of the exciter is consistent with the size of the principal soil particles to be compacted. As the exciter frequency move towards the reverberative frequency of the soil particles been compacted, soil particles then begin to sympathetically vibrate with maximum amplitudes.