Oscillation by HAMM – high-quality, cost-effective compaction

The oscillation principle at a glance:

In an oscillation drum, two eccentric shafts are fitted at a 180° angle to each other. Both unbalanced masses rotate synchronously, which causes the drum to perform a rapidly alternating forward-backward rotational movement. This results in the compaction energy being transmitted forwards and backwards tangentially into the ground below in the form of shear forces. The drum is therefore in constant contact with the ground, which means that permanent static compaction also takes place because of the weight of the machine, as well as compaction caused by the shear forces. The benefit: The compaction process is carried out more quickly and is, therefore, more efficient. Added benefit: This type of compaction conserves valuable resources and reduces CO2 emissions.

Two compaction systems in one drum

At the heart of the VIO drums from HAMM is an unbalance system, which can compact either with vibration or with oscillation. Every VIO drum is fitted with a split unbalance, which can be switched from the operator's platform – even while in motion. HAMM has hereby created an extremely flexible tool that dramatically expands the rollers’ range of application.

VIO in asphalt construction

HAMM also provides tandem rollers with VIO drums for asphalt construction. These give construction companies tremendous flexibility, since a single roller can be converted from a double vibration roller to a roller with vibration and oscillation – or even a double oscillation roller – at the push of a button.

The VIO drum allows the operator to adapt the compaction type as required to the changing asphalt temperatures and layer thicknesses. What’s more, in oscillation mode, the rollers are particularly quiet in operation, causing fewer vibrations in the surrounding area.

For maximum flexibility, there are the tandem rollers of the HD+ VIO-2 HF sales variant, which have two VIO drums. These are capable of compacting at higher frequency in nine different ways and achieve the compaction target very efficiently and very quickly. To this end, the drums contain a maintenance-free toothed belt to ensure high availability.

VIO in earthworks

VIO drums were developed for earthworks, so that compactors can give operators the flexibility of compacting with either oscillation or vibration. This means one roller can cover multiple different applications. The range of applications extends from deep compaction in vibration mode at one end to compaction with oscillation at the other end, for example over infrastructure lines, in inner-city areas close to historical buildings or vibration-sensitive buildings or railway infrastructure. Oscillation mode also produces especially homogeneous, level surfaces.

Split drums improve the quality of compaction in curves and on roundabouts, especially when major steering movements are necessary. The use of split drums minimizes shear stress on the asphalt, preventing material from being displaced and cracks from forming. This is of particular benefit when compacting types of asphalt prone to displacement.

HAMM has combined the benefits of the split drum with the advantages of oscillation to develop a split drum with oscillation. In this solution, each drum half contains a separate, mechanically independent oscillation unit.