Pemamek A12 4D Drive Unit Self-Aligning Rollerbed, 6 t

A self-aligning rollerbed drive for unbalanced and thin-walled workpieces

The Pemamek PEMA A12 4D drive unit belongs to the A series of self-aligning rollerbeds, which Pemamek recommends for managing unbalanced, thin-walled or heavy cylindrical workpieces. The roller bogies adjust automatically to the diameter of the workpiece, so weight is spread evenly, rotation speed stays constant and no separate adjustment is needed between diameters. The A series covers loads from 12 to 800 tons; the A12 is the 6 t drive unit of the family.

In the 4D version both axles of the drive unit are power driven (two power-driven axles with four rollers). Pemamek notes that rollerbeds with powered two-wheel drives are particularly suitable for conical workpieces such as wind energy towers, and that the A series gives better weight distribution than other rollerbed types, which is a notable advantage for thin-walled work.

Technical specifications

Why choose a self-aligning set

With conventional rollerbeds an operator sets the roller spacing for each vessel diameter. The A series removes that step: the bogies pivot and settle around the shell, keep both axles in contact and share the load. This helps when a workpiece changes diameter along its length, as with a tapered tower section, or when a thin shell could deform under concentrated roller loads.

A powered drive is normally combined with idler units of the same family and positioned along the length of the part. The 100% load range starts at 1,500 mm diameter while a reduced 50% load covers 700 mm upward, so a small part should be checked against the table above before specification. The datasheet prints a roller diameter of 350 mm and a total width of 75 mm, which should be compared with the wall thickness and contact requirements of thin shells. Rail car units are available as an accessory so that the idler units can be moved along the bed for different workpiece lengths.

Ordering and what to confirm before ordering

As with all Pemamek products quoted from the datasheet, the order is by model and specification. Provide the minimum and maximum diameter, whether the part is conical or thin walled, length and weight, the number of idler units and rail cars, the foot pedal or external rotation control, and the supply. Confirm the A12 limits (6 t load, 8.5 kN rotation force) against the weight of the actual workpiece including fixtures.

For larger vessel work see the Pemamek N150 2D drive unit in this series, or browse all Welding Robots & Automation. For a simple fixed-speed turning roll compare the Pandjiris MM-60/30-T turning roll.

Please also state whether the A12 4D will be paired with a matching idler unit, the roller surface requirements, the expected rotation speed within the 100 to 2,000 mm/min range and the diameter change along the workpiece, if any.