Plastic chain operation

The maintenance of sludge scrapers is various depending on configuration and type. The main activities when completing maintenance of these mechanical machines are the transmission chain tensioning and greasing. The previous generations of scrapers are mostly of steel chain type configurations which need a lot of greasing, often there is oil escape which increases wearing on the steel roller chain / sprockets and contaminates the water. The wearing increases maintenance costs and the oil leakage causes a reduced efficiency of the treatment, in worst case there could be a major failure.


With VA Tekniks replacement drive unit you can combine the best of two worlds.

Simplify maintenance and reduce the environmental impact. In many cases the sludge scrapers have been modernized below water line but without replacing the old drive units.

–    No oil leakage
–    Less spare parts
–    Slim and efficient design frees space and
increases efficiency
–    Decreased power consumption
–    Water lubricates the chain
–    Tanks are isolated from each other
(when doble-tanks)
–    Plastic chain has longer lifetime
–    Maintenance without disassembly of the drive shaft


For clarification tanks with modern sludge scraper systems but old or defect drive units.


Drive Unit

The motored gear is assembled on a vertically adjustable motor plate for tensioning of the power trans­mission chain. The transmission chain is made of acetal resin and is lubricated by the tank water. All moving parts are covered and protected by a light weight easy access aluminum hood.

Drive Shaft

The shaft is designed as a stainless steel tube with welded flanges. Plastic split sprockets are bolted to the flanges. The split sprockets enable maintenance without disassembly of the drive shaft. The drive shaft’s bearings are spherical long life heavy duty plastic bearings. The bearings are lubricated by the tank water. No additional greasing is needed.


A retrofit to plastic chain operation along with a new driveshaft means that cutting or removing the heavy driveshaft during maintenance belongs to the past. You can easily change sprockets without disassembling the driveshaft. You get rid of oil and other lubricants, you gain in increased lifetime and easy access maintenance, you make less environmental impact and you decrease your power consumption.