Plastic gearbox for drill

The rotary hammer from Dewalt has a plastic housing which, as a combination component, encloses the electric motor and gearbox at the same time. The engineering plastic "Ultradur" B4300 G6 from BASF is used. The demanding component inside the drilling tool replaces two separate housings, one of which - the gearbox housing - was previously made of die-cast magnesium. The plastic housing now encloses the electric motor and the gearbox with chain drive:

It must therefore above all be very dimensionally accurate and ensure that the axes of the transmission components are parallel and remain so even at high operating temperatures. The PBT Ultradur B4300 G6 offers the necessary rigidity and dimensional stability even in a damp environment. With the good flowing plastic, filigree contours can be executed more easily and, last but not least, the weight of the hammer drill is reduced compared to the metal housing.

Plastic recycling from and for industry and other uses

The absence of another metal component leads to simpler warehousing and logistics, the integration of difficult functions such as snap connections saves screws and assembly time. In addition, cut threads are no longer necessary and the parts costs are reduced, since plastic components are very precise and, unlike metal, do not have to be mechanically reworked. On an additional electrical insulation to voltage leading engine parts can be omitted, so that the overall design is more compact. Finally, the acoustic damping behavior of the plastic is basically better than that of metals and the injection mold more durable than the magnesium die casting tool.

Dewalt also uses BASF's technical plastics for other special applications in the rotary hammer: carbon fiber is used for the highly rigid connecting rod – the connection between the piston and the crank wheel polyamide Ultramid A3WC4 used. The yellow and black outer housing parts are made of the particularly impact-resistant Ultramid B3ZG6, while the components near the engine with contact are called live components made of Ultramid A3EG6 or Ultramid A3EG7.