A drive unit for a strapping device strapping an item to be packed with a plastic tape which is laid around it includes a motorized tensioning device and a motorized welding device for the plastic tape. The tensioning and welding device can be driven by the same electric motor which can be brought alternatively into an operative connection with the devices with freewheels connected therebetween. A problem has occurred in drive units of this type that they are relatively complicated to assembly and have problematic operational reliability under certain boundary conditions. To bypass these problems, the electric motor includes at least one shell extension which protrudes beyond it at one axial end with the result that the drive elements which have up to now been mounted separately in the housing of a strapping device can be supported directly on the electric motor which then acts as a drive unit.