Abstract: A reversible seat belt tensioner includes an electric motor (2), a belt shaft (1) drivable in the belt winding direction by the electric motor (2) via a drive wheel (10), and a drive shaft (9) transmitting the rotational movement of the electric motor (2) to the drive wheel (10). The drive shaft (9) is connected to at least one of the drive wheel (10) and the electric motor (2) via a helical gear unit. The use of a helical gear unit provides the advantage that the rotational axes of the meshing components can be arranged at angles other than 90 degrees with respect to each other because the components in the helical gear units only come into punctiform contact.

Abstract: A reversible belt tensioner (1) with a belt roller and an electric motor (3) that drives the belt roller (2) in roll-up direction, has at least two electrical contacts (11) arranged on the electric motor (3). Counter contacts (10) are fixed on the reversible belt tensioner (1), and the electrical contacts (11) of the electric motor (3) are plugged directly onto or into the counter contacts (10).

Abstract: A reversible seat belt tensioner includes an electric motor (2), a belt shaft (1) drivable in the belt winding direction by the electric motor (2) via a drive wheel (10), and a drive shaft (9) transmitting the rotational movement of the electric motor (2) to the drive wheel (10). The drive shaft (9) is connected to at least one of the drive wheel (10) and the electric motor (2) via a helical gear unit. The use of a helical gear unit provides the advantage that the rotational axes of the meshing components can be arranged at angles other than 90 degrees with respect to each other because the components in the helical gear units only come into punctiform contact.