The TPM+ power servo actuator is available in a single-stage version or as a two-stage actuator for rotary drive tasks. The reduction ratio steps are relatively small to facilitate an actuator design characterised by optimal energy efficiency and dynamics. Helical toothing in the gearhead permits significantly smoother running at the output. The influence of meshing frequencies is minimised and the overall noise level is 6dB lower than with the straight-toothed predecessor gearhead series.