a support 17 the pitch system of fig1 is triggered in such a way that the drive 6 causes the rotary bearing ring 10 to continuously rotate via the pinion 9 the rotational speed is so large that a breakaway torque does not occur even if the extender 2 rotates with the rotor blade 1 to this end it is necessary for the relative speed between the ring 11 and the rotary bearing ring 10 to exceed a critical speed even if the extender 2 rotates in the sense of rotation of the bearing ring 10 the arrangement of the bearing and pitch drives as illustrated in fig1 differs from the arrangement known from de 101 40 793 a1 in that one pitch drive interacts directly with the rotor blade to be varied in its setting whereas the known pitch systems which have two drives will always act jointly on the bearing elements fig2 and 3 show alternative aspects of the pitch system in which the drives engage the rotary bearing ring 10 jointly in fig2 the rotary bearing ring 10 is disposed outside the bearing rings 11 and 12 at its outside the bearing ring 10 has a tooth system 18 in which the pinions 9 and 16 mesh the tooth system 18 may be formed as a continuous tooth system here or may consist of two parallel tooth series as is suggested in fig2 if the drives 6 and 7 are positioned at an offset a tooth system having the width of a pinion will be sufficient i e.