Abstract: Apparatus for reducing backlash in a gear wheel that includes at least two interacting gear rims that rotate in relation to one another. An adjusting mechanism is located between the gear rims for adjusting the relative angle of rotation of the gear rims about a common axis of rotation. Each adjusting mechanism includes an hydraulic cylinder connected to a pressure medium source and which is arranged to act between the two gear rims in such a manner that a force arises that tends to displace one gear rim in relation to the other about the axis of rotation. Each of the hydraulic cylinders extends at an angle to a disk plane and is supported on a part-spherical foot portion in a bowl-shaped seat in one gear rim and a corresponding part-spherical head portion in a bowl-shaped seat in the other gear rim.