Coupling gear

A coupling gear for transmitting rotation of a first shaft onto a second shaft, said coupling gear comprising:

• a first and a second shaft;
• a first coupling wheel fixedly connected to said first shaft;
• a second coupling wheel fixedly connected to said second shaft;
• a third coupling wheel with a rotational axle driven by said first coupling wheel;
• a fourth coupling wheel with a rotational axle driven by said third coupling wheel and driving said second coupling wheel;
• a first coupler for coupling the rotational axle of said first coupling wheel and said rotational axle of said third coupling wheel;
• a second coupler for coupling said rotational axle of said third coupling wheel and said rotational axle of said fourth coupling wheel;
• a third coupler for coupling said rotational axle of said fourth coupling wheel and the rotational axle of said second coupling wheel;
• a control device for adjusting with a control movement a rotational phase of said first shaft relative to said second shaft, said control device comprising a control element for adjusting an angle between said first, second, and third couplers;
• said control device further comprising a friction member moveable into frictional engagement with at least one of said coupling wheels to thereby aid the control movement initiated by said control device.