Crankshaft assembly which is designed for an internal combustion engine, consisting of a) a crankshaft, b) a viscosity torsional vibration damper for damping elastic resonance torsional vibrations of the crankshaft and an output, c) wherein the torsional vibration damper consists of a primary mass inertia and a secondary mass inertia, d) wherein the primary mass inertia is securely fixed to the crankshaft and the secondary mass inertia is coupled to the primary mass inertia as seismic mass with a viscous fluid, e) wherein the torsional vibration damper is mounted to an output end of the crankshaft, f) wherein the functions clutch function portion - in particular designed as an elastomer clutch, and torsional vibration damper are integrated in the torsional vibration damper, g) wherein via the torsional vibration damper and the clutch function portion a main part of the performance of the internal combustion engine - more than 50% - is removable, h) wherein the torsional vibration damper is designed, in addition to the function of reducing the resonance torsional vibrations of the crankshaft, also to take on a flywheel function for reducing the rotational non-uniformity, such that the function flywheel is integrated in the torsional vibration damper, i) characterised in that the torsional vibration damper forms a flywheel mass inertia which is divided into a small primary mass inertia and a secondary mass inertia, greater in relation thereto, such that in the case of low rotational speeds, that is low frequencies, the composite of primary and secondary mass inertia behaves virtually in the manner of a rigid body, whereby its entire mass inertia is effective and the rotational non-uniformity of the motor is reduced as in the case of a flywheel, and such that in the case of high rotational speeds and high frequencies the composite of primary and secondary mass inertia behaves like a damper. a) a crankshaft, b) a viscosity torsional vibration damper for damping elastic resonance torsional vibrations of the crankshaft and an output, c) wherein the torsional vibration damper consists of a primary mass inertia and a secondary mass inertia, d) wherein the primary mass inertia is securely fixed to the crankshaft and the secondary mass inertia is coupled to the primary mass inertia as seismic mass with a viscous fluid, e) wherein the torsional vibration damper is mounted to an output end of the crankshaft, f) wherein the functions clutch function portion - in particular designed as an elastomer clutch, and torsional vibration damper are integrated in the torsional vibration damper, g) wherein via the torsional vibration damper and the clutch function portion a main part of the performance of the internal combustion engine - more than 50% - is removable, h) wherein the torsional vibration damper is designed, in addition to the function of reducing the resonance torsional vibrations of the crankshaft, also to take on a flywheel function for reducing the rotational non-uniformity, such that the function flywheel is integrated in the torsional vibration damper, i) characterised in that the torsional vibration damper forms a flywheel mass inertia which is divided into a small primary mass inertia and a secondary mass inertia, greater in relation thereto, such that in the case of low rotational speeds, that is low frequencies, the composite of primary and secondary mass inertia behaves virtually in the manner of a rigid body, whereby its entire mass inertia is effective and the rotational non-uniformity of the motor is reduced as in the case of a flywheel, and such that in the case of high rotational speeds and high frequencies the composite of primary and secondary mass inertia behaves like a damper.