Abstract: A crankshaft assembly for an internal combustion engine includes a crankshaft, an elastic member fixed to the crankshaft, and a flywheel fixed to the elastic member such that the flywheel is supported in an elastic relationship with the crankshaft. The elastic member has a rigidity in its rotating direction large enough to effectively transmit a driving power to a transmission through a clutch. On the other hand, the elastic member has a rigidity in an axial direction of the crankshaft small enough to shift a resonance frequency of a bending vibration out of a target frequency band of a forced vibration, while ensuring to prevent a failure of disengagement of the clutch.

Abstract: A vibration damper assembly comprises a torsional vibration damper with torsional springs, a mass body, and a resilient drive plate which serves as a bending stress damper. With a bearing on a reinforcement block connected to the crankshaft, the torsional vibration damper has an output member rotatably supported by the crankshaft. The resilient driver plate is operatively disposed in torque transmission relationship between the crankshaft and the mass body in such a manner as to coextend radially outwardly from the crankshaft with the torsional vibration damper.

Abstract: As a torque transmitting member, an annular resilient disc interconnects a crankshaft and an annular flywheel. The crankshaft has an axially extending cylindrical wall in opposed and spaced relationship to an inner peripheral wall of the annular flywheel. For reducing vibrations of annular resilient disc, an elastic annular body has an inner peripheral wall fixed to the crankshaft and an outer peripheral wall opposed to the inner peripheral wall of the flywheel. A heat insulating ring or heat insulating pieces are provided to reduce transmission heat from the flywheel to the elastic annular body. Alternatively, a heat insulating space or spaces may be provided.

Abstract: As a torque transmitting member, an annular resilient disc interconnects a crankshaft and an annular flywheel. The crankshaft has an axially extending cylindrical wall in opposed and spaced relationship to an inner peripheral wall of the annular flywheel. For reducing vibrations of annular resilient disc, an elastic annular body has an inner peripheral wall fixed to the crankshaft and an outer peripheral wall opposed to the inner peripheral wall of the flywheel. A heat insulating ring or heat insulating pieces are provided to reduce transmission heat from the flywheel to the elastic annular body. Alternatively, a heat insulating space or spaces may be provided.

Abstract: A crankshaft assembly for an internal combustion engine includes a crankshaft, an elastic member fixed to the crankshaft, and a flywheel fixed to the elastic member such that the flywheel is supported in an elastic relationship with the crankshaft. The elastic member has a rigidity in its rotating direction large enough to effectively transmit a driving power to a transmission through a clutch. On the other hand, the elastic member has a rigidity in an axial direction of the crankshaft small enough to shift a resonance frequency of a bending vibration out of a target frequency band of a forced vibration, while ensuring to prevent a failure of disengagement of the clutch.