A balance weight includes a main weight portion extending over a range defined by a circular-arc circumferential edge centered at a rotational shaft hole side and a pair of virtual end surfaces located on the circular-arc circumferential edge on both sides of the rotational shaft hole, a pair of extension weight portions extending from the pair of virtual end surfaces to an opposite circular-arc side of the rotational shaft hole from the circular-arc circumferential edge, the rotational shaft hole provided at the main weight portion so as to be located on a central side of the circular-arc circumferential edge, a crank shaft attachment protrusion, a crank shaft hole provided at the crank shaft attachment protrusion radially eccentrically with respect to the rotational shaft hole, and a pair of spaces formed between positions on both sides of the crank shaft attachment protrusion and the pair of extension weight portions, respectively.

A balance weight includes a main weight portion extending over a range defined by a circular-arc circumferential edge centered at a rotational shaft hole side and a pair of virtual end surfaces located on the circular-arc circumferential edge on both sides of the rotational shaft hole, a pair of extension weight portions extending from the pair of virtual end surfaces to an opposite circular-arc side of the rotational shaft hole from the circular-arc circumferential edge, the rotational shaft hole provided at the main weight portion so as to be located on a central side of the circular-arc circumferential edge, a crank shaft attachment protrusion, a crank shaft hole provided at the crank shaft attachment protrusion radially eccentrically with respect to the rotational shaft hole, and a pair of spaces formed between positions on both sides of the crank shaft attachment protrusion and the pair of extension weight portions, respectively.

A balance weight having one or more journals with a reduced mass portion disposed between a pair of journal portions that define circumferentially extending bearing surfaces. The reduced mass portion has a body, which defines a circumferentially extending bearing surface that is concentric with the bearing surfaces on the journal portions, and at least one stiffening structure that is configured to resist flexing of the journal portions relative to one another due to the transmission of bending loads through the balance shaft.

Crankshaft assemblies for vehicle assemblies, such as engine assemblies, and methods of manufacturing crankshaft assemblies are provided. The crankshaft assembly includes a first crankpin disposed between a first pair of webs and at least a first main bearing journal connected to the first pair of webs, wherein at least one of the first crankpin, the first pair of webs or the first main bearing journal is a polymeric composite including a polymer and a plurality of reinforcing fibers.

Crankshaft assemblies for vehicle assemblies, such as engine assemblies, and methods of manufacturing crankshaft assemblies are provided. The crankshaft assembly includes a first crankpin disposed between a first pair of webs and at least a first main bearing journal connected to the first pair of webs, wherein at least one of the first crankpin, the first pair of webs or the first main bearing journal is a polymeric composite including a polymer and a plurality of reinforcing fibers.

A torsional vibration damper mounted at a crankshaft of an engine is provided. The torsional vibration damper comprises a hub having a first mounting surface and a second mounting surface opposite to the first mounting surface, an inertia ring and an elastomer element disposed between the hub and the inertia ring. The hub includes a first mounting hole configured to receive the crankshaft, and at least one slot spaced apart from the first mounting hole. The slot is configured such that a center-of-gravity of the torsional vibration damper is offset from a central axis of the crankshaft.

A torsional vibration damper mounted at a crankshaft of an engine is provided. The torsional vibration damper comprises a hub having a first mounting surface and a second mounting surface opposite to the first mounting surface, an inertia ring and an elastomer element disposed between the hub and the inertia ring. The hub includes a first mounting hole configured to receive the crankshaft, and at least one slot spaced apart from the first mounting hole. The slot is configured such that a center-of-gravity of the torsional vibration damper is offset from a central axis of the crankshaft.

A vibratory compactor includes a drum, a frame supporting the drum, an eccentric shaft configured to be rotated by a vibration motor, and a primary eccentric weight attached to the eccentric shaft inside the drum. At least one active isolation eccentric weight is located outside the drum so that when the eccentric shaft is rotated, a phase of a vibration generated by the at least one active isolation eccentric weight is substantially opposite to that of a vibration generated by the primary eccentric weight.

A vibratory compactor includes a drum, a frame supporting the drum, an eccentric shaft configured to be rotated by a vibration motor, and a primary eccentric weight attached to the eccentric shaft inside the drum. At least one active isolation eccentric weight is located outside the drum so that when the eccentric shaft is rotated, a phase of a vibration generated by the at least one active isolation eccentric weight is substantially opposite to that of a vibration generated by the primary eccentric weight.

A flat plane crankshaft for an in-line four cylinder engine includes eight crank arms. A fourth crank arm and a fifth crank arm are respectively provided with counter weights. Each of a width of the fourth crank arm and a width of the fifth crank arm is configured to be smaller than a width of a second crank arm. Each of a width of the third crank arm and a width of the sixth crank arm is configured to be greater than the width of the second crank arm.