A crank angle detection device for an engine capable of achieving downsizing and enhancing appearance of the engine is provided. A crank angle detection device for an engine that includes a pulsar ring including a plurality of detection portions and rotating coaxially with a crank shaft of the engine, and a sensor detecting a passage state of the detection portions. Here, the pulsar ring is fixed to a crank web of the crank shaft. A weight for adjusting inertia balance of the crank shaft is fixed to the crank web arranged close to an end of the crank shaft in an axial direction. The weight has a shape obtained by increasing thickness of a part of the pulsar ring.

An internal combustion engine includes a crankshaft having a first end and a second end opposite the first end. The crankshaft defines a crank axis and is rotatable about the crank axis. The internal combustion engine also includes a camshaft that defines a camshaft axis and is rotatable about the camshaft axis. The internal combustion engine further includes a cam drive assembly that is operable to transfer rotation from the crankshaft to the camshaft, a balance mass rotatable about the crankshaft, and a balancer drive assembly operable to drive the balance mass through the cam drive assembly.

A counterweight forms a crankshaft of an engine, and includes: an arm connecting a crank journal and crank pin of the crankshaft; a neck extending from a first connection face of the arm in a direction opposite to the crank pin; and a substantially fan-shaped weight continuous with a portion of the neck opposite to the crank journal. The weight has left and right shoulders continuous with the neck, and each of the shoulders is tilted to be away from the neck at an angle with respect to a horizontal line orthogonal to a crankshaft center when viewed along the crankshaft center, the angle being 15 or more and 22.5 or less.

An internal combustion engine includes a crankshaft including an outer crankshaft gear and an in-line balance shaft system coupled to the crankshaft. The in-line balance shaft system is configured to balance reciprocating inertial forces of the internal combustion engine, the in-line balance shaft system is configured to provide concurrent and counter-rotating balance forces. The in-line balance shaft system includes a planetary gear set coupled to the crankshaft. The planetary gear set is coupled to the outer crankshaft gear such rotation of the crankshaft drives the planetary gear set. The planetary gear set includes an input gear and an output gear. The input gear is coupled to the crankshaft such that rotation of the crankshaft causes rotation of the input gear.

The present invention provides an internal combustion engine comprising a crankshaft, the crankshaft comprising main bearing journals and cranks for connecting the crankshaft to piston rods of the engine, wherein the crankshaft is provided with counterweights, wherein at least a first counterweight is formed as a separate element and connected to the crankshaft. The present invention is characterized in that at least a second counterweight is formed integrally with the crankshaft.

An engine assembly has a damper rotationally coupled to a crankshaft. The damper has first and second spokes connecting a hub to an inertial weight, with the inertial weight circumferentially surrounding and spaced apart from the hub. Each of the spokes has an airfoil section. The first spoke is oriented with a positive angle of attack and the second spoke is oriented with one of a negative angle of attack and a zero angle of attack. A crankshaft damper is provided by a member having first and second spokes extending radially outwardly from a huh to an outer rim supporting an inertial weight. A chord associated with the first spoke is oriented at a first angle of attack relative to a rotational plane of the member. A chord associated with the second spoke is oriented at a second angle of attack relative to the rotational plane.

A gear train for an engine is provided with a driving gear and a driven gear. The driving gear is formed by a laminate structure of a plurality of plastic sheets and a plurality of metal sheets, with the plastic and metal sheets alternating with one another. The driven gear is formed by another laminate structure of another plurality of plastic sheets and another plurality of metal sheets, with the plastic and metal sheets alternating with one another. The gear train may be provided for use with an engine crankshaft and an associated balance shaft. A method of forming the gear is also provided.

An engine system has a balance gear coupled to a balance shaft. The balance gear is formed by a disc having first and second opposite sides extending radially outwardly to a circumferential edge defining a series of teeth, with a first sector of the disc having a first aperture therethrough, and a second opposite sector of the disc having a second aperture therethrough. A damper is positioned within the second aperture and extends across the disc. The damper has a container enclosing a plurality of particles therein. Opposed ends of the container are outboard of the first and second sides of the disc. A method of forming the balance gear is also provided.

Provided herein are crankshafts comprising a first and second bearing journal both aligned along a crankshaft rotation axis, a first counterweight throw, a web throw including a first web and a second web coupled via a second crankpin, wherein the first web is coupled to the first counterweight throw via the first bearing journal, and a second counterweight throw coupled to the second web via the second bearing journal. The first web and second web each have a center of gravity (COG) offset from a plane defined by the crankshaft rotation axis and a longitudinal axis of the second crankpin. The COGs of each web can be on opposite sides of a plane defined by the crankshaft rotation axis and a longitudinal axis of the second crankpin. The COGs of each web can be substantially symmetrical relative to the plane.

A crankshaft for an in-line internal combustion engine includes at least two bearing points, and crank throws which include a first and a last crank throw. Each of the crank throws includes a counter-weight element. The first and the last crank throw each additionally include an additional weight. The crank throws are arranged angularly offset with respect to each other so that at least two of the crank throws are arranged in angular coincidence with each other. The crank throws and their respective counter-weight elements are arranged to provide for a mass balance. The first and the last crank throw, as seen in an axial direction of the crankshaft, are arranged in angular coincidence with each other. The additional weight of the first and the last crank throw are arranged in a mirrored manner, as seen in the axial direction of the crankshaft.