It is common for crankshafts of internal combustion engines to have main bearing journals provided between each of the conrod bearing journals. However, to reduce engine friction, the fewest main bearing journals that can be used while still meeting the design targets is preferred. A crankshaft for an in-line, four-cylinder engine, according to an embodiment of the disclosure, has three main bearing journals. Bridges, one each located between first and second conrod bearing journals and between third and fourth conrod bearing journals. The bridges have a cross-section with at least two concavities to improve the strength of the bridge compared to, for example, a cylindrical bridge, without greatly increasing the mass of material used in the bridge. Furthermore, a locus of a centroid of cross sections through the bridge are not coincident with an axis of rotation of the crankshaft, but instead is displaced toward the nearer conrod bearing journal.

There is presented various embodiments disclosed in this application, including an improved crankshaft system using a load connecting member which provides a greater maximum torque angle than a conventional system, thereby improving efficiency and power.

There is presented various embodiments disclosed in this application, including an improved crankshaft system using a load connecting member which provides a greater maximum torque angle than a conventional system, thereby improving efficiency and power.

A crankshaft assembly which is designed for a reciprocating-piston machine of an internal combustion engine includes a crankshaft, a torsional vibration damper for damping resonance torsional vibrations of the elastic torsion modes of the crankshaft, and an output. The torsional vibration damper has a primary mass inertia and a secondary mass inertia, the primary mass inertia being rigidly connected to a crankshaft and the secondary mass inertia being coupled as a seismic mass with a viscous liquid to the primary mass inertia. The torsional vibration damper is configured to assume the function of a flywheel for reducing rotational non-uniformity in addition to the function of reducing the resonance torsional vibrations of the crankshaft. The torsional vibration damper is attached to an output end of the crankshaft, and the torsional vibration damper forms a centrifugal mass which is divided into a primary mass inertia and a secondary mass inertia, wherein the three functions of a clutch functional section, a flywheel and a torsional vibration damper are integrated into the torsional vibration damper.

A crankshaft assembly which is designed for a reciprocating-piston machine of an internal combustion engine includes a crankshaft, a torsional vibration damper for damping resonance torsional vibrations of the elastic torsion modes of the crankshaft, and an output. The torsional vibration damper has a primary mass inertia and a secondary mass inertia, the primary mass inertia being rigidly connected to a crankshaft and the secondary mass inertia being coupled as a seismic mass with a viscous liquid to the primary mass inertia. The torsional vibration damper is configured to assume the function of a flywheel for reducing rotational non-uniformity in addition to the function of reducing the resonance torsional vibrations of the crankshaft. The torsional vibration damper is attached to an output end of the crankshaft, and the torsional vibration damper forms a centrifugal mass which is divided into a primary mass inertia and a secondary mass inertia, wherein the three functions of a clutch functional section, a flywheel and a torsional vibration damper are integrated into the torsional vibration damper.

In an overhead cam engine (10) having a first bearing (21) supported by the cylinder block (11), and a second bearing (22) supported by a bearing retaining member (60) attached to the cylinder block inside a crankcase chamber (12) for rotatably supporting a crankshaft (20), the crankshaft is provided with a reduced diameter portion (24b) having a smaller outer diameter than an adjoining part of the crankshaft on a side of the second bearing facing away from a cylinder (15) defined in the cylinder block, and a crankshaft pulley (53) is mounted on the reduced diameter portion.

A crankshaft with improved seizure resistance is provided. A crankshaft (10) is a crankshaft including journals (11) and pins (12), having a chemical composition of, in mass %: 0.35 to 0.40 % C; up to 0.70 % Si; 1.00 to 2.00 % Mn; up to 0.50 % Cr; up to 0.050 % Al; up to 0.020 % N; up to 0.020 % P; 0.005 to 0.200 % S; and balance Fe and impurities, each of the journals (11) and pins (12) having a surface microstructure containing tempered martensite in not less than 80 volume % and a surface hardness not higher than HV 450.

A crankshaft with improved seizure resistance is provided. A crankshaft (10) is a crankshaft including journals (11) and pins (12), having a chemical composition of, in mass %: 0.35 to 0.40 % C; up to 0.70 % Si; 1.00 to 2.00 % Mn; up to 0.50 % Cr; up to 0.050 % Al; up to 0.020 % N; up to 0.020 % P; 0.005 to 0.200 % S; and balance Fe and impurities, each of the journals (11) and pins (12) having a surface microstructure containing tempered martensite in not less than 80 volume % and a surface hardness not higher than HV 450.

Provided is a technique capable of exhibiting high seizure resistance even if a scratch is formed. The sliding member of the present invention is a sliding member including a base layer and a resin coating layer formed on the base layer, wherein the resin coating layer is formed of a polyamide-imide resin as a binder, barium sulfate particles, molybdenum disulfide particles having an average particle diameter which is 1.0 time or more and 2.8 times or less the average particle diameter of the barium sulfate particles, and unavoidable impurities.

To provide a technique capable of realizing an appropriate wear resistance in a resin coating layer.

The sliding member of the present invention is a sliding member including a base layer and a resin coating layer formed on the base layer, wherein the resin coating layer is formed of a polyamide-imide resin as a binder, barium sulfate particles, molybdenum disulfide particles, and unavoidable impurities, wherein the resin coating layer is composed of a plurality of overcoated application layers, and wherein the plurality of application layers are different from each other in content of hard particles.