An internal combustion engine may include a first piston reciprocatingly disposed in a first cylinder, a combustion chamber fluidly coupled with the first cylinder, and an ignition source at least partially disposed within the combustion chamber. An intake valve may provide selective fluid communication between an intake system and the combustion chamber, and an exhaust valve may provide selective fluid communication between an exhaust system and the combustion chamber. A second piston may be reciprocatingly disposed within a second cylinder. A crankshaft may be coupled with the first piston and the second piston for rotational motion associated with reciprocating movement of the first piston and the second piston.

A balancer structure for an internal combustion engine and the internal combustion engine are provided. A transmission driving gear are arranged to be rotatable integrally with a crankshaft. A transmission driven gear is arranged to be rotatable integrally with a first balance shaft. The transmission driven gear meshes with the transmission driving gear. A balancer driving gear is arranged to be rotatable integrally with the first balance shaft. A balancer driven gear is arranged to be rotatable integrally with the second balance shaft. The balancer driven gear meshes with the balancer driving gear. The first balance shaft includes an output portion. The output portion outputs torque to an engine-driven accessory.

A balance shaft includes an unbalanced shaft (3) comprising a bearing journal (8, 9), the periphery of which is merely partially cylindrical. The cylindrical partial periphery (10) of the bearing journal is oriented toward the shaft imbalance. The balance shaft also includes a needle roller cage assembly (15); and a bearing ring (13), which extends around the bearing journal, lies against the cylindrical partial periphery and forms the inner raceway of the needle roller cage assembly. The cage (27) of the needle roller cage assembly is designed to run on the end faces of the bearing ring axially on both sides by means of radially inwardly extending projections.

A rolling vibration reduction device for an internal combustion engine includes: a main inertial system configured to rotate with a crankshaft of the internal combustion engine; a driving force transmission mechanism configured to transmit a rotational driving force of the crankshaft, a direction of the rotational driving force being reversed by the driving force transmission mechanism; and a sub-inertial system configured to rotate by the rotational driving force transmitted from the driving force transmission mechanism and to reduce rolling vibration of the internal combustion engine associated with rotation of the crankshaft by rotating in an opposite direction to the crankshaft. A torsional resonance frequency in the rolling vibration reduction device is set to a value higher than an explosion primary frequency at a maximum engine speed in a preset operating region of the internal combustion engine.

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.

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.

A system for providing power to a vehicle includes a combustion engine having a low number of cylinders. A mechanically driven charging mechanism is attached to the combustion engine to provide pressurized air to the combustion engine and generate increased power. The combustion engine includes a 2nd order mass balance shaft that is operatively coupled to a crankshaft of the engine. The 2nd order mass balance shaft rotates at a higher speed than the crankshaft and counters inertial forces generated by the pistons of the engine. A compressor of the mechanically driven charging mechanism is attached to the 2nd order mass balance shaft, such that the mechanically driven charging mechanism is mechanically driven by rotation of the 2nd order mass balance shaft. The high speed of the 2nd order mass balance shaft drives the compressor of the mechanically driven charging mechanism.

Disclosed is a balancer device for an internal combustion engine, wherein: a pump mounting fixing part to which an oil pump is fixed is formed on an end surface of a lower housing member; a gear accommodation part in which a pump driving gear and a reduction gear are accommodated is provided between the oil pump and the pump mounting fixing part; a rigidity-reinforcing part in which an oil discharge passage is defined in communication with a discharge port of the oil pump is formed on the lower housing member so as to extend in a direction of extension of first and second balancer shafts on an outer side of the lower housing member; and a portion of the pump mounting fixing part formed on the end surface of the lower housing member and the rigidity-reinforcing part are made integral with each other.

An insert for a bed plate according to an embodiment of the present disclosure is coupled to a lower portion of an engine block. The insert of the bed plate includes a crankshaft seating portion disposed at a center and where a crankshaft is mounted. The insert of the bed plate also includes a ladder frame fixing portions that are disposed at opposite ends of the insert to facilitate coupling to a ladder frame. The insert of the bed plate also includes a plurality of protrusion portions that are formed on both surfaces of the insert and contact the ladder frame.

A balance shaft is proposed that includes: i) an unbalance shaft having an unbalance section and an adjacent bearing pin having a cylindrical partial circumference which is oriented towards the shaft imbalance; ii) a bearing ring which surrounds the bearing pin and bears against the cylindrical partial circumference and delimits a free space with a bearing pin back radially opposite thereto; and, iii) a clamping element which is clamped in the free space and clamps the bearing ring radially against the cylindrical partial circumference. The clamping element is intended to secure the bearing ring against axial sliding on both sides on the bearing pin, and the clamping element is connected in an axially interlocking manner to the unbalance shaft on one side and to the bearing ring on the other side.