A device for compensating for the operating clearances of an engine comprising a transmission device likely to move transversely in an engine block) during an engine cycle includes a pressing device exerting a holding force on the transmission device. The holding force is adjusted to the instantaneous speed of transverse movement of the transmission device in the engine block.

The invention relates to a power unit, in particular for a hybrid vehicle, having a two-cylinder reciprocating piston engine which comprises two pistons guided in two cylinders in a tandem arrangement and two counter-rotating crankshafts connected to the pistons by connecting rods and having an alternator that can rotate in the opposite direction to the first crankshaft and in the same direction as the second crankshaft. The invention is characterized in that the alternator is in driving engagement with at least the first crankshaft via a traction mechanism and comprises a counterbalance, wherein the first crankshaft is connected via a timing chain or a timing belt to a balancing shaft which carries a further balancing mass. The invention also relates to a vehicle, in particular a hybrid vehicle, having such a power unit.

The invention relates to a power unit, in particular for a hybrid vehicle, having a two-cylinder reciprocating piston engine which comprises two pistons guided in two cylinders in a tandem arrangement and two counter-rotating crankshafts connected to the pistons by connecting rods and having an alternator that can rotate in the opposite direction to the first crankshaft and in the same direction as the second crankshaft. The invention is characterized in that the alternator is in driving engagement with at least the first crankshaft via a traction mechanism and comprises a counterbalance, wherein the first crankshaft is connected via a timing chain or a timing belt to a balancing shaft which carries a further balancing mass. The invention also relates to a vehicle, in particular a hybrid vehicle, having such a power unit.

A moment-cancelling, four-stroke engine is disclosed. The engine includes a first cylinder having a first piston and a second cylinder having a second piston, a first crankshaft operably connected to the first piston and a second crankshaft operably connected to the second piston. The first crankshaft rotates in a first direction and the second crankshaft rotates in a second direction that is opposite the first direction to cancel the moments applied to the engine and reduce engine vibration.

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.

The invention provides an internal combustion engine comprising a piston mounted for reciprocating linear motion within a cylinder along a cylinder axis. The piston is coupled to an output shaft by a power transfer assembly arranged to convert linear motion of the piston to rotary motion of the output shaft. The piston has a first head moveable within a first chamber and a second head opposite the first head and moveable within a second chamber. The power transfer assembly has a lubrication system for lubricating moving components of the power transfer assembly. The lubrication system is sealed from the first chamber and the second chamber to prevent the passage of fluid from the lubrication system into the first chamber and the second chamber.

Methods and systems are provided for the design and manufacture of a crankshaft of a piston internal combustion engine. In one example, a crankshaft comprises a crankshaft throw, the crankshaft throw comprising a crankpin and crank webs. The crank webs are formed asymmetrically in a region of the crankpin with respect to a plane intersecting an axis of rotation of the crankshaft and a center axis of the crankpin, such that the breaking strength of the crankshaft throw is increased at a crankshaft angle of rotation which differs from the top dead center position of a piston to which the crankpin is coupled, and at which the piston exerts a maximum combustion-induced force on the crankpin.

Methods and systems are provided for the design and manufacture of a crankshaft of a piston internal combustion engine. In one example, a crankshaft comprises a crankshaft throw, the crankshaft throw comprising a crankpin and crank webs. The crank webs are formed asymmetrically in a region of the crankpin with respect to a plane intersecting an axis of rotation of the crankshaft and a center axis of the crankpin, such that the breaking strength of the crankshaft throw is increased at a crankshaft angle of rotation which differs from the top dead center position of a piston to which the crankpin is coupled, and at which the piston exerts a maximum combustion-induced force on the crankpin.

An engine having a cylinder fastened to the engine ease with the biconcave internal partition, which divides the cylinder into the upper and bottom parts. Sparking plugs are mounted on both sides of the partition. The upper and the bottom parts of the cylinder have side scavenging channels which connect suction spaces to the working spaces of both parts of the cylinder. The upper and bottom parts of the cylinder have inlet and outlet orifices. Inside the upper and inside the bottom part of the cylinder and the upper and bottom piston are placed respectively, while both pistons are directed towards each other by the working surfaces. The pistons are connected by a rod that is led through the linear bearing that is embedded in the partition forming a seal. The connecting rod is fastened to the bottom piston and by its other end it is connected to the crankshaft.