HUB-HUB CONNNECTION FOR A POWER UNIT

The invention relates to a power unit, in particular for a hybrid vehicle, including a reciprocating-piston engine and at least one generator drivingly connected to the engine, wherein the engine has at least two pistons guided in at least two cylinders in a tandem arrangement, and two crankshafts, which are connected to the pistons by connection rods that run in opposite directions, and are mechanically coupled in the same phase. The engine includes a hub-hub connection with a first connection joining a first hub to a second hub such that an angular position between the first hub and the second hub is continuously adjustable on installation. The hub-hub connection also has a second connection in the form of a connection disk configured, dimensioned and arranged with support surfaces on each of which the first hub and the second hub rest. The connection disk has a matrix with hard material elements embedded therein, in particular diamond chips, which are arranged in the support surfaces for frictional engagement of the hubs.