In a split environmental engine and multi-split environmental engine for motor vehicles, which engine includes coaxially arranged split crankshafts with a primary partial crankshaft for a primary engine disposed at the rear power output end of the engine, at least one secondary partial crankshaft for at least one secondary engine disposed at the front end of the engine, and connecting clutches;
- a crankshaft system comprising:
- a) two partial crankshafts, each of which comprises at least one pair of cranks with a firing distance of 360.degree., each of said crank pair consisting of two parallel cranks for in-line engines, and of two cranks with a relative gyration offset angle for V-engines, and two connecting rod-journals such that the two connecting rod-journals of said two cranks of one pair are positioned in the same time in their upper dead centers or respectively in their lower dead centers, and each of said partial crankshafts comprising specially arranged counterweights and being equipped with its own partial flywheel;
- b) split balance shafts consisting of partial balance shafts, each of said partial balance shafts being coordinated with one of said partial crankshaft in each partial engine and individually and oppositely driven by said partial crankshaft, said partial balance shafts beings disposed in one line and parallel to said partial crankshafts, on their sides and respectively above them, and each said partial balance shaft comprising specially arranged counterweights;
- and
- c) selectively adapted self-synchronizing clutches comprising a friction clutch-part and an axially latching-on ratchet mechanism-part, both said clutch-parts connected in parallel so that torque can be transferred by one or the other of said clutch-parts as well as by both clutch-parts together, and said friction clutch-part having as a characteristic feature a reduced torque transferring capacity resulting in a slowly sliding movement of said friction clutch-part when the torque of the firing secondary engine is applied, said ratchet mechanism-part having a characteristic grip-direction being opposite to that of the relative rotation direction between said two partial crankshafts during starting and cranking-up operations of the secondary engine, the ratchet wheel of said ratchet mechanism having only one pawl-gap for each pawl, which results in only one clutching-in point after each complete relative revolution, and which clutching-in point coincides with the synchronization-point between the two said partial crankshafts and the two said partial engines, and said self-synchronizing clutches being characterized by an automatic mutual synchronization of said partial crankshafts and said partial engines;
- whereby all components of said crankshaft system cooperate dynamically in this characteristic manner such that the split and multi-split environmental engine has equal firing distances inside of their 4-stroke partial engines, and inside of the clutched-in complete 4-stroke engines, a secured balancing of the free dynamical forces and free dynamical couples of 1st order, and an acceptable balancing of the free dynamical forces and free dynamical couples of 2nd order, and smooth running of the partial engines singly operating, and of the clutched-in complete engines.