Gear drive, e.g. for crankshaft of internal combustion engine; has extension ring to move third gear axially, so balancing tooth flange play of second gear engaging with first gear for heat expansion

摘要

The gear drive has two gears (10,14) on two shafts (12,16) and engaging with helical toothings (22,26). A third gear (18) is arranged to balance the tooth flange play of the second gear. The third gear engages with the first gear by a helical toothing and slides axially with respect to the second gear. An extension ring (28) alters the space between the second and third gears with respect to temperature. The thermal expansion of the extension ring is chosen so that a change in play due to heat-dependent variation of the space between the first and second shaft is balanced by an axial displacement of the third gear by the heat expansion of the extension ring and the effect of a helical toothing.