VARIABLE DISPLACEMENT HYDROSTATIC DRIVE FOR TRACTORS

摘要

A sputter gearbox for a four wheel drive, hydrostatically driven tractor integrates both the input drive train and the output drive train into a single gearbox. The drive mechanism eliminates the need for a separate mechanical gearbox by establishing pre-set fixed displacement settings that are electronically controlled along with the variable displacement of the hydrostatic motor and hydrostatic pump, to provide a smooth power shift through all ranges without requiring the tractor to stop. The drive mechanism is configured so that essentially all components are individually controlled so that the entire power generated by the tractor engine can be diverted to any one of the traction drive, the PTO mechanism, the auxiliary hydraulic drive or, to a somewhat lesser extent, the tractor hydraulic system. The sputter gearbox is mounted to the rear axle housing to allow the sharing of a common oil sump. The input gear set and the output gear set are also within the same common lubrication sump within the sputter gearbox.