Drive unit for vehicle propulsion consisting of a variable hydrostatic transmission followed by a gearbox

Abstract

Abstract 1. Drive unit for a propulsive drive, comprising a driving machine (1), a hydrostatic transmission (4) whose output is regulated by an actuating system (24) with an auxiliary pump (23) and a hydraulic servo-piston (26), and a manual transmission (6) connected after the hydrostatic transmission (4), preferably for machinery and motor vehicles, particularly construction vehicles whose driving machine (1) performs a plurality of drive functions concurrently, e. g. for wheel loaders, wherein the actuating system (24) of the hydrostatic transmission (4) comprises a pressure control valve (33) to which pressure is applied from the auxiliary pump (23), an on-off valve (29) for dictating the direction of actuation of the hydraulic pump (3) or of the hydraulic motor (36), and a servo-piston (26) centred by springs (25) on which pressure can be applied from both sides, characterised in that the on-off valve (29) is a control valve, to which an actuating signal is applied in order to effect the actuating movement in both directions of actuation in response to the input speed of the manual transmission (6).

Inventors

• 👤 Heinz Müller
• 👤 Ewald Wachs

Bibliographic Details