Drive system comprising a variable speed driving motor, an adjustable

Abstract

A drive system, comprising a driving motor whose speed can be adjusted by means of an operating member, an adjustable hydrostatic transmission with a pump and a hydraulic motor of which the volume throughput can be adjusted, followed by a change-speed gear, in particular one which can be shifted under load, connected to the hydrostatic transmission, wherein a control device is associated with the hydrostatic transmission, and an operating member is provided to initiate a gear shift, is arranged so that while ensuring a simple regulating concept, it exhibits subjectively good shifting behavior without costly auxiliary devices having to participate in the control response of the continuously adjustable hydrostatic transmission. This is achieved by the fact that associated with the control device is a device for determining the direction of transmission of power between the driving motor and the change-speed gear, and that after the initiation of a gear-change to a lower gear when the direction of transmission is from the change-speed gear to the driving motor, the control device adjusts the transmission ratio of the hydrostatic transmission towards a decrease in the driving speed of the hydraulic motor and that the shift can only take place at the earliest when the direction of transmission has come to be from the driving motor to the change-speed gear.