摘要 |
<p>A transmission particularly for motor vehicles such as tractors or the like which comprises a hydrostatic unit (11) associated with an internal-combustion engine. The hydrostatic unit is constituted by a first variable-delivery pump (12) which is connected, in a closed circuit, to a hydraulic motor (14) adapted to provide vehicle propulsion. In the hydrostatic unit (11) there is a second boost pump (15), to compensate for the volumetric losses of the circuit; overpressure control means; actuators; and cooling elements. The second pump (15) is connected, through the interposition of a distributor unit (17) actuated by a control pedal (18), to first actuators (23) which are adapted to vary the displacement of the first pump (11) and to second actuators (27,28) which are adapted to actuate a pedal crank (19) of the accelerator of the internal-combustion engine. <IMAGE></p> |