Unit for driving the hose drum of automatic irrigation sprinklers in general.

摘要

A unit for driving the winding drum of self-propelled irrigation sprinklers in general comprises a main duct (19) or passage for sthe irrigation water, and an adjacent cylindrical chamber (20) housing an impeller (27) and communicating with said duct via an aperture with which a member for deflecting a fraction of the flow is associated in a manner adjustable at will. The rate of said flow fraction is kept constant for the entire irrigation cycle, while the speed of rotation of the turbine is adjusted by a deviator member (29) which is associated with the turbine impeller (27) and is sensitive to the diameter on which the hose (13) is being rewound, such as to move angularly through successive steps between a position in which the trajectory of the water directed towards the turbine is not changed, and a position in which the angle of incidence between the arriving water and the turbine blades is substantially changed, with simultaneous slowing down of the turbine.