The hydraulic coupling is one of the driving parts connec-ting the diesel engine to the engine room. The coupling transmits the torque of the engine and also facilitates smo-other start-up and eliminates any shock and vibration from the driving elements.Upon start-up of the motor, the driving impeller, integral with the motor itself, begins to drag in rotation the fl uid contained within the coupling that is launched against the driven impeller and puts it in rotation. Upon start-up the pulling torque is null, and therefore it increases together with the engine speed re-volutions, until such time as it will equal the value of the pulling torque and the resistance torque. All components of the cou-pling are precision machined and subjected to strict checks to ensure the high precision required.
The hydraulic coupling consists of a box (1) made of aluminium alloy in which rotate, opposite to each other, the driving impeller(2) and the driven impeller (3).The impellers are the heart of the system: they are made from an innovative light alloy casting that allows the production of very precise and very thin jets. Each of the im-pellers is in fact equipped with fifty radial fins having minimum thickness of about 3 mm (4).