Lubrication

Illustration of the alternated forces of inertia of the 2nd order and of the balancing masses in the main operating positions.

LUBRICATION

The rotary lobe pump (3) fitted on the front of the crankcase is activated directly by the crankcase through keying. The oil withdrawn from the sump by a suction device (1) is filtered by the gauze filter on the suction device and then sent under pressure by the pump through a duct to the full-flow cartridge oil filter (6) fitted with a by-pass safety valve, which ensures that the oil passes even if the cartridge is clogged. A water-oil heat exchanger (5) is installed on the filter support to keep the oil temperature within the optimum limits.

The maximum lubricating pressure is regulated by a special limiting valve (4) fitted on the pump. After being filtered, the oil passes through a duct machined on the front engine cover and reaches the main longitudinal delivery duct in the crankcase.

From here, it is then sent along five ducts to the grooves of the main bearings and from these to those of the connecting rod journals via special ducts machined in the crankshaft. Another two vertical ducts machined in the crankcase lubricate the centre bearing of the counter-rotating shafts. To improve the cooling of the piston skirts the crankcase is fitted with spray jets (8) with built-in ball valve which opens at a pressure of 2.25 ÷ 2.75 bar.