Articulated piston for heavy duty diesel engines - has second longitudinal plane, perpendicular to the first to divide piston skirt into four quarters, one containing an inlet through which a cooling medium, can pass and impinge against the hollow cavity of the piston crown

摘要

The piston (30) has a crown (10) with and outer surface, a peripheral pending side wall and an inner surface with a pair of pin boses extending downwards from the inner surface. The inner surface and the pin bosses (14) define a hollow cooling cavity opening downwards, and a piston skirt (20). The piston skirt has a first longitudinal plane containing a pair of diametrically opposed bores (21) for receiving a wrist pin for connection to the bosses (14) of the crown (10). It also has two semi cylindrical thrust and non thrust surfaces with the thickness of the non thrust surface being less than a thickness of the thrust surface. A second longitudinal plane, perpendicular to the first divides the piston skirt into four peripheral quarters. One of the quarters contains a cooling medium inlet through which a cooling medium, injected by a nozzle, can pass and impinge against the hollow cavity of the piston crown (10) for cooling the crown. The piston skirt also has a recessed tray (25) formed in an upper surface of the skirt facing upwards and opening towards the hollow cavity with the recessed tray extending for at least the peripheral quarter containing the cooling medium inlet and defined by a pair of axially disposed side walls and a bottom wall extending radially inwards between the side walls. The recessed tray is peripherally inclined towards a quarter diametrically opposed to the cooling medium inlet for conveyance of the cooling medium collected from the hollow cavity of the crown.