Abstract: A piston head is provided which is lightweight and inexpensive yet capable of handling high mechanical and thermal loading during operation. The piston head generally includes a top head portion and a bottom head portion formed separately and connected by a friction weld. Importantly, the top head portion includes a first cooling gallery formed between the depending outer wall and a first inner depending wall and a second cooling gallery formed between the first inner depending wall and a second inner depending wall. The bottom head portion also includes corresponding first and second upper extending walls connected to the first and second inner depending walls to form the lower portion of each cooling gallery. The inner depending and upper extending walls are formed so that the ratio of the sum of the transverse thickness of the adjacent walls to the outer diameter of the piston head is approximately from 2% to 8%, and preferably 4% to 6%.

Abstract: An articulated piston for use in heavy duty diesel engines including a piston crown having an outer surface, a peripheral pending side wall and an inner surface having a pair of pin bosses extending downwardly from the inner surface with the inner surface and the pin bosses defining a hollow cooling cavity opening downwardly and extending about a circumference of the piston crown and a piston skirt with the piston skirt including a first longitudinal plane containing a pair of diametrically opposed bores for receiving a wrist pin for connection to the bosses of the crown and defining two semi-cylindrical thrust and non thrust surfaces of the skirt with a thickness of the non thrust surface being less than a thickness of the thrust surface and a second longitudinal plane, perpendicular to the first plane thereby dividing the piston skirt into four peripheral quarters.

Abstract: An articulated piston for use in heavy duty diesel engines including a piston crown having an outer surface, a peripheral pending side wall and an inner surface having a pair of pin bosses extending downwardly from the inner surface with the inner surface and the pin bosses defining a hollow cooling cavity opening downwardly and extending about a circumference of the piston crown and a piston skirt with the piston skirt including a first longitudinal plane containing a pair of diametrically opposed bores for receiving a wrist pin for connection to the bosses of the crown and defining two semi-cylindrical thrust and non thrust surfaces of the skirt with a thickness of the non thrust surface being less than a thickness of the thrust surface and a second longitudinal plane, perpendicular to the first plane thereby dividing the piston skirt into four peripheral quarters.