Piston having twisted skirt panels

摘要

A piston assembly is disclosed herein. The piston assembly is integrally formed and unitary and is centered on a central longitudinal axis. The piston assembly includes a head with ring belt having a plurality of ring grooves. The piston assembly also includes first and second skirts, each having a top edge and a bottom edge being radially narrower than the top edge. The skirts also include first and second side edges. The piston assembly also includes first and second pin bosses spaced radially inward from the ring belt to define a short-pin support arrangement. The pin bosses include respective first and second pin bores axially aligned on a pin bore axis perpendicular to the central longitudinal axis. The piston assembly also includes a plurality of panels, each extending between one of the pin bosses and one of the skirts. Each of the panels include a top portion spaced closest to the head and bottom portion spaced furthest the head and a middle portion disposed substantially equally spaced from the top and bottom portions. Each of the panels twists along its length such that a ratio defined by a first distance between the top portion and a first plane perpendicular to the pin bore axis over a second distance between the bottom portion and the first plane increases along at least part of the length.