Tenneco Inc.
DUAL GALLERY TWO STROKE PISTON

Abstract:

A piston assembly for a two-stroke internal combustion engine includes an upper part joined to a lower part by hybrid induction welding. The upper part includes an upper and lower walls radially spacing inner and outer walls to present an outer cooling gallery therebetween. The lower wall includes first portions extending radially inwardly from the outer wall to the inner wall above the skirt sections and second portions extending radially inwardly from the outer wall to the inner wall above the pin bosses. The first portions extend oblique to the center axis and undulate between the inner and outer walls to reduce the stiffness of the skirt sections. The second portions of the lower wall extend perpendicular to the center axis. Skirt sections of the piston include a lower portion with a greater radial thickness and containing ring grooves.