Abstract: A multi-speed transfer case equipped with a planetary reduction gearset and a range clutch disposed between an input shaft and an output shaft. A clutch actuation mechanism controls actuation of the range clutch to establish distinct ratio drive connections between the input shaft and the output shaft.

Abstract: A multi-speed transfer case equipped with a planetary reduction gearset and a range clutch disposed between an input shaft and an output shaft. A clutch actuation mechanism controls actuation of the range clutch to establish distinct ratio drive connections between the input shaft and the output shaft.

Abstract: A two-speed transfer case for a four-wheel drive vehicle is provided. The transfer case has a two-speed planetary gearset, a range clutch, and a range shift mechanism. The planetary gearset includes a carrier unit having at least one crack arresting feature configured to limit propagation of a stress crack. The carrier unit includes a plurality of mounting holes for securing planet gears for rotation relative to the carrier unit. The gearset includes a sun gear configured for and a ring gear, with the planet gears in meshed engagement with the sun gear and the ring gear. The crack arresting feature extends at least partially through a portion of the carrier unit and is configured to receive a crack propagating from a central aperture of the carrier unit. The crack arresting feature is disposed radially between the central aperture and the mounting holes.

Abstract: A two-speed transfer case for a four-wheel drive vehicle is provided. The transfer case has a two-speed planetary gearset, a range clutch, and a range shift mechanism. The planetary gearset includes a carrier unit having at least one crack arresting feature configured to limit propagation of a stress crack. The carrier unit includes a plurality of mounting holes for securing planet gears for rotation relative to the carrier unit. The gearset includes a sun gear configured for and a ring gear, with the planet gears in meshed engagement with the sun gear and the ring gear. The crack arresting feature extends at least partially through a portion of the carrier unit and is configured to receive a crack propagating from a central aperture of the carrier unit. The crack arresting feature is disposed radially between the central aperture and the mounting holes.

Abstract: An optimally finished gear has a surface roughness between approximately 5 micro-inches Ra to 10 micro-inches Ra. The reduced surface roughness, when located at the gear teeth, can reduce the maximum contact stress by more than fifty percent. Similarly, the subsurface shear stress can be reduced by approximately thirty percent. The reduced contact stress and reduced shear stress results from improved lubrication conditions between the gear teeth. Surface roughness greater than 10 micro-inches Ra results in increased contact of the surface peaks, while surface roughness lower than 3 micro-inches is too smooth to retain adequate lubrication between the gear teeth.