SELF-SCAVENGING, HYBRID LUBRICATION SUBSYSTEM

摘要

A self-scavenging, hybrid lubrication subsystem for a main transmission gearbox includes a sump fabricated as an integral extension of the lower portion of the gearbox wherein the sump dynamic fluid level is above the gearbox bottom. The interior sidewall of the lower gearbox is modified to include a cylindrical segment having a first radius, a throat segment having a second radius, and a transition segment contiguous with the cylindrical and throat segments. The radial discontinuity between the cylindrical and throat segments defines a nozzle inlet that directs the outflow of lubricating medium in the gearbox bottom to the sump via a nozzle. The outflow end of the nozzle is positioned above the sump dynamic fluid level. Housed within the lower gearbox is a planetary gear train that includes an annular planetary carrier plate having a deflection plate mounted thereto. The periphery of the carrier plate and the cylindrical and throat segments in combination form primary and restricted flow channels. Interaction between the deflection plate and the gearbox bottom exerts a viscous pumping action on the lubricating medium in the gearbox bottom causing it to flow outwardly into the primary and restricted flow channels. Interaction between the periphery of the rotating carrier plate and the structurally-modified sidewall exerts a viscous pumping action on the lubricating medium in the flow channels causing it to flow therethrough. Substantially all of the lubricating medium flowing through the primary flow channel is diverted through the nozzle to the sump.