Evacuated transmission case

摘要

A vehicle transmission includes at least one rotatable component and is disposed in an environment at a first pressure. A transmission housing includes a sump portion disposed near a bottom portion of the transmission housing, where the transmission housing substantially encloses the at least one rotatable component. A hydraulic fluid is disposed at least partially in the sump portion of the transmission housing and a vacuum source is in pneumatic communication with the transmission housing. The vacuum source at least partially evacuates a gas from the transmission housing so that an interior of the transmission housing is at a second pressure. The at least one rotatable component is partially exposed to a gas at the second pressure and partially submerged in the hydraulic fluid when the transmission is under a predetermined dynamic load.

主权项

1. A vehicle transmission including at least one rotatable component and disposed in an environment at a first pressure, the vehicle transmission comprising:
a transmission housing including a sump portion disposed near a bottom portion of the transmission housing, wherein the transmission housing substantially encloses the at least one rotatable component; a hydraulic fluid disposed at least partially in the sump portion of the transmission housing up to a hydraulic fill line; and a vacuum source in pneumatic communication with the transmission housing above the hydraulic fill line, and wherein the vacuum source at least partially evacuates a gas from the transmission housing so that an interior of the transmission housing is at a second pressure, and wherein the at least one rotatable component is partially exposed to the gas at the second pressure.