US Patent 12025012 Variable capacity turbocharger

A variable capacity turbocharger includes a turbine impeller, a gas inlet passage fluidly coupled to the turbine impeller, a nozzle vane located in the gas inlet passage, a drive assembly that rotates the nozzle vane, a drive chamber accommodating the drive assembly and including a region configured to store liquid in the drive chamber, and a liquid passage fluidly coupled with the drive chamber and configured to discharge the liquid from the drive chamber. A surface of the liquid passage has a greater surface roughness than the region of the drive chamber.