Patent attributes
An aircraft engine, has: a shaft rotatable about a central axis and engaged at an end thereof to a rotatable load via splines; a reference tube extending around the shaft and having a first end secured to the shaft and a second end free relative to the shaft for measuring a deformation of the shaft, the reference tube defining at least one tube aperture; an oil nozzle defining an exit flow axis intersecting the at least one tube aperture, the shaft defining at least one shaft aperture through the shaft, an oil flow path extending from the oil nozzle to the splines; and a drain outlet located radially outwardly of an inlet of the at least one shaft aperture for outputting excess oil out of an annular gap defined between the shaft and the reference tube.