Patent ID: 8690716

Claim:
A belt-driven conical-pulley transmission comprising: conical disk pairs on each of an input and an output side and carried on respective shafts, each disk pair including an axially fixed disk and an axially movable disk; an endless torque-transmitting means interconnecting the input and output disk pairs for transmitting torque therebetween; wherein at least one of the shafts includes at least one axial bore extending in the longitudinal direction of the at least one shaft, and at least one connecting bore extending from the at least one axial bore to the surface of the at least one shaft and having an outlet that is situated at a region of the shaft that is covered by the movable disk over its axial travel path, an annular chamber formed between the movable disk and the at least one shaft and bounded at one axial end by a guide surface carried by the movable disk, wherein the annular chamber is located between the outer surface of the at least one shaft and a radially inner surface of the axially movable disk, wherein the annular chamber is subjected to hydraulic pressure through the at least one connecting bore and has a dead end region adjacent to the guide surface and spaced axially along the outer surface of the at least one shaft from the connecting bore, wherein the axially movable disk is connected to the at least one shaft by a plurality of interengaged, circumferentially spaced, axially extending teeth carried by the axially movable disk and by the at least one shaft, wherein adjacent axially extending teeth are separated by respective axial grooves to provide a rotationally fixed and an axially movable connection between the axially movable disk and the at least one shaft, wherein the axial teeth carried by the at least one shaft extend into the annular chamber, and the outlet of the connecting bore is positioned at a region of the at least one shaft containing the axial teeth, and at least one discharge passageway is provided for bleeding air bubbles from the annular chamber, wherein the at least one discharge passageway includes an axial discharge groove formed in the at least one shaft and that extends from the at least one connecting bore outlet to and for connection with the dead end region of the annular chamber, and the axial discharge groove has a base that is recessed relative to the outer surface of the at least one shaft and extends between a pair of adjacent axial teeth of the at least one shaft to allow air bubbles to escape from the dead end region to the connecting bore outlet to minimize fretting corrosion on a flange carried by the axially movable disk.