Rotary cutter for excavation, especially for use with raise boring and tunnel boring machines

Claim 1

In a cutter for use in the excavation of a formation; a nonrotatable central support structure, a cutter body coaxial with and surrounding said central support structure, an antifriction bearing arrangement interposed between said central support structure and said cutter body and rotatably and nonaxially moveably supporting the cutter body on the central support structure, said antifriction bearing arrangement comprising a pair of rows of tapered rollable elements in axially spaced relation, a pair of rings engaging the radially inner sides of said elements and forming tapered races therefor, a single ring engaging the outer sides of both rows of said elements and forming tapered races therefor, said pair of rings being nonrotatably fixed to said central support structure, said single ring being fixed to said cutter body, said single ring having a cylindrical outer surface, said cutter body having a shouldered cylindrical bore in which said single ring is mounted, a clamp ring on said cutter body clamping said single ring in place therein, said pair of rings being mounted in spaced relation on said central supporting structure, said central supporting structure comprising a first tubular shaft element having a flange at one end facing the other end thereof, a second shaft element telescopically and adjustably mounted in said other end of said first shaft element and having a flange facing the said one end of said first element, and spacer elements on said first shaft element disposed between said flanges and the outer sides of said pair of rings and between the inner sides of said pair of rings for clamping said pair of rings in fixed spaced rElation on said first shaft element.