US Patent 7384104 Oscillating disc cutter with speed controlling bearings

An oscillating disc cutter including a cutting disc and a drive mechanism. The drive mechanism includes a drive shaft to effect eccentric oscillation of the cutting disc and a radial bearing disposed to permit relative rotation between the drive shaft and the cutting disc. The cutter further including a hydrostatic axial bearing disposed to react axial forces while accommodating induced rotation of the cutting disc when operatively engaged and to induce a rotational drag thereby limiting rotational peed of the cutting disc when free running. A water pressurized fluid bearing induces a predetermined axial load in the hydrostatic bearing such that a predetermined maximum running clearance in the hydrostatic bearing is maintained.