TY JOUR TI TOOTH LEG EXCESSIVE UNDERCUT ELIMINATION IN HELICAL CYLINDRICAL GEARS WITH PROTUBERANCE OF HOBBING CUTTER BASED ON GRAPHIC RUN-IN KW cylindrical gear KW graphic run-in KW leg KW tooth KW undercut KW operation JO Bulletin of Bryansk state technical university AU Safarov, D.T. AU Kondrashov, A.G. AU Fashudtinov, A.I. PY 2021 IS 2021 PB Bryansk State Technical University