FIELD: machine tool manufacture, namely thread grinding machine tools for grinding cylindrical threaded relieved articles with helical chip grooves. SUBSTANCE: machine tool includes blank unit and tool unit mutually connected by means of thread-cutting circuit having lead screw for lengthwise feed, relieving circuit with relieving cam and lengthwise rest with cross carriage. Machine tool is provided with hydraulic step motors controlled by means of hydraulic pulse generators having slide valve sleeves with designed number of working slits and kinematically joined by means of relieving cam and lead screw for lengthwise feed with cross carriage and lengthwise rest respectively. Machine tool also has hydraulic step motor for differential motion due to imparting additional rotation to relieving cam at longitudinal motion of rest during grinding threaded articles with helical chip grooves; said hydraulic step motor is controlled by hydraulic pulse generator having slide valve sleeve with working slits driven to rotation by means of gear wheel mounted on lead screw of rest. Gear ratio between feed values corresponds to relation of working slit numbers of slide valve sleeves of respective hydraulic pulse generators. EFFECT: simplified design, enhanced accuracy due to lowered length of circuit in the result of omission of row of mechanical gearings, reduced metal consumption. 1 dwg
