METHOD FOR MILLING SCREWS WITH ROUND SCREW SURFACE AT SMALL DISTANCE BETWEEN APEX AND RECESS Russian patent published in 2007 - IPC B23C3/00 B23G1/32 

FIELD: machine engineering, working screws of screw pumps of hard-to-form materials.

SUBSTANCE: method is realized with use of tool such as milling cutters. Milling cutter is subjected to independent rotation around its own axis and blank is subjected to rotation matched with lengthwise feed of tool equal to pitch of worked screw. In order to enlarge manufacturing possibilities and to enhance working accuracy, tool in the form of set including three equally spaced one from other in cross plane shaped milling cutters and mutually spaced in axial direction by distance equal to 1/3 of pitch. Rotation axes of milling cutters are inclined relative to blank axis by angle equal to leading angle of screw surface turns. Milling cutters may have separate drive units or common drive unit.

EFFECT: enlarged manufacturing possibilities, enhanced working accuracy.

2 dwg, 1 ex