PLANETARY ROLLER-SCREW DRIVE WITH MODIFIED THREAD OF PARTS Russian patent published in 2003 - IPC

FIELD: mechanical engineering. SUBSTANCE: in proposed planetary roller-screw drives torque from rotating screw is transformed into axial force through threaded rollers on translationally moving nut. Force is transmitted through multiple places of contact between mated turns of thread of nut and rollers and rollers and screw. Thread of parts of planetary roller-screw drive is modified, with profile of turns consisting of two sections of straight line with real working depth of profile H₁. Such thread is easy to made and simple for checking. Turns of thread feature higher flexural strength as compared with parts having shaped profile of turns. When turns of modified thread interact, contact strength and rigidity are greater than those in place of similar contact of parts of conventional planetary roller-screw drives and, consequently, load capacity of modified thread drive is greater. When cutting modified thread with different values of H₁, drives with any required rigidly can be easily made. EFFECT: enlarged operating capabilities. 4 dwg