GEAR FOR BOREHOLE EXPANSION Russian patent published in 1995 - IPC

FIELD: mining industry. SUBSTANCE: gear for borehole expansion includes eccentric, cylindrical rollers to reverse gear, conical rollers and guiding member. Cylindrical and eccentric rollers are put on developed necks of eccentric shaft for rotation. Longitudinal axis of each conical roller is arranged at angle which vertex is oriented towards head roller to longitudinal axis of eccentric shaft. Guiding member is placed in front of head roller and is fixed on eccentric shaft. Longitudinal axis of guiding member matches that of eccentric shaft. Guiding member is made cone-shaped and has shape of oval in cross-section. Outer side surface of each roller has convex shape, it is formed by rotation of arc about its longitudinal axis. EFFECT: simplified design, increased reliability. 3 cl, 3 dwg