SPUR GEARING Russian patent published in 2000 - IPC

FIELD: mechanical engineering. SUBSTANCE: spur gearing has gear and wheel with involute profiles in middle of teeth supplemented by circumference arcs, by convex arc at head and concave arc at roots of teeth. Sub-polar and behind-polar parts of active line of involute gearing are of the same length, and sum of their lengths is larger than pitch of gearing. Value of arc radius at points of teeth is less than sub-polar part by 0.25 of gearing modulus. When teeth of gear and wheel are in relative position corresponding to teeth engagement starting, beginning of radius is positioned on sub-polar part of engagement active line, and end of radius is combined with connection point of involute and arc sections of profile on wheel tooth point. Value of arc radius at roots of teeth is equal to length of sub-polar (behind-polar) part of active line of involute gearing. In this case, this radius origin is positioned in gearing pole, and its end is combined with connection point of involute and arc sections of profile on gear (wheel) tooth root. Depth of involute sections of profile on pint and root of tooth is determined by relation: hIa

= hIf = 0,75•m, where m is gearing modulus. Depth of arc sections on point and root of tooth is determined by relation: hda = hdf = 0,4•m, Coefficient of end overlapping of tooth profile involute sections is at least 1.2. EFFECT: reduced wear of teeth. 2 dwg