Abstract:

With the aim of the practical production, the cold precision forging technology of spur gears are researched systematically for15^#,45^# and 20 CrMnTi steel. The two-step forming technology combined closed die-forging with constrained hole divided-flow is presented. The updated design method of teethshape die based on addendum modification theory is proposed. The results show that the two-step forming technique is very effective on decreasing cold precision forging load of spur gears and the cold forged 20 CrMnTi steel spur gears have higher precision by applying the teeth-shape modification method proposed.

Key words: spur gear, cold precisions forging, constrained divided-flow, practical technology