Finish Hobbing of Medium Hardness Gears with Cermet-Tipped Hobs.

High Accurate Hobbing with Specially Designed Finishing Hobs

Introduction Load-carrying capacity of gears, especially the surface durability, is influenced by their tooth surface roughness in addition to their tooth profiles and tooth traces (Refs. 1 and 2). The harder the gears are, the smoother their tooth surfaces and the more accurately their tooth profiles should be finished in order to obtain high load-carrying capacity. Through research, the relat...

CAD-based simulation of the hobbing process for the manufacturing of spur and helical gears

Targeting an accurate and realistic simulation of the gear hobbing process, we present an effective and factual approximation based on three-dimensional computer-aided design. Hobbing kinematics is directly applied in one gear gap. Each generating position formulates a spatial surface path which bounds its penetrating volume into the workpiece. The three-dimensional surface paths generated from...

Lubricating gears with synthetic OiLs

wind gearbOx technOLOgy is developing at a fast pace, not least due to operators demanding ever more power and efficiency. Experience has shown that the lubricant used is a crucial factor in meeting the wish for ever-increasing performance. Besides strictly technical requirements, aspects of economy and ecology are receiving more and more attention in lubricant selection. The technical requirem...

To finish or not to finish?

Operating temperatures of oil-lubricated medium-speed gears: numerical models and experimental results

This paper investigates the effects of gear geometry, rotational speed and applied load, as well as lubrication conditions on surface temperature of high-speed gear teeth. The analytical approach and procedure for estimating frictional heat ̄ux and heat transfer coef®cients of gear teeth in high-speed operational conditions was developed and accounts for the effect of oil mist as a cooling medi...