Atechnologyforcoldforgingofhelicalgearwithcrowningusingelasticdeformationofdie;Developmentofnewdrivingsystemsunroof;Effectofthegear-shapercuttergrindingon8surfaceonitsgeometryandprofileerrors;Mathematicalmodelandundercuttinganalysisofmodifiedhelicalgearswithsmallernumberofteeth;Predictingtheheat-treatresponseofacarburizedhelicalgear