A novel calculation method of long period pinion axial displacement and meshing impact force for double helical gear considering asymmetry error

•A new three-dimensional loaded tooth contact analysis model of double helical gear is proposed.•The modification, cumulative pitch error and axial displacement of the pinion are considered in the model.•The meshing impact force of double helical gear considering long period asymmetry error is derived.•The influence of asymmetry error on pinion axial displacement and meshing impact force is discussed.