Basic study on transmission error for gear made from different metals laminated in width direction to provide rigidity distribution

To improve the load characteristics of the transmission error for helical gears, a gear made of laminated materials is proposed. The gear has three layers in which metals with different rigidities are laminated in the tooth width direction. The layers on both sides are made from the same metal, and a different metal is used for the central layer. A theoretical analysis was performed to investigate the effects of arranging high- and low-rigidity layers and changing the width of the central layer. The laminated gear has load characteristics different from the transmission error for a conventional homogeneous material gear. The transmission error can be reduced with the combination of a high-rigidity central layer and a low-rigidity side layers, and a low transmission error can be maintained over a wide load range by adjusting the central layer width appropriately. The principle of the reduction in the transmission error is that, by changing the rigidity along one-pitch meshing progress with laminated materials, the elastic deformation of the teeth can largely cancel out the rotational fluctuations caused by the tooth flank shape over the wide load range. A pair of laminated gears was manufactured, and testing confirmed that the laminated gear has a transmission error lower than that for a gear made from a homogeneous material. The laminated gear has the potential to achieve the lower vibration/noise generation for the wider load range than the homogeneous gear.