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Gear Transmission Error (TE) is widely recognized as the main internal source of vibration in power transmissions. It quantifies the deviations from a perfectly kinematic motion transmission which in a real case are introduced by deflections, misalignments and manufacturing errors. The TE can then be directly linked to durability, noise and diagnostics assessment. Given the relevance of this physical quantity and since gears usually attain very high stiffness, experimental techniques have been developed for measuring it with a tight constraint on measurement accuracy. Measurement procedures using encoders with a very high number of divisions (above 18000), paired with dedicated acquisition systems is the common way of achieving the required accuracy [1]. Few methods have been proposed which use low-cost digital encoders and multi-purpose acquisition systems [2,3]. The accuracy of such techniques was discussed empirically for a few case studies. In the proposed paper, the authors determine numerically how errors in encoder spacing and in acquisition clock affect gear dynamic TE measurement for an experimental case study. It is concluded that it is unnecessary to seek for increased sampling time accuracy for the speed range of interest as encoder accuracy dominates the measuring chain.

Gear Transmission Error (TE) is widely recognized as the main internal source of vibration in power transmissions. It quantifies the deviations from a perfectly kinematic motion transmission which in a real case are introduced by deflections, misalignments and manufacturing errors. The TE can then be directly linked to durability, noise and diagnostics assessment. Given the relevance of this physical quantity and since gears usually attain very high stiffness, experimental techniques have been developed for measuring it with a tight constraint on measurement accuracy. Measurement procedures using encoders with a very high number of divisions (above 18000), paired with dedicated acquisition systems is the common way of achieving the required accuracy. Few methods have been proposed which use low-cost digital encoders and multi-purpose acquisition systems. The accuracy of such techniques was discussed empirically for a few case studies. In the proposed paper, the authors determine numerically how errors in encoder spacing and in acquisition clock affect gear dynamic TE measurement for an experimental case study. It is concluded that it is unnecessary to seek for increased sampling time accuracy for the speed range of interest as encoder accuracy dominates the measuring chain.