Investigations on viscous couplings using time-averaged rotation-synchronized gamma-ray computed tomography

For controlled transfer of high torques in devices, like engine fans and/or four wheel drives, viscous couplings are frequently used. Torque transfer is realized in viscous couplings by a working fluid, mainly responsible for the transfer quality, i.e. efficiency and operating range as well as stability. Unfortunately, investigations at rapidly rotating couplings is challenging since they consist of dense material, e.g. aluminum, have no optical access and the work area is composed of ring channels being significantly smaller than on millimeter. Thus, the high-resolution computed tomography measurement system (HireCT) is used for contactless liquid investigations in an industrial viscous coupling operated under various authentic operation scenarios. Despite the limited spatial resolution of approximately 2 mm and a measuring interval of approximately 900 s sharp liquid phase distributions could be provided in both primary disc and housing side of the coupling from a single CT scan. Here, the so called time-averaged rotation synchronized CT scanning mode is applied, where the acquired projection data stream are synchronized and averaged corresponding to the rotational position of the couplings’ parts. Therefore, zero crossing signals from the primary and secondary side are simultaneously acquired. The reconstructed data comprises the cross-section of the coupling and liquid distribution correspondingly.