Hydraulic torque converter

Hydraulic torque converters resemble fluid couplings and consist of an impeller (on the input shaft), runner (on the output shaft) and a vaned diffuser which absorbs torque (T_Le) and is supported by the casing. There is a balancing of moments between the input torque (T_P) (impeller torque), the output torque (T_T) (runner torque) and the torque at the vaned diffuser (T_Le).

Given that the hydraulic torque converter is responsible for converting the impeller torque into runner torque, it is also referred to as a torque converter. Within the context of drivingcentrifugal pumps, these components only play a secondary role, except in the case of pumped storage power plants.