tropoid joint Design of a tropoid joint with tropoid star with pinions and idlers. Tropoid joints permit diffraction angles of up to 20 degrees and 30 mm axial displacement. This can be demonstrated very clearly on the model. description ordernumber 1263 see also: hydraulic coupling, automatic transmission steering gear test planetary dual-mass flywheel Dual-mass flywheel with centrifugal pendulum-type absorber