Ψάχνοντας τα junta rotoidal (9) στο google και αντίστοιχα τα junta toroidal(9,5Κ) , σιγουρεύεται κανείς ότι έχουμε να κάνουμε με τυπογραφικό λάθος.
Κοιτα και εδώ:
http://www.proz.com/kudoz/spanish_to_english/tech_engineerin...
οπότε είναι τοροειδές ή αλλιώς δακτυλιοειδές ανάλογα με την περίπτωση.
To par toroidal όμως πρέπει να είναι το turning pair.
Pairs are named in accordance with the kind of motion
they permit; thus, a journal and its bearing form a
turning pair, a cylinder and its piston a sliding pair,
a screw and its nut a twisting pair, etc. Any pair in
which the constraining contact is along lines or at
points only (as a cam and roller acting together), is
designated a higher pair; any pair having constraining
surfaces which fit each other (as a cylindrical pin and
eye, a screw and its nut, etc.), is called a lower
pair.
http://dictionary.die.net/pair
The translation workplace 
