Ahol a tengely lefelé van tolva: inverted portal axle.

A Rába weboldalán ezt írják: Portal front and rear axles for low-floor buses....

http://en.wikipedia.org/wiki/Portal_axle

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What you should know about Portal axles!
Front and rear axles are solid axles with portals, meaning the axle housings and the differentials´ centre are located above the wheel´s centre. The gearing with its reduction, inside the portal housing, transfers the power to the wheel.
Portals offer the most unique ground clearance as the axle and differential housing are lifted and not just the frame or chassis.
Due to the gearing ration inside the portal drop box, the stress on the whole driveline is significantly reduced as the full torque is only occuring at the wheel and subsequently reduced inside the portals.
http://www.killeraxles.com/bolt_on_potale_e.html

Inverted Portal Axles (IPA) for low-floor city bus With over 25 years of experience in design and manufacturing of axles for public transportation, Oerlikon Graziano offers the widest range of IPA axles for low-floor city-bus.
www.oerlikon.com...