ON-WHEEL AIR MAINTENANCE SYSTEM

An air maintenance system is disclosed comprising a vehicle wheel or rim (9); a rotatable inner ring (11) secured to the vehicle wheel or rim (9); a stationary outer ring (13) configured to maintain a constant angular position; an occlusion roller (50) rotationally fixed to the stationary outer ring (13), the occlusion roller (50) having a protruding portion (51) preferably centered axially at a radially outer surface of the occlusion roller (50) with axially outer portions of the occlusion roller (50) being radially recessed from the protruding portion (51) and supported by bearing surfaces (12) of the rotatable inner ring (11); at least two spacer rollers (70) rotationally fixed to the stationary outer ring (13) and rotationally supported by the bearing surfaces (12); and a flexible tube (20) defining a pump cavity. The the air maintenance system (10) is configured for pumping a fluid from an ambient environment into a pneumatic tire mounted to the vehicle wheel or rim (9) by applying an occluding force against the flexible tube (20) periodically occluding portions of the pump cavity. The at least two spacer rollers (70) have axially outer surfaces (71) for rotational support by bearing surfaces (12) of the rotatable inner ring (11) and a recess (72) preferably centered axially at the outer surface (71) of the spacer rollers (70) for avoiding a contact between the spacer rollers (70) and the flexible tube (20).