a flap device for an internal combustion engine includes a flow housing comprising a flow channel , an actuating shaft , a flap body arranged on the actuating shaft in the flow channel , a housing bore arranged in the flow housing , a lever fixed on the actuating shaft , a bearing bush arranged in the housing bore , and a sealing disk comprising a surface which is at least partially spherically shaped . the housing bore has the actuating shaft protrude outwards therethrough . the lever comprises a rear wall . the bearing bush has the actuating shaft mounted therein . the surface rests under tension against the rear wall of the lever .