Automatic tire pressurizing device

The invention refers to a pneumatic tire pressurizing device (1) for automatically pressurizing a load-bearing tire during rotation thereof over a surface, said tire comprising a tire volume comprising compressed air having a predetermined tire pressure. The pressurizing device (1) comprises a compression unit (31) connected to a movable device (21). The pressurizing device (1) is connectable to a wheel (2) comprising the tire, and when connected to the wheel (2) the compression unit (31) is arranged to compress air in the compression chamber (26) when the movable device (21), starting from a negative position, is affected by a sudden increase of the tire pressure due to deformation of the tire when passing an irregularity in the surface, wherein said compression unit (31) is arranged to feed the compressed air in the compression chamber (26) to the tire volume via the pressure chamber (25).