Oil-free air compressor

The invention discloses an oil-free air compressor which is provided with a motor, a crankshaft assembling mechanism and a piston cylinder, the crankshaft assembling mechanism comprises a shell, and the shell comprises a hollow containing cavity defined by a plurality of detachably connected cover bodies; the crankshaft is arranged in the containing cavity, the first end of the crankshaft is detachably connected with the power output end of the motor, and the second end of the crankshaft is detachably connected with the cover body. According to the oil-free air compressor, the crankshaft is detachably connected to the power output end of the motor and the shell of the crankshaft assembling mechanism of the compressor, when the compressor is maintained, a cover body, connected with the crankshaft, of the shell is detached, and the crankshaft is pulled outwards to be separated from the power output end of the motor, so that the crankshaft can be detached. Compared with the technical scheme that the crankshaft i