Hydraulic-powered air compressor

A portable hydraulic-powered air compressor system detachably connected to a hydraulic power system of a vehicle, the air compressor system comprising:

• a reciprocating compressor comprising:
• a compression cylinder;
• and
• a compressor piston assembly movably disposed within the compression cylinder, opposite sides of the compressor piston assembly respectively defining a rod chamber and a front chamber in an interior of the compression cylinder, the front chamber comprising an air intake port, the compressor piston assembly comprising:
• a compressor piston slidably mounted within the compression cylinder, the compressor piston comprising a disc-shaped piston with a circular recess and a central hole within the circular recess concentric with the circular recess, the disc-shaped piston further comprising an annular recess between an outer periphery of the central hole and an inner periphery of the central recess such that an annular step is formed at a boundary between the annular recess and the circular recess, the annular recess comprising at least one aperture connected in fluid communication with the rod chamber;
• and
• a valve disc comprising a larger-diameter disc portion and a smaller-diameter disc portion attached to a disc stem, the disc-shaped piston mounted on the smaller-diameter disc portion between the larger-diameter disc portion and the disc stem, an inner surface of the central hole slidably encompassing an outer surface of the smaller-diameter disc, the disc stem coupled with the piston rod,
• wherein a length of the outer surface of the smaller-diameter disc portion is larger than a length of the inner surface of the central hole and the disc-shaped piston configured to be slidable over the outer surface of the smaller-diameter disc portion between a first position and a second position along an axis parallel to the piston rod responsive to an air pressure difference between the front chamber and the rod chamber;
• and
• a hydraulic motor detachably connected to the hydraulic power system, the hydraulic motor coupled to a piston rod of the compressor piston, the hydraulic motor configured to drive a reciprocating motion of the compressor piston within the compression cylinder.