Patent ID: 8567575

Claim:
A shock absorber comprising: a piston rod; a piston valve coupled to one end of the piston rod; an inner shell having an inner space configured to receive the piston valve, the piston valve being operable to reciprocate between rebound and compression strokes, the inner space of the inner shell being divided into a rebound chamber and a compression chamber by the piston valve; an outer shell positioned outside of the inner shell and having a reservoir chamber, the reservoir chamber being configured to supply oil to the compression chamber in the rebound stroke and to recover oil in the compression stroke; a high pressure tank having a high pressure chamber installed outside of the outer shell; and a self pumping unit for sucking gas external to said self pumping unit and for pumping the sucked gas into the high pressure chamber using, via a mechanical connection to the piston rod, energy generated by reciprocating movement of the piston rod, wherein the high pressure chamber is provided on a lower side of the outer shell, and wherein the self pumping unit includes: a pumping rod connected to the piston rod and moving together with the piston rod; a pumping room being in fluid communication with the atmosphere and the high pressure chamber through first and second pumping flow passages, respectively, the pumping room being provided in the high pressure tank to allow the pumping rod to move reciprocatively in the pumping room; and first and second check valves for opening the first pumping flow passage and the second pumping flow passage, respectively, in order, according to the retreat and advance of the pumping rod, to suck the external gas into the pumping room and supply the sucked gas into the high pressure chamber.