Abstract: A kind of internal combustion hydraulic system (ICHS) is put forward, which integrates the technologies of internal combustion engine and plunger water pump. Aiming at three typical ICHS, system scheme, working mechanics, working characters and the key problems in development are discussed emphatically. Through data analogue, compared with traditional piston internal combustion driving plunger water pump in total conditions, oil consumption improves by 12%~42.78%, effective thermal efficiency by 13.63%~74.75%, running unevenness by 4.66%~15.57%, output pressure by 15.21%~76.61% and output flow by 0.69%~2.13%.

Key words: Hydraulic, Internal combustion, System scheme