LARGE-STROKE TELESCOPIC HYDRAULIC CYLINDER Russian patent published in 2000 - IPC

FIELD: transport engineering; power positive-displacement hydraulic motors. SUBSTANCE: telescopic hydraulic cylinder has coaxial main step cylinder, double-acting intermediate step sleeve-plunger and single-acting working step sleeve-plunger. Hydraulic cylinder is designed for underwater means, being provided with seals of mated surfaces, and direct-action and backpressure spaces. Hydraulic cylinder has external coaxial sleeve with open tops connected with outer surfaces of main step cylinder and working step sleeve-plunger for relative displacement. Intermediate step sleeve-plunger serves as double-acting step piston combined with working step. Backpressure space is formed by clearance between external sleeve and cylinders of steps arranged in sleeve. EFFECT: increased efficiency of operation of hydraulic cylinder owing to increased length of realized strokes in case of technological limitations of lengths of machining of inner cylindrical surfaces. 2 cl, 3 dwg