Abstract: A device for regulating the driving torque and energy absorption in hydraulic energy absorbing means such as employed in aircraft arresting mechanisms, consisting in a liquid reservoir housing in which a bladed rotor is rotative, said rotor having its blades surrounded by fixed vanes of a curvature different from that of the blades of the rotor. A ring is mounted above the blades, the ring having an annular groove or channel in which a channel-shaped capsule is positioned, the capsule being adjustable up or down in the groove, a rotative adjustment ring is mounted on a part of the housing and an outer ring carries rods that enter the housing to contact with the capsule, and the outer ring has parts engaging in guide means on the inner ring, whereby rotative adjustment of the inner ring causes raising or lowering of the capsule with respect to the rotor blades.