A pressure accumulator for connection to a hydraulic fluid-driven percussion device. The percussion device includes at least one impact piston arranged to carry out a reciprocating motion caused by the pressure from the hydraulic fluid. The pressure accumulator is arranged in communication with a hydraulic fluid space of the impact piston. The pressure accumulator includes a space that extends at least partly around the impact piston when the pressure accumulator is mounted on the percussion device. A partition divides the space into two separate pressure chambers so that the pressure chambers are located an axial direction of the impact piston in relation to each other when the pressure accumulator is mounted on the percussion device. A first of the two separate pressure chambers is intended to be filled with a compressible medium. A second pressure chamber is in fluid communication with the hydraulic fluid space of the impact piston.

Disclosed is a bellows accumulator in which a folding bellows, which serves as a movable separating element between a first media side and a second media side, has at its bellows end, a closure body which media-tightly closes of the interior of the folding bellows and, at its other bellows end, is immovably fixed relative to a storage housing. The accumulator has a valve device which, when the pressure on a liquid side drops, moves to a closed position, thereby preventing liquid from continuing to flow out of the storage housing. The closing process for the valve device is controlled using an energy store, which is arranged between the valve device and the closure body of the folding bellows in such a way that a specifiable quantity of liquid remains in the storage housing in any case, the quantity of liquid supporting the folding bellows in an expanded position.