Hydraulic impact device, piston guide and excavator

摘要

The present invention relates to a hydraulic percussive arrangement comprising a displaceable arrangement (1) in a casing (11), in which casing (11) the following are arranged at the displaceable arrangement (1): a first chamber (5) connected to a return line (7) for hydraulic oil, a bushing (6) on a first side of the first chamber (5) and separated from the first chamber (5) by a first gap (12) along the displaceable arrangement (1), and a second chamber (2) with a higher pressure of hydraulic oil than that of the first chamber (5) and arranged on a second side of the first chamber (5), separated from the first chamber (5) by a second gap (4) along the displaceable arrangement (1). According to the invention, a third chamber (8) is fixed arranged between the second gap (4) and the first chamber (5) and the third chamber (8) is connected to the first chamber (5) not only by a first passage (14) but also by a third gap (9) along the displaceable arrangement (1). The invention relates also to a piston guide in such a hydraulic percussive arrangement and to a drilling rig with such a percussive arrangement.