| 摘要 |
<p>A single supply line (11) feeds hydraulic fluid under pressure to a hydraulic percussive machine. The supply line divides into two branches, one (12) leading to a percussion motor, the other (13) leading to a rotation motor. A constant flow device (14) is provided in the line leading to the rotation motor. The constant flow device comprises a sleeve (16) having a fixed aperture (17) and a variable aperture (20). The opening of aperture (20) is varied by a spring (18). The opening of the aperture.</p> |
