| 摘要 |
<p>The rock drill is hydraulically operated and has its cutting edge (12) fixed directly (11) onto the operating spindle (9) passing through the drill body (5). The operating fluid enters at the top, through a rotary motor (2). The outlet fluid then passes (3) into a chamber and up axial slots (7) to drive the spindle down. This hydraulic fluid is exhaust (8) from the machine whilst a further portion is conducted (4) to the underside (6) of the operating piston. The difference in pressures raises the drill and the combined effect of lifting the tool between blows and part rotating it prevents jamming in cracks in the rock.</p> |
