| 摘要 |
<p>An in-hole rock drilling machine has a tubular housing (12) with a piston hammer (24) that is guided at its ends only. Its front portion is guided by a guide bushing (18) that takes support against a shoulder (13) in the housing and its rear end is guided by a valve housing (20). The guide bushing (18), the valve housing (20) and a distance tube (19) between them are clamped together against the shoulder (13) by means of a back head (22) screwed to the machine housing (12). The distance tube (19) is adapted to be compressed axially at least 0.3 pro mille of its length and preferably between 0.8 and 3 pro mille of its length when the back head is screwed into position. This arrangement gives a robust machine and to assemble and to disassemble the machine will be simple. The tolerances in length will not be critical which makes the machining of the various machine parts less critical.</p> |
