Thread device, thread joint and drill string component for percussive rock drilling

摘要

A device in a drill string component for percussive rock drilling including a thread for threading together with another drill string component including a complementary thread. The thread includes a thread groove formed by two thread flanks and an intermediate thread bottom. In operation one of the flanks forms a pressure flank. The thread groove has an essentially equally shaped sectional form along its axial extension. The thread bottom exhibits at least three surface portions with part-circular shape, as seen in an axial section. The surface portions with part-circular shape have increasing radiuses, as seen from each thread flank to an intermediate surface portion of the thread bottom. Also a thread joint and a drill string component.

主权项

1. A device in a drill string component for percussive rock drilling, the device comprising:
a thread for threading together with another drill string component comprising an interengaging thread, wherein the thread includes a thread groove formed by a first thread flank and a second thread flank, wherein in operation the first thread flank forms a pressure flank and an intermediate thread bottom, wherein the thread groove has an essentially equally shaped sectional form in an axial direction that extends along at least an engaging portion of the thread groove, wherein said intermediate thread bottom comprises at least three surface portions with part-circular shape, in the axial direction, and wherein said surface portions with part-circular shape have increasing radiuses, as seen from each thread flank to an intermediate surface portion of the intermediate thread bottom, said part-circular shape with increasing radiuses extending along at least the engaging portion of the thread groove.