| 摘要 |
<p>Downhole hammering or other vibrational apparatus comprising or including in, with respect to a hole axis, a rotatable input shaft (9) aligned with or aligned parallel to the hole axis, a rotatable shuttle assembly having two structures able to rotate relative to each other (e.g. at least one to the other) to cause interacting magnetic arrays (13, 14) to cause a relative shuttling of such structures, the shuttling axis being aligned to or substantially parallel to the hole axis, an at least substantially fluid tight enclosure (1, 3, 4, 5, 6 and 7) about the rotatable shuttle assembly; wherein the shaft (9) directly or indirectly rotates one or more magnets (10, 11) and one of the structures (e.g. nominally "the shuttle") of the shuttle assembly within the substantially fluid type enclosure carries a magnet or magnets (12) to interact with that, or those, of the input shaft (9) whereby, without direct contact, rotation of the shaft (9) by magnetic interaction can rotate the shuttle.</p> |
