Lkab Wassara Ab

Fredrik Egerström

Magnus Hörman

Magnus Fridsell

Martin Öhnström

The invention relates to a rotary device () for a down-the-hole hammer (), which rotary device is accommodated in a rotation motor housing () and mounted behind a drill housing () for transferring a torque to a drill bit () and a pressurized drive fluid () to a striking mechanism () for the drill bit. The rotary device includes a cam curve with a plurality of drive lobes (-) and working chambers () along a circumference in the rotation motor housing (), a rotor disc () carrying a plurality of radially movable vanes (-), which are accommodated in piston tracks (-) in the rotor disc. Characteristics of the rotary device are that it includes; an odd integer of a number of drive lobes (-), which is equal to or higher than three; an odd integer of a number of working chambers (), which is equal to or higher than three; an odd integer of a number of vanes (-), which is equal to or higher than three, and wherein said number of vanes are simultaneously pressurized in each working chamber ().

Drive device for rotatable operation of a drill bit of a down-the-hole hammer

An arrangement at a drill includes a drill bit intended to be inserted at its neck into a chuck in a down-the-hole drill, a control means for guiding the drill and a lining pipe, a coupling arrangement in the form of a bayonet coupling or similar with which the drill can be coupled to the control means in a manner that allows them to be separated and that in its freed condition allows the drill, together with the down-the-hole drill, to be withdrawn through the lining pipe, a flushing passage for the supply of flushing agent in front of the drill and an evacuation passage for the removal of drilling cuttings together the flushing agent. It also includes a casing shoe that can be applied at the forward end of the lining pipe and a contact surface arranged at a stationary part of the down-the-hole drill.

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Nacka, Sweden

Fredrik Egerström