ELECTRIC HAMMER Russian patent published in 2008 - IPC E21C37/00 E02D7/02 

FIELD: construction industry, particularly to drive heavy reinforced concrete and metal shelled concrete piles during ice-resistant fixed platform, including underwater one, construction.

SUBSTANCE: electric hammer comprises body with three-phase winding of linear induction motor stator adapted to receive reciprocating hollow striking armature installed therein in fluid-tight manner. The striking armature is monolithic in lower part and includes short-circuited current-conducting winding formed from outer surface thereof. Hammer comprises anvil block with damping means. Linear induction motor stator winding is installed in upper part of cylindrical electric hammer body, which is provided with tubular striking armature position sensors. Cylindrical body of electric hammer is installed inside cylindrical sealed shell so that lower and upper chambers are created. Chamber lengths are equal to cylindrical body length and striking armature travel correspondingly. The upper and lower chambers are freely connected with each other. Upper chamber is communicated with striking armature interior. Lower chamber has pipeline with check valve. Lower chamber and striking armature interiors are partly filled with heat-conductive and electrical insulation liquid. Remainder zones of lower chamber, striking armature interior and total upper chamber are filled with high-pressure heat-conductive gas. Lower chamber has protective safety valve. Vacuum chamber is created between lower monolithic striking armature part and anvil block. Damping means is installed in lower monolithic part of cylindrical electrical hammer body in fluid-tight manner and may reciprocate relatively the body. Cylindrical fluid-tight shell has additional weight. Short-circuited current-conducting winding of linear induction motor stator is linked to frequency-regulated power supply and control system.

EFFECT: increased operational reliability.

1 dwg