Patent ID: 7870911
Filing Date: 2011-01-18
Classification: E02D

Abstract:
1. A pile driver comprising: a base machine; a leader held at a front part of the base machine rotatably about an axis; and a leader revolver provided to the base machine, the leader revolver having a rotation means of rotatably holding the leader and also rotating the leader, wherein the leader revolver comprises: an outer tube that is fixed or non-rotating connected to the base machine side; a rotating inner tube concentrically arranged inside the outer tube via a pair of bearings which are disposed at two upper and lower positions; and a hydraulic motor arranged at a lower part of the leader revolver, a lower part of the leader being connected, in an integrally rotatable state, to an upper part of the rotating inner tube that protrudes upward from an opening at an upper end of the outer tube, and one of a fixed flange and a movable flange of the hydraulic motor being connected to a lower part of the rotating inner tube, and the other one of the fixed flange and the movable flange being connected to a lower part of the outer tube.