Patent ID: 8651219

Claim:
A hybrid construction machine of minimal tail swing radius type or minimal swing radius type comprising: a lower travel structure; an upper swing structure which is mounted on the lower travel structure to be capable of swiveling; a work implement which is connected to the upper swing structure to be capable of increasing and decreasing its elevation angle; a plurality of hydraulic actuators including a traveling hydraulic motor; an engine; a hydraulic pump having an input shaft coaxially connected to an output shaft of the engine and supplying hydraulic fluid to the hydraulic actuators; a generator/motor whose rotating shaft is connected to the output shaft of the engine and the input shaft of the hydraulic pump via a gear mechanism; and an electricity storage device which receives and supplies electric power from/to the generator/motor, the upper swing structure including: a swiveling frame which forms the substructure of the upper swing structure; a counter weight which is provided at a rear end position on the swiveling frame to cover the rear of the engine; a floor member which is mounted on the swiveling frame, the floor member including a floor plate serving as the foothold for the operator and a cab seat pedestal extending upward from the rear of the floor plate to overhang rearward and cover the front and top of the engine; and a support member which is mounted on the swiveling frame to extend over the engine and support a rear part of the floor member, wherein the generator/motor is placed at a vertical position where the lower end of the generator/motor is situated above the shaft center of the input shaft of the hydraulic pump, and when viewed from above at a horizontal position where the generator/motor overlaps with the hydraulic pump.