Work machine

A work machine characterized in that it comprises:

• a first swiveling base installed rotatably about a prescribed swiveling axis on an upper portion of a traveling base;
• a first operating unit supported on the first swiveling base;
• a second swiveling base installed rotatably about the swiveling axis on an upper portion of the first swiveling base;
• a second operating unit supported on the second swiveling base;
• first swivel driving means, provided between the traveling base and the first swiveling base, for driving the traveling base and the first swiveling base in rotation with respect to each other;
• second swivel driving means, provided between the first swiveling base and the second swiveling base, for driving the first and second swiveling bases in rotation with respect to each other;
• and
• a two-stage swivel joint comprising a pair of rotors having respective center holes and a single shaft fitting into the center holes of the rotors, in a rotatable fashion, the two-stage swivel joint extending inside the traveling base, the first swiveling base and the second swiveling base, in a state where a central axis of the shaft is aligned with the swiveling axis, in such a manner that hydraulic pressure fluid can be supplied to respective hydraulic circuits of the traveling base, first swiveling base and second swiveling base via the pair of rotors and the shaft.

A work machine characterized in that it comprises:

• a first swiveling base, installed rotatably about a prescribed swiveling axis on an upper portion of a traveling base, comprising a first major swiveling gearwheel and a second major swiveling gearwheel respectively having centers on the swiveling axis;
• a first operating unit supported on the first swiveling base;
• a second swiveling base installed rotatably about the swiveling axis on an upper portion of the first swiveling base;
• a second operating unit supported on the second swiveling base;
• a first swivel drive motor, an output shaft of which is fixed to a first swiveling pinion, which is held on the traveling base in a state where the first swiveling pinion engages with the first major swiveling gearwheel;
• and
• a second swivel drive motor, an output shaft of which is fixed to a second swiveling pinion, which is held on the second swiveling base in a state where the second swiveling pinion engages with the second major swiveling gearwheel.

A work machine characterized in that it comprises:

• a first swiveling base installed rotatably about a prescribed swiveling axis on an upper portion of a traveling base;
• a supporting frame section, extending from the first swiveling base in an outward radial direction from the swiveling axis and having an empty space in an inner portion thereof;
• a first operating unit supported on the first swiveling base via the supporting frame section;
• a hydraulic piping passing through the empty space in the supporting frame section, through which hydraulic coil can be caused to flow to the first operating unit;
• a second swiveling base installed rotatably about the swiveling axis on an upper portion of the first swiveling base;
• a second operating unit supported on the second swiveling base;
• first swivel driving means, provided between the traveling base and the first swiveling base, for driving the traveling base and the first swiveling base in rotation with respect to each other;
• and
• second swivel driving means, provided between the first swiveling base and the second swiveling base, for driving the first and second swiveling bases in rotation with respect to each other.

A work machine characterized in that it comprises:

• a first swiveling base installed rotatably about a prescribed swiveling axis on an upper portion of a traveling base;
• a first operating unit supported on the first swiveling base;
• a second swiveling base installed rotatably about the swiveling axis on an upper portion of the first swiveling base;
• a second operating unit supported on the second swiveling base;
• first swivel driving means, provided between the traveling base and the first swiveling base, for driving the traveling base and the first swiveling base in rotation with respect to each other;
• second swivel driving means, provided between the first swiveling base and the second swiveling base, for driving the first and second swiveling bases in rotation with respect to each other;
• and
• swivel controlling means for controlling the first swivel driving means and the second swivel driving means, respectively, and, when the first swiveling base is swiveling in one direction with respect to the traveling base, causing the second swiveling base to swivel at the same angular speed in the other direction with respect to the first swiveling base.

A work machine characterized in that it comprises:

• a first swiveling base, installed rotatably about a prescribed swiveling axis on an upper portion of a traveling base, comprising a first major swiveling gearwheel and a second major swiveling gearwheel, which are mutually similar and respectively have centers on the swiveling axis;
• a supporting frame section, extending from the first swiveling base in an outward radial direction from the swiveling axis and having an empty space in an inner portion thereof;
• a first operating unit supported on the first swiveling base via the supporting frame section;
• a hydraulic piping passing through the empty space in the supporting frame section, through which hydraulic oil can be caused to flow to the first operating unit;
• a second swiveling base installed rotatably about the swiveling axis on an upper portion of the first swiveling base;
• a second operating unit supported on the second swiveling base;
• a first hydraulic swiveling motor, an output shaft of which is fixed to a first swiveling pinion, which is held on the traveling base in a state where the first swiveling pinion engages with the first major swiveling gearwheel,
• a second hydraulic swiveling motor, an output shaft of which is fixed to a second swiveling pinion similar to the first swiveling pinion, which is held on the second swiveling base in a state where the second swiveling pinion engages with the second major swiveling gearwheel and is driven at the same number of revolutions as the first hydraulic swiveling motor when the same quantity of hydraulic oil is supplied thereto;
• swivel controlling means for supplying the same quantity of hydraulic oil to the first hydraulic swiveling motor and the second hydraulic swiveling motor, respectively, and, when the first swiveling base is swiveling in one direction, causing the second swiveling base to swivel at the same angular speed in the other direction with respect to the first swiveling base;
• and
• a two-stage swivel joint comprising a pair of rotors having respective center holes and a single shaft fitting into the center holes of the rotors, in a rotatable fashion, the two-stage swivel joint extending inside the traveling base, the first swiveling base and the second swiveling base, in a state where a central axis of the shaft is aligned with the swiveling axis and a central portion of the joint in an axial direction thereof is fixed to either one of the traveling base or the first swiveling base, whereby respective hydraulic circuits of the traveling base, the first swiveling base and the second swiveling base can be mutually connected via the pair of rotors and the shaft.