REVOLVING SUPERSTRUCTURE MOUNTING STRUCTURE

PROBLEM TO BE SOLVED: To provide revolving supertructure mounting structure capable of reducing the dispersion of backlash of a mesh part between a swing pinion of a swing gear and a ring gear of an inner ring of a swing bearing. SOLUTION: A swing gear 7 having a swing pinion 6 is mounted onto a main frame 5 of a revolving superstructure by bolts 10. An outer ring 4 of a swing bearing 2 is mounted to the main frame 5 by a bolt 13, and an inner ring of the swing bearing 2 is mounted to a base carrier. A swing gear pin 20 for connecting the swing gear 7 to the main frame 5, and a swing bearing pin 21 for connecting the outer ring 4 of the swing bearing 2 to the main frame 5, are provided, and these pins 20, 21 are arranged near a center connecting line 18 connecting the swing bearing center 1 and swing gear center 2. The swing gear 7 and the main frame 5 are provided with pinholes 22, 25 for inserting the swing gear pin 20, and the outer ring 4 of the swing bearing 2 and the main frame 5 are provided with pinholes 26, 28 for insert-ing the swing bearing pin 21.