Backlash eliminating structure of balance shaft

The utility model belongs to the technical field of engines, and particularly relates to a backlash eliminating structure of a balance shaft. Comprising a crankshaft and a driving gear, a first balance shaft and a second balance shaft are arranged on the two sides of the crankshaft respectively, a first balance gear and a second balance gear which are meshed with the driving gear are arranged on the first balance shaft and the second balance shaft respectively, and first bosses connected with a box body are arranged at the two ends of the first balance shaft and the two ends of the second balance shaft respectively. Second bosses connected with the two ends of the first balance gear and the two ends of the second balance gear are arranged on the portions, between the two first bosses, of the first balance shaft and the second balance shaft respectively, the first bosses and the second bosses are eccentrically arranged, and the first balance shaft and the second balance shaft are rotated to eliminate tooth gap