Rack-driven reciprocating type novel double-transmission speed increasing device

The utility model discloses a novel rack-driven reciprocating type double-transmission speed increasing device which comprises a first shell, a second shell and a rack, the first spring is arranged between the first shell and one end of the rack, and the other end of the rack is connected with the power source; the two first gears are symmetrically engaged with the two sides of the rack. Each of the two first gear sets comprises a second gear and a third gear; the two second gears are meshed with the two first gears respectively, each second gear set comprises a fourth gear, a fifth gear and a sliding block, the sliding blocks are arranged on the sliding way in a sliding mode, the two fourth gears are meshed with the two third gears respectively, and the two first springs are arranged between the two sliding blocks and the first shell respectively; the fifth gear is selectively meshed with the sixth gear; the two sixth gears are rotatably fixed on the first shell; the two output gears are respectively meshed