The invention relates to a paper money changing
system for a
bus coin box. The paper money changing
system comprises two rollers and a separation board arranged at the upper part of the
coin box. The
coin box is divided into a paper money
storage area and a coin
storage area by the separation board. A money conveying channel is formed at the gap between the two rollers; a separation mechanism is arranged at the
tail end of the money conveying channel and can convey paper money into the paper money
storage area. A paper money pre-storage box, a lead screw nut transmission unit, a paper money sorter, a paper money identifier, paper money boxes for containing paper money with different values, and paper money changing mechanisms are arranged in the paper money storage area. The paper money changing mechanisms contain key modules,
liquid crystal display screens, control systems, motors I, worm rods connected with output terminals of the motors I, worm wheels engaged with the worm rods, lead screws I fixed at the worm wheels, nuts I sleeving the lead screws I, dial wheel mechanism connected to the
tail ends of the nuts I, and paper money reels in carrying connection with the paper money boxes. With the
system, classification and automatic changing of inserted paper money can be realized.