According  to the historical records ,In ancient China  gears were   started to be used  if the year of 200-400 B.C , the borne  gear unearthed  from Shanxi province  was  he oldest gear  discovered in china . The southward  pointing cart  which  reflects the  ancient  scientific  and  technical achievement  was the  mechanical device which took the  gear  ad the core  structure . At the end of 17trh century ,people  stated to research the  shape of the  wheel  gear  which  could transmit  the motion . In the 18th century after the European industrial revolution ,

The  use  of  transmission  by gears had become  popular ; first the   cyclonical gear  was developed , and then involutes gears came up to  use , and until the  20ith century  the  use  of  involutes gears had  been  in the dominant position

By the end of 19th century , the principle of tooth cutting by the method  of  generating  and the specialized  machine tools  used for  tooth cutting with  this principle   appeared , thus making  the means of gear processing more  completed and make the  involutes profile  demonstrate   the great  advantages.

Only a few gear products  made in china  could  be closed to or reach the  international standard in terms of technical level as well as the quality level. Most of the  gear product  could  hardly  reach  the second class  of the international standard . One of the reasons  is that  the ability of  designing  on one’s own efforts  is poor . the technical  innovation is  one of the main  standards with which  to evaluate the  competition  of the enterprise .If an enterprise  does not focus on the R&D work , and has no long-term  strategic  consideration  and   no over passing  products  storage , it will not catch up  with the  steps  of the engine  development , the enterprise  which   now is  progressive   will become the backward  one in the future ,  and even  will be  eliminated . it has  been  really an old problem  the gear manufacturing  enterprise have o face with that  the  ability of designing on one’s own is poor , the   innovation ability on one’s own  is not strong .But with the rapid development  of  automobile, the engineering machinery and other related 

Fields , the technical  requirements on the gears  which are  used to complete with  these machineries  have come to a new stage  in terms of the  raw materials, properties , ands the strength .thus the innovation ability  has become more outstanding .