The machine tools   used for processing  gears  are broadly used  for various  manufacturing  enterprises , such as  automobile, tractor, machine tool, engineering  machinery , mine machinery , metallurgical machinery ,m petroleum  as well as  aircraft . 

The  machine tools for processing  gears  can be used for processing the cylindrical gears ,bevel gears  and other machine tools  with   the spare parts of gears  or with some parts of  body with gears .

The ancient gears   normally  were taken shape by hand- filing . In   the year of 1540, when  Mr. Teeyano, an Italian  engineer    were  making  clocks , he used to  produce a  tooth- cutting  device with rotating  file ; in the year of  1783,  Mr. Lenei , an French engineer , used to produced a machine tool for processing gears with hobbing gear and  with internal gear accessories for cutting gear racks; After the year of 1820, Mr White , an  British engineer  used to make  a machine tool for processing  both  cylindrical gears   and cone gears . The of machine tools  with  this  property  had been further developed  un till the time of  the second half of the 19th century .

In the year of 1835, Mr. Whitewoods , An Englishman  had got   the patent of  worm hobbing gear . In the year of 1858, Mr. Sheeler had got the patent of hobbing gear for processing  cylindrical gears ; and later on  through many times of improvements, until  the year of 1897,  the gear  hobbing machine  with  differential motion  device   were made by  Mr. Pufute ,  the German engineer  .  and  only   till then the  way  of  processing  the  helical gears  had been  found . After   the gear –shaped  slotting  tool had been made  ,   a gear slotting machine  were  invented by Mr. Ferias, an American engineer . 

At the beginning of the 20th  century , owing to the  requirements of Auto industry ,   a varieties  of  gear  grinding machine  had  come to  use .In about  the year of 1930,  gear shaving machine  was  produced by America ;  in the year of 1956, gear honing  machine had been  produced. After  the year of 1960, some   advanced machine tools  for processing  the cylindrical  gear with  some  extent  modern technology  had been used , for example , some large size machine tools  with digital display indicating the tooth cutting depth for  shifting  amount ;The electronic  servo-system  and digital  control system had been  used  instead of exchange gears  for mechanical driving  chain .The programmable controller  with the function of fault – diagnosis  had been used to the work  recycles and  change the cutting parameters . the digital control  gear slotting machine  for processing  the non-cylindrical  gear had been developed to be adapted to  controlling  the gear hobbing machines. The electronic  sensor on the  gear hobbing machines had been used to  inspect  and test  the motion tolerance  of the driving chain  and   to automatically  feedback  of compensating tolerance .

In the year of 1884, Mr. Bilgrams , an American engineer , had invented    a gear  shaper   for processing the    bevel gear  of straight  tooth  by using the single  planer tool according to the  generating method ; In the year of 1900, Mr. Bill designed a  machine tool  for milling   the bevel gear of straight  tooth  with  double  cutter disc.