Gear is one of the most widely used mechanical transmission parts, which has the characteristics of compact structure, large power transmission, high efficiency, long life, good reliability and accurate transmission ratio. The precision forging technology of gear has its remarkable advantages. Is increasingly by the researchers of various countries attention, has been booming.
Precision forging technology of gear refers to a gear manufacturing technology in which the complete shape of gear teeth is obtained directly from blank precision forging, and the tooth surface can be used without cutting or just a little finishing.
Compared with the traditional cutting process, gear precision forging has the following characteristics:
(1) The structure and mechanical properties of the gear are improved. Precision forging makes the fiber structure of metal materials distributed uniformly and continuously along the tooth shape, with fine grain and structure and fewer microscopic defects. Therefore, the performance of precision forging gear is superior, and the bending strength, contact fatigue strength and impact resistance of teeth are obviously higher than that of cutting gear. Generally speaking, precision forging can increase the impact strength of the gear teeth by about 15% and the flexural fatigue life by about 20%.
(2) Improved production efficiency and material utilization rate. By precision forging, gear accuracy can reach precision tolerance standards, without or with little follow-up finishing, that is, heat treatment or direct use, high productivity and material utilization.
(3) Precision forged gear can reduce the tooth profile deformation during heat treatment, improve the wear resistance of teeth and the smoothness of gear meshing, and improve the service life of the gear. Although gear forging has many advantages, and straight bevel gear precision forging technology has been successfully applied in production, many difficulties have been encountered because of the characteristics of straight gear precision forging, such as difficult filling of tooth cavity (especially the upper and lower corners), large forming force, and strict requirements of die design and manufacturing precision. For many years, researchers in various countries have made unremitting research on precision forging technology of spur gear with various theories, technical means and test methods.
