1. The accuracy of the transmission movement. It is required that the angle error of the precision gear in one revolution is limited within a certain range, so that the change of the transmission ratio of the gear pair is small, so as to ensure the accurate transmission movement.
2. The stability of the transmission movement. It is required that the rotation angle error within the range of one tooth of the precision gear is limited within a certain range, so that the instantaneous transmission ratio of the gear pair changes little, so as to ensure the smoothness of the transmission and reduce vibration, impact and noise.
3. The uniformity of load distribution. It is required that the working tooth surfaces in the transmission have good contact to ensure uniform load distribution, otherwise it will cause stress concentration on the tooth surface, premature wear and reduce service life.
4. The rationality of the transmission backlash. It is required to leave a certain backlash between the non-working tooth surfaces of the meshing gear teeth in order to store lubricating oil, compensate for elastic deformation and thermal deformation and the manufacturing and installation errors of precision gears.
