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Linear, conic, cubic, and sine relief curve are compiled and established in MATLAB, on which gear models are built in UG and a new method of establishing relief gear models is proposed in this paper. Based on the theory of elastic, contact method is used on the proposed finite element models of gears by software LS-DYNA. Total contact force of teeth face, contact force of single tooth and equivalent stress on relief gears in different cases are obtained. The results show that contact impact existing in meshing between teeth of gears is ameliorated, contact force of tooth face and equivalent stress is reduced. The effect of cubic and sine relief curve is the best. So dynamic simulation on relief gears has great significance for reducing contact force between teeth faces of gears.

The ultra-precision master gears have important application in calibrating high precision gear measuring instruments or coordinate measuring machines and in military industry. Firstly based error interference of the angle-transferring curve, the periodical translocation technique (PTT) of gear-grinding to improve the indexing accuracy of ultra-precision gears is proposed. The conclusions are drawn by precision experiment: (1) controlling 2/3~3/4 of total teeth participating in regrinding process can obtain the smaller total cumulative pitch deviation; (2) with increasing of the number of teeth participating in regrinding processes, the effects on single pitch deviation is more obvious. Finally, the total pitch deviation Fp of the specimen reaches to 0.79 μm (2.7′′), and the single pitch deviation fp reaches to 0.30 μm (1.0′′) by adopting PTT technique and both of them reaches to submicron level.The precision gear-grinding experiments show the efficiency and practicability of the PTT technique.

Material mechanics and dynamic properties affect the service life of parts, and also the normal operation of machines. In order to reduce the processing time and improve the quality of machining, a cylindrical roller was used in the research. Cylindrical ultrasonic rolling machining (CURM) is an efficient way to enhance the service properties and surface characteristics of components. CURM was designed and later tested on the 45# steel surface. The result showed that the plastic deformation of surface layer was symmetrical and the surface grain was reduced in size by approximately 4.2%. The result of the experiment showed that CURM was effective in enhancing the productivity as well as enlarging the yield strength and hardness of components.