Geometric transmission error model analysis of high precision F2C-T drive
According to the structure of the newly high precision F2C-T pin-cycloid transmission, influence factors on the transmission error were analyzed, and the error synthesis model of the various driving factors and parts were established. Taking the F2C-T455 model as an example, the theory of transmission error were analyzed, comparing contribution rate by driving factors of each part, the main influence factors of transmission error of the system were obtained.
On the analytical definition of profile modifications minimising transmission error variations in narrow-faced spur helical gears
Abstract Two original analytical formulations are presented which explicitly give the depths and extents of symmetric profile modifications minimising the fluctuations of quasi-static transmission error in narrow-faced spur and helical gears. Numerous comparisons with quasi-static and dynamic simulation results are presented which prove that the proposed theory is sound. The proposed formulae can therefore help define adapted reliefs in terms of transmission error and dynamic tooth loading with minimum effort.
Synthesis and chemical recycling of novel poly(ester-urethane)s using an enzyme.
A series of enzymatically recyclable poly(ester-urethane)s consisting of a biodegradable diurethane moiety as a hard segment and an ester moiety as an enzymatically cleavable linkage was chemo-enzymatically prepared by two routes. The poly(ester-urethane) was prepared by a) the ring-opening polymerization of a cyclic ester-urethane monomer synthesized via the transesterification reaction of biodegradable diurethanediol and dicarboxylate ester using lipase and b) the direct polycondensation of a diurethanediol and a dicarboxylate ester. A significantly higher molecular-weight poly(ester-urethane) having the highest molecular weight (Mw) of 101,000 was produced by the ring-opening polymerization of the cyclic ester-urethane monomer when compared with that produced by the polycondensation of the dicarboxylate ester with diurethanediol. The poly(ester-urethane) was readily degraded by lipase into the corresponding cyclic oligomers; the oligomers were readily repolymerized by the ring-opening polymerization using lipase for chemical recycling.