Jixie chuandong (Sep 2019)
Study on the Design of Lepelletier Planetary Gear Mechanism Automatic Transmission
Abstract
Based on the structural analysis of the existing Lepelletizer planetary gear mechanism (PGM), an optimal method for searching the feasible shifting sequence by establishing the velocity diagram based on the lever analogy is proposed. In this method, the basic links of PGM and all possible shifting elements are converted into points on the equivalent lever coordinate system, the velocity vector diagram of all possible speed ratios is drawn, and the shifts are classified. The shifting sequence is determined according to the shifting logic of transmission and the number of shifting elements as constraints, the transmission ratio of each shifting is deduced. The ratios of the each line segment in the velocity vector diagram and the characteristic parameters of the ordered lever diagram of PGM are calculated, so as to determine the attributes of all links of the transmission. The transmission which arranged with shifting elements is checked by the planar-graph. This method is used to optimize the 6~10 speed Lepelletier PGM. The results show that the two structures of 6-speed and one structure of 8-speed are the same as those of the patented ones, which proves that the method is correct and feasible.
