Study on the Transmission Characteristics of the Multi-gear Multi-degree-of-freedom Hybrid Planetary Gear Automatic Transmission Based on the Line Method

Abstract

Planetary gear transmission is widely used in vehicle automatic transmission because of its compact structure and good working conditions of gears and bearings. The transmission characteristic analysis of planetary gear automatic transmission has become one of the most important contents of automatic transmission design and maintenance. This paper takes the typical multi-gear multi-degree-of-freedom hybrid planetary gear automatic transmission Ford 10R80 as an example. Firstly, its structure is analysed, and its degree of freedom is calculated to be 5. According to this, Further analysis is made on the shift logic of the sequential up and down gears, skipping-level shifting gears and the multi-level down gears such as from© to© orfrom © to©. Then, the overall transmission nomogram is established based on the improved line method, and the power transmission characteristics of typical gears are analyzed. Finally, the transmission ratios of all gears are calculated according to the nomogram, and the calculated results are completely consistent with the data provided in the patent documents. The results show that the nomogram can not only clearly describe the speed of all the basic components in each gear but also calculate the transmission ratio of each gear quickly.