正独立式双流传动液压机械复合转向原理和分析

提出一种履带车辆正独立式双流传动液压机械复合转向系統，通过分析其转向过程的运动学、动力学和功率流，说明其转向基本原理和控制方法。该原理是在正独立式双流传动系统中，两侧设有液压和机械传动机构，分别传递转向液压功率流和转向机械功率流，两股功率流经过转向行星排汇合后输出给汇流行星排。其中：液压功率流可以控制车辆降低一侧履带速度，实现无级连续转向；机械功率流可以分流，减少液压功率流比率。该原理将正独立式传动系统的制动器有级转向改进为液压无级转向，大大减小液压泵马达的排量和功率，发扬正独立式双流传动系统体积小和质量轻的优势,使正独立双流传动具有推广的可能性和应用价值。

Analysis of Principle of Hydro-mechanical Complex Steering for Positive Independent Dual-stream Transmission

A principle of hydro-mechanical complex steering of positive independent dual-stream transmission for tracked vehicle was put forward. A basic principle and a controlling method were explained by analyzing the kinematics,dynamics and power streams.This principle was that both hydraulic and mechanical steering power streams were separately transferred by hydro-mechanic transmissions in the positive independent dual-stream transmission system,and combined by steering planetary gear set,transferred to the power summing planetary gear set.Therefore,the hydraulic power streams could control vehicle to speed down one-side track for stepless continuous steering,and the mechanical power streams could share some parts of the main power to reduce the burden(i.e.the rate) of the hydraulic power streams.The principle expresses that the step steering with brake can be improved to hydraulic stepless steering in the positive independent transmission system;the displacement and power of hydraulic pump and motor can be reduced comparatively;the lighter weight and smaller volume of positive independent dual-stream transmission are retained.It is possible to spread and adopt this valuable feasible principle.