The compound electromechanical-hydraulic transmission system with reflux power of roadheader cutting unit

Considering the higher requirements for mechanical system reliability and environmental adaptability of unmanned mining machine, a new type of compound electromechanical-hydraulic transmission system with reflux power that can continuously variable transmit according to cutting load is proposed in order to break the present transmission style. This paper explains the principle of the variable speed in the reflux electromechanical-hydraulic transmission system, deduces formulas of the speed ratio, efficiency and torque characteristic, and analyzes the performance changes of the new transmission system under different working conditions. And the result shows that the reflux power transmission system, which use hydraulic torque converter as the feature-driven element, has the characteristics of adaptive continuously variable transmission, hard rock breaking and cushioning. Additionally the new system enhances the transmission efficiency significantly and meet the higher requirements for reliability and adaptability in unmanned mining.