Efficient hydraulic-mechanical coupling hydraulic transformer

An efficient hydraulic-mechanical coupling hydraulic transformer comprises a large-flow hydraulic pump/motor (1), a small-flow hydraulic pump/motor (2), a first reversing valve (3), a second reversingvalve (4), a third reversing valve (5), a fourth reversing valve (6) and an oil tank. The large-flow hydraulic pump/motor (1) and the small-flow hydraulic pump/motor (2) are coaxially and rigidly connected. According to the efficient hydraulic-mechanical coupling hydraulic transformer, one part of hydraulic energy is converted into mechanical energy, then the mechanical energy is coupled with thehydraulic energy to achieve pressure changes, and therefore compared with the previous manner, the energy transmission efficiency is greatly improved. The hydraulic-mechanical coupling hydraulic transformer is provided with the four reversing valves, the two hydraulic pumps/motors can convert work conditions flexibly through the combination of the reversing valves, one hydraulic pump/motor can bereplaced with a small-disp