Dynamic characteristic of swash-plate mechanism applied in quasi-free-piston generator

In order to avoid instability of free-piston engine (FPE) caused by removing power transmission mechanism, a novel quasi-free-piston engine (QFPE) which applies a swash-plate to constrain piston motion instead of transmitting mechanical power is proposed. Several permanent magnets are fixed to the linkages which are driven by the swash-plate. The working principle of quasi-free-piston was presented at first. Then the dynamic model of power transmission mechanism was established based on analysis of kinematic characteristics. After the gas force which was deprived from the thermodynamic model was applied on pistons, the electrical force acting on linkages were studied. As following a combining simulation model was established and analyzed. Results shows that acceleration of linkage of QFPE is much larger than traditional engine, which could improve the responding speed of QFPE to the instantaneous power demand. Benefiting from much shorter power transmission chain, higher efficiency could be achieved. However, the energy exchange between linkages and Z-shaft may lead to unnecessary power loss which needs further research in the future.