Analysis of Self-oscillating Single-acting Hydro-impact System Operational Modes with Two Limiters of Striker Movement

A new property of self-oscillating single-acting hydro-impact systems is considered in this paper – an ability to make strikes in forward and backward directions in presence of two limiters of striker movement without structural changes in device. Mathematical models are presented for system, which includes a flow rate source, a control valve, an impact unit (body frame, striker and spring), an energy accumulator and two limiters. Program for system operational modes (op-modes) simulation is developed and dynamics of specific typical device is numerically investigated. Theoretical oscillograms of its dynamic characteristics and dependencies of integral characteristics on source and impact device parameters are analyzed. At low flow rate multiimpact self-oscillating cycles are obtained, in which the nature of dynamics phenomenon repeats after several striker-limiters interactions. Increase of flow rate leads to single-impact working mode with forward direction of striker movement, then to transition to double-impact mode with forward and backward directions and, further, to single-impact mode with backward direction. Transition boundary points, in which system op-modes changes, are found. Results of this paper can be applied in development of reversible hydro-impact devices (with impacts in forward and backward directions) for mining and construction engineering.