Synthesis of Dynamical Structure of the Hydraulic Breaker With a Vibration-Free Handle

An approach to the synthesis of a dynamical structure of the hand-held percussion machine with a vibration-free handle is presented. This is based on the consideration of the optimal dynamic conversion of energy in hand-held percussion machines founded as a solution of the equivalent problem of the optimal control [1]. For an accomplishment of the optimal regime a proper dynamic structure of the percussion machine as a multi-body vibro-impact system with one body (casing/handle) being free of vibration is found and investigated. Computer simulations and initial experiments validated the new approach. The main feature of the proposed design realising the synthesised structure is the use of a mechanism with zero differential stiffness. A hydro-pneumatic unit with zero stiffness was developed and tested. Theoretical recommendations have been applied to a commercial hydraulic breaker. A proper modification of the design and effective use of existing hydraulic power source provided a significant improvement in performance.Copyright © 2007 by ASME