Simulation of Hydraulic Breaker Performance

On Accumulator Behavior

Abstract

In this paper, using the analytical model and calculation procedure proposed by the author, the effects of gas volume and charged gas pressure in the accumulator on the performance of the large-sized hydraulic breaker have been studied, theoretically and experimentally. First, it is confirmed that the theoretical value of pressure drop ratio decreases with increase of the value of effective discharge gas volume inside the accumulator in case of the small-sized breaker, and correlates basically well with these experimental values. This is believed to indicate that these analytical model and method can analyze the accumulator behavior of an actual hydraulic breaker with extraordinary accuracy. In these simulation results, the percussion speed increases with increase of the value of the charged gas pressure within the range of calculation, while the mean supply flow rate decreases. Generally, it is considered that a proper value of the charged gas pressure inside the accumulator is 3.43MPa. However, a value of the percussion speed is almost saturated with Va=0.3l. Accordingly, an appropriate value of gas volume inside the accumulator is 0.3l, and also it should be determined by considering the size of a breaker.