Research on the Matching of Impact Performance and Collision Coefficient of Hydraulic Rock Drill

Table 3

Calculation results of impact energy of the impact piston by different lengths and masses.

Piston	γ	Stroke	Pd (MPa)	Qd (L/min)	Wd (kW)	f (Hz)	Ep (J)	Wp (kW)	Efficiency (%)
No. 1	9∼11	Long	20	93	31	35.7	571.7	20.4	65.8
		Short	20	80	26.7	40	390	15.6	58
No. 2	5∼9	Long	20	83	27.7	40	440.9	16.9	61
		Short	20	69	23	43.5	290.1	12.6	54.8
No. 3	3∼5	Long	20	71	23.6	43.5	301.9	13.1	55.5
		Short	20	58	19.3	47.6	203.9	9.7	50.3