ZhouZhongShang

The 20CrNi3 shank adapter for hydraulic rock drill was fractured after drilling for 300 meters．The fracture causes of 20CrNi3 shank adapter were analyzed through chemical composition analysis，fracture morphology and microstructure observation，mechanical properties testing． The results showed

In view of complex assembly of hydraulic rock drills that their cause of troubles and damage are numerous. The text as based on multi home made hydraulic rock drills in operation is going to introduce mainly the rotation types, impact types, water circulating types, air circulating types

The paper covers developmental conditions of hydraulic wheeled drilling rigs home and broad, their distribution as well as status of domestic and foreign manufactures. It focus on demands from users, discusses the pros and corns of the currently and predicts the developmental trends