本文概述了美国五十至七十年代对牙轮钻头改进的历史状况,重点介绍近几年来,美国对牙轮钻头的改进集中于五个方面,即:研制滑动轴承、加长喷嘴、加长喷嘴和中心扩散喷嘴的镶齿双牙轮钻头、特里普萨弗(Tripsaver)型减震器和卡维杰特(Cavijet)型空化喷嘴,并就其工作原理和效果作了较详尽的论述。 This article provides an overview of the history of roller cone bits in the United States from the 1950s to the 1970s. It highlights the improvements that the U.S. has made in recent years to roller cone bits in five areas: developing plain bearings, lengthening nozzles, lengthening nozzles and Center Injector Indent Double Tricone, Tripsaver Shock Absorber and Cavijet Cavitation Nozzle. The principle of operation and the effect are also described in detail.