螺杆钻具中的齿瓣式万向轴

目前，国内生产使用的万向轴均为化瓣式万向轴，其结构简单、加工速度快，但其寿命极短，成为制约螺杆钻具寿命的关键部位。现文以合理受力为依据，设计了与花瓣式万向轴截然相反的线型，称齿瓣式万向轴，其合理的受力、耐磨性及工艺处理使寿命成倍提高。现场使用表明，齿瓣式万向轴成为螺杆钻具中寿命最长的部件。

The gear-petal style cardan shaft used in screw drilling tools

At present,petal style cardan shaft is used and manufactured in China generally.Its structure is simple and the processing speed is fast,but its short life restricts overall performance of positive displacement mud motor.This thesis introduces the gear petal style cardan shaft whose linetype is opposite to petal style one according to the theory of reasonable stress.Its reasonable stress and the technology of abrasion proof double the life of positive displacement mud motor.Site application shows that the life of gear petal style cardan shaft is the longest among the parts of positive displacement mud motor.