This paper presents a novel steering mechanism embedded in a point-the-bit rotary steerable system (RSS) for oilfield exploitation. The new steering mechanism adopts a set of universal joints to alleviate the high alternative strain on drilling mandrel and employs a specially designed planetary gear small tooth number difference (PGSTD) to achieve directional steering. Its principle a... https://www.trangtinamthuc.com/product-category/grains/