| 主权项 |
1. A top drive mechanism for a drill rod, comprising a gooseneck connector, a washpipe assembly, an output shaft, a power mechanism for driving the output shaft to rotate, and a decelerator, wherein the gooseneck connector is connected with a high pressure pump through a high pressure hose; the washpipe assembly is connected between the gooseneck connector and the output shaft to achieve dynamic seal for the output shaft; the power mechanism is fixed onto a housing of the decelerator; an output end of the power mechanism is connected with a final gear disposed on the output shaft through the decelerator; the decelerator is fixedly disposed on a support; the gooseneck connector is fixedly provided with an upper cover plate connected with an elevating mechanism; the support and the upper cover plate are fixedly connected; a shell, located below the support, is disposed on the output shaft; the shell and the support are fixedly connected, and a cavity that accommodates the final gear is formed between lower end faces of the shell and the support, wherein: the output shaft has an integral structure formed by a shaft body and a flange; the shaft body has a stepped hollow structure; the flange is fixedly connected with the drill rod; an upper end of the shaft body passes through a bearing hole of the support to seal and butt a port of the washpipe assembly; a step I is disposed on an outer circumferential surface of the output shaft in the bearing hole; a support ring is disposed on an end face of the step I; a keyway is provided in an inner hole of the support ring; the output shaft mates with the support ring through a key I; the output shaft is further provided with a lock nut, and the lock nut fixes the support ring onto the end face of the step I; a lower portion of the support ring is provided with a self-aligning thrust roller bearing, and the self-aligning thrust roller bearing is disposed in the bearing hole of the support; an axial force of the output shaft is exerted on the support through the lock nut, the support ring, and the self-aligning thrust roller bearing, a step IV is disposed on an outer circumferential surface of the support ring, and a radial bearing I is disposed on an end face of the step IV; and
the final gear mates with the output shaft through a key II, and a radial bearing II, located at a lower end of the final gear, is disposed in a bearing hole of the shell. |
