Roller Kelly Bushing is one of the necessary tools for oil drilling operation, which is fixed at the big bushing to pass the torque to the down hole drilling tools.

According to the driving mode, it could be divided into square drive type and pin drive type. According to the kelly, there are square kelly bushing and hexagonal kelly bushing. It mainly consists of roof cover, bottom cover, axis pin, roller, fastening bolt and stals, etc.

There are four pieces of roller in the bushing which have needle bearing inside the rollers and fastened between roof and bottom cover by and pin and seals at both ends of rollers to prevent the drilling fluid from percolating. There is a stop pin fixed in the seal body to prevent rotating.

The axles of roller is fixed by four pieces of bolt M3 8 which tightening torque is 2KN m. There are four hexnuts fixed the top of four large bolts with the covers tightly to avoid loosing.