1.Description
A.Square drive Roller Kelly bushing is designed for driving Kelly in the drilling operation.
B.Roller Kelly bushing can be square drive or pin drive, and can be applicable for rotary table size from 17½ to 37½. By changing roller sizes, the bushing can accommodate square kellys from 2½ to 5¼ or hex kellys from 3 to 6. Roller Kelly bushing has three series: SD(light duty), MD(medium duty) and HD(heavy duty).
C.All technical data and properties of Roller Kelly bushing conform to the requirements of API Spec 7K.
2.Structure
Square drive Roller Kelly bushing consists of lower body half, upper body half, roller, roller pin and etc. when the bushing is installed to square kelly or hex kelly, the square part of the lower body half can be fitted in the square of the master bushing. When operating, the rotary table drive master bushing and master bushing drive Roller Kelly bushing and Roller Kelly bushing drive square kelly or hex Kelly to rotate, such is the torque transporting. The lower body half is conically shaped to readily enter the bore of the master bushing and automatically center bushing and drill string within the bore of the master bushing. Inside rollers are journal bearings which are fitted to the roller pin, when kelly rotates and moves downward, the rollers rotates with Kelly, such change sliding friction to rolling friction and minimize the abrasion of the kelly. The bushing is equipped with mud-scrapper assembly to clean the mud.
3.Model:HDS,MDS,LDS
4.Type:Heavy duty,Middle duty,Light duty
