The
crown block consists of crown basement, fast-line sheave, dead-line sheave,
main sheave, sand-line sheave, drilling line protector and sheaves for
hydraulic and air winch, bumper wood for the Crown-O-Matic and guardrail. It’s
designed with closed type and open type. The traveling system is divided into
7×6, 6×5, 5×4, and 4×3, which fit to Φ7/8”~Φ1 1/2” drilling lines. The sheave groove
conforms to the requirements of API RP 9B. The sheave groove surface is
processed with a quenching treatment. The bearing adopts centralized
lubrication for convenient operation.