The mobile service rig has a stationary section at top of mast called the crown block, here is the component called the crown sheave or crown pulley assembly unit. In oilfield usage, the term usually refers to either the pulleys permanently mounted on the top of the rig (the crown blocks), or the pulleys used for running wireline tools into the wellbore. In the case of the crown blocks, the drilling line, a heavy wire rope, is threaded between the crown blocks and the traveling blocks in a block and tackle arrangement to gain mechanical advantage.
Clay’s Industrial Supplies has inventory of both Crosby-McKissik and GSM NylaTron crown sheaves.
We also custom manufacture sheaves, pins, linkages, hubs, drill line clamps, etc. for all sizes and applications, thus endeavouring to meet your specific needs and requirements. Our proven ability, dependable processes and custom solutions will exceed your expectations.