A system includes a first transmission having a first planetary gearset, a first drive shaft, and a first annular sleeve. The first annular sleeve is positioned circumferentially about the first drive shaft, and the first annular sleeve is configured to move axially relative to the first drive shaft and the first planetary gearset from a first axial position in which the first annular sleeve engages a first sun gear of the first planetary gearset to a second axial position in which the first annular sleeve engages a first ring gear of the first planetary gearset to adjust a gear ratio of the first transmission.
Drawworks Gearbox With Redundant Braking On Input Side
A drawworks gearbox includes additional braking on the input side of the gearbox to provide a redundant emergency brake and, optionally, a separate parking brake with the drum-side brakes being the emergency brake. An air-cooled brake disc is attached to a high speed coupling connected to the gearbox input pinion. A hydraulic-apply, spring-release brake is mounted to the gearbox housing at each pinion location and arranged to act on its respective disc.