Patent attributes
A top drive system for wellbore related activities involving a drilling tubulars string. The system includes a frame structure and a top drive device with one or more top drive motors, a transmission housing, a floating quill system with a hollow vertical floating quill shaft. The top drive device has a thrust bearing housing arranged below the transmission housing and suspended via said first and second vertical frame members from the top frame member. A hollow vertical outer main shaft is suspended from the thrust bearing housing and a hollow vertical inner main shaft is arranged vertically mobile within the outer main shaft. The inner main shaft is connected to the floating quill shaft and has a lower connector end that is configured to be connected to a drilling tubulars string via a threaded connection, so as to allow for transmission of the rotary torque from the one or more top drive motors via the transmission, the floating quill shaft, the inner main shaft, to the threadedly connected drilling tubular string.
