Top drive drilling apparatus

A top drive well drilling apparatus designed to be suspended from a travelling block in a drawworks and laterally supported by a dolly running together with the well drilling apparatus along tracks or rails attached to a derrick, said drilling apparatus comprising:

• at least one driving motor, one power transmission powered by the at least one driving motor, a drive shaft driven from the power transmission and designed to be connected to a drill string, load transferring means, and a torque arresting device attached to and depending from the power transmission, wherein
• a plurality of said components of the well drilling apparatus are constructed and arranged as component modules,
• quick releasable connecting means detachably connect respectively adjacent individual component modules together, and
• the load transferring means are in the form of a load frame module that load relieves the drive shaft and the power transmission at the same time as it forms a central component module which the other component modules are constructed around.