Hydraulic winch derrick swinging mechanism - has two winches aligned to pull derrick to one side, driven by common supply

摘要

The hydraulic unit system for swivelling a derrick has two winches so aligned that they pull the derrick to one side. They are controlled by a manoeuvring valve (2) and are driven by a common hydraulic supply (3). The pressure sides (1) of the two motors are connected to a common hydraulic supply (12) which supplies a somewhat higher pressure than the maximum pressure at the take-off sides (4) and (5) of the two motors. To swivel the derrick, pressure medium is fed from the hydraulic supply (12) to the motor which pays out so that the moment on this is reduced. Consequently, the other winch can pull the derrick to its side.