LAWSON ENGINEERS LTD Ref : PJ1682
Issue Date : 06.06.2006
1 GENERAL
DESCRIPTION.
1.1 WINCH
See drawings
SW1618A-0001
Winch Assembly
The winch consists of a fabricated drum mounted on a large ring bearing together with a
smaller support bearing at the slipring end. On the internal diameter of the ring bearing
are gear teeth which mesh with the pinions of the main drive motors. The drive motors,
ring bearing and support bearing are mounted on a bed frame. Also mounted on the bed
frame are the control junction boxes and the bump (collision) frame. The coiling
(spooling) gear is mounted on the bump frame. The bump frame is completely removable
along with the coiling gear and guards.
The automatic coiling gear is a hydraulic powered, electrically actuated, system. The
coiler box is moved left to right when initiated by the umbilical cable.
Left to right movement is achieved by hydraulically driving a shaft with a standard
trapezoidal screw thread. A captive nut then drives the coiler box.
Movement of the coiler box is initiated by the amount of offlead angle of the umbilical
cable from the coiler box itself.
The horizontal travel-sensing frame is mounted on the back of the box.
The coiler box is constructed with an open top to allow the umbilical to pass through to
accommodate the change in vertical offlead angle as the A-frame moves and when
connecting the umbilical to the drum.
1.2 POWER
PACK
See drawings
SW1673X-0002
Hydraulic schematic
SW1618B-0001
Power pack assembly
SW1673X-0008 Electrical
schematic
SW1673X-0007
Electrical Cabling Diagram
Enclosed in a R.H.S. bump frame, the power pack provides hydraulic oil to run the
winch, A-frame and snubber. The two-stage electric motor driven pumps are mounted
directly below the reservoir and have flooded suction inlets.
Stage 1.
An axial displacement variable swash plate piston pump with load sensing
and power limiting facilities. It provides main power to the winch and A-
frame. A relief valve is fitted to the winch control manifold to provide a
maximum pressure cut off. A pressure reducer is fitted to this manifold to
reduce the pressure to the A-Frame supply
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