Windlass is ship deck machinery to retractable
anchor and chain on board. Using steam engine, electric motor and hydraulic
motor as power. Usually installed on the first deck of ship. The trend of its
development is to achieve operation, anchoring, mooring and automatic mooring
for a unit. According to the driving form can be divided into: manual,
electric, hydraulic.
Windlass mainly by base, bracket, chain
wheel, brakes, sprocket, gear box, control system (manual windlasses except ) and
other components, electric windlass motor and hydraulic windlass with hydraulic
pump station.
The main specifications of windlass include
diameter of anchor chain, anchor nominal speed, rated load, support load,
speed, power system voltage etc.
Windlass in ship installation to ensure the
chain and sprocket wrap angle is 117 - 120 degrees.
Anchor windlass requirements
The windlass is machinery for anchoring and
anchor drop, also used as mooring. There are some requirements for windlass:
1), the anchor should be independent of
original drive power
2), the anchor rating SWL should be not
less than 41.68d2N (4.25d2kgf), when d<25mm rating SWL should not be less than
36.8d2N (3.75d2dgf), D for chain diameter, the unit is mm. The average speed
should be no less than 9m/min when the rated tension is used.
3) windlass under rated tension and speed
should be continuous working 30min, and in not less than 1.5 times overload
tension should be continuous work 2min; in addition to anchor windlass should
be equipped with overload protection device, overload can be transferred to the
medium speed operation.
4), anchor chain sprocket on the brake
should be reliable, 45 per cent of the brake chain fracture load pull (when
freedom anchor drop at speeds of 5~7.5m/s can still stopped falling chain);
between windlass chain wheel and axle load should be a clutch, brake and clutch
manipulation is convenient and reliable; windlass operation should be along the
reverse rotation and smoothly and rapidly.
5) windlass installation shall ensure the
cable leads three eyes (hawsepipe, chain, sprocket) in line.
There are horizontal and vertical anchor windlass,
the general ship use horizontal anchor windlass. And vertical anchor windlass
also called anchor capstan and its power below deck, to save the deck area , naval
ships widely use vertical anchor windlass. Recent large ships, because the
anchor windlass size is too large, the bow deck to accommodate and operation of
adverse, therefore, using vertical anchor windlass.
Classification
of windlass
According to the driving mechanism of
energy points --- manual windlass, anchor steam windlass, electric windlass (DC
electric windlass, AC electric windlass) and hydraulic windlass (high pressure
type anchor hydraulic windlass, pressure type anchor hydraulic windlass,
pressure type anchor hydraulic windlass.
According to the center line direction -
horizontal windlass, vertical anchor chain wheel capstan
According to the arrangement – double gypsy
windlass, single gypsy windlass, combined windlass
Characteristics
of various windlass
A. manual windlass
The weight does not exceed 250kg of the
anchor, according to the working conditions, if it can be suitable for use, you
can configure the manual anchor. Manual windlass is only used in inland river
small ship, it should prevent the handle from injuring people.
B. steam windlass
Steam windlass has been widely applied in
the steam ship, currently used for large tankers. The firm structure, reliable
work, no dangers caused by fire, but the steam engine efficiency low, huge
structure, laying on the deck for a long pipeline heat loss, deck steam engine
cylinder pressure is generally not more than 0.8MPa, operation management
problems, in winter when the weather is cold, before use to fully warm engine,
to discharge the residual water.
C. electric windlass
Electric windlass is currently the most
widely used in the ship.
According to the power system of the ship,
the electric windlass has DC motor and AC. DC motor speed control
characteristics, high efficiency, but the high cost of the initial set, the
brush should be regularly maintained.
AC motor speed adjustment performance is
poor, usually only have a variable speed, depending the motor and windlass a
set of speed reducer to get a number of speed grades. This set of gear reducer,
due to the need of a large reduction ratio, and consider transmission and working
reliability of windlass and other issues, the structure is more complex, the
weight and size of the area occupied by larger deck.
Reducer transmission device often used
spherical worm and worm gear transmission, spur gear transmission, planetary
gear transmission and other transmission mode. Generally speaking, the planetary
gear reduction transmission mechanism of light weight, small size, high
transmission efficiency, maintenance is simple, so the current application
more.
D. hydraulic windlass
Hydraulic windlass is mainly rely on
hydraulic device to carry out and control the action. Hydraulic windlass because
of its hydraulic energy from motor driven oil pump device, also known as
electric hydraulic windlass. It has the following characteristics:
(1) with a good speed control performance
of the DC motor.
(2) usually uses the low speed high torque
hydraulic motor, low speed, large output torque, no longer need to set up a
huge mechanical reducer, can directly drive a chain wheel.
(3) hydraulic drive with self -brake dynamic
performance, work safety and reliability.
(4) compact structure, small weight and
size of unit power. .
(5) easy to operate, maintenance is simple.
(6) easy to realize remote control and
automation
For large, high degree automation ship, the
use of hydraulic windlass on the ship's economy, reliability is more favorable.
Hydraulic windlass can also be driven by high speed oil motor. High speed oil
motor is commonly used in the structure of the bending shaft type axial plunger
oil motor and the radial piston (or steel ball) type oil motor or vane type oil
motor. Oil motor itself is small, need to set up a larger gear reducer.
E. horizontal windlass
The chain wheel shaft of the horizontal windlass
and the center line of the reel shaft are parallel to the deck, and the whole
set of anchor equipment is installed on the deck, operation management is
convenient. But equipment occupies a large area, and easy to suffer from wind
and wave erosion. General merchant ships more use of horizontal anchor.
F. vertical windlass (capstan)
The shaft center line of the chain wheel
shaft and the center line of the vertical windlass is perpendicular to the
deck. The power system and transmission mechanism are placed deck below, only
the sprocket and drum extends out of deck, guided by a vertical shaft. No
horizontal windlass occupied deck area and easy to suffer wind erosion of the
shortcomings, but chain wheel vertical shaft under large bending moment,
management is not very convenient.
G. Double gypsy windlass
One or two drive motor in center, two
anchor chain are arranged on the left and right sides. If the original
motivation and chain wheel sharing a base is known as integrated windlass, if
separated from the prime mover and chain wheel base is known as ordinary
separation type windlass.
H. single gypsy windlass
An drive motor only to configure an anchor
chain wheel, drum and brake device, composed of independent units. Unilateral
type windlass arranged in both sides of the bow. According to the location of
the different, there is the right and left .
I. Combine windlass
Two sets of single gypsy windlass combined
to form a whole. The chain wheel on either side can by any prime mover driven,
two sets of the original motivation, enhance the vitality of the windlass.
J. Automatic brake windlass
Anchor and chain free falling property. The
deeper anchoring, the faster fall is. When anchored in deep water, the anchor
encountered hard water bottom, impact very large, prone to damage. Accelerate
speed of the whereabouts, chain sprocket pounding, an increase of possibility
"slipping chain hopping", and may produce a spark. For large ships,
anchors and chains, weight is very big, general windlass brake equipment has
not effectively control speed of the whereabouts, especially deep sea anchor
operation, long time and strenuous friction will lead to windlass heating and
burning. In this case, it is necessary to use Automatic brake windlass.
In modernization large tankers, often using
pneumatic steam windlass.
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