Steering gear ensures the ship's controllability, that is, it allows you to keep the ship on a given course and change the direction of its movement. Components steering gear are: steering wheel, steering motor, steering gear, helm station and steering gear.
The rudder serves directly to maintain or change the direction of the vessel. It consists of a steel flat or streamlined hollow structure - rudder blade and vertical rotary shaft - stock, rigidly connected to the blade. On the upper end of the stock (head), brought out to one of the decks, a sector or lever - a tiller is mounted.
An external force is applied to it, turning the stock. When the rudder is set in the center plane of a moving vessel, it will maintain the direction of movement.
If the rudder blade is tilted away from this position, the force of water pressure acting on the rudder will create a torque that will turn the boat. Steering motor is a steam, electric, hydraulic or electro-hydraulic machine that drives the steering wheel.
The steering motor is installed at the tiller and is connected to it directly, without intermediate gears, or separately from the tiller.
The steering gear transfers the power from the steering motor to the stock. The control post is installed in the wheelhouse. It serves for remote control steering machine through the steering wheel, controller or push-button control panel.
The controls are usually mounted on the same column with the autopilot unit; a magnetic directional compass and a gyrocompass repeater are installed next to it. To control the position of the rudder blade relative to the centreline plane of the vessel, steering indicators - axiometers are installed on the control column and on the frontal bulkhead of the wheelhouse.
Steering gear serves to connect the control station with the steering motor starting mechanism. Most simple transfers are mechanical, directly connecting the steering wheel to the steering motor starter.
But they have a number of significant disadvantages (low efficiency, require constant care, etc.) and are not used on modern ships. The main types of steering gears are electric and hydraulic.
fig. 61 Steering wheels
a - ordinary flat; b - streamlined; c - balanced, g - semi-balanced
By the design of the feather, rudders can be flat and streamlined.
Ordinary flat steering wheel has an axis of rotation at the leading edge of the steering wheel (Fig. 61, a). The rudder blade 1, made of steel sheet 20-30 mm thick, has stiffening ribs 2, which run alternately on one and the other side of the blade.
They are cast or forged together with a thickened vertical edge of the rudder - ruderpis 3, which has a row of loops 4 with pins 5 securely fixed in them. With these pins, the rudder is hung on loops 6 of the rudder post 9. The pins have a bronze lining, and the hinges of the ruder post are bakout bushings. The lower pin of the ruderpis enters the recess of the heel of the sternpost 10, into which a bronze or bakout bushing with hardened steel lentils at the bottom is inserted to reduce friction. The heel of the sternpost takes the entire weight of the handlebar through the lentils.
To prevent steering upward movement one of the pins, usually the upper one, has a head at the lower end. The upper part of the ruderpis is connected to the rudder stock 8 by means of a special flange 7. The flange is slightly offset from the axis of rotation, thereby forming a shoulder and facilitating the rotation of the rudder blade.
The offset flange allows, during the repair of the rudder blade, to remove it from the hinges of the rudder post without lifting the stock, uncoupling the flange and turning the blade and stock in different directions.
Ordinary flat rudders are simple in design, are durable, but create great resistance to the movement of the vessel and require a lot of effort to shift them. Therefore, on modern ships, streamlined rudders are used instead of flat rudders.
Streamlined rudder feather (Fig. 61, b) is a welded metal frame, sheathed with sheet steel (the steel shell is waterproof). Peru is streamlined. To reduce the resistance of water to the movement of the vessel, special attachments are installed on the rudder - fairings and streamline the rudder post.
Depending on the position of the rudder blade relative to the axis of its rotation, rudders are divided into ordinary, or unbalanced, balanced and semi-balanced.
At the balance wheel (Fig. 61, c) part of the feather is located towards the bow of the vessel from the axis of rotation. The area of \u200b\u200bthis part, called the balancing part, is 20 to 30% of the entire area of \u200b\u200bthe feather. When the rudder is shifted, the pressure of the counter streams of water on the balance part of the feather assists in turning the rudder, thereby reducing the load on the steering machine.
Balance rudders are generally streamlined. A semi-balanced steering wheel (Fig. 61, d) differs from a balance one in that its balancer part has a lower height than the main one.
Fastening balanced and semi-balanced rudders is carried out differently depending on the design of the stern and the stern of the vessel. In addition to the considered basic types of rudders, on some ships special rudders and thrusters are used, which significantly improve the maneuverability of the vessel. These include: active rudders, rotary nozzles, additional bow rudders and thrusters.
Active rudders are streamlined.An electric motor is mounted in a teardrop-shaped trim on the rudder, which drives a small propeller in rotation, installed behind the trailing edge of the blade. Power is supplied to the electric motor through a hollow stock.
The active rudder with the tail rotor stop allows you to effectively turn a vessel that has a low speed of movement or does not have a course, which is very important when sailing in tight spaces, when mooring and in other cases.
The swivel nozzle is a massive ring, fixed on the stock by the type of a balancing rudder. When the nozzle is turned, the jet of water thrown by the propeller changes its direction and this ensures the rotation of the vessel.
Such nozzles are used on tugs. Balance-type bow rudders are installed in addition to the main ones to improve handling on backward... They are used on ferries and some other ships.
To improve the maneuverability of the vessel thrusters are also used. Their propellers, pumps or vane propellers create a thrust in the direction perpendicular to the ship's DP, which contributes to the efficient turning of the ship. Thrusters are controlled from the wheelhouse.
Steering device - a set of mechanisms, assemblies and assemblies that provide control of the ship. The main structural elements any steering device are:
- working body - rudder blade (rudder) or rotary guide nozzle;
- stock, connecting the working body with the steering drive;
- steering drive, transmitting force from the steering gear to the working body;
- steering gear, which creates an effort to turn the working body;
- control drive connecting the steering gear with the control station.
On modern ships, hollow streamlined rudders are installed, consisting of horizontal ribs and vertical diaphragms covered with steel sheathing (Fig. 4). The sheathing is attached to the frame with electric rivets. Inner space the steering wheel is filled with resinous substances or self-expanding polyurethane foam PPU3S.
The steering wheels are depending on the location of the axis of rotation:
1) balancing (Fig. 4, 6), the axis of rotation passes through the rudder blade;
2) unbalanced (Fig. 5), the axis of rotation coincides with the leading edge of the feather;
3) semi-balanced rudders.
The moment of resistance to turning a balanced or semi-balanced rudder is less than that of an unbalanced rudder, and, accordingly, the required power of the steering gear is less.
According to the method of fastening, the rudders are divided into:
1) Suspended, which are fixed with a horizontal flange connection to the stock and are installed only on small and small small production vessels.
2) simple.
A simple single-support balancing handlebar (see Fig. 4) rests with a pin against the stop cup of the stern-post heel. To reduce friction, the cylindrical part of the pin has a bronze lining, and a bronze bushing is inserted into the heel of the sternpost. The connection of the rudder to the stock is horizontal flanged on six bolts or tapered. With a tapered connection, the tapered end of the stock is inserted into the tapered hole of the upper end diaphragm of the rudder and tightly tightened with a nut, access to which is provided through a cover set on screws included in the rudder skin. The curved stock allows for separate dismantling of the rudder and stock (with their mutual reversal).
A simple two-bearing unbalanced rudder (Fig. 5) is closed from above by a sheet diaphragm and a cast head, which has a flange for connecting the rudder to the stock and a loop for the upper pin support. Backout, bronze or other bushings are inserted into the loop of the rudder post.
Insufficient rigidity of the lower support of the balance rudders often causes vibration of the stern and rudder. This drawback is absent in the balancer rudder with a removable rudder post (Fig. 6). A pipe is mounted in the feather of such a rudder, through which a removable ruder post passes. The lower end of the rudder post is fixed with a cone in the heel of the sternpost, and the upper end is attached with a flange to the sternpost. Bearings are installed inside the pipe. The ruderpost at the points of passage through the bearings has a bronze lining. The rudder to the stock is flanged.
An auxiliary propeller is placed in the rudder lever (Fig. 7). When the rudder is shifted, the direction of the auxiliary screw stop changes and an additional moment arises that turns the vessel.
The direction of rotation of the auxiliary screw is opposite to the direction of rotation of the main one. The electric motor is located in the steering wheel or in the tiller compartment. In the latter case, the electric motor is directly connected to the vertical shaft, which transfers the rotation to the propeller gearbox. The active rudder propeller can provide the boat with a speed of up to 5 knots.
On many vessels of the fishing fleet, instead of the rudder, a rotary guide nozzle is installed (Fig. 8), which creates the same lateral force as the rudder at lower shifting angles. Moreover, the moment on the nozzle ball is about half the moment on the rudder stock. To ensure a stable position of the nozzle during shifts and increase its steering action, a stabilizer is attached to the tail part of the nozzle in the plane of the stock axis. The design and attachment of the nozzle are similar to the design and attachment of the balance bar.
Fig. 4 Working bodies of steering devices: single-support balancing rudder.
1 - stock; 2 - flange; 3 - trim of the rudder blade; 4 - cover-fairing; 5 - vertical diaphragm; 6 - horizontal rib; 7 - sternpost heel; 8 - nut; 9 - washer; 10 - steering pin; 11 - bronze facing of the pin; 12 - bronze bushing (bearing); 13 - persistent glass; 14 - channel for disassembling the thrust cup. 
Fig. 5. Working bodies of steering devices: two-support unbalanced steering wheel.
1 - stock; 2 - flange; 3 - trim of the rudder blade; 7 - sternpost heel; 8 - nut; 9 - washer; 10 - steering pin; 11 - bronze facing of the pin; 12 - bronze bushing (bearing); 15 - helmport tube; 17 - ruder post; 18 - backout. 
Fig. 6 Balancing rudder with removable rudder post.
1 - stock; 3 - trim of the rudder blade; 7 - sternpost heel; 11 - bronze lining of the pin; 12 - bronze bushing (bearing); 15 - helmport tube; 19 - ruder post flange; 20 - removable ruder post; 21 - vertical pipe. 
Figure: 7 Active steering.
3 - trim of the rudder blade; 4 - cover-fairing; 23 - gearbox with fairing; 24 - stabilizer;
Baller is a curved or straight steel cylindrical bar brought out through the helmport tube into the tiller compartment. The connection of the helmport pipe with the outer skin and deck deck is watertight. In the upper part of the pipe, a sealing gland and bearings of the stock are installed, which can be support and thrust.
The steering device must have drives: main and auxiliary, and when they are located below the cargo waterline, an additional emergency one, located above the bulkhead deck. Instead of an auxiliary drive, it is allowed to install a double main drive, consisting of two autonomous units. All actuators must operate independently of each other, but, as an exception, some common parts are allowed. The main drive must be powered by energy sources, the auxiliary drive can be manual.
The design of the rudder drive depends on the type of steering gear. The fishing vessels are equipped with electric and electro-hydraulic steering gears. The first are performed in the form of an electric motor direct current, the second - in the form of a complex electric motor - pump in combination with a plunger, vane or screw hydraulic drive... Hand-operated steering gears in combination with a steering, roller or hydraulic steering drive are found only on small and small mining vessels.
Remote control of the steering gear from the wheelhouse is provided by teledynamic transmissions called tele-steering transmissions or steering telematics. On modern fishing vessels, hydraulic and electric steering transmissions are used. They are often duplicated or combined into electro-hydraulic ones.
The electric TV transmission consists of a special controller located in the steering box and connected by an electrical system to the steering gear starting device. The controller is controlled using a handwheel, handle or button.
The hydraulic transmission consists of a hand-wheel driven hand pump and a tubing system connecting the pump to the steering gear starter. The working fluid of the system is an antifreeze mixture of water with glycerin or mineral oil.
The main and auxiliary steering drives are controlled independently and is carried out from the navigation bridge, as well as from the tiller compartment. Time of transition from main to auxiliary drive should not exceed 2 minutes. If there are control posts for the main steering drive in the wheelhouse and field cabin, the failure of the control system from one post should not impede control from another post.
The rudder shift angle is determined by the axiometer installed at each control post. In addition, on the sector of the steering drive or other parts rigidly connected to the stock, a scale is applied to determine the actual position of the rudder. Automatic consistency between speed, direction of rotation and helm position and speed, side and rudder angle is provided by a servo motor.
The rudder brake (stopper) is designed to hold the rudder during emergency repairs or when changing from one drive to another. The most commonly used tape stopper clamping directly to the rudder stock. Sector drives have block stops, in which brake shoe pressed against a special arc on the sector. In hydraulic drives, valves that block access working fluid to the drives.
Keeping the ship on a given course under favorable weather conditions without the participation of the helmsman is provided by the autopilot, the principle of operation of which is based on the use of a gyrocompass or a magnetic compass. Ordinary controls are linked to the autopilot. When the boat is on the set course, the rudder is set to zero on the axiometer and the autopilot is turned on. If, under the influence of wind, waves or current, the vessel deviates from the set course, the electric motor of the system, having received an impulse from the compass sensor, ensures the return of the vessel to the set course. When changing course or maneuvering, the autopilot is disengaged and returned to normal steering.
The general requirements of the Register for the steering gear are as follows:
- Every ship, with the exception of shipborne barges, must have reliable deviceensuring its turnability and stability on the course: steering device, a device with a rotary nozzle and others;
- Taking into account the purpose and special operation of the vessel, it is allowed to use these devices in conjunction with the means of active control of the vessel (ACS).
- The time of shifting a fully submerged rudder or a rotary nozzle by the main drive (with highest speed forward motion) from 35 ° of one side to 30 ° of the other should not exceed 28 s, auxiliary (at a speed equal to half the maximum forward speed or 7 knots, whichever is greater) from 15 ° of one side to 15 ° of the other - 60 s, emergency (at a speed of at least 4 knots) is not limited.
The Register of Part III of Chapter 2 sets out the requirements for all elements of the steering device, formulas are given for calculating the efficiency of both rudders and rotary nozzles.
The steering device is used to change the direction of movement of the vessel or keep it on a given course.
In the latter case, the task of the steering device is to counteract external forces, such as wind or current, that can cause the vessel to deviate from the desired course.
Steering devices have been known since the inception of the first floating facilities. In ancient times, steering gears were large swing oars mounted on the stern, on one side, or on both sides of the vessel.
During the Middle Ages, they began to be replaced by an articulated rudder, which was placed on the sternpost in the center plane of the ship. In this form, it has survived to this day.
The steering device consists of a rudder, stock, steering drive, steering gear, steering gear and control station (Fig. 1.34).
The steering device must have two drives: main and auxiliary.
Main steering gear - these are mechanisms, actuators for steering wheel shift, power units steering gear, and auxiliary equipment and means of applying torque to the stock (for example, a tiller or sector) necessary for shifting the rudder for the purpose of steering the vessel in normal operating conditions.
Auxiliary steering drive is the equipment necessary for steering the ship in the event of failure of the main steering gear, with the exception of the tiller, sector or other elements intended for the same purpose.
The main steering gear must ensure the rudder shift from one side 350 to the other side 350 at the maximum operating draft and forward speed of the vessel in no more than 28 seconds.
The auxiliary steering gear must ensure that the rudder is shifted from one side 150 to the other side 150 in no more than 60 seconds at the maximum operational draft of the vessel and a speed equal to half of its maximum operational forward speed.
Control of the auxiliary steering gear shall be provided from the tiller compartment. The transition from the main to the auxiliary drive must be carried out in a time not exceeding 2 minutes.
The steering wheel is the main part of the steering gear. It is located in the aft part and acts only while the vessel is under way. The main element of the rudder is a feather, which can be flat (plate) or streamlined (profiled) in shape.
By the position of the rudder pen relative to the axis of rotation of the stock, they are distinguished (Fig. 1.35):
ordinary rudder - the plane of the rudder feather is located behind the axis of rotation;
semi-balanced rudder - only most of the rudder blade is located behind the axis of rotation, due to which a reduced torque occurs when the rudder is shifted;
balance rudder - the rudder blade is located on both sides of the pivot axis so that no significant moments arise when the rudder is shifted.
Depending on the principle of operation, a distinction is made between passive and active steering wheels. Passive steering devices are called steering devices that allow the ship to turn only during the course, more precisely, during the movement of water relative to the ship's hull.
The rudder complex of vessels does not provide their necessary maneuverability when moving at low speeds. Therefore, in order to improve maneuvering characteristics, many vessels use active controls that allow the creation of thrust in directions other than the direction of the center plane of the vessel. These include: active rudders, thrusters, rotary propellers and split rotary nozzles.
An active rudder is a rudder with an auxiliary screw installed on it, located on the trailing edge of the rudder blade (Fig. 1.36). An electric motor is built into the rudder blade, which drives the propeller in rotation, which is placed in the nozzle to protect it from damage.
Due to the rotation of the rudder blade together with the propeller at a certain angle, a transverse stop arises, which determines the rotation of the vessel. The active rudder is used at low speeds up to 5 knots.
When maneuvering in confined waters, the active rudder can be used as the main propeller, which ensures high maneuverability of the vessel. When high speeds the propeller of the active rudder is disengaged, and the rudder shift is carried out as usual.
Separate swivel attachments (fig. 1.37). The swivel nozzle is a steel ring whose profile represents the wing element. The inlet area of \u200b\u200bthe nozzle is larger than the outlet area.
The propeller is located in its narrowest section. The swivel nozzle is installed on the stock and rotates up to 40 ° on each side, replacing the rudder.
Separate swivel nozzles are installed on many transport vessels, mainly river and mixed navigation, and provide their high maneuverability.
(fig. 1.38). The need to create effective means of bow control of the ship led to the equipping of ships with thrusters.
PU create a thrust force in the direction perpendicular to the diametrical plane of the vessel, regardless of the operation of the main propellers and steering device.
A large number of vessels for various purposes are equipped with thrusters. In combination with the propeller and rudder, the PU provides high maneuverability of the vessel, the ability to turn on the spot in the absence of progress, departure or approach to the berth practically lagged.
Recently, the electromotive system AZIPOD (Azimuthing Electric Propulsion Drive) has become widespread, which includes a diesel generator, an electric motor and a propeller (Fig. 1.39).
The diesel generator, located in the engine room of the ship, generates electricity, which is transmitted through cable connections to the electric motor. An electric motor that rotates the propeller is located in a special nacelle. The screw is on the horizontal axis, the number of mechanical transmission... Vinto steering column has a turning angle up to 3600, which significantly increases the ship's handling.
Advantages of AZIPOD:
saving time and money during construction;
excellent maneuverability;
fuel consumption is reduced by 10 - 20%;
the vibration of the ship's hull is reduced;
due to the fact that the diameter of the propeller is smaller - the effect of cavitation is reduced;
there is no propeller resonance effect.
One example of the use of AZIPOD is a double-acting tanker (Fig. 1.40), which moves in open water like an ordinary ship, and in ice moves astern as an icebreaker. For ice navigation, the aft part of the DAT is equipped with ice reinforcement for breaking ice and AZIPOD.
In fig. 1.41. the layout of the instruments and control panels is shown: one panel for controlling the vessel while moving forward, the second panel for controlling the vessel while moving astern forward and two control panels on the wings of the bridge.
Before each sailing to the sea, the steering gear is prepared for work: they carefully inspect all the parts, eliminate the detected faults, the rubbing parts are cleaned of old grease and lubricated again.
Then, under the direction of the officer in charge of the navigational watch, check the serviceability of the steering device in operation by a trial rudder shift. Before shifting, make sure that it is clean under the stern and that no watercraft and foreign objects interfere with the rotation of the rudder blade.
At the same time, they check the ease of rotation of the steering wheel and the absence of even minor jams. In all positions of the rudder blade, the correspondence of the indications of the steering indicators and the time spent on shifting are compared.
The tiller compartment must always be locked. The keys to it are stored in the navigator's room and in the engine room at specially designated permanent places, the emergency key is at the entrance to the tiller compartment in a locked cabinet with a glazed door.
Two independently operating communication lines shall be installed between the navigating bridge and the tiller compartment.
Upon arrival at the port and at the end of mooring, the rudder is put in a straight position, the power to the steering motor is turned off, the steering gear is inspected and, if everything is found in the proper order, the tiller compartment is closed.
Maritime site Russia no November 24, 2016 Created: November 24, 2016 Updated: November 24, 2016 Hits: 6219
Steering gear a set of mechanisms, assemblies and assemblies that ensure ship control.
The main structural elements of any steering device are:
working body - rudder blade (rudder) or rotary guide nozzle;
stock, connecting the working body with the steering gear;
steering drive, which transfers the force from the steering gear to the working body;
a steering gear that creates an effort to turn the working body;
control drive connecting the steering gear with the helm station.
On modern ships, hollow, streamlined rudders are installed, consisting of horizontal ribs and vertical diaphragms covered with steel sheathing (Fig. 1, a). The sheathing is attached to the frame with electric rivets. The inner space of the steering wheel is filled with resinous substances or self-expanding polyurethane foam PPU3S.
Depending on the location of the axis of rotation, there are balanced (Fig. 1, e, c), unbalanced (Fig. 1, b) and semi-balanced rudders... The axis of rotation of the balanced rudder passes through the rudder blade, and the unbalanced rudder coincides with the leading edge of the rudder. In a semi-balanced rudder, only the lower part of the blade protrudes into the nose from the axis of rotation. The moment of resistance to turning of a balanced or semi-balanced rudder is less than that of an unbalanced rudder, and, accordingly, the required power of the steering gear is less.
According to the method of attachment, the rudders are divided into suspended and simple ones.
The suspended rudder is attached with a horizontal flange connection to the stock and is installed only on small and small undersized production vessels. A simple single-support balancer rudder (see Fig. 1, a) rests with a pin against the thrust glass of the sternpost heel. To reduce friction, the cylindrical part of the pin has a bronze lining, and a bronze bushing is inserted into the heel of the sternpost. The connection of the rudder to the stock is horizontal flanged on six bolts or tapered. With a tapered connection, the tapered end of the stock is inserted into the tapered hole of the upper end diaphragm of the rudder and tightly tightened with a nut, access to which is provided through a cover set on screws included in the rudder skin. The curved stock allows for separate dismantling of the rudder and stock (with their mutual reversal).
Simple two-point unbalanced steering wheel(see Fig. 1, b) is closed from above with a sheet diaphragm and a cast head, which has a flange for connecting the rudder to the stock and a loop for the upper pin support. Bakout, bronze or other bushings are inserted into the loop of the rudder post.
Insufficient rigidity of the lower support balance rudders often causes vibration of the stern and rudder. This drawback is absent in the balancer rudder with a removable rudder post (see Fig. 1, c). A pipe is mounted in the feather of such a rudder, through which a removable ruder post passes. The lower end of the rudder post is fixed with a cone in the heel of the stern post, and the upper end is attached with a flange to the stern post. Bearings are installed inside the pipe. The ruderpost at the points of passage through the bearings has a bronze lining. The rudder to the stock is flanged.
Fig. 1. Working bodies of steering devices: a - single-support balancer rudder; b - two-support unbalanced steering wheel; в - balanced steering wheel with removable rudder post; g - active steering wheel; d - rotary guide nozzle with stabilizer; 1 - stock; 2 - flange; 3 - trim of the rudder blade; 4 - cover-fairing; 5 - vertical diaphragm; 6 - horizontal rib; 7 - sternpost heel; 8 - nut; 9 - washer; 10 - steering pin; 11 - bronze lining of the pin; 12 - bronze bushing (bearing); 13 - persistent glass; 14 - channel for disassembling the thrust cup; 15 - helmport tube; 16 - ruder post loop; 17 - ruder post; 18 - backout; 19 - ruder post flange; 20 - removable ruder post; 21 - vertical pipe; 22 - rudder propeller; 23 - gearbox with fairing; 24 - stabilizer; 25 - rotary guide nozzle; 26 - propeller shaft; 27 - propeller
In the active rudder (Fig. 1, d) is placed auxiliary propeller... When the rudder is shifted, the direction of the auxiliary screw stop changes and an additional moment arises that turns the vessel. The direction of rotation of the auxiliary screw is opposite to the direction of rotation of the main one. The electric motor is located in the steering wheel or in the tiller compartment. In the latter case, the electric motor is directly connected to the vertical shaft, which transfers the rotation to the propeller gearbox. The active rudder propeller can provide a boat with a speed of up to 5 knots.
On many vessels of the fishing fleet, instead of the rudder, they install swivel guide nozzle (Fig. 1, e), which creates the same lateral force as the rudder at smaller angles of shifting. Moreover, the moment on the nozzle stock is approximately two times less than the moment on the rudder stock. To ensure a stable position of the nozzle during shifts and increase its steering action, a stabilizer is attached to the tail part of the nozzle in the plane of the stock axis. The design and attachment of the nozzle are similar to the design and attachment of the balance bar.
Baller is a curved or straight steel cylindrical bar brought out through the helmport tube into the tiller compartment. The connection of the helmport pipe with the outer skin and deck deck is watertight. In the upper part of the pipe, a sealing gland and bearings of the stock are installed, which can be support and thrust.
The steering device must have drives:main and auxiliary, and when they are located below the cargo waterline, an additional emergency, located above the bulkhead deck. Instead of an auxiliary drive, it is allowed to install a double main drive, consisting of two autonomous units. All actuators must operate independently of each other, but, as an exception, some common parts are allowed. The main drive must be powered by energy sources, the auxiliary drive can be manual.
The design of the rudder drive depends on the type of steering gear. Fishing fleet ships are equipped with electric and electro-hydraulic steering gears. The first ones are made in the form of a direct current electric motor, the second ones - in the form of an electric motor - pump complex in combination with a plunger, vane or screw hydraulic drive. Hand-operated steering gears in combination with a steering, roller or hydraulic steering drive are found only on small and small production vessels.
Fig. 2. Steering wheel drives: a - sector-eubular; b - shturtrovoy; в - hydraulic plunger; g - hydraulic paddle; d - hydraulic screw; e - tiller-tal; 1 - steering wheel and steering column of the auxiliary drive; 2 - tiller; 3 - worm gear; 4 - toothed sector of the main drive; 5 - electric motor; 6 - spring shock absorber; 7 - stock; 8 - balance wheel; 9 - toothed sector of the auxiliary drive; 10 - worm; 11 - Shturtros; 12 - guide rollers; 13 - buffer springs; 14 - sector; 15 - piston-plunger; 16 - hydraulic cylinder; 17 - pump; 18 - safety valve; 19 - case; 20 - sector-shaped camera; 21 - a lionfish with blades; 22 - glass with longitudinal grooves; 23 - annular piston; 24 - glass with screw grooves; 25 - cover; 26 - square head; 27 - working cavity of the cylinder; 28 - keyway; 29 - the running end of the lapp; 30 - movable block; 31 - fixed block
On many small and medium-sized vessels, sector-toothed steering gear (Fig. 2, a). When the electric motor is running, the toothed sector, loosely mounted on the stock, transfers the force to the longitudinal tiller rigidly fixed to the stock through spring shock absorbers. Shock absorbers soften shocks that occur when the electric motor is started or when waves hit the rudder. The worm gearbox provides self-locking of the drive. An additional toothed sector rigidly mounted on the stock is provided as an auxiliary drive. The sector is operated by a manual steering column through roller wiring and an additional worm gear.
On small production vessels, they use sector rod drive (Fig. 2, b). The force of the steering gear is transmitted through the steering rope to the sector rigidly mounted on the stock. The shturtrope is made of a steel cable with a section of the Gall chain in the middle part or entirely from the chain. Both branches of the steering rope go from the sector through the guide rollers to the sprocket or the steering wheel drum. In the latter version, when the drum rotates, one branch of the steel cable is selected, and the other is vented. The slack of the shturtros is selected with screw lanyards, shocks are softened by buffer springs.
The most widespread in the fishing fleet are hydraulic steering drives: plunger, blade, screw.
Hydraulic Plunger Drive Pump (Fig. 2, c) when the electric motor is running, it pumps the working fluid from one hydraulic cylinder to another, which leads to the movement of the plunger tiller pivotally connected to the tiller rigidly mounted on the stock and the stock to turn. When a wave hits the rudder blade, the pressure in one of the hydraulic cylinders increases and the safety valve bypasses part of the working fluid into the other cylinder, damping the shock. Special device provides automatic return of the rudder blade to its original position after pressure drop in the hydraulic cylinder. Many ships have dual plunger hydraulic steering drives. Parallel working two pairs of hydraulic cylinders and two pumps provide the possibility of shifting the rudder by any pair of hydraulic pumps. In this case, the boat may not have an auxiliary rudder drive.
The tiller of the hydraulic paddle steering drive, made in the form of an impeller with blades, is located in a closed cylindrical body, divided by fixed partitions into several working chambers filled with a working fluid (two chambers in Fig. 2, d). The gaps between the blades and the body, fixed partitions and the stock are sealed. When pumping the working fluid from one chamber cavity to another, a pressure difference is created, which causes the tiller and stock to rotate.
Screw hydraulic drive(Fig. 2, e) consists of a fixed body, the middle part of which acts as a cylinder. An annular piston is placed in the cylinder: its inner surface has screw grooves in the upper part, and longitudinal grooves in the lower part. A glass with longitudinal grooves is rigidly put on the head of the stock. Another glass with helical grooves is fixedly attached to the housing cover. When fluid is supplied to the working cavity of the cylinder, the piston receives a translational motion, moving along the helical grooves of the stationary glass, turns and through the glass with longitudinal grooves turns the stock.
In addition to those listed on fishing vessels, steering drives of other types are occasionally found, mainly as auxiliary or emergency ones. In exceptional emergency situations two rumpeltals can be applied.
The hoist is two blocks with a rope stretched between them (lopar, Fig. 2, e). The end of the lapp, for which traction is produced, is called the running end, and the fixed end is called the root end. The block consists of a body, inside of which there are one or more pulleys rotating on an axis (dowel). Waistlines can be of different designs. The simplest type of hoist is a proudly fixed single pulley block that allows you to change the direction of the pull (guide block). Pride does not gain in effort.
Another type - they grabbed two and single-pulley blocks, and the root end of the lopar is fixed on a single-pulley block.
Hoists, consisting of blocks with the same number of pulleys, are called ganes, and from blocks with more than three pulleys in each block, they are called gynes. When the hoist is in operation, a force equal to the force applied to the running end occurs in all branches of the lopar, therefore total efforttransmitted by the hoist is equal to the sum of the forces in the branches of the movable block, including the force in the running end, if it comes off this block. One block of the hoist is fastened with a bracket to the hole provided in the frame, the other to the sector or tiller. The running lopars are led through a system of guide blocks to the nearest winch. The principle of operation is the same as that of rotor drive.
Remote control of the steering gear from the wheelhouse is provided by tele-dynamic transmissions called tele-steering transmissions or steering tele-motors. On modern fishing vessels, hydraulic and electric steering television transmissions have been used. They are often duplicated or combined into electro-hydraulic ones.
The electric TV transmission consists of a special controller located in the steering box and connected by an electrical system to the steering gear starting device. The controller is operated using a handwheel, handle or button.
The hydraulic transmission consists of a handwheel driven hand pump and a tubing system connecting the pump to the steering gear starting device. The working fluid of the system is an antifreeze mixture of water with glycerin or mineral oil.
The control of the main and auxiliary steering drives (powered by an energy source) is independent and is carried out from the navigation bridge, as well as from the tiller compartment. The transition time from the main to the auxiliary drive should not exceed 2 minutes. If there are control posts for the main steering drive in the wheelhouse and field cabin, the failure of the control system from one post should not impede control from another post. The time of shifting a fully submerged rudder or a rotary nozzle by the main drive (at the highest forward speed) from 35 ° of one side to 30 ° of the other should not exceed 28 s, by the auxiliary drive (at a speed equal to half the maximum forward speed or 7 knots, depending on whichever value is greater) from 15 ° of one side to 15 ° of the other - 60 s, emergency (at a speed of at least 4 knots) is not limited.
The angle, rudder shifts are determined by the axiometer installed at each control post. In addition, on the sector of the steering drive or other parts rigidly connected to the stock, a scale is applied to determine the actual position of the rudder. Automatic consistency between speed, direction of rotation and helm position and speed, side and rudder angle is provided by a servo motor.
The rudder shift limiters are made in the form of protrusions on the rudder and sternpost, which abut against each other at the maximum allowable rudder shift angle, or in the form of knits welded to the deck, against which the rudder drive sector abuts. All mechanical steering drives additionally have limit switches that turn off mechanisms before the steering wheel reaches the steering limiter. In a hydraulic plunger drive, the bottom of the drive hydraulic cylinders serve as a steering limiter.
The rudder brake (stopper) is designed to hold the rudder during emergency repairs or when changing from one drive to another. The most commonly used tape stopper clamping directly to the rudder stock. Sector drives have block stops, in which the brake shoe is pressed against a special arc on the sector. In hydraulic drives, the role of a stopper is performed by valves that block the access of the working fluid to the drives.
Keeping the ship on a given course under favorable weather conditions without the participation of the helmsman is provided by the autopilot, the principle of operation of which is based on the use of a gyrocompass or a magnetic compass. Ordinary controls are linked to the autopilot. When the boat is on the set course, the rudder is set to zero on the axiometer and the autopilot is turned on. If, under the influence of wind, waves or current the vessel deviates from the set course, the electric motor of the system, having received a pulse from the compass sensor, ensures the return of the vessel to the set course. When changing course or maneuvering, the autopilot is disengaged and returned to normal steering.
Using the steering device, you can change the direction of the boat or keep it on a given course. In the latter case, the task of the steering device is to counteract external forces, such as wind or current, that can cause the vessel to deviate from the desired course. Steering devices have been known since the inception of the first floating facilities. In ancient times, steering gears were large swing oars mounted on the stern, on one side, or on both sides of the vessel. During the Middle Ages, they began to be replaced by an articulated rudder, which was placed on the sternpost in the center plane of the ship. In this form, it has survived to this day.
Types of rudders
a - an ordinary steering wheel; b - balance wheel; c - semi-balanced steering wheel (semi-suspended); d - balance wheel (suspended); e - semi-balanced steering wheel (semi-suspended); f - active steering wheel; g - bow thruster (counter-rotating propellers); h - bow thruster (reversible propeller)
Depending on the principle of operation, a distinction is made between passive and active steering wheels. Passive steering devices are called steering devices that allow the ship to turn only during the course, more precisely, during the movement of water relative to the ship's hull. In contrast, the active rudder allows the boat to turn, whether it is moving or standing. The passive steering device consists of a steering column with a transmission, a steering gear and a rudder blade. Older designs used single-layer rudders. Currently, profile shaped rudders are mainly used (Fig. A). If you do not know how much it costs to repair a steering gear, study our price lists now.The pen of such a steering wheel consists of two convex outer shells with inside ribs and vertical diaphragms for increased rigidity. In general, the rudder feather design is all-welded and hollow inside. Exist different ways handlebar mountings. It can be hinged to the stern post (fig. A) or installed in the thrust bearing (fig. B). Other fastening methods are shown in Figures c, f.
The position of the rudder blade relative to the axis of rotation of the stock is distinguished:
Ordinary rudder - the plane of the rudder is located behind the axis of rotation;
Semi-balanced rudder - only most of the rudder blade is located behind the axis of rotation, due to which a reduced torque occurs when the rudder is shifted;
Balancing rudder - the rudder blade is located on both sides of the pivot axis so that no significant moments arise when the rudder is shifted.
Types of rudders
f - active steering wheel; g - bow thruster (counter-rotating propellers); h - bow thruster (reversible propeller)
An example of a steering gear with active rudder is shown in figure f. An electric motor is built into the rudder blade, which drives the propeller in rotation, which is placed in the nozzle to protect it from damage. Due to the rotation of the rudder blade together with the propeller at a certain angle, a transverse stop arises, which determines the rotation of the vessel. The active rudder also performs its functions when the ship is at anchor. This rudder is used on special vessels such as floating fish factories, whalers, repair and support vessels. In addition, the active steering wheel can be used as an emergency engine. The rudders are usually placed at the stern of the vessel. Only in special cases (for example, on river ferries or on canal vessels), bow rudders are also used. To increase the maneuverability of the vessel, thrusters are often used, belonging to the group of active rudders without a feather. Bow or stern thrusters are installed across the vessel in the tunnel. This tunnel also contains two propellers or an axial pump rotor. As one propeller rotates, water flows through the tunnel. Due to this, a stop appears, and the hull of the ship moves. In thrusters, propellers with variable pitch are increasingly used instead of two propellers or one rotor of an axial-flow pump. As already indicated, in order to steering gear acted, the feather of the passive rudder must stand at a certain angle. The rudder stock is driven by a steering gear mounted below deck at the stern of the vessel. There are steam, electric and hydraulic steering gears.
Electric steering gear
a - the location of the steering device
1 - steering gear; 2 - steering pin; 3 - semi-balanced steering wheel; 4 - rudder stock
b - sector steering gear with electric drive
1 - hand wheel drive (emergency drive); 2 - tiller; 3 - reducer; 4 - steering sector; 5 - engine; 6 - spring; 7 - rudder stock; 8 - shaped shaped steering wheel; 9 - segment of the worm wheel and brake; 10 - worm
In fig. b shows the obsolete design of the electric steering gear. The electric motor drives the steering sector through the gearbox, which is attached to the rudder stock. Two springs, receiving the impact of waves on the rudder blade, connect the rudder sector to the tiller; the latter, in turn, is connected through a parallel key to the rudder stock, on which the profile rudder is placed. If you need to turn the rudder, you need to start the motor at a certain speed. In the event of a malfunction of the electric steering gear, the steering wheel is set in motion using a manually operated mechanism consisting of a steering column and a steering wheel. By turning the steering wheel, the worm wheel and the emergency drive segment interacting with it, mounted directly on the rudder stock, are set in motion. The emergency steering rack is usually mounted aft on upper deck ship. On modern ships, as a rule, hydraulic steering gears are used. When the steering wheel rotates on the bridge, the telemotor sensor is triggered. Oil flowing under pressure in the pipeline causes the telemotor receiver to move, due to which the steering pump is set in motion in the appropriate direction.
Hydraulic steering gear
a - a diagram of a hydraulic drive of a steering device of the Atlas type with telemotors; b - the piston of the hydraulic steering gear
1 - connection to on-board network; 2 - cable connections; 3 - spare canister; 4 - steering pump; 5 - steering column with telemotor sensor; 6 - indicator device; 7 - receiver of telemotors; 8 - engine; 9 - hydraulic steering gear; 10 - rudder stock; 11 - steering wheel position indicator sensor
