Sensors for coordinate protection of an overhead crane. Locking devices

Security device - technical device electronic type, installed on a crane and designed to disable mechanisms in emergency situations or their warnings.

Security device - a technical device of a mechanical, electrical, hydraulic or other (non-electronic) type, installed on a crane and designed to turn off mechanisms in emergency situations or to warn the crane operator (driver) about an emergency situation.

Depending on the type of crane (bridge, tower, self-propelled jib, etc.) and the type of drive (electric, mechanical), the crane is equipped with a number of instruments and devices that ensure it safe operation. Such devices include:

a) limit switches designed to automatically stop the mechanisms of electrically driven cranes. On cranes with mechanically driven mechanisms, limit switches are not used. Requirements for equipping lifting machines with limit switches are set out in the Crane Rules;

b) blocking contacts used for electrically blocking the entrance door to the crane cabin from the landing platform, the hatch cover for the entrance to the bridge deck and other places;

C) lifting capacity limiters, designed to prevent crane accidents associated with lifting cargo weighing more than their (taking into account the hook reach) lifting capacity. Installation of the device is mandatory on jib, tower and portal cranes. Overhead cranes must be equipped with a load limiter in cases where their overload cannot be excluded due to production technology. Requirements for installing the device are contained in the Crane Regulations;

d) skew limiters, designed to prevent dangerous skew of metal structures of gantry cranes and bridge loaders due to one of the supports being ahead of the other when the crane is moving. The need to install the device is determined by calculation during design;

e) a load capacity indicator installed on jib-type cranes, in which the load capacity changes with changes in the boom radius. The device automatically shows what the crane's lifting capacity is at the set reach, which helps prevent the crane from overloading;

e) tilt angle indicator (inclinometer) - for correct installation jib cranes, except those operating on rail tracks;

g) anemometer. Tower, portal and cable cranes should be equipped with such a device to automatically sound a sound signal at wind speeds dangerous for work;

h) anti-theft devices used on cranes operating on surface rail tracks to prevent them from being stolen by the wind. The requirements for these devices are set out in the Crane Regulations;

i) automatic dangerous voltage alarm (ASON), signaling the dangerous approach of the crane boom to live wires of the power line. The device is equipped with jib self-propelled cranes (with the exception of railway cranes);

j) phase loss relay - the device is designed to protect against falling loads and booms on electric cranes in the event of a break in any of the three supply phases electrical network, by blocking the operation of the corresponding mechanisms of the lifting machine,

l) supporting parts supplied with overhead cranes, mobile cantilever cranes, tower cranes, portal cranes, cable cranes, as well as cargo trolleys (except for electric hoists) to reduce dynamic loads on the metal structure in the event of breakdown of the axles of the running wheels;

m) stops installed at the ends of the rail track to prevent lifting machines from derailing from them, as well as on jib cranes with variable boom reach to prevent it from tipping over;

m) an audible signaling device used on cranes controlled from the cabin or from a remote control (with remote control). On taps controlled from the floor, a signaling device is not installed.

Instruments and devices that ensure safe operation of a tower crane

Rice. 3.7. Instruments and devices that ensure safe operation of a tower crane.

1 – anemometer; 2 - load limiter force sensor; 3 – hook lift limiter weight; 4 – hook lift height limiter switch; 5 – boom lift angle sensor; 6 – sound signal; 7 – limit switch of the turret rotation limiter; 8 – limiter alarm panel; 9 – relay block of the load limiter; 10 – limit switch of the crane movement limiter; 11 – inventory track ruler; 12 – dead-end stop.

Safety devices and devices

Parameter name	Meaning
Article topic:	Safety devices and devices
Rubric (thematic category)	Sport

Safety instruments and devices for overhead cranes are designed to prevent overloading of the crane and its mechanisms, and derailment from the crane runway as a result of random factors, inattention and lack of efficiency of the driver; shutting down the crane mechanisms in emergency situations, as well as to protect operating personnel from injury electric shock, falls from a height, etc.

Bridge cranes use two types of safety devices: limiters and alarms.

Limiters are the main safety devices that automatically turn off a mechanism or group of crane mechanisms when a dangerous load occurs or the conditions of safe operation are violated. There are limiters for the load capacity, the height of the load, the path of movement of the cargo trolley and the bridge, and the skewing of the bridge (in long-span overhead cranes). The contacts of the limit switches are included in the crane control circuit. Resuming operation of a disabled mechanism is only possible to return the working element (load, trolley, bridge) to a safe position. For example, after the load lifting mechanism has been disabled as a result of an attempt to lift a load that is 25% greater than the crane's rated capacity, the mechanism must be engaged only to lower the load. If the load lifting height limiter is triggered, when the distance between the top of the hook suspension and the bottom of the load trolley becomes 200 mm, the load lifting mechanism can also be turned on only to lower the load.

In order to prevent the bridge or cargo trolley from leaving the rail track, end stops are installed at the ends to absorb loads when stopping. To soften a possible impact, the bridge and cargo trolley are equipped with buffers with shock absorbers.

Overhead crane alarms are audible alarm devices designed to provide warnings. service personnel about the start of any operation.

Control questions on chapter 4˸

1. Explain the areas of application of overhead cranes.

2. What is the main parameter of an overhead crane?

3. List the main parameters of overhead cranes.

4. List the main mechanisms of overhead cranes.

5. How are the designs of overhead cranes different?

6. List the safety devices and devices for overhead cranes.

7. Explain the principle of operation of the load limiter of an overhead crane.

TOWER CRANES

Safety devices and devices - concept and types. Classification and features of the category "Safety devices and devices" 2015, 2017-2018.

1.4. Instruments and safety devices for gantry cranes and bridge loaders

Instruments and safety devices for gantry cranes and bridge loaders, requirements for their installation must comply with the Rules for the Design and Safe Operation of Cranes, state standards and other regulatory documents.

In accordance with the Rules, gantry cranes and bridge loaders must be equipped with automatically activated working movement limiters: limiters for the upper and lower positions of load-handling elements, limiters for the movement of cranes and crane trolleys. To limit the upper and lower positions of the load suspension, limiters of lever and spindle types, similar to the structures installed on overhead cranes, are widely used. Lower position limiters are usually installed when it is necessary to lower the load below the level of the head of the crane rails.

To limit the movement of cranes and material handlers, as well as crane trolleys, dead-end stops are installed at the end of crane tracks and trolley rails. To prevent collisions with dead-end stops in propulsion modes, provision is made for proactive shutdown of the motors of the travel mechanisms when the crane approaches the stops using limit switches and slats installed at a distance equal to the braking distance of the crane. To absorb energy when stopping, cranes, material handlers and their trolleys are equipped with buffer devices. The limit switches of the movement mechanisms of cranes and loaders are installed on the lower parts of the supports, and the limit switches of cargo trolleys are installed at the end of the sub-trolley track, which is due to the convenience and ease of installation of supply communications.

Gantry cranes and bridge loaders must be equipped with load limiters (for each cargo winch), if overloading is possible under the conditions of the production technology. Load limiters for overhead cranes should not allow overload of more than 25%.

According to the method of fixing the actual loading parameters, load limiters can be weight, spring, torsion, lever, eccentric, electromechanical using strain gauges and electronic amplifiers.

In lever load limiters (Fig. 1.34), the force of the weight of the load G is transmitted to the double-arm lever 1 with the selected design ratio of the arms. On the other hand, the elastic force of spring 2 acts on the lever (Fig. 1.34, a). A larger arm ratio requires less spring force. When you try to lift a load beyond the permissible limit, the balance of the lever is disturbed, the spring is deformed and the lever acts on the actuator, for example, limit switch 3 (Fig. 1.34, a).

Rice. 1.34. Lever type load limiter diagram

In most cases, the transmission of force to the load limiter is carried out through a stationary equalizing block 4 of the pulley (Fig. 1.34, b), installed on the smaller arm of the lever, balanced by the force F of the spring. With this lever loading scheme, the gear ratio of the limiter lever system increases:

In the practice of crane construction, eccentric load limiters (Fig. 1.35) have become prevalent (Fig. 1.35), in which the equalizing block is installed eccentrically on the axis and, when lifting the load, overcoming the moment created by the weight 2, it rotates together with the lever 3, which acts on the limit switch 7, and in If the load limit value is exceeded, the load lifting mechanism is de-energized.

Rice. 1.35. Eccentric load limiter with load balancing

When the load is lifted to the nominal value, the resultant moment R (see Fig. 1.35) from the forces in the ropes S at the eccentricity of the e-axis is balanced by the force of the weight of the weight G on the arm L of the lever (from the axis to the center of gravity of the weight):

R * e = G * L

When the force in the rope increases beyond the norm, the balance is disturbed, the lever rotates until it acts on the limit switch and turns off the lifting mechanism.

A spring can be used as a balancing element instead of a weight. In such load limiters (Fig. 1.36), the force in ropes 7 is transmitted eccentrically installed block 5, which, when overloaded, causes the lever 4 to rotate relative to axis A, which, in turn, overcoming the resistance of the balancing spring 2, acts on the pressure bar 1, which, in turn, acts on the limit switch 3. When the force in the rope increases beyond The lifting mechanism is switched off according to the norm.

The limiter is equipped with an adjusting screw 6 for adjusting the accuracy of operation.

Rice. 1.37. Torsion bar type load limiter with spring balancing

Torsion bar type load limiters work on the same principle (Fig. 1.37), with the only difference that the balancing of lever 1 in them is ensured by the force of torsional elasticity of shaft 2. The forces in the cargo ropes are transferred to block 3, connected by rods to lever 7, acting on the switch .

All considered designs of load limiters have a common drawback - they require the installation of springs and other elements of significant dimensions and mass, since they are installed on blocks of the lifting mechanism and are triggered by large forces in the cargo ropes of the lifting mechanisms.

In this regard, load lifting limiters that use force sensors are preferable: limiters OGP-1, ONK-Yu, OGK-1, etc. In sensors of this type, the force in the ropes is transmitted to a steel ring, the deformation of which is transmitted to the rheostat rheochord, which changes the resistance in limiter circuits. If the load capacity is exceeded beyond the permissible limit, the drive of the load lifting mechanism is switched off. Forces are transmitted to the limit sensors from equalizing or load blocks installed on eccentric axles.

In terms of size and compactness, the preferred scheme is in which the force sensor is installed on a load drum, for which one of the supports is made hinged and can rotate when the shaft bends, acting on the force sensor. Load limiters of this type are used in lifting mechanisms with a symmetrical load on the drum supports, that is, with double-threaded drums.

On behalf of the Office for Boiler Inspection and Supervision of Lifting Facilities of the Gosgortekhnadzor of Russia, the All-Russian Scientific Research and Design and Technological Institute of Lifting and Transport Mechanical Engineering (VNIIPTMash) has developed a pilot batch of improved load limiters of the PS-80 series for gantry cranes: PS-80B 100U1 with a lifting capacity of up to Yut, PS-80B 200UG with a lifting capacity of up to 20 tons and PS-80B 300U1 with a lifting capacity of up to 30 tons. Such limiters consist of a strain gauge force sensor DST, which records the magnitude of the load on the crane, and an electronic logic unit that compares the current load with a given threshold of the limiter, forming control signals to disable the lifting mechanism and activate the audible alarm when the load exceeds the limit threshold. Sensors of the DST-K modification are designed for installation under the hinged supports of cargo drums; Under load, the sensor deforms and a signal proportional to the load is generated. DST-B sensors are designed for installation in equalizing blocks of load lifting mechanisms; sensors type DST-S - in hook hangers

cargo pulleys.

The installation diagram for the PS-80 limiter is shown in Fig. 1.38.

The strain gauge force sensor 1, structurally consisting of a thick-walled pipe with strain gauge sensors and an amplifying chip installed inside, is mounted in a special hinged support 3, on which the bearing support 2 of the equalizing block of the pulley system of the lifting mechanism is installed.

Rice. 1.38. Installation diagram of load limiter PS-80 Thus, the DST sensor, constantly sensing the support force from the lifted load, generates a corresponding signal, which is amplified and transmitted through a shielded cable 4 to the driver’s cabin 5. The relay setting unit 6 and the logic unit 7 installed there provide a comparison of the current load with a given limit threshold and generate the corresponding control signals. When the load increases by lifting body

exceeding the limit threshold, the sound signal is turned on and the lifting mechanism is turned off. IN Much attention is paid to the problem of identifying the actual loading of cranes by taking into account their operating hours. Thus, Sila Plus LLC and the VPIIPTMash Institute have developed a complex system “Sirena” for monitoring the loading and residual life of bridge and gantry cranes. Using the system allows you to determine the initial and actual state of the load-bearing metal structures of the crane, and during operation to monitor the decrease in its residual life. Control of the crane's loading and reduction of its residual life is carried out using load limiter sensors and a unit for collecting, processing and storing information. This information is stored for three years and is updated every time the tap is turned on. Based on the information received, the actual loading mode, the class of use of the crane and the current value of the residual life are calculated.

Gantry cranes and bridge loaders usually operate outdoors: they have significant windward areas and are exposed to wind loads. At large values wind pressure brakes do not provide reliable retention of the crane from being stolen by the wind, therefore cranes must be equipped with anti-theft grips with manual

or mechanical drive.

The grippers hold the cranes by means of frictional forces between the side surfaces of the rail heads and the jaws of the grippers. In an anti-theft gripping device with a manual drive (Fig. 1.39), to create an anti-theft friction force, the pressing force on the rail 1 of the jaws 2 is provided by screw device 3 with hand tightening. Anti-theft gripping devices are installed in the lower part of the metal structure of crane supports 4. The disadvantage of hand grippers is

long time
their closure, which is unacceptable during an emergency storm warning, as well as the impossibility of automating the closure process.

Rice. 1.39. Rail anti-theft grip with manual drive

The gripping levers 1 in the upper part are hingedly connected to the rollers 2, placed in the inclined grooves of the slider 3. When the slider moves under the influence of a screw pair 4, 5 from the drive 6 and the electric motor 7, the gripping levers, connected in the lower part by a coupler 9, rotate, clamping the rail heads , thereby providing anti-theft friction force. To center the grip relative to the rails, side rollers 8 are provided.

Gantry assembly cranes, cranes for hydroelectric power plants, and bridge loaders are usually equipped with anti-theft grips with falling (spacer) wedges (Fig. 1.41).

The wedge 1 is lifted using a hydraulic cylinder 2 or a rope winch.

The force of pressing the levers on the rail heads is provided by the force of the weight of the wedge 1 acting on the

when lowered onto rollers 3 installed in the upper part of the gripping arms 4. After removing the force of pressing the wedge on the levers, the latter return to their original position under the action of the forces of the springs 5. Anti-theft grips of this type are installed on the trolley to ensure that the jaws of the levers constantly hit the side surfaces of the rails because they bend under load.

To dampen the energy of movement of cranes and crane trolleys, dead-end stops are installed at the end of the rail tracks. To reduce shock and dynamic loads during collisions, they are equipped with buffer devices, which by design can be rubber, spring, hydraulic and friction (Fig. 1.42).

Rice. 1.42. Buffer devices: a - rubber; b - spring; c - hydraulic; g - friction

This drawback is eliminated in hydraulic buffers (Fig. 1.42, c), the impact energy in which is absorbed by forcing the liquid through the annular gap 1 between the bottoms of the piston 2 and the rod 3. The piston is filled with working fluid and is installed in the housing 4. Impact when hitting the stop is perceived by the tip 5 and the accelerator spring 6, which transmits pressure to the piston, which, when moving relative to the body, opens an annular hole in the center of the piston through which the working fluid flows. Rod 3 has a variable cross-section, which allows you to regulate the speed of fluid flow and obtain the necessary law of resistance to the movement of the piston, and hence energy absorption.

The return stroke of the piston is ensured by a return spring 7. Hydraulic buffers are more complex in design and require high technology in their manufacture and maintenance.

Friction ball buffers are simpler in design (Fig. 1.42, d), in which when the buffer rod 2, which takes up the load, moves, the balls 5 fall into the conical cavity created by the internal insert 4 and the rod, and due to the friction forces between the balls, as well as Between the body 1, conical surfaces and balls, the kinetic energy of the moving masses of the crane or loader is absorbed. The return stroke of the cones and balls is carried out by a return spring 3. Such buffers are small in size and have almost no recoil; they can be used to absorb significant movement energies of cranes and material handlers.

Gantry cranes and bridge loaders, due to their design features, are subject to such a phenomenon as distortions, i.e., running or lagging behind one of the sides of the crane when moving. Distortions of cranes as an undesirable phenomenon, causing increased loads on metal structures and mechanisms, are due to a number of reasons: deviation from the design dimensions of elements of mechanisms, metal structures and crane tracks, differences mechanical characteristics electric motors, external climatic factors, etc.

Therefore, gantry cranes and bridge loaders must be designed for the maximum possible distortion force that occurs during their movement, and, in justified cases, equipped with distortion limiters, which must operate automatically when an unacceptable amount of distortion occurs.

There is a wide variety of designs for skew limiters. One of the most common are the so-called rod skew limiters, triggered by tension-compression deformations of a special rod 1 mounted on a rigid crane support (Fig. 1.43).

Rice. 1.43. Installing a rod skewing limiter on a rigid support

When the support runs out, its stand and rod 1, attached to the support, are deformed.

To ensure the stability of the rod, limiters 2 are installed along its entire length. The deformation of the rod is transferred to the hinged lever 3 of a special profile, acting on the limit switches 4, which turn off the motors of the “run-out” support, turning them on only after the position of the supports has been aligned. A light alarm is installed on the crane control panel to warn the operator about the presence of misalignment.

Specialists from the Staro-Kramatorsk Machine-Building Plant proposed a skewing limiter installed on a flexible support. In a limiter of this design, the deformation of the support is transferred to a flexible rope 1 (Fig. 1.44), fixed to the span of the crane through a spring 2 and passing through guide rollers 3 on the bottom of the flexible supports.

When coasting, one support leg is subject to tension, the other to compression.

Deformations of the posts cause the rope to move along the rollers. The rope is attached to slats 4, which are engaged with a block of two wheels 5. A wheel of a larger diameter of the wheel block is in mesh with slats 6, fixed to a rod 7. The movement of rope 1 when the support runs out through slats 4, a block of wheels 5 and slats 6 is transmitted rod 7, which with its protrusions acts on limit switches 8, 9, 10, 11, which turn on light and sound alarms, turn off the motor drive of the run-out support when a misalignment occurs, and also start the engine after aligning the supports.

There are skew limiters that are triggered by torsional deformations of the supports when skew forces occur (Fig. 1.45).

An angular rod 2 is installed on the support 1, which, when a misalignment occurs, rotates along with the support. When turning the rod with its horizontal part, it acts on limit switch 3, which is connected to the motor circuit of the movement mechanism of the “run-out” support. When the support runs out, the motor of the movement mechanism is turned off, and when the supports are aligned, it turns on again.

In recent years, skew limiters with synchro-type sensors have been increasingly used on cranes and material handlers. Structurally it is done like this. A non-drive trolley is attached to each of the supports, from the running wheels of which the synchronous synchronizers rotate through the multiplier. The magnitude of the signal generated by the synchronizers depends on the path traversed by the trolleys when moving the crane or material handler. The selsyns are connected to a bridge circuit and, with uniform movement of both supports, the diagonals of the measuring bridge are balanced. When one of the supports runs out, the balancing of the bridge is disrupted and the generated signal is sent to electrical diagram control the support movement motor and turn it off.

Lifting and transport vehicles continuous action

Continuous machines are machines that have a continuous working cycle in which there is no return idling movement. Mainly various systems conveyors.

Conveyors different types and conveyor systems are now very widely used in industry and, in addition to performing direct functions of transporting goods, they are included as component and into technological equipment. Conveyors and conveyor systems are easy to automate.

Currently used very a large number of various types of conveyors and conveyor systems, for example, belt, plate, overhead and others. According to their design, conveyors can be belt, pulsating, walking, pushing and others. Conveyors can be stationary or mobile, with a capacity ranging from a few kilograms to a thousand tons of cargo per hour.

Various types of elevators are used to move goods in a vertical plane.

Lifting and transport machines of periodic action

Lifting and transport vehicles, which are in service with the units of the Ministry of Emergency Situations, are intended primarily to perform emergency rescue operations during the liquidation of emergency situations(dismantling rubble, lifting and moving technological equipment, providing assistance to emergency vehicles, etc.).

In addition, material handling machines are widely used in service and economic activity- during installation and dismantling of units of repaired equipment, loading and unloading of material assets in warehouses and bases of the Ministry of Emergency Situations.

The fleet of lifting and transport machines is diverse:

Jacks (mechanical, hydraulic, pneumatic - with a lifting capacity from 0.5 to 60 tons);

Hoists (manual and electric - with a load capacity from 1 to 18.5 tons);

Winches (with manual and electric drives - 0.25-5 t);

Automotive loaders (forklifts, single-bucket loaders, front-end loaders - with a lifting capacity of 3-5 tons and a load lifting height of up to 6 m, and they provide a load moving speed of up to 20 km/h); loaders are equipped with replaceable working equipment: bucket, grader, tong gripper, crane boom;

I. Classification, general characteristics and designation of jib cranes. Rostechnadzor requirements for the operation of jib cranes. General device and the layout of jib cranes with flexible suspension. General structure and layout of jib cranes with rigid suspension. General structure and principle of operation of jib crane safety devices (30 minutes)

Cranes are lifting machines with three or more movements that move the load to any point in the serviced field. The serviced field may have a different contour depending on the type of crane. For example, rectangular - for overhead and gantry cranes, ring - for slewing tower cranes, sector - for support stationary slewing cranes and any - for cranes on pneumatic wheels and crawler tracks.

Cranes are the most common group of lifting machines, which according to the degree of mobility are divided into stationary, mobile and self-propelled, and according to the type of chassis - into railway, tracked and wheeled.

The design of the cranes depends on the purpose. For example, assembly and construction cranes must lift loads greater height, and the cranes of metallurgical shops are adapted for loading furnaces and equipped with special grips for ingots.

Therefore, it is customary to distinguish between taps general purpose and special (construction, metallurgical, port). The Ministry of Emergency Situations uses general purpose cranes.

Based on the type of load-handling devices, general-purpose cranes are divided into hook cranes - for piece cargo, grab cranes - for bulk cargo, and magnetic cranes - for magnetic materials.

By design, cranes are:

Stationary rotary;

Pavements;

Goats;

Tower;

Portal;

Boom mobile.

Jib pneumatic wheeled and crawler cranes are designed to supply building structures and materials for facilities under construction, as well as for the mechanization of loading and unloading operations in warehouses. In progress installation work Cranes are also used to support structures when they are secured at the installation site (for example, installation in a jig, secured by welding or struts).

General purpose jib self-propelled cranes belong to the class of lifting machines; They are divided into pneumatic wheels, tracked ones, on a special chassis (automotive type) and automobile ones.

Pneumatic wheeled and crawler cranes differ from each other only in the type of propulsion device (running device); otherwise they have a common classification characteristic.

According to the drive mechanisms, pneumatic wheeled and crawler cranes are divided into two groups:

with single motor drive– when all working mechanisms are driven by one or more motors operating on one shaft;

with multi-motor (individual) drive mechanisms - when each mechanism is driven by a separate engine.

A single-motor drive can be mechanical or combined, a multi-motor drive can be electric (diesel-electric), hydraulic or combined (with various types drive of individual mechanisms: hydraulic and mechanical, electrical and mechanical, electrical and hydraulic).

Depending on the lifting capacity, cranes are divided into three groups: light - with a lifting capacity of up to 10 T; medium - with a carrying capacity from 10 to 25 T and heavy - with a lifting capacity of 25 T and more.

When naming cranes in full, it is necessary to indicate all their classification characteristics, however, given that such a name would be very long, individual characteristics are omitted

For jib cranes manufactured by the Ministry of Construction and Dormash, indexing has been introduced (Fig.), consisting of two letters KS (self-propelled crane) and four numbers:

The first digit characterizes the size group (load capacity in accordance with the standard size series);

The second is the type of undercarriage: 1 - tracked, 2 - widened tracked, 3 - pneumatic, 4 - on a special chassis, 5 - automobile, 6 - tractor, 7 - on a trailer;

The third digit determines the design of the boom equipment;

The fourth is the serial number of the model.

Then again follow the letters that indicate the next modernization (A, B, C) and Climatic performance(northern - HL, tropical T, tropical humid - TV).

For example, KS 3361 A is a self-propelled crane, third size group (lifting capacity 10 tons), pneumatic, with rope suspension, the first model number, which had the first modernization.

Hydraulic truck cranes are widely used in emergency rescue units of the Ministry of Emergency Situations, as they have high efficiency (maximum transport speed up to 100 km/h), maneuverability and ease of control with high performance indicators (load capacity, lifting height, etc.).

Truck cranes consist of welded metal structures, mechanical and hydraulic units, mounted on a basic automobile chassis and combined into 3 main parts:

Fixed part of the crane;

Rotating part of the crane;

Boom equipment.

The fixed part of the crane includes:

Car chassis;

Frame with outriggers;

Additional transmission for driving hydraulic system pumps;

Suspension locking mechanisms;

Pneumatic equipment.

The rotary part of the crane consists of:

Rotating frame;

Rotation mechanism;

Operator cabins;

Counterweight;

Engine and crane control drives.

Boom equipment consists of:

Two-, three- or four-section telescopic boom;

Boom winches;

Cargo rope and hook suspension;

Boom lift hydraulic cylinder.

The telescopic boom is attached to the racks of the rotating frame using an axle, and the cargo rope is fixed to the winch drum.

Drive unit crane mechanisms- hydraulic from axial piston pumps driven by the base chassis engine through a power take-off and cardan transmission.

The cargo winch is driven by an adjustable axial piston motor, which provides a wide range of speed control for lifting and lowering the load.

The outriggers are equipped with hydraulically extendable telescopic support beams.

Modern cranes are equipped with a variety of systems that ensure the safety of the work performed. For example, microprocessor-based load limiters provide information on the display about the length and reach of the boom, the load level of the crane and the weight of the load that can be lifted at the set reach and length of the boom.

Safety devices and devices on cranes

Depending on the type of crane (overhead, tower, self-propelled jib, etc.) and the type of drive (electric, mechanical), the crane is equipped with a number of instruments and devices that ensure its safe operation.

Such devices include:

a) limit switches designed to automatically stop the mechanisms of electrically driven cranes. On cranes with mechanically driven mechanisms, limit switches are not used. Requirements for equipping lifting machines with limit switches are set out in the Crane Rules;

b) blocking contacts used for electrically blocking the entrance door to the crane cabin from the landing platform, the hatch cover for the entrance to the bridge deck and other places;

c) lifting capacity limiters, designed to prevent crane accidents associated with lifting cargo weighing more than their (taking into account the hook reach) lifting capacity. Installation of the device is mandatory on jib, tower and portal cranes. Overhead cranes must be equipped with a load limiter in cases where their overload cannot be excluded due to production technology. Requirements for installing the device are contained in the Crane Regulations;

d) skew limiters, designed to prevent dangerous skew of metal structures of gantry cranes and bridge loaders due to one of the supports being ahead of the other when the crane is moving. The need to install the device is determined by calculation during design;

e) a load capacity indicator installed on jib-type cranes, in which the load capacity changes with changes in the hook reach. The device automatically shows what the crane's lifting capacity is at the set reach, which helps prevent the crane from overloading;

f) an inclination angle indicator for the correct installation of jib cranes, except for those operating on rail tracks;

g) anemometer. Tower, portal and cable cranes should be equipped with such a device to automatically sound a sound signal at wind speeds dangerous for work;

h) anti-theft devices used on cranes operating on surface rail tracks to prevent them from being stolen by the wind. The requirements for these devices are set out in the Crane Regulations;

i) automatic dangerous voltage alarm (ASON), signaling the dangerous approach of the crane boom to live wires of the power line. The device is equipped with jib self-propelled cranes (with the exception of railway cranes);

j) supporting parts that are supplied to overhead cranes, mobile cantilever cranes, tower cranes, portal cranes, cable cranes, as well as cargo trolleys (except for electric hoists) to reduce dynamic loads on the metal structure in the event of breakdown of the axles of the running wheels; k) stops installed at the ends of the rail track to prevent lifting machines from leaving them, as well as on jib cranes with variable boom reach to prevent it from tipping over;

l) an audible signaling device used on cranes controlled from the cabin or from a remote control (with remote control). On taps controlled from the floor, a signaling device is not installed.

Depending on the type of crane (overhead, tower, self-propelled jib, etc.) and the type of drive (electric, mechanical), the crane is equipped with a number of instruments and devices that ensure its safe operation. Such devices include:
a) limit switches designed to automatically stop the mechanisms of electrically driven cranes. On cranes with mechanically driven mechanisms, limit switches are not used. Requirements for equipping lifting machines with limit switches are set out in the Crane Rules;
b) blocking contacts used for electrically blocking the entrance door to the crane cabin from the landing platform, the hatch cover for the entrance to the bridge deck and other places;
c) lifting capacity limiters, designed to prevent crane accidents associated with lifting cargo weighing more than their (taking into account the hook reach) lifting capacity. Installation of the device is mandatory on jib, tower and portal cranes. Overhead cranes must be equipped with a load limiter in cases where their overload cannot be excluded due to production technology. Requirements for installing the device are contained in the Crane Regulations;
d) skew limiters, designed to prevent dangerous skew of metal structures of gantry cranes and bridge loaders due to one of the supports being ahead of the other when the crane is moving. The need to install the device is determined by calculation during design;
e) a load capacity indicator installed on jib-type cranes, in which the load capacity changes with changes in the hook reach. The device automatically shows what the crane's lifting capacity is at the set reach, which helps prevent the crane from overloading;
f) an inclination angle indicator for the correct installation of jib cranes, except for those operating on rail tracks;
g) anemometer. Tower, portal and cable cranes should be equipped with such a device to automatically sound a sound signal at wind speeds dangerous for work;
h) anti-theft devices used on cranes operating on surface rail tracks to prevent them from being stolen by the wind. The requirements for these devices are set out in the Crane Regulations;
i) automatic dangerous voltage alarm (ASON), signaling the dangerous approach of the crane boom to live wires of the power line. The device is equipped with jib self-propelled cranes (with the exception of railway cranes);
j) supporting parts supplied with overhead cranes, mobile cantilever cranes, tower cranes, portal cranes, cable cranes, as well as cargo trolleys (except for electric hoists) to reduce dynamic loads on the metal structure in the event of failure of the axles of the running wheels;
k) stops installed at the ends of the rail track to prevent lifting machines from leaving them, as well as on jib cranes with variable boom reach to prevent it from tipping over;
l) an audible signaling device used on cranes controlled from the cabin or from a remote control (with remote control). On taps controlled from the floor, a signaling device is not installed.

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