Overhead bridge crane for STR

4 Design, calculation and technical operation of Crantal M overhead bridge crane

4.1 Principle of operation, arrangement and adjustment of equipment

4.1.1 Classification and characteristics of equipment under consideration

At motor transport enterprises, lifting and transportation equipment (TVET) is widely used. First of all, in the whole variety of TVET, the simplest means of mechanization and lifting and transportation machines are distinguished. The simplest means of mechanization traditionally include small lifting equipment. These are a variety of lifts, conventional manual trolleys, platform trolleys, hoists, winches, etc. Auxiliary means of mechanization of loading and unloading operations are widespread in production and, especially in the field of warehousing of all kinds of raw materials, goods and products. This is due to their relatively low cost, small size and ease of operation .

Lifting and transportation machines are divided into lifting machines, transporting machines and loading and unloading machines (various kinds of cranes - tower, goat, bridge double-beam and single-beam - crane beams). Lifting machines include devices used for the installation and repair of technical equipment, as well as the movement of cargo between floors, loading and unloading operations. Conveying machines are used to move loads at one level in a horizontal plane over short distances. This group of hoisting machines is characterized by the possibility of simultaneous lifting and transportation of cargo and is used, as a rule, in warehouse conditions. Loading and unloading machines are the largest TRP, they have the highest load capacity.

Loading and unloading machines are divided according to the principle of operation into continuous (cyclic) and intermittent (periodic) machines. Continuous machines move loads with constant flow. The most common type of continuous loading and unloading machines are conveyors. Intermittent loading and unloading machines move goods after a certain period of time. The algorithm of their operation includes the capture of the cargo, its movement to the place of laying, the return of the cargo and the idle passage after the next batch of cargo. Intermittent machines include transport machines equipped with appropriate equipment (including construction, installation and lifting cranes). Lifting cranes are stationary and mobile. Stationary cranes have their own support or are mounted taking into account the support on the bearing structures of other structures. Mobile cranes, depending on the type of mobile device, are divided into pneumatic, caterpillar, automobile, railway, etc. Both mobile and stationary cranes are of two types: rotary and non-rotary. The principle of operation of the rotary crane implies the possibility of horizontal movement of the load due to the rotation of the crane boom around the base axis, these are various tower cranes. Tower cranes, in turn, are divided into cranes with a lifting boom and cranes with a beam boom. Non-rotating cranes are divided into bridge and goat cranes. The peculiarity of the principle of operation of such cranes is that the load in the horizontal plane moves due to the movement of the freight trolley along the crane track. The span of the crane track (at bridge cranes - bridge) is attached to the edge beams perpendicular to it, it can consist of one or two beams. Depending on this, double-beam and single-beam bridge cranes (crane beams) are distinguished. Double-beam bridge cranes have a more rigid structure and therefore have a higher load capacity than single-beam cranes. Crane beams are more compact and simple than two-beam cranes, this is due to their wider distribution. All types of cranes can be equipped with simpler lifting mechanisms of various types: these are a variety of tales, grabbers, crossarms, etc.

Cranes are electrically and manually operated. These devices are designed to move and lift relatively small loads in a limited or open space. These cranes are a lifting mechanism in which the weights are transported by means of a manual or electric hoist. The tal consists of one fixed and one movable block wheel, with the help of which the cable fixed in these blocks performs direct lifting of the load. In the structure of the crane-beam there is also a driving beam along which the hoist carries out its movement.

The crane-beam greatly facilitates the work of personnel, performs a larger amount of work, can be additionally equipped with radio control, a smooth start-up device and other options. The crane itself does not lift anything - it serves only as a guiding base for the movement of the hoist, and the lifting capacity of the crane is usually limited by its lifting capacity. Crane-beams are divided into support and suspended, with manual or electric steel, made one-, two- and multi-span. Available with various lifting capacities: 1t, 2, 3.2t, 5 and 10t.

Support bridge cranes have running rails attached to upper crane beams resting against ceiling of room or canopy. The suspension crane of the beam is attached by its running wheels to the lower crane (I-beam) beams. In addition, these devices can be divided by the number of spans (single-span and multi-span). The spans of these bridge cranes can reach up to 15 meters at a single span and up to 100 meters at a crane with several spans.

A single-beam overhead crane (crane-beam) was widely used. It is a structure in which a driving beam with a telfer is fixed to running carriages moving along I-beam tracks attached to building trusses or floor beams. For suspended single-beam cranes, the lengths of the cantilevers are taken to be multiple 0.3 m within 0.3... 1.5 m, lifting height 6... 32 m, lifting speed 0,125 and 0,130 m/s, tali movement 0.33 and 0.40 m/s, crane movement 0.5 m/s. Crane length: single-span from 3.6 to 18 m, double-span - from 16.2 to 27 m. Operating mode group 1K... 3K. The use of suspended cranes makes it possible to transfer goods from one span to another span of the warehouse or on the console when delivering cargo from a covered warehouse or receiving into the warehouse. This is achieved by docking the load-bearing beams of two overhead cranes located in adjacent spans or by docking the crane load-bearing beam with the cantilever beam.

Manual overhead cranes, as a rule, are equipped with worm or gear manual cranes. Single-beam bridge cranes provide a decrease in metal consumption, especially with large spans (25... 30 m). Used with limited usage.

According to the general characteristics, the crane of the beam is divided into industrial general-purpose devices, the crane of the beam with increased fire safety (classes PI; P-II; PIIa; P-III), as well as explosion-proof (with zone classes B1a and IIBT4). These bridge cranes are capable of operating in the temperature range from 20 to + 40 ° C, and in special cases at 40 ° C. Cranes with manual control are moved by means of chain mechanical device. Electric cranes are controlled by a reduction gear or motor-reduction motor having from 2 to 4 drives. The control itself is carried out by a person from a special cabin or using a console device.

4.3 Installation, maintenance and repair of suspended bridge

Crantal M crane

Before installation of the crane, free the units and electrical equipment from the packaging material. Unpack the boxes carefully so as not to damage the equipment. First, the upper and then the side shields are removed. All units and electrical equipment shall be thoroughly cleaned of contamination and rust. Wash the mechanisms coated with anticorrosive composition with solvent, wipe with oil and wipe dry with rags.

Select a site sufficient for free and convenient crane operation in preparation for installation and during installation. It is most advisable to place the platform in the span between the columns. Moreover, the span is chosen where there are no horizontal ties between the construction farms.

Cranes with a span of up to 16.5 m are assembled at the manufacturer, with a span of more than 16.5 m on the installation site of the crane owner

When installing a crane with a span of more than 16.5 m on the site allocated for this by the crane owner, install parallel guides from the corresponding profile of the crane rail, having withstood the required span size with an accuracy of ± 5 mm, set end beams on them with wheels. Then act in the following order: install a span beam on the end beams; in accordance with the general view drawing of the crane, install braces and make control measurements of the bridge diagonals, the difference between the diagonals must be no more than 5 mm; attach the span beam to the end beam using bolts and nuts; weld braces to slashes on span and end beams (electrode E42A, GOST 946775). Welding shall be performed at air temperature not lower than 20 0С. At the end of welding, the seams and adjacent areas shall be cleaned of slag, splashes and metal spills with the help of a tooth and a hammer.

Quality control of welded joints shall be carried out by external inspection and measurements of joints. Welds are subjected to external inspection to detect external cracks, strains, external pores. At the same time, in welded joints are not allowed. Check of compliance of dimensions of joints specified in drawings shall be performed by measuring with measuring tool and templates. Measure the diagonals of the crane bridge in plan along the centers of the running wheels. The difference between diagonals must be not more than 5 mm.

Attach the crane movement mechanism. Perform electrical installation in accordance with the accompanying technical documentation attached to the crane certificate, as well as in accordance with the "Rules for the device of electrical installations of consumers." All electrical equipment of the crane must be grounded to ensure the safety of the maintenance personnel.

There are three main methods of mounting bridge cranes.

Installation method of crane beams using the main metal structures (trusses, columns) of the building frame.

The simplest and most rational method of mounting the crane is its lifting using the main metal structures of the building frame (from rafters). If the building trusses are not high enough under the roof, lifting is carried out from transverse mounting beams resting on two rafter trusses. These beams are installed at the appropriate height above the lower belts of the rafter trusses or in the attachment units of the trusses to the posts. When using rafter trusses to lift the crane, it should be checked whether they will withstand the forces arising during installation with a dynamic coefficient (from jerks and concussions) K = 1.12 (taking into account the weight of rigging). During this check it is necessary to take into account all the forces arising during installation, their actual directions, in particular, possible deviations of ropes from the normal position.

Stresses in rafter truss elements can be 10% higher than permissible stresses accepted when calculating trusses for main and temporary loads, but not exceed 0.9 of the yield strength of steel, unless the value of permissible stresses in trusses during installation is specified by special specifications.

If during installation there will obviously be no such loads as roof, snow, then they may not be included in the calculation. In addition to the strength of the rafters, it is necessary to check their stability under horizontal forces perpendicular to the plane of the trusses, and in case of insufficient stability, to introduce additional connections between the trusses.

Installation of beam crane by means of mounting masts.

In the absence of rafter trusses or their insufficient strength, the crane is installed using a mast. Location of mast braces, braces and other ropes shall not interfere with crane lifting operations provided by the installation scheme. Lifting cranes shall not undergo severe deformation during installation. Mounting winches must be equipped with brakes and reliably fixed against shear. Wire ropes used during installation must meet the current state standards and have or have a copy of the certificate of the rope manufacturer on their tests. Ropes shall be free from damage, fractures, loops and other defects.

Minimum rope strength reserves: for lifting and bracing ropes at ratio of block diameter to rope diameter D/d = 12 is K = 3; 5;

for K=Z sling. Attachment of mounting masts is performed by at least four braces in each tier. Stress in braces of not loaded mast must be not less than 1 MPa. If there are several tiers of braces, mast curvature shall be excluded.

When lifting a crane or its parts, as well as masts, the following conditions must be observed: the angle of inclination of the structure should be no more than 450; Wooden or metal linings shall be used on sharp edges of lifting loads to prevent rope fractures; distance between axes of blocks of tightened polyspast must be at least two diameters of the block; number of clamps for rope end attachment is determined by calculation of force in rope and must be at least three .

Braces can be attached to building structures if they have sufficient strength. It is recommended to attach the mounting masts to the columns of the building or crane beams. If it is impossible to use the structures of the building for this, anchor rings, etc. Slings from the anchors should be inclined to the horizon by no more than 45 °, with a tighter approach of the bracing to the anchor, the slings should bend on the lining (log), with large forces - on the package of logs.

Installation of crane-beams by self-propelled installation cranes.

The cranes shall be installed according to the Work Execution Project (PPRK) developed by the specialized organization. Installation should be carried out by a specialized organization licensed by Rostekhnadzor bodies. Install the crane in the following sequence:

perform installation of supports from sleepers according to (height (h) of sleepers is selected depending on the type of crane and telfer), at that replacement with random objects (reinforced concrete, metal, etc.) is prohibited; using a self-propelled crane, install the mounted crane on the supports, install the electric motor in the center of the bridge beam and firmly attach it from movement during lifting using wires with a diameter of 5-6 mm; to hold and maneuver the crane when lifting, tie hemp ropes on both sides; install the installed crane according to the sling diagram, lift the crane to a height of 200300 mm above the level of supports, check the correctness and reliability of the sling, lift to a height according to the design and install it on the crane tracks. After installation of the crane the cockpit is installed .

Crane lifting is carried out according to the documentation issued by the manufacturer or according to the work execution project developed by a specialized organization for this type of crane.

Install the crane on crane tracks, check presence of permissible gaps between crane dimensions and projecting parts of the building.

After installation of the crane, the cockpit is suspended (if the crane is controlled from the cockpit).

Before starting the crane, it is necessary to check: the adjoining of current collectors to trolleys (working parts of current collectors should be located symmetrically relative to the axis of trolleys); reliability of crane track grounding;

serviceability and correctness of button post connection.

After completion of electrical installation, check:

correct installation of electrical equipment, as per technical documentation (perform its adjustment, inspect the mechanisms, at that take into account that installation of the mechanical part of the crane must be completely completed and tested by manually scrolling the mechanisms);

correct assembly of the electrical circuit, serviceability of all electrical equipment and grounding (then perform routine operations on the equipment in accordance with its maintenance instructions);

fixed contacts of equipment and other parts (during inspection, identify broken, bent and oxidized parts);

reliability of contacts attachment (remove the observed defects, start adjustment from contacts, checking the value of their final pressing on fixed working contacts);

operation of thermal relays;

insulation state and correct connection of stator windings (at high wetness of windings it is impossible to use megohmmeter 1000V, since insulation breakdown is possible; if necessary, dry the engine);

absence of rotor touching the stator and fan touching the engine housing.

Check presence of lubricant in rotors, rolling bearings, couplings. Perform external inspection of threaded joints, crane steel structures, crane tracks, locking devices.

Start the crane in operation.

Circuits of limit switches, brake electromagnets and electric motors are checked at test start of mechanisms. Test start of mechanisms is performed without load. After checking compliance of engines rotation direction, operation of limit switches is checked. The limit switch is switched off by pressing the lever in the direction of movement of the mechanism. The motor is switched off. Otherwise, press the switch lever in the opposite direction. If the motor stops, the circuit is not properly assembled. In this case, the leading ends of the control should be swapped. If limit switches do not act to stop the mechanism, check the connection of wires according to the electrical circuit, find and eliminate the fault.

Before test start of the valve make sure that the mechanical part is serviceable, that wires, power circuits and control circuits are correctly connected. Check electrical equipment and alarm equipment.

The first start of the tali, crane and lifting mechanisms is carried out separately, very carefully and with short periods of switching on low speeds throughout the path, especially on the approach to the final switches. Along the entire path of the crane movement, the position of the main current collectors in relation to the main trolleys is checked. Presence of stops at the ends of crane tracks and coordinated action of buffer shock absorbers of cranes with stops or counter crane. In case of non-conformity of the above mentioned equipment, "Rules for arrangement and safe operation of lifting cranes," the crane cannot be run-in until the observed problems are resolved.

After installation and painting works the crane shall be subjected to technical inspection. During inspection, it is subjected to static and dynamic tests.

Static testing is carried out by a load 25% higher than the crane load capacity, and is aimed at checking its strength and the strength of its individual elements. At the same time:

a steel string with a weight is attached to the upper belt of the span beam in the middle of the bridge, which provides its tension;

to count the amount of deformation on the floor of the building (or polygon) strictly along the plumb in the vertical direction, the ruler is fixed so that the movements of the suspended truck can be counted on its scale;

the crane-beam is installed above the supports of crane tracks, and the tal - in the position corresponding to the greatest deflection, in the center of the span;

The hook grabs the load and lifts to a height of 200300 mm, followed by holding in this position for 10 minutes;

immediately after lifting the test load, a new position of the load suspended on the steel string, which controls the deflection of the metal structure under load, is recorded relative to the ruler, and the result is recorded in the test report;

after 10 minutes, the load is lowered, then the absence of residual deformation of the crane bridge is checked.

If there is residual deformation resulting from the load test of the crane, the single-beam crane is not allowed to operate until the causes of deformation and the possibility of further operation of the crane are identified.

The dynamic test of the crane shall be carried out with the positive result of the static test. The dynamic test is carried out by a load 10% higher than the crane load capacity in order to check the operation of the crane mechanisms and its brakes.

During the dynamic test, the cargo is repeatedly lifted and lowered, as well as checking the operation of the crane, electric steel and brakes movement mechanisms.

The results of the technical inspection of the crane are recorded in the crane passport by the person conducting the inspection, indicating the date of the next inspection.

The record in the certificate must confirm that the crane is mounted and installed in accordance with the requirements of the "Rules for the construction and safe operation of lifting cranes," this Operating Manual and has passed the test. A crane with control from the cockpit before commissioning is to be registered with Rostekhnadzor authorities.

Maintenance is a set of measures to maintain serviceability and operability of the crane. The instruction sets out the basic rules and procedure for maintenance of the crane in order to prevent accidents and ensure its effective and long-term operation.

Maintenance is carried out during overhaul periods, without detailed disassembly of components and mechanisms and is limited to inspection, lubrication, cleaning, adjustment, tightening of fasteners, monitoring of checked parameters.

Instructions on the period, procedure and scope of technical inspections and repairs shall be defined in planned preventive repairs and production instructions developed by crane owners in accordance with the requirements of the Rules for the Construction and Safe Operation of Lifting Cranes and the Unified System for Planned Preventive Repair and Rational Operation of Technological Equipment of Machine-Building Enterprises. Maintenance of component equipment is carried out in accordance with the operating manual of factory manufacturers producing this equipment.

Depending on the scope and labor intensity, the following types of maintenance are recommended:

daily maintenance (ES);

maintenance (T01);

maintenance (T02);

seasonal maintenance (CO).

Daily maintenance includes inspection of the crane before starting operation. The operator conducts the inspection. To do this, he is given a time of 25 to 45 minutes .

Having received the key mark, the operator must:

inspect crane tracks, state of dead end stops, limit switch lines, state of flexible current supply, trolleys, grounding;

make sure that brakes, safety devices, rope and hook suspension are serviceable;

read the entry in the watch log. Make a record of crane reception;

check serviceability and serviceability of electric steel, absence of damage of current-conducting cable;

check idle operation of all mechanisms, brake operation.

Maintenance (TO1) includes works performed without disassembly of crane units and carried out with a frequency of 60 days.

TO1 works include:

works performed in the RO;

check of condition of electric steel, places of attachment of crane components (adjoining of crane supports to span structure is performed by means of towers for people lifting);

check of dead end stops condition; antitheft devices; buffers and limit switches;

tighten nuts of attachment bolts of crane movement mechanisms;

inspection and check of brakes condition, check of absence of clearances, dents;

check of condition of crane steel structures by external inspection;

check of driving track condition (state of joints welding and I-beam shelf wear);

check of gear pair condition of drive wheels;

check and inspection of crane electrical equipment, namely:

motors: check motor attachment to the base, grounding reliability, absence of moisture in the input device and density of cable sealing, reliability of contact connections;

electrical devices and devices: check attachment of the devices to the base, reliability of their grounding, ease of rotation or travel of movable parts, availability, serviceability and absence of contacts, and simultaneous switching on of them in all poles;

Wiring: Check attachment of wiring to crane and flexible cable structures to electric steel current supply carriages, presence of circuit marking tags, absence of wire and cable strands insulation disturbance, presence of bushings at places of wiring outlet from pipes. When inspecting the cable of the flexible current supply to the electric steel, pay attention to the absence of insulation cracks in the stretched area and check the presence of a protective casing to prevent this.

Maintenance (TO2) includes works performed with partial disassembly of individual units and replacement of parts of the type (gaskets, nuts, washers, elements of electrical contacts, etc.). Maintenance of TO2 is performed after 240 days.

TO2 includes the following works:

work under the TO1 programme;

check of condition of steel structures of crane, welded joints, bolted connections of end beam with span structure and mechanisms of movement;

replacement of fasteners, gaskets, electrical contacts, etc.;

check of misalignment of drive shafts, engine and reduction gear box, restoration of alignment if necessary;

inspect the hinged connections of the brakes, supports with electric steel, check the corrosion wear of the elements of the metal structure, which should not exceed 15% of the initial thickness of the tested element;

check wear of running wheels along the thickness of the rib, wear along the rolling surface, presence of dents, dyes;

check the condition of bearings of wheels, engines, if necessary, replenish the lubricant;

check the condition of the load rope according to the norms given in Annex 10 "Rules for the construction and safe operation of lifting cranes. PB1038200".

perform maintenance of crane electrical equipment, namely:

electric motors: Clean contact connections and input box from dust; seal the cable at input to the input box; replenish lubricant in bearings;

electrical devices and devices: Grind burned and replace worn contacts, clean magnetic conductors of starters from dust and dirt, lubricate rotating parts of devices with grease; adjust the contact system of the contactor (pressing contacts, solution), grind the contact surfaces of the grounding devices, seal the cable in the lead-in devices and adjust the release of the limit switches and safety devices;

wiring: Restore weakly distinguishable circuit markings; attach the wiring to the crane structure, attach the cable on cable trolleys of the current conductor to the electric steel; replace lubrication in bearings of cable trolleys; restore the damaged insulation.

Trained and certified persons at least 18 years of age, who have the necessary knowledge and skills to fulfill their duties, are allowed to perform maintenance (repair) of the crane. Crane withdrawal and repair shall be carried out by the engineer and technician (ITR) responsible for maintenance of lifting machines in serviceable condition, in accordance with the repair schedule approved by the crane owner. When the crane stops for maintenance (repair), the introductory chopper is turned off and a warning poster with the inscription "Do not turn on - people work" is posted on it. It is forbidden to stop the crane for maintenance (repair) in places where any work is performed under it.

When stopping the crane above the aisles, the latter must be closed or fenced with mesh shields and put out warning posters.

It is strictly forbidden to leave the crane on crane tracks and walk along them without work permit.

For the repair of the crane, a work permit must be issued in the manner established by the owner. The work permit must indicate measures to create safe conditions for repair work. The date and time of the crane release for repair, as well as the name of the person responsible for its execution, must be indicated in the work permit and in the operator's watch log. Wrench wrenches, pullers, jacks, hammers, chalkers must be serviceable. Permission for crane operation after repair is issued by ITR, responsible for maintenance of lifting machines in serviceable condition, with record in the watch log.

Regardless of the intensity of operation, the crane shall be subjected to technical inspection in accordance with the requirements of the "Regulations."

Extraordinary full technical inspection of the crane shall be performed after:

installation caused by installation of the crane in a new place;

reconstruction;

repair of crane metal structures with replacement of design elements or units;

overhaul or replacement of hook or hook suspension (static test only).

Static tests of the crane shall be carried out in accordance with the requirements of the "Regulation." Static tests of the crane shall be carried out under a load 25% higher than its carrying capacity in order to check its strength.

Static tests shall be carried out as follows.

The crane is installed above the supports of crane tracks, and the waist in the middle of the span, in the position corresponding to the greatest deflection of the main beam. The control load shall be lifted to a height of 100200 mm and then held in this position for 10 minutes. Residual deformation is defined as the difference in position of the main beam at the point of measurement relative to the ground before and after lifting of the control load. The crane is considered to have passed the test if within 10 minutes the load did not drop to the ground, and there will be no cracks, residual deformations and other damage in the steel structure and mechanisms.

Dynamic tests of the crane shall be carried out in accordance with the "Regulation." Dynamic tests shall be carried out with load exceeding crane load capacity by 10%. During dynamic tests all crane mechanisms shall be checked.

During dynamic tests operation of crane movement mechanisms is checked when steel is located in the center of span and at both edges of span .

At that, at least three working cycles are performed for each steel position;

The load shall be lifted to the maximum possible height. The length of the crane travel path for each cycle must be equal to at least three times the crane base.

Inspection of components and safety devices shall be carried out in accordance with the instructions of the manufacturers of this equipment and devices.