EOTs

January 21, 2015Subhajyoti Ganguly1Presentation on Cranes & Chain PulleyBy Subhajyoti Ganguly

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A. EOT Cranes

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I. Parts of EOTBridge GirderSingleDoubleBlockHookRopesPulleyRope DrumSheaveEqualizing SheaveWheelSingle FlangeDouble FlangeBearingRailsBridgeRunway

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9. Safety EquipmentEddy Current BrakingRegenerative BrakingDynamic BrakingCounter Torque BrakingHolding BrakingControl BrakingBumper/BufferStop10. MotorsSquirrel Cage Induction MotorSlip Ring Induction Motor11. WiringFestoonConductor12. ControlPendantRemote

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Agirderis a supportbeam used inconstruction. Girders often have a I-Beam cross sectionfor strength, but may also have a box shape, Z shape and other forms. Girder is the term used to denote the main horizontal support of a structure which supports smaller beams. In traditionaltimber framinga girder is called agirt.Single Girder

Double Girder

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Crane BlockCrane Block is the assembly of hook, swivel, bearing, sheaves, pins and frame suspended by the hoisting ropes.

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Alifting hookis a device for grabbing and lifting loads by means of a device such as ahoistorcrane. A lifting hook is usually equipped with a safety latch to prevent the disengagement of the lifting wire rope sling, chain or rope to which the load is attached.C-Hook

Ramshorn-Hook

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Ropes

CASAR ALPHALIFTOLIVEIRA NR MAXIPACT

ROTATION RESISTANT

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Rope DrumRope Drum is the cylindrical member around which the ropes are wound for raising/lowering the load.

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Asheaveis a wheel or roller with agroovealong its edge for holding abelt, rope or cable. When hung between two supports and equipped with a belt, rope or cable, one or more sheaves make up apulley. The wordssheaveandpulleyare sometimes used interchangeably.

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Equalizing SheaveEqualizing Sheave is a device which compensates for unequal length or stretch of a hoist rope.

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Wheels of EOT is used to move either the girder/ bridge(LT) or the trolley(CT) as per requirement.

Double Flanged WheelsSingle Flanged Wheels

January 21, 2015Subhajyoti Ganguly13Abearingis amachine elementthat constrains relative motion and reduces friction betweenmoving partsto only the desired motion. The design of the bearing may, for example, provide for freelinearmovement of the moving part or for free rotation about fixed axis; or, it maypreventa motion by controlling thevectorsofnormal forcesthat bear on the moving parts. Many bearings alsofacilitatethe desired motion as much as possible, such as by minimizing friction. Bearings are classified broadly according to the type of operation, the motions allowed, or to the directions of the loads (forces) applied to the parts.

Thrust Bearing

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Rail-Bridge & Runway, Wiring-Festoon, Controller-Pendant

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Asquirrel-cage rotoris the rotating part (rotor) used in the most common form ofAC induction motor. It consists of a cylinder of steel with aluminum or copper conductors embedded in its surface. Anelectric motorwith a squirrel-cage rotor is termed asquirrel-cage motor.

600-700% of full load current is required as starting torque.

Aslip ringis anelectromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. A slip ring can be used in any electromechanical system that requires unrestrained, intermittent or continuous rotation while transmitting power and / or data. It can improve mechanical performance, simplify system operation and eliminate damage-prone wires dangling from movable joints.

200-250% of full load current is required as starting torque

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Brake

Brakes are used to halt the motion of EOTs.

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Buffers are energy absorbing devices used for reducing the impact when a moving crane or trolley reaches the end of its permitted travel or when two moving cranes or trolleys come into contact. The device may be attached to the bridge, trolley or runway stop.

January 21, 2015Subhajyoti Ganguly18II. Types Of EOT

UnderslungOverheadGantry

January 21, 2015Subhajyoti Ganguly19III. Some Important Terms on EOTsType of EOT selectionStandardsLoad CalculationNo. of fallsPower/Torque of motorNo. of strandsWire thicknessTravelLTCTMHApproachesEndSideHookRoof to TrussOverhead Clearance

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No. of fall = 1No. of fall = 2No. of fall = 3

January 21, 2015Subhajyoti Ganguly21ClassImpact FactorDuty FactorApplicationM11.061Hot cranes, cranes for power cranes station, cranes for repair shopsM21.121Cranes for warehouse, stocking yard, machine and assembly shop and cranes for general useM31.181Store room cranes, workshop cranesM41.251.05Grabbing over head traveling cranes, magnet cranesM51.321.06Cranes for steel worksM61.41.1Ladle cranesM71.41.12Stripper cranes, soaking pit cranesM81.51.2Charging cranesForging cranes

January 21, 2015Subhajyoti Ganguly22IS Standards for EOT selection & Work Procedure

IS:807 : Code of practice for design, manufacturing, erection and testing (structural portion) of cranes and hoists

IS:816 : Code of practice for use of metal arc welding for general construction in mild steel

IS:1030 : Specification for carbon steel castings for general engineering purposes

IS:1181 : Qualifying tests for metal arc welders engaged in welding structures other than pipes

IS:1570 : Schedules for wrought steels (part-II carbon steel)

IS:1823 : Code of practice for oxy-acetylene welding for structural work in mild steel

IS:2048 : Parallel keys and keyways

IS:2062 : Steel for general structural purposes

IS:2266 : Steel wire ropes for general engineering purposes

IS:3177 : Code of practice for electric overhead travelling cranes and gantry cranes other than steel works cranes

IS:3443 : Specification for crane rail sections

IS:3681 : General plan for spur and helical gears

IS:3815 : Point hook with shanks for general engineering purpose

IS:4460 : Method of rating of machine cut spur and helical gears

IS:5571 : Guide for selection of electrical equipment for hazardous areas

IS:5749 : Forged ramshorn hooks

IS:325 : Squirrel cage induction motors

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Clearance Diagram

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Clearance Diagram

January 21, 2015Subhajyoti Ganguly25Clearance Diagram

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Clearance Diagram

January 21, 2015Subhajyoti Ganguly27B. Hot cranes

January 21, 2015Subhajyoti Ganguly28C. Chain pulley

January 21, 2015Subhajyoti Ganguly29 I. Types Of Chain Pulley

Triple spur gear chain pulley blocks

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Worm & worm wheel chain pulley blocks

January 21, 2015Subhajyoti Ganguly31 I. Types Of Chain Pulley Trolley

Push-Pull Trolleys

Hand Chain Hoists

Geared Traveling TrolleysJanuary 21, 2015Subhajyoti Ganguly32Thank you