Electric Overhead Travelling Crane | EOT Crane | EOT Crane Parts

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The most adaptable and the most widely used type of power driven crane for indoor service is undoubtedly the three motion EOT crane. It serves a larger area of floor space within its own travelling restrictions than any other permanent type hoisting arrangement.

As the name implies, this type of crane is provided with movement above the floor level. Hence it occupies no floor space and this can never interface with any movement of the work being carried out at the floor of the building.

The three motions of such crane are the hoisting motion and the cross travel motion. Each of the motions is provided by electric motors.

The above characteristics have made this type of crane suitable for medium and heavy workshop and warehouses. No engineering erection shop, machine shop, foundry, heavy stores is complete without an EOT crane.

In a steel plant, rolling mill, thermal power plant, hydraulic power plant, nuclear power plant, this type of crane is considered indispensable. In short in all industries, wherein heavy loads are to be handled, EOT crane find its application.

EOT Crane Parts:

A EOT crane consists of two distinct parts

  • 1. Bridge
  • 2. Crab

Bridge:

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The Bridge consists of two main girders fixed at their ends and connected to another structural components called the end carriages. In the two end carriages are mounted the main runners or wheels (four or more) which provide the longitudinal motion to the main bridge along the length of the workshop. The motion of the bridge is derived from an electric motor which is geared to a shaft running across the full span of the bridge and further geared to a wheel at each end. In some design separate motors may be fitted at each corner of the main bridge. The wheels run on two heavy rails fixed above the floor level along the length of the shop on two girders, called gantry girder.

Crab:

The Crab consists of the hoisting machinery mounted on a frame, which is in turn mounted on at least four wheels and fitted with suitable machinery for traversing the crab to and fro across the main girders of the crane bridge. Needless to mention that the crab wheels run on two rail sections fixed on the top flange of the main bridge. Thus the load hook has three separate motions, these being the hoisting, cross traverse of the crab, and longitudinal travel of the whole crane. Each motion is controlled independently of the other motions by separate controllers situated in a control cage or in a suitable position for controlling from the floor by pendent chains.

The essential parts are:

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  1. Bridge– 2 No’s
  2. End carriage– 2 No’s
  3. Wheel of the bridge– At least 4 No’s
  4. Crab (without auxiliary hoist)– 1 No’s
  5. Hoisting machinery set– 1 No’s
  6. Wheels of crab– At least 4 No’s
  7. Bottom Block (without auxiliary hoist)– 1 No’s
  8. Lifting hook– 1 No’s
  9. Rail on the gantry girder for crane movement– 2 No’s
  10. Rail on the bridge for crab movement– 2 No’s
  11. Operators cabin– 1 No’s

Classification Of Material Handling Equipment | Types Of Material Handling Equipment Loads

Bases on Design features and operational characteristics, material handling equipment may be broadly classified as:

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Hoisting Equipment’s:

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It constitute a group of equipment which are employed mainly for lifting or lowering of unit load or piece goods in batches. This group of equipment’s can be further sub classified into:

1. Pure Hoisting Machineries

  • Jack
  • Winches
  • Hand Hoists
  • Pulley Blocks

2. Cranes

  • EOT Crane
  • Jib Crane
  • Cantilever Crane

3. Elevators

  • Lift
  • Bucket Elevators

Conveying Equipment’s:

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It comprises of a number of equipment which are employed for handling principally bulk load (occasionally piece goods or unit load may also be handled) in continuous flow. Such machines do not have separate lifting or lowering gear. This group of equipment also can have further sub classifications as:

1. Belt Conveyor

2. Hydraulic Conveyor

3. Pneumatic Conveyor

4. Apron Conveyor

5. Screw Conveyor

6. Flight Conveyor

Surface/ Overhead Equipment’s:

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These are the group of equipment’s which are employed for handling unit load or bulk load in batches on a horizontal surface. This group of equipment may be further sub classified into:

1. Truck and Lorries

2. Railway Cars and Wagons

3. Fork Lifts

4. Overhead mono-rail / Equipment

5. Scrapers and Skidders

Types of Material Handling Equipment Loads:

It usually classified into:

1. Unit Load

2. Bulk Load

Unit Load:

Unit loads are those which are counted by numbers or units. A component of a machine, a complete machine, a structural element, a beam, a girder, building block are some examples of unit load.

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Sometimes certain quantities of free flowing materials can be placed in a container and can be handled as unit load. Hoisting equipment are primarily used for handling unit load. Unit loads are usually specified by it’s weight.

Bulk Load:

When the load is in the form of particles or lumps of homogeneous materials or powder like materials, which can not be counted by numbers, it is called as “Bulk load”.

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Examples are:

Sand, Cement, Coal, Mineral, Stone, Clay etc.,

A bulk material may be classified by it’s:

1. Bulk Density

2. Lump-Size

3. Flowability

4. Abrasiveness

5. Miscellaneous Characteristics