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  1. Bolts
  2. Ball bearings
  3. Couplings
  4. Keys
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1 Answers

Option 2 : Ball bearings

Concept:

The power is transmitted from one shaft to the other by means of keys, bolts, couplings, belts, ropes, chains, and gears.

Bolts 

  • They are basically threaded fasteners normally used with nuts.
  • It is used to connect two flanges of two different shafts which are used in transmitting the power.

Coupling

  • A coupling is a device used to connect two shafts together at their ends for transmitting power.
  • Couplings may be rigid, or they may provide flexibility and compensate for misalignment.
  • They may also reduce shock loading and vibration.

  • Types of coupling:

    Safety or slip type coupling: A safety coupling is self-disengaging when the torque is higher than the friction generated by the spring and jaw.

    [ alt="slip" src="//storage.googleapis.com/tb-img/production/19/01/slip.PNG" style="width: 200px; height: 136px;">

    Plate coupling: When shaft ends can be brought into perfect alignment, such shafts can be coupled together by means of a plate coupling. The shaft cannot be shifted in the axial direction.

    [ alt="platecoupl" src="//storage.googleapis.com/tb-img/production/19/01/platecoupl.PNG" style="width: 300px; height: 210px;">

    Clamp coupling: This coupling is built up of two parts which are placed over the connecting ends of the shafts. The clamp coupling joins two shafts when they are in alignment, and this coupling does not permit any movement of the shafts.

    [ alt="clampcou" src="//storage.googleapis.com/tb-img/production/19/01/clampcou.PNG" style="width: 240px; height: 159px;">

    Universal Coupling: It allows positive transmission of power at larger angles than are permissible with a flexible coupling.

    [ alt="universalcoupling" src="//storage.googleapis.com/tb-img/production/19/01/universalcoupling.PNG" style="width: 260px; height: 136px;">

Key

  • A key is a piece of mild steel inserted between the shaft and hub or boss of the pulley to connect these together in order to prevent relative motion between them.
  • It is always inserted parallel to the axis of the shaft.
  • Keys are used as temporary fastenings and are subjected to considerable crushing and shearing stresses. 
  • There are different types of keys.
    • Saddle key
    • Woodruff key
    • Parallel key or feather key

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[ alt="26 June 1" src="https://storage.googleapis.com/tb-img/production/19/08/26%20June_1.png" style="width: 170px; height: 49px;">

Bearing

It is a mechanical component used to reduce the friction between two rotating or sliding surfaces.

It is classified into the following types:

Journal Bearing: A journal bearing is a sliding contact bearing working on hydrodynamic lubrication and which supports the load in the radial direction.
Ball-bearing: It is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.
Roller bearing: It is a type of rolling-element bearing that uses cylindrical rollers to maintain the separation between the bearing races. The load-carrying capacity is more than ball bearing.

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