KEYS

In engineering, a key's a machine element wont to connect a rotating machine element to a shaft. The key prevents relative rotation between the 2 parts and should enable torque transmission. For a key to function, the shaft and rotating machine element must have a keyway and a keyseat, which may be a slot and pocket during which the key fits. the entire system is named a keyed joint.[1][2] A keyed joint may allow relative axial movement between the parts. commonly keyed components include gears, pulleys, couplings and washers 

TYPES OF KEYS 

• SUNK KEYS
• SADDLE KEYS
• TANGENT KEYS 
• ROUND KEYS
• SPLINES

SUNK KEY

The sunk key are provided with half in the keyway of the shaft and half in the keyway of hub or boss of the pulley. 

THE SUNK KEYS ARE FOLLOWING TYPES

FEATHER SUNK KEY

PARALLEL SUNK KEY

RECTANGULAR SUNK KEY

WOODRUFF KEY

SQUARE SUNK KEY

GIB-HEAD SUNK KEY

FEATHER SUNK KEY

Feather key is attached to at least one member of pair with which enable relative axial movement is identified as feather key. it's the actual parallel sunk key which transmits rotation and to permit axial movement

PARALLEL SUNK KEY

Parallel sunk keys could be of the oblong or square part regular in breadth and thickness everywhere.

It might be noted that the parallel key is taper less with is employed gears, pulleys, other mating parts are required to slip beside the shaft.

 

RECTANGULAR SUNK KEY

Rectangular  sunk key  usual proportions of width and thickness of the key and diameter of the shaft

or diameter of the hole in  the shaft

WOODRUFF SUNK KEY

Woodruff sunk key's easily adjustable and maybe a part of a cylindrical disc has a segmental cross-section in face view. this is often able of tilting during a recess milled call at shaft with a cutter have similar curvature as a disc from which key was prepared. This key is usually utilized in milling and automobile assembly

SQUARE SUNK EY

The simple dissimilarity between square and rectangular sunk keys is their width and thickness of equivalent   

GIB HEAD SUNK KEY

Gib head sunk key. it's an oblong sunk key with the top at one head is know as gib head key. it always provided to facilitate the removal of key

SADDLE KEYS

Saddle keys are key which is fits only in the keyway of the hub or boss of the pulley.

TYPES OF SADDLE KEYS

FLAT SADDLE KEYS

HOLLOW SADDLE KEYS

FLAT SADDLE KEYS

A saddle key is a taper key which fits in the keyway in the hub and is flat on the shaft. It is likely to slip around the shaft under the load, therefore  it is  used for light loads

HOLLOW SADDLE KEYS

A hollow saddle key's a taper key which inserts within the keyway within the hub and therefore the bottom of key's shaped to suit the curved surface of the shaft. Since hollow shafts are persisted friction, therefore these are suitable for light loads. it always used as a short-lived fastening in fixing and setting eccentrics, cams, etc

TANGENT KEYS

The tangent keys are fitted in pair at right angles each key withstands torsion in one direction only.

These are used for heavy-duty shafts

ROUND KEYS

Round keys are circular in cross-section and fit into a-holes drilled partly within the shaft and partly within the hub. they need the advantage that their keyways could also be drilled or reamed after the mating parts are assembled. Round keys are usually considered to be most appropriate for low power drives

SPLINES

Sometimes, keys are made integral with the shaft which inserts within the keyway broached within the hub. such shafts are referred to as splined shafts. These shafts have usually 6,10,16 splines. these shafts are stronger than the shafts having one keyway.