Keys and Splines
Introduction to Belt Drives
➢ Key - Mechine element, which use to prevent relative motion and to connect rotating shaft to
another mechine element.
➢ Consists of Shaft, Hub and Key.
H
➢ Keys subjected to large crushing and shearing stresses.
➢ Primary functions,
S
- Transmit torque from shaft to hub.
- Prevent relative rotational motion between shaft and mechine part.
- Prevent axial motion between shaft and hub. (except feather key or splined connnection)
W
Rectangular Sunk Keys
Square Sunk Keys
Parallel sunk Keys
Sunk Keys
:
Gib Head Sunk Keys
- Saddle Keys
Feather Sunk Keys
- Tangent Keys
Woodruff Sunk Keys
Round Keys
Splines Flat Saddle Keys
Kennedy Keys Hollow Saddle Keys
Sunk Keys
-
Half in the keyway of the shaft and other half in the keyway of the hub of the pulley.
, Rectangular Sunk Keys Square Sunk Keys
w = d/4
t = 2w/3 = d/6 w = t = d/4
Parallel Sunk Keys Gib Head Sunk Keys
H
Rectangular or square cross-section. Rectangular sunk key, Head at one end.
Taperless With Taper
Use when pully required to slide along shaft. Head - facilitate removal of key.
S
Feather Sunk Keys Woodruff Sunk Keys
W
Key attached to shaft or hub. Semi circular disk, uniform thickness.
Permits relative axial movement. Use in mechine tools & automobile applications.
Advantage : Better concentricity for high rpm
Accommodate itself to any taper.
Disadvantage : depth of keyway weekens the shaft.
doesn't allow axial movement.
Saddle Keys
-
Fit in the keyway of the hub only, Shaft holds by friction.
/
Power is transmitted by friction.
-
For light duty, low power transmission
·
Resistance to slip in flat saddle keys are slightly higher.
-
Generally used as a temporary fastening in fixing eccentrics, cams, etc
Flat Saddle Keys Hollow Saddle Keys
flat surface at the bottom. Key's bottom is shaped to fit the curved surface of shaft
Sits on flat surface, machined on the shaft
Introduction to Belt Drives
➢ Key - Mechine element, which use to prevent relative motion and to connect rotating shaft to
another mechine element.
➢ Consists of Shaft, Hub and Key.
H
➢ Keys subjected to large crushing and shearing stresses.
➢ Primary functions,
S
- Transmit torque from shaft to hub.
- Prevent relative rotational motion between shaft and mechine part.
- Prevent axial motion between shaft and hub. (except feather key or splined connnection)
W
Rectangular Sunk Keys
Square Sunk Keys
Parallel sunk Keys
Sunk Keys
:
Gib Head Sunk Keys
- Saddle Keys
Feather Sunk Keys
- Tangent Keys
Woodruff Sunk Keys
Round Keys
Splines Flat Saddle Keys
Kennedy Keys Hollow Saddle Keys
Sunk Keys
-
Half in the keyway of the shaft and other half in the keyway of the hub of the pulley.
, Rectangular Sunk Keys Square Sunk Keys
w = d/4
t = 2w/3 = d/6 w = t = d/4
Parallel Sunk Keys Gib Head Sunk Keys
H
Rectangular or square cross-section. Rectangular sunk key, Head at one end.
Taperless With Taper
Use when pully required to slide along shaft. Head - facilitate removal of key.
S
Feather Sunk Keys Woodruff Sunk Keys
W
Key attached to shaft or hub. Semi circular disk, uniform thickness.
Permits relative axial movement. Use in mechine tools & automobile applications.
Advantage : Better concentricity for high rpm
Accommodate itself to any taper.
Disadvantage : depth of keyway weekens the shaft.
doesn't allow axial movement.
Saddle Keys
-
Fit in the keyway of the hub only, Shaft holds by friction.
/
Power is transmitted by friction.
-
For light duty, low power transmission
·
Resistance to slip in flat saddle keys are slightly higher.
-
Generally used as a temporary fastening in fixing eccentrics, cams, etc
Flat Saddle Keys Hollow Saddle Keys
flat surface at the bottom. Key's bottom is shaped to fit the curved surface of shaft
Sits on flat surface, machined on the shaft
