16 March 2017

Muff coupling

What is muff coupling?

Answer :

  • A coupling in which a hollow cylinder or muff is used to connect the abutting ends of two shafts.
In muff coupling, the muff is made into two halves and they are joined together by means of bolts. Where halves are made by cast iron and bolts are by mild steels. 

Muff coupling is also called sleeve coupling or box coupling.
Muff coupling is fall in the category of rigid coupling.

Features of muff coupling :
  • Easy to manufacture.
  • Components are easy to assemble and Dismantling.
  • Their high torque capabilities make them suitable for higher RPM power transmission applications.
  • Due to rigid connection lubrication is not required.
  • Maintenance is minimal.
  • Low operational cost due to no maintenance and no lubrication
  • No moving part hence smooth and quiet operation.
Muff coupling is usually designed on shop floors by assuming standard proportions for the dimensions of the sleeve.

For the sleeve muff coupling the standard proportions used are as follows :

D = ( 2d + 13 ) mm 
L = 3.5 d

D = Outer diameter of the sleeve ( mm )
L = Axial length of the sleeve ( mm )
d = Diameter of the shaft ( mm )