oldham coupling is used to connect two shafts non parallel axis

Oldham coupling

is a mechanism for power transmission (or) torque from one shaft to another shaft not co-linear shaft. It mechanism is possible for without any backlash during the operation. It specially designed application for this purpose (Backlash). That is better than straight jaw coupling such as performance and efficiency. The Oldham coupling having three disc for its configuration. When the center disc designed in tongue and groove formation, it is used to sandwich each other both disc. The disc made from material such as plastics. Then other both disc are used to connect the drive and made from stainless steel (or) aluminium material.

Oldham coupling Assembly Drawing
Oldham coupling Assembly Drawing

Working principle of oldham coupling:

When three disc, one disc coupled to input of shaft connect and another disc coupled to output of torque. The Center disc joined each other disc.

The tongue and groove has one side is perpendicular to other side of tongue and groove.

The spring is used to this mechanism for reduce the coupling backlash.During power transmission of one drive to another, the center disc is slide on torque of each hub. The sliding motion include small amount of angular and axial misalignment. They are useful in application with parallel misalignment.

 Common materials for oldham coupling:

 Materials for mid Disc:

  • Delrin

Material for hub (side Disc):

  • stainless steel
  • alloy 2011 aluminum
  • alloy 303
  • Alloy 360 brass

Advantages of oldham coupling

  • Low moment of inertia
  • high torsional stiffness
  • Easy installation in blind
  • The Oldham coupling is a most expensive method of power transmission between drive without backlash.
  • Compact size of shape
  • The electrical isolation through center disc are not possible. Because it made from plastic materials.
  • It act as sort of fuse in machine
  • When break of first disc, the torque limit are exceed in center disc and preventing the torque transmission.


  • When damage of coupling, the machine component is most costly.
  • Relatively small angular misalignment.

Application of Oldham coupling

  • Robotics and servo applications
  • Printer and copy machines


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