Shrink-fitting & assembly

frettage-assemblage

 

Shrink-fitting assembles two parts by press fit. Generally, it is used to transfer torque from the rotating part of a shaft or to cut machining costs.

Advantages of induction shrink-fitting:

  • No risk of making chips, as opposed to press mounting
  • No risk of deformation
  • Localized heating allows for faster cooling
  • Resistance to bending, compression and rotation
  • Heat shrinking is safer than shrink-fitting with liquid nitrogen: http://www.sos-azote.com/downloads/fiche-securite-azote.pdf
  • Centering: a few microns
  • Easy removal of rings or parts mounted in a tight-fit.

Some tips for shrink-fitting: 

  • The bores must be chamfered
  • Small parts are much more difficult to shrink-fit: they have little thermal inertia and the smallest ones must be assembled or disassembled in less than a second. In this case, it may be necessary to guide and synchronize them with the heating system.
  • For larger parts, you have 30-50 seconds to carry out shrink-fitting, but as a general rule guidance remains a key point.
  • The bored part can be heated from the exterior: this is the economical solution. If it is done by the underside, for example for gears, or from the inside, it is significantly more expensive and the inductor must be adapted to the diameter of the bore. But sometimes it’s the only solution possible.

Our services:

  • Custom work
  • On-site service and repair
  • A shrink-fitting kit with its storage system
  • Shrink-fitting assembly calculation according to E22-621PR: Mechanical transmissions – shrink-fitted assemblies on cylindrical bearing – function, implementation, calculation