Automotive Process Induction Shrink Fitting

Automotive Process Induction Shrink Fitting

Inductelec systems are used in the automotive industry to shrink fit gears and rings. Shrink fitting overview - Metals will generally expand when heated and contract when cooling. This increase in size in response to temperature increase is known as thermal expansion. Induction shrink fitting is where we use this effect to either fit two parts together which are tightly dimensionally toleranced. One component is heated to between 150°C and 300°C which causes it to expand allowing the insertion or overlaying it to the mating component. When the adjoined parts return to ambient temperature, the joint becomes strained and strong shrink fitted.

Focus on shrink fitting of ring gears onto flywheels.


Features of Machine

  • 36 - 38 seconds cycle time
  • 15 kW power unit
  • Air blast cooling for induction system
  • Work coil
  • Air blast quench for completed assembly
  • Sensing of different flywheel types and correct location
  • 10 T pressing force to deal with ovality tolerance of ring gear
  • v Pyrometer to ensure component is heated within acceptable maximum and minimum parameters
  • Vision system to identify different ring gear types
Automotive Process Induction Shrink Fitting

Operation of System

  • Flywheel is brought to an agreed location so it can be slid into the machine by a pneumatic cylinder
  • Flywheel is located into tooling
  • Load starter ring into tooling
  • Press cycle start
  • Starter ring rotates
  • Work coil heats starter ring for a set time
  • Pyrometer checks starter ring is within heat parameter limits
  • Top tooling traverses down pressing flywheel onto starter ring
  • Quench initiates for set time
  • Top tooling retracts
  • Flywheel assembly lifts up
  • Shrink fitted assembly is unloaded via slide to unload location

What are the Benefits?

Features of Inductelec’s Induction Shrink Fitting technology:

  • Accurate and repeatable delivery of heat
  • Uniform heat giving predictable expansions
  • Precise control of cycle times
  • Reduced energy consumption
  • Ability to deal with ovality tolerance issues
  • Temperature control is accurate with precise control of ramp-up times and holding temperatures
  • Fewer reject parts as all aspects of the process can be monitored
  • Ease of integration into an existing production cell
  • Better quality

Other Automotive Applications

Shrink fitting:

  • Gears
  • Bearings
  • Rings

Induction hardening:

  • Clutch springs
  • Brake pads
  • Engine valves
  • Connection rods
  • Starter rings
  • Axle shafts
  • Shock absorber rods
  • Springs
  • Suspension arms