Shrink Fitting Stainless-Steel Sleeve & Shaft

Objective

Heating a stainless steel sleeve for shrink fitting on to a shaft for industrial washer

End Product

washer

Equipment

Ambrell 4.2 kW induction heating system, equipped with a remote workhead containing two 1.0μF capacitors for a total of 0.5μF

An induction heating coil designed and developed specifically for this application

Materials

Stainless steel sleeve 4.33” (109.98mm) OD, 3.58” (90.93mm) ID, 2” (50.8mm) long

Temperature

500 ºF (260 ºC)

Frequency

277 kHz

Testing

A three turn helical coil is used to heat the stainless steel sleeve. The part is placed in the coil and power is applied for 110 seconds to reach 500 ºF (260 ºC) for the shrink fit application. Once the sleeve reaches 500 ºF (260 ºC), the sleeve is placed on a stainless steel shaft and allowed to cool to shrink fit the sleeve to the shaft.

Benefits

Currently using electric ovens that run 24 hours a day, 5 days per week and their primary concern is to save on the energy cost of heating the parts in the ovens. By switching to induction heat the customer saves by only using power for 110 seconds per part vs. a continuously running electric oven. This worked out to a daily running cost of $2.16 for the induction system, compared to $46.08 for the four ovens at a $0.12/kWh cost for electricity.

The customer will save $11,418 on energy per year with a ROI of 1.75 years for the investment of the induction system. Additional cost savings from improved production efficiency and environmental cooling to counteract the effect of the ovens should also be considered in the overall ROI.

Image