Shrink-fitting a Camshaft Gear

Objective

Heating a camshaft gear with a bore size of 1.630" to shrink fit over a steel shaft that has a diameter of 1.632".

End Product

camshaft gear

Equipment

Ameritherm SP 3 and Ameritherm XP 5, 3 kW and 5 kW output solid state induction power supplies respectively, including remote heat stations and a unique three turn helical coil made from 3/16" copper tubing and having a 4.4" inside diameter.

Materials

Steel Camshaft Gear measuring 7" in diameter, 1" thick, with a bore size of 1.630"

Temperature

500º F

Frequency

163 kHz

Testing

A temperature of 500º F is required for the gear to expand 0.002" in order to slip over the shaft. Production is presently done at a rate of 15-20 gears per 24 hour shift by heating the gear on a hot plate. The hot plate heating cycle lasts for approximately 45 minutes. The customer would like to explore the options available in terms of heating times and machine size.

Benefits

A unique three (3) turn helical coil along with the various Ameritherm solid state induction power supplies were used to achieve the following results: ◦500º F was reached in three (3) minutes while using the Ameritherm XP 5, 5 kW output solid state induction power supply. ◦500º F was reached in five (5), eight (8), and ten (10) minutes using the Ameritherm Nova 3, 3 kW output solid state induction power supply. ◦5Even heating was observed as a result of the unique three (3) turn helical induction coil.

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