Introduction; Principle Of Operation - SKF TMBH 1 Instrucciones De Uso

1. Introduction

The SKF Bearing Heater TMBH 1 is intended for heating rolling bearings with an inner
diameter up to 80 to 100 mm (3 – 4 in.) and a maximum corresponding weight of
4 – 5 kg (9 – 11 lb).
Other ring-shaped metal components forming a closed circuit such as gears, pulleys,
bushings and shrink rings can also be heated. This apparatus uses a patented method of
heating based on high frequency induction. This new concept caters for optimized eficiency
and is a truly portable unit.
The unit is supplied with heating clamp, temperature probe, power cable (without plug)
and a carrying case as standard.

1.1 Principle of operation

An induction heater can be compared with a transformer using the principle of a primary
coil with a large number of windings and a secondary coil with a few windings on a mutual
core.
The input / output voltage ratio is equal to the ratio of the windings, while the energy
remains the same. In the case of the SKF Bearing Heater TMBH 1, the primary coil
is connected to a high frequency power supply. The bearing acts as a short-circuited
single-turn secondary coil through which a low AC voltage lows at high amperage,
thus generating a lot of heat. The heater itself as well as the clamp remain at ambient
temperature.
Due to different physical proportions the inner ring of a bearing will heat up faster than
the outer ring, thus reducing the radial internal clearance. As long as the recommended
temperature of 110 °C (230 °F) is not exceeded, this does not threaten to damage the
bearing.
Both greased and sealed bearings can be heated without risk of damage.
4 SKF TMBH 1