FAG induction heating coil induction heating principle!

An alternating magnetic field occurs in a coil that is loaded with an alternating current. When the bearing ring is placed in an alternating magnetic field, an induced current is generated inside it. This is actually a short circuit current that can heat the bearing. Due to the skin effect in the magnetic coupling, the current is mainly concentrated on the outer surface of the ferrule, so the outer surface of the ferrule heats up faster than the inner surface. In this way, the heat transfer to the shaft is very small, and a satisfactory clearance can be created between the bearing inner ring and the shaft of the shrink fit device.

In induction heating, the depth of heating depends on the frequency of the alternating current. The 50hz frequency we usually use (60hz in some countries) has been proven to meet the wall thickness requirements of the inner ring of most commonly used cylindrical roller bearings and needle roller bearings. After induction heating, the bearing ring is magnetized. Demagnetization can be done using the same coil. The induction heating coil is suitable for dismantling symmetrical rings such as cylindrical roller bearings and needle roller bearings, labyrinth seals, couplings, etc. with an inner diameter of not less than 90mm.

For small interferences, such as press-fits, the shaft may also heat up so quickly that the interference cannot be eliminated. In this case, it is better to use a heated aluminum ring. Induction heating coils can also be used to heat components in installations. Induction heating coils are generally planned and manufactured in proportion to a single bearing. The outer diameter and width of the same coil ferrule can only vary in a few dimensions.