BECKHOFF AL2000 Application - Manual (Page 8)

Eiserstraße 5 / D-33415 Verl / Telefon 05246/963-0 / Telefax 05246/963-149
8
Heat dissipation
Heat dissipation is a very important but difficult item. Every linear motor produces heat. The heat will mainly be
dissipated in the coil unit. There are two aspects to consider:
1. This heat must flow away to ambient. If possible, the route of the heat conduction should be traced.
2. Heat generation causes temperature differences. That can be unacceptable for accuracy or other reasons.
For your system, especially for the coil unit, the allowed temperature increase should be determined.
The coil unit is fitted with a temperature sensor. In some designs the coil unit is not capable enough of transfer-
ring the heat to the surrounding air. This counts especially for heavy loaded motors with a high ratio between
motorforce and coil unit size. Also when the motor is thermally isolated or when ventilation is prevented by a
hood. In these cases active cooling, like water cooling, is needed.
Without cooling an unacceptable heat up of the coil unit could occur. This could result in lower performance,
thermic safety stops and even damage to your motor system. Water-cooling of the motor is very effective to
reduce the heatflow and to obtain a constant temperature of the body. Water-cooling requires a water condition-
ing unit containing at least a pump and a cooler. Beware of leaking. The temperature sensor can be used to
detect failures of a watercooling system. An additional flow-sensor for controlling the cooling is strictly not nec-
essary, but yields extra safety and system information. If heat up of particular parts of the system is critical, a
thermal insulation between the coil unit and the critical parts of the slide can be considered. This can reduce,
but not nullify, the temperature rise. Sometimes small heat up also takes place in the magnet plates.