Custom-made special motors for Effmag induction heaters
Effmag Oy manufactures energy-efficient induction heaters for the aluminium extrusion industry. The new heater type has an efficiency ratio of approximately 80%, which is substantially higher than that of other heaters on the market. Since the process requires a great deal of energy, this results in substantial cost savings during the equipment life cycle. Use of compact Randax® motors has improved the efficiency of the equipment and reduced the size of the induction heater.
An induction heater consists of two rotating permanent magnet motors between which the aluminium billets run. The rotors generate a varying magnetic field that heats the aluminium billets for extrusion. The most economical way to build the heater is by using a high rotation speed, which reduces the number of permanent magnets and the physical size of the induction heater. In addition to the torque requirement, the heating process produces substantial axial bearing loads, in continuously changing directions, on the motor.
The motors that Randax developed for Effmag Oy allowed the firm to optimise the number of permanent magnets required for the heater, enabling a smaller heater which would fit into a sea transport container. A suitable bearing system, based on oil circulation and precision bearings, was designed at the same time to accommodate the bearing loads which occur at high rotation speeds.
Key benefits of using Randax® motors:
Motors designed for customer needs, taking account of the process’s special requirements and the customer’s equipment interfaces, while lowering overall product costs!
Compact and light motors helped to keep the equipment down to a logistically reasonable size!
Motor type: Permanent magnet motor
Rotation speed: 4500 RPM
Power: 90 kW
Torque: 190 Nm
Motor current: 146 A
Nominal voltage: 400 V