Linear motor offers dynamics improvement of 25%

Dean Palmer reports on a unique range of flat linear motors that offer 25% better dynamics by efficiently focussing the magnetic field created by the winding

A range of flat linear motors has been developed that incorporates a special laminated iron-core design, yielding more force per coil length than equivalent-sized motors by efficiently focussing the magnetic field created by the winding. According to the manufacturer of the motors, Aerotech, the new BLMFS5 'flat' linear motors offer a "typical dynamics improvement of up to 25% compared to other manufacturers' equivalent sized motors". The company explained that, in comparative tests with competitive linear motors of the same envelope size, the new motor delivered higher dynamics for a given temperature rise and conversely had a lower temperature rise for the same dynamics. This suggests that the motor will outperform similar sized linear motors in applications where existing motors are running too hot or not providing enough power. The motors are aimed at high-speed, point-to-point precision motion application solutions for pick-and-place systems, automated assembly and general automation. The motor is compact, with a nominal width of 66mm and a combined forcer and magnetic track height of less than 37mm. Travel range is effectively unlimited by stacking magnet tracks; available in 240mm and 420mm lengths, or customised for specific applications. Mechanical interfacing is simplified via a matrix of M5 mounting holes on the forcer and M4 clearance holes on the magnet track. The ceramic/epoxy moving forcer assembly contains Hall Effect sensors for motor commutation and a thermistor-based temperature sensor to help ensure safe operation when used in demanding applications. Also, the range is available with optional water cooling for even higher performance applications where minimal motor size is essential. The range combines a rare-earth magnet system and a low-profile package for a peak force rating of up to 1,500N, which is practically specified with and without water cooling for a continuous force rating of almost 700N at an operating temperature of 125ºC. One metre-long flying-lead cable assemblies are provided for easy, fast electrical connection for motors, HED's and thermistor. A range of brushless servo amplifiers are also available to drive the BLMFS5 according to the customer's force and speed requirements. Motion control is available from single-axis configuration using the 'Soloist Intelligent Drive' to applications of up to 32 axes of decentralised motion, using Aerotech's 'soft-motion' A3200 Automation Platform with high speed IEEE-1394 Firewire network and dedicated modules for HMI, PLC and vision systems. Customisation options for the BLMFS5 include higher power magnets to further increase force output, special mechanical interfacing and electrical connectors for simplified installation.