AUSTRALIAN Baldor has released a series of iron core, brushless, linear servo motors. The linear motor iron core (LMIC) series offers a choice of sizes and power ratings.
It features a modular track allowing designers to set travel stroke length by placing sections end to end. The motors are available in standard and low profile versions. They are capable of delivering high thrust forces, acceleration, and speed. Continuous thrust forces as high as 13,813N peak (5179N continuous) are possible, along with acceleration rates in excess of 98m/s/s, and positioning speeds of more than 8m/s.
The motors are suitable for pick and place machines, parts handlers, and semiconductor manufacturing processes. They can be used with standard trapezoidal or sinusoidal 3-phase brushless servo drives. This integrates a single-axis motion controller with a brushless ac servo drive, handles incremental and absolute positioning, and allows pre-programming of up to 256 point to point moves.
The motors are comprised of a magnetic track and a coil assembly supported by a customer-supplied bearing system. Multiple coil assemblies can be placed on the same magnetic track and controlled independently, with overlapping movement trajectories if required. The track uses multi-pole, alternating polarity, rare-earth magnets. The magnets are bonded to a steel plate with an electroless nickel finish. For most automation applications, the track is held stationary and the coil assembly is free to move. These settings can be reversed.
The coil assembly minimises cogging effects without requiring the use of skewed magnets or slots on the magnetic track. It uses laminated steel, encapsulated in thermally conductive epoxy resin. This design maximises mechanical integrity and allows efficient removal of heat from the windings. The assembly is fitted with a 3m flying lead as standard. Embedded hall-effect sensors provide feedback to the servo controller for motor phase commutation.
The standard profile motors offer a choice of 46 different coil assemblies and 24 standard magnetic track lengths, from 137.2mm to 343mm. The installed height between the base of the track and the top of the coil assembly is 54.6mm when used with a recommended bearing system. The coil assemblies are fitted with a T slot mounting plate. The smallest coil assembly is a 35W unit that measures 63.5mm x 137.2mm and is capable of producing 80N of continuous thrust force. The largest assembly is rated at 2.2kW, measures 267mm x 960.1mm, and can produce a continuous thrust force of up to 5179N.
The low profile models are designed for applications where the space between fixed and moving parts is severely limited. They use thinner magnetic tracks and coil assemblies to reduce the installed height to 32.6mm. 28 coil assemblies and 16 magnetic track lengths are available, from 137.2mm to 343mm. The smallest coil assembly can generate a continuous thrust force of 36N and measures 63.5mm x 153.4mm. The largest assembly has a continuous thrust force rating of 587N and measures 216 x 565mm.
The non-contact design means that the motors are relatively quiet in operation, as well as reliable and low maintenance.