October 1, 2018 — CNC specialist NUM has expanded its portfolio of motors for machine tool applications by launching a range of brushless torque motors.
Employing optimized magnetics, NUM’s TMX series direct drive motors have a low cogging torque. They are designed for applications that demand smooth and accurate rotation. Typical uses include direct drive machine tools, rotary tables and radial positioning units.
NUM is initially launching two TMX series frameless torque motors, with stator diameters of 140 mm and 291 mm, and intends growing the range in the future. The motors’ hollow shaft rotors utilize high flux density neodymium-iron-boron (NdFeB) magnets and offer internal space for through-motor wiring or mechanical parts. The stator windings are fully protected against over-temperature conditions and are encapsulated within a thermally optimized enclosure that offers a choice of air-cooled and water-cooled configurations.
Like all direct drive motors, the TMX series units are capable of providing continuous torque when stalled, and are designed for direct attachment to the load. This obviates the need for gearboxes or shaft couplings, to provide backlash-free rotary transmission. The rotor and frameless stator are supplied as component parts and are primarily intended for applications that require total integration of the motor within the servomechanism in order to reduce weight or volume.
NUM’s TMX series motors can produce an S1 torque density and are available with a choice of stator and rotor lengths to best suit the motion requirements of the application. By way of example, a 140 mm diameter motor with an active length of 70 mm can produce a peak torque of approximately 82 Nm at speeds up to 1,500 rpm, and a continuous (stall) torque of approximately 50 Nm.
The motors can be driven by most industry-standard servo drives, including NUM’s MDLU3 and MDLUX drives, which form part of the company’s Flexium+ CNC platform.