Magnetics Business & Technology - Fall 2012 - (Page 6)

APPLICATION FEATURE By Harald PoescH, Product Manager for Motion control Motors, usa • sieMens industry, inc. Permanent magnet motors in aPPlication Permanent magnet synchronous motors offer significant advantages on high energy consuming and high dynamic applications Newly developed mechatronic applications such as this integrated electrohydraulic pump motor, as used on a plastics injection molding machine. Permanent magnetic synchronous motors have been in use on machine tools and other production machinery for many years, owing to their reliable performance, durability, relatively low cost and electrical stability. These motors have been the standard in the machine tool industry for many decades, used on the spindle, worktable rotation, ways and part articulation, in both rotary and linear applications of controlled motion. With the advent of the machine tool robot for materials handling, workpiece and tooling changes, high-precision load/unload functions and more, the use of these motors has grown exponentially over the years. Behind the cutting theater, they’re also found on the chip conveyor, hydraulic manifold, oil reservoir and coolant pumps. Likewise, in the production machine realm, plastics/rubber molding and extrusion, papermaking, packaging, textiles, ceramic, glass, woodworking and countless other pieces of equipment have utilized these motors for motion control. Further, the essential operational principle of a permanent magnet in the rotor assembly, generating a steady magnetic field instead of the short circuit current found on asynchronous induction motor designs, has yielded many advantages for the machine designer, builder and aftermarket alike. These advantages include compact form with high torque density and less weight, higher continuous torque over a wider range of speeds, lower rotor inertia, higher dynamic performance under load, higher operational efficiencies with no magnetizing current and the corresponding absence of heat due to current in the rotor, low torque ripple effect, more robust performance compared to DC motors, good cos phi (our European term for power factor) and ultimately, better drive utilization. The challenges have been escalating costs of raw materials due to certain economic factors in the world market, though recent REM finds here in America and elsewhere may impact that situation greatly in the future. Plus, more technical aspects such as limited speed ranges in field applications and degradation due to counter voltage created by the magnets, where normally an encoder for commutation is deemed necessary, along with the inevitable limit overload condition, are being continuously addressed by the manufacturers. Typical applications for today’s advanced permanent magnetic motors include a) plastic film casting machines, b) printing presses, c) converting equipment and d) machine tool rotary tables. 6 Magnetics Business & Technology • Fall 2012

Table of Contents for the Digital Edition of Magnetics Business & Technology - Fall 2012

Magnetics Business & Technology - Fall 2012
Editor's Choice
Permanent Magnet Motors in Application
Three-Axis Magnetic Field Measurement: From Nanoteslas to 14 Tesla
Characterizing Permanent Magnet Materials with a Vibrating Sample Magnetometer
Research & Development
Magnets • Materials • Measurement
Application • Component Developments
Industry News
Advertising Index
Spontaneous Thoughts: And the Wisdom to Know the Difference

Magnetics Business & Technology - Fall 2012