Permanent Magnetic Synchronous Motors-Development, Advantages and Challenges
Due to their high reliability, durability, electrical stability and relatively low cost, permanent magnetic (mainly Neodymium magnets) synchronous motors have been used in large scale on machine tools and other production machinery for many decades, such as spindle, worktable rotation, rotary and linear applications of motion control, etc. They’re also found on chip conveyors, hydraulic manifolds, oil reservoirs and coolant pumps.
The permanent magnet in the rotor assembly generates a steady magnetic field instead of the short circuit current found on asynchronous induction motor designs and has yielded a lot of advantages for the machine designers, builders and aftermarket. These advantages include compact form with high torque density and less weight, higher and 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, lowtorque ripple effect, more robust performance, good power factor and ultimately, better drive utilization.
The escalating costs of raw materials as a result of multiple economic factors in the world market may continuously affect the development of this product. Moreover, more technical aspects such as limited speed ranges in field applications and degradation due to counter voltage created by the magnets, are also problems continuously addressed by the manufacturers.