MOTION SYSTEMS HANDBOOK
Servomotor and drive fundamentals The 2G Motion System from Kollmorgen is based on the latest thinking about single-source, systems-based design. It harnesses the capabilities of Kollmorgen’s AKD2G servo drive and AKM2G servomotor. Motor and drive are precisely matched in every element, from drive switching frequency and commutation algorithms to motor magnetics. This avoids microincompatibilities that can occur when engineers select components from various manufacturers.
Perhaps the distinguishing feature of all servomotors is that they output motion under closed-loop control. They rely on feedback from encoders as well as control signals from a controller and drive to operate the motor. Most servomotors are rotary motors and produce precise torque and speed, most often used in positioning applications. Manufacturers classify motors for constant-speed tasks by horsepower or torque at base speed. In contrast, servomotors operate over varying
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DESIGN WORLD — MOTION
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speed ranges and aren’t rated in this way. Instead they have speed-torque curves that express continuous torque capabilities (that won’t threaten to overheat the motor) and intermittent or peak torque for acceleration. Keep in mind that the term servomotor can mean different things depending on the context. Convention is that the term often (though not always) refers to what industry calls dc motors — both brushed and the costlier (but longer-lived) brushless servomotors. There are also instances of classifying induction-motor-based designs running off vector controls as servomotor setups where the design incorporates feedback (usually from an encoder) to track and control speed and sometimes even position. These induction motors motioncontroltips.com | designworldonline.com
