YASKAWA UGFSEM-A7LMG12X Minertia Coreless DC Servo Motor Specification

UGFSEM-A7LMG12X is a customized high-response coreless DC servo motor from Yaskawa classic FS Minertia series, specially developed for precision testing equipment, automated assembly and high-precision positioning machinery. The motor applies unique cup-shaped coreless rotor structure without silicon steel core inside windings, delivering ultra-low rotor inertia, nearly zero cogging torque and steady smooth low-speed running performance. It features fully enclosed natural convection cooling without external cooling fan, and comes with factory pre-mounted DC24V fail-safe electromagnetic power-off brake to secure vertically installed loads against free falling after unexpected power cut. LMG12X is an OEM-customized incremental encoder specification with exclusive pin assignment and unique wiring layout; the trailing X stands for special mechanical customization processed at factory, differing from standard LMG12 general models in shaft dimension or outgoing cable configuration.

UGFSEM is base series code of Yaskawa FS coreless DC servo motor with built-in brake option; A means integrated internal DC24V electromagnetic holding brake assembly; numeral 7 corresponds to fixed frame size and 0.7kW rated power tier; LMG represents dedicated customized incremental encoder group with proprietary connector pinout; digit 12 defines default factory cable length and base encoder resolution parameter; suffix X indicates non-standard customized modification on mechanical structure as special OEM variant.

The motor is rated at 144VDC armature input voltage and designed to pair with Yaskawa legacy dedicated Minertia DC servo amplifier series. Continuous rated output power is 0.7kW, rated full-load armature current is approximately 5.7A, rated nominal rotating speed is set at 1750rpm with stable continuous torque output. Instantaneous peak overload torque can reach up to 3.5 times rated torque to cope with rapid acceleration startup and short-term impact load conditions. The built-in brake requires independent 24VDC auxiliary supply, releasing output shaft when energized and locking shaft mechanically once brake power is disconnected. The customized LMG12X differential line-drive incremental encoder follows exclusive factory wiring definition and cannot be swapped with MMG, EAP or SOD type encoders directly. Internal stator winding is constructed in compliance with Class F insulation standard, equipped with embedded thermal sensing component that feeds overheat fault signal to matched servo drive to trigger automatic overload stop for winding protection. Surge suppression parts are installed inside terminal compartment to restrain industrial surge voltage and electromagnetic interference from surrounding inverter devices.

The motor housing adopts fully sealed IP54 protection grade and relies completely on shell natural heat dissipation without auxiliary fan structure. Front drive end is standard solid output shaft with integrated flat keyway for rigid coupling with precision miniature reducer, ball screw and timing belt wheel. Due to rear integrated brake module and X-version customized mechanical processing, overall axial dimension is slightly different from standard non-X same-power models, and total net weight is around 3.5kg with unified standard flange mounting size for direct installation on equipment frame without extra transition fixture.

Valid continuous operating ambient temperature ranges from 0°C to +40°C; permissible spare part storage temperature spans -20°C to +70°C; applicable working relative humidity is kept between 5%RH and 80%RH under non-condensing environment to avoid dew-caused internal short circuit. If installation altitude exceeds 1000 meters above sea level, continuous working load must be properly derated to compensate declined heat dissipation efficiency under thin air environment. The unit can withstand standard industrial vibration within 10Hz to 55Hz frequency range; installation locations with corrosive gas, continuous liquid splash and dense conductive dust accumulation are prohibited to extend service life of bearing, brake friction disc and internal winding components.

UGFSEM-A7LMG12X is originally matched with vintage Yaskawa dedicated Minertia DC servo driver units, supporting two main external command input modes including ±10VDC analog speed instruction and differential pulse position command transmitted from upper PLC or miniature CNC controller. The matched servo system supports free switching among position closed-loop control, speed closed-loop control and torque closed-loop control according to different production process needs. Benefiting from built-in power-off brake structure, vertical mounted equipment does not need additional external mechanical locking fixture for anti-drop protection. Since incremental-type LMG12X encoder is equipped, complete mechanical origin homing operation must be carried out after full system power outage before formal equipment startup to recover accurate mechanical zero position.

Multi-layer comprehensive safety protection is realized through coordination between internal sensing elements and paired servo amplifier. Winding over-temperature signal triggers servo automatic overload shutdown to prevent coreless winding thermal damage; open circuit or poor contact of customized LMG12X encoder cable activates dedicated encoder fault warning displayed on servo panel; winding short-circuit and abnormal overcurrent lead to hardware overcurrent protection and immediate main power cutoff; brake coil open or short fault outputs auxiliary warning prompt on matched drive terminal. All feedback signal circuits adopt noise suppression components to filter complex on-site electromagnetic interference and guarantee stable feedback signal transmission.

Direct on-site replacement requires identical original UGFSEM-A7LMG12X spare motor; non-brake C-type variant or other encoder specification standard motors cannot be directly substituted unless full connector rewiring and complete servo parameter reset are finished after replacement. Before disassembling for bearing inspection, brake maintenance or encoder overhaul, operators need to fully cut off 144VDC main armature power and 24VDC brake auxiliary power, then wait no less than 15 minutes for full discharge of servo internal DC bus capacitor to eliminate residual high voltage and avoid electric shock risk. Regular maintenance items include tightening rear connector fixing screws every three months, replenishing high-temperature resistant bearing grease after accumulating over 8000 continuous working hours and cleaning casing dust every half year to keep original heat dissipation performance. Random modification to LMG12X exclusive encoder pin definition and internal wiring layout will result in unexpected motor runaway and permanent servo drive locking fault.

This customized brake-equipped coreless DC servo motor is widely used for precision feed axes of bench micro precision processing equipment, indexing positioning turntable of tiny component automated assembly line, micro drive of optical inspection and testing equipment and compact precision packaging automation machinery, especially suitable for vertical installation working conditions with frequent start-stop movement, high dynamic response requirement and mandatory power-off anti-drop positioning constraints.