UGFMED-C9EAP21 YASKAWA MINERTIA CORELESS DC SERVO MOTOR PRODUCT SPECIFICATION

UGFMED-C9EAP21 belongs to Yaskawa classic F-series Minertia coreless DC servo motor family, a low-inertia high-response coreless direct-current servo drive unit engineered for precision automation, inspection equipment and high-speed positioning machinery. Differentiated from B-code brake models, prefix C indicates non-brake bare shaft configuration without built-in power-off electromagnetic brake, designed for horizontal installation axes that do not require gravity drop prevention after power cut. The motor adopts proprietary cup-shaped coreless rotor structure without silicon steel laminated core inside winding, featuring ultra-low rotor inertia, negligible cogging torque and ripple-free low-speed rotation; the whole unit relies entirely on natural air convection heat dissipation with no auxiliary cooling fan mounted on casing. Suffix EAP21 stands for factory-customized incremental rotary encoder with exclusive pin definition, unique internal wiring layout and fixed outgoing cable specification distinct from MMG-series encoder variants; digit 9 defines unified frame size and fixed rated power tier for this model lineup.

UGFMED = base series designation of Yaskawa Minertia coreless DC servo motor; C = non-brake standard version without integrated fail-safe electromagnetic brake assembly; numeral 9 = standard frame dimension matching 0.9kW rated power grade; EAP = customized incremental encoder specification group with proprietary terminal assignment standard; last two digits 21 = factory internal variant code determining encoder pulse resolution, factory default cable length and rear connector pin layout exclusive to this model.

The motor is standardized for 144VDC rated armature input voltage and specially matched with legacy Yaskawa Minertia dedicated DC servo amplifier drive systems. Its continuous rated output power is 0.9kW, steady full-load rated armature current stands around 7.2A under nominal working status, with fixed rated rotating speed at 1750rpm and stable continuous rated torque output during cyclic continuous load operation. Instantaneous peak overload torque can reach up to 3.5 times rated torque to satisfy high acceleration startup and short-duration impact load demands. Without built-in brake coil, this model removes independent 24VDC brake auxiliary power circuit to simplify on-site wiring layout. The customized EAP21 incremental encoder adopts differential line-drive signal output following exclusive factory pin definition, which cannot be directly replaced by MMG series encoder wiring; mismatched connector pinout will result in loss of closed-loop position feedback and abnormal motor runaway. Internal stator winding complies with Class F insulation grade, embedded built-in thermal sensing component transmits overheat fault signal to paired servo controller to trigger automatic overload stop and avoid winding burnout under long-term overloading; internal wiring cavity is pre-installed with surge suppression components to suppress industrial field impulse voltage and peripheral inverter electromagnetic interference efficiently.

The fully enclosed motor housing carries IP54 protection grade against solid dust and splash water ingress, adopting full shell natural heat dissipation without external fan structure. Front drive end is standard solid output shaft with integrated flat keyway for rigid coupling with precision reducers, miniature ball screws and timing belt transmission assemblies; owing to no rear-mounted brake module structure, overall axial length is shorter than same-frame brake-equipped B-series counterparts, and complete unit net weight is approximately 3.9kg with unified standard flange mounting dimension for direct equipment frame installation without extra transition fixtures.

Permitted continuous working ambient temperature ranges from 0°C to +40°C; spare part long-term storage temperature covers -20°C up to +70°C; applicable operating relative humidity is maintained within 5%RH~80%RH under non-condensing working condition to eliminate dew-induced internal circuit short-circuit risks. If installation altitude exceeds 1000 meters above sea level, users need to properly derate continuous operating load to compensate reduced heat dissipation efficiency under thin atmospheric environment. The motor is resistant to regular industrial vibration within 10Hz~55Hz frequency range; working locations with persistent corrosive gas, continuous liquid splashing and heavy conductive dust accumulation are prohibited to extend service life of front end bearing and internal winding components.

UGFMED-C9EAP21 is originally compatible with vintage Yaskawa dedicated Minertia DC servo drive modules, supporting two mainstream external command input modes including ±10VDC analog voltage speed instruction and differential pulse position command transmitted from upper PLC or compact CNC host controller. The matched servo control system supports seamless switching among position closed-loop control, speed closed-loop control and torque closed-loop control to adapt diverse production technological requirements. As no built-in power-off brake is configured, vertically mounted equipment using this motor must be equipped with independent external mechanical locking or holding brake structure to avoid load free falling during unexpected power failure. With incremental-type EAP21 feedback encoder equipped, complete mechanical origin homing operation must be executed after full system power cut before formal equipment startup to recover accurate mechanical zero point for subsequent precision positioning movement.

Cooperating with matched dedicated servo amplifier, the motor realizes comprehensive multi-layer safety protection mechanism. Winding over-temperature signal triggers servo automatic overload shutdown to protect coreless winding from thermal damage; open circuit or poor contact of customized EAP21 encoder cable will trigger independent encoder fault warning displayed on servo operation panel; internal winding short-circuit and abnormal overcurrent input activate driver hardware overcurrent protection with immediate main power cutoff. All internal feedback signal circuits are fitted with noise filtering components to filter complex on-site electromagnetic interference and ensure stable position feedback signal transmission.

On-site equipment maintenance replacement must adopt identical original UGFMED-C9EAP21 spare motor; brake-equipped B-series variant or other encoder specification motors cannot achieve direct substitution unless full connector rewiring and complete servo drive parameter reset work are finished after replacement. Before disassembling motor for bearing inspection and encoder overhaul, maintenance personnel shall fully cut off 144VDC main armature power supply, then wait no less than 15 minutes for full discharge of servo internal DC bus capacitance to eliminate residual high voltage and prevent electric shock accidents. Standard periodic maintenance items include tightening rear connector fixing screws every three months, replenishing high-temperature resistant bearing lubricating grease after accumulating over 8000 continuous running hours and cleaning casing accumulated dust semi-annually to retain original natural heat dissipation capacity. Random modification to exclusive EAP21 encoder pin definition and internal wiring layout will lead to out-of-control motor rotation and permanent servo driver locking failure.

This non-brake low-inertia coreless DC servo motor is widely applied for horizontal precision feed axes of bench high-precision micro machining equipment, indexing positioning platform of small precision parts automated assembly line, micro drive unit of optical inspection and testing machinery and compact precision packaging automation devices, especially suitable for horizontal installation working conditions requiring frequent start-stop motion, ultra-fast dynamic response and high-precision repeated positioning control without vertical anti-drop constraint.