UGTMEM-03LB2 Minertia Mini Series Coreless DC Servo Motor Specification

UGTMEM-03LB2 belongs to Yaskawa (Nidec) Minertia Mini compact coreless brushed DC servo motor family, originally developed for precision miniature automation, EDM wire cutting equipment, precision lab test instruments and compact small-scale automated positioning machinery. This motor features proprietary cup-type coreless rotor design without laminated silicon steel, eliminating cogging torque inherent to conventional iron-core motors and realizing ultra-smooth low-speed running with minimal torque fluctuation and ultra-low rotor inertia for fast dynamic acceleration and frequent start-stop operations. The unit is constructed without built-in electromagnetic power-off holding brake and excludes integrated DC tachometer feedback component as standard configuration; LB2 coding stands for factory fixed terminal pin definition, direct tab-type power wiring structure and exclusive internal winding cabling layout different from LB suffix variants equipped with tachometer or modified shaft structure. The product has been officially discontinued by original manufacturer and only available via aftermarket surplus or refurbished spare parts supply.

UGTMEM is the base series identifier for non-brake Minertia Mini coreless DC servo motors; digit 03 denotes medium-small frame size corresponding to standard 45W rated continuous output power. LB represents standard wiring specification group with tab terminal connection and no built-in tachometer generator; suffix 2 specifies fixed factory shaft dimension, internal wiring layout, housing machining standard and outgoing connection definition, which cannot be directly interchanged with LB1, LB3 or LB2S coded motor versions due to inconsistent pin allocation and internal circuit arrangement. Any cross replacement requires complete terminal rewiring and servo drive parameter re-calibration.

The motor is designed for 22.5VDC rated armature operating voltage and must be matched with dedicated Minertia series DC servo amplifier to build closed-loop speed control system. Under nominal standard operating condition, continuous rated output power is 45W, rated full-load armature current reaches 4.5A, rated continuous operating speed is 3000rpm with short-duration peak transient speed up to 3600rpm. Rated continuous torque stands at 0.3Nm while instantaneous peak overload torque can hit five times rated torque to cope with cyclic frequent start-stop and instantaneous impact load demands. Without onboard tachometer feedback, the servo system relies on driver-side current closed-loop or external separate encoder installation to realize precise speed regulation; internal stator winding follows Class F insulation grade with embedded built-in thermal protection component that feeds overheat trigger signal to matched servo drive for automatic power cut-off against winding over-temperature burnout. Surge absorption components are preinstalled inside internal wiring cavity to suppress industrial instantaneous voltage surge and surrounding electromagnetic interference from switching power supplies and drive modules. Armature resistance is 2.5Ω and armature inductance is 1.2mH under room-temperature standard test environment.

The fully enclosed motor housing achieves IP54 ingress protection grade and adopts full natural convection heat dissipation without auxiliary cooling fan structure. Standard solid output shaft with plain cylindrical structure is reserved for connection with small timing belt pulley, miniature precision gear reducer and micro ball screw assembly; overall flange mounting dimension is unified at 70mm×70mm square standard, overall body dimension is 70mm×70mm×55mm and net total weight of complete motor assembly is approximately 2.08kg.

Valid continuous working ambient temperature ranges from 0°C to +40°C; spare part long-term storage temperature spans -20°C to +70°C; applicable operating environment relative humidity is limited within 5%RH~80%RH under non-condensing condition to avoid dew-caused internal winding short-circuit damage. If installation altitude exceeds 1000 meters above sea level, continuous operational rated load must be properly derated to offset degraded heat dissipation efficiency under thin air circumstance. The motor can withstand regular industrial vibration within 10Hz~55Hz frequency range; installation locations with corrosive gas, continuous liquid splash and piled conductive dust are forbidden to extend service life of front-end bearing and internal brush assembly.

UGTMEM-03LB2 is exclusively compatible with original Yaskawa Minertia dedicated DC servo controllers, supporting ±10VDC analog voltage speed command as primary control input from upper-level PLC or motion controller. The matched drive system supports speed closed-loop dominant control mode; for position control application, users need to add external standalone incremental encoder on motor shaft end for position feedback and modify drive control parameters accordingly. Due to no built-in power-off brake configured, vertically installed equipment adopting this motor must be equipped with independent external mechanical locking fixture to prevent unexpected load free falling upon sudden power failure. Since no integrated speed feedback tachometer is equipped by default, low-speed stable running accuracy relies heavily on drive’s internal current loop algorithm and external optional feedback device.

Multi-layer comprehensive safety protection is realized via coordination between internal embedded thermal sensing element and matched servo drive unit. Winding over-temperature signal triggers automatic servo overload shutdown to prevent permanent thermal damage of coreless winding; open circuit or poor contact of tab-type power terminal leads to drive overcurrent fault alert and main power cutoff; winding internal short-circuit will activate hardware overcurrent protection for instant power cut. Internal armature circuit is equipped with built-in noise suppression elements to filter on-site electromagnetic interference and stabilize operating current fluctuation under complex industrial environment. Excessive brush wear caused by long-term operation will lead to abnormal current rise and corresponding drive overload warning prompt.

Field replacement requires identical original UGTMEM-03LB2 spare motor; same-power motors with tachometer-equipped LB series coding or brake-attached variants cannot be directly installed for substitution unless full terminal rewiring and comprehensive servo parameter resetting are finished after mounting. Before disassembling motor for brush replacement or bearing inspection, maintenance personnel must completely cut off 22.5VDC main armature power supply and wait no less than 15 minutes for full discharge of servo internal DC bus capacitor to eliminate residual high voltage and avoid electric shock hazard. Routine maintenance items include checking carbon brush residual length every three months, replacing worn-out carbon brush parts when residual thickness is less than 1/3 of original size, replenishing high-temperature resistant bearing grease after cumulative continuous running time exceeds 8000 working hours and cleaning housing accumulated dust every half year to retain original natural heat dissipation efficiency. Random modification on LB2 exclusive terminal pin definition and internal wiring layout will result in abnormal motor runaway and permanent servo driver locking fault.

This compact non-tachometer coreless DC servo motor is widely used for wire feed driving axis of EDM wire cutting machine tools, micro indexing rotary platform of miniature electronic component automatic assembling lines, fine driving unit of optical microscopic inspection equipment and small-sized precision laboratory testing automation equipment. It is especially suitable for horizontally mounted compact equipment with limited installation space, frequent cyclic start-stop movement and medium-precision repeated positioning control requirements.