Step Motor Technology & Applications
21Pages

The stepmotor isa positioning actuator designed toproduce motionin stepsӔ (basically200 mechanical positionsof 1.8 degreesper turn) The stepmotor can be controlledin anopen loop scheme without anyfeedback device. An encoderor a position sensorcan be used asposition feedback. Stepmotordrives supplythewinding currents necessaryto movethe motoraccording to stepcontrolpulses. >

Thestepperdirect driveis an effective competitorofgeared brushlessmotor in highprecision low speed actuators MC E M G L ED > Backlash MC= Master controllerD = Drive G =GearE =Shaft encoderL =Load StepperBrushless MC M L ED > Backlash size="-1">

FOUR LEADS / CLAMPSsteppersfit twotransistorbridges bipolar drives (right) EIGHT LEADS / CLAMPS stepperscan beconnected tothe drive in a seriesor parallel windingsconnection >

The motordissipation is basicallytheresultof the overdriverequired forhighspeed performances The overdrive (OVD)is defined asthe ratiobetweenthesupplyDC busvoltageand the motorvoltagerating (R*I) MotorsPowerbalance Pin =Pd+P > M Pd=Pcu+Pfe+Pm Pcu= R*IҲ Pfe=dependingonmotors speedand OVD Efficiency= P > M / Pin >

Themaximum allowablemotor temperatureis limited bytheinsulation materials usedinside the motor > Motor temperature =Pd*Rt+TaWhere Pd isthe powerdissipated bythe motorduringthe workingcycle >

NEMAFlange sizes HoldingTorque ranging from0.045Nmupto30Nm SplashproofӔ, Heavy DutyӔ and IP55Ӕversions available with different shaft dimensions Best performance/price ratio >

Optimized ThermalDesign Magneticdesign for highest torque High torqueball bearings characteristics >

2.Computethemotors torquerating:A motormust be able to:?Overcome any frictional loadin theapplication ?Start and Stop the totalinertia load including its rotor inertia >

3.Fromthemaximum torqueandactual speed:usingthemotors speed-torque characteristics selectthepropermotorto be usedIn the motordefinitiononemust consider:-motorto load inertiaratio -gearbox features >