What are the special features of ironless-rotor motor?
   Ironless-rotor motor is a DC, PM, servo and subminiature motor. The major difference between a common motor and an ironless-rotor motor is that ironless-rotor motor uses ironless-rotor.Ironless-rotor motor consists of the following advantages: Maximum energy exchange efficiency: the efficiency is in general over 70%,while some products even reach over 90%;
    Rapid response when start up and shut down: mechanical time constant is less than 28 milliseconds,whilst several of our products can attain in less than 10 milliseconds.
    It is responsive to speed adjustment, dependable operation stability, powerful adaptive ability.The fluctuation of running speed could be controlled in a very narrow range;
    Dependable operation stability:with its strong self-adjustment capability, self rotation is minimized;
    Light electromagnetism interference: Using high quality brush and commutator,commutation spark could be remarkably reduced, so that it's unnecessary to use anti interference equipment.
    Large power density:its weight and size are 1/3 - 1/3 less when compared with an iron core motor of same power.
    The opposite parameters of speed --voltage, speed --torque, torque --current are in the linear relation.
  How to determine the most suitable range for no load current of ironless
  rotor motor?
   The no load current of ironless rotor motor is at the range of 0.5-1.5% of stall current with the suitable requirements for motor structure design.
  How to decide motor's Assigned Power Rating?
   In general, it is assumed that Assigned Power Rating is between 1/4-1/6 of stall torque when designing motor;
    When deciding on Assigned Power Rating, the over current ability of winding has to be take into consideration;
    Set operating efficiency around 80% of motor Max. efficiency, to excel the capability of iron-less motor.
  Mechanical time constant  
   The time required for motor running up to 63% no load speed from the beginning.
  How to determine the efficiency of planetary gearbox?
    In general, one stair gear wheel transmission efficiency =90%, two stair gear wheel transmission efficiency =81%, efficiency =(90%). Gear box with better characteristics are mainly placed in this area according to genuine sample test results. The factor of gearbox efficiency should be considered during system calculations that contain gearbox.
  Why do axial play and radial play exist in ironless-rotor motors?
   Ironless-rotor motor currently has the greatest unit volume energy exchange density. Seeking for maximum unit volume energy exchange density in designing is a top icon in the level of manufacturing technology. However, the heat produced by operating motor will lead its intramural materials swelling, thus affect motor's operation status. To avoid this, motors were designed to leave certain play between materials, which are able to prevent the heat produced by motor itself or the external environment that has effect on motor's normal operation.
  What should we pay attention to when inspecting and installing ironless-rotor
  motor play?
   Due to the complex intramural construction of ironless-rotor motors, we should be particularly aware of that when examining, inspecting and installing the axial and radial load on the shaft which cannot exceed the limit stated in the manual for the sake of preventing any damages on motor's intramural construction.
Assigned Power Rating
(Unit:W)
Maximum output power
within limit for operating
range
Nominal Voltage (Unit : V)
Standard voltage in motor
design
Terminal Resistance()
The resistance between the
terminals of motor when rotor is at 25
No load speed (Unit : rpm)
Motor no load running speed at
nominal voltage
No load current (Unit : mA)
Motor no load operating current at nominal voltage
Speed constant (Unit : rpm/V)
The speed value at unit voltage at the condition of ignoring the counterwork of mechanical friction
Torque Constant (Unit:mN.m/A)
The torque value at unit current
Starting Current (Unit : mA,A)
The ratio that nominal voltage
divide by terminal resistance
Stall torque (Unit: mN.m)
The torque that the motor is in stall condition
Max. power output (MW,W)
Academic max. power output of
motor when the rotor is at 25
Max. efficiency (Unit : %)
The highest ratio that power
output is over power input
during the process of
continuous increase loading
Max. continuous current (mA,A)
Max. current value that winding permits going through when the motor is continuously operating.
Max. continuous torque (mN.m)
The torque at the max. continuous current
 

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