Technical DataCoreless Motor

Coreless Motor

What is a DC Coreless Motor?

It is a type of motor in which only the coil is wound in a cup shape without the core (iron core) in the rotor. A cylindrical magnet is placed inside the rotor.

Features of DC Coreless Motors

・Since there is no core (iron core), there is no repeated movement attracted and repulsed by the magnet, and there is no uneven rotation (cogging) and it rotates smoothly. Therefore, vibration and noise are low.

・Since the rotor is made with only a coil, it is very light and has a small moment of inertia, so it has excellent control such as responsiveness and acceleration.

・It has various merits such as low inductance of the coil, high efficiency and low current consumption, very low electrical noise, and miniaturization and quantification.

Citizen Micro DC Coreless Motors

We achieved small size and high output through excellent precision processing technology and our own winding technology (New coreless motors with φ8 have been developed for a wider range of applications from the previous φ10~24 series)

Precious metal brushes and graphite brushes can be selected (above φ13), and the precious metal brushes use our own technology for longer life.

In addition to the standard catalog products, it can be customized according to customer requirements (winding change, ball bearings, shaft length, biaxial, harness and more)

Magnetic and optical rotary encoders and various planet and spur combinations are possible.

Type Diameter Length Rated output
SCR8-17xx φ8 16.8 0.21W
SCR10-17xx φ10 17.0 0.26W
SCR10-25xx φ10 24.6 0.66W
SCR12-13xx φ12 13.2 0.12W
SCR12-18xx φ12 18.5 0.12W
SCR12-26xx φ12 26.3 0.97W
SCR13-20xx φ13 20.5 1.13W
SCR13-28xx φ13 29.0 2.01W
SCR16-25xx φ16 26.2 2.10W
SCR16-35xx φ16 36.2 1.42W
SCR17-25xx φ17 26.2 2.06W
SCR17-35xx φ17 36.2 4.34W
SCR18-37xx φ17.55 36.8 5.00W
SCR21-37xx φ21 36.8 5.74W
SCR24-32xx φ24 32.0 10.2W
Features of DC Motor Coreless Iron core
Features of Brush Material Precious metal Graphite
Electric noise
Large current load
Forward/reverse repetition
Continuous high speed
PWM/PLL control

Coreless Motor

  1. ① Cap
  2. ② Terminal
  3. ③ Brush base
  4. ④ Brush
  5. ⑤ Commutator
  6. ⑥ Coil
  7. ⑦ Shaft
  8. ⑧ Bearing
  9. ⑨ Magnet
  10. ⑩ Housing
  11. ⑪ Bearing
Coreless motor

Iron Core Motor

  1. ① Terminal
  2. ② Brush base
  3. ③ Brush
  4. ④ Bearing
  5. ⑤ Shaft
  6. ⑥ Commutator
  7. ⑦ Coil
  8. ⑧ Iron core
  9. ⑨ Magnet
  10. ⑩ Housing
  11. ⑪ Bearing
 Iron core motor