What is a micro motor(ultra compact motor)?
If a "compact motor" has an output of 75W or less, the output of a "micro motor" is generally 3W or less. At this size, even a small-capacity power source such as a dry cell battery can run the motor. Therefore, there are many DC driven micro motors. There are not any AC micro motors that meet the above definition, which is most likely because at high currents, such as 100V, there is the risk of the mechanisms inside the miniaturized motor catching fire or short-circuiting.
Orbray has successfully developed the world's smallest φ0.6mm brushless motor, and the world's smallest φ1.5 geared motor. Since the components of micro motors are tiny, and the contact life is limited in configurations that use a brush and commutator, reliability is improved by making the motor brushless.
The achievements made addressing such technological challenges are attracting attention in cutting-edge fields such as medical care, robotics, and measuring instruments. One example is the hollow shaft motor, which we've used in the Optical Inner Wall Metrology System we launched on the market.
Specifications: standard brushless motor
Pro- ducts |
Dia. [mm] |
Length [mm] |
Nominal Voltage [V] |
Nominal Values |
No-Load | Stall | Mecha- nical time constant [ms] |
Max. effici- ency [%] |
Option | CAD download |
||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Torque [mNm] |
Speed [rpm] |
Cur- rent [mA] |
Output [W] |
Speed [rpm] |
Cur- rent [mA] |
Torque [mNm] |
Cur- rent [mA] |
Connection | Bearing | Encoder | ||||||||
sleeve | BB | with | no | |||||||||||||||
BMN04-0829 | 4 | 8 | 3.0 | 0.01 | 24,200 | 53 | 0.04 | 37,000 | 28 | 0.04 | 100 | 9.2 | 22 | A (sensorless) | ○ | ☓ | 2D 3D |
2D 3D |
Catalog model
BMN04-0829Application: hollow shaft micro motor DBL024

Orbray's micro motor DBL024 belongs to the world's smallest class of hollow shaft motors. Since optical fibers can be run through the hollow shaft, it is possible to construct ultra-compact optical actuators, which are expected to contribute to breakthroughs in leading medical and industrial fields, such as OCT* and endoscopy.
Based on this hollow shaft motor technology, Orbray developed an Optical Inner Wall Metrology System for use in the industrial measurement field. This system is capable of 3D measurement of the inner circumference of small-diameter holes in components – data which was previously limited and challenging to collect.
Orbray aims to meet the needs of cutting-edge medical and industrial fields with our hollow shaft micro motor.
*Optical Coherence Tomography = technology that uses near infrared rays to take tomographic images of samples.
Examples of potential applications:
- Medical / analytical measuring device
- Development of evaluation technology for internal state and progression of wear of important equipment such as infrastructure equipment, vehicles, and aircraft
- Construction of ultra-compact manipulators that have limited wiring space