It was called uServo, which was just released in December 8th, by UFACTORY Inc, a company that is engaged in open source robotic arms. They said they designed uServe by using a lot of research and development, to focus on Quality and process naturally run good results. uServo was designed not just compatible with their robotic arm, it would will run any maker`s awesome idea, to be the core of mechanical mechanism.
Here is some technical specifications about uServo:
Motor Type Coreless
Unloaded Speed 37.9 RPM
Resolution 12bit
Maximum Power 10W
Rated voltage 5V-7.2V
Torque 15kg-cm
Size in Millimeters 40×20×43
Weight 80g
Communication Interface USB Serial Port
uServo looks very cool! There is an amazing RGB LED status ring located on the body of the uServo. When the motor is on and ready to move, the LED will shine blue, and if the conditions are not ideal, the LED will be red. You can also customize the code for the lights to display different colors based on different situations.
The uServo’s design is made up of new high precision gears with a coreless motor, improving the mechanical backlash to be less than 0.3°!
12-bit resolution, 360º operation range. Usually, hobby servo motors can only rotate about 180°, however the uServo can now rotate the full 360°.
Lastly, this little gadget is designed with bus communication and programmable firmware, you can connect multiple motors to one another through the Downlink and Uplink interface. This creative change can effectively save the IO port of main board—allowing the same control with a cleaner arrangement of wires—small but smart.
Programmable firmware is a charming design for us makers. You can program and redefine the uServo through the USB2.0 interface.
Wikipedia has a nice description:
Special magnetic motors[edit]
Rotary[edit]
Ironless or coreless rotor motor[edit]
A Miniature Coreless Motor
Nothing in the principle of any of the motors described above requires that the iron (steel) portions of the rotor actually rotate. If the soft magnetic material of the rotor is made in the form of a cylinder, then (except for the effect of hysteresis) torque is exerted only on the windings of the electromagnets. Taking advantage of this fact is the coreless or ironless DC motor, a specialized form of a PM DC motor.[62] Optimized for rapid acceleration, these motors have a rotor that is constructed without any iron core. The rotor can take the form of a winding-filled cylinder, or a self-supporting structure comprising only the magnet wire and the bonding material. The rotor can fit inside the stator magnets; a magnetically soft stationary cylinder inside the rotor provides a return path for the stator magnetic flux. A second arrangement has the rotor winding basket surrounding the stator magnets. In that design, the rotor fits inside a magnetically soft cylinder that can serve as the housing for the motor, and likewise provides a return path for the flux.
Because the rotor is much lighter in weight (mass) than a conventional rotor formed from copper windings on steel laminations, the rotor can accelerate much more rapidly, often achieving a mechanical time constant under one ms. This is especially true if the windings use aluminum rather than the heavier copper. But because there is no metal mass in the rotor to act as a heat sink, even small coreless motors must often be cooled by forced air. Overheating might be an issue for coreless DC motor designs.
Among these types are the disc-rotor types, described in more detail in the next section.
Vibrator motors for cellular phones are sometimes tiny cylindrical PM field types, but there are also disc-shaped types which have a thin multipolar disc field magnet, and an intentionally unbalanced molded-plastic rotor structure with two bonded coreless coils. Metal brushes and a flat commutator switch power to the rotor coils.
Related limited-travel actuators have no core and a bonded coil placed between the poles of high-flux thin PMs. These are the fast head positioners for rigid-disk ("hard disk") drives. Although the contemporary design differs considerably from that of loudspeakers, it is still loosely (and incorrectly) referred to as a "voice coil" structure, because some earlier rigid-disk-drive heads moved in straight lines, and had a drive structure much like that of a loudspeaker."
I'll be damned! Thanks for the info. I had no idea that is what it is called.
A year ago the theta motor on the head of one of my Mydata pick-and-place machines quit working because the brushes went out, as I recall. Made in Germany. Replacement cost about $500. Of course, I had to disassemble it and it looked exactly like the picture you posted.
Better than that, you can get brushless coreless motors! That's how its possible to get 1,000,000 rpm
electric motors (http://www.celeroton.com/en/products.html). That's 16667 rotations per second...
