Empire Magnetics offers hollow-shafted motors for industrial processes, such as manufacturing fiber optic cable and designing radar antennas, robots, and high-speed laser scanner systems. Direct-drive hollow-shaft motors increase speed and acceleration, while providing better accuracy and faster response times when compared to motor driven mechanical arrangements. Mechanical drive arrangements add inertia to a system, resulting in greater power requirements for rapid moves and increasing settling time on positional moves. The system weight may also increase and it may cause positional errors such as backlash. In applications appropriate for direct-drive hollow motors, the time of a move may be reduced by up to 80% (e.g. from approximately 50 msec to less than 10 msec).
To properly specify a direct-drive hollow-shaft motor, the design engineer needs to: define the move profile that is desired, distance, move time, settling time, duty cycle and the inertia of anything the motor is moving. For continuous moves at a constant velocity like a laser system, the demands on the motor are typically easier unless this happens to be running in a vacuum where the scanner is on a satellite designed to map the surface of a planet. High repetition rate positional moves are sensitive to inertia matching and types of coupling, in addition to harmonic vibrations in the mounting structures.
Specific industrial automation processes where the production machine benefits from a hollow motor include: cable winding, coax cable wrapping, fiber optic depositions, optical systems (where rotating the optic with the beam on centerline is advantageous), custom linear actuators and space-constrained applications where coaxial mountings make a smaller package. Additionally, Empire Magnetics provides hollow-shafted motors for extreme and challenging environments including vacuum/space, waterproof/deep sea, radiation resistant and others.
For more information, visit www.empiremagnetics.com.
Filed Under: Motion Control Tips