Limited Angle Torque Motors - H2W Technologies, Inc - #1

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H2W Technologies, Inc 28310C Ave Crocker Valencia, CA 91355 USA (888)-702-0540 (661)-702-9346 Ph (661)-702-9348 Fax www.h2wtech.com info@h2wtech.com Limited Angle Torque Motors H2W Technologies Limited Angle Torque Motors are ideal for compact, limited angular excursion (<180º), rotary, closed loop servo applications. Unlike conventional rotary brush and brushless motors, the torquers are wound in such a way that no commutation is required for motion to occur. The result is a much simpler and more reliable system. Torquers operate on the principal of the Lorentz Force (Torque) Equation Force or Torque = B X I where: B = Flux density (Tesla) I = Current (Amps) Simply stated, a current carrying conductor placed in a magnetic field will have a force (or torque) exerted upon it. This force is proportional to the direction and magnitude of the current and the flux density field. Since the permanent magnet flux density field is fixed, the direction of the rotation depends on the polarity of input current and the amount of torque that is produced is directly proportional to the magnitude of the input current. A DC linear servo amplifier is required to provide power to the torquer. The torquers are typically supplied unhoused without bearings or a shaft, but can be supplied housed if required. Coupling the torquer to your bearing system and a rotary encoder or other feedback device yields a system that is capable of intricate angular position, velocity, and acceleration control. Low moving inertia of the rotor assembly allows for high angular acceleration of the payload. The small length to diameter ratio allows the torquers to fit in spaces where conventional rotary brush and brushless DC motors will not. It should be noted that, angular excursions of greater than 180º (up to 360º) can be achieved by modifying the winding of the stator assembly. In this case the coil assembly will have 4 leads and it will have to be commutated. Advantages: • No Torque Ripple • High Angular Acceleration • No Commutation • Brushless • Low Profile Applications: • Aerospace • Semiconductor • Medical • Military H2W Technologies offers 2 distinct types of limited angle torque motors. 1. MR Series Limited Angle Torque Motor - is a toroidally wound iron core stator with a 2 ,4 or 6 pole permanent magnet rotor. This torque motor can provide angular excursions up to 180º. It is typically supplied without bearings, shaft or housing to allow for direct mounting to customer supplied bearing system. The MR Series is comprised of a toroidally wound, stationary, coil assembly with a multi-pole permanent magnet rotor. Rotor: The rare earth permanent magnet rotor always has an even number of poles, with any where from 2 to 6 poles. The maximum angular excursion with a 2- pole rotor is 180º, with a 4 pole rotor is 90º, and with a 6 pole rotor is 60º. The torque will drop off to zero at the extreme ends of the travel. For constant torque over the required rotation, the angular excursion will always be less than numbers mentioned above. The rotor is comprised of steel core with a thru hole for attaching the rotor to the shaft. Radially magnetized, multipole, rare earth, permanent magnets are bonded to the steel core. Depending on the application either Neodymium or Samarium Cobalt magnets are used. Stator: The stator is comprised of a “soft”magnetic steel toroid that is electrically insulated. Multiple sections of insulated copper magnet wire are toroidally wound on the stator toroid. Only 2 leads are brought out from the stator assembly.