source：Design World
The TMR-075-16-001-2 limited angle torque motor utilizes a toroidally wound, stationary coil assembly with a two-pole permanent magnet rotor to generate torque.
The rare earth permanent magnet rotor always has an even number of poles, with two to six poles. The maximum angular excursion with a two-pole rotor is 180o, but the torque will drop off to zero at the extents of the travel. This model has a constant torque over a range of 75° or 1.31 radians.
The rotor assembly is installed within the ID of the stator assembly. There is a magnetic attractive force between the stator and the rotor. When the stator is perfectly concentric within the rotor, the radial magnetic attractive forces are equal and opposite, and they cancel each other out.
This style of torque motor is a kit style, which eliminates the need to align multiple bearings. Kit style actuators allow the motor to be installed in the existing system with built-in clearances to make the alignment easier during the integration process. Additionally, the low-profile nature of this actuator allows for the torque to be generated in a thickness of 0.40 in. (10.2 mm), and an overall outside diameter of 1.60 in. (40.6 mm).
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 two leads are brought out from the stator assembly.
A TMR-075-16-001-2 can generate a continuous torque, with a 100% duty, of 1.3 in-oz (0.9 N-cm), and peak torque at 10% duty of 4 in-oz (2.8 N-cm).
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 the motion to occur. The result is a much simpler and more reliable system.