H2W Technologies’ new high-force, non-commutated dc linear actuator, otherwise known as a direct-drive voice-coil actuator, is designed specifically for use in cryogenic environments. Material choice and design parameters were implemented such that the motor can operate without degradation or damage when placed in a cryogenic environment. The model NCC14-78-830-1SM can generate a continuous force of 92 lb (410 N) and a peak force of 294 lb (1300 N) at a duty cycle of 10% (i.e. 1 second on, and 9 seconds off). A moving mass of 4.4 lb (1.97 kg) allows for a maximum theoretical continuous acceleration of more than 20 g.
Although the motor can generate large forces, this specific actuator was designed for a relatively high motor constant, so that the required force can be generated with a relatively low power input. Additionally, the motor was designed to maximize the stroke output while preserving a minimal actuator length.
The NCC14-78-830-1SM has a stroke of 1.4 in. (35.6 mm) and a motor constant of 6.9 lb/sqrt(W) (31 N/sqrt(W)). The voice-coil motor requires 3.8 A of continuous current and 12.1 A of peak current in order to generate the specified forces. The actuator has a diameter of 7.87 in. (200 mm) and a retracted length of 3.50 in. (89 mm).
The moving coil design ensures a hysteresis free movement as the bobbin is constructed of aluminum while the non-commutated coil allows for ripple-free motion and no cogging. The voice coil actuator has been designed with a thru hole in the magnet and coil assemblies. This allows for the integration of a shaft and bearing system through the center of the motor. Alternatively, the actuator can be used in many applications where a thru hole would be necessary such as focusing applications or fiber optic routing.
For more information, visit www.h2wtech.com.