FAULHABER has extended its BXT flat motor series by adding corresponding gearheads and integrated encoders as well as speed controllers that are also exceptionally short in the axial direction. All components have been optimised to ensure that they function perfectly together. There are three different sizes available than can solve many different drive challenges. In the case of a lower-arm prosthesis, for example, the smallest drive with a diameter of 22 mm could be used for the hand and the 16 mm long motor for the elbow. Other possible applications for the small compact drive systems are robot grippers, industrial automation, humanoid robots and even bio- robotics for motorized – i.e. power-assisting – hand exoskeletons. And with precise speed control properties, they’re also suitable for medical applications such as dialysis machines or medical pumps.

Innovative winding technology for more torque
The motors were developed based on the classic external rotor design. With innovative winding technology and optimized construction, the brushless dc servomotors produce torques up to 134 mNm within a diameter of 22, 32, and 42 mm and deliver a continuous output of up to 100 W with a high level of efficiency. This means the compact motors significantly exceed the usual standards in this drive class. In particular, the ratio of torque to installation space and weight is much better than what is common. With a high copper filling factor and the design of the pole shoes, the magnetic field is strong and the cogging torque minimized. The motors are available with or without a housing, which extends the range of potential applications.

Metallic planetary gearheads with numerous reduction ratios
The GPT metal planetary gearhead family, which features compact dimensions and high torque, is suitable for speed reduction of the flat motors. The metal gearheads achieve performance values that are comparable to those of significantly more expensive technologies available, such as those that use ceramic components. The gearheads are available with motor-compliant diameters and offer reduction ratios from 3:1 to 1,294:1 with extremely fine graduations in up to four stages. Each stage was optimized for high performance with respect to torque and speed. Depending on the diameter, the gearheads achieve continuous torques of 1, 8 and 18 Nm. Higher torques are also possible for a short period.

The gearheads are robust, tolerating continuous loads as well as rapid load changes. They’ve been developed for limited axial installation space and are significantly shorter than other models with the same diameter. The single-stage 22 mm version, for example, is only about 18 mm long and the four-stage version approx. 37 mm long. With the 42 mm gearhead, the lengths are just under 31 mm and 68 mm respectively.

Housed encoder with high positioning accuracy
All BXT motors are equipped with digital Hall sensors and together with their large number of poles allow for precise speed control. The IEF3-4096 magnetic encoder is available for precise positioning tasks and is fully integrated in the housed motor variant, increasing the length of the overall drive by just 6.2 mm. It offers three channels with index function, a line driver and a resolution of up to 4,096 lines per revolution. The combination of motor and encoder is an ideal system solution in cases where extremely precise positioning must be performed in constrained spaces and, at the same time, high torques are required such as in robotics, medical technology, laboratory automation or industrial automation.

Integrated speed controllers complete the product range
Speed controllers are also available for the BXT motors. They’re integrated in the housed versions of the BXT motors and increase the motor length by just 6.2 mm. This lets both the encoder and the speed controller be installed in the same housing and also permits a large number of common parts to be used. Speed control is performed by the digital Hall sensors integrated in the motors. The compact combination of motor and speed controller is suitable for space-critical applications and simplifies installation and commissioning.

For more information, visit www.faulhaber.com/evolved/en.