Motion components can be as simple as a coil or a magnet and as complex as a special Titanium enclosure with a magnet or coil inside. Customers that use motion components are building a larger system and would like to integrate these components. Building a motion system from components is a good way to highly focus on performance and reduce the number of parts or couplings used. It used to be that that approach was used only for very high-volume projects like computer peripherals and automotive applications, today that is not the case as many machines and products utilize this approach.
This is a common approach with direct drive applications. Torque motors components are routinely used inside precision mechanical parts to create a rotary stage or a gimbal. Robotics is the fastest growing market, in most cases the robot itself is comprised of a series of components highly integrated into each robot joint. Very few robot suppliers mount an existing motor with a shaft and coupling to their robot joint any longer.