With miniaturization often comes the challenge to produce the same amount of work as in large design, thus creating more power in a smaller envelope. Engineers should look at the different impact of dimension on motor performance criteria (efficiency, power, thermal dissipation, inertia, etc.).
Looking at Brush DC ironless motors, this technology brings providers definitive advantages versus iron-core motors. Inertia is by essence much lower in ironless motors as the self-sustaining coil is free from heavy iron armature necessary in iron core. The envelop gain is immediate as the magnet is placed inside the winding instead of around it. Having no iron in the air gap, ironless technology is freeing the drive from iron losses; therefore the efficiency of the device is increasing. Linked with efficiency is the size of power supply, often batteries for portable medical devices, which will not need to be as powerful as for an iron core model. Having no iron losses the system power losses will be limited to friction and Joule losses.
Numerous suppliers are providing small gearboxes to the global market, but only few have the possibility to engineer custom units that will fit best into the customer environment. It is an absolute necessity to design specific mechanical arrangements in order that the customers can keep their technical edge and differentiate themselves on the market. This will also help OEM’s not to be copied when they launch a new innovative device.
Motion without control isn’t an option in most of today’s applications. This is why, in addition to a custom designed mechanical system, a matching encoder is required. Resolution and precision are keys to a safe medical device.
In general, optimizing one’s application with special care towards higher efficiency, lower losses, and system integration (complete solution) is the today’s key challenge in the miniaturization of medical devices. Educated R&D helps to provide the value required for the OEM to bring an innovative and producible device.