2 reasons; first, motors and drive electronics are both heat producing systems. In order to combine them you have to derate the assembly to prevent damage, and second, motors are designed by mechanical engineers, motor drive circuits are designed by electronics engineers. The two disciplines and attending manufacturing processes are completely different.
Chuck, A primary reason to separate motors and drives in the past has been packaging the two together, and especially the ability of the drive to handle heat. There is significant technology involved in mounting the drive to the top of the motor, but it is still an issue as motor/drive combos go up in torque (with resulting increases in heat).
There is currently much discussion around the term "platform," which may be preceded by the adjectives "mobile," "wearable," "medical," "healthcare," etc. However, regardless of the platform being discussed, they usually have one key aspect in common: They tend to be wireless. So, why is this one aspect so fairly universal? The answer is convenience.
Everyone has a MEMS story. For most of us it’s probably the airbag that saved our lives or the life of a loved one. Perhaps it’s the tire pressure sensor that alerted us about deflation before we were stranded alone on a dark muddy road.
Bioimimicry is not merely a helpful design tool -- it also encourages designers to think not only about how to solve design problems by imitating nature, but how to make the products, materials, and systems they design more ecologically sound and nature-friendly.
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