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).
If you see a hitchhiker along the road in Canada this summer, it may not be human. That’s because a robot is thumbing its way across our neighbor to the north as part of a collaborative research project by several Canadian universities.
Stanford University researchers have found a way to realize what’s been called the “Holy Grail” of battery-design research -- designing a pure lithium anode for lithium-based batteries. The design has great potential to provide unprecedented efficiency and performance in lithium-based batteries that could substantially drive down the cost of electric vehicles and solve the charging problems associated with smartphones.
Robots in films during the 2000s hit the big time; no longer are they the sidekicks of nerdy character actors. Robots we see on the big screen in recent years include Nicole Kidman, Arnold Schwarzenegger, and Eddie Murphy. Top star of the era, Will Smith, takes a spin as a robot investigator in I, Robot. Robots (or androids or cyborgs) are fully mainstream in the 2000s.
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