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).
The supply chain will change significantly over the next 10 years as industry 4.0 technology enhances supply chain performance, according to the 2015 MHI Annual Industry Report, “Supply Chain Innovation — Making the impossible possible.”
The engineers and inventors of the post WWII period turned their attention to advancements in electronics, communication, and entertainment. Breakthrough inventions range from LEGOs and computer gaming to the integrated circuit and Ethernet -- a range of advancements that have little in common except they changed our lives.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.