Variable speed drive system

A variable speed drive for driving a device, the device having at least one rotary element, the variable speed drive comprising:

• a compound planetary gear set driving said rotary element of the device at a speed via an output drive shaft;
• said compound planetary gear set including a first internal ring gear adapted for engage an external drive, a plurality of planetary gears engaging said first internal ring pear and being operatively connected to a sun gear operatively associated with said output drive shaft, and a second internal ring gear engaging said plurality of planetary gears with a bearing ring interconnecting said first and second internal ring gears;
• a motor operatively connected to said compound planetary gear set, wherein said motor includes a stationary stator for applying variable amounts of torque against a rotor fixed to said second internal ring gear of said compound planetary gear set so that said rotor rotates with and controls the rotation speed of said second internal ring gear to continuously vary the rotation speed of said compound planetary gear set by applying variable amounts of torque on said rotor to produce a variable speed ratio on said output drive shaft;
• a motor control comprising an electronic control module that receives an input signal and applies said variable amounts of torque to said rotor to adjust the rotation speed of said second internal ring gear to vary the speed of said output drive shaft based on said input signal;
• and,
• wherein said motor control contains power resistors for controlling an amount of current available for said stationary stator to apply torque to said rotor;
• whereby the variable speed ratio of said output drive shaft is adjusted only by the applicant of torque through electrical current to said rotor without the application of mechanical constraints to limit rotation of any portion of said planetary gear set.