Turnkey Design Services has developed unique Variable Speed Drive Technology (VSD) that allows a gearbox driven device to perform like a motor driven device without the weight penalty and associated reduction in reliability as with a high power electric motor. This electro-mechanical drive is capable of setting and maintaining rotary speed independent of the prime mover speed. It is a self-powering drive that can be attached to an existing gearbox or incorporated into the initial design of a new device. When incorporated into the initial design, the VSD becomes an electronically controlled gearbox with power generation capability


This technology is available in fractional HP to 100 HP drives.


The technology is demonstrated in these videos.


In this video a constant speed motor (left readout) drives the VSD Technology whose output speed (right readout) is electrically varied by turning a wheel.




In this video as the prime mover speed varies between 1250-3000 RPM the VSD alternator speed is maintained between 5000-6000 RPM.





●    Always operate rotating machinery at best efficiency point

●    Reduce fuel consumption

●    Improve thermal efficiency

●    Increase hydraulic component life

●    Double power generation at idle speeds

●    Operate generator at desired frequency



ADVANTAGES over Existing CVTs:

The technology has distinct and significant advantages over existing CVT technology:

●    No disengaging or re-engaging gears for longer life and smoother operation

●    No belts result in higher power density

●    No clutch sheaves make for maintenance free

●    High horsepower capability

●    Self-powering, electronically controllable without the use of clutches or brakes




The technology provides benefits in the following industries:

●    Aerospace (Flow On Demand pumps & Air Cycle Machines)

●    Power Generation (turbine & mobile vehicles)

●    Refuse and Heavy Construction (Flow On Demand Pumps)

●    UAV (control propeller & power generation)

●    Machinery (optimize speed & torque conditions on demand)