DynaTorqueHub working principle

A high performance wave gearbox gets directly actuated by electromagnetic forces. In this case the wave gearbox is a wobble plate design where a round disc "tumbles" around a center point. The circumference of the disc "rolls" along the circumference of a second fixed stator side disc. Since the two circumferences have slightly different length, a relative motion between the two parts is induced leading to a high gear ratio. When creating the tumbling disc from ferromagnetic materials this motion can be enforced using electromagnetic coils arranged axially around the circumference of the fixed stator side disc. 

Potential advantages over classical motor/gearbox combinations

While classical designs for high torque actuators consist of a rotating electric motor and a gearbox with rotating input and rotating output shaft, the DynaTorqueHub has no rotating input shaft. This simplifies the design leading to:

• fewer parts with reduced failure modes and potential cost savings
• reduced axial length 
• zero gyroscopic effects from a fast spinning input shaft
• no acceleration counter torque

However there is one advantage sticking out above all. This is the very low mechanical inertia of the tumbling disc leading to 

• excellent acceleration performance

This characteristic makes the drive unit well suited for the next generation robotic market where robots start walking, jumping, and performing tasks requiring high dynamic motions. 

Furthermore the gear mechanism has some unique and beneficial characteristics. Since the gears are held in place by magnetic forces rather than mechanical constrains the gears can:

• accept a wide temperature range without the risk of jamming
• disengage/engage by controlling the coil currents accordingly. Enabling the output shaft to spin freely.