Dual Circular Spline Harmonic Drives: Unveiling Enhanced Torque and Performance in Specialized Gear Systems

How It Works

In a harmonic drive with two circular splines:

• The wave generator still deforms the flexspline into an elliptical shape, as in the standard design.
• Instead of engaging with just one rigid circular spline, the flexspline interacts with two circular splines , which are typically positioned concentrically or in a way that they both mesh with the flexspline’s external teeth.
• The two circular splines might have slightly different tooth counts or be arranged to work in tandem, depending on the design. For example, one could be fixed while the other serves as the output, or both could be fixed to split the load.

Real-World Examples

Advantages

• Increased Torque : More teeth in contact means better torque transmission.
• Improved Stiffness : Dual splines can reduce torsional deflection under load.
• Load Sharing : Distributing forces across two splines can enhance durability.

Trade-offs

• Complexity : Adding a second circular spline increases manufacturing and assembly challenges.
• Cost : These designs are typically more expensive.
• Size : While still compact, they may be slightly larger or heavier than single-spline versions.