Lesson 7 : HOW THE ARCHIMEDES DRIVE WORKs?

Summary of the lesson:

After laying the foundation in the last two classes, the Archimedes Academy by IMSystems finally introduces the Archimedes Drive—a novel traction-based drive that blends the best of two worlds: planetary traction drives and compound (Wolfrom) drives. The result? A revolutionary mechanism that retains the advantages of both systems while eliminating their core disadvantages.

> Part 1: Recap: Why Combine Traction and Compound Drives?

Let’s quickly revisit the building blocks of the Archimedes Drive:

  • Planetary Traction Drives replace gear teeth with traction rollers, enabling low noise, no backlash, high efficiency, and smooth operation—but suffer from low gear ratios and complex mechanisms to prevent wear and fatigue.

  • Wolfrom Drives introduce a second planetary layer to achieve extremely high gear ratios and compact design, but they struggle with low efficiency, complex manufacturing, and high cost.

So, what if you could combine their strengths?

That’s exactly what Jack, inventor and CEO of IMSystems, set out to do.

> Part 2: The Archimedes Drive: The Innovation

Jack envisioned replacing the gear-based torque transmission in a Wolfrom drive with traction rollers. That small but powerful switch gave birth to the Archimedes Drive.

Key Concept: The Flexroller

At the heart of this innovation is the flexroller—a hollow friction roller that integrates a step size. This design not only enables traction-based torque transfer but also allows for micron-scale control over gear steps—something gears can’t match.

This micrometric step difference enables ultra-high gear ratios, up to 10,000:1 in a single stage, while maintaining mechanical simplicity and compactness.

> Part 3: Why “Archimedes”?

Archimedes famously said:

“Give me a lever long enough and a fulcrum on which to place it, and I will move the world.”

The Archimedes Drive quite literally applies this idea through its internal mechanical “lever” system, using the ground annulus as a fulcrum to transmit force from a small input to a much larger output.

> Part 4: Eliminating Disadvantages, Keeping Advantages

Let’s walk through how this drive architecture improves upon both traction and compound drives:

PropertyPlanetary Traction DriveWolfrom DriveArchimedes Drive
High Efficiency❌ (30% typical)
No Backlash❌ (gears introduce play)
Lightweight / Hollow Structure
Compact Design
High Torque Density
Manufacturing Simplicity✅ (uses smooth cylinders)
Controlled End-of-Life
High Gear Ratio✅ (Micron-scale step control)

> Part 5: Engineering Highlights

  • No planetary axles: The Archimedes Drive eliminates the need for stable axles in the planet wheels by introducing a second annulus gear as the grounded element.

  • No gear meshing: Replacing traditional gear teeth with smooth friction rollers simplifies alignment and reduces manufacturing costs.

  • Micron-level precision: With step size no longer tied to discrete gear teeth, engineers can precisely tune gear ratios by controlling roller geometry alone.

Conclusion:

The Archimedes Drive isn’t just another theoretical breakthrough—it’s a practical and scalable advancement in motion control. It solves the exact problems that have limited traction and compound drives for decades, making it a serious contender for next-gen robotics, aerospace, and industrial automation.

If you were impressed by traction or Wolfrom systems individually, the Archimedes Drive will feel like a culmination of mechanical design evolution.