Machining of Hollow Shafts (crank system) with ECM Technology

For years, the hollow shaft has been established as the axle for the crank system in an eff ort to reduce weight.

However, due to the unique configuration of these workpieces, the traditional chip removal processes faced a number of unique challenges. Traditionally, the workpiece is hardened which increases tool costs, and with the low wall thickness of the hollow shaft can result in warping. With the EMAG ECM process, these problems do not exist.

Both the borehole and the external gears can be cut in hardened condition using ECM with no burrs or workpiece distortion, while also eliminating the need for finishing work.

The ECM machining process in detail:

1. ECM DEBURRING

• Defi ned edge rounding
• Multiple deburring in a single process step
• Reproducible (uniform quality)

2. ECM DRILLING

• Absolutely zero burr
• Drilling and rounding in a single process step
• Reproducible (uniform quality)

3. ECM BROACHING

• Broaching with no stress or tension
• Cost-efficient machining (tool costs)
• Soft and hard broaching in a single process step
• Reproducible (uniform quality)