The main limitations of worm gear drives are as follows:
- Lower Efficiency: Due to significant sliding friction between the worm and wheel, efficiency typically ranges from 40% to 90%, depending on materials, lubrication, and lead angle. High reduction ratios often mean lower efficiency.
- Heat Generation: Friction generates heat, requiring effective cooling or thermal management in high-duty applications.
- Wear and Material Requirements: The worm wheel is often made of bronze or composite materials to resist wear, while the worm is hardened steel. Improper material selection accelerates wear.
- Limited Power Transmission: Generally not suitable for very high-power applications (above ~50–100 kW) due to heat and efficiency constraints.
- Axial Thrust Loads: Both the worm and worm wheel experience significant axial forces, requiring robust thrust bearings.