Tested under a U.S. DOE/NREL wind-energy research contract (2005–2008). A Convoloid retrofit of a 108 kW two-stage wind gearbox ran back-to-back against an optimized involute at up to 240% of rated load. Convoloid tooth surfaces stayed stable while the involute’s micro-pitting progressed.
Gearbox failures are among the most costly and longest outages a turbine can have. Repairs need cranes, crews and weather windows.
Surface distress on heavily loaded teeth grows into pitting, debris and bearing damage. Once it starts, the clock is running.
Offshore and remote onshore sites multiply the cost of every unplanned visit. Life is worth more than first cost.
Published analysis (AGMA 11FTM19) shows 20–35% higher torque capability than an equivalent involute with the same center distance, ratio, materials and face width. Take it as margin against surface distress or as added capacity.
| Involute | Convoloid® | |
|---|---|---|
| DOE/NREL test, tooth surfaces | Micro-pitting progressed | Early micro-pitting self-arrested |
| Housing | Existing involute housing | Retrofit into the same housing |
| Noise at 200–240% load (audio) | Baseline | 12.8 dB quieter |
| Efficiency (measured) | 98.9% per gearset | 98.9% per gearset (parity) |
| Torque capability (AGMA 11FTM19) | Equivalent involute | 20–35% higher |
| Manufacturing | Carburize, harden, grind | Same processes |
Modern wind gearboxes lead with planetary stages. Convoloid sun–planet meshes have been fully designed and analyzed; a conjugate internal-ring algorithm exists, and ring-mesh optimization is a defined work package.
High-speed parallel stages can be helical or double helical. The Convoloid transverse profile carries over unchanged.
Wind is where Convoloid was put to the test at scale. The full NREL report is public. Noise results apply to steady, high-load duty.
Under a U.S. DOE/NREL wind-energy research contract (2005–2008), a Convoloid retrofit of a 108 kW two-stage gearbox ran back-to-back against an optimized involute at up to 240% of rated load. Convoloid surfaces stayed stable; the involute’s micro-pitting progressed.
See the source →Published: 20–35% higher torque capability than equivalent involute designs, rated per AGMA/ISO with the same derating factors applied to both (Berlinger & Colbourne, 2011).
See the source →US 10,527,149 in force to ~2036. European patent EP 3 387 294 granted, with Unitary Patent and UK validation, to 2036.
See the source →Noise and vibration were measured at 200–240% of rated load in the DOE/NREL test and apply to steady, high-load duty only (Convoloid 13 teeth vs involute 16 on the high-speed pinion, so mesh frequencies differ).
Barney Berlinger, Convoloid's inventor, explains what makes the tooth form different and why it matters for wind energy.
A short briefing for engineering and leadership: the problem, the technology, the comparison and the test record, in nine slides.