Grundfos Challenge Ratchet Gearbox

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This ratchet-based gearbox may seem like an unexpected choice, but it offers several benefits. Despite its stepped motion, which can lead to a less-than-smooth output, this design suits low-ratio applications perfectly. The mechanism operates in both directions and locks cogs at every rotation to minimize hysteresis. Its compact size is another advantage, allowing for a 500:1 reduction ratio with just two stages, assuming the first set of cogs has 25 teeth and the second 20 (a simple correction can fix this mistake given more time). The design also features very low wear, as there's no slip movement during load transfer like in worm drives or spur gears. Additionally, high-load areas are engaged throughout the process, ensuring a stable connection. Minimal lubrication is required due to reduced friction on moving surfaces and constant load distribution across all surfaces. Finally, ease of manufacture comes from using stamped parts for the entire mechanism, including the cage, which can be produced from one stamping and folded sheet metal, making it easy to assemble with just four screws.