Variable Oscillation Angle Fan

What it does

By optimizing the mechanical structure, the fan can provide an adjustable angular travel of oscillation, solving the limitation of fixed oscillation angle in meeting user's diverse needs.

Your inspiration

The oscillation angle of conventional fans is fixed, making it difficult to accurately match the required airflow range in practical use. Either the desired range is small and the fan's oscillation angle is too large, causing energy waste, or the desired range is too large and the fan's oscillation angle is insufficient, failing to provide complete coverage. Therefore, we aim to design a fan with adjustable angular travel of oscillation while minimally disrupting the conventional fan's structure.

How it works

There is usually a pin on the top of a household fan, pressing which makes the fan start oscillating. Apart from box fans, tower fans and bladeless fans, the oscillation mechanism is essentially a four-bar mechanism, in which the crank is driven by the fan motor via the gearbox. The rotation of the crank is what causes the fan to oscillate. By changing the length of the crank, we can change the oscillation angle of the fan. What we've designed is a length-adjustable crank with a sliding guide on one side and a bolt-nut connection on the other, which utilizes threading to achieve continuous adjustment of the crank length. It can be easily adjusted by the user using a screwdriver from outside of the fan, thereby adjusting the oscillation angle of the fan.

Design process

We observed that the oscillation angle of conventional fans is fixed, making it difficult to accurately match the required airflow range in practical use. To solve this problem, we considered adding a servo dedicated to controlling the oscillation angle, but this would increase system complexity as well as manufacturing and usage costs. Therefore, we aimed to find a solution for adjustable oscillation angle with minimal disruption to the fan's conventional structure. By disassembling an existing fan, we found that the oscillation mechanism is essentially a 4-bar mechanism. We found that changing the length of the crank alters the oscillation angle. Consequently, we designed a length-adjustable crank to replace the original fixed-length crank. After 3D printing this length-adjustable crank and replacing the original component, it ran perfectly. This achieved continuous adjustment of the oscillation angle between 40° and 100°. The fan has now run flawlessly for two years without any issues.

How it is different

Compared to conventional oscillating fans, our product allows adjustment of the oscillation angle. Relative to advanced models, our solution achieves oscillation angle adjustability at an exceptionally low cost without requiring additional independent motors. The length-adjustable crank we designed replaces just one single component in conventional oscillating fans, preserving the original structural framework, offering universal compatibility ideal for large-scale implementation.

Future plans

Our work only realizes the adjustment of the angular travel of the oscillation and can't yet support the precise adjustment of the start/end phase of the oscillation. Future work will target precise phase adjustment. Besides, our length-adjustable crank design relies on manual measuring, limiting efficiency. To position it as a universal retrofit component, we will develop an algorithm leveraging 3D scanning to auto-generate crank geometries based on target fan dimensions.

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