IMPROVED DESIGN OF A VACUUM-GENERATING FAN FOR PNEUMATIC SEEDERS

Abstract

The article presents an improved design of a vacuum-generating fan intended for use in pneumatic seeders. In conventional pneumatic seeders, the vacuum level is commonly regulated by changing the rotational speed of the fan. Such an approach may increase energy consumption, accelerate wear of transmission components and reduce operational reliability. The proposed design makes it possible to regulate the vacuum level without changing the rotational speed of the fan. This is achieved by changing the blade pitch angle relative to the air flow. The methodological basis of the work is a structural and functional analysis of the fan unit, its drive mechanism, air channels and interaction with the seed metering devices of a pneumatic seeder. The proposed construction includes a main shaft driven by the tractor power take-off, a toothed belt transmission, a rotating fan shaft, adjustable blades, a blade pitch control mechanism, a fan housing, bearings, vacuum channels and the seeder frame. The study shows that increasing the blade angle can intensify air flow and generate a higher vacuum level for heavier seeds, whereas reducing the blade angle can lower the vacuum level for lighter seeds and prevent excessive seed attraction. The proposed solution is expected to improve seed singulation, reduce energy losses, extend the service life of transmission elements and increase the adaptability of pneumatic seeders to seeds with different physical and mechanical properties.