Optimization of pruner linear motor magnetic system

Gardening is one of the most promising branches of agriculture. Intensive planting of new orchards requires rapid development of technologies and tools to support the harvesting process. The formation of the garden’s harvest largely depends on modern and high-quality pruning of tree branches. An analysis of the tool base for garden care showed that 80% of horticultural enterprises use hand tools. Pneumatic and hydraulic tools are used by 15% of enterprises. Only 5% of households use electric pruning shears when pruning trees. These secateurs are manufactured by Electrocoup, Bosch, and Makita. The domestic instrument is represented by the developments of the 80s and 90s of the last century. Therefore, there is a need to develop modern pruning shears based on a linear electric motor. Their advantages are high reliability, low noise level and low power consumption. This is especially important since tree pruning takes place over large areas and the presence of large energy sources reduces the pruner’s mobility. The linear electric drive is not used in existing pruning shears. This is due to the lack of a theory of designing magnetic systems for hand-held electrified tools. Chain methods for calculating magnetic systems have a high error, which does not allow determining the optimal design at the stage of calculations. This is primarily due to the redistribution of the magnetic flux from the stator through the air gap to the motor armature. The use of modern computer programs (ElCut), using the finite element method for calculations, will allow at the design stage to obtain the optimal design of the magnetic system with a given accuracy. Modelling and optimization of the magnetic system of the electric motor will reveal the most effective direction for the development of pruning shears for pruning trees based on a linear electric motor. The aim of the study is to optimize the magnetic system of the linear electric motor of the pruner. The optimal design of the magnetic system allows increasing the armature pulling force up to 84.35 N.