Design analysis of suitable cutter header assembly for pokkali paddy harvester

Abstract

Pokkali system of rice cultivation is a unique farming under pokkali ecosystem prevalent exclusively in central Kerala. Harvesting of paddy in pokkali is to be carried out under stagnated water level which may raise upto five feet. Hence a research was undertaken to design a suitable cutter header assembly for the harvester, as other existing harvesting machines can’t be used in pokkali fields. Existing machines were studied and their drawbacks were identified. Four different designs of cutter header assembly models were made suiting an existing amphibian weed harvester (Truxor DM 5045). The four design models were design I (multiple bat reel system), design II (single bat reel system), design III (vertical axis reel system) and design IV (floating assembly with projected conveyor system). Selection of the best model out of these four was carried out by Quality Function Deployment (QFD) Technique along with Analytical Hierarchy Process (AHP) as a sub process, statistical analysis with expert ratings on models and Finite Element Analysis (FEM) on components suspected to failure of the selected models. All the results were collectively analysed and design II (single bat reel system) was selected. Also the design I (multiple bat reel system) can be an alternative as per statistical analysis. The single bat reel type system consists of single bat reel with elongated tynes. The corrosion resistant standard type cutterbar is finalized. Other specifications such as position of assembly, material of construction, dimensions etc were discussed in detail. Further the design, development and evaluation are suggested on the selected models with reduced size machine with same features and components as in Truxor DM 5045 (Amphibian weed harvesting machine)