Concave Cover Plate Hole Layout for Even Combine Sieve Loading
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Solution Overview
Problem
Existing combine harvesters experience uneven loading of sieves in the cleaning mechanism due to the uneven distribution of threshed grain caused by the revolving action between the rotor and concave threshing and separating grates, leading to less than optimal performance and efficiency.
Innovation Solution
Installation of concave covers on the grates with strategically positioned holes that concentrate open space towards the circumferential center, promoting central unloading and optimizing the operating characteristics of the grates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional concave grates are used without cover plates, then the structure is simple and easy to manufacture, but the grain distribution is uneven causing suboptimal cleaning performance
Solution Approach 1:
The concave grate is segmented into multiple zones with different cover plate configurations. Different sections of the grate have different hole patterns or cover plate arrangements to create zone-specific grain distribution effects, ultimately achieving even loading across the entire sieve system
Solution Approach 2:
Different portions of the concave grate are equipped with different cover plate configurations. The hole patterns, cover plate positions, and opening sizes vary locally across different sections of the grate to optimize grain distribution for each specific zone's functional requirements
2Manufacturing precision
If cover plates with holes are installed on concave grates to control grain distribution, then grain distribution improves, but manufacturing complexity increases
Solution Approach 1:
The cover plates are designed with varying hole patterns, opening sizes, and positions as adjustable parameters. By modifying these geometric parameters across different cover plate configurations, precise control over grain distribution is achieved while maintaining manufacturing feasibility through standard fabrication processes
3Productivity
If the concave grate openings are fully open, then grain can pass through freely, but the sieves become overloaded and cleaning efficiency decreases
Solution Approach 1:
The cover plates serve as intermediary elements positioned between the concave grate openings and the falling grain. These intermediate structures selectively obstruct and redirect grain flow, preventing direct overload of the sieves while maintaining necessary grain passage, thereby optimizing the loading distribution across the sieve system
Data Source
AI summary
Concave cover plates for a rotary processing system of a combine harvester have strategically placed holes therein design to concentrate grain output from the concave grates of the rotary processing system at a circumferential mid-region of the concave grates to promote even loading of a set of oscillating sieves in an underlying cleaning mechanism of the combine harvester. A set of such plates are installed in a series of progressively increasing openness in the circumferential direction of the concave grates in a rearward direction through the processing system, for more grain-on-grain threshing and more centralized output at a front intake end than at spots further rearward therefrom.