Helical Threshing Rotor Wedge Opening Grain Separation
Solution Overview
Problem
Existing threshing systems in agricultural harvesters often damage grain due to prolonged exposure to threshing elements, as grain does not separate efficiently from crop material early enough, leading to increased risk of cob breakage and grain damage, particularly with larger components like ears of corn deflecting off rasp bars.
Innovation Solution
A threshing system with threshing elements mounted in a helical pattern on a rotor, featuring axially extending spaces and cylindrical projections that guide crop material toward a concave, reducing the likelihood of grain being carried over additional threshing elements by creating a wedge-shaped opening for grain to fall through, thus minimizing damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If grain remains in the threshing system longer to ensure complete separation, then separation completeness improves, but grain damage risk increases
Solution Approach 1:
The patent applies preliminary action by creating a dedicated grain fall-through opening in the concave structure before grain reaches the threshing elements. This allows grain to be separated and removed from the threshing path early in the process, preventing prolonged exposure to threshing elements that would cause damage. The opening is positioned and dimensioned to enable grain to fall through immediately after initial separation.
Solution Approach 2:
The patent segments the concave structure to include a specific fall-through opening that is spatially separated from the main threshing area. This segmentation creates a dedicated escape path for grain, allowing it to be divided into two streams: grain that falls through the opening and grain that continues with the crop material. This segmentation enables early grain removal without interfering with the overall threshing process.
2Productivity
If rasp bars are made narrower to improve grain separation, then separation efficiency improves, but larger components like ears of corn deflect off rather than flow over
Solution Approach 1:
The patent introduces an intermediary structure - the fall-through opening in the concave - that mediates between the narrow rasp bars and the grain separation process. This opening provides an alternative path for grain to exit the threshing system without requiring the crop material to flow smoothly over the rasp bars. The opening acts as a mediator that captures grain directly beneath the rasp bars, compensating for the deflection issue caused by narrow bar spacing.
3Object-affected harmful factors
If the number and size of openings in the concave are increased to allow grain to fall through earlier, then grain damage risk decreases, but the structural integrity and threshing effectiveness of the concave is compromised
Solution Approach 1:
The patent applies local quality by creating a specific localized opening in the concave structure rather than uniformly modifying the entire concave. The opening is positioned in a specific location where grain naturally falls after contact with threshing elements, and its dimensions are carefully controlled to provide adequate grain passage while maintaining the overall structural integrity of the concave. This localized modification provides grain escape functionality without compromising the strength and threshing effectiveness of the remaining concave structure.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A threshing system (22) for an agricultural harvester including a plurality of threshing elements (36) supported on a rotor (24) at spaced intervals in a generally helical pattern about an outer surface of the rotor (24), each threshing element including a set of discrete threshing bars (38) including a leading threshing bar (44) proximate the outer surface (30) of the rotor (24) and a succession of threshing bars (38) located progressively farther from the outer surface (30) forming a ramp and defining a wedge shaped opening (42) between the threshing bars (38) and the outer surface (30), each set of threshing bars (38) extending generally axially along the rotor (24) defining axially extending spaces (40) therebetween sufficiently large for passage of grain therethrough to the wedge shaped opening (42).