Angled Lamella Sieve for Combine Harvester Separation
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Solution Overview
Problem
Current lamellar sieves in combine harvesters are inefficient in air flow guidance and mechanical shock action, leading to suboptimal separation of grain and non-grain components.
Innovation Solution
The design features angled slats with protuberances and a specific angle between the upper and lower parts, creating a tapered wind tunnel effect that enhances air flow and mechanical separation, with adjustable slat pivoting to optimize air flow and separation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If lamellae have wave-like curvature and recesses at lower end, then space for downward-projecting fingers is provided, but wind deflector is significantly disrupted
Solution Approach 1:
The invention extracts the finger-like protrusions from the lower end of the lamellae and relocates them to the upper end edge. This extraction resolves the contradiction by providing the necessary space for finger engagement (now at the upper end) while eliminating the disruption to the wind deflector at the lower end, allowing smooth airflow guidance.
Solution Approach 2:
The invention inverts the traditional location of the finger-like protrusions from the lower end to the upper end edge of the lamellae. This inversion allows the wind deflector area (lower end) to remain smooth and functional while the protrusions are positioned where they can still engage with the crop mixture without interfering with airflow patterns.
2Productivity
If lamellae are pivoted to increase permeability area, then more grain can pass through, but separation efficiency may be compromised
Solution Approach 1:
The invention employs dynamically adjustable lamellae that can pivot between different angular positions. This allows the system to adapt the permeability area according to operating conditions - opening wider for high throughput when grain flow is abundant, and closing tighter for enhanced separation when purity is prioritized. The adjustment mechanism enables real-time optimization of both productivity and separation efficiency.
Solution Approach 2:
The invention changes the angular parameter of the lamellae to control the balance between permeability and separation. By adjusting the angle of the lamellae relative to the frame, the system can modify the effective opening size and airflow characteristics, thereby controlling both the quantity of grain passing through and the effectiveness of impurity removal.
3Ease of operation
If upper section of lamellae is made longer to increase air deflector area, then airflow guidance is improved, but mechanical shock action is reduced
Solution Approach 1:
The invention applies different functional qualities to different parts of the lamella structure. The upper part is designed with a longer air deflector section optimized for smooth airflow guidance, while the lower part maintains a shorter, more robust configuration optimized for mechanical shock action on the crop mixture. This local differentiation allows each section to excel at its specific function without compromising the other.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design improves the separation efficiency by creating a Venturi-like effect that amplifies the mechanical pulling and tearing of the crop mixture, effectively separating grains and seeds while maintaining high flow rates and reducing contamination.
Implementation Method 1
creating a tapered wind tunnel effect that enhances air flow and mechanical separation
Implementation Method 2
a sieve consisting of an upper and a lower sieve, and a sieve box that shakes back and forth
Implementation Method 3
amplifies the mechanical pulling and tearing of the crop mixture
Data Source
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AI summary
The invention relates to a screen and to the use thereof for a cleaning device of a combine harvester, comprising a frame (10) in which multiple identical lamellae (11) are arranged one behind the other, said lamellae extending transversely to a longitudinal and oscillating direction of the screen and having an angled shape with a folding edge (119) between a part (112) which is used as a wind collector and an upper region (111). The lamellae have the following features: a) the angle (ß) formed by the upper (111) and the lower part (112) of the lamella lies between 125° and 150°, preferably between 130° and 140°, b) the upper termination edge (114) has multiple mutually spaced protuberances (115) with a semicircular edge (116), the secant (117) of which has a length (I1) between 20 mm and 40 mm, preferably 25 mm to 35 mm, and a maximum height (h1) (measured in the vertical direction relative to the secant) of 6 mm to 12 mm, c) the upper part (111) has a total height (h2) of 25 mm to 45 mm, preferably 30 mm to 35 mm, said height being measured without the protuberances (115), d) the lower part (112) has a total height (h3) of 16 mm to 30 mm, preferably 18 mm to 24 mm, e) the upper parts (111) of successive lamellae can be pivoted onto a common plane, wherein the protuberances (115) of a lamella have a spacing (a) of at least 1 mm, preferably a spacing of 2 mm to 20 mm, from the lower folding edge (119) of the adjacent lamella (11), and f) the lamella (11) can be pivoted out of the position described in e) by an angle (α) of up to 50°, preferably 45° to 35°.