Progressive Concave Grate Spacing for Even Sieve Loading

Solution Overview

Problem

Existing combine harvesters suffer from uneven loading of sieves in the cleaning mechanism due to the uneven distribution of threshed grain, leading to reduced efficiency and underutilization of the cleaning capacity.

Innovation Solution

The concave assembly for axial flow combine harvesters features concave sections with axial bars arranged in a progressively widening pattern to balance the loading of sieves, with the spacing between bars narrowing near the intake end and widening towards the terminal end, aligning with the rotor's spin direction to optimize grain distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional concave grates with uniform bar spacing are used, then the structure is simple and easy to manufacture, but the grain distribution becomes uneven causing sieve overloading

Engineering Contradiction:

Improvecleaning capacity utilizationVSAvoidconcave grate structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The concave grate employs non-uniform bar spacing where the spacing between adjacent bars varies along the arcuate path. Specifically, the spacing is tighter in regions where grain accumulation occurs and wider in other regions, creating local variations in grain flow characteristics that prevent sieve overloading and promote even distribution across all sieves.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the geometric parameter of bar spacing from uniform to non-uniform. The spacing between adjacent bars is deliberately varied along the concave grate structure, with specific spacing values selected to control grain flow patterns and achieve balanced loading across multiple sieves, thereby optimizing cleaning capacity utilization.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If uniform bar spacing is used in concave grates, then manufacturing is easier, but grain distribution across sieves becomes uneven

Engineering Contradiction:

Improvegrain distribution uniformityVSAvoidconcave grate fabrication

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The concave grate employs non-uniform bar spacing where the spacing between adjacent bars varies along the arcuate path. Specifically, the spacing is tighter in regions where grain accumulation occurs and wider in other regions, creating local variations in grain flow characteristics that prevent sieve overloading and promote even distribution across all sieves.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the geometric parameter of bar spacing from uniform to non-uniform. The spacing between adjacent bars is deliberately varied along the concave grate structure, with specific spacing values selected to control grain flow patterns and achieve balanced loading across multiple sieves, thereby optimizing cleaning capacity utilization.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If conventional uniform spacing is used, then the design is simpler, but sieve loading becomes unbalanced reducing efficiency

Engineering Contradiction:

Improvecleaning efficiencyVSAvoidbar spacing pattern

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The concave grate employs non-uniform bar spacing where the spacing between adjacent bars varies along the arcuate path. Specifically, the spacing is tighter in regions where grain accumulation occurs and wider in other regions, creating local variations in grain flow characteristics that prevent sieve overloading and promote even distribution across all sieves.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the geometric parameter of bar spacing from uniform to non-uniform. The spacing between adjacent bars is deliberately varied along the concave grate structure, with specific spacing values selected to control grain flow patterns and achieve balanced loading across multiple sieves, thereby optimizing cleaning capacity utilization.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250380643A1Progressive Bar Spacing in Concave Grates of Axial Flow Combine Harvesters to Promote Even Loading of Sieves

Publication Date: 2025.12.18 RAZORS EDGE US INC

AI summary

In an axial flow combine harvester, axial bars of one or more concave grates include first and second series of axial bars, of which the first series is nearer to a front intake end of the assembly where crop material is introduced. In each series, spacing between adjacent axial bars grows progressively wider from relatively narrow spacing near a first end of the series to relatively wider spacing near a second end of the series. The bar spacing in the second series is also of progressively widening character relative to the bar spacing in the first series. Operational characteristics of the combine harvester are improved by installation of the grates with the relatively narrow spacing at a side of the rotor where sieve overloading is known to occur with conventional grates, and with the wider spacing at an opposing side of the rotor from where said conventional sieve overloading occurs.