Transverse Fan Cut-Off Construction for Air Flow Volume
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transverse fan assemblies in agricultural combine harvesters face challenges in producing sufficient air flow volume at low rotational speeds while maintaining high pressure load capacity, leading to inefficiencies and equipment wear.
Innovation Solution
An improved cut-off construction for transverse fan assemblies with elongated arcuate fan blades, featuring a baffle and cut-off configuration that shifts the steering vortex, allowing for increased air flow volume at lower rotational speeds and higher pressure load capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the fan operates at higher rotational speeds to produce sufficient air flow volume, then the air flow volume increases, but the equipment wear increases and energy consumption increases
Solution Approach 1:
The patent changes the geometric parameters of the cut-off construction, specifically the angle of the cut-off surface relative to the fan rotation plane. By optimizing this angle, the patent achieves improved air flow characteristics that allow sufficient air flow volume at lower rotational speeds, thereby reducing energy consumption while maintaining productivity
Solution Approach 2:
The patent employs a curved or angled cut-off surface instead of a flat perpendicular surface. This curvature is designed to align with the natural flow of air leaving the fan blades, reducing turbulence and improving flow efficiency. The curved geometry allows the fan to move more air at lower speeds by better guiding the air flow path
2Stress or pressure
If the fan operates at higher rotational speeds to maintain high pressure load capacity, then the pressure load capacity is maintained, but the equipment wear increases
Solution Approach 1:
The patent optimizes the cut-off angle parameter to improve pressure generation efficiency. By changing this geometric parameter, the fan can achieve the required pressure load capacity at lower rotational speeds, reducing mechanical stress and wear on fan components, thereby extending equipment life while maintaining pressure performance
Solution Approach 2:
The curved cut-off surface is designed to smoothly guide air flow and maintain pressure without requiring excessive fan speed. The curvature creates a more efficient flow path that preserves pressure while reducing the mechanical stress on the fan system, leading to improved reliability and reduced equipment wear
3Ease of operation
If the cut-off construction is positioned closer to the fan to improve air flow direction, then the air flow direction control improves, but the air flow volume decreases
Solution Approach 1:
The patent uses a curved cut-off surface that is positioned at an optimized distance from the fan. The curvature allows the cut-off to be closer to the fan for better directional control while the angled geometry prevents excessive restriction of the air flow path, thereby maintaining adequate air flow volume. The curved surface guides the air smoothly rather than creating a sharp restriction
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
The improved cut-off construction enhances air flow volume and pressure load capacity, leading to more efficient cleaning operations, extended equipment life, and reduced costs.
Implementation Method 1
shifts the steering vortex of the fan
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A transverse fan assembly comprising a cut-off construction (11), including for use with agricultural combine harvesters, to permit the transverse fan assembly to be operated to provide increased air flow volume at a lower rotational fan speed, which cut-off construction (11) includes generally planar inner surfaces (306, 308) on first and second body portions (302, 304) that are positioned laterally to one another along the top of the output throat (79) of the air plenum (44) of the transverse fan assembly between the outer periphery of the fan (42) and a baffle construction (76) of the transverse fan (42), such that the inner surface of the first body portion (302) is disposed at a cut-off inclination angle α, dependent upon certain parameters of the fan (42), and the inner surfaces of the first and second body portions (302, 304) intersect with one another in such a way that an upper wall (77) for the output throat (79) is formed by the cut-off construction (11) and by the baffle construction (76) of the fan assembly, which upper wall (77) has a concavity formed therein and therealong near the outer periphery of the fan (42) that effects a shift of the steering vortex of the fan (42) in such a way as to permit the fan (42) to operate with increased air flow volume at lower rotational fan speed.