Concave Adjustment and Release Unit for Combine Harvester Threshing System
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Solution Overview
Problem
Existing combine harvester designs require complex and costly mechanisms for safely releasing the concave from the threshing rotor to prevent damage from large objects, with manual resetting processes that are time-consuming and skill-dependent.
Innovation Solution
An adjustment and release unit featuring a rotary control shaft, actuator, concave support arms, and a spring arrangement in series with the actuator, allowing for angular positioning and uniform release of the concave when excessive force is applied, providing both adjustment and safety release functions without the need for complex mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a shear-bolt system is used to release the concave when large objects enter, then the combine is protected from damage, but the system requires stopping the combine and replacing the shear-bolt, causing downtime and increased maintenance complexity
Solution Approach 1:
The patent uses a disposable shear-bolt system where the bolt is designed to break under excessive load from foreign objects. This simple sacrificial component protects the expensive concave and rotor assembly while being inexpensive to replace, resolving the contradiction by accepting minor maintenance downtime in exchange for reliable protection against catastrophic damage.
Solution Approach 2:
The shear-bolt is intentionally designed to be discarded (broken) when foreign objects cause excessive force. The broken bolt is removed and replaced, allowing the combine to continue operation. This discarding approach protects the valuable threshing components while accepting the bolt as a consumable safety element.
2Productivity
If a complex resettable spring-biased system is used to release the concave, then the combine can continue operating without stopping, but the mechanism complexity and cost increase significantly
Solution Approach 1:
The patent extracts the safety release function into a separate, simple shear-bolt component rather than integrating it into a complex resettable mechanism. This isolation allows the main concave support system to remain simple while the disposable shear-bolt handles the safety function, avoiding the need for complex resetting mechanisms.
Solution Approach 2:
Instead of using expensive, complex resettable mechanisms, the patent employs inexpensive disposable shear-bolts that break under load and are simply replaced. This approach achieves continuous operation capability at minimal cost and complexity by treating the safety component as a consumable item.
3Manufacturing precision
If the concave support system is made rigid to maintain precise positioning, then the concave depth control is accurate, but the system cannot release the concave when foreign objects cause excessive force
Solution Approach 1:
The patent segments the concave support system into rigid positioning components (for precise depth control) and a sacrificial shear-bolt component (for safety release). The rigid linkages maintain accurate concave positioning during normal operation, while the separate shear-bolt provides the safety function by breaking under excessive load, resolving the contradiction between rigidity and safety.
Solution Approach 2:
The shear-bolt acts as an intermediary element between the rigid concave support structure and the foreign object load. It transmits normal operating forces while breaking under excessive force, allowing the rigid positioning system to maintain precision while the bolt provides the safety release capability when needed.
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 solution enables efficient and automatic release of the concave when foreign objects are encountered, reducing downtime and maintenance costs by using a compact spring arrangement that buffers forces, ensuring uniform clearance and protecting the system from damage.
Implementation Method 1
a spring arrangement in series with the actuator for releasing the concave in response to foreign objects entering the threshing unit against a spring bias of the spring arrangement
Data Source
AI summary
A spring release function is provided for releasing the concave of the threshing system of a combine harvester, to allow large objects to be released from the space between the threshing rotor and concave. An adjustment and release unit supports the concave beneath a threshing unit and has a rotary control shaft, an actuator for controlling an angular position of the rotary control shaft, and a set of concave support arms which extend downwardly from the rotary control shaft to the concave. A linkage including the actuator also has a series spring arrangement for releasing the concave.