Agricultural Machine Cardan Shaft Hinge Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Agricultural machines connected to tractors via a three-point hitch and power take-off face limitations when the machine is mounted at the front, particularly with high offset positions leading to unsafe and inefficient operation due to torsional and bending oscillations, which restricts lateral movement and safety.
Innovation Solution
The design features a cardan shaft with a unique internal geometry where the hinge points of the articulating means are aligned with or internal to the three-point hitch connections, allowing for safe and effective transmission of motion at 1000 rpm, enabling lateral movement without positional constraints, and includes adjustable end-stroke mechanisms for compatibility with various tractors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the hinge points of the articulating means are positioned externally to the three-point hitch connections, then the machine can achieve greater lateral displacement, but the cardan shaft experiences high offset positions causing torsional and bending oscillations that lead to unsafe operation
Solution Approach 1:
The patent inverts the conventional arrangement by positioning the hinge points internally rather than externally. Specifically, the first hinge point is positioned internally with respect to the first connection for the lift arm, and the second hinge point is positioned internally with respect to the second connection for the lift arm. This internal positioning reverses the traditional external hinge configuration, thereby reducing cardan shaft offset and eliminating the harmful oscillations while preserving lateral movement capability through the articulating means
2Adaptability or versatility
If the cardan shaft is designed with telescopic elements for flexibility, then the machine can accommodate various positions, but the shaft extends beyond safe limits in high offset configurations
Solution Approach 1:
The patent applies preliminary action by pre-positioning the hinge points internally to the connecting structure before operation. This preliminary configuration ensures that the cardan shaft operates within safe extension limits from the outset, preventing over-extension before it can occur. The internal hinge positioning establishes a geometric constraint that keeps the shaft within safe operational boundaries throughout all machine movements
3Speed
If the machine is mounted at the front of the tractor with the conventional configuration, then the power take-off can rotate at 1000 rpm, but the high offset position creates dangerous oscillations
Solution Approach 1:
The patent changes the geometric parameters of the articulating means by repositioning the hinge points from external to internal positions. This parameter change modifies the offset distance of the cardan shaft, transforming it from a high offset configuration that generates harmful oscillations to a low offset configuration that operates safely at 1000 rpm. The internal hinge positioning alters the kinematic parameters to eliminate the harmful vibrational effects
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 configuration ensures safe and precise operation of the agricultural machine with the operating head centered, allowing for increased safety and precision, and maintains structural functionality even after prolonged use, with reduced cardan shaft extension and improved alignment.
Implementation Method 1
The cardan shaft is precisely the mechanical component that transmits power from the tractor to the agricultural machines, allowing the transmission of rotary motion between two axes located in various places in space, even in conditions of continuously variable reciprocal position
Implementation Method 2
The cardan shaft generally consists of two joints connected together by two telescopic tubular elements, which can then slide into each other
Implementation Method 3
these means of articulation comprise a proximal portion and a distal portion. The proximal portion is defined by a bracket (or other means of attachment) integral with the connection structure and external to the three-point linkage, on this proximal portion being the proximal hinges of the articulated parallelogram
Data Source
Figure 1~3
Figure 4
Figure 5
AI summary
An agricultural machine (1), of the type carried by a tractor (T) from which it receives motion via a cardan shaft (5), and which is provided with a connecting structure (10) provided with connections (11, 12, 13) for a three-point hitch (31, 32, 33); between the structure (10) and the operating head (2) of the machine (1) being arranged and acting articulation means (6) which are hinged at least at one hinge point (63, 64) to said structure (10); the hinge point (63, 64) of said articulation means (5) to the connection structure (10) being arranged aligned with or internal to the connections (11, 12).