Working Machine Drive Ratio Control for Wheel Spin Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional drive systems in working machines, such as graders, lack effective mechanisms to prevent wheel spin during grading operations, especially when load increases, leading to inefficient and uncomfortable machine operation.
Innovation Solution
Implementing a power-split gearbox with a variator for continuous transmission ratio adjustment and a method that includes a limited maximum traction force curve to manage traction forces, ensuring they increase less sharply as output speed decreases, thereby preventing wheel spin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional gearbox with fixed transmission ratio is used, then the structure is simple, but wheel spin occurs during grading operations when load increases
Solution Approach 1:
The patent applies a power-split gearbox with a variator that enables continuous adjustment of the transmission ratio, transforming the static fixed-ratio system into a dynamic adjustable system. This allows real-time optimization of traction force distribution between drive wheels and grading equipment, preventing wheel spin during grading operations while maintaining operational simplicity through automated control.
Solution Approach 2:
The invention changes the transmission ratio parameter dynamically during operation. The control unit continuously monitors operating conditions and adjusts the variator to optimize the transmission ratio, thereby adapting the traction force characteristics to prevent wheel spin without requiring complex mechanical redesign of the entire gearbox structure.
2Adaptability or versatility
If the transmission ratio is fixed in selected gear, then the control system is simple, but the driving speed is permanently linked to engine speed reducing adaptability
Solution Approach 1:
The variator enables continuous adjustment of the transmission ratio, decoupling the fixed link between engine speed and driving speed. This dynamic adjustment capability allows the system to adapt to varying operational requirements, such as different grading loads and terrain conditions, while the control unit manages the complexity through automated algorithms.
Solution Approach 2:
The power-split gearbox with variator serves multiple functions: it provides continuous transmission ratio adjustment for speed adaptability, optimizes traction force distribution to prevent wheel spin, and maintains engine operating efficiency. This multi-functionality achieves high adaptability without proportionally increasing system complexity.
3Ease of operation
If maximum permissible traction force increases sharply as output speed decreases, then traction force is high, but wheel spin occurs during grading operations
Solution Approach 1:
The control unit continuously monitors the actual traction force and compares it with the limited maximum permissible traction force curve. When the actual traction force approaches the limit, the system automatically adjusts the transmission ratio through the variator to reduce traction force below the threshold, preventing wheel spin during grading operations while maintaining operational stability.
Solution Approach 2:
The system pre-defines a limited maximum permissible traction force curve that is lower than the conventional maximum. By proactively limiting the traction force to this predetermined curve before wheel spin occurs, the system prevents the harmful effect of wheel spin during grading operations while maintaining sufficient traction for effective grading.
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 method effectively prevents wheel spin during grading operations by adjusting the transmission ratio and traction forces, resulting in improved machining results and more comfortable machine operation.
Implementation Method 1
The variator can be designed as a hydrostat and have two hydraulic machines that can be connected to each other in a hydrodynamic manner
Data Source
AI summary
A method is provided for operating a drive device for a working machine having a conventional maximum traction force curve, where the maximum permissible traction force of the drive device increases as the output speed of the drive device decreases. The method includes receiving an activation signal for activating a grading operation of the working machine, where the grading operation has a limited maximum traction force curve in which the maximum permissible traction force of the drive device increases less sharply than with the conventional maximum traction force curve as the output speed of the drive device decreases. A currently maximum permissible traction force is ascertained based on the limited maximum traction force curve and a current traction force is compared with the currently maximum permissible traction force. The transmission ratio of the gearbox is adjusted toward a lower output speed of the drive device based on the comparison.