Steerable Crawler Chassis Hydraulic Power Split
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Solution Overview
Problem
Existing crawler track steering systems face issues such as increased wear and power losses due to simple structures, and are not suitable for high-speed operations, while differential steering systems are costly and complex.
Innovation Solution
A steerable crawler chassis with a power split transmission system where hydraulic motors' displacement volumes adjust based on steering angle, allowing for cost-effective and energy-efficient steering by redistributing drive energy through a closed hydraulic circuit and spur gear stages, maintaining consistent driving speed during cornering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If steering brake concepts are used to achieve speed difference between caterpillars, then the structure remains simple, but increased wear on brakes and high power losses occur
Solution Approach 1:
The patent replaces the mechanical brake-based speed differential system with a hydraulic power split transmission system. Hydraulic motors with variable displacement volumes are used to independently control the speed of each caterpillar, eliminating the need for mechanical brakes and reducing power losses associated with friction-based steering.
Solution Approach 2:
The patent changes the displacement volume parameter of the hydraulic motors to achieve speed differential between caterpillars. By varying the displacement volume of each hydraulic motor independently, the system can control caterpillar speeds without mechanical braking, thereby reducing energy losses while maintaining structural simplicity.
2Adaptability or versatility
If variable displacement hydraulic motors with independent fluid supply are used for differential steering, then comprehensive steering functionality is achieved, but mechanical engineering effort and costs increase
Solution Approach 1:
The patent merges the steering and drive functions into a single power split transmission system. The hydraulic motors serve dual purposes: providing both the driving force and the speed differential needed for steering. This integration reduces the number of separate components and mechanical engineering efforts while maintaining comprehensive steering functionality.
Solution Approach 2:
The hydraulic motors in the patent perform multiple functions simultaneously: they provide propulsion, enable speed differential for steering, and can be controlled to achieve various steering angles. This multi-functionality reduces the need for separate steering mechanisms, thereby reducing overall system complexity and cost.
3Adaptability or versatility
If planetary transmission gears are used to achieve steering capability at standstill, then comprehensive functionality is achieved, but space requirement increases
Solution Approach 1:
The patent uses a hydraulic power split transmission system with variable displacement motors to achieve steering capability at standstill. The hydraulic system provides precise control of motor speeds, enabling the vehicle to pivot in place without requiring the large space and complex mechanical structure of planetary transmission gears.
4Measurement precision
If independent hydraulic motor supply is used for differential steering, then speed control precision is improved, but power losses increase
Solution Approach 1:
The patent uses variable displacement hydraulic motors where the displacement volume can be precisely adjusted to achieve the desired speed differential. This parameter control allows for precise speed regulation of each caterpillar while optimizing hydraulic efficiency, thereby reducing power losses compared to fixed displacement systems with throttling control.
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 reduces energy losses, minimizes wear, and enables precise control for high-speed operations without compromising driving speed, supporting both efficient and sensitive steering capabilities.
Implementation Method 1
the swallowing volumes of the hydraulic motors being able to be changed depending on the steering angle in such a way that the one from the one Hydraulic medium displaced by the hydraulic motor is fed to the additional hydraulic motor
Implementation Method 2
the hydraulic medium displaced from one hydraulic motor is fed to the other hydraulic motor
Data Source
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AI summary
The invention relates to a steerable crawler chassis (4) with a right-hand and a left-hand crawler section (8) assigned to a vehicle axle (36), wherein the vehicle axle (36) accommodates at least one power-split transmission (60) and each axle section (37) assigned to one of the crawler sections (8) is operatively connected to a hydraulic motor (31, 32), wherein the displacement volumes of the hydraulic motors (31, 32) are variable depending on the steering angle in such a way that the hydraulic medium (19) displaced from one hydraulic motor (31, 32) is supplied to the other hydraulic motor (32, 31).