Hydraulic Axle Link Bearings With Damping for Rail Vehicle Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rail vehicle systems face challenges in efficiently transmitting longitudinal forces during cornering and straight-line travel, leading to instability and wear, particularly in optimizing wheelset orientation and damping performance.
Innovation Solution
The implementation of a hydraulic axle link bearing system with external connections and a damping element, featuring chambers filled with fluid and connected via internal ducts, allows for fluid exchange and introduces adjustable stiffness and damping, stabilizing the rail vehicle by transforming unstable eigenmodes into stable ones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a hydraulic axle link bearing with external connections is used to transmit longitudinal forces, then the wheelset orientation can be optimized during cornering and straight-line travel, but the system complexity increases due to external connections and multiple chambers
Solution Approach 1:
The patent combines multiple chambers (first and second chambers in each axle link bearing) into a unified hydraulic system with interconnected fluid pathways. The external connections merge the hydraulic circuits of multiple axle link bearings, allowing coordinated fluid distribution across the system to optimize wheelset orientation while managing complexity through integrated design.
Solution Approach 2:
The hydraulic system serves multiple functions simultaneously: it transmits longitudinal forces, optimizes wheelset orientation during cornering, and maintains stability during straight-line travel. The same fluid connection system performs both force transmission and orientation control, reducing the need for separate mechanisms.
2Ease of operation
If fluid is exchanged between chambers during cornering to achieve low longitudinal stiffness, then cornering performance improves, but fluid transfer time and response delay increase
Solution Approach 1:
The external connections and pre-established fluid pathways between chambers are prepared in advance, allowing immediate fluid transfer when cornering forces are applied. The system is pre-configured with connection lines and overflow ducts that enable rapid response without requiring complex real-time routing decisions.
Solution Approach 2:
The patent introduces intermediary components such as overflow ducts and connection lines that facilitate rapid fluid transfer between chambers. These intermediaries provide dedicated fluid pathways that reduce transfer resistance and enable faster response to cornering conditions compared to direct chamber-to-chamber transfer.
3Reliability
If a damping element is added to the first chamber connection to introduce damping, then driving stability and safety improve, but the device complexity and manufacturing cost increase
Solution Approach 1:
The damping element utilizes hydraulic principles by incorporating a piston and damper mechanism within the first chamber connection. The damping effect is achieved through fluid resistance in the hydraulic circuit, leveraging the existing hydraulic fluid and pressure system rather than requiring separate mechanical damping components.
Solution Approach 2:
The damping element is nested within the existing chamber connection structure, with the piston and damper mechanism integrated into the connection line between chambers. This nested design incorporates the damping function within the already-present hydraulic infrastructure, minimizing additional external components and simplifying integration.
4Force
If the second chambers are arranged upstream and first chambers downstream in the direction of travel, then longitudinal force transmission is optimized, but the arrangement complexity and installation difficulty increase
Solution Approach 1:
The patent employs asymmetric arrangement of chambers relative to the direction of travel, with second chambers positioned upstream and first chambers downstream. This asymmetric configuration optimizes the sequence of fluid pressure application and force transmission, creating a more efficient longitudinal force pathway that leverages the natural flow direction of hydraulic fluid under load.
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 enhances driving stability and safety at increased speeds by optimizing the transmission of longitudinal forces, reducing wear and noise, and allowing for adaptable damping, thereby improving the overall performance of the rail vehicle.
Implementation Method 1
Each axle link bearing has two external connections, by means of which the two chambers are connected for exchange of fluid. The two chambers are arranged opposite to one another between the two housing elements, such that in the event of a change in the position of the inner housing element relative to the outer housing element, an alternately occurring change in the volume of the two chambers is caused via an exchange of fluid.
Implementation Method 2
a damping element is provided for the exchange of fluid between a first chamber of the first axle link bearing and a first chamber of the second axle link bearing
Data Source
AI summary
An assembly transmits longitudinal forces in a rail vehicle. The assembly contains a first and second hydraulic axle link bearing, a wheel set, and a rotary frame. Each axle link bearing has a housing element and a first and second chamber filled with a fluid. In the event of a change in the position of the housing elements relative to each other, fluid is exchanged between connected chambers of the axle link bearings. The fluid exchange is produced by a change in the position of the housing elements relative to each other, and the change in position causes the transmission of longitudinal forces which are transmitted between the wheel set and the rotary frame via the axle link bearings. A first chamber of the first axle link bearing is connected to a first chamber of the second axle link bearing via a damping element in order to exchange fluid.