Variable Stiffness Bogie Axle Box Positioning Device
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Solution Overview
Problem
Traditional railway vehicle bogie axle box suspension devices face challenges in simultaneously achieving high snaking critical operation speed on straight lines and safe curve passing performance, due to rigid connections that fail to adapt to high-speed operations and varying loads, leading to increased derailment risks.
Innovation Solution
A variable stiffness positioning device is introduced, featuring a combination of vertical and longitudinal elastomers with small- and large-stiffness elastic elements, pre-compression mechanisms, and a two-stage stiffness property that adjusts based on load conditions, allowing for increased stiffness at low loads and reduced stiffness at higher loads to manage lateral forces effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If larger longitudinal positioning stiffness is used in the elastic axle box suspension device, then the snaking critical operation speed on straight lines is improved, but the lateral force on curves becomes excessively large
Solution Approach 1:
The patent applies the dynamics principle by implementing a variable stiffness positioning device that transitions from rigid to elastic connection based on operational conditions. The device includes elastic elements (springs or elastomers) that provide different stiffness characteristics during straight-line operation versus curve passing, allowing the suspension to adapt dynamically to different running states and resolve the contradiction between high-speed stability and curve-passing performance
Solution Approach 2:
The patent changes the stiffness parameter of the positioning device from fixed to variable. By using elastic elements with specific stiffness characteristics and pre-compression mechanisms, the device can adjust its effective stiffness based on load conditions, providing larger stiffness for straight-line operation to increase snaking critical speed while reducing stiffness during curve passing to limit lateral forces
2Device complexity
If rigid connection structure is used between axle box bearing saddle and guide frame, then the structure is simple, but the frictional force increases linearly and cannot adapt to high-speed operation
Solution Approach 1:
The patent replaces the rigid mechanical connection with an elastic mechanical system. The positioning device incorporates elastic elements (springs or elastomers) that substitute for the rigid connection, providing friction-based elastic positioning that adapts to high-speed operations while maintaining structural simplicity through standardized elastic components
Solution Approach 2:
The patent changes the mechanical parameter from rigid (infinite stiffness) to elastic (finite stiffness). By introducing elastic elements with specific stiffness values and pre-compression forces, the device achieves adaptability to high-speed operations while keeping the overall structure simple and maintainable
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 device enhances the snaking critical operation speed on straight lines and ensures safe curve passing by dynamically adjusting stiffness, reducing the risk of derailment and improving the overall dynamic performance and safety of railway vehicles.
Implementation Method 1
a small-stiffness elastic element and a large-stiffness elastic element, wherein the small-stiffness elastic element is arranged in an elastomer pre-compression device and is serially arranged with the large-stiffness elastic element under the action of a pre-compression load
Implementation Method 2
the small-stiffness elastic element is arranged in an elastomer pre-compression device and is serially arranged with the large-stiffness elastic element under the action of a pre-compression load
Data Source
AI summary
The present invention provides a variable stiffness positioning device for a railway vehicle bogie axle box. The variable stiffness positioning device includes a vertical elastomer arranged between the top face of an axle box bearing saddle and the bottom surface of a guide frame of a side fame, and a longitudinal elastomer arranged between the axle box bearing saddle and the front and back side faces of the guide frame of the side fame, the longitudinal elastomer is provided with at least one small-stiffness elastic element and a large-stiffness elastic element, and the small-stiffness elastic element is arranged in an elastomer pre-compression device and is serially arranged with the large-stiffness elastic element under the action of a pre-compression load F1. The longitudinal elastomer has a larger longitudinal compression stiffness when the longitudinal deformation displacement is very small, so that the railway vehicle can be guaranteed to have a higher snaking critical operation speed when operating on a straight line, and the acceleration operation demand of the vehicle is satisfied; when the longitudinal deformation displacement reaches a set numerical value, the longitudinal compression stiffness of the longitudinal elastomer starts to become small, so that when the railway vehicle passes by a curve, it can be guaranteed that the lateral force between wheel rails will not be too large, and thus the curve operation safety of the vehicle is guaranteed.