Locomotive Frame Asymmetric Recesses Vibration Decoupling
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Solution Overview
Problem
Existing shunting locomotive chassis designs are complex, expensive, and have a low stiffness-to-mass ratio, making them costly to manufacture and maintain, while also struggling to meet the frame-bogie vibration decoupling criterion effectively.
Innovation Solution
The locomotive chassis features a central plate with parallel spars having recesses for fixing mechanical or electrical elements, a metal section with an inverted 'T' or 'L' cross-section, and a load-bearing sheath with lateral plates, enhancing structural reinforcement and vibration decoupling by increasing the first frequency of vertical flexion beyond 6.5 Hz.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If lateral reinforcements (stiffening side rails) are installed on the lateral edges of the platform to support off-center equipment blocks, then the chassis can support the equipment blocks, but the mass increases significantly and the stiffness-to-mass ratio decreases
Solution Approach 1:
The patent applies asymmetry by positioning equipment blocks and their supporting recesses at non-symmetric locations on the platform (e.g., one block near the front, another near the rear at different lateral positions). This asymmetric arrangement eliminates the need for symmetric lateral reinforcements on both sides, reducing overall chassis mass while maintaining adequate support capacity for the specific equipment configuration
Solution Approach 2:
Instead of providing uniform lateral reinforcement along the entire platform edges, the patent implements localized support through recesses in the longitudinal members only at specific positions where equipment blocks are installed. This local quality approach provides support exactly where needed without adding mass to unnecessary areas, improving the stiffness-to-mass ratio
2Strength
If lateral reinforcements are installed on the side edges of the platform, then off-center equipment blocks can be supported, but the chassis complexity and manufacturing cost increase
Solution Approach 1:
The patent merges the support function into the existing longitudinal members (side members) by incorporating recesses directly into these members. This integration eliminates the need for separate lateral reinforcement components, reducing structural complexity and the number of parts that need to be manufactured and assembled
Solution Approach 2:
The longitudinal members serve multiple functions: they provide the primary lateral structure of the platform, offer mounting surfaces for equipment, and contain recesses that provide localized support for off-center equipment blocks. This multi-functionality reduces the need for additional specialized reinforcement components, simplifying the overall chassis design
3Strength
If lateral reinforcements are installed on the side edges of the platform, then off-center equipment blocks can be supported, but access to equipment blocks is hindered
Solution Approach 1:
The patent extracts the support function from the lateral edges of the platform and relocates it to recesses within the longitudinal members. This extraction removes the obstructive lateral reinforcements from the platform edges, clearing the escape corridors and improving access to equipment blocks while maintaining the necessary support capacity through the recesses
4Strength
If a load-bearing sheath is installed in the center of the lower surface to stiffen the chassis, then vertical bending stiffness is improved, but the chassis-bogie vibration decoupling criterion may not be met if the first vertical bending frequency is too low
Solution Approach 1:
The patent employs a composite structural approach by combining the load-bearing sheath (extending along the longitudinal axis) with reinforced longitudinal members that have integrated recesses. This composite structure creates a synergistic effect where the sheath provides central vertical stiffness while the asymmetrically positioned recesses and their supporting elements contribute to torsional stiffness and raise the first vertical bending frequency above 6.5 Hz, meeting the vibration decoupling criterion
Data Source
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AI summary
This locomotive frame (10) comprises a central platform (12) extending along a longitudinal axis (A) and defining a first surface (18) of the platform, on the equipment side, and a second surface (20) of the platform, on the bogie side; a pair of side members (14) mounted on the surface (18) of the platform on the equipment side, each side member (14) extending in a direction parallel to the longitudinal axis (A) of the central platform (12), the two side members (14) being mounted symmetrically with respect to a median plane (M) of the platform (12); and a load-bearing structural sheath (16) mounted on the surface (20) of the platform on the bogie side and extending along the axis (A) of the central platform (12). Each side member (14) comprises at least two recesses (42), the recesses (42) of the two side members (14) being opposite each other.