Rail Vehicle Secondary Spring Form-Fitting Connection
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Solution Overview
Problem
Existing rail vehicles face challenges in achieving a balance between safety, ease of assembly, and maintenance, particularly in low-floor designs where secondary springs interfere with passenger space and require complex force transmission systems.
Innovation Solution
A rail vehicle design featuring a positive connection between the car body and secondary spring, utilizing a conical mandrel and bushing for form-fitting connections that transmit forces without screws, allowing for efficient force transfer while preventing unwanted movements and reducing component count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If secondary springs are bolted to the car body using screws, then force transmission is reliable, but assembly and maintenance become complex and time-consuming
Solution Approach 1:
The patent replaces the screw-based mechanical fastening system with a form-fitting connection system. The connection partner on the secondary spring features a conical mandrel that fits into a corresponding conical recess in the car body, eliminating the need for screws while maintaining reliable force transmission through geometric interlocking.
Solution Approach 2:
The connection system is divided into separate connection partners: one integrated with the secondary spring and another with the car body. This segmentation allows the secondary spring to be assembled independently into the car body without requiring complex fastening operations, simplifying both assembly and maintenance procedures.
2Volume of moving object
If secondary springs are positioned higher to avoid interference, then passenger space is reduced, but safety and stability are compromised
Solution Approach 1:
The form-fitting connection system enables the secondary spring to be positioned lower (optimizing passenger space) while maintaining secure attachment. The geometric interlocking mechanism provides inherent stability without requiring the spring to be positioned higher for additional support structures.
Solution Approach 2:
Instead of positioning the secondary spring higher to ensure stability, the patent inverts the approach by using a sophisticated connection mechanism that allows the spring to be positioned lower while maintaining or even improving stability through the form-fitting connection design.
3Force
If complex force transmission systems are used, then force transmission is effective, but device complexity increases
Solution Approach 1:
The patent replaces complex multi-component fastening systems with a simple form-fitting connection. The conical mandrel and recess geometry inherently provide force transmission in multiple directions (vertical, lateral, longitudinal) without requiring additional force transmission components.
Solution Approach 2:
The form-fitting connection serves multiple functions simultaneously: it provides secure attachment, transmits vertical forces, transmits lateral forces, and transmits longitudinal forces. This multi-functionality is achieved through the geometric design of the connection partners rather than through multiple separate components.
Data Source
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AI summary
The invention relates to a rail vehicle, comprising at least one car body and at least one secondary spring for cushioning the car body on an undercarriage, wherein the car body and the secondary spring are connected to each other in a form-closed manner, which form-closed connection acts at least parallel to a vertical axis of the car body toward the car body and perpendicularly to the vertical axis of the car body.