Rail Vehicle Bogie With Offset Motors and Pivoting Ball Ring
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Solution Overview
Problem
In railway vehicles, particularly those for intra-urban transport, there is a challenge in reducing the bulk of bogies under the body to maintain a lowered floor while minimizing the vehicle's transverse bulk and ensuring sufficient space for rotation, which is crucial for passenger accessibility and seat capacity without increasing the rail vehicle's footprint.
Innovation Solution
The bogie design features offset motors relative to wheels, integrated axle boxes with reducers, and a load cross member with a ball ring, allowing for a pivoting mechanism that supports a lowered floor while minimizing lateral bulk by positioning motors and axle boxes externally, thus maximizing free volume and accommodating rotational movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If all masses are moved laterally relative to the cars to reduce the bulk of the bogie under the body, then the lowered floor is maintained, but the width of the rail vehicle and the gauge of the bogie increase
Solution Approach 1:
The patent relocates masses from the transverse dimension (lateral placement outside wheel space) to the longitudinal dimension (placement along the length of the vehicle). Motors are positioned at the ends of the bogie frame rather than laterally offset, and axle boxes are integrated into the frame structure. This dimensional shift reduces transverse bulk while maintaining the lowered floor configuration.
Solution Approach 2:
The bogie frame serves multiple functions simultaneously: it provides structural support, positions motors longitudinally at its ends, integrates axle boxes, and maintains the lowered floor geometry. This multi-functionality eliminates the need for separate lateral mass placements, reducing overall transverse width while achieving all necessary functions.
2Volume of moving object
If the bulk of the bogie under the body is reduced to maintain a lowered floor, then passenger accessibility is improved, but the space necessary for rotation is constrained
Solution Approach 1:
Rotation capability is maintained by positioning the rotation axis vertically through the bogie frame rather than requiring lateral clearance. The load cross member with ball ring arrangement enables rotation around a vertical axis, allowing the body to rotate relative to the bogie without increasing transverse bulk, thus preserving both lowered floor configuration and rotational adaptability.
3Power
If motors are positioned laterally relative to wheels, then wheel drive is achieved, but the transverse bulk of the railway vehicle increases
Solution Approach 1:
Motor positioning shifts from lateral placement (transverse direction) to longitudinal placement at the ends of the bogie frame. The drive transmission system uses universal joints and cardan shafts to transmit power from the longitudinally positioned motors to the wheels, eliminating the need for lateral motor offset while maintaining full wheel drive capability.
4Ease of manufacture
If the bogie width is increased to accommodate lateral mass placement, then motor and axle box positioning is simplified, but the gauge of the bogie increases
Solution Approach 1:
Motors are positioned at the longitudinal ends of the bogie frame rather than laterally offset, and axle boxes are integrated into the frame structure. This longitudinal arrangement achieves simplified positioning and assembly while maintaining a compact transverse gauge suitable for urban rail environments.
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 design enables a railway vehicle with an integral lowered floor, maintaining a small transverse bulk and allowing sufficient space for passenger movement and seat capacity while accommodating both fixed and pivoting bogie applications, ensuring efficient use of space and accessibility.
Implementation Method 1
a load cross member (80) comprising a ball ring (82) hinged in a rotatable manner around an axis of rotation (s) extending in a direction of elevation (Z-Z) substantially perpendicular to the transverse direction, the ball ring being intended to support a railway vehicle body
Data Source
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AI summary
The invention relates to a bogie (10) for a low-floor railway vehicle comprising: - a chassis (12); and - four wheels (14) mounted on the chassis (12), each wheel (14) being rotatable about a respective axis of rotation extending along the same transverse direction (Y-Y'), said wheels (14) defining a space (E) between them, the space (E) extending between planes extending from the wheels (14) along the transverse direction (Y-Y'). The bogie (10) also comprises: - four motors (16), positioned outside the space (E); and - four gearboxes (18), positioned inside the space (E). Each motor (16) drives one of the wheels (14) via one of the gearboxes (18) associated with the wheel (14). Each wheel (14) is mechanically independent of the other wheels (14).