Self-Adaptive Rotary Arm Bogie Positioning via Curved Rolling

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Solution Overview

Problem

Conventional rotary arm positioning devices in railway bogies lack adaptability to changing vertical vibrations and loads, leading to poor track adaptability, uncontrollable wheelbase changes, and reduced service life due to excessive bending moments on vibration isolating components.

Innovation Solution

A self-adaptive rotary arm positioning device with a rotary arm body and vibration isolating cushion, where the upper surface and lower surface are in rolling fit with a curved member, allowing for timely rotation and accurate positioning, reducing friction and bending moments, and maintaining a constant wheelbase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the rotary arm body rotates to adapt to vertical movement, then the adaptability to track conditions improves, but the positioning accuracy of vibration isolating components deteriorates due to uncontrollable wheelbase changes

Engineering Contradiction:
Improveadaptability to track conditionsVSAvoidpositioning accuracy of vibration isolating components
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent introduces a curved guide surface between the rotary arm body and the vibration isolating cushion. This curved surface guides the rotation of the rotary arm body along a predetermined arc trajectory, ensuring that the rotation is controlled and predictable. The curvature of the guide surface matches the expected rotation path, allowing the rotary arm to adapt to vertical movements while maintaining precise positioning of the vibration isolating components relative to the frame.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent changes the geometric parameters of the connection interface by introducing a curved guide surface with specific radius and profile. This curved geometry transforms the rotation motion into a controlled path, where the position of the rotary arm body changes in a predictable manner. By carefully designing the curvature parameters, the system achieves both adaptability to vertical displacements and maintains stable positioning of vibration isolating components.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the sliding surfaces slide relative to each other to adapt to vertical movement, then the adaptability improves, but the service life of vibration isolating components deteriorates due to excessive bending moments

Engineering Contradiction:
Improveadaptability to load changesVSAvoidservice life of vibration isolating components
Core Design Contradiction:
Adaptability or versatilityVSDuration of action of stationary object

Solution Approach 1:

The curved guide surface replaces the traditional planar sliding interface. Instead of sliding along a flat surface which creates uneven contact and bending moments, the rotary arm body rotates along a curved path guided by the curved surface. This curved guidance distributes the contact forces more evenly and aligns them with the natural load paths of the vibration isolating components, significantly reducing bending moments and extending component life.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent transitions from a static sliding pair to a dynamic rotation mechanism guided by a curved surface. The rotary arm body can dynamically adjust its position by rotating along the curved guide, allowing continuous adaptation to varying load conditions. This dynamic adjustment mechanism ensures that the vibration isolating components always operate in their optimal load range, avoiding excessive bending moments that would occur with rigid sliding connections.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If the rotary arm body rotates freely to adapt to vertical vibration, then the adaptability improves, but the wheelbase control deteriorates resulting in wheelbase difference and reduced critical speed

Engineering Contradiction:
Improveadaptability to vertical vibrationVSAvoidwheelbase consistency
Core Design Contradiction:
Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The curved guide surface defines a precise arc trajectory for the rotation of the rotary arm body. This curved path ensures that the rotation is limited to a specific angular range, preventing excessive rotation that would change the wheelbase. The geometry of the curved surface is designed to accommodate vertical vibrations while maintaining the wheelbase within acceptable tolerances, thus preserving the critical speed of the vehicle.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent carefully selects and optimizes the geometric parameters of the curved guide surface, including its radius, curvature, and profile shape. These parameters are chosen to allow sufficient rotation for adapting to vertical vibrations while constraining the rotation enough to maintain wheelbase consistency. By adjusting these geometric parameters, the system achieves the optimal balance between adaptability and wheelbase control.

Inventive Principle:
Principle #35Parameter changes

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

Improves adaptability and positioning accuracy, increases critical speed, reduces derailment and wheel load, and extends the service life of components by allowing the rotary arm to self-adapt to load changes without excessive bending moments.

Implementation Method 1

both the upper surface and the lower surface are in rolling fit with a curved member at least in a front-rear direction

Methodology Applied
Scientific EffectRolling fit: Roller

Data Source

PatentEP3725637B1Bogie and self-adaptive rotary arm positioning device thereof
Publication Date: 2024.01.31 CRRC QIQIHAR ROLLING CO LTD
  • EP3725637B1 patent drawingFigure 1~2
  • EP3725637B1 patent drawingFigure 3~4
  • EP3725637B1 patent drawingFigure 5

AI summary

A self-adaptive rotary arm positioning device, comprising a rotary arm body (1) and a vibration isolating cushion (2). One end of the rotary arm body (1) is rotatably connected to a frame of a bogie by means of a rotary arm joint (3), and an upper surface (4) of the other end is connected to a lower surface (5) of the vibration isolating cushion (2). The upper surface (4) and the lower surface (5) have a vertical distance therebetween, and are in rolling fit with a curved member (6) at least in front and rear directions. The vertical distance is used for providing space for the rotation of the other end of the rotary arm body (1) about the rotary arm joint; or, the upper surface (4) and the lower surface (5) are matching arc-shaped surfaces or spherical surfaces, and the arc-shaped surfaces or the spherical surfaces extend from front to back. The extending length of the upper surface (4) in the front and rear directions is greater than the extending length of the lower surface (5) in the front and rear directions. Also disclosed is a bogie. The bogie and the self-adaptive rotary arm positioning device thereof can provide space for the rotation of the other end of the rotary arm body about the rotary arm joint.