Railway Brake Device Torque Stabilization via Curved Lever Contact

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Solution Overview

Problem

The existing disc brake device for railway vehicles experiences variation in rotating torque as the output shaft tilts relative to the rotating lever, leading to inconsistent braking force due to changing direction of the output shaft's pressure on the rotating lever.

Innovation Solution

The brake device incorporates a rotating lever with a lever contact portion that changes contact position with the output shaft linearly, maintaining a constant operation direction for the output shaft, and includes a roller with a curved surface for reduced resistance, allowing the output shaft to move linearly and rotate the lever with minimal torque variation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the output shaft tilts relative to the rotating lever as the rotating lever rotates, then the rotating lever can rotate through a larger range, but the rotating torque varies due to changing direction of the output shaft's pressure

Engineering Contradiction:
Improverotational range of rotating leverVSAvoidrotating torque consistency
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The lever contact portion is designed with a curved surface (circular arc shape) instead of a flat surface. This curved surface allows the contact point to move along the arc as the rotating lever rotates, maintaining a constant perpendicular distance from the rotation center to the force application point. This geometric solution resolves the contradiction by enabling rotational movement while keeping the torque arm length constant, thus maintaining consistent rotating torque throughout the rotation range.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Stability of the object's composition

If the contact position between the output shaft and rotating lever is fixed, then the rotating torque remains constant, but the resistance increases during contact position changes

Engineering Contradiction:
Improverotating torque consistencyVSAvoidresistance during contact position change
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The curved surface of the lever contact portion enables smooth rolling contact instead of sliding contact. As the rotating lever rotates, the contact point naturally transitions along the curved surface, reducing friction and resistance. This curvature allows the mechanism to maintain constant torque while minimizing energy loss during the dynamic contact position change.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The design allows the contact position to dynamically adjust along the curved surface of the lever contact portion during rotation. This dynamic adaptation enables the system to maintain optimal contact conditions throughout the rotation, reducing resistance while preserving torque consistency. The contact point automatically finds its proper position on the curved surface as rotation progresses.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3822144A1Brake device
Publication Date: 2021.05.19 NABTESCO CORP
  • EP3822144A1 patent drawingFigure 1
  • EP3822144A1 patent drawingFigure 2
  • EP3822144A1 patent drawingFigure 3

AI summary

A brake device (50) includes a first cylinder (51) having a cylindrical shape. The first cylinder (51) contains a first piston (52) configured to move linearly along the axial direction of the first cylinder (51). The first piston (52) has fixed thereto an output shaft (53) configured to move linearly along the axial direction of the first cylinder (51). The output shaft (53) is coupled with a rotating lever (55). When the output shaft (53) moves linearly, the rotating lever (55) rotates by converting the linear movement of the output shaft (53) into a rotational movement. A roller (58) of the rotating lever (55) is inserted in an insertion hole (53A) of the output shaft (53) and contacts with an inner peripheral surface of the insertion hole (53A) at a changing contact position. The rotating lever (55) is coupled with a rotating arm (60A). The rotating arm (60A) has attached thereto a mounting portion (65) to which a brake pad (86) is fixed.