Railway Axle Bearing Labyrinth Seal With Low-Friction Shield Nesting
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Solution Overview
Problem
Existing sealing devices for railway axle rolling bearings are inadequate in preventing infiltration of external contaminants like water and dust, especially in static conditions, and often increase rotational friction or require large axial dimensions.
Innovation Solution
A compact, integrated sealing device with a two-stage axial labyrinth seal design, featuring a step-shaped annular recess and asymmetrical C- and U-shaped shields made of metallic or synthetic plastic materials, which provides effective hydraulic sealing while minimizing friction and axial length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If elastomer annular lips are provided to make contact with shields for sliding-contact sealing, then sealing effectiveness is improved, but rotational friction increases undesirably
Solution Approach 1:
A lubricant is introduced as an intermediary substance within the winding path between the two shields. This lubricant layer enables effective sealing through the labyrinthine path while minimizing direct contact and friction between the shields and the bearing rings, thus reducing rotational friction during operation.
2Reliability
If two non-contacting annular shields are used to define a winding path, then hydraulic sealing action is improved, but axial dimensions increase
Solution Approach 1:
The two shields are positioned and oriented such that they nest within the existing bearing structure, utilizing the radial space between the inner and outer rings. This nesting arrangement allows the shields to define an effective winding sealing path while maintaining compact axial dimensions that fit within the bearing's existing envelope.
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
The sealing device effectively prevents water and contaminant infiltration in both static and dynamic conditions, reduces friction, and maintains a compact design, offering cost-effectiveness and preventing corrosion due to fretting.
Implementation Method 1
shaped so as to define between them a winding path so as to ensure a hydraulic sealing action
Implementation Method 2
the rotation of one of the shields, associated with the ring of the rolling bearing rotating during use, produces on the external contaminants a centrifuging effect which moves them away from the winding path
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
Sealing device (10) and associated rolling bearing (1), wherein a radially inner ring (6), rotating during use, of the rolling bearing is provided with a step-shaped annular recess (16) formed on a radially outer side surface (18) of an end (12) of the inner ring, a first shield (21) shaped as a C in radial cross-section being keyed onto a corresponding end (11) of an outer ring (5) of the bearing and having a radially inner end (23) which is L-shaped and inserted inside the annular recess (16) of the inner ring; a second shield (24) shaped in radial cross-section as a U is keyed angularly integral with the inner ring (6) inside the annular recess (16) and facing the first shield so as to receive inside the U the radially inner L-shaped end (23) of the first shield with radial clearance both radially on the outside and on the inside, forming with the radially inner end of the first shield (23) a two-stage axial labyrinth sealing system.