Elastic Oil Transfer Ring Sealing for Pressure-Stable Assemblies

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Solution Overview

Problem

Existing oil transfer systems in rotation applications, such as planetary gearboxes, suffer from oil leakage and pressure drop due to imperfect sealing between rotating and stationary components.

Innovation Solution

An elastic oil transfer ring with a U-shaped cross-section and oversize contact surfaces is used to create a snug and sealing contact with the groove walls, reducing leakage and maintaining pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a rigid ring is used to seal between rotating and stationary components, then manufacturing precision can be improved, but adaptability to misalignment and thermal expansion deteriorates

Engineering Contradiction:

Improvesealing contact precisionVSAvoidadaptability to misalignment and thermal expansion

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent employs a flexible sealing ring made of elastomeric material that can deform elastically to accommodate misalignment and thermal expansion between rotating and stationary components. This flexible membrane approach allows the sealing surface to adapt to dimensional changes while maintaining continuous contact, resolving the contradiction between manufacturing precision and adaptability.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent utilizes the elastic properties of the sealing ring material, allowing it to change its physical parameters (shape, volume) in response to thermal expansion and misalignment. The elastomeric material's ability to undergo reversible deformation enables the seal to maintain effectiveness under varying operating conditions, bridging the gap between precision sealing and environmental adaptability.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a rigid ring with precise fit is used, then oil leakage is reduced, but sensitivity to external interference factors increases

Engineering Contradiction:

Improvesealing effectivenessVSAvoidsensitivity to misalignment and thermal expansion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The flexible elastomeric sealing ring continuously adapts its shape to maintain contact with the groove surfaces, ensuring reliable sealing while being insensitive to misalignment and thermal expansion. The material's elasticity allows it to compensate for dimensional changes without compromising sealing effectiveness.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The elastomeric material inherently provides cushioning against external interference factors through its elastic deformation capability. This prior cushioning effect protects the sealing interface from the harmful impacts of misalignment and thermal expansion before they can cause leakage or failure.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Adaptability or versatility

If an elastic sealing ring is used, then adaptability to external factors is improved, but manufacturing precision deteriorates

Engineering Contradiction:

Improveadaptability to operating conditionsVSAvoiddimensional precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent accepts reduced dimensional precision in the elastomeric sealing ring as intentional, relying instead on the material's elastic properties to achieve functional precision during operation. The flexible ring deforms to conform to the groove surfaces, making the final sealing precision dependent on elastic behavior rather than manufacturing tolerances.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The sealing ring's physical parameters (shape, volume, thickness) are designed to change under operating conditions, allowing the component to achieve its precise sealing function dynamically rather than statically. This parameter change capability compensates for lower manufacturing precision while enhancing adaptability.

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

The solution effectively reduces oil leakage and pressure drop, ensuring consistent oil pressure across a wide range of operating conditions, and is less sensitive to external interference factors like misalignment or thermal expansion.

Implementation Method 1

an elastic oil transmission ring (2) made of an elastic material, e.g. a polyamide material

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20250198516A1Assembly having two components and an oil transfer ring

Publication Date: 2025.06.19 ZF FRIEDRICHSHAFEN AG

AI summary

An arrangement including two components with differential speed and an elastic oil transmission ring. One of the two components forms a groove for accommodating the oil transfer ring. The oil transfer ring has a U-shaped cross-section with a first lip and a second lip, wherein the first and second lips are spaced apart and run parallel to each other. The first and second lips each form a contact surface on their outer sides. The contact surfaces lie against two opposing wall surfaces of the groove when the oil transfer ring is mounted between the two components. The contact surfaces are spaced further apart than from each other than the two wall surfaces of the groove when the oil transfer ring is not mounted between the two components.