Transmission Shaft Sealing With Oil Leak Diversion and Detection

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Solution Overview

Problem

Existing transmissions lack effective mechanisms to prevent lubricating oil from leaking and to detect leaks, which can lead to safety issues and equipment damage.

Innovation Solution

The transmission design includes a sealing system with radially protruding sealing rings that divert leaked lubricating oil into a ring-shaped depression, where it can be detected by a sensor, and a secondary sealing ring for additional protection, ensuring reliable drainage and detection of leaks, even at low speeds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a shaft seal is used to prevent lubricating oil leakage, then sealing performance is improved, but the system cannot detect when the seal fails and oil leaks

Engineering Contradiction:
Improvesealing performanceVSAvoidleak detection capability
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements a feedback mechanism by placing a sensor in the annular recess to detect lubricating oil that has leaked through the shaft seal. When oil is detected in the recess, the sensor sends a signal to the control unit, which then generates a warning message. This closed-loop feedback system allows the system to monitor seal performance and alert operators to leakage issues, resolving the contradiction between maintaining sealing performance and enabling leak detection.

Inventive Principle:
Principle #23Feedback

2Use of energy by moving object

If the gearbox is filled with lubricating oil for lubrication, then lubrication performance is improved, but oil leakage poses safety risks and environmental hazards

Engineering Contradiction:
Improvelubrication performanceVSAvoidsafety risks from oil leakage
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of oil leakage into a beneficial detection opportunity. The annular recess serves as a collection zone for leaked oil, and the sensor positioned in this recess transforms the presence of leaked oil from a purely harmful condition into a detectable signal. This allows the system to maintain full lubrication while converting leakage from an undetected hazard into a monitored condition that triggers warnings, thus resolving the contradiction between lubrication performance and safety risks.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of operation

If a radially protruding sealing ring is used to divert leaked oil, then oil diversion capability is improved, but the system requires sufficient shaft speed to effectively fling oil into the recess

Engineering Contradiction:
Improveoil diversion capabilityVSAvoidshaft speed requirement
Core Design Contradiction:
Ease of operationVSSpeed

Solution Approach 1:

The patent implements preliminary action by designing the radially protruding sealing ring to begin diverting oil at the earliest possible moment. The sealing ring's radial projection creates a centrifugal force mechanism that activates as soon as the shaft rotates, directing oil toward the annular recess before significant leakage can occur. This preliminary diversion action reduces the amount of oil that needs to be managed and ensures detection occurs as early as possible in the leakage process, mitigating the issue of speed requirements by establishing the diversion mechanism in advance.

Inventive Principle:
Principle #10Preliminary action

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 enhances safety by preventing lubricating oil leaks and allowing for timely detection and warning, ensuring the transmission operates reliably and reducing the risk of damage from oil escape.

Implementation Method 1

when the shaft speed exceeds a minimum threshold, the lubricating oil is flung from the radially protruding sealing ring into the recess

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

Even at speeds below the minimum threshold, such as when the shaft is stationary, the lubricating oil is diverted from the sealing ring into the recess

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3529518B1Transmission having a shaft, a housing part and an adapter housing
Publication Date: 2021.03.24 SEW EURODRIVE GMBH & CO KG
  • EP3529518B1 patent drawingFigure 1
  • EP3529518B1 patent drawingFigure 2
  • EP3529518B1 patent drawingFigure 3

AI summary

A transmission, having a shaft, a housing part and an adapter housing, wherein the housing part and the adapter housing are connected, wherein a first bearing for mounting the shaft is received in the adapter housing, wherein a second bearing for mounting the shaft is received in the housing part, wherein a spatial region which is filled at least partially with lubricating oil is arranged in the housing part, which spatial region is delimited and/or sealed towards the adapter housing by means of at least one first shaft sealing ring, wherein the sealing ring is arranged on the shaft on that side of the first shaft sealing ring which faces away from the spatial region, in particular on that side of the first shaft sealing ring which faces away axially from the spatial region, which sealing ring is connected fixedly to the shaft so as to rotate with it, in particular is pressed and/or pushed onto the shaft, wherein the sealing ring protrudes at least partially into a recess of the adapter housing, wherein the recess comprises a circumferential depression which is delimited towards the shaft by a wall region of the adapter housing, wherein the sealing ring makes contact with or radially protrudes beyond the wall region, in particular with the result that lubricating oil which flows downwards axially on the shaft is discharged into the recess or depression, wherein a sensor for detection of lubricating oil which is discharged into the depression is arranged on the adapter housing, in particular in a radially directed bore which opens into the depression.