Integrated Gearbox Circulation Filtration for Reversing Drives

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Solution Overview

Problem

Existing drive devices for material handling, such as mining excavators and wind turbines, face increased wear and reduced service life due to the need for additional wear-prone components in circulation pumps used for gearbox lubricant filtration, and directional changes complicate continuous lubricant circulation.

Innovation Solution

The circulation pump is integrated into the transmission, eliminating the need for a separate drive and reducing wear-prone components by using existing transmission elements, with a hydraulic rectifier ensuring consistent lubricant direction during reversals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a circulation pump is added to filter gearbox lubricant, then wear in the gearbox is reduced and service life is extended, but the pump itself becomes an additional wear-prone component that may fail and negate the benefits

Engineering Contradiction:
Improvegearbox service lifeVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The circulation pump is merged with the gearbox by integrating the pump housing into the gearbox housing and using the gearbox output shaft to directly drive the pump impeller. This combination eliminates the need for separate drive components such as external motors, couplings, and additional gear stages, reducing the number of wear-prone components while maintaining the lubricant circulation and filtration function

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gearbox output shaft serves a dual function: it drives the gearbox output (primary function) and simultaneously drives the circulation pump impeller (secondary function). This multi-functionality eliminates the need for a separate drive mechanism for the pump, reducing component count and potential failure points while maintaining both gearbox operation and lubricant circulation

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If the circulation pump is directly coupled to the motor or gearbox, then the pump is driven by existing components, but the pump's direction of flow reverses with the motor's drive direction, preventing continuous lubricant circulation through the filter

Engineering Contradiction:
Improvedrive train componentsVSAvoidcontinuous circulation
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The pump impeller blades are designed with a specific geometric configuration that enables the pump to deliver fluid in a consistent direction regardless of the rotation direction. The blade angle and curvature are optimized to exploit the centrifugal force and pressure gradient created during rotation, ensuring that the pump maintains its pumping capability in both clockwise and counter-clockwise rotation directions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system accepts periodic reversals in pump rotation direction (caused by motor reversibility) but maintains continuous useful action through the filter by designing the pump to function effectively in both directions. The filtration process continues uninterrupted despite the periodic reversal of pump rotation, as each rotation cycle still moves lubricant through the filter

Inventive Principle:
Principle #19Periodic 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 configuration minimizes wear and maintains efficient lubricant filtration with reduced component susceptibility, maintaining service life and operational reliability without increasing the drive device's size.

Implementation Method 1

the pump impeller (8) rotating with a gearbox element... the impeller of the circulation pump rotating with a gearbox element

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

a circulating filter device for filtering the gearbox lubricant in circulation

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3337929B1Drive device having circulation filtering
Publication Date: 2023.11.08 LIEBHERR COMPONENTS BIBERACH GMBH
  • EP3337929B1 patent drawingFigure 1
  • EP3337929B1 patent drawingFigure 2~3
  • EP3337929B1 patent drawingFigure 4

AI summary

The invention relates to a drive device, in particular in the form of a pivoting drive for material-transferring devices such as mining excavators, comprising a motor, a gearing connected to the motor, which is lubricated by a gearing lubricant, and a circulation filter device for filtering the gearing lubricant in circulation, wherein the circulation filter device has at least a circulation pump for circulating the gearing lubricant. According to the invention, the circulation pump is integrated in the gearing, wherein the pump wheel of the circulation pump is designed as a peripheral wheel and is arranged for conjoint rotation with a gearing element.