Mining Cutting Unit Deflector for Gearbox Seal Protection
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Solution Overview
Problem
Mining machines experience significant downtimes due to damage of seals protecting the gearbox, which are torn by parts ripped out of the mesh during cutting operations, leading to costly and lengthy maintenance.
Innovation Solution
A deflector is arranged coaxially outward of the seal in the gap between the rotating and stationary parts, guiding torn mesh parts away from the seal and reducing the gap size, with engagement pieces to catch and transport material, and additional cutting edges to shred it into smaller pieces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cutting unit operates without a deflector, then the structure is simpler and easier to manufacture, but the seal is vulnerable to damage from torn mesh parts causing extended downtimes
Solution Approach 1:
A deflector is introduced as an intermediary component between the rotating part and the seal. The deflector has an outer surface that deflects torn mesh parts away from the seal, preventing direct contact and damage. This mediator component protects the seal without requiring fundamental changes to the cutting unit structure.
Solution Approach 2:
The cutting unit is segmented into functional zones: the rotating part with cutting elements, the deflector as a protective intermediate component, and the sealed gearbox. This segmentation allows the deflector to be independently positioned and optimized for seal protection without affecting the entire system design.
2Ease of manufacture
If the gap between the rotating part and stationary part is larger, then assembly is easier and tolerance requirements are reduced, but torn mesh parts can more easily reach and damage the seal
Solution Approach 1:
The deflector serves as a protective barrier within the gap, allowing larger gap dimensions for easier assembly while preventing torn mesh parts from reaching the seal. The deflector's positioning surface creates a controlled pathway that redirects debris away from critical components.
3Reliability
If the deflector is positioned radially outward of the seal, then the seal is protected from direct impact, but the deflector must effectively guide material away from the gap
Solution Approach 1:
The deflector features a curved outer surface with a specific radius of curvature that optimally deflects torn mesh parts. The curvature is designed to redirect material away from the gap entrance while maintaining structural integrity and effective sealing protection.
Data Source
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AI summary
The invention relates to cutting unit (3) comprising at least one rotating part (5) for rotating about a rotation axis (RA) with a number of cutting elements (8); a gear box (14) for driving the rotating part (5); at least one stationary part (12) receiving the gearbox and the rotatable mounted rotating part (5), wherein a first front edge (28) of the stationary part (12) is arranged at a distance (d) along the rotation axis (RA) to a facing second front edge (30) of the rotating part (5); and a seal (38) protecting the gear box (14) and being arranged in a gap (36) defined between stationary part (12) and rotating part (5). The invention suggests a deflector (40) extending at least partly in a circumferential direction (C) and being arranged coaxial to rotation axis (RA) in the gap (36) radially outward of the seal (38).