Concave-Convex Tooth Profile for Underground Winning Machine Feed System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing feed systems for underground winning machines, such as shearer loaders, experience increased wear on drive sprocket teeth due to higher loads and frequent engagement, leading to reduced service life and efficiency.
Innovation Solution
The feed system incorporates rack bars with concavely arched tooth flanks forming a trough and convexly arched drive sprocket tooth surfaces forming a crown, reducing surface pressures by up to 12% and enhancing centering, along with altered tooth profiling and end teeth design for improved running behavior and reduced wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional rack teeth with planar tooth flanks are used, then the structure is simple and easy to manufacture, but surface pressure is high and wear on drive sprocket teeth increases
Solution Approach 1:
The rack teeth are designed with concavely arched tooth flanks that form a trough cross-section, and the drive sprocket teeth are designed with convexly arched surfaces that form a crown cross-section. This curved geometry distributes the contact pressure more uniformly across the tooth surfaces, reducing peak surface pressures by up to 12% and minimizing wear on the drive sprocket teeth while maintaining manufacturing feasibility.
2Force
If steeply inclined tooth flanks are used, then lifting of the winning machine is suppressed, but transverse force components may cause disturbing influences
Solution Approach 1:
Asymmetrical end teeth are provided at both ends of the rack bars, where the tooth flank facing the inner rack teeth has a steeper angle relative to the vertical than the outer tooth flank. This asymmetrical configuration optimizes the force distribution at the ends of the rack bars, suppressing lifting of the winning machine while minimizing disturbing influences from transverse force components during operation.
3Reliability
If multiple radii zones are used on tooth flanks, then running behavior is improved and wear is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The tooth flanks are designed with multiple radii zones having different radii of curvature, where the radius of curvature changes in a predetermined manner from the tooth base to the tooth tip. This gradual parameter change optimizes the contact characteristics and running behavior of the teeth, reducing wear and improving reliability while maintaining achievable manufacturing precision through systematic radius transitions.
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
A feed system, rack bar and drive sprocket for moving an underground winning machine having a travel drive with drive sprocket having symmetrically profiled teeth, and rack bars with a plurality of rack teeth being arranged between a supporting strip and a guide strip of the rack bar. The tooth flanks of the teeth are inclined in the direction of movement and diverge towards the tooth tip for the interaction with tooth surfaces of teeth of drive sprocket. In order to improve the interaction between the teeth and produce less wear, the two tooth flanks of each rack tooth are concavely arched and form a trough between guide strip and supporting strip transversely to the direction of movement, with the trough rising towards the tooth tip, and the two tooth surfaces of each drive sprocket tooth is convexly arched and forms a crown transversely to the direction of movement.