Cogged V-Belt Arc-Valley Structure for Crack-Resistant Bending
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Solution Overview
Problem
Large-sized cogged V-belts used in power transmission mechanisms for agricultural machines face challenges in maintaining high lateral pressure resistance and transmission force while preventing cracks in the cog valley due to stress concentration from bending deformation, as existing designs fail to adequately address the increased load and tension in large-scale applications.
Innovation Solution
The cogged V-belt features a design with multiple cog ridges and valleys, where the cog valley's cross-sectional shape includes a bottom portion formed by combining continuous arcs with decreasing curvature radius, a tension member layer, and a compression rubber layer, ensuring stress dispersion and increased contact area with the pulley, and the cog ridge has a straight side surface for enhanced frictional power transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the thickness of the entire belt is increased to improve lateral pressure resistance and transmission force, then lateral pressure resistance and transmission force are improved, but bendability deteriorates
Solution Approach 1:
The belt is segmented into cog ridges and cog valleys, creating a corrugated structure that allows the belt to bend more easily while maintaining overall thickness for strength. The cog valleys act as hinge points that facilitate bending without compromising the lateral pressure resistance provided by the thicker belt structure.
Solution Approach 2:
The belt employs a composite structure combining rubber material with embedded cords or wires in the cog valleys. This composite construction provides both the thickness needed for lateral pressure resistance and the flexibility required for bendability, as the cord-reinforced valleys guide bending while the rubber provides structural integrity.
2Strength
If the thickness of the entire belt is increased to improve transmission force, then transmission force is improved, but bending fatigue resistance deteriorates
Solution Approach 1:
The segmented cog structure distributes bending stresses across multiple valleys rather than concentrating them in a single thick section. Each cog valley acts as an independent stress relief point, reducing the cumulative fatigue effect on the belt during repeated bending cycles while maintaining the overall thickness for transmission force.
Solution Approach 2:
The cord-reinforced cog valleys provide structural support that prevents excessive deformation and stress concentration during bending. This composite construction enhances bending fatigue resistance by creating a more durable bending zone that can withstand repeated cyclic loading while the overall belt thickness maintains transmission force capability.
3Ease of operation
If the curvature radius of the bottom portion of the cog valley is decreased to improve bendability, then bendability is improved, but stress concentration increases causing cracks
Solution Approach 1:
The bottom portion of the cog valley is designed with a curved, arc-shaped cross-section instead of a sharp corner. This curvature distributes stress more evenly during bending, preventing stress concentration at sharp points that would lead to crack initiation, while still maintaining the flexibility needed for bendability.
Solution Approach 2:
The cord or wire embedded in the cog valley bottom provides tensile strength that counteracts the stress concentration effects. This composite reinforcement prevents crack formation and propagation in the rubber material at the curved bottom portion, allowing the use of optimized curvature for bendability without sacrificing crack resistance.
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 effectively enhances lateral pressure resistance and transmission force while reducing stress concentration at the cog valley, preventing cracks and ensuring durability under high load conditions in large-scale agricultural machinery applications.
Implementation Method 1
the cog valley has a cross-sectional shape in a cross section in the belt longitudinal direction, including: a bottom portion formed by combining a plurality of continuous arcs; and side walls of the cog valley inclined with respect to a belt thickness direction, in which the plurality of arcs forming the bottom portion has curvature radius decreasing as a distance from a deepest portion of the cog valley increases
Implementation Method 2
as the frictional power transmission belt, V-belts, V-ribbed belts, flat belts, and the like are known... cog ridges ensure a large frictional power transmission surface to improve the lateral pressure resistance and the transmission force
Implementation Method 3
the belt distorts in a state where bending stress due to bending deformation is generated on the outer peripheral side of the cord and compression stress due to compression deformation is generated on the inner peripheral side of the cord... the fatigue of a compression rubber layer repeatedly bent in the cog valley increases
Data Source
AI summary
The present invention relates to a cogged V-belt, including a cog portion containing cog ridges and cog valleys, and having a belt thickness of 19 to 36 mm and a cog height of 14 to 19 mm, in which the cog valley has a cross-sectional shape including a bottom portion formed by combining a plurality of continuous arcs and side walls of the cog valley, in which the plurality of arcs has curvature radius decreasing as a distance from a deepest portion of the cog valley increases, and includes a first arc passing through the deepest portion of the cog valley, having a diameter larger than a virtual circle tangent to the deepest portion and the both side walls and having a curvature radius of 7 to 10 mm.