Timing Belt Clamp Geometry for Stress Riser Reduction
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Solution Overview
Problem
Timing belts experience premature failure due to stress risers caused by manufacturing processes, which reduce their operating life, especially when joined using conventional clamps that concentrate strain energy at trapezoidal notches and tensile cords.
Innovation Solution
A clamp design featuring at least one arcuate concave surface across its width, which corresponds with the peak of a second member when fastened, disperses strain energy by alleviating stress risers and reducing their magnitude, thereby enhancing belt life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional clamp is used to join timing belt ends, then the belt can be formed into an endless loop, but stress risers concentrate at the trapezoidal notches and tensile cords causing premature failure
Solution Approach 1:
The clamp features a concave surface with a specific profile that corresponds to the peak of the second member, creating a localized stress distribution pattern. This local quality change in the clamp's contact surface geometry redirects and disperses the stress away from the critical tensile cord regions, preventing stress concentration at the notches while maintaining overall clamp functionality.
Solution Approach 2:
The invention changes the geometric parameters of the clamp's contact surface by introducing a concave profile with specific curvature that matches the peak geometry of the mating member. This parameter change in the surface geometry transforms the stress distribution pattern from concentrated to dispersed, thereby eliminating the harmful stress risers that cause premature belt failure.
2Ease of manufacture
If standard clamp designs are used, then manufacturing is simple, but the clamp geometry concentrates strain energy at critical belt locations
Solution Approach 1:
The clamp incorporates a concave surface with a specific profile corresponding to the peak of the second member, creating a localized stress distribution pattern that disperses strain energy. This local geometric feature is integrated into the clamp design to prevent stress concentration at the belt's tensile cords and notches, thereby improving joint strength without significantly complicating the overall manufacturing process.
3Force
If the clamp applies uniform pressure across the belt, then the belt ends are securely joined, but stress risers are concentrated at the trapezoidal notches
Solution Approach 1:
The clamp's concave surface with a profile corresponding to the peak of the second member creates a non-uniform local pressure distribution. This local quality in the contact geometry ensures that higher pressure is applied in regions that disperse stress away from the tensile cords, while reducing pressure at the critical notch locations, thereby maintaining secure joining without stress concentration.
Solution Approach 2:
The concave surface of the clamp features a curved profile that corresponds to the peak geometry of the mating member. This curvature is specifically designed to match and engage with the peak, creating a stress-dispersing contact pattern that prevents stress risers from forming at the belt's critical locations while maintaining adequate holding force.
Data Source
AI summary
A clamp having a first member, a second member connectable to the first member and a second surface having a first groove and a second groove, each groove for receiving a toothed belt tooth, a peak is disposed between each groove, the second member cooperatively engages the first member to engage the toothed belt there between, and the first member having at least one arcuate concave surface extending across a clamp width, the arcuate concave surface corresponding with the second member peak when the second member is fastened to the first member.