Tire Building Drum Sleeve Segmentation for Axial Tension
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Solution Overview
Problem
Existing tire building drums with center sleeves experience reduced lifetime due to axial tension, and alternative designs without center sleeves cause deformation or displacement of tire components during operation, leading to uneven surfaces and difficulties in stitching.
Innovation Solution
A tire building drum with a crown section and bead-lock section, featuring a sleeve that extends around crown segments with a fixed first circumferential edge and an unfixed second edge, allowing the crown segments to move from a crown-down to a crown-up position without altering the exposure to tire components, thereby maintaining a consistent surface for tire shaping and preventing sleeve contraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a center sleeve extends completely over the center section from one end to the other end, then the structural integrity and support for tire components is improved, but the lifetime of the center sleeve is reduced due to repeated axial tension
Solution Approach 1:
The center section is divided into multiple crown segments arranged circumferentially, with gaps between them. This segmentation eliminates the need for a continuous center sleeve while maintaining structural integrity through the segmented arrangement that allows independent movement and reduces tensile stress concentration.
Solution Approach 2:
Instead of using a continuous sleeve that spans the entire center section, the invention inverts the approach by using discrete crown segments with gaps between them. This inversion transforms the continuous load-bearing structure into a segmented one that reduces axial tension while maintaining support functionality.
2Duration of action of stationary object
If a shoulder seal with a free end is used to avoid axial tension, then the lifetime of the seal is improved, but the free end slides over tire components causing deformation and displacement
Solution Approach 1:
The invention extracts the sealing function from the traditional shoulder seal design and integrates it into the crown segments themselves. The crown segments with gaps provide both structural support and sealing functionality, eliminating the need for separate shoulder seals that slide over tire components.
Solution Approach 2:
The sealing function and structural support function are merged into the crown segments. The gaps between crown segments serve both as structural features for reducing tension and as sealing interfaces, combining multiple functions into a single integrated component.
3Productivity
If the crown segments are moved from crown-down to crown-up position, then the tire shaping process is improved, but the exposure of crown segments to tire components changes causing uneven surfaces
Solution Approach 1:
The crown segments are designed to move dynamically between crown-down and crown-up positions during the tire building process. This dynamic movement allows the drum to adapt to different stages of tire shaping while maintaining consistent surface contact through the gap configuration that ensures uniform exposure throughout the cycle.
Data Source
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AI summary
The invention relates to a tire building drum and a method for building a tire, the tire building drum comprises a crown section and a bead-lock section, wherein the bead-lock section defines a bead- lock position, wherein the crown section comprises crown segments (30) movable with respect to the base from a crown-down position into a crown-up position in a crown-up direction, wherein the crown segments together form a crown surface, a leading edge and a shoulder, wherein the drum further comprises a sleeve that extends around the crown segments in the circumferential direction, wherein the sleeve comprises a first circumferential edge (61) that is fixed to the crown segments at a side of the shoulder facing away from the bead-lock section, a second circumferential edge (62) that is located between the shoulder and the bead-lock position, wherein the second circumferential edge is unfixed at least when the crown segments are in the crown-down position.