Fluid-Expanded Roller Bushing for Vibration-Stable Shaft Coupling
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Solution Overview
Problem
Conventional yarn and cloth feed roller systems experience loosening of couplings due to vibrations, requiring frequent halts in production for tightening, which is undesirable.
Innovation Solution
A roller assembly featuring a bushing with a bladder that expands radially upon fluid receipt to frictionally engage a shaft, using an actuator to control fluid flow and an alignment feature for rotational positioning, eliminating the need for keyways and allowing quick assembly and disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional couplings (screws, keys, cam mechanisms) are used to connect the roller to the shaft, then the connection can be established, but the coupling becomes loose over time due to vibration, requiring production halts for tightening
Solution Approach 1:
The patent uses a bladder filled with fluid (hydraulic or pneumatic) that can be inflated to expand and create frictional engagement between the bushing and the shaft. The actuator controls fluid flow into the bladder, causing it to expand radially and press against the shaft, providing a secure coupling without mechanical fasteners that loosen due to vibration.
Solution Approach 2:
The invention changes the physical state of the coupling mechanism from a fixed mechanical structure to a dynamically adjustable friction-based connection. By controlling the fluid pressure in the bladder, the degree of expansion and frictional engagement can be adjusted, allowing the coupling to adapt to operational conditions and maintain stability without loosening.
2Reliability
If conventional couplings with multiple components (headers, keys, cams, screws) are used, then the roller can be connected to the shaft, but the device complexity increases and assembly/disassembly requires production halts
Solution Approach 1:
The complex mechanical coupling structure (keys, keyways, cams, screws, and their alignment features) is replaced with a simple bushing containing a fluid-filled bladder. The actuator controls the bladder's expansion to create the necessary engagement, dramatically reducing the number of parts and simplifying the overall coupling structure while maintaining reliable connection.
Solution Approach 2:
The bladder acts as a flexible element that can expand and contract as needed. This flexible membrane replaces rigid mechanical components, allowing the coupling to adapt to slight misalignments and providing smooth engagement without the need for precise mechanical tolerances and multiple alignment features.
3Reliability
If conventional couplings are used, then the roller can be secured to the shaft, but material usage increases and manufacturing costs rise
Solution Approach 1:
The invention replaces substantial mechanical components (metal headers, keys, multiple screws, cam mechanisms) with a lightweight bladder filled with fluid. This significantly reduces the amount of material required for the coupling structure while maintaining or improving the security and reliability of the connection through frictional engagement.
Solution Approach 2:
The coupling mechanism combines different materials and states - a flexible bladder (likely rubber or elastomer) filled with fluid (hydraulic oil or gas), mounted within a bushing structure. This composite approach provides both the structural support and the frictional engagement needed for secure coupling, using less material than conventional all-metal mechanical couplings.
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
The solution effectively reduces coupling loosening, enables quick component replacement, uses less material, and improves concentricity between the roller and shaft, minimizing production interruptions and manufacturing costs.
Implementation Method 1
a bladder that is configured to expand radially upon receipt of a fluid to reduce the operative circumference of the inner bore
Implementation Method 2
an actuator that is configured to cause the fluid from the vessel of the flange to flow into the bladder of the sleeve
Implementation Method 3
The actuator can be actuated to cause the bushing to frictionally engage the shaft to inhibit rotational movement between the bushing and the shaft
Data Source
AI summary
A roller assembly having a central axis can comprise a roller having an outer surface and defining an inner bore. The apparatus can further comprise a bushing comprising a sleeve having an outer surface and defining an inner bore. The inner bore of the sleeve can have an operative circumference. The sleeve comprises a bladder that is configured to expand radially upon receipt of a fluid to reduce the operative circumference of the inner bore. The bushing can further comprise a flange extending radially outwardly from the sleeve. The flange defines a vessel containing fluid therein. The vessel is in fluid communication with the bladder of the sleeve. The bushing comprises an actuator that is configured to cause the fluid from the vessel of the flange to flow into the bladder of the sleeve. An alignment feature can be configured to rotationally position the roller relative to the bushing.