Pull-Cylinder Piston Coupling Ring Assembly Against Loosening
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Solution Overview
Problem
Existing piston unit couplings in pulling cylinders face issues with loosening under operating loads, especially when exact positioning is required, and current solutions either lack reliability or are complex, costly, or difficult to disassemble.
Innovation Solution
A piston unit design featuring a piston rod with an outer ring groove and a two-part coupling ring, along with a resilient fixing ring, provides a form-fitting and secure axial connection, preventing loosening in both directions of movement without preload forces, allowing for easy assembly and disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If threaded connections with adhesive or lock nuts are used to couple piston and piston rod, then the connection can be assembled, but the coupling becomes loose under operating stress
Solution Approach 1:
The coupling ring is designed as a resilient element that dynamically adapts to operating loads. The ring deforms elastically under stress to maintain constant contact pressure between the piston, piston rod, and coupling ring, preventing loosening while accommodating dynamic movement. This dynamic adaptation eliminates the loosening problem inherent in static threaded connections.
Solution Approach 2:
The coupling system changes the physical state of the coupling ring from rigid to resilient, allowing elastic deformation. This parameter change enables the coupling to absorb stress variations and maintain secure connection under operating conditions, transforming the connection from a static assembly to a dynamically adaptive system.
2Reliability
If locking elements are added to prevent loosening, then connection security improves, but the device complexity increases
Solution Approach 1:
The coupling ring combines multiple functions into a single component: it couples the piston to the piston rod, provides locking action through its resilient nature, and accommodates dynamic movement. This merging eliminates the need for separate locking elements like lock nuts or clamps, reducing component count while maintaining connection security.
Solution Approach 2:
The resilient coupling ring serves multiple purposes simultaneously: structural coupling, stress absorption, locking prevention, and alignment maintenance. This multi-functionality replaces what would traditionally require multiple specialized components, simplifying the overall device while improving reliability.
3Reliability
If material-to-material connections like welding are used, then connection security improves, but manufacturing complexity and thermal stress increase
Solution Approach 1:
The coupling ring acts as an intermediary element between the piston and piston rod, providing a mechanical coupling that avoids direct material-to-material fusion. This intermediary approach eliminates welding-related thermal stress and manufacturing complexity while maintaining secure connection through elastic deformation and constant contact pressure.
4Reliability
If additional screw connections with lock nuts or clamps are provided, then loosening prevention improves, but device complexity and assembly time increase
Solution Approach 1:
The coupling system segments the connection function into the resilient coupling ring that inherently prevents loosening through its elastic properties, eliminating the need for additional screw connections, lock nuts, or clamps. This segmentation approach solves the loosening prevention problem while maintaining assembly simplicity.
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 design ensures a completely secure and reliable coupling, reduces production costs, and allows for easy assembly and disassembly, eliminating the risk of loosening and minimizing material usage while maintaining high concentricity and buckling stability.
Implementation Method 1
a resilient fixing ring, provides a form-fitting and secure axial connection, preventing loosening in both directions of movement
Data Source
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AI summary
The invention relates to a pull-cylinder piston unit comprising a piston rod (1), a piston (2), a coupling ring (3), and a fixing ring (4), wherein the piston rod (1) has an outer ring groove (5), wherein the piston (2) has an axial bore (2.1) in which the piston rod (1) is received, and an inner ring groove (6) open axially on one side towards a piston bottom end (2.2), wherein the inner ring groove (6) has a coupling ring section (6.1) and an adjacent fixing ring section (6.2), and wherein the fixing ring section (6.2) has an undercut contour (6.3), wherein the outer ring groove (5) and the coupling ring section (6.1) form a coupling ring groove space (7) in which the coupling ring (3) is arranged, wherein the coupling ring (3) is split and is divided by the coupling ring section (6.1) is radially enclosed and wherein the piston (2) is axially fixed on one side in a tensile direction by the coupling ring (3) on the piston rod (1), wherein the fixing ring (4) is arranged in the fixing ring section (6.2) between the undercut contour (6.3) and the coupling ring (3), wherein the fixing ring (4) is resiliently designed and engages in a relaxed position in the fixing ring section (6.2) of the inner ring groove (6) and wherein the fixing ring (4) axially and positively secures the piston (2) on the piston rod (1) on one side in a return direction.