Hydraulic Cylinder Piston Coupling Using Annular Cylindrical Bodies
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Solution Overview
Problem
Existing hydraulic cylinder piston units face challenges in reliably transmitting high tensile and compressive forces while ensuring operational reliability, ease of assembly and disassembly, and cost-effectiveness, with existing solutions often compromising on stability, assembly effort, or material usage.
Innovation Solution
A piston unit design featuring a piston rod with a first radial groove and a piston with a second radial groove forming a rectangular annular space, where cylindrical bodies are used for force transmission, providing a form-fitting coupling that allows for high-force transmission without preloading and is easily assembled and disassembled.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a nut is used to secure the piston on the piston rod, then the piston can be fastened, but the attachment reliability is insufficient under high forces
Solution Approach 1:
The coupling is divided into multiple cylindrical bodies (at least two) arranged in an annular space between the piston and piston rod. Each cylindrical body independently transmits force, distributing the load and increasing overall reliability compared to a single nut connection.
Solution Approach 2:
Multiple cylindrical bodies are combined within the annular space to create a composite coupling structure. This merged configuration provides both high strength through load distribution and high reliability through redundancy, as failure of one cylindrical body does not compromise the entire connection.
2Reliability
If a split ring and multiple piston parts are used to prevent axial displacement, then the piston can be secured, but the assembly effort and cost increase
Solution Approach 1:
The cylindrical bodies serve multiple functions simultaneously: they prevent axial displacement of the piston, transmits hydraulic forces, and provide structural support. This multi-functionality reduces the need for separate components like split rings and clamping screws, simplifying the overall design.
Solution Approach 2:
The invention extracts and eliminates unnecessary components from the traditional design. By using cylindrical bodies that perform multiple functions, elements such as split rings, sealing grooves, and clamping screws are removed, reducing the number of parts and assembly complexity.
3Reliability
If threads are used to connect the piston and piston rod, then they can be fastened, but protection against unintentional loosening requires additional measures
Solution Approach 1:
The cylindrical bodies act as intermediary elements between the piston and piston rod, creating a positive mechanical coupling that inherently prevents loosening. This intermediary structure eliminates the need for threaded connections and additional anti-loosening measures, as the cylindrical bodies are retained by the annular space geometry.
4Reliability
If traditional coupling methods are used, then the piston can be connected, but material usage and costs increase
Solution Approach 1:
The cylindrical bodies are simple, inexpensive components that can be easily manufactured from common materials. While individually simple, their collective arrangement provides high reliability without requiring expensive specialized components or excessive material usage in the piston and piston rod themselves.
Data Source
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AI summary
The invention relates to a piston unit of a hydraulic cylinder, comprising a piston rod (1), a piston (2), and a plurality of cylinder molded bodies (3), wherein along an outer periphery, the piston rod (1) has a first radial groove (4), and along an inner periphery, the piston (2) has a second radial groove (5). The first radial groove (4) and the second radial groove (5) have the same axial position and axial extension, wherein the first radial groove (4) and the second radial groove (5) form a common circumferential annular space (6), which has a rectangular hollow cross section. The piston (2) has an access channel (7), which on the external side is delimited by the outer periphery of the piston (2), and on the internal side is delimited by the second radial groove (5). The access channel (7) provides an access to the annular space (6), wherein the plurality of cylinder molded bodies (3) are arranged in the annular space (6) such that a longitudinal axis of the cylinder molded bodies (3) is oriented parallel to a longitudinal axis of the piston rod (1) and the piston (2). The end faces of the cylinder molded bodies are connected in a form-fitting manner to the axial walls of the annular space (6), wherein the cylinder molded bodies (3) can be introduced into the annular space (6) via the access channel (7).