Threaded Work Cylinder Sealing by Tapered Pressure Contact

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Solution Overview

Problem

Existing screw working cylinders require additional elastic sealing elements for reliable sealing against the environment, which increases production complexity and costs, and may not perform well under varying pressure conditions.

Innovation Solution

A screw working cylinder design featuring a cylinder tube with a tapered wall section and a closure part with a mating annular surface, forming a pressure contact that provides a continuous sealing plane through elastic deformation within the material's elasticity limit, eliminating the need for additional sealing elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If elastic sealing elements are inserted to seal the screw connection, then sealing reliability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvesealing reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the elastic sealing elements from the screw connection assembly. Instead of adding sealing rings or gaskets, the solution uses the inherent elastic deformation of the tapered cylindrical section of the closure element to create the sealing function, thereby simplifying the device structure while maintaining sealing reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The closure element's tapered cylindrical section serves dual functions: structural connection and sealing. The elastic deformation of this section under tightening force automatically creates the sealing pressure against the cylinder tube's sealing surface, eliminating the need for separate sealing components and reducing device complexity.

Inventive Principle:
Principle #25Self-service

2Reliability

If elastic sealing elements are inserted to seal the screw connection, then sealing reliability is improved, but manufacturing cost increases

Engineering Contradiction:
Improvesealing reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention removes the need for purchasing and installing separate elastic sealing elements (such as O-rings or sealing glands), thereby directly reducing material costs and assembly expenses while maintaining effective sealing through the elastic deformation mechanism of the tapered closure element.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sealing function is merged into the closure element's structural design. The tapered cylindrical section inherently provides both mechanical fastening and sealing functions, eliminating the need for additional sealing components and reducing overall manufacturing costs.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If additional sealing elements are used, then sealing performance is improved, but assembly complexity increases

Engineering Contradiction:
Improvesealing performanceVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the sealing function from separate components and integrates it into the closure element's tapered section. This eliminates the need for separate sealing element installation steps, reducing assembly complexity while maintaining sealing performance through elastic deformation.

Inventive Principle:
Principle #2Taking out (Extraction)

4Loss of substance

If the cylinder tube wall thickness is reduced in the tapered section, then material usage and component size are reduced, but structural strength may be compromised

Engineering Contradiction:
Improvematerial usageVSAvoidstructural strength
Core Design Contradiction:
Loss of substanceVSStrength

Solution Approach 1:

The cylinder tube features a tapered section with locally reduced wall thickness only in the specific area where elastic deformation is needed for sealing. The rest of the cylinder tube maintains full wall thickness for structural integrity. This localized thinning reduces overall material usage while preserving necessary strength in critical areas.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The wall thickness parameter of the cylinder tube is varied along its length, with the tapered section having reduced thickness compared to the main body. This parameter change enables material reduction and weight savings while the elastic deformation capability of the thinned section provides the sealing function without compromising overall structural strength.

Inventive Principle:
Principle #35Parameter changes

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

This design ensures reliable sealing without additional sealing elements, reduces material usage and assembly torque, allows for smaller component dimensions, and maintains functionality over long-term use, with reversible deformation ensuring consistent sealing performance across pressure ranges.

Implementation Method 1

forming a pressure contact that provides a continuous sealing plane through elastic deformation within the material's elasticity limit

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3559480B1Threaded work cylinder
Publication Date: 2023.03.29 BUMACH ENG INT BV
  • EP3559480B1 patent drawingFigure 1
  • EP3559480B1 patent drawingFigure 2
  • EP3559480B1 patent drawing

AI summary

The invention relates to a screw-threaded working cylinder comprising a tubular cylinder (1), a closure (2) and a piston unit (3), wherein the tubular cylinder (1) has an end region (4), the end region (4) of the tubular cylinder (1) has a first thread (5) and the piston unit (3) is contained in the tubular cylinder (1), the closure (2) has a second thread (6) and the second thread (6) of the closure (2) is screwed into the first thread (5) of the tubular cylinder (1) in the final mounting position, and is characterised in that the end region (4) of the tubular cylinder (1) has a tapered wall section (7), the tapered wall section (7) has an axial annular surface (8) and the closure (2) has a mating axial annular surface (9), the axial annular surface (8) and the mating axial annular surface (9) are pressed into an interlocking contact in the final mounting position and form a pressure contact surface (10), the pressure contact surface (10) forms a sealing plane, contact stress in the area of the pressure contact surface (10) causes the tubular cylinder (1) and the closure (2) to be deformed, and deformation occurs within an elasticity limit both when a pressure is applied by a pressure medium and when no pressure is applied by a pressure medium.