Sliding Rod Seal Profile With Studs for Low-Friction High-Pressure Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Seal elements for axially sliding rods in hydraulic cylinders face high friction and temperature issues under pressure, leading to material softening and extrusion risks, which are not adequately addressed by existing solutions despite the use of anti-extrusion rings.
Innovation Solution
A seal element with a specific profile featuring studs on the inner sliding surface reduces contact area and friction, creates an oil chamber for lubrication, and has a large radius of curvature to minimize extrusion risks without the need for additional anti-extrusion components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the seal element operates under high pressure conditions, then the sealing capacity is improved, but the operating temperature increases and material softening occurs
Solution Approach 1:
The seal element is divided into multiple functional zones: a first sealing zone with a first sealing ring for primary sealing, a second sealing zone with a second sealing ring for secondary sealing, and intermediate zones with grooves for pressure management. This segmentation allows each zone to handle specific aspects of sealing under high pressure, distributing the thermal and mechanical loads to prevent overall material softening.
Solution Approach 2:
The invention introduces axial dimensionality by creating intermediate zones between the first and second sealing zones, separated by grooves. This axial separation allows for independent control of pressure and temperature in different regions, enabling the seal to maintain effectiveness under high pressure while managing thermal buildup through the layered structure.
2Reliability
If the contact surface between seal element and rod is increased, then the sealing capacity is improved, but the friction and sliding resistance increase
Solution Approach 1:
The sealing contact is segmented into discrete sealing rings at different axial positions rather than a continuous contact surface. Each sealing ring provides localized sealing contact, maintaining adequate sealing capacity while reducing the total cumulative friction compared to a large continuous contact area.
Solution Approach 2:
Different regions of the seal element have different contact characteristics: the first and second sealing rings provide localized high-contact-area sealing zones, while the intermediate zones with grooves provide low-contact-area regions that reduce friction. This local differentiation optimizes the balance between sealing capacity and sliding resistance.
3Reliability
If anti-extrusion rings are added to prevent extrusion, then the resistance to extrusion is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The anti-extrusion function is merged into the seal element itself through the grooved structure and multi-zone design. The grooves and intermediate zones create geometric constraints that prevent extrusion without requiring separate anti-extrusion rings, thereby maintaining extrusion resistance while reducing overall device complexity.
Solution Approach 2:
The seal element performs multiple functions simultaneously: sealing (through the sealing rings), pressure management (through the grooves and intermediate zones), and extrusion prevention (through the geometric constraints of the grooved structure). This multi-functionality eliminates the need for separate anti-extrusion components.
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 significantly reduces operating temperatures and extrusion risks, ensuring a reliable, long-lasting, and cost-effective seal with reduced friction and no need for anti-extrusion components, even under high pressure conditions.
Implementation Method 1
allows oil to be held on the sliding surface in front of the sealing lip, thus creating an oil chamber to lubricate the sealing lip
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A seal element (1) for an axially sliding rod, in particular a rod of a hydraulic cylinder, comprises a ring body (2) extending about an axis (A) and comprising a base portion (3) and two radially opposite arms (4, 5) that project diverging from the base portion (3) and are provided with respective opposite radial sealing lips (6, 7); the ring body (2) having a pair of opposite lateral sides (14, 15) provided with a radially inner lateral surface (16) and a radially outer lateral surface (17) respectively; the radially inner lateral surface (16) is provided with a plurality of studs (23) projecting radially from the radially inner lateral surface (16) toward the axis (A) and angularly spaced apart from one another about the axis (A).