Hydraulic Percussion Sealing Device Pressure Peak Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sealing devices for hydraulic percussion apparatuses face issues with frictional heating and breakage due to pressure peaks, especially at high translation velocities and frequencies, leading to fluid leakage.
Innovation Solution
A sealing device with an inner sealing ring featuring a converging protective surface and an annular groove, which reduces pressure peaks by forming a progressive nozzle and increasing the passage surface, protecting the sealing lip and ensuring reliable sealing between the guide body and striking piston.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing device with a sealing lip is used to ensure sealing between the guide body and striking piston, then sealing effectiveness is improved, but frictional heating increases which may lead to destruction of the sealing lip
Solution Approach 1:
The sealing device is divided into distinct functional components: an inner sealing ring with the sealing lip for dynamic sealing, and a separate protective portion with converging surfaces that directs fluid flow. This segmentation allows the sealing lip to perform its sealing function while the protective structure manages the fluid dynamics separately, reducing direct friction and heating on the sealing lip.
Solution Approach 2:
The converging protective surfaces act as an intermediary between the high-velocity fluid and the sealing lip. These surfaces progressively reduce fluid velocity and redirect flow away from the sealing lip, serving as a mediator that protects the sealing lip from direct exposure to high-speed fluid impact and associated frictional heating.
2Productivity
If the striking piston moves at high translation velocity and frequency, then productivity is improved, but pressure peaks increase which may lead to breakage of the sealing lip
Solution Approach 1:
The converging protective surfaces perform a preliminary action by progressively reducing the velocity of the incompressible fluid before it reaches the sealing lip. This pre-conditioning of the fluid flow occurs upstream of the sealing lip, allowing the sealing lip to operate under more favorable flow conditions even during high-velocity piston movement.
Solution Approach 2:
The converging surfaces change the flow parameters of the incompressible fluid by progressively reducing its velocity and redirecting its flow direction. This parameter modification occurs gradually through the converging geometry, transforming high-velocity direct flow into lower-velocity redirected flow that exerts reduced pressure peaks on the sealing lip.
3Ease of manufacture
If a simple sealing structure is used to reduce manufacturing costs, then ease of manufacture is improved, but reliability under high pressure conditions deteriorates
Solution Approach 1:
The protective portion is integrated with the inner sealing ring as a single component, merging the sealing function and the fluid flow management function into one piece. This integration reduces the total number of components and assembly steps while maintaining the protective function that enhances sealing reliability under high pressure conditions.
Solution Approach 2:
The inner sealing ring serves multiple functions: it provides the sealing lip for dynamic sealing, and its integrated protective portion with converging surfaces manages fluid flow and reduces pressure peaks. This multi-functionality achieves improved reliability without adding separate components, thereby maintaining ease of manufacture.
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 the amplitude of pressure peaks, preventing breakage of the sealing lip and enhancing the reliability of the sealing device, while also reducing manufacturing costs by minimizing the number of components and machining operations.
Implementation Method 1
The configuration of the converging protective surface allows to form, with the outer surface of the striking piston, a progressive annular nozzle adapted to progressively reduce the thickness and the flow rate of the incompressible fluid flowing towards the sealing lip, and hence to reduce the amplitude of the pressure peaks generated by the flowing of the incompressible fluid.
Implementation Method 2
the presence of the annular groove between the sealing lip and the converging protective surface allows to reduce the inlet velocity of the incompressible fluid on the sealing lip by increasing the passage surface of the incompressible fluid
Implementation Method 3
the contact between such a sealing device and the striking piston causes a non-negligible rubbing, and hence a frictional heating of the striking piston
Data Source
AI summary
The sealing device includes an inner sealing ring including an annular inner sealing portion provided with a sealing lip intended to cooperate in a sealed manner with the outer surface of a striking piston of a hydraulic percussion apparatus, and an outer sealing element mounted around the inner sealing portion and intended to bear in a sealed manner at the bottom of an annular housing arranged on a guide body of the hydraulic percussion apparatus. The inner sealing ring further includes an annular protective portion axially shifted relative to the inner sealing portion and internally delimited by at least one converging protective surface, annular and converging towards the sealing lip, and an annular groove opening into the inside the inner sealing ring, the annular groove being disposed between the sealing lip and the converging protective surface.