HBY seals are a type of hydraulic seal, specifically buffer seals, designed to work with rod seals in hydraulic systems. They are used to prevent excessive pressure build-up between the buffer seal and the primary rod seal, and also to protect the rod sealing area from pressure spikes. HBY seals often incorporate an anti-extrusion ring, typically made of a hard material like POM or PA, to resist extrusion under high pressure and shock loads.
Here's a more detailed breakdown.
Function:
HBY seals act as a buffer, absorbing pressure fluctuations and preventing pressure traps that can damage the primary rod seal. They also allow oil to reach the primary seal at low pressure, preventing it from running dry.
Structure:
They typically consist of a soft polyurethane (PU) sealing element and a harder anti-extrusion ring made of POM or PA. The sealing lip is often designed with a notch or special shape to allow for pressure release and prevent pressure traps.
Applications:
They are commonly used in heavy-duty hydraulic applications, particularly in construction machinery, and are suitable for both dynamic and static sealing.
Advantages:
HBY seals offer several benefits, including protection against pressure spikes and extrusion, long service life, and easy installation. They can also improve the overall durability and performance of hydraulic systems.
Materials:HBY seals are typically made of polyurethane (PU) for the sealing element and either POM (polyoxymethylene) or PA (polyamide) for the anti-extrusion ring.
Pressure Range:
HBY seals can handle a wide range of pressures, from low to high, and can be used in both low and high-pressure applications.
In essence, HBY seals are a specialized type of hydraulic seal designed to enhance the performance and reliability of hydraulic systems, particularly in demanding applications where pressure fluctuations and extrusion are a concern.