Seal arrangement prevents trapped pressure
19 November 2007
A problem on some tandem seal arrangements used in hydraulic cylinders is pressure build-up between the seals. To remedy this, Trelleborg Sealing Solutions has introduced Turcon Stepseal V. Its innovative technology, incorporating a number of patented features, prevents pressure being trapped in even the most difficult of arrangements.
In hydraulic cylinders, used in everything from precise positioning equipment in machine tools to heavy earth moving machinery in the toughest working environments, the requirements for sealing are varied and difficult. The applications are dynamic, often operating at high speeds and significant pressures. A single seal is rarely good enough, and in most cases, a configuration of seals is required.
Typically, to optimise sealing integrity, a cylinder will include between three and five different dynamic seal and scraper types, some in tandem arrangement. Though configurations that use Turcon Stepseal are usually effective, in some designs, pressure can still build up between two seals. Based on their experience in hydraulic applications, engineers at Trelleborg Sealing Solutions looked for an even more effective geometry for these exceptional situations. The result is Turcon Stepseal V.
Turcon Stepseal V incorporates a number of features. These include a patented hydrostatic pressure relief system, which provides rapid pressure actuation and pressure balancing under all service conditions. A machined valve groove ensures precise opening and closing of the relief channel, providing robust performance of the relief function independent of hardware deflection.
The inherent friction characteristics, wear and abrasion resistance of Turcon, the Trelleborg Sealing Solutions proprietary PTFE based material, is enhanced with Stepseal V’s contoured rear chamfer for hydrodynamic back-pumping. In back-pumping technology, on the forward stroke of the shaft, an oil lubricating film is distributed under the seal. On the return stroke, the oil is back-pumped into the system, preventing leakage, reducing dynamic friction and breakaway force, even after extended periods of rest.
Contact Details and Archive...