Lip seal EVD

repairdevicecylinder

The EVD Externally Adjustable Sealing System is a revolution in the fluid sealing technology. The patented system provides for the first time the possibility of externally adjusting and influencing the sealing function and frictional behaviour of a seal during operation. Where extremely smooth operation of a hydraulic cylinder is an absolute requirement, it can now be externally adjusted and finely tuned to obtain optimum performance for the operating conditions. Using the EVD in general applications it is possible to compensate for wear by externally increasing the seal pretension to extend the life of the seal. Costs associated with cylinder removal and repair and production downtime are hence reduced by extended maintenance periods. The EVD system comprises a sealing element (15 to 17), similar to the TDI rod seal, incorporating a pressure cavity (18), in which the seal tension is generated, and an adjustment device (1 to 14) for varying the seal tension pressure. The system is suitable for all new cylinder designs and can also be adjusted and retrofitted to existing cylinders fitted with a TDI rod seal.