Lip seal TDT series

PURfittingcompression

The HUNGER tandem seal type TDT is designed for use with telescopic cylinders. It can be used with mineral oils or compressed air. The TDT seal is manufactured in PUR and has two sealing lips on the inside. Prior to fitting, these lips protrude beyond the nominal diameter of the seal. Following installation, seal compression forces the lips against the telescopic cylinder stages, thereby providing a sealing function at zero pressure. Under increasing pressure and compression of the seal, the sealing lips are pressed against the telescopic cylinder stages. The sealing edge of the second lip produces an annular cavity, where any seepage oil that has passed the first lip is collected. The seepage oil is held back by the sealing edge such that the emerging telescopic cylinder stages remain dry. During the return stroke, the collected oil is forced back into the cylinder. When combined with a surface finish of Ra 0.1 - 0.3 μm of the running surface, minimum friction levels are achieved with highly efficient sealing and a long service life. When used with the HUNGER FI type bearings, a simple and compact construction is possible for all telescopic cylinder stages.