Wiper Seal / Scraper seal
The function of the wiper seal is to prevent dirt particles from entering hydraulic or a pneumatic circuit, e.g. cylinders and valves. Contamination of the media will damage the seal, also possibly the surface of the housing and the guide bush. The pre-load and the sharp scraper edge wipes off the oil film passing the seal.
You could use bellows to provide complete protection but they are expensive and complicated to produce. Bellows can easily be damaged therefore their use is normally restricted to special applications.
Wiper Seal Types
In most cases a wiper seal having one-lip made of wear resistant elastomer will ensure that no contamination passes into the media. Precise fitting and the correct wiper is vitally important. Protection of the scraping edge from damage and good contact with the groove and piston rod diameter is mandatory for ensuring the wiper performs at its best.
A wiper seal is made from elastomeric or thermoplastic materials, e.g. polyurethane, and some have a metal case for stiffness. Numerous special designs are available for applications where compensation for large radial movements or a stiffer inner lip is required.
The Fuzion Trading team is well qualified to assist with the selection of the correct wiper seal for your application.