Rotary shaft seals

Radial shaft seals (RSS) are used between rotating and stationary machine components or between two components in relative motion and consist of two main parts: 
  • A cylindrical outer covering of sheet steel (case) or an elastomer that has the requisite interference fit to seal statically against the housing bore. 
  • A sealing lip made of an elastomeric or thermoplastic material that seals dynamically and statically against the shaft. The lip has a sealing edge that is formed by moulding, cutting or grinding. It is normally pressed against the counterface surface of the shaft, with a defined radial load, by a garter spring. The edge of the sealing lip and the shaft counterface surface form the most important functional area of a radial shaft seal. The sealing effect of the lip can be enhanced by designing the contact area of the lip with hydrodynamic features.

DIMER_SEALS_Rotary shaft seals

Some radial shaft seal designs have an auxiliary lip that protects the primary sealing lip from dust and other contaminants. A suitable lubricant in the space between the primary sealing lip and the auxiliary lip can reduce wear and delay corrosion. Contaminants that have passed the auxiliary lip will eventually cause damage in the counterface surface area. A build-up of heat can also occur between the two lips, resulting in premature wear. Radial shaft seals can also be supplied with an auxiliary dust lip against the ingress of dirt and risk of corrosion. 

WAD and WBD shapes with two sealing lips are used to seal two media or to separate them. WAO or WBO shapes without a spring ring are designated for applications with lower technical demands.

WAV – with two dust-proof lips
WAC– with a helix for reverse transport to the left
WAH– with a helix for reverse transport to the right
WAT– with a helix for reverse transport to the left and a dust-proof lip
WAU– with a helix for reverse transport to the right and a dust-proof lip
WAB– with a helix for reverse transport to the left and a helix on the dust-proof lip
WAE– with a helix for reverse transport to the right and a helix on the dust-proof lip
WAF– with helixes with alternately left and right leads with a dust-proof lip
WAX– with grooves on the external coat
 
WBV– with a helix for reverse transport to the left
WBH– with a helix for reverse transport to the right
WBT– with a helix for reverse transport to the left and a dust-proof lip
WBU– with a helix for reverse transport to the right and a dust-proof lip
WBB– with a helix for reverse transport to the left and a helix on the dust-proof lip
WBE– with a helix for reverse transport to the right and a helix on the dust-proof lip
WBW– with helixes with alternately left and right leads
 
WCL - with a closed rubber cup
WCP- with a closed PTFE cup
WCR– with a tight rubber collar and a dust-proof lip
 

V-RINGS

V-seals are used as shaft and bearing sealing e.g. against the ingress of dirt, dust and dispersed water emulsion. Sealing with a V-ring allows easy installation. The installation area and contact surface are simplified considerably. V-ring is an extraordinarily economical seal which has been demonstrated by tests on all types of machines.

V-ring is an elastomer seal made of highly resistant NBR. Other elastomers can also be used for the production of V-rings (such as FPM for a temperature range from –25°C to 200°C).