What a VR seal does differently
Preloaded diaphragm sealing concepts on reusable support bodies. The result is one third of the friction power of a standard shaft seal — and the option of doing without any post-treatment of the shaft.
Design guidelines
Shaft, mating surface, surface finish, hardness, housing bore, installation space and sealing gap — the dimensions and tolerances that make a VR seal hold.
To the guidelinesElastomers
15 standard grades from NBR to FFKM, plus special materials for food, medical technology, PFAS-free requirements and metal detectability.
To the material overviewFriction power
Why a VR seal draws 20 watts instead of 60, what that saves in electricity and CO₂ over a year — and the p-v diagrams for NBR, HNBR and FPM.
To friction powerInstallation and storage
Installation mandrel, assembly sleeve, grease chamber and the installation process in six steps — and how the seal is stored until then.
To installation and storageThe annular gap decides
With rotating shafts the sealing lip of a pressurized rotary shaft seal twists. The shear stresses that arise in the elastomer are a function of pressure, surface speed, coefficient of friction and annular gap.
If the distance ds between the shaft and the support body bore is too great, material burns and shearing of the sealing lip can occur in service. The annular gap is therefore the decisive factor — and one the designer can influence — in whether a seal will withstand the specified pressure and surface speed.
We cover this through the support body bore D3 — D1 + 1.0 mm in the standard range, D1 + 0.5 mm at increased pressure. For very small gaps the stamped sheet-metal version gives way to a one-piece turned support body — that is type SOA.
For annular gaps below 0.10 mm we recommend gunmetal RG7 as the support body material, to rule out damage to the shaft.
Every design, material and size in one PDF
60 pages of design know-how: pressure and p-v diagrams, design guidelines, the elastomer overview and the complete size table with 541 sizes. You receive the link by e-mail straight away.
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