Centrifugal Seal (CS)

Bearing illustration

If dust and water get inside a bearing, this leads to premature failure. Therefore choosing the right protective seals is important for the working life of a stainless steel bearing unit. The centrifugal seal (CS) is designed for harsh conditions where there is a risk of contamination.

Why Choose a Centrifugal Seal?

Dusty, abrasive environments are one of the most difficult for bearings. Because when handling powders or in processes generating dust, the protection of bearings against contamination requires special consideration. Radial oil seals, such as the AS and SA seals made of nitrile rubber, are selected mainly for ordinary conditions. But they are generally unsatisfactory in harsh or dusty conditions. Over time, the nitrile rubber is attacked by dirt, water, sand and various other contaminants. Small particles get into the soft material of the rubber. And the lip can cause fretting of the shaft (causing a groove under the lip). Tiny particles of moisture on the shaft can be drawn past the lip. And a jet of water sprayed at high pressure directly at the lip seal penetrates past the seal into the bearing.

Bearing illustration

Extreme Bearing has developed the centrifugal seal to solve these problems! Many Extreme Bearing housings feature centrifugal seals specially developed to repel dirt and contaminants using centrifugal force generated by the shaft. The CS seal works for speeds up to 5 m/s and for temperatures from -25°C up to 95°C.

Triple Barrier Bearing Labyrinth Seal

Bearing illustration

CS seals are superior against sand, dirt and detergents

  1. Double Lip Centrifugal Seal - Primary barrier using centrifugal force
  2. Grease-filled Housing - Secondary barrier preventing contamination ingress
  3. 2-RS Bearing Seal - Tertiary protection integrated into bearing

Firstly, the centrifugal seal made of rubber attached to the shaft provides a primary barrier. Because it repels dirt and contaminants using the centrifugal force generated by the shaft. Secondly, the bearing housing is filled with grease to prevent contaminants from entering and damaging the bearing. Finally, there is a type of bearing seal called 2-RS to protect the bearing.

Working Principle

The rubber of the CS-seal clamps around the shaft and is turning with the shaft vertically against the stator ring. Because the lips are positioned vertically against the stator ring, the dirt will be repelled by the centrifugal force from the sealing lips. The rotor ring can be moved eccentrically in relation to the stator ring. In this way, the centrifugal seal is able to absorb any misalignment of the shaft without creating wear on the rubber lips.

Bearing illustration

The grease passes the retaining edge through the lubrication channels under the stator ring and between the two sealing lips and stator ring. This makes sure that any dirt is flushed away. The clamping of the rubber rotor ring around the shaft means that the bearing can be assembled even on a shaft which has suffered light surface damage such as a groove.

Key Benefits

Bearing illustration
  • Centrifugal Force Protection - Uses shaft rotation to repel contaminants
  • Double Lip Design - Enhanced sealing capability
  • Self-Cleaning Action - Grease flow flushes away dirt
  • Misalignment Tolerance - Eccentric movement capability
  • Damaged Shaft Tolerance - Can seal on slightly damaged surfaces
  • Speed Range - Up to 5 m/s
  • Temperature Range - -25°C to 95°C
  • Superior to Standard Seals - Outperforms AS/SA seals in harsh conditions

CS Seal Dimensions

When applying the CS bearing labyrinth seal, it must be taken into account that it is not flush with the surface of the housing and expands the dimensions of the housing slightly:

20 32 3
25 40 3
30 46 3
35 50 3
40 60 3
45 60 3
50 70 3
55 70 3
60 80 3

When to Use CS Centrifugal Seals

  • Dusty and abrasive environments
  • Washdown applications
  • High-pressure water spray areas
  • Powder handling processes
  • Detergent exposure
  • Food processing plants
  • Agricultural applications
  • Mining and quarries
  • Any environment where AS/SA seals fail prematurely

The CS centrifugal seal represents a significant advancement in bearing protection technology for harsh environments.

Ce à quoi ces joints résistent – NBR (joints AS / SA / CS)

La liste ci-dessous présente les produits chimiques, fluides et gaz auxquels l’élément d’étanchéité en NBR (caoutchouc nitrile) des joints AS, SA et CS résiste de manière fiable. Une coche dans une colonne de température indique que le joint convient à ce milieu à cette température. Les cases vides signalent que le milieu n’est pas recommandé à cette température — choisissez alors un joint de qualité supérieure (FKM, silicone ou PTFE).

Valeurs indicatives basées sur des tableaux industriels (Parker O-Ring Handbook, Trelleborg, ERIKS). L’utilisateur final est responsable de la validation de l’adéquation à son application spécifique — la concentration, la pression, la sollicitation mécanique et le temps d’exposition comptent. En cas de doute, contactez Extreme Bearing pour une recommandation sur mesure.

Substance chimique 20°C / 68°F 60°C / 140°F 100°C / 212°F
Formaldehyde (40%)
Ascorbic acide
Citric acide
Acides gras (>C6)
Oxalic acide
Phthalic acide
Stearic acide
Tannic acide (10%)
Tartaric acide
Boric acide
Carbonic acide
Silicic acide
Sulfites
Ammonia, aqueux
Soude caustique et potasse
Lime (CaO)
Alum
Aluminium chlorure
Aluminium sulfate
ammonium chlorure
Brines, saturé
Solution de bromure (K)
Calcium chlorure
Chlorates of Na, K, Ba
Chlorides of Na, K, Ba
Copper salts (most)
Ferric chlorure
Ferrous sulfate
Lead acetate
Mercuric chlorure
Mercury
Nickel salts
Nitrates de Na, K et NH3
nitrite (Na)
Silver nitrate
sodium carbonate
sodium silicate
sodium sulfure
Stannic chlorure
Sulphates (Na, K, Mg, Ca)
Zinc chlorure
Cyclohexane
Naptha
Petroleum spirits
Paraffin wax
Huiles diesel
Huiles minérales
Huiles végétales et animales
Alcohols
Methanol
Glycerine
Glycols
Glycol, ethylene
Acétylène
Fluides frigorigènes fluorés
Soufre
Eau distillée
Eau douce
Eau dure
Eau de mer
Air humide
Bière
Jus de fruits
Gelatine
Jus de viande
Produits laitiers
Molasses
Amidon
Sugar, syrups & jams
Suif
Urea (30%)
Levure
Detergents, synthetic
Silicone fluids
Agents mouillants (<5%)
Ethanol
Isopropanol (IPA)
Propylene glycol
eau/glycol coolant
Fluide hydraulique (HL, HLP, HM, minéral)
Fluide hydraulique HFA (huile dans eau)
Fluide hydraulique HFC (eau-glycol)
Liquide de frein (DOT 3/4, glycol)
essence / petrol
Kerosene
Jet carburant (JP-4/JP-5/JP-8)
fioul / carburant huile
LPG (propane, butane)
AdBlue (solution d’urée 32,5%)
Transformer huile
Turbine huile
Gear huile
Fluide de transmission ATF
Graisse silicone
Graisse au savon de lithium
comprimé air, sec
Nitrogen (N2)
Carbon dioxide (CO2)
Hydrogen (H2)
Helium (He)
Argon (Ar)
Ethylene (C2H4)
Propylene (C3H6)
Methane (CH4)
Gaz naturel
Carbon monoxide (CO)
Fluide frigorigène R22 (HCFC)
Fluide frigorigène R134a (HFC)
Fluide frigorigène R1234yf (HFO)
Fluide frigorigène R717 (ammoniac)
Fluide frigorigène R744 (CO2)
Vin
Café / thé
Jus de légumes
Nettoyant CIP alcalin (1-3%)
Pentane
Hexane
Heptane
Octane
Isobutylene
Butanol (n-butanol)
n-Propanol
Oleic acide
Palmitic acide
Adipic acide
Lauric acide
ammonium sulfate
ammonium nitrate
Copper sulfate
Zinc sulfate
Magnesium sulfate
Magnesium chlorure
Barium chlorure
potassium chlorure
sodium thiosulphate
Fluide frigorigène R32 (HFC)
Fluide frigorigène R410A (mélange HFC)
Fluide frigorigène R454B (mélange HFO)
Fluide frigorigène R1234ze (HFO)
Fluide frigorigène R290 (propane)
Fluide frigorigène R600a (isobutane)
Hexafluorure de soufre (SF6)
Nitrous oxide (N2O)
Olive huile
Soybean huile
Palm huile
Rapeseed (canola) huile
Fish huile
Beurre
Cheese curds / whey
Œufs (crus / liquides)
Moutarde
liquide sugar / glucose syrup
Quaternary ammonium compounds (QACs)
Solution de chlorhexidine
Cutting huile (eau-soluble emulsion)
Cutting huile (neat, minérale)
HVO renewable diesel
Marine heavy carburant huile (HFO)
Boue de forage (base eau)
Boue de forage (base huile)
Coulis de ciment
Coulis de cendres volantes
Solution de cyanure (extraction aurifère, NaCN)